應用於智慧型血管支架系統之具無線傳輸功能可撓微型壓力感測器

Abstract

本研究基於微機電技術開發了一可整合於血管支架的心血管壓力感測器。此壓力感測器具有無線量測、可撓性及被動式驅動等特性，並預期能透過心導管手術與血管支架一同植入人體血管中。此外，為了符合能於人體內達成長期血壓之監測功能，感測器採用具生物相容性之聚一氯對二甲苯為基材，與聚二甲基矽氧烷為元件之主要結構材料。感測器利用微機電技術於基材上製作平面電感線圈與上下電容板電極，透過簡單的對折封裝形成LC諧振電路。其中，平行板電容可視為壓力感測單元，而平面電感線圈則能無線傳輸壓力感測訊號。本研究採用Phase-dip技術獲取L-C壓力感測器受到外接壓力時的共振頻率變化，達成無線壓力量測之功能。最後，為了測試此壓力感測器於類似人體血液環境中的表現，本研究也將開發之感測器分別於空氣、去離子水與0.9%生理食鹽水中進行量測。在0mmHg至250mmHg壓力範圍內，於空氣、去離子水與0.9%生理食鹽水壓力響應度分別為-14.18 kHz/mmHg、-8.69 kHz/mmHg與-7.31 kHz/mmHg，而且壓力-共振頻率具有高度線性關係。

In this work, we propose a wireless, flexible passive pressure sensor for monitoring cardiovascular pressure. The device is designed to be inserted into a stent that can be deployed within a blood vessel using a catheter-based delivery system for monitoring cardiovascular pressure. Aimed toward long-term continuous blood pressure monitoring in the intravascular environment, the sensor employs biocompatible polymeric material Parylene-C as the substrate material. By utilizing micromachining techniques, a parallel-plate capacitor and an inductor coil were implemented in the sensor as an inductor–capacitor (LC) resonant tank for pressure sensing and wireless signal transmission. Using the Phase-dip technique, the resonant frequency shift (i.e., the pressure signals) of the resonant tank are wirelessly retrieved. The fabricated device was wirelessly measured in air, DI water and 0.9% saline. The measured results showed a linear frequency response in the pressure range from 0 mmHg to 250 mmHg. The pressure responsivities were approximately -14.18 kHz/mmHg, -8.69 kHz/mmHg and -7.31 kHz/mmHg in air, DI water and 0.9% saline, respectively.