Modeling and trajectory control of a bio-inspired minimally invasive surgery tool

Bionic engineering has greatly inspired the development of minimally invasive surgical (MIS) instruments. This paper presents a dual-drive intact lesion excision system (DILES) for MIS, inspired by the proboscis of a bloodworm. In its folded state, the tool maintains a small diameter, allowing easy insertion into human tissue. Upon unfolding, it can excise and encapsulate diseased tissue larger than its own diameter, enabling complete removal of lesions through a minimally sized incision. The tool features retractable flexible claws for stable deployment and radiofrequency (RF) transmitters for precise cutting. To improve the performance of the elastic components, this study introduces a dual-drive control method that increases cutting force and enhances motion stability. The coordinated actuation of the RF transmitters and claws allows the DILES to adjust its tissue capture size. This enhancement significantly improves the motion stability of the tool. A nonlinear elastic rod model is used to describe the relationship between tip deformation and drives motion. The positioning experiment under unloaded conditions reveals control errors of less than 1 mm. To address the unfolding resistance of the DILES encountered in breast tissue, a catenary model is introduced to enhance the accuracy of cutting trajectory prediction. The cutting experiment confirms that trajectory errors are below 1.5 mm. In the adipose tissue cutting experiment, the tool with a main tube diameter of 6.3 mm was used to resect lesions with an average size of 25 mm × 10 mm × 10 mm. These results confirm the tool’s ability to completely remove large lesions.