| Summary: | 碩士 === 國立成功大學 === 醫學工程研究所 === 87 === Auscultation is a simple and noninvasive way in examining abdominal diseases. However, it is subjective and highly dependent on clinician''s experience. Therefore, it is needful to find an objective way to diagnose the abdominal disease through computer-aided analysis.
In this study, a system was designed for bowel sound capture and analysis. The system consists of microphone, amplifier circuits, band-pass filter and related software. The captured signals will pass through the A/D converter and be transformed into digital format, and then stored in hard disk for off-line processing. The adaptive filter algorithm was used to eliminate background noise and then STFT was applied to extract features of bowel sound.
Twenty-three normal subjects were recruited as the controls and sixty-three patients with abdominal diseases were tested in the experiment. Bowel sound were continuously recorded for three minutes in noisy environment. The result showed that averaged peak frequency of the bowel sound spectrum is 290.0 with S.D. 15.7 Hz for the controls and 330.1 with S.D. 18.1 Hz for the patients. Using maximum-likelihood decision criterion in determining the decision rule, we have found the boundary is located at 313.6 Hz. The total probability of error is 16.3%.
We conclude that the system is convenient and efficient in clinical application by simply placing the stethoscope over the right iliac fossa wall. The system can also be used for long-term monitoring of bowel functions with only little modification is needed.
|
|---|
