Lateral flow assay reader based on human perception and method relating thereto

Patent metadata

Field	Value
Publication number	US-11788968-B2
Application number	US-202017070868-A
Country	US
Kind code	B2
Filing date	Oct 14, 2020
Priority date	Nov 30, 2016
Publication date	Oct 17, 2023
Grant date	Oct 17, 2023

Abstract

An instrument for reading a lateral flow assay device by detecting color changes based on human perception includes an optics module having a camera, a signal processor, a storage memory and a comparator circuit. The storage memory has stored therein a dataset of sample readings of reference assay devices similar in structure and function to that of the lateral flow assay device. The sample readings are based on human visual perceptions of colorimetric changes in the detection zones of the reference assay devices. The comparator circuit compares the measured colorimetric data relating to the assay device read by the instrument with the stored database of sample readings based on human visual perceptions of the colorimetric changes of the reference assay devices, and generates a comparison signal which is provided to the signal processor. The signal processor generates a determination signal indicative of the presence, absence or quantity of an analyte.

First claim

What is claimed is:

1. An instrument for reading an assay device placed in optical proximity thereto for performing an assay to determine the presence, absence or quantity of an analyte in a fluid sample, the assay device having a sample deposit zone on which a fluid sample to be tested is placed and further having a detection zone in which a visually perceptible colorimetric change may occur when the assay device detects the presence, absence or quantity of an analyte in the fluid sample, the instrument comprising:
an optics module, the optics module having at least one light source and a light detector, the at least one light source emitting light and being positioned on the instrument to direct the light onto the detection zone of the assay device placed in optical proximity to the instrument, the light detector receiving reflected or fluoresced light emanating from the detection zone of the assay device in response to the light directed thereon by the at least one light source, and generating an output signal in response to the reflected or fluoresced light received by the light detector, the output signal being indicative of a colorimetric change in the detection zone of the assay device;
a signal processor in electrical communication with the optics module, the signal processor receiving the output signal from the light detector and converting the signal into measured colorimetric data;
a memory in electrical communication with the signal processor; and
a comparator circuit in electrical communication with the signal processor, the comparator circuit comparing the measured colorimetric data relating to the assay device read by the instrument with a dataset of sample readings of reference assay devices similar in structure and function to that of the assay device read by the instrument, the sample readings being based on human visual perceptions of colorimetric changes in the detection zones of the reference assay devices, and generating a comparison signal in response thereto, the signal processor receiving the comparison signal from the comparator circuit and in response thereto generating a determination signal indicative of the presence, absence of quantity of an analyte in the fluid sample tested by the assay device read by the instrument.

2. An instrument as defined by claim 1 , which further comprises:
a housing, the housing having side walls defining an interior cavity, the optics module, signal processor, memory and comparator circuit being situated within the interior cavity.

3. An instrument as defined by claim 2 , wherein one of the side walls of the housing has formed therein a receptacle for at least partially receiving therein the assay device read by the instrument, the at least one light source and the light detector of the optics module being in optical communication with the receptacle and an assay device received thereby.

4. An instrument as defined by claim 1 , which further comprises:
a main housing, the main housing having side walls defining an interior cavity;
wherein the optics module is situated within the interior cavity of the main housing; and
wherein the signal processor, memory and comparator circuit are situated in a remote location from the main housing of the instrument.

5. An instrument as defined by claim 1 , which further comprises:
a main housing, the main housing having side walls defining an interior cavity;
wherein the optics module is situated within the interior cavity of the main housing; and
wherein the dataset of sample readings based on human visual perceptions of the colorimetric changes of the reference assay devices is stored at a remote location from the main housing of the instrument.

6. The instrument of claim 1 , wherein the assay device is a reversible flow chromatographic binding assay device.

7. The instrument of claim 1 , wherein the assay device comprises colloidal gold particles.

8. In combination:
an assay device for performing an assay to determine the presence, absence or quantity of an analyte in a fluid sample, the assay device having a sample deposit zone on which a fluid sample to be tested is placed and further having a detection zone in which a visually perceptible colorimetric change may occur when the assay device detects the presence, absence or quantity of an analyte in the fluid sample; and
an assay reader which detects color changes based on human perception, the assay device being placed in optical proximity to the assay reader, the assay reader including:
an optics module, the optics module having at least one light source and a light detector, the at least one light source emitting light and being positioned with respect to the assay device to direct the light emitted thereby onto the detection zone of the assay device, the light detector receiving reflected or fluoresced light emanating from the detection zone of the assay device in response to the light directed thereon by the at least one light source, and generating an output signal in response to the reflected or fluoresced light received by the light detector, the output signal being indicative of a colorimetric change in the detection zone of the assay device;
a signal processor in communication with the optics module, the signal processor receiving the output signal from the light detector and converting the signal into measured colorimetric data;
a memory in electrical communication with the signal processor; and
a comparator circuit in electrical communication with the signal processor, the comparator circuit comparing the measured colorimetric data relating to the assay device read by the assay reader with a dataset of sample readings of reference assay devices similar in structure and function to that of the assay device read by the assay reader, the sample readings being based on human visual perceptions of colorimetric changes in the detection zones of the reference assay devices, and generating a comparison signal in response thereto, the signal processor receiving the comparison signal from the comparator circuit and in response thereto generating a determination signal indicative of the presence, absence or quantity of an analyte in the fluid sample tested by the assay device read by the assay reader.

9. A combination as defined by claim 8 , wherein the assay reader further includes a housing, the housing having side walls defining an interior cavity, the optics module, signal processor, memory and comparator circuit being situated within the interior cavity.

10. A combination as defined by claim 9 , wherein one of the side walls of the housing of the assay reader has formed therein a receptacle for at least partially receiving therein the assay device read by the assay reader, the at least one light source and the light detector of the optics module being in optical communication with the receptacle and an assay device received thereby.

11. A combination as defined by claim 8 , wherein the assay reader further includes a main housing, the main housing having side walls defining an interior cavity;
wherein the optics module is situated within the interior cavity of the main housing; and
wherein the signal processor, memory and comparator circuit are situated in a remote location from the main housing of the assay reader.

12. A combination as defined by claim 8 , wherein the assay reader further includes a main housing, the main housing having side walls defining an interior cavity;
wherein the optics module is situated within the interior cavity of the main housing; and
wherein the dataset of sample readings based on human visual perceptions of the colorimetric changes of the reference assay devices is stored at

Assignees

• Idexx Lab Inc

Inventors

• Farrell Robert P

Classifications

• G01N33/54388

  based on lateral flow · CPC title

• G01N21/78 Primary

  producing a change of colour · CPC title

• G01N33/48785

  Electrical and electronic details of measuring devices for physical analysis of liquid biological material not specific to a particular test method, e.g. user interface or power supply · CPC title

• G01N33/48792

  Data management, e.g. communication with processing unit (for in vivo diagnostics A61B5/0002; transmission systems for measured values G08C) · CPC title

• G01N33/54373

  involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings · CPC title