Instrument for performing a diagnostic test on a fluidic cartridge

A cartridge reader for carrying out a diagnostic test on a fluid sample contained in a fluidic cartridge in the cartridge reader,

• wherein the fluidic cartridge comprises:
• a network of channels,
• bellows for moving the fluid sample along the network of channels,
• a plurality of pneumatically actuated valves in the network of channels;
• and
• a pneumatics interface, and
• wherein the cartridge reader comprises:
• a pneumatics system, comprising:
• (i) a pneumatics interface, comprising a plurality of pneumatic interface ports, configured to couple to the pneumatics interface on the fluidic cartridge;
• (ii) a positive pressure sub-system comprising first and second positive pressure reservoirs and a first pump configured to provide a supply of positive pressure to maintain the first and second positive pressure reservoirs at first and second positive pressures, respectively, wherein the first and second positive pressures are different and a valve selectively coupling the first pump to the first and second positive pressure reservoirs;
• and
• (iii) a negative pressure sub-system comprising a negative pressure reservoir and a second pump configured to provide a supply of negative pressure to maintain the negative pressure reservoir at a negative pressure,
• a valve system comprising a plurality of solenoid valves, each connected to a pneumatic interface port and configured to couple to that pneumatic interface port at least one of:
• the first and second positive pressure reservoirs and the negative pressure reservoir, wherein the first and second pressure reservoirs apply pressure to different pneumatic interface ports,
• a controller to operate the first and second pumps and the plurality of solenoid valves according to a predetermined cycle during the diagnostic test such that during the cycle:
• a first subset of pneumatic interface ports is selectively coupled to either the first positive pressure reservoir or the negative pressure reservoir for actuating the bellows and the pneumatically actuated valves on the cartridge;
• and
• a second subset of pneumatic interface ports coupled to the second positive pressure reservoir and operable to evacuate surplus fluid from at least a portion of the network of channels in the fluidic cartridge.