Descriptive transtelephonic pacing intervals for use by an emplantable pacemaker

• US 5,899,928 A
• Filed: 05/06/1997
• Issued: 05/04/1999
• Est. Priority Date: 05/14/1996
• Status: Expired due to Fees

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Sholder, Jason A., Valikai, Kenneth
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): EVANISKO, GEORGE ROBERT
• Application Number:
  US08/851,922
• Time in Patent Office: 728 Days
• Field of Search: 128/904, 600/510, 607/27, 607/32, 607/29, 607/59, 607/60
• US Class Current: 607/27
• CPC Class Codes: A61N 1/3727 characterised by the modulation technique

Abstract

A system and method for pulse modulating a cardiac pacing signal provides a way to have the pulse modulation characteristics be descriptive of critical information relating to the operational performance of an implanted pacemaker. The patient'"'"'s ECG/EKG signal is modulated by varying the pulse-intervals of a prescribed plurality of ventricular stimulation pulses in a manner descriptive of important pacer/patient information, such as Pacemaker Battery Status, Pacemaker Sensor Function, Impedance of the Atrial Lead, Impedance of the Ventricular Lead, Existence of Specified Rhythmic Conditions, Indicated Extrsystoles Rates, and other related parameters. The resulting pulse-modulated signal is suitable for transtelephonic transmission to remote locations for subsequent demodulation and analysis. The preferred method comprises the steps of determining or measuring parametric information for selected pacemaker parameters of the implanted pacemaker, varying the pulse characteristics (i.e. timing intervals) of the ventricular stimulation pulses generated by the implanted pacemaker to be descriptive of the parametric information for the selected pacemaker parameters, and triggering the generation of a prescribed plurality of ventricular stimulation pulses having such descriptive pulse characteristics.

Claims

1. In an implantable cardiac pacemaker including means for generating ventricular stimulation pulses, a method of selectively pulse-modulating a predetermined number of the ventricular stimulation pulses with descriptive pacemaker parametric information, said pulse-modulated ventricular stimulation pulses being applied to a patient'"'"'s heart to produce a pulse-modulated cardiac signal suitable for transtelephonic transmission to a receiver located at a remote location, the method comprising the steps of:

(a) ascertaining parametric information for a plurality of parameters;

(b) varying pulse characteristics of said predetermined number of ventricular stimulation pulses to be descriptive of said parametric information for the plurality of parameters; and

(c) delivering to a patient'"'"'s heart said predetermined number of ventricular stimulation pulses having said descriptive pulse characteristics, said predetermined number of ventricular stimulation pulses further having sufficient energy to cause captured;

whereby the cardiac signal is pulse-modulated by said predetermined number of ventricular stimulation pulses to contain said descriptive parametric information.

2. The method, as set forth in claim 1, wherein the step of varying said pulse characteristics comprises varying the timing interval between said predetermined number of ventricular stimulation pulses to be descriptive of said parametric information for said plurality of parameters.

3. The method, as set forth in claim 2, further comprising an initial step of initializing a pulse modulation routine, said initializing step further including the steps of:

(i) defining the plurality of parameters to include parameters that relate to at least one of the status of the pacemaker operation and the status of patient'"'"'s condition;

(ii) defining a pulse modulation sequence, said pulse modulation sequence including a predetermined number of descriptive pulse segments, each of said descriptive pulse segments being characterized by the occurrence of two successive ventricular stimulation pulses;

(iii) associating each parameter with one of said descriptive pulse segments; and

(iv) defining prescribed timing intervals for each of said descriptive pulse segments that are descriptive of said parametric information for said associated parameters.

4. The method, as set forth in claim 3, wherein the step of defining said pulse modulation sequence further comprises:

defining said pulse modulation sequence to include a pair of identification pulse segment followed by the predetermined number of descriptive pulse segments, said descriptive pulse segments having said prescribed timing intervals that are descriptive of said parametric information for said plurality of parameters.

5. The method, as set forth in claim 3, wherein the step of defining said pulse modulation sequence further comprises defining said pulse modulation sequence to include an identification pulse segment followed by six descriptive pulse segments, said descriptive pulse segments having said prescribed timing intervals that are descriptive of said parametric information for said measured parameters.

6. The method, as set forth in claim 2, wherein the step of generating said predetermined number of ventricular stimulation pulses further comprises:

generating a pair of identification pulses followed by the predetermined number of descriptive pulses having timing intervals between pulses that are descriptive of said parametric information for said plurality of parameters.

7. The method, as set forth in claim 6, wherein the step of generating a plurality of ventricular stimulation pulses further comprises generating a pair of identification pulses followed by six descriptive pulses wherein said timing intervals between pulses are descriptive of said parametric information for a respective parameter.

8. The method, as set forth in claim 6, wherein said timing intervals between successive descriptive pulses are of a duration that is sufficient to ensure overdrive pacing.

9. The method, as set forth in claim 6, wherein said timing intervals between successive descriptive pulses range in duration from about 500 ms to about 700 ms.

10. The method, as set forth in claim 2, wherein the step of varying said timing intervals between said plurality of ventricular stimulation pulses further comprises the step of:

setting said timing intervals between each of said plurality of ventricular stimulation pulses to prescribed values wherein each combination of prescribed values is indicative of said parametric information for a respective parameter.

11. The method, as set forth in claim 1, further comprising the step of initially triggering said implantable pacemaker to perform steps (a) through (c) above by placing a magnet over said pacemaker.

12. The method, as set forth in claim 1, further comprising the steps of:

recording said pulse-modulated cardiac signal and transtelephonically transmitting said recorded pulse-modulated cardiac signal to a remote location.

13. The method, as set forth in claim 12, further comprising the step of:

receiving and analyzing said transmitted, pulse-modulated cardiac signal to extract said parametric information contained therein.

14. The method, as set forth in claim 1, wherein the step of defining said measured parameters further includes defining a measured parameter indicative of the status of a battery in said implantable pacemakers.

15. The method, as set forth in claim 1, wherein the ascertaining step further includes ascertaining a parameter indicative of the status of an atrial lead coupled to said implantable pacemaker.

16. The method, as set forth in claim 1, wherein the ascertaining step further includes ascertaining a parameter indicative of the status of a ventricular lead coupled to said implantable pacemaker.

17. The method, as set forth in claim 1, wherein the ascertaining step further includes ascertaining a parameter indicative of the status of a sensor coupled to said implantable pacemaker.

18. The method, as set forth in claim 1, wherein the step of defining said measured parameters further includes defining a measured parameter indicative of extrsystoles rate of the patient.

19. The method, as set forth in claim 1, wherein the step of defining said measured parameters further includes defining a measured parameter indicative of arrhythmic conditions of the patient.

20. A cardiac pacing system that selectively provides a pulse-modulated cardiac pacing signal descriptive of pacemaker parametric information, said pulse-modulated cardiac pacing signal being suitable for transtelephonic transmission to a receiver located at a remote location, the cardiac pacing system comprising:

an implantable pacemaker, said pacemaker including means for generating ventricular stimulation pulses having sufficient energy to cause capture; and

processing means for controlling the operation of said pacemaker, said processing means including;

means for defining a plurality of parameters;

means for ascertaining parametric information for said plurality of parameters;

means for triggering the generation of a sequence of a plurality of ventricular stimulation pulses;

means for varying pulse characteristics of the sequence of plurality of ventricular stimulation pulses wherein said pulse characteristics are descriptive of said parametric information for said plurality of parameters so that a patient'"'"'s cardiac signal is pulse-modulated with said parametric information.

21. The cardiac pacing system of claim 20, wherein said means for varying said pulse characteristics of said plurality of ventricular stimulation pulses further comprises means for varying timing intervals between said plurality of ventricular stimulation pulses to be descriptive of said parametric information for said plurality of parameters.

22. The cardiac pacing system of claim 21, wherein said plurality of ventricular stimulation pulses further comprises at least one identification pulses followed by the sequence of descriptive pulses, said descriptive pulses having timing intervals that are descriptive of said parametric information for said plurality of parameters.

23. The cardiac pacing system of claim 21, wherein said means for varying timing intervals between said plurality of ventricular stimulation pulses to be descriptive of said parametric information for said plurality of parameters further comprises:

(i) means for defining a plurality of descriptive pulse segments, each of said descriptive pulse segments characterized by the occurrence of two successive ventricular stimulation pulses from said plurality of ventricular stimulation pulses;

(ii) means for associating each of the plurality of parameters with one of said descriptive pulse segments; and

(iii) means for varying the timing interval of each of said descriptive pulse segments to be indicative of said parametric information for said associated parameter.

24. The cardiac pacing system of claim 21, wherein said means for varying said timing intervals between said plurality of ventricular stimulation pulses further includes means for setting said timing intervals between each of said plurality of ventricular stimulation pulses to prescribed values such that each combination of prescribed values is indicative of the parametric information for said associated parameter.

25. The cardiac pacing system of claim 20, further comprising:

means for recording said pulse-modulated cardiac pacing signal; and

means for transtelephonically transmitting said recorded signal to a remote location.

26. The cardiac pacing system of claim 25, further comprising means for receiving and analyzing said pulse-modulated signal to extract said parametric information contained therein.

27. A cardiac stimulation device that selectively provides a cardiac pacing signal encoded with descriptive operational information, comprising:

pulse generating means for generating ventricular stimulation pulses having sufficient energy to cause capture; and

processing means for pulse-modulating the ventricular stimulation pulses with descriptive operational information, the processing means including;

means for determining descriptive information for a plurality of operational conditions;

means for triggering a sequence of ventricular stimulation pulses;

means for pulse-modulating the sequence of ventricular stimulation pulses, wherein each of the modulated pulses contain the descriptive information of a corresponding operational condition; and

means for applying the sequence of pulse-modulated ventricular stimulation pulses to a patient'"'"'s heart so that the cardiac signal has the descriptive information encoded therein.

28. The cardiac stimulation device of claim 27, wherein the pulse-modulating means comprises:

means for varying timing intervals between the plurality of ventricular stimulation pulses.

29. The cardiac stimulation device of claim 27, wherein the pulse-modulating means comprises:

means for varying pulse amplitude between the plurality of ventricular stimulation pulses.

30. The cardiac stimulation device of claim 27, wherein the pulse-modulating means comprises:

means for varying pulse width between the plurality of ventricular stimulation pulses.

31. The cardiac stimulation device of claim 27, wherein the pulse-modulating means comprises:

means for varying pulse number between the plurality of ventricular stimulation pulses.

32. The cardiac stimulation device of claim 27, further comprising:

means for transtelephonically transmitting the pulse-modulated cardiac signal to a remote location.

33. The cardiac stimulation device of claim 27, wherein the plurality of operating conditions includes the status of a battery.

34. The cardiac stimulation device of claim 27, wherein the plurality of operating conditions includes the status of an atrial lead coupled to the cardiac stimulation device.

35. The cardiac stimulation device of claim 27, wherein the plurality of operating conditions includes the status of an ventricular lead coupled to the cardiac stimulation device.

36. The cardiac stimulation device of claim 27, wherein the plurality of operating conditions includes the status of a sensor coupled to the cardiac stimulation device.

37. The cardiac stimulation device of claim 27, wherein the plurality of operating conditions includes an extrasystoles rate of the patient.

38. The cardiac stimulation device of claim 27, wherein the plurality of operating conditions includes the status of a patient'"'"'s arrhythmic condition.