Pain management based on respiration-mediated heart rates

• US 10,631,776 B2
• Filed: 01/11/2018
• Issued: 04/28/2020
• Est. Priority Date: 01/11/2017
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: Annoni, Elizabeth Mary, Clark, Bryan Allen, Thakur, Pramodsingh Hirasingh, Srivastava, Kyle Harish
• Primary Examiner(s): Mahmood, Nadia A
• Application Number:
  US15/867,756
• Publication Number:
  US 20180192941A1
• Time in Patent Office: 838 Days
• Field of Search: 607 46
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/4824 Touch or pain perception evaluation A61B5/4821 takes precedence
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61N 1/0534 Electrodes for deep brain stimulation
• CPC Class Codes: A61N 1/36062 Spinal stimulation
• CPC Class Codes: A61N 1/36071 Pain
• CPC Class Codes: A61N 1/36139 with automatic adjustment
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means
• CPC Class Codes: A61N 1/37264 Changing the program; Upgrading firmware

Abstract

This document discusses, among other things, systems and methods for managing pain of a subject. A system may include a sensor circuit configured to sense a respiration signal and a heart rate signal. A pain analyzer circuit may determine respiratory cycles and respiratory phases in a respiratory cycle, and generate one or more signal metrics indicative of respiration-mediated heart rate variation. The pain analyzer may generate a pain score using the signal metrics indicative of respiration-mediated heart rate variation. The pain score may be output to a user or a process. The system may include an electrostimulator to generate and deliver closed-loop pain therapy according to the pain score.

Claims

1. A system for managing pain of a patient, the system comprising:

a sensor circuit coupled to one or more physiological sensors and configured to sense a respiration signal and a heart rate signal from the patient;

a pain analyzer circuit coupled to the sensor circuit, the pain analyzer circuit configured to;

generate one or more signal metrics indicative of respiration-mediated heart rate variation using the sensed respiration signal and the heart rate signal; and

generate a pain score using a combination of the generated one or more signal metrics each weighted by a respective weight factor; and

an output unit configured to output the pain score to a user or a process.

2. The system of claim 1, further comprising:

an electrostimulator configured to generate electrostimulation energy to treat pain; and

a controller circuit coupled to the pain analyzer circuit and the electrostimulator, the controller circuit configured to control the electrostimulator to deliver a pain therapy and to control the electrostimulation energy generated by the electrostimulator according to the pain score.

3. The system of claim 2, wherein the electrostimulator is further configured to deliver at least one of:

a spinal cord stimulation;

a brain stimulation;

or

a peripheral nerve stimulation.

4. The system of claim 2, wherein:

the controller circuit is further configured to deliver first electrostimulation to the patient in response to the pain score exceeding a threshold value, and to deliver second electrostimulation to the patient in response to the pain score falling below the threshold value; and

the first electrostimulation differs from the second electrostimulation with respect to at least one of an electrostimulation energy, an electrostimulation pulse shape, or an electrostimulation pattern.

5. The system of claim 1, further comprising a respiratory phase detector configured to detect a plurality of respiratory cycles and at least one of an inspiration phase or an expiration phase in each of the plurality of respiratory cycles,

wherein the pain analyzer circuit is further configured to synchronize heart rates from the heart rate signal to the plurality of respiratory cycles, and to determine the respiration-mediated heart rate variation using the synchronized heart rates.

6. The system of claim 5, wherein the respiration-mediated heart rate variation indicates a difference between heart rates during the inspiration phase and heart rates during the expiration phase.

7. The system of claim 5, wherein the respiration-mediated heart rate variation indicates a variability of the synchronized heart rates within one or more of the plurality of respiratory cycles.

8. The system of claim 5, wherein the respiration-mediated heart rate variation includes at least one of:

a heart rate variability during the inspiration phase;

a heart rate variability during the expiration phase;

or

a difference between the heart rate variability during the inspiration phase and the heart rate variability during the expiration phase.

9. The system of claim 1, wherein the sensor circuit is further configured to:

sense a physiological signal using at least one of the one or more physiological sensors; and

filter the sensed physiological signal, via a first filter circuit, to generate the respiration signal, or filter the sensed physiological signal, via a second filter circuit, to generate the heart rate signal;

wherein the second filter circuit uses a center frequency higher than a center frequency used by the first filter circuit.

10. The system of claim 9, wherein the sensor circuit is further configured to sense the physiological signal including at least one of:

a cardiac electrical signal;

a heart sound signal;

a blood pressure signal;

a blood flow signal;

a tissue strain signal;

or

a tissue impedance signal.

11. The system of claim 2, further comprising an implantable neuromodulator device (IND) that includes one or more of the sensor circuit, the pain analyzer circuit, or the electrostimulator.

12. A method for managing pain of a patient using an implantable neuromodulator device (IND), the method comprising:

sensing a respiration signal and a heart rate signal from the patient via a sensor circuit;

generating one or more signal metrics indicative of respiration-mediated heart rate variation using the sensed respiration signal and the heart rate signal;

generating a pain score using a combination of the generated one or more signal metrics each weighted by a respective weight factor; and

outputting the pain score to a user or a process.

13. The method of claim 12, further comprising delivering a pain therapy via the IND, the pain therapy including electrostimulation energy determined according to the pain score.

14. The method of claim 12, further comprising:

detecting a plurality of respiratory cycles and at least one of an inspiration phase or an expiration phase in each of the plurality of respiratory cycles;

synchronizing heart rates from the heart rate signal to the plurality of respiratory cycles; and

determining the respiration-mediated heart rate variation using the synchronized heart rates.

15. The method of claim 14, wherein the respiration-mediated heart rate variation indicates a difference between heart rates during the inspiration phase and heart rates during the expiration phase.

16. The method of claim 14, wherein the respiration-mediated heart rate variation indicates a variability of the synchronized heart rates within one or more of the plurality of respiratory cycles.

17. The method of claim 14, wherein the respiration-mediated heart rate variation includes at least one of:

a heart rate variability during the inspiration phase;

a heart rate variability during the expiration phase;

or

a difference between the heart rate variability during the inspiration phase and the heart rate variability during the expiration phase.

18. The method of claim 12, wherein sensing the respiration signal and the heart rate signal includes:

sensing a physiological signal using a physiological sensor; and

filtering the sensed physiological signal, via a first filter circuit, to generate the respiration signal, or filtering the sensed physiological signal, via a second filter circuit, to generate the heart rate signal, wherein the second filter circuit uses a center frequency higher than a center frequency used by the first filter circuit.

19. At least one non-transitory machine-readable medium including instructions that, when executed by a machine, cause the machine to:

receive a respiration signal and a heart rate signal sensed from a patient;

generate a plurality of signal metrics from the received two or more signals;

generate one or more signal metrics indicative of respiration-mediated heart rate variation using the sensed respiration signal and the heart rate signal;

generate a pain score using a combination of the generated one or more signal metrics each weighted by a respective weight factor; and

output the pain score to a user or a process.

20. The at least one non-transitory machine-readable medium of claim 19, wherein the instructions, when performed by the machine, cause the machine to:

detect a plurality of respiratory cycles and at least one of an inspiration phase or an expiration phase in each of the plurality of respiratory cycles;

synchronize heart rates from the heart rate signal to the plurality of respiratory cycles; and

determine the respiration-mediated heart rate variation using the synchronized heart rates.