Serially-Connected Soft Continuum Robots for Endovascular Emergencies

Endovascular surgeries generally rely on push-based catheters and guidewires, which require significant training to master and can still result in high stress being exerted on the anatomy, especially in tortuous paths. Because these procedures are so technically challenging to perform, many patients have limited access to high-quality treatment. Although various robotic systems have been developed to enhance navigation capabilities, they can also apply high stresses due to sliding against the vascular walls, impeding movement and raising the risk of vascular damage. Soft growing robots offer a promising alternative since their method of movement via eversion minimizes interaction forces with the environment and enables follow-the-leader navigation through tortuous paths. However, reliable steering of small-scale growing robots remains a significant challenge. We propose a robot architecture that combines a hydraulically-actuated, soft growing robot with a soft, tendon-driven notched continuum robot to overcome the challenges of steering for small-scale growing robots in endovascular procedures. The soft notched continuum robot successfully steers around the most difficult aortic arch type, and a 2.67 mm diameter growing robot-comparable in size to current catheters-deploys from the tip, pulling an aspiration catheter through extremely tortuous vessels. We present the design, manufacturing, and control of the notched continuum robot, growing robot, and proximal actuation subsystem. Overall, this robotic architecture facilitates active steering in proximal anatomy and navigation in tortuous distal vessels, with potential to reduce procedure times and expand access to care.