DOUBLE RATE DEMAND PACEMAKER

• US 3,623,486 A
• Filed: 10/01/1969
• Issued: 11/30/1971
• Est. Priority Date: 10/01/1969
• Status: Expired due to Term

• Current Assignee: Warner-Lambert Company (Pfizer Inc.)
• Original Assignee: Barouh V. Berkovits
• Inventors: Berkovits, Barouh V.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US04/862,695
• Time in Patent Office: 790 Days
• Field of Search: 128/419P 331/113,179 307/271
• US Class Current: 607/30
• CPC Class Codes: A61N 1/37211 Means for communicating with stimulators
• CPC Class Codes: A61N 1/37217 characterised by the communication link, e.g. acoustic or tactile

Abstract

A double rate demand pacer having a bistable magnetic reed switch connected to an RC charging circuit for selectively shortcircuiting one of two series-connected resistors. The pacer can be switched between two rates dependent upon the polarity of a magnetic pole brought into its vicinity. A monostable magnetic reed switch is also incorporated in the circuit. A magnetic field of either polarity operates the monostable magnetic reed switch to place the pacer in the continuous mode; as soon as the magnetic field is removed, the pacer reverts to the demand mode with the rate being determined by the polarity of the lastapplied magnetic field.

Claims

1. A demand pacer comprising terminal means for connection to a patient'"'"''"'"'s heart, pulse-generating means for applying periodic pulses to said terminal means, means for detecting the natural beating of said patient'"'"''"'"'s heart and in response thereto for inhibiting the generation of the next pulse which would otherwise be generated by said pulse-generating means, circuit means including bistable magnetic reed switch means connected to said pulse-generating means for controlling said pulse-generating means to operate at a particular one of two possible rates in accordance with the state of said bistable magnetic reed switch means, and monostable magnetic reed switch means for selectively preventing the inhibiting of the operation of said pulsegenerating means.

2. A pacer in accordance with claim 1 wherein said monostable magnetic reed switch means includes a pair of normally open contacts which can be held closed only in the presence of a magnetic field, and said bistable magnetic reed switch means includes a pair of contacts which can be opened or closed in the presence of magnetic fields of respective opposite polarities and remain open or closed after the magnetic fields are removed.

3. A pacer in accordance with claim 2 wherein said circuit means includes an RC charging circuit having two resistors connected in series, said bistable magnetic reed switch means being connected in parallel across one of said two resistors.

4. A pacer in accordance with claim 1 wherein said monostable magnetic reed switch means includes a pair of contacts normally in a first state and responsive to the continued presence of a magnetic field to being held in a second state, and said bistable magnetic reed switch means includes a pair of contacts which can be opened or closed in the presence of magnetic fields of respective opposite polarities and remain open or closed after the magnetic fields are removed.

5. A pacer in accordance with claim 4 wherein said circuit means includes an RC charging circuit having two connected resistors, said bistable magnetic reed switch means being connected to change the combined impedance of said two resistors dependent upon the state of said bistable magnetic reed switch means.

6. A pacer in accordance with claim 1 wherein said circuit means includes an RC charging circuit having two connected resistors, said bistable magnetic reed switch Means being connected to change the combined impedance of said two resistors dependent upon the state of said bistable magnetic reed switch means.

7. A pacer in accordance with claim 6 wherein said two resistors are connected in series and said bistable magnetic reed switch means is connected in parallel across one of said two resistors.

8. A demand pacer in accordance with claim 1 said pulse-generating means further including timing circuit means for establishing intervals between said pulses, said timing circuit means controlled by said bistable magnetic reed switch means.