Drive unit for a liquid handling device and liquid handling device

A medical device, comprising:

• a liquid handling unit comprising (i) a reservoir adapted to receive a liquid and (ii) a pump mechanism operable to move the liquid from the reservoir;
• and
• a drive unit comprising
• a drive unit housing;
• a drive member retained in the drive unit housing and movable relative to the drive unit housing to drive an operation of the medical device, the drive member comprising a coupler output portion configured to be operatively connected to the liquid handling unit;
• a drive mechanism retained in the drive unit housing, wherein the drive mechanism is coupleable to the drive member via a mechanism interface and configured to transfer a driving force or torque to the drive member;
• and
• a sealing member configured to establish a sealed interface with the drive member, the drive member being movable relative to the sealing member from a first position to a second position, and a tightness of the sealed interface being different in the first position than in the second position,
• wherein the sealed interface defines a sealed section of an interior of the drive unit housing, the mechanism interface is arranged within the sealed section and the coupler output portion is arranged outside of the sealed section, and
• wherein the pump mechanism of the liquid handling unit comprises a pump driver operatively coupled to the coupler output portion of the drive member of the drive unit via a coupler input portion of the liquid handling unit.