MULTI-SENSOR BASED CARDIAC STIMULATION

• US 20170113052A1
• Filed: 10/26/2016
• Published: 04/27/2017
• Est. Priority Date: 10/26/2015
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: An, Qi, Thompson, Julie A., Yu, Yinghong, Zhang, Yi, Thakur, Pramodsingh Hirasingh
• Granted Patent: US 10,350,418 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R
• 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 1/36514 controlled by a physiological quantity other than heart potential, e.g. blood pressure controlled by two or more physical parameters A61N1/36585
• CPC Class Codes: A61N 1/36521 the parameter being derived from measurement of an electrical impedance
• CPC Class Codes: A61N 1/36535 controlled by body position or posture
• CPC Class Codes: A61N 1/3655 controlled by body or blood temperature
• 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 1/36592 controlled by the heart rate variability
• CPC Class Codes: A61N 1/3682 with a variable atrioventricular delay
• 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 1/37264 Changing the program; Upgrading firmware

Abstract

Devices and methods for improving device therapy such as cardiac resynchronization therapy by determining a value for a device parameter are described. An ambulatory medical device (AMD) can include a sensor circuit to sense a physiological signal and generate two or more signal metrics, and detect an event of worsening cardiac condition using the two or more signal metrics. In response to the detection of worsening cardiac condition, the AMD can determine, for a stimulator, a value of at least one stimulation parameter based on temporal responses of two or more signal metrics. The temporal responses include near-term and long-term responses to the stimulation. The AMD can program the stimulator with the determined parameter value, and generate stimulation according to the determined parameter value to stimulate target tissue.

Claims

1. An ambulatory medical device (AMD), comprising:

a stimulation generator circuit configured to generate stimulation for stimulating a target tissue in a patient according to at least one stimulation parameter;

a signal sensor circuit including a sense amplifier circuit to sense one or more physiological signals and a filter circuit to generate two or more signal metrics from the sensed one or more physiological signals;

a cardiac condition detector circuit including a blending circuit to use the two or more signal metrics to generate a cardiac condition indicator, and a comparator circuit to detect an event of worsening cardiac condition using the cardiac condition indicator; and

a stimulation programmer circuit coupled to the cardiac condition detector circuit and the signal sensor circuit, the stimulation programmer circuit configured to;

in response to the detection of the event of worsening cardiac condition, determine a parameter value for the at least one stimulation parameter based on information about temporal responses of the two or more signal metrics; and

program the stimulation generator circuit with the determined parameter value.

2. The medical device of claim 1, wherein:

the cardiac condition detector circuit is configured to generate the cardiac condition indicator including a hemodynamic status indicator using two or more signal metrics from one or more of a heart sound signal, an impedance signal, a blood pressure signal, a respiration signal, or a cardiac timing interval signal, the hemodynamic status indicator indicating a change or a rate of change of hemodynamic status of the patient; and

the stimulation programmer circuit is configured to determine the parameter value when the hemodynamic status indicator falls outside a specified range.

3. The medical device of claim 1, wherein:

the cardiac condition detector circuit is configured to generate the cardiac condition indicator including a metabolic demand indicator using one or more of a heart rate signal, a respiration signal, a posture signal, a time signal, a temperature signal, a perspiration signal, or a physical activity signal, the metabolic demand indicator indicating a change of metabolic demand in the patient; and

the stimulation programmer circuit is configured to determine the parameter value when the metabolic demand indicator falls outside a specified range.

4. The medical device of claim 1, wherein:

the cardiac condition detector circuit is configured to receive information about development of comorbidity in heart failure (HF) including presence or severity of one or more of hypertension, atrial fibrillation, diabetes mellitus, pneumonia, or renal failure; and

the stimulation programmer circuit is configured to determine the parameter value in response to the development of comorbidity in HF.

5. The medical device of claim 1, further comprising a timer circuit to determine time elapsed during which the at least one stimulation parameter is set and maintained at a specified parameter value,

wherein the stimulation programmer circuit is configured to determine the parameter value in response to the elapsed time exceeds a specified threshold.

6. The medical device of claim 1, wherein the stimulation generator circuit is configured to generate on or more of:

cardiac resynchronization therapy (CRT) stimulation of a first site of a left ventricle (LV) of the heart and a second site of a right ventricle (RV) of the heart, according to one or more stimulation parameters including an atria-ventricular delay (AVD), a RV-LV delay (VVD), or a lower rate limit (LRL) for stimulation;

or

multisite stimulation of at least first and second sites of a left ventricle (LV), according to one or more stimulation parameters including an atrio-ventricular delay (AVD) or a relative timing between the stimulation of at least the first and second sites of the LV.

7. The medical device of claim 1, wherein the stimulation programmer circuit includes:

a sensor dynamic response analyzer circuit configured to determine respective dynamic response indicators based on the information about the temporal responses of the two or more signal metrics, the respective dynamic response indicators indicating responsiveness of the two or more signal metrics to the stimulation;

a weight factor generator circuit configured to produce, for the two or more signal metrics, respective weight factors using the respective dynamic response indicators; and

a blending circuit configured to generate a stimulation efficacy indicator using a combination of at least some of the two or more signal metrics each weighted by the respective weight factor,

wherein the stimulation programmer circuit determines the parameter value for the at least one stimulation parameter when the stimulation efficacy indicator meets a specified condition.

8. The medical device of claim 7, wherein:

the sensor dynamic response analyzer circuit is configured to determine, for the two or more signal metrics, respective dynamic response indicators including one or more of near-term response indicators during a near-term period (T_N) with respect to the stimulation, or one or more long-term response indicators during a long-term period (T_L) with respect to the stimulation;

the weight factor generator circuit is configured to produce, for the two or more signal metrics, respective weight factors including one or more of near-term weight factors (W_N) corresponding to the near-term period or long-term weight factors (W_L) corresponding to the long-term period; and

the blending circuit is configured to generate the stimulation efficacy indicator including a near-term stimulation efficacy indicator using a combination of at least some of the two or more signal metrics each weighted by the respective near-term weight factors, or a long-term stimulation efficacy indicator using a combination of at least some of the two or more signal metrics each weighted by the respective long-term weight factors.

9. The medical device of claim 7, wherein the weight factor generator circuit is configured to produce, for the two or more signal metrics, respective weight functions describing weight factor as a respective function of time,

wherein the weight function includes a decay function of time if the corresponding signal metric is more responsive to stimulation during the near-term period than during the long-term period, or a growth function of time if the corresponding signal metric is less responsive to stimulation during the near-term period than during the long-term period.

10. The medical device of claim 7, further comprising a sensor metric selector circuit configured to receive information about selection or deselection among the two or more signal metrics according to the at least one stimulation parameter, wherein the blending circuit is configured to generate the stimulation efficacy indicator using a combination of the selected signal metrics each weighted by the respective weight factor.

11. The medical device of claim 10, wherein the stimulation generator circuit is configured to deliver cardiac resynchronization therapy (CRT) stimulation to a right ventricle (RV) and a left ventricle (LV) of the heart, wherein the sensor metric selector circuit is configured to receive the information including:

selecting one or more of S1 amplitude or heart rate if the stimulation parameter is atria-ventricular delay (AVD);

selecting at least Q-LV interval if the stimulation parameter is RV-LV delay (VVD);

selecting at least a blood pressure metric if the stimulation parameter is lower rate limit LRL;

or

selecting one or more of impedance metric or physical activity metric if the stimulation parameter is capture threshold.

12. An ambulatory medical device (AMD), comprising:

a stimulation generator circuit configured to generate stimulation for simulating a target tissue in a patient according to at least one stimulation parameter;

a signal sensor circuit including a sense amplifier circuit to sense one or more physiological signals and a filter circuit to generate two or more signal metrics from the sensed one or more physiological signals;

a cardiac condition detector circuit including a blending circuit to use the two or more signal metrics to generate a cardiac condition indicator, and a comparator circuit to detect an event of worsening cardiac condition using the cardiac condition indicator; and

a stimulation programmer circuit coupled to the cardiac condition detector circuit and the signal sensor circuit, the stimulation programmer circuit configured to;

in response to the detection of the event of worsening cardiac condition;

adjust at least one stimulation parameter;

program the stimulation generator circuit to deliver stimulation using the adjusted at least one stimulation parameter; and

determine an effectiveness of the adjustment or whether further adjustment of the at least one stimulation parameter is needed based on information about temporal responses of the two or more signal metrics.

13. A method, comprising:

sensing one or more physiological signals and generating two or more signal metrics from the sensed one or more physiological signals;

generating a cardiac condition indicator using the two or more signal metrics;

detecting an event of worsening cardiac condition using the cardiac condition indicator;

in response to the detection of the event of worsening cardiac condition, configuring a stimulator including adjusting a parameter value of at least one stimulation parameter;

using the stimulator to generate stimulation according to the at least one stimulation parameter with the adjusted parameter value and deliver the stimulation to a target tissue in a patient;

sensing temporal responses of the two or more signal metrics;

determining a parameter value for the at least one stimulation parameter based on the temporal responses; and

programming the stimulation generator with the determined parameter value.

14. The method of claim 13, wherein generating a cardiac condition indicator includes one or more of:

generating a hemodynamic status indicator using two or more signal metrics from one or more of a heart sound signal, an impedance signal, a blood pressure signal, a respiration signal, or a cardiac timing interval signal, the hemodynamic status indicator indicating a change or a rate of change of hemodynamic status of the patient;

generating a metabolic demand indicator using one or more of a heart rate signal, a respiration signal, a posture signal, a time signal, a temperature signal, a perspiration signal, or a physical activity signal, the metabolic demand indicator indicating a change of metabolic demand in the patient;

or

receiving information about development of comorbidity in heart failure (HF) including presence or severity of one or more of hypertension, atrial fibrillation, diabetes mellitus, pneumonia, or renal failure;

wherein determining the parameter value includes determining the parameter value in response to the hemodynamic status indicator or the metabolic demand indicator falling outside a respective range, or the development of comorbidity in HF.

15. The method of claim 13, further comprising timing elapsed time during which the at least one stimulation parameter is set and maintained at a specified parameter value,

wherein determining the parameter value includes determining the parameter value in response to the elapsed time exceeds a specified threshold.

16. The method of claim 13, wherein using the stimulator to generate the stimulation includes generating cardiac resynchronization therapy (CRT) stimulation of a first site of a left ventricle (LV) of the heart and a second site of a right ventricle (RV) of the heart, according to one or more stimulation parameters including an atrio-ventricular delay (AVD), a RV-LV delay (VVD), or a lower rate limit (LRL) for stimulation.

17. The method of claim 13, wherein using the stimulator to generate the stimulation includes generating multisite stimulation of at least first and second sites of a left ventricle (LV), according to one or more stimulation parameters including an atrio-ventricular delay (AVD) or a relative timing between the stimulation of at least the first and second sites of the LV.

18. The method of claim 13, wherein determining the parameter value for the at least one stimulation parameter includes:

based on the temporal responses of the two or more signal metrics, determining respective dynamic response indicators indicating responsiveness of the two or more signal metrics to the stimulation;

producing, for the two or more signal metrics, respective weight factors using the respective dynamic response indicators;

generating a stimulation efficacy indicator using a combination of at least some of the two or more signal metrics each weighted by the respective weight factor; and

determining the parameter value for the at least one stimulation parameter when the stimulation efficacy indicator meets a specified condition.

19. The method of claim 18, wherein the dynamic response indicators include one or more of near-term response indicators during a near-term period (T_N) with reference to the stimulation, or one or more long-term response indicators during a long-term period (T_L) with reference to the stimulation,

wherein producing the respective weight factors includes producing, for the two or more signal metrics, respective one or more of near-term weight factors (W_N) corresponding to the near-term period or long-term weight factors (W_L) corresponding to the long-term period;

and

wherein generating the stimulation efficacy indicator includes generating a near-term stimulation efficacy indicator using a combination of at least some of the two or more signal metrics each weighted by the respective near-term weight factors, or a long-term stimulation efficacy indicator using a combination of at least some of the two or more signal metrics each weighted by the respective long-term weight factors.

20. The method of claim 19, wherein producing the respective weight factors includes producing, for the two or more signal metrics, respective weight functions describing weight factor as a respective function of time,

wherein the weight function includes a decay function of time if the corresponding signal metric is more responsive to stimulation during the near-term period than during the long-term period, or a growth function of time if the corresponding signal metric is less responsive to stimulation during the near-term period than during the long-term period.