Pneumatically Driven Soft Robotic Retractor for Minimally Invasive Retroperitoneal Surgery

Retroperitoneal minimally invasive surgery demands stable, atraumatic tissue retraction to expose the operative field. Rigid metallic retractors commonly used in clinical practice may concentrate mechanical stress on soft organs and vessels, increasing the risk of tissue contusion and bleeding. Soft robotic devices constructed from hyperelastic elastomers can adaptively distribute contact force and conform to complex anatomical surfaces. This study develops a pneumatically actuated soft robotic retractor for retroperitoneal laparoscopic procedures. The retractor is composed of multi-chamber silicone actuators, and its expansion geometry and output force can be continuously regulated by adjusting air pressure. Force sensing arrays are embedded on the contact surface to provide real-time force feedback and prevent excessive tissue compression. Cadaveric tests verify that the soft retractor can maintain stable surgical exposure while keeping contact pressure within the safe physiological range. The current limitation is the relatively large volume of the pneumatic drive unit. This soft robotic retractor provides a safer tissue-retraction option for urological and retroperitoneal minimally invasive surgery.