US Patent 7833201 Flashback chamber visual enhancement

Featured is a medical infusion device for vascular access with enhanced flashback visualization that includes a hub assembly having a flashback chamber. The hub assembly includes a proximal portion, a distal portion and a substantially transparent window section intermediate the proximal portion and distal portion. A needle is coupled to the flashback chamber so that fluid flows through the lumen of the needle into the flashback chamber after the needle is inserted into a blood vessel. A contrasting member is disposed on at least a portion of the hub assembly, so that when blood enters the flashback chamber, the contrasting member provides a high-contrast background when viewed through the window section.