Abstract: An ECG signal detection device that includes a differential amplifier input circuit and a driven reference electrode lead is disclosed. More specifically, the ECG signal detection device includes a differential amplifier input circuit and three-electrode leads, two of which terminate at a common patient coupling device such as an electrode pad or a defibrillator paddle. The third electrode lead terminates at a second, separate patient coupling device. Two electrical cords that include the electrode leads extend between the patient coupling devices and the differential amplifier input circuit. One electrical cord includes the two-electrode leads that terminate at the common patient coupling device.

Abstract: A method and apparatus for cardiac pacing are provided in which pacing pulses are delivered at an increased rate in response to a detected intrinsic heart rate drop and a special rate drop response detection scheme is temporarily disabled until an intrinsic heart rate exceeds a predetermined threshold value. If the pacing rate reaches the lower pacing rate without sensing intrinsic activity, heart rate drop detection remains disabled and lower rate pacing continues. Rate drop detection is re-enabled whenever sufficient sensed intrinsic activity indicates that a sudden intrinsic rate drop could occur again. Thus, the subsequent reduction in heart rate requiring therapy is declared only if a sensed intrinsic heart rate drops from above an intermediate value (herein defined as a re-enable rate) that is set above the lower pacing rate and an upper pacing rate.

Abstract: A method and system nodal rhythm detection and treatment is provided. Detecting consecutive atrial events within a nodal activity window around ventricular events identifies nodal rhythm. Nodal rhythm is treated by calculating and applying a new atrial escape interval adjusted by the interval between the atrial and ventricular events.

Abstract: On occasion, a physician may wish to monitor, test, adjust, or otherwise interact with an implantable medical device (IMD) implanted in the body of a patient, but the patient is not physically present. The physician may receive information from the IMD remotely. To better prompt the physician to recall the patient, the invention provides techniques for presenting the image of the patient, along with information pertaining to the IMD implanted in the patient. In one embodiment, the invention is directed to a method that includes storing a digital image of a patient in memory in the IMD. In other embodiments the invention is directed to methods for communicating information so that an image of the patient may be presented along with information pertaining to the IMD.

Abstract: A deflectable stylet system optimized for use in conjunction with a lead of the type having a fixation helix that is screwed into body tissue by rotation of the lead's connector pin is disclosed. The system includes an attachment that is rotatable and longitudinally slidable with respect to the handle of a deflectable stylet. A lead coupled to the attachment may be moved longitudinally with respect to a stylet to account for slight variances in the lead length. In one embodiment, the attachment couples to the lead via a pushbutton mechanism that can be locked to the lead using one hand. The attachment may be rotated to thereby rotate the lead connector. This allows for retraction and extension of a retractable fixation helix, and for further attachment or detachment of a fixation helix to adjacent tissue. In one embodiment, the attachment may be longitudinally rigidly positioned in predetermined locations with respect to the handle.

Abstract: An information remote monitor (IRM) is implemented to collect medical device data locally in a patient's home for transmission to a remote location. Specifically, the IRM integrates data from an external pressure reference (EPR) and an implanted medical device (IMD), preferably the Chronicle™, for remote transmission to a server or a clinical center for follow-up, monitoring and evaluation. The IRM utilizes wireless telemetry to downlink to the IMO and directly engages the EPR to download barometric pressure data to correct cardiac pressure readings from the Chronicle™ or IMO. The IRM may be connected serially to a PC and the PC may control the functions of the IRM. In the alternate, the PC may be used to transfer data from the IRM, through a Web-enabled network system, to a server or a remote location. The IRM utilizes an integral modem to dial a server and transfer patient data via FTP, PPP and TC/PIP protocols.

Abstract: A capacitor structure comprises a shallow drawn encasement having first and second major sides and a peripheral wall coupled to the first and second sides. A cathode is disposed within the encasement proximate the first and second major sides, the cathode having a cathode lead. A central anode a having an anode lead is disposed within the encasement, and a bipolar, insulative feedthrough extends through the encasement through which electrical coupling may be made to the anode lead and the cathode lead.

Abstract: An anode-limited battery and method of assembly are provided in which a lithium anode subassembly is constructed from two pieces of lithium foil. An elongated thicker piece of lithium foil is cohesively bonded at one end to a shorter, thinner piece of lithium foil. An optional current collector stabilizes the area of the cohesive bond. The thicker lithium foil forms the inner windings of a coiled electrode, which face reactive cathode material on both sides. The thinner foil forms the outermost winding, which faces reactive cathode material on only one side. Thus, an appropriate amount of lithium is available for cathode discharge. The method of electrode assembly allows a narrow tolerance of the lithium anode such that the benefits of an anode-limited cell may be realized.

Abstract: In one embodiment, a testing regimen is implemented to reduce test time. Specifically, a structure and method to power up and stabilize all die on the wafer prior to testing each die is implemented. More specifically, parallel powering schemes including die stabilization procedures are used to ready the wafer for testing. A wafer probe tester is indexed from one die to the next for an uninterrupted testing of all die in the wafer subsequent to all die power up and stabilization.

Abstract: A method for the treatment of a stenosis or an occlusion in a blood vessel in which an occlusive device is first delivered and activated at a site distal to the occlusion to at least partially occlude the vessel. A therapy catheter is then introduced to treat the occlusion and a debris removal device is delivered to aspirate debris from the vessel. The present invention eliminates the need for a separate irrigation catheter and irrigation fluid which allows the procedure to be performed quickly and efficiently, and is especially useful in the removal of occlusion from saphenous vein grafts, the coronary and carotid arteries, arteries above the aortic arch and vessels of similar size and pressure.

Abstract: A drive mechanism for delivery of infusion medium. A coil surrounds a piston channel. An armature is located adjacent the coil. The armature is moveable toward a forward position in response to the electromagnetic field produced by activation of the coil. A piston located within the piston channel is moveable within the channel to a forward position in response to movement of the armature. The armature and piston are moved toward a retracted position when the coil is not energized. In the retracted position, a piston chamber formed between the piston and a valve member is filled with infusion medium. As the piston is moved to its forward position, piston chamber volume is reduced and pressure within the piston chamber increases and moves the valve member into an open position. Medium from the piston chamber is then discharged into an outlet chamber.

Abstract: An improved system and method for detecting dislodgement of an implantable medical device (IMD) such as a catheter or lead is disclosed. The system includes means for generating multiple, orthogonally-related signals within a body. For example, three current signals having a current path substantially oriented in the X, Y, and Z directions may be generated within the body. The invention further includes an IMD having an affixation device such as a helix at a distal tip for attachment to body tissue, and at least two sensing devices to sense the signals generated within the body. The difference in signal levels between two of the sensing devices may be measured. For example, a voltage potential difference created by the currents within the body may be measured between two electrodes. This measured signal level has components in the X, Y, and Z directions, and may therefore be used to define a directional vector in three-dimensional space. This vector is indicative of the orientation of the IMD.

Abstract: A shape memory alloy (SMA) actuator includes a groove formed in a surface of a shape memory alloy (SMA) substrate establishing a trace pattern for a layer of conductive material formed over an electrically insulative layer. The trace pattern includes a first end, a second end, and a heating element disposed between the first and second ends. The SMA substrate is trained to deform at a transition temperature achieved when electricity is conducted through the conductive material via first and second interconnect pads terminating the first and second ends of the trace pattern.

Abstract: An electrically insulative layer of a shape memory alloy (SMA) actuator includes an inorganic material formed upon a portion of an SMA substrate. A conductive material formed upon a portion of the electrically insulative layer in a trace pattern includes a first end, a second end, and a heating element disposed between the first and second ends. The SMA substrate is trained to deform at a transition temperature achieved when electricity is conducted through the conductive material via first and second interconnect pads terminating the first and second ends of the trace pattern.

Abstract: A balloon catheter includes an inflation shaft and an elongated guidewire shaft. A relatively short, distal portion of the guidewire shaft is attached to, or enveloped within, a distal portion of the inflation shaft. A proximal portion of the guidewire shaft is detached from and independent of a proximal portion of the inflation shaft. The detached portion of the guidewire shaft contains perforations at pre-determined points along its length that define removable segments thereof. The removable segments remain attached to the guidewire shaft under normal conditions, but may be torn away from the guidewire shaft to provide access to a guidewire within a guidewire lumen thereof.

Abstract: A patient-controlled system for temporarily disabling an electrical cardioverting therapy in order to prepare the patient psychologically and physiologically for the pain associated with electrical cardioversion therapy. In an example embodiment, the system includes a capacitive circuit capable of charging and discharging in order to apply the electrical therapy. The implanted medical device automatically causes the capacitive circuit to charge and discharge at least once within a selected period. The system includes a patient activator device that communicates with the implanted device. A disabling circuit is also included within the implanted medical device that temporarily disables the electrical therapy application in response to the patient activator device. The system further includes an alerting arrangement that alerts the patient activator device in response to the disabling circuit.

Abstract: Bi-Ventricular or AV synchronous cardiac pacing systems that pace and sense in at least one atrial heart chamber and deliver ventricular pacing pulses to right ventricular (RV) and left ventricular (LV) sites separated by a V—V delay for treatment of heart failure are disclosed that optimize one or more of the AV delay and V—V delay to enhance left ventricular filling and cardiac output as a function of QRS duration. A system and method for monitoring the QRS duration, processing such signals to provide data from which the onset or progression of heart failure is determined, and adjusting synchronous pacing delay parameters including SAV delay and/or PAV delay and/or V—V delay to enhance cardiac output as a function of QRS duration is provided. The SAV, PAV, and/or the V—V delays can be varied from the prevailing delays as a function of measured QRS duration so as to minimize the width of the QRS complex.

Abstract: Methods for anodizing sintered valve metal anodes for use in wet electrolytic capacitors implemented in implantable medical devices (IMDs). The methods generally include immersing a pressed valve metal anode in an anodizing electrolyte and developing an anode-electrolyte system. Subsequently, subjecting the anode-electrolyte system to a potential that is ramped up to a target voltage in a pulsed fashion and delivering voltage potential pulses to the anode. The pulses are preferably decreased in pulse width as the potential increases. The pulse width of the applied pulses is preferably defined by means of a duty, such that the applied pulse duty cycle is substantially 100% initially and declines over the formation time as the formation voltage increases to the target potential to substantially 1.0% or less. The pulses are preferably applied for a hold time following achievement of the target formation potential, as the pulse current declines toward zero current flow.

Abstract: A medical information communication system and corresponding methods are described. The system permits monitoring the performance of an implantable medical device (IMD) implanted within a body of a patient, monitoring the health of the patient, or remotely delivering a therapy to the patient through the IMD. The IMD is capable of bi-directional communication with a communication module, a mobile telephone and/or a Personal Data Assistant (PDA) located outside the patient's body. The system may comprise the IMD, the communication module and/or a mobile telephone and/or a PDA, a remote computer system, and a communication system capable of bi-directional communication, where the communication module, the mobile telephone and/or the PDA are capable of receiving information from the IMD or relaying information thereto.

Abstract: An improved switching system for use with an implantable medical device (IMD) is described. The system utilizes Micro-Electrical-Mechanical system (MEMs) switches in place of one or more switches formerly implemented using transistor networks. Any type of switching circuit used within an IMD may be implemented using this technology. For example, MEMs switches may be utilized in a circuit for selectably delivering electrical stimulation to a patient, and/or in a circuit for providing surge protection. The fabrication of the MEMs switches may be performed using one or more separate tubs or wells on a silicon substrate to isolate switching circuitry from other IMD circuitry.