DETECTION OF CARDIAC ARRHYTHMIAS USING A PHOTOPLETHYSMOGRAPH

• US 20070213624A1
• Filed: 05/17/2007
• Published: 09/13/2007
• Est. Priority Date: 11/22/2004
• Status: Active Grant

• Current Assignee: Widemed Technologies Ltd.
• Original Assignee: Widemed Ltd.
• Inventors: Reisfeld, Daniel, Kogan, Simon
• Granted Patent: US 7,794,406 B2
• Time in Patent Office: Days
• US Class Current: 600/504
• CPC Class Codes: A61B 5/08 Detecting, measuring or recording devices for evaluating the respiratory organs A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/082 Evaluation by breath analysis, e.g. determination of the chemical composition of exhaled breath A61B5/083, A61B5/091 take precedence
• CPC Class Codes: A61B 5/1135 by monitoring thoracic expansion
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/4809 Sleep detection, i.e. determining whether a subject is asleep or not
• CPC Class Codes: A61B 5/4812 Detecting sleep stages or cycles
• CPC Class Codes: A61B 5/4815 Sleep quality
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6838 Clamps or clips
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/7232 involving compression of the physiological signal, e.g. to extend the signal recording period
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61B 5/7267 involving training the classification device
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

A method for diagnosis includes receiving from a sensor coupled to a body of a patient a photoplethysmograph signal, which is indicative of blood flow in the body. The photoplethysmograph signal is processed so as to identify at least one irregularity in a heart rhythm of the patient. A record indicating a time of occurrence of the at least one irregularity is made and processed so as to diagnose a pathological cardiac condition of the patient.

Claims

1. A method for diagnosis, comprising:

receiving from a sensor coupled to a body of a patient a photoplethysmograph signal, which is indicative of blood flow in the body;

processing the photoplethysmograph signal so as to identify at least one irregularity in a heart rhythm of the patient;

making a record indicating a time of occurrence of the at least one irregularity; and

processing the record so as to diagnose a pathological cardiac condition of the patient.

2. The method according to claim 1, wherein the irregularity comprises a premature heart beat.

3. The method according to claim 1, wherein the irregularity comprises a premature ventricular contraction (PVC).

4. The method according to claim 1, wherein receiving the photoplethysmograph signal comprises monitoring the photoplethysmograph signal while the patient is sleeping.

5. The method according to claim 1, wherein receiving the photoplethysmograph signal comprises monitoring the photoplethysmograph signal while the patient is reclining.

6. The method according to claim 1, wherein receiving the photoplethysmograph signal comprises monitoring the photoplethysmograph signal while the patient is at rest.

7. The method according to claim 1, wherein receiving the photoplethysmograph signal comprises monitoring the photoplethysmograph signal to detect a pattern of periodic breathing while processing the photoplethysmograph signal so as to identify the at least one irregularity in the heart rhythm.

8. The method according to claim 1, wherein processing the photoplethysmograph signal comprises extracting from the photoplethysmograph signal waveforms that are indicative of a cycle of the blood flow, and identifying an aberrant waveform among the extracted waveforms.

9. Apparatus for diagnosis, comprising:

a sensor, which is configured to be coupled to a body of a patient and to output a photoplethysmograph signal, which is indicative of blood flow in the body; and

a processor, which is coupled to process the photoplethysmograph signal so as to identify at least one irregularity in a heart rhythm of the patient, to make a record indicating a time of occurrence of the at least one irregularity, and to process the record so as to diagnose a pathological cardiac condition of the patient.

10. The apparatus according to claim 9, wherein the irregularity comprises an abnormal heart beat.

11. The apparatus according to claim 9, wherein the irregularity comprises a premature ventricular contraction (PVC).

12. The apparatus according to claim 9, wherein the processor is configured to monitor the photoplethysmograph signal while the patient is sleeping.

13. The apparatus according to claim 9, wherein the processor is configured to monitor the photoplethysmograph signal while the patient is reclining.

14. The apparatus according to claim 9, wherein the processor is configured to monitor the photoplethysmograph signal while the patient is at rest.

15. The apparatus according to claim 9, wherein the processor is configured to monitor the photoplethysmograph signal to detect a pattern of periodic breathing while processing the photoplethysmograph signal so as to identify the at least one irregularity in the heart rhythm.

16. The apparatus according to claim 9, wherein the processor is configured to extract from the photoplethysmograph signal waveforms that are indicative of a cycle of the blood flow, and to identify an aberrant waveform among the extracted waveforms.

17. A computer software product, comprising a computer-readable medium in which program instructions are stored, which instructions, when read by a computer, cause the computer to receive a photoplethysmograph signal, which is indicative of arterial blood flow in a body or a patient, and to process the photoplethysmograph signal so as to identify at least one irregularity in a heart rhythm of the patient, to make a record indicating a time of occurrence of the at least one irregularity, and to process the record so as to diagnose a pathological cardiac condition of the patient.

18. The product according to claim 17, wherein the instructions cause the computer to monitor the photoplethysmograph signal while the patient is sleeping.

19. The product according to claim 17, wherein the instructions cause the computer to extract from the photoplethysmograph signal waveforms that are indicative of a cycle of the arterial blood flow, and to identify an aberrant waveform among the extracted waveforms.