Ophthalmic Microscope Depth of Field via Oscillating Optics
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Solution Overview
Problem
Conventional ophthalmic surgical microscopes face challenges in achieving an adequate depth of field without increasing costs or bulk, and they do not utilize the critical flicker fusion rate to enhance image perception.
Innovation Solution
An ophthalmic surgical microscope with a movable optical element that oscillates at a frequency greater than the critical flicker fusion rate, coupled with an actuator and a computing device to control the oscillation, generates a volumetric image by creating multiple focal planes, improving the depth of field and image perception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a larger objective lens is implemented to increase depth of field, then the depth of field is improved, but the cost and bulk of the microscope increase
Solution Approach 1:
The patent applies the dynamics principle by making the optical element movable instead of stationary. The optical element oscillates along the optical pathway at a frequency above the critical flicker fusion rate, dynamically creating multiple focal planes that the observer's brain integrates into a single volumetric image with enhanced depth of field perception.
Solution Approach 2:
The patent employs mechanical vibration by oscillating the optical element at high frequency (above CFF rate). This vibration creates a sequence of focal planes at different positions along the optical pathway, which are perceived by the observer as an extended depth of field without requiring a larger objective lens.
2Measurement precision
If diaphragm apertures are implemented to increase depth of field, then the depth of field is improved, but the photon flux or amount of light passing through the microscope is reduced
Solution Approach 1:
The optical element dynamically oscillates to create multiple focal planes over time, allowing each plane to be fully illuminated without requiring aperture reduction. The temporal integration of these planes by the observer's visual system creates the depth of field effect without compromising light intensity.
Solution Approach 2:
The optical element performs periodic oscillation at a frequency above the critical flicker fusion rate, creating a sequence of illuminated focal planes. This periodic action allows full illumination of each focal plane while the rapid succession creates the perception of extended depth of field.
3Measurement precision
If conventional methods are used to increase depth of field, then the depth of field is improved, but the device complexity and cost increase
Solution Approach 1:
The patent replaces complex mechanical systems (large objective lenses, diaphragm mechanisms) with a simpler oscillating optical element driven by an actuator. This substitution achieves depth of field enhancement through controlled motion rather than through complex optical hardware.
Solution Approach 2:
The patent changes the temporal parameter of the optical system by introducing oscillation at a specific frequency (above CFF rate). This parameter change transforms the static optical pathway into a dynamic system that creates multiple focal planes over time, achieving depth of field enhancement without structural 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 enhances spatial awareness for surgeons by providing a larger depth of field without the need for large objective lenses or reduced apertures, improving surgical procedure efficacy and usability while avoiding costly conventional methods.
Implementation Method 1
The critical flicker fusion (CFF) rate is a quantity in psychophysics describing the frequency beyond which flicker or individual images in a successive set are no longer independently perceivable by an observer. Above the CFF rate, the observer's brain integrates or fuses the individual images into a single image.
Implementation Method 2
the movable optical element being configured to oscillate in a direction along the optical pathway
Data Source
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AI summary
An ophthalmic surgical microscope can include a movable optical element positioned in an optical pathway of light reflected from a surgical field. The movable optical element can be configured to oscillate in a direction along the optical pathway. The microscope can include an actuator coupled to the movable optical element and configured to move in response to a control signal. The microscope can include a computing device in communication with the actuator and configured to generate the control signal to move the movable optical element. In some embodiments, the computing device is configured to generate the control signal to move the movable optical element with an oscillation frequency greater than the critical flicker fusion rate.