Nav: Home

Sustainable sensors to detect, predict muscle fatigue

July 28, 2016

It may be clammy and inconvenient, but human sweat has at least one positive characteristic - it can give insight to what's happening inside your body. A new study published in the ECS Journal of Solid State Science and Technology aims to take advantage of sweat's trove of medical information through the development of a sustainable, wearable sensor to detect lactate levels in your perspiration.

"When the human body undergoes strenuous exercise, there's a point at which aerobic muscle function becomes anaerobic muscle function," says Jenny Ulyanova, CFD Research Corporation (CFDRC) researcher and co-author of the paper. "At that point, lactate is produce at a faster rate than it is being consumed. When that happens, knowing what those levels are can be an indicator of potentially problematic conditions like muscle fatigue, stress, and dehydration."

Utilizing green technology

Using sweat to track changes in the body is not a new concept. While there have been many developments in recent years to sense changes in the concentrations of the components of sweat, no purely biological green technology has been used for these devices. The team of CFDRC researchers, in collaboration with the University of New Mexico, developed an enzyme-based sensor powered by a biofuel cell - providing a safe, renewable power source.

Biofuel cells have become a promising technology in the field of energy storage, but still face many issues related to short active lifetimes, low power densities, and low efficiency levels. However, they have several attractive points, including their ability to use renewable fuels like glucose and implement affordable, renewable catalysts.

"The biofuel cell works in this particular case because the sensor is a low-power device," Ulyanova says. "They're very good at having high energy densities, but power densities are still a work in progress. But for low-power applications like this particular sensor, it works very well."

In their research, entitled "Wearable Sensor System Powered by a Biofuel Cell for Detection of Lactate Levels in Sweat," the team powered the biofuel cells with a fuel based on glucose. This same enzymatic technology, where the enzymes oxidize the fuel and generate energy, is used at the working electrode of the sensor which allows for the detection of lactate in your sweat.

Targeting lactate

While the use of the biofuel cell is a novel aspect of this work, what sets it apart from similar developments in the field is the use of electrochemical processes to very accurately detect a specific compound in a very complex medium like sweat.

"We're doing it electrochemically, so we're looking at applying a constant load to the sensor and generating a current response," Ulyanova says, "which is directly proportional to the concentration of our target analyte."

Practical applications

Originally, the sensor was developed to help detect and predict conditions related to lactate levels (i.e. fatigue and dehydration) for military personnel.

"The sensor was designed for a soldier in training at boot camp," says Sergio Omar Garcia, CFDRC researcher and co-author of the paper, "but it could be applied to people that are active and anyone participating in strenuous activity."

As for commercial applications, the researchers believe the device could be used as a training aid to monitor lactate changes in the same way that athletes use heart rate monitors to see how their heart rate changes during exercise.

On-body testing

The team is currently working to redesign the physical appearance of the patch to move from laboratory research to on-body tests. Once the scientists optimize how the sensor adheres to the skin, its sweat sample delivery/removal, and the systems electronic components, volunteers will test its capabilities while exercising.

"We had actually talked about this idea to some local high school football coaches," Ulyanova says, "and they seem to really like it and are willing to put forth the use of their players to beta test the idea."

After initial data is gathered, the team will be able to work with other groups to interpret the data and relate it to the physical condition of the person. With this, predictive models could be built to potentially help prevent conditions related to individual overexertion.

Future plans for the device include implementing wireless transmission of results and the development of a suite of sensors (a hybrid sensor) that can detect various other biomolecules, indicative of physical or physiological stressors.
-end-


The Electrochemical Society

Related Heart Rate Articles:

Pupil dilation and heart rate, analyzed by AI, may help spot autism early
Autism and other neurodevelopmental disorders often aren't diagnosed until a child is a few years of age, when behavioral interventions and speech/occupational therapy become less effective.
Heart rate variation due to stress affects auditory attention
Study shows that brain activity related to auditory perception parallels heart rate, offering new perspectives for the treatment of attention and communication disorders.
In HIE, lower heart rate variability signals stressed newborns
In newborns with hypoxic-ischemic encephalopathy, lower heart rate variability correlates with autonomic manifestations of stress shortly after birth, underscoring the importance of this reading as a valuable biomarker, according to Children's research presented during the Pediatric Academic Societies 2019 Annual Meeting.
Your blood pressure and heart rate change to meet physical and social demands
Blood pressure and heart rate are not fixed, but rather they adapt to meet physical and social demands placed on the body, according to new research from Binghamton University, State University at New York.
Your genes determine how your heart rate responds to exercise
Your genes can determine how your heart rate and blood pressure respond to exercise -- and may act as an early warning of future problems with your heart or blood vessels -- according to new research published in The Journal of Physiology.
Women under-treated for heart attacks die at twice the rate of men
Cardiac specialists say they are alarmed by new research findings led by the University of Sydney showing that women admitted to 41 Australian hospitals with serious heart attacks were half as likely as men to receive appropriate diagnostic tests and treatment, and less likely to be referred for cardiac rehabilitation and prescribed preventive medications at discharge.
Heart attack risk on the rise for pregnant women and death rate remains high
Study shows that the risk of having a heart attack while pregnant, giving birth, or during the two months after delivery, continues to increase for American women.
CPAP may reduce resting heart rate in prediabetic patients
Patients with prediabetes who also have obstructive sleep apnea (OSA) may improve their resting heart rate, an important measure of cardiovascular health, by using continuous positive airway pressure (CPAP) to treat their OSA, according to a randomized, controlled trial presented at the ATS 2018 International Conference.
Wide variation in rate of death between VA hospitals for patients with heart disease, heart failure
Death rates for veterans with ischemic heart disease and chronic heart failure varied widely across the Veterans Affairs (VA) health care system from 2010 to 2014, which could suggest differences in the quality of cardiovascular health care provided by VA medical centers.
Obesity linked with higher chance of developing rapid, irregular heart rate
People with obesity are more likely to develop a rapid and irregular heart rate, called atrial fibrillation, which can lead to stroke, heart failure and other complications, according to Penn State researchers.
More Heart Rate News and Heart Rate Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.