SYSTEM AND METHOD FOR WAKING AN IMPLANTABLE MEDICAL DEVICE FROM A SLEEP STATE

• US 20070250126A1
• Filed: 04/25/2006
• Published: 10/25/2007
• Est. Priority Date: 04/25/2006
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Zhang, Cheng, Chavan, Abhijeet, Maile, Keith, Von Arx, Jeffrey
• Granted Patent: US 7,650,185 B2
• Time in Patent Office: Days
• US Class Current: 607/16
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61N 1/3706 Pacemaker parameters stimulation threshold A61N1/371
• CPC Class Codes: A61N 1/37217 characterised by the communication link, e.g. acoustic or tactile
• CPC Class Codes: A61N 1/37252 Details of algorithms or data aspects of communication system, e.g. handshaking, transmitting specific data or segmenting data
• CPC Class Codes: A61N 1/37264 Changing the program; Upgrading firmware
• CPC Class Codes: A61N 1/37288 Communication to several implantable medical devices within one patient

Abstract

A system and method for waking up an implantable medical device (“IMD”) from a sleep state in which power consumption by the IMD is essentially zero. The IMD may be adapted to perform one or more designated measurement and/or therapeutic functions. In one embodiment, the IMD includes a wake-up sensor that is adapted to sense the presence or absence of a wake-up field generated by another IMD or an external device. The wake-up field may, in some embodiments, be an electromagnetic field, a magnetic field, or a physiologically sub-threshold excitation current (i.e., E-field). Upon sensing by the wake-up sensor of the wake-up field, other components of the IMD, which may include a controller, a sensing and/or therapy module, and/or a communications module, are awakened to perform one or more designated functions.

Claims

1. A method carried out by a satellite implantable medical device for being awakened from a sleep state by a primary implantable medical device, the satellite implantable medical device including a wake-up sensor, a control module, a physiologic sensor, and a communication module, the method comprising:

waiting in a sleep state;

detecting, by the wake-up sensor, the presence of a wake-up field generated by the primary implantable medical device; and

responsive to the presence of the wake-up field, causing the control module to change from the sleep state to an active state and cause the communications module to transmit a measurement of at least one physiologic parameter to the primary implantable medical device, the at least one physiologic parameter being measured by the physiologic sensor.

2. The method of claim 1 wherein the communication module is adapted for acoustic communication, and further wherein the physiologic sensor includes a pressure sensor adapted to measure pressure within a blood vessel, and wherein the at least one physiologic parameter is a pulmonary arterial blood pressure.

3. The method of claim 1 further comprising:

inductively coupling a first inductive coil of the primary implantable medical device to a second inductive coil of the satellite implantable medical device; and

passing an alternating current through the first inductive coil to generate an electromagnetic field,

wherein the detecting step comprises detecting the electromagnetic field by the second inductive coil and generating an output voltage across the second inductive coil.

4. The method of claim 1 further comprising the step of causing, at a scheduled time before the detecting step, the wake-up sensor to change from the sleep state to an active state.

5. The method of claim 4 further comprising the step of returning the wake-up sensor to the sleep state after a predetermined time interval if no wake-up field is present.

6. The method of claim 5 wherein the wake-up field is a magnetic field, and wherein the detecting step includes detecting the presence of the magnetic field.

7. The method of claim 5 wherein the wake-up field is an electric field characterized by an electrical excitation current, and wherein the detecting step includes detecting the presence or absence of the electrical excitation current.

8. A method of waking an implantable medical device from a low-power state, the method comprising:

providing a first implanted medical device including a wake-up field generator and a first communication module;

providing a second implanted medical device including a battery, a wake-up sensor operable to detect the wake-up field, a physiologic sensor, a control module, and a second communication module, wherein the second implanted device is initially in a low-power state;

detecting a presence of the wake-up field; and

responsive to the presence of the wake-up field, causing the control module to change from the low-power state to an active state and cause a measurement of at least one physiological parameter to be transmitted to the first implanted device via the second communication module.

9. The method of claim 8 wherein the second communication module is adapted for acoustic communication, and further wherein the physiologic sensor includes a pressure sensor, and wherein the at least one physiologic parameter is a pulmonary arterial blood pressure.

10. The method of claim 9 further comprising:

inductively coupling a first inductive coil of the first implanted device to a second inductive coil of the second implanted device; and

passing an alternating current through the first inductive coil to generate an electromagnetic field,

wherein the detecting step comprises detecting the electromagnetic field by the second inductive coil and generating an output voltage across the second inductive coil.

11. The method of claim 9 further comprising the step of causing, at a scheduled time before the detecting step, the wake-up sensor to change from the low power state to the active state.

12. The method of claim 11 further comprising the step of causing the wake-up sensor to return to the low-power state after a predetermined time interval if no wake-up field is present.

13. The method of claim 12 wherein the wake-up field is a magnetic field, and wherein the detecting step includes sensing the presence of the magnetic field.

14. The method of claim 12 wherein the wake-up field is an electric field characterized by an electrical excitation current, and wherein the detecting step includes detecting the presence or absence of the electrical excitation current.

15. A system for waking up an implantable medical device from a sleep state, the system comprising:

a primary implantable device including a wake-up field generator operable to generate a wake-up field, and a first communication module; and

a satellite implantable device including;

a control module;

a second communication module, wherein the control module and the second communication module are adapted to change between a sleep state and an active state; and

means for detecting the wake-up field.

16. The system of claim 15 wherein the satellite implantable device further comprises a physiologic sensor adapted to measure at least one physiological parameter.

17. The system of claim 16 wherein the second communication module is adapted for acoustic communication, and further wherein the physiologic sensor includes a pressure sensor, and wherein the at least one physiologic parameter is a pulmonary arterial blood pressure.

18. The system of claim 15 wherein the wake-up field generator includes a first inductive coil, and wherein the wake-up field is an electromagnetic field, and wherein the means for detecting the wake-up field include a second inductive coil inductively coupled to the first inductive coil.

19. The system of claim 15 wherein the wake-up field generator is adapted to generate a magnetic field, and wherein the means for detecting the wake-up field include a magnetic field sensor.

20. The system of claim 15 wherein the satellite implantable device further comprises timer circuitry operable to cause, at a first predetermined time interval, the means for detecting the wake-up field adapted to change from a sleep state to an active state in which the means for detecting the wake-up field are operable to detect the wake-up field.

21. The system of claim 20 wherein the timer circuitry is further adapted to cause the means for detecting the wake-up field to return to the sleep state upon passage of second predetermined time interval.

22. The system of claim 21 wherein the wake-up field generator includes a magnetic field generator, and wherein the means for detecting the wake-up field include a magnetic field sensor.

23. The system of claim 21 wherein the wake-up field generator is adapted to generate a physiologically sub-threshold electrical excitation current, and wherein the means for detecting the wake-up field include an electric field sensor adapted to detect the excitation current.