Automatic analysis device

An automatic device for preparing a sample for analysis, the automatic device comprising:

• an incubator in which a reaction vessel is arranged;
• a dispensing mechanism that includes a nozzle movable upward or downward and a liquid surface detection mechanism for sensing a level of liquid in the reaction vessel, the dispensing mechanism dispenses the sample and a reagent into the reaction vessel;
• and
• a control unit that controls the dispensing mechanism to agitate a mixed liquid of the sample and the reagent in the reaction vessel, wherein the mixed liquid is agitated by suctioning the mixed liquid in the reaction vessel and performing a plurality of re-discharging operations of the mixed liquid into the reaction vessel,
• wherein performing the plurality of re-discharging operations include:
• performing a first re-discharge of the mixed liquid into the reaction vessel at a first discharge flow rate during a first period,
• determining a first speed for moving the nozzle upward during the first period such that a top of the nozzle is located near a liquid surface of the mixed liquid at an end of the first period and the first speed is higher than a speed at which the liquid surface of the mixed liquid rises due to the first re-discharging of the mixed liquid,
• moving the nozzle upward during the first period at the first speed,
• performing a second re-discharge the mixed liquid into the reaction vessel at a second discharge flow rate when a tip of the nozzle is located at or above the liquid surface of the mixed liquid, wherein is the mixed liquid is re-discharged into the reaction vessel at the discharge flow second rate for a second period that is subsequent to the first period, and
• moving the nozzle upward at a second speed that is lower than the first speed during the second period, wherein the nozzle is moved upward at the second speed,
• wherein at an end of the second period the tip of the nozzle is located at or above the liquid surface of the mixed liquid.