Method for hemodynamic optimization using plethysmography

• US 8,914,108 B2
• Filed: 01/06/2014
• Issued: 12/16/2014
• Est. Priority Date: 12/10/2009
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Bornzin, Gene A., Hou, Wenbo, Karst, Edward, Wenzel, Brian J., Fayram, Timothy A.
• Primary Examiner(s): Lavert, Nicole F
• Application Number:
  US14/148,504
• Publication Number:
  US 20140336719A1
• Time in Patent Office: 344 Days
• Field of Search: 607 17- 18, 607/119
• US Class Current: 607/18
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/726 using Wavelet transforms
• 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 1/36564 controlled by blood pressure
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters
• 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 1/36843 Bi-ventricular stimulation
• CPC Class Codes: A61N 1/3686 configured for selecting the electrode configuration on a lead A61N1/3688 takes precedence

Abstract

Time delays between a feature of a signal indicative of electrical activity of a patient'"'"'s heart and a feature of a plethysmograph signal indicative of changes in arterial blood volume are used to arrange the operation of an implantable device, such as a pacemaker. Shorter time delays between the feature of the signal indicative of electrical activity of a patient'"'"'s heart and the feature of the plethysmograph signal indicative of changes in arterial blood volume are indicative of larger cardiac stroke volumes. The time delay can be used to select a pacing site or combination of pacing sites and/or to select a pacing interval set.

Claims

1. A system, comprising:

at least one implantable lead comprising at least one electrode;

at least one pulse generator coupleable to the at least one lead and configured to deliver cardiac stimulation to pacing sites adjacent the at least one electrode;

at least one sensing circuit configured to obtaining a signal indicative of electrical activity of the patient'"'"'s heart;

at least one plethysmograph sensor configured to obtain a plethysmograph signal indicative of changes in arterial blood volume; and

at least one processor for use in selecting a pacing site at which to deliver cardiac stimulation to a patient;

wherein for each of a plurality of pacing sites and/or combination of pacing sites within the patient, the system is configured to use the at least one lead, the at least one pulse generator, the at least one sensing circuit, and the at least one processor, to

deliver cardiac stimulation using the pacing site or the combination of pacing sites;

obtain the signal indicative of electrical activity of the patient'"'"'s heart while the pacing site or the combination of pacing sites is being used to deliver cardiac stimulation;

obtain the plethysmograph signal indicative of changes in arterial blood volume while the pacing site or the combination of pacing sites is being used to deliver cardiac stimulation; and

determine a time delay between a predetermined feature of the signal indicative of electrical activity and a predetermined feature of the plethysmograph signal indicative of changes in arterial blood volume; and

wherein the system is also configured to select a pacing site or a combination of pacing sites, from the plurality of pacing sites, based on the time delays.

2. The system of claim 1, wherein the system is configured to select as the pacing site or the combination of pacing sites one of the following:

the pacing site or the combination of pacing sites that corresponds, to the shortest of the time delays;

the pacing site or the combination of pacing sites that corresponds to the shortest of the time delays at which phrenic nerve stimulation did not occur; and

any one of the pacing sites or the combination of pacing sites that corresponds to any one of the time delays that meet a predetermined criteria.

3. The system of claim 1, wherein:

the at least one sensing circuit is configured to obtain one of an intracardiac electrogram (IEGM), a subcutaneous electrocardiogram (subQ ECG), and surface electrocardiogram (surface ECG) while the pacing site or the combination of pacing sites is being used to deliver cardiac stimulation;

the at least one plethysmograph sensor is configured to obtain one of a photoplethysmography (PPG) signal and an impedance plethysmography (IPG) signal while the pacing site or the combination of pacing sites is being used to deliver cardiac stimulation; and

wherein the system is also configured to

detect a predetermined feature indicative of ventricular depolarization of the one of the IEGM, the subQ ECG and the surface ECG;

detect a predetermined feature of the one of the PPG signal and the IPG signal; and

determine the time delay between the predetermined feature indicative of ventricular depolarization and the predetermined feature of the one of the PPG signal and the IPG signal.

4. The system of claim 1, wherein the plethysmograph sensor is at least 1 cm remote from the pacing site or combination of pacing sites.

5. The system of claim 1, wherein the predetermined feature of the plethysmograph signal indicative of changes of arterial blood volume comprises one of:

a minimum amplitude;

a maximum upward slope;

a maximum amplitude;

a maximum downward slope; and

a dicrotic notch.

6. The system of claim 1, wherein the cardiac stimulation is delivered to provide cardiac resynchronization therapy (CRT).

7. A system, comprising:

at least one implantable lead comprising at least one electrode;

at least one pulse generator coupleable to the at least one lead and configured to deliver cardiac stimulation to pacing sites adjacent the at least one electrode;

at least one sensing circuit configured to obtaining a signal indicative of electrical activity of the patient'"'"'s heart;

at least one plethysmograph sensor configured to obtain a plethysmograph signal indicative of changes in arterial blood volume;

at least one processor for use in selecting a pacing interval parameter set to deliver cardiac stimulation to a patient;

wherein for each of a plurality of pacing interval parameter sets, the system is configured to use the at least one lead, the at least one pulse generator, the at least one sensing circuit, and the at least one processor, to

deliver cardiac stimulation using the pacing interval parameter set;

obtain the signal indicative of electrical activity of the patient'"'"'s heart while the pacing interval parameter set is being used to deliver cardiac stimulation;

obtain the plethysmograph signal indicative of changes in arterial blood volume while the pacing interval parameter set is being used to deliver cardiac stimulation; and

determine a time delay between a predetermined feature of the signal indicative of electrical activity and a predetermined feature of the plethysmograph signal indicative of changes in arterial blood volume; and

wherein the system is also configured to select a pacing interval parameter set, from the plurality of pacing interval parameter sets, based on the time delays.

8. The system of claim 7, wherein system is also configured to select the pacing interval parameter set, from the plurality of pacing interval parameter sets, based on an amplitude of the plethysmograph signal indicative of changes in arterial blood volume.

9. The system of claim 7, wherein the system is configured to select as the pacing interval parameter set:

the pacing interval parameter set that corresponds to the shortest of the time delays;

the pacing interval parameter set that corresponds to the shortest of the time delays at which phrenic nerve stimulation did not occur; and

any one of the pacing interval parameter sets that corresponds to any one of the time delays that meet a predetermined criteria.

10. The system of claim 7, wherein:

the at least one sensing circuit is configured to obtain one of an intracardiac electrogram (IEGM), a subcutaneous electrocardiogram (subQ ECG), and surface electrocardiogram (surface ECG) while the pacing interval parameter set is being used to deliver cardiac stimulation; and

the at least one plethysmography sensor is configured to obtain one of a photoplethysmography (PPG) signal and an impedance plethysmography (IPG) signal while the pacing interval parameter set is being used to deliver cardiac stimulation;

wherein the system is also configured to

detect a predetermined feature indicative of ventricular depolarization of the one of the IEGM, the subQ ECG and the surface ECG;

detect a predetermined feature of the one of the PPG signal and the IPG signal; and

determine the time delay between the predetermined feature indicative of ventricular depolarization and the predetermined feature of the one of the PPG signal and the IPG signal.

11. The system of claim 7, wherein the at least one plethysmograph sensor is at least 1 cm remote from the pacing site or combination of pacing sites.

12. The method of claim 7, wherein each pacing interval parameter set includes at least one of the following pacing interval parameters:

atrio-ventricular (AV) delay;

interventricular (VV) delay;

interatrial (AA) delay; and

intraventricular delay.

13. The system of claim 7, wherein the predetermined feature of the plethysmograph signal indicative of changes of arterial blood volume comprises one of:

a minimum amplitude;

a maximum upward slope;

a maximum amplitude;

a maximum downward slope; and

a dicrotic notch.

14. The system of claim 7, wherein the cardiac stimulation is delivered to provide cardiac resynchronization therapy (CRT).