Laparoscopic Liver Resectioning Tool

Medical Device Design II

The XCISION Laparoscopic Liver Resectioning tool was the second project that I completed with a team of three other engineers for the Medical Device Design II course. This monopolar RF ablation tool allows the surgeon to clamp and ablate liver tissue in a fast and reliable manner.

In the images above, you can see the progression from renderings out of Solidworks to the realized physical prototype. Although this initial prototype was very basic, it was designed to house a motor, electronic components, and a mini-LCD display (eliminating the need for a rack and pinion system). During this project, I was able to further my knowledge in 3D printing by creating the jaws of the device on a brass selective laser melting printer. In addition to printing, I started to work with finite element analysis software to understand where trouble areas might exist when a load was applied to the device.

The prototype was fully functional and the applied jaw force was tested with an axial force gauge. During initial force testing, the jaw subassembly linkage broke and another one was machined immediately to replace it. After testing was successfully completed, a redesign was completed to include some of the features that are standard with many of today's laparoscopic tools.

The redesigned device (pictured above) was modeled with the existing end effector. The new handle offered increased ergonomic comfort across a range of hand sizes, button-actuated clamping and cauterizing features, and a shaft rotation knob for increased maneuverability. The end effector was then modified to add plated RF electrodes for the ablation system.

This course was an applied engineering design course covering detailed design development planning, design criteria generation, failure modes identification, engineering analysis, and systems thinking in medical device development. Emphasis was placed on engineering design analysis in the context of Design for Function in the Preliminary Design, and Detailed Design stages of the medical device development cycle. FDA mandated Design Controls, Design for Manufacture & Assembly, Risk Analysis, & FMEA techniques were also covered.