ENGS 89/90 Reports

Degree Program


Year of Graduation


Project Advisor

Fridon Shubitidze


Solomon Diamond and Rafe Steinhauer

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Publication Date



Spinal fusion surgeries require substantial resources, result in long recovery times, and can cause unintended damage to the patient. PEER Technologies is working to revolutionize the spinal fusion space with the development of a new procedure, termed C-LIF. PEER’s C-LIF procedure is minimally invasive, minimizing patient tissue damage and decreasing recovery time, but lacks the sensory information present in open surgery. Our team investigated how different sensing modalities could be used to account for this lost information. We began by identifying relevant sensing modalities, interviewing spinal surgeons, and performing ex-vivo testing in excised pig spines. We then developed a benchtop testing setup and procedure to determine if the sensors could distinguish between materials during drilling. We eliminated confounding variables while mimicking the proposed C-LIF procedure as closely as possible. This involved developing testing protocols, acquiring sensor hardware, and creating a new drill bit and physical testing apparatus. All three sensing modalities: audio, speed, and bioimpedance, were able to classify the drilled benchtop materials with greater than 90% accuracy, indicating that they are effective at material classification in the benchtop setting. Future work should involve integrating the confounding variables back into sensor testing, and following the steps set out by our team, determining which sensing modalities are most effective at material classification in ex-vivo tissue. The final goal is to develop a control algorithm that integrates all chosen sensing modalities and displays a single metric to the surgeon.

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