fig13

Figure 13. SPID design. Explanation of the SPID design is given in Figure A-C. (A) Perspective view with distal and proximal balloons activated; (B) Cross-section showing the balloon and the available internal space of the SPA; (C) Five steps of the bionic motion, where (i) t lead-a is the time to activate the proximal balloon, (ii) t hydrotherapy center is the activation time of the SPA based on the orientation of the colonic lumen, (iii) t_DB-a is the activation time of the distal balloon, (iv) t_PB-D is the deactivation time of the proximal balloon, and (v) t_SPA-D is the deactivation time of the SPA to allow advancement. Adapted under the Creative Commons Attribution (CC BY 4.0) license^[46]. DOF: Degree of freedom; SPA: soft pneumatic actuator; SPID: soft pneumatic inchworm double-balloon.