Keeping tabs on your body is always good advice, regardless if you're floating aboard the international space station or simply recovering from a medical procedure with feet planted firmly on the earth. For most people, that usually means routine checkups at the doctor's office, but astronauts don't have such luxury in Earth orbit.
However, researchers at NASA and Stanford University are developing a LifeGuard system to keep astronauts informed of their physiology while drifting in zero gravity. The system is a collection of biosensors that feeds health and physiology data to a compact wearable device designed to record an astronaut's vital signs, much like an airplane's black box records flight information. Since the getup is easy to wear, it doesn't lock astronauts down to banks of diagnostic machinery and wall plugs of other, bulkier monitoring systems.
Currently, space station astronauts wear physiological monitoring equipment during exercise sessions, a concoction of wires and sensor pads to records their vital signs while running on the treadmill. Some health monitoring is also conducted during spacewalks through the astronaut spacesuits.
"There are tons of applications for medical use, home use, athletic training and uses in many other areas," Greg Kovacs, a Stanford University professor and one of the LifeGuard project leaders, said in an e-mail interview. "There is, if anything, too much interest."
The interest stems from the fact that, while developed to monitor astronauts, LifeGuard can be worn by anybody.
The medical community has expressed interest in using it to monitor patients with new pacemakers, while high-performance athletes hope to track their body's performance in training, project researchers said. During an emergency, paramedics could learn the physiological state of someone wearing LifeGuard just by checking their data, they added.
New center launched
Stanford researchers worked with NASA's Ames Research Center in Moffett Field, Calif., to develop LifeGuard. The two institutions recently launched the National Center for Space Biological Technologies, a collaborative center to enhance medical monitoring and biological experimentation for future space exploration efforts.
"This is really designed to do just a few things very well," said Carsten Mundt, a project engineer at NASA Ames and the center's chief engineer.
The system can monitor skin temperature, heart rate, respiration and blood pressure, as well as an astronaut's position in space using three tiny accelerometers attached to a wearable central processor called a CPOD, Mundt added.
Keeping tabs with CPOD
At the heart of LifeGuard is CPOD — or Crew Physiologic Observation Device — a small computer processor that can store up to eight hours of data, about 32 megabytes, in flash memory, and download it later into a base computer. The device is small enough to strap around the waist and runs on two AAA batteries.
Kovacs, who has worn a CPOD on expeditions to Chile's Licancabur volcano, said the device unobtrusive and comfortable enough to sleep, work and climb while wearing it.
The CPOD also contains Bluetooth wireless technology, allowing real-time transmission of physiological data to the base unit, which can then relay the information to ground-based mission controllers. That streaming ability could be crucial for NASA flight surgeons keeping watch over astronauts during the most strenuous of spacewalks or the most routine station keeping tasks. They could, for example, identify a potential health concern before an astronaut is even aware he or she is in danger.
"The progression in wireless technology has made this possible," Mundt told Space.com. "In general, microchip packaging has led to chips that are extremely small so you can pack things in really tight."
In addition to Kovacs' CPOD shakedown runs during treks to Licancabur volcano, LifeGuard researchers have tested CPOD's performance in NASA's KC-135 zero-gravity training aircraft, as well on the ocean floor aboard the Aquarius laboratory in the NASA Extreme Environment Mission Operations program.
The next steps
Mundt said the next step is testing CPOD's performance in NASA's neutral buoyancy tank, where astronauts train for spacewalks and space station construction missions.
CPOD and the rest of the LifeGuard system will also have to be radiation-hardened and undergo outgassing tests, to see how its materials will behave in Earth orbit, before it can be rated for a trip into space, he added.
"There's a bunch of shake-and-bake tests we have to probably go through," Mundt said.
But a non-radiation-hardened, commercial CPOD could be ready a year after researchers decide to pursue a commercial version of the device, Kovacs said.
The portions of LifeGuard and CPOD that touch the body have all been approved by the Food and Drug Administration, he said, adding that his team will seek approval for other components once applications call for it.