Leadless cardiac pacemaker triggered by conductive communication

• US 20070088398A1
• Filed: 10/13/2006
• Published: 04/19/2007
• Est. Priority Date: 10/14/2005
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories)
• Original Assignee: Nanostim, Inc (Abbott Laboratories)
• Inventors: Jacobson, Peter
• Granted Patent: US 8,352,025 B2
• Time in Patent Office: Days
• US Class Current: 607/9
• CPC Class Codes: A61M 25/0662 Guide tubes
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/0573 chacterised by means penetrating the heart tissue, e.g. helix needle or hook
• CPC Class Codes: A61N 1/0587 Epicardial electrode systems; Endocardial electrodes piercing the pericardium
• CPC Class Codes: A61N 1/059 Anchoring means
• CPC Class Codes: A61N 1/3621 for treating or preventing abnormally high heart rate
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy
• CPC Class Codes: A61N 1/36514 controlled by a physiological quantity other than heart potential, e.g. blood pressure controlled by two or more physical parameters A61N1/36585
• CPC Class Codes: A61N 1/36542 controlled by body motion, e.g. acceleration
• CPC Class Codes: A61N 1/368 comprising more than one electrode co-operating with different heart regions A61N1/3622, A61N1/3627 take precedence
• CPC Class Codes: A61N 1/3684 for stimulating the heart at multiple sites of the ventricle or the atrium
• CPC Class Codes: A61N 1/36842 Multi-site stimulation in the same chamber
• CPC Class Codes: A61N 1/3704 Circuits specially adapted therefor, e.g. for sensitivity control
• CPC Class Codes: A61N 1/3706 Pacemaker parameters stimulation threshold A61N1/371
• CPC Class Codes: A61N 1/3708 for power depletion
• CPC Class Codes: A61N 1/372 Arrangements in connection with the implantation of stimulators
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/37217 characterised by the communication link, e.g. acoustic or tactile
• CPC Class Codes: A61N 1/37252 Details of algorithms or data aspects of communication system, e.g. handshaking, transmitting specific data or segmenting data
• CPC Class Codes: A61N 1/3727 characterised by the modulation technique
• CPC Class Codes: A61N 1/37288 : Communication to several implantable medical devices within one patient
• CPC Class Codes: A61N 1/37512 : Pacemakers
• CPC Class Codes: A61N 1/37518 : Anchoring of the implants, e.g. fixation
• CPC Class Codes: A61N 1/3756 : Casings with electrodes thereon, e.g. leadless stimulators
• CPC Class Codes: A61N 1/3925 : Monitoring; Protecting
• CPC Class Codes: A61N 1/3956 : Implantable devices for applying electric shocks to the heart, e.g. for cardioversion
• CPC Class Codes: A61N 1/39622 : Pacing therapy
• CPC Class Codes: A61N 2001/058 : Fixing tools
• CPC Class Codes: H04B 13/005 : Transmission systems in which the medium consists of the human body

Abstract

A leadless cardiac pacemaker configured for implantation in electrical contact with a left ventricular cardiac chamber and configured for leadless triggered left-ventricular pacing for cardiac resynchronization therapy (CRT) in response to conducted signals from a pulse generator.

Claims

1. A cardiac pacing system comprising:

a leadless cardiac pacemaker configured for implantation in electrical contact with a left ventricular cardiac chamber and configured for leadless triggered left-ventricular pacing for cardiac resynchronization therapy (CRT) in response to conducted signals from a pulse generator.

2. The system according to claim 1 further comprising:

the leadless cardiac pacemaker configured for leadless triggered left-ventricular pacing in response to conducted signals from at least one implanted leadless or electrode-lead pulse generator.

3. The system according to claim 1 further comprising:

at least one implanted leadless or electrode-lead pulse generator configured to conduct signals to the leadless cardiac pacemaker that trigger left-ventricular pacing.

4. The system according to claim 1 further comprising:

the leadless cardiac pacemaker configured for operation as a left-ventricular pacemaker for cardiac resynchronization therapy using a cardioverter-defibrillator (CRT-D) or cardiac resynchronization therapy using an otherwise conventional pacemaker (CRT-P), in response to wireless conducted signals from at least one implanted leadless or electrode-lead pulse generator, the wireless conducted signals being conducted pacing and/or cardiac signals.

5. The system according to claim 1 further comprising:

the leadless cardiac pacemaker comprising;

a hermetic housing configured for placement on or attachment to the inside or outside of a cardiac chamber; and

at least two electrodes abutting or adjacent to the housing and configured for delivering pacing pulses and receiving triggering signals from the pulse generator.

6. The system according to claim 5 further comprising:

the at least two electrodes configured for sensing electrical activity from cardiac chamber muscle.

7. The system according to claim 5 further comprising:

the at least two electrodes configured for bi-directional communication with at least one other device within or outside the body.

8. The system according to claim 5 further comprising:

the leadless pacemaker configured to communicate with a non-implanted programmer or at least one implanted pulse generator via the at least two electrodes that are also used for delivering pacing pulses, the leadless pacemaker configured for antenna-less and telemetry coil-less communication.

9. The system according to claim 5 further comprising:

the leadless pacemaker configured to communicate to a non-implanted programmer or at least one implanted pulse generator via communication that adds nothing to transmitted power requirements above power requirements for cardiac pacing.

10. The system according to claim 1 further comprising:

the leadless cardiac pacemaker configured for leadless triggered left-ventricular pacing in response to conducted signals selected from a group consisting of a signal from a separate implanted pulse generator, a signal from at least one electrode-lead of a separate implanted pulse generator, a right-ventricular pacing pulse delivered by an implanted pulse generator, an atrial pacing pulse delivered by an implanted pulse generator, a signal delivered in combination with a cardioversion function, and a signal delivered in combination with a defibrillation function.

11. The system according to claim 1 further comprising:

the leadless cardiac pacemaker operative as a “

slave”

left-ventricular leadless cardiac pacemaker triggered by an atrial pacing pulse or right-ventricular pacing pulse of the pulse generator operative for right-ventricular and/or atrial pacing.

12. The system according to claim 1 further comprising:

the leadless pacemaker configured for implantation adjacent to the inside or outside wall of a cardiac chamber and configured for leadless conductive communication with the pulse generator.

13. The system according to claim 1 further comprising:

the leadless pacemaker configured for left-ventricular pacing triggered by conducted communication from the pulse generator implanted within the body, the left-ventricular pacing triggered by a right-ventricular pacing pulse or atrial pacing pulse delivered by the pulse generator.

14. The system according to claim 1 further comprising:

at least two electrodes abutting or adjacent to the housing and configured for delivering pacing pulses and operative as an incoming communication channel for receiving triggering signals from the pulse generator, the triggering information comprising an electrical potential difference resulting from a right-ventricular pacing pulse or an atrial pacing pulse of an implanted pulse generator and electrode-lead system.

15. The system according to claim 14 further comprising:

a controller coupled to the at least two electrodes adapted to examine triggering information validity and, for a valid condition, activating delivery of a pacing pulse following a predetermined delay of zero or more milliseconds.

16. The system according to claim 14 further comprising:

the incoming communication channel adapted to communicate information selected from a group consisting of pacing rate, pulse duration, sensing threshold, delay intervals, refractory time intervals, stimulation pulse amplitudes, and parameters commonly programmed from an external programmer in a pacemaker; and

the at least two electrodes further operative as an outgoing communication channel adapted to communicate information selected from a group consisting of programmable parameter settings, pacing and sensing event counts, battery voltage, battery current, information commonly displayed by external programmers used with pacemakers, and echoed information from the incoming channel to confirm correct programming.

17. The system according to claim 14 further comprising:

a controller coupled to the at least two electrodes adapted to examine the potential difference resulting from a pacing pulse, decode information encoded in the pacing pulse, and evaluate the decoded information for pacing pulse signature validation.

18. The system according to claim 1 further comprising:

a controller coupled to the at least two electrodes adapted to examine output pulse duration from an implanted pulse generator for usage as a signature for determining triggering information validity and, for a signature arriving within predetermined limits, activating delivery of a pacing pulse following a predetermined delay of zero or more milliseconds, the predetermined delay being determined from a method in a group consisting of preset at manufacture, programmed via an external programmer, and adaptively monitoring and conforming to duration of a triggering signal.

19. The system according to claim 1 further comprising:

a controller coupled to the at least two electrodes adapted to examine output pulse amplitude, duration, and rate from an implanted pulse generator for usage as a signature for determining triggering information validity and, for a signature arriving within predetermined limits, activating delivery of a pacing pulse following a predetermined delay of zero or more milliseconds.

20. The system according to claim 1 further comprising:

a controller coupled to the at least two electrodes adapted to trigger delivery of a left-ventricular pacing pulse from an atrial pacing pulse of an implanted pulse generator for cardiac resynchronization therapy (CRT) after a selected atrio-ventricular delay of 50 to 300 milliseconds, the controller further adapted to vary the atrio-ventricular delay according to time since a last delivered left-ventricular pacing pulse whereby a shorter atrio-ventricular delay is selected for a higher atrial rate.

21. A cardiac pacing system comprising:

a leadless cardiac pacemaker configured for implantation in electrical contact with a cardiac chamber and configured for receiving and evaluating triggering information from an implanted pulse generator via an electrical signal conducted from an atrial or ventricular pacing pulse delivered by the implanted pulse generator.

22. The system according to claim 21 further comprising:

at least one implanted leadless or electrode-lead pulse generator configured to conduct signals that trigger left-ventricular pacing to the leadless cardiac pacemaker by direct conduction using modulated signals at a frequency in a range from approximately 10 kHz to 100 kHz.

23. The system according to claim 21 further comprising:

the leadless cardiac pacemaker comprising;

a hermetic housing configured for placement on or attachment to the inside or outside of a cardiac chamber; and

at least two electrodes abutting or adjacent to the housing and configured for delivering pacing pulses and receiving triggering signals from the pulse generator.

24. The system according to claim 21 further comprising:

at least two electrodes abutting or adjacent to the housing and configured for delivering pacing pulses and operative as an incoming communication channel for receiving triggering signals from the pulse generator, the triggering information comprising an electrical potential difference resulting from a pacing pulse.

25. The system according to claim 21 further comprising:

a controller coupled to the at least two electrodes adapted to examine triggering information validity and, for a valid condition, activating delivery of a pacing pulse following a predetermined delay of zero or more milliseconds.

26. The system according to claim 21 further comprising:

a controller coupled to the at least two electrodes adapted to examine output pulse duration from an implanted pulse generator for usage as a signature for determining triggering information validity and, for a signature arriving within predetermined limits, activating delivery of a pacing pulse following a predetermined delay of zero or more milliseconds, the predetermined delay being determined from a method in a group consisting of preset at manufacture, programmed via an external programmer, and adaptively monitoring and conforming to duration of a triggering signal.

27. The system according to claim 21 further comprising:

a controller coupled to the at least two electrodes adapted to examine output pulse amplitude from an implanted pulse generator for usage as a signature for determining triggering information validity and, for a signature arriving within predetermined limits, activating delivery of a pacing pulse following a predetermined delay of zero or more milliseconds.

28. The system according to claim 21 further comprising:

a controller coupled to the at least two electrodes adapted to trigger delivery of an atrial pacing pulse in response to sensing of an atrial heartbeat in sinus rhythm and in response to detection of sinus rhythm below a selected rate for atrial demand pacing.

29. The system according to claim 21 further comprising:

a controller coupled to the at least two electrodes adapted to limit synchronous pacing pulse delivery rate to a selected maximum rate.

30. The system according to claim 21 further comprising:

a plurality of leadless cardiac pacemakers configured for implantation in electrical contact with at least one cardiac chamber and distributed epicardially, the leadless cardiac pacemaker plurality adapted to be timed from an initial triggering pulse for generating simultaneous pulses for defibrillation or cardioversion therapy.

31. The system according to claim 21 further comprising:

the leadless cardiac pacemaker further configured for retriggering by the implanted pulse generator whereby the leadless cardiac pacemaker generates a pacing pulse after a predetermined time with no received triggering signal and the predetermined time is preset slightly longer than a pacing interval of the implanted pulse generator, the leadless cardiac pacemaker functioning as a synchronized redundant pacemaker.

32. A cardiac pacing system comprising:

a leadless cardiac pacemaker configured for implantation in electrical contact with a cardiac chamber and configured for delivering a pacing pulse and encoding outgoing communication in the pacing pulse whereby a power requirement for the outgoing communication adds nothing to a power requirement for current in delivering the pacing pulse.

33. The system according to claim 32 wherein:

the outgoing communication power requirement does not add to a power requirement for pacing whereby power is used for a dual purpose.

34. The system according to claim 32 further comprising:

the leadless cardiac pacemaker comprising;

a hermetic housing configured for placement on or attachment to the inside or outside of a cardiac chamber; and

at least two electrodes abutting or adjacent to the housing and configured for delivering pacing pulses and receiving triggering signals from the pulse generator, and bi-directional communication with the at least one implanted and/or non-implanted device.

35. A method for communicating in an implantable device comprising:

generating stimulation pulses at an implanted biostimulator;

encoding information onto generated stimulation pulses at the implanted biostimulator by selective alteration of stimulation pulse morphology that is benign to therapeutic effect and energy cost of the stimulation pulse; and

conducting the stimulation pulses into body tissue via electrodes for antenna-less and telemetry coil-less communication.

36. The method according to claim 35 further comprising:

generating cardiac pacing pulses at an implanted leadless cardiac pacemaker;

encoding information onto generated cardiac pacing pulses at the implanted leadless cardiac pacemaker by selective alteration of pacing pulse morphology that is benign to therapeutic effect and energy cost of the pacing pulse; and

conducting the cardiac pacing pulses into body tissue via electrodes for antenna-less and telemetry coil-less communication.

37. The method according to claim 36 further comprising:

encoding information onto generated cardiac pacing pulses at the implanted leadless cardiac pacemaker comprising pacemaker state information, battery voltage, lead impedance, sensed electrocardiogram amplitude, pacemaker current drain, and programmed parameters.

38. The method according to claim 36 further comprising:

encoding information onto generated cardiac pacing pulses at the implanted leadless cardiac pacemaker by selective alteration of pacing pulse morphology that is benign to therapeutic effect and energy cost of the pacing pulse;

detecting at the implanted leadless cardiac pacemaker a natural cardiac depolarization;

inhibiting cardiac pacing pulse delivery with delay for delivery during a refractory period following the natural cardiac depolarization; and

conducting the cardiac pacing pulses into body tissue via electrodes for antenna-less and telemetry coil-less communication.

39. The method according to claim 36 further comprising:

distinguishing a generated cardiac pacing pulse from a natural cardiac depolarization in an electrocardiogram comprising comparative pattern recognition of a pacing pulse and an R-wave produced during a cardiac cycle.

40. The method according to claim 35 further comprising:

generating stimulation pulses on stimulating electrodes of an implanted biostimulator; and

encoding information onto generated stimulation pulses comprising gating the stimulation pulses for selected durations at selected timed sections in the stimulation pulses whereby gating removes current flow through the stimulating electrodes and timing of the gated sections encodes the information.

41. The method according to claim 35 further comprising:

generating stimulation pulses on stimulating electrodes of an implanted biostimulator; and

encoding information onto generated stimulation pulses comprising selectively varying timing between consecutive stimulation pulses.

42. The method according to claim 35 further comprising:

generating stimulation pulses on stimulating electrodes of an implanted biostimulator; and

encoding information onto a series of generated stimulation pulses comprising selectively varying pacing pulse width.

43. The method according to claim 35 further comprising:

charging a tank capacitor in preparation for stimulation pulse generation;

generating stimulation pulses on stimulating electrodes of an implanted biostimulator;

encoding information onto generated stimulation pulses;

44. The method according to claim 43 further comprising:

timing one or more windows between pulse generation;

disabling charging of the tank capacitor during the one or more timed windows; and

enabling a receive amplifier in the implanted biostimulator while the tank capacitor is disabled whereby operation of a communications amplifier and charging of the tank capacitor are made mutually exclusive.

45. The method according to claim 35 further comprising:

controlling gain setting for a receiving amplifier/filter;

invoking a low-gain setting for normal operation and detecting presence of a biostimulation pulse; and

invoking a high-gain setting for detecting and decoding information encoded in the detected biostimulation pulse.

46. The method according to claim 35 further comprising:

charging a tank capacitor in preparation for stimulation pulse generation;

detecting a supply voltage drop below a pre-specified level; and

terminating charging of the pacing tank capacitor when the supply voltage drops below the pre-specified level

47. The method according to claim 35 further comprising:

charging a tank capacitor in preparation for stimulation pulse generation;

detecting supply voltage; and

reducing tank capacitor charge current whereby the supply voltage is prevented from dropping below a pre-specified level.

48. A biostimulation system comprising:

a biostimulator configured for implantation in electrical contact with a biological tissue and configured for receiving and evaluating triggering information from an implanted pulse generator via an electrical signal conducted from a stimulation pulse delivered by the implanted pulse generator.

49. A cardiac pacing system comprising:

a leadless cardiac pacemaker configured for implantation in electrical contact with a left ventricular cardiac chamber and configured for leadless triggered left-ventricular pacing in response to conducted signals from a pulse generator and powered by a battery contained within a volume of less than one cubic centimeter.