The present invention relates to chemical test equipment in general, and more specifically to test strip readers.
Test strips are a well-known media to test for the presence of particular chemical species in the air, pools, smoke stacks, water, and the like. These test strips are typically single-use disposables and/or consumables provided in bulk a container, typically a plastic vial with removable or flip-top cap.
For example, pool maintenance requires periodic regular testing of pool water and careful maintenance by chemical additives. The testing and balancing of swimming pool water can be a difficult process for the owner. There are myriad test kits available with different capabilities. At minimum a suitable test kit will test for available chlorine, cyanuric acid, pH, total alkalinity, and calcium hardness. Reagent test strips are a very common testing modality. Water test strips usually have a plurality of reagent test areas, each test area undergoing a color change in response to contact with a particular chemical constituent. The presence and concentrations of these constituents of interest can be determined by a colorimetric analysis of the color changes undergone by the test strip. Usually, this analysis involves a color comparison between the test area or test pad and a color standard or scale.
A variety of conventional test strip reading instruments exist which can determine the color change of a test strip.
U.S. Pat. No. 6,614,530 to Duez et al. (Biophotonics S.A.) issued Sep. 2, 2003 shows a method for the colorimetric measurement of a defined region on an image using a color camera, and discloses color-correction of tristimulus (R, G, B) values by selection of an area within an image in order to correct the imperfection in the homogeneity of the sensor and of the illuminant.
U.S. Pat. No. 5,408,535 to Howard, III et al. (Miles, Inc.) issued 18 Apr. 1995 shows a video test strip reader for evaluating test strips that uses a video imager or camera. The reader is connectable to a computer which choreographs imaging at the proper times and calculates the test results, such as the concentration of the constituents of interest.
U.S. Pat. No. 8,655,009 to Chen et al. (Teco Diagnostics) issued 18 Feb. 2014 shows a method and apparatus for color-based reaction testing of biological materials by capturing, in an uncalibrated environment, a digital image of an exposed test strip, together with an adjacently-located reference color chart or on-strip color chart. The image data specifically representing the individual test pads on the test strip, as well as the reference color blocks on the reference chart, are then located within the captured image, and compared to identify any color matches.
U.S. Pat. No. 8,703,057 to Morris (Hach Co.) issued 22 Apr. 2014 shows an electronic device for analyzing an aqueous solution with a housing configured to receive a single test strip.
U.S. Pat. No. 6,285,454 to Douglas et al. (Mercury Diagnostics, Inc.) issued 4 September 2001 shows an assay system that accurately docks a removable test strip with an optics system including an illumination LED and photodetector.
U.S. Pat. No. 8,142,722 to Morris et al. (Hach Co.) issued 27 Mar. 2012 shows a handheld portable electronic test strip tester.
U.S. Pat. No. 7,339,673 to Roman (Siemens Healthcare) issued 4 Mar. 2008 shows a miniature read head for a photometric test strip reader.
U.S. Pat. No. 8,145,431 to Kloepfer et al. (Advanced Medical Products GmbH) issued 27 Mar. 2012 shows a smart-phone-based body fluid test strip positioner. The test strip positioner positions a test strip in the FOV of the phone's camera lens to permit the camera to capture an image. A light source disposed within the positioner illuminates the analyte containing test strip to facilitate the capture of the image of the test strip. Software in the smart phone performs quantitative analysis.
United States Patent Application 20100254581 by Neeser et al. (Reveal Sciences) published 7 Oct. 2010 shows a method and apparatus for analyzing samples by obtaining an image using any mobile consumer device, storing and transmitting the image to a remote server, analyzing the image using an analysis software on a remote server, and sending the results of the analysis back to the consumer device.
U.S. Pat. No. 7,262,779 to Sones (Applied Vision Company, LLC) issued 28 Aug. 2007 shows a differential imaging colorimeter which utilizes a RGB color camera to provide accurate differential colorimetry.
United States Patent Application 20110275162 by Xie et al. (Alverix, Inc.) published 10 Nov. 2011 shows a low-cost assay test strip reader in which the strip is placed in a shuffle that moves it past a photodetector, which detects an optical signal at a single point. The movement of the test strip with respect to the detector allows it to scan a length of the test strip.
U.S. Pat. No. 9,569,858 to Babcock et al. (Taylor Technologies, Inc.) issued 14 Feb. 2017 shows a cloud-based system for water analysis using test strip readers each configured to obtain a digital image of a reagent test strip, normalize and analyze color information in the digital image by colorimetric analysis, and transmit colorimetric values to a cross-platform cloud-based system for analysis.
The foregoing references are configured to read a test strip and compare it to a fixed reference standard. What is needed is a way to read, reference positions, catalogue/index, calibrate, image, correct and analyze multiple test strips at a time using a single reader.
Accordingly, it is an object of the present invention to provide an improved test strip reader capable of reading, indexing, calibrating, correcting and interpreting multiple test strips at a time.
Yet another object is to provide a test strip reader with insertion carriage that makes it possible to load multiple test strips into an imaging station with minimal effort and maximum positional precision.
These and other features and benefits are achieved with an improved test-strip reader with insertion carriage that makes it possible to load multiple test strips into an imaging station with minimal effort and maximum precision. The multi-strip reader uses advanced lighting and imaging technology to make it possible to measure various reagents via multiple strips all at once including, for example, Free Chlorine (1C), total alkalinity (TL), cyanuric acid (CYA), total chlorine (CL), bromine (Br), and total alkalinity (pH) as typical of a pool or spa, thereby providing faster, more accurate, and more affordable test results. It maximizes ease and efficiency of use and minimizes risk of user error.
The insertion carrier loads a plurality of test strips at once to the imaging station, and the system automatically identifies them, references their positions, catalogues/indexes them, calibrates them, images them and analyzes them. The apparatus makes the loading and imaging process simple and foolproof for the user by a combination of hardware and software. The hardware employs a roller carriage with pneumatic spring-assist insertion and ejection. The carriage includes a test platform with a plurality of imaging beds to seat and position the strips, and a clamping mechanism to affix them therein. When the user places the test strips in the clamping mechanism and then in the carriage and initiates inward insertion into the enclosure, the remainder of the imaging and analysis process is completed automatically with an internal imaging assembly. The apparatus makes it possible to measure various reagents via multiple strips, up to eleven (11) tests in one minute including:
For a more complete understanding of the invention, its objects and advantages, refer to the remaining specification and to the accompanying drawings.
Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments and certain modifications thereof when taken together with the accompanying drawings in which:
The present invention is multiple test strip reader configured to read a plurality of test strips at once and automatically identify them, reference their positions, catalogue/index them, calibrate them, image them, and analyze them, all with a single imaging unit. The device makes the loading and imaging process for multiple strips simple and foolproof for the user, allowing simultaneous measurement of various reagents via multiple strips. The multiple test strip reader employs a roller carriage with pneumatic spring-assisted insertion and ejection. The carriage includes a test platform with a plurality of imaging beds, one bed for each test strip, and a clamping mechanism to affix them therein. When the user places the test strips in the carriage with the clamping mechanism and initiates inward insertion into the enclosure, the remainder of the imaging and analysis process is completed automatically with an internal imaging assembly. The apparatus makes it possible to measure various reagents all at once including, for example, Free Chlorine (FC), total alkalinity (TA), cyanuric acid (CYA), total chlorine (TC), bromine (Br), Borate (Bo), Salt, Phosphate (PO4), Iron (Fe) and Copper (Cu), total hardness (TH) and pH as typical of a pool or spa. It maximizes ease and efficiency of use and minimizes risk of user error. For descriptive purposes the following components are given the following reference numerals in the FIGs:
indicates data missing or illegible when filed
Referring back to
Movement of the carriage 124 into and out from the imaging enclosures 10, 122 is guided on the roller bearings atop tracks 127 and at the position furthest inside enclosures 10,122 there is a latch mechanism 265 that is of the push to close/push to open variety and secures carriage 124 into the correct position for subsequent imaging of test strips 134.
A CMOS imaging unit 80 is mounted directly above the imaging enclosure 122 for imaging strips.
Specifically, the LEDs/indicator lights 81/52 flash green, yellow or red. In addition, the light board 83 bears four (4) white LEDs that shine into light diffusers 87 as shown, which in turn directs white light down toward the test strips for illumination thereof. The LED diffusers 87 help “smooth out” the light and minimize “hot spots”. The four diffusers 87 are translucent white frosted hemispherical panels and are fixed to light board 83 and used to spread light from the LEDs evenly inside the chassis 14.
A user would then take clamp assembly 150 that is properly loaded with test strips 134 (
After sampling, the user is then places clamp assembly 150 into place on rolling carriage 124 atop roller tray 126 such that clamp 150 is properly located and inserts the carriage 124 into imaging enclosure 122 until latch mechanism 265 engages with and holds catch 264, at which point the test strips lie directly in the field of view of the illuminated CMOS camera 80 for full frontal illumination and imaging. In this imaging position the CMOS imager 80 images the strips without substantial glare interference to or from the illumination. The remote computer runs a software application that automatically triggers a still image frame from the CMOS imager 80. This image includes all strips and test strip pads on the strip, as well as a calibration label 139 (
At step 420 the software sub-divides each pad into a checkerboard array of sub-areas. Given a subdivided image the software performs an image analysis on each cell.
At step 425 a calibration module employs an averaging sequence across the subdivided cells to account for and calculates a mean value for the cell. The imaging process is inherently prone to pixel variance across each sample region and the averaging process smooths the variance. This mean is used as the sample value for that subcell.
At step 430 the software initiates a flatfield adjustment to account for lighting variations within a given picture. Flatfield adjustments for all subcell regions are calculated from white-only calibration regions of the calibration row. The flatfield adjustment assumes that these areas should be “white”, and compensates for any variation.
At step 440 the software initiates a Grayscale adjustment using the permanent greyscale calibration references 304 to account for variation in image-capture-hardware (RGB/gamma distribution/etc.), aging of ambient lighting, etc.
At step 450 the calibration module compares the sample image back to the calibration standards stored in the program for each analyte and decides which calibration value is the best match for the sample image.
Finally at step 460 the color values computed for each test pad 135 are uploaded and cataloged, and every correction that was applied is uploaded and cataloged by device in a test history for the device. The test history for the device is monitored over time to provide drift alerts of the color values of reference colors 302 and 304 to the user.
It should now be apparent that the above-described multi-strip reader provides a platform for more efficient reading, indexing, calibrating, correcting and interpreting multiple test strips at a time. It makes it possible to load multiple test strips into an imaging station with minimal effort and yet maximum positional precision.
Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth in the appended claims.
The present application derives priority from U.S. provisional application Ser. No. 63/279,726 filed Nov. 16, 2021.
Number | Date | Country | |
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63279726 | Nov 2021 | US |