APPARATUS AND METHOD FOR QUANTIFICATION OF THE DESYNCHRONIZATION BETWEEN THE CLOCKS OF TWO HBC ACTIVE IMPLANTS

• US 20140228913A1
• Filed: 04/21/2014
• Published: 08/14/2014
• Est. Priority Date: 02/09/2011
• Status: Active Grant

• Current Assignee: Sorin CRM SAS (MicroPort Scientific Corp.)
• Original Assignee: Sorin CRM SAS (MicroPort Scientific Corp.)
• Inventors: Molin, Renzo Dal, Ghildiyal, Ashutosh
• Granted Patent: US 9,302,115 B2
• Time in Patent Office: Days
• US Class Current: 607/60
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/37288 Communication to several implantable medical devices within one patient
• CPC Class Codes: A61N 1/39622 Pacing therapy
• CPC Class Codes: G06F 1/06 Clock generators producing several clock signals G06F1/08 - G06F1/14 take precedence
• CPC Class Codes: G06F 1/12 Synchronisation of different clock signals provided by a plurality of clock generators
• CPC Class Codes: H04B 17/00 Monitoring; Testing of line transmission systems H04B3/46; arrangements for monitoring or testing transmission systems employing electromagnetic waves other than radio waves H04B10/07
• CPC Class Codes: H04B 3/46 Monitoring; Testing
• CPC Class Codes: H04J 3/06 Synchronising arrangements for television systems H04N5/04; bit-synchronisation H04L7/00
• CPC Class Codes: H04Q 1/20 Testing circuits or apparatus; Circuits or apparatus for detecting, indicating, or signalling faults or troubles

Abstract

A method of determining desynchronization between a first implantable medical device and a second implantable medical device. The method includes receiving a synchronization query from the first device at the second device, that is transmitted in response to the first device detecting a predetermined transition of a first clock of the first device, the first clock having a first pulse rate. The method further includes determining a number of pulses of a second clock of the second device occurring between reception of the synchronization query and a predetermined transition of a third clock of the second device, the third clock having the first pulse rate. The second clock has a second pulse rate higher than the first pulse rate. The method further includes determining the desynchronization between the first device and the second device based on the determined number of pulses of the second clock.

Claims

1. A method of determining a desynchronization between a first implantable medical device and a second implantable medical device, the method comprising:

receiving a synchronization query from the first implantable medical device at the second implantable medical device, the synchronization query being transmitted in response to the first implantable medical device detecting a predetermined transition of a first clock of the first implantable medical device, the first clock having a first pulse rate;

determining a number of pulses of a second clock of the second implantable medical device occurring between reception of the synchronization query and a predetermined transition of a third clock of the second implantable medical device, the third clock having the first pulse rate, and the second clock having a second pulse rate higher than the first pulse rate; and

determining the desynchronization between the first implantable medical device and the second implantable medical device based on the determined number of pulses of the second clock.

2. The method of claim 1, further comprising selectively activating the second clock before the determination of the number of pulses of the second clock, and deactivating the second clock after detection of the predetermined transition of the third clock of the second implantable medical device.

3. The method of claim 1, further comprising:

determining a number of pulses of a fourth clock of the first implantable medical device occurring between transmission of the synchronization query and reception of a response signal to the synchronization query, the fourth clock having the second pulse rate; and

determining the desynchronization between the first implantable medical device and the second implantable medical device based on both the determined number of pulses of the second clock and the determined number of pulses of the fourth.

4. The method of claim 1, wherein the first pulse rate is selected from the range of 15 and 50 kHz.

5. The method of claim 1, wherein the second pulse rate is at least 10 times faster than the first pulse rate.

6. The method of claim 1, wherein determining the desynchronization between the first implantable medical device and the second implantable medical device comprises applying a relation of the form:

OFFSET=T_clk−

D,

wherein OFFSET is the value of a temporal offset corresponding to the desynchronization, T_clk is the period of the pulse signals of the first clock, and D is the duration corresponding to the result from determining the number of pulses of the second clock.

7. The method of claim 3, wherein determining the desynchronization between the first implantable medical device and the second implantable medical device comprises applying a relation of the form:

OFFSET=T_clk−

[(D₁+D₂)/2],

wherein OFFSET is the value of a temporal offset corresponding to the desynchronization, T_clk is the period of the pulse signals of the first and the third clock, D₁ is the duration corresponding to the result from determining the number of pulses of the second clock, and D₂ is the duration corresponding to the result from determining the number of pulses of the fourth clock.

8. An active implantable medical device, comprising:

an apparatus for providing information to determine a desynchronization between the active implantable medical device and a second medical device, the apparatus comprising;

a transmitter/receiver of wireless communications;

a first clock having a first pulse rate; and

a second clock having a second pulse rate higher than the first pulse rate;

the apparatus configured to;

receive a synchronization query from the second medical device, the synchronization query being transmitted in response to a predetermined transition of a third clock of the second medical device, the third clock having the first pulse rate;

determine a number of pulses of the second clock of the apparatus occurring between reception of the synchronization query and a predetermined transition of the first clock of the apparatus; and

transmit a response signal to the second medical device configured to allow the second medical device to determine the desynchronization between the active implantable medical device and the second medical device based on the determined number of pulses of the second clock.

9. The device of claim 8, wherein the apparatus is further configured to activate the second clock before the determination of the number of pulses of the second clock, and deactivate the second clock after detection of the predetermined transition of the first clock of the apparatus.

10. The device of claim 8, wherein the first pulse rate is selected from the range of 15 and 50 kHz.

11. The device of claim 8, wherein the second pulse rate is at least 10 times faster than the first pulse rate.

12. The device of claim 8, wherein determining the desynchronization between the active implantable medical device and the second medical device comprises applying a relation of the form:

OFFSET=T_clk−

D,

wherein OFFSET is the value of a temporal offset corresponding to the desynchronization, T_clk is the period of the pulse signals of the first clock, and D is the duration corresponding to the result from determining the number of pulses of the second clock.

13. The device of claim 8, wherein the active implantable medical device is an autonomous leadless capsule.

14. A computer-readable storage medium having instructions stored thereon that, when executed by a processor of an implantable medical device, cause the implantable medical device to perform operations comprising:

selectively activating a first clock of the implantable medical device upon reception of a synchronization query from a second medical device, the first clock having a first pulse rate;

determining a number of pulses of the first clock of the implantable medical device occurring between reception of the synchronization query and a predetermined transition of a second clock of the apparatus, wherein the first pulse rate is higher than a second pulse rate of the second clock;

wherein the synchronization query is transmitted in response to a predetermined transition of a third clock of the second medical device, the third clock having the second pulse rate; and

wherein the operations further comprise;

deactivating the first clock of the implantable medical device after detection of the predetermined transition of the second clock; and

determining the desynchronization between the implantable medical device and the second medical device based on the determined number of pulses of the first clock.

15. The computer-readable medium of claim 14, wherein determining the desynchronization between the implantable medical device and the second medical device comprises applying a relation of the form:

OFFSET=T_clk−

D,

wherein OFFSET is the value of a temporal offset corresponding to the desynchronization, T_clk is the period of the pulse signals of the second clock, and D is the duration corresponding to the result from determining the number of pulses of the first clock.

16. A system for determining a desynchronization between a first implantable medical device and a second implantable medical device, comprising:

a first implantable medical device comprising;

a first transmitter/receiver of wireless communications;

a first clock having a first pulse rate; and

a second clock having a second pulse rate higher than the first pulse rate; and

a second implantable medical device comprising;

a second transmitter/receiver of wireless communications;

a third clock having the first pulse rate; and

a fourth clock having the second pulse rate;

wherein the system is configured to;

detect a predetermined transition of the first clock of the first implantable medical device and in response, transmit a synchronization query to the second implantable medical device;

receive the synchronization query at the second implantable medical device;

determine a number of pulses of the fourth clock of the second implantable medical device occurring between reception of the synchronization query and a predetermined transition of the third clock of the second implantable medical device;

transmit a response signal from the second implantable medical device to the first implantable medical device;

determine a number of pulses of the second clock of the first implantable medical device occurring between transmission of the synchronization query and reception of the response signal; and

determine the desynchronization between the first implantable medical device and the second implantable medical device based on both the determined number of pulses of the second clock and the determined number of pulses of the fourth clock.

17. The system of claim 16, further configured to:

activate the second clock before the determination of the number of pulses of the second clock and deactivate the second clock after reception of the response signal; and

activate the fourth clock before the determination of the number of pulses of the fourth clock and deactivate the fourth clock after detection of the predetermined transition of the third clock.

18. The system of claim 16, wherein at least one of the first implantable medical device and the second implantable medical device is an autonomous leadless capsule.

19. The system of claim 16, wherein the first pulse rate is selected from the range of 15 and 50 kHz.

20. The system of claim 16, wherein the second pulse rate is at least 10 times faster than the first pulse rate.

21. The system of claim 16, wherein determining the desynchronization between the first implantable medical device and the second implantable medical device comprises applying a relation of the form:

OFFSET=T_clk−

[(D₁+D₂)/2],

wherein OFFSET is the value of a temporal offset corresponding to the desynchronization, T_clk is the period of the pulse signals of the first and the third clock, D₁ is the duration corresponding to the result from determining the number of pulses of the second clock, and D₂ is the duration corresponding to the result from determining the number of pulses of the fourth clock.