Spring-less Check Valve for Surgical Handpiece
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Solution Overview
Problem
Existing ophthalmologic surgical handpieces for cataract removal are limited by complexity, reliability, and the need for positive differential pressure to open check valves, which can lead to inefficiencies and reduced effectiveness in liquefaction techniques.
Innovation Solution
A handpiece design featuring a flow control member that can move between open and closed positions without a spring or biasing member, allowing for check valves to crack open without applied pressure, reducing moving parts and enhancing reliability, and incorporating a pulse engine to manage fluid flow for efficient liquefaction during cataract extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring or biasing member is used in the check valve, then the valve can reliably close to prevent backflow, but the device complexity increases and reliability decreases due to additional moving parts
Solution Approach 1:
The patent removes the spring or biasing member from the check valve assembly, extracting the problematic component that caused reliability issues. The flow control member is designed to function without any biasing element, eliminating the additional moving parts that reduced system reliability while maintaining the valve's backflow prevention capability through pure hydrodynamic forces.
Solution Approach 2:
The patent replaces the mechanical spring-based closing mechanism with a hydrodynamic pressure-based system. Instead of using elastic mechanical force from a spring, the valve utilizes fluid pressure differentials and hydrodynamic forces to control the opening and closing of the flow control member, substituting a mechanical system with a fluid-based system.
2Reliability
If positive differential pressure is applied to open the check valve, then the valve can control flow direction, but the efficiency decreases and complications may arise
Solution Approach 1:
The patent changes the operational parameters of the check valve by eliminating the requirement for positive differential pressure to open the valve. The flow control member is designed to respond to minimal pressure differentials or even gravity-assisted flow, allowing the valve to open and close based on natural flow direction rather than requiring sustained positive pressure, thereby improving surgical efficiency.
3Reliability
If the flow control member is positioned precisely to crack open without pressure, then the reliability increases, but the manufacturing precision requirements increase
Solution Approach 1:
The patent employs asymmetric geometry in the flow control member and its seating surfaces to achieve reliable crack-open functionality. The asymmetric design creates natural flow path preferences that guide the valve to open in the correct direction without requiring precise symmetric positioning, tolerating manufacturing variations while maintaining reliable operation.
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 achieves reliable and efficient cataract liquefaction with fewer moving parts and no need for positive differential pressure, improving the overall reliability and effectiveness of cataract removal procedures.
Implementation Method 1
In the open position, a pressure increase from the pulse engine, and traveling along a second flow path to the flow control member, can move the flow control member to the closed position
Data Source
AI summary
A hand piece for a surgical instrument is provided. The handpiece has an inlet, a chamber (with upstream and downstream portions), a flow control member, a pulse engine, and an outlet. The inlet communicates with the upstream portion of the chamber. The downstream portion of the chamber communicates with the engine. The engine communicates with the outlet. In a closed position of the member, flow from the inlet moves the member to the open position thereby allowing flow through the flow path. In the open position, pulses from the engine move the member to the closed position before pulses from the pulse engine can flow through the flow path, thereby preventing flow through the flow path.