Researchers are working on developing an armband with three dry electrodes that...
Researchers are working on developing an armband with three dry electrodes that could track heart rate.
Source: Caitlin Knowles

Ideal placement for armband to track vitals

North Carolina State University researchers took a step forward in the development of an armband that could track the heart’s electrical activity without requiring bulky wiring or sticky gel on the skin.

Specifically, the researchers determined the ideal placement for three electrodes in their band design, and how tightly the band needs to be worn, to best detect electrical signals from the heart.

The findings are the latest advance in a multi-institutional effort to develop an armband that takes electrocardiogram (ECG) measurements in order to track heart rate. They are ultimately envisioning a device that could be worn as an arm sleeve throughout the day, powered by energy captured from body heat or movement.

“This study is the first step in identifying all of the components to make the armband a reality,” said the study’s first author, Braden M. Li, a Ph.D. candidate in NC State’s Wilson College of Textiles. “We identified the ideal electrode location to gather heart signals and figured out how the armband pressure affects the electrocardiogram quality.”

In the study, the researchers studied the placement of electrodes in various locations on a volunteer’s upper left arm in order to identify the best placement of three electrodes for tracking the heart’s electrical activity. They identified the best placement from among 50 different combinations. While electrodes are conventionally used “wet,” or along with a gel substance in ECG devices, researchers are working on a design that would use dry electrodes since they have the potential to be used over a longer period of time as part of a wearable device.

They also measured the pressure and heart signal of three different sizes of the band in order to understand how tightly it needs to be worn. “If we don’t have enough compression, then we don’t get the same quality of data that we need,” said the study’s senior author, Jesse S. Jur, professor of textile engineering, chemistry and science at NC State.

They made the band prototype by screen printing the electrodes into a plastic film through a method uncovered in a previous study in Jur’s lab at NC State. Then, they heat pressed the electrodes on to a polyester and spandex fabric. “Screen printing is a very traditional process in textile manufacturing,” Li said. “We wanted to choose a manufacturing process that could be easily translated into the textile process.”

The work is part of a multi-institution research effort conducted through the National Science Foundation-funded, engineering research-based Center for Advanced Self-Powered Systems of Integrated Sensors and Technologies (ASSIST). The researchers in the center are working to develop wearable devices that can be powered by the body’s own thermal or mechanical energy. For the armband, they are working on the design to get the best heart signal while using the least amount of energy.

They are designing the armband with three electrodes, rather than with 12, so that it could potentially be powered by the wearer. While increasing the number of leads could capture the heart’s electrical signal with greater accuracy, they are working on a design that could be more easily worn, and by a person of any body type.

“Part of the goal for the ASSIST center is to design self-powered, wearable electronics,” Jur said. “We’re always balancing how much power would be required for the sensors system, data processing and communication in order to match that for the power you might be able to harvest from the body.”

The study was published in IEEE Sensors Journal.

Subscribe to our newsletter

Related articles

E-textiles made with new cellulose thread

E-textiles made with new cellulose thread

Researchers have developed a thread made of conductive cellulose, which offers practical possibilities for electronic textiles.

Decentralized patient monitoring: Sensors quickly detect changes in vital signs

Decentralized patient monitoring: Sensors quickly detect changes in vital signs

The Fraunhofer Institutes project M³Infekt aims to develop a multi-modal, modular and mobile system of sensors for monitoring infectious diseases.

Sensor detects signs of burnout in sweat

Sensor detects signs of burnout in sweat

Engineers have developed a wearable sensing chip that can measure the concentration of cortisol – the stress hormone – in human sweat.

An all-in-one health monitor

An all-in-one health monitor

Engineers have developed a skin patch that can continuously track blood pressure and heart rate while measuring the wearer’s levels of glucose as well as lactate.

3D printed transparent fibers can sense breath

3D printed transparent fibers can sense breath

Researchers used 3D printing techniques to make electronic fibres, each 100 times thinner than a human hair, creating sensors beyond the capabilities of conventional film-based devices.

Wearable sensor for patients with inflammatory bowel disease

Wearable sensor for patients with inflammatory bowel disease

Researchers have designed a wearable device that monitors sweat for biomarkers that could signal flare-ups of inflammatory bowel disease (IBD).

Wearable sensor tracks biochemical data

Wearable sensor tracks biochemical data

Scientist are developing a patch that monitors the sweat of high performance athletes for medical information.

Smart fabrics with bioactive inks monitor body

Smart fabrics with bioactive inks monitor body

Researchers have developed biomaterial-based inks that respond to and quantify chemicals released from the body or in the surrounding environment by changing color.

Smart textile fibers measure wearer’s health

Smart textile fibers measure wearer’s health

Researchers have developed electronic fibers that, when embedded in textiles, can collect a wealth of information about our bodies by measuring subtle and complex fabrics deformations.

Popular articles

Subscribe to Newsletter