Acousto-Optic Modulator for Motion-Resistant OCT Scanning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional non-invasive optical coherence tomography (OCT) systems face limitations due to motion-related artifacts and signal-to-noise ratio issues, which affect the accuracy and practicality of imaging and analysis, especially in human tissue analysis.
Innovation Solution
The system generates a composite reference beam with multiple components of different path lengths and frequency content, allowing for simultaneous acquisition of interferometric signals from various depths, thereby avoiding motion-related artifacts and enhancing signal separation through electronic filtering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional OCT systems use electromechanical scanning (galvanometers, moving coils, rotating polygons) to achieve depth scanning, then scanning capability is provided, but scan speed is limited, alignment problems occur, and signal-to-noise ratio deteriorates
Solution Approach 1:
The patent replaces electromechanical scanning systems (galvanometers, moving coils, rotating polygons) with an acousto-optic modulator that uses acoustic waves to diffract and steer the laser beam. This substitution eliminates moving parts, enabling high-speed scanning while improving signal-to-noise ratio by avoiding mechanical alignment issues and vibration-related noise.
2Ease of operation
If conventional OCT systems use electromechanical scanning components, then depth scanning is achieved, but alignment problems and mechanical complexity increase
Solution Approach 1:
The patent eliminates galvanometers, moving coils, and rotating polygons by using an acousto-optic modulator that controls beam direction through acoustic field modulation rather than mechanical movement. This reduces mechanical complexity and eliminates alignment instability caused by moving parts.
3Measurement precision
If long physical scans are used to differentiate signals or locate reference areas, then measurement accuracy improves, but motion artifacts increase and scan time increases
Solution Approach 1:
The patent uses periodic acoustic modulation through the acousto-optic modulator to encode depth information at different frequencies. This allows signal differentiation through frequency domain analysis rather than requiring long physical scans, thereby reducing motion artifacts and scan time while maintaining measurement accuracy.
Solution Approach 2:
The patent replaces long physical scans with acousto-optic modulation that achieves signal differentiation through frequency-encoded depth information. This eliminates the need for extended mechanical scanning, reducing both scan time and motion-related artifacts.
4Speed
If acousto-optic scanning is used to achieve high speed scanning, then scan speed improves, but cost increases, device size increases, and thermal control problems arise
Solution Approach 1:
The patent uses an acousto-optic modulator driven by electrical signals to achieve high-speed scanning without the thermal management issues of continuous-wave lasers. The pulsed operation and efficient acoustic-to-optical conversion reduce heat generation, simplifying thermal control while maintaining high scan speeds.
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 approach enables accurate and compact non-invasive imaging and analysis with improved precision and repeatability, reducing sensitivity to motion artifacts and enhancing scanning speed and accuracy in analyzing human tissue and analyte concentrations.
Implementation Method 1
Light scattered back from the target is combined with the reference beam to form the measurement signal. Because of the short coherence length only light that is scattered from a depth within the target such that the total optical path lengths of the probe and reference are equal combine interferometrically.
Data Source
AI summary
A non-invasive imaging and analysis system suitable for non-invasive imaging and analysis of defects or malignant aspects of targets such as cancer in skin or human tissue and suitable for measuring concentrations of specific components, such as blood glucose concentration includes an optical processing system which generates a probe and composite reference beam. The system also includes a means for applying the probe beam to the target to be analyzed and modulates at least some of the components of the composite reference beam such that signals with different frequency content are generated. The system combines a scattered portion of the probe beam and the composite beam interferometrically to simultaneously acquire information from multiple depths within a target. It further includes electronic control and processing systems.