We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us

Download Mobile App


ATTENTION: Due to the COVID-19 PANDEMIC, many events are being rescheduled for a later date, converted into virtual venues, or altogether cancelled. Please check with the event organizer or website prior to planning for any forthcoming event.

Wearable Sweat Sensor Provides Continuous Monitoring for Health Conditions

By HospiMedica International staff writers
Posted on 17 Aug 2022
Print article
Image: The new wearable sensor detects even more compounds in human sweat (Photo courtesy of Caltech)
Image: The new wearable sensor detects even more compounds in human sweat (Photo courtesy of Caltech)

If you have ever had your blood drawn, whether to check your cholesterol, kidney function, hormone levels, blood sugar, or as part of a general checkup, you might have wondered why there is not an easier, less painful way. Now there might be. Researchers have unveiled a new wearable sensor that can detect in human sweat even minute levels of many common nutrients and biological compounds which can serve as indicators of human health.

The sensor technology was developed by a team of researchers from the California Institute of Technology (Caltech, Pasadena, CA, USA) whose research has focused on wearable sensors with medical applications, and this latest work represents the most precise and sensitive iteration yet. Previous versions of their sweat sensors relied on enzymes embedded within them to detect a limited number of relevant compounds. While antibodies could be used in sensors to detect more compounds at low concentrations, that technique had a big weakness: antibodies in the sensor can only be used once, meaning the sensors will wear out.

The new sensor technology includes what the researchers call molecularly imprinted polymers, which are like artificial, reusable antibodies. To picture how they work, imagine a hypothetical object shaped like a plus sign. If you take that object and pour silicone rubber over the top of it, let the rubber harden, and then pull the molecule out of the rubber, you now have a chunk of rubber with a plus-shaped hollow in it. Only objects with that same size and shape will fit nicely into the hollow. Molecularly imprinted polymers work the same way, but on a much smaller scale. If you want to make a sensor that can detect, for example, the amino acid glutamine, you prepare the polymer with the glutamine molecules inside. Then, through a chemical process, remove the glutamine, and you have a polymer with holes in it that are the exact shape of glutamine.

The innovation by the Caltech researchers combines that specially formed polymer with a material that can be oxidized or reduced under an applied electrical voltage when in contact with human sweat. As long as those glutamine-shaped holes are open, sweat comes into contact with the inner layer of the sensor and an electrical signal is generated. But as glutamine molecules come into contact with the polymer, they slip into those holes that were made for them. As those holes become plugged with glutamine molecules, less sweat is able to contact the inner layer, and the electrical signal becomes weaker. By monitoring that electrical signal, the researchers can then deduce how much glutamine is present in the sweat. More glutamine means a weaker signal. Less glutamine results in a stronger signal. And unlike antibodies, the polymer can easily be "cleaned" for reuse through the application of a weak electrical signal that destroys the target molecule or empties out the hole it was in.

The second innovation in their research is the use of microfluidics, a technology that utilizes tiny channels less than a quarter millimeter wide to manipulate small amounts of fluids. Microfluidics allow the sensor to operate when even a miniscule amount of sweat is present. Human skin can be artificially stimulated to sweat out drug molecules delivered by electrical current, but previous sensors required more sweat, and thus more current, which could be uncomfortable for the user, according to the researchers. Thanks to microfluidics and the use of a different type of drug, the sensor now needs less sweat, and the current needed to generate the sweat can be very small. So far, the sensor technology has been shown to work on human subjects in laboratory settings, and the researchers hope to test it in larger-scale human trials.

"This approach allows us to detect a bunch of new crucial nutrients and metabolites. We can monitor when we eat and watch nutrient levels change," said Wei Gao, assistant professor of medical engineering, Heritage Medical Research Institute investigator, and Ronald and JoAnne Willens Scholar. "It not only monitors nutrients, but also hormones and drugs. It can provide continuous monitoring for many health conditions."

Related Links:

BMP Whole Blood Analyzer: GEM Premier ChemSTAT
Gold Supplier
POC Test Reader
Calcitonin ELISA Test
Calcitonin AccuBind ELISA Test System
Pre-Eclampsia Screening Assay

Print article



view channel
Image: AI transforms smartwatch ECG signals into a diagnostic tool for heart failure (Photo courtesy of Pexels)

AI-Based Smartwatch Accurately Detects Heart Failure Using ECG Signals

People with a weak heart pump might not have symptoms, but this common form of heart disease affects about 2% of the population and 9% of people over 60. When the heart cannot pump enough oxygen-rich blood,... Read more

Surgical Techniques

view channel
Image: Bioelectric medicine could stem excessive blood loss (Photo courtesy of Pexels)

Wearable Neurostimulation Solution Could Stem Excessive Blood Loss in the OR

A wearable neurostimulation solution focused on lessening excessive blood loss could save precious time for surgical teams in the operating room. A collaboration between Spark Biomedical, Inc.... Read more

Patient Care

view channel
Image: The digital stretcher scales are designed specifically for emergent situations in hospitals and emergency rooms (Photo courtesy of DETECTO)

Portable High-Capacity Digital Stretcher Scales Provide Precision Weighing for Patients in ER

For emergency arrivals into a hospital, time is of the essence for gathering patient weights. Now, digital stretcher scales specifically designed for emergent situations in hospitals and emergency rooms... Read more

Health IT

view channel
Image: Using digital data can improve health outcomes (Photo courtesy of Unsplash)

Electronic Health Records May Be Key to Improving Patient Care, Study Finds

When a patient gets transferred from a hospital to a nearby specialist or rehabilitation facility, it is often difficult for personnel at the new facility to access the patient’s electronic health records... Read more


view channel
Image: The global visualization instruments for MIS market is estimated to surpass USD 21 billion by 2031 (Photo courtesy of Pexels)

Global Visualization Instruments for MIS Market Driven by Increasing Demand for Endoscopy Procedures

The last few years have witnessed an increase in patient preference for medical surgeries that involve fewer incisions. As a result, the demand for visualization instruments, which aid in achieving improved... Read more
Copyright © 2000-2022 Globetech Media. All rights reserved.