Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Wearable sweat sensor detects gout-causing compounds

27.11.2019

There are numerous things to dislike about going to the doctor: Paying a copay, sitting in the waiting room, out-of-date magazines, sick people coughing without covering their mouths. For many, though, the worst thing about a doctor's visit is getting stuck with a needle. Blood tests are a tried-and-true way of evaluating what is going on with your body, but the discomfort is unavoidable. Or maybe not, say Caltech scientists.

In a new paper published in Nature Biotechnology, researchers led by Wei Gao, assistant professor of medical engineering, describe a mass-producible wearable sensor that can monitor levels of metabolites and nutrients in a person's blood by analyzing their sweat.


A laser-engraved, flexible sensor can monitor health conditions through sweat.

Credit: Caltech

Previously developed sweat sensors mostly target compounds that appear in high concentrations, such as electrolytes, glucose, and lactate. Gao's sweat sensor is more sensitive than current devices and can detect sweat compounds of much lower concentrations, in addition to being easier to manufacture, the researchers say.

The development of such sensors would allow doctors to continuously monitor the condition of patients with illnesses like cardiovascular disease, diabetes, or kidney disease, all of which result in abnormal levels of nutrients or metabolites in the bloodstream.

Patients would benefit from having their physician better informed of their condition, while also avoiding invasive and painful encounters with hypodermic needles.

"Such wearable sweat sensors have the potential to rapidly, continuously, and noninvasively capture changes in health at molecular levels," Gao says. "They could enable personalized monitoring, early diagnosis, and timely intervention."

Gao's work is focused on developing devices based on microfluidics, a name for technologies that manipulate tiny amounts of liquids, usually through channels less than a quarter of a millimeter in width.

Microfluidics are ideal for an application of this sort because they minimize the influence of sweat evaporation and skin contamination on the sensing accuracy. As freshly supplied sweat flows through the microchannels, the device can make more accurate measurements of sweat and can capture temporal changes in concentrations.

Until now, Gao and his colleagues say, microfluidic-based wearable sensors were mostly fabricated with a lithography-evaporation process, which requires complicated and expensive fabrication processes. His team instead opted to make their biosensors out of graphene, a sheet-like form of carbon.

Both the graphene-based sensors and the tiny microfluidics channels are created by engraving the plastic sheets with a carbon dioxide laser, a device that is now so common that it is available to home hobbyists.

The research team opted to have their sensor measure respiratory rate, heart rate, and levels of uric acid and tyrosine. Tyrosine was chosen because it can be an indicator of metabolic disorders, liver disease, eating disorders, and neuropsychiatric conditions.

Uric acid was chosen because, at elevated levels, it is associated with gout, a painful joint condition that is on the rise globally. Gout occurs when high levels of uric acid in the body begin crystallizing in the joints, particularly those of the feet, causing irritation and inflammation.

To see how well the sensors performed, the researchers ran a series of tests with healthy individuals and patients. To check sweat tyrosine levels, which are influenced by a person's physical fitness, they used two groups of people: trained athletes and individuals of average fitness.

As expected, the sensors showed lower levels of tyrosine in the sweat of the athletes. To check uric acid levels, they took a group of healthy individuals and monitored their sweat while they were fasting as well as after they ate a meal rich in purines, compounds in food that are metabolized into uric acid.

The sensor showed uric acid levels rising after the meal. Gao's team also performed a similar test with gout patients. Their uric acid levels, the sensor showed, were much higher than those of healthy people.

To check the accuracy of the sensors, the researchers also drew blood samples from the gout patients and healthy subjects. The sensors' measurements of uric acid levels strongly correlated with levels of the compound in the blood.

Gao says the high sensitivity of the sensors, along with the ease with which they can be manufactured, means they could eventually be used by patients at home to monitor conditions like gout, diabetes, and cardiovascular diseases. Having accurate real-time information about their health could even allow a patient to adjust their own medication levels and diet as required.

"Considering that abnormal circulating nutrients and metabolites are related to a number of health conditions, the information collected from such wearable sensors will be invaluable for both research and medical treatment," Gao says.

###

The paper describing the research, titled, "A laser-engraved wearable sensor for sensitive detection of uric acid and tyrosine in sweat," appears in the Nov. 25 issue of Nature Biotechnology. Co-authors are Yiran Yang (MS '18), Yu Song, Xiangjie Bo, Jihong Min (MS '19), Minqiang Wang, Jiaobing Tu, and Adam Kogan of Caltech; Haixia Zhang of Peking University; On Shun Pak of Santa Clara University; Lailai Zhu of Princeton; and Tzung K. Hsiai and Zhaoping Li of UCLA. Hsiai is also a visiting associate at Caltech.

Funding for the research was provided by the Rothenberg Innovation Initiative program, the Carver Mead New Adventures Fund, and the American Heart Association.

Media Contact

Emily Velasco
evelasco@caltech.edu
626-395-6487

 @caltech

http://www.caltech.edu 

Emily Velasco | EurekAlert!
Further information:
https://www.caltech.edu/about/news/wearable-sweat-sensor-detects-gout-causing-compounds
http://dx.doi.org/10.1038/s41587-019-0321-x

Further reports about: compounds metabolites tyrosine uric acid wearable sweat sensors

More articles from Health and Medicine:

nachricht Diabetes mellitus: A risk factor for early colorectal cancer
27.05.2020 | Nationales Centrum für Tumorerkrankungen (NCT) Heidelberg

nachricht Ultra-thin fibres designed to protect nerves after brain surgery
27.05.2020 | Martin-Luther-Universität Halle-Wittenberg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Biotechnology: Triggered by light, a novel way to switch on an enzyme

In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".

Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...

Im Focus: New double-contrast technique picks up small tumors on MRI

Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.

researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...

Im Focus: I-call - When microimplants communicate with each other / Innovation driver digitization - "Smart Health“

Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.

When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...

Im Focus: When predictions of theoretical chemists become reality

Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.

Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...

Im Focus: Rolling into the deep

Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.

A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

New 5G switch provides 50 times more energy efficiency than currently exists

27.05.2020 | Information Technology

Return of the Blob: Surprise link found to edge turbulence in fusion plasma

27.05.2020 | Physics and Astronomy

Upwards with the “bubble shuttle”: How sea floor microbes get involved with methane reduction in the water column

27.05.2020 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>