Dispensing device and method
The present invention determines whether or not a mounted tip and a dispensing amount match with each other in order to prevent contamination in a dispensing device. The present invention is provided with a pipette mechanism 108, 109 that performs suction and discharge, a motor 102 that drives the pipette mechanism, and a pressure sensor 113 that detects a pressure of the pipette mechanism. A dispensing tip 110 is mounted to the pipette mechanism. A control computer 116 controls the motor 102 , drives the pipette mechanism in a suction or discharge direction, and determines a type of the dispensing tip 110 on the basis of a difference in pressure waveform detected by the pressure sensor 113.
1. A dispensing device for suctioning a liquid sample with a dispensing tip and discharging a predetermined amount of the suctioned liquid sample to perform dispensing, the dispensing device comprising:
a pressure sensor configured to measure an internal pressure of the dispensing device;
a pipette mechanism comprising a piston and a receiving piston configured to perform suction and discharge;
an automatic drive stage to drive the dispensing device in a vertical direction;
a drive unit configured to drive the piston of the pipette mechanism, wherein the dispensing tip is mounted on the pipette mechanism and the drive unit is configured to drive the pipette mechanism in a suction or discharge direction; and
a control unit configured to:
control the drive unit based an output of the pressure sensor,
determine a type of the dispensing tip based on a pressure waveform measured by the pressure sensor while the pipette mechanism is performing suction or discharge, by:
driving the dispensing device with the automatic stage in the vertically downward direction while the piston is driven in the suction direction or in the discharge direction and while measuring the pressure with the pressure sensor,
detecting that the dispensing tip reaches a liquid level using the pressure measurements,
obtaining a slope of an approximate straight line of a pressure waveform obtained during a time while the drive unit is performing suction or discharge from the time of liquid level detection, and
comparing the slope of the approximate straight line with a value measured in advance, in order to determine the type of dispensing tip.
2. The dispensing device according to claim 1 ,
wherein the control unit is configured to output an error notification upon determining that an inappropriate dispensing tip is mounted as a result of determining the type of the dispensing tip.
3. The dispensing device according to claim 1 ,
wherein the control unit is configured to store a liquid level position upon determining that an appropriate dispensing tip is mounted as a result of determining the type of the dispensing tip.
4. The dispensing device according to claim 1 ,
wherein a dispensing tip with a filter is used as the dispensing tip, and
wherein the type of the dispensing tip is determined based on the pressure waveform obtained when a liquid is suctioned beyond a specification volume of the dispensing tip with the filter.
5. A dispensing method for a dispensing device for suctioning a liquid sample with a dispensing tip and discharging a predetermined amount of the suctioned liquid sample to perform dispensing, the dispensing method comprising:
measuring an internal pressure of the dispensing device;
performing suction and discharge, by a pipette mechanism including a piston and a receiving piston;
driving the dispensing device in a vertical direction;
driving, by a drive unit, the piston of the pipette mechanism, and mounting the dispensing tip on the pipette mechanism, and driving, by the drive unit, the pipette mechanism in a suction or discharge direction;
controlling, by a control unit, the drive unit based an output of the pressure sensor; and
determining, by the control unit, a type of the dispensing tip based on a pressure waveform measured by the pressure sensor while the pipette mechanism is performing suction or discharge, by:
driving the dispensing device with the automatic stage in the vertically downward direction while the piston is driven in the suction direction or in the discharge direction and while measuring the pressure with the pressure sensor,
detecting that the dispensing tip reaches a liquid level using the pressure measurements,
obtaining a slope of an approximate straight line of a pressure waveform obtained during a time while the drive unit is performing suction or discharge from the time of liquid level detection, and
comparing the slope of the approximate straight line with a value measured in advance, in order to determine the type of dispensing tip.
6. The dispensing method according to claim 5 , further comprising:
outputting an error notification upon determining that an inappropriate dispensing tip is mounted as a result of determining the type of the dispensing tip.
7. The dispensing method according to claim 5 , further comprising:
storing a liquid level position upon determining that an appropriate dispensing tip is mounted as a result of determining the type of the dispensing tip.
8. The dispensing method according to claim 5 ,
wherein a dispensing tip with a filter is used as the dispensing tip; and
wherein the type of the dispensing tip is determined based on the pressure waveform obtained when a liquid is suctioned beyond a specification volume of the dispensing tip with the filter.