Rigid Access Cannula for Patent Blood Flow in Obstructed Catheters
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Solution Overview
Problem
Existing blood collection methods, particularly using peripheral intravenous catheters, face challenges such as clot formation, fibrin sheaths, and softening of catheter materials, leading to obstructed blood withdrawal, hemolysis, and reduced blood quality over time.
Innovation Solution
A system and method involving a cannula with increased rigidity inserted through a previously placed catheter to maintain a patent lumen, straighten tortuous paths, and avoid obstructions, ensuring laminar blood flow and improved blood quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a peripheral intravenous catheter is used for blood collection, then initial blood withdrawal is effective, but over time clot formation and fibrin sheaths obstruct the lumen leading to reduced blood quality
Solution Approach 1:
The system divides the catheter into two separate components: a base catheter that remains in the vessel and a removable access catheter that is inserted through the base catheter. This segmentation allows the access catheter to be fresh and free of obstructions while the base catheter remains in place, solving the problem of luminal obstruction over time.
Solution Approach 2:
The base catheter is placed in advance to establish vascular access, and the access catheter is pre-prepared and sterile. When needed, the access catheter is inserted through the base catheter before use, ensuring it is free of fibrin sheaths and clots that would form in a single continuous catheter over time.
2Device complexity
If a single catheter is used for both insertion and blood withdrawal, then device complexity is reduced, but the catheter softens over time causing tortuous blood flow paths
Solution Approach 1:
The catheter system is segmented into a base catheter that provides initial access and a separate access catheter that is inserted through it. The access catheter can be made of more rigid material since it is shorter and only needs to maintain patency during the blood draw procedure, while the base catheter remains in place.
Solution Approach 2:
The base catheter acts as an intermediary structure that provides a stable pathway through the vessel wall. The access catheter is then inserted through this intermediary base catheter to provide the rigid, patent lumen needed for blood withdrawal, separating the functions of vascular access and blood collection.
3Reliability
If repeated venipuncture is performed to obtain blood samples, then fresh blood can be collected, but patient discomfort and procedural time increase
Solution Approach 1:
The base catheter is placed in advance during an IV insertion procedure, establishing a permanent access pathway. Subsequent blood draws can be performed through the access catheter without requiring new venipuncture procedures, saving time and reducing patient discomfort while maintaining fresh blood sample quality.
Solution Approach 2:
The base catheter provides continuous vascular access that can be used for multiple blood draws over time. The access catheter can be inserted and removed as needed for individual blood collection events, allowing continuous useful action without repeating the invasive venipuncture procedure.
Data Source
AI summary
A blood collection system can include a cannula for insertion into a catheter system that comprises a hub with an internal chamber, a distal port in fluid communication with the internal chamber and coupled with a catheter tube that can be preplaced in a blood vessel of a patient, and an access port in fluid communication with the internal chamber. The cannula can be inserted in the catheter tube and can include a distal opening that is positioned within the blood vessel of a patient and is in fluid communication with an interior of the blood vessel to permit blood to flow into a lumen of the cannula, and can include a proximal opening positioned within the internal chamber to permit blood to flow from the cannula into the internal chamber and through the access port of the hub.