Apparatus for analyzing blood

• US 5,741,213 A
• Filed: 10/25/1996
• Issued: 04/21/1998
• Est. Priority Date: 10/25/1995
• Status: Expired due to Fees

• Current Assignee: Toa Medical Electronics Co., Ltd.
• Original Assignee: Toa Medical Electronics Co., Ltd.
• Inventors: Ishihara, Ken, Kouchi, Yasuhiro, Asano, Kaoru
• Primary Examiner(s): Bahr, Jennifer
• Assistant Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US08/736,822
• Time in Patent Office: 543 Days
• Field of Search: 600/309, 600/310, 600/322, 600/476, 600/473, 600/479, 600/407, 356/39, 382/128, 382/133, 382/134, 382/199
• US Class Current: 600/310
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: G06V 20/69 Microscopic objects, e.g. biological cells or cellular parts

Abstract

An apparatus for analyzing blood includes an image capturing device for capturing an image including at least one object blood cell and an analyzer for analyzing the captured image as an image F(x, y) in an x-y coordinate system. The analyzer includes an edge calculator for calculating an edge intensity distribution E(x, y) representing an outline of the image F(x, y); a weight memory for storing in advance a weight distribution W(i, j) corresponding to an average outline of the object cell; an assessment value calculator for obtaining an assessment value C (x, y) at each point (x, y) by calculating a degree of correspondence between the edge intensity distribution E (x, y) and the weight distribution W(i, j) for each point (x, y); and an extractor for extracting a point (x, y) at which the assessment value C(x, y) is larger than a predetermined value, thereby determining that the object blood cell is present at the point (x, y). The apparatus is useful as a device for identifying the object blood cell.

Claims

1. An apparatus for analyzing blood including an image capturing device for capturing an image including at least one object blood cell and an analysis device for analyzing the captured image as an image F(x, y) in an x-y coordinate system, the analysis device comprising:

edge calculation means for calculating an edge intensity distribution E(x, y) representing an outline of the image F(x, y);

weight storage means for prestoring a weight distribution W(i, j) corresponding to an average outline of the at least one object blood cell;

assessment value calculation means for obtaining an assessment value C(x, y) at each point (x, y) by calculating a degree of correspondence between the edge intensity distribution E(x, y) and the weight distribution W(i, j) for each point (x, y); and

extraction means for extracting a point (x, y) at which the assessment value C(x, y) is larger than a predetermined value, thereby determining that the at least one object blood cell is present at the point (x, y), so that the at least one object blood cell is identified.

2. An apparatus for analyzing blood according to claim 1, wherein the assessment value calculation means calculates the assessment value C(x, y) at the point (x, y) by the following equation:

##EQU4## where the right hand side of the above equation represents a sum of products of the edge intensity distribution and the weight distribution when the when both distributions are overlapped with each other so that the point (x, y) in the edge intensity distribution corresponds to the point (0,

     0) in the weight distribution.

3. An apparatus for analyzing blood according to claim 1, wherein the weight distribution W(i, j) is an annular distribution data corresponding to the outline of the object blood cells.

4. An apparatus for analyzing blood according to claim 1, wherein the edge calculation means calculates the edge intensity distributions E1(x, y), E2(x, y), . . . En(x, y) corresponding to n different directions radiating from a point (x, y), the weight storage means stores the weight distributions W1(i, j), W2(i, j), . . . Wn(i, j) corresponding to the n different directions, and the assessment value calculation means calculates the assessment value by summing up the assessment values Cl(x, y), C2(x, y), . . . Cn(x, y) calculated corresponding to the n different directions.

5. An apparatus for analyzing blood according to claim 4, wherein each of the weight distributions W1(i, j), W2(i, j), . . . Wn(i, j) is a portion of annular distribution data corresponding to the outline of the object blood cells.

6. An apparatus for analyzing blood according to claim 1, wherein the weight distribution W(i, j) is calculated based on data obtained by summing up the edges extracted beforehand from a plurality of images of blood cells with the edge calculation means.

7. An apparatus for analyzing blood according to claim 1, wherein the image capturing device comprises an illuminator and an imaging device, the illuminator serving to illuminate a detection region including a blood vessel within a living body, and the imaging device serving to sequentially capture images of the illuminated detection region, and

the analysis further comprises differential image creating means that creates a reference image using at least one of the sequentially captured images of the same detection region and, assuming another of the captured images to be an object image, creates a differential image by taking a difference between the object image and the reference image, whereby the image F(x, y) is defined by the differential image.

8. An apparatus for analyzing blood according to claim 7, wherein the analysis device further comprises digitizing means for digitizing the reference image and the object image, whereby the differential image is defined by a difference between the digitized reference image and the digitized object image.

9. An apparatus for analyzing blood according to claim 1, wherein the analysis device comprises a neural network including the edge calculation means the weight storage means, the assessment value calculation means, and the extraction means.

10. An apparatus for analyzing blood according to claim 1, further comprising fixing means for relatively fixing a living body and the image capturing means so that the image capturing means is fixed on a surface of the living body corresponding to a desired detection region.

11. An apparatus for analyzing blood according to claim 1 further comprising calculation means for calculating the number of the object blood cells identified during a predetermined period of time when the image capturing device sequentially captures a plurality of images of a region including a blood vessel of a living body.

12. A method of analyzing blood using the apparatus of claim 1, the method comprising the steps of:

sequentially capturing a plurality of images of a region including a blood vessel of a living body,

identifying object blood cells in the plurality of images, and calculating the number of per unit volume.