“In its current state, this application is a sophisticated next-generation video gaming system, but we foresee a number of other exciting and valuable uses for this technology. We are in the early stages of exploring some of these applications,” said Hunter Smith, Waterloo Labs team member and applications engineer at National Instruments. “A key component of this hands-free, ‘eyes only’ video gaming system is Analog Devices’ high-speed ADCs. We plan to continue using ADI’s data converters to help us push design boundaries to develop new applications and products.”
How Ocular Game Control Works
The hands-free video gaming system uses Analog Devices’ AD7401 isolated ADC and a National Instruments Single-Board RIO daughter card that features a real-time processor, reconfigurable FPGA (field-programmable gate array), and analog and digital I/O on a single board programmed with NI LabVIEW software. Eye movement is measured by placing four electrodes around the player’s eyes and a final reference electrode at the base of the ear. The electrodes then measure the very small electrical signals that are generated inside the eye when a player shifts his eyes up, down, or side-to-side in correspondence with the movement of the on-screen game character. Next, a differential signal between the electrodes is amplified by Analog Devices’ AD8221 precision instrumentation amplifier and low-noise amplifier before passing through the ADI ADC and on to the daughter card for processing. For an explanation of the signal chain, see video.
“This first-of-its kind hands-free, ‘eyes only’ video gaming system is another example of how ADI’s signal processing technology continues to revolutionize conventional end-user experiences,” said Steve Hinderliter, converter marketing director, Analog Devices. “ADI’s data conversion and signal conditioning technology continues to define the user experience by regulating the quality and speed of the information from the sensor and signal source all the way to the digital world and back.”