Surgical cassette with multi-zone fluid chamber

surgical cassette having an aspiration chamber disposed therein, said aspiration chamber (26) comprising: a detection part fluid level (132) disposed proximate the bottom of said aspiration chamber, operably coupled to a fluid conduit (56) the cassette for receiving a fluid of surgical aspiration and having a first cross-sectional area, operating said first cross-sectional area of ​​said sensing portion operably to provide accurate evidence and accurate level changes continuous fluid during use of said cassette; and storage portion (130) disposed near the top of said aspiration chamber and fluidly coupled to said sensing portion and having a second area greater than said first cross sectional area cross section, operating said portion storage functionally to provide storage fluid suitable fluid surgical aspiration during the exchange of a bag coupled collection fluid to said suction chamber means, and said detecting portion being disposed within said suction chamber (26), so that the fluid surgical suction between first functionally in the aspiration chamber through said sensing portion (132) from the fluid conduit (58) and substantially fills said sensing portion (132) before entering said storage portion (130).