Interventional medical systems and associated methods

• US 10,080,888 B2
• Filed: 11/16/2015
• Issued: 09/25/2018
• Est. Priority Date: 11/16/2015
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Kelly, Tomas K, Francis, Gwenda, Geraghty, Brendan P, McHugh, Pat, Ward, Sean
• Primary Examiner(s): TYSON, MELANIE RUANO
• Application Number:
  US14/942,609
• Publication Number:
  US 20170136231A1
• Time in Patent Office: 1,044 Days
• Field of Search: 606129
• CPC Class Codes: A61M 25/0074 Dynamic characteristics of the catheter tip, e.g. openable, closable, expandable or deformable
• CPC Class Codes: A61M 25/0108 using radio-opaque or ultrasound markers
• CPC Class Codes: A61M 25/0147 with movable mechanical means, e.g. pull wires
• CPC Class Codes: A61N 1/0573 chacterised by means penetrating the heart tissue, e.g. helix needle or hook
• CPC Class Codes: A61N 1/0575 with drug delivery
• CPC Class Codes: A61N 1/0587 Epicardial electrode systems; Endocardial electrodes piercing the pericardium
• CPC Class Codes: A61N 1/059 Anchoring means
• CPC Class Codes: A61N 1/086 Magnetic resonance imaging [MRI] compatible leads
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators

Abstract

A shaft of an interventional medical system catheter has a distal end formed by opposing elastically deformable retention features that protrude into a lumen of the shaft, and that define an expandable distal opening of the lumen. The retention features secure an implantable medical device to the catheter by an interlocking engagement within a gap defined by a necked-in portion of a device holding member. Each retention feature includes a distal-facing surface defining the distal opening, and, when an elongate release member of the catheter, which extends within the shaft lumen, applies a push force against proximal-facing surfaces of the features, the distal opening expands from a constricted to an open configuration, wherein the open configuration allows passage of the device holding member through the distal opening, and the constricted configuration allows for the interlocking engagement with the device.

Claims

1. An interventional medical system comprising a relatively compact implantable medical device and a catheter;

the medical device comprising a hermetically sealed housing, an electrode mounted in proximity to a distal end of the housing, a fixation member mounted to the distal end of the housing, and a holding member joined to a proximal end of the housing and protruding proximally therefrom, the holding member including a head and a necked-in portion that defines a gap between the head and the proximal end of the housing;

the catheter comprising an elongate inner assembly and an elongate outer tubular member, the outer tubular member including an elongate lumen extending along a length thereof and including a distal-most opening formed at a distal end of the outer tubular member, the distal-most opening allowing passage of the medical device therethrough, and the inner assembly extending along, and being in sliding engagement within the lumen of the outer tubular member; and

the catheter inner assembly comprising;

an elongate shaft including a distal end and an elongate lumen, the distal end of the shaft comprising opposing elastically deformable retention features that protrude into the shaft lumen, each retention feature including a distal-facing surface and a proximal-facing surface, the distal-facing surfaces defining a distal opening of the shaft lumen, the distal opening being expandable from a constricted configuration to an open configuration by moving the retention features from a relaxed condition to a deformed condition, respectively, the open configuration allowing passage of the device holding member through the distal opening of the shaft lumen, and the constricted configuration allowing for an interlocking engagement of the retention features within the gap defined by the necked-in portion of the device holding member; and

an elongate release member configured to slide within the shaft lumen and to apply a push force against the proximal-facing surfaces of the shaft retention features, the push force moving the retention features to the deformed condition to expand the distal opening of the shaft lumen from the constricted to the open configuration; and

wherein the outer tubular member of the catheter is movable between a retracted position and an advanced position, the distal end of the inner assembly shaft being exposed distal to the distal-most opening of the outer tubular member when the outer tubular member is in the retracted position, and the distal end of the inner assembly shaft being contained within the lumen of the outer tubular member when the outer tubular member is in the advanced position.

2. The system of claim 1, wherein the distal opening of the catheter inner assembly shaft lumen tapers from a first, distal-most diameter to a second diameter, the first diameter being greater than the second diameter, and the second diameter being expandable from the constricted configuration to the open configuration.

3. The system of claim 2, wherein the first, distal-most diameter of the distal opening of the catheter inner assembly shaft lumen is approximately maintained when the retention features are moved to the deformed condition to expand the second diameter of the distal opening of the catheter inner assembly shaft lumen.

4. The system of claim 2, wherein the first, distal-most diameter of the distal opening of the catheter inner assembly shaft lumen also expands when retention features are moved to the deformed condition to expand the second diameter of the distal opening of the catheter inner assembly shaft lumen.

5. The system of claim 1, wherein the elongate release member of the catheter inner assembly comprises a tube, the tube including a distal-most edge configured to push against the proximal-facing surfaces of the shaft retention features.

6. The system of claim 1, wherein the shaft of the catheter inner assembly includes two pairs of the opposing elastically deformable retention features, each retention feature including free edges that extend within the shaft lumen, and the free edges of adjacent retention features extending alongside and in close proximity with one another within the shaft lumen, when the retention features are in the relaxed condition.

7. The system of claim 1, wherein the elongate release member of the catheter inner assembly comprises a rod, the rod including a distal-most surface configured to interface with a proximal-most surface of the device holding member, such that the release member applies the push force against the proximal-facing surfaces of the shaft retention features through the holding member.

8. The system of claim 1, wherein the elongate release member of the catheter inner assembly comprises a rod, the rod including a distal tip configured to apply the push force against the proximal-facing surfaces of the shaft retention features.

9. The system of claim 1, wherein the distal-facing surface of each retention feature of the catheter inner assembly shaft is a first of at least two distal-facing surfaces thereof, a second of the at least two distal-facing surfaces being located between the first distal-facing surface and the proximal-facing surface, the second distal-facing surface conforming to a contour of the head of the device holding member, when the retention features are in interlocking engagement within the gap defined by the necked-in portion of the device holding member.

10. The system of claim 1, wherein

the distal-facing surface of each retention feature of the catheter inner assembly shaft is a first of at least two distal-facing surfaces thereof, a second of the at least two distal-facing surfaces being spaced proximally apart from the first distal-facing surface;

the proximal-facing surface of each retention feature of the catheter inner assembly shaft is a first of three proximal-facing surfaces thereof, a second of the three proximal-facing surfaces being located between the first and second distal-facing surfaces, and a third of the three proximal-facing surfaces being located between the second distal-facing surface and the first proximal-facing surface;

the holding member of the medical device includes another necked-in portion spaced proximally from the necked-in portion that defines the gap between the holding member and the proximal end of the housing, the other necked-in portion defining an intermediate gap of the device holding member; and

the retention features also interlock within the intermediate gap of the device holding member when the features are in interlocking engagement within the gap between the device holding member and the proximal end of the device housing.

11. The system of claim 1, wherein the shaft of the catheter inner assembly further includes a relatively limp zone extending proximally from the distal end of the shaft, the relatively limp zone being more flexible than the distal end of the shaft.

12. The system of claim 1, wherein:

the shaft of the catheter inner assembly includes two pairs of the opposing elastically deformable retention features, each retention feature comprising at least three retaining struts and at least one passageway strut, the retaining struts forming or supporting the distal-facing surface of the corresponding retention feature, and the passageway strut forming or supporting the proximal-facing surface of the corresponding retention feature;

each retaining strut and passageway strut of each retention feature includes a perimeter end and a central end, each perimeter end being secured to an inner surface of the shaft distal end, the central ends of the struts of each retention feature being joined together at the distal-facing surface thereof, the perimeter ends of the at least three retaining struts of each retention feature being co-planar and spaced apart from one another, and the perimeter end of the at least one passageway strut of each retention feature being offset proximally from the perimeter ends of the corresponding retaining struts; and

each retaining strut and passageway strut includes a flex zone located between the perimeter and central ends thereof.

13. The system of claim 12, wherein:

each of the retaining and passageway struts of the opposing elastically deformable retention features comprises a shape-memory member; and

a crimp in each shape-memory member forms the flex zone of the corresponding strut.

14. The system of claim 12, wherein the elongate release member of the catheter inner assembly comprises a rod, the rod including a distal-most surface configured to interface with a proximal-most surface of the head of the device holding member, such that the release member applies the push force against the proximal-facing surfaces of the shaft retention features through the holding member.