Automatic sample analyzer

An automatic sample analyzer comprising, a plurality of sticks which have a plurality of reagent portions corresponding to different examination items so as to be divided into a plurality of groups of sticks by combinations of the examination items, a plurality of cassettes each having an outlet and a discriminatory mark, the discriminatory mark corresponding to one of the group of the sticks so as to accommodate the one of the group of the sticks, a removal device for automatically taking a desired one of the sticks of the cassettes by using a single removal mechanism.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an automatic sample analyzer for analyzing 
urine, blood etc. 
2. Description of the Prior Art 
Conventionally, various methods are known with respect to measurement of, 
for example, sugar, protein, or occult blood etc. in urine. In one of the 
methods, which is widely put to practical use, a plurality of elongated 
sheetlike sticks each having a plurality of reagent portions are 
accommodated in a cassette, the sticks are taken out of the cassette one 
by one such that the reagent portions of each stick are dipped in the 
sample (urine) and reaction at the reagent portions are subjected to color 
comparison. 
Automatic removal devices for taking the above described sticks out of the 
cassette are known, for example, from Japanese Patent Laid-Open 
Publication No. 49-77693, No. 63-252250 etc. 
In these devices disclosed in the above publication, a removal mechanism is 
constructed together with a cassette, therefore only one kind of stick 
accommodated in a single cassette can be taken out of the cassette by the 
single removal mechanism. 
Meanwhile, there are various combinations of examination items of the 
sample. Therefore, in an automatic sample analyzer using the above 
described automatic removal devices, unnecessary items are analyzed in 
certain cases, thereby resulting in economic loss. To avoid the loss, it 
can be thought to provide a plurality of cassettes, which accommodate 
different kind of sticks, corresponding to each combination of examination 
items, and a plurality of the removal devices corresponding to each 
cassette. However, in this case, a drawback is that the removal mechanism 
becomes complicated in its construction and expensive. 
SUMMARY OF THE INVENTION 
Accordingly, an essential object of the present invention is to provide an 
automatic sample analyzer in which desired sticks are automatically taken 
out of a plurality of cassettes by a single removal mechanism, each of 
said cassettes accommodating a kind of sticks having a plurality of 
reagent portions corresponding to a combination of examination items such 
that different kind of sticks are accommodated in different cassettes. 
A further object of the present invention is to provide a cassette for the 
automatic sample analyzer. 
In accomplishing these and other objects, according to one embodiment of 
the invention, there is provided an automatic sample analyzer comprising: 
a plurality of sticks which have a plurality of reagent portions 
corresponding to different examination items so as to be divided into a 
plurality of groups of sticks by combinations of the examination items; a 
plurality of cassettes each having an outlet and a discriminatory mark, 
the discriminatory mark corresponding to one of the group of the sticks so 
as to accommodate the one of said group of the sticks; a removal device 
for automatically taking a desired one of the sticks out of the cassettes 
by using a single removal mechanism. 
Further scope of applicability of the present invention will become 
apparent from the detailed description given hereinafter. However, it 
should be understood that the detailed description and specific examples, 
while indicating preferred embodiments of the invention, are given by way 
of illustration only, since various changes and modifications within the 
spirit and scope of the invention will become apparent to those skilled in 
the art from this detailed description.

DETAILED DESCRIPTION OF THE INVENTION 
Before the description of the present invention proceeds, it is to be noted 
that like parts are designated by like reference numerals throughout the 
accompanying drawings. 
As shown in FIGS. 1 and 2, the automatic sample analyzer according to the 
present invention is constituted roughly by a plurality of cassettes 10, a 
cassette accommodating section 30, a removal device 40, a sample 
accommodating section 70, a dripping device 80, a base section 100 for 
taking sticks out of the cassette, a transfer section 110 for accelerating 
a reaction of the sample on the stick and conveying the stick, and an 
examination section 120. 
As shown in FIGS. 5a and 5b, the cassette 10 has a form of approximately a 
rectangular thin parallelepiped by being combined a main casing 10a with a 
cover casing 10b. In an accommodating room 11 of the cassette 10 
projecting upward, a drying agent is accommodated. 
As shown in FIG. 5a, a pair of rodlike projections 12 project from upper 
opposite side portions of the main casing 10a, and a torsion spring 13 is 
wound around each of the projections 12. One end of the torsion spring 13 
is brought into pressing contact with a projection 14 provided adjacent to 
each of the projections 12 so as to be supported by the projection 14. The 
other end of the torsion spring 13 is brought into pressing contact with a 
slide plate 15 which is slidably inserted into the main cassette 10a (See 
FIG. 5b). Further, vertically extending elongated opening 16 is formed at 
an upper central portion of the main casing 10a and a pair of protrusions 
17 extend symmetrically in opposite lateral direction from a vertically 
central portion of the elongated opening 16. A pair of engageable portions 
10c are formed on inner faces of opposite side walls of the main casing 
10a, respectively, while a pair of engageable recesses 18 are, 
respectively, formed on outer faces of opposite side walls of the main 
casing 10a. At lower portion of the main casing 10a, a bottom wall 20a is 
provided such that the bottom wall 20a forms a half of bottom 20 of the 
cassette 10. There are a plurality of kinds of the sticks 25 classified by 
combinations of different examination items such that the sticks 25 of the 
same kind are accommodated in each cassette 10. A discriminatory mark 23 
for indicating one of the kind of sticks 25 accommodated in each cassette 
10, e.g., a bar code is adhered on the bottom wall 20a of each cassette 
10. At one of end portions of the bottom wall 20a, a recess portion 22a is 
formed, and at opposite end portions, inclined faces are formed. 
On the other hand, at the cover casing 10b, a bottom wall 20b is provided 
facing to the bottom wall 20a of the main casing 10a so as to form a slit 
21. And thus, a sensor hole 22 is formed by the recess portion 22b 
provided at the bottom wall 20b and the recess portion 22a. Further, at a 
corner of lower portion of the cassette 10 disposed more adjacent to the 
sensor hole 22 than another corner, an outlet 24 is formed such that a 
sheet of stick 25 can be passed through the outlet 24. Meanwhile, at the 
opposite ends of the slit 21, opposed faces are inclined so as to be 
spaced farther away from each other towards each of the opposite ends of 
the slits 21. 
As shown in FIGS. 7 and 8, the stick 25 is made by adhering a pair of pads 
27, 28 and a plurality of reagent portions 29, respectively, on one face 
of the elongated rectangular sheet 26 such that the pads 27, 28 are 
situated at opposite ends of the sheet 26, and the reagent portions 29 
each corresponding to a different examination item are situated between 
the pads 27, 28. 
As shown in FIG. 8, thickness of the pads 27, 28 are larger than that of 
each reagent portion 29. Length L1 of the pad 27 disposed more adjacent to 
the outlet 24 of the cassette 10 than the pad 28 is larger than both a 
distance L2 between the pad 27 or 28 and a corresponding neighboring one 
of the reagent portions 29, and a distance L3 between neighboring ones of 
the reagent portions 29. 
Meanwhile, although there may be a case in which a length of a region 
having no reagent portion becomes larger than the length of the pad 27 
depending on the number of the examination items, in this case, it is 
preferred that a dummy having the same thickness as that of the reagent 
portion 29 is adhered on a position on which reagent portion is to be 
adhered. 
Although, the above described reagent portion 29 of the stick 25 shown in 
FIGS. 7 and 8 is made by impregnating reagent into a sheetlike piece, and 
adhering the piece on the sheet 26, the reagent portion 29 can be made by 
printing. In this case, the pads 27, 28 become unnecessary. 
In advance of loading the stick 25 into the cassette 10, at first a pair of 
the torsion springs 13 are mounted around the projections 12 of the main 
casing 10. Thereafter, the slide plate 15 is pressed into the main casing 
10a and pushed up against a force of the torsion springs 13 such that the 
engageable claw 15a provided at central portion of side edge of the slide 
plate 15 is engaged with the protrusion 17, and the opposite ends of the 
slide plate 15 is engaged with the engageable portions 10c, whereby the 
slide plate 15 is prevented from getting out from the main casing 10a, and 
positioned as shown by two-dot chain line in FIG. 5b. Further, after 
predetermined number of sticks 25 (e.g., a hundred sticks in this 
embodiment) of the same kind are mounted in the main casing 10a directing 
the reagent portion 29 to upward at one time, the cover casing 10b is fit 
on the main casing 10a, and fixed to the main casing 10a by, for example, 
hot melting. Finally, the engageable claw 15a of the slide plate 15 is 
disengaged with the protrusion 17 through the elongated opening 16 such 
that the sticks 25 are pressed toward the bottom portion 20 by the force 
of the torsion springs 25. 
As shown in FIGS. 2 and 3, the cassette accommodating section 30 is 
constructed by providing five pairs of opposing recess portions 34 for 
supporting cassettes 10 at predetermined intervals between a pair of 
support plates 33 disposed between a front plate 31 and a rear plate 32 of 
the analyzer. In the recess portion 34 of each support plate 33, a ball 
35, e.g., plunger-type ball urged towards the recess portion 34, is 
projected elastically such that the ball 35 is engaged with engageable 
recess portion 18 of the cassette. 
The removal device 40, which is constituted by a base assembly 41 and a 
drive mechanism 42 for actuating the base assembly 41, is disposed under 
the cassette accommodating section 30. 
As shown in FIGS. 9 and 10, in one of the example of the base assembly 41, 
a support table 44 is disposed on a base portion 43, and an arm 45 is 
provided on an upper face of the support table 44 rotatably about an axis 
46, and about an axis 47 by being forced in a direction of an arrow. In a 
rear end portion of the arm 45, a ball 50 is projected such that 
rotational movement of the arm 45 is restricted elastically by engaging 
the ball 50 with a holder 51 standing on the support table 44. At an upper 
face of the front end portion of the arm 45, a pair of rotatable rollers 
48 are provided at predetermined distance. Between these rollers 48, a 
push pin 49 is projected. To a rear face of the base portion 43, a rear 
table 52 is coupled. On the rear table 52, a first sensor 53 for 
identification of the kind of the cassette 10, and a second sensor 54 for 
detecting of presence or absence of the stick 25 in the cassette 10 are 
provided so as to deviate from each other in the vertical direction of 
FIG. 10. 
Meanwhile, the base assembly 41, is disposed slidably on a rail portion 57 
of a movable frame 56 described below, and fixed through a fixing plate 55 
to a belt 61 described below. 
The drive mechanism 42 is provided so as to actuate the base assembly 41, 
as described above. At opposite ends of the movable frame 56, on which the 
base assembly 41 is disposed slidably, pulleys 58, and 59 are arranged. In 
FIG. 3, left pulley 59 is provided rotatably, while right pulley 58 is 
engaged with spline shaft 60 passing through the pulley 59. Over the 
pulleys 58 and 59, a belt 61 is trained. The base assembly 41 is carried 
in X--X direction indicated by an arrow(See FIG. 2) by forward and reverse 
rotation of the motor 62 through the fixing plate 55, the spline shaft 60, 
the pulley 58 and the belt 61. 
The movable frame 56 itself, on which the base assembly 41 is disposed, is 
provided slidably on a pair of rails 63, and fixed to a belt 67 trained 
over a pulley 64 provided in front of(under, in FIG. 2) the cassette 
accommodating section 30, and a pulley 66 mounted around a shaft of the 
motor 65. The movable frame 56 is carried in Y--Y direction indicated by 
an arrow (See FIG. 2) through the belt 67 and the spline shaft 66 by 
forward and reverse rotation of the motor 65. Meanwhile, an interrupting 
plate 107 provided on lower central portion of the movable frame 56 is 
detected by a sensor 105, whereby movement of the movable frame 56 is 
stopped in the direction of an arrow D. 
Accordingly, as shown in FIG. 11, the base assembly 41 is carried along a 
rectangular path from starting position (base point) ST by the drive 
mechanism 42. Namely, in an operation for reading the discriminatory mark 
23 indicating the kind of the cassette 10 described below, the base 
assembly 41 situated at the starting position ST is carried sequentially 
from the position of a cassette 10 situated in upper position in FIG. 2 in 
the cassette accommodating section 30 toward lower portion by rectangular 
motion (See sequential numerals (1),(2), . . . ,(5) in FIG. 11). 
Meanwhile, in the operation for reading the discriminatory mark 23, a 
movement of the base assembly 41 in a direction of an arrow A is performed 
so as to pass a position in which the first sensor 53 can read the 
discriminatory mark 23 provided on the lower face of the cassette 10 
without the cassette 10 interfering with the push pin 49. Further, as 
shown by reference numeral (6) in FIG. 11, upon completion of reading of 
the discriminatory mark 23, the base assembly 41 is slightly carried in 
the direction of an arrow C and then, is displaced in the direction of an 
arrow D such that presence or absence of the stick 25 is detected through 
a sensor hole 22 of each cassette 10 by the second sensor 54. 
In an operation for taking the stick 25 out of the cassette 10, the stick 
25 is taken out of a cassette 10 having the discriminatory mark 23 
corresponding to predetermined combination of the examination items. In 
this case, the base assembly 41 is carried in the direction of the arrow A 
along a path (1') or (2') . . . or (5') in FIG. 11 such that the push pin 
49 can pass through the slit 21 of the cassette 10. 
As shown in FIG. 1, the sample accommodating section 70 is made in a form 
of upward opening box having rectangular cross section, and provided two 
pairs of belts 71 at the bottom portion. The belts 71 of each pair are 
disposed at predetermined distance in a longitudinal direction shown by an 
arrow W, and driven together. Namely, each pair of the belts 71 is driven 
in a direction of an arrow E or F by motors which are not shown. Further, 
at the outside of opposite longitudinal edge portions, first projection 
pieces 72 and second projection pieces 73 are provided each slidably 
together and at predetermined distance on the bottom face of the sample 
accommodating section 70. In the sample accommodating section 70, a 
plurality of sample racks (not shown) supporting a plurality of standing 
test tubes each containing a sample are accommodated. The sample racks are 
conveyed in a direction of an arrow E or F by the belts 71, and conveyed 
in a direction of an arrow G intermittently by predetermined length so as 
to make each test tube situate at a dripping position by the first 
projection pieces 72, and conveyed in a direction of an arrow H by the 
second projection pieces 73. 
The dripping device 80 is constituted by a nozzle 81 and a nozzle carrying 
mechanism 82. 
Upper end of the nozzle 81 is communicated with a suction means and a 
discharge means (both of them are not shown) so as to suck and drip the 
sample, and mounted on an nozzle holder 84. The nozzle holder 84 is 
mounted slidably on a vertical guide 85 standing on a movable table 83 
described below, and attached to a belt 88 trained over a pulley 86 
provided on upper end of the vertical guide 85, and a pulley 87 engaged 
with spline shaft 90 described below (See FIG. 4). 
Further, the vertical guide 85 is attached to the movable table 83 mounted 
slidably on horizontal guide 89 extending horizontally. The movable table 
83, which is movable together with the pulley 87, is attached to a belt 95 
trained over a pulley 92 provided at front portion (right-hand end in FIG. 
4) of a side wall 91 projecting from a main body of the sample analyzer, 
and a pulley 94 mounted on a shaft of a motor 93. A belt 98 is trained 
over a pulley 96 mounted on one end of the spline shaft 90, and a shaft of 
a motor 97. 
Accordingly, the belt 88 is driven by the spline shaft 90 and then, the 
nozzle 81 is movable vertically in FIG. 4 such that the nozzle 81 is 
situated at predetermined position. Further, the belt 95 is driven 
directly by the motor 93 such that the nozzle 81 is carried through the 
movable table 83 in a horizontal direction in FIG. 4, and can be situated 
at each of a interrupting position Q, a sampling position R, a cleaning 
position S, dripping positions T1, T2, T3, T4 and T5. 
The base section 100 for taking the sticks out of the cassette 10 is 
constituted by a conveying plate 101 and a pair of push claws 102 coupled 
with each other. The stick 25 in the cassette 10 is pushed out onto the 
conveying plate 101 by a push pin 49 of the removal device 40, and pushed 
upward in FIG. 2 at the opposite end portions by the push claws 102. On 
left-hand push claw 102 in FIG. 2, inclined face is formed such that a 
stick 25 can be directed to normal direction by the inclined face, even if 
the stick 25 is pushed out obliquely from the cassette 10. The push claws 
102 is coupled to the movable frame 56 of the removal device 40 such that 
the stick 25 is conveyed to the transfer section 110 with a movement of 
the base assembly 41 in a direction of an arrow D after dripping the 
sample to the stick 25 as described below. 
The transfer section 110 is constituted by a temperature controlled table 
111 and a conveyer 113 provided on the temperature controlled table 111. 
The conveyer 113 includes a pair of belts 113a which extend in the 
direction of the arrows C and D, and are juxtaposed at a predetermined 
distance smaller than the length of the stick 25. A plurality of 
projections 113b are formed on each of the belts 113a at a predetermined 
distance substantially equal to the width of the stick 25. The belts 113a 
are driven intermittently at a predetermined period of 16 sec. in this 
embodiment so as to transport to an examination section 120, the sticks 25 
each having the sample dripped thereon. Further, over the temperature 
controlled table 111, a temperature controlled plate, which is not shown, 
is disposed. In the examination section 120, results of reaction between 
each reagent on the stick 25 and the sample is read such that reaction 
values corresponding to the results are compared with reference values 
input beforehand and are analyzed. Thereafter, the results of the 
examination are printed out by a printer 131. 
Meanwhile, reference numeral 130 shows operation panel, and 132 shows 
reading portion for reading of the barcode the sample. 
Upon turning on a power source of the automatic sample analyzer of the 
above described arrangement, the drive mechanism 42 is actuated so as to 
cause the base assembly 41 to start the rectangular motion in forward 
direction of the analyzer (See FIG. 11). Thus, the discriminatory mark 23 
of each cassette 10 is read by the first sensor 53, the data concerning 
the position and the kind of the cassette 10 are stored in a memory unit 
of a computer which is not shown. Thereafter, the base assembly 41 travels 
along a left end surface of each cassette 10 such that presence or absence 
of the stick 25 in the cassette 10 is detected through the sensor hole 22 
of each cassette 10 by the second sensor 54, the result of the detection 
is stored in the memory unit. Namely, the above described operation is 
performed automatically by turning on the electric power source. Further, 
the operation is performed also automatically by closing a cover A shown 
in FIG. 1. 
Next, for each sample, the examination items are indicated by bar code or 
are input by using keys. And then, upon depressing a start button which is 
not shown, the dripping device 80 is actuated automatically so as to suck 
the sample by the nozzle 81 when the sample is situated at the sampling 
position R. Thereafter, the nozzle 81 travels to the cleaning position S, 
and the sample of required amount for measuring a specific gravity of the 
sample is discharged and then, the nozzle 81 travels to the dripping 
position T (T1 or T2 or . . . T5). Meanwhile, the dripping position T 
corresponds to a position of the cassette 10 selected according to a 
combination of the examination items of the sample. 
On the other hand, the drive mechanism 42 is actuated with the motion of 
the nozzle 81 such that the base assembly 41 is carried in the direction 
of the arrow C by motor 65 according to a combination of the examination 
items of the sample, and positioned to right-hand side of the 
predetermined cassette 10. Further, the base assembly 41 is carried in the 
direction of the arrow A by the motor 62 such that push pin 49 passes 
through the slit 21, and pushes out a sheet of stick 25 through the outlet 
24 from the cassette 10. At this time, the rollers 48 provided at the end 
of the base assembly 41 assist the movement of the push pin 49 by rolling 
on the underside of the cassette 10, and the arm 45 flexes properly so as 
to compensate for offset in relative position of the slit 21 and the base 
assembly 41. The stick 25 is pushed continuously until first reagent 
portion arrives at the dripping position T, thereafter pushed 
intermittently so as to each reagent portion is situated at the dripping 
position T sequentially. And thus, very small amount of sample 
(approximately 5 to 10 .mu.l in this embodiment) is dripped from the 
nozzle 81 to each reagent portion 29. Upon the completion of all 
drippings, the stick 25 is wholly pushed out onto the conveying plate 101 
by the push pin 49, and pushed to the transfer section 110 by the push 
claw 102 when the base assembly 41 is returning in the direction of the 
arrow D. Further, in the transfer section 110, the stick 25 is conveyed 
for predetermined period of time (approximately one minute in this 
embodiment) such that a reaction at the each reagent portion is 
accelerated, and conveyed to the examination section 120 and then, the 
result of the reaction at the each reagent portion 29 is analyzed by color 
comparison in the examination section 120. 
Meanwhile, when the operation for taking the sticks 25 out of one cassette 
10 is performed, the second sensor 54 detects presence or absence of a 
next stick 25 in this cassette 10, and when the next stick is absent, the 
second sensor 25 outputs a signal to the memory unit such that a next 
stick 25 is taken out of another cassette 10 in the next operation, and if 
another cassette 10 does not exist, a warning is given. 
Hereinafter the above described operations are repeated, and the stick 25 
corresponding to each sample situated at the sampling position R is 
suitably taken so as to perform the above described analyze. 
When a sample should be examined interruptedly, the nozzle 81 can be 
carried to the interrupting position Q, and the above described 
examination can be performed in a same manner by predetermined operation 
through a operation panel 130. Meanwhile, in the case that the examination 
is interrupted for example by a stoppage of electric power, the base 
assembly 41 remains at a position in which the base assembly 41 is 
situated when the stoppage happens, therefore the analyzer has a function 
for confirming the position of the base assembly 41. 
Further, with respect to the cassette, two or more cassettes 10 of the same 
kind, each of which accommodates the same kind of sticks, can be provided, 
whereby when sticks 25 in a cassette 10 are exhausted, a time for 
exchanging the cassette 10 for new one can be shortened. 
Furthermore, in the above described embodiment, urine is used as an example 
of the sample, however the sample is not confined to urine, but may be 
blood etc. 
As is clear from the above description, in an automatic sample analyzer of 
the invention, since the cassette is automatically identified, and the 
stick corresponding to predetermined examination item from the desired 
cassette, proper examination can be performed. 
Further, by providing a pad of predetermined form at the opposite ends of 
the stick, the removal of the stick from the cassette can be performed 
smoothly. 
Furthermore, since the stick in the cassette is depressed through the slide 
plate by the torsion spring, the sticks being accommodated in the cassette 
can be taken out of the cassette with certainty until the last stick. 
Furthermore, since an engageable claw is provided on the slide plate, and 
an engageable member is provided on the upper portion of a side face of 
the cassette such that the engageable claw is detachably engaged with the 
engageable member, an operation of the stick can be performed easily. 
Although the present invention has been fully described in connection with 
the preferred embodiments thereof with reference to the accompanying 
drawings, it is to be noted that various changes and modifications are 
apparent to those skilled in the art. Such changes and modifications are 
to be understood as included within the scope of the present invention as 
defined by the appended claims unless they depart therefrom.