摘要:
A method and apparatus for determining the availability of unipolar and/or bipolar pacing/sensing paths in a body-implantable cardiac pacing system. In one embodiment, a pacemaker system includes impedance monitoring circuitry for periodically measuring impedance between pairs of electrodes that are potentially available for pacing and/or sensing. This impedance monitoring circuitry includes circuitry for delivering excitation pulses between pairs of potentially available electrodes (including the pacemaker canister in the case of unipolar pacing or sensing), and for monitoring the current and voltage between those pairs of electrodes during delivery of an excitation pulse. Availability of a pair of electrodes for pacing and/or sensing is indicated if the impedance between a pair of electrodes is found to lie within a predetermined range. Detection of availability of a particular pair of electrodes is used initially as an indication that the pacing system has been implanted, and is also used to distinguish between unipolar and bipolar leads in the pacing system.
摘要:
A rate-responsive cardiac pacemaker comprising a minute ventilation circuit and an activity circuit. The minute ventilation circuit computes a first target pacing rate as a function of measurements of the patient's pleural blood impedance, and the activity circuit computes a second target pacing rate as a function of measured levels of patient activity. A rate control function establishes a rate-responsive pacing rate based on the first and second target pacing rates. The minute ventilation circuit delta-modulates an analog impedance waveform and maintains short-term and long-term weighted averages of delta-modulator output counts. Variations in the difference between the short-term and long-term weighted average values are determinative of the first target pacing rate. Variations in an activity sensor output signal are determinative of the second target pacing rate. Physician-programmable parameters for the pacemaker include selection of a rate-response setting, upper and lower pacing rate limits, and rate-smoothing attack and decay settings.
摘要:
Apparatus and method according to the disclosure relate to a mechanically and electrically coupling a plurality of electrodes to major opposing surface portions of an implantable medical device (IMD). The surface portions can comprise major opposing surfaces of a connector module of the IMD and/or substantially planar metallic surfaces of the IMD. The electrodes provide a subcutaneous cardiac activity sensing device via the plurality of electrodes which can be used in conjunction with one or more electrodes disposed in an insulative shroud coupled to the peripheral, minor surfaces of the IMD.
摘要:
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.
摘要:
A system for minimizing power dissipation within an implantable medical device through use of adiabatic logic is disclosed. The system includes a first and a second sub-circuit of the implantable medical device. An electrical connection interconnects the first and the second sub-circuits, the electrical connection including a capacitive element. Circuitry, which charges the capacitive element of the electrical connection to generate a ramp logic signal, is connected to the capacitive element. The ramp logic signal includes a frequency of less than 500 kilohertz, thereby creating a low frequency, low power system which reduces energy dissipation to the surrounding environment.
摘要:
Methods and apparatus for communication of implantable medical device (IMD) information, including interrogation of programmed parameter values, operating modes and conditions of operation, confirmation of programmed changes thereof, interrogation of data stored in the IMD, and patient warnings or other messages by RF transmission of audible sounds generated by the IMD are disclosed. The IMD includes an RF transmitter that broadcasts or transmits audible sounds including voiced statements or musical tones stored in analog memory correlated to a programming or interrogation operating algorithm or to a warning trigger event. The broadcast radio signal is received, and the audible sounds are demodulated and reproduced by a radio receiver as voiced statements or musical is tones that convey human understandable messages comprising IMD information generated during programming and interrogation sessions and warnings or status messages to the patient at other times.
摘要:
Methods and apparatus for communication of implantable medical device (IMD) information, including interrogation of programmed parameter values, operating modes and conditions of operation, confirmation of programmed changes thereof, interrogation of data stored in the IMD, and patient warnings or other messages by RF transmission of audible sounds generated by the IMD are disclosed. The IMD includes an RF transmitter that broadcasts or transmits audible sounds including voiced statements or musical tones stored in analog memory correlated to a programming or interrogation operating algorithm or to a warning trigger event. The broadcast radio signal is received, and the audible sounds are demodulated and reproduced by a radio receiver as voiced statements or musical tones that convey human understandable messages comprising IMD information generated during programming and interrogation sessions and warnings or status messages to the patient at other.
摘要:
Methods and apparatus for communication of implantable medical device (IMD) information, including confirmation of programming and programmed parameter values, operating modes and programmed changes thereof and data stored in the IMD, by emission of audible sounds by the IMD are disclosed. The IMD includes an audio transducer that emits audible sounds including voiced statements or musical tones stored in analog memory correlated to a programming or interrogation operating algorithm or to a warning trigger event. The audible sounds can comprise the sole uplink transmission or may augment the contemporaneous uplink RF transmission of stored data, and/or programmed operating modes and parameters and/or device operations and states in an interrogation or during programming. To conserve energy, the audible sounds accompanying interrogation and programming of the IMD are at a low volume that preferably cannot be heard without use of an external audio amplifier or stethoscope. Voiced statements warning of battery energy depletion or imminent delivery of a therapy are emitted at a higher volume that is sufficient to be heard by the patient, so that the patient can take appropriate action. The volume of audible sounds confirming programmed changes made by a patient using a limited function programmer or magnet is also increased so that the patient can hear them.
摘要:
Apparatus and method according to the disclosure relate to substantially planar cardiac-sensing electrodes and a shroud member utilizing protruding surface features such as one or more discrete and/or elongated projections, bumps, bosses and the like. For example, the exposed exterior surface of an electrode includes one or more protruding features that promote flow of body fluids therearound and potentially reduce tissue encapsulation.
摘要:
A feedthrough assembly for an implantable medical device includes one or more electrically conductive pins extending through apertures in a case of the medical device with the electrically conductive pins being insulated from the case. The feedthrough assembly further includes a printed circuit board having a diode protection circuit mounted thereon. The printed circuit board forms at least a part of electrically conductive paths for connection of the electrically conductive pins to a medical device circuit assembly mounted within the case. The printed circuit board further provides for electrical connection of the diode protection circuit mounted thereon between the electrically conductive pins and the case.