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The primary purpose of this project is to demonstrate that patients can be safely immobilized using air in the general torso area so that radiation can be administered to that region. The primary target will be to treat tumors in the lungs and liver. By immobilizing patients during treatment it allows for the radiation to be consistent in targeting the desired region of the body, which would not be the case if the patient was moving. Air was chosen as the desired medium to immobilize the patient because of comfort and it provides an easy medium for radiation to travel through which does not interfere with the radiation. Through research the limiting factor of human body was the pulmonary cycle which was determined to be approximately 0.15 Psi. In order to use air for immobilization airbags were incorporated as a means to hold the air and once pressurized would be used as the restraint force on the patient. As a means to demonstrate that air in fact could be used to immobilize a patient a prototype of a radiation chamber was built to provide a proof of concept. The radiation chamber frame was built to completely encapsulate the patient 360 degrees. The two airbags were placed in the frame which provides complete immobilization of the patient from all angles. The patient had to be standing while the radiation was being administered in order to target certain areas which could not be included if the patient was sitting or lying down. A circular frame was the desired shape of the frame because it allows for radiation to enter and exit the chamber at the same angle regardless of where it is administered. The radiation chamber requires the use of radiation safe materials in any given area where the frame comes into contact with radiation, for this reason non-metallic materials were used. The chamber prototype was built using wood and plexiglass. Finite element analysis simulated an allowable applied pressure of 6.0 Psi applied to the shell. Prior to the given prototype, there was no means available to immobilize a patient while standing for radiotherapy. Experimental tests demonstrated that a person could be immobilized in the general torso area using air.

Publication Date



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

Ergonomic Immobilization Frame for Radiotherapy [View Image]


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