This work was funded by the Dorothy J. Wingfield Phillips Chancellor Faculty Fellowship. Emily Kight was funded by NSF GRFP.

1. Fabricate and assemble the urinalysis device
<ol>
	<li>Fabricate the base plate (Figure 1A).
	<ol>
		<li>Use a computer-aided design (CAD) software to draw a rectangular area with dimensions 2.1641 in x 0.0547 in x 6.3828 in (W x H x L) using the polyline tool.</li>
		<li>Measure the test area (rectangular area encompassing the distance between the first and last pad and the width of the pads) on the dipstick. 
		NOTE: This information is needed to draw the through-holes that hold ...

<ol>
	<li>Lei, R., Huo, R., Mohan, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expert+Review+of+Molecular+Diagnostics+Current+and+emerging+trends+in+point-of-care+urinalysis+tests.">Expert Review of Molecular Diagnostics Current and emerging trends in point-of-care urinalysis tests.</a> Expert Review of Molecular Diagnostics. 00, 1-16 (2020).</li><li>Kavuru, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dipstick+analysis+of+urine+chemistry:+benefits+and+limitations+of+dry+chemistry-based+assays.">Dipstick analysis of urine chemistry: benefits and limitations of dry chemistry-based assays.</a> Postgraduate Medicine. 5481, (2019).</li><li>Pugia, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Technology+Behind+Diagnostic+Reagent+Strips.">Technology Behind Diagnostic Reagent Strips.</a> Laboratory Medicine. 31, 92-96 (2000).</li><li>Dungchai, W., Chailapakul, O., Henry, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrochemical+detection+for+paper-based+microfluidics.">Electrochemical detection for paper-based microfluidics.</a> Analytical Chemistry. 81, 5821-5826 (2009).</li><li>Van Delft, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prospective,+observational+study+comparing+automated+and+visual+point-of-care+urinalysis+in+general+practice.">Prospective, observational study comparing automated and visual point-of-care urinalysis in general practice.</a> BMJ Open. 6, 1-7 (2016).</li><li>. Urisys 1100 Analyzer Available from: <a target="_blank" href="https://diagnostics.roche.com/us/en/products/instruments/urisys-1100.html">https://diagnostics.roche.com/us/en/products/instruments/urisys-1100.html</a> (2020)</li><li>Filippini, D., Lundstr&#246;m, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+strategy+and+instrumental+performance+of+a+computer+screen+photo-assisted+technique+for+the+evaluation+of+a+multi-parameter+colorimetric+test+strip.">Measurement strategy and instrumental performance of a computer screen photo-assisted technique for the evaluation of a multi-parameter colorimetric test strip.</a> Analyst. 131, 111-117 (2006).</li><li>Shen, L., Hagen, J. A., Papautsky, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Point-of-care+colorimetric+detection+with+a+smartphone.">Point-of-care colorimetric detection with a smartphone.</a> Lab on a Chip. 12, 4240-4243 (2012).</li><li>Ra, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Smartphone-Based+Point-of-Care+Urinalysis+under+Variable+Illumination.">Smartphone-Based Point-of-Care Urinalysis under Variable Illumination.</a> IEEE Journal of Translational Engineering in Health and Medicine. 6, 1-11 (2018).</li><li>Yetisen, A. K., Martinez-Hurtado, J. L., Garcia-Melendrez, A., Da Cruz Vasconcellos, F., Lowe, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+smartphone+arebeorithm+with+inter-phone+repeatability+for+the+analysis+of+colorimetric+tests.">A smartphone arebeorithm with inter-phone repeatability for the analysis of colorimetric tests.</a> Sensors and Actuators, B: Chemical. 196, 156-160 (2014).</li><li>Wang, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Integration+of+cell+phone+imaging+with+microchip+ELISA+to+detect+ovarian+cancer+HE4+biomarker+in+urine+at+the+point-of-care.">Integration of cell phone imaging with microchip ELISA to detect ovarian cancer HE4 biomarker in urine at the point-of-care.</a> Lab on a Chip. 11, 3411-3418 (2011).</li><li>Zhang, D., Liu, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biosensors+and+bioelectronics+on+smartphone+for+portable+biochemical+detection.">Biosensors and bioelectronics on smartphone for portable biochemical detection.</a> Biosensors and Bioelectronics. 75, 273-284 (2016).</li><li>Choi, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Smartphone-based+urine+reagent+strip+test+in+the+emergency+department.">Smartphone-based urine reagent strip test in the emergency department.</a> Telemedicine and e-Health. 22, 534-540 (2016).</li><li>Kwon, L., Long, K. D., Wan, Y., Yu, H., Cunningham, B. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Medical+diagnostics+with+mobile+devices:+Comparison+of+intrinsic+and+extrinsic+sensing.">Medical diagnostics with mobile devices: Comparison of intrinsic and extrinsic sensing.</a> Biotechnology Advances. 34, 291-304 (2016).</li><li>Vashist, S., Schneider, E., Luong, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Commercial+Smartphone-Based+Devices+and+Smart+Applications+for+Personalized+Healthcare+Monitoring+and+Management.">Commercial Smartphone-Based Devices and Smart Applications for Personalized Healthcare Monitoring and Management.</a> Diagnostics. 4, 104-128 (2014).</li><li>. Inui Available from: <a target="_blank" href="https://www.inuihealth.com/inui/home">https://www.inuihealth.com/inui/home</a> (2020)</li><li>. Healthy.io Available from: <a target="_blank" href="https://healthy.io/">https://healthy.io/</a> (2020)</li><li>. Scanwell Available from: <a target="_blank" href="https://www.scanwellhealth.com">https://www.scanwellhealth.com</a> (2020)</li><li>Smith, G. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robust+dipstick+urinalysis+using+a+low-cost,+micro-volume+slipping+manifold+and+mobile+phone+platform.">Robust dipstick urinalysis using a low-cost, micro-volume slipping manifold and mobile phone platform.</a> Lab on a Chip. 16, 2069-2078 (2016).</li><li>Du, W., Li, L., Nichols, K. P., Ismagilov, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SlipChip.">SlipChip.</a> Lab on a Chip. 9, 2286-2292 (2009).</li></ol>

Traditional dipstick urinalysis is affordable and convenient but requires manual attention to detail to yield accurate results. Manual dipstick urinalysis is subject to variable lighting conditions, individual color perception differences and cross-contamination. Many clinics and hospitals already have instruments to automate urine dipstick analysis, but the instruments are usually bulky, expensive, and still rely on proper performance of the dip-wipe method. Additionally, these instruments require yearly calibration and...

Urine is a non-invasive source of multiple metabolic indicators of disease or health. Urinalysis, the physical and/or chemical analysis of urine, can be performed quickly to detect renal disease, urinary tract disease, liver disease, diabetes mellitus, and general hydration1. Urinalysis dipsticks are affordable, semi-quantitative diagnostic tools that rely on colorimetric changes to indicate approximate physiological levels. Each dipstick can perform a wide variety of assays including testing for pH, osmolality, hemoglobin/myoglobin, hematuria, leukocyte esterase, glucose, proteinuria, nitrite, ketone, and bilirubin2. The principle of dipstick urinalysis relies on the occurrence of a timed reaction through which a color change on the dipstick pad can be compared to a chart to determine analyte concentration3. Given their affordability and ease of use, dipsticks are one of the most common tools for urinalysis in healthcare.
Traditionally, dipstick urinalysis relies on a trained nurse or medical technician to manually insert the dipstick into a cup of urine sample, wipe off excess urine, and compare the color pads to chart colors at specific times. While the dip-and-wipe method is the gold standard for dipstick analysis, its reliance on human visual assessment limits the quantitative information that can be obtained. Moreover, the two manual steps of dipstick urinalysis &#8211; the dip-wipe step and colorimetric result comparison &#8211; require accurate technique, which limits the possibility of reliable testing in home settings by patients directly. Cross-contamination of the sample pads due to wiping can cause inaccurate color changes. Additionally, inconsistent volumes resulting from the lack of volume control during wiping can result in improper measurement of analyte concentrations. Importantly, the time between dipping the urine (i.e., the start of the assay) and comparison to a chart is critical for accurate analysis of the results and is a huge potential source of human error. The difficulty in manual colorimetric comparison is that many pads must be read at the same time, while some pads are read at different times. Even perfectly timed color comparisons still depend on the visual acuity of the human reader, who may suffer from color blindness or perceive different colors in different lighting environments4. These challenges underscore why clinicians can only rely on dipstick urinalysis performed by trained personnel. However, an automated urinalysis system could address all the aforementioned concerns by eliminating the need for manual dip-wipe steps, incorporating timing controls, and enabling simultaneous color comparisons with calibrated color references. This, in turn, would reduce user error, allowing for possible adoption in home settings.
In the last 20 years, automatic analyzers have been employed to read the results of dipstick urine tests with the same accuracy as or exceeding visual analysis5. Many clinics and doctor offices use such machines to rapidly analyze and print traditional dipstick results. Most urinalysis machines minimize visual inspection errors and ensure consistency in results6. They are easy to use and more efficient than manual inspection but still require the user to perform the dip-wipe method correctly. Hence, these machines have limited ability to be operated by untrained persons such as at-home users; moreover, they are extremely expensive.
Recently, cell phones have emerged as a resourceful tool for various biological colorimetric measurements7,8,9,10, including for urinalysis11,12,13. Given their remote sensing capabilities and high imaging resolution, cell phones have become effective healthcare analytical devices14,15. Indeed, the FDA has cleared several smartphone-based home urine tests16,17,18. Some of the new smartphone-based commercial products incorporate established urinalysis dipsticks, while others feature proprietary colorimetric pads. All such products feature proprietary methods to calibrate for different lighting conditions across different phones types. Still, a problem with these solutions is that the user must manually take a picture at the right time in addition to carrying out a proper manual dip-wipe method (i.e., without cross-contamination). Notably, none of these tests control the volume deposited onto the dipsticks, which we have found can affect the color change19 and interpreted physiological result. The present gaps and costs in the workflows of these devices suggest an additional need to enable a human-free, volume-controlled urine deposition procedure and hands-free dipstick photography.
We describe a protocol for volume-controlled, automated dipstick urinalysis without the need for a manual dip-wipe step. The key to the automated process is a device19 whose underlying principle is based on the SlipChip20 and that transfers liquid between different layers using surface chemistry effects. In brief, the hydrophobic coating on the transfer slide and surrounding plate sleeve force the liquid to move effortlessly through the device and to release onto the dipstick pad once the slide is in its final position, at which point the bottom hydrophobic barrier is replaced with air. Additionally, the coordinated light-blocking box standardizes the lighting conditions, camera angle of view, and the distance for camera focus to ensure accurate and repeatable results that are not influenced by ambient lighting conditions. An accompanying software app automates the capture of images and colorimetric analysis. Following description of the protocol, we provide representative results of the urinalysis test under different conditions. Comparisons with the standard dip-wipe method demonstrate reliability of the proposed method.

<table>
	<tbody>
		<tr>
			<td>Black Cast Acrylic Sheet 
			12&#34; x 24&#34; x 1/8&#34;</td>
			<td>McMaster Carr</td>
			<td>8505K742</td>
			<td>$14.27</td>
		</tr>
		<tr>
			<td>Chart sticker</td>
			<td>Stickeryou.com</td>
			<td></td>
			<td>$12.39</td>
		</tr>
		<tr>
			<td>Clear Scratch- and UV-Resistant Cast Acrylic Sheet 
			12&#34; x 24&#34; x 1/16&#34;</td>
			<td>McMaster Carr</td>
			<td>8560K172</td>
			<td>$9.52</td>
		</tr>
		<tr>
			<td>disposable polyethylene transfer pipet</td>
			<td>Fischer Brand</td>
			<td>13-711-9AM</td>
			<td>lot# 14311021</td>
		</tr>
		<tr>
			<td>Fortus ABS-M30</td>
			<td>Stratasys</td>
			<td>345-42207</td>
			<td>lot# : 108078</td>
		</tr>
		<tr>
			<td>Githut: https://github.com/Iftak/UrineTestApp</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Innovating Science - Replacement Fluids for Urinalysis Diagnostic Test Kit (IS3008)</td>
			<td>Amazon</td>
			<td></td>
			<td>$49</td>
		</tr>
		<tr>
			<td>Nonwhitening Cement for Acrylic 
			Scigrip 4, 4 oz. Can</td>
			<td>MCM</td>
			<td>7517A1</td>
			<td>$9.22</td>
		</tr>
		<tr>
			<td>Rust-Oleum 274232 Repelling treatment base coat-9 oz and top-coat 9-oz , Frosted Clear</td>
			<td>Amazon</td>
			<td>Color: Frosted Clear</td>
			<td>$6.99</td>
		</tr>
		<tr>
			<td>Urinalysis Reagent Strips 10 Panel (100 Tests) MISSION BRAND</td>
			<td>Medimpex United, Inc</td>
			<td>MUI-MS10</td>
			<td>$10.59</td>
		</tr>
	</tbody>
</table>

low-cost, volume-controlled dipstick urinalysis for home-testing

Dipstick urinalysis provides quick and affordable estimations of multiple physiological conditions but requires good technique and training to use accurately. Manual performance of dipstick urinalysis relies on good human color vision, proper lighting control, and error-prone, time-sensitive comparisons to chart colors. By automating the key steps in the dipstick urinalysis test, potential sources of error can be eliminated, allowing self-testing at home. We describe the steps necessary to create a customizable device to perform automated urinalysis testing in any environment. The device is cheap to manufacture and simple to assemble. We describe the key steps involved in customizing it for the dipstick of choice and for customizing a mobile phone app to analyze the results. We demonstrate its use to perform urinalysis and discuss the critical measurements and fabrication steps necessary to ensure robust operation. We then compare the proposed method to the dip-and-wipe method, the gold standard technique for dipstick urinalysis.

Figure 4 demonstrates how the urine is transferred to the dipstick during a urinalysis test. During a typical test, the transfer of urine is not observable because the box occludes the view. Once the sample is deposited in the inlet using a pipette (Step 3.1), it will fill the holes on the slide (Figure 4A). Figure 4B and Figure 4C, respectively, show the progressive movement of the urine across the pla...

Watch this Scientific Journal Video about Low-Cost, Volume-Controlled Dipstick Urinalysis for Home-Testing at JoVE.com

Low-Cost, Volume-Controlled Dipstick Urinalysis for Home-Testing

Dipstick urinalysis is a quick and affordable method of assessing one&#8217;s personal state of health. We present a method to perform accurate, low-cost dipstick urinalysis that removes the primary sources of error associated with traditional dip-and-wipe protocols and is simple enough to be performed by lay users at home.

Dipstick urinalysis provides quick and affordable estimations of multiple physiological conditions but requires good technique and training to use ...

Manual performance of urinalysis dipstick relies on good technique and time-sensitive comparison to chart colors, but automating key steps, we can eliminate potential sources of error and allow home testing. So as a device, it's customizable, inexpensive to manufacture and easy to assemble. It can be used to perform automated urinalysis in any environment.Although critical measurements in fabrication steps are necessary to ensure robust operation, the device implementation is simple and provides accurate and reliable results. After designing the device in an appropriate computer aided design software program, print the inlet cover, top plate, slide and box on a laser cutter into the urinalysis device-based plate on a 3D printer. Use sandpaper to sand the top face area of the base plate between the ledges to roughen the surface.To assemble the inlet and top plate, use acrylic cement to glue the inlet cover onto the top plate where the inlet hole is located. Tape the ledges of the base plate with adhesive tape and holding a can of hydrophobic spray eight to 12 inches away, spray the base plate, top plate, and slide with four to eight coats. The device should have a milky white appearance upon drying.After waiting 12 hours for the base plate to completely dry, remove the tape from the ledges. When the spray has completely dried, align the completed top plate with the ledges of the base plate and use acrylic cement to glue the two pieces together to create the plate sleeve. Then use a clamp to secure the pieces together while drying.While the device is drying, download a QR code from an online QR code generator into the commercially printed vinyl chart sticker from the manufacturer's website. Print the desired code and chart on paper with sticky adhesive backing. Place the QR code 0.17 inches from the right of the first through hole adjacent to the row of through holes and do use clear tape to cover and secure the code to the slide.Then place the vinyl chart sticker to the plate sleeve so that it is aligned with each through hole. To prepare the test, download the urine test mobile application from GitHub and install the app onto a mobile phone. Read the instructions and adjust the analyte names and reading times to be adjusted to match those for the dipstick of interest.Insert the dipstick into the through holes under the plate sleeve and place the plate sleeve inside the box so that the notch is aligned with the box gap. Place the slide into the plate sleeve so that the through holes are aligned with the inlet and place the phone on the top of the box with the back camera lens facing the viewing through hole. Confirm that the phone position will allow an image of the test strip to be acquired through the camera lens and launch the urine test application.Then align the phone so that the dipstick coincides with the boundaries of the black rectangular overlay on screen and click start to begin the test. To analyze a urine sample, use a disposable polyethylene transfer pipette to deposit approximately 500 microliters of urine into the inlet hole and push the slide into the plate sleeve until it is stopped by the base plate top to initiate the test. Here, representative results from a urinalysis test performed with a high-quality smartphone can be observed.As expected, the color of the dipstick did not change in response to water. With the final value for the standard urine, matching with the normal urinary glucose threshold level, and the final value for the high glucose condition being elevated above the normal value. It is important to note that the correct value is not attained for 30 seconds, illustrating the importance of setting the timing readout interval correctly.Using a smartphone with a lower image resolution and flashlight specifications, a significant reduction in the image color and quality of the dipstick panel is observed. The color matching algorithm used by the smartphone application for the urinalysis test, however, yields the same results for the analyte concentrations despite the differences in the physical appearance of the colors of the dipstick pads. Comparing the results captured by an automated urinalysis device to those obtained using the traditional dip-and-wipe method and the commercial urine standard reveals that the accuracy of the automated urinalysis device system depends on the volume transferred to each dipstick pad.Therefore, it is critical that the device is able to accurately and consistently transfer the required urine volume to the dipstick pads. One limitation of this technique is that the hydrophobic coatings may peel with frequent use, thus altering the transferred volume and potentially reducing the accuracy. Additionally, the acrylic bonding may also weakened with repeated testing.The protocol can be used to use with any kind of dipstick with different brands by sending the timers and adjusting the phone app. The method provides increased accuracy of results even when performed by non-trained individuals, suggesting that it as amenable to patient self-testing.

low-cost-volume-controlled-dipstick-urinalysis-for-home-testing

Research

JoVE Journal

Bioengineering

5.4K visualizações.  Vanderbilt University. O desempenho manual da vareta de urina depende de uma boa técnica e comparação sensível ao tempo com as cores dos gráficos, mas automatizando etapas-chave, podemos eliminar possíveis fontes de erro e permitir testes em casa. Assim, como um dispositivo, é personalizável, barato de fabricar e fácil de montar. Pode ser usado para realizar a urinálise automatizada em qualquer ambiente.Embora medidas críticas nas etapas de fabricação sejam necessárias para garantir uma operaç...