Pulse generator

Abstract: Apparatus for multi-channel transverse epidural spinal cord stimulation uses a multi-channel pulse generator driving a plurality of electrodes mounted near the distal end of a lead. These electrodes are mounted in one or more lines, generally perpendicular to the lead axis, and have a planar surface along one surface of the lead. The lead is implanted adjacent to spinal cord dura mater with the electrodes transverse and facing the spinal cord. Pulses generated by the pulse generator for each channel are normally simultaneous, of equal amplitude and of equal duration, however, the pulse generator is arranged such that pulses for each channel can selectably alternate in time, can selectably be of unequal amplitude, or both. The changes in pulse timing and magnitude permit shifting the electrical stimulation field and the resulting paresthesia pattern after installation to accommodate improper lead placement or postoperative dislocation and to minimize unwanted motor responses.

Abstract: Improved assemblies, systems, and methods provide an implantable pulse generator for prosthetic or therapeutic stimulation of muscles, nerves, or central nervous system tissue, or any combination. The implantable pulse generator is sized and configured to be implanted subcutaneously in a tissue region. The implantable pulse generator includes an electrically conductive laser welded titanium case. Control circuitry is located within the case, and includes a primary cell or rechargeable power source, a receive coil for receiving an RF magnetic field to recharge the rechargeable power source, and a microcontroller for control of the implantable pulse generator. Improved assemblies, systems, and methods also provide a stimulation system for prosthetic or therapeutic stimulation of muscles, nerves, or central nervous system tissue, or any combination. The stimulation system provides at least one electrically conductive surface, a lead connected to the electrically conductive surface, and an implantable pulse generator electrically connected to the lead.

Abstract: A pulse generator housing for enclosing and containing pulse generator defibrillation circuitry. The housing is formed entirely of electrically conductive metal defining an electrically conductive outer surface which is connected to the pulse generator circuitry for delivering defibrillating energy to the heart. The pulse generator housing is implanted in the pectoral region proximate the heart with the conductive surface facing the heart. Regions of the conductive outer surface may be electrically isolated and dedicated for separately sensing and shocking. The outer surface may be coated with platinum. Additional coiled segment electrodes may extend from the housing and be electrically connected to the conductive outer surface so as to increase the effective conductive surface area. A sensor is provided to determine whether the housing is inside or outside a body of a patient to disconnect the pulse generator housing conductive surface from the pulse generator circuitry when the unit is outside the body of a patient.

Abstract: An apparatus suitable for use in an implantable automatic defibrillation system for automatically generating a multiphasic defibrillation pulse waveform in response to sensed fibrillation has first and second series charge-storing capacitors having a common terminal and two other terminals each at different potentials. A controller senses cardiac fibrillation and generates a control signal which causes a charging circuit to charge the capacitors to selected voltage levels in sequentially alternating charge generation and charge coupling cycles. A voltage level detector senses the stored voltage level, disables the charging circuit when the sensed voltage reaches a predetermined level, and informs the controller that the capacitors are fully charged. The controller then communicates control signals indicative of pulse magnitude, duration, and polarity to a multiphasic pulse generator having a number of high-power switches and corresponding switch drivers interposed in circuit between the heart and the terminals of the charge-storing capacitors. The drivers control the conduction states of the switches according to the control signals to establish selected circuit paths between the three terminals and the heart, and to thereby deliver to the heart a multiphasic waveform having pulses with the selected parameters of magnitude, duration, and polarity.