Blood vessel detecting apparatus

• US 6,569,104 B2
• Filed: 07/14/1999
• Issued: 05/27/2003
• Est. Priority Date: 07/16/1998
• Status: Expired due to Fees

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Ono, Shigeaki, Tanaka, Shinya
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): MANTIS MERCADER, ELENI M
• Application Number:
  US09/351,903
• Publication Number:
  US 20020058874A1
• Time in Patent Office: 1,413 Days
• Field of Search: 600/478, 600/489, 600/564, 600/479, 600/480, 351/206, 351/209, 351/476
• US Class Current: 600/504
• CPC Class Codes: A61B 3/1233 for measuring blood flow, e.g. at the retina
• CPC Class Codes: A61B 5/489 Blood vessels
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives

Abstract

Disclosed is a blood vessel detecting apparatus which accurately detects a blood vessel using an image pickup element having a plurality of pixels to pick up an image of a blood vessel, a detector for detecting a pixel output estimated as a blood vessel on the basis of pixel the output from the image pickup elements, and a determination unit for, when the detector detects pixel outputs that are likely to be a plurality of blood vessels, determining a correct number of blood vessels using the pixel output or an area image pickup element.

Claims

1. A blood vessel detecting apparatus comprising:

a light source for irradiating a target vessel portion with a laser beam;

an image pickup device which picks up a blood vessel image of an eye; and

a processing system electrically coupled to said image pickup device, the system determining the target vessel portion of the eye from the blood vessel image irradiated by the laser beam and whether the target vessel portion comprises a single blood vessel or more than a single blood vessel,

wherein the determination of whether the target vessel portion of the eye comprises a single blood vessel or more than a single blood vessel is used to determined at least one of the blood flow velocity, diameter and blood flow volume.

2. An apparatus according to claim 1, wherein when said processing system detects specific portions on the target vessel portion that are likely to be blood vessels, and determines whether the target vessel portion comprises a single vessel or more than a single blood vessel on the basis of the distance between the specific portions.

3. An apparatus according to claim 2, wherein said processing system comprises a circuit for differentiating the output of said image pickup device, and a circuit for detecting a change in sign of signals from said differentiating circuit.

4. An apparatus according to claim 1, further comprising a deflecting optical system for deflecting a blood vessel image to project the target vessel portion on said image pickup device.

5. An apparatus according to claim 4, further comprising a measuring system for measuring the blood flow velocity in the target vessel portion.

6. An apparatus according to claim 5, wherein said measuring system comprises a light source for irradiating the target vessel portion with a laser beam and photosensors for receiving scattered light from the target vessel portion.

7. A blood vessel detecting apparatus comprising:

a two-dimensional area sensor which picks up a two-dimensional blood vessel image of an eye in which blood flows in a blood flow direction and outputs a signal representing the two-dimensional blood vessel image; and

a processing system that executes signal processing on the signal output by said two-dimensional area sensor to extract data representing a feature of the blood vessel, said data including at least one of the features such as the number of blood vessels, blood flow direction of the blood vessel and the position of the blood vessel on the basis of the blood vessel image picked up by said two-dimensional area sensor in a direction perpendicular to the blood flow direction.

8. An apparatus according to claim 7, wherein said feature includes information of a diameter of the blood vessel.

9. An apparatus according to claim 7, wherein said processing system integrates the output signal of said two-dimensional area sensor with respect to the blood flow direction after the extraction of data representing a feature of the blood vessel.

10. An apparatus according to claim 7, further comprising a deflecting optical system for deflecting a blood vessel image to project a target vessel portion on said two-dimensional area sensor.

11. An apparatus according to claim 7, further comprising a measuring system for measuring the blood flow velocity in the blood vessel whose image is picked up by said two-dimensional area sensor.

12. An apparatus according to claim 11, wherein said measuring system comprises a light source for irradiating the blood vessel whose image is subsequently picked up by said two-dimensional area sensor with a laser beam and photosensors for receiving scattered light from the irradiated blood vessel.

13. An apparatus according to claim 7, further comprising an image rotator which rotates the blood vessel image so as to align the blood flow direction of the blood vessel with a coordinate system of the two-dimensional area sensor.

14. A blood vessel detecting apparatus comprising:

an image pickup device having a plurality of pixels for picking up an image of a blood vessel;

discriminating means for discriminating the number of blood vessels on the basis of an output from said image pickup device;

tracking means for tracking a predetermined blood vessel on the basis of information on the detected number of blood vessels; and

velocity measuring means for measuring the velocity of the blood flowing in the blood vessel on which the tracking operation has been performed by said tracking means.

15. A blood vessel detecting apparatus comprising:

an image pickup device having a plurality of pixels for picking up an image of a blood vessel;

discriminating means for discriminating the number of blood vessels on the basis of an output from said image pickup device;

diameter calculation means for calculating the diameter of a predetermined blood vessel on the basis of information of the detected number of blood vessels;

velocity measuring means for measuring the velocity of the blood flowing in the predetermined blood vessel; and

blood flow volume calculation means for calculating the blood flow volume flowing in the predetermined blood vessel on the basis of the diameter of the predetermined blood vessel and the velocity of the blood measured by said velocity measuring means.

16. A blood vessel detecting apparatus comprising:

an image pickup device having a plurality of pixels for picking up an image of a blood vessel;

discriminating means for discriminating the number of blood vessels on the basis of an output from said image pickup device;

tracking means for tracking a predetermined blood vessel on the basis of information of the discriminated number of vessels;

diameter calculation means for calculating the diameter of the predetermined blood vessel on the basis of information of the discriminated number of blood vessels;

velocity measuring means for measuring the velocity of the blood flowing in the predetermined blood vessel on which the tracking operation is performed; and

blood flow volume calculation means for calculating the blood flow volume flowing in the predetermined blood vessel on the basis of the diameter of the predetermined blood vessel and the velocity of the blood measured by said velocity measuring means.

17. A blood vessel detecting apparatus comprising:

irradiation means for irradiating a target blood vessel;

image pickup means for picking up a blood vessel portion including the target blood vessel irradiated by said irradiation means to output an image pickup signal;

signal processing means for carrying out an operation on the image pickup signal as outputted;

determination means for determining whether the target blood vessel contains a single blood vessel or plural blood vessels, and a position of the target blood vessel, on the basis of the image pickup signal processed by said signal processing means; and

control means for controlling a performance of said apparatus on the basis of a determination result of said determination means.

18. An apparatus according to claim 17, wherein said image pickup means comprises one-dimensional or two-dimensional CCD.

19. An apparatus according to claim 17, further comprising tracking means for tracking the target blood vessel, wherein said control means controls said tracking means to track the target blood vessel on the basis of the determination result of said determination means.

20. An apparatus according to claim 17, further comprising diameter measuring means for measuring a diameter of the target blood vessel, wherein said control means controls said diameter measuring means to measure the diameter of the target blood vessel on the basis of the determination result of said determination means.

21. An apparatus according to claims 17, 18 or 19, further comprising blood flow velocity measuring means for measuring a blood flow velocity of the target blood vessel.