Abstract: A biostimulator, such as a leadless cardiac pacemaker, having a flexible circuit assembly, is described. The flexible circuit assembly is contained within an electronics compartment between a battery, a housing, and a header assembly of the biostimulator. The flexible circuit assembly includes a flexible substrate that folds into a stacked configuration in which an electrical connector and an electronic component of the flexible circuit assembly are enfolded by the flexible substrate. An aperture is located in a fold region of the flexible substrate to allow a feedthrough pin of the header assembly to pass through the folded structure into electrical contact with the electrical connector. The electronic component can be a processor to control delivery of a pacing impulse through the feedthrough pin to a pacing tip. Other embodiments are also described and claimed.

Abstract: A biostimulator, such as a leadless cardiac pacemaker, including a fixation element to engage tissue and one or more backstop elements to resist back-out from the tissue, is described. The fixation element can be mounted on a housing of the biostimulator such that a helix of the fixation element extends distally to a leading point. The leading point can be located on a distal face of the helix at a position that is proximal from a center of the distal face. The backstop elements can include non-metallic filaments, such as sutures, or can include a pinch point of the biostimulator. The backstop features can grip the tissue to prevent unscrewing of the fixation element. Other embodiments are also described and claimed.

Abstract: A biostimulator, such as a leadless cardiac pacemaker, having a flexible circuit assembly, is described. The flexible circuit assembly is contained within an electronics compartment between a battery, a housing, and a header assembly of the biostimulator. The flexible circuit assembly includes a flexible substrate that folds into a stacked configuration in which an electrical connector and an electronic component of the flexible circuit assembly are enfolded by the flexible substrate. An aperture is located in a fold region of the flexible substrate to allow a feedthrough pin of the header assembly to pass through the folded structure into electrical contact with the electrical connector. The electronic component can be a processor to control delivery of a pacing impulse through the feedthrough pin to a pacing tip. Other embodiments are also described and claimed.

Abstract: Disclosed herein is a delivery system for delivering a leadless pacemaker. The delivery system may include a catheter, which may be a guide catheter. The catheter includes a distal end, a proximal end opposite the distal end, a lumen extending between the distal end and the proximal end, and a locking hub operably coupled to the proximal end. The locking hub includes a lumen segment of the lumen. In one implementation, self-biasing of the lumen segment places the lumen segment out of alignment with a rest of the lumen. Deflecting the lumen segment against the self-biasing of the lumen segment places the lumen segment in coaxial alignment with the rest of the lumen. In another implementation, self-biasing of the lumen segment reduces an inner diameter of the lumen segment and actuation of the locking hub expands the inner diameter.

Abstract: A biostimulator, such as a leadless cardiac pacemaker, including a fixation element and an electrode mounted on a resilient scaffold, is described. The fixation element and the resilient scaffold are coupled to a housing of the biostimulator. The resilient scaffold can support the electrode against a target tissue at a location that is radially offset from a location where the fixation element anchors the housing to the target tissue. A flexibility of the resilient scaffold allows the electrode to conform to a shape and movement of the target tissue when the housing is rigidly fixed to the target tissue by the fixation element. The resiliently supported electrode that is radially offset from the anchor point can reliably pace the target tissue without piercing the target tissue. Other embodiments are also described and claimed.

Abstract: In at least one embodiment, a system and method for implanting an implantable medical device (IMD) within a patient may include an IMD including a housing and an attachment member, and a delivery catheter including a tethering snare that is configured to be selectively extended out of the delivery catheter and retracted into the delivery catheter. In at least one embodiment, a system and method for implanting an implantable medical device (IMD) within a patient may include an IMD including a housing and an attachment member, wherein the attachment member includes a central passage connected to a connection chamber, and a delivery catheter including first and second tethers that may be moved outwardly from and retracted into the delivery catheter.

Abstract: Disclosed herein is a delivery catheter for implanting a leadless biostimulator. The delivery catheter includes a shaft and a tubular body having a lumen and an atraumatic end. The atraumatic end includes at least one of a braided, woven or mesh construction configured to facilitate the atraumatic end changing diameter. When a distal portion of the shaft is coupled to a proximal region of the leadless biostimulator, at least one of distally displacing the tubular body relative to the shaft or proximally displacing the shaft relative to the tubular body causes the leadless biostimulator to be received in the volume of the atraumatic end and the atraumatic end to encompass the leadless biostimulator. Conversely, at least one of proximally displacing the tubular body relative to the shaft or distally displacing the shaft relative to the tubular body causes the leadless biostimulator to exit the volume of the atraumatic end.

Abstract: A biostimulator, such as a leadless cardiac pacemaker, including a fixation element to engage tissue and one or more backstop elements to resist back-out from the tissue, is described. The fixation element can be mounted on a housing of the biostimulator such that a helix of the fixation element extends distally to a leading point. The leading point can be located on a distal face of the helix at a position that is proximal from a center of the distal face. The backstop elements can include non-metallic filaments, such as sutures, or can include a pinch point of the biostimulator. The backstop features can grip the tissue to prevent unscrewing of the fixation element. Other embodiments are also described and claimed.

Abstract: In at least one embodiment, a system and method for implanting an implantable medical device (IMD) within a patient may include an IMD including a housing and an attachment member, and a delivery catheter including a tethering snare that is configured to be selectively extended out of the delivery catheter and retracted into the delivery catheter. In at least one embodiment, a system and method for implanting an implantable medical device (IMD) within a patient may include an IMD including a housing and an attachment member, wherein the attachment member includes a central passage connected to a connection chamber, and a delivery catheter including first and second tethers that may be moved outwardly from and retracted into the delivery catheter.

Abstract: Disclosed herein is a delivery catheter for implanting a leadless biostimulator. The delivery catheter includes a shaft and a tubular body having a lumen and an atraumatic end. The atraumatic end includes at least one of a braided, woven or mesh construction configured to facilitate the atraumatic end changing diameter. When a distal portion of the shaft is coupled to a proximal region of the leadless biostimulator, at least one of distally displacing the tubular body relative to the shaft or proximally displacing the shaft relative to the tubular body causes the leadless biostimulator to be received in the volume of the atraumatic end and the atraumatic end to encompass the leadless biostimulator. Conversely, at least one of proximally displacing the tubular body relative to the shaft or distally displacing the shaft relative to the tubular body causes the leadless biostimulator to exit the volume of the atraumatic end.

Abstract: A leadless biostimulator has a housing including an electronics compartment, an electronics assembly mounted in the electronics compartment, a proximal electrode that disposed on and/or integrated into the housing, and an electrical feedthrough assembly. The electrical feedthrough assembly includes a distal electrode and a flange. The flange is mounted on the housing. The distal electrode is electrically isolated from the flange by an insulator and configured to be placed in contact with target tissue to which a pacing impulse is to be transmitted by the leadless biostimulator. A mount is mounted on the flange and thereby mounted on the electrical feedthrough assembly. A fixation element is mounted on the mount and configured to facilitate fixation of the leadless biostimulator to tissue of a patient.

Abstract: An electrical feedthrough assembly, which is configured to be mounted on a housing of a leadless biostimulator, comprises an electrode body including a cup having an electrode wall extending distally from an electrode base around an electrode cavity, an electrode tip mounted on a distal end of the electrode body, and a filler in the electrode cavity between the electrode base and the electrode tip, wherein the filler includes a therapeutic agent. The electrode tip is configured to be placed in contact with target tissue to which a pacing impulse is to be transmitted by the leadless biostimulator. A pin extends proximally from the electrode base, wherein the pin is configured to be into contact with an electrical connector of an electronics assembly within the housing of the leadless biostimulator.

Abstract: A medical tool includes a rotation mechanism that further includes a warning feature. The warning feature provides an indication when the rotation mechanism has achieved a number of rotations.

Abstract: A leadless biostimulator, such as a leadless pacemaker, includes a housing sized and configured to be implanted within a heart of a patient and includes both primary and secondary fixation features. The primary fixation feature is adapted to rotate to fix the leadless biostimulator to a wall of the heart during initial implantation. Once the leadless biostimulator is implanted, the secondary fixation feature is adapted to resist counter-rotation of the leadless biostimulator. The primary fixation feature may include a fixation helix configured to affix the housing to the heart by rotating in a screwing direction. The secondary fixation feature may include an apex to engage the heart to resist unscrewing of the primary fixation feature.

Abstract: A biostimulator, such as a leadless cardiac pacemaker, including coaxial fixation elements to engage or electrically stimulate tissue, is described. The coaxial fixation elements include an outer fixation element extending along a longitudinal axis and an inner fixation element radially inward from the outer fixation element. One or more of the fixation elements are helical fixation elements that can be screwed into tissue. The outer fixation element has a distal tip that is distal to a distal tip of the inner fixation element, and an axial stiffness of the outer fixation element is lower than an axial stiffness of the inner fixation element. The relative stiffnesses are based on one or more of material or geometric characteristics of the respective fixation elements. Other embodiments are also described and claimed.

Abstract: A medical tool includes a rotation mechanism that further includes a warning feature. The warning feature provides an indication when the rotation mechanism has achieved a number of rotations.

Abstract: A leafless biostimulator, such as a leadless pacemaker, includes a housing sized and configured to be implanted within a heart of a patient and includes both primary and secondary fixation features. The primary fixation feature is adapted to rotate to fix the leadless biostimulator to a wall of the heart during initial implantation. Once the leadless biostimulator is implanted, the secondary fixation feature is adapted to resist counter-rotation of the leadless biostimulator. The primary fixation feature may include a fixation helix configured to affix the housing to the heart by rotating in a screwing direction. The secondary fixation feature may include an apex to engage the heart to resist unscrewing of the primary fixation feature.

Abstract: A biostimulator, such as a leadless cardiac pacemaker, including coaxial fixation elements to engage or electrically stimulate tissue, is described. The coaxial fixation elements include an outer fixation element extending along a longitudinal axis and an inner fixation element radially inward from the outer fixation element. One or more of the fixation elements are helical fixation elements that can be screwed into tissue. The outer fixation element has a distal tip that is distal to a distal tip of the inner fixation element, and an axial stiffness of the outer fixation element is lower than an axial stiffness of the inner fixation element. The relative stiffnesses are based on one or more of material or geometric characteristics of the respective fixation elements. Other embodiments are also described and claimed.

Abstract: A biostimulator, such as a leadless cardiac pacemaker, including a fixation element and an electrode mounted on a resilient scaffold, is described. The fixation element and the resilient scaffold are coupled to a housing of the biostimulator. The resilient scaffold can support the electrode against a target tissue at a location that is radially offset from a location where the fixation element anchors the housing to the target tissue. A flexibility of the resilient scaffold allows the electrode to conform to a shape and movement of the target tissue when the housing is rigidly fixed to the target tissue by the fixation element. The resiliently supported electrode that is radially offset from the anchor point can reliably pace the target tissue without piercing the target tissue. Other embodiments are also described and claimed.

Abstract: Disclosed herein is a medical leadless pacemaker delivery system adapted to engage and disengage with leadless pacemakers to allow for the repeated use of the leadless pacemaker delivery system in delivering and implanting multiple leadless pacemakers into a patient heart in a serial or repeated manner. The leadless pacemaker delivery system includes a handle, an attachment mechanism, a torque portion, and a rotation limiter. The handle includes a housing. The attachment mechanism is operably coupled to the housing and configured to actuate between a released state and an engaged state. The torque portion is operably coupled to the housing and rotatable relative to the housing to transition the attachment mechanism between the released and engaged states. The torque portion includes a shaft. The rotation limiter is in sliding engagement with the shaft between a first stop and a second stop. The rotation limiter includes a first helical thread.