Abstract: A medical device communications system uses subthreshold pulses, modulated to provide relatively high speed electrical communications with inexpensive external devices connectable to a body with the implant by surface leads.

Abstract: A medical device and method for placing a medical tube, such as a catheter or a shunt, or a medical electrical lead within a patient is disclosed. The medical device of the present invention comprises a passer having a proximal end and a distal end, the passer defining a channel between the proximal end and the distal end. The medical device of the present invention further comprises an obturator having an elongated body, and a first end and a second end, the second end comprising a cradle. In accordance with the invention, the obturator has a removable probe having a first section that fits within the cradle and a second section having a tunneling tip that is exposed outside of the cradle. The obturator is placed into the passer so that the tunneling tip of the probe is exposed outside of the passer at the distal end of the passer. The cradle has dimensions to receive and hold in place a portion of the medical tube or medical lead after the probe is removed from the cradle.

Abstract: A system and method is described for preferentially stimulating dorsal column fibers while avoiding stimulation of dorsal root fibers. The invention applies hyperpolarizing pre-pulses and depolarizing pre-pulses to neural tissue, such as spinal cord tissue, through a lead placed over the spinal cord having the electrodes arranged on a line approximately transverse to the axis of the spine. To increase the threshold needed to stimulate dorsal root fibers, the anodal pulse given by each lateral contact of the electrodes has to be preceded by a depolarizing pre-pulse and simultaneously, the central electrode contact gives a hyperpolarizing pre-pulse, thereby reducing the stimulation threshold for the dorsal column fibers to subsequent depolarizing pulses.

Abstract: An external defibrillator having an output circuit that allows a defibrillation pulse to be discharged to a patient is provided. The output circuit, charging circuit, preamplifier circuit, impedance measurement circuit, energy storage device, battery, and measurement and control circuits of the defibrillator are all referenced to a common ground. The use of a common ground is simpler and less expensive than previous designs which utilized isolation stages and circuits for isolating the high and low voltage circuitry. The output circuit is in the form of an H-bridge which contains three SCR legs and one IGBT leg. Each of the legs contains a single semiconductor switch. The IGBT is placed in the northwest leg of the H-bridge. The two lower legs each contain SCRs, one or both of which may be driven by DC gate drive signals.

Abstract: A system and method is described for preferentially stimulating dorsal column fibers while avoiding stimulation of dorsal root fibers. The invention applies hyperpolarizing pre-pulses and depolarizing pre-pulses to neural tissue, such as spinal cord tissue, through a lead placed over the spinal cord having the electrodes arranged on a line approximately transverse to the axis of the spine. To increase the threshold needed to stimulate dorsal root fibers, the anodal pulse given by each lateral contact of the electrodes has to be preceded by a depolarizing pre-pulse and simultaneously, the central electrode contact gives a hyperpolarizing pre-pulse, thereby reducing the stimulation threshold for the dorsal column fibers to subsequent depolarizing pulses.

Abstract: The invention presents techniques for reducing the interference to telemetry from an implanted medical device caused by a source of controllable noise. In the context of an implanted system that includes a defibrillator system and a telemetry system, for example, the invention reduces the interference by suspending energy storage during telemetry. The invention further provides for suspending energy storage operation gradually rather than abruptly, by gradually reducing the duty cycle of a clock that controls the energy storage.

Abstract: A medical device for multi-vector sensing of cardiac depolarization signals is disclosed. Specialized algorithm is implemented to enhance multi-vector electrode sensing. Further a geometric shape is optimized to enable space-volume efficiencies for deployment and navigation of the medical device for implant in a patient.

Abstract: A system is described for allowing medical data obtained at a local site to be transferred to a data processing system located at a remote site. This medical data may include video data and/or data obtained from one or more medical devices such as a fluoroscopy device or an electrocardiograph (ECG) signal monitoring device. The data may be viewed on one or more display windows of the remote data processing system to allow a remotely-located expert to participate in an examination or medical procedure being conducted at the local site. In one embodiment, the remote data processing system also receives screen data from an implantable medical device programmer that is located at the local site. This screen data may include data associated with the configuration of the programmer, the configuration of an implantable medical device, and other information obtained from a patient such as physiological waveforms. Routing of all data may be performed by a communication hub operating as a stand alone device.

Abstract: An ablation system and a method of its use. The system includes a first elongated ablation component carrying a longitudinally extending mechanism for delivery of ablation energy along its length, and a second elongated ablation component movable relative to the first ablation component. The first and second components are provided with a mechanism mounted to and extending along the first and second components for magnetically attracting the first and second components toward one another along the length of the first mechanism for delivery of ablation energy. Preferably, the second elongated ablation component also carries a longitudinally extending mechanism for delivery of ablation energy along its length.

Abstract: Polymer-coated medical devices having improved structural integrity and drug elution profile, and related methods. Treatment of a polymeric undercoat layer to reflow the undercoat polymer results in a substrate/coating interface with improved adhesion.

Abstract: This invention is an electrical stimulation apparatus for delivering an electrical field or electrical current over a predetermined period of time to a vascular tissue (150) in order to stimulate a cell initiated thrombolytic peptide response in cells within the vascular tissue. The electrical stimulation apparatus includes an electrical field or electrical current generating unit including a power support, a control mechanism interconnected with the power supply, and a plurality of electrodes designed to generate an electrical field or electrical current proximal to, or within to the vascular tissue. The amplitude of the electrical field or electrical current delivered to or generated proximal to, or within the vascular tissue, and the duration of the period of delivery are sufficient to stimulate production of thrombolytic peptides in the vascular tissue.

Abstract: A catheter shaft for a balloon catheter includes a centrally-located guidewire lumen. A body portion of the catheter shaft includes arc-shaped nodes that define a guidewire track within the guidewire lumen. Each node provides a single contact point for a guidewire within the guidewire lumen, thereby limiting frictional contact due to “rolling” friction, rather than “sliding” friction, between the catheter shaft and an inserted guidewire. The nodes include a crown region that includes the contact point. The crown region may be formed of a material having a lower coefficient of friction than the remaining portion of the catheter shaft. At least one node has an inflation lumen extending therethrough. The inflation lumen is in fluid communication with an interior of an inflatable balloon.

Abstract: A pulse detection apparatus, software, and method that uses signal data obtained from an accelerometer placed on a patient's body to detect the presence of a cardiac pulse. The accelerometer is adapted to sense movement due to a cardiac pulse and produce accelerometer signal data in response thereto. Processing circuitry analyzes the accelerometer signal data for a feature indicative of a cardiac pulse and determines whether a cardiac pulse is present in the patient based on the feature. In one aspect, the feature may be a temporal energy feature, such as a relative change in energy. In another aspect, the feature may be a spectral energy feature such as the energy or frequency of a peak in the energy spectrum of the signal. In yet another aspect, the feature may be obtained by comparing the accelerometer signal data with a previously-identified pattern known to predict the presence of a cardiac pulse. Multiple features may also be obtained and classified to determine the presence of a cardiac pulse.

Abstract: A method of determining kidney failure in a patient using an implantable medical device is described. In one embodiment, a first magnitude of a first polarization signal is measured. An additional magnitude of an additional polarization signal is measured after a first interval. A deflection differential between the first magnitude and the additional magnitude is determined and kidney failure in the patient is determined when the deflection differential is greater than an established threshold.

Abstract: An implantable device including an elastically compressible member coupled to a distal end of a lead and further coupled to at least one electrode. The compressible member is in a contracted state when the electrode is being delivered to an implant site. At the implant site, the compressible member is expanded to urge the electrode into contact with tissue. Compressible member further includes a keyed structure to engage a stiffening member such as a stylet. The stiffening member is used both to deliver the electrode to the implant site, and to rotate the compressible member, if necessary, so that the electrode contacts predetermined body tissue. According to one aspect of the invention, an introducer having an inner lumen with a diameter that is smaller than that of the compressible member may be used to disengage the stiffening member from the compressible member.

Abstract: Methods are provided for forming a die package. The method comprises stiffening a flexible substrate to provide a first flexibility of the flexible substrate, forming a mounting element on a first side of the flexible substrate, and mounting a first die on the first side of the flexible substrate to couple the first die to the mounting element. Further, the method comprises mounting a second die on a second side of the flexible substrate and mounting a third die on the second side of the flexible substrate to couple the second and third die to the mounting element, respectively. Furthermore, the method comprises adjusting the stiffening to provide a second flexibility of the flexible substrate that is greater than the first flexibility, and stacking the second die and the third die to provide an overlap of a portion of the second die and a portion of the third die.

Abstract: An improved system and method that is capable of delivering multiple electrode assemblies to predetermined implant sites within a body is disclosed. The system includes an elongated member such as an introducer sheath. The introducer includes an elongated channel along at least a distal end portion of the introducer. The elongated channel opens to the exterior surface of the introducer through an elongated slot. One or more electrode assemblies may be retained within the elongated channel such that the leads exit the introducer via the elongated slot. The elongated introducer further includes a lumen that is in fluid communication with channel through openings, or gaps. The electrode assemblies are loaded within the channel at predetermined positions with respect to the openings. A distal end of a stiffening member such as a stylet may then be advanced within the lumen and through a selected one of the openings to engage an electrode assembly.

Abstract: An automated external defibrillator (AED) (10) designed for use by a rescuer with minimal or no training during a medical emergency is provided. The AED implements a user interface program (22) which guides the rescuer through operation of the AED and application of CPR and defibrillation therapy to a patient by displaying a series of visual instructions on a graphic display (14) or other visual output device, and by providing additional aural instructions via a speaker (18) or other aural output device. The rescuer merely needs to press a start button (12) to initiate operation of the AED and begin CPR and defibrillation instruction.

Abstract: The present invention provides active agent delivery systems for use in medical devices, wherein the active agent delivery systems include an active agent and a miscible polymer blend that includes a polyurethane and a second polymer, preferably one that has at least one Tg equal to or higher than all Tg's of the polyurethane.

Abstract: An implanted medical device (e.g. infusion pump) and handheld communication device wherein the implantable device is capable of operating under control of different software programs, wherein a first program operates after resetting the implantable device and is not capable of providing significant medical functionality but is capable of selected telemetry operations including telemetry operations that allow replacement software to be downloaded, and wherein a second program may be caused to take control of the device and is capable of significant medical functionality and selected telemetry operations but is incapable of receiving replacement software. A software image may be received in multiple messages where each message is provided with its own validation code and wherein a validation code for the whole image is provided and wherein each provided validation code must compared to a derived validation code prior to accepting the validity of the replacement software.