Characterization, Simulation and Control of a Soft Helical Pneumatic Implantable Robot for Tissue Regeneration

Therapies for tissue repair and regeneration have remained sub-optimal, with limited approaches investigated to improve their effectiveness, dynamic and control response. We introduce a Soft Pneumatic Helically-Interlayered Actuator (SoPHIA) for tissue repair and regeneration of tubular tissues. The actuator features shape configurability in two and three dimensions for minimal or non-invasive in vivo implantation; multi-modal therapy to apply mechanical stimulation axially and radially, in accordance to the anatomy of tubular tissues; and anti-buckling structural strength. We present a model and characteristics of this soft actuator. SoPHIA reaches up to 36.3% of elongation with respect to its initial height and up to 7 N of force when pressurized at 38 kPa against anatomically-realistic spatial constraints. Furthermore, we introduce the capabilities of a physical in vivo simulator of biological tissue stiffness and growth, for the evaluation of the soft actuator in physiologically-relevant conditions. Lastly, we propose a model-based multi-stage control of the axial elongation of the actuator according to the tissue's physiological response. SoPHIA has the potential to reduce the invasiveness of surgical interventions and increase the effectiveness in growing tissue due to its mechanically compliant, configurable and multi-modal design.