無線可程式化之電刺激器 -模擬下肢步態之時序

Abstract

由於神經退化或損傷使病患肌肉失去應有之功能，導致其失去站立或行走的基本行動能力。雖然神經電刺激自1930年代以來，便開始應用在防止肌肉萎縮的治療上，但是由於缺乏一套標準的刺激參數，目前仍無法廣泛應用於臨床上恢復行動能力之治療，因此需要設計有效安全的刺激參數。電刺激訊號由以下參數構成：欉波持續時間(train duration)，欉波間隔時間(train-to-train duration)，脈波持續時間(pulse duration)，欉波內脈波間隔時間(pulse-to-pulse duration)，以及振幅(amplitude)。對於一些需要許多不同肌肉共同完成的動作，例如站立與步行等，需多條肌肉在特定時序內持續收縮以完成高協調性的動作，則需要多通道、同步化之刺激程序。因此，我們需要一個完善由刺激參數設定平台，供我們決定由坐到站立之刺激參數。為了達成此目的，本論文建構了一獨立的無線神經電刺激器，此裝置以labVIEW為軟體操作介面，而以FPGA為主控硬體。這個裝置已被應用於牛蛙實驗之參數測定，及木製模型之時序參數測試模擬，以驗證其有效性。未來有利於應用在發展神經損傷病患之適當刺激參數，以恢復其行動能力。

Peripheral nerve degeneration or damage causes loss of muscle function and thus results in the inability to perform basic actions such as standing or walking. Although electrical nerve stimulation has been used to prevent muscle atrophy since 1930, it is still not widely adopted in clinical therapy for mobility restoration due to the lack of standard parameters for the stimulation signal. Efficient stimulation protocols need to be designed for this signal and applied to human denervated muscles. The stimulation signal consists of pulse trains with parameters including train duration, train-to-train duration, pulse duration, pulse-to-pulse duration and amplitude. For actions such as walking, various muscles are involved in a synergic activity and need to continuously contract at certain times and thus multiple synchronized stimulation signals are needed. To determine efficient protocols that can transfer a patient from sit to stand position and maintain standing, a stimulator with multiple finely adjustable channels is needed. A wireless electrical nerve stimulation stand-alone system consisting of a FPGA (Field Programmable Gate Array) as the main controller and a GUI(graphical user interface) using LabVIEW was developed for this purpose. Experiments were done on frogs to determine appropriate stimulation parameters. A wooden model with muscle wire was used to test timing sets for muscle synchronization. This system might have potential to be used in designing appropriate protocols for functional restoration of immobile patients.