Full Content is available to subscribers

Subscribe/Learn More  >

Micromachined Electrical Conductivity Probe for RF Ablation of Tumors

[+] Author Affiliations
Ming Yi, Hrishikesh V. Panchawagh, Roop L. Mahajan

University of Colorado at Boulder

Zhengjun Liu, S. Nahum Goldberg

Harvard Medical School

Paper No. IMECE2005-82064, pp. 53-56; 4 pages
  • ASME 2005 International Mechanical Engineering Congress and Exposition
  • Advances in Bioengineering
  • Orlando, Florida, USA, November 5 – 11, 2005
  • Conference Sponsors: Bioengineering Division
  • ISBN: 0-7918-4213-4 | eISBN: 0-7918-3769-6
  • Copyright © 2005 by ASME


RF ablation is an important technique in cancer treatment. It has been proposed that the effective area treated via RF ablation can be increased by increasing the local electrical conductivity. This is achieved by injection of NaCl solution into the tissue. For an accurate and effective RF ablation treatment using this new method, it is necessary to measure the local electrical conductivity, which varies spatially due to diffusion of sodium chloride. In this paper, we propose a micro probe to measure the local tissue electrical conductivity. The probe consists of two in-plane miniature electrodes separated by a small gap. When the electrodes are in contact with the tissue, the electrical resistance across them can be used to calculate the electrical conductivity. The probe is fabricated by standard photolithography techniques. The substrate material is polyimide and the electrodes are made of gold. A four-electrode probe is used to calibrate the new electrical conductivity micro probe using different concentrations of saline water. The resistance measurements are carried out using an impedance analyzer on different frequencies. The frequency of choice for RF ablation of tumors is 500k Hz and is the one selected for calibration and testing. The micro-probe calibration is then verified by measuring electrical conductivity of a phantom and comparing it with the result measured by the four-electrode probe. Finally, some in vivo tests are performed and the results are compared with literate data.

Copyright © 2005 by ASME



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

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 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