Publikasi/Publication

Journal Articles

2017

[1] Basith, Aidatunisadina Linazizah; Setiawan, Stanley; Arifin, Achmad; Arrofiqi, Fauzan; Nuh, Muhammad, "Design and Tests of A Wearable Functional Electrical Stimulation (FES) System for Knee Joint Movement Using Cycle-To-Cycle Control Method", Journal of Theoretical and Applied Information Technology, 15th June 2017. Vol.95. No 11. pp. 2523-2571.

Paralysis has became more widespread nowadays. Mostly caused by stroke, spinal cord injury, and multiple
sclerosis, the growing number of paralysis case also implied for a better treatment for its bearer. Some of
the main problems for individual with paralysis is to improve health problems related to paralysis and to
decrease the dependence to other people by regaining muscle function. In this study, a wearable functional electrical stimulation with cycle-to-cycle control system for knee joint movement restoration was developed. The system consists of sensor system, electrical stimulator, and fuzzy logic controllers. The controller was developed as Single Input Single Output (SISO) controller for knee flexion movement and Multi Input Single Output (MISO) controller for knee extension movement. Sensor system was used to measure angle of knee joint. A combination of two inertial sensors, accelerometer and gyroscope, made up the sensor system. The angle measured by sensor system was also used as feedback to realize closed-loop control. The data from the system could be monitored and saved as database using user interface program in a PC/laptop. Tests with neurologically intact subjects was done to test the performance of the system designed. It resulted in small number of RMSE and Settling Index for both maximum knee flexion and maximum knee extension control. The system designed was expected to be developed further to provide a full wearable FES system for lower limb motoric restoration.
Keywords: Functional Electrical Stimulation, Cycle-to-cycle Control, Knee Joint, Fuzzy System

[2] Setiawan Rachmad; Arifin Achmad; Budiman Fajar; Soeprijanto Adi;, "Programmable Amplitude of Portable Electrical Stimulator for Multi-Channel Functional Electrical Stimulator (Fes) System", Journal of Theoretical and Applied Information Technology, Vol. 95, No. 9, pp. 1974-1982, 2017

2016

[1] Dikairono, Rudy; Sardjono, Tri Arief; Yulianto, Lucas;, "SISTEM NAVIGASI DAN PENGHINDAR RINTANGAN PADA MOBILE ROBOT MENGGUNAKAN GPS DAN PENGUKUR JARAK ULTRASONIK", JAVA Journal of Electrical and Electronics Engineering, Vol. 11, No. 1, 2016

Seiring perkembangan teknologi, teknologi robot juga ikut berkembang. Salah satu perkembangan dalam teknologi robot adalah navigasi mobile robot. Sistem navigasi mobile robot ini memanfaatkan GPS dan kompas pada android sebagai penentu posisi dan arah, serta ultrasonik sebagai sensor pendeteksi rintangan. Android dihubungkan dengan mikrokontroler sebagai penghasil sinyal kontrol pada mobile robot menggunakan sistem komunikasi Bluetooth . Data dikirimkan melalui Bluetooth untuk dikonversi menjadi suatu sinyal kontrol kemudi pada motor. Implementasi dari sistem yang dibuat menghasilkan mobile robot yang dapat bergerak secara otomatis menuju titik yang telah ditentukan oleh user. Data kontrol kemudi yang diberikan adalah belok kanan, belok kiri dan maju lurus dengan dua level kecepatan yakni lambat dan cepat. Namun, ketika ultrasonik mendeteksi rintangan, maka perintah dari android akan diabaikan sementara dan laju mobile robot mengikuti perintah kemudi dari hasil pembacaan ultrasonik. Hasil dari 10 kali pengujian tanpa rintangan menunjukkan proses navigasi mobile robot mencapai tingkat keberhasilan 60% untuk radius target 5 meter, dan 70% untuk radius target 8 meter. Sedangkan pada pengujian navigasi dengan rintangan mencapai tingkat keberhasilan 50% untuk panjang rintangan 100 cm dengan radius target 5 meter dan 60% untuk panjang rintangan 50cm dengan radius target 8 meter

[2] Hendradi, Rimuljo; Arifin, Achmad; Shida, Hiro; Gunawan, Suhendar; Purnomo, Mauridhi Hery; Hasegawa, Hideyuki; Kanai, Hiroshi;, "ANALYSIS AND METHODS TO TEST CLASSIFICATION OF NORMAL AND PATHOLOGICAL HEART SOUND SIGNALS", Journal of Theoretical and Applied Information Technology, Vol. 90, No. 1, pp. 222-236, 2016

An acute shortage of cardiologists and many rural clinics were run by nurses in Indonesia. We proposed to develop of a screening technique based on artificial intelligence that classifies of normal and pathological heart sound signals of human subjects due to signs important and symptoms for heart diagnosis based on knowledge of auscultation experts. Heart sound signal analysis system consisted of three stages. Firstly, preprocessing. Secondly, feature extraction with respect to the cardiac cycle based on wavelet analysis to differentiate normal and pathological heart sounds. Feature reduction using PCA was also carried out to reduce the dimension of the heart sound feature vectors for classification. Thirdly, three classifiers: ANN MLP-BP, FCM clustering and HCM clustering to classify normal, systolic murmur, diastolic murmur, and continuous murmur, respectively. The performance of each classifier was evaluated with statistical validation method. From our experimental results, the three classifiers that showed significant potential in their use as an alternative diagnostic tool were compared. The ANN achieved the best performance as an automated classifier rather than FCM and HCM methods. Its performance was 100% for sensitivity, specificity, and accuracy, respectively, of input 20,000 features. Furthermore, for input 300 features, the performance was 98.90%, 99.37%, and 99.03% for sensitivity, specificity, and accuracy, respectively. The heart sound signal analysis system was suitable to classify of normal and pathological cases. The proposed method was considered very important for objective screening and very useful as an alternative diagnostic tool that complies with the requirements for rural clinics. We hoped that the method would be beneficial in study of auscultatory technique for medical students. Surrogate data modeling of pathological heart sounds signals as an alternative tool of the heart sound simulator and for classification purpose was further study. Keywords:

[3] Hendradi, Rimuljo; Arifin, Achmad; Shida, Hiro; Gunawan, Suhendar; Purnomo, Mauridhi Hery; Hasegawa, Hideyuki; Kanai, Hiroshi;, "Signal Processing and Extensive Characterization Method of Heart Sounds Based on Wavelet Analysis", International Review of Electrical Engineering (IREE), Vol. 11, No. 1, pp. 55, Praise Worthy Prize, 2016

One of the valuable methods of cardiac valve diagnosis can be performed by auscultation. We proposed a signal processing and extensive characterization method based on wavelet analysis to investigate important characteristics of heart sounds of normal and pathologic systolic murmur human subjects. Time-scale maps yielded by wavelet transform calculation were solved using magnitude thresholding operation and centre of gravity to restrict temporal and frequency-related of valvular activities. From our experimental results, temporal and frequency-related parameters of S1, S2, and their components could be characterized precisely. Application of our method was adequate to characterize the heart sounds objectively, clearly, systematically, and comprehensively. The method was considered valuable to explain mechanisms of cardiac valves functions. We expected that the method would be helpful for clinical diagnosis as well as developing of heart sound modelling and educational purpose. Next topic of our study was addressed for classification of the heart sounds.
link: www.praiseworthyprize.org

[4] Subur, Joko; Sardjono, Tri Arief; Mardiyanto, Ronny;, "Braille Character Recognition Using Artificial Neural Network", IPTEK Journal of Proceedings Series, Vol. 2, No. 1, 2016

Braille letter is characters designed for the blind, consist of six embossed points, arranged in a standard braille character. Braille letters is touched and read using fingers, therefore the sensitivity of the fingers is important. Those characters need to be memorized, so it is very difficult to be learned. The aim of this research is to create a braille characters recognition system and translate it to alpha-numeric text. Webcam camera is used to capture braille image from braille characters on the paper sheet. Cropping, grayscale, thresholding, erotion, and dilation techniques are used for image preprocessing. Then, artificial neural network method are used to recognize the braille characters. The system can recognize braille characters with 99% accuracy even when the braille image is tilted up to 1 degrees.

2015

[1] Fitrianto, Idil; Arifin, Achmad; Nuh, Mohammad;, "Rancangan Kontroler Perangkat Keras EH1 Milano Dengan Modul Wireless Electronics", Jurnal Teknik ITS, Vol. 4, No. 1, pp. A53--A58, 2015

Teknologi dalam dunia robot medis perkembangannya sangat pesat sekali, salah satunya adalah EH1 Milano yang dimiliki oleh salah satu laboratotium yang ada di kampus ITS Surabaya. Modul lengan robot EH1 Milano sebelumnya telah di riset oleh mahasiswa teknik elektro. Kekurangan dari riset tersebut, sistem perangkat keras masih terlalu rumit karena interface antara robot dan user masih menggunakan kabel. Sistem yang dirancang menggunakan modul Wireless Electronics untuk mengatasi masalah pengkabelan dan modul yang digunakan adalah modul Bluetooth model HC dengan jarak jangkauan sampai dengan 50 meter dan waktu pairing rata-rata 8 detik. Sensor flex dengan karakteristik sensor yang linier, dengan error percentage terkecil sebesar 0,58% sedangkan terbesar 15,13% terhadap garis linier dapat menggantikan sensor yang sebelumnya digunakan. Untuk penelitian berikutnya dapat ditambahkan EMG sebagai pembanding impuls dari sensor flex dengan sinyal electromyogram dari tiap-tiap jari.
link: www.ejurnal.its.ac.id

[2] Fuad, Muhammad Faris Zaini; Arifin, Achmad; Nuh, Mohammad;, "Perbaikan Sistem Kendali Robot Tangan EH1 Milano Menggunakan Sistem Kendali Loop Tertutup", Jurnal Teknik ITS, Vol. 4, No. 1, pp. A59--A64, 2015

Teknologi robotika sangat berkembang pesat dan penggunaanya semakin luas. Prensilia EH1 Milano dikembangkan sebagai organ buatan untuk menggantikan peranan tangan manusia yang cacat atau diamputasi. Robot EH1 Milano dilengkapi satu buah motor untuk masing-masing jari, sensor proximity untuk mendeteksi jari terbuka atau tertutup penuh, dan sensor arus yang digunakan untuk mengatur kekuatan genggaman dari robot tangan. Sebelumnya telah dibuat sistem mikrokontroler untuk mengendalikan robot tangan EH1 Milano, dengan sensor gerak berupa sarung tangan yang dilengkapi potensiometer, akan tetapi belum dapat melakukan gerakan menggenggam benda. Dalam penelitian ini dirancang sistem untuk mengendalikan robot EH1 Milano menggunakan sensor gerak berupa sebuah sarung tangan yang diengkapi flex sensor, yang berfungsi untuk mendeteksi gerakan tangan manusia dengan menggunakan kendali PID. Flex sensor digunakan karena lebih sensitif terhadap perubahan gerakan tangan dan memudahkan untuk mengendalikan robot untuk melakukan gerakan menggenggam benda. Dari pengujian yang dilakukan menunjukkan bahwa dengan sistem kendali yang diterapkan, robot tangan EH1 Milano dapat melakukan gerakan menggenggam benda dengan diameter lebih dari 5 cm. Performansi yang dihasilkan sistem kendali yang dibuat cukup baik dengan RMSE rata-rata tertinggi sebesar 0.102%± 0.016%. Untuk penelitian selanjutnya perlu perbaikan pada sensor gerak untuk ibu jari, agar pergerakan pada ibu jari dapat dilakukan dengan maksimal.
link: ejurnal.its.ac.id

2014

[1] Nurmadyansyah, Rizky; Nurmadyansyah, Rizky Fauzy; Arifin, Achmad;, "Perancangan dan Implementasi Sistem Kendali Robot Tangan Prensilia", Jurnal Teknik ITS, Vol. 3, No. 1, pp. F1-F6, 2014

Teknologi robotika pada bidang medis terus berkembang dan penggunaannya semakin luas. Pada tugas akhir ini sistem kendali loop tertutup untuk robot tangan telah dikembangkan dan dievaluasi. Sistem kendali dengan komponen utama mikrokontroler untuk mengendalikan robot tangan IH2 Azzurra mampu bekerja secara real-time. Sistem yang dibuat memiliki antarmuka UART dengan baud rate sebesar 115,2kbps yang dapat menerima masukan dari sensor gerak berupa sarung tangan dan menghasilkan keluaran berupa suatu perintah sebagai masukan robot tangan. Perintah ini mampu mengatur kecepatan motor pada masing-masing jari robot tangan sesuai dengan gerakan tangan melalui sensor gerak. Metode sistem kendali yang digunakan adalah sistem kendali PID diskrit berbasis mikrokontroler ATMEGA8. Performansi dari sistem kendali yang dirancang dapat dilihat secara langsung menggunakan perangkat lunak berbasis PC yang telah dibuat. Selain itu, perangkat lunak PC dapat memperbaharui firmware pada mikrokontroler secara langsung dan parameter-parameter penting pada sistem dapat ditampilkan dalam bentuk grafik, atau disimpan pada media penyimpanan berbasis PC sehingga lebih mudah untuk dianalisa lebih lanjut. Performansi yang dihasilkan sistem cukup baik, dilihat dari nilai error steady state tertinggi sebesar 3,137%, settling time tertinggi sebesar 3,8 detik, overshoot tertinggi sebesar 3,529%, dan RMSE rata-rata tertinggi yang dihasilkan sebesar  0,0595%±0,0119%. Kebutuhan daya pada sistem relatif rendah yakni 111,9mW. Sehingga catu daya baterai li-ion berkapasitas standar dapat digunakan untuk mencatu sistem selama kurang lebih 29,4 jam atau 1,225 hari. Tingkat portabilitas dari sisi kebutuhan daya sudah terpenuhi untuk sistem ini.
link: ejurnal.its.ac.id

2013

[1] Kurniaji, Paskalis; Pirngadi, Harris; Sardjono, Tri Arief;, "Perancangan dan Simulasi Ultrasonik Doppler Gelombang Kontinyu 4MHz Berbasis Mikrokontroler ATmega16", Jurnal Teknik ITS, Vol. 2, No. 1, pp. A42-A45, 2013

Dalam penelitian ini telah dirancang sebuah sistem ultrasonik yang akan digunakan untuk mengukur kecepatan aliran darah. Sistem yang dirancang ini menggunakan prinsip ultrasonik doppler gelombang kontinyu dengan frekuensi 4MHz. Prinsip kerja dari sistem ini adalah dengan memancarkan gelombang sinus yang memiliki frekuensi 4 MHz  ke bagian pembuluh darah oleh tranduser pemancar, dan gelombang pantul yang dihasilkan dari reflektor sel darah merah akan diterima kembali oleh tranduser penerima. Gelombang pantul yang diterima oleh tranduser penerima ini akan memiliki frekuensi yang berbeda dari gelombang yang dipancarkan. Untuk mendapatkan perbedaan frekuensi ini, maka digunakan dua buah sumber generator gelombang sebagai bagian dari simulasi sistem. Rentang frekuensi yang digunakan untuk proses simulasi sistem adalah 4MHz – 4.007 MHz. Dari hasil pengujian dan simulasi, telah diperoleh nilai kecepatan aliran pada sudut <30° sebesar 50.74 cm/s dan nilai kecepatan aliran minimum pada sudut >80° memiliki kecepatan sebesar 1.3 cm/s dengan estimasi cepat rambat gelombang di dalam medium darah sebesar 1500m/s. Hasil pengujian dan simulasi untuk sudut doppler yang sesuai adalah untuk pengujian  kecepatan aliran pada sudut  <60°.
link: ejurnal.its.ac.id

[2] Sardjono, Tri Arief; Wilkinson, Michael H. F.; Veldhuizen, Albert G.; van Ooijen, Peter M. A.; Purnama, Ketut E.; Verkerke, Gijsbertus J.;, "Automatic Cobb angle determination from radiographic images.", Spine, Vol. 38, No. 20, pp. E1256-62, LWW, 2013

STUDY DESIGN: Automatic measurement of Cobb angle in patients with scoliosis.\n\nOBJECTIVE: To test the accuracy of an automatic Cobb angle determination method from frontal radiographical images.\n\nSUMMARY OF BACKGROUND DATA: Thirty-six frontal radiographical images of patients with scoliosis.\n\nMETHODS: A modified charged particle model is used to determine the curvature on radiographical spinal images. Three curve fitting methods, piece-wise linear, splines, and polynomials, each with 3 variants were used and evaluated for the best fit. The Cobb angle was calculated out of these curve fit lines and compared with a manually determined Cobb angle. The best-automated method is determined on the basis of the lowest mean absolute error and standard deviation, and the highest R2.\n\nRESULTS: The error of the manual Cobb angle determination among the 3 observers, determined as the mean of the standard deviations of all sets of measurements, was 3.37°. For the automatic method, the best piece-wise linear method is the 3-segments method. The best spline method is the 10-steps method. The best polynomial method is poly 6. Overall, the best automatic methods are the piece-wise linear method using 3 segments and the polynomial method using poly 6, with a mean absolute error of 4,26° and 3,91° a standard deviation of 3,44° and 3,60°, and a R2 of 0.9124 and 0.9175. The standard measurement error is significantly lower than the upper bound found in the literature (11.8°).\n\nCONCLUSION: The automatic Cobb angle method seemed to be better than the manual methods described in the literature. The piece-wise linear method using 3 segments and the polynomial method using poly 6 yield the 2 best results because the mean absolute error, standard deviation, and R2 are the best of all methods.\n\nLEVEL OF EVIDENCE: 3.

2012

[1] Herjuno, Dimas; Rivai, Muhammad; Sardjono, Tri Arief;, "Teledekteksi Gas pada Mobile Robot yang dikendalikan Gelombang Radio", Jurnal Teknik ITS, Vol. 1, No. 1, pp. A160--A163, 2012

Beberapa tahun terakhir terjadi peristiwa hilangnya nyawa manusia karena keracunan gas alam diarea pertambangan. Ada pula terjadi peristiwa dicurigainya bungkusan atau kemasan yang diduga adalah barang yang membahayakan jiwa. Karena banyaknya peristiwa yang meresahkan dan membahayakan masyarakat, maka dibutuhkan suatu alat yang dapat melakukan pengecekan pada suatu area atau benda dimana manusia tidak terlibat secara langsung atau melakukan kontak secara langsung yang dapat membahayakan manusia. Pada penlitian ini telah dibuat robot yang dilengkapi dengan sensor gas, sistem mikrokontroler serta beberapa perangkat jaringan seperti router, kamera ip yang digunakan untuk mensupport kelengkapan sistem. Dibutuhkan juga sebuah server komputer yang dapat memberikan perintah maupun memantau dari jarak jauh. Berdasarkan hasil pengukuran, resistansi sensor pada saat tidak terdeteksi gas bernilai paling tinggi 30KΩ dan resistansi sensor saat terdeteksi gas bernilai paling rendah sebesar 3KΩ. Dalam pengujian keseluruhan alat , robot ini berhasil bergerak sesuai perintah yang diberikan melalui gelombang radio dan mendeteksi gas dengan keberhasilan sebanyak 10 kali dari 10 kali percobaan dengan kecepatan rata-rata 0,12 m/s
link: www.ejurnal.its.ac.id

[2] Tompunu, Alan Novi; Kusumanto, RD D; Sardjono, Tri Arief;, "IMPLEMENTASI ALGORITMA LEAST MEAN SQUARE UNTUK PENINGKATAN KUALITAS SUARA PENDERITA TUNA LARING BERBASIS PROCESSOR TMS320C6713", Semantik, Vol. 2, No. 1, 2012

Seseorang yang telah mengalami laryngectomy biasa disebut dengan tuna laring. Laryngectomy adalah penghapusan laringdan pemisahan jalan napas dari hidung, mulut, dan kerongkongan. Laryngectomee bernafas melalui sebuah lubang di leher,yaitu stoma. Ada tiga usaha yang telah dilakukan untuk rehabilitasi suara tersebut yaitu dengan esophageal speech,tracheoesophageal dan eletrolarynx. Pembangkitan suara dengan eletrolarynx paling sering diadopsi untuk phonation.Kejelasan wicara electrolarynx dipengaruhi oleh noise yang dihasilkan oleh perangkat tersebut maupun noise yang timbul darilingkungan sekitarnya. Tujuan dari penelitian ini adalah untuk memberikan salah satu alternatif penyelesaian masalah bagipenderita tuna laring agar memiliki kejelasan dalam berbicara menggunakan perangkat electrolarynx neck-type, Servox SI –SERVOXD, dengan cara menggunakan adaptive filter berdasarkan algoritma least mean square. Dua microphone digunakansecara simultan, untuk memperoleh rekaman sinyal wicara dan noise melalui Starter-Kit DSP TMS320C6713. Microphonepertama digunakan untuk merekam wicara dan noise. Microphone kedua digunakan untuk merekam background noise.Pengukuran signal to noise ratio (SNR) telah dilakukan untuk mengetahui perbandingan antara sinyal ucapan dengan sinyalnoise. Dari hasil eksperimen, diperoleh bahwa nilai SNR sebelum pemfilteran sebesar 10.817 ± 2.5 dB dan setelah pemfilteransebesar 28,312 ± 9,7 dB dan terjadi peningkatan kualitas wicara electrolarynx sebesar 17,4948 ± 11.2 dB dengan bantuan Starter-Kit DSP TMS320C6713. Kata kunci : penderita tuna laring, electrolarynx, least mean square, DSP TMS 320C6713.

[3] Triwiyatno, Aris; Nuh, Mohammad; Santoso, Ari; Sutantra, I Nyoman;, "Engine Torque Control of Spark Ignition Engine using Fuzzy Gain Scheduling", International Journal of Electrical Electronics Research & Innovation (IJEERI), Vol. 10, No. 1, pp. 83, 2012

In the spark ignition engine system, driver convenience is very dependent on satisfying engine torque appropriate with the throttle position given by the driver. Unfortunately, sometimes the fulfillment of engine torque is not in line with fuel saving efforts. This requires the development of high performance and robust power train controllers. One way to potentially meet these performance requirements is to introduce a method of controlling engine torque using fuzzy gain scheduling. By using this method, the throttle opening commanded by the driver will be corrected by throttle correction signal that guarantees engine torque output will follow the desired engine torque input, and also reducing fuel consumption. In this case, spark ignition engine with automatic transmission is used to meet a good performance under this controller design.
link: journal.uad.ac.id

2011

[1] Agustinah, Trihastuti; Jazidie, Achmad; Nuh, Mohammad;, "Fuzzy tracking control based on H∞ performance for nonlinear systems", WSEAS Trans. Sys. Cont, Vol. 6, pp. 393-403, 2011

This paper presents a fuzzy tracking control design based on H∞ performance for nonlinear systems. The Takagi-Sugeno fuzzy model is employed to approximate a nonlinear system. Based on the H∞ tracking performance, the nonlinear system output is controlled to track a reference signal, and at the same time the tracking performance is attenuated to a prescribed level. Linear matrix inequalities (LMI) techniques are used to solve the fuzzy tracking control problem. The proposed method has been applied to control of a laboratory pendulum-cart system. Hence, the performance has been evaluated in simulations as well as in real-time control

[2] Agustinah, Trihastuti; Jazidie, Achmad; Nuh, Mohammad;, "Swinging up and tracking controller design for a pendulum-cart system using hybrid fuzzy control", European Journal of Scientific Research, Vol. 62, No. 2, pp. 182-197, 2011

This paper presents the design and implementation of a hybrid fuzzy control for the swinging up and the tracking control of a pendulum-cart system. First, a fuzzy swing-up controller is developed to swing the pendulum up from its pendant position to upright position using a simple control strategy. Next, a fuzzy tracking controller is designed based on a synthesis of the tracking control theory of linear multivariable control and the Takagi– Sugeno fuzzy model. The stabilizing compensator based on observer is chosen because the states of the system are not all directly measurable. The concept of parallel distributed compensation is employed to design fuzzy tracking controller from the T–S fuzzy model. Numerical simulation and real-time experiment are provided to demonstrate the effectiveness of the proposed method. Keywords:

[3] Arifin, Achmad; Budiarmoko, Alfian;, "Aplikasi Bioelectrical Impedance Untuk Mengukur Gerakan Sendi Lutut Pada Bidang Sagital", Jurusan Teknik Elektro – FTI, Institut Teknologi Sepuluh Nopember : Surabaya, 2011

Jaringan tubuh manusia tersusun dari berbagai material kompleks yang memiliki sifat-sifat listrik yang berbeda. Bioelectrical Impedance (BI) mengacu pada perlawanan aliran arus yang melalui jaringan tubuh tersebut. BI ini memiliki nilai yang bervariasi tergantung dari perubahan komposisi material pada jaringan tubuh. Perubahan tersebut dapat terjadi akibat adanya gerakan atau karena suatu penyakit tertentu. Tugas Akhir ini bertujuan untuk mengembangkan rangkaian pengukuran BI serta aplikasinya untuk menganalisa perubahan BI terhadap perubahan sudut dari sendi lutut / knee joint pada bidang sagital. Metode yang digunakan untuk mengukur perubahan BI terhadap gerakan knee joint ialah dengan menginjeksikan arus sinusoidal yang konstan dengan amplitudo 250µA dan Frekuensi 50KHz pada bagian kanan abdomen dan telapak kaki bagian atas, serta mencatat perubahan drop tegangan diantara dua titik tertentu pada kaki. Perubahan drop tegangan ini diproses pada rangkaian Instrumentasi BI, yang terdiri dari rangkaian Instrumentasi Amplifier sebagai penguat sinyal, rangkaian High Pass Filter untuk menghilangkan noise pada frekuensi rendah, serta rangkaian Demodulation Amplitudo untuk mendapatkan tegangan eksak dari BI. Data BI yang diperoleh kemudian diubah dalam bentuk digital menggunakan ADC mikrokontroler ATMega32 dan dikirim ke komputer melalui komunikasi serial untuk diolah pada program khusus. Dengan penguatan 194.35 kali pada rangkaian instrumentasi amplifier, hasil nilai BI berubah antara ±2.3V hingga ±1.5V untuk perubahan sudut knee joint dari 0° hingga 120°. Ketidaklinearan antara BI dengan sudut knee joint mengakibatkan error yang cukup besar yaitu 64o, dimana minimum error yang terjadi sebesar 0o. Pengaruh posisi penempatan elektroda sangat vital terhadap kelinearan hasil pengukuran ini. Oleh karena itu, penelitian lebih lanjut tentang penempatan elektroda ini sangat diperlukan untuk pengembangan kedepannya. Hasil pengukuran sudut menggunakan sistem pengukuran BI ini dapat diaplikasikan untuk berbagai keperluan, salah satunya ialah sebagai pengganti electro-goniometer dalam sistem rehabilitasi FES. I.

[4] Dikairono, Rudy; Sardjono, Tri Arief; Purwanto, Djoko;, "Pengembangan Perencanaan Gerak Robot Kartesian Berbasis PLC", JAVA Journal of Electrical and Electronics Engineering, Vol. 9, No. 1, pp. 23-28, 2011

[5] Sardjono, Tri Arief; Purwanto, Djoko; Ibadillah, Achmad Fiqhi;, "Sistem Penjejakan Obyek Dengan Stereo Vision", JAVA Journal of Electrical and Electronics Engineering, Vol. 9, No. 1, 2011

[6] Triwiyatno, Aris; Nuh, Mohammad; Santoso, Ari; Sutantra, I Nyoman;, "Engine Torque Control of Spark Ignition Engine Using Robust Fuzzy Logic Control", IACSIT International Journal of Engineering and Technology, Vol. 3, No. 4, pp. 2-8, 2011

Due to government regulations and policies aimed at improving fuel economy and reducing emissions, it is increasingly important to achieve control over transient behavior and meet performance objectives over the life of the vehicle. This requires the development of high performance and robust power train controllers. The performance objectives are often conflicting, or at best interrelated. Controlling engine torque is one way to potentially meet these performance requirements. Spark ignition engine is a combustion engine that operates with a very wide operating point. Each point of engine operation provides different properties to each other, so that the control treatment to be given varies a great deal. This problem led to a single controller design becomes very difficult to be realized. In this research, a new design method of fuzzy robust control proposed to provide an alternative solution to build an integrated-control that can anticipate a system that works on a wide operating point and have different characters for each operating point. From the simulation results, it can be concluded that the design of robust fuzzy controller can be used simultaneously for several operating point without having to redesign the controller. Index

[7] Triwiyatno, Aris; Nuh, Mohammad; Santoso, Ari; Sutantra, I Nyoman;, "A New Method of Robust Fuzzy Control : Case Study of Engine Torque Control of Spark Ignition Engine", International Journal of Academic Research, Vol. 3, No. 5, pp. 178-185, 2011

[8] Triwiyatno, Aris; Nuh, Mohammad; Santoso, Ari; Sutantra, I Nyoman;, "Engine Torque Control of Spark Ignition Engine Using Robust Fuzzy Logic Control", IACSIT International Journal of Engineering and Technology, Vol. 3, No. 4, pp. 352-358, 2011

Due to government regulations and policies aimed at improving fuel economy and reducing emissions, it is increasingly important to achieve control over transient behavior and meet performance objectives over the life of the vehicle. This requires the development of high performance and robust power train controllers. The performance objectives are often conflicting, or at best interrelated. Controlling engine torque is one way to potentially meet these performance requirements. Spark ignition engine is a combustion engine that operates with a very wide operating point. Each point of engine operation provides different properties to each other, so that the control treatment to be given varies a great deal. This problem led to a single controller design becomes very difficult to be realized. In this research, a new design method of fuzzy robust control proposed to provide an alternative solution to build an integrated-control that can anticipate a system that works on a wide operating point and have different characters for each operating point. From the simulation results, it can be concluded that the design of robust fuzzy controller can be used simultaneously for several operating point without having to redesign the controller.

[9] Triwiyatno, Aris; Nuh, Mohammad; Santoso, Ari; Sutantra, I Nyoman;, "Engine Torque Control of SI Engine using Linear Quadratic Integral Tracking ( LQIT ) Optimal Control", Iptek, Vol. 22, No. 4, pp. 190-197, 2011

Due to the needs of improving fuel economy and reducing emissions, it is increasingly important to achieve control over robustness behavior and meet performance objectives over the life of the vehicle. This requires the development of high performance and optimal power train controllers. The performance objectives are often conflicting, or at least interrelated. One way to potentially meet these performance requirements is to introduce a method of controlling engine torque of Spark Ignition (SI) engine using Linear Quadratic Integral Tracking (LQIT) optimal control. The goal is to develop simple algorithms which can control engine torque well, thus providing fuel control more efficient and simultaneously improving engine performance due to the needs of the driver based on throttle opening information. In this case, spark ignition engine with automatic transmission simulation model is used to meet a good performance under this controller design.
link: iptek.its.ac.id

2010

[1] Arifin, Fatchul; Sardjono, Tri Arief; Purnomo, Mauridhy Hery;, "Electrolarynx Voice Recognition Utilizing Pulse Coupled Neural Network", IPTEK The Journal for Technology and Science, Vol. 21, No. 3, 2010

The laryngectomies patient has no ability to speak normally because their vocal chords have been removed. The easiest option for the patient to speak again is by using electrolarynx speech. This tool is placed on the lower chin. Vibration of the neck while speaking is used to produce sound. Meanwhile, the technology of "voice recognition" has been growing very rapidly. It is expected that the technology of "voice recognition" can also be used by laryngectomies patients who use electrolarynx.This paper describes a system for electrolarynx speech recognition. Two main parts of the system are feature extraction and pattern recognition. The Pulse Coupled Neural Network – PCNN is used to extract the feature and characteristic of electrolarynx speech. Varying of β (one of PCNN parameter) also was conducted. Multi layer perceptron is used to recognize the sound patterns. There are two kinds of recognition conducted in this paper: speech recognition and speaker recognition. The speech recognition recognizes specific speech from every people. Meanwhile, speaker recognition recognizes specific speech from specific person. The system ran well. The "electrolarynx speech recognition" has been tested by recognizing of “A” and "not A" voice. The results showed that the system had 94.4% validation. Meanwhile, the electrolarynx speaker recognition has been tested by recognizing of “saya” voice from some different speakers. The results showed that the system had 92.2% validation. Meanwhile, the best β parameter of PCNN for electrolarynx recognition is 3.
link: iptek.its.ac.id

[2] Purnama, Ketut E.; Wilkinson, Michael. H. F.; Veldhuizen, Albert G.; Van Ooijen, Peter. M. A.; Lubbers, Jaap; Burgerhof, Johannes G.M. M; Sardjono, Tri A.; Verkerke, Gijbertus J.;, "A framework for human spine imaging using a freehand 3D ultrasound system", Technology and Health Care, Vol. 18, No. 1, pp. 1-17, IOS Press, 2010

The use of 3D ultrasound imaging to follow the progression of scoliosis, i.e., a 3D deformation of the spine, is described. Unlike other current examination modalities, in particular based on X-ray, its non-detrimental effect enables it to be used frequently to follow the progression of scoliosis which sometimes may develop rapidly. Furthermore, 3D ultrasound imaging provides information in 3D directly in contrast to projection methods. This paper describes a feasibility study of an ultrasound system to provide a 3D image of the human spine, and presents a framework of procedures to perform this task. The framework consist of an ultrasound image acquisition procedure to image a large part of the human spine by means of a freehand 3D ultrasound system and a volume reconstruction procedure which was performed in four stages: bin-filling, hole-filling, volume segment alignment, and volume segment compounding. The overall results of the procedures in this framework show that imaging of the human spine using ultrasound is feasible. Vertebral parts such as the transverse processes, laminae, superior articular processes, and spinous process of the vertebrae appear as clouds of voxels having intensities higher than the surrounding voxels. In sagittal slices, a string of transverse processes appears representing the curvature of the spine. In the bin-filling stage the estimated mean absolute noise level of a single measurement of a single voxel was determined. Our comparative study for the hole-filling methods based on rank sum statistics proved that the pixel nearest neighbour (PNN) method with variable radius and with the proposed olympic operation is the best method. Its mean absolute grey value error was less in magnitude than the noise level of a single measurement.

2009

[1] Triwiyatno, Aris; Nuh, Mohammad; Santoso, Ari; Sutantra, I Nyoman;, "Fuzzy State Observer Design for Engine Torque Control System of Spark Ignition Engine", TRANSMISI, Vol. 11, No. 3, pp. 159-165, 2009

The T-S (Takagi-Sugeno) model approach consists to construct nonlinear or complex dynamic systems that cannot be exactly modeled, by means of interpolating the behavior of several LTI (Linear Time Invariant) sub models. Since T-S observer based controller has been considered to develop some systematic design algorithms to guarantee the stability and specific performances for the T-S model based systems, this paper represent a new design of fuzzy state observer to estimate the states of engine torque control system of spark ignition engine. Keywords: T-S model, T-S observer, fuzzy state observer, engine torque, spark ignition engine.

[2] Triwiyatno, Aris; Nuh, Mohammad; Santoso, Ari; Sutantra, I Nyoman;, "T-S Fuzzy Model Design for Engine Torque Control System of Spark Ignition Engine", TRANSMISI, Vol. 11, No. 1, pp. 177-182, 2009

On many occasions, fuzzy rule-based systems have been demonstrated to be powerful tools in modeling, decision making and automatic control. The T-S model approach consists to construct nonlinear or complex dynamic systems that cannot be exactly modeled by mathematical model, by means of interpolating the behavior of several LTI (Linear Time Invariant) sub models . In this paper, a new modification fuzzy model based on T-S model will be designed to represent engine torque control system of spark ignition engine, since spark ignition engine is a high non linear system with wide uncertainties that very difficult to be modeled by mathematical model. Keywords: T-S model, fuzzy model, engine torque, spark ignition engine.

[3] WATANABE, Takashi; MASUKO, Tomoya; ARIFIN, Achmad;, "Preliminary Tests of a Practical Fuzzy FES Controller Based on Cycle-to-Cycle Control in the Knee Flexion and Extension Control", IEICE TRANSACTIONS on Information and Systems, Vol. E92-D, No. 7, pp. 1507-1510, The Institute of Electronics, Information and Communication Engineers, 2009

2008

[1] WATANABE, Takashi; MASUKO, Tomoya; ARIFIN, Achmad; YOSHIZAWA, Makoto;, "A Feasibility Study of Fuzzy FES Controller Based on Cycle-to-Cycle Control: An Experimental Test of Knee Extension Control", IEICE TRANSACTIONS on Information and Systems, Vol. E91-D, No. 3, pp. 865-868, The Institute of Electronics, Information and Communication Engineers, 2008

2007

[1] Purnama, Ketut E; Wilkinson, Michael H F; Veldhuizen, Albert G; van Ooijen, Peter; Lubbers, Jaap; Sardjono, Tri A; Verkerke, Gijbertus J;, "Ultrasound imaging for human spine: imaging and analysis", International Journal of Computer Assisted Radiology and Surgery, Vol. 2, pp. S114--S116, SPRINGER HEIDELBERG TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY, 2007

The results of ultrasound imaging of the human spine of a volunteer and the derivation of vertebral axial rotation (AR) and vertebral tilt (VT) are presented. The ARs and VTs were derived semi-automatically. In an ultrasound volume, the vertebral parts were enhanced using a length attribute filter, and localized using Robust Automatic Threshold Selection (RATS). Afterwards, a pair of two prominent regions of each vertebra was selected by ultrasound landmark points. Then, the centers of mass of these regions were used to calculate the ARs and VTs. The ARs and VTs were also determined manually based on the set of landmark points. The difference between the two methods determined the accuracy of the semi-automatic method. The overall results can be categorized into a confident, moderate, and less confident region, respectively, T3-T9, L3-L4, and other vertebrae. For the manual landmark determination, the confident region gave an error range of the ARs determination of 0 degrees-2.1 degrees/0.4 degrees-1.2 degrees (intraobserver/interobserver), and in the VTs determination it had the range of 0.3 degrees-3.2 degrees/0.2 degrees-1.9 degrees (intraobserver/interobserver). The difference between the results of semi-automatic method and the manual results was in the range -1.6 degrees to 1.3 degrees. The results confirm that ultrasound imaging is feasible to scan the human spine, and a semi-automatic method to derive ARs and VTs is also feasible.

2006

[1] Arifin, A.; Watanabe, T.; Hoshimiya, N.;, "Design of Fuzzy Logic Controller of the Cycle to Cycle Control for Swing Phase of Hemiplegic Gait Induced by FES", IEICE Trans. Inf. & Syst., Vol. E89-D, No. 4, pp. 1525-1533, The Institute of Electronics, Information and Communication Engineers, 2006

The goal of this study was to design a practical fuzzy controller of the cycle-to-cycle control for multi-joint movements of swing phase of functional electrical stimulation (FES) induced gait. First, we designed three fuzzy controllers (a fixed fuzzy controller, a fuzzy controller with parameter adjustment based on the gradient descent method, and a fuzzy controller with parameter adjustment based on a fuzzy model) and two PID controllers (a fixed PID and an adaptive PID controllers) for controlling two-joint (knee and ankle) movements. Control capabilities of the designed controllers were tested in automatic generation of stimulation burst duration and in compensation of muscle fatigue through computer simulations using a musculo-skeletal model. The fuzzy controllers showed better responses than the PID controllers in the both control capabilities. The parameter adjustment based on the fuzzy model was shown to be effective when oscillating response was caused due to the inter-subject variability. Based on these results, we designed the fuzzy controller with the parameter adjustment realized using the fuzzy model for controlling three-joint (hip, knee, and ankle) movements. The controlled gait pattern obtained by computer simulation was not significantly different from the normal gait pattern and it could be qualitatively accepted in clinical FES gait control. The fuzzy controller designed for the cycle-to-cycle control for multi-joint movements during the swing phase of the FES gait was expected to be examined clinically. Keywords:

[2] Arifin, Achmad; WATANABE, Takashi; Hoshimiya, Nozomu;, "Design of fuzzy controller of the cycle-to-cycle control for swing phase of hemiplegic gait induced by FES", IEICE transactions on information and systems, Vol. 89, No. 4, pp. 1525-1533, The Institute of Electronics, Information and Communication Engineers, 2006

The goal of this study was to design a practical fuzzy controller of the cycle-to-cycle control for multi-joint movements of swing phase of functional electrical stimulation (FES) induced gait. First, we designed three fuzzy controllers (a fixed fuzzy controller, a fuzzy controller with parameter adjustment based on the gradient descent method, and a fuzzy controller with parameter adjustment based on a fuzzy model) and two PID controllers (a fixed PID and an adaptive PID controllers) for controlling two-joint (knee and ankle) movements. Control capabilities of the designed controllers were tested in automatic generation of stimulation burst duration and in compensation of muscle fatigue through computer simulations using a musculo-skeletal model. The fuzzy controllers showed better responses than the PID controllers in the both control capabilities. The parameter adjustment based on the fuzzy model was shown to be effective when oscillating response was caused due to the inter-subject variability. Based on these results, we designed the fuzzy controller with the parameter adjustment realized using the fuzzy model for controlling three-joint (hip, knee, and ankle) movements. The controlled gait pattern obtained by computer simulation was not significantly different from the normal gait pattern and it could be qualitatively accepted in clinical FES gait control. The fuzzy controller designed for the cycle-to-cycle control for multi-joint movements during the swing phase of the FES gait was expected to be examined clinically.
link: search.ieice.org

[3] 柴田聡; 渡邉高志; ARIFIN, Achmad; 吉澤誠; 星宮望;, "片麻痺者の歩行遊脚期の cycle-to-cycle 制御に基づく FES 制御法: 床反力を考慮したモデルシミュレーション", 生体医工学, Vol. 44, No. 4, pp. 687-695, Japanese Society for Medical and Biological Engineering, 2006

2005

[1] Arifin, Achmad; WATANABE, Takashi; Hoshimiya, Nozomu;, "Computer Simulation Test of Fuzzy Controller for the Cycle-to-Cycle Control of Knee Joint Movements of Swing Phase of FES Gait", IEICE TRANSACTIONS on Information and Systems, Vol. E88-D, No. 7, pp. 1763-1766, The Institute of Electronics, Information and Communication Engineers, 2005

2004

[1] Arifin, Achmad; Watanabe, Takashi; Yoshizawa, Makoto;, "A test of fuzzy controller of cycle-to-cycle control for controlling three-joint movements of swing phase of FES gait", バイオメカニズム学術講演会予稿集, Vol. 25, pp. 43-46, バイオメカニズム学会, 2004

2003

[1] Arifin, A; Watanabe, T; Hoshimiya, N;, "A Test of Fuzzy Controller for Cycle-to-Cycle Control of FES-induced Hemiplegic Gait: Computer Simulation in Single-joint Control", 生体医工学: 日本エム・イー学会誌, Vol. 41, No. 1, pp. 68, 社団法人日本生体医工学会, 2003

[2] Arifin, Achmad; Watanabe, Takashi; Hoshimiya, Nozomu;, "Design of Fuzzy Controllers for Cycle-to-Cycle Control of Swing Phase of FES-induced Hemiplegic Gait", バイオメカニズム学術講演会予稿集, Vol. 24, pp. 199-202, バイオメカニズム学会, 2003

2002

[1] ARIFIN, Achmad; WATANABE, Takashi; HOSHIMIYA, Nozomu;, "Cycle-to-Cycle Control of Swing Phase of FES-induced Hemiplegic Gait : A Computer Simulation with Different Controllers", IEICE technical report. ME and bio cybernetics, Vol. 102, No. 481, pp. 1-4, The Institute of Electronics, Information and Communication Engineers, 2002

Conference Proceedings

2017

[1] Aliansyah; Achmad Nur, Arifin; Achmad, Purwanto; Djoko , Fatoni; Muhammad Hilman, "Extraction of Brain Signal during Motor Imagery Task for Wheelchair Control Command", International Conference on Research & Innovation in Computer, Electronics and Manufacturing Engineering (RICEME-17), Feb. 2-3, 2017. Bali (Indonesia). pp. 25.

Abstract—Paralysis is a disease that causes loss of function from one or more muscle. When someone is paralyzed, the brain still works to obtain information about body activities. While doing or imagining movement, the similar response occurs in the brain. The purpose of this study was to detect any change the value of Event Related Desynchronization/Event Related Synchronization (ERD/ERS) during event. Time-frequency domain analysis was used to determine the frequency dominant when it occurred. This
information would be used as a Band Pass Filter for calculating the value of ERD/ERS. In this research, EEG signals were acquired from channel C3, C3-F3, C4, and C4-F4 base on international system
10/20 from EEG. The findings show that the range of frequency dominant from selected channels on all subject is 8-12Hz. The value of ERD/ERS was changed 64.43% in channel C3 and 60% in channel
C3-F3 whereas in channel C4 was 64.43% and 66.67% in channel C4-F4. The change of value of ERD/ERS would be used as control command for wheelchair in the next research topic.

2016

[1] Arifin, A; Arrofiqi, F; Watanabe, T; Nuh, M; Basith, A. L.;, "Embedded Fuzzy Logic Controller for Functional Electrical Stimulation System", 2016 International Seminar on Intelligent Technology and Its Application, pp. 89-94, 2016

Functional electrical stimulation (FES) is one of the most common techniques used to improve motor function in individuals with paralysis. In this study, fuzzy logic controller implemented in embedded system for wearable FES was developed. The controller was designed as Single Input Single Output (SISO) and Multi Input Single Output (MISO) controllers to manage electrical stimulation for seven muscles in thigh and shank and to induce certain joint movements. The system was realized in two steps utilizing 32-bit ARM microcontrollers, STM32F429 and STM32F103C8T6, respectively. Closed-loop control was used in the system and realized using feedback from the sensors. Serial communication was utilized for data transmission between embedded system and PC/laptop as monitoring station. Experiments done to test the performance of SISO controller of knee flexion proved that the system was able to adjust burst duration and to control joint movement induced. The system designed was expected to be helpful for clinical application of motor function improvement

[2] Hikmah, Nada Fitrieyatul; Arifin, Achmad; Sardjono, Tri Arief; Suprayitno, Eko Agus;, "A sequential hypothesis testing of multimodal cardiac analysis", Asea Uninet Scientific and Plenary Meeting 2016, pp. 63-77, 2016

Focus of our research group is development of integrated cardiac analysis system. A measurement and analysis system of cardiovascular system can be realized in an integrated system that includes all cardiac vital signs [1]. We have tested a signal processing framework of multimodal cardiac signals, electrocardiogram, carotid pulse, and phonocardiogram of normal subjects [2]. This paper describes a follow up effort in analysis and classification of heart conditions. Multimodal cardiac signals were recorded from 20 normal and 3 abnormal subjects. The measurements were performed after obtaining the consent of subjects. The data were recorded using a special instrument designed by our group, and digitized with 1 kHz sampling frequency. The recordings were performed in 10 trials, with 5 second for each trial. Parameters of the cardiac signals were extracted. Sequential hypothesis testing [3] was used in classification stage to produce a diagnosis of normal and abnormal heart based on the extracted parameters. The overlapping problem was solved by selecting two thresholds, upper and lower, resulted in no decision taken while the value of data tested was in the overlapping zone. The results of normal subjects showed that 90% of the data were identified in the 3rd test and 100% of the data could be identified after the 4th test, while the abnormal subjects showed that 80% of data were identified in the 3rd test and 100% of the data could be identified after the 4th test. The classification result recommended the proposed method should be realized in clinical use.

[3] Mujibtamala, Arizal; Imron, Nanda; Arifin, Achmad; Purwanto, Djoko;, "Realisasi Kontrol Hirarki Untuk Pengaturan Kecepatan Kursi Roda Elektrik Berdasarkan Subject Intension Menggunakan Bioelectrical Impedance", SEMINAR NASIONAL INOVASI DAN APLIKASI TEKNOLOGI DI INDUSTRI (SENIATI) 2016, pp. 1-7, 2016

Makalah ini menjelaskan metode kontrol kecepatan kursi roda elektrik, yang didedikasikan untuk orang dengan keterbatasan alat gerak tangan dan kaki. Pada penelitian sebelumnya, bioelectrical impedance digunakan sebagai perintah kontrol kecepatan kursi roda elektrik. Penelitian ini dikembangkan kontrol kecepatan yang dapat direalisasikan pada jalan datar, berdasarkan keinginan subjek. Instrumentasi bioelectrical impedance digunkanan sebagai sistem untuk membaca keinginan pengguna kursi roda elektrik melalui perubahan impedasi pada otot trapezius, 3 elektroda disposable digunakan sebagai interface antara tubuh subjek dan instrumentasi bioelectrical impedance, dimana masing-masing elektroda diletakkan pada bahu kanan, bahu kiri dan tepat di bagian tulang belakang, perubahan impedansi pada masing-masing bahu akan diterjemahkan oleh konrol hirarki sehingga dapat dibaca oleh sistem mikrokontroler untuk menggerakkan kursi roda elektrik. Perintah kontrol belok kanan, belok kiri, maju dengan kecepatan 1, kecepatan 2 dan kecepatan 3 masing masing didapat ketika ada perubahan impedansi yang melebihi threshold pada bahu kiri, bahu kanan dan kedua bahu digerakkan ke depan secara trigger untuk meningkatkan kecepatan kursi roda elektrik saat berjalan maju. Variabel kecepatan maju masing- masing sebesar 20, 30 dan 40 RPM, sedangkan untuk perintah kontrol berhenti, dilakukan dengan menggerakkan kedua bahu ke depan dan ditahan selama 1,5 detik. Hasil percobaan menunjukkan persentase keberhasilan sebesar 75% pada pengujian jalan datar. Percobaan dilakukan pada 4 orang subjek normal dengan masing-masing subjek melakukan percobaan sebanyak 5 kali.

2015

[1] Al Kindhi, Berlian; Sardjono, Tri Arief;, "Pattern Matching Performance Comparison as Big Data Analysis Recomendations for Hepatitis C Virus (HCV) Sequence DNA", 2015 Third International Conference on Artificial Intelligence, Modelling and Simulation Pattern, pp. 99-104, 2015

A data bank can provide very useful information while mined properly.[27] In order to be optimally extracted, data mining can be done by observing capacity and characteristics of the data; so it can generates Knowledge Discovery in Databases as expected. For instance in Gene Bank, every single record of DNA, there are at least ten thousand sequences recorded. If the data is more than a hundred records, it will be a big sequence of data to be processed. Hepatitis C Virus (HCV) is a liver disease which can infect humans through blood. HCV infection can be asymptomatic, or it can be hepatitis acute, chronic, furthermore cirrhosis. Hepatitis C is generally does not show symptoms in the early stages. About 75 percent people with hepatitis C did not realize that they had infected until liver damage years later. Therefore needed a sequences DNA Mining is needed to analyse the DNA history whether it is infected by HCV or not. This study compares several methods of string matching to discover which methods have the best performance in processing DNA mining. In addition, this study also analyzed DNA HCV genetic mutations trend as a Knowledege Discovery in Database in DNA mining. Keywords

[2] Arrofiqi, Fauzan; Arifin, Achmad; Indrajaya, Benicditus;, "Design of wearable system for closed-loop control of gait restoration system by Functional Electrical Stimulation", 2015 International Seminar on Intelligent Technology and Its Applications, ISITIA 2015 - Proceeding, pp. 131-136, IEEE, 2015

This paper describes design and test of a wearable FES system for the purpose of improving the performance of gait in patients with post-stroke. The prototype system that was developed includes electrical stimulator and sensor systems. Electrical stimulator was designed to generate pulse train that was realized using non-isolated boost converter. Sensor system was designed to measure gait phases that was realized using FSR sensors and to measure lower limb joint angles that was realized using a fusion of gyroscope and accelerometer-based tilt angle sensor. In order to remove measurement error due to bias error of the gyroscope and fluctuation of tilt sensor, Kalman filter was used to estimate true lower limb joint angles. Each system was tested separately. Testing was done by measuring the stimulator's output on the tibialis anterior muscle stimulation in normal subjects. The characteristics of pulse train in accordance with the desired specifications and capable of producing contractions in the tibialis anterior muscle. Sensor system was tested to measure gait parameters in subjects who walk normally. Comparison of the measured data with existing research data, showed the same pattern of the signal, the magnitude value is still in the standard deviation value of comparative data.
link: ieeexplore.ieee.org

[3] Bangsawan, Hadid Tunas; Mardiyanto, Ronny; Sardjono, Tri Arief;, "Six key points lip's feature extraction using adaptive threshold segmentation", 2015 International Seminar on Intelligent Technology and Its Applications (ISITIA), pp. 261-266, IEEE, 2015

Key points of lip give important cues of lip shape. The application of lip's shape tracking could be used for speech recognition, lip reading and many multimedia applications. In this paper, a novel adaptive threshold segmentation for six key points lip's feature extraction algorithm is proposed. First, Viola Jones method is used to detects face in an image frame, after that the ROI of mouth is set. Color transformation in RGB space and adaptive threshold are used for lip segmentation. Further step, contour of the segmented lip is defined and filled in with certain color. Finally, the six key points, which are left and right corners, lower point, and three points of the Cupidon's bow of lip are scanned. The performance of the proposed method is satisfactory and compared with existing methods it brings a significant improvement in accuracy.
link: ieeexplore.ieee.org

[4] Hikmah, Nada Fitrieyatul; Arifin, Achmad; Sardjono, Tri Arief; Suprayitno, Eko Agus;, "A signal processing framework for multimodal cardiac analysis", 2015 International Seminar on Intelligent Technology and Its Applications, ISITIA 2015 - Proceeding, pp. 125-130, IEEE, 2015

The heart is a complex organ in the cardiovascular system which its measurement and analysis system in clinical level should be realized in an integrated system including all cardiac vital signs. A previous study combined ECG and PCG analysis could detect murmur symptom. However, the heart mechanical activity could not be described. This study developed a multimodal analysis of cardiac signals consisting of ECG signals, carotid pulse, and PCG. The purpose of this study was to develop and test an appropriate signal processing framework to facilitate parameter extraction and to enhance understanding of underlying mechanisms in the cardiac physiology. Frequency and time-frequency domain analysis of cardiac signals were performed to design sophisticated digital filters. Recursive digital filters were chosen in realizing segmentation methods and the advanced signal processing techniques were performed in parameter extraction. Results show the proposed method was able to detect QRS complex, P and T waves in ECG signal with 88% sensitivity and also percussion wave with 85.62% sensitivity. Sistolic (S1) and diastolic (S2) heart sound also could be separated. Classification of normal and the disease type of heart based on the cardiac parameters resulted by the presented signal processing framework would be next research topic.
link: ieeexplore.ieee.org

[5] Kuswadi, Son; Barakbah, Ali Ridho; Nuh, Mohammad;, "An integrated project-based learning for Intelligent Control lecture and practice at polytechnics graduate school", 2015 International Electronics Symposium (IES), pp. 100-104, IEEE, 2015

This paper presents an integrated project-based learning of lecture and laboratory practice on Intelligent Control course in Master degree Program, at Politeknik Elektronika Negeri Surabaya (PENS). This first skill-based graduate engineering education program in Indonesia, was started since 2013 to fulfill the lack of professional engineers in advanced level to be ready as innovators and leader in industries. Moreover, since the role of PENS as National Resources Polytechnics in electrical and information related fields, this program also provide practical-oriented graduate level education for the country's polytechnic lecturer that inline with the nature of polytechnic education. We will present one of example how we deliver our integrated knowledge and skill to the students, in this case Intelligent Control course. The course enable student learn the knowledge given by lecturer in the classroom, and - together with lecturer - the students design and implement practice in laboratory to get hands on practical ability. By project-based learning, students more actively involve in the learning process, and hence the student-centered learning could be realized.
link: ieeexplore.ieee.org

[6] Subur, Joko; Sardjono, Tri Arief; Mardiyanto, Ronny;, "Braille Character Recognition Using Find Contour Method", Electrical Engineering and Informatics (ICEEI), 2015 International Conference on, pp. 699-703, IEEE, 2015

Braille letters is characters designed for the blind, composed of six embossed points, arranged in a standard braille character. Braille letters is touched and read using fingers, therefore the sensitivity of the fingers is important. Those characters need to be memorized, so it is very difficult to be learned. The aim of this research is to create a braille characters recognition system and translate it to alpha-numeric text. Webcam camera is used to capture braille image from braille characters on the paper sheet. Cropping, grayscale, thresholding, erotion, and dilation techniques are used for image preprocessing. Then, find contour method and image recognition lookup table method are used to recognize the braille characters. The system can recognize braille characters with 100% accuracy even when the braille image is tilted up to 0.5 degrees
link: ieeexplore.ieee.org

[7] Wibowo, Madha Christian; Sardjono, Tri Arief;, "Spinal Curvature Determination from X-Ray Image using GVF Snake", Information & Communication Technology and Systems (ICTS), 2015 International Conference on, pp. 35-40, IEEE, 2015

Scoliosis is where the spine is curved, forming a "C" or "S" shape. The treatments are differs depending on the severity of Cobb Angle. But Cobb Angle measurement has a very low accuracy because of the unclear feature of spine in x-ray image. This paper discuss about spinal curvature determination using GVF Snake as the segmentation method and modified top-hat filter as pre-processing method. GVF Snake could fit the "S" shape best with parameters alpha=0.9, beta=0.5, and gamma=0.3. 10 frontal spinal x-ray images of scoliosis patients were used as segmentation samples. The modified top-hat filter is used for pre-processing the image with combination of disk sizes and attenuation factors of 1, 3, 5, 7, and 9. The average error of the qualified contour results is 6569 pixels. The best result gave an error of 3118 which is still couldn't fit the desired contour well.
link: ieeexplore.ieee.org

[8] Arifin, Achmad; Budiman, Fajar; Arrofiqy, Fauzan; Indrajaya, Bededictus Mawar; Ma'ar;, "Wearable Gait Measurement for Two Sensors and Force Sensing Resistor", International Conference on Sensor, Sensor System and Actuator (ICSSSA), 2015

2014

[1] Arifin, Fatchul; Sardjono, Tri Arief; Purnomo, Mauridhi Hery;, "The Relationship Between Electromyography Signal of Neck Muscle and Human Voice Signal for Controlling Loudness of Electrolarynx", Biomedical Engineering: Applications, Basis and Communications, Vol. 26, No. 5, pp. 1450054, National Taiwan University, 2014

Human voice intonation is affected by pitch and loudness. Pitch is related to the frequency of human voice, while loudness is related to the magnitude of human voice. Someone who does not have vocal cords, has no ability to produce voice. This problem is suffered by laryngectomy patients. Over half of all laryngectomy patients worldwide use electrolarynx for the rehabilitation of their speech ability. Unfortunately, the electrolarynx voice produces monotonic and flat intonation. Small changes in pitch and loudness of electrolarynx will give a better expression in laryngectomy patients. However, previous researches have focused on utilization of electromyography (EMG) signal of neck muscle for only pitch control. In this research, the relationship between human voice intonation (i.e. frequency and magnitude) and EMG signals of neck muscles was studied by looking for their correlation and their mutual information. Human voice signal and EMG signal of neck muscle were recorded simultaneously while subjects w...
link: www.worldscientific.com

[2] Nurmadyansyah, Rizky Fauzy; Arifin, Achmad;, "Discrete PID Control System Performance for IH2 Azzurra Hand Robot", Seminar on Intelligent Technology and Its Applications 2014, 2014

Robotic technology for various application keep growing and widely used. In this research, a closed loop control system for a robot prosthetic hand was developed and evaluated. Control system with microcontroller as a main component to controlling an IH2 Azzurra hand robot capable to run in real time. It has UART interface with 115,2kbps baud rate which be able to get an input from moving sensor and produce output that is command as input for hand robot. It can control motor speed for each finger referenced to hand posture through moving sensor. Discrete PID control based microcontroller is control system method that be used in this system. System performance that be designed can be seen directly using made PC software. Moreover, the important parameters can be made to chart or stored to storage based on PC, so advanced analysis can be obtained easily. System performance that be obtained is good enough, referenced to maximum RMSE is 0,0496% for ring-little finger control system. For further application, this control system can be developed for medical application such as neuroscience and prosthetic or industrial application such as telecontrol system.

[3] Setiawan, Rachmad;, "Design of Portable Electrical Stimulator for Multi-channel Functional Electrical Stimulation (FES)", Seminar on Intelligent Technology and Its Applications 2014, 2014

Fundamental research about Functional Electrical Stimulation (FES) indicates that FES could be used to restorate motor system of patient experiencing damage at arrangement of central nerve resulted from cerebrospinal of cord injury (SCI) and also stroke. Operation of human body organ impulse activated by FES is difficult and very complex because of nonlinearity from response neuro-muscular system, various from response musculo-skeletal system to electrical stimulation, time delay which is long, and fatigue phenomenon (muscle fatigue). Therefore, to overcome obstacle in operation of FES hence closed loop control applied to yield accurate impulse. For the application of closed-loop control at level klinis, FES system must be designed multi-channel and portable that patient feels balmy. The realized FES stimulator was a boost converter with duty cycle 90%, because it yielded relatively linear and higher output voltage. Keyword: Functional Electrical Stimulation, closed loop control, boost converter Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

2013

[1] Madona, Putri; Arifin, Achmad; Sardjono, Tri Arief; Hendradi, Rimuljo;, "Segmentasi Suara Jantung S1 dan S2 Menggunakan Kurva Amplop", The 13th Seminar on Intelligent Technology and Its Applications, pp. 109-114, 2013

Proses segmentasi suara jantung adalah tahapan yang penting dalam analisa suara jantung. Mengetahui lokasi dan interval dari suara jantung S1 dan S2 serta komponen-komponennya yang didapatkan melalui proses segmentasi dapat menjadi informasi tentang kondisi kerja jantung. Salah satu metode segmentasi yang bisa digunakan adalah wavelet transform dan kurva amplop. Dalam penelitian ini digunakan Discrete Wavelet Transform (DWT), serta 2 algoritma kurva amplop yaitu Moving Average Filter dan Normalized Average Shannon Energy untuk segmentasi 28 data suara jantung yang terdiri dari normal dan 3 murmur. Perhitungan pada kedua algoritma kurva amplop tersebut menghasilkan kurva amplop yang bergeser dari sinyal aslinya. Semakin lebar window yang digunakan semakin besar pergeseran yang terjadi. Dari hasil segmentasi menunjukkan bahwa periode sistolik mempunyi durasi yang lebih pendek dan lebih konstan dibandingkan periode diastolik. Dan interval suara jantung S1 murmur sistolik lebih panjang dibandingkan suara jantung normal sementara interval suara jantung S2 murmur diastolik lebih panjang dibandingkan suara jantung normal. Algoritma segmentasi yang digunakan telah menunjukkan kemampuan dalam segmentasi suara jantung S1, S2 dan komponen-komponennya dengan tingkat keberhasilan 71.43%. Sebagai langkah selanjutnya perlu dilakukan ekstraksi ciri pada suara jantung S1 dan S2 hasil segmentasi untuk mengetahui kandungan frekuensi dari masing-masing suara jantung tersebut. Kata

[2] Nasuha, Aris; Sardjono, Tri Arief; Purnomo, Mauridhi Hery;, "Lip segmentation and tracking based on Chan-Vese model", 2013 International Conference on Information Technology and Electrical Engineering (ICITEE), pp. 155-158, 2013

Lip reading has wide spread application, e.g. audio-visual Automatic Speech Recognition (AV-ASR), silent speech interface and person identification. Lip segmentation is one of important step in lip reading, because it provides basic information to be processed in subsequent steps. Lip tracking is a process of locating lip to associate lip in consecutive video frames. Chan-Vese model is a region-based segmentation algorithm, which also can be used as tracking method. This algorithm can detect boundary of object which not defined by gradient, while classical active contour can't be applied. This method also can detect object by any initial curve in the image, not necessarily surround the object. This paper investigates about lip segmentation and tracking based on Chan-Vese model, preceded by the color segmentation. © 2013 IEEE.
link: www.scopus.com

2012

[1] Arifin, Achmad; Arrofiqi, Fauzan; Setiawan, Rachmad; Supeno, Bambang; Tasripan; Pujiono; Tasripan, Pujiono;, "A Wearable Human Movement Measurement System: ~ Sensor Fusion and Signal Processing Method ~", The 13th Seminar on Intelligent Technology and Its Applications, pp. 189-193, 2012

We studied a method of joint angle measurement during movements using wearable sensor for rehabilitation purpose. The method utilized fusion of two types of inertial sensors, gyroscope and accelerometer-based tilt angle sensor. In order to remove measurement error due to bias error of the gyroscope and fluctuation of tilt sensor, Kalman filter was used to estimate true joint angle. The method was tested experimentally in measuring knee joint angle during cyclic movements using a physical model of knee joint. The measured joint angle data in 24 trials were assessed statistically comparing to the joint angle data measured by the electronic goniometer instrumented in the physical knee joint model. The designed Kalman filter reduced measurement error significantly. The method of sensor fusion and Kalman filtering showed high accuracy reflected by low RMSE: 2.66±0.64 degree, and high correlation coefficient: 0.97±0.05. By utilizing the Kalman filter, fusion of the gyroscope and tilt sensor would be applicable as a wearable, low-cost human movement measurement system, or in realizing a wearable control system for human movement rehabilitation.

[2] Hakim, Luqman; Arifin, Achmad; Sardjono, Tri Arief;, "Identifikasi Suara Serak Berbasis Transformasi Wavelet Dan Algoritma Jaringan Syaraf Tiruan", The 13th Seminar on Intelligent Technology and Its Applications, pp. 119-124, 2012

Paper ini membahas identifikasi suara serak berbasis transformasi wavelet dan algoritma jaringan syaraf tiruan (JST). Serak merupakan indikator gangguan pada pita suara, sehingga identifikasi jenis suara normal dan serak yang sistematis dapat membantu diagnosa gangguan pita suara. Continous Wavelet Transform (CWT) dengan fungsi morlet digunakan untuk mengeksplorasi karakter sinyal suara dalam domain waktu dan frekuensi secara simultan Data objek penelitian berupa suara vokal “A”, “E”, “I”, “O”,”U” normal dan serak karena radang tenggorokan.Topologi JST terdiri 900 neuron pada layer input, 40 neuron pada hidden layer 1 dan 2, dan 10 neuron layer output. Hasil CWT menunjukan perbedaan karakter waktu-frekuensi antara sinyal suara normal dan serak. Pengujian menggunakan yang sudah dilatih (50 data, terdiri atas 5 sampel dari setiap vokal normal dan serak) 100% teridentifikasi dengan tepat. Kemampuan JST mengenali data baru diuji secara online dengan suara normal dan suara serak secara random. Didapatkan nilai sensitifitas 84%, spesifisitas 86%, dan efisiensi rata–rata 85% untuk kelima jenis suara vokal. Dengan hasil tersebut dapat diketahui bahwa CWT dan JST dapat digunakan untuk mengidentifikasi jenis suara normal dan serak. Hasil penelitian ini diharapkan dapat dikembangkan hingga terealisasi sisitem identifikasi jenis penyakit daerah pita suara berdasarkan analisa suara pasien.

[3] Hendradi, Rimuljo; Arifin, Achmad; Hery Purnomo, Mauridhi; Gunawan, Suhendar;, "Exploration of cardiac valvular hemodynamics by heart sound analysis of hypertensive cardiac disease background patients", Proceeding - 2012 IEEE International Conference on Computational Intelligence and Cybernetics, CyberneticsCom 2012, pp. 153-157, IEEE, 2012

Heart sounds reflect heart valve activities, cardiac muscle contractions, and hemodynamics of heart. Auscultation technique is one of valuable methods for diagnosis. There are limitations in traditional auscultation stimulate utilization of signal processing methods to extract important characteristics of the heart sounds. We proposed Continuous Wavelet Transform (CWT) as time-frequency analysis for exploration of cardiac valvular hemodynamics of two normal subjects with hypertensive heart disease history. Decimation and a wavelet denoising were used for filtering. A normalized average Shannon energy was used for heart sound signal segmentation. Time-scale maps resulted by calculation of CWT were processed using thresholding method to localize temporal and frequency-related information of valvular activities of each cardiac sub-cycle. The temporal and frequency-related parameters were spaced time between systolic (S1) and diastolic (S2), activities of mitral (M1) and tricuspid (T1) valves during systolic period, aortic (A2) and pulmonary (P2) valves during diastolic period, and split time between valve activities in each cycle. Results of this study were considered to be valuable to explain the cardiac valvular hemodynamics of heart sounds precisely. The results indicate the benefit of the developed method to be applied in analyzing heart sound characteristics. The results are very helpful information for clinical use. Next topic of our research was addressed to expand the analytical method to other pathological background. The research work would be finalized by development of software analysis of cardiac pathology diagnostic system.
link: ieeexplore.ieee.org

[4] Indrajaya, Benedictus; Setiawan, Rachmad; Arifin, Achmad;, "Penentuan Lower Limb Joint Angles Berdasar Respon Akselerometer dalam Pengembangan Wearable Sensor untuk FES", The 6th Electrical Power, Electronics, Communications, Controls, and Informations Seminar, 2012

Banyaknya pasien yang mengalami kelumpuhan, misal, akibat stroke memerlukan rehabilitasi kelumpuhan anggota geraknya. Functional Electrical Stimulation (FES) dapat secara efektif dalam membantu restorasi kelumpuhan fungsi motorik. Untuk sistem FES terinduksi gait (gaya berjalan), memerlukan sistem sensor untuk memonitor lower limb joint angles sebagai feedback. Pada paper ini kami mengusulkan penggunaan sensor akselerometer dan giroskop untuk mengukur lower limb joint angles, yaitu sudut sendi heap, knee dan ankle. Pengunaan sensor berteknologi MEMSs dengan ukuran yang kecil bertujuan agar sistem sensor mudah dipakai dan nyaman bagi pasien. Dijabarkan bagaimana penentuan persamaan lower limb joint angles berdasar vektor akselerasi akselerometer yang terpasang pada segmen tubuh, paha, betis dan telapak kaki, untuk mengukur sudut tilt tiap segmen. Pengujian dilakukan dengan menggunakan model kaki dari seorang subyek dengan skala 1:1 didapat hasil yang linier dengan nilai RMSE sudut heap = 0,96o, RMSE sudut knee = 1,25o dan RMSE sudut ankle = 1,81o. Dengan metode yang diusulkan peletakan posisi sensor lebih mudah dilakukan. Berdasar hasil penelitian ini, kedepan akan dilanjutkan penelitian tentang penentuan lower limb joint angles pada subyek yang berjalan dengan normal gait

[5] Lutfi, Fuad; Arifin, Achmad;, "Klasifikasi Sinyal Elektrokardiografi Menggunakan Wavelet Transform dan Neural Network", The 13th Seminar on Intelligent Technology and Its Applications, Vol. 62, pp. 136-140, 2012

Elektrokardiografi (EKG) merupakan metode yang umum digunakan untuk mengukur kinerja jantung manusia melalui aktivitas elektrik jantung. Pada penelitian ini telah direalisasikan sebuah sistem yang mampu menganalisis dan mengklasi-fikasikan kelainan sinyal EKG. Continuous Wavelet Transform (CWT) dengan fungsi Morlet digunakan untuk mengeksplorasi karakteristik time-frequency sinyal EKG. Klasifikasi sinyal EKG dilakukan dengan Artificial Neural Network (ANN) metode algoritma backpropagation. Konfigurasi ANN adalah 20.000 neuron pada lapisan masukan, 50 neuron pada lapisan tersembunyi, dan 3 neuron pada lapisan keluaran. Sinyal EKG yang digunakan diambil dari database MIT-BIH Arrhythmia, termasuk sinyal denyut normal dan sinyal denyut bundle branch blok (BBB). Hasil komputasi CWT menunjukkan perbedaan karakteristik time-frequency yang signifikan antara sinyal normal dan sinyal BBB. Dalam pengujian kinerja klasifikasi ANN dengan data yang sebelumnya telah dilatih (sejumlah 25 data untuk 3 kelas : normal, left bundle branch block, right bundle branch block), masing-masing kelas 100% dikenali. Pengujian dengan data yang belum dilatih, ANN mengenali data dengan akurasi 87,04%. Dalam pengujian dengan validasi silang, ANN menunjukkan kinerja yang baik dengan sensitivitas 87% dan spesifisitas 95%. Hasil pengujian menunjukkan efektivitas pengenalan pola sinyal EKG menggunakan CWT dan ANN. Oleh karena itu, metode yang diusulkan ini diharapkan dapat diwujudkan dalam pengembangan Sistem Cerdas Diagnosa Jantung untuk aplikasi klinis.

[6] Madona, Putri; Arifin, Achmad; Tri, Arief; Hendradi, Rimuljo;, "Analisa Suara Jantung Berbasis Complex Continuous Wavelet Transform", Conference Paper, 2012

Penyakit jantung merupakan salah satu penyakit berbahaya yang masih menjadi penyebab utama kematian di seluruh dunia. Penyakit jantung valvular merupakan salah satu jenis penyakit jantung yang disebabkan ketidaknormalan fungsi katup-katup jantung. Teknik auskultasi tradisional yang masih umum dijalankan hingga saat ini mengandung kelemahan yang utama, yaitu faktor variabilitas intra- subjek dan inter-subjek, sehingga dapat mengakibatkan perbedaan hasil diagnosa. Dalam rangka mengembangkan sistem auskultasi modern diperlukan suatu metode yang mampu menganalisa suara jantung dengan baik. Oleh karena itu diusulkan sebuah metode analisis data suara jantung menggunakan Complex Continuous Wavelet Transform. Data yang digunakan adalah 28 data suara jantung yang dikumpulkan dari database publik serta 16 data dari pengambilan sampel suara jantung normal dari subjek normal menggunakan stetoskop digital. Prosedur pemrosesan sinyal untukmengekstrak fenomena fisik tersembuyi dari sinyal suara jantung terdiri dari 3 tahap. Pertama, Discrete Wavelet Transform, digunakan untuk mengurangi background noise pada sinyal asli. Kedua, sinyal disegmentasi menggunakan Normalized Average Shannon Energy. Ketiga, karakteristik dari sinyal akan diekstrak menggunakan Complex Continuous Wavelet Transform (CWT). Metode CWT yang telah diusulkan ini, menunjukkan kemampuan dalam mengekstrak dan mengidentifikasi suara jantung pertama S1, suara jantung kedua S2 dan komponen- komponennya. Hasil kontur time-frekuensi yang merefleksikan aktifitas mekanik dari katup maupun otot jantung diharapkan dapat digunakan dalam mendiagnosa kelainan jantung manusia.

[7] Puspasari, Ira; Arifin, Achmad; Hendradi, Rimuljo;, "Ekstraksi Ciri Komponen Aortik dan Pulmonari Suara Jantung Diastolik dengan Menggunakan Analisis Nonstasioner", The 6th Electrical Power, Electronics, Communications, Controls, and Informations Seminar, pp. 1-5, 2012

-Dalam rangka mengembangkan sistem diagnosa suara jantung secara elektronik, bagian ekstraksi ciri menjadi bagian yang sangat penting. Oleh karena itu, perlu dipelajari metode ekstraksi ciri yang efektif untuk menggali dinamika yang terkandung dalam data suara jantung. Pada penelitian ini telah dipelajari lebih spesifik dari beberapa metode ekstraksi ciri, dengan metode pengolahan sinyal non stasioner: Short Time Fourier Transform dan Wavelet Transform. Dari hasil penelitian durasi S2 suara jantung normal sebesar 0.071 ± 0.01017, durasi A2 sebesar 0.021 ± 0,0096 detik dari total data, dan durasi P2 sebesar 0.016 ± 0,0039 detik. Dari hasil suara mitral regurgitasi, tampak bahwa countour yang dihasilkan dari S2 tidak terpisah sedurasi S2 sebesar 0.02537 ± 0.00115 detik. Hasil penelitian ini menunjukkan bahwa terdapat time split pada komponen A2 dan P2 yaitu sebesar 0.03 ± 0.0144 detik untuk jantung normal. Penelitian selanjutnya adalah pemodelan suara jantung yang diharapkan mampu lebih mendiskripsikan dan memberikan informasi tentang karakteristik suara jantung secara objektif.

[8] Subiyanto, Lilik; Sardjono, Tri Arief;, "Deteksi Cacat pada Material Baja Menggunakan Ultrasonik Non-Destructive Testing dengan Metode Continuous Transform", Seminar Nasional Teknologi Informasi & Komunikasi Terapan (Semantik), Vol. 2012, No. Semantik, pp. 466-472, 2012

Ultrasonik Non-Destructive Testing (NDT) adalah salah satu teknik pengujian material tanpa merusak benda uji melalui pantulan gelombang ultrasonik. Pengujian ini dilakukan untuk mendeteksi adanya cacat (flaw) atau retak (crack) padamaterial secara dini, dan menghindari kegagalan saat digunakan. Propagasi gelombang ultrasonik didalam struktur baja mengalami pemantulan atau pembelokan pada saat mengenai medium dengan indek yang berbeda. Propagasi gelombang ultrasonik tersebut kemudian diekstrak menggunakan metode Continuous Wavelet Transform (CWT) untuk merepresentasikan permukaan material yang didasarkan pada frekuensi dan waktu pantul/belok sebagai dasar jarak keberadaan rongga (cacat). CWT mempunyai keunggulan pada proses analisis sinyal yang lebih cepat dibandingkandengan metode lain seperti transformasi fourier dan mempunyai kemampuan untuk mentransformasikan sinyal nonstasioner dalam domain waktu-frekuensi. Material uji yang digunakan pada penelitian ini adalah baja rendah karbon (steel 1020) , sedangkan peralatan penunjang utama yang digunakan adalah probe ultrasonik tipe pulse-echo singleprobe 4MHz. Software utama yang digunakan untuk pengolahan sinyal pada penelitian ini adalah DELPHI. Dari hasilanalisis sinyal diketahui bahwa NDT dengan metode CWT mampu merekonstruksi cacat material dengan baik. Kata kunci : Ultrasonik NDT, Flaw, Crack, Pulse-echo, Continuous Wavelet Transform.

[9] Supeno, Bambang; Setiawan, Rachmad; Arifin, Achmad;, "Disain Wireless Functional Electrical Stimulator Menggunakan X-Bee Pro", The 6th Electrical Power, Electronics, Communications, Controls, and Informations Seminar, 2012

Secara garis besar semua jenis gerakan itu dapat dikelompokkan menjadi dua bagian besar, yaitu gerakan tubuh bagian atas (upper limb) dan bawah (lower limb). Semua jenis gerakan, termasuk berjalan, merupakan hasil dari sebuah proses rumit yang melibatkan otak, sumsum tulang belakang, saraf perifer, otot, tulang dan sendi. Paralyzed lower limbs adalah suatu kondisi klinis pada pasien yang berupa kelumpuhan anggota tubuh bagian bawah. FES (Functional Electrical Stimulator) adalah merupakan salah satu divais yang dipergunakan sebagai metode terapi restorasi gerakan pasien dengan paralyzed lower limbs untuk mengaktifkan jaringan motoriknya, sehingga pasien dapat berjalan. Harapan utama dari penelitian ini adalah adanya disain sistem FES dengan komunikasi data tanpa kabel. Dengan Wireless FES yang menggunakan X-Bee Pro, diharapkan dapat semakin memudahkan dan mempercepat proses restorasi kelumpuhan pasien bagian bawah. Kata

[10] Suprayitno, Eko Agus; Arifin, Achmad;, "Sistem Instrumentasi Sinyal Electrocardiography Untukanalisa Dinamika Jantung", Seminar Nasional Fisika Terapan III , Departemen Fisika, FST, Universitas Airlangga Surabaya,15, 2012

Klasifikasi sinyal jantung sangat penting untuk mengetahui penyakit jantung yang seringkali datang secara tiba-tiba. Untuk mendukung pentingnya klasifikasi sinyal jantung, maka beberapa pekerjaan pendahuluan terkait pembuatan instrumentasi pendeteksian sinyal jantung (Electrocardiography) dihasilkan informasi bahwa hasil penguatan rata-rata instrumentasi Diferensial Amplifier ECG didapatkan sebesar (279.65 ± 14.66) kali. Untuk Low Pass Filter Analog Orde 4 dengan frekuensi cutoff 100 Hz dihasilkan penguatan -3 dB di area frekuensi 120 Hz. Hasil uji Notch Filter 1 dan Notch Filter 2 menghasilkan tegangan output (Vout) terkecil di frekuensi 50 Hz dengan besar Vout masing-masing (0.14 ± 0.00) volt dan (0.094 ± 0.009) volt serta Quality factor (Q) keduanya sama yaitu 6.28. Analisa sinyal jantung (ECG) dengan menggunakan DFT memberikan informasi bahwa pada sinyal jantung, area frekuensinya terjadi di area 3 Hz sampai 26 Hz. Penelitian ini selanjutnya akan dikembangkan pada Multimodal Cardiac Analysis dengan menampilkan sinyal ECG, sinyal Phonocardiography (PCG) dan sinyal Tekanan Darah (diwakili sinyal Carotid Pulse) secara simultan untuk mendapatkan informasi anatomi dan fisiologi jantung yang lebih kompleks.

[11] Suprayitno, Eko Agus; Hendradi, Rimuljo; Arifin, Achmad;, "Analisa Sinyal Electrocardiography dan Menggunakan Continuous Wavelet Transform", The 6th Electrical Power, Electronics, Communications, Controls, and Informations Seminar, pp. 1-6, 2012

Pada paper ini telah dikembangkan sistem analisa aktivitas jantung berdasarkan sinyal suara jantung (PCG) dan sinyal jantung (ECG) yang ditampilkan secara simultan dan di analisa menggunakan CWT. Sinyal suara jantung yang diambil pada empat titik jantung (Left Ventricle (LV), Right Ventricle (LV), Pulmonary Artery (PA), dan Aortic (AO)) secara simultan dengan sinyal jantung menghasilkan informasi suara jantung frekuensi dominannya banyak berada pada bunyi suara jantung pertama (S1) dan pada sinyal jantung frekuensi dominannya berada pada area glombang QRS kompleks. Ditinjau dari waktu kejadian, frekuensi suara S1 ada pada range 188 Hz - 229 Hz dengan range waktu 0,2 detik - 0,32 detik; suara jantung S2 pada 197 Hz - 535 Hz dengan range waktu 0,52 detik - 0,69 detik; suara jantung S3 ada pada 141 Hz - 212 Hz dengan waktu 0,8 detik; suara jantung S4 ada pada 169 Hz - 273 Hz pada waktu ke 0,16 detik. Sinyal QRS kompleks frekuensinya ada pada 94 Hz - 134 Hz dengan range waktu ke 1,2 detik - 1,3 detik. Ini menunjukkan bahwa suara S1 terjadi hampir bersamaan dengan timbulnya QRS kompleks. Penelitian selanjutnya akan dikembangkan lagi pada Multimodal Cardiac Analysis.
link: https:

[12] Wardana, P Susetyo; Arifin, Achmad;, "Instrumentasi dan Pendeteksian Sinyal EMG Dinamik selama Elbow Joint Bergerak", The 6th Electrical Power, Electronics, Communications, Controls, and Informations Seminar, pp. 1-5, 2012

Sinyal Electromyograph adalah salah satu sinyal penting yang menunjukan aktifitas otot manusia, sedangkan untuk merekam data sinyal EMG yang mempunyai karakteristik amplitude cukup kecil (0 – 10 mV) dan frekuensi pada range 20 – 500 Hz diperlukan rangkaian pendukung seperti penguat differential, filter low pass, high pass dan notch filter. Sinyal EMG yang dihasilkan oleh sebuah instrumentasi EMG memerlukan beberapa analisa yang membuktikan bahwa yang diperoleh adalah sinyal EMG bukan noise. Untuk menganalisa sinyal EMG dalam kawasan frekuensi digunakan (Discrete Fourier Transform) DFT dan (Mean Power Frequency) MPF. Dari penelitian ini diperoleh nilai MPF pada otot Triceps brachii untuk gerakan Elbow Flexion sebesar 75,156 Hz sedangkan gerakan Elbow Extension sebesar 65,069 Hz, gerakan Elbow Supination sebesar 27,627 Hz, gerakan Elbow Pronation sebesar 47,659 Hz. Dari keempat data MPF diatas membuktikan bahwa Instrumentasi EMG telah berfungsi merekam data sinyal EMG yang berada pada frekuensi 20 – 500 Hz

[13] Yasak, Abdul; Arifin, Achmad;, "Ekstraksi Parameter Temporal Sinyal ECG Menggunakan Difference Operation Method", The 13th Seminar on Intelligent Technology and Its Applications, 2012

Sinyal ECG merupakan salah satu sinyal yang dapat digunakan untuk mendeteksi kelainan jantung. Tiap-tiap komponen sinyal ECG menggambarkan proses fisiologis selama satu siklus aktivitas jantung. Deteksi ketidaknormalan jantung dapat dilakukan dengan mengetahui parameter temporal dari sinyal ECG. Pada penelitian ini dilakukan eksperimen metode ekstraksi parameter temporal sinyal ECG dengan menggunakan metode Difference Operation Method (DOM)untuk ekstraksi fitur sinyal ECG. Parameter temporal yang diekstrak meliputi interval R-R, durasi kompleks QRS, dan laju detak jantung. Metode ini diuji dengan menggunakan data ECG dari ECG MIT database dengan tiga kondisi, normal, right bundle branch block (RBBB) dan left bundle branch block (LBBB). Hasil penelitian menunjukkan metoda DOM dapat mengekstrak parameter temporal ECG. Masing-masing kondisi jantung mempunyai ciri yang khas dari parameter temporal yang diekstrak. Kami mendeteksi ada kasus tertentu dimana batas antara satu kondisi dengan yang lain mempunyai batas yang fuzzy. Hal ini akan ditindaklanjuti dengan metoda klasifikasi yang sesuai dengan karakter data sesuai hasil penelitian ini. KataKunci:Difference

[14] Yatmono, Sigit; Arifin, Fatchul; Sardjono, Tri Arief; Purnomo, Mauridhy Hery;, "Pengenalan Suara Vocal Berbasis Microcamera", Prosiding Seminar Nasional Aplikasi Sains & Teknologi (SNAST) Periode III, No. November, pp. 146-152, 2012

Suara merupakan salah satu alat komunikasi manusia yang utama. Tanpa suara, manusia tidak akan dapat lagi berkomunikasi, menyampaikan kemauannya kepada orang lain secara bebas. Berbagai usaha agar para penderita tuna laring (laringnya diambil, karena menderita kanker stadium tinggi) dapat kembali berbicara telah banyak dilakukan. Diantaranya melalui suara perut esophagus dan menggunakan alat electrolarynx. Berbicara dengan suara perut bukanlah hal yang mudah. Untuk dapat melakukanya para pasien harus belajar ekstra keras. Sedangkan berbicara menggunakan alat elektrolarynx, disamping harga alatnya yang sangat maha,l suara yang dihasilkannya pun sangat datar, tidak ada intonasi sama sekali. Suara yang dihasilkan nya “mirip robot”. Oleh karena itu perlu ada inovasi lain bagaimana mendesain alat bantú wicara bagi pasien tunalaring.Dalam paper ini akan disajikan bagaimana dapat mengenali suara vocal berbasis microcamera. Microcamera digunakan untuk merekam bentuk mulut ketika mengucapkan vocal tertentu. Selanjutnya citra hasil perekaman diolah untuk dikenali. Pengenalan dilakukan dengan menggunakan algoritma Jaringan syaraf tiruan. Hasil pengujian menunjukkan sistem yang dibangun mempunyai validitas 78,3 %. Hasil yang disajikan dalam paper ini diharapkan akan dapat menjadi dasar pengembangan alat bantú wicara bagi pasien tunalaring

2011

[1] Agustinah, Trihastuti; Jazidie, Achmad; Nuh, Mohammad;, "Hybrid fuzzy control for swinging up and stabilizing of the pendulum-cart system", 2011 IEEE International Conference on Computer Science and Automation Engineering, Vol. 4, pp. 109-113, IEEE, 2011

This paper presents the design and implementation of a hybrid fuzzy control for the swinging up and stabilizing of the pendulum-cart system. The fuzzy swing-up controller is employed to swing the pendulum up from its pendant position to the stabilization zone in the upright position using as few rules as possible. After the pendulum reaches the zone, the fuzzy stabilizing controller is then switched to stabilize the inverted pendulum at the upright position. The controller is designed based on a robust performance state feedback controller using Linear Matrix Inequalities (LMI) approach for Takagi-Sugeno fuzzy systems. Numerical simulation and real-time experiment are presented to show the effectiveness of the method.
link: ieeexplore.ieee.org

[2] Firdaus, Sukma; Arifin, Achmad;, "Analisa Nonstasioner Pada Auditory Evoked Responses", Conference Paper, 2011

Auditory evoked responses (AER) adalah representasi dari proses neurofisiologi di dalam otak akibat stimulus suara pada sistem pendengaran. Sinyal AER merupakan sinyal nonstasioner, hal ini disebabkan karena otak selalu menghasilkan respons dengan frekuensi yang tidak konstan disetiap waktu. Salah satu metode analisa yang dapat digunakan untuk sinyal nonstasioner adalah analisa time-frequency. Analisa time-frequency yang digunakan dalam penelitian ini adalah continuous wavelet transform (CWT). Dalam penelitian ini, dilakukan analisa terhadap rentang skala dengan magnitudo yang lebih besar. Rentang skala tersebut adalah 20x10-2 hingga 80x10-2. Nilai magnitudo pada rentang skala tersebut lebih besar dari pada sebelum dan sesudah stimulus. Hal tersebut juga terjadi pada subyek yang dikondisikan dengan mata terbuka. Terdapat perbedaan pada kondisi mata tertutup dan mata terbuka, perbedaan tersebut adalah nilai magnitudo pada mata tertutup lebih besar dari pada mata terbuka. Perubahan nilai magnitudo pada mata tertutup jauh lebih tegas berada pada daerah VI dan VII dalam gambar plot hasil perhitungan CWT. Sedangkan pada mata terbuka, nilai magnitudo direntang tersebut lebih melebar. Waktu respon tercepat terdapat pada perekaman ke-10 subyek 1 untuk kondisi mata terbuka dengan waktu tempuh sebesar 0.045 detik, sedangkan waktu respon paling lama terdapat pada perekaman ke-8 subyek 1 kondisi mata tertutup dengan waktu tempuh sebesar 0.220 detik. Dari penelitian ini diperoleh, bahwa pendekatan analisa nonstasioner dengan menggunakan CWT, mampu menunjukkan sifat kenonstasioneran dari sinyal AER.

[3] Lutfi, Fuad; Arifin, Achmad;, "Karakterisasi Sinyal Elektrokardiografi menggunakan Transformasi Wavelet Kontinyu", Konferensi Nasional Forum Teknik Elektro 2011, 2011

2010

[1] Agustinah, Trihastuti; Jazidie, Achmad; Nuh, Mohammad; Haiping Du, Haiping; Du, Haiping;, "Fuzzy tracking control design using observer-based stabilizing compensator for nonlinear systems", 2010 International Conference on System Science and Engineering, pp. 275-280, IEEE, 2010

This paper presents fuzzy tracking control design for nonlinear systems. The design methodology is a synthesis of the tracking control theory of linear multivariable control and the Takagi-Sugeno fuzzy model. The observer-based stabilizing compensator type from multivariable tracking control theory is used, because not all states of the nonlinear system are fully available or measured while Takagi-Sugeno (T-S) fuzzy model is used to represent the dynamic of nonlinear system. The concept of parallel distributed compensation is employed to design fuzzy tracker and fuzzy observer from the T-S fuzzy model. The stability analysis of the designed system is derived via the Lyapunov function. Numerical simulation and real-time experiment are provided to illustrate the tracking control design procedure and performance of the proposed methods for practical application.
link: ieeexplore.ieee.org

[2] Arifin, Fatchul; Sardjono, Tri Arief; Purnomo, Mauridhy Hery;, "Esophageal speech Recognition Utilizing Pulse Coupled Neural Network.", The 6th International Converence on Boiomedical Engineering., pp. 1-4, 2010

The laryngectomies patient has no ability to speak normally because their vocal chords have been removed. The simplest option for the patient to speech again is esophageal speech. Meanwhile, the voice recognition technology has been increased rapidly. In order the voice recognition technology also can be used by esophageal speech correctly, the esophageal speech recognition technology must be developed. This paper describes a system for esophageal speech identification. Two main parts of the system, feature extraction and pattern recognition were used in this system. The Pulse Coupled Neural Network – PCNN is used to extract the feature and characteristic of esophageal speech. The pattern recognition, multi layer perceptron, will recognize the sound patterns. From the experiments and results It can be concluded that the system can recognize esophageal speech very well up to 95,8 %. It is also can be known that PCNN can be utilized as feature extractor very well. Keywords:

2009

[1] Purnama, I. K. E.; Wilkinson, M. H. F.; Veldhuizen, A. G.; van Ooijen, P. M. A.; Sardjono, T. A.; Lubbers, J.; Verkerke, G. J.;, "Following scoliosis progression in the spine using ultrasound imaging", World Congress on Medical Physics and Biomedical Engineering, IFMBE Proceedings, Vol. 25, No. 2, pp. 600-602, Springer Berlin Heidelberg, 2009

Scoliosis is a three-dimensional deformation of the spine which is characterized by a lateral deviation of the spine and axial rotation of the vertebrae. It must be monitored frequently to be in time to start the treatment in case of progression. Nowadays, X-ray is used, but has a detrimental effect and provide only 2D data. Ultrasound would allow a frequent and 3D view on the spine and thus is ideal to follow scoliosis progression. A feasibility study on ultrasound is presented. A freehand 3D ultrasound system was used to scan the back of a volunteer. In the resulting ultrasound volume, the vertebral features such as transverse processes, laminae, and superior articular processes appear prominently along with the non-vertebral features like muscles, head of the ribs and parts of the pleura. The 3D orientation of the vertebrae, determined by the axial rotation and vertebral tilt was determined semiautomatically. The axial rotation and vertebral tilt measurements in the region of the thoracic vertebrae T4 - T9 delivered good accuracy, in other regions the accuracy was acceptable. In conclusion, imaging the human spine using ultrasound is feasible. The result provides a basis towards the aim to follow scoliosis progression using ultrasound.
link: link.springer.com

[2] Saito, Hiroki; Watanabe, Takashi; Arifin, Achmad;, "Ankle and knee joint angle measurements during gait with wearable sensor system for rehabilitation", IFMBE Proceedings, Vol. 25, No. 9, pp. 506-509, Springer Berlin Heidelberg, 2009

A method of joint angle measurement during gait using wearable sensors for rehabilitation was studied in this paper. The method corrected joint angles measured by gyroscopes using joint angles measured by accelerometers with Kalman filter. Although gyroscopes could measure joint angles, their offset drift caused error in measurement of joint angles. At first, we made up small sensor units consist of a gyroscope and an accelerometer. Then, the method was validated with the developed sensor units in measurement of ankle and knee joint angles of three healthy subjects under walking on short distance pathway and on treadmill for long time. The measured joint angles were compared with reference joint angles measured with optical motion measurement system simultaneously. The result for short distance walking showed low RMS errors and high correlation coefficients (3.19deg and 0.918 for the ankle joint, 2.98deg and 0.993 for the knee joint in average). The result for treadmill walking also showed low RMS errors and high correlation coefficients (3.04deg and 0.960 for the ankle, 4.19deg and 0.994 for the knee in average). Although the measurement accuracy decreased in some of trials of a specific subject because of sensor attachment position, the experimental results suggested that joint angle could be measured with good accuracy independent of measurement period of time, walking speeds and subjects. © 2009 Springer-Verlag.
link: link.springer.com

[3] Sardjono, T. A.; Hidayati, R; Purnami, N; Noortjahja, A; Verkerke, G. J.; Purnomo, M. H.;, "A preliminary result of voice spectrum analysis from laryngectomised patients with and without electro larynx: A case study in Indonesian laryngectomised patients", Instrumentation, Communications, Information Technology, and Biomedical Engineering (ICICI-BME), 2009 International Conference on, pp. 1-5, IEEE, 2009

Laryngectomy is the treatment to totally remove the larynx in order to clear out laryngeal cancer. The trachea is led outside to the neck and thus is separated from the esophagus. The patient no longer breathes through its mouth but through a hole in his neck. This drastic change in the human body causes a loss of the ability of speech for the patient. Patient will learn to speech using esophageal speech or using an electro-larynx. This paper describes the preliminary speech spectrum analysis resulted from the normal voice and Indonesian laryngectomised patient with and without electro larynx. The voice will be recorded and analyzed using a spectrum analysis application to know the fundamental frequency. The result shows that the fundamental frequency of `a' and `b' sound from laryngectomised patient without electrolarynx are 363 Hz and 727 Hz, respectively. By using an electrolarynx those frequency are 888 Hz and 1000 Hz, respectively. It is hope that these result can be used to develop a new electronic voice producing element with an appropriate voice based on each human voice characteristics.
link: ieeexplore.ieee.org

2008

[1] Arifin, Achmad; Saito, Hiroki; WATANABE, Takashi;, "An error reduction method of portable, low-cost joint angle sensor system for human movement measurement and control (ME とバイオサイバネティックス)", 電子情報通信学会技術研究報告. MBE, ME とバイオサイバネティックス, Vol. 108, No. 314, pp. 31-34, 一般社団法人電子情報通信学会, 2008

2007

[1] Pumama, K.E.; Wilkinson, M.H.F.; Veidhuizen, A.G.; Van Ooijen, P.M.A.; Lubbers, J.; Sardjono, T.A.; Verkerke, G.J.;, "Branches filtering approach for max-tree", VISAPP 2007 - 2nd International Conference on Computer Vision Theory and Applications, Proceedings, Vol. IFP, pp. 328-332, 2007

A new filtering approach called branches filtering is presented. The filtering approach is applied to the Max-Tree representation of an image. Instead of applying filtering criteria to all nodes of the tree, this approach only evaluate the leaf nodes. The expected objects can be found by collecting a number of parent nodes of the selected leaf nodes. The more parent nodes involve the wider the area of the expected objects. The maximum value of the number of parents (PLmax) can be determined by inspecting the output image before having unexpected image. Different images have found have different PLmax values. The branches filtering approach is suitable to extract objects in a noisy image as long as these objects can be recognised from its prominent information such as intensity, shape, or other scalar or vector values. Furthermore, the optimum result can be achieved if the areas which have the prominent information are present in the leaf nodes. The experiments to extract bacteria from noisy image, localizing bony parts in a speckled ultrasound image, and acquiring certain features from a natural image appeared to be feasible give the expected results. The application of the branches filtering approach to a 3D MRA image of human brain to extract the blood vessels gave also the expected image. The results show that the branches filtering can be used as an alternative filtering approach to the original filtering approach of Max-Tree.

[2] Sardjono, T. A.; Wilkinson, M. H. F.; van Ooijen, P. M. A.; Veldhuizen, A. G.; Purnama, K. E.; Verkerke, G. J.; Ooijen, P M A Van;, "Spinal Curvature Determination from an X-Ray Image Using a Deformable Model", 3rd Kuala Lumpur International Conference on Biomedical Engineering 2006, Vol. 15, pp. 291-295, Springer Berlin Heidelberg, 2007

This paper presents a spinal curvature determination from frontal X-ray images of scoliotic patients. A new deformable model, Modified CPM (Charged Particles Model), has been developed and used to determine the spinal curvature. The Modified CPM is a new approach of a deformable model based on CPM, which was introduced in 2004. The X-ray image is charged negatively according to the edge-map or gradient-magnitude image. The particles are attracted towards the contour of the object of interest, because this contour is very dark, thus charged very negatively. We modified the CPM by putting springs between the particles to prevent the particles from moving away and keep the movement of the particles in the appropriate distance without reducing the flexibility to follow the curvature. The results of the implementation show the effectiveness of the modified charged-particle model for spinal curvature determination on X-ray images.
link: link.springer.com

[3] Watanabe, Takashi; Arifin, A.; Masuko, T.; Yoshizawa, M.;, "An Experimental Test of Fuzzy Controller Based on Cycle-to-Cycle Control for FES-induced Gait : Knee Joint Control with Neurologically Intact Subjects", 11th Mediterranean Conference on Medical and Biomedical Engineering and Computing 2007, pp. 2007-2007, Springer Berlin Heidelberg, 2007

Functional Electrical Stimulation (FES) can be effective in assisting or restoring paralyzed motor functions caused by the spinal cord injury or the celebrovascular disease. The purpose of this study was to develop a control method of gait induced by FES. We had proposed a fuzzy control system based on cycle-to-cycle control for controlling hip, knee and ankle joints during the swing phase of FESinduced gait and evaluated it in computer simulation studies. In this report, the fuzzy controller was tested experimentally in controlling maximum knee extension angle stimulating the vastus muscles using surface electrodes with neurologically intact subjects. The fuzzy controller worked properly in regulating stimulation burst duration time and the maximum knee extension angle was controlled well. The experimental results suggested that the fuzzy controller would be practical in clinical applications for the control of FES-induced gait. However, it was also suggested that electrical stimulation with large burst duration time or muscle fatigue caused a change in muscle response.
link: link.springer.com

2006

[1] Arifin, Achmad; Watanabe, Takashi; Yoshizawa, Makoto; Hoshimiya, Nozomu;, "A Test of Stimulation Schedules for the Cycle-to-Cycle Control of Multi-joint Movements in Swing Phase of FES-induced Hemiplegic Gait", バイオメカニズム学会誌, Vol. 30, No. 1, pp. 31-35, 2006

This paper described a computer simulation test of six different stimulation schedules for the cycle-to-cycle control of swing phase of functional electrical stimulation (FES) induced hemiplegic gait. The stimulation schedules were evaluated in controlling the hip, the knee and the ankle joint movements on the point of view of acceptable quality of the gait that was similar to the natural gait pattern. Five stimulation schedules were knowledge-based stimulation schedules and one stimulation schedule was an EMG-based stimulation schedule. Two acceptable stimulation schedules were found by the evaluation. Results of this study showed that combination of the timing pattern of muscle activation and knowledge of joint movements and muscle function is necessary in design of stimulation schedule for FES gait. Co-activation of the ilopsoas, the hamstrings and the vastus muscle at the beginning of swing phase and that of the tibialis anterior and the soleus at the end of swing phase were found to be effective in controlling swing phase. The knowledge-based generation of stimulation schedule would be effective and necessary in clinical application.

[2] Arifin, Achmad; Yoshizawa, M;, "A Computer Simulation Study on the Cycle-to-Cycle Control Method of Hemiplegic Gait Induced by Functional Electrical Stimulation", RECORD OF ELECTRICAL AND COMMUNICATION ENGINEERING CONVERSAZIONE TOHOKU UNIVERSITY, Vol. 74, No. 2, pp. 58, TOHOKU DAIGAKU DENTSU DANWAKAI, 2006

[3] Purnama, K E; Wilkinson, M H F; Veldhuizen, A G; PMAv, Ooijen; A, Sardjono T; Brendel, B; Others;, "Imaging the whole spine using a free-hand 3D ultrasound system", The 52th annual meeting of the orthopaedic research society CD-ROM, 2006

2003

[1] Arifin, A; Watanabe, T; Hoshimiya, N;, "Computer simulation study of the cycle-to-cycle control using fuzzy controllers for restoring swing phase of FES-induced hemiplegic gait", Proc. Symp. on Med. & Biol. Eng, pp. 131-139, 2003

[2] Arifin, A.; Watanabe, T.; Hoshimiya, N.;, "Fuzzy controller for cycle-to-cycle control of swing phase of FES-induced hemiplegic gait: a computer simulation in two-joints control", Proceedings of the 25th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE Cat. No.03CH37439), Vol. 2, pp. 1519-1522, IEEE, 2003

This paper described a test of fuzzy controller for controlling knee and ankle movements of swing phase of FES-induced hemiplegic gait. We developed five fuzzy controllers to control electrical stimulation for the hamstrings, the quadriceps, the gastrocnemius medialis, the tibialis anterior and the soleus muscles. The fuzzy controllers regulated burst durations of stimulation pulse trains to maintain certain maximum angles of knee flexion, knee extension, ankle plantar flexion, and ankle dorsiflexion and to prepare good initial contact. Capabilities of fuzzy controller in automatic generation of stimulation burst duration and compensating muscle fatigue were tested by computer simulation using musculo-skeletal model. The fuzzy controller generated standard burst duration in automatic generation of stimulation burst duration in a few cycles and compensated muscle fatigue fast.
link: ieeexplore.ieee.org

2002

[1] Ari, Santoso; Belier, B.; Nuh, M.; Jazidie, Ach; Rameli, M.; Castagne, M.; Falgayrttes, P.;, "Applied of look up table controller based of FLC (fuzzy logic controller) in non-linear system AFM (atomic force microscopy)/PSTM (photon scanning tunnel microscope)", Circuits and Systems, 2002. APCCAS'02. 2002 Asia-Pacific Conference on, Vol. 2, pp. 565-568, IEEE, 2002

The problems of AFM/PSTM with piezoelectronic motor are how to control the fast and precise motion of the piezoelectronic because of its nonlinear hysteresis characteristic. On the other hand, in order to scan the surface and optical characteristics simultaneously in semiconductor material using AFM/PSTM, high speed microscope motion is required. FLC is one of the most effective algorithms to control a nonlinear system. This paper, the application of FLC to AFM/PSTM as a class nonlinear system is proposed. A look up table (LUT) controller based on FLC is used in order to overcome the quick response of the piezoelectronic motor. It was shown that the obtained images are noisy and the filter could not perfectly eliminate the noise. Nevertheless, the LUT controller based on FLC is able to overcome the nonlinear and noise problems well.
link: ieeexplore.ieee.org

[2] Nuh, M.; Jazidie, A.; Muslim, M.A.;, "Automatic detection of epileptic spikes based on wavelet neural network", IEEE Asia-Pacific Conference on Circuits and Systems, Proceedings, APCCAS, Vol. 2, pp. 483-486, IEEE, 2002

© 2002 IEEE. Detecting and classifying sharp transients in EEG (Electroencephalograph) recording by visual screening is a laborious and time-consuming task. That is why, there is an urgent need to construct a computer algorithm to detect automatically that type of EEG transient phenomena. The use of an artificial neural network as a classifier and wavelet analysis as pre-processing give promising results to answer that need. This paper proposes to develop a new method for the automatic detection of epileptic spikes based on Wavelet Neural Networks (WNN). A proper selection of scaling in WNN is introduced to overcome the problem of very long time duration during training. The result shows that proper selection of wavelet scaling can decrease training duration without decreasing WNN performance.
link: ieeexplore.ieee.org

2001

[1] Nuh, Mohammad; Jazidie, Achmad; Kuswadi, Son; Kemalasari;, "Temperature distribution pattern in normal and cancer tissues: the effect of electromagnetic wave", 2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Vol. 4, pp. 3904-3908, 2001

Temperature distribution pattern on normal and cancer tissues caused by the Electromagnetic wave effect is presented in this paper. First, the pattern is modelled by using Bio Heat Transfer Equation and then the Galerkin Finite Element method is used to solve the equation via computer simulation. From the simulation results it can be shown that the temperature change on the cancer tissues is relatively constant and 0.4 o C higher than the change on the normal tissues. From this phenomenon it can be understood that the damage of the cell of the cancer tissues is greater than the damage of the cell of the normal tissues. Therefore it is possible to use the Hyperthermia technique with electromagnetic wave for cancer therapy. The simulation results can be also used to decide the control strategy for giving the dose energy of electromagnetic wave which is flowed out to the cancer tissues.
link: ieeexplore.ieee.org

1999

[1] Kuswadi, Son; Widodo, W; Wahyudi, S; NUH, Mohammad; Saito, Osami;, "Flexible arm structure control using adaptive fuzzy network", Proceeding 1999 International Symposium on Nonlinear Theory and Its Applications (NOLTA'99), Hilton Waikoloa, Hawaii, USA, Nov, pp. 527-530, 1999

Books/Thesis

2008

[1] Setiawan, Rachmad;, "Teknik Akuisisi Data", Graha Ilmu Yogyakarta, 2008

2007

[1] Sardjono, Tri Arief;, "Spinal X-ray image analysis in scoliosis", 2007

In this thesis new image analysis methods are discussed to determine the curvature of scoliotic patients characterised by the Cobb angle and to enhance the vertebral parts based on features from a frontal X-ray image. Chapter 1 provides some background information on scoliosis, how to diagnose it, the treatment options and the problems related to spinal X-ray images. Then, a problem definition is formulated and a general block diagram of a proposed solution is explained briefly, followed by a detailed explanation of each part. The knowledge of the vertebral geometry helps us to have a better understanding about the relevant features of a vertebra so that we can develop an image analysis system that can detect those features

2006

[1] Setiawan, Rachmad;, "Mikrokontroler MCS-51", Graha Ilmu Yogyakarta, 2006

[2] Setiawan, Rachmad;, "Mikroprosesor 8088", Graha Ilmu Yogyakarta, 2006

[3] Setiawan, Rachmad;, "Teknik Interface", Graha Ilmu Yogyakarta, 2006

1900

[1] Setiawan, Rachmad;, "Programmable Peripheral Interface 8255A", Diktat Kuliah, 1900

Others

1999

[1] Kuswadi, Son; Basuki, Achmad; Nuh, Mohammad; Saito, Osami;, "A Genetic Algorithm For Polytechnic Time Tabling (EEPIS Timetabling Case Study)", pp. 1-5, 1999

Timetabling of polytechnic case study using genetic algorithm will be presented. The proposed modified GA operators reflect the distinctive aspects of the polytechnic education compared with university. The both hard and soft constraints almost same with the university case, except its capacity constraint because polytechnic uses packet system, instead of credit system as university did. The proposed algorithm is verified through several experiments using some mutation probability values