Abstract: In a system for retrieving an implanted device, a flared inner surface of a catheter tubular sidewall may define a distal-most opening of a device receptacle; the opening has a first diameter equal to that of the receptacle, and a second diameter, coincident with a distal-most edge of the tubular sidewall, and at least 5% greater than the receptacle diameter. Alternately, a retrieval tool in sliding engagement within a lumen of a catheter includes a shaft assembly, through which a snare member passes, and which includes a collapsible spring-biased perimeter sidewall; the sidewall defines a capture member passageway approximately coaxial, and in fluid communication with a lumen of the shaft assembly. A distal-most opening of the passageway has a spring-biased diameter that is greater than that of a distal-most opening of a device receptacle of the catheter, and a collapsed diameter that is less than the receptacle distal-most opening diameter.

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.

Abstract: An engagement subassembly of a catheter, for retrieving an implanted medical device, may include at least three segments or, alternately, capture members being spring biased outward from a longitudinal axis of the subassembly, wherein a device receptacle of the catheter forces the capture members/segments, against the spring bias thereof, toward the axis. Each capture member includes a spring-biased wire and a grip, which is located between proximal and distal portions of the corresponding wire, and which is configured to interlock within a gap between a device attachment feature and housing; a length of each wire distal portion may be approximately equal to that of the device housing. An interlocking edge of each segment interlocks within the gap between the attachment feature and housing, when a distal-facing surface of each segment, which tapers outward from the axis in a distal direction, comes into confronting engagement with the device housing.

Abstract: An implantable medical device is tethered to a delivery catheter by a length of a tether, which extends through an attachment feature of the device and between a free end thereof and a secured end thereof, wherein the secured end is fixedly coupled to a tubular member of the catheter in proximity to a distal end thereof, and the free end is engaged against an inner surface of a sidewall that extends within the tubular member. The free end of the tether may be engaged against the inner surface by an enlarged distal tip of an elongate wire that extends within a lumen defined by the inner surface of the sidewall. An operator may move the distal tip of the wire out through a distal opening of the lumen, thereby pushing the free end of the tether out from engagement with the surface, to untether the device from the catheter.

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.

Abstract: An engagement subassembly of a catheter, for retrieving an implanted medical device, may include at least three segments or, alternately, capture members being spring biased outward from a longitudinal axis of the subassembly, wherein a device receptacle of the catheter forces the capture members/segments, against the spring bias thereof, toward the axis. Each capture member includes a spring-biased wire and a grip, which is located between proximal and distal portions of the corresponding wire, and which is configured to interlock within a gap between a device attachment feature and housing; a length of each wire distal portion may be approximately equal to that of the device housing. An interlocking edge of each segment interlocks within the gap between the attachment feature and housing, when a distal-facing surface of each segment, which tapers outward from the axis in a distal direction, comes into confronting engagement with the device housing.

Abstract: In a system for retrieving an implanted device, a flared inner surface of a catheter tubular sidewall may define a distal-most opening of a device receptacle; the opening has a first diameter equal to that of the receptacle, and a second diameter, coincident with a distal-most edge of the tubular sidewall, and at least 5% greater than the receptacle diameter. Alternately, a retrieval tool in sliding engagement within a lumen of a catheter includes a shaft assembly, through which a snare member passes, and which includes a collapsible spring-biased perimeter sidewall; the sidewall defines a capture member passageway approximately coaxial, and in fluid communication with a lumen of the shaft assembly. A distal-most opening of the passageway has a spring-biased diameter that is greater than that of a distal-most opening of a device receptacle of the catheter, and a collapsed diameter that is less than the receptacle distal-most opening diameter.

Abstract: An interventional medical system includes an elongate shaft, a steering assembly coupled to the shaft, a snare member, and a passageway configured to allow passage of the snare member therethrough and into a first longitudinally extending lumen of the shaft; wherein the passageway is spaced distally from the steering assembly actuator by no more than 3 cm to 3.5 cm, and the passageway includes an elastic sealing perimeter. The passageway may, in some cases, be formed in a tapered member of the steering assembly that couples a proximal end of the shaft to a core of the steering assembly.

Abstract: An implantable medical device is tethered to a delivery catheter by a length of a tether, which extends through an attachment feature of the device and between a free end thereof and a secured end thereof, wherein the secured end is fixedly coupled to a tubular member of the catheter in proximity to a distal end thereof, and the free end is engaged against an inner surface of a sidewall that extends within the tubular member. The free end of the tether may be engaged against the inner surface by an enlarged distal tip of an elongate wire that extends within a lumen defined by the inner surface of the sidewall. An operator may move the distal tip of the wire out through a distal opening of the lumen, thereby pushing the free end of the tether out from engagement with the surface, to untether the device from the catheter.

Abstract: A tether assembly for a delivery tool that deploys an implantable medical device includes an elongate shaft and an attachment member coupled to a distal end of the shaft, wherein the attachment member includes an external thread and an end wall, the end wall extending orthogonally with respect to a direction of travel within a valley of the external thread to provide a hard stop for a threaded attachment bore of the medical device, when the bore is mated with the external thread. The tether assembly may extend within a lumen defined by an elongate tube of an inner assembly of the delivery tool, such that the attachment member thereof is located in proximity to a distal member of the inner assembly, the distal member being coupled to a distal end of the tube and forming a distal opening of the lumen.