Document Type
Thesis
Date of Award
5-31-1989
Degree Name
Master of Science in Electrical Engineering - (M.S.)
Department
Electrical Engineering
First Advisor
Peter Engler
Second Advisor
Joseph Frank
Third Advisor
Stanley S. Reisman
Abstract
The microwave interferometer is utilized to pick up vibrations of the anterior (front) chest wall, produced by cardiac activity. This instrument is capable of remotely measuring the vibrations at distances up to four feet through clothing, by using low level microwave energy at 9.3 Ghz. The vibrations picked up from subjects are filtered, and processed through a PC to correlate with EKG signals, and thereby evaluate the instrument as a non-invasive, non-contacting cardiac monitor.
The subjects lie on their back with the microwave energy illuminating their chest, and their cardiovascular dynamics are recorded simultaneously with EKG signals. The EKG is recorded so as to serve as the reference timing signal. These signals are recorded through two channels and directed to a low pass analog filter. After low pass filtering the signals are fed to an A/D converter, and the digitized data are stored on the fixed disk of the PC. These data are then separated into individual channels, and after processing through the application software package ILS, the EKG and Interferometer signals are cross correlated. The unprocessed EKG signals are displayed with the unprocessed signals from the Interferometer; the second display is between processed EKG and the signals from the Interferometer. The subjects were also made to lie face down, and signals were recorded from the posterior (back) chest wall.
The recordings from seventeen subjects appear to have a close relation to the mechanical events in the cardiac cycle, and also the recordings from front and back appear similar to each other.
Recommended Citation
Chakravarthi, Suresh, "Non invasive monitoring of cardiovascular dynamics through a microwave interferometer" (1989). Theses. 2725.
https://digitalcommons.njit.edu/theses/2725
