Last year, a rogue drone buzzed a crowd at an Albuquerque outdoor festival, injuring a bystander, according to a recent report in The Washington Post. Drones have smuggled drugs into an Ohio prison, impeded firefighting efforts, and nearly collided with three airliners over New York City.

The explosive increase in the number of hobby-sized drones, along with their frequent involvement in dangerous situations, has given rise to creative and sophisticated anti-drone technologies. Airbus Defense and Space has developed a counterdrone system using radars and infrared cameras to track and disable threatening drones. Battelle’s shoulder-mounted DroneDefender system uses radio beams to interfere with the drone’s controls. And a team from Michigan Technological University recently demonstrated a large, six-rotor, defensive drone that shoots a big net at an intruder drone from a distance of up to 40 feet.

Now Dutch police are trying a new approach to hunting rogue drones, using a centuries-old weapon: trained eagles.

“It’s a low-tech solution to a high-tech problem,” police spokesman Dennis Janus told the AFP news service during a public demonstration last month of the birds’ newly developed skills. “The eagles see the drones as prey and intercept them as they are flying, before landing where they feel safe with the drone still in their claws.”

In a video demonstration of the eagle versus drone contest, police showed how they trained a female bald eagle named Hunter not just to grab the drone out of the air, but to take it to “a place designated by the police.”

The Dutch police force will deploy the eagles to hunt drones that may be posing a danger to the public, such as during state visits or when they are flying too close to airports. Like other anti-drone technologies, the eagles help eliminate the public safety risk involved in using firepower to shoot drones out of the sky.

A raptor training company, Guard From Above, partnered with police last year to study whether eagles could be effective in a counterdrone role, according to IEEE Spectrum. As a result of the successful tests, the Dutch police have purchased four 5-month-old bald eagle chicks. They will train about 100 officers to work with the eagles before deploying them next summer to several police units across the Netherlands.

Large drones might pose some danger to the eagles, so the police are developing a special talon protector made of Kevlar, IEEE Spectrum reported. But typical hobby-sized drones didn’t seem to pose a big problem.

“None of the eagles were hurt,” said Janus, “but as for the drones, none of them survived.”

Flash diagnosis

Scientists have turned the ubiquitous smartphone into an instant medical device—one that helps doctors diagnose anemia without drawing blood.

Researchers at the University of Washington created HemaApp, which uses a smartphone’s built-in camera and flash to assess hemoglobin levels in red blood cells, a basic diagnostic test for anemia. The flash shines light through the patient’s fingertip, the camera records the color of the blood, and the app analyzes the color to estimate hemoglobin concentrations.

In tests, HemaApp performed as well as an expensive, FDA-approved device that measures hemoglobin levels by clipping onto the patient’s finger.

Doug Hawkins, a pediatrics professor at the UW School of Medicine, said HemaApp could improve doctors’ ability to screen patients in places with few medical resources: “Anemia is one of the most common problems affecting adults and children worldwide.” —M.C.

Watching your step

Our risk of taking a tumble increases as we age, and the consequences of even a minor fall can be serious, and in many cases life-threatening.

University of Missouri researchers studying the relationship between an elderly person’s stride and the risk of falling have developed an in-home monitoring system that could alert caregivers to the likelihood of an imminent fall. The camera-based system monitors both gait speed and stride length, sending email alerts and a picture when it detects a decrease in either.

Using data collected from a Columbia, Mo., retirement residence, the researchers from the MU Sinclair School of Nursing and the College of Engineering found that when an elderly person’s gait declined by about 2 inches per second, the probability of a fall in the next three weeks was 86 percent. Similarly, a shortened stride length was associated with a 51 percent probability of a fall within three weeks.

“For many older adults the risk of falling impacts how long seniors can remain independent,” said Marilyn Rantz, an MU professor emerita of nursing. “Being able to predict that a person is at risk of falling will allow caretakers to intervene with the necessary care to help seniors remain independent as long as possible.” —M.C.