Bulged Elastomeric Membrane for Stable Medical Pump Delivery

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Solution Overview

Problem

Existing medical elastomeric pumps deliver medical fluids at a delivery rate that varies with the fill level, necessitating throttle elements to stabilize the flow, which is undesirable for consistent administration.

Innovation Solution

The elastomeric membrane is designed with multiple bulge sections that form separate pump volume sections, allowing for a hydraulic parallel connection to stabilize delivery pressure and rate, achieved through varying elastic properties, thicknesses, and cross-linking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single pump volume is used in the elastomeric membrane, then the membrane structure is simple, but the delivery rate varies significantly with fill level

Engineering Contradiction:
Improvemembrane structureVSAvoiddelivery rate consistency
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The pump volume is divided into multiple pump volume sections (first, second, third sections) with different expansion characteristics. Each section contains sub-compartments that expand at different rates, creating a segmented structure that collectively provides more stable delivery pressure across varying fill levels while maintaining reasonable structural complexity

Inventive Principle:
Principle #1Segmentation

2Reliability

If throttle elements are added downstream to stabilize flow rate, then delivery rate consistency is improved, but device complexity increases

Engineering Contradiction:
Improvedelivery rate consistencyVSAvoidpump structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The elastomeric membrane itself is designed to provide flow stabilization through its multi-section structure with different expansion characteristics. The membrane's inherent mechanical properties create the necessary pressure regulation without requiring separate throttle elements, allowing the device to self-regulate its delivery rate

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If the elastomeric membrane is highly elastic to accommodate fill variations, then fill level tolerance is improved, but delivery pressure control deteriorates

Engineering Contradiction:
Improvefill level toleranceVSAvoiddelivery pressure control
Core Design Contradiction:
Adaptability or versatilityVSStress or pressure

Solution Approach 1:

Different regions of the elastomeric membrane are designed with different elastic properties. The first pump volume section has different expansion characteristics than the second and third sections, allowing each region to contribute differently to pressure regulation while collectively accommodating fill level variations

Inventive Principle:
Principle #3Local quality

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

This design ensures a more consistent delivery rate of medical fluids, reducing dependence on fill state variations and enhancing patient safety.

Implementation Method 1

the elastomeric membrane is elastically stretched when the pump volume is at least partially filled with the medical fluid, whereby the elastically stretched elastomeric membrane exerts a delivery pressure on the pump volume for conveying the medical fluid

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4106841B1Elastomeric membrane for a medical elastomeric pump, and medical elastomeric pump with such an elastomeric membrane
Publication Date: 2025.08.13 B BRAUN MELSUNGEN AG
  • EP4106841B1 patent drawingFigure 1
  • EP4106841B1 patent drawingFigure 2
  • EP4106841B1 patent drawingFigure 3~4

AI summary

A medical elastomer pump of this type and an elastomeric membrane of this type are known, the elastomeric membrane forming a pump volume for receiving and delivering the medical fluid and, in a filled state of the pump volume in which the latter is filled at least in part with the medical fluid, being resiliently stretched, as a result of which the resiliently stretched elastomeric membrane applies a delivery pressure onto the pump volume for delivering the medical fluid. According to the invention, the elastomeric membrane comprises a plurality of bulge portions which, at least in the filled state, are convex, each forming a bulge, wherein the bulges each form a pump volume portion of the pump volume. Use in infusion therapy.