Device and method for scanning and centering containers filled with fluid

Abstract: An analyzer is described including a scanning means (1) for detecting different diameters of containers (4) arranged in a tray (5) and filled with body fluid, said scanning means (1) being arranged at an aspirating station (30). The scanning means (1) consists of two movable scanning elements (2 and 3) and a sensor (6) formed by an optoelectronic interrupter switch which is associated with said scanning elements (2 and 3) and can successively be covered by the flags (27, 29) mounted at the upper side of the scanning elements (2, 3). The sensor (6) produces a signal length (60) which depends on the diameter of container (4) positioned at the scanning station (46). Container (4) is thereby centered and fixed in tray (5) by means of scanning element (2) and spring element (21) and tray (5) is centered and fixed on transport path (40) by means of scanning element (3) and spring element (22). The signal length (60) produced by the scanning means (1) and fed to a microprocessor (55) of a control unit (50) is used for controlling the position and dip-in speed of a proboscis (36) of an aspirator (35) when body fluid is removed from a container (4).

Description: The invention relates to a device for scanning and centering containers of different diameters filled with a liquid and arranged in a tray, in particular test tubes filled with body fluid and fed to an aspirating station for body fluids in an analyzer. Analyzers featuring automatic scanning and centering means for handling a number of samples or body fluids are known. A centering means for liquid containers of different diameters that are arranged in a cassette in a single row is known from EP-A 0 159 346, said means being provided within the cassette in the form of activator means. In connection with EP-A 0 159 347, devices for scanning liquid containers in the area of a mixing and aspirating station are known with the position - related to the transport path - of the liquid container relative to the aspirator being detected and the identifications provided on the liquid container being scanned through openings provided in the lateral wall of the cassette. The containers closed by means of stoppers are transported horizontally and moved to an inclined position for liquid removal with the stopper pointing down. For liquid removal the rubber stopper is pierced by a hollow needle of an aspirator. It is the object of the present invention to provide a device of the generic type by means of which the different diameters of the containers can be detected, the containers can be centered and fixed in a predetermined position in an aspirating station for body fluids, and the body fluid can be completely removed from the containers regardless of their diameters. Moreover, the processing rate for the samples is to be increased considerably in order to meet the requirements of a quick and reliable diagnosis. The above object is attained in that the scanning means consists of two movable scanning elements and a sensor that can successively be covered by said elements. Expediently, the scanning elements can be moved individually or jointly from an initial position to an end position. Such movement of the scanning elements is advantageously effected in succession. The invention provides for the sensor to be covered in the initial position by means of the first scanning element and in the end position by means of the second scanning element. Moreover, the scanning elements are advantageously used for centering and fixing the container in a tray and the tray itself on the transport path. A method according to the invention for centering and scanning containers is characterized in that for detecting the diameter of a container the number of stepping pulses of the stepping motor in response to the signal length generated by the sensor are counted by the microprocessor, and in that the data obtained are used for controlling the aspirator. Additional features of an embodiment of the invention illustrated in the drawing as well as the subclaims will show the details of the device according to the invention. Fig. 1 shows a top view of the device according to the invention comprising an input station, a transport path and two processing stations, Fig. 2 shows a lateral view of the scanning means according to Fig. 1 illustrating a tray equipped with containers, Fig. 3 is a cross-section along the line A-A in Fig. 2 illustrating the scanning means according to Fig. 1 comprising two scanning elements and a sensor, Fig. 4 shows a cross-section along the line B-B in Fig. 3 illustrating the scanning means according to Fig. 3 (lateral view), Fig. 5 is the block diagram of a control unit, Figs. 6a and 6b show diagrams indicating the typical signals generated by the sensor according to Fig. 3 in response to the diameters of two different containers. An analyzer illustrated in Fig. 1 consists of an input station comprising four tray tracks 45 arranged side by side for test tubes or elongated trays 5 carrying containers 4, and a transport path 40 which is formed as an elongated housing 42 and is pivotable about a fulcrum 41 so as to be aligned with any of the tray tracks 45 as well as a scanning station 46. Furthermore, the analyzer features at the outer side of the scanning station 46 a scanning means 1 for scanning the diameter of a container 4 and an aspirator 35 including a proboscis 36 for removing body fluid from a container 4. The scanning means 1 and the aspirator 35 are associated with an aspirating station 30 arranged on the central axis of the scanning station 46 and the transport path 40, respectively, and about halfway down the transport path 40. The scanning means 1 is arranged adjacent the aspirating station 30 and aligned with its central axis 31 extending normal to the central axis of the transport path 40 located in the scanning station 46. The transport path 40 is about twice as long as a tray 5. A laterally guided and longitudinally displaceable tray movement member 49 is arranged at the transport path 40 and connected to housing 42, said member being used for moving tray 5 from the input station 44 to the aspirating station 30 and back. Figs. 2 - 4 show the scanning means 1 with a tray 5 positioned on transport path 40 and equipped with containers 4 as well as the tray movement member 49 and its drive elements and a pulse generator 110. Tray 5 is in a position in which the vertically extending central axis 8 of a container 4 is aligned with the center of the aspirating station 30 and thus with the center of scanning means 1 along the longitudinal side of transport path 40. Furthermore, Fig. 2 illustrates drive elements for pivoting the transport path 40 whose arrangement and mode of operation will be described in the following. Housing 42 of transport path 40 is substantially closed on all sides and consists of a housing portion 90 of U-shaped cross-section and a bottom portion 91 of L-shaped cross-section which are connected such that an elongate opening 92 is formed. With its lower end portion the tray movement member 49 extends through the said elongate opening 92 into the interior of housing 42 and is connected to a toothed belt 93 arranged therein. Below the bottom portion 91 a stepping motor 98 is arranged which by means of a drive gear 94 and a guide roller 95 drives the toothed belt 93 and thus the tray movement member 49. An encoder wheel 111 is mounted on a drive shaft 96 driven by the toothed belt 93, the rotary movement of said wheel being sensed by a photoelectric switch 112. Encoder wheel 111 and switch 112 represent the pulse generator 110. At the upper end portion of the tray movement member 49 a hook 97 is arranged which upstream of guide post 37 extends horizontally beyond the centerline of transport path 40 and for transporting tray 5 engages with an eyelet 124 arranged on the front face of tray 5. Adjacent to the stepping motor 98 an additional stepping motor 114 is mounted to the bottom portion 91 and by means of a drive gear 101 and a toothed belt 102 drives a gear 103 for pivoting the transport path 40 about a journal 104, i. e. fulcrum 41. A gear 103 engages an arcuate rack 105 which in the area of the exits 43 of tray tracks 45 is connected to a support plate 106. On support plate 106 two supports 107 and 107' are arranged which are mounted to housing 42 of transport path 40 and during pivotable movement of transport path 40 slide thereon. Each of the exits 43 of tray tracks 45 is associated with a retaining means 108 which is operated by means of an electromagnet 109. Fig. 3 shows scanning means 1 and tray 5 as well as one of the containers 4 having a lid 24. Scanning means 1 is comprised of a scanning element 2, a scanning element 3 and a sensor 6 which are all arranged on a support member 20. Furthermore, support member 20 is provided with a cover 25 for the scanning elements 2, 3 and the sensor 6, at the upper end portion of cover 25 a vertically pivotable stripper 23 for lid 24 being mounted which in its inoperative position exerts pressure on lid 24 by means of a pressure spring and in the area of the lid has a passageway for proboscis 36 of the aspirator 35 (see Fig. 1). Scanning element 2 consists of a cylindrical pin 26 which at the end facing container 4 is pointed and at the opposite end has a flag 27. Scanning element 3 consists of a guide member 28 and a flag 29, with said guide member 28 having a bore in its horizontally extending longitudinal axis 14 and flag 29 being arranged at the end portion as in the case of scanning element 2. Guide member 28 which is shorter than pin 26 of scanning element 2 is slideably supported on pin 26 by means of its bore. At the side of the scanning means 1 facing container 4 guide member 28 is also supported by a support means 15 under cover 25 of support member 20. Along the longitudinal axis 14, pin 26 is also slideably supported by a support means 16 of support member 20, said support means being arranged between flags 27 and 29. The longitudinal axis 14 common to scanning elements 2 and 3 is in alignment with center axis 31 of aspirating station 30, that is to say normal to the vertically extending central axis 8 of container 4 and normal to the longitudinal side of transport path 40 (see Figs. 1 and 2). The scanning elements 2 and 3 are arranged in the upper area of tray 5 and container 4, respectively. Pin 26 of scanning element 2 extends through guide member 28, projects from scanning means 1 and further extends through an aperture 121 provided in an exterior wall 120 of tray 5. Guide member 28 of scanning element 3 also projects from scanning means 1 and extends as far as the exterior wall 120 of tray 5. Pressure is thereby exerted on scanning elements 2 and 3 by means of spring elements 21, 22. The two spring elements 21, 22 are designed as helical springs coaxially supported by pin 26. One end portion of inner spring element 21 rests on support means 16 and the other on washer 17 permanently connected to pin 26. One end portion of the outer spring element 22 also rests on support means 16 and the other on guide member 28. In this representation, the scanning elements 2 and 3 are shown in end positions 13 and 13' determined by the diameter of container 4 and by the width of tray 5. The pressure forces of spring elements 21, 22 are dimensioned such that container 4 can be centered and fixed in a receptacle 122 of tray 5 and tray 5 itself can be centered and fixed with its widened base 123 on transport path 40 by means of the guide posts 37 provided thereon. For this purpose, receptacle 123 of tray 5 is octagonal in cross-section and thus features for container 4 a prism-shaped nest in an exterior wall 120' (see Fig. 1.) Furthermore, the spring elements 21 and 22 are dimensioned such that the scanning elements 2 and 3 are positioned in the initial positions 12 and 12' shown in dotted lines when transport path 40 has been pivoted out of scanning station 46. The initial positions 12 and 12' are thereby limited by means of flags 27 and 29 as well as their positions relative to the support means 16 and 15 associated therewith. In the initial positions 12 and 12' the scanning element 2 projects beyond scanning element 3 by an amount which is larger than the largest admissible radius of a container 4. The flags 27 and 29 of scanning elements 2 and 3 are arranged one behind the other along the longitudinal axis 14 so as to be in alignment with each other and extend vertically upwards into a scanning range of sensor 6. As shown in the drawing, sensor 6 is covered by flag 29 of scanning element 3 positioned in its end position 13'. If the scanning elements 2 and 3 are positioned in the initial positions 12 and 12' when transport path 40 has been pivoted out of scanning station 46, sensor 6 is covered by flag 27 of scanning element 2. In Fig. 4 the scanning elements 2, 3 and sensor 6 are shown in cross-section as seen in the direction of their longitudinal axis 14 or in the direction of container 4 held in tray 5. Pin 26 of scanning element 2 and guide member 28 of scanning element 3 are thereby centrally aligned with the centerpoint of a widening 125 of an aperture 121 in the exterior wall 120 of tray 5, the centerpoint being located on central axis 8 of container 4. Widening 125 is arranged symmetrically to aperture 121 and has an octagonal shape. Widening 125 as well aperture 121 are limited by means of a flange 126 of exterior wall 120. The widening 125 has been adapted to the dimensions of the scanning elements 2 and 3 such that it is larger than the diameter of pin 26 but smaller than the outer diameter of guide member 28. As a result, guide member 28 partly covers flange 126 of widening 125 and rests thereon during the scanning procedure (see Figs. 3 and 4). Sensor 6 is formed by an optoelectric interrupter switch. According to their position along longitudinal axis 14, the flags 27 and 29 mounted at the upper end of scanning elements 2 and 3 extend into the scanning range of sensor 6 and pass or interrupt the horizontally extending light beam (see Fig. 3). The device operates as follows: First, one or several trays 5 equipped with containers 4 or test tubes are inserted in the four tray tracks 45 of the input station 44. The individual containers 4 are filled with body fluid and generally closed by lids 24. If now a processing procedure is started via a keyboard 51 of a control unit 50 shown in Fig. 5, said procedure will proceed according to a program stored in a memory (ROM) 52 and in accordance with the processing instructions of memory (RAM) 53 in cooperation with a microprocessor 55. After starting the processing procedure, the transport path 40 driven by the stepping motor 114 is pivoted to tray track 45 of input station 44 holding tray 5 with the containers 4 selected. During this procedure, tray movement member 49 driven by the stepping motor 98 is moved towards input station 44, with hook 97 engaging eyelet 124 of tray 5 as soon as transport path 40 has reached the tray track 45 selected. When transport path 40 is in alignment with tray track 45, retaining means 108 is removed downwardly from the exit 43 and tray 5 together with the containers 4 is moved onto transport path 40 by the tray movement member 49. When tray 5 has completely moved onto transport path 40, the transport path is pivoted towards the scanning station 46 and thus to the scanning means 1 while tray 5, i. e. the container 4 selected, is simultaneously moved towards the aspirating station 30. The position of container 4 along the transport path 40 is detected in response to tray movement member 49 in that the pulses produced by the pulse generator 110 in proportion to the length of the transport path are counted by the control unit 50. Pivoting of the transport path 40 and movement of tray 5 are controlled by means of control unit 50 such that the container 4 selected has reached the position of the aspirating station 30 on the transport path before the transport path moves into the area of the scanning station 46. When transport path 40 reaches the scanning station 46 and the scanning means 1, first the scanning element 2 by means of container 4 and then scanning element 3 by means of tray 5 are moved from their initial positions 12 and 12' to their end positions 13 and 13'. Pivotal movement of transport path 40 is terminated as soon as container 4 is exactly positioned in aspirating station 30 as well as centered and fixed in tray 5 under the action of the scanning elements. During the pivotal movement the receiver element of sensor 6 is first uncovered by flag 27 of scanning element 2 and subsequently re-covered by flag 29 of scanning element 3 when said element 3 has reached its end position 13'. As shown in Figs. 6a and 6b, the receiver element of sensor 6 produces during its being uncovered a signal having a high-level signal 62 the length 60 of which is determined by the diameter of the scanned container 4. This means that a small diameter relative to a large one produces a shorter signal due to the receiver being uncovered by the scanning element 2 somewhat later, the end position 13' of scanning element 3 being identical with both diameters. For detecting the diameter (proportional to signal length 60), the stepping pulses 63 of stepping motor 114 of the pivot drive system are counted by the microprocessor 55 of control unit 50 for the duration of the high-level signal 62 and stored in memory (RAM) 53. Subsequently, aspirator 35 is activated by control unit 50 for removal of body fluid from container 4 positioned at the aspirating station 30. Now the movement of proboscis 36 of aspirator 35 to the center of the opening 9 of container 4 and the dip-in speed and depth of proboscis 36 into the body fluid are controlled in response to the number of stepping pulses 63. Prior to dipping into the body fluid, proboscis 36 guided through an aperture of stripper 23 pierces the lid 24 placed on container 4. After removel of body fluid, proboscis 36 is moved to its upper initial position. During this upward movement the lid 24 clinging to the proboscis 36 is stripped off by the stripper 23 and re-placed on container 4. Body fluid adhering to proboscis 36 is thereby removed by means of the lid and returned into container 4. When the proboscis 36 has been pivoted away, transport path 40 controlled by control unit 50 is pivoted out of the scanning station 46 and, according to the program, the next container 4 is moved to the position of transport path 40 corresponding to the aspirating station 30. During this procedure, transport path 40 is pivoted back to the scanning station 46 and the above described process is repeated until the required body fluids have been removed from all containers 4 of tray 5. Then tray 5 containing the emptied containers 4 is returned to its tray track 45 of input station 44 and the next tray 5 from a further tray track 45 is moved onto the transport path 40. If tray 5 is incorrectly equipped, that is to say if a container 4 is missing, sensor 6 is not uncovered by the scanning elements 2 and 3 and thus no signal is produced. This leads to an error message by the control unit 50 indicated on a display panel 54 (see Fig. 5). Fig. 1 1 scanning means Fig. 2, 3 & 4 4 container Fig. 2, 3 & 4 5 tray Fig. 2, 3 & 4 30. aspirating station Fig. 4 31 center axis Fig. 2 35 aspirator 36 proboscis Fig. 3 37 guide post Fig. 3 40 transport path Fig. 2 & 3 41 fulcrum Fig. 2 42 housing 43 exit 44 input station Fig. 2 45 tray track Fig. 2 46 scanning station 47 48 49 tray movement member Fig. 2 & 3 Fig. 2 90 housing position (transport) 91 bottom portion 92 elongate opening 93 toothed belt (tray movement member) 94 drive gear 95 guide roller 96 drive shaft 97 hook 98 stepping motor 99 100 101 drive gear (transport) 102 toothed belt 103 gear 104 journal 105 rack 106 support plate 107 support 108 retaining means 109 electromagnet 110 pulse generator 111 encoder wheel 112 photoelectric switch 113 114 stepping motor (transport) Fig. 3 2 scanning element Fig. 2 & 4 3 scanning element Fig. 2 & 4 6 sensor Fig. 2 & 4 8 central axis (container) Fig. 2 & 4 9 opening Fig. 2 10 11 12 initial position (scanning element (2)) 12' initial position (scanning element (3)) 13 end position (scanning element (2)) 13' end position (scanning element (3)) 14 longitudinal axis 15 support means (cover) 16 support means (pin) 17 annular disk 18 19 20 support member Fig. 2 21 spring element 22 spring element 23 stripper Fig. 3 24 lid 25 cover 26 pin (scanning element (2)) 27 flag 28 guide member (scanning element (3)) 29 flag 120 exterior wall (tray) 120' exterior wall 121 aperture 122 receptacle 123 base 124 eyelet Fig. 2 Fig. 4 125 widening (tray/aperture) 126 flange 130 Fig. 5 50 control unit 51 keyboard 52 memory (ROM) 53 memory (RAM) 54 display panel 55 microprocessor Fig. 6a & 6b 60 signal length 61 low-level signal 62 high-level signal 63 stepping pulse

Claims: Device for scanning and centering containers of different diameters filled with a liquid and arranged in a tray, in particular test tubes filled with a body fluid and fed to an aspirating station (30) for body fluids in an analyzer, characterized in that the scanning means (1) consists of two movable scanning elements (2, 3) and a sensor (6) associated with said elements (2) and (3). Device according to claim 1, characterized in that the scanning elements (2, 3) can be moved individually or jointly from an initial position (12, 12') to an end position (13, 13'). Device according to claims 1 and 2, characterized in that the scanning elements (2, 3) can be moved one after the other. Device according to claims 1 through 3, characterized in that the sensor (6) is covered whenever one scanning element (2) is in the initial position (12) or the other scanning element (3) is in its end position (13'). Device according to claims 1 through 4, characterized in that the scanning elements (2, 3) and the sensor (6) are arranged on a support member (20). Device according to claims 1 through 5, characterized in that the scanning elements (2, 3) are arranged in the upper region of the container (4) and are oriented normal to its central axis (8). Device according to claims 1 through 6, characterized in that the scanning elements (2, 3) are arranged normal to a transport path (40) for the containers (4) held in tray (5) and in alignment to a center axis (31) of the aspirating station (30) for body fluids. Device according to claims 1 and 6, characterized in that the transport path (40) can be pivoted about a fulcrum (41) from a tray track (45) to a scanning station (46) for containers (4), and in that prior to its arrival at the scanning station (46) a container (4) to be scanned can be oriented along the transport path (40) with respect to its scanning position, i. e. aspirating position. Device according to claims 1 through 8, characterized in that by means of spring elements (21, 22) the scanning elements (2, 3) can be moved to their initial positions (12, 12') in the direction of the transport path (40) and by means of the container (4) to be scanned and the tray (5) they can be moved to their end positions (13, 13') in the opposite direction. Device according to claim 9, characterized in that the end position (13) of one scanning element (2) is determined by the diameter of container (4) and the end position (13') of the other scanning element (3) is determined by the width of tray (5). Device according to claims 9 and 10, characterized in that in its initial position (12) one scanning element (2) extends beyond the other scanning element (3) by an amount which is larger than the largest admissible radius of a container (4). Device according to claims 9 through 11, characterized in that in the scanning station (46) and the aspirating station (30) container (4) can be centered and fixed in tray (5) by means of one scanning element (2) and the tray (5) can be centered and fixed in the transport path (40) by means of the other scanning element (3). Device according to claim 1, characterized in that for controlling the aspirator (35) the electrical signals produced by the scanning means (1) in response to the diameter of container (4) are fed to a microprocessor (55) of a control unit (50). Device according to claims 1 and 13, characterized in that the signal length (60) of sensor (6) depends on the diameter of container (4). Device according to claim 14, characterized in that the signal length (60) can be detected by the pivot drive system of the transport path (40) by means of the number of stepping pulses (63) of the stepping motor (114). Method of operating a device according to any of the claims 1-15, characterized in that for detecting the diameter of a container (4) the number of stepping pulses (63) of a stepping motor (114) in response to the signal length (60) of the sensor (6) are counted by the microprocessor (55), and in that the data obtained are used for controlling the aspirator (35). Method according to claim 16, characterized in that the dip-in depth of a proboscis (36) of the aspirator (35) into the body fluid of a container (4) is controlled in response to the control data obtained. Method according to claims 16 and 17, characterized in that the movement of the proboscis (36) to the center of the opening (9) of container (4) is controlled in response to the control data obtained. Method according to claim 16, characterized in that the dip-in speed of the proboscis (36) of the aspirator (35) into the liquid in container (4) is controlled in response to the control data obtained.

Inventors: WUERSCHUM HANS-PETER C O KODAK, WUERSCHUM, HANS-PETER, C/O KODAK AKTIENGESELLSCHAFT, Würschum, Hans-Peter, c/o Kodak Aktiengesellschaft
Applicants: EASTMAN KODAK CO, KODAK AG, CLINICAL DIAGNOSTIC SYSTEMS, INC.
Application year: 1991
Main classification: G01N35
IPC codes: G01N1, G01N35