Smartphone-Based Apparatus and Method

A method for obtaining a point-of-collection, selected qualitative and/or quantitative indicia of an analyte on a test platform, comprising:

• providing a modular assay test platform (e.g., test strip) having at least one test region and a control region;
• providing an analyte to be tested on the at least one test region;
• obtaining an image of the at least one test region containing the analyte and the control region;
• selecting an array of pixels in the image of the at least one test region containing the analyte and the control region;
• determining a RGBA color value for each of the arrays of pixels;
• extracting a test image region for analysis;
• converting the RGBA array to an alternate color space as determined by the specific test including but not limited to HSL, HSV, or greyscale;
• determining one of a median, mean, maximum, minimum, or other statistical measure of the color or intensity value for various regions of the test platform that may or may not contain test or control areas and creating at least a 1D array containing these values;
• if necessary, determining a low-frequency variation in color or intensity value over the array and, if necessary, performing illumination correction and background subtraction;
• detecting a peak or valley in the adjusted array corresponding to the test and control regions to be measured;
• determining a depth, width, height (for example, based on intensity or color maxima/minima), and/or area (for example, based on integrated color or intensity) of these peaks or valleys which correspond to detection or control regions of the test platform;
• and
• determining a qualitative presence of the selected indicia of the analyte by the number of peaks or valleys present, and/or a quantitative value of the selected indicia of the analyte by quantitative comparison of two or more peaks or valleys.

A smartphone accessory for use in a smartphone-based point-of-collection, system, comprising:

• a housing that can be removeably attached to the smartphone in a manner that at least optically couples the smartphone accessory to a resident smartphone camera;
• a lens that allows for adjustment of the focal length of the smartphone camera to enable imaging of the test strip in a compact device,
• wherein the housing is opaque such that the smartphone accessory is substantially externally light-tight when a test strip is disposed therein,
• further wherein the housing includes at least one of a designed-in optical pathway and a light diffuser in the housing for providing diffuse illumination of a surface of the test strip disposed therein from an internal light source resident in the housing or an external light source resident in the smartphone to which the smartphone accessory can be attached.