微型電化學感測系統之雙向無線傳輸應用與探討

Bi-directional wireless transmission studies of a miniaturized electrochemical-based biosensor

黃健峰(Jian-feng Huang)

指導教授 ： 婁世亮

中原大學/工學院/醫學工程研究所/碩士(2007年)

https://doi.org/10.6840/cycu200700621

摘要

定期生理參數檢測對慢性病患者極其重要卻也極具負擔。以糖尿病患者為例，每天的血糖監測是其賴以保命所必須。因此輕便精準生理訊號檢測儀的研發殊為重要。
電化學檢測方式具有微量量測、快速反應、準確度高和感測電路容易微小化及分析之優點。本研究以植入式系統為概念，整合無線雙向傳輸的技術與微型電化學感測器進行葡萄糖檢測，藉此探討整合系統之表現。
在本研究課程中，業已完成一套微型雙向無線電化學感測系統，主要可分為信號擷取分析子系統與微型電化學感測子系統兩部分。射頻傳輸頻率為820 kHz，發射線圈輸出功率均方根值為46.3 W，資料傳輸率為1200 bps。經無線傳輸距離探討，得知接收端耦合功率至少要大於76.5 mW才得以驅動微型電化學感測子系統正常運作，據此，進一步探究得本系統之傳輸距離最遠為3.2公分。在感測功能驗證方面，本系統偵測電流靈敏度為20 nA；在過氧化氫濃度介於0.002 ~ 0.1 mM時，感測電流線性度高達0.999；偵測葡萄糖濃度介於1 ~ 12 mM時，感測電流線性度可達0.997。於空氣或豬肉介質中發射線圈與接收線圈相距3公分並不會影響本系統感測功能性及準確性。注射維生素C的動物實驗結果證實本系統可以在老鼠體內正常進行感測。總理本研究，結果顯示吾人研製之微型雙向無線電化學感測系統，具有良好的感測線性關係，並克服無線傳輸距離困擾，達到淺層皮下植入檢測功能。

關鍵字

E類功率放大器 ； 生物感測器 ； 電化學 ； 無線傳輸

並列摘要

Vital signs and physiological parameters are important measurements reflecting physical conditions of human body. For some chronic illnesses, periodically measuring physiological parameters is essential. However the measurement procedures can be painful and tiresome. Taking diabetes patients as an example, daily finger pricks for blood sugar monitor is a must to assure patients’ normal physical conditions. From the patient’s point of view, this is not only a physically pain but also a mentally torture. Thus, to minimize any further burdens to the patients, the blood meter designs must be user friendly, compact and accurate.
A miniaturized wireless glucose biosensor based on electrochemistry technique was developed in this course. It involves an external controller and an implant unit. They are linked by radio frequency (RF) techniques where power and signals can be transmitted wirelessly and bi-directionally. The RF settings used in this study were 820 kHz, 46.3 W (rms) and 1200 bps for carrier frequency, output power and data transmission, respectively. Through a series of bi-directional transmission studies in air, the results indicated the power received by the implant unit to assure its proper function must be no less than 76.5 mW. Yet, the distance limit was no greater than 3.2 cm; otherwise, the power obtained in the implant dropped significantly. In the sensing studies, the media used between the controller and the implant were either air or pork and was 3.0 cm apart. All measurements were recorded via the bi-directional transmission fashion. The current sensitivity of the implant sensing circuitry was able to achieve 20 nA. For the concentration of the hydrogen peroxide in 0.002 ~ 0.1 mM, the response curve was almost a perfect line with a linearity of 0.999. When the glucose concentration of 1 ~ 12 mM was applied the response curve was alike a line with a linearity of 0.997. An in-vivo study on the developed system was carried out as well. The internal unit was hermetically packed by PDMS and was then implanted in a male rat. The response current signals received wirelessly upon the injections of ascorbic acid confirmed that the system has a potential to become an implantable biosensor.

並列關鍵字

Biosensor ； Wireless transmission ； Class E ； Electrochemistry

參考文獻

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