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EP-4740999-A2 - TETHER ASSEMBLIES FOR MEDICAL DEVICE DELIVERY SYSTEMS

EP4740999A2EP 4740999 A2EP4740999 A2EP 4740999A2EP-4740999-A2

Abstract

A tether head assembly of a delivery system includes an inner retainer and an outer retainer that defines an aperture comprising a receptacle configured to receive an attachment member of a medical device, a passageway, and a groove. The inner retainer is movable within the groove between a second position in which the passageway is dimensioned to receive the attachment member and a first position in which the passageway is dimensioned to prevent passage of the attachment member. A tether handle assembly defines a channel, a force transmitter within the channel, a slidable member partially received within a first end of the channel and a button partially received within a second end of the channel.

Inventors

  • DRAKE, RONALD A.
  • STENER, LESTER O.
  • COLIN, Brian P.

Assignees

  • Medtronic, Inc.

Dates

Publication Date
20260513
Application Date
20200506

Claims (15)

  1. A system comprising: a medical device (10) configured to be implanted at a tissue of a patient, the medical device comprising: a housing (80) defining a proximal end (82) and a distal end (84) of the medical device; a shroud structure disposed at the proximal end of the medical device and defining a cavity, and an attachment member (14) disposed within the cavity; and a tether assembly (12) comprising: a tether handle assembly (13); a tether head assembly (18) comprising: an inner retainer (36), and an outer retainer (38), wherein the outer retainer defines an aperture (42), the aperture comprising: a receptacle (44) configured to receive the attachment member, and a passageway (46) extending from a distal end of the outer retainer proximally to the receptacle; and a pull wire (34) extending from the tether head assembly to the tether handle assembly; wherein the inner retainer is separate from and coupled to the pull wire; and wherein the inner retainer is configured to extend at least partially into the passageway to prevent passage of the attachment member.
  2. The system of claim 1, wherein the attachment member comprises a strut fixedly attached to the shroud structure.
  3. The system of claim 2, wherein the strut extends from a first end to a second end, and wherein the strut is fixedly attached to the shroud structure at both the first end and the second end.
  4. The system of any one of claims 1 to 3, wherein the attachment member defines an elongate holding surface spaced apart from the proximal end of the housing.
  5. The system of any one of claims 1 to 4 wherein the attachment member extends along a length orthogonal to the longitudinal axis of the medical device.
  6. The system of any one of claims 1 to 5, wherein when the attachment member is disposed within the receptacle of the tether head assembly, a distal portion of the outer retainer is configured to enter the cavity of the shroud structure.
  7. The system of claim 6, wherein when the distal portion of the outer retainer is disposed within the cavity of the shroud structure, the distal portion of the outer retainer is configured to interface with the shroud structure.
  8. The system of any one of claims 1 to 7, wherein the inner retainer is configured to move at least partially between a first position wherein a distal portion of the inner retainer partially extends into the passageway and a second position wherein the distal portion of the inner retainer is positioned proximal to the passageway, wherein when the inner retainer is in the first position, the inner retainer is configured to inhibit movement of the attachment member out of the receptacle, and wherein when the inner retainer is in the second position, the inner retainer is configured to allow movement of the attachment member into or out of the receptacle.
  9. The system of any one of claims 1 to 8, further comprising an intermediate member joining the shroud to a proximal end of the housing.
  10. A medical device comprising: a housing extending along a longitudinal axis and defining a proximal end and a distal end of the medical device, and a housing width along a direction orthogonal to the longitudinal axis; a shroud structure disposed at the proximal end of the medical device and defining a cavity and a shroud width, the shroud width being narrower than the housing width; and an attachment member disposed within the cavity, wherein the attachment member provides an elongate holding surface spaced apart from the proximal end, and wherein the elongate holding surface extends along a length orthogonal to the longitudinal axis, wherein the attachment member is configured to be received within a receptacle of a tether head assembly to secure the attachment member to the tether head assembly, and wherein when the attachment member is received within the receptacle, the shroud structure is configured to interact with the tether head assembly to inhibit relative motion between the medical device and the tether head assembly.
  11. The medical device of claim 10, wherein the attachment member comprises a strut fixedly attached to the shroud structure.
  12. The medical device of claim 11, wherein the strut extends from a first end to a second end, and wherein the strut is fixedly attached to the shroud structure at both the first end and the second end.
  13. The medical device of any one of claims 11 to 12, wherein the cavity of the shroud structure is configured to receive at least a portion of the tether head assembly when the attachment member is disposed within the receptacle of the tether head assembly, wherein the at least a portion of the tether head assembly comprises at least a portion of an outer retainer of the tether head assembly and at least a portion of an inner retainer of the tether head assembly, and wherein the inner retainer of the tether head assembly is separate from and coupled to a pull wire of the tether head assembly.
  14. The medical device of claim 13, wherein the shroud structure is configured to interact with the at least a portion of the tether head assembly disposed within the cavity.
  15. The medical device of any one of claims 11 to 14, further comprising an intermediate member joining the shroud to a proximal end of the housing

Description

TECHNICAL FIELD This disclosure relates generally to medical devices, and, more particularly, to systems for delivering medical devices. BACKGROUND Some types of implantable medical devices (IMDs), such as cardiac pacemakers or implantable cardioverter defibrillators systems, may be used to provide cardiac sensing and therapy for a patient via one or more electrodes. Some IMDs include an implantable pulse generator that includes a housing that encloses electronic components, which may be configured to be implanted subcutaneously in the chest of the patient or within a chamber of a heart of the patient, as examples. IMDs having a pulse generator that is configured to be implanted within a chamber of the heart may be referred to as an intracardiac device or a leadless implantable medical device. A medical device delivery system including a delivery catheter may be used to deliver an intracardiac device transvenously to an implant site within a heart of a patient and release the device after the device has been fixed at the implant site. The medical device delivery system then may be withdrawn from the patient. SUMMARY In general, this disclosure is directed to examples of tether assemblies of medical device delivery systems and to techniques using such tether assemblies. Example tether assemblies may include a distal tether head assembly configured to releasably retain an attachment member of a medical device, e.g., an intracardiac device. Additionally, or alternatively, a tether assembly of a medical device delivery system may include a tether handle assembly configured to retain a proximal end of a pull wire of the tether assembly. The tether handle assembly includes one or more components (e.g., an actuator) configured to transmit force to a tether head assembly via the pull wire. The techniques may include applying a force to the actuator of the tether handle assembly move the pull wire, thereby enabling removal of the attachment member from the tether head assembly at a treatment site. The tether head assembly may include an inner retainer and an outer retainer. The outer retainer may define an aperture including a receptacle configured to receive an attachment member of a medical device and a passageway extending from a distal end of the outer retainer proximally to the receptacle. The aperture further may include a groove extending from the distal end of the outer retainer proximally at least to the receptacle. The inner retainer may be movable between a first position and a second position. When the inner retainer is in the first position, the distal portion of the inner retainer may be partially received in the groove and extend into the passageway, thereby narrowing the passageway. The passageway thus may be dimensioned to prevent passage of the attachment member therethrough when the inner retainer is in the first position, such as to prevent passage of the attachment member from the receptacle when the attachment member is loaded onto the tether assembly during a medical procedure to deliver the medical device. When the inner retainer is in the second position, the inner retainer does not narrow the passageway and the passageway thus may be dimensioned to receive the attachment member of the medical device, such as when the medical device is being loaded onto the tether assembly or released from the tether assembly. The inner retainer may be biased to the first position. When the proximal movement of the pull wire is discontinued and/or when the attachment member has been passed through the passageway and is received within the receptacle defined by the outer member, an elastically-compressible member of the tether head assembly may expand and apply distally-directed force to the inner retainer, thereby moving the inner retainer from the second position to the first position. In other examples, a tether head assembly configured to retain an attachment member of a medical device may include a retainer or other such component that is not biased to return to such a first position. The act of loading a medical device onto such other tether assemblies prior to delivery to a heart of a patient may require two people (e.g., clinicians). A first person may be required to hold the medical device in position while a second person opens the tether head assembly, such as by proximally moving a pull wire of the tether assembly to move the inner retainer from a first position in which the tether assembly is "closed" to a second position in which the tether assembly is "open." The first person then may load the attachment member of the medical device onto the tether head assembly (e.g., by placing the attachment member in a receptacle defined by the tether head assembly) and the second person may distally move the pull wire to return the tether head assembly to the first position and retain the attachment member within the receptacle. Loading a medical device onto a tether assembly using two people may add time