摘要:
In general, the invention is directed to an IMD having a piezoelectric transformer to power a lead-based sensor. The IMD powers the piezoelectric transformer with a low amplitude signal. The piezoelectric transformer serves to convert the voltage level of the low amplitude signal to a higher voltage level to drive the sensor produced by a battery in the IMD to voltage levels appropriate for IMD operation. A piezoelectric transformer offers small size and low profile, as well as operational efficiency, and permits the IMD to transmit a low amplitude signal to a remote sensor deployed within an implantable lead. In addition, the piezoelectric transformer provides electrical isolation that reduces electromagnetic interference among different sensors.
摘要:
An implantable medical device includes a control circuit for controlling the operation of the device and for obtaining physiological data from a patient in which the medical device is implanted. The implanted device also includes a communication circuit for transmitting the physiological data to an external device. A first power source is coupled to the control circuit and provides power to the control circuit. A second power source is coupled to the communication circuit and provides power to the communication circuit.
摘要:
The locus of electrically excitable tissue where action potentials are induced can be controlled using the physiological principle of electrotonus. In one embodiment, first and second pulses are applied to first and second electrodes, respectively, to generate first and second subthreshold potential areas, respectively, within the tissue. The locus within the tissue where action potentials are induced is determined by a superposition of the first and second subthreshold areas according to the physiological principle of electrotonus. In another embodiment, a two-dimensional array of electrodes are formed. The cathode may be positioned near the center of the two-dimensional array or may be left out. The first and second subthreshold areas may thereby be steered. An array of anodal rings may be used to contain the field of excitation.
摘要:
An implantable pump apparatus and method of operating the implantable pump for infusing a fluid into a body as described. An expandable fluid reservoir member includes a first end, a second end, an inlet for receiving the fluid from an outside source and an outlet for dispensing the fluid into the body. A first conductor is operably attached to the first end of the expandable fluid reservoir member. A second conductor is operably attached to the second end of the expandable fluid reservoir member. The level of fluid within the expandable fluid reservoir member is determined by measuring an inductance value at the first conductor that is proportional to the distance between the first conductor and the second conductor.
摘要:
A pacing system is provided having a lead with a pressure transducer or other sensor, the lead being characterized by having only a single conductor connecting the pacemaker with the signals from the sensor and the signals to and from the lead tip electrode. A connecting circuit mounted in the lead near the distal end is powered by a low level alternating constant current square wave to provide multiplexed signals on the conductor. The lead connecting circuit comprises a switching device connected to a sensor, such as a piezoelectric pressure transducer, so that for positive current pulses delivered to the lead, the transducer output is added in series with any cardiac signal sensed by the tip electrode; while for negative currents the pressure transducer is isolated and only the tip electrode signal information is connected back to the pacemaker. The pacemaker contains processing circuitry for decoding the respective cardiac signals and pressure signals from the multiplexed signals.
摘要:
The locus of electrically excitable tissue where action potentials are induced can be controlled using the physiological principle of electrotonus. In one embodiment, first and second pulses are applied to first and second electrodes, respectively, to generate first and second subthreshold potential areas, respectively, within the tissue. The locus within the tissue where action potentials are induced is determined by a superposition of the first and second subthreshold areas according to the physiological principle of electrotonus. In another embodiment, a two-dimensional array of electrodes are formed. The cathode may be positioned near the center of the two-dimensional array or may be left out. The first and second subthreshold areas may thereby be steered. An array of anodal rings may be used to contain the field of excitation.
摘要:
Apparatus and method for independently delivering a plurality of therapy programs in an implantable medical device. A therapy controller configures the device to generate independent pulse trains associated with a plurality of therapy programs and dynamically configures the electrodes to deliver the independent pulse trains to the patient. Once configured, the implantable medical device delivers the plurality of therapy programs to the patient wherein the therapy programs may overlap in time.
摘要:
Apparatus and method provide flexibility in generating a stimulation waveform to an electrode of an Implantable Neuro Stimulator (INS). The stimulation waveform is synthesized for each rate period interval. Each rate period interval is partitioned into time intervals, during which stimulation pulses, recharging, and time duration delays may be induced. With the embodiment of the invention, a second stimulation pulse, having different electrical characteristics than a first stimulation pulse, may be generated during the rate period interval. An embodiment utilizes apparatus comprising a waveform controller and a waveform generator that are controlled by the waveform controller. The waveform controller uses waveform parameters to instruct the waveform generator to form stimulation pulses. Any of the components may be adjusted or deleted in the generation of the stimulation waveform. The embodiment enables any of the associated waveform parameters to be updated at the waveform controller in order to alter the stimulation waveform.
摘要:
The locus of electrically excitable tissue where action potentials are induced can be controlled using the physiological principle of electrotonus. In one embodiment, first and second pulses are applied to first and second electrodes, respectively, to generate first and second subthreshold potential areas, respectively, within the tissue. The locus within the tissue where action potentials are induced is determined by a superposition of the first and second subthreshold areas according to the physiological principle of electrotonus. In another embodiment, a two-dimensional array of electrodes are formed. The cathode may be positioned near the center of the two-dimensional array or may be left out. The first and second subthreshold areas may thereby be steered. An array of anodal rings may be used to contain the field of excitation.
摘要:
There is provided an implantable device with two or more output stages for delivering concurrent output pulses to two or more sites within a patient's body. Each output circuit has a common architecture, including a switchable generator which has a plurality of storage capacitors and switches for arranging the capacitors either to be charged by the battery, or to discharge a stimulus pulse. A programmable regulator is provided for further regulation of the output voltage; and a multiplexer connects the output to the desired electrodes placed at the patient site. For concurrent dual pulse-dual site stimulation, a pair of active rectifier switches are connected between the negative terminal of each output stage and the battery positive terminal, whereby at the time of concurrent pulse delivery, the output stage having the greatest negative voltage relative to battery plus has its negative terminal connected to the battery plus terminal, while the other output stage is disconnected from the battery so that it floats. This arrangement reduces crosstalk current while ensuring continued positive biasing of the semi-conductor switches in each output stage.