洗腎廔管有洗腎病患的「生命線」之稱，根據統計，在建立廔管後三年之內，人工廔管與自體廔管發生阻塞機率分別高達58%與20%。若廔管嚴重阻塞造成透析效率降低，輕則噁心、嘔吐；重則導致死亡。目前臨床上較常使用超音波影像系統或血管造影技術，來評估廔管阻塞程度，相當昂貴且耗時。本研究利用自行設計的都卜勒超音波搭配超音波感測器，結合無線傳輸功能，開發量測血液流速功能的可攜式裝置。藉由量測廔管與動靜脈吻合處兩端的平均流速(AFR)與血流變異比(RFV)，評估廔管阻塞程度。

Hemodialysis fistulas have been hailed as the "lifeline" for patients on dialysis. According to statistics, the probability of an AVG or an AVF becoming blocked within three years after its creation was 58% and 20%, respectively. Severe fistula blockage will lead to lower dialysis efficiency, which can cause nausea and vomiting in the mild case and death in the extreme case. In current clinical care, an ultrasound imaging system or angiography was more often used as a way to assess the degree of stenosis (DOS); however both are expensive and time-consuming. In this study, a portable device for blood flow measurement was developed, which combined a self-designed Doppler ultrasound, several ultrasonic sensors and a wireless transmission function. The DOS was assessed by measuring average flow rates (AFR) and ratios of flow variability (RFV) at both ends of an arteriovenous anastomosis.