Diabetics may soon be able to pass on the traditional finger prick blood test to monitor their glucose levels.
A team from the University of Bath has developed a non-invasive adhesive patch that draws glucose out from fluid between cells across hair follicles that are individually accessed through an array of miniature sensors using a small electric current.
“A non-invasive—that is, needle-less—method to monitor blood sugar has proven a difficult goal to attain,” Richard Guy, a professor from the Department of Pharmacy & Pharmacology, said in a statement. “The closest that has been achieved has required either at least a single-point calibration with a classic ‘finger-stick,’ or the implantation of a pre-calibrated sensor via a single needle insertion. The monitor developed at Bath promises a truly calibration-free approach, an essential contribution in the fight to combat the ever-increasing global incidence of diabetes.”
With the patch, glucose is collected in small reservoirs. Measurements can be taken every 10 to 15 minutes over the course of several hours.
The test is advantageous to other wearable sensors because it can operate on a small area over an individual hair follicle—significantly reducing the inter-skin and intra-skin variability in glucose extraction and increasing the accuracy of the measurements taken so that calibration through a blood sample is not necessary.
“The specific architecture of our array permits calibration-free operation, and it has the further benefit of allowing realization with a variety of materials in combination,” Adelina Ilie, PhD, from the Department of Physics, said in a statement. “We utilized graphene as one of the components as it brings important advantages: specifically, it is strong, conductive, flexible, and potentially low-cost and environmentally friendly.
“In addition, our design can be implemented using high-throughput fabrication techniques like screen printing, which we hope will ultimately support a disposable, widely affordable device.”
During the study, the researchers tested the patch on both pigskin and healthy human volunteers. In the pig tests, the team showed that they could accurately track glucose levels across the range seen in diabetic human patients. During the human testing, the patch was able to track blood sugar variations throughout the day.
The researchers will now attempt to refine the design to optimize the number of sensors in the array and demonstrate the full functionality over an entire day. They also plan to conduct a number of clinical trials.
The researchers believe the new technology could eventually yield a low-cost, wearable sensor that sends regular, clinically relevant glucose measurements to the wearer’s phone or smartwatch wirelessly to alert them that they may need to take action.
The World Health Organization predicts the worldwide incidence of diabetes to rise from 171 million in 2000 to 366 million in 2030.
The study was published in Nature Nanotechnology
