Title :
Contactless recording of cardiac related thoracic conductivity changes
Author :
Guardo, R. ; Trudelle, S. ; Adler, A. ; Boulay, C. ; Savard, P.
Author_Institution :
Dept. de Genie Biomed., Ecole Polytech. de Montreal, Que., Canada
Abstract :
Cardiac related changes in the electrical conductivity distribution of the thorax were recorded in real-time with an electromagnetic sensor consisting of a 3.5 cm radius coil, a 4 MHz oscillator and an active RF voltmeter. Operation of the sensor is based on measuring changes in the amplitude of a marginal RF oscillator, caused by eddy current losses in the heart region. Signals recorded from 6 normal subjects in multiple sessions (1 hour to 1 month) showed good repeatability. The average SNR for signals recorded with the coil placed over the sternum was 34 dB. A possible application of this type of sensor is for non-invasive continuous assessment of left ventricular ejection fraction
Keywords :
bioelectric phenomena; biomedical measurement; cardiology; electric admittance measurement; 1 h to 1 month; 3.5 cm; 34 dB; 4 MHz; active RF voltmeter; cardiac related thoracic conductivity changes; contactless recording; eddy current losses; electromagnetic sensor; heart region; left ventricular ejection fraction; marginal RF oscillator; noninvasive continuous assessment; normal subjects; signal repeatability; thorax; Coils; Conductivity; Contacts; Current measurement; Electromagnetic measurements; Loss measurement; Oscillators; Radio frequency; Thorax; Voltmeters;
Conference_Titel :
Engineering in Medicine and Biology Society, 1995., IEEE 17th Annual Conference
Conference_Location :
Montreal, Que.
Print_ISBN :
0-7803-2475-7
DOI :
10.1109/IEMBS.1995.579839
