Portable Recording System- for Electrogastrogram Application

• Main Authors: Jin-Kae Jang, 張津愷
• Other Authors: 郭德盛
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/80023009926782411716

博士 === 國立臺灣大學 === 電機工程學研究所 === 95 === Cutaneous electrogastrogram (EGG) is the electrical activity of the stomach. It is a non-invasive measurement via cutaneous electrodes. EGG is considered to be a motility index to of the stomach. A recording of EGG is usually used when a patient is suspected of having a functional disorder. The functional disorder means that the muscles of the stomach or the nerves controlling the muscles do not work as they should be. The EGG can help clinicians to diagnose the cause of chronic nausea and vomiting they are functional disorder of the stomach. For studying EGG signal, an EGG bedside recording system in addition to the software for acquisition and analysis was created. Ambulatory recording systems for biomedical signals are very important in detecting and diagnosing paroxysmal attack or sudden onset of symptoms. With a long-term ambulatory recording of signals, researchers and clinicians could have more opportunities to investigate and analyse these acute symptoms. Based on the experiences of the bedside EGG recording system, two types of portable EGG recorders were designed in this thesis. First one was designed based on a microcontroller. This portable recorder is a modular design, which contains a motherboard and daughterboards for the recording of electrogastrogram (EGG), electrocardiogram (ECG), and electroencephalogram (EEG) signals. The second one was based on a digital voice recorder. A compact circuit was designed to make the commercial audio recording device being able to record the low frequency EGG. Both of them are compact dimension yet low power consumption. They are suitable for long-term portable recording of biomedical signals. Based on our bedside EGG system and the ultrasonic image of the stomach, the relationship between the emptying and the EGG was studied. The decrease in volume measured by the ultrasound showed the gastric emptying, while the power of the dominant frequency displayed the same trend as the ultrasonic measurement. We also use this system to study the relationship of gastric sound and EGG. The result showed that the dominant frequency decreased and the dominant power increased when the gastric sound appeared.