Procedures for Evaluating Nonperturbing Temperature Probes in Microwave Fields
Christian U. Hochuli · 1981
The RAMAL probe caused the least perturbation of temperature distributions in simulated tissue spheres but was unstable over time, while the NARDA and VITEK systems were more stable in calibration and the Cetas probe was nonoperational.
Plain English Summary
Researchers developed evaluation procedures for nonperturbing temperature probes in microwave fields, including a precision calibration system, a thermographic camera system to measure heating patterns in a simulated muscle sphere at 2450 MHz, and a TEM transmission cell for electromagnetic interference testing from 250 kHz to 100 MHz. The calibration accuracy was ±0.017°C at 25°C over one day and ±0.023% over six months. Testing of four probes found the RAMAL probe caused the least perturbation but was unstable over time, while NARDA and VITEK were more stable and the Cetas probe was nonoperational.
Why This Matters
Preliminary thermographic camera measurements showed that inserting the nonperturbing probes into the muscle sphere still caused some perturbation of the heating pattern. However, the new probes were about half as perturbing as a conventional thermistor thermometer with metallic leads. For probes used less than one day after calibration, the total calibration uncertainty was ±0.017°C at 25°C and ±0.020°C at 45°C. The evaluation procedures also included tests for temperature stability over time and radiofrequency interference in the instrumentation. Additional electromagnetic interference checks were performed at 915 MHz and 2450 MHz.
Exposure Information
Specific exposure levels were not quantified in this study.
Show BibTeX
@article{procedures_for_evaluating_nonperturbing_temperature_probes_in_microwave_fields_g6005,
author = {Christian U. Hochuli},
title = {Procedures for Evaluating Nonperturbing Temperature Probes in Microwave Fields},
year = {1981},
}