Magnetic Spring Drainage Device for Chronic Subdural Hematoma

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current drainage devices for chronic subdural hematomas face challenges in maintaining a consistent negative pressure without causing harm to the brain and in preventing cerebrospinal fluid leaks, as they either fail to generate sufficient negative pressure or allow air and CSF to be sucked in excessively.

Innovation Solution

A tubular reservoir with a flexible wall and a rigid cover, prestressed with internal or external springs, combined with magnetic forces to maintain a constant negative pressure of around 30 mmHg, and featuring connections and flow restrictions to control drainage and prevent air entry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If gravity-induced drainage with collection container is used, then drainage is simple and passive, but air is sucked in forming bubbles that stop drainage

Engineering Contradiction:
Improvedrainage operationVSAvoiddrainage continuity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent replaces the passive gravity-induced mechanical drainage system with an active vacuum-driven system. A vacuum source creates negative pressure to actively suck out fluid, preventing air bubbles from forming and blocking the drainage pathway, thus ensuring continuous reliable drainage while maintaining ease of operation through automated vacuum control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a vacuum source as an intermediary element between the hematoma cavity and the collection container. This vacuum intermediary actively manages the drainage process by creating controlled negative pressure, preventing air entry and bubble formation that would otherwise stop gravity-based drainage.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If true suction drainage with mechanical bellows or vacuum bottles is used, then negative pressure is generated to prevent air entry, but negative pressure exceeds safe limits for brain tissue

Engineering Contradiction:
Improvedrainage reliabilityVSAvoidbrain tissue damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a feedback control system where a pressure sensor continuously monitors the negative pressure in the drainage system. When pressure approaches unsafe levels, the control unit automatically adjusts the vacuum source to maintain pressure within the safe range (-5 to -30 mmHg), ensuring reliable drainage without causing brain tissue damage.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent transitions from static vacuum systems (bellows, vacuum bottles) to a dynamic controlled vacuum system. The vacuum source is actively regulated through feedback control to dynamically adjust negative pressure levels, maintaining them within safe physiological limits while ensuring continuous effective drainage.

Inventive Principle:
Principle #15Dynamics

3Productivity

If uncontrolled suction drainage is used, then drainage efficiency is high, but cerebrospinal fluid is sucked in large quantities causing harm

Engineering Contradiction:
Improvedrainage efficiencyVSAvoidcerebrospinal fluid loss
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent uses feedback control through pressure sensors and control units to monitor and regulate negative pressure levels. By maintaining pressure within specific safe ranges, the system achieves efficient drainage of hematoma fluid while preventing excessive suction that would draw in large quantities of cerebrospinal fluid, thus protecting against harmful fluid loss.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent carefully controls and changes the pressure parameter within specific physiological limits (-5 to -30 mmHg). This parameter control ensures high drainage efficiency for hematoma removal while preventing the pressure from becoming so negative that it would cause excessive cerebrospinal fluid infiltration and loss.

Inventive Principle:
Principle #35Parameter changes

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 achieves a consistent negative pressure, limiting the volume flow and preventing air and cerebrospinal fluid from entering, thereby reducing the risk of rebleeding and improving drainage efficiency while ensuring patient safety.

Implementation Method 1

At least one spring (4) is arranged inside or outside the reservoir (100) in such a way that it pushes the base (2) and the cover (3) apart

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

At least one arrangement of one or more magnets (11, 12) compensates for the characteristic curve of the spring (4) in such a way that the force is kept approximately constant

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Implementation Method 3

a tubular reservoir (100) with a flexible wall (1) and a rigid cover (3) and base (2)

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3302599B1Device for drainage, in particular for drainage of a chronic subdural hematoma
Publication Date: 2021.09.22 PRIMED HALBERSTADT MEDIZINTECHN
  • EP3302599B1 patent drawingFigure 1~2
  • EP3302599B1 patent drawingFigure 3
  • EP3302599B1 patent drawingFigure 4

AI summary

The invention relates to a device for drainage, comprising a tubular reservoir (100) having a pliable wall (1), a rigid cover (3), and a rigid bottom (2), and having at least one spring (4), which exerts a force that presses the cover (3) and the bottom (2) apart, wherein the cover (3) is movable in the direction of the bottom (2) in order to place the spring into the start position. According to the invention, the device has one or more magnets (11, 12), which are configured such that the magnets exert an additional force onto the reservoir (100) in such a way that a resulting force pressing the cover (3) and the bottom (2) apart is substantially constant across that part of the spring path.