Cardiac pacer circuitry to facilitate testing of patient heart activity and pacer pulses
First Claim
1. An improved implantable electronic heart pacer having a self-contained power source, said pacer including terminal means for connection to the heart of a patient, pulse generator means connected to said terminal means for supplying stimulating pulses thereto, timing means for controlling the rate of delivery of said stimulating pulses, and heart beat detecting means for preventing delivery of said stimulating pulses when the patient has normal heart activity, said timing means having a test mode rate and a demand mode rate which is different from said test mode rate, at least one of said test mode rate and said demand mode rate being dependent upon remaining useful life of said power source, said improvement comprising:
- means responsive to an externally applied magnetic field, for inducing said timing means to operate at said test mode rate;
delay means responsive to removal of said magnetic field for inducing said timing means to operate at said demand mode rate for a first predetermined period of time;
means for inactivating said heart beat detecting means only after application of said magnetic field for a second predetermined period of time, said inactivating means being operative during application of said magnetic field and during said first predetermined period of said delay means;
means responsive to an externally applied magnetic pulse having a duration which is short compared with the normal demand mode pulse-to-pulse interval to inhibit said pulse generator means when said pulse generator means is pacing in said demand mode.
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Accused Products
Abstract
A demand cardiac pacer having provisions for determining power source life status both during normal heart operation and during heart stimulation by the pacer. An external magnetic pulse of relatively long duration induces a test mode in the circuit, the pacer reverting to the pacing mode immediately after removal of the magnetic stimulus. When producing pacing pulses in the pacing mode, testing of the patient'"'"'s heart is facilitated by providing an external magnetic pulse of relatively short duration which is insufficient to place the pacer in the test mode but of sufficient length to inhibit pacing pulses. This invention applies to preset frequency pacers as well as to programmable pacers and includes means for observing the preprogrammed pulse frequency immediately after programming.
28 Citations
13 Claims
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1. An improved implantable electronic heart pacer having a self-contained power source, said pacer including terminal means for connection to the heart of a patient, pulse generator means connected to said terminal means for supplying stimulating pulses thereto, timing means for controlling the rate of delivery of said stimulating pulses, and heart beat detecting means for preventing delivery of said stimulating pulses when the patient has normal heart activity, said timing means having a test mode rate and a demand mode rate which is different from said test mode rate, at least one of said test mode rate and said demand mode rate being dependent upon remaining useful life of said power source, said improvement comprising:
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means responsive to an externally applied magnetic field, for inducing said timing means to operate at said test mode rate; delay means responsive to removal of said magnetic field for inducing said timing means to operate at said demand mode rate for a first predetermined period of time; means for inactivating said heart beat detecting means only after application of said magnetic field for a second predetermined period of time, said inactivating means being operative during application of said magnetic field and during said first predetermined period of said delay means; means responsive to an externally applied magnetic pulse having a duration which is short compared with the normal demand mode pulse-to-pulse interval to inhibit said pulse generator means when said pulse generator means is pacing in said demand mode. - View Dependent Claims (2, 3, 4)
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5. An improved implantable electronic heart pacer having a selfcontained power source, said pacer including terminal means for connection to the heart of a patient, pulse generator means connected to said terminal means for supplying stimulating pulses thereto, timing means for controlling the rate of delivery of said stimulating pulses and having a demand mode rate, heart beat detecting means for preventing delivery of said stimulating pulses when the patient has normal heart activity, and means for resetting said timing means upon detection of each normal heart beat, said improvement comprising:
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means, in conjunction with said heart beat detecting means, responsive to an externally applied single energy pulse having a duration which is short compared with the normal demand mode pulse-to-pulse interval to inhibit said pulse generator means from producing a heart-stimulating pulse and to reset said timing means; means responsive to a predetermined series of closely spaced energy pulses of similar short duration for inactivating said heart beat detecting means; and delay means responsive to cessation of said series of energy pulses for inducing said timing means to operate at said demand mode rate for a predetermined period of time, said inactivating means being operative during said predetermined period of time. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13)
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Specification