0
2010 Design of Medical Devices Conference Abstracts

Hertz Contact Based Scaling of Puncture Forces for Large Scale Needle Prototypes Using a Gelatinous Tissue Phantom OPEN ACCESS

[+] Author and Article Information
Stacy L. Figueredo, Alexander H. Slocum

Massachusetts Institute of Technology

J. Med. Devices 4(2), 027515 (Aug 09, 2010) (1 page) doi:10.1115/1.3442791 History: Published August 09, 2010; Online August 09, 2010

Abstract

In order to test small scale medical devices, it is often necessary to prototype them on a larger scale such that proof-of-concept tests can be made more affordably and design details can be tested more easily. This article discusses a method of scaling large needle prototypes for testing in a gelatin phantom such that puncture forces match those expected for the actual-size needle when puncturing tissue. Using Hertz contact force equations to account for the differences in prototype materials and size, as well as for the tissue phantom properties, 10× scale prototype needles were inserted into a gelatin phantom and puncture forces were compared with those of a real scale prototype in bovine liver tissue. Results showed that for a 19 gauge (1.06 mm) stainless steel needle tip, where a maximum doctor-applied load of 5 N was desired to pierce liver tissue, loads of 0.44 N using Hertz point contact, and 0.31 N using Hertz line contact methods were predicted to puncture liver tissue, and an average load of 0.31 N was observed in force-displacement measurements. With a 10× scale stereolithographed needle prototype, Hertz point contact predicted a load of 0.31 N to puncture a gelatin phantom, Hertz line contact theory predicted 0.37 N, and an average load of 0.73 N observed in force displacement measurements. Similar contact mechanics based scaling methods might be applied to cutting devices.

Copyright © 2010 by American Society of Mechanical Engineers
This article is only available in the PDF format.

References

Figures

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.

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