Abstract: A leadless biostimulator, such as a leadless cardiac pacemaker, having a header assembly that includes overmolded components, is described. The header assembly includes a helix mount overmolded on a flange of an electrical feedthrough assembly. A fixation element is mounted on the helix mount. The overmolded helix mount fills a recess in an outer surface of the flange to robustly join the header assembly components. The electrical feedthrough assembly includes an electrode contained within the flange to deliver electrical impulses to a target anatomy, and an insulator that separates the electrode from the flange. The overmolded helix mount can conform or adhere to the outer surfaces of the flange and the insulator to electrically isolate the electrode from the flange. Other embodiments are also described and claimed.

Abstract: A pacing lead conversion tool and a method of using the pacing lead conversion tool to reversibly convert an extendable cardiac pacing lead into a fixed cardiac pacing lead. The pacing lead conversion tool includes a locking lumen configured to receive a pacing lead. The locking lumen includes a connector body segment to receive a connector body of the pacing lead in a first friction fit and a pin segment to receive a connector pin of the pacing lead in a second friction fit. The friction fits allow for relative rotation between a lead body of the pacing lead and the connector pin when the pacing lead conversion tool is twisted, and prevents relative rotation between the lead body and the connector pin when the cardiac pacing lead is burrowed through a target tissue. Other embodiments are also described and claimed.

Abstract: A leadless biostimulator, such as a leadless cardiac pacemaker, having a header assembly is described. The header assembly includes a helix mount mounted on a flange. An inner surface of the helix mount conforms to an outer surface of the flange, and the outer surface has a non-circular profile such that the conforming surfaces interfere with rotation of the helix mount relative to the flange. The non-circular profile includes a linear segment, such as a radial segment, that resists rotational movement of the helix mount. The helix mount has a protrusion that extends into a recess of the flange to interfere with longitudinal movement between the helix mount and the flange. The protrusion is formed before or after mounting the helix mount on the flange. The interfering surfaces threadlessly interconnect the header assembly components. Other embodiments are also described and claimed.

Abstract: A biostimulator, such as a leadless pacemaker, has electrode(s) coated with low-polarization coating(s). A low-polarization coating including titanium nitride can be disposed on an anode, and a low-polarization coating including a first layer of titanium nitride and a second layer of platinum black can be disposed on a cathode. The anode can be an attachment feature used to transmit torque to the biostimulator. The cathode can be a fixation element used to affix the biostimulator to a target tissue. The low-polarization coating(s) impart low-polarization to the electrode(s) to enable an atrial evoked response to be detected and used to effect automatic output regulation of the biostimulator. Other embodiments are also described and claimed.

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 leadless biostimulator, such as a leadless cardiac pacemaker, having a header assembly is described. The header assembly includes a helix mount mounted on a flange. An inner surface of the helix mount conforms to an outer surface of the flange, and the outer surface has a non-circular profile such that the conforming surfaces interfere with rotation of the helix mount relative to the flange. The non-circular profile includes a linear segment, such as a radial segment, that resists rotational movement of the helix mount. The helix mount has a protrusion that extends into a recess of the flange to interfere with longitudinal movement between the helix mount and the flange. The protrusion is formed before or after mounting the helix mount on the flange. The interfering surfaces threadlessly interconnect the header assembly components. Other embodiments are also described and claimed.

Abstract: An implantable medical device includes an electrode and an insulative material secured to the electrode via an adhesive. The electrode includes a metal substrate and a metal coating. The metal substrate includes a connection segment and an active segment along a length of the metal substrate. The metal coating is disposed on an outer surface of the metal substrate along the connection segment and the active segment. The insulative material surrounds the connection segment of the metal substrate without surrounding the active segment, and the adhesive adheres to the metal coating on the connection segment.

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 leadless biostimulator, such as a leadless pacemaker, including a header assembly having a monolithic controlled release device (MCRD) for therapeutic agent elution, is described. The MCRD is in fluid communication with a space between an insulator and an electrode of the header assembly to elute therapeutic agent into the space when the leadless biostimulator is implanted. The therapeutic agent can elute through the space around the electrode to provide controlled elution of the therapeutic agent to a surrounding environment. The electrode can extend longitudinally through the insulator cavity to a distal tip that provides a stable surface area and controlled impedance for pacing a target tissue. Other embodiments are also described and claimed.

Abstract: A leadless biostimulator, such as a leadless cardiac pacemaker, having a header assembly is described. The header assembly includes a helix mount mounted on a flange. An inner surface of the helix mount conforms to an outer surface of the flange, and the outer surface has a non-circular profile such that the conforming surfaces interfere with rotation of the helix mount relative to the flange. The non-circular profile includes a linear segment, such as a radial segment, that resists rotational movement of the helix mount. The helix mount has a protrusion that extends into a recess of the flange to interfere with longitudinal movement between the helix mount and the flange. The protrusion is formed before or after mounting the helix mount on the flange. The interfering surfaces threadlessly interconnect the header assembly components. Other embodiments are also described and claimed.

Abstract: A biostimulator, such as a leadless pacemaker, having electrode(s) coated with low-polarization coating(s), is described. A low-polarization coating including titanium nitride can be disposed on an anode, and a low-polarization coating including a first layer of titanium nitride and a second layer of platinum black can be disposed on a cathode. The anode can be an attachment feature used to transmit torque to the biostimulator. The cathode can be a fixation element used to affix the biostimulator to a target tissue. The low-polarization coating(s) impart low-polarization to the electrode(s) to enable an atrial evoked response to be detected and used to effect automatic output regulation of the biostimulator. Other embodiments are also described and claimed.

Abstract: A biostimulator, such as a leadless pacemaker, having electrode(s) coated with low-polarization coating(s), is described. A low-polarization coating including titanium nitride can be disposed on an anode, and a low-polarization coating including a first layer of titanium nitride and a second layer of platinum black can be disposed on a cathode. The anode can be an attachment feature used to transmit torque to the biostimulator. The cathode can be a fixation element used to affix the biostimulator to a target tissue. The low-polarization coating(s) impart low-polarization to the electrode(s) to enable an atrial evoked response to be detected and used to effect automatic output regulation of the biostimulator. Other embodiments are also described and claimed.

Abstract: A leadless biostimulator, such as a leadless cardiac pacemaker, having a header assembly that includes overmolded components, is described. The header assembly includes a helix mount overmolded on a flange of an electrical feedthrough assembly. A fixation element is mounted on the helix mount. The overmolded helix mount fills a recess in an outer surface of the flange to robustly join the header assembly components. The electrical feedthrough assembly includes an electrode contained within the flange to deliver electrical impulses to a target anatomy, and an insulator that separates the electrode from the flange. The overmolded helix mount can conform or adhere to the outer surfaces of the flange and the insulator to electrically isolate the electrode from the flange. Other embodiments are also described and claimed.

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.