A wearable device that monitors a user's environment, heart rate and other physical attributes has been developed with the goal of predicting and preventing asthma attacks.
The system, called the Health and Environmental Tracker (HET), is composed of a suite of new sensor devices that are worn on the wrist and connected to a patch that adheres to the chest.
The patch includes sensors that track a patient's movement, heart rate, respiratory rate, the amount of oxygen in the blood, skin impedance and wheezing in the lungs.
The wristband focuses largely on environmental factors, monitoring volatile organic compounds and ozone in the air, as well as ambient humidity and temperature. The wristband also includes additional sensors to monitor motion, heart rate and the amount of oxygen in the blood.
The system also has one nonwearable component: a spirometer, which patients breathe into several times a day to measure lung function.
"Right now, people with asthma are asked to use a peak flow meter to measure lung function on a day-to-day basis," said James Dieffenderfer with North Carolina State University who is working on the project.
"That information is used to inform the dosage of prescription drugs used in their inhalers. For HET, we developed a customised self-powered spirometer, which collects more accurate information on lung function and feeds that data into the system."
Data from all of these sensors is transmitted wirelessly to a computer, where custom software collects and records it.
According to the Centers for Disease Control and Prevention, asthma affects more than 24 million people in the United States. Asthma patients currently rely on inhalers to deal with their symptoms, which can include often-debilitating asthma attacks.
"The uniqueness of this work is not simply the integration of various sensors in wearable form factors," said Veena Misra who also worked on the project.
"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 is important because it gives the devices a long battery life, and will make them compatible with the power generated by the body - which is not a lot."
"We have tested the system in the benchtop and on a limited number of human subjects for proof of concept demonstration and have confirmed that all of the sensors work, and that the system accurately compiles the data,"
The researchers plan to begin testing the system on a larger subject population this summer in the hope of an eventual commercial rollout.
Another team recently demonstrated an alcohol monitoring wearable device that can be worn on the wrist.