Abstract: Disclosed is a method for stacking semiconductor chips, including positioning a first chip and manipulating a second chip to a distance above the first chip that is no greater than a selected distance, and releasing the second chip to drop into a stacked configuration on the first chip. The selected distance is such as to avoid damage to either of the chips. Embodiments are disclosed for setting the drop distance of the second chip within the selected distance.

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: An implantable endocardial, multi-lumen lead wherein the distal end of the lead body is cored to provide a stopped bore co-axial with the axis of the lead body. A distal electrode is inserted into the stopped bore without an additional tubular segment and glue joint. A first lumen in the lead body has an axis which is off set from the axis of the lead body itself. A low voltage conductor passes through the first lumen. A second lumen is also offset from the axis of the lead body. The lumens may have a circular or other cross section. A plurality of non-coaxial lumens may be provided.

Abstract: A memory device particularly useful in size-constrained electronic products, such as cardiac stimulators. To provide additional memory for such size-constrained products, memory chips are stacked one on top of another. The memory chips are configured to facilitate bonding without crossed contacts, using aligned bonding pads, vias, or castellations. Each memory chip also includes an address selection circuit that receives signals from one or more address lines to selectively enable and disable the memory chips in the stack.

Abstract: A cardiac stimulator lead is provided that includes a two-stage extendable/retractable fixation. A cardiac stimulator lead comprises a connector for connecting to a cardiac stimulator, a tubular insulating sleeve having a first end coupled to the connector and a second end, and an electrode coupled to the second end and having a longitudinal bore. An extendable/retractable corkscrew is positioned in the bore. In one aspect, the bore is configured so that the corkscrew will not extend fully unless tissue is present to engage the corkscrew.

Abstract: An implantable endocardial defibrillation lead having an elongated lead body with multiple lumens therein. Windows, cut through the lead body, provide access to selected ones of the lumens at selected locations along the lead body. In addition, a method and an apparatus for forming windows in a multilumen lead body are disclosed. A ferromagnetic stylet is inserted into a selected lumen. The lead body is oriented in a jig by application of an electromagnetic field. A grinder or punch cuts a window into the selected lumen.

Abstract: An apparatus and method for laser stripping coated cables for endocardial defibrillation leads comprising a jig for holding at least one insulated wire, the jig having a base plate, a linear stripping area on the plate, a first clasp mounted on the plate for holding a first end of the wire, at least two primary pins mounted on the plate on a first side of the linear stripping area, at least one secondary pin mounted on the plate on a second side of the linear stripping area, and a second clasp mounted on the plate for holding a second end of the wire; and a laser effective to remove insulation from the insulated wire, the laser being mounted to effectively remove insulation in the linear stripping area.

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: Device and method are disclosed in which leads with pacing and defibrillating electrodes are implanted into both the right and left ventricles of a patient's heart to enable simultaneous pacing of both ventricles to reduce the width of the QRS complex of the patient's cardiac activity to a more normal duration, and, when appropriate, to apply electrical shock waveforms to both ventricles simultaneously for lower energy defibrillation of the ventricles. In applying the defibrillation therapy, the defibrillating electrode in the left ventricle may be used as the anode and the defibrillating electrode in the right ventricle may be used as the cathode, or both ventricular defibrillating electrodes may be the anode and the metal case in which the shock waveform generator is implanted may be the cathode.

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: Methods and apparatus for treating fibrillation utilize biphasic waveforms. A cardiac stimulator includes a defibrillation circuit that uses a pulse width modulated capacitive discharge to generate various biphasic waveforms, one or more of which may be delivered to the heart to treat the fibrillation.

Abstract: A multiprogrammer system for monitoring and optimizing implantable device performance. In one embodiment, the system includes at least two programming devices and an implantable device. Each of the programming devices may be used to perform inquiry and programming operations on the implantable device. In an inquiry operation, the programming device retrieves some or all of the configuration parameters from the implantable device. In a programming operation, the programming device provides one or more modified parameters to the implantable device. As part of the programming operation, the programming device is configured to verify that it is aware of the implantable device's current parameters before sending the modified parameters. In other words, the current programming device verifies that the implantable device's parameters have not been altered by another programming device since the current programming device's last interaction with the implantable device.

Abstract: A lead assembly adapted for endocardial fixation to a human heart is provided. The lead assembly includes a lead body that has a proximal end provided with a connector for electrical connection to a cardiac stimulator. The cardiac stimulator may be a pacemaker, a cardioverter/defibrillator, or a sensing instrument. The distal end of the lead body is connected to a tubular electrode housing. The lead body consists of one or more noncoiled conductor cables surrounded by a coextensive insulating sleeve. Each conductor cable consists of a conducting element covered by a coextensive insulating sleeve. The conducting element may be a single filament wire or a plurality of individual conductor wires. In contrast to conventional leads, the lead body of the present invention does not require coiled conductor wires. Lead body diameters of 1.04 mm or smaller are possible.

Abstract: A method is disclosed for rapidly removing electrically insulative coating material from a portion of the titanium housing of an implantable cardiac pulse generator. Pulsed excimer laser radiation ablates an organic coating, such as parylene or a similar polymer, to micromachine a conductive window having sharply defined boundaries or edges. An implantable cardiac pulse generator having an electrically conductive window produced according to the method is also disclosed. The method is suitable for high volume automated production of face or edge window pulse generators, and is also applicable for removal of biomolecular films from other medical articles.

Abstract: A system is provided for optically communicating with an implantable device. In one embodiment, the system includes an implantable device having a large memory and an external unit which downloads information from the memory for analysis and display. The implantable device includes a light-emitting diode (LED) and a modulator for driving the LED. Although various frequencies can be used, frequencies which experience relatively little attenuation through body tissue are presently preferred. The external device includes a photo-multiplier tube (PMT) and a demodulator for equalizing and demodulating the detection signal produced by the PMT in response to detected light. A high bandwidth channel (perhaps as much as 500 Mbits/sec) is created by these components. This channel advantageously allows for a substantially reduced download time.

Abstract: An ionically conductive polymeric composition for coating a hot can defibrillator electrode is disclosed. A polymeric coating, such as polyethylene oxide containing NaCl or a similar ionic medium, coats and fills the pores of a high surface area electrode to provide a continuous ionic network from the can to the adjacent body tissue. In certain embodiments, the underlying high surface area, porous electrode is made by chemically etching a smooth electrode surface, such as that of a conventional titanium housing, followed by applying a thin coating of a noble metal such as platinum. In other embodiments, a noble metal or an oxide thereof, such as platinum black or iridium oxide, is applied to a titanium housing to form a porous, high surface area electrode. The conductive polymeric coating is then applied over the porous noble metal or metal oxide.

Abstract: A circuit substrate utilizes buried edge connectors. The buried edge connectors are mechanically disposed within the edge of the substrate and have substantial thickness. The configuration and method for making the same provides relatively large edge connectors mechanically constrained in the edge of a circuit substrate.

Abstract: An apparatus for using a laser beam to remove or ablate an insulating coating from a desired segment of an insulating coating from a desired segment of an insulated conductor (wire) without damaging or causing mechanical stress to the wire. A lens can be used to focus the laser beam at a focal point and a support to locate the insulated conductor in a position between the lens and the focal point in a path of the laser bean. A reflector can be aligned with the opening so as to reflect the laser beam portion back toward the conductor. The support can include a generally planar coil guide such as a Y-shaped groove.

Abstract: A lead assembly adapted for endocardial fixation to a human heart is provided. The lead assembly includes a lead body that has a proximal end provided with a connector for electrical connection to a cardiac stimulator. The cardiac stimulator may be a pacemaker, a cardioverter/defibrillator, or a sensing instrument. The distal end of the lead body is connected to a tubular electrode housing. The lead body consists of one or more noncoiled conductor cables surrounded by a coextensive insulating sleeve. Each conductor cable consists of a conducting element covered by a coextensive insulating sleeve. The conducting element may be a single filament wire or a plurality of individual conductor wires. In contrast to conventional leads, the lead body of the present invention does not require coiled conductor wires. Lead body diameters of 1.04 mm or smaller are possible.