Abstract: In some examples, an implantable medical device delivery catheter comprises a handle and an elongated member disposed within the handle, the elongated member comprising an elongated member lumen configured to receive an inner tool that is configured to extend through a lumen of the delivery catheter, including the elongated member lumen, and interface with an implantable medical device. The handle further comprises a clamping assembly comprising a button configured to be actuated toward a longitudinal axis of the elongated member in a direction transverse to the longitudinal axis to compress the elongated member against the inner tool to restrain movement of the inner tool through the elongated member lumen.

Abstract: In some examples, 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. In some examples, 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. Distally-directed force applied to the button may cause the force transmitter to apply proximally-directed force to the slidable member, moving the slidable member and an attached pull wire proximally.

Abstract: A lead delivery apparatus and a method of delivering a medical lead to an anatomic target site. The method includes inserting a hydraulic plug into an internal delivery lumen of a delivery shaft, and coupling a medical lead to the hydraulic plug. Hydraulic pressure is applied to the hydraulic plug through the delivery lumen, thereby moving the hydraulic plug toward an anatomic target site, and advancing the medical lead toward the target site.

Abstract: This disclosure provides tools and implant techniques utilizing such tools to gain access to and implant a medical device, such as a medical electrical lead, within extravascular spaces. In one example, this disclosure provides a tool for creating a sub-sternal tunnel in a patient. The tool comprises a relatively straight guide member extending from a first end thereof to a second end thereof, a tunneling member extending from a first end thereof to a tip thereof, the tunneling member extending alongside and coplanar with the guide member, the first end of the tunneling member and the first end of the guide member being joined together, and a handle coupled to the guide member.

Abstract: Techniques of forming a foamed insulation material from gypsum waste are disclosed herein. One example technique includes mechanically comminuting the gypsum waste from an original size into particles of gypsum at a target size smaller than the original size and mixing the particles of the gypsum with a binder to form a mixture of particles and binder. The binder is configured to bind the particles of gypsum upon hydration. The example technique can further include performing air entrainment on the mixture until a foam is formed from the mixture having the particles of gypsum and binder. The foam has water that causes the binder to bind the particles of gypsum. The example technique can then include removing moisture from the mixture with the formed foam to form a foamed insulation material from the particles of gypsum.

Abstract: In some examples, a medical device delivery system includes a device cup configured to retain the medical device at the distal end of a catheter, the cup having a cylindrical body defining at least one vent hole extending from an exterior surface of the body to an interior surface of the body, and at least one internal rib extending inwardly from the interior surface, the rib configured to contact the medical device.

Abstract: In some examples, 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. In some examples, 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. Distally-directed force applied to the button may cause the force transmitter to apply proximally-directed force to the slidable member, moving the slidable member and an attached pull wire proximally.

Abstract: A reservoir of a system for deploying an implantable lead to an extravascular location delivers a flow of fluid through a lumen of one or both of a tunneling tool and an introducer of the system. In some cases, the tunneling tool includes a pressure sensor assembly for monitoring a change in a pressure of the flow through the lumen thereof. Alternately, or in addition, a flow-controlled passageway, through which the flow of fluid from the reservoir is delivered to the lumen of the introducer, includes a compliant chamber to hold a reserve of the fluid. Fluid from the reserve may be drawn into the lumen of the introducer as the tunneling tool is withdrawn therefrom. Alternately, the introducer may include a chamber located between two seals, wherein fluid that fills the chamber is drawn distally into the lumen of the introducer, as the tunneling tool is withdrawn therefrom.

Abstract: A tool includes a handle, a plunger actuator proximate the handle, a shaft extending from the handle, a plunger, an engagement mechanism. The shaft includes a proximal end and a distal end, and the shaft defines a channel extending along a length of the shaft. A first actuation of the plunger actuator causes the plunger to translate along the length of the shaft in a distal direction. A second actuation of the plunger actuator causes the plunger to translate along the length of the shaft in a proximal direction. The engagement mechanism is disposed on the distal end and is configured to engage an implantable medical device, and release the implantable medical device in response to the plunger exerting a contact force on the implantable medical device exceeding a reaction force of the engagement mechanism when the plunger translates along the length of the shaft in the distal direction.

Abstract: An active return curve deflectable catheter includes an elongate catheter body, a fixation member, a deflection assembly, and a pull wire. The fixation member is coupled to a distal portion of the elongate catheter body. The deflection assembly includes a hub coupled to a proximal end of the elongate catheter body, a handle, and a control member. The pull wire extends from the control member through the hub assembly to the fixation member. The elongate catheter body is configured to deflect from an initial configuration to a deflected configuration in response to a pull force applied to the pull wire by actuation of the control member in a first direction.

Abstract: An intracardiac ventricular pacemaker includes a pulse generator for delivering ventricular pacing pulses, an impedance sensing circuit, and a control circuit in communication with the pulse generator and the impedance sensing circuit. The pacemaker is configured to produce an intraventricular impedance signal, detect an atrial systolic event using the intraventricular impedance signal, set an atrioventricular pacing interval in response to detecting the atrial systolic event, and deliver a ventricular pacing pulse in response to the atrioventricular pacing interval expiring.

Abstract: An apparatus for forming a passageway through tissue includes a dilator mounted to a shaft, wherein the dilator includes a first portion, which has an increasing taper from a first outer diameter to a larger second outer diameter, and a second portion, which has a decreasing taper from the first portion to a distal end of the dilator, and which includes an external non-cutting thread formed along the decreasing taper. Lumens of the dilator and shaft provide a conduit for means to pierce through the tissue, for example, an elongate wire that includes a piercing tip. In some cases, the dilator first portion is expandable to, and contractible from, the larger second outer diameter, wherein the apparatus may include a spreading member configured to slide between the shaft and the first portion. The apparatus may be included in a system with an introducer sheath.

Abstract: A system for delivery of a leadless pacemaker. The system includes a catheter with an elongate flexible tubular body with a proximal end and a distal end, wherein the distal end of the tubular body includes a delivery cup with an external surface having an inflatable compliant balloon; and a pacing capsule of the leadless pacemaker releasably retained in the delivery cup. The pacing capsule includes an arrangement of tines configured to deploy and pierce a target tissue at a desired pacing capsule implant site in a coronary sinus of a patient. The balloon, when at least partially inflated, is configured to urge the delivery cup against the target tissue during deployment of the pacing capsule.

Abstract: A deflectable catheter includes an elongate member having a wall defining a longitudinally extending lumen extending from a proximal end to a distal end, a fixation member coupled to a distal portion of the elongate member, and a pull wire extending through the wall of the elongate member from the proximal end of the elongate member to the fixation member. The pull wire is coupled to the fixation member and constrained along its length such that the elongate member is configured to deflect from an initial configuration to a deflected configuration in response to a pull force applied to the pull wire and actively return from the deflected configuration to the initial configuration in response to a push force applied to the pull wire.

Abstract: In some examples, a system includes a catheter comprising an elongated shaft defining a lumen, and a tether assembly. The tether assembly may include an elongate body, a tether head assembly attached to a distal end of the elongate body, where the tether head assembly includes an attachment mechanism configured to releasably attach to an attachment member of a medical device, and a positioning element fixedly positioned over the elongate body and configured to align the attachment mechanism with the attachment member when the tether head assembly is extended distally out of the lumen. The positioning element may include a distal end, a proximal end, and a length between the distal end and proximal end that is less than a length of the elongate body. The tether head assembly, elongate body, and positioning element may be movable within the lumen of the elongated shaft.

Abstract: An active return curve deflectable catheter includes an elongate member, a fixation member, a deflection assembly, and a pull wire. The fixation member is coupled to a distal portion of the elongate member. The deflection assembly includes a hub assembly coupled to a proximal end of the elongate member, a handle, and a control member. The pull wire extends from the control member through the hub assembly to the fixation member. The elongate member is configured to deflect from an initial configuration to a deflected configuration in response to a pull force applied to the pull wire by actuation of the control member in a first direction.

Abstract: A deflectable catheter includes an elongate member having a wall defining a longitudinally extending lumen extending from a proximal end to a distal end, a fixation member coupled to an exterior surface of the wall on a distal portion of the elongate member, and a pull wire extending through the wall of the elongate member from the proximal end of the elongate member to the fixation member. The pull wire is coupled to the fixation member and constrained along its length such that the elongate member is configured to deflect from an initial configuration to a deflected configuration in response to a pull force applied to the pull wire and actively return from the deflected configuration to the initial configuration in response to a push force applied to the pull wire.

Abstract: A guide wire system configured to guide a medical device (e.g., a medical lead) to a target area within a patient. The guide wire system may be configured to penetrate and pass through a tissue wall in the patient to guide the medical device to the target area. The guide wire system includes a support section configured to expand to substantially maintain a position relative to the tissue wall. The guide wire system includes a pull wire configured to cause the support portion to expand. The expanded support section may provide counter-traction to a distal force on the tissue wall exerted by a medical device during, for example, fixation of the medical device to the target area, or other stages of an implantation. The support section is configured to re-establish an initial configuration for proximal withdrawal from the tissue wall.

Abstract: In some examples, a medical device system includes an electrode. The medical device system may include impedance measurement circuitry coupled to the electrode, the impedance measurement circuitry may be configured to generate an impedance signal indicating impedance proximate to the electrode. The medical device system may include processing circuitry that may be configured to identify a first component of the impedance signal. The first component of the impedance signal may be correlated to a cardiac event. The processing circuitry may be configured to determine that the cardiac event occurred based on the identification of the first component of the impedance signal.

Abstract: An intracardiac ventricular pacemaker includes a pulse generator for delivering ventricular pacing pulses, an impedance sensing circuit, and a control circuit in communication with the pulse generator and the impedance sensing circuit. The pacemaker is configured to produce an intraventricular impedance signal, detect an atrial systolic event using the intraventricular impedance signal, set an atrioventricular pacing interval in response to detecting the atrial systolic event, and deliver a ventricular pacing pulse in response to the atrioventricular pacing interval expiring.