# US 4,794,450 A · Method and apparatus for judging agglutination pattern

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 4,794,450 A
- Document ID: US4794450A
- Status: Granted
- Kind: A
- Application number: 07/090,477
- Filed: 1987-08-28
- Granted: 1988-12-27
- Earliest claimed: 1986-08-29
- Assignees: Fujirebio Inc.
- Inventors: Tomo Saito; Yasusuke Sakurabayashi; Toshitsugu Inouchi; Norihiro Suzuki
- Web page: https://patentgrep.com/patent/US4794450A

## CPC

- G01N 21/82: producing a precipitate or turbidity
- G01N 33/53: Immunoassay; Biospecific binding assay; Materials therefor
- G01N 2021/5961: {using arrays of sources and detectors}
- G01N 2201/0461: Simultaneous, e.g. video imaging
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

An apparatus for judging an agglutination has a transparent plate stand 5 for supporting a microplate 7 and perforated with positioning openings 9 for centering of each well 8 of the microplate. A light source and TV camera 12 are disposed above the microplate, an image memory 13 stores the output of the camera, a processor 15 differentiates the stored image to determine its profile, and the picture elements of the differentiated image having intensity levels larger than zero are counted. A calculator 17 produces coefficients of variation, which are plotted against the image profile and compared with a reference value to remove contrast irregularities.

## Claims

### Claim 1

A method of judging an agglutination pattern comprising the steps of:
setting a reference value, and
judging the testing agglutination pattern,
said reference value setting step including the steps of:
(a) storing video images of a plurality of agglutination images,
(b) differentiating the video images to produce differential images;
(c) producing an area of the profile of the differential images;
(d) producing a variation coefficient of each picture element of a differential image having a luminance level not zero from a standard deviation of the picture elements,
(e) plotting the relationship between the variation coefficients and the area of the profile,
(f) inputting a visual judgement of a plurality of agglutination images to plot the images on a plot of said relationship,
(g) determining a linear line on the relationship plot so that an overlapping portion of positive and negative agglutination regions of the plot of the visual judgement on the plot of said relationship is obtained, and
(h) storing the result obtained from step (g) of determining the linear line, and
said agglutination judging step including the steps of:
(i) executing the above steps (a) to (e) for independently prepared agglutination images, and
(j) comparing the result obtained in step (i) with the linear line stored in step (h).

### Claim 2 (depends on 1)

The method as claimed in claim 1, wherein step (b) comprises the steps of dividing said video image into a partition of sectors and determining a difference in brightness between each picture element of said video image in each sector and other picture elements disposed radially outwardly of said each picture element.

### Claim 3 (depends on 1)

The method as claimed in claim 1, wherein step (c) comprises assigning a first and a second picture element arranged in each horizontal scanning line, which have two most significant values of difference, as those constituting the profile.

### Claim 4

An apparatus for judging an agglutination, comprising: a plate stand which is light transmittable for placing a microplate and perforated with positioning openings for positioning a central position of each well of the microplate, a light source disposed to illuminate the plate stand, a TV camera provided for light irradiated from above the microplate placed on the plate stand to be incident, an image memory for storing an output image of the TV camera, a processor for differentiating the stored image to determine the profile of the image, a counter for counting picture elements having intensity levels larger than zero of the differentiated image, means for producing a coefficient of variation, a plotter for producing the relationship between the coefficient of variation from the output of the counter and the counted value, and a comparator for comparing the output of the plotter with a reference value.

### Claim 5 (depends on 4)

The apparatus as claimed in claim 4, wherein said processor and said counter determine the central position of each well by the light transmitted through the positioning openings, then divide the image of each well into a plurality of picture elements radiating outwardly from the central position, differentiate the value totalized from the difference of the intensities of outward picture elements in the divided portions as the differentiated value of each picture element, sequentially compare the differential values of the picture elements, and count the number of picture elements between two most significant differential values.