The invention relates to the guidance, positioning and placement confirmation of intravascular devices, such as catheters, stylets, guidewires and other flexible elongate bodies that are typically inserted percutaneously into the venous or arterial vasculature. Currently these goals are achieved using x-
ray imaging and in some cases
ultrasound imaging. This invention provides a method to substantially reduce the need for imaging related to placing an
intravascular catheter or other device. Reduced imaging needs also reduce the amount of
radiation that patients are subjected to, reduce the time required for the procedure, and decrease the cost of the procedure by reducing the time needed in the
radiology department. An aspect of the invention includes, for example, an endovenous access and
guidance system. The
system comprises: an elongate flexible member adapted and configured to access the venous vasculature of a patient; a sensor disposed at a distal end of the elongate flexible member and configured to provide
in vivo non-
image based ultrasound information of the venous vasculature of the patient; a processor configured to receive and process
in vivo non-
image based ultrasound information of the venous vasculature of the patient provided by the sensor and to provide position information regarding the position of the distal end of the elongate flexible member within the venous vasculature of the patient; and an
output device adapted to output the position information from the processor.