Ring Device to Induce Hemostasis

Skin cancer is the most common type of cancer in the United States. Mohs Micrographic Surgery (MMS) is the gold standard in treating the two most common skin cancers. In MMS however, nearly 45% of complications are due to excessive bleeding. Therefore, we strove to design a ring device to be used during MMS to achieve intraoperative hemostasis that could also be used in tandem with an electrosurgical pen as well as withstand the autoclave. Many designs were made in Autodesk Fusion 360 then 3D printed in polylactic acid. Two designs were chosen to be 3D printed in stainless steel after qualitative and quantitative analysis. These steel prototypes were polished and tested for efficacy using physical models. The physical models consisted of silicone gel in a petri dish with a canal to act as a blood vessel and a portion of silicone removed from the center to simulate the cancerous tissue removed. As liquid perfused through the vessel, the prototype was applied to the circumference of the “wound” and flow was stopped. The average force needed to close the vessel compared favorably with the amount of force predicted by a clinician. Finally, the rings of the devices were coated in an insulation material to enable use with an electrosurgical pen. A virtual model of the cheek and forehead were developed in Fusion. A canal was cut through the models to simulate an open vessel. A steel ring was placed atop of the skin layer with an applied load. It was expected that the vessel would close under pressure, but due to limitations in the precision of the computational mesh, vessel closure was not observed (even under 100N). Given the devices induced hemostasis at the expected force, the next step would be to test on patients and optimize the manufacturing practices.