Force Analysis for Surgical Instruments: Assessing Tissue Damage Risk from Incremental Clicks on Tissue Mimics

Background: Surgical instruments are used to grasp, manipulate, or remove tissues. Excessive tool-tissue interaction forces can result in tissue damage and complications. We aim to study short and long Allis, Babcock and Kocher, and quantify the forces encountered by their end effectors.

Methods: 3D-printed TPE and silicone were used as tissue mimics. A load cell and height gauge were used to measure the force subjected to, and displacement of, the mimics with subsequent clicks on each instrument.

Results: For silicone, forces encountered at end effectors of surgical instruments are higher in the short than long Babcock; higher in the long than short Kocher; higher in the short than long Allis. TPE was different in that the force measured was higher in the long than short Allis.

Conclusion: While shape of the stress-strain curve for the 3D-printed mimic closely resembled the curve of body tissues, force magnitudes in the silicon sample more accurately reflected stress-strain characteristics of body tissues. Local distribution of forces at the tips might differ by material, thereby affecting the stress field and force-displacement. We plan to model forces encountered by the mimics using analysis with ANSYS to eliminate the effect of the shape of the instrument tip.