Delivering blood samples to the lab by drone could be an option for doctors and nurses in developing countries.
A proof-of-concept study shows that the most common, routine blood tests aren’t distorted even after vials of delicate samples travel nearly 40 minutes on hobby-sized unpiloted aircraft.
That means that drones can potentially move patients’ blood and other samples scores of miles across impoverished rural areas without modern road networks. Without air transport, those samples can’t be shipped quickly to dedicated labs that conduct tests needed for diagnosis and treatment.
“Biological samples can be very sensitive and fragile,” says Timothy Kien Amukele, a pathologist at the Johns Hopkins University School of Medicine and director of a laboratory collaboration with Uganda’s Makerere University. The concerns with drones, he says, include sudden acceleration on takeoff and jostling when a vehicle lands on its belly.
“Such movements could have destroyed blood cells or prompted blood to coagulate and I thought all kinds of blood tests might be affected,” Amukele says, “but our study shows they weren’t, so that was cool.”
Packed for flight
The study has been published by the online journal PLOS ONE. Amukele’s team collected six blood samples from each of 56 healthy adult volunteers at the Johns Hopkins Hospital. The samples were then driven to a flight site an hour’s drive from the hospital on days when the temperature was in the 70s Fahrenheit. There, half of the samples were packaged to prevent leaks and protect vials from the in-flight environment.
Those samples were then loaded into a hand-launched fixed-wing drone and flown for periods of six to 38 minutes. To comply with Federal Aviation Administration rules, the flights were conducted in an unpopulated area, stayed below 100 meters and remained in the line of sight of the certified pilot.
The samples were driven back to a Johns Hopkins Hospital lab, where they underwent 33 common laboratory tests that together account for around 80 percent of all such analyses. Included were tests for sodium, glucose, and red blood cell count.
Comparing lab results of the flown vs. non-flown blood of each volunteer, Amukele says, in all but one case, “the flight really had no impact.”
The exception—a test for total carbon dioxide (the so-called bicarbonate test)—did yield differing results for some of the flown and non-flown samples. Amukele says the team isn’t sure why, but the reason could be that up to eight hours elapsed before the tests. There were no consistent differences between flown vs. non-flown blood, Amukele says, and it’s unknown whether the out-of-range results were due to the time lag or because of the drone transport.
“The ideal way to test that would be to fly the blood around immediately after drawing it, but neither the FAA nor Johns Hopkins would like drones flying around the hospital,” he says with a smile.
The likely next step is a pilot study in a location in Africa, where health care clinics are sometimes 60 or more miles away from labs.
“A drone could go 100 kilometers in 40 minutes,” Amukele says. “They’re less expensive than motorcycles, are not subject to traffic delays, and the technology already exists for the drone to be programmed to ‘home’ to certain GPS coordinates, like a carrier pigeon.”
Other contributors to the research are from Johns Hopkins, the University of Michigan, Dana Howard Engineering, and Jeff Street Engineering. Startup funds from Johns Hopkins University School of Medicine supported the work.
Source: Johns Hopkins University