Self-Powered Paper-Based 'SPEDs' may Lead to New Medical-Diagnostic Tools

A new medical-diagnostic device made out of paper detects biomarkers and identifies diseases by performing electrochemical analyses - powered only by the user's touch - and reads out the color-coded test results, making it easy for non-experts to understand. The self-powered, paper-based electrochemical devices, or SPEDs, are designed for sensitive diagnostics at the "point-of-care," or when care is delivered to patients, in regions where the public has limited access to resources or sophisticated medical equipment.

"You could consider this a portable laboratory that is just completely made out of paper, is inexpensive and can be disposed of through incineration," said Ramses V. Martinez, an assistant professor of industrial and biomedical engineering at Purdue University. "We hope these devices will serve untrained people located in remote villages or military bases to test for a variety of diseases without requiring any source of electricity, clean water, or additional equipment."

"SPEDs are inexpensive, lightweight, flexible and easy to use," Martinez said.

Research findings are detailed in a paper appearing on Aug. 22 in Advanced Materials Technologies.

The test is initiated by placing a pinprick of blood in a circular feature on the device, which is less than two-inches square. SPEDs also contain "self-pipetting test zones" that can be dipped into a sample instead of using a finger-prick test.

The top layer of the SPED is fabricated using untreated cellulose paper with patterned hydrophobic "domains" that define channels that wick up blood samples for testing. These "micro?uidic channels" allow for accurate assays that change color to indicate specific testing results. A machine-vision diagnostic application also was created to automatically identify and quantify each of these "colorimetric" tests from a digital image of the SPED, perhaps taken with a cellphone, to provide fast diagnostic results to the user and to facilitate remote-expert consultation.

The bottom layer of the SPED is a "triboelectric generator," or TEG, which generates the electric current necessary to run the diagnostic test simply by rubbing or pressing it. The researchers also designed an inexpensive handheld device called a potentiostat, which is easily plugged into the SPED to automate the diagnostic tests so that they can be performed by untrained users. The battery powering the potentiostat can be recharged using the TEG built into the SPEDs.

"To our knowledge, this work reports the ?rst self-powered, paper-based devices capable of performing rapid, accurate, and sensitive electrochemical assays in combination with a low-cost, portable potentiostat that can be recharged using a paper-based TEG," Martinez said.

He co-authored the paper with graduate students Aniket Pal and Debkalpa Goswami; visiting scholars Hugo E. Cuellar and Heloisa F. N. Caurin; and Randy Kuang, a high school student who participated in the research.

The research paper describes the SPEDs, the portable potentiostat and a machine-vision algorithm that is able to recognize the color-coded information. SPEDs are compatible with mass-printing technologies, such as roll-to-roll printing or spray deposition. They can perform "multiplexed" analyses enabling the highly sensitive and accurate detection of various targets for a range of point-of-care testing applications. And they can be used to power other electronic devices to facilitate telemedicine applications in resource-limited settings.

The SPEDs were used to detect biomarkers such as glucose, uric acid and L-lactate, ketones, and white blood cells, which indicate factors related to liver and kidney function, malnutrition and anemia. Future versions of the technology will contain several additional layers for more complex assays to detect diseases such as dengue fever, yellow fever, malaria, HIV and hepatitis, Martinez said.

Aniket Pal, Hugo E Cuellar, Randy Kuang, Heloisa F N Caurin, Debkalpa Goswami, Ramses V Martinez.
Self-Powered, Paper-Based Electrochemical Devices for Sensitive Point-of-Care Testing.
Adv. Mater. Technol. 2017, 1700130. doi: 10.1002/admt.201700130.

Most Popular Now

Artificial Intelligence Predicts Dementi…

Imagine if doctors could determine, many years in advance, who is likely to develop dementia. Such prognostic capabilities would give patients and their families time to plan and manage treatment...

Using Machine Learning to Improve Patien…

Doctors are often deluged by signals from charts, test results, and other metrics to keep track of. It can be difficult to integrate and monitor all of these data for...

Researchers Uncover Security Issues with…

Use caution when entering personal health information into a convenient app on your mobile device, because not all apps are created equal when it comes to protecting your privacy, warns...

Self-Powered Paper-Based 'SPEDs' may Lea…

A new medical-diagnostic device made out of paper detects biomarkers and identifies diseases by performing electrochemical analyses - powered only by the user's touch - and reads out the color-coded...

New App Uses Smartphone Selfies to Scree…

Pancreatic cancer has one of the worst prognoses - with a five-year survival rate of 9 percent - in part because there are no telltale symptoms or non-invasive screening tools...

Nurses Becoming e-Nurses by Using Patien…

The ambitions of NHS Digital’s e-nursing week and the Royal College of Nursing's (RCN) 'Every nurse an e-nurse' campaign are being realised by nurses across the UK, who are seeing...

New Diagnostic Tool Spots First Signs of…

Researchers have developed the first tool that can diagnose Parkinson's disease when there are no physical symptoms, offering hope for more effective treatment of the condition. There are currently no...

Stroke Patient Improvement with a Brain-…

University of Adelaide researchers have shown that it is possible for stroke patients to improve motor function using special training involving connecting brain signals with a computer. In a "proof-of-principle...

eHealth Hub Call: Lean Startup Academy

The Lean Startup Academy is an unique opportunity to mature your business by systematically testing your ideas against the market with the support of experts. The course will help you...

Google Glass App Helps Autistic Children…

A prototype software application, to be used with the optical head-mounted display Google Glass, has been designed as a social-skills coach for children with autism spectrum disorder (ASD). A new...

Philips Innovations at IFA 2017 Put Cons…

At this year's Internationale Funkausstellung (IFA) in Berlin, Germany, Royal Philips (NYSE: PHG, AEX: PHIA) showcases new products and services that empower consumers to take an active role in managing...