Manual Negative Pressure Wound Pump With Constant-Force Piston

Solution Overview

Problem

Existing negative pressure wound therapy devices are costly, complex, and require electronic components, making them environmentally harmful and difficult to use, while devices without electric pumps are less effective in maintaining a constant negative pressure.

Innovation Solution

A negative pressure device with a single-piece, hollow cylindrical housing containing a piston and a constant-force mechanism, allowing manual operation without electronic components, which generates and controls sub-atmospheric pressure using a finger-activated piston for easy use and effective suction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electric pumps are used to generate negative pressure, then the negative pressure value is constant and effective, but the device cost is extremely high and environmental impact is significant

Engineering Contradiction:

Improvenegative pressure constancyVSAvoiddevice cost and environmental impact

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the electric pump component from the negative pressure wound therapy device, replacing it with a manual piston mechanism. This extraction of the electronic component eliminates the need for power supply, reduces device cost, and simplifies disposal while maintaining therapeutic effectiveness through mechanical pressure generation.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The device enables self-service operation through manual piston activation, allowing healthcare providers to generate negative pressure without requiring electrical infrastructure or complex electronic controls. The mechanical system is self-contained and can be operated directly at the patient's bedside.

Inventive Principle:

Principle #25Self-service

2Reliability

If electric pumps are used to generate negative pressure, then the negative pressure value is constant and effective, but the device requires electronic components that are difficult to dispose of

Engineering Contradiction:

Improvenegative pressure constancyVSAvoiddisposal difficulty

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent removes the electric pump component from the negative pressure wound therapy device, replacing it with a manual piston mechanism. This extraction of the electronic component eliminates the need for power supply, reduces device cost, and simplifies disposal while maintaining therapeutic effectiveness through mechanical pressure generation.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The device is designed as a disposable mechanical system without valuable electronic components that would require special recycling. The entire device can be disposed of after use without complex separation processes, making it economically and environmentally advantageous for single-use applications.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If electric pumps are used to generate negative pressure, then the negative pressure value is constant and effective, but the device is complicated to use and limits use to specialized personnel

Engineering Contradiction:

Improvenegative pressure constancyVSAvoidoperation complexity

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces the electronic pump system with a purely mechanical piston-based pressure generation system. This substitution eliminates complex electronic controls, sensors, and power management requirements, resulting in a device that can be operated through simple manual actions by any trained healthcare provider.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The device enables self-service operation through manual piston activation, allowing healthcare providers to generate negative pressure without requiring electrical infrastructure or complex electronic controls. The mechanical system is self-contained and can be operated directly at the patient's bedside.

Inventive Principle:

Principle #25Self-service

4Device complexity

If devices without electric pumps are used, then the device is simpler and more cost-effective, but the negative pressure value is not constant and effectiveness is reduced

Engineering Contradiction:

Improvedevice simplicity and costVSAvoidnegative pressure constancy

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent employs a spring-loaded piston mechanism that dynamically maintains constant negative pressure throughout the piston's movement cycle. The spring force compensates for pressure variations, ensuring stable therapeutic pressure is applied to the wound throughout the operation cycle.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The device operates through periodic piston cycles where the spring-loaded mechanism automatically restores the piston to its initial position after each depression. This periodic action maintains continuous negative pressure application while allowing simple manual operation, combining reliability with ease of use.

Inventive Principle:

Principle #19Periodic action

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 constant negative pressure comparable to electrically powered devices, is cost-effective, environmentally friendly, and easy to use, with a compact design that allows single-handed operation and real-time monitoring of the suction process.

Implementation Method 1

A negative pressure device with a single-piece, hollow cylindrical housing containing a piston and a constant-force mechanism, allowing manual operation without electronic components, which generates and controls sub-atmospheric pressure

Methodology Applied

Scientific EffectNegative pressure generation: Pressure Gradient

Implementation Method 2

A negative pressure device with a single-piece, hollow cylindrical housing containing a piston and a constant-force mechanism

Methodology Applied

Scientific EffectConstant force mechanism: Spring

Data Source

PatentEP4192540B1Negative pressure medical device

Publication Date: 2026.02.25 MEDICUD SRL

Figure 1A~1B
Figure 2A~2B
Figure 3A~3B

AI summary

Negative pressure device (1, 1') for treating a wound and removing a fluid from said wound comprising a longitudinal housing (10) having a first end (101) configured to be connected to the wound and a second end (102) opposite the first end (101), wherein the longitudinal housing (10) is a structure in a single piece, hollow and cylindrical, a piston (11) sliding inside the housing (10) to generate the negative pressure, a constant-force mechanism (12, 12') configured to be loaded and activate the piston (11), wherein said constant- force mechanism (12, 12') is fixed to the second end (102) of the longitudinal housing (10) and to the sliding piston (11) and is placed inside the housing (10), and a valve system (13) for drawing air from the housing (10) when the piston (11) slides towards the first end (101) of the housing (10) and for bringing the wound fluid into the housing (10) when the piston (11) slides towards the second end (102) of the housing (10), wherein the constant-force mechanism (12, 12') is entirely contained inside the longitudinal housing (10) where the piston (11) and the second end (102) of the longitudinal housing (10) comprises a rear opening (14) such as to allow the insertion of one or more fingers of an individual's hand to manually slide the piston (11) and load the constant-force mechanism (12, 12').