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External beam radiotherapy is a powerful tool to combat cancer, but requires precise positioning of patients. The standard practice involves patients lying on treatment tables within immobilization equipment. These systems have limited clearance between treatment sources and the patient that can be uncomfortable or claustrophobic for patients. Patients may move when uncomfortable, leading to improper dose delivery, possibly causing painful side effects or further cancers. We present an alternative, open configuration patient positioning solution for more ergonomic setup options with competitive positioning capabilities compared to conventional systems.

Our ergonomic positioning system consists of a seat for patients on a scissor lift for vertical positioning, a gantry system for horizontal positioning, all assembled onto a rotating base for treatment of tumors from any angle. Motion up to ±25 cm in 3D was achieved by controlling stepper motors with a Raspberry Pi computer. Computer-aided design was performed to complete finite element analysis on all load-bearing structures to ensure a maximum load of 200 lbs.

The design developed allows new treatment configurations with static radiation sources while the positioning system moves at a distance, which allows greater flexibility in patient positioning. Replacing conventional treatment tables enables patients to be seated during treatment, which could improve patient comfort for more comfortable immobilization and more effective radiotherapy.

Publication Date



Radiation Therapy, Patient Setup, Mechanical Systems, Ergonomics


Engineering | Mechanical Engineering | Nuclear Engineering

Faculty Advisor/Mentor

Dr. Woon-Hong Yeo

VCU Capstone Design Expo Posters


© The Author(s)

Date of Submission

May 2018

Radiotherapy Ergonomic Patient Positioning System