Alternative designs, materials and manufacturing methods for medical devices such as guidewires. Some embodiments are directed to a guidewire, including a core wire having a proximal portion and a distal portion, and an elongated distal assembly defining an inner lumen, the elongated distal assembly connected to the core wire adjacent the distal portion of the core wire, wherein the elongated distal assembly includes a plurality of separate and discrete interlocking segments. Some other embodiments are directed to a guidewire including a tubular segment connected to the distal portion of the corewire, wherein the tubular segment includes a plurality of notches therein to increase the lateral flexibility of the segment while maintaining rotational torqueability.