JPH025416Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention relates to a sample pipettor of an automatic analyzer that always aspirates and dispenses a fixed amount of specimen (serum).

(B) Prior Art In conventional automatic analyzers, even if the sample pipettor becomes clogged while aspirating a sample due to contamination with foreign matter, there is no method for detecting this. As a result, analysis is carried out on the assumption that a fixed amount of sample is always being aspirated and discharged by the sample pipettor, resulting in fatal drawbacks such as failure to perform measurements due to insufficient sample volume.

(c) Purpose This invention was developed in view of the above circumstances, and the purpose is to obtain a sample pipettor equipped with a means for detecting when the sample pipetter aspirates foreign matter and the nozzle becomes clogged. do.

(d) Configuration This invention is a sample pipettor that drives a pump by connecting a plunger to a sliding plate that moves up and down along an axis, and the sliding plate can be moved at any arbitrary point on its movement trajectory. A means for detecting whether a certain position on the sliding plate has not passed within the scheduled time is provided near the movement locus of the sliding plate, and when a certain position on the sliding plate does not pass through the position within the scheduled time, this is detected and the nozzle is activated. This system is designed to detect blockages such as the following.

(E) Example A sample pipettor according to this invention will be explained based on the drawings.

FIG. 1 shows an embodiment of the sample pipettor according to this invention, in which a plunger 2 of a pump 1 is attached to a sliding plate 6 by a drive lever 3. (Note 8 is the packing) This sliding plate 6
is connected by a steel belt 5 to a pulley 4 which is directly connected to the shaft of a pulse motor (not shown).
As a result, the pump 1 is driven as the sliding plate 6 moves up and down along the shaft 7. Further, a light shielding plate 13 is provided at an arbitrary position on the sliding plate 6, and a photo interrupter 14 is provided at an arbitrary position on the movement trajectory of the light shielding plate 13. Note that 9 is a sample suction/discharge nozzle, 10 is a cleaning water suction nozzle, and 11 is a nozzle switching valve, which allows cleaning with cleaning water after the sample suction/discharge is completed.

Based on the above configuration, the sample is aspirated from the sample cup 12 and discharged into the reaction tube 15. At this time, if the nozzle 9 is not clogged, the sliding plate 6 will move for a certain period of time as shown by the arrow in the figure. Since the vertical movement is performed at intervals, the sliding plate 6 can be moved at any arbitrary position, that is, the light shielding plate 13
passes through an arbitrary position on the movement trajectory of the sliding plate 6, that is, the photo interrupter 14 within a scheduled time (a predetermined time during the movement process).

However, if a blockage occurs, the load on the pulse motor (drive source) increases and it goes out of step, causing the sliding plate 6 to no longer move up and down at regular intervals.
The light shielding plate 13 also does not pass the photo interrupter 14 within the scheduled time. Therefore, by detecting this, it is possible to detect that the nozzle or flow path system is clogged.

Further, in the above embodiment, the photointerrupter is used to check for passage at one arbitrary location, but if a rotary encoder or the like is used to check for passage at several locations, blockage detection will be more accurate.

(F) Effect As detailed above, this device can always detect whether or not the nozzle of the sample pipettor is clogged, so it can prevent the worst-case scenario of inability to measure or poor measurement due to insufficient sample volume. without inviting
This allows for safe analysis even if there is a foreign substance in the sample.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the sample pipettor according to this invention. 1... Pump, 4... Pulley, 5... Steel belt, 6... Sliding plate, 9... Sample suction/discharge nozzle, 13... Light shielding plate, 14... Photo interrupter.

Claims (1)

[Claims for Utility Model Registration] 1. In a sample pipettor that drives a pump by connecting a plunger to a sliding plate that moves up and down along an axis, any point on the sliding plate that moves up and down along the axis A sample pipettor characterized in that a means for detecting whether the sliding plate passes through a predetermined position at a predetermined time is provided near the movement trajectory of the sliding plate. 2. The sample pipettor according to claim 1, wherein the detection means is a photointerrupter.