Breath-Saving Bracelet

Wearable system for asthma attack prevention.

For those with asthma, attacks can come on unexpectedly and interrupt daily activities, from exercising to just taking a walk on the sidewalk. A feeling of panic arises in asthmatics when suddenly, without warning, their lungs seize up and they’re struggling to inhale much-needed air. Through painful wheezing, they grab their inhaler and, after a few puffs, feel somewhat back to normal again. Never knowing when the attack will strike next causes added anxiety and stress throughout the day.

Fortunately, engineers have developed a possible solution to help detect factors leading to an attack. The wearable wristband, called the Health and Environmental Tracker (HET), monitors heart rate, the environment and other physical factors. This way, the users can determine what action should be taken to prevent asthma attacks from occurring in the first place.

Wristband prototype (HET) that monitors a user’s environment, heart rate and other physical attributes to predict and prevent asthma attacks. (Image courtesy of James Dieffenderfer.)

Wristband prototype (HET) that monitors a user’s environment, heart rate and other physical attributes to predict and prevent asthma attacks. (Image courtesy of James Dieffenderfer.)

How to Predict and Prevent an Asthma Attack

The HET system combines a wristband containing several sensing devices with a patch that adheres to the chest.The patch sensors track movement, heart rate, respiratory rate, the amount of oxygen in the blood, skin obstruction and wheezing in the lungs.

The other half, the wristband, focuses on environmental factors such as volatile organic compounds and ozone in the air, ambient humidity and temperature.

Additional sensors in the wristband include the monitoring of motion, the heart and the amount of oxygen in the blood.

However, to measure lung function, a nonwearable component is required: the spirometer. By breathing in the spirometer several times throughout the day, lung function is measured.

Using an electronic spirometer.

Using an electronic spirometer.

Sometimes, asthma attacks come on suddenly when going out for a jog. These attacks can be prevented if the patient is more aware of what body responses lead to an attack. With a self-powered spirometer, the information collected is more accurate than the peak flow meters used to determine the amount of prescription drugs needed in each inhaler. The HET system is also capable of transmitting data from the spirometer to the system. Data from the HET sensors transmits wirelessly to a computer for records keeping.

As VeenaMisra, coauthor and a professor of electrical and computer engineering, said,“The impact here is that we have been able to demonstrate power consumption levels that are in the sub-milliwatt levels by using nano-enabled novel sensor technologies. Comparable, existing devices have power consumption levels in the hundreds of milliwatts.”

“This ultra-low power consumption gives the devices a long battery life and will make them compatible with the power generated by the body—which is not a lot. It enables a pathway to realize the ASSIST center’s vision of self-powered wearable sensors in the near future.”

Easier Breathing Ahead

HET was developed by researchers from the National Science Foundation’s Nanosystems Engineering Research Center for Advanced Self-Powered Systems of Integrated Sensors and Technologies (ASSIST) at North Carolina State University. Affecting more than 24 million people in the United States alone according to the Centers for Disease Control and Prevention, asthma is a common problem begging for new solutions.

This summer, researchers plan to test a larger scale population of asthma sufferers in order to determine the top physiological and environmental factors that will help predict and prevent attacks. Taking HET a step further, AlperBozkurt (the testbed leader of the ASSIST center) believes that users will be able to “synch the HET to their smartphones so that they can monitor their health on the go. After these tests are completed, and the prediction software created, we are hoping that a fully functional HET system will be available.”

So along with reading text messages and emails, HET users will be able to keep their health in check and breathe just a bit easier every day.

For another example of improved health monitoring via wearables, check out this story on wearable sweat sensors.