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:
Apr. 07, 1992
Filed:
Feb. 08, 1991
Bruce A Pritchard, McMinnville, OR (US);
Daniel J Powers, McMinnville, OR (US);
Jim T Belesiu, Portland, OR (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A cardiograph has a remote front end which is connected to a host via a cable. The front end includes a clock and an analog-to-digital converter. The converter periodically holds and samples patient ECG signals. Each conversion takes place within the same fixed length of time. A clock signal is transmitted to the host on one of the conductors in the cable while digital words, each of which represents a sampled value of the ECG signal, are serially transmitted on another conductor in the cable. The clock signal synchronizes ac voltages applied to several power supplies with the sampling rate of the converter so that the ECG signal is sampled at the same phase of each ac voltage applied to the power supplies. The sampling thus occurs at the same phase, and thus the same amplitude, of each periodic noise cycle induced by the power supply electromagnetic fields. The periodic noise is thus removed from the sampled signal while a dc offset equal to the amplitude of the periodic noise at the sampling phase is added.