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:
Oct. 19, 1976
Filed:
Mar. 06, 1975
Brian A Brastad, Wayzata, MN (US);
Medtronic, Inc., Minneapolis, MN (US);
Abstract
Apparatus is disclosed for sensing and transmitting the stimulating pulse of an implanted pacemaker over readily available, low-bandwidth transmission media to a remote receiver capable of measuring the pulse width to provide an indication of the condition of the pacemaker energy source, e.g. a battery. In particular, the sensing and transmitting apparatus detects the electrical activity, e.g. the EKG, of a patient through attached electrodes and modulates a carrier or tone of a suitable frequency to be transmitted over the low-bandwidth transmission line to the receiver, along with a pulse signal multiplied by a selected, fixed factor dependent upon the carrier frequency of the signal and the other information to be transmitted to the receiver. In one illustrative embodiment, the signal is multiplied by an analog circuit which includes a detection circuit responsive to the leading and trailing edges of the stimulating pulse to generate corresponding first and second signals, an integrating circuit, a first switch responsive to the first signal for applying a first reference potential to the integrating circuit to integrate the first reference signal for a period corresponding to that of the width of the stimulating pulse, and a second switch responsive to the second signal to apply a second reference potential to the integrating circuit for a second period of time, whereby the total of the first and second periods correspond to the multiplied width of the stimulating pulse.