US Patent 7740614 Indwelling needle assembly

An indwelling needle assembly has an inner needle having a sharp point at its tip, an inner needle hub fixed to a base section of the inner needle, a hollow outer needle into which the inner needle is inserted, an outer needle hub fixed to a base section of the outer needle, and a tube inserted into the inner needle hub and connected to the base section of the outer needle hub such that the inner cavity of the tube communicates with the inner cavity of the outer needle. The center axis of the outer needle and the center axis of the tube at its head section are substantially parallel with each other with the inner needle inserted into the outer needle.