Abstract: A method and apparatus for detecting an RF signal transmitted between an implantable medical device (IMD) and an external medical device programmer in a telemetry session and discriminating the telemetry transmitted RF signal from transient and steady state noise corrupting it. The external programmer includes a programmer telemetry antenna tuned circuit adapted to be driven into oscillation to generate tuned circuit output signals in response to telemetry uplink transmissions of telemetry uplink signals from the IMD, wherein the tuned circuit output signals can exhibit noise artifacts due to contamination by electrical noise. An RF telemetry receiver section detects and demodulates the telemetry uplink signals from the tuned circuit output signals and provides a demodulated uplink signal having a demodulated uplink signal amplitude that varies with time as a function of telemetry uplink signal amplitudes and noise artifacts.

Abstract: A left atrium ablation catheter (4), including a sheath (8) and a deflectable electrophysiology catheter (10) housed within the sheath, is used to ablate coronary tissue at a target site within the left atrium (LA) of a heart. The electrophysiology catheter has ablation electrodes (24) along the tip (10). The ablation catheter is introduced into the right atrium (RA) through either the superior vena cava (SVC) or the inferior vena cava (IVC). The distal open end of the sheath is guided through a punctured hole in the interatrial septum and into the left atrium. The distal end (20) of the sheath is either precurved or is steerable so the electrode tip can be directed to the coronary target site in the left atrium. The electrode tip is sized and configured to create the desired lesion at the target site without movement of the electrode tip.

Abstract: A peripheral memory patch apparatus for attachment to a patient's skin includes a high capacity memory for storing physiologic data uplinked from an implantable medical device. A resilient substrate provides support for a memory, microprocessor, receiver, and other electronic components. The substrate flexes in a complimentary manner in response to a patient's body movements. The substrate is affixed to the patient's skin with the use of an adhesive which provides for comfort and wearability. The low profile peripheral patch apparatus is preferably similar in size and shape to a standard bandage, and may be attached to the patient's skin in an inconspicuous location. A status indicator provides for a visual, verbal, or tactile indication of the operational status of the peripheral memory patch.

Abstract: A cardiac pacing lead for pacing the atria and a method of its use. The lead is provided with a mechanism for maintaining an atrial pacing electrode adjacent stimulable tissue in a patient's superior vena cava and an additional electrode locatable in the right ventricle or elsewhere when the atrial electrode is so located One such mechanism for maintaing the atrial electrode's position may be a lead body displaying pre-formed laterally extending curves sized to span a patient's superior vena cava, with the atrial electrode located thereon.

Abstract: An implantable sensor assembly for use with an implantable medical device are disclosed. The sensor assembly preferably includes two or more physiologic sensors coupled to the medical device via a pair of lead conductors, or alternatively an oxygen sensor having certain features. The oxygen sensor permits more accurate and reliable measurement of oxygen saturation in blood masses flowing within the human body.

Abstract: A method and apparatus for determining the occurrence of a mis-location of an atrial electrode in a cardiac stimulation device having an atrial pulse generator coupled with the atrial electrode and a ventricular sense amplifier coupled to a ventricular electrode. The device paces the atrium in a first pacing mode employing atrial pacing pulses at a first energy level and in a test mode employs higher energy atrial pacing pulses. In the test mode the device measures PR intervals between atrial pacing pulses following sensed ventricular depolarizations and determines that the atrial electrode is mis-located responsive to occurrence of a threshold number of short PR intervals or that the atrial electrode is appropriately located responsive to occurrence of a threshold number of long PR intervals. Operation of the device in the test mode may be pre-conditioned on an absence of atrial tachyarrhythmia.

Abstract: A guidewire placed lead employing a seal at its distal end in order to prevent entry of body fluid into the lead. The seal is particularly designed to allow radial expansion of the outer circumference of the seal due to passage of the guidewire through the seal, reducing the force required to pass the guidewire through the seal, while retaining a good sealing characteristics. The seal may extend a distance distally from the tip electrode, and include a hollow, resilient, cup-shaped seal member, configured so that the seal can readily expand radially as the guidewire passes through it. Alternatively, the seal may be located within the body of the electrode and the electrode configured so that it may be radially or laterally expanded, also allowing radial expansion of the seal during passage of the guidewire. In this case, the electrode may be rendered expandable by means of one or more slits arranged along the electrode body, extending from a point proximal to the guidewire seal.

Abstract: A medical lead adaptor that provides a rapid, secure, insulated connection of the lead connector end assembly of a cardiac lead having electrodes adapted to be placed in or on the body with an external medical device is disclosed. The adaptor connector assembly is configured with an elongated receptacle to accept a bipolar, in-line, or a unipolar lead connector end sharing common dimensions. The elongated receptacle includes connector pin and ring receptacle contacts spaced apart from one another therein. In a preferred embodiment, an elongated slot that extends laterally of the elongated receptacle cooperates with a lock mechanism to allow the lateral insertion of the lead connector end assembly, with a stylet wire inserted into the cardiac lead body lumen, into the elongated receptacle. When inserted therein, the lead connector ring and/or pin are nested into contact with the ring and/or pin receptacle contacts and are held there by the lock mechanism.

Abstract: An implantable medical device determines activity levels and Heart Rate and from a combination of these produces a value for a heart rate activity coefficient (HRAC). This value has significant diagnostic and patient tracking value. Methods and apparatus for determining this HRAC value are described. This enables physician review of patient cardiac status. Additional physiologic data can be recorded along with the HRAC data if desired, and this too, as well as the HRAC data alone, may be reported out from the implanted device to a medical communications system for alarm purposes, titrating drugs/therapies or other monitoring tasks. Further, substitutes for heart rate measurements and activity measurements are described which can be used to augment or substitute for heart rate measurements and activity measurements.

Abstract: Power consumption in medical devices is reduced through the use and operation of multiple digital signal processing systems. Each processor of the multiple systems performs at least one particular function in a predetermined time period. The multiple digital signal processors of such systems can be operated at lower clock frequencies relative to those that would be required by one of such processors to complete the multiple functions within the predetermined time period. With reduced clock frequency, power consumption is reduced. Further, with reduced clock speed, supply voltages applied to such digital signal processors may also be reduced.

Abstract: A high energy density capacitor comprising an organic polymeric dielectric material having a dielectric constant of at least about 7; wherein the organic polymeric dielectric material comprises polymerized alkyl (alpha-substituted)acrylate monomers having at least one dipole group; wherein when the monomers are polymerized, the dipole group is attached to the main polymeric chain through a heteroatom-containing linking group.

Abstract: The present invention is a body implantable medical lead and method for constructing the lead. The lead has at least one electrode located along the lead body that is recessed from the outer surface of the lead body. The recessed electrode helps to prevent contact between the electrode and electrodes on a different lead when the different leads are brought into contact with each other.

Abstract: An implantable medical device such as a defibrillator is described. The device includes an hermetically sealed housing containing a flat electrolytic capacitor and an energy source such as a battery. The battery is connected to the capacitor and provides charge thereto. The capacitor stores the charge at a relatively high voltage. The charge stored in the capacitor is discharged through a defibrillation lead to a site on or in the heart when fibrillation of the heart is detected by the implantable medical device. Methods of making and using the implantable medical device, the capacitor, and their various components are disclosed.

Abstract: A cardiac pacemaker and a method of its use. The pacemaker paces a patient's heart in a tachyarrhythmia prevention pacing mode for an extended time period, defines a metric of success of the tachyarrhythmia prevention pacing mode, monitors the metric over the extended time period and, responsive to the monitored metric, adjusts the tachyarrhythmia prevention pacing mode. Adjustment of the tachyarrhythmia prevention pacing mode may take the form of pacing the patient's heart with a different set of electrodes, pacing the patient's heart with a different tachyarrhythmia prevention pacing mode and/or terminating operation of the tachyarrhythmia prevention pacing mode.

Abstract: An arrangement for introducing and implanting the electrode(s) of an endocardial implantable cardiac lead at a cardiac implantation site within a heart chamber or vessel. An elongated guide body formed of flexible material and extending between a guide body proximal end and a guide body distal end is advanced transvenously to position the guide body distal end in relation to the cardiac implantation site. A guide body tracking mechanism is coupled with the lead distal end for receiving and slidingly engaging the guide body to allow the cardiac lead to be advanced along the guide body until the electrode is positioned at the cardiac implantation site. A pusher mechanism formed of an elongated pusher body of flexible material extends between a pusher body proximal end and a pusher body distal end and has a cardiac lead engaging mechanism for engaging the cardiac lead at or adjacent the distal lead end.

Abstract: Power consumption in medical and battery powered devices is reduced through the use and operation of a data monitor which measures, senses or detects signals, inputs or outputs in a medical device before they are input to a principal or main digital signal processor, controller or microprocessor. In response to detecting or measuring such a signal which meets certain amplitude, frequency and/or phase characteristics, the data monitor directs or controls voltage supply circuits to increase or decrease the voltages provided to certain circuits within the medical device. The voltages so employed are tailored to reduce the amount of power consumed by the medical device while preserving computational performance.

Abstract: A lead and a lead system for dispersion of a cardioversion/defibrillation electrode formed of one or more small diameter defibrillation electrodes in a heart chamber and for attaching a pace/sense electrode in contact with the heart. The small diameter defibrillation electrode or electrodes extend distally from the distal end of the lead body. If multiple electrodes are employed, they are preferably biased to spread apart when unrestrained and have a cross-section size small enough to be inserted into interstices of trabeculae in the ventricular chamber. The distal ends of the defibrillation electrodes may be free of attachment to the lead body or may be attached by a weak bond to the distal portion of the lead.

Abstract: An implantable medical device for treatment of cardiovascular disorders by stimulating a selective nerve, the device including an implantable pulse generator, an implantable electrode body and a reservoir. The electrode body includes an electrode electrically connected to the pulse generator. Further, the electrode body is configured to sustain long-term contact between the electrode and the nerve. The reservoir maintains a nerve stimulating drug, such as a veratrum alkaloid, and defines a delivery surface through which the drug is released from the reservoir. Finally, the reservoir is operatively associated with the electrode body to deliver the nerve stimulating drug directly to the nerve. During use, the electrode and the delivered drug stimulate the nerve to effect control over the cardiovascular system of the patient.

Abstract: Techniques using one or more drugs, electrical stimulation or both to treat depression or manic depression by means of an implantable signal generator and electrode and/or an implantable pump and catheter. A catheter is surgically implanted in selected sites in the brain to infuse the drugs, and one or more electrodes are surgically implanted in the brain at selected sites to provide electrical stimulation.