Patent ID: 7594901

Claim:
A surgical cassette having an aspiration chamber disposed therein, said aspiration chamber comprising: a fluid level sensing portion having a first transverse cross sectional area, said sensing portion providing accurate and precise evidence of continuous fluid level changes during use of said cassette; and a storage portion fluidly coupled to said sensing portion during application of vacuum to said aspiration chamber and having a second transverse cross sectional area larger than said first transverse cross sectional area, said storage portion providing adequate fluid storage during use of said cassette; whereby said sensing portion is disposed proximate a bottom of said aspiration chamber so that a surgical aspiration fluid first enters said sensing portion at a bottom of said aspiration chamber and substantially fills said sensing portion before entering said storage portion, said storage portion being disposed proximate a top of said aspiration chamber; whereby said first transverse cross sectional area provides improved measurement sensitivity of both said continuous fluid level changes and a calculated aspiration flow rate of said surgical fluid; and whereby said second transverse cross sectional area provides a sufficient amount of said surgical fluid to support a non-interrupted surgical procedure during exchange of a collection bag fluidly coupled to said aspiration chamber.