Physicians make widespread use of catheters today in medical procedures to gain access into interior regions of the body.  It is important that the physician can control carefully and precisely the movement of the catheter within the body, especially during procedures that ablate tissue within the heart.  These procedures, called electrophysiological therapy, are becoming more widespread for treating cardiac rhythm disturbances. 
During these procedures, a physician steers a catheter through a main vein or artery (which is typically the femoral artery) into the interior region of the heart that is to be treated.  The physician then further manipulates a steering mechanism to place the electrode carried on the tip of the catheter into direct contact with the tissue that is to be ablated.  The physician directs radio frequency energy into the electrode tip to ablate the tissue and form a lesion. 
Cardiac ablation especially requires the ability to precisely bend and shape the tip end of the catheter to position the ablation electrode.