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:
Mar. 17, 1981
Filed:
Oct. 24, 1979
Scott W Carlson, Blaine, MN (US);
James T Bartelt, Shoreview, MN (US);
Cardiac Pacemakers, Inc., St. Paul, MN (US);
Abstract
An electronic test instrument for measuring the refractory interval of a demand-type cardiac pacer pulse generator. The normal pulse-to-pulse interval of the pacer under test is measured by accumulating regularly occurring timing signals in a first counter during the interpulse period. At a predetermined time after the occurrence of the first pulse defining the interval, a pseudo R-wave is generated and applied to the pacer under test. The next pulse-to-pulse interval is then measured in a second counter in a fashion similar to the first measurement and a test is made to determine if the second interval exceeds the first by a prescribed amount. If so, it is known that the pseudo R-wave was effective to reset the pacer's pulse generator. If not, the time of occurrence of the next pseudo R-wave is delayed by a further known amount and the operation is repeated over and over until an extension of the normal pulse-to-pulse interval is noted. When a point is reached where the pseudo R-wave is displaced in time from a first pacer pulse just enough to cause resetting of the pacer's pulse generator, a measure is made of the displacement interval and this value is visually displayed.