Multi-directional Force and Tactile Sensor Sleeves for Micro Catheters and Cannulas

Robot-assisted minimally invasive surgery with catheters and steerable cannulas such as Concentric Tube Robots can improve the postoperative patient experience. Haptic sensing for tooltip can reduce the chance of complications in such procedures, such as vessel irritation, vasospasm, perforation, and aneurysm rupture. This paper investigates the design of an affordable multi-directional micro force and tactile sensor by comparing two sensing modalities: (i) Electrical Impedance sensing (EIS) via tissue impedance and electrical noise measurement, and (ii) Force Sensitive Resistance (FSR) measurement. For both of these techniques, we successfully developed two bi-directional sensor sleeves that were designed to envelope cannulas of varying dimensional configurations. In in-vitro phantom experiments with realistic mechanical and electrical proprieties, We showcased that the proposed designs have the potential to be used as an affordable disposable multi-modal bi-directional tactile and force sensor for off-the-shelf vascular intervention catheters.