Expandable Cannula for High Flow Rate and Vessel Patency
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Solution Overview
Problem
Existing cannulas face challenges in achieving high blood flow rates without causing vessel occlusion or tissue damage, as they either have fixed diameters leading to increased resistance or require larger diameters that can disrupt physiological flow and cause ischemia or venous congestion.
Innovation Solution
A cannula with an expandable distal end that transitions from a non-expanded to an expanded state after insertion, featuring openings to maintain vessel patency and prevent occlusion, allowing for variable diameter adaptation to the vessel size and ensuring blood flow to downstream areas while minimizing resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a large diameter cannula is used to achieve high blood flow rates, then flow rate increases, but vessel occlusion and tissue ischemia occur
Solution Approach 1:
The cannula employs a dynamic structure where the distal end can expand after insertion to increase the lumen diameter for higher flow rates, while the proximal end remains collapsible to minimize vessel occlusion and allow physiological blood flow to continue downstream
Solution Approach 2:
The cannula is divided into functionally distinct segments: a proximal end that remains collapsible to maintain vessel patency, a central section with intermediate properties, and a distal end that expands to maximize flow rate, with each segment optimized for its specific function
2Object-affected harmful factors
If a small diameter cannula is used to minimize vessel damage, then vessel occlusion is reduced, but blood flow resistance increases
Solution Approach 1:
The cannula transitions from a small collapsed state during insertion to a larger expanded state at the distal end for blood withdrawal, dynamically adjusting diameter to minimize both insertion trauma and flow resistance
Solution Approach 2:
The distal end of the cannula is nested within the central section during insertion, allowing the cannula to pass through tissue with minimal diameter, then the nested structure expands at the distal end to provide a large lumen for high flow rates
3Device complexity
If a fixed diameter cannula is used, then device complexity is reduced, but adaptability to different vessel sizes is limited
Solution Approach 1:
The cannula incorporates expandable and collapsible sections that allow it to adapt its diameter to match different vessel sizes, transitioning between collapsed and expanded states based on the specific application requirements
Solution Approach 2:
The cannula's physical parameters, particularly diameter, are made variable through the expandable distal end and collapsible proximal end, allowing the same device to be adapted to different vessel diameters and flow rate requirements
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 expandable cannula design ensures secure fit, prevents vessel collapse, reduces blood trauma, and maintains physiological blood flow, allowing for efficient oxygenation and perfusion of tissues while minimizing the risk of ischemia and venous congestion.
Implementation Method 1
the distal end (14) has an expandable structure (16) which can be converted from a non-expanded state to an expanded state
Data Source
AI summary
There is disclosed a device for cannulation of a hollow organ, in particular of an arterial or venous blood vessel of a mammalian body, e.g., human, said device comprising a cannula that has a proximal end, a distal end, and a central section located between the proximal end and distal end. The distal end has an expandable structure which can be converted, for example by means of a dilator, from a non-expanded state to an expanded state, and the expandable structure comprises openings at least in the expanded state.