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:
May. 03, 1977
Filed:
Mar. 15, 1976
Robert A Walters, Pittsburgh, PA (US);
Russell E Hirtz, Springdale, PA (US);
ARCO Medical Products Company, Leechburg, PA (US);
Abstract
A circuit for measuring the refractory period of a heart pacer includes first, second and third monostable multivibrators. The first monostable multivibrator is reset by the reception of a pacer stimulation pulse to produce a state change for a time period longer than the stimulation pulse interval of the pacer. The second monostable multivibrator is triggered by the trailing edge of the stimulation pulse, and has a variable time constant to produce a state change for a controlled period of time. The third monostable multivibrator applies a pulse to the pacer at the conclusion of the state change of the second monostable multivibrator. A counter is provided which counts the stimulation pulses produced by the pacer, and is connected to a resistive time constant circuit, to add additional time controlling resistors into the time constant circuit of the second monostable multivibrator. A latch circuit discontinues the advancement of the counter after the first monostable multivibrator state change is reached, and a pulse width monitor indicates the time width of the state change of the second monostable multivibrator to thereby indicate the refractory period of the pacer.