Spool Valve Fluid Control for Surgical Hydraulic Systems
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Solution Overview
Problem
Current laparoscopic surgical instruments face challenges such as difficulty in accessing obstructed body parts, sterilization issues, and the use of hazardous hydraulic fluids that can evaporate, leading to fluid level monitoring and replenishment problems, as well as a lack of direct tactile feedback which can result in accidental device misuse.
Innovation Solution
A hydraulic device utilizing a single spool valve to control fluid communication between control and slave portions, allowing for 'brake mode' to prevent inadvertent motion, 'use mode' for full operation, and 'storage mode' to replenish fluid and prevent evaporation, with optional use of O-rings and seal tubes for sealing connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional hydraulic oils are used in surgical environments, then hydraulic system operation is enabled, but safety hazards increase due to leakage and rupture risks
Solution Approach 1:
The patent changes the chemical composition parameter of the hydraulic fluid from conventional hydraulic oils to biocompatible alternatives such as water-based fluids or mineral oils with controlled evaporation rates. This parameter change maintains hydraulic system operation while eliminating safety hazards associated with conventional oils in surgical environments.
2Object-affected harmful factors
If water or mineral oils are used as hydraulic fluid, then medical compatibility is improved, but fluid evaporation increases leading to monitoring and replenishment requirements
Solution Approach 1:
The patent modifies the evaporation rate parameter of the hydraulic fluid by selecting materials with lower vapor pressure. This allows the system to use medically compatible fluids while minimizing evaporation losses to acceptable levels that do not require frequent monitoring and replenishment.
3Device complexity
If a single spool valve is used to control fluid communication, then device complexity is reduced, but control functionality must be expanded to handle multiple modes
Solution Approach 1:
The patent designs the single spool valve to perform multiple functions by incorporating different port configurations and flow paths within the same valve body. The valve can operate in brake mode (blocking fluid communication), use mode (allowing fluid communication), and storage mode (isolating fluid chambers), thereby reducing device complexity while maintaining adaptability across multiple control modes.
4Object-affected harmful factors
If brake mode is implemented to prevent inadvertent motion, then safety is improved, but operational flexibility may be reduced
Solution Approach 1:
The patent implements a dynamic control system where the spool valve can be rapidly positioned between brake mode (preventing inadvertent motion) and use mode (allowing full operational flexibility). The dynamic switching capability ensures that safety constraints are temporarily applied only when needed, while maintaining full operational flexibility during active use through quick mode transitions.
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 solution prevents unwanted motion and fluid loss, enhancing the robustness and precision of hydraulic systems, allowing safe and efficient operation in sensitive environments.
Implementation Method 1
a single spool valve controls fluid communication between hydraulic cylinders operating in the control and slave portions of the device
Implementation Method 2
allowing the hydraulic system to replenish fluid lost to evaporation or leakage
Implementation Method 3
spool valves may be used that incorporate O-rings to seal one or more of the connections between the spool valve and hydraulic lines
Data Source
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AI summary
A spool valve for controlling fluid communication among hydraulic cylinders operating control and slave portions of a surgical device. The spool valve may be used to disconnect the control and the slave portions from one another such that there is no fluid communication between the control and slave portions. The spool valve may be used to engage or allow fluid communication between the control and slave. The spool valve may also be used to allow fluid communication between the slave and control portion and a fluid reservoir, thus allowing the hydraulic system to replenish fluid lost to evaporation, leakage, or other escape. The spool valve includes a body portion having at least two ports and a spool having at least one passageway moveable to a position so as to communicate with the at least two ports.