Heat exchange systems, devices and methods

A fluidly activated liquid pumping system comprising:

• a controller;
• and
• a disposable cassette comprising:
• (a) at least one reciprocating positive-displacement pump, each pump comprising:
• (i) a curved rigid chamber wall;
• (ii) a flexible membrane attached to the rigid chamber wall, the flexible membrane and rigid chamber wall defining a pumping chamber;
• (iii) a rigid limit structure for limiting movement of the membrane and limiting the maximum volume of the pumping chamber, the flexible membrane and the rigid limit structure defining an actuation chamber;
• (iv) a port in the rigid limit structure fluidly connecting the actuation chamber to a fluid source supplying fluid at a positive or negative pressure to actuate the flexible membrane;
• and
• (v) a pressure transducer configured to measure a fluid pressure in the pumping chamber or the actuation chamber and to provide pressure information to the controller;
• (b) an inlet valve configured to be controllable by the controller for directing liquid into the pumping chamber through an inlet in the rigid chamber wall;
• and
• (c) an outlet valve configured to be controllable by the controller for directing liquid out of the pumping chamber through an outlet in the rigid chamber wall;
• wherein
• the controller is configured to detect the presence of air in the pumping chamber by controlling the application of a known fluid pressure to the actuation chamber via the port, by commanding the inlet valve and the outlet valve to a closed position, and by monitoring a rate of change of pressure measured by the pressure transducer.