Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed:
Field of the invention:
[0001] The present invention relates to a method and a control unit for analyzing a sample loaded in a pathology device.

Background of the invention:
[0002] Whole slide imaging (WSI) slide holder flatness is always challenge where sub-micron flatness required to capture multiple focused images in array with minimum number of focus and tissue surface also challenge as to maintain sub-micron level flatness.

[0003] A US patent application 20070167839 discloses a system for multispectral confocal mapping of a tissue, comprising: a light source; an optical fiber having an aperture providing a confocal pinhole, a scanner being free-space coupled to said aperture and operative to scan the tissue and provide intensity signals for each of a plurality of points therein; a switch or modulator operative to convert input signals to optical pulses; a reflector that receives the optical pulses and provides a temporal sequence of wavelength selective reflections; and, a detector optically coupled to receive the temporal sequence of wavelength selective reflections.

Brief description of the accompanying drawings:
[0004] An embodiment of the disclosure is described with reference to the following accompanying drawing,
[0005] Fig. 1 illustrates a control unit for analyzing a sample in a device according to an embodiment of the present invention; and
[0006] Fig. 2 shows a flowchart of a method for analyzing a sample in a device, according to the present invention.
[0007] Detailed description of the embodiments:
[0008] Fig. 1 illustrates a control unit for analyzing a sample in a device according to an embodiment of the present invention. The device 12 comprises a slide holder 16 to accommodate the sample 14 and an image capturing unit 18 adapted to capture at least one image of the sample 14. The control unit 10 identifies a region of interest on the sample 14 and creates a grid structure on the identified region of interest. The control unit 10 selects multiple focus points positioned at predefined locations in the grid and captures the selected multiple focal points images by focusing on each of the selected focus point. The control unit 10 assigns a focal point value to each of the multiple focus points for forming a focus matrix. The control unit 10 captures multiple images of the sample 14 by moving the image capturing unit 18 in a predefined pattern from one of the focus point to next focus point for analyzing of the sample 14.
[0009] Further the construction of the device and the control unit is explained in detail. According to one embodiment of the invention, the device 10 is a digital pathology device that has a sample holder 16 for loading the sample 14. The image capturing unit 18 is a camera and the material in the sample 14 can be any body fluid comprising tissue, blood, urine, semen, bone fluid and the like. For ease of understanding, the sample 14 contains a tissue of a patient. According to one embodiment of the invention, the device 12 comprises three supporting elements for the image capturing unit 18, one for each axis. For instance, a first supporting element moves the image capturing unit 18 in an x-axis and a second supporting element for moving the image capturing unit 18 in a y-axis and a third supporting element for moving the image capturing unit 18 in a z-axis.
[0010] When the sample 14 is loaded in the sample holder 16, the control unit 10 identifies a region of the interest on the sample 14 where the content/material of the sample 14 is visible. The each of identified ideal region has the main focused image and a corresponding grid structure. The control unit 10 is chosen from a group of control units comprising a microprocessor, a microcontroller, a digital circuit, an integrated circuit and the like.
[0011] The predefined location in the grid comprises a corner location of the grid, a side center location of the grid and a center location of the grid. For instance, the formed grid structure will have ten focus points. The control unit 10 captures each of the focus points by the z-axis movement of the image capturing unit from an initial position and assigns a focal point value to each of the captured focal point in the grid structure for forming a focus matrix.
[0012] For example, the control unit 10 focuses and captures the first focal point in the first corner location of the region of the interest, then the control unit 10 captures that focal point and assigns a focal point value of 6085. The control unit 10 then assigns coordinates for the captured focal point like (0,0,6085). The same method is repeated for the other focal points.
[0013] The control unit 10 moves the z-axis supporting element for capturing the multiple focus points on the grid structure and one focus point z axis movement is compared with the next focus point and a difference value between adjacent two focus points is calculated. The control unit 10 distributes a calculated difference with a distance between the two adjacent focal points in the x-axis and the y-axis direction. The control unit 10 then combines all captured images to form a main image of sample 14 for analyzing.
[0014] According to one embodiment of the invention, the sample 14 comprises a tissue of at least one body appendage of a human being. The image capturing unit 18 adapted to capture multiple focused images in a predefined pattern movement via the x-axis and the y- axis along with the z- axis movement.
[0015] Figure 2 illustrates a flowchart of a method for analyzing a sample 14 in a device, according to the present invention. The device 12 comprises a slide holder 16 to accommodate a sample 14. The device 12 comprises an image capturing unit 18 for capturing at least one image of the sample 14. In step S1, a region of interest on the sample 14 is identified and a grid structure on the identified region of interest is created. In step S3, multiple focus points positioned at predefined locations are selected in the grid structure and the selected multiple focal points images are captured by focusing on each of the selected focus point. In step S4, a focal point value is assigned to the each of the multiple focus points for forming a focus matrix. In step S5, multiple images of the sample 14 by moving the image capturing unit 18 in a predefined pattern from one of the focus points to next focus point for analyzing of the sample 14.
[0016] The method is explained in detail. The sample 14 is loaded in the sample holder 16 of the device 10. Upon detecting the sample 14 in the sample holder 16, the control unit 10 identifies region of interest on the sample 14. The control unit 10 forms first the focus matrix and starts capturing the entire sample with reference to the focal points. The selected region of interest on the sample 14 is scanned/captured for forming the grid structure.

[0017] The control unit 10 identifies the multiple focal points from the predefined locations as mentioned above (each corner of grid, a side center of the grid and an array grid center location). The control unit 10 captures each of the identified focal point by the z-axis supporting element and each captured image of the focus points is stored after assigning a focal point value for each of captured image. During this process, the z-axis movement is started from an initial position in the created grid. For instance, the grid will have ten focus points and z-axis movement will be from the initial position moving towards the end of the grid in a predefined pattern. Wherein one such pattern is called a snake pattern or line by line pattern. Due to this movement of the supporting element, the control unit 10 captures three images of three focal points in each row of the grid. For more understanding, if the first focus point is present at the start of the grid, the next/second focus point will be at the center of the first row of the grid and the third focus point will be at the end of the first row.

[0018] The control unit 10 compares each focus point z axis movement with adjacent/next focus point and a difference value will be distributed with distance between focus points in X axis and Y axis. For example, if there are five blocks present between two focus points, then the difference value is distributed with distance between the first focus point and the second focus point. Now each focus point is assigned with a focal point value and the difference is distributed with distance between two focus points. Thus, the control unit 10 forms a focus matrix array in which focused images are captured.

[0019] After the formation of the focus matrix, the control unit 10 moves the slid holder 16 for capturing the images of the whole sample 14. The control unit moves the slide holder to starting point of the grid structure and moves Z- axis supporting element for moving the image capturing unit to focus point and to capture the focused image. Then the control unit 10 moves the slide in x-axis and y-axis for capturing next image. Simultaneously, the control unit 10 checks the focus matrix for the requirement of the z-axis in the respective grid structure.
[0020] The control unit 10 moves slide holder 16 in x-axis and y-axis to capture next image and simultaneously the control unit 10 checks the focus matrix, if any movement required in Z axis in respective grid. Based on the focus matrix and captured focus point image, the control unit 10 adjusts the Z-axis supporting element and repeats the above disclosed method for all focal points. The captured images are combined to form a main focused image of the sample to be analyzed.
[0021] With the above disclosed method, an optical image-based flatness calibration becomes easy to implement and the method provides a simple system. The above disclosed method doesn’t require any additional components and any type of flatness can be calibrated. The time required for the above disclosed slide imaging is very minimum. Any kind of changed in slide holder 16 flatness and tissue flatness over a period can be calibrated and it is also useful for capturing more images in grid with a smaller number of focuses.

[0022] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.
 
, Claims:We claim: -
1. A control unit (10) for analyzing a sample (14) in a device (12), said device (12) comprises a slide holder (16) to accommodate said sample (14) and an image capturing unit (18) adapted to capture at least one image of said sample (14); said control unit (10) adapted to:
- identify a region of interest on the sample (14) and to create a grid structure on said identified region of interest;
- select multiple focus points positioned at predefined locations in said grid and capture said selected multiple focal points images by focusing on each of said selected focus point;
- assign a focal point value to said multiple focus points for forming a focus matrix;
- capture multiple images of said sample (14) by moving said image capturing unit (18) in a predefined pattern from one said focus point to next said focus point for analyzing of said sample (14).
2. The control unit (10) as claimed in claim 1, wherein said predefined locations in said grid comprising a corner location of said grid, a side center location of said grid and a center location of said grid.
3. The control unit (10) as claimed in claim1, wherein each said focal point value is captured by a z-axis movement of said image capturing unit (18) from an initial position.
4. The control unit (10) as claimed in claim 1, wherein said one focus point z axis movement is compared with said next focus point and a difference value between adjacent two said focus points is calculated.

5. The control unit (10) as claimed in claim 4, wherein said calculated difference is distributed with a distance between said two adjacent focal points in an x-axis and a y-axis direction.
6. The control unit (10) as claimed in claim 1, wherein said control unit (10) adapted to combine all said captured images to form a main image of said sample (14) for analyzing.
7. The control unit (10) as claimed in claim 1, wherein said sample (14) comprises a tissue of at least one body appendage of a human being.
8. The control unit (10) as claimed in claim 1, wherein said image capturing unit (18) adapted to capture multiple focused images in a predefined pattern movement via an X axis and a Y axis along with the Z axis movement.

9. A method for analyzing a sample (14) in a device (12), said device (12) comprises a slide holder (16) to accommodate said sample (14) and an image capturing unit (18) adapted to capture at least one image of said sample (14); said method comprising:
- identifying a region of interest on the sample (14) and to create a grid structure on said identified region of interest;
- selecting multiple focus points positioned at predefined locations in said grid and capture said selected multiple focal points images by focusing on each of said selected focus point;
- assigning a focal point value to said multiple focus points for forming a focus matrix;
- capturing multiple images of said sample by moving said image capturing unit in a predefined pattern from one said focus point to next said focus point for analyzing of said sample (14).