Two-sided telemetry in implantable cardiac therapy devices

• US 5,919,214 A
• Filed: 11/12/1997
• Issued: 07/06/1999
• Est. Priority Date: 11/12/1997
• Status: Expired due to Fees

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Ciciarelli, Timothy E., Archer, Stephen T.
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): EVANISKO, GEORGE ROBERT
• Application Number:
  US08/967,872
• Time in Patent Office: 601 Days
• Field of Search: 607/31, 607/32, 607/60, 128/903
• US Class Current: 607/32
• CPC Class Codes: A61N 1/37211 Means for communicating with stimulators
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: Y10S 128/903 Radio telemetry

Abstract

A method for ensuring two-sided telemetry in implantable cardiac therapy devices by making at least one of the following operating parameters selectable (reversible): (1) the direction of current detection of the telemetry circuitry of the implantable cardiac therapy device; (2) the direction of the magnetic field produced by the transmit coil of an external telemetry device (programming wand); (3) the direction of the magnetic field produced by the T/R coil of the implantable cardiac therapy device; and/or (4) the direction of current detection of the telemetry circuitry of the programming wand. In a presently contemplated implementation, when it is desired to read-out data from the implantable cardiac therapy device and/or to re-program the device parameters, a telemetry operation is attempted in the normal manner, i.e., it is initiated by the programming wand. If the communication is unsuccessful, then the direction of the magnetic field produced by the transmit coil of the programming wand is reversed, and the telemetry operation repeated. If the transmission of command data from the programming wand to the implantable cardiac therapy device is successful, but the transmission of read-out data from the device to the programming wand is unsuccessful, then the direction of current detection of the telemetry circuitry of the programming wand is reversed, and the telemetry operation is attempted again; alternatively, the direction of the magnetic field produced by the T/R coil of the implantable cardiac therapy device can be reversed. Thus, no matter what the orientation of the device and external telemetry device, successful two-way telemetry between the device and the programming wand is possible. Thus, the telemetry can be considered "two-sided". In an alternative embodiment, the telemetry operation can be initiated by the implantable cardiac therapy device. In this case, if the communication is unsuccessful, then the direction of the magnetic field produced by the T/R coil of the device is reversed.

Claims

1. A method for telemetrically communicating with an implantable medical device having a receive coil and first telemetry circuitry, using an external telemetry device having a transmit coil and second telemetry circuitry, the method comprising the steps of:

flowing current in a first current direction through the transmit coil of the telemetry device, to thereby produce a magnetic field having a first field direction;

holding the telemetry device in proximity to the implantable medical device, whereby a current which flows in the first current direction is induced in the receive coil of the implantable medical device to communicate with the implantable medical device;

determining whether communication has been successfull or unsuccessful; and

,

if it is determined in the determining step that communication has been unsuccessful, then flowing the current in a second current direction through the transmit coil of the telemetry device, to thereby produce a magnetic field having a second field direction, whereby a current which flows in the second current direction is induced in the receive coil of the implantable medical device.

2. The method as set forth in claim 1, wherein the implantable medical device comprises an implantable cardiac therapy device.

3. The method as set forth in claim 1, wherein the telemetry device comprises a programming wand.

4. A telemetry system for telemetrically communicating with an implantable medical device, comprising:

a communication coil;

means for selectively flowing a current pulse in either a first direction or a second direction through the communication coil, to thereby produce a selectively reversible magnetic field pulse and to provide telemetric communication;

means for detecting whether the telemetric communication was successful; and

means for flowing the current pulse in an opposite direction if the telemetric communication was unsuccessful.

5. The telemetry system as set forth in claim 4, wherein the communication coil comprises a transmit coil.

6. A system, comprising:

an implantable medical device having a receive coil and first telemetry circuitry;

an external telemetry device having a transmit coil and second telemetry circuitry for transmitting a signal from the transmit coil of the external telemetry device to the receive coil of the implantable medical device to thereby provide telemetric communication between the implantable medical device and the external telemetry device;

means for flowing current in a first direction through the transmit coil of the external telemetry device;

means for detecting whether a telemetric communication between the external telemetry device and the implantable medical device has been successful or not; and

,

means responsive to detection of an unsuccessful telemetric communication for reversing the direction of current flow through the transmit coil of the external telemetry device.

7. A system, comprising:

an external telemetry device for providing telemetric communication with an implantable medical device the external telemetry device having a receive coil;

an implantable medical device having a transmit coil;

means for flowing current in a first direction through the transmit coil of the implantable medical device to provide telemetric communication with the external telemetry device;

means for detecting whether a telemetric communication has been successful or not; and

,

means responsive to detection of an unsuccessful telemetric communication for reversing the direction of current flow through the transmit coil of the implantable medical device.

8. A method for telemetrically reading out data from an implantable medical device having a transmit coil and first telemetry circuitry, using an external telemetry device having a receive coil and second telemetry circuitry, the method comprising the steps of:

flowing current in a first current direction through the transmit coil of the implantable medical device, to thereby produce a magnetic field having a first field direction;

holding the telemetry device in proximity to the implantable medical device, whereby a current which flows in the first direction is induced in the receive coil of the telemetry device;

determining whether a read-out has been successful or unsuccessful; and

,

if it is determined that the read-out has been unsuccessful, then flowing the current in a second current direction through the transmit coil of the implantable medical device, to thereby produce a magnetic field having a second field direction, whereby a current which flows in the second current direction is induced in the receive coil of the telemetry device.

9. A method for telemetrically reading out data from an implantable medical device having a transmit coil and first telemetry circuitry, using an external telemetry device having a receive coil and second telemetry circuitry, the method comprising the steps of:

flowing current in a first current direction through the transmit coil of the implantable medical device, to thereby produce a magnetic field having a first field direction;

holding the telemetry device in proximity to the implantable medical device, whereby a current which flows in the first current direction is induced in the receive coil of the telemetry device;

determining whether the read-out has been successful or unsuccessful; and

,

if it is determined in the determining step that the read-out has been unsuccessful, then reversing the direction of current flow of the second telemetry circuitry of the telemetry device.

10. A method for telemetrically communicating with an implantable medical device having a receive coil and first telemetry circuitry, using an external telemetry device having a transmit coil and second telemetry circuitry, the method comprising the steps of:

flowing current in a first current direction through the transmit coil of the telemetry device, to thereby produce a magnetic field having a first field direction;

holding the telemetry device in proximity to the implantable medical device, whereby a current which flows in the first current direction is induced in the receive coil of the implantable medical device;

determining whether or not the second telemetry circuitry has detected a signal in the receive coil; and

,

if it is determined that the second telemetry circuitry has not detected a signal in the receive coil, then reversing the direction of current flow in the transmit coil.

11. The method as set forth in claim 10, wherein the implantable medical device comprises an implantable cardiac therapy device.

12. The method as set forth in claim 10, wherein the telemetry device comprises a programming wand.