0
Research Papers

Development and Analysis of a Novel Parallel Manipulator Used in Four-Dimensional Radiotherapy

[+] Author and Article Information
Henry Arenbeck

Boll Automation GmbH,
Industriestraße 6,
Kleinwallstadt 63839, Germany
e-mail: H.Arenbeck@bollautomation.de

Isabel Prause

Department of Mechanism Theory and Dynamics
of Machines,
RWTH Aachen University,
Kackertstraße 16-18,
Aachen 52072, Germany
e-mail: prause@igm.rwth-aachen.de

Dirk Abel

Institute of Automatic Control,
RWTH Aachen University,
Steinbachstr. 54,
Aachen 52074, Germany
e-mail: D.Abel@irt.rwth-aachen.de

Burkhard Corves

Department of Mechanism Theory and
Dynamics of Machines,
RWTH Aachen University,
Kackertstraße 16-18,
Aachen 52072, Germany
e-mail: corves@igm.rwth-aachen.de

1Corresponding author.

Manuscript received July 28, 2016; final manuscript received January 15, 2017; published online March 20, 2017. Assoc. Editor: Marcia K. O'Malley.

J. Mechanisms Robotics 9(3), 031006 (Mar 20, 2017) (10 pages) Paper No: JMR-16-1216; doi: 10.1115/1.4035990 History: Received July 28, 2016; Revised January 15, 2017

Radiotherapy (RT) enables a selective destruction of tumor cells, although the treatment area is limited to the irradiated volume. Any RT technique comes along with multiple sources of error, which can lead to a deviation of the dose that is applied to the patient. Phantoms—structures that replicate a human and include measurement technology to assess the applied dosage—are used to make such errors observable. Past RT-technologies assumed static tumors. Correspondingly, most existing phantoms comprise only static components. Nowadays, RT is at a transition stage toward techniques which explicitly account for physiological motion. These techniques require phantoms generating such motion. Consequentially, a demand for new kinds of manipulators, which operate with a RT-phantom, has come up and will further increase in the future. Key demands of such manipulators are among others, the generation of full rigid body motion, high acceleration, high stiffness, compactness, little weight, and easy portability. Another indispensable feature is the spatial separation of mechatronic components and phantom structure to ensure human equivalency of the latter. In this work, a new kind of parallel kinematic manipulator (PKM), which is tailored to the requirements of RT-phantom technology, is presented. The PKM consists of low cost standardized mechanical components and sets the target structures, which are located inside a human-equivalent area, into translational and rotational motion in three degrees-of-freedom (DOFs). Only a part of the end-effector is located within the human-equivalent area. All the remaining parts of the PKM are located outside that area. Two versions of the manipulator are presented in detail: their kinematics are derived and their kinetostatic properties are compared. This includes a workspace analysis and the analysis of the transmission behavior in general, meaning the influence of the most important design parameters on the performance. It can be shown that practical differences of both kinematics are negligible, while the modified version provides significant mechanical advantages. In conclusion, a first special purpose manipulator for application in the evolving field of RT-phantom technology is presented. The PKM, which employs a novel kinematic structure, provides higher suitability for its purpose than any other robotic system employed so far for the same purpose.

Copyright © 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

The robot and its main mechanical components (base version)

Grahic Jump Location
Fig. 2

Kinematic structure of the robot (base version)

Grahic Jump Location
Fig. 3

Kinematic structure of the robot (modified version)

Grahic Jump Location
Fig. 4

Reference frames of the phantom robot

Grahic Jump Location
Fig. 5

Workspace with enclosed largest sphere of the selected configuration

Grahic Jump Location
Fig. 6

Reachable workspace volume for different parameter settings

Grahic Jump Location
Fig. 7

Volume of largest sphere within the reachable workspace

Grahic Jump Location
Fig. 8

Maximum actuator torque for each point of the prescribed workspace

Grahic Jump Location
Fig. 9

Maximum actuator velocities for each point of the prescribed workspace

Grahic Jump Location
Fig. 10

Maximum actuator torque within the largest cubes

Grahic Jump Location
Fig. 11

Maximum actuator velocity within the largest cubes

Grahic Jump Location
Fig. 12

Maximum required power within the largest cubes

Grahic Jump Location
Fig. 13

Norm of deviation of the Jacobian matrices for both versions

Grahic Jump Location
Fig. 14

Magnitude of structural rotations for base version

Grahic Jump Location
Fig. 15

Magnitude of structural rotations for modified version

Grahic Jump Location
Fig. 16

Prototype of 4D-phantom

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In