The System 2000 Comprehensive Rotational Vestibular Chair smoothly accelerates and changes direction without inertial artifact even at higher frequencies and with heavier patients. The dc torque motor in the base and the linear servo amplifier were engineered to provide quiet, precisely controlled rotation in patients up to 400lbs. The complete system can be installed in a traditional 10ft x12ft exam room without expensive AC power modifications or room renovations.

To prevent patient orientation and for testing in complete darkness, a rotational chair booth is part of the system. Communication with the patient takes place with a 2-way intercom and infrared video monitoring. The booth has ventilation fans for patient comfort and LED lighting that can be used when the patient is not rotating.

A true optokinetic stimuli must fill the patients visual field. Only a full-field projector can create a perception of self-motion in subjects who stare at the stimuli as it rotates around them. A pinpoint of intense light in the center of the optokinetic drum projects clear stripes on the booth wall from floor to ceiling filling the patient’s entire visual field. These stripes are rotated by a servo motor for OKN tests and the stripes are stationary for vision-enhanced VOR tests.

A focused solid state laser with precise, dual galvanometers produces a red dot on the booth wall for gaze, pursuit, and saccade tests in both the vertical and horizontal directions. For subjective visual vertical (SVV) tests these XY galvanometers oscillate rapidly to draw a red line on the booth wall. As a measure of static otolith function, via the perception of verticality, the patient tells the examiner to rotate the laser line left or right until it appears to be vertical. For patients who have difficulty sitting up straight due to back or neck issues, there is a forward adjustable head support with an integral distance ruler to correctly set the laser calibration angle.

Prior to testing, binocular goggles are placed on the patient’s face, both eye images are adjusted for clarity of image, a Velcro strap connects the goggles to the head support for head stability. Then via software, the eye images are centered on the computer screen. During testing, even when the patient slouches in their chair or sits straighter, the eye images can be centered and the tracking adjusted from the computer keyboard without re-entering the booth. These goggles features improve trace quality and also reduce testing time.