Scroll pump

A scroll pump comprising:

• an inlet for receiving fluid to be pumped;
• an outlet for conveying pumped fluid from the scroll pump;
• and
• two scroll members comprising a fixed scroll and an orbiting scroll interleaving with the fixed scroll and mounted such that rotation of a motor imparts an orbital motion to the orbiting scroll relative to the fixed scroll, each of said scroll members comprising a base from which an involute wall extends to define a pumping chamber for conveying fluid from the inlet to the outlet and which, with orbital movement of the orbiting scroll, transitions from an open configuration, in which the pumping chamber receives fluid from the inlet along a first flow path, to a closed configuration, in which the pumping chamber is substantially isolated from the inlet;
• wherein a base of one of the scroll members includes a channel in fluid communication with the inlet and positioned so that, when the pumping chamber is in an open configuration, the pumping chamber receives fluid from the inlet along an additional flow path passing through the channel.