Retractable Blood Collection Needle with Visual Flow Confirmation

The patent applies local quality by making only the critical observation area (the region around the one-way valve seat and blood collection chamber) transparent, while other parts of the device can remain opaque. This allows medical staff to visually confirm blood flow through the transparent window without requiring the entire device to be transparent, thus balancing manufacturing cost with detection capability.

The patent utilizes color changes by incorporating a transparent or translucent material that allows light transmission in the critical observation area. This enables the blood (which has a distinct red color) to be visually detected against the transparent background, providing clear visual confirmation of successful venous injection without adding significant manufacturing complexity.

The patent applies the nested doll principle by placing the needle within a protective sheath or housing structure. After blood collection, the needle can be retracted into or covered by the protective housing, which nests around the needle tip. This provides automatic protection against staff injury while maintaining simple operation, as the protective mechanism is integrated into the device structure itself.

The patent implements self-service by designing an automatic needle retraction or covering mechanism that activates upon completion of blood collection. The device itself performs the protective action without requiring additional manual steps from the operator - for example, a spring-loaded mechanism that automatically covers the needle tip when the plunger is pushed, or a snap-fit protective cap that closes automatically.

The patent applies merging by integrating the protective function directly into the existing blood collection device structure. Rather than adding a separate, complex retraction mechanism, the protection feature is combined with the plunger assembly or housing structure that already exists in the device. This reduces overall complexity while still achieving needle tip protection through shared structural elements.

The patent implements the disposable principle by using a simple, low-cost protective cap or sheath that can be easily attached or integrated into the device. This protective element is designed to be simple and inexpensive, potentially disposable, rather than a complex mechanical retraction system. The protection is achieved through a straightforward structural addition rather than a complex mechanism.