Magnetoresistive power sensor for measurement "in situ" of RF power absorbed by tissue

Author

Vountesmeri, Valeri

Author_Institution

Centro de Instrum., Univ. Nacional Autonoma de Mexico, Mexico City, Mexico

Volume

1

fYear

1999

fDate

1999

Firstpage

114

Abstract

A new magnetoresistive sensor for its use in medicine apparatus of RF heating and hyperthermia is present. This sensor has DC output signal which is proportional to RF power absorbed in tissue. The operating principle of the sensor consists of multiplication of the instantaneous value of the RF current and voltage in a microstrip transmission line by using the special constructed magnetoresistive element. At an operating frequency 915 MHz in a 20% bandwidth it has a sensitivity of 22 μV/W, insertion losses less than 0.1 dB and no linearity less than 3% up to 300 Watts. The uncertainties caused by the reflected waves with arbitrary phase are less than 3.5% up to VSWR=3.

Keywords

biomedical equipment; biomedical measurement; hyperthermia; magnetic sensors; magnetoresistive devices; power measurement; 0.1 dB; 300 W; 915 MHz; DC output signal; RF current; RF heating; RF power; RF voltage; hyperthermia; in situ; magnetoresistive power sensor; medicine apparatus; microstrip transmission line; tissue; uncertainties; Heating; Hyperthermia; Magnetic sensors; Magnetoresistance; Microstrip; Power measurement; RF signals; Radio frequency; Thermal sensors; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Instrumentation and Measurement Technology Conference, 1999. IMTC/99. Proceedings of the 16th IEEE

ISSN

1091-5281

Print_ISBN

0-7803-5276-9

Type

conf

DOI

10.1109/IMTC.1999.776730

Filename

776730