食道酸鹼與胃電記錄分析系統

Abstract

目前市面上，量測生醫訊號的儀器，大大小小有不下數百種，但是能夠同時記錄食道酸鹼與胃電訊號的系統，少之又少，於是我們製作了一個能夠長時間、攜帶方便，並可同時記錄食道酸鹼和胃電記錄的系統，這系統不僅僅紀錄胃食道酸鹼與胃電，更可更換模組紀錄其他的電生理訊號。此外，還有一個更大的特點就是在儲存媒體的部分，我們使用SD記憶卡，儲存二十四小時以上的生理訊號，量測結束後，藉由一般電腦的讀卡機，將檔案讀出，做訊號處理與分析。 由前人的研究和文獻的探討中發現，胃酸食道逆流與胃電圖有一定的相關性，但因為從體表量測到的胃電訊號，除了重要的胃電訊號外，還有量測時因動作(如：呼吸)等因素所造成的雜訊，造成分析上的困難。目前我們是以ICA的分析方式將訊號分離，雖然可以清楚地將胃的慢波分離出來，但還是夾雜著其他的訊號，因此我們增加了EGG channel數來幫助分析，分析的結果發現，ICA的確有助於EGG訊號的分離，使我們更清楚看到胃的慢波訊號。

A 24 hours ambulatory esophageal pH and electrogatrogram (EGG) recording system has been set up in this project. The unique feature of our system is that it can record the esophageal pH and EGG signals simultaneously. Current commercial available devices only measure the esophageal pH or EGG signals separately and no ambulatory EGG recording system is available now. We planned to improve our previous system to let it be more mobile for patients without disturbing their daily activity. A small thin memory card (SD card) is applied for data recording instead of the storage by PDA. Except size reducing, power saving is another benefit using the memory card. With this new ambulatory recording system, the examination will be more comfortable and more patients can be persuaded to receive the 24 hours recording of pH and EGG. Some bad situations such as disconnection of cable to PDA during examination can be avoided. Therefore, more complete and comprehensive information can be approached for further analysis. The measured EGG signals may include a lot of other undesired signals, such as respiration. We use independent component analysis (ICA) to separate the mixed EGG signals in this study. The gastric slow waves can be extracted out by ICA, but the signals are still mixed with some noise. The EGG channels are increased from 2 to 3 to evaluate if the increased channel has any additional benefit for data analysis. The results show that ICA and the increase of EGG channels really help signals separation and let us see the gastric slow waves more clearly.