Drive unit for intravascular circulatory support systems

A drive unit for controlling an expandable member in an intravascular circulatory support system, the drive unit comprising:

• a motor including a rotor and a stator;
• a ball nut carrying a ball screw, wherein the ball nut is affixed to the rotor;
• and
• a bellows having a first end and a second end and a bellows cavity located between said first end and said second end, wherein:
• the first end is defined as being fixed and as having a pneumatic output, and
• the second end is defined by a dynamic flange configured to receive the ball screw, the dynamic flange having a recess directed toward the bellows cavity, the recess receiving and nesting at least a portion of the motor within the bellows cavity,
• wherein the ball nut converts rotation of the rotor into linear motion of the ball screw within the ball nut and actuates the bellows, thereby moving air into or out of the pneumatic output.