Cardiac pacemaker

• US 4,157,720 A
• Filed: 09/16/1977
• Issued: 06/12/1979
• Est. Priority Date: 09/16/1977
• Status: Expired due to Term

• Current Assignee: Wilson Greatbatch
• Original Assignee: Wilson Greatbatch
• Inventors: Greatbatch, Wilson
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/833,920
• Time in Patent Office: 634 Days
• Field of Search: 128/419 P, 128/419 PG, 128/419 PS
• US Class Current: 607/36
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators

Abstract

A cardiac pacemaker including a pulse generator and an electrical source such as a battery completely enveloped in a small size housing. An electrode operatively connected to the pulse generator has a helically-shaped portion extending outwardly from the housing in fixed relation thereto. The housing is of sufficiently small size to permit the pacemaker to be implanted in conjunction with a limited thoracotomy by turning the housing to rotatively insert the electrode into the heart tissue of the patient, i.e. into the myocardium. The housing can be of electrically conducting material, insulated from the electrode, and a portion of the housing can serve as an indifferent electrode.

Claims

1. A cardiac pacemaker comprising:

(a) a pulse generator having an output and providing output electrical pulses suitable for cardiac stimulation;

(b) a source of electrical energy connected to said pulse generator;

(c) a housing completely enveloping said pulse generator and source, said housing including first and second generally oppositely-directed surface portions meeting in a peripheral portion, said housing having at least one axis extending through said surface portions about which said housing is turnable;

(d) a stimulating electrode operatively connected to said pulse generator output and having a helically shaped portion extending outwardly from said first surface portion of said housing in fixed relation thereto and in a direction substantially along said housing axis, said helically shaped portion having a cross-sectional dimension substantially smaller than the cross-sectional dimension of said housing measured in a direction substantially perpendicular to said axis;

(e) said pacemaker being implanted in a patient by turning said housing about said axis to rotatively insert said electrode into the heart tissue of the patient until said first surface portion of said housing is substantially in contact with the heart tissue, said second surface portion of said housing contacting neighboring body tissue when said pacemaker is implanted;

(f) said pacemaker being held in place by the combination of the insertion of said electrode in the heart tissue and supporting contact between said housing second surface portion and the neighboring body tissue;

(g) another electrode on said housing electrically coupled to said pulse generator and adapted to contact the neighboring body tissue of the patient; and

(h) electrical insulating means operatively associated with said housing for insulating said stimulating electrode from said other electrode.

2. A cardiac pacemaker according to claim 1, wherein said electrode has an axis of rotation substantially coincident with said housing axis.

3. A cardiac pacemaker according to claim 2, wherein the dimension of said housing measured substantially parallel to said axis of rotation is smaller than the dimension of said housing measured substantially perpendicular to said axis of rotation.

4. A cardiac pacemaker according to claim 3, wherein said dimension measured substantially parallel to said axis is less than one-half said dimension measured substantially perpendicular to said axis.

5. A cardiac pacemaker according to claim 1, wherein said electrode extends from said first surface portion generally centrally thereof.

6. A cardiac pacemaker according to claim 5, wherein said first and second surface portions both are generally circular in shape.

7. A cardiac pacemaker according to claim 1, wherein said housing is of metal and said electrical insulating means is between said electrode and said first surface portion whereby said second surface portion serves as said other electrode.

8. A cardiac pacemaker according to claim 7, wherein said insulating means is coextensive with said first surface portion and said pulse generator is coupled electrically to said housing second portion whereby said second surface portion of said housing serves as said other electrode.

9. A cardiac pacemaker according to claim 1, wherein each of said housing surface portions is substantially smooth and continuous.

10. A cardiac pacemaker according to claim 1, wherein said electrical insulating means is operatively associated with said first housing surface portion and said second housing surface portion is electrically conductive and further including electrical conductivity means operatively associated with said second housing surface portion and operatively connected to said pulse generator whereby said second housing surface portion serves as said other electrode.