Abstract: A composition, article, and method for increasing the hydrolytic stability of a polymer; wherein a composition includes: a polymer comprising functional groups having hydrolyzable bonds; a carbodiimide compound; and a weak base (or hindered amine); wherein the carbodiimide compound and weak base (or hindered amine) are used in amounts effective to decrease the rate and/or extent of hydrolytic degradation of the polymer relative to either used alone in the same amount with the polymer.

Abstract: An implantable medical device includes ventricular and atrial portions, and a flexible leadlet that extends therebetween. An open channel of the atrial portion, formed along a core thereof, is sized to receive the leadlet therein, when the leadlet is folded over on itself. An interventional medical system includes the device and a delivery tool; a tubular sidewall of the tool defines a lumen and has a tether extending therein. A slot formed in the sidewall extends proximally from an open end thereof, coincident with a distal opening of the lumen. When the atrial portion is contained within the lumen, a segment of the leadlet extends alongside the atrial portion; another segment of the leadlet, being folded over on itself, proximal to the atrial portion, has the tether engaged therewith. The slot may allow passage of the leadlet therethrough, when the atrial portion is positioned for deployment through the distal opening.

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 medical delivery device for delivering a medical device includes a navigable elongated member, a deployment bay, and a compression mechanism. The deployment bay may be configured to house the medical device as the medical device is navigated to the target site. The deployment bay may be at a distal end of the delivery device and may include a distal opening through which the medical device may be deployed. The compression mechanism is configured to longitudinally compress in response to a predetermined force such that the elongated member and deployment bay are relatively closer together along a longitudinal axis of the delivery device.

Abstract: This disclosure describes various tools and associated methods suitable for gaining access to extravascular spaces. The various tools and associated methods utilize a boring tip that may rotate to aid in safely and effectively crossing diaphragmatic attachments. The boring tip may, in some instances not have any sharp edge. For example, the boring tip may have a dome shape but including at least one surface recessed and offset from a summit of the dome shape. Various mechanisms may be used to control rotation of the boring tip as described herein.

Abstract: Methods and systems for positioning a leadless pacing device (LPD) in cardiac tissue are disclosed. A delivery device is employed that comprises a proximal end, a distal end and a lumen therebetween sized to receive the LPD. The LPD has a leadlet extending therefrom that includes a means to fixate the leadlet to tissue. The delivery device comprises an introducer to introduce the LPD into the lumen of the delivery device. The LPD is loaded in the distal end of the lumen of the delivery device. The leadlet extends proximally from the LPD while the fixation means extends distally toward the LPD. A LPD mover is configured to advance the LPD out of the delivery device. A leadlet mover is configured to advance the leadlet out of the lumen delivery device and cause the leadlet to engage with cardiac tissue.

Abstract: This disclosure describes various examples of multi-purpose tools and associated methods for safely gaining access to extravascular spaces. The multi-purpose tools described herein are particularly suited for safely gaining access to the sub-sternal space underneath the sternum/ribcage as well as tunneling subcutaneously above the ribcage for the purpose of positioning of a medical electrical lead. This eliminates the need for separate tools for tunneling in different extravascular spaces by providing a single tool capable of the multiple uses.

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: This disclosure describes various tools and associated methods suitable for gaining access to extravascular spaces. The various tools and associated methods utilize a boring tip that may rotate to aid in safely and effectively crossing diaphragmatic attachments. The boring tip may, in some instances not have any sharp edge. For example, the boring tip may have a dome shape but including at least one surface recessed and offset from a summit of the dome shape. Various mechanisms may be used to control rotation of the boring tip as described herein.

Abstract: Methods and systems for positioning a leadless pacing device (LPD) in cardiac tissue are disclosed. A delivery device is employed that comprises a proximal end, a distal end and a lumen therebetween sized to receive the LPD. The LPD has a leadlet extending therefrom that includes a means to fixate the leadlet to tissue. The delivery device comprises an introducer to introduce the LPD into the lumen of the delivery device. The LPD is loaded in the distal end of the lumen of the delivery device. The leadlet extends proximally from the LPD while the fixation means extends distally toward the LPD. A LPD mover is configured to advance the LPD out of the delivery device. A leadlet mover is configured to advance the leadlet out of the lumen delivery device and cause the leadlet to engage with cardiac tissue.

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 frequency component and a second frequency component of the impedance signal, and provide an indication of a location of the electrode in a patient based on the first frequency component and the second frequency component.

Abstract: An improved assembly for securing an implantable medical device for retrieval from an implant site includes a plurality of snares, wherein distal openings of a first snare carrier lumen and a second snare carrier lumen have a pre-set offset established therebetween. First and second snare shafts, to which first and second snare loops are coupled, respectively, extend within the corresponding snare carrier lumens such that each loop is located in proximity to the corresponding distal opening of the lumen. The pre-set offset allows an operator to simultaneously position the snare loops around the device; and, when the operator retracts the snare shafts to collapse the snare loops until the loops fit snuggly around the device, the pre-set offset can help to align the device for retrieval.

Abstract: The present disclosure is directed to a shuttle apparatus for detachably joining a catheter to a guidewire so that the joined catheter, extending alongside the guidewire, is in sliding engagement with the guidewire without extending around the guidewire. The apparatus comprises a collar member sized for mounting in sliding engagement around a length of the guidewire, the collar member having a longitudinal axis that approximately aligns along the length, when mounted thereabout, the length being defined between a proximal-most point of the guidewire and a distal point of the guidewire, the distal point being offset proximally from a distal-most point of the guidewire. The apparatus further comprises a plug member coupled to the collar member, the plug member having a longitudinal axis, and the plug member being sized to fit within an opening of the catheter for detachable engagement therewith.

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 catheter assembly includes a pull wire and a control member subassembly, wherein the pull wire is secured to a post of the subassembly that may extend through a slot of a handle, and an engagement feature of the subassembly, being supported by an elastically deformable support of the subassembly resting on a railway of the handle, confronts a mating feature of the handle to interlock therewith, responsive to the support being un-deformed. The post, engagement feature, and support may be integrally formed together in a single-piece component, wherein the engagement feature may be one or two rows of teeth formed in a surface of an upper portion of the component, and the support may be a pair of flexible cantilever beam members of a lower portion of the component. Furthermore, the mating surface and railway may be integrally formed in an inner surface of a shell of the handle.

Abstract: A tool operable with a catheter in an interventional medical system retrieves a medical device from an implant site, wherein the device includes an attachment feature that forms an annular recess to be engaged by a lasso of the tool for snaring the device, and a distal-most sidewall of the catheter defines a receptacle into which the snared device is retrieved. A guide of the tool includes a sidewall defining a lumen in which the lasso extends for deployment out from a distal opening thereof, to snare and retrieve the implanted device. The sidewall establishes a radial offset between the guide lumen distal opening and the distal-most sidewall of the catheter, when the guide lumen distal opening and a distal opening of the receptacle are located in close proximity to one another, which radial offset is greater than a length of the annular recess formed by the device attachment feature.

Abstract: A catheter for delivering a medical device to an implant site within a receptacle of a distal-most portion thereof, includes a coiled spring member, which has one or more proximal turns, secured to a shaft proximal portion, one or more distal turns, secured to the distal-most portion, and a plurality of open-pitch turns that extend between the proximal and distal turns and are, preferably, pre-loaded by longitudinal compression prior to forming a sheath thereover. A deflection assembly pull wire extends through a lumen of the shaft proximal portion and alongside the plurality of open-pitched turns of the spring member, wherein a pull wire proximal end extends proximally out from a proximal opening of the lumen of the proximal portion and into a handle of the catheter, for coupling to a control member subassembly, and a pull wire distal end is secured to the shaft distal-most portion.

Abstract: A composition, article, and method for increasing the hydrolytic stability of a polymer; wherein a composition includes: a polymer comprising functional groups having hydrolyzable bonds; a carbodiimide compound; and a weak base (or hindered amine); wherein the carbodiimide compound and weak base (or hindered amine) are used in amounts effective to decrease the rate and/or extent of hydrolyic degradation of the polymer relative to either used alone in the same amount with the polymer.

Abstract: A lead delivery apparatus and a method of delivering a medical lead to an anatomic target site. An elongated lead advancement member is coupled to a delivery shaft. The delivery shaft is inserted to the target site. The delivery shaft is temporarily attached to the target site using a fixator. A medical lead is inserted over the lead advancement member and pushed over the lead advancement member toward the target site.

Abstract: A fixation mechanism of an implantable medical device is formed by a plurality of tines fixedly mounted around a perimeter of a distal end of the device. Each tine may be said to include a first segment fixedly attached to the device, a second segment extending from the first segment, and a third segment, to which the second segment extends. When the device is loaded in a lumen of a delivery tool and a rounded free distal end of each tine engages a sidewall that defines the lumen, to hold the tines in a spring-loaded condition, the first segment of each tine, which has a spring-biased pre-formed curvature, becomes relatively straightened, and the third segment of each tine, which is terminated by the free distal end, extends away from the axis of the device at an acute angle in a range from about 45 degrees to about 75 degrees.