Optical Wireless Link Enables Cable-Free 4K Endoscopic Imaging

Cabled endoscopes can hamper workflow in minimally invasive surgery and complicate infection control in the operating room. Power, lighting, and data lines drape across patients and floors, creating hygiene risks and ergonomic obstacles. Conventional wireless radio links often fall short on reliability, security, and latency for clinical use. To help address these challenges, researchers have developed a light-based wireless link that enables an endoscope to stream 4K images during laparoscopy.

The prototype was developed within the OWIMED (Optical Wireless Communication for Medical Imaging Devices) project by the Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institut (HHI), in collaboration with IT Concepts GmbH and St. Joseph Krankenhaus in Berlin-Tempelhof. The approach replaces radio with optical wireless transmission using light (LiFi). Eliminating data and power cords supports cleaner setups and more efficient instrument handling in the operating room (OR). The system targets short-range, high-throughput image transfer while meeting medical technology demands.

The wireless endoscope integrates its own LED light source and a battery-powered LiFi module. Additional compact LiFi modules are mounted on the surgical light to receive the optical signal and relay it to the monitor, where images from the abdominal cavity are displayed in 4K quality. This configuration removes external lighting and data cables while preserving a clear line of sight between the endoscope and receivers.

A modulator switches the endoscope’s LED on and off faster than the eye can perceive, and a photodiode converts the resulting light pulses into electrical signals. The optical link is bidirectional, allowing camera settings to be adjusted from the monitor. LiFi modules provide homogeneous hemispherical propagation across a 180-degree radius to maintain a robust, high-speed connection.

An integrated camera chip and on-board microprocessor compress data with low latency and reduced power consumption. The surgical team at St. Joseph Krankenhaus provided continuous input during development and evaluated the prototype and LiFi infrastructure in an OR using a surgical simulator with a medical phantom. Testing indicated strong performance for latency, reliability, data rates, light quality, and ergonomics, and the team reported favorable usability compared with cabled systems.

“Instead of radio waves, we use modulated LED light for wireless communication. Due to the locally limited propagation of light, wireless transmission with light (LiFi) is ideal for medical technology. We can already meet the requirements for high data rates over short distances,” said Anagnostis Paraskevopoulos, a research scientist at the Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institut (HHI), who leads the project.

“We were able to demonstrate with the tests that our LiFi solution functions very well with regard to latency, i.e., data lag, as well as reliability, data rates, light quality and ergonomics. The feedback from the surgical team was entirely positive. Once our system is fully developed, the doctors would prefer it over the cabled variant,” added Paraskevopoulos.

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Fraunhofer Institute for Telecommunications, HHI