Development of a Prototype Video Head Impulse Test System Using an iPhone for Screening of Peripheral Vestibular...

Area of Science:

• Neurology
• Ophthalmology
• Biomedical Engineering

Background:

• The Head Impulse, Nystagmus, and Test of Skew (HINTS) examination is crucial for diagnosing occipital fossa stroke.
• The traditional Head Impulse Test (HIT) is subjective and challenging to perform accurately.
• Existing video HIT (vHIT) systems can be cumbersome and less accessible for widespread clinical use.

Purpose of the Study:

• To develop and evaluate a prototype smartphone-based video Head Impulse Test (vHIT) system using an iPhone.
• To assess the feasibility and accuracy of the iPhone-vHIT system compared to a commercial vHIT system.
• To provide an accessible tool for screening peripheral vestibular dysfunction.

Main Methods:

• Developed a prototype vHIT system utilizing an iPhone camera and gyro sensor for eye and head movement analysis.
• Captured high-speed videos (120 frames per second) with an iPhone fixation brace to prevent blurring.
• Compared iPhone-vHIT performance against a commercial EyeSeeCam vHIT system in a healthy individual and a patient with vestibular neuritis.

Main Results:

• The iPhone-vHIT system generated comparable vHIT waveforms to the EyeSeeCam system.
• Effectively detected reduced vestibulo-ocular reflex gain in a patient with vestibular neuritis.
• The iPhone-vHIT system at 120 fps demonstrated lower sensitivity to catch-up saccades compared to EyeSeeCam.

Conclusions:

• Smartphone-based vHIT systems offer a potential for more accessible vestibular diagnostics.
• The developed iPhone-vHIT application is currently the only available smartphone-based vHIT system for screening peripheral vestibular dysfunction.
• The prototype iPhone-vHIT system holds promise for clinical application, particularly for examining the lateral semicircular canal.