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Wireless movement-tracking system could collect health and behavioral data
Radio-frequency signals can be used to track peoples' movements in their own homes.
We live in a world of wireless signals flowing around us and bouncing off our bodies. MIT researchers are now leveraging those signal reflections to provide scientists and caregivers with valuable insights into people's behavior and health.
The system, called Marko, transmits a low-power radio-frequency (RF) signal into an environment. The signal will return to the system with certain changes if it has bounced off a moving human. Novel algorithms then analyze those changed reflections and associate them with specific individuals.
The system then traces each individual's movement around a digital floor plan. Matching these movement patterns with other data can provide insights about how people interact with each other and the environment.
In a paper being presented at the Conference on Human Factors in Computing Systems this week, the researchers describe the system and its real-world use in six locations: two assisted living facilities, three apartments inhabited by couples, and one townhouse with four residents. The case studies demonstrated the system's ability to distinguish individuals based solely on wireless signals — and revealed some useful behavioral patterns.
In one assisted living facility, with permission from the patient's family and caregivers, the researchers monitored a patient with dementia who would often become agitated for unknown reasons. Over a month, they measured the patient's increased pacing between areas of their unit — a known sign of agitation. By matching increased pacing with the visitor log, they determined the patient was agitated more during the days following family visits. This shows Marko can provide a new, passive way to track functional health profiles of patients at home, the researchers say.
"These are interesting bits we discovered through data," says first author Chen-Yu Hsu, a PhD student in the Computer Science and Artificial Intelligence Laboratory (CSAIL). "We live in a sea of wireless signals, and the way we move and walk around changes these reflections. We developed the system that listens to those reflections … to better understand people's behavior and health."
The research is led by Dina Katabi, the Andrew and Erna Viterbi Professor of Electrical Engineering and Computer Science and director of the MIT Center for Wireless Networks and Mobile Computing (Wireless@MIT). Joining Katabi and Hsu on the paper are CSAIL graduate students Mingmin Zhao and Guang-He Lee and alumnus Rumen Hristov SM '16.
Predicting "tracklets" and identities
When deployed in a home, Marko shoots out an RF signal. When the signal rebounds, it creates a type of heat map cut into vertical and horizontal "frames," which indicates where people are in a three-dimensional space. People appear as bright blobs on the map. Vertical frames capture the person's height and build, while horizontal frames determine their general location. As individuals walk, the system analyzes the RF frames — about 30 per second — to generate short trajectories, called tracklets.
A convolutional neural network — a machine-learning model commonly used for image processing — uses those tracklets to separate reflections by certain individuals. For each individual it senses, the system creates two "filtering masks," which are small circles around the individual. These masks basically filter out all signals outside the circle, which locks in the individual's trajectory and height as they move. Combining all this information — height, build, and movement — the network associates specific RF reflections with specific individuals.
But to tag identities to those anonymous blobs, the system must first be "trained." For a few days, individuals wear low-powered accelerometer sensors, which can be used to label the reflected radio signals with their respective identities. When deployed in training, Marko first generates users' tracklets, as it does in practice. Then, an algorithm correlates certain acceleration features with motion features. When users walk, for instance, the acceleration oscillates with steps, but becomes a flat line when they stop. The algorithm finds the best match between the acceleration data and tracklet, and labels that tracklet with the user's identity. In doing so, Marko learns which reflected signals correlate to specific identities.
The sensors never have to be charged, and, after training, the individuals don't need to wear them again. In home deployments, Marko was able to tag the identities of individuals in new homes with between 85 and 95 percent accuracy.
Striking a good (data-collection) balance
The researchers hope health care facilities will use Marko to passively monitor, say, how patients interact with family and caregivers, and whether patients receive medications on time. In an assisted living facility, for instance, the researchers noted specific times a nurse would walk to a medicine cabinet in a patient's room and then to the patient's bed. That indicated that the nurse had, at those specific times, administered the patient's medication.
The system may also replace questionnaires and diaries currently used by psychologists or behavioral scientists to capture data on their study subjects' family dynamics, daily schedules, or sleeping patterns, among other behaviors. Those traditional recording methods can be inaccurate, contain bias, and aren't well-suited for long-term studies, where people may have to recall what they did days or weeks ago. Some researchers have started equipping people with wearable sensors to monitor movement and biometrics. But elderly patients, especially, often forget to wear or charge them. "The motivation here is to design better tools for researchers," Hsu says.
Why not just install cameras? For starters, this would require someone watching and manually recording all necessary information. Marko, on the other hand, automatically tags behavioral patterns — such as motion, sleep, and interaction — to specific areas, days, and times.
Also, video is just more invasive, Hsu adds: "Most people aren't that comfortable with being filmed all the time, especially in their own home. Using radio signals to do all this work strikes a good balance between getting some level of helpful information, but not making people feel uncomfortable."
Katabi and her students also plan to combine Marko with their prior work on inferring breathing and heart rate from the surrounding radio signals. Marko will then be used to associate those biometrics with the corresponding individuals. It could also track people's walking speeds, which is a good indicator of functional health in elderly patients.
"The potential here is immense," says Cecilia Mascolo, a professor of mobile systems in the Department of Computer Science and Technology at Cambridge University. "With respect to imaging through cameras, it offers a less data-rich and more targeted model of collecting information, which is very welcome from the user privacy perspective. The data collected, however, is still very rich, and the paper evaluation shows accuracy which can enable a number of very useful applications, for example in elderly care, medical adherence monitoring, or even hospital care."
"Yet, as a community, we need to aware of the privacy risks that this type of technology bring," Mascolo adds. Certain computation techniques, she says, should be considered to ensure the data remains private.
- Privacy is a human right, we need a GDPR for the world - Microsoft ... ›
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- What do your kitchen appliances know about your health? - Big Think ›
The father of all giant sea bugs was recently discovered off the coast of Java.
- A new species of isopod with a resemblance to a certain Sith lord was just discovered.
- It is the first known giant isopod from the Indian Ocean.
- The finding extends the list of giant isopods even further.
Humanity knows surprisingly little about the ocean depths. An often-repeated bit of evidence for this is the fact that humanity has done a better job mapping the surface of Mars than the bottom of the sea. The creatures we find lurking in the watery abyss often surprise even the most dedicated researchers with their unique features and bizarre behavior.
A recent expedition off the coast of Java discovered a new isopod species remarkable for its size and resemblance to Darth Vader.
The ocean depths are home to many creatures that some consider to be unnatural.
According to LiveScience, the Bathynomus genus is sometimes referred to as "Darth Vader of the Seas" because the crustaceans are shaped like the character's menacing helmet. Deemed Bathynomus raksasa ("raksasa" meaning "giant" in Indonesian), this cockroach-like creature can grow to over 30 cm (12 inches). It is one of several known species of giant ocean-going isopod. Like the other members of its order, it has compound eyes, seven body segments, two pairs of antennae, and four sets of jaws.
The incredible size of this species is likely a result of deep-sea gigantism. This is the tendency for creatures that inhabit deeper parts of the ocean to be much larger than closely related species that live in shallower waters. B. raksasa appears to make its home between 950 and 1,260 meters (3,117 and 4,134 ft) below sea level.
Perhaps fittingly for a creature so creepy looking, that is the lower sections of what is commonly called The Twilight Zone, named for the lack of light available at such depths.
It isn't the only giant isopod, far from it. Other species of ocean-going isopod can get up to 50 cm long (20 inches) and also look like they came out of a nightmare. These are the unusual ones, though. Most of the time, isopods stay at much more reasonable sizes.
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During an expedition, there are some animals which you find unexpectedly, while there are others that you hope to find. One of the animal that we hoped to find was a deep sea cockroach affectionately known as Darth Vader Isopod. The staff on our expedition team could not contain their excitement when they finally saw one, holding it triumphantly in the air! #SJADES2018
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What benefit does this find have for science? And is it as evil as it looks?
The discovery of a new species is always a cause for celebration in zoology. That this is the discovery of an animal that inhabits the deeps of the sea, one of the least explored areas humans can get to, is the icing on the cake.
Helen Wong of the National University of Singapore, who co-authored the species' description, explained the importance of the discovery:
"The identification of this new species is an indication of just how little we know about the oceans. There is certainly more for us to explore in terms of biodiversity in the deep sea of our region."
The animal's visual similarity to Darth Vader is a result of its compound eyes and the curious shape of its head. However, given the location of its discovery, the bottom of the remote seas, it may be associated with all manner of horrifically evil Elder Things and Great Old Ones.
The first nation to make bitcoin legal tender will use geothermal energy to mine it.
This article was originally published on our sister site, Freethink.
In June 2021, El Salvador became the first nation in the world to make bitcoin legal tender. Soon after, President Nayib Bukele instructed a state-owned power company to provide bitcoin mining facilities with cheap, clean energy — harnessed from the country's volcanoes.
The challenge: Bitcoin is a cryptocurrency, a digital form of money and a payment system. Crypto has several advantages over physical dollars and cents — it's incredibly difficult to counterfeit, and transactions are more secure — but it also has a major downside.
Crypto transactions are recorded and new coins are added into circulation through a process called mining.
Crypto mining involves computers solving incredibly difficult mathematical puzzles. It is also incredibly energy-intensive — Cambridge University researchers estimate that bitcoin mining alone consumes more electricity every year than Argentina.
Most of that electricity is generated by carbon-emitting fossil fuels. As it stands, bitcoin mining produces an estimated 36.95 megatons of CO2 annually.
A world first: On June 9, El Salvador became the first nation to make bitcoin legal tender, meaning businesses have to accept it as payment and citizens can use it to pay taxes.
Less than a day later, Bukele tweeted that he'd instructed a state-owned geothermal electric company to put together a plan to provide bitcoin mining facilities with "very cheap, 100% clean, 100% renewable, 0 emissions energy."
Geothermal electricity is produced by capturing heat from the Earth itself. In El Salvador, that heat comes from volcanoes, and an estimated two-thirds of their energy potential is currently untapped.
Why it matters: El Salvador's decision to make bitcoin legal tender could be a win for both the crypto and the nation itself.
"(W)hat it does for bitcoin is further legitimizes its status as a potential reserve asset for sovereign and super sovereign entities," Greg King, CEO of crypto asset management firm Osprey Funds, told CBS News of the legislation.
Meanwhile, El Salvador is one of the poorest nations in North America, and bitcoin miners — the people who own and operate the computers doing the mining — receive bitcoins as a reward for their efforts.
"This is going to evolve fast!"
If El Salvador begins operating bitcoin mining facilities powered by clean, cheap geothermal energy, it could become a global hub for mining — and receive a much-needed economic boost in the process.
The next steps: It remains to be seen whether Salvadorans will fully embrace bitcoin — which is notoriously volatile — or continue business-as-usual with the nation's other legal tender, the U.S. dollar.
Only time will tell if Bukele's plan for volcano-powered bitcoin mining facilities comes to fruition, too — but based on the speed of things so far, we won't have to wait long to find out.
Less than three hours after tweeting about the idea, Bukele followed up with another tweet claiming that the nation's geothermal energy company had already dug a new well and was designing a "mining hub" around it.
"This is going to evolve fast!" the president promised.
How were mRNA vaccines developed? Pfizer's Dr Bill Gruber explains the science behind this record-breaking achievement and how it was developed without compromising safety.
- Wondering how Pfizer and partner BioNTech developed a COVID-19 vaccine in record time without compromising safety? Dr Bill Gruber, SVP of Pfizer Vaccine Clinical Research and Development, explains the process from start to finish.
- "I told my team, at first we were inspired by hope and now we're inspired by reality," Dr Gruber said. "If you bring critical science together, talented team members together, government, academia, industry, public health officials—you can achieve what was previously the unachievable."
- The Pfizer-BioNTech COVID-19 Vaccine has not been approved or licensed by the Food and Drug Administration (FDA), but has been authorized for emergency use by FDA under an Emergency Use Authorization (EUA) to prevent COVID-19 for use in individuals 12 years of age and older. The emergency use of this product is only authorized for the duration of the emergency declaration unless ended sooner. See Fact Sheet: cvdvaccine-us.com/recipients.