Pulse validation

• US 10,470,717 B2
• Filed: 02/18/2016
• Issued: 11/12/2019
• Est. Priority Date: 02/18/2016
• Status: Active Grant

• Current Assignee: Philips Healthcare Informatics Incorporated (Koninklijke Philips N.V.)
• Original Assignee: Capsule Technologies Incorporated (Koninklijke Philips N.V.)
• Inventors: Lading, Lars, Baek, David Boettcher
• Primary Examiner(s): Cheng, Jacqueline
• Assistant Examiner(s): Tran, Tho Q
• Application Number:
  US15/047,103
• Publication Number:
  US 20170238878A1
• Time in Patent Office: 1,363 Days
• Field of Search: 600500
• 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 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 5/726 using Wavelet transforms

Abstract

Various embodiments identify valid arterial pulses of a subject. The method may include accessing one or more measured pulses from one or more arterial measurement sensors. The processor may identify one or more valid pulses from the one or more measured pulses based on a comparison of one or more pulse characteristics of the one or more measured pulses to one or more reference pulses. The one or more pulse characteristics are determined based on the one or more measured pulses and a wavelet transform. The wavelet transform is determined based on the one or more reference pulses.

Claims

1. A method of identifying valid pulses from one or more measured pulses obtained with a measuring device positioned on a subject'"'"'s body, wherein the measuring device performs measurements of arterial dynamics, the method comprising:

accessing, by a processor, sensor data representing the one or more measured pulses from one or more arterial measurement sensors of the measuring device;

determining, by the processor, an estimated pulse rate based on the one or more measured pulses and a first wavelet transform;

identifying, by the processor, at least one measured pulse from the one or more measured pulses within the sensor data based on the estimated pulse rate;

determining, by the processor, whether the identified at least one measured pulse includes one or more valid pulses based on a comparison of one or more first pulse characteristics of the identified at least one measured pulse to one or more second pulse characteristics of one or more reference pulses comprising the one or more valid pulses, wherein the one or more first pulse characteristics are determined based on the identified at least one measured pulse and a second wavelet transform, and wherein the second wavelet transform is determined based on the one or more reference pulses; and

based on determining that the identified at least one measured pulse includes one or more valid pulses, outputting, by the processor, a vital sign measurement result of the subject'"'"'s body computed using a first part of the identified at least one measured pulse that includes the one or more valid pulses and not using a second part of the identified at least one measured pulse that does not include the one or more valid pulses.

2. The method of claim 1, wherein the one or more reference pulses are determined based on age of the subject, body mass index of the subject, weight of the subject, height of the subject, gender of the subject, a state of the subject or any combination thereof.

3. The method of claim 2, wherein the state of a subject comprises a sleep state, a stressed state, a happy state, a depressed state, an exercise state, or a low movement state.

4. The method of claim 1, wherein the one or more reference pulses are determined based on previously validated pulses.

5. The method of claim 1, wherein the accessing, by the processor, the one or more measured pulses from one or more arterial measurement sensors comprises:

determining one or more segments of measurement signals based on time localization, amplitude, pulse rate, or any combination thereof; and

identifying the one or more measured pulses based on the one or more segments of measurement signals.

6. The method of claim 1, wherein determining, by the processor, whether the at least one measured pulse includes one or more valid pulses comprises:

determining, by the processor, one or more peak normalized correlation of the at least one measured pulse based on the one or more first pulse characteristics and the one or more reference pulses; and

identifying, by the processor, the one or more valid pulses based on a comparison of the one or more peak normalized correlation of the at least one measured pulse and one or more correlation thresholds.

7. The method of claim 6, wherein the one or more first pulse characteristics comprises one or more locations of the one or more measured pulses, one or more pulse shapes of the one or more measured pulses, one or more pulse lengths of the one or more measured pulses, one or more amplitudes of the one or more measured pulses, or any combination thereof.

8. The method of claim 1, further comprising:

identifying, by the processor, the one or more valid pulses from the first part of the identified at least one measured pulse; and

in response to the identified one or more valid pulses meeting or exceeding one or more thresholds, determining, by the processor, one or more new reference pulses based on the one or more identified valid pulses or updating, by the processor, the one or more reference pulses based on the one or more identified valid pulses.

9. The method of claim 1, wherein at least one of the first wavelet transform or the second wavelet transform is based on a tailored mother wavelet.

10. The method of claim 9, wherein the tailored mother wavelet represents a sum of displaced reference pulses multiplied by a truncating function defining a number of pulses appearing in the sum of displaced reference pulses.

11. The method of claim 1, wherein the one or more reference pulses are determined based on a first model representing a stroke volume versus time and a second model representing a propagation of a pulse through an arterial system.

12. The method of claim 1, wherein the one or more reference pulses are determined based on previous measured pulses obtained with the measuring device positioned on the subject'"'"'s body, the previous measured pulses being determined to include the one or more valid pulses.

13. The method of claim 1, wherein the first wavelet transform is determined based on the one or more reference pulses.

14. A measuring device, comprising:

one or more arterial measurement sensors configured to measure arterial dynamics from an artery when positioned on a subject'"'"'s body; and

one or more processors coupled to the one or more arterial measurement sensors, the one or more processors capable of;

accessing one or more measured pulses from the one or more arterial measurement sensors;

determining an estimated pulse rate based on the one or more measured pulses and a first wavelet transform;

identifying at least one measured pulse from the one or more measured pulses based on the estimated pulse rate;

determining whether the identified at least one measured pulse includes one or more valid pulses based on a comparison of one or more first pulse characteristics of the identified at least one measured pulse to one or more second pulse characteristics of one or more reference pulses comprising the one or more valid pulses, wherein the one or more first pulse characteristics are determined based on the identified at least one measured pulse and a second wavelet transform, and wherein the second wavelet transform is determined based on the one or more reference pulses; and

based on determining that the identified at least one measured pulse includes one or more valid pulses, outputting, by the one or more processors, a vital sign measurement result of the subject'"'"'s body computed using a first part of the identified at least one measured pulse that includes the one or more valid pulses and not using a second part of the identified at least one measured pulse that does not include the one or more valid pulses.

15. The measuring device of claim 14, wherein the one or more reference pulses are determined based on age of the subject, body mass index of the subject, weight of the subject, height of the subject, gender of the subject, a state of the subject or any combination thereof.

16. The measuring device of claim 15, wherein the state of a subject comprises a sleep state, a stressed state, a happy state, a depressed state, an exercise state, or a low movement state.

17. The measuring device of claim 14, wherein the one or more reference pulses are determined based on previously validated pulses.

18. The measuring device of claim 14, wherein the accessing the one or more measured pulses from the one or more arterial measurement sensors comprises:

determining one or more segments of measurement signals based on time localization, amplitude, pulse rate, or any combination thereof; and

identifying the one or more measured pulses based on the one or more segments of measurement signals.

19. The measuring device of claim 14, wherein determining whether the at least one measured pulse include one or more valid pulses comprises:

determining one or more peak normalized correlation of the at least one measured pulse based on the one or more first pulse characteristics and the one or more second pulse characteristics; and

identifying the one or more valid pulses based on a comparison of the one or more peak normalized correlation of the at least one measured pulse and one or more correlation thresholds.

20. The measuring device of claim 19, wherein the one or more first pulse characteristics comprises one or more locations of the one or more measured pulses, one or more pulse shapes of the one or more measured pulses, one or more pulse lengths of the one or more measured pulses, one or more amplitudes of the one or more measured pulses, or any combination thereof.

21. The measuring device of claim 14, the one or more processors further capable of:

identifying the one or more valid pulses from the first part of the identified at least one measured pulse; and

in response to the identified one or more valid pulses meeting or exceeding one or more thresholds, determining one or more new reference pulses based on the one or more identified valid pulses or updating the one or more reference pulses based on the one or more identified valid pulses.

22. The measuring device of claim 14, wherein the wavelet transform is based on a tailored mother wavelet.

23. The measuring device of claim 22, wherein the mother wavelet represents a sum of displaced reference pulses multiplied by a truncating function defining a number of pulses appearing in the sum of displaced reference pulses.

24. A measuring device, comprising:

means for accessing one or more measured pulses from one or more arterial measurement sensors;

means for determining an estimated pulse rate based on the one or more measured pulses and a first wavelet transform;

means for identifying at least one measured pulse from the one or more measured pulses based on the estimated pulse rate;

means for determining whether the identified at least one measured pulse includes one or more valid pulses based on a comparison of one or more first pulse characteristics of the identified at least one measured pulse to one or more second pulse characteristics of one or more reference pulses comprising the one or more valid pulses, wherein the one or more first pulse characteristics are determined based on the identified at least one measured pulse and a second wavelet transform, and wherein the second wavelet transform is determined based on the one or more reference pulses; and

means for, based on determining that the identified at least one measured pulse includes one or more valid pulses, outputting a vital sign measurement result of the subject'"'"'s body computed using a first part of the identified at least one measured pulse that includes the one or more valid pulses and not using a second part of the identified at least one measured pulse that does not include the one or more valid pulses.

25. The measuring device of claim 24, wherein the one or more reference pulses are determined based on age of the subject, body mass index of the subject, weight of the subject, height of the subject, gender of the subject, a state of the subject or any combination thereof;

and

wherein the state of a subject comprises a sleep state, a stressed state, a happy state, a depressed state, an exercise state, or a low movement state.

26. The measuring device of claim 24, wherein the one or more reference pulses are determined based on previously validated pulses.

27. The measuring device of claim 24, wherein the means for accessing the one or more measured pulses from the one or more arterial measurement sensors comprises:

means for determining one or more segments of measurement signals based on time localization, amplitude, pulse rate, or any combination thereof; and

means for identifying the one or more measured pulses based on the one or more segments of measurement signals.

28. The measuring device of claim 24, wherein the means for determining whether the identified at least one measured pulse includes one or more valid pulses comprises:

means for determining one or more peak normalized correlation of the identified at least one measured pulse based on the one or more first pulse characteristics and the one or more second pulse characteristics; and

means for identifying the one or more valid pulses based on a comparison of the one or more peak normalized correlation of the identified at least one measured pulse and one or more correlation thresholds.

29. A non-transitory computer-readable medium for identifying valid pulses, comprising:

at least one instruction to access one or more measured pulses from one or more arterial measurement sensors;

at least one instruction to determine an estimated pulse rate based on the one or more measured pulses and a first wavelet transform;

at least one instruction to locate one or more of the measured pulses based on the estimated pulse rate;

at least one instruction to determine whether the identified at least one measured pulse includes one or more valid pulses based on a comparison of one or more first pulse characteristics of the identified at least one measured pulse to one or more second pulse characteristics of one or more reference pulses comprising the one or more valid pulses, wherein the one or more first pulse characteristics are determined based on the identified at least one measured pulse and a second wavelet transform, and wherein the second wavelet transform is determined based on the one or more reference pulses; and

at least one instruction to, based on determining that the identified at least one measured pulse includes one or more valid pulses, outputting a vital sign measurement result of the subject'"'"'s body computed using a first part of the identified at least one measured pulse that includes the one or more valid pulses and not using a second part of the identified at least one measured pulse that does not include the one or more valid pulses.

30. The non-transitory computer-readable medium of claim 29, wherein the at least one instruction to determine whether the one or more measured pulses include one or more valid pulses comprises:

at least one instruction to determine one or more peak normalized correlation of the one or more measured pulses based on the one or more first pulse characteristics and the one or more second pulse characteristics; and

at least one instruction to identify the one or more valid pulses based on a comparison of the one or more peak normalized correlation of the identified at least one measured pulse and one or more correlation thresholds.