Schematic Face Contrast Cards for Pediatric Visual Assessment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current pediatric contrast sensitivity tests are limited by examiner bias, time-consuming, and lack reliability, especially in young children with visual and multiple impairments, as they often require complex equipment and specialized personnel, and existing tests may not accurately measure contrast sensitivity function or be sensitive to various visual disorders.
Innovation Solution
The development of the Double Happy Contrast Sensitivity Test (DH CS test) using a schematic smiling face stimulus that is symmetrical and can be defined in terms of spatial frequency, allowing for a two-alternative forced-choice procedure that reduces examiner bias and is easier to administer, with a card design that maintains objectivity and provides a clear distinction between right and left orientations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the HH face stimulus is used in a centered image configuration, then the test can be administered with simple equipment, but the examiner becomes aware of the stimulus location which introduces examiner bias
Solution Approach 1:
The stimulus is deliberately made asymmetrical and placed in a non-centered position on the card. This ensures the examiner cannot predict or know the stimulus location in advance, eliminating examiner bias while maintaining simple administration procedures.
2Illumination intensity
If the HH stimulus extends to the edge of the card, then the stimulus is easily visible, but the examiner's fingers may cover a portion of the stimulus
Solution Approach 1:
The stimulus is positioned in a specific non-centered location on the card rather than extending to all edges. This localized positioning ensures the stimulus remains fully visible while preventing the examiner's fingers from covering it during administration.
3Reliability
If VEP is used to measure contrast sensitivity, then objective measurement is achieved, but complex equipment and specialized personnel are required
Solution Approach 1:
The patent replaces complex physiological measurement systems (VEP) with a simple behavioral testing approach using visual contrast cards. This substitution maintains objective measurement while eliminating the need for complex equipment and specialized personnel.
4Measurement precision
If sine-wave gratings are used to measure CSF, then contrast sensitivity can be assessed, but the test becomes time-consuming and requires two people
Solution Approach 1:
The patent uses simple, disposable visual contrast cards with schematic face stimuli instead of complex, time-consuming sine-wave grating equipment. This approach maintains measurement precision while significantly reducing test time and personnel requirements.
Data Source
AI summary
A visual stimulus for a set of contrast cards is provided which comprises a hollow outer circle, opposing and identical first and second arc segment within the outer circle which are symmetrical about the vertical diameter of the outer circle, a first filled-in circle and a second filled-in circle being identical in diameter to the first filled-in circle, each residing on opposite ends of the horizontal diameter of the outer circle and each being equidistant from the center of the outer circle, a filled-in center element having a rotational center on the center of the outer circle, the center element being symmetrical about both the horizontal and vertical diameter of the outer circle.