Flexible wearable electronic skin patch offers new way to monitor alcohol levels

Engineers at the University of California San Diego have developed a flexible wearable sensor that can accurately measure a person’s blood alcohol level from sweat and transmit the data wirelessly to a laptop, smartphone or other mobile device. The device can be worn on the skin and could be used by doctors and police officers for continuous, non-invasive and real-time monitoring of blood alcohol content.

The device consists of a temporary tattoo—which sticks to the skin, induces sweat and electrochemically detects the alcohol level—and a portable flexible electronic circuit board, which is connected to the tattoo by a magnet and can communicate the information to a mobile device via Bluetooth. The work, led by nanoengineering professor Joseph Wang and electrical engineering professor Patrick Mercier, both at UC San Diego, was published recently in the journal ACS Sensors.



“Lots of accidents on the road are caused by drunk driving. This technology provides an accurate, convenient and quick way to monitor alcohol consumption to help prevent people from driving while intoxicated,” Wang said. The device could be integrated with a car’s alcohol ignition interlocks, or friends could use it to check up on each other before handing over the car keys, he added.

“When you’re out at a party or at a bar, this sensor could send alerts to your phone to let you know how much you’ve been drinking,” said Jayoung Kim, a materials science and engineering PhD student in Wang’s group and one of the paper’s co-first authors.

Blood alcohol concentration is the most accurate indicator of a person’s alcohol level, but measuring it requires pricking a finger. Breathalyzers, which are the most commonly used devices to indirectly estimate blood alcohol concentration, are non-invasive, but they can give false readouts. For example, the alcohol level detected in a person’s breath right after taking a drink would typically appear higher than that person’s actual blood alcohol concentration. A person could also fool a breathalyzer into detecting a lower alcohol level by using mouthwash.

Recent research has shown that blood alcohol concentration can also be estimated by measuring alcohol levels in what’s called insensible sweat—perspiration that happens before it’s perceived as moisture on the skin. But this measurement can be up to two hours behind the actual blood alcohol reading. On the other hand, the alcohol level in sensible sweat—the sweat that’s typically seen—is a better real-time indicator of the blood alcohol concentration, but so far the systems that can measure this are neither portable nor fit for wearing on the body.

Now, UC San Diego researchers have developed an alcohol sensor that’s wearable, portable and could accurately monitor alcohol level in sweat within 15 minutes.

“What’s also innovative about this technology is that the wearer doesn’t need to be exercising or sweating already. The user can put on the patch and within a few minutes get a reading that’s well correlated to his or her blood alcohol concentration. Such a device hasn’t been available until now,” Mercier said.

Full story can be found from University of California San Diego website.

Wearable noninvasive and continuous hemoglobin concentration monitor FDA approved

Masimo announced FDA 510(k) clearance for Radius-7® – the first and only wearable, tetherless, noninvasive rainbow® monitor. Radius-7, which connects to the Root® patient monitoring and connectivity platform, is now available in the U.S. with breakthrough Masimo rainbow® technology. With this clearance, Radius-7 with Root now enables noninvasive monitoring of more than 10 parameters, including, for the first time in a wearable device, total hemoglobin (SpHb®), a breakthrough measurement that noninvasively and continuously measures hemoglobin concentration.



SpHb monitoring may provide additional insight to the directional trend of hemoglobin between invasive blood samplings – when the SpHb trend is stable and the clinician may otherwise think hemoglobin is decreasing; when SpHb trend is rising and the clinician may otherwise think hemoglobin is not rising fast enough; or when the SpHb trend is decreasing and the clinician may otherwise think hemoglobin is stable. SpHb may thus help clinicians make more timely and informed decisions, and has been shown to help clinicians provide more timely blood transfusions* and reduce blood transfusions in cases such as neurosurgery and orthopedic surgery.1,2

Professor Christer Svensen, Professor of Anesthesiology and Intensive Care at the Karolinska Institute in Stockholm, Sweden, who has been using Radius-7 as part of a research study, commented, "We are currently performing a noninvasive continuous study monitoring respiratory rate, heart rate and saturation for all patients admitted to a surgical ward. Additionally, we are monitoring SpHb for selected postsurgical patients, which can be extremely beneficial because it can provide insight into hemoglobin trends between invasive blood samplings. Such insight may lead clinicians to confirm trends by performing blood draws sooner than they might otherwise have done, which may then suggest the need to intervene."

For the first time, it is possible to offer patients freedom of movement while providing such important monitoring, and studies have shown that patient mobility is a key factor in more rapid patient recovery.3,4 When monitoring ambulating patients, Radius-7 communicates to Root at the bedside and thereby to Masimo Patient SafetyNet™ to alert clinicians of critical changes in oxygen saturation, pulse rate, respiration, and hemoglobin, among other parameters. Radius-7 is lightweight, weighing only 0.34 lbs, and attaches to the arm, thus allowing untethered monitoring whether a patient is in or out of bed – which also reduces the need for nursing assistance, as there is no need to disconnect from or reconnect to a bedside monitor. Each Radius-7 comes with two "hot-swappable" rechargeable battery modules (one with the patient, one charging), each with a battery life of 12 hours, minimizing monitoring interruption.

"Never before could patients be monitored for such key parameters as continuous SpHb, which can help clinicians make more timely and informed blood management decisions, while patients are fully mobile. Previous wearable patient monitors were hampered by a limited range of measurements and false alarms due to motion," said Joe Kiani, Founder and CEO of Masimo. "Root with Radius-7 with rainbow SET, coupled with Patient SafetyNet for mobile clinician notification, is now an even more versatile and powerful monitoring system, all while promoting freedom of patient movement and quicker recovery times."

Details can be found from Masimo website by following this link.

New wearable devices aim to predict and prevent asthma attacks

Researchers have developed an integrated, wearable system that monitors a user’s environment, heart rate and other physical attributes with the goal of predicting and preventing asthma attacks. The researchers plan to begin testing the system on a larger subject population this summer.

The system, called the Health and Environmental Tracker (HET), is composed of a suite of new sensor devices and was developed by researchers from the National Science Foundation’s Nanosystems Engineering Research Center for Advanced Self-Powered Systems of Integrated Sensors and Technologies (ASSIST) at North Carolina State University.

    

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.

“Our goal was to design a wearable system that could track the wellness of the subjects and in particular provide the infrastructure to predict asthma attacks, so that the users could take steps to prevent them by changing their activities or environment,” says Alper Bozkurt, the principal investigator of a paper describing the work and an assistant professor of electrical and computer engineering at NC State.

“Preventing an attack could be as simple as going indoors or taking a break from an exercise routine,” says James Dieffenderfer, lead author of the paper and a Ph.D. student in the joint biomedical engineering program at NC State and the University of North Carolina at Chapel Hill.

The HET system incorporates a host of novel sensing devices, which are incorporated into a wristband and 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,” Dieffenderfer says. “That information is used to inform the dosage of prescription drugs used in their inhalers.

“For HET, we developed a customized self-powered spirometer, which collects more accurate information on lung function and feeds that data into the system,” Dieffenderfer adds.

Data from all of these sensors is transmitted wirelessly to a computer, where custom software collects and records the data.

“The uniqueness of this work is not simply the integration of various sensors in wearable form factors,” says Veena Misra, co-author of the paper and a professor of electrical and computer engineering at NC State. “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,” says Misra, who is also the director of the ASSIST Center. “It enables a pathway to realize the ASSIST Center’s vision of wearable sensors powered by energy from the body in the near future.”

“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,” Misra says. “This summer, we plan to begin testing HET in a controlled environment with subjects suffering from asthma and a control group, in order to identify which environmental and physiological variables are effective at predicting asthma attacks.”

“Once we have that data, the center can begin developing software that will track user data automatically and give users advance warning of asthma attacks,” says Bozkurt, who as testbed leader of the ASSIST Center is overseeing HET system integration. “And that software will allow users to synch the HET to their smartphones so that they can monitor their health on the go. After these tests are completed, and the prediction software created, we are hoping that a fully functional HET system will be available.”

More information can be found from NC State Universtiy website by following this link.

Flexible, wearable, tricorder-like EKG sensor

Engineers at the University of California San Diego have developed the first flexible wearable device capable of monitoring both biochemical and electric signals in the human body. The Chem-Phys patch records electrocardiogram (EKG) heart signals and tracks levels of lactate, a biochemical that is a marker of physical effort, in real time. The device can be worn on the chest and communicates wirelessly with a smartphone, smart watch or laptop. It could have a wide range of applications, from athletes monitoring their workouts to physicians monitoring patients with heart disease.



Nanoengineers and electrical engineers at the UC San Diego Center for Wearable Sensors worked together to build the device, which includes a flexible suite of sensors and a small electronic board. The device also can transmit the data from biochemical and electrical signals via Bluetooth.

Nanoengineering professor Joseph Wang and electrical engineering professor Patrick Mercier at the UC San Diego Jacobs School of Engineering led the project, with Wang's team working on the patch's sensors and chemistry, while Mercier's team worked on the electronics and data transmission. They describe the Chem-Phys patch in the May 23 issue of Nature Communications.

"One of the overarching goals of our research is to build a wearable tricorder-like device that can measure simultaneously a whole suite of chemical, physical and electrophysiological signals continuously throughout the day," Mercier said. "This research represents an important first step to show this may be possible."

Most commercial wearables only measure one signal, such as steps or heart rate, Mercier said. Almost none of them measure chemical signals, such as lactate.

That is the gap that the sensor designed by researchers at the Jacobs School of Engineering at UC San Diego aims to bridge. Combining information about heart rate and lactate--a first in the field of wearable sensors--could be especially useful for athletes wanting to improve their performance. Both Mercier and Wang have been fielding inquiries from Olympic athletes about the technologies the Center for Wearable Sensors produces.

"The ability to sense both EKG and lactate in a small wearable sensor could provide benefits in a variety of areas," explained Dr. Kevin Patrick, a physician and director of the Center for Wireless and Population Health Systems at UC San Diego, who was not involved with the research. "There would certainly be interest in the sports medicine community about how this type of sensing could help optimize training regimens for elite athletes," added Patrick, who is also a member of the Center for Wearable Sensors. "The ability to concurrently assess EKG and lactate could also open up some interesting possibilities in preventing and/or managing individuals with cardiovascular disease."

The researchers' biggest challenge was making sure that signals from the two sensors didn't interfere with each other. This required some careful engineering and a fair bit of experimentation before finding the right configuration for the sensors.

A press relaease can be found by following this link.

Printed wearable sensors monitor movement sequences

Accessories like smart bracelets or smart watches are trending as »personal health coaches«, prompting the bearer to provide for sufficient sleep and activity or a healthy diet. Sensor-embedded textile solutions are a far more challenging and also more expensive approach. Often, function will override appearance. The new materials developed by Fraunhofer ISC might offer a cost-efficient alternative with the extra benefit of more adjustable appearance options.


      

In cooperation with Fraunhofer ISIT and with support of the project partners from the industry, the new sensor technology will be incorporated into a prototype shirt. This so-called MONI shirt will feature a number of functions but is foremost designed to monitor movement sequences. In an initial step, Fraunhofer ISC has developed novel piezoelectric polymer sensor printing pastes free from toxic solvents while Fraunhofer ISIT has provided the evaluation electronics. The next development steps are planned in close dialogue with the industry partners. They will include field tests on several types of textiles and applications, the further optimization of the electronics as well as wear and washability tests.

The sensor materials coming to use are flexible, transparent and suitable for various applications also beside of smart textiles: They register pressure and deformation and can thus serve as touch or motion sensors. Their sensitivity to temperature deviations further enables monitoring of temperature changes or non-contact interaction, e. g. as proximity sensors.

A simple screen printing process is all it takes to apply the sensor pastes onto textile fabrics or plastic films. Manufacturing encompasses two steps: First, the pattern is printed. Then, the sensors are subjected to an electric field making the piezolectric polymers align to adopt the targeted pressure sensitivity. The cost-efficient screen printing process is a definite plus when it comes to industrial use. It is the key to mass production of printed sensors on textiles.

Thanks to its transparency and flexibility, the new sensor material offers freedom of design in color and form for textiles and garments. As the sensors are much thinner than a human hair and applicable in whatever form, the wearer will hardly notice them embedded in a garment. There’s yet another benefit: the sensors do not require any power source like a battery. Instead, they harvest energy.

Smart textiles like this could be employed in health care or assisted living. In eldercare, everyday life movement sequences could be monitored and failure noticed. Additionally, it would be possible to monitor body signals of in-patients, such as temperature or breathing. This could be especially beneficial for bedridden patients or babies. Some day, even heart rate surveillance may be possible. Last but not least, functional sensor clothing could achieve cost reductions in the health care system. On top of assuming patient monitoring functions it could add to preventive health care.

In Addition to printed sensors on textiles Fraunhofer ISC shows textilintegrated pressure sensors made of silicone e. g. to measure pressure in shoes.

More information can be found from Fraunhofer ISC website by following this link.