An improved bladder for pump control during ECMO procedures.

A new inline reservoir called the Better-Bladder, now FDA-cleared for long term use, overcomes some disadvantages of the silicone bladder and bladder box used in extracorporeal membrane oxygenation circuits. The Better-Bladder provides compliance in the venous line and allows for noninvasive pressure measurements. Both features are useful for controlling pump speed as a function of venous line pressure. Bench tests showed that the Better-Bladder measures pressure noninvasively within +/- 4% of invasive (i.e., liquid contacting) pressure measurements in a range from -200 to +500 mmHg and at temperatures from 10 degrees C to 37 degrees C. After 60 days, the error in noninvasive pressure measurement with the Better-Bladder was less than +/- 3%. The Better-Bladder withstood pressurization to 1700 mmHg for ten days without leaking or failing in other ways. The advantages of the Better Bladder, along with its accuracy and durability, suggest its use for short and long term pumping applications.