Systems and methods for packed pacing using bifurcated pacing pulses of opposing polarity generated by an implantable medical device

• US 9,956,413 B2
• Filed: 10/11/2012
• Issued: 05/01/2018
• Est. Priority Date: 10/11/2012
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Bornzin, Gene A.
• Primary Examiner(s): Alter, Alyssa M
• Application Number:
  US13/649,795
• Publication Number:
  US 20140107720A1
• Time in Patent Office: 2,028 Days
• Field of Search: 607 9
• CPC Class Codes: A61N 1/3615 Intensity
• CPC Class Codes: A61N 1/36167 Timing, e.g. stimulation onset
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy

Abstract

Techniques are provided for use with implantable medical devices to deliver packed pacing using split or bifurcated pulses of opposing polarity in different cardiac cycles. In one example, packed single-phase pulses are delivered by the device during a first cardiac cycle that serve to stimulate heart tissue. During the next cardiac cycle, packed single-phase stimulation pulse of opposing polarity are delivered that serve to recharge the pacing capacitors and also serve to stimulate heart tissue. By separating the pulses into separate cardiac cycles, near simultaneous multisite packed stimulation can be achieved within each cardiac cycle while providing for charge balancing and without interfering with sensing. Non-packed pacing with bifurcated pulses is also described.

Claims

1. A method for use with an implantable cardiac stimulation device equipped for delivering output pulses via a plurality of electrodes, the method comprising:

during a first cardiac cycle, generating a first plurality of closely spaced single-phase primary stimulation pulses for delivery to the heart of the patient during the first cardiac cycle with each pulse of the plurality of primary pulses being delivered using a different pair of electrodes wherein an amplitude of the primary stimulation pulses is higher than a stimulation threshold at each of the different pairs of electrodes for the corresponding single phase pulse; and

during a second cardiac cycle, generating a corresponding second plurality of closely spaced single-phase secondary stimulation pulses for delivery to the heart of the patient during the second cardiac cycle with each pulse of the plurality of secondary stimulation pulses being delivered using a different pair of electrodes, the secondary pulses being opposite in polarity to corresponding primary pulses delivered with a corresponding pair of electrodes and configured as recharge pulses in relation to the corresponding primary pulses, wherein an amplitude of the secondary stimulation pulses is higher than a stimulation threshold at each of the different pairs of electrodes for the corresponding single phase pulse.

2. The method of claim 1 wherein the set of single-phase primary stimulation pulses are delivered at closely successive times to one another to provide near simultaneous stimulation at multiple locations during the first cardiac cycle and wherein the set of single-phase secondary stimulation pulses are likewise delivered at closely successive times to one another to provide near simultaneous stimulation at multiple locations during the second cardiac cycle.

3. The method of claim 1 wherein the set of single-phase secondary pulses are configured to achieve charge balance relative to the set of single-phase primary pulses.

4. The method of claim 1 wherein first and second cardiac cycles are consecutive.

5. The method of claim 1 wherein first and second cardiac cycles are non-consecutive.

6. The method of claim 1 wherein the set of single-phase primary pulses and the set of single-phase secondary pulses each include two pulses.

7. The method of claim 1 wherein single-phase primary pulses and the single-phase secondary pulses are balanced with each secondary pulse having an equal and opposite voltage to a corresponding primary puke and with each of the pulses having about the same duration.

8. The method of claim 1 wherein single-phase primary pulses and the single-phase secondary pulses are unbalanced with the secondary pulses having differing voltages and durations to corresponding primary pulses.

9. The method of claim 1 further including a preliminary step of setting pulse amplitudes and pulse widths for the single-phase primary pulses and for the single-phase secondary pulses.

10. The method of claim 9 wherein the preliminary step of setting the pulse amplitudes and pulse widths for a selected pair of electrodes comprises:

for each individual electrode of a selected electrode pair for use in delivering the pulses, measure anodic and cathodic voltage thresholds for a selected pulse width within a unipolar pacing configuration then divide each electode'"'"'s cathodic and anodic voltage threshold by the respective electrode'"'"'s pacing impedance to provide four current thresholds;

for the selected electrode pair, measure a bipolar pacing resistance for the pair, multiply each of the current thresholds by the respective bipolar pacing resistance, and then select a highest threshold voltage from among the measured voltage thresholds and divide by the bipolar pacing resistance for the electrode pair to yield a worst case value for that electrode pair;

set the pulse amplitude for use with the electrode pair based on the resulting worst-case value (Vth).

11. The method of claim 10 wherein setting the pulse amplitude for use with a balanced configuration based on the resulting worst case value comprises:

Vth * 2 * a safety factor.

12. The method of claim 11 wherein the safety factor is at least 1.5.

13. The method of claim 9 wherein the preliminary step of setting the pulse amplitudes and pulse widths includes using strength duration curves to set the pulse amplitudes and pulse widths.

14. The method of claim 13 wherein the strength duration curves are represented using one or more of a:

lookup table or a functional equivalent to a lookup table.

15. A system for use with an implantable cardiac stimulation device equipped for delivering output pulses via a plurality of electrodes, the system comprising:

a single-phase primary pulse packed pacing system operative during a first cardiac cycle to generate a plurality of closely spaced single-phase primary stimulation pulses for delivery to the heart of the patient with each pulse of the plurality of primary pulses being delivered using a different pair of electrodes during the first cardiac cycle, wherein an amplitude of the primary stimulation pulses is higher than a stimulation threshold at each of the different pairs of electrodes for the corresponding single phase pulse; and

a single-phase secondary pulse packed pacing system operative during a second cardiac cycle to generate a plurality of closely spaced single-phase secondary stimulation pulses for delivery to the heart of the patient during the second cardiac cycle with each pulse of the plurality of secondary stimulation pulses being delivered using a different pair of electrodes, the secondary pulses being opposite in polarity to the primary pulses and configured as recharge pulses in relation to corresponding primary pulses, wherein an amplitude of the secondary stimulation pulses is higher than a stimulation threshold at each of the different pairs of electrodes for the corresponding single phase pulse.

16. A system for use with an implantable cardiac stimulation device equipped for delivering output pulses via a plurality of electrodes, the system comprising:

means, operative during a first cardiac cycle, for generating a plurality of closely spaced single-phase primary stimulation pulses for delivery to the heart of the patient with each pulse of the plurality of primary pulses being delivered using a different pair of electrodes during the first cardiac cycle, wherein an amplitude of the primary stimulation pulses is higher than a stimulation threshold at each of the different pairs of electrodes for the corresponding single pulse; and

means, operative during a second cardiac cycle, for generating a plurality of closely spaced single-phase secondary stimulation pulses for delivery to the heart of the patient with each pulse of the plurality of secondary stimulation pulses being delivered using a different pair of electrodes during the second cardiac cycle, the secondary pulses being opposite in polarity to the primary pulses and configured as recharge pulses in relation to corresponding primary pulses, wherein an amplitude of the secondary stimulation pulses is higher than a stimulation threshold at each of the different pairs of electrodes for the corresponding single pulse.