Method and apparatus for detecting arterial stenosis

• US 20020151795A1
• Filed: 02/28/2002
• Published: 10/17/2002
• Est. Priority Date: 03/02/2001
• Status: Active Grant

• Current Assignee: Echosense Jersey Limited
• Original Assignee: Yoram Palti
• Inventors: Palti, Yoram
• Granted Patent: US 6,730,030 B2
• Time in Patent Office: Days
• US Class Current: 600/454
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00

Abstract

A high-speed non-invasive method and apparatus for detecting and measuring arterial stenosis without requiring imaging is disclosed. A Doppler ultrasound system automatically and repeatedly scans an area of interest to construct at least one velocity profile through segments of arteries over an area of interest. The velocity profiles and delta velocity profiles are automatically analyzed to determine a number of parameters indicative of potentially stenotic areas within the artery. These parameters may include: i) the average or peak velocity across the velocity profile, ii) the peak delta velocity across the velocity profile, iii) blunt flow present in the velocity profile, iv) turbulence in the blood flow, and v) the degree of skew in the velocity profile. The delta velocity profile defined as the change in the velocity profile with respect to the length of the artery is used to examine how the above parameters change along the length of the artery. The parameters and their changing value along the length of the artery indicative of stenosis are detected and compared with predefined threshold values to determine potentially stenotic areas. Scanning by the Doppler ultrasound system is triggered at a predefined point in an ECG cycle of the patient.

Claims

1. A method of detecting stenosis of an artery comprising the steps of:

scanning an area of interest using a Doppler ultrasound scanner to construct at least one velocity profile of blood flow in an artery in the area of interest; and

analyzing the velocity profile to determine potentially stenotic areas within the artery.

2. The method according to claim 1, further comprising the steps of:

defining a reference coordinate system relative to the area of interest; and

determining an orientation of the Doppler ultrasound scanner in the reference coordinate system upon detecting potentially stenotic areas within the artery.

3. The method according to claim 1, wherein the Doppler ultrasound system comprises at least one scanner, and further comprising the step of positioning at least one scanner relative to the area of interest for detecting stenosis thereof.

4. The method according to claim 3, wherein the Doppler ultrasound system comprises a plurality of scanners.

5. The method according to claim 2, wherein the step of defining a reference coordinate system further comprises the step of measuring angles of reference between one or more scanners of the Doppler ultrasound system and a selected reference point.

6. The method according to claim 1, further comprising the step of constructing a delta velocity profile of blood flow along the length of the artery.

7. The method according to claim 1 wherein the step of analyzing the velocity profile comprises the steps of:

measuring at least one parameter indicative of a potentially stenotic artery; and

determining from the at least one measured parameter whether stenosis may be present in the artery.

8. The method according to claim 7, wherein the at least one parameter is selected from the group consisting of V, DH, B, N, S, v, dh, b, n, s and w.

9. The method according to claim 7, wherein the at least one parameter is compared with a predefined threshold value to determine potentially stenotic areas within the artery.

10. The method according to claim 7 further comprising scoring the degree of stenosis and determining coordinates of the potentially stenotic artery.

11. The method according to claim 7, further comprising the steps of sorting the measured parameters and consolidating repetitive information.

12. The method according to claim 1 wherein the Doppler ultrasound system is carried on a robotic arm.

13. The method according to claim 1, further comprising the step of triggering scanning by the Doppler ultrasound system based on a window in an ECG of the patient.

14. The method according to claim 1, further comprising the step of reconstructing a path of the artery for detecting stenosis over a length of the artery.

15. The method according to claim 1, wherein the step of analyzing the velocity profile to determine potentially stenotic areas within the artery comprises comparing velocity profiles of the artery in the systole stage to velocity profiles of the artery in the diastole stage.

16. The method according to claim 1, wherein the step of analyzing the velocity profile to determine potentially stenotic areas within the artery comprises comparing a direction of flow in the potentially stenotic area in the systole stage and the diastole stage.

19. The method according to claim 18 further comprising the steps of:

using the velocity profile and delta velocity profile to determine parameters selected from the group consisting of V, DH, B, N, S, v, dh, b, n, s ,w, Δ

v/Δ

L, Δ

dh/Δ

L, Δ

b/Δ

L, Δ

n/Δ

L, Δ

s/Δ

L, Δ

w/Δ

L, (Δ

v/Δ

L)_a, (Δ

dh/Δ

L)_a, (Δ

b/Δ

L)_a, (Δ

n/Δ

L)_a, (Δ

s/Δ

L)_a, and (Δ

w/Δ

L)_a; and

comparing one or more of the parameters with predefined threshold values to determine potentially stenotic areas within the artery.

17. A method of detecting arterial stenosis comprising the steps of:

using a Doppler ultrasound system to measure a plurality of parameters indicative of a potentially stenotic artery;

determining from the measured parameters the presence and/or degree of stenosis in the artery; and

scoring the degree of stenosis and determining coordinates of the potentially stenotic artery.

18. A method of detecting arterial stenosis comprising the steps of:

detecting a signal representative of the velocity of blood flow in an artery;

constructing a velocity profile and delta velocity profile of the blood flow in the artery; and

based on the velocity profile and delta velocity profile, identifying potentially stenotic areas in the artery.

20. A method of detecting arterial stenosis comprising the steps of:

detecting a defined point within an ECG;

upon detection of the defined point, scanning a segment of the artery using a Doppler ultrasound system to construct a velocity profile and delta velocity profile of blood flow through the artery; and

analyzing the velocity profile as well as the delta velocity profile to determine potentially stenotic areas within the artery.

21. An apparatus for detecting stenosis of an artery, which comprises:

a Doppler system for scanning an area of interest and for receiving Doppler echoes from an artery in the area of interest; and

a processor for receiving the echoes and for constructing a velocity profile of blood flow through the segment of artery, the processor analyzing the velocity profile to determine potentially stenotic areas within the artery.

22. The apparatus according to claim 21, further comprising means for defining a reference coordinate system relative to an area of interest, the processor being adapted to determine a location of the Doppler ultrasound system in the reference coordinate system.

23. The apparatus according to claim 21, wherein the Doppler ultrasound system comprises a plurality of scanners.

24. The apparatus according to claim 22, further comprising means for measuring angles of reference between one or more scanners of the Doppler ultrasound system and a selected reference point in the reference coordinate system.

25. The apparatus according to claim 21, wherein the processor constructs a delta velocity profile of blood flow the arteries present in the area of interest.

26. The apparatus according to claim 21, wherein the processor detects at least one parameter indicative of the presence of stenosis.

27. The apparatus according to claim 26, wherein at least one parameter indicative of the presence of stenosis is selected from the group consisting of V, DH, B, N, S, v, dh, b, n, s, w, Δ

v/Δ

L, Δ

dh/Δ

L, Δ

b/Δ

L, Δ

n/Δ

L, Δ

s/Δ

L, Δ

w/Δ

L, (Δ

v/Δ

L)_a, (Δ

dh/Δ

L)_a, (Δ

b/Δ

L)_a, (Δ

n/Δ

L)_a, (Δ

s/Δ

L)_a, and (Δ

w/Δ

L)_a.

28. The apparatus according to claim 26, wherein the processor compares the parameter with a predefined threshold value to determine potentially stenotic areas within the artery.

29. The apparatus according to claim 21 further comprising a robotic arm for carrying the Doppler ultrasound system.

30. The apparatus according to claim 21 further comprising:

means for measuring a plurality of parameters indicative of a potentially stenotic artery;

means for determining from the measured parameters the degree of stenosis in the artery; and

means for scoring the degree of stenosis and determining coordinates of the potentially stenotic artery.

31. The apparatus according to claim 21, further comprising a trigger for detecting a window in an ECG of the patient and for triggering scanning by the Doppler ultrasound system based on detection of the window.

32. An apparatus for detecting arterial stenosis comprising:

a Doppler ultrasound system for measuring at least one parameter indicative of a potentially stenotic artery; and

a processor for determining from the measured parameters the degree of stenosis in the artery, the processor scoring the degree of stenosis and determining coordinates of the potentially stenotic artery.

33. The apparatus according to claim 32, wherein the processor reconstructs the path of at least a portion of the artery.

35. The apparatus according to claim 34 further comprising:

means for using the velocity profile and delta velocity profile to determine at least one parameter selected from the group consisting of V, DH, B, N, S, v, dh, b, n,s W, Δ

v/Δ

L, Δ

dh/Δ

L, Δ

b/Δ

L, Δ

n/Δ

L, Δ

s/Δ

L, Δ

w/Δ

L, (Δ

v/Δ

L)_a, (Δ

dh/Δ

L)_a, (Δ

b/Δ

L)_a, (Δ

n/Δ

L)_a, (Δ

s/Δ

L)_a, and (Δ

w/Δ

L)_a; and

means for comparing one or more of the parameters with predefined threshold values to determine potentially stenotic areas within the artery.

34. An apparatus for detecting arterial stenosis, which comprises:

means for detecting a signal representative of the velocity of blood flow in an artery;

means for constructing a velocity profile and a delta velocity profile of the blood flow in the artery; and

means for identifying potentially stenotic areas in the artery based on the velocity profile and delta velocity profile.