Over 1,000 aspirants, including 62 from India, have been shortlisted for an ambitious private mission to send four men and women on a one-way trip to Mars in 2024 to establish a More »
Electrical engineers at the University of California, San Diego demonstrated a new wireless communication technique that works by sending magnetic signals through the human body. The new technology could offer a lower power and more secure way to communicate information between wearable electronic devices, providing an improved alternative to existing wireless communication systems, researchers said. They presented their findings Aug. 26 at the 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society in Milan, Italy.
While this work is still a proof-of-concept demonstration, researchers envision developing it into an ultra low power wireless system that can easily transmit information around the human body. An application of this technology would be a wireless sensor network for full-body health monitoring.
“In the future, people are going to be wearing more electronics, such as smart watches, fitness trackers and health monitors. All of these devices will need to communicate information with each other. Currently, these devices transmit information using Bluetooth radios, which use a lot of power to communicate. We’re trying to find new ways to communicate information around the human body that use much less power,” said Patrick Mercier, a professor in the Department of Electrical and Computer Engineering at UC San Diego who led the study. Mercier also serves as the co-director of the UC San Diego Center for Wearable Sensors.
Communicating magnetic signals through the human body
The new study presents a solution to some of the main barriers of other wireless communication systems: in order to reduce power consumption when transmitting and receiving information, wireless systems need to send signals that can easily travel from one side of the human body to another. Bluetooth technology uses electromagnetic radiation to transmit data, however these radio signals do not easily pass through the human body and therefore require a power boost to help overcome this signal obstruction, or “path loss.”
In this study, electrical engineers demonstrated a technique called magnetic field human body communication, which uses the body as a vehicle to deliver magnetic energy between electronic devices. An advantage of this system is that magnetic fields are able to pass freely through biological tissues, so signals are communicated with much lower path losses and potentially, much lower power consumption. In their experiments, researchers demonstrated that the magnetic communication link works well on the body, but they did not test the technique’s power consumption. Researchers showed that the path losses associated with magnetic field human body communication are upwards of 10 million times lower than those associated with Bluetooth radios.
“This technique, to our knowledge, achieves the lowest path losses out of any wireless human body communication system that’s been demonstrated so far. This technique will allow us to build much lower power wearable devices,” said Mercier.
Lower power consumption also leads to longer battery life. “A problem with wearable devices like smart watches is that they have short operating times because they are limited to using small batteries. With this magnetic field human body communication system, we hope to significantly reduce power consumption as well as how frequently users need to recharge their devices,” said Jiwoong Park, a Ph.D student in Mercier’s Energy-Efficient Microsystems Lab at the UC San Diego Jacobs School of Engineering and first author of the study.
The researchers also pointed out that this technique does not pose any serious health risks. Since this technique is intended for applications in ultra low power communication systems, the transmitting power of the magnetic signals sent through the body is expected to be many times lower than that of MRI scanners and wireless implant devices.
Another potential advantage of magnetic field human body communication is that it could offer more security than Bluetooth networks. Because Bluetooth radio communicates data over the air, anyone standing within 30 feet can potentially eavesdrop on that communication link. On the other hand, magnetic field human body communication employs the human body as a communication medium, making the communication link less vulnerable to eavesdropping. With this technique, researchers demonstrated that magnetic communication is strong on the body but dramatically decreases off the body. To put this in the context of a personal full-body wireless communication network, information would neither be radiated off the body nor be transmitted from one person to another.
“Increased privacy is desirable when you’re using your wearable devices to transmit information about your health,” said Park.
Demonstrating magnetic communication with a proof-of-concept prototype
The researchers built a prototype to demonstrate the magnetic field human body communication technique. The prototype consists of copper wires insulated with PVC tubes. On one end, the copper wires are hooked up to an external analyzer and on the other end, the wires are wrapped in coils around three areas of the body: the head, arms and legs. These coils serve as sources for magnetic fields and are able to send magnetic signals from one part of the body to another using the body as a guide. With this prototype, researchers were able to demonstrate and measure low path loss communication from arm to arm, from arm to head, and from arm to leg.
Researchers noted that a limitation of this technique is that magnetic fields require circular geometries in order to propagate through the human body. Devices like smart watches, headbands and belts will all work well using magnetic field human body communication, but not a small patch that is stuck on the chest and used to measure heart rate, for example. As long as the wearable application can wrap around a part of the body, it should work just fine with this technique, researchers explained.
The joy of running. That sense of well-being, freedom and extra energy that runners often experience is not just a matter of endorphins. A study at the University of Montreal Hospital Research Centre (CRCHUM) shows that the “runner’s high” phenomenon is also caused by dopamine, an important neurotransmitter for motivation.
“We discovered that the rewarding effects of endurance activity are modulated by leptin, a key hormone in metabolism. Leptin inhibits physical activity through dopamine neurons in the brain,” said Stephanie Fulton, a researcher at the CRCHUM and lead author of an article published in the journal Cell Metabolism.
Secreted by adipose tissue, leptin helps control the feeling of satiety. This hormone also influences physical activity. “The more fat there is, the more leptin there is and and the less we feel like eating. Our findings now show that this hormone also plays a vital role in motivation to run, which may be related to searching for food,” explained Stephanie Fulton, who is also a professor at Université de Montréal’s Department of Nutrition.
Hormone signals that modulate feeding and exercise are in fact believed to be closely linked. Endurance running capacity in mammals, particularly humans, is thought to have evolved to maximize the chances of finding food. This study suggests that leptin plays a critical role both in regulating energy balance and encouraging behaviours that are “rewarding” for the person’s metabolism, i.e., engaging in physical activity to find food.
The researchers studied voluntary wheel running in mice in cages. These mice can run up to seven kilometres a day. In a laboratory, the physical activity of normal mice was compared with that of mice who underwent a genetic modification to suppress a molecule activated by leptin, STAT3 (signal transducer and activator of transcription-3). The STAT3 molecule is found in the neurons that synthesize dopamine in the midbrain. This “mesolimbic dopaminergic pathway” is a like a motivational highway in the brain.
“Mice that do not have the STAT3 molecule in the dopaminergic neurons run substantially more. Conversely, normal mice are less active because leptin then activates STAT3 in the dopamine neurons, signalling that energy reserves in the body are sufficient and that there is no need to get active and go looking for food,” explained Maria Fernanda Fernandes, first author of the study.
And is leptin as important for motivation to be active in humans? Yes. “Previous studies have clearly shown a correlation between leptin and marathon run times. The lower leptin levels are, the better the performance. Our study on mice suggests that this molecule is also involved in the rewarding effects experienced when we do physical exercise. We speculate that for humans, low leptin levels increase motivation to exercise and make it easier to get a runner’s high,” summed up Stephanie Fulton.
Mice, humans and mammals in general are thought to have evolved to increase the return on effective food acquisition behaviours. Ultimately, hormones are sending the brain a clear message: when food is scarce, it’s fun to run to chase some down.
Six Nasa recruits have shut themselves inside a dome in Hawaii to begin a year-long isolation programme that will simulate life on Mars to help the US space agency prepare for the pioneering mission to the red planet.
The group began the isolation experiment on August 28, and now face 365 days without fresh air, food or privacy.
The group consists of a French astrobiologist, a German physicist and four Americans; a pilot, an architect, a doctor/journalist and a soil scientist.
They are living in a self-contained solar-powered dome, which measures only 11 metres in diameter and is six metres tall.
It is estimated that the first human mission to Red Planet could last between one to three years.
The participants will each have a small sleeping cot and a desk inside their rooms and will be eating food such as powdered cheese and canned tuna, ‘Ibtimes.co.uk’ reported.
The group has limited access to the internet, and must wear a spacesuit if they