Segmented Pressure Valve for Hydrocephalus Drainage
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Solution Overview
Problem
Current drainage systems for hydrocephalus patients face challenges such as the siphon effect, leading to overdrainage, complications like reduced ventricular size and subdural hematomas, and are sensitive to implantation position, physical activity, and subcutaneous pressure, with existing devices often causing either hyperdrainage or hypodrainage due to their design limitations.
Innovation Solution
A drainage device with independent pressure regulation mechanisms for lying and standing positions, featuring a shutter and passage restriction that allow partial closure, reducing hysteresis and maintaining a minimum safety flow rate, and adjustable opening and closing pressures to accommodate varying patient positions and sizes without external contact, using a magnetic coupling or radio frequency control for adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a differential pressure valve is used to regulate cerebrospinal fluid drainage, then drainage control is achieved, but the device becomes sensitive to implantation position and subcutaneous pressure, causing either hyperdrainage or hypodrainage
Solution Approach 1:
The drainage device is segmented into two independent pressure regulation mechanisms: a first mechanism for regulating drainage when the patient is lying down, and a second mechanism for regulating drainage when the patient is standing. Each mechanism operates independently with its own pressure threshold, eliminating the sensitivity to implantation position that plagues single-mechanism devices.
Solution Approach 2:
The device dynamically adapts its resistance characteristics based on patient position. When the patient is lying down, the first mechanism provides low resistance; when standing, the second mechanism provides high resistance. This dynamic adaptation ensures reliable drainage control across different positions without requiring precise implantation placement.
2Object-affected harmful factors
If anti-siphon devices are implanted to counteract the siphon effect, then overdrainage is reduced, but the devices become sensitive to implantation position and may cause hypodrainage if positioned incorrectly
Solution Approach 1:
The anti-siphon function is segmented from the general drainage regulation function. The second pressure regulation mechanism specifically addresses the siphon effect during standing position with its higher pressure threshold, while the first mechanism ensures adequate drainage during lying position. This segmentation ensures both siphon mitigation and drainage adequacy regardless of implantation position.
3Productivity
If flow-regulated devices with reduced passage section are used to limit drainage flow, then average flow control is achieved, but the devices become highly sensitive to obstruction by debris and protein deposits
Solution Approach 1:
Different local qualities are applied to different drainage paths: the first mechanism has a larger passage section optimized for high-flow situations and resistance to obstruction, while the second mechanism has a smaller passage section optimized for precise flow control during standing position. This local differentiation allows the system to maintain both flow control and obstruction resistance.
4Reliability
If devices arranged in series are used to increase resistance, then drainage control in vertical position is improved, but intracranial pressure increases mechanically compared to lying position
Solution Approach 1:
The pressure regulation is segmented into two independent mechanisms that operate in parallel rather than in series. The first mechanism handles lying position drainage with low resistance, while the second mechanism handles standing position drainage with high resistance. This parallel segmentation allows each mechanism to independently regulate pressure without compounding resistance effects, reducing intracranial pressure variation between positions.
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 device effectively regulates cerebrospinal fluid drainage independently of subcutaneous and atmospheric pressures, reducing the risk of obstruction and allowing for automatic adjustment based on patient position, thereby minimizing complications associated with over or under-drainage.
Implementation Method 1
a first pressure-regulated valve capable of opening at a first predetermined opening pressure and allowing the passage of fluid
Implementation Method 2
a second valve capable of closing with a minimum safety flow rate, at a pressure predetermined closing pressure greater than the first opening pressure
Implementation Method 3
a third pressure-regulated valve being able to open at a second predetermined opening pressure higher, preferably at least 10%, more preferably at least 20%, higher than the closing pressure
Data Source
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AI summary
The present invention relates to a drainage device comprising: - an inner chamber, - at least one entry portal and one exit portal communicating with the internal chamber, - at least one shutter placed at least partially in the inner chamber, - at least a first valve seat associated with the entry portal, it being possible for the shutter to fit over the first seat in order to isolate the entry portal from the exit portal, in particular when the differential pressure between the entry and exit portals is less than a predetermined first opening pressure, - at least one passage restriction associated with the exit portal, it being possible for the shutter to close off said restriction, allowing a minimum safe flow rate of greater than or equal to 2.5 ml/h even in a maximum closing-off position, referred to as “closed position”, in particular reached for differential pressures between the entry and exit portals of greater than or equal to a predetermined closing pressure.