微流道晶片結合半自動攜帶式離心裝置應用於凝血狀況檢測

Abstract

本研究開發攜帶式半自動離心裝置 (semi-automatic centrifuge) 結合微流道晶片進行凝血狀況檢測，此裝置透過半自動設計，僅需手動旋轉操作手柄 (hand crank)，即可完成定扭矩彈簧 (constant torque spring) 的蓄力，並通過齒輪間的組合達到提升離心平臺輸出轉速的效果。離心力作為晶片內血液樣品與反應試劑的驅動力，於微流道內設計凹槽產生高低差，增加其混合效果的同時，透過流道出口端微狹縫 (microslit) 的過濾機制來析全血血液樣品中的凝血酶時間 (thrombin time)。再利用行動裝置進行數據運算和資料上傳，即時監測患者的凝血狀況。為了觸發血液中凝血級聯反應 (coagulation cascade)，預先將凝血酶 (thrombin) 添加至流道中，使血液中原本易於溶解的纖維蛋白原 (soluble fibrinogen) 轉變為不可溶解的網狀纖維蛋白 (insoluble fibrin strands)，並纏繞於紅血球上形成血液凝塊 (blood clot)，這些凝塊形成共價鍵時會進行收縮，同時也提升凝塊的機械強度。此時，當血液凝塊被離心力驅動至高度僅有 5.29 μm 的微狹縫時，狹縫的微小高度能有效阻擋血液凝塊，使血液凝塊堆積於微狹縫前形成紅色線段，通過觀察紅色線段長度來辨識凝血酶時間。另外，我們結合血容比校準公式，與未校準的實驗結果相比，可以有效消除血容比差異的影響，能夠依據凝血長度分辨不同凝血狀況。本離心平臺上整合塑膠毛細管進行血容比檢測，幫助我們在每次檢測中可獲取更全面的血液資訊。最後，根據人類臨床檢體的檢測結果與 Bland-Altman plot 分析，發現本研究的凝血酶時間檢測結果與血容比檢測結果與臨床檢測結果有高度一致性。期望本平臺能夠為抗凝血治療的患者或是醫療資源匱乏地區提供即時檢測和長期的血液監測。

In this work, we developed a portable semi-automatic centrifuge for coagulation status detection integrated with a microfluidic chip. The device utilizes a semi-automatic design, manually rotating a hand crank to store energy in a constant torque spring. This mechanism through the gear design, enhances the output rotation speed of the centrifuge platform. Within the microfluidic channel, blood samples and reagents are mixed through centrifugal force, with strategically designed grooves creating height variations to optimize the mixing process. Simultaneously, a microslit filtration mechanism at the channel outlet analyzes thrombin time in whole blood samples. Data computation and upload are performed using a mobile device to monitor the real-time coagulation status of patients. To initiate the coagulation cascade, thrombin is pre-loaded into the microchannel, where it converts soluble fibrinogen into insoluble fibrin strands that entrap red blood cells, forming blood clots. These clots contract upon the formation of covalent bonds, thereby increasing their mechanical strength. The thrombin time is determined by observing the length of the blood clots accumulated at the microslit, which has a height of 5.29 μm and effectively blocks the blood clots to form a red line. Additionally, by incorporating a hematocrit calibration formula, the effects of hematocrit variation are effectively minimized, allowing for distinct differentiation of different coagulation statuses based on clot length. We have also integrated a plastic capillary tube on the centrifuge platform for hematocrit detection, ensuring comprehensive blood information with each measurement. Finally, based on the results of human clinical samples and Bland-Altman plot analysis, it was found that the thrombin time and hematocrit measurements in this study are highly consistent with clinical test results. With the help of this platform, anticoagulant therapy patients and those in underserved areas can get real-time testing and long-term blood monitoring.