Easily movable blood purification systems

A dialysis system comprising:

• a dialyzer having a blood compartment;
• a blood circuit in fluid communication with the blood compartment of the dialyzer, including,
• an arterial line,
• an venous line,
• a valve configured to occlude at least a part of the blood circuit, and
• a blood pump configured to move a fluid through the blood circuit and to be actuated in at least one of a normal pump direction through the blood circuit and a reverse pump direction through the blood circuit, oppositely to the normal pump direction;
• a cassette including a portion of the blood circuit;
• a subsystem configured to control a dialysis treatment having a processor, a sensor, and a blood pumping mechanism configured to cooperate with the blood pump of the blood circuit;
• a housing in which the subsystem is arranged, the housing having an opening configured to insert the cassette;
• a movable support arranged in the housing and configured to hold the sensor and/or the blood pumping mechanism of the subsystem;
• a cassette holder configured to removably receive the cassette;
• and
• a loading system configured to move the movable support by an axial movement to a first position and to a second position relatively to the housing while the cassette holder is fixedly arranged in the housing, the loading system having an electric motor controlled by the processor, a drive assembly coupled to the electric motor, and a guiding assembly configured to cooperate with the drive assembly.