Abstract: An implantable barometric pressure sensor coupled with an implantable medical device (IMD) provides a barometric pressure related, reference pressure value for use in combination with an absolute pressure value measured by an implantable absolute pressure sensor coupled to the IMD. In one embodiment, the barometric pressure sensor is implanted under the skin and subcutaneous tissue layer at or near the implant site of the IMD. In variations of this embodiment, the barometric pressure is formed as part of a connector module of the IMD or extends from the connector module. In a further embodiment, a percutaneous access device is provided which is adapted to be implanted to extend through the skin and subcutaneous tissue layer of the patient and is coupled with the barometric pressure sensor to provide for an air chamber extending between the atmosphere and the barometric pressure sensor.

Abstract: Power consumption in medical devices is reduced through the operation of circuits at clock speeds of lower levels to adequately complete desired functions during predetermined time periods (e.g., blanking interval, upper rate interval, etc.) just-in-time prior to subsequent required functional processes; by providing supply voltages tailored for various circuits of an integrated circuit; by operating two or more circuits of an integrated circuit at different clock frequencies; by changing the supply voltage level “on the fly” as required by specific circuit timing functions required for various circuitry based on clock frequencies used to control operation of such circuitry; and/or by tailoring back gate bias or adjusting back gate bias “on the fly” for circuits based on the supply voltage level applied to the circuits.

Abstract: A signal processor operates on a microprocessor or state machine based system to ensure that the central processing unit (CPU) and pulse generator (PG) have finished their instructions before allowing a new transition on the system master clock. The CPU and PG contain circuitry which allows them to indicate when they are busy. These signals are fed to the signal processor to indicate when the CPU and PG are ready to start another instruction. The signal processor functions to prevent a noise glitch on the system clock from causing another operation to start before the one in process has finished. The output of the signal processor becomes the master clock signal used by the system.

Abstract: An apparatus and method for communicating acoustic telemetry data produced by an implantable medical device over a communication channel includes a signal generator, a modulator, and an acoustic transmitter each provided in the implantable medical device. The modulator modulates a carrier signal with an information signal representative of information acquired or produced by the implantable medical device so as to produce a modulated information signal. The modulated information signal may have a frequency content that is readily accommodated by a public exchange communication channel. The transmitter transmits the modulated information signal as an acoustic information signal in a form communicable over the communication channel. The acoustic information signal may constitute telephonic tones which are directly communicable over a conventional telephone connection.

Abstract: An implantable medical device which preferably has a segmented looping memory for storing triggered physiologic events also has autotriggers to record the ECGs and any other relevant physiologic signals occurring during triggering events. The problem is that in the far field R-wave sensing is difficult because of noise. Denial and extensible accommodation periods are introduced into the R-wave sensing registration for triggering data storage. If the event is sensed during an accommodation period the sense will not add an R-wave sense to the trigger's count of R-waves. It may cause resetting of the trigger count in some circumstnaces. Typical triggering events may include arrhythmia's and syncopal events. Preferably the device can function without a microprocessor. An outside device or other patient activated manual trigger may be included. Auto triggers and manually set triggers may be of different sizes. Electrode spacing can be critical. Additional sensors may be provided to the device.

Abstract: An electrochemical cell and electrode assembly in which an alkali metal anode and a cathode assembly are wound together in a unidirectional winding having substantially straight sides such that the winding will fit into a prismatic cell. The anode and cathode are arranged in the winding to provide for even utilization of reactive material during cell discharge by placing cathode and anode material in close proximity throughout the electrode assembly in the proportions in which they are utilized. The winding also contributes to even utilization of reactive material by employing multiple tabs on the cathode assembly to ensure that cathode material is evenly utilized throughout the electrode assembly during cell discharge and also so that connections to the tabs are readily made.

Abstract: This invention relates to an intraluminal stent having a lumen-wall contacting surface and a lumen-exposed surface wherein the stent comprises a first polymer composition comprising fibrin and wherein the stent is suitable to deliver virus to the wall of a lumen of the body. The invention also relates to methods for making the stent and to methods for delivering nucleic acid to cells accessible from a wall of a body lumen.

Abstract: An implantable medical device (IMD) capable of monitoring physiologic data, distinguishing relatively noisy and noise free physiologic data, and recording noisy and relatively noise free segments of physiologic data in separate memory registers of a limited memory for retrieval and analysis at a later time. Preferably the physiologic data comprises the sampled EGM of the heart detected from sense electrode pairs that are implanted in the patient at sites where extraneous electrical noise, e.g., electromyographic signals, are also capable of being detected. The sense electrode pairs can constitute one or both sense electrodes located on or adjacent to the atrial and/or ventricular heart chambers and coupled to the IMD by a lead body or sense electrode pairs that are located remotely from the heart, e.g. at a subcutaneous implantation site of the IMD.

Abstract: Power consumption in medical and battery powered devices is reduced through the use and operation of multiple digital signal processing systems and through the application of different supply voltages to analog and digital circuits, respectively. 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. A source applies a first fixed supply voltage to the digital circuits of the medical or battery powered device and a voltage generation circuit (e.g.

Abstract: A body implantable pressure sensor attached to an endocardial lead for implantation in a heart chamber or cardiac blood vessel for sensing blood pressure and providing blood pressure signals to an implanted or external hemodynamic monitor and/or therapy delivery device and method of fabrication thereof. A pressure sensor module is formed of an elongated receptacle having an elongated receptacle cavity for receiving a calibrated, micro-machined pressure transducer having a pressure responsive element. The receptacle cavity is covered by a diaphragm disposed alongside the lead body and in parallel with the lead axis. The receptacle cavity is filled with a incompressible oil for transferring pressure forces that are applied to the diaphragm to the pressure transducer. The oil is introduced through a fill port, and the fill port is sealed after the oil is introduced to prevent leakage of the oil from the receptacle cavity and to complete the hermetic sealing of the receptacle cavity.

Abstract: An atrial lead system and a method of employing it to provide single electrode bi-atrial pacing. The system includes an atrial pacing lead having electrode located on a distal portion thereof and a guide catheter having a longitudinal lumen and a lateral aperture open to the longitudinal lumen of the catheter proximal to a distal end of the catheter through which the distal portion of the lead may be advanced. The electrode is preferably an active fixation electrode or is associated with an active fixation device. The system is employed by first advancing the guide catheter to the ostium of a patient's coronary sinus and inserting the distal end of the guide catheter into the coronary sinus such that the lateral aperture of the catheter is located in the patient's right atrium. The atrial pacing lead is then advanced through the lumen of the guide catheter such that the electrode exits the lateral aperture of the guide catheter and the electrode is affixed to the tissue of the atrial septum.

Abstract: A receiving and filtering circuit includes an antenna, a demodulator circuit coupled to the antenna, and a digital median filter that removes high frequency content of a demodulated digital information signal to produce a filtered digital information signal corresponding to an analog data signal transmitted by a body implantable medical apparatus. The digital filter may include a multiple stage delay line coupled to a multiple tap selection device, a plurality of delay blocks coupled to a register, or a multiple stage delay line coupled to a voting unit. The voting unit produces a first binary output in response to a majority of delay line stages storing a first value, and produces a second binary output in response to a majority of delay line stages storing a second value. The digital filter may also comprise a digital signal processor. The digital filter may include a first filter block and a second filter block. The second filter block may be selectively activated or bypassed.

Abstract: An accelerometer device which can be mounted on a substrate, e.g., a circuit board enclosed in a medical device, includes an accelerometer sensing element having an axis of sensitivity and further includes first and second multilayer end caps. The substrate generally defines a mounting plane. The accelerometer sensing element includes a device body having a longitudinal axis extending between generally parallel first and second ends thereof and further includes a principal surface extending between the first and second ends of the device body parallel to the longitudinal axis. The axis of sensitivity of the sensing element is generally perpendicular to a plane defined by the principal surface. Further, the accelerometer sensing element includes conductive pad regions on each of the first and second ends of the device body.

Abstract: Methods and apparatus for communication of implantable medical device (IMD) information, including interrogation of programmed parameter values, operating modes and conditions of operation, confirmation of programmed changes thereof, interrogation of data stored in the IMD, and patient warnings or other messages by RF transmission of audible sounds generated by the IMD are disclosed. The IMD includes an RF transmitter that broadcasts or transmits audible sounds including voiced statements or musical tones stored in analog memory correlated to a programming or interrogation operating algorithm or to a warning trigger event. The broadcast radio signal is received, and the audible sounds are demodulated and reproduced by a radio receiver as voiced statements or musical tones that convey human understandable messages comprising IMD information generated during programming and interrogation sessions and warnings or status messages to the patient at other.

Abstract: An introducer of the type employing an elongated introducer sleeve for receiving a catheter or lead body and an associated hemostasis clamp including a clamping member configured to engage the outer circumference of the introducer sleeve. The clamp is provided with a mechanism for maintaining the clamping member in engagement with said outer circumference of the sleeve to compress the outer circumference of the sleeve around a catheter or lead body inserted therethrough. In some embodiments the clamp takes the form of a hinged clamp provided with two jaws each having a recess adapted to engage a portion of the other circumference of the introducer sleeve. In other embodiments the clamp takes the form of interacting ramped members. The clamp is maintained in engagement with the sleeve either resiliently or by means of a latch.

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: An implantable system that includes a carrier and eukaryotic cells, which produce and release a therapeutic agent, and a stimulating element for stimulating the release of the therapeutic agent. The system can also include a sensing element for monitoring a physiological condition and triggering the stimulating element to stimulate the delivery device to release the therapeutic agent. Alternatively, the patient in which the system is implanted can activate the stimulating element to release the therapeutic agent.

Abstract: In a pacemaker, a method and apparatus for providing rate response in proportion to the patient's metabolic demand for cardiac output as determined in response to the patient's breathing rate or respiratory minute ventilation or contraction strength, optionally augmented by the patient's activity level. An implantable pulse generator (IPG) has one or more pacing leads having a proximal end coupled to the IPG and a distal end in contact with a patient's heart. A pressure wave transducer mounted in the IPG in relation to the proximal end of the pacing lead senses pressure waves transmitted from the distal end of the pacing lead to the proximal end thereof. The pressure waves originate from disturbances imparted to the lead by heart contractions and breathing. A further isolated, reference sensor is also incorporated into the IPG in a similar fashion. An activity signal processor is coupled to the pressure wave or reference sensor for providing a patient activity physiologic signal.

Abstract: The present invention generally relates to implantable medical devices and more particularly to various means for ultrasonically welding, swaging or staking various components in an implantable medical device, most preferably by employing appropriately configured covers or lids. Covers or lids are attached to header or connector modules mounted on an hermetically enclosed and sealed enclosure, where the connector or header module and enclosure comprise an implantable medical device. The covers or lids preferably trap or otherwise secure any of a number of various connector or header module components within the header or connector modules. Examples of such trapped or secured components include grommets, set screw connector blocks, seals, feedthrough wires, multi-beam contacts, electrical contacts, antennas, radio-opaque markers, connector ribbons and the like.

Abstract: A closed container is filled through a metal fill port which is then sealed with a rigid metal ball press fitted into the port passageway.