Patent Description:
In an automatic analysis device, in order to perform component analysis on biological samples such as serum and urine (hereinafter referred to as samples), a sample and a reagent are reacted, and a change in color tone or turbidity caused thereby is optically measured by a photometric unit such as a spectrophotometer.

In order to react the sample and the reagent, it is necessary to perform dispensation from a container in which the sample and the reagent are contained into a reaction container. Accordingly, the automatic analysis device includes a dispensing device configured to automatically aspirate and dispense the sample or the reagent (hereinafter, generally referred to as a liquid) from the container in which the sample and the reagent are contained into the reaction container.

In a liquid dispensing unit configured to aspirate and dispense the sample by a syringe pump, dispensing performance and life of each part are influenced by a number of components constituting the syringe pump. Particularly, the syringe pump includes a seal component for each part with a plunger as one of limited-life products.

The seal component is generally made of a soft material such as a resin, and seals the liquid in a syringe while receiving sliding resistance when the plunger is operated. When the seal component is damaged due to uneven wear, liquid leakage from the syringe and change in dispensed liquid volume due to pressure loss occur, which may be a factor in a failure of providing an accurate analysis result. In PTL <NUM>, a plunger pump configured to prevent a contact surface of a plunger from hitting an edge of a cam by varying and sliding the contact surface of the plunger with respect to the cam, thereby preventing early wear of the members. Furthermore, PTL <NUM> discloses a device having a drive assembly to pick and to isolate a target analyte. Furthermore, PTL <NUM> discloses a manual controller for microsyringes, wherein the accuracy can be improved by inputting a calibration factor for the syringe to correct for variations in the volume of the syringe within manufacturing tolerances. Eventually, PTL <NUM> discloses an apparatus for high-speed precision dispensing, wherein text file control is applied to allow high-speed precision dispensing of one or more reagents with a wide dynamic range of dispense volumes in complex combinatorial patterns, ratios and arrays onto or into multiple predetermined locations of a desired target or substrate. PTL <NUM> relates to micromanipulation of a target analyte, though more specifically, to picking and isolating the target analyte, and discloses that a drive is connected to a piston of a pump using a coupling.

Recently, processing capacity of the automatic analysis device has been greatly improved, and a speed improvement of an associated operation unit is to be achieved. In addition, in recent years, there are also some facilities, such as large hospitals and inspection centers, in which an application of operating the automatic analysis device is continued for <NUM> hours, and the operating time of the device is getting longer. As a result of the above, a deterioration rate of each part is increased, leading to troublesome maintenance work. Accordingly, in order to lengthen a maintenance cycle of the automatic analysis device, extending the life of the components of each part has become a major issue. Particularly, recent automatic analysis devices are equipped with a large number of syringe pumps used to feed various liquids, and maintenance work of replacing a seal piece is generally required once every few months for the syringe pump to ensure performance of the syringe pumps.

As a main factor of deterioration of each part constituting the syringe pump, the uneven wear of the seal piece which seals the liquid in the syringe pump is mentioned. The syringe pump is composed of many components, and tolerances and backlashes of each part lead to bias during driving, which are one cause of the uneven wear of the components in the syringe pump. In particular, the seal piece made of the soft material is likely to be damaged due to the uneven wear. That is, the period for replacing the seal piece can be greatly extended by preventing the occurrence of the uneven wear.

Preferable embodiments are defined in the dependent claims.

By greatly reducing a moment when the plunger of the syringe pump is operated, it is possible to provide an automatic analysis device in which uneven wear is prevented by reducing an uneven load on a seal piece in the syringe pump and prolongs a maintenance cycle.

Hereinafter, embodiments of the invention will be described in detail with reference to the drawings. In addition, components having a same function are denoted by same reference symbols throughout the drawings for describing the embodiments.

<FIG> is an example of a schematic configuration diagram of an automatic analysis device to which the present embodiment is applied. In <FIG>, an automatic analysis device <NUM> includes: a sample disk <NUM> capable of mounting a plurality of blood collection tubes (sample containers) <NUM> for holding samples; a first reagent disk <NUM> and a second reagent disk <NUM> capable of mounting a plurality of reagent containers <NUM> for holding reagents; and a reaction disk <NUM> with a plurality of reaction containers <NUM> disposed on a circumference thereof.

The automatic analysis device also includes: a probe (sample probe) <NUM> configured to dispense the sample aspirated from the blood collection tube <NUM> into the reaction container <NUM>; a first reagent probe <NUM> configured to dispense the reagent aspirated from the reagent container <NUM> in the first reagent disk <NUM> into the reaction container <NUM>; and a second reagent probe <NUM> configured to dispense the reagent aspirated from the reagent container <NUM> in the second reagent disk <NUM> into the reaction container <NUM>.

The automatic analysis device further includes: a stirring device <NUM> configured to stir a liquid in the reaction container <NUM>; a container cleaning mechanism <NUM> configured to clean the reaction container <NUM>; a light source <NUM> provided near an inner circumference of the reaction disk <NUM>; a spectrometric detector <NUM>; a computer <NUM> connected to the spectroscopic detector <NUM>; and a controller <NUM> configured to control an operation of the entire automatic analysis device and to exchange data with the outside.

The sample probe <NUM> is connected to a corresponding syringe pump <NUM> through a dispensing path. Although not shown in <FIG>, syringe pumps corresponding to probes of the sample probe <NUM>, the first reagent probe <NUM>, and the second reagent probe <NUM> are connected to the automatic analysis device <NUM> through a flow path.

<FIG> shows an external view of the syringe pump of the present embodiment, and <FIG> shows an axial sectional view taken along a central axis of a plunger. The syringe pump <NUM> in the automatic analysis device includes: a syringe tube <NUM> capable of storing a liquid therein; a plunger <NUM> capable of moving up and down in a longitudinal direction of the syringe tube <NUM>; a plunger upper pressing component <NUM> in contact with the plunger <NUM>; a power transmission unit <NUM> configured to transmit power to the plunger <NUM> via the plunger upper pressing component; and a plunger lower pressing component <NUM> in contact with the power transmission unit <NUM>. When the plunger <NUM> moves up and down in the syringe tube <NUM>, an internal volume of the syringe tube <NUM> is changed, and the liquid is aspirated and dispensed. Arrows in the figure indicate a flow direction of the liquid inside the syringe tube <NUM>. The syringe pump <NUM> is provided with a motor <NUM>, and a rotational force of the motor <NUM> is transmitted to a power transmission plate <NUM> by a rotation transmission unit <NUM> that can be connected to the motor <NUM> via a reduction gear. Then, the rotational force of the motor <NUM> transmitted to the power transmission plate <NUM> is transmitted to the plunger <NUM> through the plunger upper pressing component <NUM> and the plunger lower pressing component <NUM> configured to move the plunger up and down. Accordingly, an aspiration/dispensation operation of the syringe can be performed. Here, a shape of the power transmission plate <NUM> is shown in <FIG>. As shown in <FIG>, a tip portion 4a of the power transmission plate <NUM> has an inclined structure that becomes thinner in a direction of the plunger. When the inclined structure is provided, an operation of replacing the syringe tube <NUM> becomes easy.

The power transmission plate <NUM> configured to transmit the rotational force from the motor <NUM> and the upper pressing component <NUM> of the plunger <NUM> configured to transmit a force when the plunger <NUM> moves up are in point contact with each other at one point of a contact part 5a as shown in <FIG>. In addition, the power transmission plate <NUM> and the lower pressing component <NUM> of the plunger <NUM> configured to transmit a force when the plunger <NUM> moves down are in point contact with each other at one point of a contact part 6a as shown in <FIG>. Further, the contact part 5a and the contact part 6a are provided on a moving axis of the plunger <NUM>. The upper pressing component <NUM> of the plunger <NUM> and the lower pressing component <NUM> of the plunger <NUM> are fixed by a connecting component <NUM>. The connecting component <NUM> has an upper hole in which the plunger upper pressing component <NUM> is inserted and fixed from an upper side, and a lower hole in which the lower pressing component <NUM> is inserted and fixed from a lower side, but the upper hole and lower hole are disposed on the moving axis of the plunger <NUM>. In order to dispose the upper hole and the lower hole on the same axis in the connecting component <NUM>, it is desirable that these holes are processed in a consistent operation. The upper hole and the lower hole in the figure are simple cylindrical holes, but as long as the upper hole and the lower hole fix the upper component and lower component configured to press the plunger, both holes should just be provided on the moving axis of the plunger <NUM> regardless of the shape. Therefore, there is no problem even if the shape of the hole is, for example, a polygon.

When the plunger <NUM> moves up and down, the power transmission plate <NUM> and the plunger upper and lower pressing components are in contact with each other, whereas the points where the force is transmitted are the contact part 5a and the contact part 6a, and the contact part is on the moving axis of the plunger. Accordingly, when the plunger moves, no moment is generated with respect to the plunger in the movement. In the syringe pump <NUM>, a seal piece <NUM> is attached between the plunger <NUM> and the syringe tube <NUM> such that the liquid inside does not leak due to the operation of the plunger <NUM>. When the plunger <NUM> operates, the plunger <NUM> operates while sliding with the seal piece <NUM>. The seal piece <NUM> is generally made of a soft material such as a resin, and since an inner diameter of the seal piece <NUM> is set to be smaller than an outer diameter of the plunger <NUM>, the contents in the syringe tube <NUM> do not leak even when the plunger <NUM> moves up and down. Since a form of the present embodiment is realized, no uneven load on the seal piece <NUM> due to the moment by the plunger <NUM> is generated. As a result, the uneven wear of the seal piece <NUM> can be significantly delayed. In addition, the replace timing of the seal piece due to the uneven wear of the seal piece <NUM> can be delayed.

In addition, in the present embodiment, the contact part 5a and the contact part 6a of the plunger upper and lower pressing component in contact with the power transmission plate <NUM> are spherical. However, as long as both contact parts are in point contact with the power transmission plate <NUM>, and the contact parts 5a, 6a of the plunger <NUM> and the upper and lower pressing components are on the moving axis of the plunger <NUM>, the contact part may be in any shape. For example, the tip portion thereof may be a cone or a polygonal shape. On the other hand, for example, the power transmission plate <NUM> may be spherical as shown in <FIG>, and the power transmission unit of the plunger may be a flat surface. The power transmission plate <NUM> and the plunger <NUM> and the plunger pressing components <NUM> and <NUM> may be made of any material as long as they are not soft materials that can be easily deformed. Examples of the material include metals and ceramics.

In addition, in the present embodiment, the plunger upper pressing component <NUM> and the plunger <NUM> are separate components, but the two can also be a single component as the same component. In this case, as shown in <FIG>, for example, a plunger pressing component 8a is formed by processing one end of the plunger <NUM> into a shape that may be in contact with other components in point contact on a hemisphere or the like. <FIG> shows a sectional view of the syringe pump <NUM> in an axial direction of the plunger <NUM> when one end of the plunger <NUM> as shown in <FIG> is processed into the shape that may be in contact with other components in point contact on a hemisphere or the like.

In addition, in the present embodiment, the plunger <NUM> and a rotating axis 2a of the motor are not on the same axis, but in order to implement the present embodiment, the rotating axis 2a of the motor and the moving axis of the plunger <NUM> also may be provided on the same axis as shown in <FIG>.

For comparison with the present embodiment, examples of syringes different from the present embodiment are shown in <FIG> and <FIG>. <FIG> is an external view of a syringe pump different from the present embodiment. <FIG> is a sectional view as seen from the direction of the arrow passing through the central axis of the plunger constituting the syringe pump of <FIG>. The end of the plunger has a shape that is sandwiched between the power transmission plate <NUM>, and depending on a tolerance of each component on the structure, the power transmission plate <NUM> is not completely parallel to a horizontal surface. When the plunger operates, as shown in <FIG>, a moment <NUM> is generated with the contact point of the plunger <NUM> and the power transmission plate <NUM> as a base point due to the inclination of the component. The moment <NUM> generated by the operation of the plunger is transmitted to the seal piece <NUM> provided inside the syringe tube <NUM>, and an uneven load is applied to the seal piece <NUM>. Since the load concentrates on a certain location with respect to the seal piece <NUM>, uneven wear occurs, which may cause damage to the seal piece <NUM>.

An example of a syringe pump capable of reducing the influence of an impact load applied to the power transmission plate and the plunger pressing components in a configuration the same as the configuration of the first embodiment will be described.

There may be a small gap between the plunger upper pressing component <NUM> or the plunger lower pressing component <NUM> and the power transmission plate <NUM> for ensuring assemblability. In such a case, the power transmission plate <NUM> moves by the gap, and when the power transmission plate <NUM> is in contact with the plunger upper pressing component <NUM> and the plunger lower pressing component <NUM>, an impact load is applied due to the contact of respective components. The impact load can cause wear and damage to the power transmission plate <NUM>, the plunger upper pressing component <NUM> and the plunger lower pressing component <NUM>, and the plunger <NUM> and the seal piece <NUM>.

Therefore, for example, an example shown in <FIG> can be considered as a method for preventing the impact load caused by such a small gap. In the syringe pump of <FIG>, an elastic body <NUM> such as a spring is provided in a pressing fixing member <NUM>. The elastic body <NUM> makes it possible to press the plunger lower pressing component <NUM> against the power transmission plate <NUM>. Accordingly, the small gap can be eliminated as much as possible, and the impact load can be prevented.

The elastic body <NUM> is compressed by a lowermost pressing component <NUM> and the elastic body <NUM> is designed to have a compressive force larger than a maximum sliding resistance that can be generated between the plunger and the seal piece. Therefore, even when the plunger is operated, no gap is generated between the plunger upper pressing component <NUM> or the plunger lower pressing component <NUM> and the power transmission plate <NUM>. In addition, when the syringe tube <NUM> is taken out of the syringe pump <NUM> during a regular maintenance, the compressive force of the elastic body <NUM> is removed by removing the compressive force by the lowermost pressing component <NUM>.

When the compressive force of the elastic body <NUM> is removed, a gap is formed between the plunger upper pressing component <NUM> or the plunger lower pressing component <NUM> and the power transmission plate <NUM>, and the syringe tube <NUM> can be easily mounted and removed. <FIG> shows a schematic diagram when the elastic body <NUM> is removed.

Claim 1:
An automatic analysis device (<NUM>), comprising:
a dispensing unit configured to aspirate and dispense a liquid; and
a syringe pump (<NUM>) configured to feed and aspirate a liquid into and from the dispensing unit, wherein
the syringe pump (<NUM>) includes:
a syringe tube (<NUM>) capable of storing a liquid;
a plunger (<NUM>) capable of moving up and down in a longitudinal direction of the syringe tube (<NUM>);
a plunger upper pressing component (<NUM>) in contact with the plunger (<NUM>);
a power transmission unit (<NUM>) configured to transmit power to the plunger (<NUM>) via the plunger upper pressing component (<NUM>); and
a plunger lower pressing component (<NUM>) in contact with the power transmission unit (<NUM>), wherein
the plunger upper pressing component (<NUM>) and the plunger lower pressing component (<NUM>) are fixed by a connecting component (<NUM>),
characterized in that:
the plunger upper pressing component (<NUM>) and the power transmission unit (<NUM>) are in point contact with each other, and the power transmission unit (<NUM>) and the plunger lower pressing component (<NUM>) are in point contact with each other.