WO2023053104A1 - Method and system for tracking and analysis of particles due to thermal variations - Google Patents

Abstract

Disclosed herein is a method, and its implementing system, whereby tracking and analysis of objects of interest (namely, particulates) due to thermal variations can be conveniently and rapidly undertaken, if any present and seen, in one or more photographic images of a sample being analyzed.

Description

Method and system for tracking and analysis of particles due to thermal variations”

Cross references to related applications: This non-provisional patent application claims the benefit of US provisional application no. 63/251641 filed on 03 October 2021 , the contents of which are incorporated herein in their entirety by reference.

Statement Regarding Federally Sponsored Research or Development: None applicable

Reference to Sequence Listing, a Table, or a Computer Program Listing Compact Disc Appendix: None

Field of the invention

This invention relates generally to the field of image processing and particularly to applications thereof for qualitative and quantitative analyses. An isolated embodiment of the present invention is disclosed in this paper, which relates specifically to a method, and its implementing system, whereby tracking and analysis of objects of interest (namely, particulates) due to thermal variations can be conveniently and rapidly undertaken, if any present and seen, in one or more photographic images of a sample being analyzed.

Background of the invention and description of related art

Image processing generally refers to digitization of optical images, and performing operation(s) on the so-converted data to augment and/or extract further meaningful information, preferably in an automated manner. Signal dispensation of source data, approach for processing said input source data and interpretation of post-processing output are major areas of interdisciplinary research in field of the present invention wherein image visualization, restoration, retrieval, measurement and recognition are prime loci of progressive investigation.

Particle analysis and particle characterization are major areas of research in new drug or formulation development in pharmaceutical industry. A proper analysis of particle size and shape reduces development time to a great extent. However, most of the current microscopic analysis is done manually which requires more time besides being prone to subjective interpretation and requires an expert to take the decision.

Processing of microphotographic images, in above parlance, is found to be employed variably in state- of-art technologies for study of microscopic particles wherein identifying indicia among their physical, chemical, compositional, morphological attributes and/ or physiological behaviors are utilized for qualitative and/ or quantitative determinations including identification and size distribution of the particles under study. However, such implements are presently limited to non-visual light microscopy applications such as X-ray microtomography (pCT), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and the like. Therefore, it would be advantageous to have some means for availing advantages of image processing technology for visual light I optical microscopy, particularly particle analysis applications.

Conventionally, detection and classification of particles has been practiced via sieving, sedimentation, dynamic light scattering, electrozone sensing, optical particle counting, XRD line profile analysis, adsorption techniques and mercury intrusion or further indirect methods such as surface area measurements. However, resolution of these techniques leave a lot to be desired, besides relying on availability of expensive equipment and collateral prior expertise of skilled operators for arriving at the determination intended. Such analysis, as will be obvious to the reader, tends to be less reproducible due to unavoidable personal biases and therefore inaccurate for faultless determinations. There is hence a need for some way that makes possible the integration of image analytics for particle classification in optical microscopy applications.

The art therefore requires a particle identification and classification technology that is capable of plug- and-play integration in existing optical microscopy application environments with minimal bias on capital, integration and operative expenses and at the same time, being of a nature that allows accurate and precise implementation by any person even ordinarily skilled in the art. Ability to succinctly discern despite strong variability among objects of interest, low contrast, and/or high incidence of agglomerates and background noise are additional characters desirable in said particle identification and classification technology presently lacking in state-of-art.

A better understanding of the objects, advantages, features, properties and relationships of the present invention will be obtained from the underlying specification, which sets forth the best mode contemplated by the inventor of carrying out the present invention.

Objectives of the present invention

The present invention is identified in addressing at least all major deficiencies of art discussed in the foregoing section by effectively addressing the objectives stated under, of which:

It is a primary objective to provide a methodology for tracking and analysis of objects of interest (namely, particulates) due to thermal variations can be conveniently and rapidly undertaken, if any present and seen, in one or more photographic images of a sample being analyzed.

It is another objective further to the aforesaid objective(s) that the method so provided is fully automated via fast and optimized computational logic with low processing time, low demands on processor resources, and effective use of available computer memory stores. It is another objective further to the aforesaid objective(s) that the method so provided is error-free and lends itself to accurate implementation even at hands of a user of average skill in the art.

It is another objective further to the aforesaid objective(s) that implementation of the method so provided does not involve any complicated or overtly expensive hardware.

It is another objective further to the aforesaid objective(s) that implementation of the method is possible via a remote server, in a software-as-a-service (SaaS) model.

The manner in which the above objectives are achieved, together with other objects and advantages which will become subsequently apparent, reside in the detailed description set forth below in reference to the accompanying drawings and furthermore specifically outlined in the independent claims. Other advantageous embodiments of the invention are specified in the dependent claims.

Brief description of drawings

The present invention is explained hereinunder with reference to the following drawings, in which,

FIG. 1 is a flowchart describing general logic for implementation of the present invention substantially according to the disclosures hereof.

FIG. 2 is a sample report outputted by the present invention.

The above drawings are illustrative of particular examples of the present invention but are not intended to limit the scope thereof. In above drawings, wherever possible, the same references and symbols have been used throughout to refer to the same or similar parts. Though numbering has been introduced to demarcate reference to specific components in relation to such references being made in different sections of this specification, all components are not shown or numbered in each drawing to avoid obscuring the invention proposed.

The above drawings are illustrative of particular examples of the present invention but are not intended to limit the scope thereof. Though numbering has been introduced to demarcate reference to specific components in relation to such references being made in different sections of this specification, all components are not shown or numbered in each drawing to avoid obscuring the invention proposed.

Attention of the reader is now requested to the detailed description to follow which narrates a preferred embodiment of the present invention and such other ways in which principles of the invention may be employed without parting from the essence of the invention claimed herein. Summary of the present invention

The present invention propounds a fast and resource-optimized computer-implemented automated methodology for tracking and analysis of objects of interest (namely, particulates) due to thermal variations can be conveniently and rapidly undertaken, if any present and seen, in one or more photographic images of a sample being analyzed.. Ingenuity of said methodology is identified in its approach of using Hot-stage microscopy wherein thermal analysis enables the study of materials (classification of material based on particle size, particle shape and various other morphological traits) as a function of temperature and time.

Detailed description

Principally, general purpose of the present invention is to assess disabilities and shortcomings inherent to known systems comprising state of the art and develop new systems incorporating all available advantages of known art and none of its disadvantages.

Accordingly, the disclosures herein are directed towards establishment of a method, and its implementing system, whereby tracking and analysis of objects of interest (namely, particulates) due to thermal variations can be conveniently and rapidly undertaken, if any present and seen, in one or more photographic images of a sample being analyzed. The setup comprises of a heating stage (hot stage) with a sample holder coupled with a suitable microscope and a powerful 21 CFR part 1 1 compliant software, which tracks the changes in particle size and particle morphology with respect to temperature and time.

In the embodiment recited herein, the reader shall presume that images referred are ones obtained from a microscope having a thermal stage which is fitted with an imaging system such as a camera. For this, a sample to be analyzed is processed using standard microscopy sample preparation and taken on stage of microscope for microphotography. As will be realised further, resolution of the present invention is correlated with optics of the microscope, and not the camera or computing system involved. Camera fitments for optical microscopes are inexpensive and commonly available. Assemblage and operations of these components requires no particular skill or collateral knowledge. Hence, the present invention is free of constraints entailing otherwise from capital, operation and maintenance costs besides negating the requirement of trained skilled operators for implementation of the present invention.

Reference is now made to the accompanying FIG. 1 , which is a flowchart describing general logic for implementation of the present invention. As seen here, execution of the present invention begins at step (01) where the user initializes I starts the application of the present invention (named “ipvPHot” and referred so throughout this document). This triggers step (02), in which the user is prompted (via suitable user interface) to create I select method to set particle range, magnification selection, particle detection method etc, and furthermore, temperature ramps (such as a starting and ending temperature point, with or without intermediate temperature points there-between, thus calling for heating and / or cooling by the thermal stage as per temperature points to be arrived at), with temperature intervals against time period in which they are to be reached from one another, to capture images against change in temperature for a set time Execution of selected process results in step (03), reading of image captured. In an alternative embodiment the step (03) may be alternatively practiced, in which the user creates temperature ramps to capture images against rise in temperature, then starts capturing image automatically as per schedule set by ramp, to finally result in capture of images for the set time. Users choice as to particle identification method is obtained in step (04), wherein it is determined, in step (05) if the same is contour based particle detection, and the execution flow allowed to thus follow, the pathway at branched-point (07) if contour-based, or if not, at branched-point (06) which is an alternative method being edge-based particle identification method.

With continued reference to the accompanying FIG. 1 , it can be seen that the contour based particle identification method includes a sub-process indicated via a first step (08) in which contours in image of same gray value variation (gradient) are found, and thereafter subjected in step (09) to an object identification protocol including a) Forming contour groups; and b) Finding best contour from group from user criteria selection (for example, sharpness, bounding box, circularity, perimeter).

With yet continued reference to the accompanying FIG. 1 , it can be seen that the edge based particle identification method includes a sub-process indicated by step (10) including a) Finding and labeling edges; b) Identifying complete edges as objects; and c) Connecting edge points to complete edges for incomplete edges if edge end points are close.

With yet continued reference to the accompanying FIG. 1 , it can be seen that once particle identification is had by either of the methods mentioned above, the data is subjected in step (11) to feature computation on basis of size, shape, color, and texture. Here, filters are applied in step (12), from a prearranged group including a) Size Filter - Filter Particles not in defined range; b) Sharpness Filter - Filter blur particles (less than defined sharpness); and c) Agglomeration Filter - Filter non isolated particles identified on shape features. Thereafter, it is determined in step (13), whether or not the image processed is the first image. If yes, particle tracking list is created via step (14). If not, overlapping particle in previous tracked list image is sought via step (15). Next, it is also determined, in step (18), whether or not the image processed is the last image. If not, next image is selected for processing at step (19) which causes a loop to step (03). Accordingly, filtered object data is logged into the computer memory for each successive image captured and plotted across the time period (thus constituting a graph) of the temperature ramp defined by the user using which plotting, the attributes of detected particles can be studied across the thermal change applied. If the image is the last image however, the array of particle track is computed at step (20) for size, circularity, intensity, and texture, which is displayed at step (21) in form of display particle tracking report statistics, thereby ending a typical execution cycle in step (22). Via implementation logic disclosed, it shall be appreciated how tracking and analysis of objects of interest (namely, particulates) due to thermal variations is brought about by the present invention. As will be generally realized, applicability and/ or performance of the present invention is not designed to be dependent on any particular sample composition and/ or preparation techniques. Accordingly, the present invention is able to process microphotographic images of samples including dry powder, liquid, gel, jelly, aerosols, emulsions, suspension, dispersion and so on and in practice, has been observed to provide results in few seconds.

Salient features of the present invention: a) US FDA 21 CFR part 1 1 compliant software b) D10, D50, D90 values c) Selective measurement of particle based on size, shape & thermal properties d) Capture morphological changes with respect to temperature and time e) Quick analysis & immediate generation of customized report.

Industrial applicability:

As will be appreciated by the reader, the present invention lends itself to a variety of applications, a few mentioned for sample being- a) Compound morphology b) Solid-solid transformations c) Interaction between different compounds d) Sublimation and evaporation e) Melting or liquefaction upon f) Solidification upon cooling

As will be realized further, the present invention is capable of various other embodiments and that its several components and related details are capable of various alterations, all without departing from the basic concept of the present invention. Accordingly, the foregoing description will be regarded as illustrative in nature and not as restrictive in any form whatsoever. Modifications and variations of the system and apparatus described herein will be obvious to those skilled in the art. Such modifications and variations are intended to come within ambit of the present invention, which is limited only by the appended claims.

Claims

We claim,

1 ) A method for tracking and analysis of objects of interest, particulates in particular, in a sample on the basis of thermal variations of said objects of interest, the method comprising- a) Constituting an application environment by communicatively associating an optical microscope having a thermal stage to a computer, wherein-

■ the method for tracking and analysis of particles due to thermal variations is provisioned for execution, as an executable software, on said computer; and

■ the optical microscope is outfitted with a digital camera for capturing images from the field of view of said microscope and relaying said captured images in real time to said computer for processing by the executable software provisioned on said computer. b) Defining, via a computer user interface of the executable software, a set of scanning parameters being opted at instance of the user between-

■ Particle range, magnification, time, imaging periodicity and particle detection method; and

■ Temperature ramps, with temperature intervals against time period in which they are to be reached from one another, to capture images against change in temperature for a set time. c) In accordance with the defined set of scanning parameters, causing at least one image to be captured from the microscope to serve as basis for processing by the executable software; d) In accordance with logic of the executable software-

■ At user-defined imaging periodicity, capturing successive images of the sample;

■ On basis of particle detection method opted for by the user, executing a subprocess specific to the corresponding particle detection method, to determine particles if any present and seen in the sample being processed;

■ Once particles are identified, computing feature data corresponding to said particles on basis of their size, shape, color, and texture;

■ Applying at least one filter on basis of size, sharpness, and agglomeration to the feature data generated to remove artifacts and result in filtered object data;

■ Determining whether the image being processed is the first image of total fields, and based on this determination, causing the execution of a suitable sub-process for either between creation of a particle tracking list and seeking of overlapping particle in previous tracked list image, respectively;

7 ■ Logging of filtered object data for each successive image captured and plotting the same across the time period of the temperature ramp defined by the user;

■ Determining whether the image being processed is the last image of total fields, and based on this determination, causing the execution of a suitable sub-process for either between computation and reporting of array of particles tracked for size, circularity, intensity, and texture and selecting of next image for processing, respectively. ) The method for tracking and analysis of objects of interest, particulates in particular, in a sample on the basis of thermal variations of said objects of interest according to claim 1 , wherein the particle detection method is chosen as one among- a) contour based particle detection method; and b) edge based particle identification method. ) The method for tracking and analysis of objects of interest, particulates in particular, in a sample on the basis of thermal variations of said objects of interest according to claims 1 and 2, wherein if contour based particle detection method is opted for by the user, the sub-process to determine particles if any present and seen in the sample being processed comprises- a) Identifying contours in said at least one image, therein selecting contours of same gray value variation to form contour groups; and b) determining, among said contour groups, the best contours on basis of the predefined parameters for object determination, said parameters being sharpness, bounding box, circularity, perimeter. ) The method for tracking and analysis of objects of interest, particulates in particular, in a sample on the basis of thermal variations of said objects of interest according to claims 1 and 2, wherein if edge based particle identification method is opted for by the user, the sub-process to determine particles if any present and seen in the sample being processed comprises- a) Identifying similar edge objects in both sample and reference images; b) Mapping of relative object positions by finding relative edge objects in the reference area of interest and sample image; and c) Matching of unique patterns to therefore reach an assessment of the degree of matching between the selected sample and reference images, said assessment being quantified via enumeration as an absolute count of matches observed which are saved in memory as percentage of matches observed and relative area of interest position mapped. ) The method for tracking and analysis of objects of interest, particulates in particular, in a sample on the basis of thermal variations of said objects of interest according to claim 1 , wherein the

8 executable software is provisioned for execution on the computer by either between a standalone installation and online access from a cloud server in a software-as-a-service model.

9