Picture this: your medical first responder descends from the sky like a friendly, unmanned starship. Hovering over your door, it drops a device with recorded instructions to help a bystander jumpstart your heart that has stopped. This, after the 911 call but before the ambulance arrives.
This is exactly what happened on Dec. 9, 2021, when a 71-year-old man in Sweden suffered a cardiac arrest while shoveling snow. A passerby, seeing him collapse, called for an ambulance. In just over three minutes, a drone swooped overhead carrying an Automated External Defibrillator (AED). The patient was revived on the spot before the ambulance arrived to rush him to the hospital where he made a full recovery. The revolutionary technology saved his life.
In 2020, Sweden became the first country to deploy drones carrying AEDs to people in sudden cardiac arrest, when survival odds depend on getting CPR and an electric shock to the heart from a defibrillator within 5 minutes—nearly always before emergency responders arrive.
In the U.S. alone, more than 356,00 cardiac arrests occur outside of hospitals each year; 9 out of 10 of these people die. Plus, the risk of permanent brain injury increases after the first three minutes the heart stops beating. After nine minutes, damage to the brain and other organs is usually severe and irreversible.
“The fundamental technology can be applied to a lot of other emergency situations.”
Once the stuff of sci fi, the delivery of life-saving medical equipment by drone will be commonplace in the near future, experts say. The Swedish team is hailing their study as the first-ever proof of concept for using drones in emergency medicine. The drones arrived only two minutes before the ambulance in most cases but that’s significant during cardiac arrest when survival rates drop 10% every minute.
Since that 2020 pilot, the drones have been tweaked for better performance. They can travel faster and after dark today, and route planning has been optimized, says Mats Sällström, chief executive officer of Everdrone, the technical and development guru for the project, who is collaborating with researchers at the Karolinska Institutet and Sweden’s national emergency call center, SOS Alarm.
When an emergency call comes in, the operator determines if it’s a cardiac arrest. If so, the caller gets CPR instructions while an ambulance is summoned and a control center is notified automatically to dispatch a drone. If conditions allow, the drone flies to the scene via a GPS signal from the caller’s cell phone. Once dropped at the location, the AED beeps to signal its arrival. The AED talks the user through every step when it’s opened while the emergency operator offers support.
Public health officials have tried placing AEDs in public spaces like airports and shopping malls for quick access but the results have been disappointing. Poor usage rates of 2% to 3% have been attributed to bystanders not knowing where they are, not wanting to leave victims, or the site being closed when needed.
Some people fear they could harm the victim or won’t know how to use the AED but not to worry, says Wayne Rosamond, a professor of epidemiology at the University of North Carolina Gillings School of Global Public Health, who studies AED drones. “[The device] won’t shock someone unless they need to be shocked,” he says.
The AED instructions are foolproof, echoes Timothy Chan, professor of engineering at the University of Toronto, who has been building optimization models to design drone networks in Ontario, Canada. All the same, he says, community education will be essential for success. “People have more awareness about drones than AEDs,” he’s found.
Rosamond and Chan are among scientists around the world inspired by Sweden to do their own modeling, simulation and feasibility studies on drone-delivered AEDs.
“Scandinavia is way ahead of us,” notes Rosamond. “There is a tremendous amount of regulatory control over flying drones in the U.S.” In addition to Federal Aviation Administration restrictions, medical drones in the U.S. must comply with HIPAA laws surrounding confidentiality and security of patient information.
To date, Sweden has expanded drone operations and home bases around the country and throughout Europe. Since April 2021, the team has deployed 1-4 drones per week, says Sällström.
Certain weather conditions remain an obstacle. The drones cannot be dispatched safely in rain, snow and heavy wind. Close, heavily populated neighborhoods with high-rise buildings also present challenges.
“Semi-urban areas with residential low-rise [1-5 stories] buildings are the sweet spot for our operations,” Sällström says. “However, as the system matures, we will pursue operations in practically all-weather conditions and also in densely populated areas.” The team is also trying to improve drone speed and battery life to enable flights to rural and remote areas in the future.
Chan predicts that delivering AEDs via drone will be a regular occurrence in five years. In addition, he says, “The fundamental technology can be applied to a lot of other emergency situations.”
Drones could carry medications for anaphylactic shock and opioid overdose, or bring tourniquets and bandages to trauma victims, Chan suggests. Other researchers are looking at the delivery of glucose for low blood sugar emergencies and the transport of organs for transplant.
The sky is no longer the limit.
Brittany Trang was staring at her glass test tube, which suddenly turned opaque white. At first, she had thought that the chemical reaction she tested left behind some residue, but when she couldn’t clean it off, she realized that the reaction produced corrosive compounds that ate at the glass. That, however, was a good sign. It meant that the reaction, which she didn’t necessarily expect to work, was in fact, working. And Trang, who in 2020 was a Ph.D. researcher in chemistry at Northwestern University, had reasons to be skeptical. She was trying to break down the nearly indestructible molecules of per- and polyfluoroalkyl substances or PFAS—the forever chemicals called so because they resist heat, oil, stains, grease, and water, and thus don’t react or break down in the environment.
“The first time I ran this, I was like, oh, like there's a bunch of stuff stuck to the glass, but when I tried to clean it, it wasn’t coming off,” Trang says, recalling her original experiment and her almost-disbelief at the fact she managed to crack the notoriously stubborn and problematic molecules. “I was mostly just surprised that it worked in general.”
In the recent past, the world has been growing increasingly concerned about PFAS, the pollutants that even at low levels are associated with a litany of adverse health effects, including liver damage, thyroid disease, high cholesterol, pregnancy complications and several cancers. Used for decades in manufacturing and in various products such as fire retardant foam, water-repellant clothes, furniture fabrics, Teflon-coated pans, disposable plates, lunch containers and shoes, these super-stable compounds don’t degrade in the environment. The forever chemicals are now everywhere: in the water, in soil, in milk, and in produce.
As of June 2022, the Environmental Working Group, a nonprofit watchdog organization, found 2,858 locations in 50 states and two territories to be heavily contaminated with PFAS while many farmers had been forced to dump their milk or spinach because the levels of these compounds were in some cases up to 400 times greater than what’s considered safe. And because PFAS are so pervasive in the environment and the food we eat, they are in our bodies too. One study found some levels of PFAS in 97 to 100 percent of participants tested.
Because these compounds were made to be very stable, they are hard to destroy. So far, the only known way to break down PFAS has been to “cook” them under very harsh conditions. The process, known as pyrolysis, requires upwards of 500 degrees Centigrade, high pressure and absence of oxygen, which is energy expensive. It involves sophisticated equipment and the burning of fossil fuels. Trang, who worked in the laboratory of William Dichtel, managed to break PFAS at 120 degrees Centigrade (248 F) without using strong pressure. After she examined the results of her process with various techniques that help quantify the resulting compounds and confirmed that PFAS had indeed degraded into carbon and the corrosive fluorine that clouded her glass, she was thrilled that it worked in such simple conditions.
“That's really what differentiates our finding from everything else that's out there,” Dichtel said about their discovery at a press conference announcing the study last month. “When we're talking about low temperatures, we're at 120 degrees Celsius and sometimes even quite a bit lower than that, and especially ambient pressure.”
The process used by Trang’s team was the exact opposite of the typical organic synthesis method.
Trang’s journey into PFAS degradation began with a paper she read about the nuances of the chemicals’ molecular structure. A long molecule comprised primarily of carbon and fluorine atoms, along with oxygen and hydrogen, it has what Trang describes as a head and a tail. At the head sits a compound called carboxylic acid while the fluorine atoms make up the tail portion, with the atomic bonds so strong they aren’t possible to break without harsh treatment. But in early 2020, Trang read that a solvent called dimethylsulfoxide, or DMSO, commonly used in labs and industry, can make the carboxylic acid “pop off” its place. The DMSO doesn’t react with carboxylic acid but sort of displaces it, leaving the rest of the typically indestructible PFAS molecule vulnerable.
Trang found that its exposed fluorine tail would react with another common chemical compound, sodium hydroxide, causing a cascade of reactions that ultimately unravel the rest. “After you have decarboxylated the head, the hydroxide is able to react with the tail,” Trang says. “That's what sets off a cascade of reactions that degrades the rest of the molecule.”
That pathway took time to figure out. Trang was able to determine that the molecule carboxylic acid head popped off, but before she was able to figure out the rest, her lab and the entire Northwestern University went into lockdown in early March of 2020. “I was able to do three experiments before the shutdown,” she recalls. For the next few months, she sat at home, reading scientific literature to understand how to continue the degradation process. “I had read a bunch of literature and had a bunch of ideas for what may or may not work,” she says. By the time she could return to work, she had a plan. “I added sodium hydroxide in my batch of experiments when the lab reopened.”
The process used by Trang’s team was the exact opposite of the typical organic synthesis method. “Most organic chemists take two molecules and squish them together to make one big molecule. It’s like taking two Legos and putting them together to make one thing that was larger,” she says. “What we are doing is kind of smashing the Lego with two bits and looking at what was left to figure out how it fell apart.” The team published their discovery in the journal Science.
Although very promising, the process isn’t quite ready for industrial applications, and will take time to adapt, Trang says. For starters, it would have to be scaled up to continuously clean large quantities of water, sewage or other substances that can be contaminated with PFAS. The process will also have to be modified, particularly when it comes to removing PFAS from drinking water because as an industrial chemical, DMSO is not suitable for that. Water companies typically use activated carbon to filter out PFAS and other pollutants, so once that concentrated waste is accumulated, it would be removed and then treated with DMSO and hydroxide to break down the molecules. “That is what our method would likely be applied to,” Trang says—the concentrated waste rather than a reservoir because “you wouldn't want to mix DMSO with your drinking water.”
There are some additional limitations to the method. It only breaks down one class of forever chemicals, but there are others. For example, the molecules of perfluoroalkane sulfonic acids, or PFSA, don’t have a carboxylic head that DMSO can displace. Instead, PFSA have a sulphonic acid as their molecular head, which would require a different solvent that still needs to be discovered. “There is certainly the possibility of activating sulphonates in similar ways [to what] we've done [with] carboxylates,” Dichtel said, and he hopes this will happen in the future. Other forever chemical types may have their own Achilles’ heels, waiting to be discovered. “If we can knock that sulphonated headgroup off the molecule and get to the same intermediates we get to in this study,” Dichtel added, “it's very reasonable to assume that they'll degrade by very similar pathways.” Perhaps another team of inquisitive chemists will take on the challenge.
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
Here are the promising studies covered in this week's Friday Five:
- A new mask can detect Covid and send an alert to your phone
- More promising research for a breakthrough drug to treat schizophrenia
- AI tool can create new proteins
- Connections between an unhealthy gut and breast cancer
- Progress on the longevity drug, rapamycin
And an honorable mention this week: Certain exercises may benefit some types of memory more than others