Patent ID: 7786457

Claim:
A system comprising: a cassette receiver to receive a surgical cassette; wherein the surgical cassette is at least partially formed of a cassette material defining a first chamber comprising a first wall and a second wall and a second chamber, adjacent to the first chamber, comprising a third wall and a fourth wall; and a first light source to project light along a transmission path into the first wall of the surgical cassette, wherein the light source is positioned so that at least a majority of the light is reflected if a cassette material/first fluid interface intersects the transmission path and a majority of the light is not reflected if a cassette material/second fluid interface intersects the transmission path; and a first sensor to receive reflected light through the second wall of the surgical cassette and generate an output that indicates illumination of the sensor; wherein the first light source is mounted in a first wall of the cassette receiver; wherein the first sensor comprises a plurality of portions mounted in a second wall of the cassette receiver; a second light source to project light along a transmission path into the third wall of the surgical cassette, wherein the second light source is positioned so that at least a majority of the light is reflected if a cassette material/first fluid interface intersects the transmission path and a majority of the light is not reflected if a cassette material/second fluid interface intersects the transmission path; and a second sensor to receive reflected light through the fourth wall of the surgical cassette and generate an output that indicates illumination of the sensor; wherein the second light source is mounted in a third wall of the cassette receiver; wherein the second sensor comprises a plurality of portions mounted in a fourth wall of the cassette receiver; wherein the output of the first and second sensors indicate respective illumination amounts of each of the sensor portions in the respective first and second sensors; and wherein the second wall of the cassette receiver and the first wall of the cassette receiver meet at a corner of the cassette receiver; wherein the first wall of the first chamber and the second wall of the first chamber meet at a corner of the first chamber; wherein the third wall of the second chamber and the fourth wall of the second chamber meet at a corner of the second chamber.