Synchronization of wireless catheters

• US 9,241,633 B2
• Filed: 01/29/2013
• Issued: 01/26/2016
• Est. Priority Date: 07/20/2011
• Status: Active Grant

• Current Assignee: Biosense Webster Israel Ltd. (Johnson & Johnson)
• Original Assignee: Biosense Webster Israel Ltd. (Johnson & Johnson)
• Inventors: Kilim, Nahum, Govari, Assaf, Altmann, Andres Claudio, Ephrath, Yaron
• Primary Examiner(s): Porter, Jr., Allen
• Application Number:
  US13/752,922
• Publication Number:
  US 20140039289A1
• Time in Patent Office: 1,092 Days
• Field of Search: 600/509, 607/32, 607/59, 607/60, 370/350, 370/503
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0015 characterised by features of the telemetry system
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/6852 Catheters
• CPC Class Codes: H04J 3/06 Synchronising arrangements for television systems H04N5/04; bit-synchronisation H04L7/00
• CPC Class Codes: H04J 3/0635 Clock or time synchronisation in a network timer in protocols H04L69/28
• CPC Class Codes: H04J 3/0647 Synchronisation among TDM nodes
• CPC Class Codes: H04J 3/0658 Clock or time synchronisation among packet nodes
• CPC Class Codes: H04J 3/0661 using timestamps
• CPC Class Codes: H04J 3/0667 Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays arrangements for monitoring round trip delays in packet switching networks H04L43/0864
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04L 1/00 Arrangements for detecting or preventing errors in the information received correcting synchronisation H04L7/00
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information
• CPC Class Codes: H04Q 2209/845 where the measuring is synchronized between sensing devices
• CPC Class Codes: H04Q 9/04 Arrangements for synchronous operation

Abstract

A method includes disposing multiple medical probes to acquire physiological data concurrently from a living body. The data is sent from the multiple medical probes by transmitting over wireless channels respective sequences of data packets that are marked with respective packet numbers. A synchronization signal that is broadcast to the multiple probes is received in the probes. In response to receiving the synchronization signal, the packet numbers that are to be assigned in the probes to subsequent data packets in the respective sequences are reset.

Claims

1. A method, comprising:

disposing multiple medical probes comprising a plurality of catheters, each catheter comprising multiple electrodes to acquire physiological data concurrently from a living body in accordance with a respective internal clock signal;

sending the data from each catheter by transmitting over wireless channels respective sequences of data packets that are marked with respective packet numbers, the data in each data packet beginning at a predefined electrode of each catheter and continue cycling over the multiple electrodes of each catheter according to a predefined multiplexing order;

receiving in the probes a synchronization signal that is broadcast to each catheter; and

in response to receiving the synchronization signal, resetting the packet numbers that are to be assigned in each catheter to subsequent data packets in the respective sequences, wherein the respective internal clock signal of each probe is free-running irrespective of the synchronization signal.

2. The method according to claim 1, and comprising transmitting an acknowledgement packet from each catheter in response to receiving the synchronization signal at each catheter, and time-synchronizing the data sent from each catheter based on respective acknowledgement packets transmitted by each catheter.

3. The method according to claim 2, wherein transmitting the acknowledgement packet comprises indicating in each acknowledgement packet a respective time offset at which the synchronization signal was received at each catheter, relative to a data packet produced by each catheter.

4. The method according to claim 3, wherein time-synchronizing the data comprises synchronizing the data based on multiple time offsets indicated in the acknowledgement packets transmitted by each catheter.

5. The method according to claim 3, wherein time-synchronizing the data comprises estimating, based on multiple time offsets indicated in the acknowledgement packets transmitted by each catheter, a time period during which the data is not synchronized, and discarding the data belonging to the estimated time period.

6. The method according to claim 2, wherein transmitting the acknowledgement packet comprises indicating in each acknowledgement packet a respective last packet number of a last data packet that was transmitted from each catheter before reception of the synchronization signal, and wherein time-synchronizing the data comprises synchronizing the data based on multiple last packet numbers indicated in the acknowledgement packets transmitted by each catheter.

7. The method according to claim 2, and comprising presenting the time-synchronized data to an operator.

8. The method according to claim 1, and comprising evaluating a predefined criterion, and transmitting the synchronization signal upon meeting the criterion.

9. The method according to claim 8, wherein evaluating the criterion comprises estimating a time difference between each catheter based on the received data packets, and comparing the time difference to a threshold.

10. The method according to claim 8, wherein transmitting the synchronization signal comprises sending the synchronization signal at periodic intervals.

11. A medical probe comprising a catheter for use in a set of multiple catheters operating concurrently, the catheter comprising:

one or more electrodes, which are configured to acquire physiological data from a living body with which the catheter is in contact in accordance with an internal clock signal; and

circuitry, which is configured to send the data from the catheter by transmitting over a wireless channel a sequence of data packets that are marked with respective packet numbers, the data in each data packet beginning at a predefined electrode of the catheter and continue cycling over the one or more electrodes of the catheter according to a predefined multiplexing order and to receive a synchronization signal that is broadcast to the multiple catheters, and, in response to receiving the synchronization signal, to reset the packet numbers that are assigned in the catheter to subsequent data packets in the sequence, wherein the internal clock signal is free-running irrespective of the synchronization signal.

12. The probe according to claim 11, wherein the circuitry is configured to transmit an acknowledgement packet in response to receiving the synchronization signal, so as to enable time-synchronizing the data sent from the multiple catheters based on respective acknowledgement packets transmitted by the multiple catheters.