The ongoing study shows promise in the general development of self-powered wearable biosensors, the researchers say, in a development that has implications for clinical laboratory testing
Years back, it would be science fiction to describe a wearable garment that can not only measure an individual’s biomarkers in real-time, but also generates the power the device needs from the very specimen used for the measurement. Clinical laboratory managers and pathologists may find this new technology to be an interesting milestone on the path to wearable diagnostic devices.
With cases of diabetes on the rise across the globe, innovative ways to monitor the disease and simplify care is critical for effective diagnoses and treatment. Now, a team of researchers at Tokyo University of Science (TUS) in Japan have recently developed a diaper that detects blood glucose levels in individuals living with this debilitating illness.
Of equal interest, this glucose-testing diaper has a self-powered sensor that utilizes a biofuel cell to detect the presence of urine, measure its glucose concentration, and then wirelessly transmit that information to medical personnel and patients. The biofuel cell generates its own power directly from the urine.
Glucose in urine provides valuable data regarding blood sugar levels and can be used as an alternative to frequent blood draws to measure those levels. Monitoring the onset and progression of diabetes is crucial to making patient care easier, particularly in elderly and long-term care patients. Widespread use of these diapers in skilled nursing facilities and other healthcare settings could create an opportunity for clinical laboratories to do real-time monitoring of the blood sugar measurements and alert providers when a patient’s glucose levels indicate the need for attention.
“Besides monitoring glucose in the context of diabetes, diaper sensors can be used to remotely check for the presence of urine if you stock up on sugar as fuel in advance,” said Isao Shitanda, PhD, Associate Professor at the Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, in a TUS press release. “In hospitals or nursing care sites, where potentially hundreds of diapers have to be checked periodically, the proposed device could take a great weight off the shoulders of caregivers,” he added.
The TUS researchers published their findings in the peer-reviewed journal ACS Sensors, titled, “Self-Powered Diaper Sensor with Wireless Transmitter Powered by Paper-Based Biofuel Cell with Urine Glucose as Fuel.”
Creating Electricity from Urine
Through electrochemistry, the scientists created their paper-based biofuel cell so that it could determine the amount of glucose in urine via reduction oxidation reactions, or redox for short. Using a process known as “graft polymerization,” they developed a special anode that allowed them to “anchor glucose-reactive enzymes and mediator molecules to a porous carbon layer, which served as the base conductive material,” the press release noted.
The biosensor was tested using artificial urine at different glucose levels. The energy generated from the urine then was used to power up a Bluetooth transmitter to remotely monitor the urine concentration via a smartphone. The TUS researchers determined their biofuel cell was able to detect sugar levels present in urine within one second. The diaper with its sensor could help provide reliable and easy monitoring for diabetic and pre-diabetic patients.
“We believe the concept developed in this study could become a very promising tool towards the general development of self-powered wearable biosensors,” Shitanda said in the press release.
According to the Isao Shitanda, PhD (above), lead author of the TUS study, 34.2 million people, or just over 10% of the US population, were diagnosed with diabetes in 2020. The federal Centers for Disease Control and Prevention estimates that an additional 7.3 million people have diabetes and are undiagnosed. A self-powered biosensor that detects diabetes and prediabetes in urine could help clinical laboratories and doctors catch the disease early and/or monitor its treatment. (Photo copyright: Tokyo University of Science.)
The World Health Organization (WHO) estimates that 422 million people globally were living with diabetes in 2014, and that 1.5 million deaths could be attributed directly to diabetes in 2019.
Other “Smart Diaper” Products
The Lumi by Pampers smart diaper contains RFID sensors that detect moisture and alert parents or caregivers when it is time to change the baby’s diaper. These smart diapers help prevent skin irritations and other health issues that can arise from leaving a soiled diaper on for too long. And in “New ‘Smart Diaper’ Tests Baby’s Urine for Urinary Tract Infections, Dehydration, and Kidney Problems—Then Alerts Baby’s Doctor,” Dark Daily reported on a smart diaper developed by Pixie Scientific of New York that could test a baby’s urine for various urinary conditions.
A panel of colored squares embedded on the front of the diaper changed color if specific chemical reactions fell outside normal parameters. If such a color change was observed, a smart phone application could relay that information to the baby’s doctor to determine if any further testing was needed.
Since we wrote that ebriefing in 2013, Pixie Scientific has expanded its product line to include Pixie Smart Pads, which when added to a diaper, enable’s caregivers to monitor wearers for urinary tract infections (UTI) and report findings by smartphone to their doctors.
These examples demonstrate ways in which scientists are working to combine diagnostics with existing products to help people better manage their health. Wearable electronics and biosensors are increasingly helping medical professionals and patients monitor bodily functions and chronic diseases.
As clever as these new wearable devices may be, there is still the need to monitor the diagnostic data they produce and interpret this data as appropriate to the patient’s state of health. Thus, it is likely that pathologists and clinical laboratory professionals will continue to play an important role in helping consumers and providers interpret diagnostic information collected by wearable, point-of-care testing technology.
—JP Schlingman
Related Information
Making Patient Care Easier: Self-powered Diaper Sensors That Monitor Urine Sugar Levels
National Diabetes Statistics Report, 2020
The Smart Diaper is Coming. Who Actually Wants it?