An apparatus for accessing the lumen of a vessel. The apparatus includes a reusable handheld device and a disposable cartridge. The reusable handheld device includes a imaging device attachment utilized to secure an image capturing instrument, an arm coupled to the imaging device attachment, and a depth scale coupled to the arm, wherein the depth scale provides a scale indicating an insertion depth. The disposable cartridge attaches to the reusable handheld device. The disposable cartridge includes a sheath, needle or guidewire coupled to the disposable cartridge. The sheath or needle extends to the insertion depth when fully advanced, thereby allowing the sheath, needle, or guidewire to access the lumen of a vessel.
