Active medical device for monitoring the status of a patient suffering from a risk of heart failure

• US 9,668,660 B2
• Filed: 01/15/2016
• Issued: 06/06/2017
• Est. Priority Date: 07/13/2012
• Status: Active Grant

• Current Assignee: Sorin CRM USA (MicroPort Scientific Corp.)
• Original Assignee: Sorin CRM USA (MicroPort Scientific Corp.)
• Inventors: Giorgis, Lionel, Baumann, Oliver
• Primary Examiner(s): Flory, Christopher A
• Application Number:
  US14/997,303
• Publication Number:
  US 20160128581A1
• Time in Patent Office: 508 Days
• Field of Search: 600481, 600509, 600513, 600519
• 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 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/0255 Recording instruments specially adapted therefor
• CPC Class Codes: A61B 5/6869 Heart
• 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: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B

Abstract

An active medical device is configured to receive inputs and to calculate a hemodynamic parameter representative of myocardium contractility determined from an endocardial acceleration signal. The microcontroller acquires heart rate and hemodynamic parameter pairs of values during a plurality of cardiac cycles. The microcontroller is configured to distribute the pairs of values into discrete bins to develop a profile for analysis. The microcontroller is configured to conduct an analysis comprising calculating an index representative of the patient'"'"'s clinical status. The hemodynamic parameter representative of the myocardial contractility is a time interval separating the first and the second peak of endocardial acceleration.

Claims

1. A computerized method for evaluating heart status of a patient, comprising:

using a microcontroller coupled to heart rate and endocardial acceleration sensors to calculate a hemodynamic parameter;

storing a plurality of heart rate and hemodynamic parameter pairs in bins, the bins grouped by heart rate, for both a long-term patient profile and a short-term patient profile;

calculating a difference between the long-term profile and the short-term profile for each bin and multiplying each resultant difference by a weight for the bin;

using the resulting products to calculate an index representative of the weighted difference between the long-term profile and the short-term profile; and

generating an output from a device using a determination based on the index.

2. The computerized method of claim 1, wherein the hemodynamic parameter is the duration between two peaks of endocardial acceleration.

3. The computerized method of claim 1, wherein the hemodynamic parameter is the endocardial acceleration amplitude.

4. The computerized method of claim 1, wherein the determination based on the index comprises comparing the index to a threshold.

5. The computerized method of claim 4, wherein generating an output from the device comprises generating a graphical representation of a bar graph, wherein each heart rate bin forms a bar and each bar illustrates the long term profile data and the short term profile data for the bin.

6. The computerized method of claim 4, wherein generating an output comprises transmitting an alert from the device to a remote system.

7. The computerized method of claim 1, further comprising modelling the short-term profile using a linear regression model or a quadratic regression model.

8. The computerized method of claim 7, wherein parameters generated from the linear regression model or the quadratic regression model are used to calculate the index.

9. The computerized method of claim 1, wherein the bins grouped by heart rate are indicative of a discrimination between different activity phases of the patient.

10. The computerized method of claim 9, wherein the different activity phases of the patient include phases of effort, rest and recovery.

11. The computerized method of claim 9, further comprising defining triplets of values during different cardiac cycles, the triplets of values including a first value indicating an activity, as second value indicating the heart rate, and a third value indicating a time interval separating a first peak and a second peak of endocardial acceleration.

12. The computerized method of claim 11, further comprising developing a three dimensional graphical profile of the triplets, and placing the triplets in predetermined frequency classes of the three dimensional graphical profile.

13. The computerized method of claim 1, further comprising modifying a configuration of the device based on the index representative of the weighted difference between the long-term profile and the short-term profile.

14. A computerized method for evaluating heart status of a patient, comprising:

tracking a plurality of heart rate, hemodynamic parameter, and activity triplets for a patient using sensor readings;

grouping the tracked triplets into at least three heart rate bins spanning at least three activity level bins;

comparing short term performance within each activity to long term performance within each activity level, wherein the comparison comprises evaluating the bin-to-bin hemodynamic parameter changes within each activity level; and

transmitting an alert from a device to a remote system based on the index.

15. The computerized method of claim 14, wherein the comparison further comprises:

multiplying a hemodynamic parameter assigned to a bin by a weighting value.

16. The computerized method of claim 15, wherein the comparison further comprises:

calculating a difference between a long term performance and a short term performance for each heart rate bin and activity level bin pair.

17. The computerized method of claim 16, wherein the comparison further comprises:

calculating an index representative of the difference between the long-term performance and the short-term performance.

18. The computerized method of claim 14, wherein the activity levels include levels of rest, effort and recovery.

19. The computerized method of claim 14, further comprising developing a three dimensional graphical profile of discrete values according to the tracked triplets, and placing the triplets in predetermined frequency classes of the three dimensional graphical profile.