Neurostimulation and recording of physiological response for the treatment of chronic cardiac dysfunction
Systems and methods are provided for delivering neurostimulation therapies to patients for treating chronic heart failure. A neural fulcrum zone is identified and ongoing neurostimulation therapy is delivered within the neural fulcrum zone. The implanted stimulation device includes a physiological sensor for recording the patient's response to the neurostimulation therapy on an ambulatory basis over extended periods of time.
1. A neurostimulator adapted to deliver a stimulation signal to a patient, said stimulation signal comprising an ON time and an OFF time, the neurostimulator comprising:
a control system comprising a processor configured to:
activate the neurostimulator to deliver the stimulation signal;
during the OFF time of the stimulation signal, acquire a baseline signal comprising a baseline heart rate from a heart rate sensor;
during the ON time of the stimulation signal, acquire a response signal comprising a heart rate response from the heart rate sensor; and
change an intensity of the stimulation signal, based on the baseline signal and the response signal, to cause a transition heart rate response in the patient, the transition heart rate response being between tachycardia and bradycardia and comprising a heart rate change between the baseline heart rate and the heart rate response that is less than a predefined threshold.
2. The neurostimulator of claim 1 , wherein the control system is further configured to periodically record the baseline signals and the response signals for a period of at least one week.
3. The neurostimulator of claim 1 , wherein the control system is further configured to periodically record the baseline signals and the response signals for a period of at least one month.
4. The neurostimulator of claim 1 , wherein the control system is further configured to periodically record the baseline signals and the response signals for a period of at least one year.
5. The neurostimulator of claim 1 , wherein the control system is configured to transmit recorded baseline signals and response signals to an external computing device.
6. The neurostimulator of claim 1 , wherein the stimulation signals are configured to treat a chronic cardiac dysfunction.
7. The neurostimulator of claim 1 , wherein the stimulation signals are vagus nerve stimulation signals.
8. The neurostimulator of claim 1 , wherein the control system is configured to acquire the baseline signal after a delay period following completion of the ON time of the stimulation signal.
9. The neurostimulator of claim 1 , wherein the control system is configured to acquire the response signal after a delay period following initiation of the ON time of the stimulation signal.
10. The neurostimulator of claim 1 , wherein the control system is further configured to calculate a baseline signal average of a plurality of OFF times of the stimulation signal and to calculate a response signal average of a plurality of ON times of the stimulation signal.
11. A method of operating a neurostimulator adapted to deliver a stimulation signal to a patient, said stimulation signal comprising an ON time and an OFF time, the method comprising:
activating the neurostimulator to deliver the stimulation signal;
during the OFF time of the stimulation signal, acquiring a baseline signal comprising a baseline heart rate from a heart rate sensor;
during the ON time of the stimulation signal, acquiring a response signal comprising a heart rate response from the heart rate sensor; and
changing an intensity of the stimulation signal, based on the baseline signal and the response signal, to cause a transition heart rate response in the patient, the transition heart rate response between tachycardia and bradycardia and comprising a heart rate change between the baseline heart rate and the heart rate response that is less than a predefined threshold.
12. The method of claim 11 , further comprising periodically recording the baseline signals and the response signals for a period of at least one week.
13. The method of claim 11 , further comprising periodically recording the baseline signals and the response signals for a period of at least one month.
14. The method of claim 11 , further comprising periodically recording the baseline signals and the response signals for a period of at least one year.
15. The method of claim 11 , further comprising transmitting recorded baseline signals and response signals to an external computing device.
16. The method of claim 11 , wherein the stimulation signals are configured to treat a chronic cardiac dysfunction.
17. The method of claim 11 , wherein the stimulation signals are vagus nerve stimulation signals.
18. The method of claim 11 , wherein acquiring the baseline signal comprises acquiring the baseline signal after a delay period following completion of the ON time of the stimulation signal.
19. The method of claim 11 , wherein acquiring the response signal comprises acquiring the response signal after a delay period following initiation of the ON time of the stimulation signal.
20. The method of claim 11 , further comprising:
calculating a baseline signal average of a plurality of OFF times of the stimulation signal; and
calculating a response signal average of a plurality of ON times of the stimulation signal.