Variable-Flow Restrictor Mitigating Post-Occlusion Surge in Ocular Surgery
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Solution Overview
Problem
Current ocular surgical devices face challenges in managing post-occlusion surge (POS) during phacoemulsification, which can lead to adverse effects such as tearing of the posterior capsule due to rapid pressure changes, and existing flow restriction devices either restrict flow too much or become inefficient due to blockages, compromising surgical performance and convenience.
Innovation Solution
A multi-stage variable-flow restrictor with a conical valve and spider membrane/spring mechanism that provides proportional closure in response to surge conditions, maintaining a constant flow and minimizing blockages while allowing unrestricted reflux, effectively stabilizing eye pressure and preventing POS damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a fixed flow restrictor is used to prevent post-occlusion surge, then eye pressure stability is improved, but tissue removal efficiency deteriorates due to excessive flow restriction
Solution Approach 1:
The flow restrictor transitions from a fixed restriction to a dynamic, variable restriction through the valve assembly. The valve member can adjust its position relative to the valve seat, changing the flow restriction level dynamically based on operating conditions (occlusion vs. normal flow), thus preventing POS while maintaining efficient tissue removal during normal surgery.
Solution Approach 2:
The system changes the flow restriction parameter dynamically. During occlusion, high restriction is applied to prevent surge; during normal operation, lower restriction is applied to maintain efficient aspiration. This parameter adjustment is achieved through the valve's response to pressure differential changes.
2Object-affected harmful factors
If a small-bore needle or restrictive tubing is used to limit surge, then POS prevention is improved, but blockage susceptibility increases
Solution Approach 1:
The flow path is segmented into multiple pathways: the main aspiration pathway through the needle/tip and an additional pathway through the valve assembly. This segmentation allows the system to restrict surge through the valve while maintaining a separate, less restrictive pathway for normal tissue removal, reducing blockage risk.
Solution Approach 2:
The valve assembly acts as an intermediary component between the aspiration source and the surgical tip. It mediates the flow control function, providing surge protection without requiring the main aspiration pathway to be overly restrictive, thus preventing blockages while still limiting POS.
3Stress or pressure
If flow restriction is increased to stabilize eye pressure, then POS mitigation is improved, but irrigation-aspiration balance deteriorates
Solution Approach 1:
The valve dynamically adjusts flow restriction parameters based on real-time pressure conditions. During occlusion, high restriction stabilizes eye pressure; during normal operation, reduced restriction maintains proper irrigation-aspiration balance. This dynamic parameter adjustment prevents both POS and imbalance.
Solution Approach 2:
The system uses pressure differential feedback to control valve position. The valve responds to changes in pressure conditions (occlusion detected by increased pressure differential), automatically adjusting flow restriction to maintain eye pressure stability while preserving irrigation-aspiration balance during normal surgery.
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 multi-stage variable-flow restrictor effectively mitigates the risks associated with POS by maintaining stable eye pressure and preventing damage during ocular surgery, while maintaining efficient tissue removal and minimizing the need for device removal post-surgery.
Implementation Method 1
A multi-stage variable-flow restrictor with a conical valve and spider membrane/spring mechanism that provides proportional closure in response to surge conditions
Implementation Method 2
A multi-stage variable-flow restrictor with a conical valve and spider membrane/spring mechanism that provides proportional closure in response to surge conditions
Implementation Method 3
the aspirating vacuum to build (such as to a preset vacuum shutoff limit) until the blockage is broken. Upon breaking of the occlusion, stored energy in the tubing causes a rapid surge flow from the patient's eye
Implementation Method 4
Flow restrictor for surgical device
Data Source
AI summary
An apparatus, system and method for providing a flow restrictor suitable for inclusion in an aspiration flow of an ocular surgical device. The flow restrictor includes a conical valve head suitable for insertion into a valve stage, wherein, upon the insertion, the valve head at least substantially impedes the aspiration flow; a flexible spider membrane having a plurality of valve passages that open and close with the flexation of the membrane, wherein the membrane is connective with the valve head and forces the insertion of the valve head into the valve stage proportionally to the aspiration flow; a circular receiving plate for receiving the aspiration flow, wherein the circular receiving plate imparts the proportional insertion to the membrane; and a plurality of ribs integral to at least one of the valve head and the valve stage that provides a minimum for the aspiration flow when the insertion is full.