人工電子耳新型電流操控技術之處理與測試

Abstract

在以往人工電子耳中電極的數量決定了使用者所能聽到的聲音頻率的多寡，因為一個實體電極即代表了一個可刺激的位置，直到電流操控技術的出現—同時利用兩相鄰電極進行刺激來產生位於此電極對中間區域的刺激，這類刺激稱為虛擬通道，此技術能夠更精準地刺激聽神經以此增進使用者的音準感知能力。我們第一個在台灣對應用了電流操控技術的電子耳使用者進行音準辨認與差異辨認的臨床測試，這兩個測試是用來計算電流操控技術能為使用者增加多少聽覺通道，結果顯示每一位使用者從電流操控技術中得到的幫助程度差異很大，所以「針對使用者建立個人化耳蝸的模型並利用此模型去更精確地模擬多電極電流操控技術的刺激情形，進而發展個人化的電流刺激策略」此一概念將會被提出。此個人化模型是根據臨床測量電子耳使用者耳蝸的電生理特性所建構並且會利用新式的音準辨認實驗結果來印證模型的正確性。

The number of electrodes of traditional cochlear implant determines the number of channels that users could perceive. Intermediate channels, also called virtual channels, between two neighboring electrodes can be created by simultaneous electrical stimulation in cochlear implant systems through controlled channel interaction, called current steering. Since current steering allows more precise electrical stimulation to the auditory nerves, it is assumed that it can improve the pitch perception of cochlear implant recipients. We conducted the first pitch ranking and pitch discrimination clinical experiment on cochlear implant patients using current steering technology in Taiwan to evaluate the number of virtual channels created by current steering could be perceived by CI users. It is found that the hearing and current steering performance of CI users vary from patient to patient. A patient specific cochlear implant model is needed to design an optimzed current steering strategy and this model would allow us to simulate the electrical stimulation more precisely for a particular CI user This patient specific CI model is constructed based on the electrophysiological property measured from real CI users and has been studied on two CI users.