Surgical System Occlusion Detection via Rate of Change
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current occlusion detection systems in phacoemulsification surgery are limited by their reliance on fixed aspiration vacuum levels, which can lead to premature or delayed adjustments in power delivery, resulting in inefficient cutting and increased risk of tissue overheating.
Innovation Solution
A method that determines the rate of change of aspiration vacuum and irrigation pressure to accurately identify stages of occlusion, allowing for dynamic adjustment of power delivery to the ultrasound handpiece, including onset, pre-occlusion, full occlusion, and recovery phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If fixed aspiration vacuum levels are used for occlusion detection, then the detection system is simple to operate, but the cutting efficiency decreases and tissue overheating risk increases
Solution Approach 1:
The patent transitions from fixed vacuum threshold detection to dynamic rate-of-change detection. The system continuously monitors how quickly vacuum levels change rather than relying on static thresholds, enabling adaptive response to evolving occlusion conditions while maintaining operational simplicity through automated calculations.
Solution Approach 2:
The invention changes the detection parameter from absolute vacuum level to rate of change of vacuum level. By monitoring dP/dt (rate of pressure change), the system can detect occlusion onset, progression, and resolution more accurately, allowing dynamic power adjustment that maintains cutting efficiency while preventing overheating.
2Device complexity
If fixed aspiration vacuum levels are used for occlusion detection, then the detection system is simple, but the precision of occlusion stage identification deteriorates
Solution Approach 1:
The system employs dynamic rate-of-change analysis to identify distinct occlusion stages. By calculating the derivative of pressure over time and comparing it against threshold ranges, the system can differentiate between occlusion onset, full occlusion, and recovery phases with high precision, despite maintaining relatively simple hardware.
Solution Approach 2:
The patent implements continuous feedback by monitoring vacuum pressure changes in real-time and automatically adjusting ultrasonic power delivery based on detected occlusion stages. This closed-loop control enhances measurement precision by continuously adapting to changing surgical conditions rather than relying on pre-set fixed thresholds.
3Device complexity
If power delivery is adjusted based on fixed vacuum levels, then the control system is simple, but the temperature control of tissue deteriorates
Solution Approach 1:
The invention changes the control parameter from static vacuum threshold to dynamic rate of pressure change. By monitoring how quickly vacuum levels change, the system can predict temperature trends and adjust power delivery proactively, preventing tissue overheating before it occurs while maintaining relatively simple control architecture.
Solution Approach 2:
The system performs preliminary action by detecting rate of pressure change that precedes full occlusion. By identifying trends in dP/dt values, the system can reduce power delivery in advance of complete occlusion, preventing temperature buildup before it becomes problematic, rather than reacting after overheating occurs.
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 cutting efficiency by optimizing power delivery during occlusions while preventing tissue overheating, improving surgical precision and safety by accurately detecting occlusion stages and adjusting power accordingly.
Implementation Method 1
The crystals are controlled by the console and supply ultrasonic vibrations that drive both the horn and the attached cutting tip during phacoemulsification
Implementation Method 2
The vibrating cutting tip liquefies or emulsifies the lens so that the lens may be aspirated out of the eye
Data Source
AI summary
A surgical system that is able to sense the onset of an occlusion or other surgical event as well as when an occlusion breaks. To help avoid overheating of the tip, the system of the present invention predicts the temperature of the eye using irrigation flow rate and reduces the power to the handpiece automatically if an overheating situation is predicted. Alternatively or in addition, the system of the present invention monitors the power drawn by the handpiece, which is indicative of the cutting load on the tip, and automatically adjusts the power or stroke of the tip to compensate for increased loads on the tip.