Novel Bionics Assessment of Anorectal Mechanosensory Physiology

Abstract

Biomechatronics (bionics) is an applied science that creates interdisciplinary bonds between biology and engineering. The lower gastrointestinal (GI) tract is difficult to study but has gained interest in recent decades from a bionics point of view. Ingestible capsules that record physiological variables during GI transit have been developed and used for detailed analysis of colon transit and motility. Recently, a simulated stool named Fecobionics was developed. It has the consistency and shape of normal stool. Fecobionics records a variety of parameters including pressures, bending, and shape changes. It has been used to study defecation patterns in large animals and humans, including patients with symptoms of obstructed defecation and fecal incontinence. Recently, it was applied in a canine colon model where it revealed patterns consistent with shallow waves originating from slow waves generated by the interstitial Cells of Cajal. Novel analysis such as the “rear-front” pressure diagram and quantification of defecation indices has been developed for Fecobionics. GI research has traditionally been based on experimental approaches. Mathematical modeling is a unique way to deal with the complexity. This paper describes the Fecobionics technology, related mechano-physiological modeling analyses, and outlines perspectives for future applications.

Fecobionics Evaluation of Biofeedback Therapy in Patients With Fecal Incontinence

“…We found 24% reduction in symptoms, and 7 patients (58%) were considered responders. This is close to what have been reported by others, such as 53% ( 38 ) and 63% ( 39 ). It is better than that in another study ( 37 ) that by the way also showed no improvement in the QOL score.…”

“…However, large-scale studies are required to further assess subtype phenotypes and treatment effects. Future studies may take advantage of improved wireless devices that in addition can measure the anorectal angle and the bag shape (38)(39)(40)(41)(42). Future studies may also examine the efficacy of Fecobionics as a therapeutic tool for performing biofeedback treatment in FI patients.…”

Feasibility study of defecation studied with a wireless Fecobionics probe in normal subjects

“…The basic design of the previous Fecobionics prototype has been previously described (Chen et al, 2020; Gregersen, 2020; Gregersen, Sun, et al, 2021; Kassab et al, 2021; Sun et al, 2019). Previous versions recorded pressures only or did not have an integrated graphical user interface.…”

“…Other studies have been done on patients with FI including patients with low anterior resection syndrome (LARS) and CC including obstructed defecators (Chen et al, 2021b; Gregersen et al, 2020; Gregersen, Chen, et al, 2021). Furthermore, pilot studies have been done with an early stage integrated Fecobionics prototype in colon and anorectum (Gregersen, 2020; Gregersen, Sun, et al, 2021; Gregersen, Wang, et al, 2021; Kassab et al, 2021; Sun et al, 2020).…”

“…Therefore, parameters like the rectoanal pressure gradient (RAPG) have been developed for ARM studies but the value of the RAPG has been disputed (Grossi et al, 2016). We designed Fecobionics to integrate important functional measures in a single test (Chen et al, 2020, 2021a, 2021b; Gregersen, 2020; Gregersen et al, 2019, 2018; Gregersen, Chen, et al, 2021; Gregersen, Sun, et al, 2021; Gregersen, Wang, et al, 2021; Kassab et al, 2021; Sun et al, 2019, 2020; Zhuang et al, 2021). The foundation was laid with the device that measured axial pressures in contrast to the radial pressures measured by ARM.…”