Engineers have developed a wearable monitor patch prototype as a health monitoring device for athletes. It can measure biochemical and electrical signals in the human body simultaneously. It is similar to the tricorder device used by Dr McCoy to check the health of a crew member in the TV series, Star Trek. The scientists are based at the Departments of NanoEngineering and Electrical Engineering and the Jacobs School of Engineering in UC San Diego.
The patch is called the ‘Chem-Phys patch’ and has been designed to measure real-time levels of lactate which indicate physical activity. The patch can also measure the athlete's heart activity. The device is a thin, flexible, adhesive piece of polyester which can be manufactured through screen printing. An electrode which can sense lactate is printed in the centre of the patch and two electrocardiogram electrodes (EKG) are placed either side in order to sense the heart’s electrical signals. The team found it important that the electrode signals did not cross which could cause problems for accuracy of the monitoring device. They separated the lactate sensor from the EKG readers so that the small voltage which passes through the lactate sensor did not disrupt the EKG readings. They also made sure that only sweat could reach the lactate sensor, using a printed layer of soft water-repellent silicone rubber to keep the sweat away from the other electrodes. Each sensor was connected to a small circuit board which includes a Bluetooth low-energy chip and a micro controller to enable the information to be sent to a laptop, smart watch or smartphone.
The Chem-Phys patch has been tested on 3 athletes as they cycled intensely for 15-30 minutes. The patch was worn on their chest near their sternum and two also wore heart rate monitors on the wrist to assess how the EKG electrodes were working. The commercial heart rate monitors matched the Chem-Phys readout. The engineers also found that the athletes' lactate readings matched readings previously collected during physical activity.
The patches have only been tested on a few individuals, but there is the potential to develop the patch further. Athletes are already used to wearing smart watches or devices used to monitor their health including heart rate and the number of steps taken. Recently researchers at the University of California-Berkeley developed a device to measure sweat, dehydration and fatigue which could be worn as part of a wrist band or headband which also sends its results to a computer. The engineers of Chem-Phys plan to improve the patch further by working on the way the patch and board are connected as well as adding to vital signs monitoring and the number of chemicals that their patch can track including magnesium and potassium.
The patch has possible interest for professional and serious athletes to help them monitor their health and optimise their training. The patch may also have some medical applications in monitoring patients with cardiovascular disease.
They just might need a snappier name!
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