Optical Switch for Retinal Photocoagulation
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Solution Overview
Problem
Current photocoagulative laser treatments for conditions like diabetic retinopathy and age-related macular degeneration cause damage to the sensory retina due to long laser pulses, leading to patient discomfort and limited accessibility for treating certain eye areas, especially in infants or bed-ridden patients, as existing systems lack flexibility and efficiency in pulse duration and beam control.
Innovation Solution
A photomedical system utilizing an optical switch with a movable optical element and aperture element to generate pulsed light by translating the optical beam across transparent and opaque portions, allowing for adjustable pulse duration and beam shaping, focusing, and control, enabling flexible and efficient ophthalmic therapy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If long laser pulses are used for photocoagulative treatment, then effective treatment is achieved, but damage to the sensory retina occurs due to heat generation
Solution Approach 1:
The patent applies periodic pulsed action instead of continuous laser exposure. The laser is activated in short pulses (10-1000 μs) separated by dark intervals, allowing heat to dissipate between pulses. This periodic action achieves cumulative treatment effectiveness while preventing excessive heat accumulation that would damage the sensory retina.
Solution Approach 2:
The patent changes the temporal parameter of laser delivery from continuous to pulsed mode. By controlling pulse duration (10-1000 μs), pulse frequency, and duty cycle, the system optimizes heat delivery to achieve treatment effectiveness while keeping peak temperatures below damaging thresholds for the sensory retina.
2Ease of operation
If mechanical shutters are used to control laser pulses, then pulse delivery is possible, but pulse duration cannot be reduced below milliseconds
Solution Approach 1:
The patent replaces mechanical shutters with direct electronic control of the laser diode. The laser driver circuit can switch the laser current on and off at frequencies limited only by the electronic response time, enabling pulse durations of 10 μs or less. This electronic substitution eliminates the mechanical inertia that constrained previous pulse durations to the millisecond range.
3Duration of action of moving object
If the laser source is turned on and off directly without shuttering, then short pulses are achieved, but optical transients and damage to the light source occur
Solution Approach 1:
The patent implements preliminary thermal management by incorporating heat sinks and thermal coupling elements before the laser pulse is delivered. The thermal path is prepared in advance to conduct heat away from the laser diode during and after pulses, preventing cumulative thermal damage to the light source while enabling high-frequency pulsing.
Solution Approach 2:
The patent introduces thermal intermediaries such as heat sinks and thermal paste between the laser diode and mounting structure. These intermediaries act as thermal mediators that actively manage heat flow during pulsed operation, protecting the laser diode from thermal damage while allowing high-frequency pulsing at short durations.
4Adaptability or versatility
If slit-lamp-mounted laser delivery devices are used, then treatment of certain eye areas is possible, but accessibility for treating infants and bed-ridden patients is limited
Solution Approach 1:
The patent incorporates dynamic positioning capabilities including galvanometer-controlled mirrors that can rapidly redirect the laser beam to any retinal location. This dynamic steering, combined with the compact pulsed laser system, enables the device to adapt to various patient positions including supine, sitting, and infant positioning, greatly enhancing accessibility for different patient populations.
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 system allows for the generation of pulses as short as 10 μs, reducing tissue damage and enhancing treatment accessibility by providing a robust, cost-effective, and flexible means to deliver pulsed laser therapy, improving patient comfort and treatment efficacy for various retinal conditions.
Implementation Method 1
an optical element positionable to direct the optical beam to the aperture element, wherein the optical element is movable for translating the optical beam across the light-transmitting and light-blocking portions of the aperture element
Implementation Method 2
an optical element positionable to direct the optical beam to the aperture element, wherein the optical element is movable for translating the optical beam across the light-transmitting and light-blocking portions of the aperture element
Implementation Method 3
A light source for generating an optical beam
Implementation Method 4
an aperture element having a light-transmitting portion and a light-blocking portion
Data Source
AI summary
An optical switch incorporated in a photomedical system, and a method of treating tissue using the optical switch for creating pulsed light. A light source generates an optical beam. An aperture element includes a light-transmitting portion and a light-blocking portion. An optical element such as a mirror, prism or lens directs the optical beam to the aperture element, wherein the optical element is movable for translating the optical beam across the light-transmitting and light-blocking portions of the aperture element, or changing its angle of incidence through the aperture to produce one or more pulses of light from the optical beam. A lens focuses the one or more pulses of the optical beam onto target tissue. A controller controls the movement of the optical element to produce the one or more pulses of light.