Lavage Unit Bellows Pump Linear Flow Path

Solution Overview

Problem

Current lavage units are not ergonomically designed to be held in various orientations, leading to inefficiencies in fluid delivery and debris removal due to pressure drops caused by circuitous fluid paths and complex conduit designs.

Innovation Solution

A lavage unit with a pivotally attached barrel and motor located in the handgrip, featuring a pump with a bellows having a linear inlet path, reducing pressure drop and allowing ergonomic handling in different orientations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the lavage unit uses conduits with U-shaped turns to supply fluid to the bellows pump, then the pump can be positioned within the handpiece structure, but pressure drop occurs and fluid delivery efficiency is reduced

Engineering Contradiction:

Improveergonomic handlingVSAvoidpressure drop

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

The pump chamber is divided into two separate chambers: a first chamber for fluid intake and a second chamber for fluid discharge. This segmentation allows the fluid to travel in a linear path from the inlet to the outlet without requiring U-shaped turns, thereby reducing pressure drop while maintaining compact handpiece integration

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent repositions the fluid flow path from a two-dimensional curved path (U-shaped turns) to a three-dimensional linear path through the bellows pump chambers. The fluid enters the first chamber, moves linearly through the bellows mechanism, and exits from the second chamber, eliminating the need for complex conduit curves

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Device complexity

If the lavage unit uses complex conduit curves to connect fluid supply lines to the bellows pump, then the pump can be integrated within the handpiece, but the design complexity and manufacturing cost increase

Engineering Contradiction:

Improveconduit designVSAvoidmanufacturing cost

Core Design Contradiction:

Device complexityVSEase of manufacture

Solution Approach 1:

The pump chamber is divided into two separate chambers: a first chamber for fluid intake and a second chamber for fluid discharge. This segmentation allows the fluid to travel in a linear path from the inlet to the outlet without requiring U-shaped turns, thereby reducing pressure drop while maintaining compact handpiece integration

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The complex U-shaped conduit curves are extracted and eliminated from the design. Instead, simple linear conduits are used to connect the fluid supply to the bellows pump inlet and the pump outlet to the discharge, significantly simplifying the overall conduit design and manufacturing

Inventive Principle:

Principle #2Taking out (Extraction)

3Productivity

If the bellows pump uses a linear inlet path for fluid flow, then pressure drop is reduced and fluid delivery efficiency improves, but the pump chamber design becomes more complex with two separate chambers

Engineering Contradiction:

Improvefluid delivery efficiencyVSAvoidpump chamber design

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The pump chamber is divided into two separate chambers: a first chamber for fluid intake and a second chamber for fluid discharge. This segmentation allows the fluid to travel in a linear path from the inlet to the outlet without requiring U-shaped turns, thereby reducing pressure drop while maintaining compact handpiece integration

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The two-chamber pump design is integrated into a single bellows pump unit that is compactly housed within the handpiece. The first and second chambers are positioned adjacent to each other, with the bellows mechanism connecting them, creating a unified compact assembly that maintains linear fluid flow while occupying minimal space

Inventive Principle:

Principle #5Merging (Combining)

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

Enhances ergonomic handling and reduces pressure drop, improving fluid delivery efficiency and simplifying the design by eliminating the need for complex conduit curves.

Implementation Method 1

The bellows is reciprocated to first draw fluid into the pump chamber defined by the bellows and then force the fluid out of the chamber

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentUS11419973B2Medical/surgical lavage unit with a pump that includes a bellows chamber and a supplemental chamber

Publication Date: 2022.08.23 STRYKER CORP

AI summary

A lavage unit may include a handpiece configured to house a pump to which an irrigation tube is connected. The pump may include a bellows defining a pump chamber. When the bellows is reciprocated by a linkage, the bellows draws irrigation fluid from the irrigation tube into the pump chamber and then discharges the fluid out of the pump chamber through an outlet. The pump further includes a section formed from compressible or flexible material that defines a supplemental chamber. The linkage is connected to said pump to alternatively compress the bellows forming the pump chamber and the material forming the supplemental chamber. During the movement of the linkage a valve located between the pump chamber and the supplemental chamber reciprocates with the linkage.