Ophthalmic Console Valve Timing for High-Cycle Vitrectomy
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Solution Overview
Problem
Existing ophthalmic surgical systems, particularly vitrectomy cutting tools, face limitations in achieving high cycle rates due to restricted pressure differences between work chambers, which are influenced by switching time delays and fluid pressures, leading to reduced efficiency and increased vibrations.
Innovation Solution
A console for an ophthalmic surgical system with a control unit that adjusts the switching signals of work valves to overlap temporally, allowing for extended switched-on states and reduced simultaneous switched-off states, thereby optimizing pressure differences and cycle rates without modifying the handpiece or valves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the work fluid pressure is increased to achieve higher cycle rates, then the cutting speed improves, but the vibrations and acoustic noise increase
Solution Approach 1:
The control unit anticipates the switching time delays of the work valves and pre-adjusts the switching signals to create a temporal overlap between the switch-on states of the first and second work valves. This preliminary timing adjustment allows the system to achieve higher cycle rates without requiring excessive work fluid pressure, thereby reducing vibrations and acoustic noise while maintaining productivity
2Productivity
If the switching time delays of the work valves are reduced to increase cycle rate, then the productivity improves, but the reliability of the valve switching may be compromised
Solution Approach 1:
The control unit dynamically adjusts the timing of the switching signals based on the actual switching time delays of the work valves. By creating a temporal overlap where both valves are in their switch-on state simultaneously for a controlled duration, the system optimizes the cycle rate while ensuring reliable switching. This dynamic timing adjustment allows the system to operate at higher speeds without compromising valve reliability
3Productivity
If the duty cycle is adjusted to increase the switched-on state duration, then the cutting speed improves, but the energy consumption increases
Solution Approach 1:
The control unit implements a periodic switching pattern where the first and second work valves are switched on and off in a coordinated sequence. The temporal overlap creates a periodic action that optimizes the duty cycle, allowing the valves to be in the switched-on state longer during the overlap period while maintaining efficient energy usage. This periodic control pattern increases cutting speed without proportionally increasing energy consumption
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 configuration enhances cycle rates, reduces vibrations, and minimizes fluid pressure requirements, improving the performance of vitrectomy cutting tools by extending switched-on states and avoiding simultaneous off-states, thus enhancing surgical efficiency.
Implementation Method 1
a control unit which is electrically coupled to the first and to the second electric drive unit and which is configured to actuate the first and the second electric drive unit with respective first and second electrical switching signals such that a respective switching signal successively over time applies a switch-on electric potential for the switched-on switching state and a switch-off electric potential for the switched-off switching state to the respective electric drive unit
Implementation Method 2
the handpiece is configured with appropriate adaptations, for example for treatment of the vitreous humor of the eye or else retina as a vitrectomy cutting tool, as a handpiece for phacoemulsification or the like
Data Source
AI summary
A console is for an ophthalmic surgical system for operating a handpiece driven by a work fluid. The work fluid is supplied to a respective work chamber depending on the switching states of work valves. The valves are switched between a switched-on state and a switched-off state by a respective drive unit by respective electrical switching signals being applied to the drive units. Each valve switches from the switched-off switching state into the switched-on switching state during a switch-on time delay and switches from the switched-on state to the switched-off state during a switch-off time delay. The switching signals at least intermittently adopt the switch-on electric potential concurrently during a difference time period if the switch-on delay is longer than the switch-off delay, with a length of time of the difference period arising on the difference between the switch-on delay and the switch-off delay of the valves.