Lead locking mechanism for cardiac pacers

• US 4,784,141 A
• Filed: 08/04/1987
• Issued: 11/15/1988
• Est. Priority Date: 08/04/1987
• Status: Expired due to Term

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories)
• Original Assignee: Cordis Leads Incorporated
• Inventors: Peers-Trevarton, Charles A.
• Primary Examiner(s): Jaworski, Francis
• Assistant Examiner(s): Manuel, George
• Application Number:
  US07/081,354
• Time in Patent Office: 469 Days
• Field of Search: 128/419 P, 128/419 PS, 439/784, 439/805
• US Class Current: 607/37
• CPC Class Codes: A61N 1/3752 Details of casing-lead connections

Abstract

A lead locking mechanism suitable for use in a cardiac pacer is provided for axial in-line lead attachment in a pacer neck thereby permitting reduction in pacer neck thickness. The lead locking mechanism includes a substantially fixed annular collar and a hollow screw member threadedly mounted within the annular collar. The annular collar and hollow screw member confine a radially contractable and expandable lead locking member therebetween which functions to clamp a lead connector pin in response to movement of the hollow screw member.

Claims

1. A lead locking mechanism for use within a longitudinal aperture through a neck portion of a cardiac pacer, said lead locking mechanism clamping a lead connector to close an electrical circuit, said lead locking mechanism comprising:

a substantially fixed annular collar mounted within the longitudinal aperture, said annular collar having an opening sized and shaped to closely slidably receive the lead connector, said annular collar having a threaded axially directed internal surface, said annular collar further including an internal frusto-conical chamfer surface that is defined between said axially-directed internal surface and said opening of the annular collar;

a hollow screw member threadedly mounted within said threaded axially directed internal surface of the annular collar, said hollow screw member having an annular core sized and shaped to closely receive the lead connector, said hollow screw member having a frusto-conical end surface; and

a lead connector locking ring confined between said internal frusto-conical chamfer surface of the annular collar and said frusto-conical end surface of the hollow screw member, said lead locking ring having a pair of generally oppositely facing frusto-conical ramp portions that extend between respective end faces of the locking ring and a circumferential portion of the locking ring that is between said respective end faces and that extends beyond said end faces of the locking ring, said locking ring further including a hollow central annular core and an axially directed slot which is a circumferential split of the locking ring that contracts into secure ring-like engagement of the lead connector when said hollow screw member is threadedly moved into said substantially fixed annular collar.

2. The lead locking mechanism of claim 1, wherein said hollow screw member has an externally oriented end face that is a closed end, and said closed end includes a screw head having tool engaging means for threadedly advancing and retracting said hollow screw member.

3. The lead locking mechanism of claim 2, wherein said closed end of the hollow screw member has an annular portion radially spaced from the longitudinal aperture through the neck portion of the cardiac pacer, said annular portion has an annular retention groove, and a sealing ring is in said annular retention groove and engages and seals the longitudinal aperture through the neck portion of the cardiac pacer.

4. In a cardiac pacer provided with a case and a neck portion secured onto the case, the neck portion having a longitudinal aperture therethrough, and a lead locking mechanism clamping a lead connector to close an electrical circuit, the improvement of a lead locking mechanism comprising:

a substantially fixed annular collar mounted within the longitudinal aperture, said annular collar having an opening sized and shaped to closely slidably receive the lead connector, said annular collar having a threaded axially directed internal surface, said annular collar further including an internal frusto-conical chamber surface that is defined between said axially-directed internal surface and said opening of the annular collar;

a hollow screw member threadedly mounted within said threaded axially directed internal surface of the annular collar, said hollow screw member having an annular core sized and shaped to closely receive the lead connector, said hollow screw member having a frusto-conical end surface; and

a lead connector locking ring confined between said internal frusto-conical chamfer surface of the annular collar and said frusto-conical end surface of the hollow screw member, said lead locking ring having a pair of generally oppositely facing frusto-conical ramp portions that extend between respective end faces of the locking ring and a circumferential portion of the locking ring that is between said respective end faces and that extends beyond said end faces of the locking ring, said locking ring further including a hollow central annular core and an axially directed slot which is a circumferential split of the locking ring that contracts into secure ring-like engagement of the lead connector when said hollow screw member is threadedly moved into said substantially fixed annular collar.

5. The cardiac pacer according to claim 4, wherein said hollow screw member has an externally oriented end face that is a closed end, and said closed end includes a screw head having tool engaging means for threadedly advancing and retracting said hollow screw member.

6. The cardiac pacer according to claim 5, wherein said closed end of the hollow screw member has an annular portion radially spaced from the longitudinal aperture through the neck portion of the cardiac pacer, said annular portion has an annular retention groove, and a sealing ring is in said annular retention groove and engages and seals the longitudinal aperture through the neck portion of the cardiac pacer.