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 implantable medical lead comprising a lead body defining a lumen. The lead body includes one or more tines substantially at a distal end of the lead body. An inner member extending within the lead body lumen is configured to rotate relative to the lead body and configured to cause a rotation of a dilator. The dilator is configured such that the rotation causes or enables a lateral translation of the dilator from a first position proximal to a lead body opening to a second position distal to the lead body opening. The implantable medical lead may include a probe wire configured to slidably translate through an inner lumen of the dilator.

Abstract: A relatively compact implantable medical device includes a fixation member formed by a plurality of fingers mounted around a perimeter of a distal end of a housing of the device; each finger is elastically deformable from a relaxed condition to an extended condition, to accommodate delivery of the device to a target implant site, and from the relaxed condition to a compressed condition, to accommodate wedging of the fingers between opposing tissue surfaces at the target implant site, wherein the compressed fingers hold a cardiac pacing electrode of the device in intimate tissue contact for the delivery of pacing stimulation to the site. Each fixation finger is preferably configured to prevent penetration thereof within the tissue when the fingers are compressed and wedged between the opposing tissue surfaces. The pacing electrode may be mounted on a pacing extension, which extends distally from the distal end of the device housing.

Abstract: A pacemaker is configured to operate in an atrial synchronous ventricular pacing mode and, after expiration of a conduction check time interval, switch to an asynchronous ventricular pacing mode that includes setting a ventricular pacing interval to a base pacing rate interval. The pacemaker is further configured to determine when atrioventricular block detection criteria are satisfied during the asynchronous ventricular pacing mode and, responsive to the atrioventricular block detection criteria being satisfied, switch back to the atrial synchronous ventricular pacing mode.

Abstract: An implantable medical device, such as a sensor for monitoring a selected internally detectable physiological parameter of a patient, is attached to a fixation assembly that is deployable within the patient to position and orient the sensor to enable it to perform its function. The fixation assembly is formed having at least one flexible asymmetric connector where each fixation member includes a plurality of loops, wherein a first loop of the plurality of loops has a maximum pitch that is different from a maximum pitch of a second loop of the plurality of loops. The attachment of the housing and the fixation assembly includes providing a tubular member that is welded to the housing and crimped over a section of the fixation assembly.

Abstract: A system includes an inflow loading assembly configured to compress an inflow portion of the implantable medical device as the implantable medical device is advanced through the inflow loading assembly. The system also includes an outflow loading assembly removably coupled to the inflow loading assembly. The outflow loading assembly is configured to partially compress an outflow portion of the implantable medical device during coupling to the inflow loading assembly. The inflow loading assembly includes one or more biasing features that are configured to asymmetrically compress the inflow portion of the implantable medical device.

Abstract: Systems, devices, and techniques are described for adjusting electrical stimulation based on detected ECAPs. In one example, a medical device includes processing circuitry configured to control stimulation circuitry to deliver a first electrical stimulation pulse and sensing circuitry to detect, after delivery of the first electrical stimulation pulse, an ECAP signal. The processing circuitry may be configured to determine a characteristic value of the ECAP signal, determine an ECAP differential value that indicates whether the characteristic value of the ECAP signal is one of greater than a selected ECAP characteristic value or less than the selected ECAP characteristic value, determine, based on the ECAP differential value, a gain value, determine, based on the gain value, a parameter value that at least partially defines a second electrical stimulation pulse, and control the stimulation circuitry to deliver the second electrical stimulation pulse according to the parameter value.

Abstract: An intracardiac ventricular pacemaker having a motion sensor is configured to produce a motion signal including an atrial systolic event and a ventricular diastolic event indicating a passive ventricular filling phase, set a detection threshold to a first amplitude during an expected time interval of the ventricular diastolic event and to a second amplitude lower than the first amplitude after an expected time interval of the ventricular diastolic event. The pacemaker is configured to detect the atrial systolic event in response to the motion signal crossing the detection threshold and set an atrioventricular pacing interval in response to detecting the atrial systolic event.

Abstract: An example medical device includes an optical sensor, processing circuitry, an antenna, and a power source. The optical sensor includes a light source; a reference optical beacon having a first fluorophore that emits a first fluorescence proportional to a first concentration of a substance proximate the beacon; a test optical beacon having a reagent substrate that reacts with an analyte to produce the substance and a second fluorophore that emits a second fluorescence proportional to a second concentration of the substance proximate the test beacon; and a photodetector to detect the first and second fluorescence. The processing circuitry determines a difference between the first and second fluorescence, which is indicative of the concentration of the analyte. The antenna and power source enable the medical device to operate completely within a biological system for continuous analyte monitoring.

Abstract: This disclosure describes implantable medical leads and medical device systems utilizing the leads. In some examples, an implantable medical lead comprises a first defibrillation electrode and a second defibrillation electrode, the first and second defibrillation electrodes configured to deliver anti-tachyarrhythmia shocks, and a pace electrode disposed between the first defibrillation electrode and the second defibrillation electrode, the pace electrode configured to deliver a pacing pulse that generates an electric field proximate to the pace electrode. The implantable medical lead further comprises a shield disposed between the first defibrillation electrode and the second defibrillation electrode and over a portion of an outer surface of the pace electrode, wherein the shield is configured to impede the electric field in a direction from the pace electrode away from a heart.

Abstract: A delivery system for delivery of a radially expandable device to an implantation site in a patient, the delivery system including an elongated tubular member comprising a distal tip and an outer surface, first and second balloon portions spaced proximally from each other and the distal tip along a length of the tubular member, an annular space between the first and second balloon portions, a plurality of clip deployment tubes extendably moveable relative to the outer surface of the tubular member, and a plurality of clips, wherein each clip is moveable within a length of one of the clip deployment tubes between a retracted position and a deployed position.

Abstract: An implantable medical device system is configured to sense cardiac events in response to a cardiac electrical signal crossing a cardiac event sensing threshold. A control circuit is configured to determine a drop time interval based on a heart rate and control a sensing circuit to hold the cardiac event sensing threshold at a threshold value during the drop time interval.

Abstract: An expandable introducer includes a hub having a distal end and a proximal end, and a sheath coupled to the hub and extending distally therefrom, the sheath defining a central lumen. The sheath is configured to radially expand from a radially unexpanded, folded state having a first diameter and to a radially expanded, unfolded state having a second diameter larger than the first diameter in response to a device passing through the central lumen. A wall of the sheath includes a thick wall region having a first wall thickness and a thin wall region having a second wall thickness smaller than the first wall thickness, wherein the thick wall region includes a coil embedded within the wall of the sheath.

Abstract: An implantable medical device includes an enclosure sleeve and a top cap. The enclosure sleeve comprises an enclosure wall with at least a portion of the enclosure wall comprising the grade 5 titanium and having a thickness between 0.007 inches and 0.009 inches. The enclosure sleeve includes an open top end and an open bottom end that is opposite the open top end. The top cap includes a feedthrough block, a first top cap end portion, and a second top cap end portion. The first top cap end portion is configured to couple to the open top end of the enclosure sleeve, and the second top cap end portion configured to be positioned within the enclosure sleeve.

Abstract: In some examples, a processor determines a patient state based on activity of a bioelectrical brain signal of a patient in one or more frequency sub-bands of a frequency band of interest. For example, a processor may determine a patient state based on the power level of a bioelectrical brain signal of the patient in one or more frequency sub-bands of a frequency band, or based on a spectral pattern of a bioelectrical brain signal in a frequency band, such as a shift in a power distribution between sub-bands, a change in the peak frequency within one or more sub-bands, a pattern of the power distribution over one or more frequency sub-bands, or a width or a variability of one or more sub-bands exhibiting a relatively high or low level of activity.

Abstract: An implantable medical device (IMD) includes a body, a fixation component, and an interface assembly. The body extends from a proximal portion to a distal portion along a longitudinal axis. The fixation component includes a penetrator tine. The penetrator tine includes an incisive distal end configured to penetrate a tissue to fix the IMD to the tissue. The electrode interface assembly includes a proximal section and a distal section. The proximal section is attached to and extends distally from the distal portion of the body along the longitudinal axis. The distal section extends from the proximal section of the electrode interface assembly and defines a non-incisive distal end. The distal end of the electrode interface assembly is configured to contact the tissue to control a depth of tissue penetration of the penetrator tine.

Abstract: Extravascular implant tools that utilize a bore-in mechanism to safely access extravascular locations and implant techniques utilizing these tools are described. The bore-in mechanism may include a handle and a helix extending from the handle. The bore-in mechanism is used, for example, in conjunction with a tunneling tool to traverse the diaphragmatic attachments to access a substernal location. The tunneling tool may be an open channel tunneling tool or a conventional tunneling tool (e.g., metal rod).

Abstract: A device, such as an IMD, having a tissue conductance communication (TCC) transmitter controls a drive signal circuit and a polarity switching circuit by a controller of the TCC transmitter to generate an alternating current (AC) ramp on signal having a peak amplitude that is stepped up from a starting peak-to-peak amplitude to an ending peak-to-peak amplitude according to a step increment and step up interval. The TCC transmitter is further controlled to transmit the AC ramp on signal from the drive signal circuit and the polarity switching circuit via a coupling capacitor coupled to a transmitting electrode vector coupleable to the IMD. After the AC ramp on signal, the TCC transmitter transmits at least one TCC signal to a receiving device.

Abstract: This disclosure is directed to techniques for detecting and mitigating inaccurate sensing in a medical system. In some examples, one or more sensors of the medical system may include at least one electrode configured to sense an impedance of a portion of a patient's body proximate to the electrode and processing circuitry of the medical system may detect an inaccuracy in the data corresponding to the one or more patient physiological parameters based upon data including at least the sensed impedance of the portion of the patient body; correct at least a portion of the inaccuracy in the data corresponding to the one or more patient physiological parameters; and generate, for display on a display device, output data indicating the inaccuracy in the data corresponding to the one or more patient physiological parameters.

Abstract: Occlusion apparatus comprise a radially expandable frame extending along a frame axis from a first axial end to a second axial end. The occlusion apparatus further comprise a first lattice of sutures extending across a first opening defined by the first axial end of the radially expandable frame. Methods are also provided that radially expand a frame from a radially collapsed orientation to a radially expanded orientation after retracting a capsule. Methods further comprise filling an interior area of the radially expandable frame with support material to facilitate maintenance of the radially expandable frame in a radially expanded orientation. The first lattice of sutures inhibits the support material from exiting the interior area through the first opening.