The backside of this Garmin smartwatch shows the sensors that use light to illuminate blood vessels in order to measure heart rate.Tina Arnold/Flickr
One approach is to create sensors that detect compounds in sweat from the skin. These compounds can provide a lot of information about a person’s health. pH, sodium ions, glucose and alcohol content are just some of the things that emerging sweat sensors can detect. Tears also contain compounds from the body, so researchers are investigating chemical sensing using contact lenses and smart lenses.
Sweat rate can also be measured, which can be used as an indicator of temperature, so these sensors are being examined for use in helping detect Covid-19.
Toward detecting viruses
The drawback of many existing wearable sensors is that they can’t actually detect the presence of a virus such at SARS-CoV-2. To do this, they would have to detect virus-specific RNA.
RNA detection typically involves several steps, including extracting RNA from a sample, making many copies of the RNA and identifying the RNA. Although there has been a lot of progress in miniaturizing RNA detection equipment for use in rapid, point-of-care testing, there’s still a ways to go before it can fit in wearable devices.
Much of the ongoing research on developing rapid, point-of-care pathogen detection uses “lab-on-a-chip” technology. Lab-on-a-chip refers to the goal of shrinking laboratory tests that once required many large pieces of equipment to the size of a computer chip or microscope slide.
An example is a Covid-19 diagnostic test undergoing clinical trials. The test’s sensor is a specialized ion-sensitive field-effect transistor (ISFET) that is designed to respond to the presence of the virus RNA. The device can perform a test in less than one hour, but requires a sample collected by nasal swab.
While this technology is not wearable, it could become the launching point for future virus-detecting wearables because these can be made small and use little power. A wearable device that continuously monitors a person and indicates that they’ve contracted or been exposed to the virus would allow the person to seek treatment and isolate themselves to prevent further spread.
Sonic screwdrivers and tricorders
Fans of Dr. Who know the sonic screwdriver, and Star Trek followers know the tricorder. The ideal wearable of the future would be similar to these wondrous fictional devices. It would be able to detect the presence of the virus in the environment around the wearer, providing the opportunity to leave before becoming exposed.
But airborne virus detection requires significant equipment to collect air samples and analyze them. Other methods, such as the plasmonic photothermal biosensor, provide promising results, but still require the user to perform the analysis. It will be some time before a smartwatch will be able to alert its wearer to the presence of a dangerous virus.
Wearable and accessible
For all the promise of wearables as tools to tackle the Covid-19 pandemic, and future pandemics, there are barriers to widespread use of the devices. Most wearables are expensive, can be difficult to learn to use by non-native English speakers, or are developed without data from a broad population base. There’s a risk that many people won’t accept the technology.
Continued development of broadly accepted health-based wearables should include community input, as outlined in a National Academies Workshop Summary. By ensuring that everyone has access to wearables, and accepts them, the devices can help keep people healthy in the midst of a global pandemic. Ongoing research should result in improved technology that, with care, will benefit all of society.
This article was originally published on The Conversation by Albert H. Titus at The State University of New York. Read the original article here.