Design Analysis and Experimental Study of Robotic Chair for Proton Heavy Ion Radiotherapy

Abstract

Proton heavy ion radiotherapy is widely used and currently represents the most advanced radiotherapy technology. However, at present, proton heavy ion radiotherapy chairs in fixed beam radiotherapy rooms do not have a head and neck positioning function. This paper presents a novel design for a proton heavy ion radiotherapy chair with a head and neck positioning device. The design of the posture adjustment mechanism and the head and neck positioning device of the treatment chair is based on U-TRIZ theory and ergonomics, respectively. A positive kinematic analysis of the posture adjusting mechanism was carried out, as well as a workspace analysis of the head and neck positioning device. Finally, positioning error experiment and ergonomic evaluation were performed on a prototype of the head and neck positioning device. The proposed design of the treatment chair satisfies the requirements for posture adjustment and achieves the head and neck positioning function. The experimental results also provide a basis for further optimization of the design.

Considerations for Upright Particle Therapy Patient Positioning and Associated Image Guidance

“…Recently, Zhang et al (44) presented design considerations for a patient chair for particle therapy based on a Steward hexapod platform to provide the six-degree-of-freedom (6DOF) motion required for positioning and position correction following image guidance. For improved stability of the device, they propose an additional push rod attached to the center of the treatment chair guiding the motion of the hexapod.…”

“…For greatest flexibility, the positioning system should also provide a 360°motion around the vertical axis to enable all treatment directions. Existing prototypes, in addition, consider up to ± 20°tilt around the lateral axis (6,8,9,44,45). Sufficient experience for the optimal tilt around the lateral axis for different treatment sites is not yet reported in literature, such that the current generation of chair designs may provide more/less flexibility than needed.…”

“…In contrast, hexapod platforms present a compact solution (35,44,45). Hexapods are well suited to support the patient and can achieve high positioning accuracy (45).…”

“…extended, and provide a limited range of rotation (44). Zhang et al ( 45) circumvented these problems, by adding a translational platform on top of the hexapod and a 360°platform underneath it, effectively increasing the work space to that desired for patient positioning in head&neck cases.…”

Validation and practical implementation of seated position radiotherapy in a commercial TPS for proton therapy

“…In this technical note, we aim to validate and provide readers with a guideline for the practical implementation of these new features for chair-based treatments. Treatments in the seated position are a costeffective solution for particle therapy centers that have partial or fixed beamlines [2][3][4][5][6]. Over the past five years, more than 300 ocular patients have been treated in a seated position through an off-the-shelf chair at Seattle Cancer Care Alliance proton therapy center (SCCA-PT).…”