Laser Beam Calibration via Image Capture for Ophthalmic Surgery
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Solution Overview
Problem
Current methods for calibrating laser beam delivery systems in ophthalmological surgery lack precision and accuracy, particularly in iris calibration and hysteresis measurement, leading to potential errors in corneal sculpting and increased risk of eye damage during procedures like LASIK and PRK.
Innovation Solution
The use of an image capture device, such as a microscope camera, to calibrate laser beam positioning, shape, and size by imaging a known object and comparing it to marks created on a calibration surface, allowing for precise determination of laser beam characteristics and iris calibration, including hysteresis measurement, without significantly increasing system cost or complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual inspection with eye loops is used for calibration, then system cost and complexity are kept low, but measurement precision and calibration accuracy deteriorate to about ±0.1 mm
Solution Approach 1:
The patent uses an image capture device to create a digital copy/image of the ablation mark on the calibration surface. This optical copy allows for precise digital measurement and analysis of the mark's position, shape, and size without requiring complex mechanical measurement systems or manual inspection, thereby achieving high measurement precision while keeping the system relatively simple
Solution Approach 2:
The patent replaces the mechanical measurement approach (manual inspection with eye loops) with an optical imaging system. The image capture device optically records the ablation mark, and computer algorithms automatically analyze the images to determine calibration parameters, eliminating the need for manual mechanical measurement and significantly improving precision
2Manufacturing precision
If visual measurement by operator is used for calibration, then system cost is kept low, but manufacturing precision and calibration accuracy deteriorate due to human error
Solution Approach 1:
The calibration system performs self-measurement through automated image capture and analysis. The computer automatically processes the captured images, calculates the ablation mark characteristics, and determines calibration parameters without human intervention in the measurement process, eliminating human error while maintaining system simplicity
Solution Approach 2:
The system captures images of the ablation marks, automatically analyzes them to determine the actual beam position and shape, and uses this feedback information to calibrate the laser beam delivery system. This closed-loop feedback mechanism ensures high calibration precision by continuously comparing expected versus actual beam characteristics
3Reliability
If current calibration methods are used, then system cost is maintained, but reliability and patient safety deteriorate due to potential off-center ablation and eye damage
Solution Approach 1:
The system performs calibration measurements before actual surgery using test ablations on a calibration surface. By capturing and analyzing images of these preliminary ablation marks, the system determines beam position and shape characteristics in advance, ensuring reliable and safe surgery by identifying and correcting any beam delivery errors before they could affect the patient
Solution Approach 2:
The image capture device creates a permanent optical record (copy) of the ablation marks for detailed analysis. This copied image can be stored, reviewed, and measured multiple times to accurately determine beam characteristics and calibration parameters, improving reliability by allowing thorough verification of beam positioning accuracy
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 enhances calibration accuracy and precision, ensuring accurate corneal ablation and reducing the risk of off-center tissue removal, thereby improving the success of vision correction surgeries like LASIK and PRK.
Implementation Method 1
imaging the mark on the calibration surface with the image capture device
Implementation Method 2
A pulsed laser beam is directed onto the calibration surface so as to leave a mark on the calibration surface
Data Source
AI summary
The present invention provides improved methods and systems for laser beam positioning, shape profile, size profile, drift, and/or deflection calibration using an image capture device, such as a microscope camera, for enhanced calibration accuracy and precision. The methods and systems are particularly suited for iris calibration and hysteresis measurement of a variable diameter aperture. One method for calibrating laser pulses from a laser eye surgery system using an image capture device comprises imaging a known object with an image capture device. A pulsed laser beam is directed onto a calibration surface so as to leave a mark on the calibration surface. The mark on the calibration surface is then imaged with the image capture device. The laser eye surgery system is calibrated by comparing the image of the mark on the calibration surface to the image of the known object.