Abstract: An implantable drug infusion device includes a bulkhead having a chamber and a shield for the bulkhead. A transducer is secured to the shield. An electronic module is located in the bulkhead for controlling operation of a pump assembly. A biasing member is in electrical contact with the electronic module and the transducer such that current transmitted from the electronic module to the transducer through the biasing member actuates the transducer.

Abstract: There is provided a pacemaker system having the capability of providing therapy for preventing conditions likely to lead to myocardial infarction or ventricular arrhythmia during patient morning time. Specifically, a therapy is initiated before calculated patient awakening time, for raising pacing rate slowly so as to shorten QT interval to an acceptable level relative to rate at the time of patient awakening, and specifically a level that achieves satisfactory diastolic filling time. The pre-awakening therapy pacing routine is designed to overcome normal QT prolongation which occurs during sleep state, and which is delayed after patient awakening. In the event that criteria for an acceptable diastolic filling time are not met at or after patient awakening, the pacemaker takes steps to control rate, such as ceasing synchronous pacing and limiting automatic rate response.

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: 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: 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 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 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 improved apparatus and method for evaluating platelet functionality of a blood sample. The apparatus includes a plurality of test cells. Each of the cells includes a platelet function restoration agent, an anticoagulant agent, and a clotting reagent. At least one of the cells also includes a platelet activating agent. The clotting time is determined for each of the aliquot portions, and the relative clotting times of the aliquot portions in the cells are determinative of the platelet functionality of the sample. The method includes the steps of combining a platelet function restoration agent, an anticoagulant agent, a platelet activating agent, and the sample of blood to be tested to form a test mixture. The platelets of the sample are activated by adding a clotting reagent to the test mixture at the start of the activated clotting time test, and the activated clotting time test is terminated upon detecting a predetermined change in a property of the test mixture.

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: The displacement of refill valves in an implantable drug delivery device is reduced to permit the housings of a drug delivery device to remain compact in size while permitting reservoirs of increased depth to be used. In a preferred embodiment, a collapsible link is provided as a telescoping member incorporating a coil spring. As the valve is pulled into contact with its seat, a detectable pressure increase is sensed in the refill device. In accordance with the invention, as the drug supply contained in the reservoir depletes, the reservoir surface moves towards a collapsed position, compressing the coil spring and eventually contacting the valve stem, thereby lifting the valve from its seat. By virtue of telescoping link, the valve stem length and therefore the valve travel may be reduced as compared to prior art devices, thus eliminating the need for increased housing depth when deeper reservoirs are used. The collapsible link may be comprised of a second spring combined with a telescoping link.

Abstract: An introducer system for a lead, catheter, probe or the like, employing a dilator and introducer sheath assembly for dilating a body vessel in preparation for introducing the lead, etc., through the lumen of the introducer sheath that provides for the injection of radiopaque contrast media to observe the cause of an impediment to advancement of the assembly into the vessel lumen. The dilator is formed of an elongated dilator body having a guide wire lumen therein for receiving and being advanced over the guide wire and a hub assembly at the proximal end of the guide wire body. An injection lumen is also formed in the dilator body isolated from the guide wire lumen and in fluid communication with a side port formed in the hub assembly and an injection port formed in the distal end of the dilator body. Preferably, the injection port is formed in a tapered distal end portion of the dilator.

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: A hub for connecting a medical catheter in fluid communication with a medical device, such as a syringe, includes a tubular shaped body member which has an outer surface that is formed with a plurality of grips. The hub also has a pair or diametrically opposed wings which extend from the outer surface of the body member and it has a proximal end which is formed as a female luer fitting for engagement with the medical device. The distal end of the hub is formed with a spiral strain relief element having a passageway which receives the proximal end of the medical catheter. In operation, the spiral relief element supports the medical catheter and prevents kinking of the catheter near the hub during flexure of the catheter by providing for a progressive transition from the relative rigidity of the hub to the flexure required by the catheter.

Abstract: The present invention discloses techniques for controlling abnormal involuntary movement (AIM) disorders as experienced by persons with Parkinson's disease under high dosage of levodopa by electrical stimulation and/or drug infusion. The present invention utilizes an implantable signal generator and an electrode and/or an implantable pump and catheter. High electrical stimulation pulses and/or drug therapy is provided to predetermined portions of the brain to blocking neural activity in the Centremedian-Parafasicularis nucleus thereby reducing activity in the medial pallidal nucleus (GPi) which, in turn, reduces the AIM disorder. A sensor may be used to detect the symptoms resulting from the AIM disorder. A microprocessor or algorithm may then analyzes the output from the sensor to regulate the stimulation and/or drug therapy delivered to the brain.

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 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: A prosthetic lamina that replaces a portion of the lamina bone structure is described. The prosthetic lamina may be configured with means for delivering a variety of medical treatments, such as electrodes for electrical stimulation, fluid channels, catheters for dispensing drugs and means for healing bone tissue.

Abstract: A pacing system and method for providing multiple chamber pacing of a patient's heart, and in particular, pacing programmed for treatment of various forms of heart failure. The system utilizes impedance sensing for determining optimum pacing parameters, e.g., for pacing the left ventricle so that left heart output is maximized. The impedance sensing also is used for determination of arrhythmias or progression of heart failure. Impedance sensing is provided for between selected pairs of the four chambers, to enable optimizing of information for control and diagnosis. In a preferred embodiment, impedance measurements are obtained for determining the timing of right heart valve closure or right ventricular contractions, and the timing of delivery of left ventricular pace pulses is adjusted so as to optimally synchronize left ventricular pacing with the right ventricular contractions.

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 medical device system such as a pacemaker system is provided wherein pressure signals representative of a patient's cardiac movements are transmitted through a pacing lead to the pacemaker, where they are sensed and utilized for control of pacemaker operation. In a preferred embodiment, the invention utilizes a standard pacing lead, which may already be in place within the patient, the lead having a lumen through which relative pressure signals are transmitted from the patient's heart to the proximal end of the lead. The proximal end of the lead is connected to a pressure sensor, mounted either in the pacemaker header portion or within the hermetically sealed pacemaker can. The sensor signals are coupled to appropriate processing circuitry and are used for control of one or more pacing parameters, such as pacing rate.