Phacoemulsification Handpiece Sensor Layout for Post-Occlusion Surge Control
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Solution Overview
Problem
Current ultrasonic phacoemulsification systems face challenges in detecting occlusion clearance in the aspiration line due to the placement of pressure/vacuum sensors in the fluidic cassette, leading to delayed detection and increased risk of post occlusion surge, which can destabilize the eye chamber and cause surgical complications.
Innovation Solution
An ultrasonic phacoemulsification handpiece with a piezoresistive MEMS pressure sensor integrated into the extension lumen, decoupled from ultrasonic vibrations through a loose fit design, and a surge control system that includes a normally closed aspiration valve for rapid pressure release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pressure/vacuum sensor is placed in the fluidic cassette on the console, then the sensor is protected from ultrasonic vibration damage, but the detection of occlusion clearance is delayed due to the long tubing distance
Solution Approach 1:
The system divides the sensing function into two parts: a simple occlusion detection sensor placed in the handpiece near the tip, and the main pressure control system in the console. This segmentation allows immediate local detection while maintaining protected centralized control.
Solution Approach 2:
A simple occlusion detection sensor acts as an intermediary between the phacoemulsification tip and the main console system. This intermediary provides timely local detection signals to trigger the console's surge control mechanisms without requiring the main sensor to be exposed to ultrasonic vibrations.
2Loss of time
If the pressure sensor is placed in the ultrasonic phacoemulsification handpiece near the phacoemulsification tip, then the occlusion clearance can be detected in time, but the ultrasonic vibration can affect or damage the pressure sensor
Solution Approach 1:
The sensing system is segmented into a simple occlusion detection sensor in the handpiece and the main pressure control system in the console. The handpiece sensor only needs to detect occlusion status, not measure absolute pressure, reducing its complexity and vulnerability to ultrasonic vibration.
Solution Approach 2:
The detection threshold and sensitivity parameters of the handpiece sensor are optimized to detect occlusion clearance events reliably without requiring the sensor to withstand full ultrasonic vibration levels. The system changes from continuous pressure measurement to event-based occlusion detection.
3Object-affected harmful factors
If the built-up negative pressure is released rapidly after occlusion clearance detection, then the post occlusion surge is reduced, but the intraocular pressure stability may be compromised
Solution Approach 1:
The system applies preliminary anti-action by detecting occlusion clearance before the surge fully develops and immediately initiating pressure release. This preemptive action prevents the harmful surge effect from occurring in the first place, rather than correcting it after the fact.
Solution Approach 2:
The system uses real-time feedback from the occlusion detection sensor to dynamically adjust the aspiration pressure. When occlusion clearance is detected, the feedback loop triggers immediate pressure release, and when occlusion is detected, it maintains controlled negative pressure, creating a stable adaptive control system.
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
The handpiece design maintains ultrasonic performance while providing timely detection of occlusion clearance, reducing the risk of post occlusion surge and ensuring stable intraocular pressure during cataract removal surgery.
Implementation Method 1
an extension part and a sensor (307) mounted on the extension lumen (305)
Implementation Method 2
ultrasonic phacoemulsification handpiece (105) connected to the console (101) by the handpiece cable (106); the handpiece cable (106) usually contains an ultrasonic signal line
Data Source
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AI summary
This invention discloses an ultrasonic phacoemulsification handpiece with a sensor and a surge control system and a method. The central aspiration lumen of the ultrasonic phacoemulsification handpiece consists of two components of plug-in loose fit: a fixed lumen (304) and an extension lumen (305); a small pressure sensor (307) is mounted on the extension lumen (305), but still able to keep the easy-to-use size and maintain the ultrasonic performance of the handpiece. The extension lumen (305) minimizes the effect of ultrasonic vibration on the sensor (307) while maintaining sufficient stiffness for installing and removing the phacoemulsification tip (202). The design of the handpiece transducer reduces the effect of this sensor installation on the ultrasonic performance. For ultrasonic phacoemulsification cataract removal surgery, the short distance from the pressure sensor to the surgical site provides a technical solution for reliably controlling the risk of the post occlusion surge.