Admittance measurement for tuning bi-ventricular pacemakers

• US 20120150252A1
• Filed: 12/02/2011
• Published: 06/14/2012
• Est. Priority Date: 12/10/2010
• Status: Active Grant

• Current Assignee: Admittance Technologies, Inc., Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Admittance Technologies, Inc., Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Feldman, Marc D., Porterfield, John, Larson, Erik, Valvano, Jonathan W., Pearce, John A.
• Granted Patent: US 10,076,669 B2
• Time in Patent Office: Days
• US Class Current: 607/18
• CPC Class Codes: A61B 5/0538 invasively, e.g. using a catheter
• CPC Class Codes: A61N 1/36521 the parameter being derived from measurement of an electrical impedance
• CPC Class Codes: A61N 1/36571 controlled by blood flow rate, e.g. blood velocity or cardiac output
• CPC Class Codes: A61N 1/3682 with a variable atrioventricular delay
• CPC Class Codes: A61N 1/36843 Bi-ventricular stimulation

Abstract

An apparatus for treating a heart of a patient includes a first lead and at least a second lead for pacing the heart adapted to be in electrical communication with the heart. The apparatus includes a microcontroller in communication with the first and second leads which triggers the first lead at either different times or the same time from when the microcontroller triggers the second lead. Alternatively, the apparatus includes a microcontroller in communication with the first and second leads that determines heart volume, including stroke volume, end-systolic volume, and calculated values including ejection fraction, from admittance from signals from the first and second leads and uses the admittance as feedback to control heart volume ejected, as measured by stroke volume, calculated values such as ejection fraction, and control end-systolic volume, with respect to the first and second leads. A method for treating the heart of a patient.

Claims

1. An apparatus for treating a heart of a patient comprising:

a first lead and at least a second lead for pacing the heart adapted to be in electrical communication with the heart; and

a microcontroller in communication with the first and second leads which triggers the first lead at either different times or a same time from when the microcontroller triggers the second lead.

2. The apparatus of claim 1 including a pacing circuit in communication with microcontroller which receives a signal from the microcontroller to activate the pacing circuit.

3. The apparatus of claim 2 including an admittance circuit which measures volume regarding the heart in communication with the microcontroller, the microcontroller controls when the admittance circuit measures volume, the microcontroller determines from the admittance circuit whether stroke volume, ejection fraction and end-systolic volume regarding the heart are increasing or decreasing over time, and changes the pacing circuit'"'"'s operation to maximize the stroke volume and ejection fraction and to minimize the end-systolic volume.

4. The apparatus of claim 3 including a pacemaker enclosure and wherein the admittance circuit is disposed in the pacemaker enclosure.

5. The apparatus of claim 4 wherein the microcontroller is disposed in the enclosure and including a wireless transmitter disposed in the enclosure which transmits a condition signal indicating whether the heart'"'"'s condition is getting worse, better, or is without change.

6. The apparatus of claim 5 wherein the pacing circuit paces each ventricle of the heart separately, where each ventricle is paced separately using a variable time delay between a first and a second pace, or takes into account delay between atrial pacing and ventricular pacing, or a combination thereof.

7. The apparatus of claim 6 including at least a third lead for multiple admittance measurements adapted to be in electrical communication with the heart.

8. An apparatus for treating the heart of a patient comprising:

a first lead and at least a second lead for pacing the heart adapted to be in electrical communication with the heart; and

a microcontroller in communication with the first and second leads that determines heart volume, including stroke volume, end-systolic volume, and calculated values, including ejection fraction, from admittance from signals from the first and second leads and uses the admittance as feedback to control heart volume ejected, as measured by stroke volume, calculated values such as ejection fraction, and control end-systolic volume, with respect to the first and second leads.

9. A method for treating a heart of a patient comprising the steps of:

triggering with a microcontroller a first lead in electrical communication with the heart at various times for pacing the heart; and

triggering with the microcontroller a second lead in electrical communication with the heart at different times than the various times for pacing the heart so that the microcontroller triggers the first lead at different times from when the microcontroller triggers the second lead.

10. The method of claim 9 including the step of determining stroke volume, and systolic volume, and ejection fraction of the heart using epicardial admittance.

11. The method of claim 10 including the step of pacing the heart by separately pacing each ventricle of the heart using a variable time delay between a first and a second pace, or by taking into account delay between atrial pacing and ventricular pacing, or by a combination thereof.

12. The method of claim 11 including the step of re-measuring stroke volume, and systolic volume, and ejection fraction after changing how the heart is paced.

13. The method of claim 12 including the step of comparing the determining step and the re-measuring step, and repeating them until the stroke volume and ejection fraction are maximal, and end-systolic volume is minimal.

14. A method for treating the heart of a patient comprising the steps of:

determining heart volume, including stroke volume, calculated values such as ejection fraction, and end-systolic volume, from admittance with a microcontroller from signals from a first lead and a second lead in electrical communication with the heart; and

using the admittance as feedback to the microcontroller to control heart volume ejected, as measured by stroke volume, calculated values such as ejection fraction, and control end-systolic volume, with respect to the first and second leads.