Instrument and system for rapid microorganism identification and antimicrobial agent susceptibility testing
Inventors
Ashby, Austin • Showalter, Wayne • Cote, Jasmin
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-10273521-B2
Publication Date
2019-04-30
Expiration Date
Abstract
A system for automated microorganism identification and antibiotic susceptibility testing comprising a reagent cartridge, a reagent stage, a cassette, a cassette, stage, a pipettor assembly, an optical detection system, and a controller is disclosed. The system is designed to dynamically adjust motor idle torque to control heat load and employs a fast focus process for determining the true focus position of an individual microorganism. The system also may quantify the relative abundance of viable microorganisms in a sample using dynamic dilution, and facilitate growth of microorganisms in customized media for rapid, accurate antimicrobial susceptibility testing.
Core Innovation
An automated microorganism imaging system is described that performs autofocusing on a microorganism to be imaged using reflective-spot based imaging. The system includes a first light source generating a reflective spot on an image plane and a second light source projecting light to capture an image of the microorganism on the image plane. A movable objective is positioned between the first and second light sources and the image plane, and is moved to out-of-focus positions having focal points in front of and behind the image plane.
The system captures two or more images of the reflective spot with the objective in at least two out-of-focus positions and uses intensity weightings of the reflective spots to modify the objective position toward an in-focus position. The reflective spot information is used with a focus algorithm that includes spot-intensity weighting and a prescan to determine spot offset/intensity behavior. The described approach enables rapid virtual true-focus autofocus of individual microorganisms.
The disclosed system is integrated into automated ID/AST workflows using fluorescence microscopy and reagent handling components. Automated microorganism identification is performed via FISH using multiple species-specific probes and universal probes with probability modeling to support polymicrobial samples. Automated AST workflows include immobilization, growth monitoring, quantitative interpretation with MIC and S/I/R categorical reporting, and additional processing such as dynamic dilution for viable cell quantitation and customized nutrient-depleted and fastidious-compatible media formulations.
Claims Coverage
This consolidated set identifies one independent claim focused on reflective-spot-based autofocusing using intensity weightings across two or more out-of-focus objective positions, modified toward an in-focus position. Dependent claims add how intensity weightings are formed and introduce a prescan to characterize intensity/offset behavior across multiple focus positions for calculating the objective focus position.
Reflective-spot autofocusing using intensity weightings from multiple out-of-focus objective positions
A system for autofocusing on a microorganism that generates a reflective spot on an image plane with a first light source, captures images of the microorganism and the reflective spot with a movable objective and an image sensor, and uses a controller that receives two or more images of the reflective spot captured with the objective in at least a first and a second out-of-focus position to modify the objective position to an in-focus position based on intensity weightings of the reflective spots.
Intensity weighting based on greyscale values and pixel position
A controller operation where the intensity weightings of the reflective spots relate to a greyscale value associated with each pixel and are weighted according to each pixel's position relative to a center.
Prescan acquiring intensity weightings across multiple focus positions
A controller operation where a prescan acquires intensity weightings over a plurality of focus positions of the objective.
Prescan determining offset versus focus position
A controller operation where a prescan obtains an offset versus focus position relationship for a plurality of focus positions of the objective.
Calculating objective focus position from intensity weightings and prescanned intensity/offset
A controller operation that calculates a focus position using the intensity weightings of the reflective spots together with the prescan to determine the position of the objective.
Across the independent claim and its dependents, the core claim coverage is the reflective-spot autofocus approach that moves a movable objective toward in-focus using intensity weightings from out-of-focus images, with dependent claims specifying greyscale/pixel-position intensity weighting and a prescan that characterizes intensity/offset behavior across multiple focus positions to compute the objective focus position.
Stated Advantages
Enables accurate rapid virtual true-focus autofocus of individual microorganisms using a fast focus algorithm with spot-intensity weighting and a prescan.
Documented Applications
Automated microorganism identification using fluorescence microscopy and FISH with species-specific and universal probes, including use of Bayesian/probability expectation modeling for polymicrobial samples.
Automated antimicrobial susceptibility testing (AST) workflows including immobilization, growth monitoring, and quantitative interpretation using MIC and S/I/R categorical reporting.
Interested in licensing this patent?