SoftTract: A Novel Peristaltic Design for Improving Control and Performance of GI Tract Simulants

Peristalsis has inspired the creation of diverse robotic systems in the study of ailments affecting gastrointesti-nal tract function, and the development of physical simulators for this vital series of organs. SoftTract is a novel prototype pneumatic design using overlapping concentric pneumatic con-strictors to increase the effectiveness of artificial peristalsis. SoftTract exploits an all-soft body with in-extensible mesh reinforcement to move and manipulate an artificial bolus. This actuation concept is demonstrated in a prototype SoftTract which shows improved performance and the benefit of increased media control within the device. The overlapping of chambers reduces the potential for media to become stuck in boundary regions between sequential units and reduces the complexity of control. The design further replicates the compliance of the natural tissues through the use of an all-soft composition. Experimental trials demonstrate a maximum average bolus transport speed of 5.1 mm/s with a sealing pressure of 0.25 bar. This pressure is crucial in preventing debris regurgitation, surpassing the performance of the human oesophagus. The pliable SoftTract prototype circumvents the limitations of rigid materials, thus advancing the ultimate objective of realizing an artificial oesophagus replacement.