Related Experiment Video
Updated: Aug 11, 2025

A Single-Channel and Non-Invasive Wearable Brain-Computer Interface for Industry and Healthcare
Published on: July 7, 2023
Evaluating a Novel, Portable, Self-Administrable Device ("Beacon") That Measures Critical Flicker Frequency as a Test
Philip Vutien1,2, Richard Li3, Ravi Karkar3,4
1University of Washington, Division of Gastroenterology and Hepatology, Seattle, Washington, USA.
Introduction:
We compared critical flicker frequency (CFF) thresholds obtained using a novel portable device "Beacon" with thresholds from the commercially available Lafayette Flicker Fusion System (Lafayette-FFS) in patients with cirrhosis.
Methods:
One hundred fifty-three participants with chronic liver disease underwent CFF testing using Beacon and Lafayette-FFS with a method-of-limits and/or forced-choice protocol.
Results:
Beacon demonstrated excellent test-retest reliability (intraclass correlation 0.91-0.97) and good correlation with the Lafayette-FFS values (intraclass correlation 0.77-0.84). Forced-choice CFF were on average 4.1 Hz higher than method-of-limits descending CFFs.
Discussion:
Beacon can be self-administered by patients with chronic liver disease and cirrhosis to measure CFF, a validated screening test for minimal hepatic encephalopathy.

