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Biomedical subjects

N Hoshimiya

Publications and source records attributed to N Hoshimiya.

36 records · Page 2Linked to original sources

A multichannel FES system for the restoration of motor functions in high spinal cord injury patients: a respiration-controlled system for multijoint upper extremity.

A multichannel functional electrical stimulation (FES) system for the restoration of quadriplegic upper extremity function is described. The system is composed of a personal computer NEC PC-8801mkII, peripheral electronic circuits, CRT display and respiratory sensors for volitional control by the patient, and percutaneous electrodes. A C4 quadriplegic patient could drink canned tea by herself by using this FES system. Distinct features of the system are as follows: 1) Versatile volitional control was realized by controlling the memory allocation of the stored stimulation data by voluntary respiratory signals. 2) Sophisticated fine control of the fingers, wrists, and elbow was realized by creating the multichannel stimulation data from recorded myoelectric activities of normal subjects during movements of the upper limb.

Arm↗

Functional electrical stimulation for the control of the upper extremities.

A multi-channel functional electrical stimulation (FES) system for the restoration of hand function of the quadriplegic is described. The system is composed of a personal computer NEC PC-880lmkII, peripheral electronic circuits and two kinds of sensors, i.e. an analog displacement sensor for volitional control (channel 1) and a logical sensor (high pitch sound or head switch, channel 2). Combination of the two channel signals allow three major function: 1) designation of the desired prehension pattern among cylindrical grasp, key grip and parallel extension grip; 2) selection of the operation status--'start', 'proportional control', 'hold', 'stop'--and, 3) volitional control which can be controlled by the shoulder movement. In the clinical application, Caldwell-Reswick type multistrand stainless steel percutaneous electrodes were used. In this FES system, standard multi-channel stimulation patterns were obtained from electromyographical analysis of joint movement of the upper extremities in normal subjects which gave us precise information about a role of each muscle during various kinds of motion. Such stimulation patterns have enabled us to restore motor function of the paralyzed upper extremities for activities of daily living (ADL).

Electric Stimulation↗

Ensemble noise and current relaxation analysis of K+ current in single isolated salivary acinar cells from rat.

The K+ channel in rat parotid gland acinar cells were investigated by ensemble current noise analysis in single isolated cells employing the giga-seal whole cell current recording mode. Sets of 20-40 identical de- and hyperpolarization voltage steps were applied and the resultant current records were processed by computer to obtain the mean and the variance of the current. The time-course of the mean current could be fitted by the sum of two exponentials, suggesting a 3-state model. The simplest plausible hypothesis is a model with one open and two closed states. Assuming this model, the relationship between the variance (sigma 2) and the mean current (I) could be fitted by the function sigma 2/I = i--I/N. The estimated single channel i/V-relations were similar to those taken from single channel current recordings, and the size of the population of channels per cell (N) was 76 +/- 26 (n = 12). The validity of the model was tested by a successful simulation of the time-course of the variance.

Animals↗