Automatic chemistry analyzer

A device for determining at least one parameter of a liquid sample, the device comprising:

• (a) a body;
• (b) a motorized sample station disposed within the body, the sample station being sized and dimensioned to retain a plurality of sample containers and having a sample extraction site, the sample station being movable within the body such that, when the sample station retains a plurality of sample containers, individual sample containers can alternatively be moved to and away from the sample extraction site;
• (c) a motorized reagent station disposed within the body, the reagent station being sized and dimensioned to retain a plurality of reagent containers and having a reagent extraction site, the reagent station being movable within the body such that, when the reagent station retains a plurality of reagent containers, individual reagent containers can alternatively be moved to and away from the reagent extraction site;
• (d) a motorized random access analyzing station disposed within the body, the random access analyzing station being sized and dimensioned to retain a plurality of reaction cuvettes and having at least one cuvette mixing site, a cuvette washing site, a random access analyzing station analyzing site and an analyzer disposed proximate to the random access analyzing station analyzing site for determining at least one parameter of a sample disposed within the cuvettes, the random access analyzing station being movable within the body such that, when the random access analyzing station retains a plurality of cuvettes, individual cuvettes can alternatively be moved to and away from (1) the cuvette mixing site, (2) the cuvette washing site and (3) the random access analyzing station analyzing site;
• (e) a sample probe arm assembly attached to the body, the sample probe arm assembly including (1) a sample probe arm, (2) a hollow sample probe having an internal chamber, an open lower end and an open upper end and (3) an elongate rotatable sample stirring rod having a lower end and an upper end, the lower end of the sample stirring rod including a sample stirring rod paddle attached thereto, the sample probe and the sample stirring rod being disposed generally vertically but angled inwardly towards one another and being disposed in close proximity to one another, the sample probe being vertically movable between a lower sample probe position and an upper sample probe position, the sample stirring rod being movable independent of the sample probe between a lower sample stirring rod position and an upper sample stirring rod position, the sample probe and sample stirring rod being disposed within the sample probe arm assembly such that, when the sample probe is at the lower sample probe position and the sample stirring rod is at the lower sample stirring rod position, the lower end of the sample probe is spaced apart from the lower end of the sample stirring rod by a distance of between about 1.7 and about 5.3 mm, the sample probe arm being movable between a first sample probe arm position wherein the sample probe is immediately above the sample extraction site and a second sample probe arm position wherein the sample probe is immediately above the at least one cuvette mixing site;
• (f) a sample probe arm motor for moving the sample probe arm between the first sample probe arm position and the second sample probe arm position;
• (g) a sample probe positioning motor for moving the sample probe between the lower sample probe position and the upper sample probe position;
• (h) a sample stirring rod positioning motor for moving the sample stirring rod between the lower sample stirring rod position and the upper sample stirring rod position;
• (i) a sample stirring rod rotating motor for rotating the sample stirring rod;
• (j) a sample probe pressure altering assembly for alternatively applying a positive pressure and a negative pressure to the interior chamber of the sample probe;
• (k) a reagent probe arm assembly attached to the body, the reagent probe arm assembly including (1) a reagent probe arm, (2) a hollow reagent probe having an internal chamber, an open lower end and an open upper end and (3) an elongate rotatable reagent stirring rod having a lower end and an upper end, the lower end of the reagent stirring rod including a reagent stirring rod paddle attached thereto, the reagent probe and the reagent stirring rod being disposed generally vertically but angled inwardly towards one another and being disposed in close proximity to one another, the reagent probe being vertically movable between a lower reagent probe position and an upper reagent probe position, the reagent stirring rod being movable independent of the reagent probe between a lower reagent stirring rod position and an upper reagent stirring rod position, the reagent probe and reagent stirring rod being disposed within the reagent probe arm assembly such that, when the reagent probe is at the lower reagent probe position and the reagent stirring rod is at the lower reagent stirring rod position, the lower end of the reagent probe is spaced apart from the lower end of the reagent stirring rod by a distance of between about 1.7 and about 5.3 mm, the reagent probe arm being movable between a first reagent probe arm position wherein the reagent probe is immediately above the reagent extraction site and a second reagent probe arm position wherein the reagent probe is immediately above the at least one cuvette mixing site;
• (l) a reagent probe arm motor for moving the reagent probe arm between the first reagent probe arm position and the second reagent probe arm position;
• (m) a reagent probe positioning motor for moving the reagent probe between the lower reagent probe position and the upper reagent probe position;
• (n) a reagent stirring rod positioning motor for moving the reagent stirring rod between the lower reagent stirring rod position and the upper reagent stirring rod position;
• (o) a reagent stirring rod rotating motor for rotating the reagent stirring rod;
• (p) a reagent probe pressure altering assembly for alternatively applying a positive pressure and a negative pressure to the interior chamber of the reagent probe;
• (q) a cuvette wash station attached to the body, the cuvette wash station including at least one hollow cuvette wash station probe having an internal chamber, an open lower end and an open upper end, the cuvette wash station probe being vertically movable between a lower cuvette wash station probe position and an upper cuvette wash station probe position, the cuvette wash station being disposed such that the cuvette wash station probe is immediately above the cuvette washing site;
• (r) a cuvette wash station probe positioning motor for moving the cuvette wash station probe between the lower cuvette wash station probe position and the upper cuvette wash station probe position;
• and
• (s) a cuvette wash station probe supply and disposal assembly for alternatively (1) providing pressurized washing liquid from a source of washing liquid to the cuvette wash station probe for washing a cuvette disposed within the random access analyzing station at the cuvette washing site and (2) providing a negative pressure to the internal chamber of the cuvette wash station probe for removing waste liquids from a cuvette disposed within the random access analyzing station at the analyzing site and for transferring such waste liquids to a disposal site.