The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 01, 1992
Filed:
Sep. 29, 1989
Bruce C Mather, San Antonio, TX (US);
Dean C Winter, San Antonio, TX (US);
Colin Electronics Co., Ltd., , JP;
Abstract
A monitoring system for providing an accurate indication of a patient's respiration rate. The system is effective in eliminating or significantly reducing the effects of heart sounds and ambient noise. The system comprises means for obtaining a first signal waveform containing components corresponding to the patient's breath sounds, as well as components corresponding to heart sounds and ambient noise. The signal is passed through a digital bandpass filter having a passband selected to remove heart sounds and ambient noise to produce a second waveform. From the second waveform the total energy is computed of a portion of the signal within a moving window of predetermined length. The resulting energy envelope signal is smoothed and then high-pass filtered by removing the average DC value of the signal over a predetermined preceding time interval. Respiration is detected by identifying significant, positive-going zero crossings of the resulting signal through a band about zero. The zero-band threshold used to obtain this waveform can be controlled by the operator or pre-set for a particular sensitivity.