應用於連續脈搏波量測之高靈敏度觸覺感測器陣列開發

Abstract

本研究開發了一高靈敏度的壓力感測器陣列，並將其應用於連續脈波之監測。本研究所提出的感測器由表面具有微結構的高分子材料所組成。感測器將被放置在橈動脈表層的皮膚，並施以一外加壓力固定。根據動脈張力測定法，所測定到的脈波訊號會和血壓值呈現正相關。而藉由陣列化感測器的使用，在量測時，至少會有1至2個感測單元能夠量測到穩定且清晰地脈波訊號，增加感測之效率與使用的便利性。 本研究所提出的壓力感測器陣列由雙層表面具有微結構的導電高分子所組成。其中，導電高分子由PDMS混合多壁奈米碳管所構成，表面的微結構則是利用尼龍濾膜作為模具，將尼龍濾膜表面的的孔隙結構轉印而成。特性量測結果顯示，此元件具有高靈敏度、重複性佳、製程簡單且具可撓性等。本研究亦成功的利用提出的元件量測到脈波訊號，而所量測到的訊號透過Fast Fourier Transform (FFT)與Hilbert Haung Transform (HHT)處理，也能成功的將訊號的漂移與高頻雜訊消除。而在未來的研究中，亦可將此脈波訊號與實際血壓值做轉換，並應用到學術與臨床醫學上使用。

In this work, a highly sensitive piezoresistive tactile sensing array for continuous blood pulse wave monitoring was presented. The polymer-based sensing device was patterned with microdome structures by using nylon membrane filter substrates. The sensing array is placed and pressed on the superficial radial artery. Based on the tonometric method, blood pressure can be estimated from the measured blood pulse wave signals. By using a linear sensing array, at least 1 or 2 sensing channel can easily acquire excellent blood pulse signals without making much effort on aligning the sensing device with the artery. The proposed sensing array consists of two conductive polymer films which are made by dispersing multi-wall carbon nanotubes (MWCNT) into PDMS matrix patterned with microdome structures by using a membrane filter substrate. Characterization of the proposed sensing elements was conducted. The proposed device features advantages such as high sensitivity, good repeatability, flexibility and simple fabrication process. Experimental results show that continuous blood pulse wave signal can be tracked by the proposed sensing array. The drift and the high frequency noise can be successfully eliminate by applying Fast Fourier Transform (FFT) and Hilbert Haung Transform (HHT).The measured blood pulse wave signal can potentially transformed into real blood pressure value in the future.