OCT Apparatus Light Path Length Compensation for Wide-Angle Scanning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing OCT apparatuses face challenges in acquiring high-quality wide-angle OCT data due to limitations in optical configurations and light path length adjustments, particularly when using angle-of-view switching optical systems.
Innovation Solution
The OCT apparatus incorporates an angle-of-view switching optical system that adjusts the light path length by using multiple reference light paths and a dispersion correcting unit, allowing for increased scanning range and improved signal strength by compensating for changes in light path length and dispersion during the insertion and retraction of the angle-of-view switching optical system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If an angle-of-view switching optical system is inserted to expand the scanning range on the fundus, then the scanning range is increased, but the light path length changes causing degradation of OCT data quality
Solution Approach 1:
The light path length of the reference light is dynamically adjusted to match the changed light path length of the measurement light when the angle-of-view switching optical system is inserted. This dynamic adjustment maintains the balance between reference and measurement light paths, preventing degradation of OCT data quality while enabling expanded scanning range.
Solution Approach 2:
The system changes the light path length parameter of the reference light in response to the insertion of the angle-of-view switching optical system. By adjusting this parameter to compensate for the change in measurement light path length, the system maintains optimal interference conditions and preserves OCT data quality during wide-angle scanning.
2Area of stationary object
If an angle-of-view switching optical system is inserted to expand the scanning range, then the scanning range is increased, but dispersion changes causing degradation of OCT data quality
Solution Approach 1:
The dispersion correction parameter is changed in response to the insertion of the angle-of-view switching optical system. The system selects or adjusts the dispersion correction value to match the new optical configuration, compensating for dispersion changes and maintaining high-quality OCT data acquisition during wide-angle scanning.
3Measurement precision
If the light path length of reference light is adjusted to compensate for insertion of angle-of-view switching optical system, then OCT data quality is maintained, but device complexity increases
Solution Approach 1:
The system replaces complex mechanical adjustment mechanisms with electronic control and software-based light path length adjustment. By using electronic actuators and digital signal processing to compensate for light path length changes, the system maintains OCT data quality while minimizing mechanical complexity.
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
This solution enables the acquisition of high-quality wide-angle OCT data with enhanced signal strength and image resolution, effectively addressing the limitations of previous technologies by compensating for light path length and dispersion changes, thereby improving the scanning range and image quality.
Implementation Method 1
a dispersion correcting unit configured to correct an amount of change according to insertion and retraction of the angle-of-view switching optical system, which is an amount of change in dispersion between the measurement light and the reference light
Implementation Method 2
an OCT optical system and may be capable of processing a spectral interference signal output from a detector of the OCT optical system
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An OCT apparatus includes an OCT optical system, a processor that processes a signal from the OCT optical system, and a light guiding optical system disposed on a measurement light path of the OCT optical system. The light guiding optical system forms a pivot point, at which a measurement light turns based on motion of an optical scanner deflecting the measurement light, in an anterior portion of a subject eye, and guides the measurement light passed through the pivot point to a fundus. The OCT optical system includes a compensation unit that compensates for an amount of change in a light path length of the measurement light path between a state in which an angle-of-view switching optical system is inserted and a state in which the angle-of-view switching optical system is retracted.