Relax and tighten—a haptics-based approach to simulate sphincter tone assessment

Abstract

Digital Rectal Examination (DRE) is a physical examination performed by clinicians to diagnose anorectal and prostate abnormalities. Amongst these, sphincter tone assessment is a crucial task where a clinician asks the patient to relax or squeeze, whilst measuring its function by the amount of pressure felt on the examining finger. DRE is difficult to learn and current models fail to reproduce the dynamic function of anorectal abnormalities. We propose a haptics-based approach to incorporate sphincter tone into our current simulator by motor-controlled pulling and releasing of cables that are coiled around a silicone model of the sphincters. A range of healthy and abnormal sphincter tone cases can be modelled by controlling the motors symmetrically and asymmetrically.