Abstract: An apparatus includes a power adapter having a housing and a circuit at least partially disposed in the housing. The housing is configured to be coupled to an implantable device for disposition in a body. The circuit is configured to be electrically connected to a power circuit of the implantable device when the housing is coupled to the implantable electrical conductor. When the housing is coupled to the implantable electrical conductor and implanted in a body, the circuit is configured to (1) receive, transcutaneously from a power supply, a first energy, (2) convert the first energy to a second energy, and (3) transfer, to the implantable device, the second energy such that the second energy powers the implantable device.

Abstract: An implantable medical device (IMD) includes a heterogeneous housing configured to receive and store one or more components of the IMD. The housing includes an intrinsically non-conductive and non-magnetic base material and at least one dopant with a property of at least one of electrical conductance and magnetic permeability. The base material and the dopant form a first region of the housing including a first skin depth and a second region of the housing including a second skin depth different than the first skin depth.

Abstract: A medical lead with at least a distal portion thereof implantable in the brain of a patient is described, together with methods and systems for using the lead. The lead is provided with at least two sensing modalities (e.g., two or more sensing modalities for measurements of field potential measurements, neuronal single unit activity, neuronal multi unit activity, optical blood volume, optical blood oxygenation, voltammetry and rheoencephalography). Acquisition of measurements and the lead components and other components for accomplishing a measurement in each modality are also described as are various applications for the multimodal brain sensing lead.

Abstract: Implantation of a cardiac stimulus system using the intercostal veins. Superior, intercostal, and inferior access methods are discussed and disclosed. Superior access may be performed by entering the brachiocephalic vein from a jugular, subclavian, or other vein, and then accessing the internal thoracic vein, traversing a portion of the internal thoracic vein and then accessing an intercostal vein therefrom. Inferior access may be accomplished inferior to the lower rib margin via the superior epigastric vein, advancing superiorly into the internal thoracic vein and then accessing an intercostal vein therefrom. Intercostal access may include creating an opening in an intercostal space between two ribs and advancing a needle using ultrasound guidance to enter the intercostal vein directly.

Abstract: A method for subcutaneously treating pain in a patient includes first providing a neurostimulator with an IPG body and at least a primary, a secondary, and a tertiary integral lead with electrodes disposed thereon. A primary incision is opened to expose the subcutaneous region below the dermis in a selected portion of the body. A pocket is then opened for the IPG through the primary incision and the integral leads are inserted through the primary incision and routed subcutaneously to desired nerve regions along desired paths. The IPG is disposed in the pocket through the primary incision. The primary incision is then closed and the IPG and the electrodes activated to provide localized stimulation to the desired nerve regions and at least three of the nerves associated therewith to achieve a desired pain reduction response from the patient.

Abstract: Molded headers, implantable signal generators having molded headers, and associated systems and methods are disclosed herein. An implantable signal generator in accordance with a particular embodiment includes a can having a shell and a battery positioned at least partially within the shell. An output terminal can be operably coupled to the battery and positioned to provide electrical power to a signal delivery device. A pre-molded header having a plurality of openings can be coupled to the can, and the output terminal can be positioned at least partially within an individual opening.

Abstract: Communication and charging assemblies for medical devices are disclosed herein. A communication and charging assembly in accordance with a particular embodiment includes a support element, with a communication antenna and a charging coil coupled to the support element. The charging coil can include wire loops having a plurality of wires and the support element can include a mounting surface shaped to match the charging coil and the communication antenna. In one embodiment, the communication and charging assembly are mounted in a header of an implantable signal generator.

Abstract: A device and method for manufacturing an implantable cardiac monitor device are provided. The method joins a feed-through assembly to a device housing having electronic components therein. The feed-through assembly includes conductors having distal ends connected to the electronic components and has proximal ends projecting from the feed-through assembly. The method assembles a header having a sensing electrode and an antenna embedded within a non-conductive header body. The electrode and antenna includes corresponding interconnection plates. The header body includes a housing mounting surface that includes at least one passage aligned with an interconnect cavity that includes the interconnection plates. The header body further includes a window exposing the interconnect cavity and interconnect regions.

Abstract: Implementations described and claimed herein provide systems and methods for delivering and retrieving a leadless pacemaker. In one implementation, a leadless pacemaker has a docking end, and the docking end having a docking projection extending from a surface. A docking cap has a body defining a chamber. The docking cap has a proximal opening into the chamber. The proximal opening is coaxial with a longitudinal axis of a lumen of a catheter. A retriever has a flexible grasper with a first arm disposed opposite a second arm. Each of the first arm and the second arm form a hinge biased radially outwards from the longitudinal axis. The docking cap locks the first arm and the second arm on the docking projection when the body is sheathed over the retriever until the flexible grasper is disposed within the chamber.

Abstract: An electrical stimulation lead latching kit includes a connector having a housing that defines a lead lumen and a latching lumen that at least partially intersects the lead lumen; and a latching device including a latching pin, a handle, and an attaching element that attaches the latching pin to the handle. The latching pin has a longitudinal surface and is configured for insertion into the latching lumen, and the attaching element is configured to enable the latching pin to detach from the handle when the latching pin is in the latching lumen. When the latching pin is positioned in the latching lumen and a portion of an electrical stimulation lead or lead extension is positioned in the lead lumen, the longitudinal surface of the latching pin engages the electrical stimulation lead or lead extension to latch the electrical stimulation lead or lead extension to the connector.

Abstract: An lithium-iodine electrochemical cell and method of making is described. The cell comprises a lithium anode and a cathode of a charge transfer complex which includes iodine and preferably polyvinylpyridine. The iodine-containing cathode is in operative contact with both the anode the cell casing serving as the cathode current collector. Preferably the casing is composed of stainless steel that has been thermally annealed at temperatures of 1,800° F. or less. The annealed stainless steel has a grain size of about ASTM 7 or finer. When the iodine-containing cathode material in liquid form is filled into the casing, it contacts the inner casing surface. The passivation layer that subsequently forms at the contact interface affects cell impedance during discharge. It is desirable to maintain the internal impedance as low as possible.

Abstract: Medical devices provide metallic connector enclosures. The metallic connector enclosures may be constructed with relatively thin walls in comparison to polymer connector enclosures to aid in miniaturizing the medical device. The metallic connector enclosures may be constructed with interior surfaces that deviate less from an ideal inner surface shape in comparison to polymer connector enclosures to allow for better concentricity of electrical connectors. The metallic connector enclosures may include a panel that allows access to the cavity of the connector enclosure where set screw blocks, lead connectors, spacers, seals, and the like may be located. Furthermore, the lead connectors within the metallic connector enclosures may be separated from the metallic connector enclosure by being positioned within non-conductive seals that reside within features included in cavity walls of the connector enclosure.

Abstract: An implantable cardiac monitoring device and method of manufacture are provided. The device comprises a device housing having electronic components therein. A feedthrough assembly is joined to the device housing. The device comprises an antenna. A header body is mounted to the device housing and encloses the antenna and feedthrough assembly. The antenna includes a pin mounting section and a plate shaped radiating section. The pin mounting and radiating sections are interconnected by a ribbon section having a predetermined length to at least partially tune the antenna to a communication frequency. The radiating section is positioned proximate to, and shaped to extend along, an outer surface of the header body.

Abstract: An implantable medical device (IMD) includes a housing that is formed of a biocompatible material such as silicone. The housing includes integral contact receptacles that house individual contacts, which contacts are electrically connected to electrical circuitry within a main interior cavity of the housing. The integral contact receptacles receive electrode leads, and the contacts are aligned with electrode terminals on the proximal end of the electrode leads, which establishes an electrical connection between the electrical circuitry and electrodes at the distal end of the leads. The housing is filled with a silicone gel such as a tacky diphenyl silicone gel. The silicone gel provides electrical, mechanical, and thermal insulation, and prevents the ingress of bodily fluids when the IMD is implanted.

Abstract: Disclosed herein is an implantable electronic device for use with an implantable medical lead. The implantable electronic device includes a housing and a header connector assembly coupled to the housing and adapted to receive the proximal lead end of the implantable medical lead. The header connector assembly includes a connector assembly including a connector, a feedthru extending through the housing, and a conductor coupling the feedthru to the connector. The conductor includes a first conductor segment and a second conductor segment offset from the first conductor segment and each of the first conductor segment and the second conductor segment are resistance welded to the connector.

Abstract: A feedthrough assembly and methods of making the feedthrough assembly are shown. A feedthrough assembly including a ferrule disposed about an insulator and having an outer surface and a first aperture defined by an inner surface, wherein the first aperture is sized and shaped to include a reservoir for a braze material, the reservoir including a base, the base having a width sized to accommodate a preform of the braze material, and at least two ledges formed by the inner surface, each ledge having a first surface facing inwardly toward the insulator and a second surface facing upwardly is shown. Methods of making the feedthrough assembly including such a ferrule are shown.

Abstract: Technology is provided for a tracking constellation assembly for use in a virtual reality system. The tracking constellation assembly includes a translucent panel having an outward facing surface, and an inward facing surface and a mounting surface each opposite the outward facing surface. The translucent panel is substantially opaque to visible light and translucent to infrared light. The assembly includes a flexible circuit board including first and second opposed surfaces. A spacer interconnects the first surface of the flexible circuit board and the mounting surface of the translucent panel. Infrared light emitting diodes are connected to the flexible circuit board and positioned to direct light through the translucent panel.

Abstract: A pulse generator comprises a header connector assembly coupled with a housing. The header connector assembly includes a connector assembly and a header enclosing the connector assembly. The connector assembly includes an electrically insulative segment, a first electrically conductive segment, and a second electrically conductive segment axially spaced apart from the first electrically conductive segment by the electrically insulative segment. Each electrically conductive segment includes a connector ring, a spring housing and a spring supported by the spring housing. The connector ring and spring housing are in electrical communication with each other. The electrically insulative segment includes an insulator ring that is positioned between the first and second electrically conductive segments. The insulator ring includes a first end and a second end axially opposite the first end.

Abstract: A leadless pacing system includes a leadless pacing device and a sensing extension extending from a housing of the leadless pacing device. The sensing extension includes one or more electrodes with which the leadless pacing device may sense electrical cardiac activity. The one or more electrodes of the sensing extension may be carried by a self-supporting body that is configured to passively position the one or more electrodes proximate or within a chamber of the heart other than the chamber in which the LPD is implanted.

Abstract: An implantable medical device (IMD) has a housing enclosing an electronic circuit. The housing includes a shield member defining a first portion of an interior cavity of the implantable medical device and a skirted feedthrough assembly. The feedthrough assembly includes a shield extender having a top face and a sidewall that extends from the top face so that the top face and the sidewall are a single continuous component. At least one feedthrough aperture extends through the top face.

Abstract: Connector enclosure assemblies for medical devices provide an angled lead passageway. The lead passageway which is defined by electrical connectors and intervening seals within the connector enclosure assembly establishes the angle relative to a base plane of the connector enclosure assembly. Various other aspects may be included in conjunction with the angled lead passageway, including an angled housing of the connector enclosure assembly, feedthrough pins that extend to the electrical connectors where the feedthrough pins may include angled sections, and a set screw passageway set at an angle relative to the lead passageway to provide fixation of a lead within the lead passageway.

Abstract: Methods, systems, and devices are disclosed for wirelessly charging electronic devices. In one aspect, a wireless charging transmitter device includes a three-dimensional coil array electrically coupled to a power source and Power Source structured to include two or more coils to produce an electromagnetic field that emanates from the three-dimensional coil array, in which the coils are arranged such that at least two coils are perpendicular to each other to direct the electromagnetic field. The wireless charging transmitter device is operable to wirelessly charge an electronic device by providing the electromagnetic field at a receiver coil of the electronic device to convert the electromagnetic energy to electrical energy to power the electronic device.

Abstract: Systems and methods involve an intrathoracic cardiac stimulation device operable to provide autonomous cardiac sensing and energy delivery. The cardiac stimulation device includes a housing configured for intrathoracic placement relative to a patient's heart. A fixation arrangement of the housing is configured to affix the housing at an implant location within cardiac tissue or cardiac vasculature. An electrode arrangement supported by the housing is configured to sense cardiac activity and deliver stimulation energy to the cardiac tissue or cardiac vasculature. Energy delivery circuitry in the housing is coupled to the electrode arrangement. Detection circuitry is provided in the housing and coupled to the electrode arrangement. Communications circuitry may optionally be supported by the housing. A controller in the housing coordinates delivery of energy to the cardiac tissue or cardiac vasculature in accordance with an energy delivery protocol appropriate for the implant location.

Abstract: One aspect relates to a device including a hollow body, an inner volume and a surrounding volume. The inner volume includes an electronic component and the hollow body encloses the inner volume and includes a first component, a second component and an electrode. The first component is electrically conductive and the second component electrically insulates the electrode from the first component. The electrode includes a cermet, connects the inner volume to the surrounding volume in an electrically conductive manner, and includes a contact surface. The contact surface contacts eukaryotic tissue and has a maximum distance from the electronic component of less than 80 mm.

Abstract: A modular system of plastic walls having embedded and coextensive electrically conductive components configured to electrically connect with each other when the walls are mated. The walls have joining edges that form joint seams with other walls when joined together to create an enclosure. When enough walls are used to surround a storage space, a Faraday cage is created. The walls additionally have portions of tortuous paths at each joining edge that mate with a complementary portion of a tortuous path of another wall when the walls are joined together. A torturous path seal is thereby created at each joint seam. The plastic walls can be configured in a multiplicity of combinations to create various enclosures necessary for RFID-enabled storage and tracking of medical articles. Containers, enclosures, cabinets, and drawers of differing heights and sizes can be made and they may be stacked or otherwise assembled.

Abstract: The application of a titanium hydride coating on a ceramic, preferably an alumina ceramic, as a facile and inexpensive approach to bond gold to the ceramic during brazing is described. During the brazing process, the deposited titanium hydride is first partially decomposed to form pure titanium intermixed with titanium hydride. The combination of pure titanium and titanium hydride contributes to improved adhesion of gold with the alumina ceramic without any detrimental reaction between pure titanium and gold. The titanium hydride coating can be applied by dip/spray/paint coating.

Abstract: Disclosed herein is an implantable electronic device having a housing containing an electrical circuit. The implantable electronic device further includes an antenna assembly coupled to the electrical circuit. The antenna assembly has an antenna with a dielectric antenna body within which an antenna trace is disposed. Portions of the antenna trace are disposed in offset transverse layers in a non-overlapping arrangement, thereby reducing capacitive coupling between the layers of the antenna trace. In certain implementations, the antenna assembly has one or more capacitive features that selectively overlap portions of the antenna trace and facilitate tuning of the antenna.

Abstract: Embodiments presented herein are generally directed to a perioperative implant cover configured to cover at least a portion of an implantable component during portions of the perioperative period (i.e., preoperative, intraoperative, and postoperative phases of surgery) in which the implantable component is susceptible to bacteria contamination. By covering the implantable component during these portions of the perioperative period, the cover reduces the possibility of bacteria contamination and subsequent perioperative colonization.

Abstract: Systems and methods for implantable medical devices and headers are described. In an example, an implantable medical device includes a device container including an electronic module within the device container. A modular header core includes a header core module including at least one bore hole configured to receive a lead, an antenna attachment module coupled to the header core, and an antenna engaged with the antenna attachment module. The antenna attachment module is configured to locate the antenna in a selected position with respect to the header core module.

Abstract: In some examples, the disclosure relates to a medical device comprising a lead including an electrically conductive lead wire; and an electrode electrically coupled to the lead wire, the electrode including a first portion and a second portion, wherein the first portion defines an exposed outer surface of the electrode and is electrically coupled to the second portion along a first interface, wherein the second portion is electrically coupled to the lead wire along a second interface different from the first interface via welding to couple the lead wire to the electrode, wherein an electrical signal may be transferred between the lead wire and exposed outer surface of the first portion via the second portion, and wherein the first portion is formed from a first material having a first composition, and the second portion is formed from a second material having a second composition different from the first composition.

Abstract: An active implantable medical device comprising a therapeutic device, a controller and at least one rechargeable battery, wherein a single hermetically sealed housing encapsulates a therapeutic device, controller and rechargeable battery. A hermetically sealed housing additionally encapsulates a wireless interface and a commutator.

Abstract: In some examples, an implantable medical device (IMD) comprises an electrochemical cell compartment that may define a barrier between an inside of the compartment and an outside of the compartment. The IMD may include an electrically conducting pad. The IMD may comprise an electrically conducting pin coupled to the pad. The pad may include top and bottom sides. The pin may extend from the bottom side of the pad. The pad may be positioned outside of the compartment and the pin may extend through an aperture in the compartment from inside the compartment to pad positioned outside of the electrochemical cell compartment. The IMD may include an electrically insulating material surrounding the aperture and between the bottom side of the pad and the compartment. The insulating material may insulate the pad from the barrier and form a seal between the inside of the compartment and the outside of the compartment.

Abstract: An implantable active medical device includes a housing defining a hermetic cavity, a lead connector receptacle extending into the implantable active medical device, and a solid state light source disposed within the hermetic cavity and optically coupled to the lead connector receptacle.

Abstract: A leadless pacing system includes a leadless pacing device and a sensing extension extending from a housing of the leadless pacing device. The sensing extension includes one or more electrodes with which the leadless pacing device may sense electrical cardiac activity. The one or more electrodes of the sensing extension may be carried by a self-supporting body that is configured to passively position the one or more electrodes proximate or within a chamber of the heart other than the chamber in which the LPD is implanted.

Abstract: A medical lead is provided for use in a pulse stimulation system of the type which includes a pulse generator for producing electrical stimulation therapy. The lead comprises an elongate insulating body and at least one electrical conductor within the insulating body. The conductor has a proximal end configured to be electrically coupled to the pulse generator and has a DC resistance in the range of 375-2000 ohms. At least one distal electrode is coupled to the conductor.

Abstract: A device for providing an implantable lead with wireless energy, the device including: a housing configured for implantation in a patient's body; one or more non-inductive antennas substantially enclosed within the housing and configured to receive electromagnetic energy radiated from a source located outside of the patient's body; electronic circuitry coupled to each of the one or more non-inductive antennas and configured to extract electric power and excitation waveforms from the radiated electromagnetic energy as received by the one or more non-inductive antennas; and one or more connection pads substantially enclosed within the housing, wherein the connection pads are configured to couple with one or more electrodes in the implantable lead and form an electric connection over which the connection pads provide the extracted excitation waveforms from the electronic circuit to the electrodes in the implantable lead, the implantable lead being separate from the device.

Abstract: An implant includes a biocorrodible metallic material having a coating. The coating contains at least one layer in which ionic channels are embedded.

Abstract: An embodiment bump on trace (BOT) structure includes a contact element supported by an integrated circuit, an under bump metallurgy (UBM) feature electrically coupled to the contact element, a metal ladder bump mounted on the under bump metallurgy feature, the metal ladder bump having a first tapering profile, and a substrate trace mounted on a substrate, the substrate trace having a second tapering profile and coupled to the metal ladder bump through direct metal-to-metal bonding. An embodiment chip-to-chip structure may be fabricated in a similar fashion.

Abstract: An implantable medical device includes an enclosure having a sidewall and a welded seam in the sidewall, the seam extends along a perimeter of the enclosure. A thermoform is located adjacent a surface of the enclosure and is secured in place within the enclosure. A metalized surface is located adjacent an interior surface of the enclosure sidewall and is secured in place by the thermoform. The metalized surface extends along a perimeter of the enclosure and is configured to obstruct laser energy during a weld seam process. The metalized surface may be provided as a separate backup band component or may be integrated in a perimeter sidewall of the thermoform.

Abstract: Disclosed are a housing for a medical implant, a medical implant for a human or animal organism, a method for manufacturing a medical implant, and a system comprising a medical implant and a transceiver unit that can be coupled to the medical implant.

Abstract: An Implantable Medical Device (IMD) is disclosed having a bi-directional short-range far-field Radio-Frequency (RF) data antenna, operable in accordance with a short-range RF standard such as Bluetooth for example. The antenna is neither located inside the conductive case of the IMD, nor in the non-conductive header of the IMD that includes the lead connectors. Instead, the antenna is outside of the case, proximate to and generally planar with a flat planar side of the case that faces outward of the patient when the IMD is implanted. Dielectric materials keep the antenna from shorting to the case and to the patient's tissue. Because the antenna is not located within the conductive case, data communications to and from the antenna are less subject to attenuation. Not locating the antenna in the header reserves room for the header's lead connectors, thus simplifying IMD design.

Abstract: The function of a strain relief loop of an implantable medical lead is preserved by inhibiting restriction of the strain relief loop from tissue growth onto the strain relief loop. The restriction may be inhibited by either obstructing tissue growth and/or by utilizing a mechanical advantage to overcome the restriction. The tissue growth may be obstructed be isolating the interior of the strain relief loop such as by enclosing the strain relief loop or including an object within the loop. The mechanical advantage to overcome restriction from tissue growth may be provided in various ways such as utilizing a spring loaded mechanism or a structure such as an elastic mesh, tube, or mold having an inherent bias toward a steady state position.

Abstract: Various fixation techniques for implantable medical device (IMDs) are described. In one example, an assembly comprises an IMD; and a set of active fixation tines attached to the IMD. The active fixation tines in the set are deployable from a spring-loaded position in which distal ends of the active fixation tines point away from the IMD to a hooked position in which the active fixation tines bend back towards the IMD. The active fixation tines are configured to secure the IMD to a patient tissue when deployed while the distal ends of the active fixation tines are positioned adjacent to the patient tissue.

Abstract: A hybrid system forming an active implantable medical device includes a subcutaneous autonomous capsule and at least one intracorporeal autonomous leadless capsule. The subcutaneous capsule is a hybrid capsule having a seal body of dimensions comparable to those of a leadless capsule, but extended by a detection/stimulation microlead, without any intermediate connector. The leadless capsule includes a seal body, anchoring means in a wall of an organ and a detection/stimulation electrode. The hybrid capsule and the leadless capsules each include transmitter/receiver means for intracorporeal mutual wireless communication so as to constitute a network wherein the hybrid capsule is the master and leadless capsules are the slaves. The hybrid capsule further includes means for centralizing data transmitted by the leadless capsules and for exchanging data with remote external equipment.

Abstract: An implantable magnetic resonant imaging (MRI) safe stylus for biomedical devices is described. In one example, the stylus includes a set of stylus modules. One or more of the stylus modules includes a core rod formed of silicon carbide (SiC) material, a recording array mounted on the core rod, and a stimulation array mounted at a distal end of the core rod. The stylus also includes a hemispherical cap formed of SiC material. In part due to the construction and choice of materials used in the stylus, it does not substantially couple with electromagnetic fields during an MRI, for example. Therefore, the stylus does not produce excessive additional heat. The designs described herein also rely on the high thermal transport but low heat capacity of SiC to provide a thermal pathway which will conduct induced heat throughout the stylus, to dissipate heat more evenly.

Abstract: Frame structures, assemblies and methods for use in implantable medical devices. The frames may include one or more first polymeric portions and one or more second polymeric portions coupled to the one or more first polymeric portions. The one or more first polymeric portions may have a higher durometer than the one or more second polymeric portions. The one or more second polymeric portions may provide an interference fit between the one or more second polymeric portions and the housing and/or between the one or more second polymeric portions and one or more components disposed in the housing.

Abstract: A method of preparing an article having a slippery surface includes providing a metal-containing surface, chemically modifying the metal-containing surface to roughen the metal-containing surface, and disposing a lubricating layer on the roughened metal-containing surface, wherein the lubricating layer is substantially stabilized on the roughened metal-containing surface.

Abstract: Technology is provided for a tracking constellation assembly for use in a virtual reality system. The tracking constellation assembly includes a translucent panel having an outward facing surface, and an inward facing surface and a mounting surface each opposite the outward facing surface. The translucent panel is substantially opaque to visible light and translucent to infrared light. The assembly includes a flexible circuit board including first and second opposed surfaces. A spacer interconnects the first surface of the flexible circuit board and the mounting surface of the translucent panel. Infrared light emitting diodes are connected to the flexible circuit board and positioned to direct light through the translucent panel.

Abstract: One aspect is a method of fabricating a housing for an implantable medical device, including forming a first housing portion of metal using an additive manufacturing process such that features are integrated into the first portion. A second housing portion of metal is also formed. The first and second housing portions are joining thereby sealing an internal space of the housing within first and second portions and fully containing the features such that they are hermetically sealed relative to an external space outside the housing.

Abstract: Techniques and systems for monitoring cardiac arrhythmias and delivering electrical stimulation therapy using a subcutaneous device (e.g. subcutaneous implantable (SD)) is described. In one or more other embodiments, SD is implanted into a patient's heart. Electrical signals are then sensed which includes moderately lengthened QRS duration data from the patient's heart. A determination is made as to whether cardiac resynchronization pacing therapy (CRT pacing) is appropriate based upon the moderately lengthened QRS duration in the sensed electrical signals. The CRT pacing pulses are delivered to the heart using electrodes. In one or more embodiments, the SD can switch between fusion pacing and biventricular pacing based upon data (e.g. moderately lengthened QRS, etc.) sensed from the heart.