Abstract: A cardiac stimulator lead is provided that includes a connector for connecting to a cardiac stimulator and an insulating sleeve that has a first end coupled to the connector and a second end. The second end has an opening therein. An electrode is positioned in the insulating sleeve and has a piercing member. The electrode is moveable axially from a retracted position to an extended position wherein the piercing member projects from the opening. A conductor wire is disposed in the sleeve and coupled between the connector and the electrode for transmitting electric signals between the cardiac stimulator and the electrode. A lubricant is provided inside the insulating sleeve for lubricating the movement of the electrode. The lubricant reduces the potential for sticking, particularly for silicone lead sleeves.

Abstract: An implantable medical device including an enclosure and a header portion attached to the enclosure. The header includes a lead cavity into which a lead can be inserted. The lead cavity includes a compression device, such as a spring, for aligning a highly visible indicator plunger at least partially hidden from view inside the volume defined by an annular electrode, or other opaque object, partially surrounding the lead cavity. The plunger includes at least a portion that is easily visible to a surgeon during implantation of the medical device. When a lead is inserted into the lead cavity, the end of the lead pushes against the indicator plunger thereby moving the plunger and compressing the spring. When the lead is fully inserted into the lead cavity, the plunger becomes visible as it is pushed away from the volume defined by the annular electrode. In this way, the plunger provides a positive indication that the lead has been fully inserted into the header.

Abstract: A cardiac stimulator lead is provided that includes a connector for connecting to a cardiac stimulator and a tubular insulating sleeve that has a first end coupled to the connector and a second end. An electrode is coupled to the second end and has a longitudinal bore. An extendable/retractable corkscrew is positioned in the bore. In one aspect, the lead includes a radiopaque member moveable with the corkscrew to verify axial movement. In another aspect, the bore is configured so that the corkscrew will not extend fully unless tissue is present to engage the corkscrew. In another aspect, a shape-memory polymeric washer is included to restrict fluid influx after corkscrew deployment.

Abstract: An implantable endocardial defibrillation lead having a looped cable conductor for conducting at least high voltage defibrillation shocks. A coil electrode is connected to an elongated, flexible, electrically non-conductive lead body and is supplied with electrical power for delivering electrical shocks to the heart through a looped cable conductor that extends through the lead body and is associated with a power source.

Abstract: An implantable medical interventional device responds to detection of any of a plurality of cardiac dysrhythmias in a human patient by performing an appropriate therapy which may include cardiac pacing, cardioversion or defibrillation according to the nature of the detected dysrhythmia. A first sensor detects whether and what type of dysrhythmia is occurring. A generator produces pulses and/or shocks for delivery to the patient's heart according to whether a detected dysrhythmia is bradycardia or slow pathologic tachycardia on the one hand, or fast tachycardia or fibrillation on the other hand. An optimizer in the device at all times maintains a substantial match of the cardiac pacing rate to the hemodynamic needs of the implant patient under conditions of rest and physical activity; including sensing and distinguishing periods of patient physical activity and rest, and generating a signal representative thereof to control the cardiac pacing rate accordingly.

Abstract: An endocardial apparatus for pacing four chambers of a heart, comprising: a power source housed in an implantable can, first, second and third leads having proximal and distal ends, each lead being electrically connected to the power source at its proximal end and extending into a vein proximal the heart, the first lead connecting at its distal end to an electrode that is in electrical contact with the right atrium of the heart, the second lead connecting at its distal end to an electrode that is in electrical contact with the right ventricle of the heart, the third lead connecting at a point proximal its distal end to a first electrode that is in electrical contact with the inside of the coronary sinus and oriented so as to stimulate the left atrium of the heart and connecting at its distal end to a second electrode that is in electrical contact with the inside of the great cardiac vein and oriented so as to stimulate the left ventricle of the heart.

Abstract: In one aspect of the present invention, a cardiac lead is provided that includes a connector for coupling to a cardiac stimulator that has a first rotatable member, and a tubular insulating sleeve that has a first end coupled to the connector and a second end. A tip assembly is coupled to the second end. The tip assembly has a second rotatable member. A coiled wire is coupled between the first rotatable member and the second rotatable member. The coiled wire is composed of a shape-memory material and is operable to transmit torque between the first rotatable member and the second rotatable member. Where the lead is provided with a bend, the shape-memory coiled wire retains a straight set, enabling smooth rotation of a fixation corkscrew without precession of the lead tip.

Abstract: An interventional medical device has a capability to sense cardiac dysrhythmias and to selectively respond with one among a hierarchy of therapies appropriate to terminate the sensed dysrhythmia and return the heart of the patient in whom the device is adapted to be implanted to normal sinus rhythm. The device includes a therapy generator having a housing and electronics for conducting bidirectional communication with the patient. The bidirectional communication is carried out by detecting the occurrence of a predetermined dysrhytlnia, such as atrial fibrillation, to alert the patient of such occurrence, and by responding to instructions from the patient following such alert for addressing the detected predetermined dysrhythmia. The detection is performed by electrodes mounted directly on the header of the device housing to both detect occurrence of the atrial fibrillation and for alerting the patient thereof by stimulating body tissue such as pectoral muscle in the vicinity of the header electrodes.

Abstract: A medical interventional device is structured for implantation in a human patient, to respond to detection of cardiac activity of the patient indicative of cardiac dysrhythmias. The device includes a cardiac therapy system responsive to a detected arrhythmia in either the atrial or ventricular chambers for automatic therapeutic treatment by selective application of an appropriate therapy regimen consisting of pacing, cardioverting or defibrillating waveforms of predetermined type and energy content to the chamber diagnosed as that in which the dysrhythmia originated. The device incorporates a DDD or DDD-R pacemaker for dual chamber sensing of electrical (ECG) activity, and for constant pacing of the atrium and atrioventricular synchronization. A fuzzy logic subsystem is used for diagnosis including identification of the originating heart chamber.

Abstract: An implantable cardiac pacemaker is adapted to be selectively non-invasively upgraded from time to time after implantation to provide a plurality of different diagnostic, functional, and pacing operational modes in the form of respective combinations of single and dual chamber sensing and pacing and rate-adaptive pacing of a patient's heart to correct any of various cardiac arrhythmias attributable to cardiac pacing or cardiovascular disorders, and of extended memory and physiological monitoring functions. The pacemaker is implemented to make available the plurality of different pacing operational and other functional modes, and is programmable to selectively enable current operation of at least one of the available pacing operational modes according to current needs of the patient while inhibiting current operation of all other available pacing operational modes and any other non-selected functional modes.

Abstract: A connector apparatus system and method for providing a direct electrical connection to an implanted medical device for recharging batteries, reprogramming memory, or accessing data. The apparatus consists of a needle-like male connector in conjunction with an implantable female connector that is attached to the implanted medical device and contains a self-resealing elastomeric septum entry port. The female connector comprises a recepticle chamber that is densely packed with a plurality of randomly intertwining, thin, flexible, and conductive metal fibers. External battery charging equipment can be connected to the implanted medical device's internal battery with the connector apparatus system. The required circuit path for recharging can be completed by the use of two single polarity connector pairs, one single polarity connector pair in conjunction with a grounding plate, or one bipolar connector pair.

Abstract: A resistor may be embedded into a substrate. A portion of the resistor may be exposed, by segmenting the substrate, for instance, so that the resistor may be trimmed to a desired resistance level. Alternatively, a portion of a resistor may be embedded into a substrate, with another portion of the resistor being disposed on the outer surface of the substrate. The portion of the resistor on the outer surface may be trimmed to adjust the resistance of the resistor to a desired level.

Abstract: A cardiac lead joint assembly is provided for connecting a polymeric sleeve to a tubular metallic structure, such as the tubular metallic connector that connects to the header of a cardiac stimulator. The joint assembly includes a tubular metallic member, which may be the tubular connector, an electrode, or some other structure in the lead. The tubular metallic member has an annular groove formed on the exterior surface thereof. A polymeric annular member is disposed around the tubular metallic member and is seated in the annular groove. The polymeric sleeve is disposed over a portion of the tubular metallic member and is secured to the polymeric annular member by an adhesive. The joint assembly provides a polymer-to-polymer interface for adhesive bonding.

Abstract: A cardiac lead includes a connector for coupling to a cardiac stimulator and a flexible insulating sleeve having a first end coupled to the connector. An inner crimp sleeve is coupled to the insulating sleeve and an outer crimp sleeve crimped around the inner crimp sleeve. A first conductor wire is provided that has at least a first loop and a second loop. A second conductor wire is provided that has a third loop. The first and second conductor wires are spiraled together so that the third loop is positioned between the first and second loops and is crimped between the inner crimp sleeve and the outer crimp sleeve. The arrangement eases the passage of a stylet past the union of two wires, reducing the potential for stylet buckling. An aperture is provided in the outer crimp sleeve.

Abstract: A method and apparatus for evaluating heart rate variability of the heart of a person in order to forecast a cardiac event. A cardiac stimulator receives heart beat signals from the heart and determines a measurement of heart rate variability based on statistical data derived from the heart beat signals and sensing data derived from a sensor. This measurement of heart rate variability is compared with previously stored heart rate variability zones defining normal and abnormal heart rate variability. These zones are modifiable after the occurrence of a cardiac event. Once a cardiac event is detected, a pathway is computed which extends from a generally normal heart rate variability condition to an abnormal heart rate variability condition. Subsequent measurements of heart rate variability are compared with this pathway. Selective therapy regimes are initiated depending on the measurement of heart rate variability.

Abstract: A tubular sleeve is provided for enabling a physician to impart a preselected shape in an implantable tubular device, such as a cardiac lead, a catheter, or some other tubular structure. The sleeve may be deformed by the surgeon before or at the time of implantation to customize the shape of the tubular device to the particular anatomical structures to be encountered by the device. To retain the deformation imparted by the physician, the sleeve may be composed of a heat-sensitive shape-memory material or an elastomeric material provided with a plastically deformable rib.

Abstract: A cardiorespiratory monitor that generates bioimpedance sensing signals that produce substantially no interference with bioimpedance signals generated by implanted devices. The monitor detects the bioimpedance signal generated by the implanted device, using a voltage detector or a telemetry circuit, for example. The monitor analyzes this detected signal to generate a bioimpedance sensing signal that will not interfere with the sensed signal. For instance, if the monitor produces a pulsed sensing signal, the pulses are delivered in an interval of the detected signal where no pulses are present. Similarly, if the monitor produces a high frequency AC sensing signal, the zero crossings of the AC sensing signal are positioned during the delivery of a pulse by the implanted device.

Abstract: A cardiac stimulator lead is provided that includes a lead body that has a connector for coupling to a cardiac stimulator and a flexible insulating sleeve that has a first outer diameter. An electrode is coupled to the insulating sleeve. A conductor wire is coupled between the connector and the electrode. An annular seat is coupled to the lead body and is composed of a thermally-sensitive shape-memory polymeric material whereby the seal is deformable in situ from a temporary shape with a second outer diameter to a permanent shape with a third outer diameter that is greater than the second outer diameter. A shape-memory polymeric suture sleeve may be included that can tightly clamp the lead sleeve in situ.

Abstract: A cardiac pacemaker includes circuitry which receives a raw impedance signal from the sensor leads of the pacemaker, derives data from the impedance signal that is descriptive of the impedance signal over an entire (or a large part of the) cardiac cycle, develops first order parameters which define that cycle, and provides these parameters to a microprocessor for control of the pacing signal. These parameters may also be used to determine other information about the functioning of the pacemaker. The present invention may also be applied to the determination of tachycardia of an intrinsically paced heart, as well as other applications.

Abstract: A header assembly for coupling a cardiac lead to a cardiac stimulator is provided. The header assembly includes a header that has a bore for receiving one end of the cardiac lead. The bore has a first longitudinal axis. A connector housing is coupled to the header and has a second bore substantially aligned with the first bore. A biasing member is disposed within the connector housing and has a portion projecting into the second bore to bias the end of the cardiac lead against the walls of the second bore. A set-screw is threadedly coupled to the housing and is operable to secure the cardiac lead to the connector housing when tightened.