# Patent

## Title
Laboratory sample distribution system and corresponding method of operation

## Abstract

A laboratory sample distribution system is presented. The laboratory sample distribution system comprises a number of container carriers. The container carriers each comprise at least one magnetically active device such as, for example, at least one permanent magnet, and carry a sample container. The system further comprises a transport plane to carry the container carriers and a number of electro-magnetic actuators being stationary arranged below the transport plane. The electro-magnetic actuators move a container carrier on top of the transport plane by applying a magnetic force to the container carrier.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of PCT/EP2012/071762, filed Nov. 2, 2012, which is based on and claims priority to EP 11187977.1, filed Nov. 4, 2011, which are hereby incorporated by reference.


BACKGROUND
The present disclosure generally relates to a laboratory sample distribution system and a corresponding method of operation.
Laboratory sample distribution systems are used to distribute samples or specimens, for example, blood samples or specimens, between various different laboratory stations or specimen-processing instruments, such as pre-analytical stations, analytical stations and post-analytical stations.
In one prior art system, a drive mechanism which operates to advance specimen-container racks on a surface by producing an X/Y movable magnetic field below the surface. The movable magnetic field is produced by permanent magnets carried by an X/Y movable magnetic truck assembly. The magnetic field produced by each magnet magnetically couples with magnetically-attractive members carried in a base portion of each specimen-transport rack. The magnetic bond between the magnets and magnetically-attractive members is sufficiently strong that, as the magnetic truck assembly moves in the X/Y plane, a magnetically-coupled rack follows. Due to mechanical constraints caused by the X/Y movable magnetic truck assembly independent simultaneous movements of multiple specimen-transport racks are difficult to implement. Further, specimen-containers can only be moved together in specimen-transport rack quantities.
Therefore, there is a need to provide a laboratory sample distribution system and a corresponding method of operation that is highly flexible and offers a high transport performance.
SUMMARY
According to the present disclosure, a laboratory sample distribution system is presented. The system comprises a plurality of container carriers. Each container carrier can comprise at least one magnetically active device and can carry a sample container. The system can further comprise a transport plane to carry the container carriers and a plurality of electro-magnetic actuators stationary arranged below the transport plane. The electro-magnetic actuators can move a container carrier on top of the transport plane by applying a magnetic force to the container carrier.
Accordingly, it is a feature of the embodiments of the present disclosure to provide a laboratory sample distribution system and a corresponding method of operation that is highly flexible and offers a high transport performance. Other features of the embodiments of the present disclosure will be apparent in light of the description of the disclosure embodied herein.



BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:
FIG. 1 illustrates a laboratory sample distribution system having a transport plane formed by multiple sub planes according to an embodiment of the present disclosure.
FIG. 2 illustrates a top view of an exemplary sub plane shown in FIG. 1 according to an embodiment of the present disclosure.
FIG. 3 illustrates a detailed perspective side view of the sub plane shown in FIG. 2 according to an embodiment of the present disclosure.
FIG. 4 illustrates a container carrier according to a first embodiment of the present disclosure.
FIG. 5 illustrates a container carrier and a corresponding electro-magnetic actuator according to a second embodiment of the present disclosure.
FIG. 6 illustrates a simulated magnetic flux density for a container carrier positioned on top of an electro-magnetic actuator not activated and an adjacent electro-magnetic actuator activated according to an embodiment of the present disclosure.
FIG. 7 illustrates a side view of an embodiment of a sub plane comprising a magnetizable coupling element providing a magnetic coupling between adjacent electro-magnetic actuators according to an embodiment of the present disclosure.
FIG. 8 illustrates movement of a container carrier and an activation order of corresponding electro-magnetic actuators according to a first embodiment of the present disclosure.
FIG. 9 illustrates movement of a container carrier and an activation order of corresponding electro-magnetic actuators according to a second embodiment of the present disclosure.
FIG. 10 illustrates a sub plane according to a further embodiment of the present disclosure.



DETAILED DESCRIPTION
In the following detailed description of the embodiments, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration, and not by way of limitation, specific embodiments in which the disclosure may be practiced. It is to be understood that other embodiments may be utilized and that logical, mechanical and electrical changes may be made without departing from the spirit and scope of the present disclosure.
A laboratory sample or specimen distribution system according to a first embodiment can comprise a plurality of container carriers such as, for example about 50 to about 500 container carriers. The container carriers cannot be self-powered. The container carriers can comprise at least one magnetically active, i.e. magnetically attractive, device and can carry a single sample container. Further, the system can comprise a two dimensional transport plane or supporting surface, which may be completely planar and can carry at least part of the container carriers. A number of electro-magnetic actuators such as, for example about 50 to about 5000 electro-magnetic actuators, can be arranged stationary or fixed below the transport plane. The electro-magnetic actuators can move a container carrier on top of the transport plane in at least two different directions by applying or causing a magnetic force to the container carrier, i.e. to the magnetically active device of the container carrier.
The transport plane can support the container carriers in a way to allow movement along directions as guided by magnetic forces. Accordingly, the transport plane can be continuous in at least those directions of movements to allow a smooth travel of the container carriers. In order to allow a flexible transfer of carriers along many lateral directions, a flat transport plane can be an advantage. On a microscopic level, it can be advantageous to employ a surface with many small protrusions in order to reduce friction between the transport plane and the bottom surface of the container carrier.
The transport plane can further transmit the magnetic field of the electro-magnetic actuators. Accordingly, the transport plane can be made from magnetically transmissive materials such as, for example, glass or plastics. Further, the thickness of the transport plane can be a compromise between mechanical stability and magnetic shielding. A transport plane having a thickness of about 2 to about 10 mm can be well suited.
The magnetically active device can be a device to cause magnetic forces in interaction with a corresponding magnetic field. The magnetically active device may comprise at least one permanent magnet. By the multiple electro-magnetic actuators interacting individually with corresponding container carriers, it can be possible to independently and simultaneously move multiple individual sample containers along a given grid over the transport plane offering high transport flexibility, which can mean that single containers can be transported independently from each other to desired locations on the transport plane.
The transport plane may be formed of multiple adjacent sub-planes. The system may comprise a cover profile covering the transport plane, i.e. covering the sub-planes forming the transport plane. The cover profile can simplify the cleaning of the transport plane and can avoid disturbing gaps between adjacent sub-planes. Further, the cover profile can mitigate height differences between adjacent sub-planes. The cover profile may be fluidtight. The cover profile may be just overlying the transport plane or may be glued to the top surface of the sub-planes to stabilize the arrangement and to prevent spacing which can reduce magnetic forces.
The cover profile may be a glass plate, a non-magnetic metal plate such as, for example, an aluminum plate, or a foil of plastic material such as, for example, a foil of polyethylene or PTFE (poly-tetra-fluoro-ethylene). A glass plate can be chemically resistant, easily washable and stiff, so that height differences between sub-planes may be mitigated. For flexible cover profiles, a suitable thickness of the cover profile can be a compromise between mechanical stability, height mitigation and magnetic shielding. In the case of plastic materials, a cover profile having a thickness of about 1 to about 10 mm can be well suited.
The surface of the container carriers and the surface of the transport plane, i.e. the surface of the cover profile, may be arranged to reduce friction between the surfaces, for example, by coating the container carriers and/or the transport plane or cover profile and/or by roughening the contact surfaces of the container carriers and/or of the cover profile.
The electro-magnetic actuators may be arranged in rows and columns forming a grid having a given, for example, constant, grid dimension. The grid dimension can specify a distance between adjacent or consecutive electro-magnetic actuators in a given row or column.
The container carriers may have a stand. The stand may have a circular cross section having a diameter that is equal to or less than the grid dimension. This dimensioning can make it possible that two carriers moving on direct adjacent rows or columns formed by electro-magnetic actuators can pass by each other without collision.
The electro-magnetic actuators may be arranged in rows and columns forming a grid or matrix. Adjacent rows may have different grid dimensions selected either from a first grid dimension or a second grid dimension and adjacent columns may have different grid dimensions selected either from the first grid dimension or the second grid dimension, wherein the second grid dimension is larger, for example, twice as large, as the first grid dimension.
The container carriers each can have a stand. The stand can have a circular cross section having a diameter that can be equal to or less than the larger grid dimension.
The circular cross section of the stand can reduce the likelihood of a stand collision of container carriers moving adjacent in different directions. Compared, for example, with quadratic stands, this can reduce the required safety distance between adjacent positions and the requirements on positioning accuracy. Further, the circular stand can improve the self-supporting of the container carrier, for example, can prevent that the containers carrier tilts under normal operating conditions.
The dimensioning of the size or diameter of the stand smaller than or equal to the larger grid dimension (i.e. the distance between the electro-magnetic actuators forming the larger grid), wherein the larger grid dimension can be twice as large as the first grid dimension, can make it possible that two carriers moving on adjacent tracks formed by electro-magnetic actuators arranged according to the smaller grid dimension can pass by each other without collision. On the other hand, the footprint can be large enough to provide a smooth transport without much tilting.
The electro-magnetic actuators may be arranged in rows and columns forming a grid or matrix of active transport fields. The rows and columns can have either a first grid dimension g1 or a second grid dimension g2, wherein g2=2*g1. Adjacent rows and adjacent columns can have different grid dimensions. The grid dimension can specify a distance between adjacent or consecutive electro-magnetic actuators in a given row or column. In other words, the electro-magnetic actuators can be arranged in the form of a grid or matrix, wherein the grid or matrix can have blank positions representing omitted electro-magnetic actuators. This arrangement can consider that diagonal movements of the container carriers may not be necessary to reach a specific destination on the transport plane, since the specific destination can be reached based on movements along the rows and columns. This arrangement of the electro-magnetic actuators can reduce the number of required electro-magnetic actuators significantly (by, for example, 33%) compared to a solution having a constant grid dimension. Nevertheless, if a diagonal movement is required, it can be self-evident that the rows and columns may be provided having a constant grid dimension, for example, forming a transport plane being divided in active transport fields with equal dimensions.
If the transport plane is divided into multiple sub-planes, each sub-plane may have a first outer face, a second outer face, a third outer face and a fourth outer face at which further planes can be arranged in a tiling manner to form a transport plane. This approach can offer the ability to provide transport planes of desired shape. This can be a big advantage to serve the needs an individual laboratory might have due to the laboratory stations present or due to spatial restraints.
The approach to build the transport plane from sub-planes can be combined with the concept of rows having different grid dimensions to reduce the number of needed electro-magnetic actuators. Sub-planes can be employed where along the first and the second outer face the electro-magnetic actuators can be arranged in a first grid dimension g1 and along the third and the fourth outer face the electro-magnetic actuators can be arranged in a second grid dimension g2, wherein g2=2*g1. Multiple sub-planes can be arranged adjacent in a tiling manner to form the transport plane, wherein adjacent outer faces of different sub-planes have different grid dimensions.
The container carriers each may have a stand. The stand can have a circular cross section covering approximately five electro-magnetic actuators if positioned in the center of a cross formed by five electro-magnetic actuators. The electro-magnetic actuator in the center of the cross may be fully covered wherein the four outer electro-magnetic actuators may be covered by half if the stand is positioned in the center of the cross formed by the five electro-magnetic actuators. The stand may have a diameter in the range of about 3.5 cm to about 4.5 cm.
The ratio between the size or diameter of the stand relative to the distance between the electro-magnetic actuators can make it possible that two carriers moving on adjacent tracks can pass by each other without collision. On the other hand, the footprint can be large enough to provide a smooth transport without much tilting.
Each electro-magnetic actuator may comprise a ferromagnetic core. The ferromagnetic core can cause a holding force acting on the at least one magnetically active device of a container carrier placed on top of the electro-magnetic actuator if the electro-magnetic actuator is not driven by an actuating current.
The at least one permanent magnet may be ball-shaped, wherein a north pole or a south pole of the ball-shaped permanent magnet can be directed to the transport plane. In other words, an axis extending through the opposite poles of the ball-shaped permanent magnet can be perpendicular to the transport plane. A diameter of the ball-shaped permanent magnet may be approximately 12 mm. The ball-shaped permanent magnet can cause an optimized magnetic field in interaction with the electro-magnetic actuators, e.g. compared with a bar magnet, resulting in higher magnetic force components in a lateral movement direction.
The permanent magnet in conjunction with a ferromagnetic core of a currently adjacent non-activated electro-magnetic actuator can cause an unwanted magnetic retention force. The retention force can hinder the desired movement of the container carrier away from the currently adjacent non activated electro-magnetic actuator towards an activated electro-magnetic actuator. Increasing the distance between the permanent magnet and the transport plane, i.e. also increasing the distance between the permanent magnet and the electro-magnetic actuators, can reduce this magnetic retention force. Unfavorably, an increasing distance can also lower a desired magnetic transport force in a lateral movement direction. Therefore, a distance between a center of the at least one permanent magnet and a bottom surface of the container carrier, the bottom surface in contact with the transport plane, may be selected within a range of about 5 mm to about 50 mm. The given distance range can provide an optimized compromise between a desired magnetic transport force in movement direction and an unwanted magnetic retention force.
The container carriers may comprise a first permanent magnet arranged in the center of a stand of the container carrier and a second permanent magnet having a ring shape arranged in the stand surrounding the first permanent magnet. This arrangement can provide high flexibility in causing push and pull magnetic forces, especially if more than one electro-magnetic actuator is activated at a given time. The first and second permanent magnets may have a reverse polarity, i.e. a south pole of the first permanent magnet and a north pole of the second permanent may point to the transport plane, or vice versa. The ring shaped second permanent magnet may constitute a circular area having a diameter that can be smaller than a distance between axes of electro-magnetic actuators of the transport plane.
The container carriers may comprise a RFID tag storing a unique ID. This can enable matching a sample container ID, e.g. a barcode, with the corresponding container carrier. The unique carrier ID can be read by an optional RFID reader being part of the system and being placed at one or more specific locations within the system.
The RFID tag may comprise a ring shaped antenna arranged in a stand of the container carrier. This antenna arrangement can make it possible to read the RFID tag by a RFID reader antenna below the transport plane. Thus, the transport plane itself and/or areas above the transport plane may be designed free of any disturbing RFID reader antennas.
The electro-magnetic actuators may comprise a ferromagnetic core guiding and amplifying a magnetic field. The electro-magnetic actuators may have a center finger and four outer fingers, each of the fingers extending perpendicular to the transport plane. Only the center finger may be surrounded by a coil driven by an actuating current. This arrangement can reduce the number of coils needed for activating the electro-magnetic actuators, wherein the center finger and the outer fingers can interact advantageously by providing push and pull forces, respectively, especially if the container carrier comprises a first permanent magnet arranged in the center of the stand and a second permanent magnet having a ring shape arranged in the stand surrounding the first permanent magnet.
The system may further comprise a container carrier sensing device to sense the presence and position of container carriers located on the transport plane. The container carrier sensing device can provide for an optimized tracking of container carriers placed on top of the transport plane.
The container carrier sensing device may be embodied based on infra-red (IR) based reflection light barriers. These light barriers may be arranged in recesses in the transport plane or may be arranged below a transport plane which can be at least partially transparent for the employed light. In the latter case, a closed transport plane can be provided which inter alia can be easier to clean.
The system may comprise a magnetizable coupling element to provide a magnetic coupling between adjacent electro-magnetic actuators. Due to the coupling element, the activated electro-magnetic actuator can automatically cause a magnetic field in the adjacent actuators having an inverse polarization. This can automatically provide respective pull and push forces even if only a single electro-magnetic actuator is activated, e.g. by a corresponding activating current.
The system may comprise a security cover to cover the transport plane and the container carriers placed on the transport plane. The security cover can cover the transport plane and the container carriers placed on the transport plane such that the container carriers can move unhindered over the transport plane. The security cover may e.g. be made of transparent plastic. The security cover can prevent contamination and unintentional access to the transport plane. The security cover may have a footprint which can be approximately equal to the footprint of the transport plane.
The security cover may have an open state and a closed state, wherein in the open state, the transport plane or dedicated areas of the transport plane may be accessible by a user and in the closed state, the transport plane may not be accessible by a user, thereby preventing damage and/or manual access causing unwanted positions of container carriers placed on the transport plane. The security cover may have flaps or sections operable such that specific sections/areas on the transport plane can be accessible. The security cover can further prevent pollution of the transport plane.
A method for the versatile transport of sample containers can be achieved with a laboratory sample distribution system comprising a number of container carriers as described above. The container carriers can comprise at least one magnetically active device and can carry a sample container. The laboratory sample distribution system can further comprise a transport plane to carry the container carriers and a number of electro-magnetic actuators being stationary arranged below the transport plane. The electro-magnetic actuators can move a container carrier on top of the transport plane by applying a magnetic force to the container carrier. The method can comprise activating at least one of the electro-magnetic actuators to apply a magnetic force to a container carrier within an operating distance of the at least one activated electro-magnetic actuator. Activating an electro-magnetic actuator can mean that a magnetic field can be generated by the electro-magnetic actuator. Activating may be done by generating a driving current applied to a coil surrounding a ferromagnetic core.
The speed of a container carrier moving across the transport plane may be set by setting a period between a successive activation of adjacent electro-magnetic actuators. If this duration is set shorter, the speed can increase and vice versa. By changing the duration dynamically, a container carrier may be accelerated or slowed down.
The electro-magnetic actuators may be activated in response to a sensed position of the container carrier to be applied with the magnetic force. The electro-magnetic actuators may be activated such that a polarity of the generated magnetic field can depend on a position of the container carrier relative to the electro-magnetic actuator. This can cause position-depended pull and push forces. In a first position range when the container carrier is moving towards the activated electro-magnetic actuator, the pull force may attract the container carrier towards the activated electro-magnetic actuator. In a second position range when the container carrier has traversed the electro-magnetic actuator, the push force may push the container carrier away from the activated electro-magnetic actuator now generating a magnetic field having an opposite polarity. Additionally, the magnetic field strength may be changed in response to the sensed position to provide a steady movement of the container carrier. The electro-magnetic actuators may be adapted to generate magnetic fields having only a single polarity to simplify the system. In this case, the activated electro-magnetic actuator may generate the pull force in the first position range when the container carrier is moving towards the activated electro-magnetic actuator. In the second position range when the container carrier has traversed the electro-magnetic actuator the electro-magnetic actuator may be deactivated.
For moving a first container carrier along a first transport path, a first group of electro-magnetic actuators may be activated along the first transport path. For independently and at least partially simultaneously moving a second container carrier along a second transport path, a second group of multiple electro-magnetic actuators may be activated along the second transport path. “Simultaneously” can indicate that during a certain time interval both the first and the second container carrier can move. The electro-magnetic actuators of the first or the second group may be activated one after the other along the respective transport path. Alternatively, two or more adjacent electro-magnetic actuators along the respective transport path may be activated at least partially overlapping in time.
A movement of a container carrier placed on a field on top of a first electro-magnetic actuator to an adjacent field on top of a second electro-magnetic actuator may comprise activating the first and the second electro-magnetic actuator and a third electro-magnetic actuator adjacent to the first electro-magnetic actuator and opposite to the second electro-magnetic actuator and part of the same row or column as the first and the second electro-magnetic actuators in a predetermined order.
If the container carriers comprise a first permanent magnet arranged in the center of a stand of the container carrier and a second permanent magnet having a ring shape arranged in the stand surrounding the first permanent magnet the method may further comprise activating the second electro-magnetic actuator such that a resulting pull-force regarding the second permanent magnet having a ring shape can be generated and activating the third electro-magnetic actuator such that a resulting push-force regarding the second permanent magnet can be generated; after a predetermined time interval or at a predetermined position of the container carrier: activating the first electro-magnetic actuator such that a resulting pull-force regarding the second permanent magnet can be generated and that a resulting push-force regarding the first permanent magnet can be generated; and after a second predetermined time interval or at a second predetermined position of the container carrier: activating the second electro-magnetic actuator such that a resulting pull-force regarding the second permanent magnet can be generated. A movement between adjacent electro-magnetic actuators can be done in a sequence of three activation patterns regarding three adjacent electro-magnetic actuators. This can lead to a continuous uniform movement with a high positioning accuracy. The first and second time interval or the first and the second position may be determined based on a sensed position of the container carrier provided by the container carrier sensing device.
Referring initially to FIG. 1, FIG. 1 shows a laboratory sample distribution system 100. The laboratory sample distribution system 100 can be used to distribute samples or specimens, e.g. blood samples, contained within sample containers or sample tubes 3 between different laboratory stations or specimen-processing instruments 22, such as pre-analytical stations, analytical stations and post-analytical stations typically used in laboratory systems.
The laboratory sample distribution system 100 can comprise a number of container carriers or Single-Tube-Carriers 1 each can carry a corresponding sample container 3 over a transport plane 4. Multiple electro-magnetic actuators 5 (see FIGS. 2 and 3) can be stationary arranged below the transport plane 4. Each of the electro-magnetic actuators 5 can move a container carrier 1 in operating distance of a corresponding electro-magnetic actuator 5 by applying a magnetic force to the container carrier 1.
The depicted transport plane 4 can be divided into four quadratic sub-planes 23, the sub-planes 23 can be adjacent to one another. The transport plane can be covered by an optional cover profile 24, the cover profile 24 can be fluidtight and can cover gaps and mitigate height differences between adjacent sub-planes 23. The material of the cover profile 24 can provide a low friction coefficient. The cover profile 24 may e.g. be a glass plate or a foil of polyethylene or PTFE (poly-tetra-fluoro-ethylene).
FIG. 2 shows a schematic top view on an exemplary sub-plane 23 of FIG. 1. The sub-plane can have a first outer face 20, a second outer face 21, a third outer face 18 and a fourth outer face 19. Along the first and the second outer face 20 and 21, the electro-magnetic actuators 5 can be arranged in a first grid dimension g1. Along the third and the fourth outer face 18 and 19, the electro-magnetic actuators 5 can be arranged in a second grid dimension g2, wherein g2=2*g1. The grid dimension g1 may e.g. be about 20 mm.
The electro-magnetic actuators 5 can be arranged in rows and columns, for example, 16 rows and 16 columns, the rows and columns having either a first grid dimension g1 or a second grid dimension g2, wherein g2=2*g1, and adjacent rows having a different grid dimension and adjacent columns having a different grid dimension. If a position or field on the transport plane has to be accessible as a target destination, a corresponding electro-magnetic actuator can be provided below that target destination. If a specific field or area has not to be accessible, an electro-magnetic actuator may be omitted at that position.
FIG. 2 depicts two exemplary container carriers each having a stand 8 with a circular cross section having a diameter D that is approximately 1% to 20% smaller than the larger grid dimension g2. Due to this, two carriers moving on adjacent tracks can pass by each other without collision. On the other hand, the footprint can be large enough to provide a smooth transport without much tilting.
FIG. 3 shows detailed perspective side view of the sub-plane 23 shown in FIG. 2. As illustrated, each electro-magnetic actuator 5 can be fixed on a carrier plate 26 and can comprise a ferro-magnetic cylindrical core 5a extending basically perpendicular to the transport plane 4. A coil 5b can surround the ferro-magnetic cylindrical core 5a. The coil 5b can be applied with an actuating current provided by a driver unit (not shown) over electrical contacts 5c. If driven by an actuating current, each electro-magnetic actuator 5 can generate a magnetic field. When this field interacts with a permanent magnet 2 (see FIG. 4) in the container carrier 1, it can provide a driving force moving the container carrier 1 along the transport plane 4. The ferro-magnetic cylindrical core 5a can bundle and amplify the magnetic field generated by the coil 5b. 
In the most simple form, each container carrier 1 may be exposed to a driving force generated by a single activated electro-magnetic actuator 5 proximate to the corresponding container carrier 1 thereby pulling the container carrier 1 towards the activated electro-magnetic actuator 5. Further, it can be possible to superpose push and pull driving forces of multiple electro-magnetic actuators 5 proximate to the corresponding container carrier 1.
Further, it can be possible to activate multiple electro-magnetic actuators 5 at the same time to move multiple different container carriers 1 independent of each other along predetermined paths over the transport plane 4.
In order to sense the presence and position of container carriers 1 located on the transport plane 4, a container carrier sensing device can be provided. One embodiment can comprise a printed circuit board 25 having multiple IR based reflection light barriers 17 arranged in a grid on top as shown in FIG. 3.
The IR based reflection light barriers 17 can detect container carriers 1 placed on top of a corresponding light barrier 17 since the container carriers 1 can be arranged to reflect IR radiation emitted by the light barriers 17. If no container carrier is present, no reflected IR light can get into the IR sensor of a corresponding light barrier 17.
FIG. 4 shows a container carrier 1 according to a first embodiment. The container carrier 1 can comprise a ball-shaped permanent magnet 2. A distance 1 between a center of the at least one permanent magnet 2 and a bottom surface 8a of the container carrier, the bottom surface 8a can be in contact with the transport plane 4, can lie within a range of about 5 mm to about 50 mm and may be approximately 12 mm. A height h of the container carrier 1 may be approximately 42 mm.
The permanent magnet 2 may be made from hard ferromagnetic materials. These can include e.g. iron ore (magnetite or lodestone), cobalt and nickel, as well as the rare earth metals. A north pole N of the permanent magnet 2 can be directed towards the transport plane.
A stand 8 of the container carrier can have a circular cross section having a diameter of approximately 3.5 cm to 4.5 cm covering approximately five electro-magnetic actuators 5 if positioned in the center of a cross formed by the five electro-magnetic actuators 5. The electro-magnetic actuator in the center of the cross can be fully covered, wherein the four outer electro-magnetic actuators can be nearly covered by half. Due to this, two carriers moving on adjacent tracks can pass by each other without collision. On the other hand, the footprint can be large enough to provide a smooth transport without much tilting.
The container carriers may comprise a sample container fixer which may e.g. be incorporated in form of flexible flat spring 28. The flexible flat spring 28 can be at the side wall of the cylindrical opening of the container carrier 3. The flexible flat spring 28 can safely fix the sample container 3 within the container carrier 1, even if the sample container 3 has a smaller diameter than the corresponding opening.
If different sample container types are used, e.g. having different form factors, it can be even possible to provide specific container carriers with different inner diameters corresponding to respective sample container types.
FIG. 5 shows a container carrier 1′ according to a second embodiment having a different magnet arrangement and a corresponding electro-magnetic actuator 5′. The container carrier 1′ can comprise a first permanent magnet 6 arranged in the center of a stand 8 of the container carrier 1′ and a second permanent magnet 7 having a ring shape arranged in the stand 8 surrounding the first permanent magnet 6. The permanent magnets 6 and 7 can have a reverse polarity. A north pole of the center permanent magnet 6 and a south pole of the ring shaped permanent magnet 7 can be directed towards the transport plane 4.
Further, the container carrier 1′ can comprise a RFID tag 9 storing a unique ID corresponding to a specific container carrier. The RFID tag 9 can comprise a ring shaped antenna 10 which can be arranged in the stand 8 of the container carrier 1′ between the first and the second permanent magnet 6 and 7.
The corresponding electro-magnetic actuator 5′ can comprises a ferromagnetic core having a center finger 11 and four outer fingers 12, 13, 14, and 15, each of the fingers extending perpendicular to the transport plane 4, wherein only the center finger 11 can be surrounded by a coil 16 being driven by an actuating current Ia. This arrangement can reduce the number of coils needed for activating the electro-magnetic actuator 5′ compared with the embodiment shown in FIG. 3, wherein the center finger 11 and the outer fingers 12 to 15 can interact advantageously by providing push and pull forces, respectively, especially if the container carrier 1′ is arranged as shown.
FIG. 6 shows a simulated magnetic flux density B for the case that a container carrier as depicted in FIG. 4 is positioned on top of an electro-magnetic actuator 5_2 not being activated and an adjacent electro-magnetic actuator 5_3 being activated. Different flux densities B can be represented by corresponding hachures.
As shown, the ball shaped permanent magnet 2 in conjunction with a ferromagnetic core of the non-activated electro-magnetic actuator 5_2 can cause an unwanted magnetic retention force F2 pulling the permanent magnet 2 towards the ferromagnetic core of the non-activated electro-magnetic actuator 5_2, thereby causing an unwanted force-component in opposite direction of the desired movement and additionally increasing friction between the corresponding surfaces of the transport plane and the stand. The activated electro-magnetic actuator 5_3 can generate a force F1.
In order to reduce these unwanted effects, it can be possible to generate an opposing magnetic field by reversely activating the electro-magnetic actuator 5_2 pushing the container carrier, thereby reducing friction. Alternatively or additionally, it can be possible to choose an optimized distance between the permanent magnet 2 and the transport plane, see also the description regarding FIG. 4. Nevertheless, the magnetic forces in a desired movement direction using a ball-shaped permanent magnet 2 can be higher compared to a bar magnet, since the resulting distances between the magnetically active spherical surface of the permanent magnet 2 and the active electro-magnetic actuator 5_3 can be smaller.
FIG. 7 shows a side view of an embodiment of a sub-plane comprising a magnetizable coupling element 27 providing a magnetic coupling between adjacent electro-magnetic actuators 5. As shown, only the electro-magnetic actuator 5_3 can be activated by driving the corresponding coil with a driving current and can cause a magnetic flow guided by the coupling element 27 and extending in the ferromagnetic cores of the non-activated electro-magnetic actuators 5_2 and 5_3. As a result, a magnetic push force can be generated by the electro-magnetic actuator 5_2 in interaction with the permanent magnet 2 reducing friction and superimposing in the desired direction with a pull force generated by the activated electro-magnetic actuators 5_3.
FIG. 8 shows a movement of a container carrier 1 and an activation order of corresponding electro-magnetic actuators 5_1 to 5_5 according to a first embodiment. As shown, at time t=0 only the electro-magnetic actuator 5_2 can be activated such that it can generate a pull force moving the container carrier 1 in the shown direction.
At time t=1, the container carrier 1 has moved such that it can reside on top of the electro-magnetic actuator 5_2, what e.g. can be sensed by the container carrier sensing device. In order to continue the movement electro-magnetic actuator 5_2 can be deactivated and electro-magnetic actuator 5_3 can be activated, thereby pulling the container carrier 1 forward.
At time t=2, the container carrier 1 has moved such that it can reside on top of the electro-magnetic actuator 5_3. In order to continue the movement electro-magnetic actuator 5_3 can be deactivated and electro-magnetic actuator 5_4 can be activated, thereby pulling the container carrier 1 forward.
The above steps can be repeated as long as a movement is desired. Concluding, a group of multiple electro-magnetic actuators 5_1 to 5_5 along a transport path can be sequentially activated to move the container carrier 1 along the first transport path.
Since the electro-magnetic actuators 5 can be activated independently, it can be possible to independently and simultaneously move a plurality of different container carriers 1 along different paths, wherein self-evidently collisions have to be avoided.
FIG. 9 shows a movement of a container carrier 1′ and an activation order of corresponding electro-magnetic actuators 5_1 to 5_3 according to a second embodiment. FIG. 5 shows the container carrier 1′ in more detail. In the shown embodiment, a movement of the container carrier 1′ placed on a first electro-magnetic actuator 5_2 to an adjacent second electro-magnetic actuator 5_3 can comprise activating the first and the second electro-magnetic actuators 5_2 and 5_3 and a third electro-magnetic actuator 5_1 adjacent to the first electro-magnetic actuator 5_2 in a specific order and polarity. The electro-magnetic actuators 5_1 to 5_3 can be part of the same row or column and can be activated generating a south-pole (S) or a north-pole (N) pointing towards the container carrier 1′.
In a first step, at t=0, the second electro-magnetic actuator 5_3 can be activated such that a resulting pull-force regarding the second permanent magnet 7 having a ring shape can be generated and the third electro-magnetic actuator 5_1 can be activated such that a resulting push-force regarding the second permanent magnet 7 can be generated.
After the container carrier 1′ reaches a first predetermined position at time t=1, what e.g. can be sensed by the container carrier sensing device, the second and third electro-magnetic actuators 5_1 and 5_3 can be deactivated and the first electro-magnetic actuator 5_2 can be activated such that a resulting pull-force regarding the second permanent magnet 7 can be generated and that a resulting push-force regarding the first permanent magnet 6 can be generated.
After the container carrier 1′ reaches a second predetermined position at time t=2, the first and the third electro-magnetic actuators 5_1 and 5_2 can be deactivated and the second electro-magnetic actuator 5_3 can be activated such that a resulting pull-force regarding the second permanent magnet 7 can be generated.
In one embodiment, a movement between adjacent electro-magnetic actuators 5_2 and 5_3 can be performed in a sequence of three activation patterns regarding three adjacent electro-magnetic actuators 5_1 to 5_3. This can lead to a continuous uniform smooth movement with a high positioning accuracy.
FIG. 10 shows a further embodiment of a sub-plane 23′. According to this embodiment, the electro-magnetic actuators 5 can be arranged in rows and columns forming a grid having a single grid dimension g3. The distance between adjacent or consecutive electro-magnetic actuators 5 in each row and each column can be g3.
FIG. 10 depicts two exemplary container carriers each having a stand 8 with a circular cross section having a diameter D that can be approximately 1% to 20% smaller than the grid dimension g3. Due to this, two carriers moving on adjacent tracks can pass by each other without collision. On the other hand, the footprint can be large enough to provide a smooth transport without much tilting.
Having described the present disclosure in detail and by reference to specific embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the disclosure defined in the appended claims. More specifically, although some aspects of the present disclosure are identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not necessarily limited to these preferred aspects of the disclosure.

## Claims

1. A laboratory sample distribution system, the system comprising:
a plurality of container carriers, wherein each container carrier comprises one magnetically active device and carries a sample container;
a transport plane to carry the container carriers; and
a plurality of electro-magnetic actuators stationary arranged below the transport plane, wherein the electro-magnetic actuators move a container carrier on top of the transport plane by applying a magnetic force to the container carrier, wherein the plurality of electro-magnetic actuators is arranged in rows and columns forming a grid, wherein adjacent rows and adjacent columns have different grid dimensions selected either from a first grid dimension (g1) or a second grid dimension (g2), wherein the grid dimensions specify a distance between adjacent electro-magnetic actuators in a given row or column, wherein the second grid dimension (g2) is larger than the first grid dimension (g1), and wherein the container carriers each have a stand, wherein the stand has a circular cross section having a diameter (D) that is equal to or less than the larger grid dimension.

2. The system according to claim 1, wherein the transport plane is formed by multiple adjacent sub-planes.

3. The system according to claim 2, further comprising,
a cover profile covering the sub-planes.

4. The system according to claim 3, wherein the cover profile covers gaps and mitigates height differences between adjacent sub-planes.

5. The system according to claim 3, wherein the cover profile is fluidtight.

6. The system according to claim 3, wherein the cover profile is glued to the top surface of the sub-planes.

7. The system according to claim 3, wherein the cover profile comprises a glass plate, a non-magnetic metal plate, a foil of plastic material, or combinations thereof.

8. The system of according to claim 7, wherein the non-magnetic metal plate is an aluminum plate.

9. The system of according to claim 7, wherein the foil of plastic material is a foil of polyethylene or PTFE (poly-tetra-fluoro-ethylene).

10. The system according to claim 3, wherein a bottom surface of the container carriers and the surface of the cover profile are arranged to reduce friction between the surfaces.

11. The system according to claim 2, wherein each sub-plane has a first outer face, a second outer face, a third outer face and a fourth outer face, wherein along the first and the second outer face the electro-magnetic actuators are arranged in a first grid dimension g1 and along the third and the fourth outer face the electro-magnetic actuators are arranged in a second grid dimension g2, wherein g2=2*gl.

12. The system according to claim 1, wherein the plurality of electro-magnetic actuators are arranged in rows and columns forming a grid having a grid dimension (g3).

13. The system according to claim 12, wherein the container carriers each have a stand, wherein the stand has a circular cross section having a diameter (D) that is equal to or less than the grid dimension (g3).

14. The system according to claim 1, wherein the container carriers each have a stand, wherein the stand has a circular cross section covering five electro-magnetic actuators if positioned in the center of a cross formed by five electro-magnetic actuators.

15. The system according to claim 14, wherein the electro-magnetic actuator in the center of the cross is fully covered, wherein the four outer electro-magnetic actuators are covered by half if the stand is positioned in the center of the cross formed by the five electro-magnetic actuators.

16. The system according to claim 14, wherein the stand has a diameter in the range of 3.5 cm to 4.5 cm.

17. The system according to claim 1, wherein each electro-magnetic actuator comprises a ferromagnetic core, wherein the ferromagnetic core causes a holding force acting on the at least one magnetically active device of the container carrier placed on top of the electro-magnetic actuator if the electro-magnetic actuator is not driven by an actuating current.

18. The system according to claim 1, wherein the at least one magnetically active devices is a permanent magnet.

19. The system according to claim 18, wherein the permanent magnet is ball-shaped.

20. The system according to claim 1, wherein each container carrier comprises a first permanent magnet arranged in the center of a stand of the container carrier and a second permanent magnet having a ring shape arranged in the stand surrounding the first permanent magnet, wherein the first and second permanent magnets have a reverse polarity and the ring shaped second permanent magnet comprises a circular area having a diameter that is less than a distance between axes of adjacent electro-magnetic actuators.

21. The system according to claim 1, wherein each container carrier comprises a RFID tag storing a unique ID corresponding to a specific container carrier.

22. The system according to claim 1, wherein each electro-magnetic actuator comprises a ferromagnetic core having a center finger and four outer fingers, wherein each finger extends perpendicular to the transport plane.

23. The system according to claim 1, further comprising,
a container carrier sensing device to sense the presence and/or position of container carriers located on the transport plane.

24. The system according to claim 1, further comprising,
a magnetizable coupling element to provide a magnetic coupling between adjacent electro-magnetic actuators.

25. The system according to claim 1, further comprising,
a security cover to cover the transport plane and the container carriers placed on the transport plane.

26. The system according to claim 25, wherein the security cover has an open state and a closed state, wherein in the open state, the transport plane is at least partially accessible by a user and in the closed state, the transport plane is not accessible by a user.

27. A method of operating a laboratory sample distribution system according to claim 1, the method comprising:
activating at least one of the electro-magnetic actuators to apply a magnetic force to a container carrier within an operating distance of the at least one activated electro-magnetic actuator.

28. The method according to claim 27, further comprising,
activating the at least one electro-magnetic actuator in response to a sensed position of the container carrier to be applied with the magnetic force.

29. The method according to claim 27, further comprising,
activating a first group of multiple electro-magnetic actuators along a first predetermined transport path to move a corresponding first container carrier along the first transport path.

30. The method according to claim 29, further comprising,
independently and at least partially simultaneously to the activating of the first group of multiple electro-magnetic actuators activating a second group of multiple electro-magnetic actuators along a second predetermined transport path to move a corresponding second container carrier along the second transport path.