Quantitative assessment of impedance tomography for temperature measurements in microwave hyperthermia

被引：7

作者：

Amasha, H.M. ^{[1
]}

Anderson, A.P. ^{[1
]}

Conway, J. ^{[1
]}

Barber, D.C. ^{[1
]}

机构：

[1] Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom

来源：

Clinical Physics and Physiological Measurement | 1988年 / 9卷 / SUPPL. A期

关键词：

Electric Measurements--Impedance - Heat Transfer--Monitoring - Microwaves--Medical Applications - Temperature Measurement;

D O I：

10.1088/0143-0815/9/4A/009

中图分类号：

学科分类号：

摘要：

The objective of this study is a noninvasive assessment of the thermal dose in microwave hyperthermia. The invention is to monitor the induced temperature rise via the change in the resistivity of body tissue, and hence control the microwave power during treatment. An initial feasibility study using electrical impedance tomography in vivo has indicated that a microwave induced temperature difference of a suitable magnitude can be mapped from a knowledge of the temperature coefficient of conductivity for tissue (typically 2% per °C). The accuracy of the currently employed reconstruction algorithm is assessed from data simulated by finite element prediction methods. A circular arrangement of electrodes surrounding a conductive sheet is used to evaluate the voltage distribution on the boundary of the sheet. A range of regions inside the circular field is chosen, and the conductivity is changed uniformly by steps of 1% up to 10%. Images of these changes are produced. It is noticed that the algorithm underestimates the values of resistivity change for the small areas and overestimates the change for the larger areas.

引用

页码：49 / 53