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. 01, 1997
Filed:
Dec. 06, 1995
Bruce A Pritchard, McMinnville, OR (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An ECG system for a 12-lead ECG test includes ten electrodes--consisting of six ventricle electrodes V1-V6, a right arm electrode RA, a left arm electrode LA, a left leg electrode LL, and a right leg electrode RL--which generate electrical signals indicative of heart activity within a human patient. The EGG system also includes a plurality of conductors connected to corresponding electrodes and a signal acquisition system connected to the conductors. The EGG system also has an offset adjustment system operatively coupled to the signal acquisition system. The offset adjustment system identifies a selected voltage level (such as a maximum or minimum voltage level) of at least one of the electrical signals generated by an associated electrode and manipulates that voltage level to produce an offset adjustment signal. This offset adjustment signal is used to bring voltage levels of all of the electrical signals produced by the electrodes within a signal acquisition range of the signal acquisition system. The ECG system further includes a potential adjusting feedback circuit coupled between the offset adjustment system and one of the electrodes (such as the right leg electrode RL) to supply a reference potential to that electrode. The potential tends toward the offset adjustment signal to offset the electric potentials of the human patient by an equal amount. This offset has the effect of moving the range of electrode voltages into the range of the signal acquisition system and yields a maximum signal acquisition range of approximately 300 mV, which can be resolved to 5 .mu.V increments using a 16-bit A/D converter.