Lighting conditions on the test strip are standardized and enhanced with white and green light-emitting diodes (LEDs) to improve the contrast between the background and test lines. Software was written to measure the optical activity of the CCD and produce a digital output in the form of translating the series of bars and spaces into 1s and 0s, as previously described. Thresholds were calibrated according to the strip manufacturer's specifications and the Substance Abuse and Mental Health Services Administration (SAMHSA) cutoff levels. The eReader has essentially only one moving part, the plunger mechanism. The plunger bracket is attached to an integrated light shield lowered onto the eCup lid to block ambient light from the camera. Once the eCup is inserted into the reader and the eScreen Web-based CCF is completed, an instruction is sent to the reader to begin the test. The plunger locks the eCup into the reader during the testing process and proceeds with the imaging and analysis in the background, which allows the collector to proceed with the next collection. An internal timing routine accurately measures the point in time that the plunger is activated, thereby wetting the test strips. Three minutes after the test strips are aliquoted, a series of images are taken and analyzed every 15 s until all test lines and control lines are imaged or until 8 min, when the test will end. Results considered perfect negatives, e.g., no drugs, or adulterants present and normal specimen validity, are reported instantly to the customer's myeScreen.com® Web site. The light shield and plunger mechanism are withdrawn, and the operator notified when the test is completed. Once complete, the reader automatically releases the specimen, and reports the result to the eScreen Web server. Customers pick up their test results on their portal.
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