System, Methods And Apparatus For Waking An Autonomous Active Implantable Medical Device Communicating By Pulses Transmitted Through The Interstitial Tissues Of The Body

• US 20120093245A1
• Filed: 10/18/2011
• Published: 04/19/2012
• Est. Priority Date: 10/18/2010
• Status: Active Grant

• Current Assignee: Sorin CRM USA (MicroPort Scientific Corp.)
• Original Assignee: Sorin CRM USA (MicroPort Scientific Corp.)
• Inventors: Makdissi, Alaa, Amara, Karima, Ghildiyal, Ashutosh
• Granted Patent: US 8,577,327 B2
• Time in Patent Office: Days
• US Class Current: 375/259
• CPC Class Codes: A61B 5/0028 Body tissue as transmission medium, i.e. transmission systems where the medium is the human body
• CPC Class Codes: A61N 1/37217 characterised by the communication link, e.g. acoustic or tactile
• CPC Class Codes: A61N 1/37276 characterised by means for reducing power consumption during telemetry
• CPC Class Codes: A61N 1/37288 Communication to several implantable medical devices within one patient

Abstract

An autonomous active medical implantable device, with a power supply and a wake-up circuit that responds to receipt of specific pulses transmitted through the interstitial tissues of the body transmitter device (40) generates trains of modulated pulses applied to electrodes (22, 24), and a receiver (50) processes (e.g., filter, amplify and demodulate) pulses collected on electrodes (22′, 24′). The receiver circuits (50) are selectively activated from a dormant (sleep) state in which they are not powered by a power source (34), to an operational (active) state in which they are powered and able to process (e.g., filter, amplify and demodulate) the collected pulses specific wake-up pulse train, configured in a predetermined characteristic pulse pattern triggers passive wake-up circuits (66) in the receiver (50) to switch the receiver circuits from the sleep state to the operational state.

Claims

1. A system for wireless communication between at least two active medical devices in which at least one active medical device is a transmitter device and at least one active implantable medical device is a receiver device, wherein:

the transmitter device comprises a first pair of electrodes and a transmitter means (40) for generating modulated pulse trains comprising a wake-up plurality of pulses in a series corresponding to a communication to the receiver device, and a wake-up signal preceding said pulse train, said wake-up signal having a predetermined characteristic pulse pattern, and for applying said wake-up signal and modulated pulse train pulses said to electrodes (22, 24); and

the receiver device comprises an energy source, at least one active circuit element, a second pair of electrodes (22′

, 24′

), and a receiver means (50) for collecting a signal at said electrodes and processing said received signal to identify therein a received wake-up signal and modulated pulse train corresponding to said wake-up signal and modulated pulse train from said transmitter means, and means for demodulating said received modulated pulse train into a received pulse train corresponding to said plurality of pulses;

wherein said receiver means (50) further comprises means for selectively switching said at least one active circuit element between a sleep state not powered by said energy source (34) and an operational state powered for processing said signal using said at least one active circuit element; and

,

wake-up circuit means (66) for discriminating said received wake-up signal having said predetermined characteristic pulse pattern, and in response, switching the receiver means from the sleep state to the operational state, wherein;

said wireless communication is an intracorporeal communication of electrical pulses conducted by the interstitial tissues of a patient'"'"'s body; and

the wake-up circuit means comprises a detector circuit (74, 84) and a hysteresis comparator (76, 88).

2. The system of claim 1, wherein the wake-up circuit means has no active amplifier circuit.

3. The system of claim 1 wherein said wake-up signal comprises a biphasic pulse and said modulated pulse train (68, 70, 80, 82) further comprises a biphasic pulse train, each biphasic pulse having a positive alternation and a negative alternation.

4. The system of claim 1, wherein the wake-up circuit means has a permanent energy consumption of less than 10 nW.

5. The system of claim 1, wherein said predetermined characteristic pattern further comprises an initial pulse (68) having a high amplitude (A_w) corresponding to the wake-up signal, and wherein said following succession of pulses (70) have lower amplitude (A) than said high amplitude.

6. The system of claim 5, wherein the predetermined characteristic pattern further comprises a latency period (T_w) between said initial pulse and the following succession of pulses.

7. The system of claim 5, wherein the receiver means further comprises one of a peak level detector and a peak-to-peak detector (74), of the received signal.

8. The system of claim 5, wherein the wake-up circuit means further comprises means (78) for inhibiting the switching of the receiver means from the sleep state to the operational state upon detection of a received pulse having a width that is greater than an upper predetermined limit (T).

9. The system of claim 1, wherein the receiver means further comprising a predetermined value corresponding to an authorized wake-up signal, said predetermined characteristic pattern further comprises a first specific sequence of pulses (80, 82) of uniform amplitude (A) encoding a predetermined binary value forming a wake-up code, and the wake-up circuit means comprises means (84-100) for identifying the received signal and decoding therefrom a binary value encoded by said received signal first specific sequences of pulses, and comparing said decoded binary value with said predetermined value.

10. The system of claim 9, wherein the first specific sequence of pulses further comprises a plurality of distinct bursts of pulses, some of said bursts being a first number of pulses (80) encoding a ‘

1’

bit and the other bursts being a second number of pulses (82), different from the first number, encoding a ‘

0’

bit,

and wherein the receiver means further comprises an envelope detector (84) delivering as output a series of binary values each obtained by integration of a received corresponding burst of pulses, and means (96, 98, 100) for comparing said series of bits to said predetermined value.

11. The system of claim 10, wherein the envelope detector (84) comprises a voltage multiplier circuit (86).

12. The system of claim 10, wherein the second number of pulses (80) is double the first number of pulses (82).

13. The system of claim 1 wherein said modulated pulse train includes said wake-up pulse preceding said plurality of pulses, and the means for demodulating said received signal further comprises means for demodulating said received modulated pulse train into a received pulse train corresponding to said wake-up signal and said following plurality of pulses.

14. An autonomous active implantable medical device having wireless communications with a remote active medical device, having a receiver device comprising:

an energy source;

at least one active circuit element;

a pair of electrodes (22′

, 24′

), and

a receiver means (50) for collecting a signal at said pair of electrodes and processing said received signal to identify therein a wake-up signal and a received modulated pulse train, said receiver means further comprising means for demodulating said received modulated pulse train into a received pulse train and identifying in said received pulse train a plurality of pulses;

means for selectively switching said at least one active circuit element between a sleep state not powered by said energy source (34) and an operational state powered for processing said signal using said at least one active circuit element; and

,

wake-up circuit means (66) for discriminating said received signal and identifying therein a first signal having a predetermined characteristic pulse pattern and corresponding to a wake-up signal, and in response, switching the receiver means from the sleep state to the operational state, wherein;

said signal further comprises an intracorporeal communication of electrical pulses conducted by the interstitial tissues of a patient'"'"'s body; and

the wake-up circuit means further comprises a detector circuit (74, 84) and a hysteresis comparator (76, 88).

15. The device of claim 14, wherein the wake-up circuit means has no active amplifier circuit.

16. The device of claim 14 wherein said wake-up signal further comprises a biphasic pulse and said modulated pulse train (68, 70, 80, 82) further comprises a biphasic pulse train, each biphasic pulse having a positive alternation and a negative alternation.

17. The device of claim 14, wherein the wake-up circuit means has a permanent energy consumption of less than 10 nW.

18. The device of claim 14, wherein said predetermined characteristic pattern further comprises an initial pulse (68) having a high amplitude (A_w) corresponding to the wake-up signal, and wherein said following succession of pulses (70) have lower amplitude (A) than said high amplitude.

19. The device of claim 18, wherein the predetermined characteristic pattern further comprises a latency period (T_w) between said initial pulse and the following succession of pulses.

20. The device of claim 18, wherein the receiver means further comprises one of a peak level detector and a peak-to-peak detector (74), of the received signal.

21. The device of claim 18, wherein the wake-up circuit means further comprises means (78) for inhibiting the switching of the receiver means from the sleep state to the operational state upon detection of a received pulse having a width that is greater than an upper predetermined limit (T).

22. The device of claim 14, wherein the receiver means further comprising a predetermined value corresponding to an authorized wake-up signal, said predetermined characteristic pattern further comprises a first specific sequence of pulses (80, 82) of uniform amplitude (A) encoding a predetermined binary value forming a wake-up code, and the wake-up circuit means comprises means (84-100) for indentifying the received signal and decoding therefrom the first signal as a binary value encoded by said received signal first specific sequences of pulses, and comparing said decoded binary value with said predetermined value.

23. The device of claim 22, wherein the first specific sequence of pulses further comprises a plurality of distinct bursts of pulses, some of said bursts being a first number of pulses (80) encoding a ‘

1’

bit and the other bursts being a second number of pulses (82), different from the first number, encoding a ‘

0’

bit,

and wherein the receiver means further comprises an envelope detector (84) delivering as output a series of binary values each obtained by integration of a received corresponding burst of pulses, and means (96, 98, 100) for comparing said series of bits to said predetermined value.

24. The device of claim 23, wherein the envelope detector (84) comprises a voltage multiplier circuit (86).

25. The device of claim 23, wherein the second number of pulses (80) is double the first number of pulses (82).

26. The device of claim 14 wherein said modulated pulse train includes said wake-up pulse preceding said plurality of pulses, and the means for demodulating said received signal further comprises means for demodulating said received modulated pulse train into a received pulse train corresponding to said wake-up signal and said following plurality of pulses.

27. An active medical device having wireless communication with a remote active medical device, having a transmitter device, comprising:

a first pair of electrodes, and

a transmitter means (40) for generating modulated pulse trains comprising a wake-up plurality of pulses in a series corresponding to a communication to said remote device, and a wake-up signal preceding said pulse train, said wake-up signal having a predetermined characteristic pulse pattern, and for applying said wake-up signal and modulated pulse train pulses said to electrodes (22, 24);

wherein said predetermined characteristic pattern further comprises an initial pulse (68) having a high amplitude (A_w) corresponding to the wake-up signal, and wherein said following succession of pulses (70) have lower amplitude (A) than said high amplitude, and

wherein

said wireless communication is an intracorporeal communication of electrical pulses conducted by the interstitial tissues of a patient'"'"'s body.

28. The device of claim 27 wherein said wake-up signal further comprises a biphasic pulse and said modulated pulse train (68, 70, 80, 82) further comprises a biphasic pulse train, each biphasic pulse having a positive alternation and a negative alternation.

29. The device of claim 27, wherein the predetermined characteristic pattern further comprises a latency period (T_w) between said initial pulse and the following succession of pulses.

30. The device of claim 27, wherein said predetermined characteristic pattern further comprises a first specific sequence of pulses (80, 82) of uniform amplitude (A) encoding a predetermined binary value forming a wake-up code.

31. The device of claim 30, wherein the first specific sequence of pulses further comprises a plurality of distinct bursts of pulses, some of said bursts being a first number of pulses (80) encoding a ‘

1’

bit and the other bursts being a second number of pulses (82), different from the first number, encoding a ‘

0’

bit.

32. The device of claim 30, wherein the second number of pulses (80) is double the first number of pulses (82).

33. The device of claim 27 wherein the device comprises an autonomous leadless capsule.

34. The device of claim 27 wherein said transmitter means further comprises means for generating a modulated pulse train including said wake-up signal followed by said plurality of pulses.