即時肺部電阻抗成像之軟體設計

Abstract

電阻抗成像（Electrical Impedance Tomography，EIT）是利用電訊號量測結果來重建的電阻抗分佈圖。此技術已在工業和醫療領域作為其中一種斷層掃描的工具來觀察量測體的內部。例如工業中有用來監控鋼水經過浸入式澆注嘴的流動概況，醫療領域則用來掃描身體各部位的切面等。儘管電阻抗成像技術的成本較為低廉，相對於其他斷層掃描影像工具，它還未被普及應用是因為其影像解析不高。2015年，本實驗室已完成第一個EIT硬體的原型，並具有虛擬通道技術來提高影像解析度。在利用生理食鹽水的假體實驗中，更細分的虛擬通道已被確定能夠提高解析度。因此下一步便是朝向人體實驗來驗證其改善解析度的可能，尤其是肺部電阻抗斷層成像的應用。本論文將報告此EIT系統的軟體設計方法以應用於即時肺部斷層掃描的監測。此外，一些其他延伸的分析工具也會提及。基於安全考量，本論文的肺部電阻抗成像資料並非由本機擷取，而是利用EIT社群所貢獻的資料。儘管如此，本軟體仍可控制本機硬體，所以預期重建結果也可被重複實現。

Electrical impedance tomography (EIT) is an impedance distribution image reconstructed from the electrical measurement. In industry and medical sector, it has been used as an alternative imaging tool to monitor the internal condition of measured subject. For instance, the industry uses it to image the flow profile of molten steel through a submerged pouring nozzle; in medical EIT can scan the cross section of various human body parts. Despite low cost of the EIT, it is still not widely used due to its low spatial resolution compare to other cross section imaging machines. In 2015, our laboratory had finished the first prototype of EIT hardware equipped with virtual channel stimulation technique in order to improve the EIT resolution. The image reconstructed from saline phantom experiment had confirmed the technique can improve the image resolution with finer virtual channel stimulation. So the next step is to verify the observation in human body, particularly the lungs EIT. This thesis reports the EIT software implementation designed for monitoring the lungs in real time and proposes some extended tools for analysis purpose. Due to safety reason, the lungs EIT data in this thesis is based on contributed data in EIT community instead of collecting from our machine. However, the software can control the hardware and its reconstruction result is expected to be reproducible.