Cannula Capture Mechanism for Automatic Needle Shielding
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Solution Overview
Problem
Existing vascular access devices face challenges with accidental needle sticks and blood exposure during needle withdrawal due to the risk of blood splattering and the need for secure needle tip shielding.
Innovation Solution
A cannula capture mechanism that transitions a needle from an unshielded to a shielded position, using an inner and outer housing with compressible portions and interlocking components to securely trap the needle, preventing its exit from both ends of the housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the needle is withdrawn from the catheter assembly, then the needle can be separated for disposal, but the risk of accidental needle sticks and blood exposure increases
Solution Approach 1:
The shield is pre-positioned within the needle assembly, ready to automatically cover the needle tip upon withdrawal from the catheter. This preliminary positioning ensures that the protective action is already in place before the hazardous moment of separation occurs, eliminating the need for manual shielding operations.
Solution Approach 2:
The needle assembly performs its own shielding function through the automatic deployment mechanism. When the needle is withdrawn, the spring-loaded shield automatically advances to cover the needle tip without requiring external intervention or additional components, making the system self-protecting.
2Ease of operation
If the needle is withdrawn from the catheter assembly, then the catheter can remain in place for IV access, but blood may drip or splatter from the needle tip
Solution Approach 1:
The hazardous blood-containing needle is extracted and isolated from the catheter assembly through the withdrawal mechanism. The automatic shield deployment accompanies this extraction, ensuring that the separated needle component is immediately contained and cannot generate blood splatter even if bent or manipulated during disposal.
Solution Approach 2:
The automatic shield acts as an intermediary barrier between the blood-containing needle and the external environment. This intermediate protective layer prevents direct contact between blood and external surfaces, blocking the transmission pathway for blood-borne pathogens during the needle withdrawal and disposal process.
3Ease of operation
If bending forces are applied to the needle during withdrawal, then the needle can be guided for proper placement, but energy is imparted to the needle assembly causing blood to splatter or spray
Solution Approach 1:
The shield is pre-positioned and spring-loaded to activate before any bending or energy transfer occurs during needle manipulation. This ensures that even if bending forces are applied for guidance, the protective barrier is already in place to contain any resulting blood spray or splatter.
Solution Approach 2:
The spring-loaded shield mechanism provides beforehand cushioning by being pre-loaded with elastic energy. When the needle undergoes bending or sudden movements during withdrawal, the shield's spring mechanism absorbs and dampens the energy transfer, preventing the needle from vibrating or shaking in a way that would generate blood spray.
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 mechanism effectively prevents accidental needle sticks and blood exposure by securely locking the needle in the shielded position, reducing the risk of contamination and ensuring safe disposal.
Implementation Method 1
the outer housing may include a spring portion, wherein the spring portion is compressible along a longitudinal axis aligned with the cannula
Implementation Method 2
a compressible portion of the outer housing may be compressed when the outer housing is in the compressed state and decompressed when the outer housing is in the decompressed state
Implementation Method 3
The outer housing may be constructed of an elastomeric material or a rigid material
Data Source
Figure 1~2B
Figure 3A~3B
Figure 4A~4B
AI summary
A cannula capture mechanism 12 may include an inner housing 18, outer housing 20, and a cannula 14. The outer housing may be configured to move between a compressed and a decompressed state. When the cannula is retracted proximally within the inner housing, the inner housing may contract radially inward causing the outer housing to move to the decompressed state and extend distally over a distal portion of the inner housing to seal the distal portion of the inner housing.