METHODS AND SYSTEMS THAT USE IMPLANTED POSTURE SENSOR TO MONITOR LEFT ATRIAL PRESSURE AND/OR INTER-THORACIC FLUID VOLUME

• US 20110125207A1
• Filed: 12/30/2009
• Published: 05/26/2011
• Est. Priority Date: 11/20/2009
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories)
• Inventors: Qu, Fujian, Koh, Steve, Nabutovsky, Yelena, Soriano, Alex, Gutfinger, Dan E.
• Granted Patent: US 9,462,959 B2
• Time in Patent Office: Days
• US Class Current: 607/6
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/1116 Determining posture transitions
• CPC Class Codes: A61B 5/4878 Evaluating oedema
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• 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 1/3684 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 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: A61N 1/37258 Alerting the patient
• CPC Class Codes: A61N 1/39622 Pacing therapy

Abstract

In specific embodiments, a method to monitor left atrial pressure and/or intra-thoracic fluid volume of a patient, comprises (a) monitoring posture of the patient using a posture sensor implanted within the patient, and (b) using portions of an impedance signal, obtained using implanted electrodes, to monitor the left atrial pressure and/or intra-thoracic fluid volume of the patient. Each portion of the impedance signal used to monitor the left atrial pressure and/or intra-thoracic fluid volume of the patient corresponds to a period after which the patient has maintained a predetermined posture for at least a predetermined period of time, and during which the patient has remained in the predetermined posture.

Claims

1. A method to monitor left atrial pressure and/or intra-thoracic fluid volume of a patient comprising:

(a) storing data indicative of an impedance signal for at least a first specified period of time, obtained using implanted electrodes, and a corresponding posture of the patient, as determined using an implanted posture sensor;

(b) identifying, based on the stored data, one or more snapshots of the impedance signal where prior to each snapshot the patient maintained a predetermined posture for at least a second specified period of time, and during the snapshot the patient maintained the predetermined posture for at least a third specified period of time; and

(c) monitoring the left atrial pressure and/or intra-thoracic fluid volume of the patient based on a portion of the stored data associated with the identified one or more snapshots of the impedance signal.

2. The method of claim 1, further comprising, after step (b), writing over or otherwise erasing the stored data, indicative of the impedance signal and the corresponding posture of the patient, not associated with the identified snapshots.

3. The method of claim 1, wherein after the first specified period of time steps (a), (b) and (c) are repeated for further periods of time of the same or different length until actively interrupted.

4. The method of claim 1, wherein step (c) includes identifying when the left atrial pressure and/or intra-thoracic fluid volume is undesirably abnormal and one or both of triggering an alert and adjusting therapy administered to the patient in response to identifying the abnormality.

5. The method of claim 4, wherein steps (a), (b) and (c) are performed by an implanted device including and/or connected to the implanted electrodes;

and wherein when an alert is triggered, the method further comprises;

(d) transmitting the alert from the implantable device to a non-implanted device; and

(e) displaying a visual warning and/or issuing an audible warning by way of the non-implanted device in response to the alert.

6. The method of claim 4, wherein steps (a), (b) and (c) are performed by an implanted system including and/or connected to the implanted electrodes;

and wherein when therapy administered to the patient is adjusted, the method further comprises;

(d) adjusting medication based on a physician pre-determined formula; and

(e) displaying a visual indication of the medication adjustment to the patient.

7. The method of claim 4, wherein steps (a), (b) and (c) are performed by an implanted system including and/or connected to the implanted electrodes;

and wherein when therapy administered to the patient is adjusted, the method further comprises;

(d) adjusting electrical therapy administered by an implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D).

8. The method of claim 1, wherein step (c) comprises monitoring the left atrial pressure of the patient based on a portion of the stored data associated with the identified one or more snapshots of the impedance signal.

9. The method of claim 1, wherein step (c) comprises monitoring the intra-thoracic fluid volume of the patient based on a portion of the stored data associated with the identified one or more snapshots of the impedance signal.

10. A system to monitor left atrial pressure and/or intra-thoracic fluid volume of a patient, comprising:

an implantable posture sensor adapted to determine a posture of the patient; and

memory adapted to store data indicative of an impedance signal for at least a first specified period of time, obtained using implanted electrodes, and a corresponding posture of the patient, as determined using an implanted posture sensor;

a monitor adapted to

identify, based on the stored data, one or more snapshots of the impedance signal where prior to each snapshot the patient maintained a predetermined posture for at least a second specified period of time, and during the snapshot the patient maintained the predetermined posture for at least a third specified period of time; and

monitor the left atrial pressure and/or intra-thoracic fluid volume of the patient based on a portion of the stored data associated with the identified one or more snapshots of the impedance signal.

11. A method to monitor left atrial pressure and/or intra-thoracic fluid volume of a patient, comprising:

(a) monitoring posture of the patient using a posture sensor implanted within the patient; and

(b) using portions of an impedance signal, obtained using implanted electrodes, to monitor the left atrial pressure and/or intra-thoracic fluid volume of the patient;

wherein each said portion of the impedance signal, being used to monitor the left atrial pressure and/or intra-thoracic fluid volume of the patient, corresponds to a period after which the patient has maintained a predetermined posture for at least a predetermined period of time, and during which the patient has remained in the predetermined posture.

12. The method of claim 11,

wherein the impedance signal is obtained continuously;

further comprising, prior to step (b), storing only the portions of the impedance signal corresponding to a period after which the patient has maintained the predetermined posture for at least the predetermined period of time, and during which the patient has remained in the predetermined posture; and

wherein step (b) comprises using the stored portions of the impedance signal to monitor the left atrial pressure and/or intra-thoracic fluid volume of the patient.

13. The method of claim 11, further comprising, prior to step (b):

identifying periods when the patient has maintained the predetermined posture for at least the predetermined period of time; and

obtaining the impedance signal in response to identifying that the patient has maintained the predetermined posture for at least the predetermined period of time, and during which the patient remains in the predetermined posture.

14. The method of claim 11, wherein step (b) includes identifying when the monitored left atrial pressure and/or intra-thoracic fluid volume is undesirably abnormal and one or both of triggering an alert and adjusting therapy administered to the patient in response to identifying the abnormality.

15. The method of claim 14, wherein steps (a) and (b) are performed by an implanted system including the implanted posture sensor and the implanted electrodes;

and wherein when an alert is triggered, the method further comprises;

(c) transmitting the alert the from the implanted system to a non-implanted system; and

(d) displaying a visual warning and/or issuing an audible warning by way of the non-implanted system in response to the alert.

16. The method of claim 14, wherein steps (a) and (b) are performed by an implanted system including the implanted posture sensor and implanted electrodes;

and wherein when therapy administered to the patient is adjusted, the method further comprises;

(c) adjusting medication based on a physician pre-determined formula; and

(d) displaying a visual indication of the medication adjustment to the patient.

17. The method of claim 14, wherein steps (a) and (b) are performed by an implanted system including the implanted posture sensor and implanted electrodes;

and wherein when therapy administered to the patient is adjusted, the method further comprises;

(c) adjusting electrical therapy administered by an implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D).

18. A system to monitor left atrial pressure and/or intra-thoracic fluid volume of a patient, comprising:

an implantable posture sensor adapted to determine a posture of the patient; and

a monitor adapted to use portions of an impedance signal, obtained using implanted electrodes, to monitor the left atrial pressure and/or intra-thoracic fluid volume of the patient, wherein each said portion of the impedance signal, used to monitor the left atrial pressure and/or intra-thoracic fluid volume of the patient, corresponds to a period after which the patient has maintained a predetermined posture for at least a predetermined period of time, and during which the patient has remained in the predetermined posture.