Bidirectional Vascular Cannula with Secondary Opening for Ischemia Prevention
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Solution Overview
Problem
Current bidirectional cannula devices for extracorporeal life support systems cause ischemia in lower limbs due to occlusion and require complex positioning mechanisms that hinder fluid flow and increase insertion time.
Innovation Solution
A bidirectional vascular cannula device with a moving mechanism and secondary opening that allows blood flow in both directions, featuring a slider and flexible tongue plate for alignment with the blood vessel wall, enabling efficient blood delivery and stable positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a single-directional cannula is used to supply blood toward the heart, then adequate blood flow to the heart is achieved, but the blood vessel is occluded and blood flow to the extremity is blocked causing ischemia of the lower limbs
Solution Approach 1:
The cannula is divided into multiple functional segments: a main passage for blood flow toward the heart, and a secondary opening with a movable blocking member that can be selectively opened or closed. This segmentation allows independent control of blood flow directions, enabling the device to supply blood to the heart while preventing ischemia in lower limbs by allowing collateral flow through the secondary opening when needed.
2Object-affected harmful factors
If an additional cannula is inserted into the blood vessel to deliver blood to the lower limbs, then ischemia problem is solved, but more hardware equipment and monitoring devices are required increasing insertion time
Solution Approach 1:
The device merges the functions of a single-directional cannula and a bidirectional flow control system into one integrated structure. The movable blocking member integrated into the tubular wall allows the single cannula to perform both blood delivery to the heart and controlled blood delivery to lower limbs, eliminating the need for additional separate cannulas and reducing insertion time while preventing ischemia.
3Manufacturing precision
If a positioning mechanism is added to position the cannula in the blood vessel, then cannula positioning is improved, but the structure becomes complicated and occupies great space inside the cannula adversely affecting fluid flow
Solution Approach 1:
The positioning function is extracted from a complex mechanical positioning mechanism and integrated into the movable blocking member itself. The blocking member's movement along the tubular wall and its engagement features provide positioning capabilities without requiring separate complex positioning hardware, thus maintaining precise cannula positioning while minimizing structural complexity and preserving fluid flow capacity.
4Manufacturing precision
If a positioning mechanism with great space occupation is installed in the cannula, then cannula positioning is achieved, but the amount of fluid flow is adversely affected
Solution Approach 1:
The blocking member is designed to be movable along the tubular wall rather than fixed, allowing dynamic adjustment of its position. This dynamic positioning capability enables the device to adapt to different vascular conditions while maintaining open fluid pathways. The blocking member can be positioned to allow maximum fluid flow when not blocking the secondary opening, thus achieving positioning functionality without permanently obstructing fluid flow.
Data Source
AI summary
A bidirectional vascular cannula device includes a tube and a moving mechanism having a through hole. The tube includes a tubular wall which defines therein a passage having opposite proximal and distal opened ends. The tubular wall has a secondary opening formed therethrough. Oxygenated blood infused into the passage from the proximal opened end is delivered to one end of the blood vessel from the distal opened end, and a part of the blood is delivered to the other end of the blood vessel through the secondary opening and the through hole so as to obviate ischemic caused by cannula occlusion. The moving mechanism is operable to be moved to permit a part of the moving mechanism to project outwardly and to be attached to the inner wall of the blood vessel for positioning the cannula device.