Li-Fi Scrubs Into the Operating Room

The visible light communication scheme could offer hospitals a potentially faster, more reliable option than Wi-Fi

3 min read
Neuro surgery operation room at FN Motol University Hospital, Prague used for the LiFi channel measurements
Researchers used this neurosurgery operation room at Motol University Hospital in Prague to make channel measurements for Li-Fi. Six Li-Fi receivers are positioned along the sides of the operating table.
Photo: Fraunhofer Heinrich-Hertz Institute

Li-Fi, which is short for “light fidelity,” is a wireless technology that uses optical light to transmit information (as opposed to Wi-Fi, which also transmits light, but at much lower radio frequencies.) Proponents claim that Li-Fi could deliver more reliable data transmission at faster rates than Wi-Fi.

Since Harald Haas, a professor at the University of Edinburgh, popularized the term Li-Fi in 2011, companies including the former Philips Lighting—now Signify—and Haas’s own pureLiFi have tried to commercialize the technology. It’s been tested in offices, schools, and even airplanes, but has so far struggled to gain widespread adoption. 

Now, Li-Fi has completed its first tests in a hospital—a place where its reliability and speed may prove particularly valuable. A team of researchers from the Fraunhofer Heinrich-Hertz Institute (HHI) in Berlin and the Czech Technical University (CTU) in Prague published results from a demonstration, which they announced at the recent Optical Networking and Communication Conference in San Diego. Their new study lays the groundwork for possibly someday using Li-Fi in a medical setting.

The researchers set up multiple Li-Fi transmitters and receivers in a neurosurgery operating room at Motol University Hospital in Prague. In a series of tests, the Li-Fi system managed to transfer data quickly and without complete signal loss. They achieved data rates of up to 600 megabits per second—better than most Wi-Fi connections and cellular networks.

Prior to this work, “there was no experimental study happening in a medical scenario for Li-Fi,” says Sreelal Maravanchery Mana, a lead author and researcher at HHI. “This is the first time we are doing realistic measurements [in a medical environment].”

In a basic Li-Fi setup, data is sent to a transmitter—an LED—which converts it into light that pulses far too fast for the human eye to see. A receiver detects the pattern of light pulses from the LED and converts that pulse pattern back into data. Because Li-Fi uses higher-frequency light than Wi-Fi does, it could, in theory,  have a higher bandwidth and therefore transmit data more quickly.

Wi-Fi has been critical to managing the number of smart devices that now populate hospitals and operating rooms. Any technology that limits wires, which can pose a safety hazard in hospitals, is welcomed. But devices that use Wi-Fi can interfere with one another, causing connection loss. “Wireless devices which are transferring medical data must be highly reliable,” says Heikki Karvonen, a researcher at the University of Oulu in Finland, who was not involved with the study. It’s important, Karvonen says, that the devices “coexist” with one another.

Not everyone is convinced that this crowding is a major problem for hospitals: one study simply recommends that smartphones running on Wi-Fi networks be kept an arm's length away from medical devices using Wi-Fi to prevent interference.

And Li-Fi isn’t perfect. While it doesn’t face interference from other medical devices, it can still be interrupted. Unlike Wi-Fi’s radio frequencies, which can pass through walls, optical light is easily blocked by humans or objects. To get around this issue, the HHI researchers used four transmitters and six receivers around the operating room, for a total of 24 channels between transmitters and receivers.

“Even if 23 of those channels are blocked, you still have one and you can have a very robust communication,” says Dominic Schulz, a researcher at HHI. During an operation, it’s possible doctors or nurses could block some of the links between transmitters and receivers by walking between them. The team plans to continue testing different Li-Fi setups in hospitals, and eventually use the technology to transmit data to medical devices being used during an actual surgery.

Currently, the U.S. Food and Drug Administration (FDA) has no official position on Li-Fi. “When planning to use Li-Fi—or any other wireless technology—in medical devices, care should be taken to match the device wireless functions with the wireless technology’s capabilities and expected performance,” says Mohamad Omar Al Kalaa, an electrical engineer at the FDA.

Whether Li-Fi’s LED transmitters and receivers become a fixture in hospitals remains, quite literally, to be seen.

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The Cellular Industry’s Clash Over the Movement to Remake Networks

The wireless industry is divided on Open RAN’s goal to make network components interoperable

13 min read
Photo: George Frey/AFP/Getty Images

We've all been told that 5G wireless is going to deliver amazing capabilities and services. But it won't come cheap. When all is said and done, 5G will cost almost US $1 trillion to deploy over the next half decade. That enormous expense will be borne mostly by network operators, companies like AT&T, China Mobile, Deutsche Telekom, Vodafone, and dozens more around the world that provide cellular service to their customers. Facing such an immense cost, these operators asked a very reasonable question: How can we make this cheaper and more flexible?

Their answer: Make it possible to mix and match network components from different companies, with the goal of fostering more competition and driving down prices. At the same time, they sparked a schism within the industry over how wireless networks should be built. Their opponents—and sometimes begrudging partners—are the handful of telecom-equipment vendors capable of providing the hardware the network operators have been buying and deploying for years.

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