Design of a Robotic Cannula for Robotic Lumbar Discectomy

Yang Ding, Purdue University

Abstract

In this thesis, the design of the robotic cannula for minimally invasive robotic lumbar discectomy is presented. Lumbar discectomy is the surgery to remove the herniated disc material that is pressing on a nerve root or spinal cord. Recently, a robotic approach to performing this procedure has been proposed that utilizes multiple teleoperated articulated instruments inserted into the surgical workspace using a single cannula. In this paper, a new robotic cannula system to work in conjunction with this new procedure is presented. It allows for the independent teleoperated control of the axial position and rotation of up to three surgical instruments at the same time. The mechanical design, modeling, controller design, and the performance of the prototype of the new system are presented in this paper demonstrating a fully functioning device for this application. A novel worm gear and rack system allow for the instrument translation while and embedded gear trains produce the rotational movement. Steady-state errors of less than 10 µm for translation and less than 0.5◦ for rotation motion are achieved in position tracking; steady-state errors of less than 100 µm/sec of translation and less than 0.5◦/sec for rotation motion are obtained in speed tracking.

Degree

M.Eng.

Advisors

Cappelleri, Purdue University.

Subject Area

Design|Medical personnel|Medicine|Physical therapy|Surgery|Therapy

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