摘要:
A method and system for performing device identification is disclosed. A source signal may be directed from an energy source towards the surface of a device for reflection therefrom. An interference pattern may be detected from the surface of the device, such as by a sensor. A determination as to whether a match exists between the representation of the interference pattern and a stored representation of an interference pattern may be performed. If a match exists, the device may be identified based on the stored representation of the interference pattern. Otherwise, a representation of the interference pattern may be stored and a unique identifier may be assigned to the stored representation of the interference pattern.
摘要:
A system and method for determining and predicting a patient's susceptibility to neurological dysfunction based on measured electrophysiological parameters employs a self-contained implantable device with depth electrodes implanted in desired locations in the patient's brain. The patient's neurological tissue is stimulated to determine excitability and refractoriness (or inhibition period) parameters, which are employed to identify susceptibility to abnormal neurological activity, particularly epileptic seizures.
摘要:
An implantable neurostimulator adapted to provide adaptive electrical brain stimulation includes a detection subsystem for isolating an electrographic signal characteristic and a stimulation system for applying an adaptive stimulation signal based at least in part upon the electrographic signal characteristic and correlated with the electrographic signal. Undesired learning of and acclimation to stimulation characteristics are avoided and stimulation efficacy is improved by adapting or otherwise varying the adaptive stimulation signal in relation to the electrographic signal.
摘要:
A method for delivering cardiac therapy, particularly defibrillation therapy, using an implantable cardioverter-defibrillator (ICD) or other cardiac therapy device. The method can be used either alone or in conjunction with any other suitable defibrillation (or other cardiac) therapy regimen. If used in conjunction with a conventional or other suitable defibrillation therapy regimen, the method can be considered to precondition the heart in advance of delivery of the defibrillation shock(s), in order to reduce the defibrillation threshold (DFT), and thus reduce the overall energy required for delivery of effective defibrillation therapy. In either case, in accordance with the method, the voltage gradients (VGs) across a plurality of different regions of the heart are sensed, e.g., using an endocardial sensor array (ESA), and a respective plurality of electrograms (EGMs) are produced in respective EGM channels. The excitable gaps (i.e., the intervals between successive activations) in the different VG regions of the heart are then brought into phase alignment with one another by appropriately timing the delivery of electrical stimulation (e.g., one or more pulses). In this connection, either the timing of the next activation interval can be advanced by delivering an electrical stimulus (pulse) during the excitable gap or in the late repolarization phase of the previous activation, or the activation interval can be extended by delivering an electrical stimulus earlier in the repolarization phase of the previous activation, leading to an extension of the refractory period (i.e., RPE). If three or more EGM channels are used, the excitable gaps in the different VG regions are preferably brought into phase with one another by first bringing the region associated with the near-field EGM channel into phase alignment with the region associated with the EGM channel of the adjacent (next highest) VG region and then successively entraining the thusly entrained regions with the regions associated with the EGM channels corresponding to the successively more distant VG regions, until the regions associated with all EGM channels are brought into phase alignment with one another. Also disclosed is a cardiac therapy device (e.g., an ICD) for implementing this method.
摘要:
A method for making anode foil plates for use with layered electrolytic capacitors and capacitors made with such plates. A high purity aluminum foil is provided for generation of anode foil plates. Sheets of the foil are highly etched to provide a very high surface area. Following the etch process, the foil is partially cut or punched into plates from the etched sheets in the general shape of the finished capacitor housing with a portion remaining connected to the supporting foil. The supporting foil with the partially punched-out etched plates are subjected to a forming process by applying a voltage to the plates in the presence of an electrolyte to provide formed anode foil plates with edges which do not have to be reformed during capacitor aging and which do not have any particulates at cut edges. The formed anode plates are layered with cathode plates and separators in a capacitor housing with an electrolyte to provide a finished capacitor.
摘要:
A capacitor optimized for use in an implantable medical device such as an implantable defibrillator is disclosed. In its simplest form, the capacitor comprises a thin planar dielectric sheet that has an array of cells open to one or both sides. Metallization is applied to the surface of the cells such that the walls of adjacent cells form a capacitor with the wall that separates the cells serving as the dielectric. The metallization pattern that forms the electrical connection to the cells may be patterned to limit the allowable current flow to each individual cell, thereby providing a fuse in the case of local dielectric failure.
摘要:
A high voltage charger operates in a three-phase cycle. In a first phase, the high voltage charger operates at a fixed frequency. In a second phase, the high voltage charger operates at a variable frequency designed to draw a substantially constant average current from a power source. In the third phase, the high voltage charger returns to fixed frequency operation. The variable frequency is the reciprocal of the sum of an on-time and an off-time of the switch. In one embodiment, the on-time is provided by the time required for the switch to reach a predetermined maximum and the off-time is provided by the time over which a magnetic field in a transformer collapses.
摘要:
A lead for use with an implantable cardioverter/defibrillator system is disclosed. In the preferred embodiment, the lead combines a right ventricular endocardial electrode, a superior vena cava electrode and one or more atrial sensing electrodes on a single catheter lead. The distal end of the lead is transvenously implanted, typically through an incision in the cephalic or subclavian vein. The proximal end of the lead is then tunneled below the fascia to the location of the pulse generator. Ventricular sensing and/or pacing electrode(s) may also be included at the distal end of the combined lead to provide ventricular intracardiac electrogram sensing and bradycardia pacing.
摘要:
An implantable cardiac defibrillator is provided having an energy source, a capacitor, and means coupled to the energy source for charging the capacitor. The capacitor comprises a planar layered structure of anode plates, cathode plates and means separating the anode plates and cathode plates. A polymeric envelope containing electrolyte encloses the layered structure. Electrical contact means extend from the anodes and cathodes to outside the envelope.
摘要:
An implantable medical device includes electrodes coupled to a patient's heart and sensing circuitry having inputs connected to the electrodes for sensing cardiac electrical signals. The sensing circuitry includes a digital waveform analyzer system which performs direct analysis of digitized ECG heart signals from the atrial and/or ventricular channels. This eliminates the need for the system microprocessor to perform direct analysis on raw ECG data. The benefit being that complex software algorithms are not required, saving microprocessor memory space. System current drain is also reduced since the microprocessor need not be active during every ECG sample.