利用無線近紅外線光譜儀進行腦組織氧分壓評估

Abstract

在臨床上，腦組織氧分壓的監測對於創傷性腦損傷的患者而言是一項重要的指標。但這是一種侵入性的量測方法，且並不方便於實時的監控。近年來，近紅外線光譜儀被廣泛應用於神經科學，並能以非侵入性的方式評估腦部缺血及缺氧。在本論文中，利用了一個無線近紅外線光譜儀和一個腦組織氧分壓探測器監測大鼠的腦部在不同撞擊力道的氧合狀態。在液壓衝擊的實驗中，所有大鼠被隨機分配於四種不同力道之組別。並隨著不同的撞擊力道來觀察含氧和非含氧血紅素的濃度變化與腦組織氧分壓之相關性。2,3,5氯化三苯基四氮唑(TTC)染色法則是用於評估腦梗死體積。結果顯示，近紅外線光譜儀之參數之變化量會在撞擊點後立即下降後逐漸回升，而後維持於一個穩定的狀態。腦組織氧分壓之變化量的趨勢則與之相似。TTC染色結果顯示了腦梗死體積會隨著撞擊力道增加而上升，且含氧血紅素及腦組織氧分壓之變化量則隨著撞擊力道增加而降低。含氧血紅素及腦組織氧分壓之變化量間的相關係數為0.77，而非含氧血紅素及腦組織氧分壓之變化量間為0.08。由此可見含氧血紅素之變化量與腦組織氧分壓之變化量間有高的正相關性。這意味著含氧血紅素之變化量可提供為參考參數來估計腦組織分壓。

Monitoring partial pressure of oxygen in the brain tissue (PbtO2) is an important standard for traumatic brain injury (TBI) patients in clinical. But it is an invasive measurement and inconvenient for real-time monitoring. Recently, Near-infrared spectroscopy (NIRS) is widely used in neuroscience, and can assess cerebral ischemia and hypoxia non-invasively. In this thesis, a novel wireless NIRS system, and the PbtO2 monitoring system were used to monitor the oxygenation of rat brains under different impact strengths. And all rats were randomly assigned to four different impact strength groups in the fluid percussion injury experiments. The relationships of the concentration changes of HbO2 and HbR, and PbtO2 under and after TBI with different impact strengths were also investigated. Triphenyltetrazolium chloride (TTC) staining was used for infarction volume evaluation. Results show that Δ[HbO2], Δ[HbR], and Δ[HbT] dropped immediately after the impact and increased gradually then maintain a stable status. And Δ[PbtO2] had a similar change tendency with the NIRS parameters. The result of the TTC staining showed the infarction volume was increased with the increased impact strength, and Δ[HbO2] and Δ[PbtO2] were decreased with the increased impact strength. The correlation coefficient between Δ[PbtO2] and Δ[HbO2] is 0.77, and between Δ[HbR] and Δ[HbO2] is 0.08. It can be discovered that Δ[HbO2] is highly and positively correlated to Δ[PbtO2]. That means the Δ[HbO2] may be available to be the reference parameter to estimate the partial pressure of oxygen in the brain tissue.