A new apparatus, 
algorithm, and method (all called Invention) are introduced herein to support navigation and placement of an 
intravascular catheter using the 
electrical conduction system of the heart (ECSH) and control electrodes placed on the patient's 
skin. According to the present Invention, an 
intravascular catheter can be guided both in the arterial and venous systems and positioned at different desired locations in the vasculature in a number of different clinical situations. The 
catheter is connected to the apparatus using, for example, sterile extension cables, such that the apparatus can measure the electrical activity at the tip of the 
catheter. Another 
electrode of the apparatus is placed for reference on the patient's 
skin. In one embodiment of the present Invention, a control 
electrode is placed on the patient's chest over the manubrium of the sternum below the presternal notch. In this case, if a 
catheter is inserted in the venous 
system, for example in the basilic 
vein, the Invention will indicate if the tip of the catheter navigates from the 
insertion point in the basilic 
vein into the subclavian 
vein on the same side, into the subclavian vein counter laterally, into the 
jugular vein, into the 
superior vena cava, into the cavoatrial junction (CAJ), into the 
right atrium (RA), into the right 
ventricle (RV), or into the 
inferior vena cava (IVC). For the same location of a control 
electrode, if a catheter is inserted in the arterial 
system, the Invention will indicate when the tip of the catheter is navigating into the arch of the 
aorta, into the 
right coronary artery, into the left 
circumflex artery, or into the left 
ventricle (LV). In another embodiment of the present Invention, a control electrode can be placed on the sternum over the xiphoid process. In one embodiment of the present invention, a catheter can be inserted in the arterial systems by arterial radial, brachial or axillary access. In another embodiment of the present Invention, a catheter may be inserted into either the arterial or the venous systems by femoral or saphenous access. In one aspect of the present Invention, navigation maps are introduced for different locations in the vasculature which allow for easy identification of the location of the catheter tip. In another aspect of the present Invention, a novel 
algorithm is introduced to compute a navigation 
signal in real time using electrical signals from the tip of the catheter and from control electrodes. In another aspect of the present Invention, a novel 
algorithm is introduced to compute in 
real time navigation parameters from the navigation 
signal computes according to the present Invention. In another aspect of the present Invention, a method is introduced which makes use of the navigation 
signal to allow for placing an 
intravascular catheter at a desired location in the vasculature relative to the ECSH and to the control electrodes placed on the 
skin. In another aspect of the present Invention, the electrical signals obtained from control electrodes and from the tip of the catheter may be generated by the natural ECSH, e.g., the sino-atrial node (SAN), by artificial (implanted) pacemakers or by electrical generators external to the body. In yet another aspect of the Invention, an apparatus is introduced which supports 
data acquisition required by the computation of a navigation signal according to the present Invention.