Sept. - Dec. 2020
Background
E25Bio is an MIT-based biotech startup which makes rapid viral assays for testing in remote locations. These lateral flow assays can detect Zika, Dengue, West Nile Virus, Ebola, Covid-19, Chikungunya, and other viruses. To quantify a population’s test results, the cameras on personal electronic devices may be used in combination with image recognition and location-based networking. This allows for accurate contact tracing and metering of infected populations with geographic accuracy.
Figure 1a: Covid-19 lateral flow assay
Problem
The assays have a reflective layer that can obscure the results (red line is located beneath the reflective layer) in certain lighting conditions, such as in broad daylight or when using a flash. Image recognition software can be inaccurate when direct (specular) reflections are present, so the goal is to eliminate them.
Figure 1b: Flash reflection can obscure red indication line
Figure 2: Drawing of cross-polarizing arch design. Arch is made of polarizing film, with a window of 90-degree rotated film. Light enters through the walls of the arch and the photo is taken down through the window.
Method
We developed a cross-polarized photo enclosure that can be constructed from planar sheets of material which are included in the assays’ packaging. A user can take a photo of their test results through the enclosure window and an app on their personal electronic device will process the image, read the results of the test, and record their status in a database. The spectral reflections directly off the assay’s reflective surface are completely cancelled as a result of a 90 degree polarization offset. An embodiment of the design is shown in the following drawing, render, and photo.
Result
This design has been filed in the provisional U.S. Patent App. No. 63/138,412. The company plans to include the two planar components needed for this design as part of the packaging for their lateral flow assays.
Figure 3: Render of the final design, made from polarizing film and styrene sheet.
Skills Developed
> Design documentation: lab notebook, progress summaries, drawings, prototype documentation, design reviews
> Patent process: prioritizing function over form
> Conceptualizing alternative embodiments, materials, and manufacturing processes
> Researching alternative use cases and applications