HEMODYNAMIC PERFORMANCE ENHANCEMENT THROUGH ASYMPTOMATIC DIAPHRAGM STIMULATION

20230277855

18/196148

May 11, 2023

An implantable system, and methodology, for improving a heart's hemodynamic performance featuring (a) bimodal electrodes placeable on the diaphragm, out of contact with the heart, possessing one mode for sensing cardiac electrical activity, and another for applying cardiac-cycle-synchronized, asymptomatic electrical stimulation to the diaphragm to trigger biphasic, diaphragmatic motion, (b) an accelerometer adjacent the electrodes for sensing both heart sounds, and stimulation-induced diaphragmatic motion, and (c) circuit structure, connected both to the electrodes and the accelerometer, operable, in predetermined timed relationships to the presences of valid V-events noted in one of sensed electrical and sensed mechanical, cardiac activity, to deliver diaphragmatic stimulation. The circuit structure includes accelerometer-linked computer structure for enabling selective review, for later operational modifications, of stimulation-produced diaphragmatic motions, and in a modified form, may additionally include timing-adjustment substructure capable of making adjustments in the mentioned timed relationships.

1. A method for improving hemodynamic performance of a heart through electrical stimulation of a diaphragm, the method comprising: detecting a cyclic cardiac event of a patient; delivering an electrical stimulation therapy to a diaphragm of the patient timed to the detection of the cyclic cardiac event, wherein the electrical stimulation therapy is defined by a plurality of stimulation parameters; monitoring an intrathoracic pressure associated with an intrathoracic cavity of the patient to determine whether an adjustment of one or more of the plurality of stimulation parameters is warranted; and adjusting one or more of the stimulation parameters based on the monitoring.

2. The method of claim 1, wherein detecting a cyclic cardiac event comprises sensing electrical cardiac activity through one or more of a plurality of electrodes placed adjacent to the diaphragm or in direct contact with the diaphragm.

3. The method of claim 1, wherein electrical stimulation is applied to the diaphragm through at least one of a plurality of electrodes placed adjacent to the diaphragm or in direct contact with the diaphragm.

4. The method of claim 1, wherein monitoring a pressure associated with the intrathoracic cavity comprises: obtaining a signal indicative of the intrathoracic pressure; deriving a measure of intrathoracic pressure from the obtained signal; evaluating the measure of intrathoracic pressure against a baseline measure of intrathoracic pressure; and determining to adjust one or more of the stimulation parameters based on the evaluation.

5. The method of claim 4, wherein the signal indicative of the intrathoracic pressure is obtained from a pressure sensor implanted within the intrathoracic cavity of the patient.

6. The method of claim 5, wherein the pressure sensor comprises one of an accelerometer, a motion sensor, and a heart sound sensor.

7. An apparatus for affecting a pressure within an intrathoracic cavity of a patient, the apparatus comprising: one or more electrodes configured for placement on or near a diaphragm of the patient; a pressure measurement source configured to provide a signal indicative of a pressure within an intrathoracic cavity of the patient; and a controller configured to: detect a cyclic cardiac event of the patient based on a signal obtained from the one or more electrodes; deliver an electrical stimulation therapy to a diaphragm of the patient through the one or more electrodes, wherein delivery of the electrical stimulation therapy is timed to the detection of the cyclic cardiac event, and the electrical stimulation therapy is defined by a plurality of stimulation parameters; monitor a pressure associated with the intrathoracic cavity based on the signal provided by the pressure measurement source, to determine whether an adjustment of one or more of the plurality of stimulation parameters is warranted; and adjust one or more of the stimulation parameters based on the monitoring.

8. The apparatus of claim 7, wherein: the pressure measurement source is a pressure sensor and the signal indicative of the pressure corresponds to a signal representing one of intrathoracic pressure, right atrial pressure, right ventricular pressure, left ventricular pressure, aortic pressure, and pulmonary artery pressure, and the controller monitors a pressure associated with the intrathoracic cavity by being further configured to: derive a measure of interest from the signal indicative of a pressure within an intrathoracic cavity of the patient; evaluate the measure of interest against a baseline measure of interest; and determine to adjust one or more of the stimulation parameters based on the evaluation.

9. The apparatus of claim 8, wherein the measure of interest is a pressure measurement at or near a fiducial point within a cardiac cycle, and the baseline measure of interest is one of: a) a pressure measurement at or near the fiducial point within a cardiac cycle, derived from a previously obtained signal indicative of the pressure, or b) a nominal value of the measure of interest.

10. The apparatus of claim 9, wherein the fiducial point is located at or near a cardiac event, or a period after a cardiac event.

11. The apparatus of claim 8, wherein: the controller evaluates the measure of interest against a baseline measure of interest by being further configured to determine if the measure of interest represents an increase in negative pressure relative to the baseline measure of interest or a decrease in negative pressure relative to the baseline measure of interest, and the controller determines to adjust one or more of the stimulation parameters based on the evaluation, by being further configured to: adjust one or more of the stimulation parameters when the measure of interest represents a decrease in negative pressure, and maintain the stimulation parameters when the measure of interest represents an increase in negative pressure or a steady state negative pressure.

12. The apparatus of claim 7, wherein: the pressure measurement source is a motion sensor and the signal indicative of the pressure corresponds to a signal representing one of movement of the diaphragm or heart sounds, the controller monitors a pressure associated with the intrathoracic cavity by being further configured to detect an event of interest from the signal indicative of the pressure, the event of interest corresponding to a respiration cycle event, and the controller adjusts at least one of the stimulation parameters by being configured to: withhold delivering a stimulation pulse timed to be delivered at or near a time of the respiration cycle event; and change one or more parameters of a stimulation pulse timed to be delivered at or near a time of the respiration cycle event.

13. The apparatus of claim 12, wherein the respiration cycle event is an end of an inspiration stage of a respiration cycle.

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