用於評估脈動血氧量測性能之具備散射校正的假體系統

Abstract

脈動血氧濃度是臨床上非侵入式方法判斷患者缺氧的重要依據之一，傳統血中含氧測定儀是利用紅光波段與近紅光波段所計算出來的R-ratio值進行換算而得，醫療用血氧儀需經過臨床測試其準確性後才可獲得上市許可。然而，臨床測試卻存在著高成本、高風險、高難度等缺點。因此，我們使用了脈動血氧假體系統來消弭以上所提缺點，來達到低成本、低風險、低操作難度的特性。本假體系統主體為黑色不透光壓克力，實驗溶液為0.02 mM去氧血紅蛋白與0.02 mM氧合血紅蛋白，利用透光度80%之衰光片模擬血液散射性質並使用凸輪機構模擬人類心律，結果顯示，假體系統可模擬脈動血氧濃度70%～100%，並將心律固定在85 bpm有效取代臨床測試。此外，利用市售六台血中含氧測定儀進行分析其量測準確性，由分析結果顯示，醫療級血氧儀在準確度上醫療級血氧儀(2%～2.75%)明顯高於指尖式血氧機(3.2%～4.2%)。我們相信我們所提出的假體系統在將成為後續取代高成本、高風險的臨床測試的起點。

Peripheral oxygen saturation is a critical basis for a clinical non-invasive method of deciding on patients with hypoxia. The typical pulse oximeter is based on converting the R-ratio value from red and near-red light. Medical oximeters must be clinical trial tested for accuracy before getting the listing permit. However, clinical testing has disadvantages such as high cost, high risk, and great difficulty. Phantom systems could solve the shortcomings of high risk, high price, and great hardship. The phantom system is structured by black opaque acrylic with two flexible chambers, an optical fader, and a pulsed flow generator. The two chambers are filled with 0.02 mM deoxyhemoglobin and oxyhemoglobin, respectively. A neutral density filter with 80% transmittance mimics the blood scattering properties. And the cam mechanism is used to simulate the human heart rhythm in a pulsed flow generator. The results show that the phantom system can mimic 70% to 100% of peripheral oxygen Saturation, effectively replacing clinical tests. In addition, the measurement performance of six commercially available pulse oximeters was evaluated by the proposed phantom. The results show the accuracy of medical-grade oximeters (2%～2.75%) is better than that of fingertip oximeters (3.2%～4.2%) when SpO2 is less than 80%. Therefore, we believe that the proposed phantom system will become the starting point for the subsequent replacement of high-cost and high-risk clinical tests.