Astronauts don't currently have their vitals measured around the clock, and are typically only wired up for experiments such as this one, which was designed to measure changes in Circadian Rhythms. Image: NASA Johnson/Flickr
For such a complicated piece of technology, floating high above the Earth, the International Space Station takes a decidedly low-tech approach to measuring the health of its inhabitants.
"The astronauts have weekly tagups with flight surgeons and medical personnel, and do numerous assessments throughout their time on orbit as [the medical monitoring experiment] page indicates, but they are not wired up around the clock," NASA's space station spokesperson Daniel Huot wrote when I asked over email.
The reason for my out-of-the-blue inquiry: A Canadian company called Carre Technologies—perhaps better known as Hexoskin, also the name for its line of smart, sensor-laden exercise shirts—was recently awarded a contract by the Canadian Space Agency (CSA) for the development of an "On-Astronaut Wireless Sensor System," or OAWSS.
The system, which will consist of five different wireless sensors that stick to a wearer's skin, is intended to measure an astronaut's various vitals, practically around the clock, and then make that data available to researchers in real-time.
CSA, which has funded various health related projects in recent years, wants "to learn more about physiology in space during long term missions, so we can send people to other planets, and other bodies in the solar system, so beyond the moon," Hexoskin co-founder and CEO Pierre-Alexandre Fournier said in phone interview. "The next goal would be going to Mars, so what we're doing with them. When we're building these monitoring systems and medical systems, we're preparing for a mission to Mars."
Hexoskin has two years to make an engineering prototype of the OAWSS a reality.
According to Fournier, the system is composed of two parts: five sensors, and complementary software to collect and organize the data each sensor collects (EKG, body temperature, and body movement are mandatory, while the remaining two sensors could measure respiratory rate, respiratory volume, oxygen saturation, blood pressure, EEG, or stress using a microphone and voice stress analysis).
"I can't reveal too much, but we do have prototypes, and we did have prototypes when we bid for the contract"
The sensors are actually more like stickers than your typically wearable—no more than 5mm in height, according to the space agency's March 2015 request for proposals—and will be required to stick to the skin for at least two weeks using a "biocompatible adhesive." Fournier said Hexoskin is partnering with companies that have prior experience producing such adhesives, while Hexoskin focuses on hardware and software.
"There's the adhesive and there's the actual sensor that has to be part of that sticker. So, for example, you need an electrode or temperature sensor and you need to design it in a way that's still flexible and comfortable and thin, and then at the same time, you need to get very accurate results from that design. So there's a lot of design challenges," Fournier said.
"I can't reveal too much, but we do have prototypes, and we did have prototypes when we bid for the contract." Fournier added that, while they've already performed tests of their prototypes worn on the skin, nothing can be demoed publicly at this point.
The OAWSS complements a previous system Hexoskin developed for the Canadian space agency in 2012, called AstroSkin (in fact, AstroSkin was later commercialized as the HexoSkin product, and an updated version was just announced at this year's Consumer Electronics Show). Both AstroSkin and HexoSkin rely on sensors embedded in a form-fitting shirt, which are in turn wired to a central device.
"The shirts in most situations are more comfortable or more intuitive to use, but in some situations, it's better to just put stickers on people," Fournier said. "In an emergency situation for example, you don't want to put the shirt on somebody that gets to the ER. It's a lot easier to put a sticker on them."
But the wireless approach has its share of challenges, too. For example, "for each hour of operation, [sensors] shall transmit data at least 90 percent of the time," the RFP reads, and will also need to collect and transmit data continuously for at least two weeks without removal or being plugged in.
That's a long time, even at low power, for a device mere millimeters in size to operate—but it won't be the battery technology that Hexoskin improves upon on. "Pretty much everybody works with the same battery technology," explained Fournier, "and you need things that have been tested if you want to build a system that's been sent to space."
Rather, optimization will come from the software and design of the electrical circuitry, which are being configured to use as little power as possible.
"We've done calculations before we bid on the contract, because in the end we have to deliver,” Fournier said. “We have to know that we can deliver. We have to know that it is at least physically possible to deliver this system. So we've done our homework regarding that. But it's still very challenging.”