- 學位論文
壓阻式即時血壓感測器之研發
Development of a piezoresistive real-time blood pressure sensor
摘要
本論文的研究目的為量測血壓達到提早監測與預防心血管疾病。隨著高齡化社會的來臨，許多慢性疾病皆需要血壓監控來確保病患狀況穩定，但由於市面上較常用的血壓計體積過大，在攜帶上及量測上都較為不便，本論文為了改善現有市面上血壓計為目標，希望將其發展成穿戴式裝置，將其輕量化、微小化，在未來達成與科技產品連接，達到非接觸式、即時監控的量測目標。 本論文以假設在沒有任何外力之下，表層皮膚的變形是來自於其內部血管的壓力波的波動所造成，以此探討相關的幾何結構去驗證其形變量，並且將其結構簡化成較簡易的機械模型去探討皮膚與血壓的關係，藉由應變規所量測的訊號透過模型去反推回內部的血壓壓力值，由於應變規在解析形變量上更為精準，這在微小化的過程中尤其重要。 為了更有效的驗證，本論文建立了一個體外的架構去模擬真實的人體結構，並利用馬達幫浦注水至通道然後改變其供電電壓產生壓力波，並在其人工結構的表面上安置感測器去去驗證其可行度，由結論可得知，內部的壓力波的確會造成皮膚表層的變形，只要能將裝置貼合皮膚順利，即可藉由應變規所量測的訊號反推回內部壓力值，得到即時監控下量測的血壓， 最後，本論文設計了一個簡易的裝置便於使用者穿戴使用，以達到穩定的量測環境，而可以專注在模型的建立推導上，只要能得知人們一般皮膚的機械性質，即可藉由訊號反推回內部血管壓力值。
並列摘要
The objective of this thesis is to develop a blood-pressure measuring method for providing a real-time monitoring and early warning of cardiovascular diseases. The major disadvantages of the commonly-used sphygmomanometers found on the market are bulky and heavy for outdoor applications. In this thesis, we develop a wearable, blood-pressure measuring device with a light weight and small volume. In this thesis, the proposed noninvasive measuring technique is based on detecting surface deformations of human skins and then calculating the blood pressures. With the assumption of no external forces on the skin surface, the deformation was primarily caused by the fluctuations of the pressure waves in the deeply-embedded arteries surrounded by human tissues. We proposed a simplified mechanical model to convert the surface-skin deformations measured by the strain gauge into the blood pressures of arteries. For experimental validations, we constructed the artificial human structure composed of the pump and the hollow PDMS tube to analogize the case that a heart pumps out blood pressure waves flowing in arteries. It was demonstrated that the pressure waves in the channel of the PDMS tube could be detected and recorded by the strain gauge attached on the surface of the artificial structure.Then, we developed a prototype for vitro tests with real humans. The experimental results shown that real human blood pressures could be measured with our proposed device with a good accuracy. In the future, the proposed device can be improved by integrating a wireless communication and a microprocessor for portable capabilities.