著者

駒井 啓二 富永 晟浩 川村 次郎 松矢 正利 福井 信佳 田中 政敏 西原 一嘉

出版者

バイオメカニズム学会

雑誌

バイオメカニズム (ISSN:13487116)

巻号頁・発行日

vol.8, pp.155-164, 1986-09-25 (Released:2016-12-05)

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Using surface electrodes, we have developed and tested clinically FES systems for lower and upper limbs of hemiplegic patients and for upper limbs of quadriplegic patients. Furthermore, we have studied fatigue of muscle contraction caused by FES and intermittent sinusoidal high frequency stimulation. We have developed a peroneal stimulator for hemiplegic patients. Now, we are waiting approval of the Ministry of Welfare before putting it on the market in Japan. Clinical factors of hemiplegia relating to the peroneal stimulator were analyzed in 80 patients. It was found that hemiplegic patients who were slightly spastic and above stage IV of lower limb functional level (Brunnstrom) were good candidates for using the FES. According to our experience. FES was very suitable for the Japanese life style. We also developed a one-channel stimulator for upper limbs of hemiplegic patients. The stimulator was suitable for patients who have hypertonus of finger flexors. We have developed a two-channel stimulator for C_5-level quadriplegic patients. Finger flexors and extensors of only one hand are stimulated through two pairs of surface electrodes by this stimulator. The stimulator is controlled by a toggle switch which is manipulated by the other hand. Although the method of control is on/off in this system, strength of stimulation is increased gradually at the start of so that finger movement is gradual. In order to get active prehension and release by two-channel stimulation, a splint which stabilizes the wrist and thumb in the functional position was used. Furthermore, four fingers, the index finger to small finger, were held together by the finger support. In performance tests with three patients, it has been proven that quadriplegic patients are able to restore grasping by using this stimulator. We have measured muscle fatigue during FES and the period which is required for its cessation. In case of 60-second stimulation, 60-second off time was required for 90% restoration of grasping force. We have studied intermittent sinusoidal high frequency stimulation both in order to increase grasping force and to control pain. It was found that the grasping force by intermittent sinusoidal high-frequency stimulation (5.7kgf) is larger than grasping force by low-frequency stimulation (3.2kgf). However, patients who were stimulated by intermittent sinusoidal high frequency complained of more numbness than those stimulated by low-frequency stimulation.