Filtering systems and filtering manifolds for use with filtering systems

A filtering device for filtering cerebrospinal fluid, the filtering device comprising:

• a controller assembly having a socket formed therein;
• a filter cassette configured to be removably secured to the socket, the filter cassette defining a filter housing formed from a plurality of discrete layers coupled together and defining a fluid pathway therein;
• a membrane disposed between two adjacent layers of the filter housing;
• wherein the filter housing has an asymmetric shape that allows the filter cassette to be removably secured to the socket in a singular orientation;
• one or more laterally projecting latching projections extending from the filter housing, the latching projections being configured to engage the controller assembly so as to releasably secure the filter housing to the socket;
• and
• a filtering section defined by a widened region of the fluid pathway that is configured to slow the passage of fluid therethrough in order to allow gravity filtration of fluid passing therethrough.