Non-invasive algorithm for bowel motility estimation using a back-propagation neural network model of bowel sounds

Abstract

BackgroundRadiological scoring methods such as colon transit time (CTT) have been widely used for the assessment of bowel motility. However, these radiograph-based methods need cumbersome radiological instruments and their frequent exposure to radiation. Therefore, a non-invasive estimation algorithm of bowel motility, based on a back-propagation neural network (BPNN) model of bowel sounds (BS) obtained by an auscultation, was devised.MethodsTwelve healthy males (age: 24.8 ± 2.7 years) and 6 patients with spinal cord injury (6 males, age: 55.3 ± 7.1 years) were examined. BS signals generated during the digestive process were recorded from 3 colonic segments (ascending, descending and sigmoid colon), and then, the acoustical features (jitter and shimmer) of the individual BS segment were obtained. Only 6 features (J1, 3, J3, 3, S1, 2, S2, 1, S2, 2, S3, 2), which are highly correlated to the CTTs measured by the conventional method, were used as the features of the input vector for the BPNN.ResultsAs a results, both the jitters and shimmers of the normal subjects were relatively higher than those of the patients, whereas the CTTs of the normal subjects were relatively lower than those of the patients (p < 0.01). Also, through k-fold cross validation, the correlation coefficient and mean average error between the CTTs measured by a conventional radiograph and the values estimated by our algorithm were 0.89 and 10.6 hours, respectively.ConclusionsThe jitter and shimmer of the BS signals generated during the peristalsis could be clinically useful for the discriminative parameters of bowel motility. Also, the devised algorithm showed good potential for the continuous monitoring and estimation of bowel motility, instead of conventional radiography, and thus, it could be used as a complementary tool for the non-invasive measurement of bowel motility.

Bowel Sounds Identification and Migrating Motor Complex Detection with Low-Cost Piezoelectric Acoustic Sensing Device

“…They studied sound occurrence over time before and after eating. Kim et al used a similar microphone-based sensor attached to the abdomen for long-term BS recordings [16,21]. They extracted the jitter and shimmer from BS for gut motility estimation.…”

Optimum Unit Time on Calculating Occurrence Frequency of Bowel Sounds for Real-Time Monitoring of Bowel Peristalsis

“…This system can record bowel sounds detecting them by digital signal processing for long time and analyze the BS as soon as the data is recorded. Although there are some researches on longterm bowel sound monitoring [6]- [10], our concept is different from other group's studies. We focus on especially temporal change of occurrence frequency of bowel sounds; that is, transition of the number of bowel sounds generated in a unit time.…”

A flexible skin-mounted wireless acoustic device for bowel sounds monitoring and evaluation

“…Herein, the device has a channel length l of 15.5 mm, an inlet diameter of 21.87 mm, and an outlet diameter of 9.04 mm. The channel section can be ideally modeled as a short slim pipe (Figure 2(b)) whose length l and radius a are much smaller than the bowel sound wavelength (0.34-6.8 m) [7,8,10,28]. When there is a wave with the velocity v, the acoustic resistance R a is given by [29] R a = l…”

“…Auscultation of physiological sounds exists as a simple but classical and extensively employed method for medical investigation, especially for cardiac and pulmonary sounds. Similarly, bowel sounds generated from the movement of the intestinal contents and gas during peristalsis, are recognized clinically as useful indicators of intestinal function [7][8][9][10]. For example, hyperactive bowel sounds ("loud", "high-pitched" and "tinkling" sounds) may be the result of diarrhea or early intestinal obstruction while hypoactive bowel sounds (very diminished or absent sounds) are correlated with bowel obstruction, paralytic ileus, torsion of the bowel, or peritonitis, and can cause diminished peristalsis [11,12].…”