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S Onyshko

Publications and source records attributed to S Onyshko.

5 recordsLinked to original sources
PubMed1989

Dual-pathway model of the human vestibulo-ocular reflex.

The purpose of the study was to investigate, evaluate and refine an existing dual-pathway VOR model by comparing the model responses with the responses of human subjects. Based on data of subjects' VOR responses, the physiological parameters and some gain constants in a dual-pathway model were adjusted to suit the human VOR data. As a result, the improved model can produce and exhibit the fundamental nystagmus patterns of human VOR responses to the head motions around a vertical axis for a wide range of frequencies and magnitudes. It was found that there is good agreement on quantitative analysis between the outcome of human VOR responses and the model output. Also, it was found that the quantitative analysis of slow-phase eye-movement data confirmed the previously published results.

Biomedical Engineering↗
PubMed1987

A microcomputer-based prosthetic limb controller: design and implementation.

This paper describes the design and implementation of a microcomputer based myoelectric limb controller. This controller was constructed for use as a feasibility study of, and a development tool for, microcomputer-based myoelectric limb controller applications. Features of this approach include flexibility and computational power. The present design uses low-power CMOS technology to provide a system in which most of the new computationally and decision orientated myoelectric signal processing algorithms can be used. Two CMOS microprocessors, a CD80C86 and a MC146805E2, are used, but microcomputer power consumption is only 120 mA.

Biomedical Engineering↗
PubMed1975

A voluntarily controlled electrohydraulic above-knee prosthesis.

Most above-knee amputees to date are using prostheses employing either constant friction or some type of programed hydraulic damping which the wearer has no control over and which limits his gait speeds. A new system was designed and tested in which voluntary control of a lower-limb prosthesis is derived from the EMG signals of residual thigh muscles in the stump. These signals, after suitable conditioning, open or close solenoid valves, which form a closed hydraulic loop around the damping cylinder in the knee joint. Thus, the amputee is able to voluntarily vary the resistance to knee flexion, from free swing to full lock, by operating valves controlling the resistance to flow around a hydraulic cylinder. The main advantages of this system are a variable and more aesthetic gait, stability over uneven terrain, and because the lock prevents only knee flexion, the amputee can rise on his prosthesis and so use a passive appendage as an active element of his skeleton. The results of this project demonstrate that the concept of an EMG voluntarily controlled hydraulic prosthesis is viable; however, continuing effort is required to make this system lighter, more compact, and cosmetically acceptable.

Biomechanical Phenomena↗
PubMedDate not supplied

A low-power multichannel electromyographic signal data acquisition system.

The development of a stand-alone low-power EMG data acquisition system is described. The resulting design operates at low power (approximately 350 mW) and gives four channels of signal measurement with a maximum sampling rate of 10 kHz. Therefore, the data acquisition system described is ideal for low power data acquisition using a microcomputer. The digitized results are available to the microcomputer in a 12 bit signed magnitude form. This system was designed and implemented for use in a microcomputer-based myoelectric limb controller, however, its use is not limited to this application.

Biomedical Engineering↗