Concentric Guidewire Assembly Core Wire Centering

The patent introduces a mandrel as an intermediary tool during the coil spring formation process. The mandrel serves as a temporary support structure that holds the core wire in the correct central position while the coil spring is being formed around it. After the coil spring is complete, the mandrel is removed, leaving the core wire properly centered without requiring additional spacers or complex assembly procedures. This resolves the contradiction by enabling easy manufacturing (through simple mandrel removal) while achieving perfect steerability (through accurate core wire centering).

The patent extracts the core wire centering function from the final guidewire structure itself and transfers it to a temporary mandrel used only during manufacturing. Instead of incorporating permanent spacers or additional spring sections into the guidewire design, the mandrel provides the necessary centering support during coil formation and is then completely removed. This eliminates the need for additional components in the final product, reducing manufacturing complexity while maintaining high centering precision.

The mandrel is designed as a disposable, temporary manufacturing aid that serves its purpose during coil spring formation and is then discarded. It is not part of the final guidewire structure, so it does not create permanent stiffness points or reduce flexibility. The mandrel enables precise core wire centering during manufacturing without compromising the flexibility and mechanical properties of the finished guidewire, unlike permanent spacers or additional spring sections that would remain in the final structure.