Method and apparatus for monitoring the cardiovascular condition, particularly the degree of arteriosclerosis in individuals

• US 6,676,608 B1
• Filed: 05/23/2000
• Issued: 01/13/2004
• Est. Priority Date: 04/19/2000
• Status: Expired due to Term

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Cheetah Medical Ltd.
• Inventors: Keren, Hanan
• Primary Examiner(s): Winakur, Eric F.
• Assistant Examiner(s): MALLARI, PATRICIA C
• Application Number:
  US09/577,001
• Time in Patent Office: 1,330 Days
• Field of Search: 600/481, 600/485, 600/483, 600/490-493, 600/500-507
• US Class Current: 600/481
• CPC Class Codes: A61B 5/0285 Measuring or recording phase velocity of blood waves
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6838 Clamps or clips

Abstract

A method and apparatus for monitoring the presence of arteriosclerosis in an individual includes detecting an ECG signal of the individual'"'"'s heart, detecting a blood front wave in a peripheral artery of the individual, and measuring the time lag between a predetermined reference point of the detected blood front wave and a predetermined reference point in the ECG signal to provide an indication of the cardiovascular condition of the individual, particularly arteriosclerosis or arterial obstruction.

Claims

1. A method of monitoring the cardiovascular condition of an individual to determine the presence of arteriosclerosis in the individual, comprising:

detecting an ECG signal of the individual'"'"'s heart;

detecting a blood front wave in a peripheral artery of the individual;

measuring the time lag between the start of said detected blood front wave and the peak of the R-wave in the ECG signal;

examining the shape of said blood front wave by analyzing its power spectral density to determine the ratio of the high-frequency power component S_HF to the low frequency power components (S_LS);

and comparing said shape of the blood front wave with a reference corresponding to the shape of the blood front wave in a healthy person to provide, from the measured time lag and the comparison of said shapes, an indication of the presence of arteriosclerosis in the individual.

2. The method according to claim 1, wherein said time lag is measured by concurrently displaying both the detected ECG signal and said detected blood front wave to enable said time lag to be visually measured.

3. The method according to claim 1, wherein said blood front wave is detected non-invasively by applying a probe to a body extremity supplied by said peripheral artery.

4. The method according to claim 3, wherein said probe is applied to a finger or toe of the individual.

5. The method according to claim 3, wherein said probe is an optical oximeter measuring the oxygen saturation of the blood.

6. A method of detecting arteriosclerosis in an individual comprising:

detecting the blood front wave in a peripheral artery of the individual;

examining the shape of the blood front wave by analyzing its power spectral density to determine the ratio of the high-frequency power component (S_HF) to the low frequency power component (S_LF);

and comparing its shape with a reference corresponding to the shape of the blood front wave in a healthy person to provide an indication of the presence of arteriosclerosis in the individual.

7. The method according to claim 6, wherein the blood front wave in a peripheral artery is detected by applying a probe to an external part of the body supplied by the peripheral artery.

8. Apparatus for detecting arteriosclerosis in an individual comprising:

a probe attachable to an external body part of an individual supplied by a peripheral artery;

and a display system for displaying the blood front wave to enable its shape to be examined and compared with a reference corresponding to the shape of the blood front wave in a healthy person, to provide an indication of the presence of arteriosclerosis in the individual; and

a special density analyzer for determining and displaying the ratio of the high frequency power component (S_HF) to the low frequency power component (S_LF) of the blood front wave.

9. The apparatus according to claim 8, wherein said probe is a finger probe or a toe probe.

10. A method of monitoring the cardiovascular condition of an individual to determine the presence of arteriosclerosis in the individual, comprising:

detecting an ECG signal of the individual'"'"'s heart;

detecting a blood front wave in each of at least two different peripheral arteries supplying blood to different body parts of the individual; and

measuring the time lag between the start of each of said detected blood front waves with respect to each other and with respect to the peak in the R-wave in the ECG signal, to provide an indication of the existence of arteriosclerosis or an arterial obstruction in at least one of said body parts, and the location thereof.

11. The method according to claim 10, wherein the two body parts are a finger and a toe of the individual.

12. The method according to claim 10, wherein the two body parts are different fingers or different toes of the individual supplied by different peripheral arteries.

13. A method of monitoring the cardiovascular condition of an individual, comprising:

detecting a first blood front wave in a body part of the individual supplied by a peripheral artery;

detecting a second blood front wave in another body part of the individual supplied by a different peripheral artery;

measuring the time lag between predetermined reference points of said first and second blood front waves,

measuring the power spectral density of at least one of said blood front waves to determine the ratio of the high-frequency power component (S_HF) to the low-frequency power component (S_LF);

and utilizing said measured time lag and power spectral density to provide an indication of the cardiovascular condition of the individual.

14. The method according to claim 13, wherein each of said probes is an optical oximeter measuring the oxygen saturation of the blood.

15. The method according to claim 13, wherein an ECG signal of the individual'"'"'s heart is also detected, and the time lag between a predetermined reference point of the ECG signal, and a predetermined reference point of each of said blood front waves, is measured to provide an indication of the cardiovascular condition of the individual.

16. The method according to claim 15, wherein said predetermined reference point of the ECG signal is the peak of the R-wave therein.

17. The method according to claim 13, wherein said predetermined reference point is the start of the respective blood front wave.

18. The method according to claim 13, wherein said blood front waves are detected non-invasively by probes applied to different body extremities of the individual supplied by different peripheral arteries.

19. The method according to claim 13, wherein one of said probes is applied to a finger or a toe of the individual, and the other of said probes is applied to another finger or another toe of the individual.

20. Apparatus for monitoring the cardiovascular condition of an individual to determine the presence of arteriosclerosis in the individual, comprising:

an ECG detector for detecting the ECG signal of the individual'"'"'s heart, including the R-wave thereof;

two probes constructed and dimensioned so as to be attachable to two different body parts of the individual supplied by different peripheral arteries for detecting the blood front wave in each of the two body parts of the individual;

and a measuring system for measuring the time lag between a predetermined reference point of each blood front wave and the predetermined reference point of the ECG signal such as to provide an indication of the presence of arteriosclerosis in the individual.

21. The apparatus according to claim 20, wherein each of said probes is an optical oximeter measuring the oxygen saturation of the blood in said body extremity.

22. The apparatus according to claim 20, wherein said measuring system includes an oscilloscope for concurrently displaying the ECG signal and the blood front wave signals of the individual.

23. The apparatus according to claim 20, wherein said apparatus further includes a spectral density analyzer for determining the ratio of the high frequency power component (S_HF) to the low frequency power component (S_LF), or S_HF/S_LF, of at least one of the blood front waves.

24. The apparatus according to claim 20, wherein one of said probes is a finger probe, and the other of said probes is a toe probe.

25. The apparatus according to claim 20, wherein both of said probes are finger probes or toe probes attachable to different fingers or toes of the individual.