LEADLESS MEDICAL SYSTEM FOR QUANTIFYING VENTRICLE TO VENTRICLE DYSSYNCHRONY

• US 20180021585A1
• Filed: 07/19/2017
• Published: 01/25/2018
• Est. Priority Date: 07/20/2016
• Status: Abandoned Application

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: An, Qi, Yu, Yinghong, Kane, Michael J., Thakur, Pramodsingh Hirasingh, Stahmann, Jeffrey E.
• Application Number:
  US15/654,342
• Publication Number:
  US 20180021585A1
• Time in Patent Office: Days
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 5/02028 Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction
• CPC Class Codes: A61B 5/02158 provided with two or more sensor elements
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/0535 Impedance plethysmography for measuring blood flow A61B5/0295
• CPC Class Codes: A61B 5/1073 Measuring volume, e.g. of limbs
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• 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 1/36521 the parameter being derived from measurement of an electrical impedance
• 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 1/37 Monitoring; Protecting
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators
• CPC Class Codes: A61N 1/3758 Packaging of the components within the casing

Abstract

A medical system includes two or more leadless implantable medical devices, each implanted in a different ventricle of the heart and each including a housing, a first electrode secured relative to the housing, a second electrode secured relative to the housing, and a pressure sensor secured relative to the housing. Each of the leadless implantable medical devices may further include circuitry in the housing operatively coupled to the corresponding first electrode, second electrode, and pressure sensor. The medical system may be configured to determine and store a plurality of pressure-pressure data pairs and/or impedance-impedance data pairs generated by the two or more leadless implantable medical devices, from which a representation of a pressure-pressure loop or volume-volume loop may be determined, to facilitate cardiac resynchronization therapy (CRT), patient health status monitoring, and/or the management of a non-CRT cardiac therapy.

Claims

1. A leadless cardiac pacemaker (LCP) system configured to sense cardiac activity and to pace a patient'"'"'s heart, the system comprising:

a first leadless cardiac pacemaker (LCP), the first LCP comprising;

a housing;

a first electrode secured relative to the housing and exposed to the environment outside of the housing;

a second electrode secured relative to the housing and exposed to the environment outside of the housing, the second electrode is spaced from the first electrode;

a pressure sensor secured relative to the housing and is coupled to the environment outside of the housing; and

circuitry in the housing in communication with the first electrode, the second electrode, and the pressure sensor, the circuitry configured to determine at a first time during a cardiac cycle a first pressure via the pressure sensor;

a second LCP, the second LCP comprising;

a housing;

a first electrode secured relative to the housing and exposed to the environment outside of the housing;

a second electrode secured relative to the housing and exposed to the environment outside of the housing, the second electrode is spaced from the first electrode;

a pressure sensor secured relative to the housing and is coupled to the environment outside of the housing; and

circuitry in the housing in communication with the first electrode, the second electrode, and the pressure sensor the circuitry configured to determine at the same first time as the circuitry in the first LCP a first pressure via the pressure sensor to generate a first pressure-pressure data pair.

2. The LCP system of claim 1, wherein at least one of the circuitry of the first or second LCP is configured to wirelessly transmit the first pressure-pressure data pair to a remote device.

3. The LCP system of claim 1, wherein the circuitry of the first and second LCP are each configured to determine, at a second time during the cardiac cycle, a second pressure via the corresponding pressure sensor, resulting in a second pressure-pressure data pair.

4. The LCP system of claim 3, wherein the first time corresponds to an S₁ heart sound and the second time corresponds to an S₂ heart sound.

5. The LCP system of claim 3, wherein the circuitry of the first and second LCP are each further configured to determine, at a plurality of times between the first time and the second time, a plurality of corresponding pressures via the corresponding pressure sensor, resulting in a plurality of additional pressure-pressure data pairs.

6. The LCP system of claim 5, wherein at least one of the circuitry of the first or second LCP is further configured to wirelessly transmit the first pressure-pressure data pair, the second pressure-pressure data pair, and the plurality of additional pressure-pressure data pairs to a remote device.

7. The LCP system of claim 6, wherein the remote device is configured to generate and display a pressure-pressure loop that is based at least in part on the first pressure-pressure data pair, the second pressure-pressure data pair, and the plurality of additional pressure-pressure data pairs.

8. The LCP system of claim 7, wherein the remote device is configured to store and display a plurality of pressure-pressure loops generated over a period of time.

9. The LCP system of claim 1, wherein at least one of the circuitry of the first or second LCP is further configured to record contextual data indicating the patient'"'"'s physiological state present during the cardiac cycle.

10. The LCP system of claim 9, wherein the indication of the patient'"'"'s physiological state comprises one or more of a level of activity, sleep/wakefulness, a disease status, an effect of a therapy, a heart rate, a respiratory rate, a blood gas, a blood analyte, or a posture.

11. The LCP system of claim 1, wherein the circuitry of the first and second LCP are each further configured to average the first pressures over a plurality of cardiac cycles, resulting in an averaged first pressure-pressure data pair for the first time during an averaged cardiac cycle.

12. The LCP system of claim 5, wherein:

the circuitry of the first LCP is configured to determine an impedance between the first and second electrodes of the first LCP at each of a plurality of times during the cardiac cycle;

the circuitry of the second LCP is configured to determine an impedance between the first and second electrodes of the second LCP at each of the plurality of times during the cardiac cycle to generate a plurality of impedance-impedance data pairs; and

wherein at least one of the circuitry of the first or second LCP is configured to wirelessly transmit the plurality of impedance-impedance data pairs to a remote device.

13. A leadless medical device comprising:

a housing;

a first electrode secured relative to the housing and exposed to the environment outside of the housing;

a second electrode secured relative to the housing and exposed to the environment outside of the housing, the second electrode is spaced from the first electrode;

a pressure sensor secured relative to the housing and is coupled to the environment outside of the housing; and

circuitry in the housing in operatively coupled to the first electrode, the second electrode, and the pressure sensor, the circuitry configured to determine a pressure via the pressure sensor at a plurality of times during a cardiac cycle of a patient to generate a plurality of time/pressure pairs that correspond to the cardiac cycle, the circuitry further configured to wirelessly communicate the plurality of time/pressure pairs to a remote device via the first electrode and the second electrode.

14. The leadless medical device of claim 13, wherein the circuitry receives a synchronization marker from the remote device, and the plurality of times are expressed relative to the synchronization maker.

15. The leadless medical device of claim 13, wherein the circuitry further wirelessly communicates a synchronization marker to the remote device, and the plurality of times are expressed relative to the synchronization maker.

16. A method, comprising:

receiving a measure of right ventricle pressure from a first leadless medical device implanted in the right ventricle (RV) of a patient'"'"'s heart and a measure of left ventricle pressure from a second leadless medical device implanted in the left ventricle (LV) of the patient'"'"'s heart for each of a plurality of times during a cardiac cycle; and

generating a pressure-pressure loop that is based at least in part on the measure of right ventricle pressure and the measure of left ventricle pressure for each of the plurality of times during the cardiac cycle; and

displaying the pressure-pressure loop on a display and/or altering an operation of the first leadless medical device and/or the second leadless medical device based at least in part on the pressure-pressure loop.

17. The method of claim 16, wherein the first leadless medical device and the second leadless medical device are leadless cardiac pacemakers, and the method further comprises changing one or more pacing parameters of the first leadless medical device and/or one or more pacing parameters of the second leadless medical device to improve synchronization between the RV and the LV of the patient'"'"'s heart.

18. The method of claim 16, wherein the first leadless medical device and the second leadless medical device are leadless cardiac pacemakers, and the method further comprises changing an in implant site of the first leadless medical device and/or the implant site of the second leadless medical device to improve synchronization between the RV and the LV of the patient'"'"'s heart.

19. The method of claim 16, wherein the cardiac cycle is an averaged cardiac cycle, and the measure of right ventricle pressure and the measure of left ventricle pressure are averaged pressures for each of the plurality of times during the averaged cardiac cycle.

20. The method of claim 16, further comprising receiving contextual data indicating a patient'"'"'s physiological state present during the cardiac cycle, and wherein the patient'"'"'s physiological state comprises one or more of a level of activity, sleep/wakefulness, a disease status, an effect of a therapy, a heart rate, a respiratory rate, a blood gas, a blood analyte, or a posture.