Methods and apparatuses for implantable medical device telemetry power management
An implantable medical device includes a radio-frequency (RF) telemetry circuit and a power connection module through which the RF telemetry circuit is connected to an energy source such as a battery. The power connection module connects power from the energy source to at least one portion of the RF telemetry circuit when a user initiates an RF telemetry session. After the RF telemetry session is completed, the power connection module shuts off the at least one portion of the RF telemetry circuit. Power-on examples include a wireless telemetry activation signal received by a low power radio receiver in the implantable device, a physical motion detected by an activity sensor in the implantable device, an activation of an inductive telemetry circuit in the implantable device, a magnetic field detected by a magnetic field detector in the implantable device, and/or a telemetry activation signal detected by a sensing circuit included in the implantable device. Power-off examples include a wireless termination signal received by the implantable device, a delay timeout following the RF telemetry session, and/or a signal received by an inductive telemetry circuit in the implantable device.
1. A system including:
an implantable medical device, the implantable medical device including:
a far-field radio-frequency (RF) first telemetry circuit;
a power connection module, coupled to the first telemetry circuit, to connect/disconnect power to at least a portion of the first telemetry circuit; and
a wireless signal detector, coupled to the power connection module, to control a conductivity state of the power connection module upon detecting a predetermined wireless signal, wherein the predetermined wireless signal constitutes an electrical current introduced into a body of a subject in which the implantable medical device is implanted, and wherein the same wireless signal detector is also used to detect at least one of a cardiac signal and a respiration signal.
2. The system of claim 1 , in which the implantable medical device includes an implantable cardiac rhythm management device, and the first telemetry circuit provides at least a six-foot telemetry range.
3. The system of claim 1 , further including a remote device far-field RF second telemetry circuit, electromagnetically coupled to the first telemetry circuit, to provide long-range communications with the implantable medical device.
4. The system of claim 1 , wherein the same wireless signal detector is used to detect both the predetermined wireless signal and the cardiac signal.
5. The system of claim 1 , wherein the same wireless signal detector is used to detect both the predetermined wireless signal and the respiration signal.
6. A system including:
an implantable medical device, the implantable medical device including:
a far-field radio-frequency (RF) first telemetry circuit;
a power connection module, coupled to the first telemetry circuit, to connect/disconnect power to at least a portion of the first telemetry circuit; and
a telemetry activation sensing circuit, coupled to the power connection module, to control a conductivity state of the power connection module upon a detection of a predetermined telemetry activation signal, wherein the predetermined telemetry activation signal constitutes an electrical current introduced into a subject into which the implantable medical device is implanted, and wherein the same telemetry activation sensing circuit is also used to detect at least one of a cardiac signal and a respiration signal.
7. The system of claim 6 , in which the implantable medical device includes an implantable cardiac rhythm management device, and the first telemetry circuit provides at least a six-foot telemetry range.
8. The system of claim 6 , further including a cardiac sensing lead, coupled to the telemetry activation sensing circuit, and in which the telemetry activation sensing circuit includes:
an amplifier having an input and an output, the input coupled to the cardiac sensing lead; and
a filter, coupled to the output of the amplifier.
9. The system of claim 6 , further including an external interface device adapted to be communicatively coupled to the implantable medical device, the external interface device including an electrical current generator adapted to introduce an electrical current into a body to be received by the telemetry activation sensing circuit to connect power to at least a portion of the first telemetry circuit.
10. The system of claim 9 , in which the external device further includes a surface electrocardiograph (ECG) electrode to introduce the electrical current into the body.
11. The system of claim 9 , in which the external device further includes at least two conductive surfaces, coupled to the electrical current generator, to introduce the electrical current into the body through contacts between the metal surfaces and the body.
12. The system of claim 6 , wherein the same telemetry activation sensing circuit is used to detect both the predetermined telemetry activation signal and the cardiac signal.
13. The system of claim 6 , wherein the same telemetry activation sensing circuit is used to detect both the predetermined telemetry activation signal and the respiration signal.
14. A method including:
connecting at least one portion of a far-field radio-frequency (RF) first telemetry circuit in an implantable medical device to an energy source through a power connection module;
introducing a predetermined electrical current signal into a body;
detecting the predetermined electrical current signal introduced into the body using a sensing circuit that is also used to detect at least one of a cardiac signal and a respiration signal; and
changing a conductivity state of the power connection module when the predetermined electrical current signal is detected.
15. The method of claim 14 , in which the implantable medical device includes an implantable cardiac rhythm management device, and the first telemetry circuit provides at least a six-foot telemetry range.
16. The method of claim 14 , in which introducing the predetermined electrical current signal into the body is carried out through a plurality of surface electrocardiograph (ECG) electrodes.
17. The method of claim 14 , in which introducing the predetermined electrical current signal into the body is carried out through a plurality of conductive contacts of an external device.
18. The method of claim 14 , in which the electrical current signal is an approximately sinusoidal signal having a frequency of about 30 kilohertz.
19. The method of claim 14 , wherein the same sensing circuit is used to detect both the predetermined electrical current signal and the cardiac signal.
20. The method of claim 14 , wherein the same sensing circuit is used to detect both the predetermined electrical current signal and the respiration signal.
21. A method including:
connecting at least one portion of a far-field radio-frequency (RF) first telemetry circuit in an implantable medical device to an energy source through a power connection module;
detecting a predetermined first telemetry activation signal wherein the first telemetry activation signal includes an electrical current signal introduced into a body in which the implantable medical device is located, the detecting including using a sensing circuit that is also used to detect at lest one of a cardiac signal and a respiration signal;
changing a conductivity state of the power connection module when the first telemetry activation signal is detected to connect power to the at least one portion of the first telemetry circuit;
detecting a predetermined second telemetry activation signal; and
starting data transmission using the first telemetry circuit when the second telemetry activation signal is detected.
22. The method of claim 21 , further including sending the second telemetry activation signal from a remote device at a predetermined frequency.
23. The method of claim 22 , in which the second telemetry activation signal including a digital key adapted to identify a particular implantable medical device.
24. The method of claim 21 , wherein the same sensing circuit is used to detect both the first telemetry activation signal and the cardiac signal.
25. The method of claim 21 , wherein the same sensing circuit is used to detect both the first telemetry activation signal and the respiration signal.