Determination system for determining a heart failure risk

Patent metadata

Field	Value
Publication number	US-11337659-B2
Application number	US-201716072661-A
Country	US
Kind code	B2
Filing date	Jan 16, 2017
Priority date	Jan 28, 2016
Publication date	May 24, 2022
Grant date	May 24, 2022

Abstract

The invention relates to a determination system for determining a heart failure risk for a subject (4). The determination system (1) comprises a photoplethysmogram providing unit for providing a photoplethysmogram of the subject and a heart failure risk determination unit for determining the heart failure risk based on the provided photoplethysmogram. A photoplethysmogram can be provided in an unobtrusive way by using a photoplethysmogram sensor without requiring a physician's attendance. In particular, it is not necessarily required to measure electrocardiograms, to carry out blood tests and to perform a coronary angiography for determining the heart failure risk. The heart failure risk can therefore be determined in a technically relatively simple way without requiring a physician's attendance.

First claim

The invention claimed is:

1. A determination system for determining a heart failure (HF) risk for a subject, wherein the determination system comprises:
a photoplethysmogram providing unit for providing a photoplethysmogram of the subject; and
a heart failure risk determination unit for determining the heart failure risk based on the provided photoplethysmogram, wherein the heart failure risk determination unit is adapted to:
detect at least one of a presence of a postextrasystolic potentiation (PESP) and a disturbed force-frequency relation (FFR) based on the provided photoplethysmogram,
determine peak values of peaks at different times, which are indicative of heights of peaks of a left ventricular pressure over time,
determine frequency values for different times, which are indicative of a frequency of the left ventricular pressure over time, wherein the frequency values are defined by an inverse of temporal distances between consecutive ones of the peaks of the left ventricular pressure, for determining a temporal behavior of characteristics of the left ventricular pressure based on the photoplethysmogram,
provide rules which include a frequency deviation threshold and which define the heart failure risk depending on whether a deviation between temporally consecutive frequency values is larger than the frequency deviation threshold, and
determine the heart failure risk based on: (i) the detection of the at least one of the presence of the PESP and the disturbed FFR; (ii) the determined temporal behavior; and (iii) the provided rules, which include the frequency deviation threshold, and which define the heart failure risk depending on whether the deviation between temporally consecutive frequency values is larger than the frequency deviation threshold.

2. The determination system of claim 1 , wherein providing the rules includes providing a first peak value threshold and a second peak value threshold, and wherein the heart failure risk determination unit is adapted to:
detect the presence of the postextrasystolic potentiation as a case where (a) and (b) are both true, where (a) is true when a peak value is smaller than the first peak value threshold and wherein (b) is true when a following peak value is not larger than the second peak value threshold.

3. The determination system of claim 1 , wherein the rules define the detection of the disturbed force frequency relation as detecting that the frequency values increase over time, while peak values which are indicative of heights of peaks of the left ventricular pressure do not increase over time, and wherein the heart failure risk is determined based on the rules.

4. The determination system of claim 1 , further comprising an activity state providing unit for providing an indication of an activity state of the subject, wherein the rules include an activity frequency threshold that depends on the activity state, wherein the rules define the heart failure risk as depending on whether the frequency values are larger than the activity frequency threshold for a respective activity state, and wherein the heart failure risk is determined based on the rules.

5. The determination system of claim 1 , further comprising a breathing rate providing unit for providing a breathing rate of the subject, wherein the HF risk determination unit is adapted to determine the HF risk based on the provided breathing rate.

6. The determination system of claim 5 , further comprising an activity state providing unit for providing an indication of an activity state of the subject, wherein the HF risk determination unit is adapted to provide a breathing rate threshold that depends on the activity state and to determine the HF risk as depending on whether the breathing rate is larger than the breathing rate threshold for a respective activity state.

7. The determination system of claim 5 , wherein the breathing rate providing unit is adapted to determine the breathing rate based on the photoplethysmogram and to provide the determined breathing rate.

8. The determination system of claim 1 , wherein the heart failure risk determination unit is adapted to detect atrial fibrillation of the subject's heart based on the provided photoplethysmogram and to determine the heart failure risk based on the detection of the atrial fibrillation.

9. A method for determining a heart failure (HF) risk for a subject, wherein the method comprises:
providing a photoplethysmogram of the subject by a photoplethysmogram providing unit; and
ascertaining a heart failure risk based on the provided photoplethysmogram by:
detecting at least one of a presence of a postextrasystolic potentiation and a disturbed force-frequency relation based on the provided photoplethysmogram,
determining peak values of peaks at different times, which are indicative of heights of peaks of a left ventricular pressure over time,
ascertaining frequency values for different times, which are indicative of a frequency of the left ventricular pressure over time and are defined by an inverse of temporal distances between consecutive ones of the peaks of the left ventricular pressure, for ascertaining a temporal behavior of characteristics of the left ventricular pressure based on the photoplethysmogram,
providing rules which include a frequency deviation threshold and which define the heart failure risk depending on whether a deviation between temporally consecutive frequency values is larger than the frequency deviation threshold, and
ascertaining the heart failure risk based on: (i) the detection of the at least one of the presence of the postextrasystolic potentiation and the disturbed force-frequency relation; (ii) the ascertained temporal behavior; and (iii) the provided rules, which include the frequency deviation threshold, and which define the heart failure risk depending on whether the deviation between temporally consecutive frequency values is larger than the frequency deviation threshold.

10. The determination system of claim 1 , wherein the heart failure risk determination unit is adapted to assign the determined heart failure risk to one of at least two defined degrees of heart failure risk, including at least a first degree of heart failure risk and a second degree of heart failure risk which is greater than the first degree of heart failure risk, and wherein the determination system is configured to generate an optical, and/or acoustical, and/or tactile alarm when the heart failure risk determination unit assigns the heart failure risk to the second degree of heart failure risk.

11. The method of claim 9 , further comprising:
assigning the determined heart failure risk to one of at least two defined degrees of heart failure risk, including at least a first degree of heart failure risk and a second degree of heart failure risk which is greater than the first degree of heart failure risk; and
generating an alarm when assigning of the determined heart failure risk reaches the second degree of heart failure risk.

12. The method of claim 9 , wherein providing the rules includes providing a first peak value threshold and a second peak value threshold, and wherein the method comprises:
detecting the presence of the postextrasystolic potentiation as a case where (a) and (b) are both true, where (a) is true when a peak value is smaller than the first peak value threshold and wherein (b) is true when a following peak value is not larger than the second peak value threshold.

13. The method of claim 9 , wherein the rules define the detection of the disturbed force frequency relation as detecting that the frequency values increase over time, while peak values which are indicat

Assignees

• Koninklijke Philips Nv
• Koninklijke Philps N V

Inventors

• Aarts Ronaldus Maria

Classifications

• G16H50/20

  for computer-aided diagnosis, e.g. based on medical expert systems · CPC title

• A61B5/7278

  Artificial waveform generation or derivation, e.g. synthesizing signals from measured signals · CPC title

• A61B5/02416

  using photoplethysmograph signals, e.g. generated by infrared radiation (A61B5/14552 takes precedence) · CPC title

• A61B5/02116

  of pulse wave amplitude (A61B5/02225 takes precedence) · CPC title

• G16H50/30

  for calculating health indices; for individual health risk assessment · CPC title