<p>Chronic kidney disease (CKD) affects millions worldwide but remains under-diagnosed, especially in resource-limited settings. Current diagnostic methods, including visual and dipstick urinalysis, lack quantitative accuracy, while laboratory-based tests remain inaccessible for routine or remote monitoring. Here we present SpectraPhone, a smartphone-integrated, portable spectrometer designed for quantitative, point-of-care urinalysis. Leveraging the smartphone’s built-in camera and flashlight, SpectraPhone captures high-resolution spectral data to accurately quantify hematuria and albuminuria, which are both biomarkers of CKD. Through rigorous optical characterization and empirical validation, SpectraPhone demonstrates superior quantification performance, accurately measuring red blood cell concentrations (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">$R^2$</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>R</mi> <mn>2</mn> </msup> </math></EquationSource> </InlineEquation> = 0.9913, RMSE = 61.6086 RBC/<InlineEquation ID="IEq2"> <EquationSource Format="TEX">$\upmu$</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="normal">μ</mi> </math></EquationSource> </InlineEquation>L, MAE = 43.9077 RBC/<InlineEquation ID="IEq3"> <EquationSource Format="TEX">$\upmu$</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="normal">μ</mi> </math></EquationSource> </InlineEquation>L) and albumin levels (<InlineEquation ID="IEq4"> <EquationSource Format="TEX">$R^2$</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>R</mi> <mn>2</mn> </msup> </math></EquationSource> </InlineEquation> = 0.9981, RMSE = 11.8525 mg/dL, MAE = 8.4985 mg/dL), significantly surpassing the capabilities of conventional qualitative methods. With the addition of bromophenol blue reagent, SpectraPhone achieves more accurate urine albumin measurements (<InlineEquation ID="IEq5"> <EquationSource Format="TEX">$R^2$</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>R</mi> <mn>2</mn> </msup> </math></EquationSource> </InlineEquation> = 0.9997, RMSE = 4.2583 mg/dL, MAE = 3.2625 mg/dL), enabling clinical-grade albuminuria detection. SpectraPhone’s affordability, ease of use, and robust performance highlight its potential to transform routine CKD screening, facilitate early detection, improve disease management, and increase healthcare access globally.</p>

Development of a smartphone based spectrometer for high-resolution urinalysis

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2026年2月12日

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Kefan Song,
Ilan Mandel,
Jason Cobb,
Tanzeem Choudhury,
Alexander T. Adams

摘要

Chronic kidney disease (CKD) affects millions worldwide but remains under-diagnosed, especially in resource-limited settings. Current diagnostic methods, including visual and dipstick urinalysis, lack quantitative accuracy, while laboratory-based tests remain inaccessible for routine or remote monitoring. Here we present SpectraPhone, a smartphone-integrated, portable spectrometer designed for quantitative, point-of-care urinalysis. Leveraging the smartphone’s built-in camera and flashlight, SpectraPhone captures high-resolution spectral data to accurately quantify hematuria and albuminuria, which are both biomarkers of CKD. Through rigorous optical characterization and empirical validation, SpectraPhone demonstrates superior quantification performance, accurately measuring red blood cell concentrations ( $R^2$ $R^{2}$ = 0.9913, RMSE = 61.6086 RBC/ $\upmu$ $μ$ L, MAE = 43.9077 RBC/ $\upmu$ $μ$ L) and albumin levels ( $R^2$ $R^{2}$ = 0.9981, RMSE = 11.8525 mg/dL, MAE = 8.4985 mg/dL), significantly surpassing the capabilities of conventional qualitative methods. With the addition of bromophenol blue reagent, SpectraPhone achieves more accurate urine albumin measurements ( $R^2$ $R^{2}$ = 0.9997, RMSE = 4.2583 mg/dL, MAE = 3.2625 mg/dL), enabling clinical-grade albuminuria detection. SpectraPhone’s affordability, ease of use, and robust performance highlight its potential to transform routine CKD screening, facilitate early detection, improve disease management, and increase healthcare access globally.