多功能呼吸檢測儀之研發於氣喘評估應用

Abstract

氣喘一直是全球性的慢性疾病，其盛行率在20到44歲，而成年人達5％，兒童更超過10％，由於患者經由口或鼻子呼出的一氧化氮含量和氣喘疾病具有高相關性，另外，患者的肺容積及呼氣流速都比一般正常人差，因此本研究著重於多功能呼吸檢測儀之研發作為氣喘評估的指標，利用微熱絲晶片並結合微控制器達成手持式裝置，使用前可自行選擇使用者，吹氣時可將呼吸訊號即時地顯示在面板上並做相關的數值運算，系統也內建藍芽傳輸，可依據使用者代碼將每次量測的資訊傳輸到遠端桌面電腦，而此系統主要是評估肺容積及呼氣流速。另外，本研究同時研發表面電漿共振(surface plasmon resonance, SPR)之氣體感測器，並以一氧化氮為偵測目標，預期未來可將呼吸檢測儀結合氣體感測器，以達成氣喘評估的雙重指標。 在SPR氣體感測器的感測層研發，主要有兩種，第一為金與三氧化鎢混合之奈米薄膜，利用不同比例的金與三氧化鎢薄膜之介電係數進行SPR共振角位置及深度之最佳化數值模擬後，進一步以配合脈衝雷射沉積系統(Pulsed laser deposition, PLD)之製程完成薄膜製作；第二為導電高分子PEDOT (poly(3,4-ethylenedioxythiophene)，以循環伏安法電化學的方式沉積在金膜上，並利用不同製程參數調控PEDOT厚度。人體呼出的氧化氮大於16ppb可以作為診斷是否為氣喘的臨界值，因此利用導電高分子以及創新的奈米混合薄膜，以低濃度的偵測範圍並結合微小化系統做為未來發展的目標，以達成完整的氣喘評估平台。

Asthma is a global chronic disease prevalent among the age group of 20 to 44 years. People affected by asthma account for 5% of adult population and reach even over 10% of all children. The nitric oxide (NO) exhaled from nose or mouth is highly correlated to asthma, so NO is regarded as an indicator of asthma. Besides, the patient’s lung volume and expiration flow are inferior to the normal. This research focused on the development of multi-functional respiratory device which can be used for asthma assessment; the device is a prototype system made of the hot wire chip with microcontroller. The current function includes switching user, expiration test and real time data display on the LCD, and Bluetooth transmission of the data to remote PC using user specific code. The key parameters monitored by this system are lung volume and respiration flow. In addition, we also attempt to develop a surface plasmon resonance (SPR) sensor to detect NO. Combined with the SPR gas sensor, the respiratory device is capable of simultaneously measuring more than two indicators of asthma. There are two types of design for SPR gas sensor. The first one is Au-WO3 composite nanofilm; the optimal SPR resonance is found by adjusting the volume fraction of Au-WO3 using a simulation software and the design is then fabricated using Pulsed Laser Deposition (PLD) technology; the second one is conductive polymer PEDOT deposited by cyclic voltammetry unto the Au film. The PEDOT thickness can be controlled by varying the fabrication condition. The exhaled NO concentration over 16ppb is regarded as the diagnostic criterion in asthma assessment; therefore, a miniature device using the conductive polymer and the innovative composite nanofilm to achieve low concentration level sensing is a goal in the future development of asthma detection device.