Elastomeric Cassette Ridge for High Pressure Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Prior art peristaltic pumps using rotating roller heads face issues with cassette failure under transient high positive pressures, as the friction fit construction method is inadequate for handling such pressures, potentially leading to elastomer/substrate interface failure.
Innovation Solution
A surgical cassette with a molded flow channel on an elastomeric sheet bonded or mechanically attached to a rigid substrate, featuring a raised ridge or boss integrally formed on the elastomeric sheet to ensure firm engagement with the surgical console, preventing dislodgment under high pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the elastomeric sheet is bonded or mechanically attached to the rigid substrate using friction fit construction, then the cassette assembly is simplified, but the assembly fails under transient high positive pressures
Solution Approach 1:
The elastomeric sheet features a raised ridge at specific locations where it contacts the rigid substrate, creating localized high-friction zones. This concentrates the attachment strength at critical areas rather than distributing it uniformly, allowing the assembly to withstand transient high positive pressures while maintaining overall simplicity.
Solution Approach 2:
The raised ridge on the elastomeric sheet creates a curved or elevated contact surface that engages with the rigid substrate. This geometric feature increases the normal force and friction at the interface, preventing slippage under pressure while maintaining a simple bonded or mechanically attached construction.
2Reliability
If the elastomeric sheet is firmly pressed against the surgical console, then the sheet remains secure under high pressures, but the cassette cannot be properly drawn against the pump head
Solution Approach 1:
The raised ridge is positioned at specific locations on the elastomeric sheet where high pressure engagement is needed, while other areas remain flexible and compliant. This allows the cassette to be drawn against the pump head at locations away from the ridge, while the ridge provides secure engagement with the surgical console under pressure.
Solution Approach 2:
The elastomeric sheet is effectively segmented into different functional zones: the raised ridge area provides firm engagement with the surgical console, while other areas maintain flexibility for cassette installation and removal. This segmentation allows both secure attachment and ease of operation.
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 solution effectively reduces the likelihood of cassette failure by maintaining secure attachment of the elastomeric sheet to the substrate, even under high transient pressures, enhancing the reliability of the fluidic system during surgical procedures.
Implementation Method 1
The friction fit construction method is inadequate for handling such pressures
Implementation Method 2
The elastomeric sheet contains a raised ridge or boss integrally formed as part of the elastomeric sheet
Data Source
Figure 1~4
Figure 3
AI summary
A surgical cassette (10) is provided having a molded flow channel (34) contained on an elastomeric sheet (30) that is bonded or mechanically attached to a rigid substrate. A surgical console (24) contains a cassette receiving area having a pump head with rollers that are mounted radially from the axis of rotation of the pump motor and compress the elastomeric flow channels against the rigid substrate. The cassette is held in place against the pump head by a latching mechanism that draws the cassette against the pump head. The periphery of the or each elastomeric sheet (25,26,28,30,100) contains a raised ridge (36) or boss integrally formed as part of the elastomeric sheet at, near or around the area(s) of the sheet that are subject to high transient or static fluid pressures. The ridge (36) allows the elastomeric sheet to be firmly pressed against the cassette receiving portion of the surgical console, yet still allow the cassette to be drawn against the pump head. The firm engagement of the sheet ridge (36) against the cassette receiving portion of the surgical console helps to ensure that the elastomeric sheet does not become dislodged when the cassette is exposed to high transient pressures.