DESC:SYSTEM AND METHOD TO AUTO-CALIBRATE A SCANNING BRIGHT-FIELD MICROSCOPE
FIELD OF THE INVENTION
The present invention generally relates to the field of scientific instruments. Particularly, the present invention relates to microscope and more particularly, relates to system and method to auto-calibrate a scanning bright-field microscope.

BACKGROUND OF THE INVENTION
A microscope is precision optical equipment, which is mainly used for micro structural observation in various fields with a wide range of uses. One type of microscope is a scanning microscope that produces images of samples by scanning a multiple layers of the surface of the sample.

In one approach, a plurality of attributes is measured which characterises the element in the image captured by scanning bright-field microscope. Further, to get a precise and an accurate measurement of the plurality of attributes, the scanning bright-field microscope must be calibrated prior to measuring the plurality of attributes. In one approach, if the scanning bright-field microscope is not calibrated prior to measuring the plurality of attributes, the plurality of attributes contains a plurality of inaccuracies due to various causes such as a vibration, a backlash, an optics tilt, or the like. One way to calibrate the scanning bright-field microscope is by having a reference image with known attributes like a physical dimension and a shape of the sample being scanned. However, in such systems, the plurality of attributes required for calibration is complex. Also the complexity of the plurality of attributes makes the system complex and hence such system is time consuming.

In another approach, a user calibrates the scanning bright-field microscope by using a plurality of interactive image processing tools on a computer screen. The user also calibrates using distance between one or more elements of the image of reference and the image being captured using the same plurality of interactive image processing tools. However, in such systems the user must identify a position of one or more elements of the image very precisely. Also such a value of the position of one or more elements of the image varies from one user to another.

In yet another approach, the scanning bright-field microscope is attached with a sensor to measure an inaccuracy of the system. The sensor may be a laser sensor, a photoelectric sensor, or the like. However, in such systems the size of the scanning bright-field microscope increases due to the addition of the sensor.

US9147104 discloses a method of classifying, with a computer processor, at least one feature of cells from a low contrast, digital image. The method includes generating a contrast-enhanced image by applying a high-pass filter to the low contrast, digital image. The contrast-enhanced image is smoothed with a first low pass filter. A background image, generated from the low contrast, digital image, is subtracted from the smoothed, contrast-enhanced image to form an analysis image. The at least one feature is identified in analysis image. The method is about getting contrast-enhanced image using water based lenses.

US20170285320 discloses automated slide scanning system, comprising one or more optical elements, including an objective, having an optical path configured to be disposed within view of a camera of a portable device. An automated stage disposed within the optical path, the automated stage comprising a platform configured for receiving a slide containing a biological sample and having a drive mechanism for translating the stage in at least one direction with respect to said objective. A communications interface coupled to the automated stage, and is configured for receiving a command from the portable device to control operation of the mechanical stage. However, the system has used a pre-defined special calibration sample positioned within the optical path to calibrate images of the sample.

Hence, there is a need for system and method to auto-calibrate the scanning bright-field microscope to address the aforementioned issues.

OBJECTS OF THE INVENTION
One or more of the problems of the conventional prior art may be overcome by various embodiments of the system and method of the present invention.

It is the primary object of the present invention to provide to a system to auto-calibrate a scanning bright-field microscope.

It is another object of the present invention, wherein the system automatically matches image quality of a sample with a glass lens based microscope.

It is another object of the present invention, wherein the system calibrates glass lens based microscopic scanner to capture the image optimally without using any hardware based feedback loop thus reducing the number of components used.

It is another object of the present invention, wherein the system auto-calibrates before every sample is scanned thus reducing dependency on calibration samples.

It is another object of the present invention, wherein the system diagnoses inaccuracies of the scanning bright-field microscope and auto-calibrates the measured inaccuracies.

It is another object of the present invention to provide a method for auto-calibrating a scanning bright-field microscope.

SUMMARY OF THE INVENTION
Thus according to the basic aspect of the present invention, there is provided a system to auto-calibrate a scanning bright-field microscope, comprising:
scanning bright-field microscope configured to focus a sample;
an image capturing device operatively coupled to the scanning bright-field microscope to capture a plurality of images of the sample;
a processing unit operatively coupled to the image capturing device to process the captured image; and
a storage module operatively coupled to the image capturing device,
wherein the processing unit includes a self-diagnosing module operatively coupled to the image capturing module to diagnose a plurality of inaccuracies in the scanning bright-field microscope, and an auto-calibration module operatively coupled to the self-diagnosing module to re-calibrate the scanning bright-field microscope automatically,
wherein the scanning bright-field microscope is auto-calibrated based on the processed and stored image of the sample, and
wherein the system auto-calibrates before every sample is scanned thus reducing dependency on calibration samples.

It is another aspect of the present invention, wherein the scanning bright-field microscope includes a motorized stage configured to hold the sample; and one or more optics tube operatively coupled to the motorized stage.

It is another aspect of the present invention, wherein the plurality of inaccuracies include a vibration, a backlash, and an optical tilt.

It is another aspect of the present invention, wherein the system calibrates glass lens based microscopic scanner to capture the image optimally without using any hardware based feedback loop thus reducing the number of components used.

Another aspect of the present invention is directed to provide a method for auto-calibrating a scanning bright-field microscope, comprising the steps of:
capturing an image of a sample using an image capturing device;
sending the captured image to a processing unit to check the calibration, wherein by diagnosing plurality of inaccuracies of the scanning bright-field microscope and auto-calibrating the measured inaccuracies based on the processed and stored image of the sample;
verifying the captured image to check clarity level and focusing level of the scanning bright-field microscope using the focus value of the captured image; and
storing the verified image in a storage module,
wherein the method performing auto-calibration before every sample is scanned thus reducing dependency on calibration samples.

It is another aspect of the present invention, wherein if the captured image is blurred image, the processing unit sends a signal to the image capturing module to capture another image of the sample and the new captured image is processed further.

It is another aspect of the present invention, wherein the method further comprising based on the plurality of inaccuracies sending signal to motorized stage of the scanning bright-field microscope by the processing unit to auto-calibrate the measured inaccuracies.

It is another aspect of the present invention, wherein the plurality of inaccuracies include a vibration, a backlash, and an optical tilt.

BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1: is a block diagram of a system to auto-calibrate a scanning bright-field microscope in accordance with an embodiment of the present invention.
Figure 2: is a block diagram of a scanning bright-field microscope in accordance with an embodiment of the present invention.
Figure 3: is a block diagram of a processing module in accordance with an embodiment of the present invention.
Figure 4: is a flow chart representing the steps involved in a method for auto-calibrating a scanning bright-field microscope in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING FIGURES
The present invention as herein described relates to system and method to auto-calibrate a scanning bright-field microscope.
Referring to Figure 1, the system (10) comprises a scanning bright-field microscope (20) configured to focus a sample; an image capturing device (30) operatively coupled to the scanning bright-field microscope (20); a processing unit (40) operatively coupled to the image capturing device (30); and a storage module (50) operatively coupled to the image capturing device. The image capturing device (30) is configured to capture a plurality of images of the sample. In one embodiment, the image capturing device (30) may include a camera or a scanner.

Referring to Figure 2, the scanning bright-field microscope (20) includes a motorized stage (25) configured to hold the sample; and one or more optics tube (28) operatively coupled to the motorized stage (25). The motorized stage (25) is a mechanical device in a microscope that holds the specimen slide in place and can also smoothly translate the slide in all required direction. In one embodiment, the motorized stage (25) is made up of one or more actuators and each of the actuators are driven by one or more motors, said actuators and motors are stacked together for a controlled movement of the motorized stage (25) in a plurality of directions.

The optics tube (28) is configured to focus the sample on the motorized stage (25), said optics tube is a mechanical tube usually placed on the top edge of a microscope to which a plurality of eyepieces is inserted to view the sample on the motorized stage (25). In one embodiment, each of the optics tubes (28) may include a plurality of lenses on both ends. Further, the optics tube (28) may be placed perpendicular to the motorized stage (25).

In an embodiment, the scanning bright-field microscope (20) may be coupled to a processing unit. The processing unit is configured to process the image of the sample captured by the image capturing device and adjust the calibration of the scanning bright-field microscope automatically. In one embodiment, the processing unit may be an application which may be interfaced to a hand held device like Smartphone or tablet.

The processing unit (40) is configured to process the captured image. Referring to Figure 3, the processing unit (40) includes a self-diagnosing module (45) operatively coupled to the image capturing module (30) and an auto-calibration module (48) operatively coupled to the self-diagnosing module (45). The self-diagnosing module (45) is configured to diagnose a plurality of inaccuracies in the scanning bright-field microscope (20). In one embodiment, the plurality of inaccuracies may be a vibration which may occur due to a plurality of causes. As used herein, the vibration is a periodic motion of a plurality of particles in an alternately opposite direction from a position of equilibrium. In such embodiments, the vibrations may damp over time which may increase the time required for damping before reading the image which may also delays the next process and hence the scanning time may increase.

In one specific embodiment, the plurality of causes for the vibration may be regular use of a plurality of components in the scanning bright-field microscope (20) which may make the plurality of components wear out. In another specific embodiment, the plurality of causes for the vibration may be due to a wear and tear of the plurality of components in the scanning bright-field microscope (20).

In another embodiment, the plurality of inaccuracies may be a backlash which may occur due to a plurality of causes. In one specific embodiment, the plurality of causes may be the wear and tear of the plurality of components in the scanning bright-field microscope (20). As used herein, the backlash is a lag in an actual position of a system. In yet another embodiment, the plurality of inaccuracies may be an optical tilt which may occur due to a plurality of causes. As used herein, optical tilt is a tilt in or a deviation in a direction of a beam of propagation of light. In one specific embodiment, the plurality of causes may be manual displacement of an optical lens, which may lead to optical tilt. Further, the optical tilt may cause the image capturing device (30) to capture a plurality of distorted images of the sample.

The auto-calibration module (48) is configured to re-calibrate the scanning bright-field microscope (20) automatically. In one embodiment, the scanning bright-field microscope (20) may be auto-calibrated based on the processed and stored image. The storage module (50) is configured to store the plurality of processed images.

Referring to Figure 4, a method (100) for auto-calibrating a scanning bright-field microscope comprising: at step 110, capturing an image of a sample using an image capturing device (30). In an embodiment, the image capturing device (30) may be a camera or a scanner. At step 120, sending the captured image to a processing unit. In one embodiment, a plurality of captured images of the sample may be sent to the processing unit (40) to check the calibration. At step 130, verifying clarity level of the captured image. In one embodiment, the plurality of captured images is verified to check the focusing level of the scanning bright-field microscope using the focus value of the captured image. At step 140, storing the verified image. In one embodiment, the verified image of the sample may be stored in a storage module (50). In another embodiment, the storage module (50) may be a hand held device, a secure digital (SD) card or a computer.

In one embodiment, the processing unit (40) checks if the plurality of captured images is clear images or blurred images. Further, if the plurality of captured images is clear images, the processing unit (40) stores the clear images. If the plurality of captured images is blurred images, the processing unit (40) sends a signal to the image capturing module (30) to capture another image of the sample and the plurality of new captured images is processed further. In one embodiment, the plurality of inaccuracies of the scanning bright-field microscope (20) such as the vibration of the scanning bright-field microscope may be detected and calibrated based on the plurality of captured images. The processing unit (40) may send a signal to the motorized stage (25) of the scanning bright-field microscope (20) to adjust the placement of the motorized stage to get the focused image of the sample which may be captured by the image capturing device (30). The image capturing device (30) may capture the plurality of images of the sample and may compare the plurality of captured images with the previously captured and verified image. Further the process may be repeated until a clear image of the sample is obtained. Also, the time taken to obtain a proper focused image may be recorded as a threshold time after which the vibration of the scanning bright-field microscope (20) may become negligible. Further, the plurality of images captured after the threshold time may be stored in the storage module (50) permanently.

In another embodiment, the plurality of inaccuracies of the scanning bright-field microscope (20) such as the backlash of the scanning bright-field microscope may be detected and calibrated based on the plurality of captured images. The processing unit (40) may send the signal to the motorized stage of the scanning bright-field microscope (20) to vertically oscillate to and fro for a plurality of times between a plurality of points. Further the plurality of points may be so chosen to get the focused image at its maximum level. After each oscillation, the image of the sample may be captured by the image capturing device (30) and may also record a value for a focus level of the plurality of captured images. Also the value for the focus level of the plurality of captured images at to and fro oscillation may be plotted on a graph separately and the obtained graph may have the same plots for both to and fro movement of the scanning bright-field microscope (20). Further, the graph of the to and fro movements may have a shift between them which may be equal to the backlash of the scanning bright-field microscope (20). Also, the value for the focus level of the plurality of captured images may yield a mean value and a variance value of the backlash of the scanning bright-field microscope (20). As used herein, mean value is an average value of a plurality of points divided by a total number of values. Also variance value is a measure of how far a data set id from the mean value. Further, with the mean value and the variance value, a probability distribution of an actual position of the scanning bright-field microscope (20) may be obtained. As used herein, the probability distribution is a statistical function that describes all possible value that a random variable may take within a given range. Further, a plurality of the backlash may be stored in the storage module (50) which may be further used to calculate the probability distribution of a current position of the scanning bright-field microscope (20) at any point of time.

In yet another embodiment, the plurality of inaccuracies of the scanning bright-field microscope (20) such as the optics tilt of the scanning bright-field microscope may be detected and calibrated based on a captured image. The processing unit (40) after capturing the image of the sample may analyse and predict an amount of optics tilt by analysing the variance value and the focus value of the captured image. Further, a de-focused part of the captured image may be discarded. In yet another embodiment, by analysing the variance value and the focus value of the captured image, the processing unit may send a signal to the optics tube which may fix the optics tilt.

The advantages of the present invention are as follows:
Maintaining the size of the scanning bright-field microscope as no extra component is required.
The system capture the image optimally without using any hardware based feedback loop thus reducing the number of components used.
The system is cost effective.
The system produces accurate measurements of the plurality of attributes.
The system can diagnose the inaccuracies of the scanning bright-field microscope and also auto-calibrate the measured inaccuracies.
It will be understood by those skilled in the art that the foregoing detailed description is exemplary and explanatory of the invention and are not intended to be restrictive thereof. The scope of embodiments is by no means limited by these specific examples.
,CLAIMS:WE CLAIM:
1. A system to auto-calibrate a scanning bright-field microscope, comprising:
scanning bright-field microscope (20) configured to focus a sample;
an image capturing device (30) operatively coupled to the scanning bright-field microscope (20) to capture a plurality of images of the sample;
a processing unit (40) operatively coupled to the image capturing device (30) to process the captured image; and
a storage module (50) operatively coupled to the image capturing device,
wherein the processing unit (40) includes a self-diagnosing module (45) operatively coupled to the image capturing module (30) to diagnose a plurality of inaccuracies in the scanning bright-field microscope (20), and an auto-calibration module (48) operatively coupled to the self-diagnosing module (45) to re-calibrate the scanning bright-field microscope (20) automatically,
wherein the scanning bright-field microscope (20) is auto-calibrated based on the processed and stored image of the sample, and
wherein the system auto-calibrates before every sample is scanned thus reducing dependency on calibration samples.

2. The system as claimed in claim 1, wherein the scanning bright-field microscope (20) includes a motorized stage (25) configured to hold the sample; and one or more optics tube (28) operatively coupled to the motorized stage (25).

3. The system as claimed in claim 1, wherein the plurality of inaccuracies include a vibration, a backlash, and an optical tilt.

4. The system as claimed in claim 1 calibrates glass lens based microscopic scanner to capture the image optimally without using any hardware based feedback loop thus reducing the number of components used.

5. A method for auto-calibrating a scanning bright-field microscope, comprising the steps of:
capturing an image of a sample using an image capturing device;
sending the captured image to a processing unit to check the calibration, wherein by diagnosing plurality of inaccuracies of the scanning bright-field microscope and auto-calibrating the measured inaccuracies based on the processed and stored image of the sample;
verifying the captured image to check clarity level and focusing level of the scanning bright-field microscope using the focus value of the captured image; and
storing the verified image in a storage module,
wherein the method performing auto-calibration before every sample is scanned thus reducing dependency on calibration samples.

6. The method as claimed in claim 5, wherein if the captured image is blurred image, the processing unit sends a signal to the image capturing module to capture another image of the sample and the new captured image is processed further.

7. The method as claimed in claim 5 further comprising based on the plurality of inaccuracies sending signal to motorized stage of the scanning bright-field microscope by the processing unit to auto-calibrate the measured inaccuracies.

8. The method as claimed in claim 7, wherein the plurality of inaccuracies include a vibration, a backlash, and an optical tilt.