Intervention is one of the therapeutic methods such as for diseases in the heart, blood vessel, liver, brain, digestive organs and urinary organs. This therapy is usually performed by making a hole of a few millimeters in diameter in the skin and inserting a thin tube, called a catheter, into the blood vessel for treatment. This technique is called interventional cardiology when the treated region is the heart and the interventional radiology (IVR) when the treated region is as the liver and brain that handled by the radiology department. These diseases can also be treated with pharmacotherapy or surgical therapy. However, pharmacotherapy is sometimes insufficient for serious conditions, while surgery tends to be a major operation as it is accompanied with general anesthesia and large invasive incisions. In contrast, intervention therapy is gaining popularity dues to its less invasiveness. As the smaller incision size speeds up post-operation recovery, the patient's QOL (Quality Of Life) can be improved with a reduced hospitalization period of 3 to 5 days. This is also expected to decrease the economic burden of the patient. PTCA is one of the interventional therapies applied for treatment of angina and myocardial infarction. When a coronary artery is narrowed or blocked due to deposition of cholesterol, plaque, etc., the PTCA is used to widen the vessel using a thin tube with a balloon (diameters from 1 to 5 mm) attached to the distal end (called a balloon catheter), and reconstruct the blood passage. Blood flow can be obstructed in a coronary artery in which cholesterol or other substances are deposited. With PTCA, cross the lesion with a thin wire with a diameter of about 0.3 mm, called a guidewire. Advance a balloon catheter along the guidewire, up to the position where the vessel is narrowed. Dilate the balloon in the narrowed vessel section to expand it from inside. Widening of the narrowed vessel reconstructs the blood passage and recovers blood flow.