Analysis of Paper-Based Colorimetric Assays With a Smartphone Spectrometer

Woodburn, Elizabeth; Long, Kenneth D.; Cunningham, Brian T.

doi:10.1109/jsen.2018.2876631

Cited by 27 publications

(10 citation statements)

References 28 publications

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“…3 ) as might be obtained in a manufacturing facility or by an at-home consumer. I also intentionally used ambient room lighting and made no special effort to create consistent lighting conditions between photographs, although a smartphone’s built-in flash could be used to create consistent lighting for at-home use if necessary 12 – 18 .…”

Section: Resultsmentioning

confidence: 99%

CandyCodes: simple universally unique edible identifiers for confirming the authenticity of pharmaceuticals

Grover

2022

Sci Rep

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Counterfeit or substandard medicines adversely affect the health of millions of people and cost an estimated $200 billion USD annually. Their burden is greatest in developing countries, where the World Health Organization estimates that one in ten medical products are fake. In this work, I describe a simple addition to the existing drug manufacturing process that imparts an edible universally unique physical identifier to each pill, tablet, capsule, caplet, etc. This technique uses nonpareils (also called sprinkles and “hundreds and thousands”), tiny inexpensive multicolor candy spheres that are normally added to other candies or desserts as decorations. If nonpareils are applied at random to a pill immediately after manufacture, the specific pattern they form is unlikely to ever be repeated by random chance; this means that the pattern (or “CandyCode”) can be used to uniquely identify the pill and distinguish it from all other pills. By taking a photograph of each CandyCoded pill after manufacture and recording the location and color of each nonpareil, a manufacturer can construct a database containing the CandyCodes of all known-authentic pills they produce. A consumer can then simply use a cellphone to photograph a pill and transfer its image to the manufacturer’s server, which determines whether the pill’s CandyCode matches a known-good CandyCode in their database (meaning that the pill is authentic) or does not have a match in the database (in which case the consumer is warned that the pill may be counterfeit and should not be consumed). To demonstrate the feasibility of using random particles as universal identifiers, I performed a series of experiments using both real CandyCodes (on commercially produced chocolate candies) and simulated CandyCodes (generated by software). I also developed a simple method for converting a CandyCode photo to a set of strings for convenient storage and retrieval in a database. Even after subjecting CandyCodes to rough handling to simulate shipping conditions, the CandyCodes were still easily verifiable using a cellphone camera. A manufacturer could produce at least $$10^{17}$$ 10 17 CandyCoded pills—41 million for each person on Earth—and still be able to uniquely identify each CandyCode. By providing universally-unique IDs that are easy to manufacture but hard to counterfeit, require no alteration of the existing drug formulation and minimal alteration of the manufacturing process, and need only a cameraphone for verification, CandyCodes could play an important role in the fight against fraud in pharmaceuticals and many other products.

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Section: Resultsmentioning

confidence: 99%

CandyCodes: simple universally unique edible identifiers for confirming the authenticity of pharmaceuticals

Grover

2022

Sci Rep

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“…An automated evaluation of urine test strips that using smartphones has already been investigated in previous work. A large number of these studies focused on improving accuracy and reproducibility by employing custom build equipment like custom-built opaque boxes or optical attachments to the camera were used [5] – [9] .…”

Section: Related Workmentioning

confidence: 99%

Smartphone-Based Colorimetric Analysis of Urine Test Strips for At-Home Prenatal Care

Flaucher

Nissen

Jäger

et al. 2022

IEEE J. Transl. Eng. Health Med.

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Objective: Clinical urine tests are a key component of prenatal care. As of now, urine test strips are evaluated through a time consuming, often error-prone and operator-dependent visual color comparison of test strips and reference cards by medical staff. Methods and procedures: This work presents an automated pipeline for urinalysis with urine test strips using smartphone camera images in home environments, combining several image processing and color combination techniques. Our approach is applicable to off-the-shelf test strips in home conditions with no additional hardware required. For development and evaluation of our pipeline we collected image data from two sources: i) A user study (26 participants, 150 images) and ii) a lab study (135 images). Results: We trained a region-based convolutional neural network that is able to detect the urine test strip location and orientation in images with a wide variety of light conditions, backgrounds and perspectives with an accuracy of 85.5%. The reference card can be robustly detected through a feature matching approach in 98.6% of the images. Color comparison by Hue channel (0.81 F1-Score), Matching factor (0.80 F1-Score) and Euclidean distance (0.70 F1-Score) were evaluated to determine the urinalysis results. Conclusion: We show that an automated smartphone-based colorimetric analysis of urine test strips in a home environment is feasible. It facilitates examinations and provides the possibility to shift care into an at-home environment. Clinical impact: The findings demonstrate that routine urine examinations can be transferred into the home environment using a smartphone. Simultaneously, human error is avoided, accuracy is increased and medical staff is relieved.

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“…Yang等 [88] 扩增的特异性引物序列. 一旦掺入目标物(如鸡肉), 其 [91] ; (b) 单链DNA与探针之间的液相杂交 [91] ; (c) 侧流试纸条检测 [87] ; (d) 侧流条带膜法检测SARS-CoV-2 [92] ; (e) 基于NAT-FP/NAT-RP和mPCR-LFS的肉类掺假多重检测联合检测验证平台 [93] ; (f) 离心辅助侧流层析测定(CLFIA) [95] ; (g) 分子印迹技术辅助金免疫层析检测 [98] ; (h) 使用智能手机光谱仪进行基于纸张的比色分析 [99] (网络版彩图)…”

Section: 要对纳米纤维和抗体的共价结合进行研究来充分了解其机理unclassified

Recent advances in structural improvements and chemicalmodifications of lateral flow assay devices

Qu¹,

Deng²,

Pang³

et al. 2021

Sci. Sin.-Chim

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Lateral flow assay (LFA) is an important paper-based technique amenable for rapid and point-of-care testing. It features as low cost and simple operations. However, a main challenge often comes from weak detection signals and low sensitivity. Here we summarize the advances in new research aiming at improving the sensitivity of LFA through structural improvements, chemical modifications, and other auxiliary methods. We discuss the principle and operation, performance, unique features, advantages and remaining issues of each improvement strategy. We highlight current challenges and provide perspectives on future research directions with respect to developing new strategies for improving LFA.

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Analysis of Paper-Based Colorimetric Assays With a Smartphone Spectrometer

Cited by 27 publications

References 28 publications

CandyCodes: simple universally unique edible identifiers for confirming the authenticity of pharmaceuticals

CandyCodes: simple universally unique edible identifiers for confirming the authenticity of pharmaceuticals

Smartphone-Based Colorimetric Analysis of Urine Test Strips for At-Home Prenatal Care

Recent advances in structural improvements and chemicalmodifications of lateral flow assay devices

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