The main purpose of this study is to develop a method that can objectively evaluate the intestinal motility of patients with functional gastrointestinal disorders through non-invasive means. The research question focuses on whether the asymmetry in electronic stethoscope (ES) arrangements can enhance the accuracy of bowel sound (BS) source localization, which is crucial for detailed assessments of intestinal motility. This study introduced a new index called the angle-based asymmetry degree ( \(AD\) ), derived from the interior angles of the quadrilateral formed by the ESs, to quantitatively evaluate the asymmetry of four-ES-based arrangement patterns. We conducted simulations in an abdominal acoustic environment to compare the effects of symmetric and asymmetric ES arrangements on BS source localization accuracy. The influence of different \(AD\) values on localization performance was also analyzed under various signal-to-noise ratio ( \(SNR\) ) conditions. The simulations revealed that BS source localization accuracy improved as the \(AD\) increased. Asymmetric ES arrangements significantly enhanced the localization accuracy compared to conventional symmetric arrangements, even in environments with high levels of noise. Additionally, various ES arrangement patterns corresponding to different \(AD\) values demonstrated improvements in localization accuracy. The study concludes that using asymmetric ES arrangements based on the newly proposed \(AD\) index substantially improves BS source localization accuracy. These findings suggest that asymmetry in ES placements can be a critical factor in enhancing non-invasive evaluations of intestinal motility, thereby contributing to the development of more effective BS source localization technologies. The results hold promise for practical applications in diagnosing and managing functional gastrointestinal disorders.
