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US 8,608,635 B2Granted
TET system for implanted medical device
AssigneeHeartWare, Inc.
InventorsBarry Yomtov, John Robert Batty
Life of this patent
Estimating the term…
Abstract
A TET system is operable to vary an amount of power transmitted from an external power supply to an implantable power unit in accordance with a monitored condition of the implantable power unit. The amount of power supplied to the implantable power unit for operating a pump, for example, can be varied in accordance with a cardiac cycle, so as to maintain the monitored condition in the power circuit within a desired range throughout the cardiac cycle.
Claims18
A circulatory assist device comprising:
- (a) a pump adapted for implant in a patient, the pump having an electric motor, the pump having a time-varying power demand which is adapted to vary with a cardiac cycle of the patient;
- (b) an implantable power unit adapted for mounting within a body of the patient, the implantable power unit having a secondary coil, a power circuit connected to the secondary coil for supplying power to the pump so that power applied to the secondary coil can be transmitted to the pump, and a monitoring circuit operable to monitor a condition of the power circuit and to send a transcutaneous telemetry signal representing the monitored condition,
- (c) an external power supply having a primary coil adapted for transcutaneous inductive coupling with the secondary coil, a drive circuit operable to apply an alternating current to the primary coil, and a control circuit operable to receive the telemetry signal and to adjust the alternating current in the primary coil at least in part in response to the telemetry signal,
- the monitoring circuit and control circuit being operable to monitor the condition of the power circuit and to adjust the alternating current in the primary coil in accordance therewith so as to vary the alternating current in the primary coil substantially in accordance with the cardiac cycle, and so as to vary an amount of the power applied to the secondary coil in accordance with the time-varying power demand of the pump in intervals of less than one second of a plurality of periodic intervals during the cardiac cycle, such that during each interval the external power supply is adapted to apply as much power to the secondary coil as needed to power the pump.
1 more element
A circulatory assist device comprising:
- (a) an implantable pump adapted for mounting within the body of the patient, the pump having an electric motor with a time-varying power demand adapted to vary with a cardiac cycle of the patient;
- (b) an implantable power unit adapted for mounting within the body of the patient, the implantable unit having a secondary coil, a power circuit connected to the secondary coil for supplying power to the pump so that power applied to the secondary coil can be transmitted to the pump, and a monitoring circuit operable to monitor a condition being a voltage of the power circuit and to send a transcutaneous telemetry signal representing the monitored condition,
- (c) an external power supply having a primary coil adapted for transcutaneous inductive coupling with the secondary coil, a drive circuit operable to apply an alternating current to the primary coil, and a control circuit operable to receive the telemetry signal and to adjust the alternating current in the primary coil at least in part in response to the telemetry signal,
- wherein the control circuit is operable to adjust the alternating current in the primary coil in response to the telemetry signal so as to vary the alternating current in the primary coil substantially in accordance with the monitored condition and maintain the monitored condition in the power circuit within a desired range in each of a plurality of intervals during the cardiac cycle, each interval having a duration of less than one second.
1 more element
A circulatory assist device comprising:
- (a) a pump adapted for implant in a patient, the pump having an electric motor with a time-varying power demand which is adapted to vary substantially in accordance with a cardiac cycle of the patient;
- (b) an implantable power unit adapted for mounting within the body of the patient, the implantable power unit having a secondary coil, a power circuit connected to the secondary coil for supplying power to the pump so that power applied to the secondary coil can be transmitted to the pump, and a monitoring circuit operable to monitor a condition of the power circuit and to send a transcutaneous telemetry signal representing the monitored condition at periodic intervals of less than one second during the cardiac cycle,
- (c) an external power supply having a primary coil adapted for transcutaneous inductive coupling with the secondary coil, a drive circuit operable to apply an alternating current to the primary coil, a receiver operable to receive the telemetry signal, a prediction circuit operable to generate a predictive signal estimating an instantaneous power demand of the pump based upon the received telemetry signal and a signal representing at least the heartbeat of the patient, a control circuit operable to adjust the alternating current in the primary coil at least in part in response to the received telemetry signal and the predictive signal, so as to maintain the monitored condition within a desired range substantially throughout the cardiac cycle, such that during each interval the external power supply is adapted to apply as much power to the secondary coil as needed to power the pump.
Dependencies are inferred from the claim text.