Functional Vision Head Impulse Testing for Maximum Head Acceleration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vestibular system evaluation methods fail to determine the function of the Vestibular Ocular Reflex (VOR) at maximum head acceleration, as current systems cannot display optotypes briefly enough during high-speed head movements.
Innovation Solution
A system comprising an eye measurement device, motion sensing device, display device, and processing unit that records pupil position and head movement, displays images at maximum head acceleration, and receives user input to assess VOR function, using protocols like fvHIT, AHR, DVA, GST, and VPT to evaluate vestibular system function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current systems display optotypes during head movement, then visual acuity can be measured, but the optotype cannot be displayed briefly enough at maximum head acceleration to ensure accurate VOR function determination
Solution Approach 1:
The system pre-calculates and pre-positions optotypes at multiple locations before head movement occurs. When maximum head acceleration is detected, the system immediately displays the pre-positioned optotype at the appropriate location, eliminating the delay that would occur if the optotype had to be positioned during the head movement itself.
Solution Approach 2:
The system dynamically adjusts the display timing and location of optotypes based on real-time head movement parameters. The display is triggered at specific moments during head acceleration phases, and the optotype location is continuously updated to compensate for head position changes, ensuring the optotype remains visible and measurable throughout the movement.
2Measurement precision
If the system measures both eye velocity and head velocity to determine VOR gain, then objective mathematical measurement is achieved, but the complexity of the measurement system increases
Solution Approach 1:
The system combines eye movement tracking and head movement sensing into a single integrated measurement apparatus. The eye tracking camera and head acceleration sensor work together as a unified system, sharing data processing resources and control logic, which reduces the overall complexity compared to having separate measurement systems.
Solution Approach 2:
The measurement system is designed to perform multiple functions: tracking eye velocity, measuring head velocity, determining VOR gain, and providing feedback for corrective eye movement assessment. This multi-functionality consolidates what would otherwise require separate specialized devices into a single versatile system.
Data Source
AI summary
Embodiments of the present application relate to a system for evaluating the function of the vestibular system of a test subject. The system can include an eye measurement device configured to record a pupil position, a velocity value, and/or an acceleration value of at least one of the eyes of the test subject, a motion sensing device configured to sense a movement and/or location of at least the head of the test subject and to provide at least one motion signal representing an acceleration value and/or a velocity value of a rotation of the head of the test subject in at least one plane, a display device configured to display at least one image, a user input device for receiving a user input, a processing device connected to the eye measurement device, the motion sensing device, and the display device.