Sample container carrier, laboratory sample distribution system and laboratory automation system
Applicable field and prior art
The invention relates to a sample container carrier for a laboratory sample distribution system, to a laboratory sample distribution system comprising such a sample container carrier, and to a laboratory automation system comprising such a laboratory sample distribution system.
Laboratory sample distribution systems comprising sample container carriers are typically used for laboratory automation systems. Such laboratory automation systems may comprise laboratory stations like pre-analytical, analytical and/or post-analytical stations. An example for such a laboratory sample distribution system is disclosed in WO 201 1 /138448 A1 . The laboratory sample distribution system comprises a transport plane and a plurality of electro-magnetic actuators positioned below the transport plane. It further comprises a number of sample container carriers, being adapted to carry sample containers. Such sample containers can, for example, be tubes made of transparent material. Problem and solution
It is an object of the invention to provide for a sample container carrier, a laboratory sample distribution system and a laboratory automation system being energy efficient and reliable.
The object is solved by a sample container carrier according to claim 1 , a laboratory sample distribution system according to claim 12 and a laboratory automation system according to claim 14.
The invention relates to a sample container carrier for a laboratory sample distribution system.
The sample container carrier is adapted to carry one or more sample containers, e.g. in form of conventional sample tubes.
The sample container carrier is further adapted to be moved over a, e.g. horizontal, transport plane of the laboratory sample distribution system.
The sample container carrier comprises a magnetically active device being adapted to interact with a magnetic field generated by means of the laboratory sample distribution system such that a magnetic move force is applied to the sample container. It is to be understood that the sample container carrier can comprise a plurality of magnetically active devices, e.g. in order to intro- duce a preferred orientation in the sample container carrier. The magnetically active device can be a permanent magnet, an electromagnet, and/or be made of or comprise ferromagnetic material.
The sample container carrier further comprises a cover covering the magnetically active device.
The cover may be made of or comprise a material having a relative permeability μτ larger than 1 , preferably larger than 10, preferably larger than 100, preferably larger than 1000, preferably larger than 10000.
The cover may be made of or comprise ferromagnetic or ferrimagnetic material.
The cover may be made of or comprise a magnetically soft material, preferably construction steel. This material has been proven to show suitable properties for the intended use and is cheap and easily available.
The cover can, for example, have a dome shape, which has been proven suitable for the intended use.
The cover aligns and concentrates magnetic field lines originating from the magnetically active device such that a magnetic field line density is increased in a desired direction towards the transport plane, where the magnetic field of the magnetically active device is intended to interact with the magnetic field generated by means of the laboratory sample distribution system. This allows for a reduced electric power consumption when driving the sample container carriers over the transport plane.
According to an embodiment, the magnetically active device and/or the cover are vertically aligned with a bottom of the sample container carrier.
According to an embodiment, the sample container carrier comprises a sliding member, wherein the sliding member is adapted to be in contact with the transport plane if the sample container carrier is placed on the transport plane. The cover and the sliding member define a, e.g. closed, cavity. The magnetically active device is arranged inside the cavity. The sample container carri-
er slides on the transport plane on its sliding member. The sliding member may be adapted such that friction between the transport plane and the sliding member is reduced.
According to an embodiment, the cover has an opening or is open in the direction of the sliding member. This allows for a preferable outlet of magnetic field lines towards the transport plane, especially when the magnetically active device is placed under the cover and above the sliding member.
The magnetically active device and/or the cover may have a circular cross-section in a horizontal direction. The term "horizontal" refers to a typical orientation of the sample container carrier in use. Thus, a preferred orientation of the sample container carrier may be omitted. According to an embodiment, the cover comprises a plate positioned above the magnet, wherein the plate preferably extends laterally beyond the magnetically active device. This allows for a shielding of magnetic field lines above the magnet.
According to an embodiment, the cover at least partially laterally surrounds the magnetically active device. This allows for a shield or field guiding all around the magnetically active device. Alternatively, the cover may comprise a number of sectors laterally surrounding the magnetically active device, the sectors being distant from each other. Such an embodiment allows for a preferred orientation or a plurality of preferred orientations. For example, the cover may comprise between two and ten sectors.
According to an embodiment, laterally surrounding portions of the cover are distant from the magnetically active device. This allows for a dedicated bending of magnetic field lines leaving the magnetically active device at its upper side.
According to an embodiment, laterally surrounding portions of the cover and/or portions of the cover positioned above the magnet have a thickness adapted to prevent magnetic saturation at typical magnetic fields induced by the magnetically active element. Such typical magnetic fields can, for example, have a value of about 0.7 T. Saturation would lead to a decreased capacity of the cover to bend the magnetic field lines as intended.
According to an embodiment, portions of the cover being positioned above the magnet at least partially abut the magnetically active device. This leads to an increased coupling of magnetic field lines from the magnetically active device to the cover. For example, the cover could abut the magnetically active device with the plate discussed above.
According to an embodiment, the cover has the form of a cap imposed on the magnetically active device.
According to another implementation, the cover and the magnetically active device together have the form of a mushroom, wherein the magnetically active element forms the post of the mushroom and the cover forms the cap of the mushroom. Such implementations have been proven suitable for typical applications.
According to an embodiment, the sample container carrier comprises holding means for a sample container in order to carry a sample container. The holding means may comprise a cone element forming a cone as an intake for the sample container. The holding means may further comprise a number of spring arms positioned at the top of the sample container carrier, the spring arms being adapted to engage the sample container laterally. Such implementations have been proven suitable for holding and transporting typical sample containers with the sample container carrier.
According to an embodiment, the holding means is positioned above the cover. This allows for a laterally compact design of the sample container carrier.
The invention further relates to a laboratory sample distribution system, comprising a number (1 to 500) of sample container carriers according to the invention, a transport plane, being adapted to support the sample container carriers, a number (4 to 1024) of electro-magnetic actuators, being stationary arranged below the transport plane, the electro-magnetic actuators being adapted to generate a magnetic field to move a respective sample container carrier on top of the transport plane, and a control device, being configured to control the movement of a respective sample container carrier on top of the transport plane by driving the electro-magnetic actuators such that the respective sample container carrier move along corresponding transport paths. The transport plane can also be denoted as a transport surface. Supporting the sample container carriers can also be denoted as carrying the sample container carriers. The electromagnetic actuators of the laboratory sample distribution system may be used in order to generate magnetic fields that drive the sample container carriers over the transport plane. The sample container carriers can be moved in two dimensions, allowing for great flexibility when trans- porting sample container carriers, for example between laboratory stations.
According to an embodiment, a radius of the cover in a horizontal cross-section is identical to or slightly smaller than a minimal distance between a center of an electro-magnetic actuator and a circumference of a directly adjacent electro-magnetic actuator. Such a design has been proven suitable for an efficient transport of sample container carriers over the transport plane. Alterna- tively, it can be said that the radius is approximately a minimal distance between a center of an electro-magnetic actuator and a circumference of an adjacent electro-magnetic actuator.
The distance between actuators is in a typical implementation 20 mm or about 20 mm.
The transport plane can be made of electroconductive material and can be grounded. The ferromagnetic cover may also be formed of electroconductive material, e.g. iron steel, etc. The ferromagnetic cover may have a cap-shape or bell-shape. A lower end of the ferromagnetic cover, defining an opening of the cap or bell, can be adapted to be in direct contact with the transport plane if the sample container carrier is placed on the transport plane. The ferromagnetic cover and the transport plane define a cavity if the sample container carrier is placed on the transport plane. The magnetically active device can be arranged inside the cavity. The magnetically active device can be fixed to the ferromagnetic cover at an upper end of the ferromagnetic cover. The ferromagnetic cover can comprise holding means for a sample container, e.g. being placed at an upper end of the ferromagnetic cover. The holding means may e.g. be embodied as a blind hole, e.g. having a circular cross section, adapted to receive the sample container. This embodiment prevents an electrostatic charging of the transport plane and of the bottom of the sample container carriers, if the sample container carriers move over the transport plane.
The magnetically active device or magnetic element of the sample container carrier can be arranged such that the magnetic move force depends from an angularity of the sample container carrier being placed on the transport plane. By means of such an embodiment, it is possible to introduce preferred directions in a sample container carrier. Compared to the prior art, which uses sample container carriers without preferred directions, effects like involuntary rotation of sample container carriers can be prevented. This can, for example, save energy and stabilize movement.
The term that the magnetic move force depends from an angularity may imply that the magnetic move force, for example the amount of the magnetic move force, depends from an orientation of the sample container carrier relative to an external magnetic field. For example, if the sample container carrier is rotated by a certain amount around a vertical axis, the magnetic move force
may have another amount or may point in another direction, although the sample container carrier is observed at the same position.
The magnetically active device can have a horizontal cross section of a regular polygon, preferably a square cross section.
The ferromagnetic cover or guiding device can have a horizontal cross section comprising a number of sectors, preferably embodied as arms, wherein the sectors are distant from each other and are each originating at a common central part of the guiding device.
The sectors can be arranged to form a cross.
The sliding member can have a horizontal cross section comprising a number of arms extend- ing from a central part, wherein the sliding member has a concave horizontal cross section between the arms.
The sliding member can comprise a number of lower edges, the lower edges surrounding a portion of the sliding member being adapted to be in contact with the transport plane, wherein the lower edges are at least partially bevelled. The sliding member may have a centrally located recess in which the sliding member is not in contact with the transport plane. The recess may be surrounded by a portion of the sliding member being adapted to be in contact with the transport plane.
The electro-magnetic actuators, especially respective magnetic coils, and/or magnetic cores, can have a horizontal cross section of a regular polygon, preferably a square cross section. The just discussed implementations with the specific design of the cover relative to the electromagnetic actuators allow for a flow of magnetic field lines that has been proven especially effective for driving the sample container carriers with the electro-magnetic actuators.
The invention further relates to a laboratory automation system, comprising a number of a pre- analytical, analytical and/or post-analytical (laboratory) stations, and a laboratory sample distri- bution system as described above adapted to transport the sample container carriers and/or sample containers between the laboratory stations. The laboratory stations may be arranged adjacent to the laboratory sample distribution system.
Pre-analytical stations may be adapted to perform any kind of pre-processing of samples, sample containers and/or sample container carriers.
Analytical stations may be adapted to use a sample or part of the sample and a reagent to generate a measuring signal, the measuring signal indicating if and in which concentration, if any, an analyte is existing.
Post-analytical stations may be adapted to perform any kind of post-processing of samples, sample containers and/or sample container carriers.
The pre-analytical, analytical and/or post-analytical stations may comprise at least one of a decapping station, a recapping station, an aliquot station, a centrifugation station, an archiving station, a pipetting station, a sorting station, a tube type identification station, and a sample quality determining station.
Short description of the drawings
The invention will now be described in detail with respect to the drawings, wherein
Figs. 1 a, 1 b show a sample container carrier in respective exploded views, Fig. 2 shows the sample container carrier in a sectional view,
Fig. 3 shows the sample container carrier in a perspective sectional view,
Fig. 4 shows the sample container carrier in a perspective top view,
Figs. 5a, 5b show a permanent magnet with respective field lines without and with a cover,
Fig. 6 shows a laboratory automation system comprising a laboratory sample distribu- tion system, the laboratory sample distribution system comprising the sample container carrier, and
Fig. 7 shows a sample container carrier according to a further embodiment in a sectional view.
Detailed description of the drawings
Figs. 1 a and 1 b show a sample container carrier 10 according to an embodiment of the invention. Fig. 1 a shows the sample container carrier 10 in an exploded view from above, whereas fig. 1 b shows the sample container carrier 10 in an exploded view from below. A sliding member 20 is arranged at the bottom of the sample container carrier 10. The sliding member 20 is embodied as a disk that can slide over a transport plane of a laboratory sample distribution system. The sliding member 20 comprises four posts 22 extending to the upper side, wherein the posts 22 are intended for attaching further elements of the sample container carrier 10. Above the sliding member 20, a magnetically active device in form of a permanent magnet 30 is arranged. The permanent magnet 30 is made of a hard ferromagnetic material and is permanently magnetized such that it generates a magnetic field similar to a coil having a vertical axis.
Above the magnet 30, a cover 40 is arranged, which is made of a soft ferromagnetic material. The cover 40 comprises a top plate 46 positioned above the magnet and laterally extending over the magnet, and a laterally surrounding portion 48. The laterally surrounding portion 48 completely surrounds the magnet 30, thus omitting a preferred orientation of the sample container carrier 10. The cover 40 further comprises three posts 42 extending at the top side of the cover 40 and a ring 44 being arranged over the posts 42. The posts 42 and the ring 44 are adapted to mechanically couple holding means 12 over the cover 40. The holding means 12 comprises a cone element 50 and a spring element 60. The cone element 50 is inserted into the ring 44 and comprises a cone 52 with an inner diameter decreasing from the upper side to the lower side. This cone 52 can laterally hold tube-shaped sample containers even with different diameters.
The spring element 60 is embodied as a disk having a bore 62 in the center of the disk. The bore is adapted such that a sample container can be put through. The spring element 60 further comprises three spring arms 64 positioned around the bore 62. The spring arms 64 are adapted to laterally engage and thus fix a tube-shaped sample container.
Fig. 2 shows a sectional view of the sample container carrier 10 in an assembled condition. As depicted, the permanent magnet 30 rests on the sliding member 20. The top plate 46 rests on
the permanent magnet 30. Thus, these elements are in direct contact. The surrounding element 48 of the cover 40 laterally surrounds the permanent magnet 30 with a radial distance.
The cone element 50 and the spring element 60 of the holding means 12 are positioned just above the cover 40. The posts 22 fix the sliding element 20. For further details, reference is made to the above description of figs. 1 a and 1 b.
Fig. 3 shows the sample container carrier 10 in another sectional view, which is now perspective. With regard to the elements of the sample container carrier 10, reference is made to the above description of figs. 1 a, 1 b and 2.
As depicted, the cone 52 provides for a lateral support of a sample container contained in the holding means 12.
Fig. 4 shows the sample container carrier 10 in an assembled condition and in a perspective view. The sample container carrier 10 is adapted to move over a transport plane of a laboratory sample distribution system with its sliding member 20 and can be driven by a magnetic field generated by electro-magnetic actuators of the laboratory sample distribution system and inter- acting with the magnetic field of the permanent magnet 30. The sample container carrier 10 can contain or carry a sample container in the holding means 12.
Figs. 5a and 5b schematically depict a comparison between magnetic field lines of the permanent magnet 30 with and without the cover 40.
Fig. 5a shows the permanent magnet 30 without the cover 40. As depicted, the magnetic field lines generated by the permanent magnet 30 symmetrically extend to the upper side and to the lower side.
Fig. 5b shows the permanent magnet 30 with the cover 40 imposed on it. As depicted, the permanent magnet 30 and the cover 40 together have the shape of a mushroom, wherein the magnet 30 forms the post. The magnetic field lines generated by the permanent magnet 30 of fig. 5b are guided by means of the cover 40, such that the magnetic field lines are concentrated within the cover 40. As a result, a distorting upper and lateral magnetic stray field is reduced. This reduces an unwanted magnetic coupling between sample container carriers positioned or moving adjacent to each
other on the transport plane. Further, the magnetic flux directed towards the transport plane and the electro-magnetic actuators positioned below the transport plane is increased, thus increasing the resulting magnetic drive force. Thus, energy consumption of the laboratory sample distribution system can be reduced. Fig. 6 shows a laboratory automation system 5 comprising a first laboratory station 6, a second laboratory station 7, and a laboratory sample distribution system 100. The laboratory stations 6, 7 are positioned adjacent to the laboratory sample distribution system 100 so that samples contained in sample containers 10 can be distributed between the laboratory stations 6 and 7 by means of the laboratory sample distribution system 100. The laboratory sample distribution system 100 comprises a transport plane 1 10, on which sample container carriers 10 can move. In fig. 6, only one sample container carrier 10 is schematically depicted, wherein it should be noted that typical laboratory sample distribution systems 100 comprise a plurality of sample container carriers 10. The sample container carrier 10 contains a sample container 15 adapted to comprise a sample. A plurality of electro-magnetic actuators 120 is arranged below the transport plane 1 10, each comprising a ferromagnetic core 125. The electro-magnetic actuators 120 are adapted to generate a magnetic field used to move the sample container carriers 10 on the transport plane 1 10. Further, a plurality of Hall sensors 130 is positioned on the transport plane 1 10, wherein the Hall sensors 130 are adapted to determine a respective position of a sample container car- rier 10.
The lateral extension of the sample container carrier 10 is such that it extends over an electromagnetic actuator 120 over which it is positioned to the edges of respective neighboring electromagnetic actuators. This has been proven to yield high efficiency when moving the sample container carrier 10 over the transport plane 1 10 by means of the electro-magnetic actuators 120.
The laboratory sample distribution system 100 further comprises a control unit 150, wherein the control unit 150 is adapted to drive the electro-magnetic actuators 120 such that the sample container carrier 10 moves according to a predetermined path.
The control unit 150 is further connected to the Hall sensors 130 in order to determine the posi- tion of each sample container carrier 10. The control unit 150 can direct sample container carriers 10 independent from one another to any laboratory station 6, 7.
Due to the sample container carrier 10 being configured according to the invention having a ferromagnetic cover 40 covering the permanent magnet 30, energy consumption of the laboratory sample distribution system 100 can be reduced and accuracy of positioning can be increased. Fig. 7 shows a sample container carrier 10' according to a further embodiment in a sectional view.
The sample container carrier 10' comprises the magnetically active device in the form of a permanent magnet 30 and a bell-shaped ferromagnetic cover 40' formed of electroconductive material, e.g. iron steel. A lower portion 49 of the ferromagnetic cover 40', defining an opening of the ferromagnetic cover 40', is adapted to be in direct contact with the transport plane 1 10 when the sample container carrier 10' is placed on the transport plane 1 10. The ferromagnetic cover 40' and the transport plane 1 10 define a cavity when the sample container carrier 40' is placed on the transport plane 1 10. The magnetically active device 30 is arranged inside the cavity.
The magnetically active device 30 is fixed to the ferromagnetic cover 40' at an upper end of the ferromagnetic cover 40'.
The ferromagnetic cover 40' comprise holding means 12' for a sample container. The holding means 12' are embodied as a blind hole in the ferromagnetic cover 40' having a circular cross section, adapted to receive a sample container.
The transport plane 1 10 according to this embodiment is made of electroconductive material and is grounded.
This embodiment prevents an electrostatic charging of the transport plane 1 10 and of the sample container carriers 10' when the sample container carriers 10' move over the transport plane 1 10.