Ophthalmic Apparatus Dynamic Scan Area Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional magnification correction techniques for optical coherence tomography (OCT) in ophthalmic examinations require external devices, making them unsuitable for screening examinations and facilities without such equipment, leading to inaccurate diagnoses due to variations in axial length and diopters affecting the scanned area size.
Innovation Solution
An integrated ophthalmic apparatus combining OCT with a fundus camera, featuring an optical path length adjustment mechanism and a controller that adjusts the optical scanner's deflection angle based on axial length and diopter characteristics, ensuring consistent scan area sizes without external data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If OCT scan is performed under a fixed scan condition, then the scan configuration is simple and consistent, but the scanned area size varies depending on axial length and diopter
Solution Approach 1:
The patent implements dynamic adjustment of the optical scanner's deflection angle based on the measured axial length and diopter values. The controller automatically modifies scan conditions in real-time according to the subject's eye characteristics, transforming a static fixed-scan system into a dynamic adaptive system that maintains consistent scanned area sizes across different eye types.
Solution Approach 2:
The patent changes the deflection angle parameter of the optical scanner based on axial length and diopter measurements. By adjusting this key parameter according to the subject's eye characteristics, the system compensates for variations in eye optics and ensures that the scanned area on the fundus remains consistent regardless of the subject's axial length or refractive power.
2Measurement precision
If external devices are used for magnification correction, then measurement precision can be improved, but device complexity increases and applicability to screening examinations is reduced
Solution Approach 1:
The patent combines the OCT imaging system with the axial length and diopter measurement capabilities into a single integrated apparatus. By merging these previously separate functions into one system, the patent eliminates the need for external devices while maintaining measurement precision, thereby reducing device complexity and improving applicability to screening examinations.
Solution Approach 2:
The OCT apparatus performs self-correction by using its own measurement data (axial length and diopter) to adjust its scanning parameters. The system measures the eye's optical characteristics and automatically compensates for magnification errors without requiring external correction devices, enabling the apparatus to serve itself and eliminate dependencies on additional equipment.
3Manufacturing precision
If the deflection angle of the optical scanner is adjusted based on axial length and diopter, then scanned area consistency is improved, but control complexity increases
Solution Approach 1:
The patent implements a feedback control mechanism where the controller receives axial length and diopter measurements, calculates the appropriate deflection angle adjustment, and applies the correction to the optical scanner. This closed-loop feedback system automates the complex control process, reducing manual intervention while maintaining precise scanned area consistency across different eye types.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate OCT scans of consistent area sizes regardless of axial length and diopter variations, applicable for screening and facilities without external devices, reducing false positives and negatives in diagnoses.
Implementation Method 1
superpose returning light of the measurement light from the subject's eye on the reference light to generate interference light
Implementation Method 2
an optical scanner configured to deflect the measurement light for scanning the eye fundus
Implementation Method 3
an optical path length changing device configured to change at least one of an optical path length of the measurement light and an optical path length of the reference light
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
An ophthalmic apparatus (1) of an exemplary embodiment is capable of applying OCT to the fundus (Ef) of a subject's eye (E), and includes an optical system, an optical scanner (44), an optical path length changing device (41, 114), a focus adjustment device (43, 43A), and a controller (210, 231). The optical system splits light output from a light source (101) into measurement light (LS) and reference light (LR), projects the measurement light onto the fundus (Ef), generates interference light (LC) by superposing returning light of the measurement light (LS) from the subject's eye (E) on the reference light (LR), and detects the interference light (LC). The optical scanner (44) deflects the measurement light (LS) in a two dimensional manner for scanning the fundus (Ef). The optical path length changing device (41, 114) changes at least one of an optical path length of the measurement light (LS) and an optical path length of the reference light (LR). The focus adjustment device (43, 43A) performs focus adjustment of a measurement arm. The controller (210, 231) calculates an estimated value of an axial length of the subject's eye (E) from a process of controlling the optical path length changing device (41, 114), performs focus adjustment of the measurement arm to calculate an estimated value of a diopter of the subject's eye (E) from a process of controlling the focus adjustment device (43, 43A), and controls the optical system and the optical scanner (44) based on a deflection range of the optical scanner (44) set based on the estimated value of the axial length and the estimated value of the diopter.