Balloon blowing process with metered volumetric inflation

This invention generally relates to intravascular balloon catheters, such as are used in percutaneous transluminal coronary angioplasty (PTCA) and stent delivery. A balloon for a balloon catheter and a method of manufacture The method entails providing a polymeric tubular member having an inner lumen and a longitudinal axis. An incompressible fluid is introduced into the inner lumen at a predetermined volumetric flow rate, expanding the polymeric tubular member to a desired outer diameter. The volumetric flow rate of fluid may be predetermined to not over-inflate the balloon. The balloon is blown slower because no initial pressure need be exceeded, so higher blow up ratios may be achieved without sacrificing any strength of the balloon. The balloons embodying features of the invention have thinner walls, yet maintain the same physical and mechanical properties of a thicker walled balloon manufactured in today's methods. Therefore, the process of the invention will lead to lower profile balloon catheters for balloon catheters with the same outer diameter balloon on them. Alternatively, a balloon with the same wall thickness as a balloon made from standard techniques will yield a much stronger balloon.