Passive Shielding Needle Assembly with Skin Sensor Lever
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Solution Overview
Problem
Existing blood collection sets often fail to securely and passively shield used needle cannulas without causing self-ejection from the patient during activation of the safety feature, and lack a guide for locating ideal puncture sites.
Innovation Solution
A blood collection set with a shielding needle assembly featuring a hub and shield member in telescoping association, driven by a biasing member, and a pivoting skin sensor lever that maintains the needle cannula exposed until insertion or removal, then automatically retracts it within the shield without axial force greater than skin friction, while providing a guide for puncture site location.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a passive safety shield is activated upon needle removal, then the needle is shielded to prevent accidental sticks, but the needle may be self-ejected from the patient due to excessive axial force
Solution Approach 1:
A skin sensor lever is introduced as an intermediary component between the needle hub and the safety shield activation mechanism. The lever remains in contact with the patient's skin during insertion and maintenance phases, and its disengagement upon skin release triggers the shield activation. This intermediary ensures that activation occurs only after intentional needle removal, preventing premature shielding that could cause self-ejection.
Solution Approach 2:
The safety shield activation system uses the patient's own skin contact as the triggering mechanism. When the needle is intentionally removed from the skin, the loss of skin contact with the lever automatically initiates the shielding process without requiring additional user action. This self-service approach ensures safety activation is tied directly to the completion of the medical procedure.
2Measurement precision
If the needle cannula is securely held in place during insertion, then accurate puncture placement is achieved, but the needle cannot be easily removed when needed
Solution Approach 1:
The system transitions from a static retention state during insertion to a dynamic release state upon skin contact loss. The lever maintains engagement with the needle hub during accurate placement, then automatically disengages and triggers shield activation when skin contact is lost, enabling easy removal while maintaining precision during the procedure.
3Reliability
If the safety shield is activated immediately upon needle insertion, then accidental sticks during insertion are prevented, but the needle cannot be properly positioned in the patient
Solution Approach 1:
The safety shield is prepared and positioned in advance but remains inactive during insertion. The skin sensor lever maintains engagement during the positioning phase, preventing premature activation. Only after the needle is properly positioned and the procedure is complete does the lever disengage, triggering the pre-positioned shield to activate and provide safety protection.
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
Ensures secure and automatic shielding of the needle cannula without self-ejection, enhancing user safety and facilitating precise needle placement through the skin sensor lever's guidance.
Implementation Method 1
a coil spring disposed between the needle hub and the shield member for biasing the needle hub and the shield member telescopically away from each other
Implementation Method 2
the forward portion of the lever is in frictional engagement with a patient's skin and is movable during contact with the patient's skin
Data Source
AI summary
A shielding needle assembly is provided with a hub having a needle cannula with a puncture tip extending from a forward end thereof, and a shield member in telescoping association with the hub. A drive member biases the hub and the shield member away from each other for relative telescopic movement between a first position in which the puncture tip extends from a forward end of the shield member, and a second position in which the puncture tip is encompassed within the shield member. A pivoting lever maintains the hub and the shield member in the first position against the bias of the drive member. The lever is pivotable during contact with a patient's skin surface, thereby releasing the hub and the shield member from the first position and permitting the drive member to bias the hub and the shield member toward the second position.