Apparatus and method for image analysis of a fluid sample undergoing a polymerase chain reaction (PCR)
Inventors
Patel, Tej Rushikesh • Revilla, Ryan Alan • Heltsley, Roy James
Assignees
Publication Number
US-10519493-B2
Publication Date
2019-12-31
Expiration Date
2036-06-17
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
Apparatuses and for causing a point-of-care polymerase chain reaction and analyzing the polymerase chain reaction at the point-of-care, particularly when unwanted bubbles are present during the polymerase chain reaction, are described herein. In a general embodiment, a device for analyzing a polymerase chain reaction in a fluid sample includes a current source configured to cause the polymerase chain reaction by heating the fluid sample within a target zone, a camera imaging device configured to record a plurality of images of the fluid sample in the target zone while the current source causes the polymerase chain reaction, and a controller configured to (i) distinguish wanted objects in the plurality of images from an unwanted object in the plurality of images, and (ii) determine whether the fluid sample tests positive or negative for a bacteria or virus based on the wanted objects.
Core Innovation
The invention describes apparatuses and methods for performing a point-of-care polymerase chain reaction (PCR) and analyzing the PCR in real time, particularly addressing the presence of unwanted bubbles during the reaction. The device includes a current source configured to heat the fluid sample located within a target zone to induce the PCR, and a camera imaging device configured to record multiple images of the fluid sample during the reaction. A controller is provided to distinguish wanted objects such as nucleic acid molecules or cells within these images from unwanted objects such as air bubbles, and to determine whether the fluid sample tests positive or negative for a bacteria or virus based on analysis of the wanted objects.
The problem being solved relates to the limitations of point-of-care in vitro diagnostic tests using nucleic acid amplification tests (NAATs) like PCR. While NAATs have high sensitivity and specificity and can detect infectious agents early, the challenges include complicated equipment and processes. Additionally, unwanted bubbles formed during PCR can compromise analysis accuracy. The invention aims to enable PCR at the point-of-care with simpler equipment, while accurately analyzing PCR results even when unwanted air bubbles are present in the fluid sample, by imaging and selectively processing image data to exclude or weight the influence of bubbles.
Claims Coverage
The patent contains independent claims covering devices and methods for analyzing PCR in fluid samples, focusing on image-based detection, reaction control, and data analysis in the presence of unwanted objects.
Device for PCR analysis with object discrimination
A device including a current source to heat a fluid sample within a target zone, a camera imaging device to record multiple images during PCR, and a controller configured to distinguish wanted objects (nucleic acid molecules or cells) from unwanted objects (not matching average size or shape) and determine positive or negative test results based on wanted objects.
Detection and handling of air bubbles during PCR
The controller detects air bubbles as unwanted objects by identifying those that expand in size during PCR, and adapts analysis to exclude or weight image regions accordingly.
Image analysis by dividing target zone into bins
The controller analyzes images by dividing the target zone into a grid of bins and selecting bins overlapping wanted object clusters for fluorescence measurement, excluding bins overlapping unwanted objects or not meeting brightness thresholds, and assigning weights to bins based on proximity to unwanted objects.
Controller configured to report inconclusive tests
The controller can report an inconclusive test if one or more unwanted objects are identified during image analysis.
User interface with selectable preprogrammed analyses
The device includes a user interface allowing a user to select from multiple preprogrammed analyses to perform on the fluid sample.
Use of fluorescence excitation light in image capture and analysis
A device wherein a light source projects fluorescence excitation during PCR, and the controller analyzes fluorescence values from bins within recorded images to determine test results.
Method for analyzing PCR by heating, imaging, binning, and fluorescence calculation
A method including heating the fluid sample to cause PCR, recording images during the reaction with fluorescence excitation, dividing the target zone into bins, calculating fluorescence values from selected bins weighted and/or excluding bins overlapping unwanted objects, and determining positive or negative test results.
The claims collectively cover devices and methods utilizing controlled heating and real-time imaging of fluid samples undergoing PCR, analyzing images by subdividing target zones to discriminate wanted nucleic acid or cell objects from unwanted objects such as bubbles, calculating fluorescence values accordingly, and enabling accurate determination of positive or negative test outcomes even in the presence of artifacts.
Stated Advantages
Enables accurate PCR analysis at point-of-care despite the presence of unwanted bubbles that can compromise reaction integrity.
Uses image analysis methods subdividing the target zone into bins to selectively include or weight fluorescence measurements, improving reliability of test results.
Supports user-selectable preprogrammed analyses via a user interface, enhancing usability and flexibility.
Allows real-time monitoring and analysis of PCR amplification and melt curves, providing detailed and high sensitivity diagnostic information.
Capable of detecting a variety of pathogens with high sensitivity and specificity equivalent to laboratory tests while reducing sample preparation complexity.
Documented Applications
Point-of-care diagnostic testing for bacteria, viruses, fungi, and parasitic pathogens using nucleic acid amplification with a disposable test card and fluid microchannel system.
Detection and analysis of infectious agents including, but not limited to, Bacillus anthracis, Brucella species, Dengue virus, smallpox virus, Candida species, and Plasmodium falciparum.
Quantification and analysis of nucleic acid molecules or cells within bodily fluid samples such as whole blood, serum, urine, saliva, and tears.
Use in low-resource settings for early detection of infection with minimal user training and low complexity apparatus.
Integration with a GPS sensor to enable aggregation of test results related to specific locations for epidemiological tracking of pathogen prevalence.
Interested in licensing this patent?