ARMA-based spectral bandwidth for evaluation of bowel motility by the analysis of bowel sounds

Approximately 10%-20% of adults and adolescents suffer from irritable bowel syndrome (IBS) worldwide. IBS is characterized by chronic gastrointestinal dysfunction which may reflect in altered motility. Currently, the diagnosis of IBS is made through expensive invasive radiographic and endoscopic examinations. However these are inconvenient and unsuited for community screening. Bowel sounds (BSs) can be easily recorded with non-invasive and low-cost equipment. Recently, several researchers have pointed out changes in features obtained from BS according to the pathological condition of bowel motility. However a widely accepted, simple automatic BS detection algorithm still has to be found, and the appropriate recording period needs to be investigated for further evaluation of bowel motility. In this study we propose a novel simple automatic method to detect the BSs based on the 3 dB bandwidth of the frequency peaks in the autoregressive moving average spectrum. We use the measure, sound-to-sound interval (SSI) obtained by the proposed method, to capture bowel motility. In this paper, we show that the proposed method for automatic detection could achieve a sensitivity of 87.8 +/- 5.88%, specificity of 91.7 +/- 4.33% and area under the curve of 0.923 when working on 16 healthy volunteers during mosapride administrations. Furthermore, we show that the measured SSI averaged over a period of 30 min can clearly capture bowel motility. Our findings should have the potential to contribute toward developing automated BS-based diagnosis of IBS.