Laboratory sample distribution system and method of operating the same

Abstract

This invention discloses a laboratory sample dispensing system (100). It includes: multiple sample container carriers (130), each adapted to carry one or more sample containers (132); a transfer plane (110) adapted to support the sample container carriers (130); multiple electromagnetic actuators (120) fixedly arranged below the transfer plane (110), which move the sample container carriers (130) by applying magnetic force to them; multiple inductive sensors (140) distributed above the transfer plane (110); and a control unit (160) configured to drive... An electromagnetic actuator (120) controls the movement of the sample container carrier (130) on top of the transfer plane (110); and an evaluation unit (170) is configured to linearize the output signal received from at least one of the inductive sensors (140) by means of a linearization algorithm, wherein the evaluation unit (170) is further configured to determine at least the distance between at least one of the sample container carriers (130) and at least one of the inductive sensors (140) based on the output signal value of the linearized output signal value.

Description

Technical Field

[0001] This invention relates to laboratory sample dispensing systems. It also relates to methods for operating such systems. Background Technology

[0002] Laboratory sample dispensing systems are used in laboratory automation systems that include multiple laboratory stations, such as pre-analytical stations, analytical stations, and / or post-analytical stations. These systems dispense sample containers between laboratory stations and other equipment. The sample containers are typically made of transparent plastic or glass and have an opening on the top. They can hold samples such as blood samples or other medical samples.

[0003] A typical laboratory sample dispensing system, calibration apparatus, and method for calibrating magnetic sensors are disclosed in WO 2011 / 138448 A1 or US 2016 / 0069715 A. As disclosed, a sample container carrier moves on a transport plane, wherein multiple electromagnetic actuators are arranged below the transport plane to drive the sample container carrier. Multiple magnetic sensors, such as Hall effect sensors, are arranged above the transport plane to detect the corresponding position of the sample container carrier. Position detection of the sample container carrier is crucial not only for ensuring correct transport but also for the low-level implementation of the drive logic.

[0004] However, Hall sensors are highly susceptible to the magnetic field of the actuator coil, requiring excessive power to operate and generating excessive heat. Furthermore, the position detection accuracy provided by Hall sensors is insufficient due to the presence of blind zones on the surface of the transfer plane in the sample dispensing system. Another drawback of Hall sensors is the high cost of incorporating a large number of sensors, each requiring a mechanically constructed recess to accommodate the sensor within the drive surface.

[0005] Therefore, inductive sensors can serve as an alternative technology for position sensing. Inductive sensors are based on an inductor used as a sensing coil, which generates an output signal based on induced eddy currents from a conductive surface. Specifically, inductive sensing technology utilizes a capacitor and an inductor to form an LC resonator, also known as an LC tank circuit. This circuit can be used to detect the presence of a conductive object within an alternating electromagnetic field. Whenever a conductor interacts with an alternating electromagnetic field, eddy currents are induced on the conductor's surface. Lenz's law states that the induced current will flow in the opposite direction to the magnetic field, thus measurably weakening the originally generated magnetic field. This effectively reduces the inductance of the resonant circuit, and therefore lowers the resonant frequency, as the resonant frequency changes whenever the inductor is affected. This change is proportional to the distance of the metal surface target relative to the sensing coil (antenna).

[0006] However, this output signal is non-linear because it is measured in a plane parallel to the transmission plane, rather than at a distance from the LC resonant circuit. Therefore, it only provides information about the distance between the antenna and the target, not about their relative positions, as the signal strength is symmetrical about the center of the sensing coil. Furthermore, the signal strength increases as the metal surface approaches the center of the coil during its movement along the transmission plane, but also increases as the vertical distance between the metal surface and the sensor coil, perpendicular to the transmission plane, decreases due to wear and / or manufacturing tolerances. Summary of the Invention

[0007] The disclosed sample dispensing system and its operating method are designed to overcome the aforementioned drawbacks, and more specifically, to provide appropriate determination of the position and direction of movement of the sample carrier. In other words, the disclosed sample dispensing system and its operating method aim to overcome problems related to the nonlinear and symmetrical behavior of inductive sensors.

[0008] This problem is solved by a sample dispensing system having the features of the independent claims and a method for operating the sample dispensing system. Advantageous embodiments that can be implemented individually or in any combination are set forth in the dependent claims and throughout the specification.

[0009] As used below, the terms “have,” “include,” or “contain,” or any grammatical variation thereof, are used in a non-exclusive manner. Thus, these terms can refer either to a situation where no other features exist in the entity described in this context besides those introduced by these terms, or to a situation where one or more other features exist. For example, the statements “A has B,” “A includes B,” and “A contains B” can all refer to a situation where no other elements exist in A besides B (i.e., A consists only of B), and to a situation where entity A contains one or more other elements besides B, such as element C, elements C and D, or even other elements.

[0010] Furthermore, it should be noted that the terms "at least one," "one or more," or similar expressions indicating that a feature or element may exist once or more are generally used only once when the corresponding feature or element is introduced. In the following text, in most cases, when referring to the corresponding feature or element, the expressions "at least one" or "one or more" will not be used repeatedly, even though the corresponding feature or element may exist only once or more.

[0011] Furthermore, as used below, the terms "preferredly," "more preferably," "particularly," "more particularly," "specifically," "more specifically," or similar terms are used in combination with optional features without limiting the possibility of substitution. Therefore, features introduced by these terms are optional features and are not intended to limit the scope of the claims in any way. As those skilled in the art will recognize, the invention can be practiced using alternative features. Similarly, features introduced by "in embodiments of the invention" or similar expressions are intended to be optional features, without limiting alternative embodiments of the invention, without limiting the scope of the invention, and without limiting the possibility of combining features introduced in this way with other optional or non-optional features of the invention.

[0012] According to a first aspect, this disclosure provides a laboratory sample dispensing system. The sample dispensing system includes a plurality of sample container carriers. Each sample container carrier is adapted to carry one or more sample containers. Furthermore, each sample container carrier includes at least one magneto-activated device and at least one conductive member. The sample dispensing system also includes a transfer plane adapted to support the sample container carriers. The sample dispensing system also includes a plurality of electromagnetic actuators fixedly arranged below the transfer plane. The electromagnetic actuators are adapted to move the sample container carriers on top of the transfer plane by applying a magnetic force to the sample container carriers. The sample dispensing system also includes a plurality of inductive sensors distributed above the transfer plane. The sample dispensing system also includes a control unit configured to control the movement of the sample container carriers on top of the transfer plane using signals provided by the inductive sensors by driving the electromagnetic actuators, such that the sample container carriers move along corresponding transfer paths. The sample dispensing system also includes an evaluation unit configured to linearize the output signal received from at least one of the inductive sensors using a linearization algorithm. The evaluation unit is further configured to determine the distance between at least one of the sample container carriers and at least one of the inductive sensors based on the output signal value of the linearized output signal.

[0013] The sample container carrier allows movement along the transport plane while carrying the sample container. Under the control of the control unit, an electromagnetic actuator fixedly positioned below the transport plane is driven, causing the sample container carrier to move. The position of the corresponding sample container carrier can be detected by an inductive sensor. To overcome problems related to the nonlinear and symmetric behavior of the inductive sensor during operation of the magnetic transport system provided by the transport plane and the electromagnetic actuator, the evaluation unit uses a linearization algorithm. The linearization algorithm converts the nonlinear signal into a linear signal or linear graph indicating the distance between the target and the center of the inductive sensor, represented by its coil or inductor, as the sample container carrier moves along the horizontal plane. This linearization algorithm also takes into account the signal symmetry around the coil center. Therefore, unless otherwise stated, the term "distance" as used herein refers to a horizontal distance. The term "horizontal" as used herein refers to an indication of a direction parallel to the transport plane, while the term "vertical" as used herein refers to an indication of a direction perpendicular to the transport plane. Therefore, unless otherwise stated herein, the distance can be a horizontal distance.

[0014] The evaluation unit can be further configured to determine the movement direction of at least one of the sample container carriers and at least one of the inductive sensors based on at least two distinct output signal values ​​of the linearized output signal, wherein the at least two distinct output signal values ​​indicate two distinct distances between the at least one of the sample container carriers and at least one of the inductive sensors. Therefore, the linearization algorithm allows the evaluation unit to reliably monitor the movement direction of the sample container carriers.

[0015] The evaluation unit can be further configured to determine the departure of at least one sensing area of ​​the sample container carrier relative to one of the inductive sensors and the approach of at least one sensing area of ​​the sample container carrier relative to an adjacent inductive sensor. Therefore, the linearization algorithm allows the evaluation unit to reliably monitor the time it takes for the sample container carrier to leave the sensing area of ​​one coil of an inductive sensor and approach the sensing area of ​​an adjacent or neighboring inductive sensor coil.

[0016] The evaluation unit can be further configured to track the movement of at least one of the sample container carriers from a starting position on the transport plane to its final destination on the transport plane. Therefore, the linearization algorithm allows the evaluation unit to track the direction of movement of each sample container carrier along each logical position from its starting position to its final destination.

[0017] An inductive sensor may each include at least one inductor and at least one capacitor, arranged in a tank circuit. This circuit detects the presence of a conductive object within an alternating electromagnetic field. Whenever a conductor interacts with an alternating electromagnetic field, eddy currents are induced on the conductor's surface. Lenz's law states that the induced current will flow in the opposite direction to the magnetic field, thus measurably weakening the originally generated magnetic field. This effectively reduces the inductance of the resonant circuit, and therefore lowers the resonant frequency, as the resonant frequency changes whenever the inductor is affected. This change is proportional to the distance of the conductive object relative to the sensing coil, which acts as an antenna.

[0018] The inductor can be positioned below the transfer plane. Therefore, the inductor may not impede the movement of the sample container carrier.

[0019] The inductor can be arranged parallel to the transport plane. Therefore, the electromagnetic field generated by the inductive sensor is symmetrical in the transport plane surrounding the center of the inductor.

[0020] Linearization algorithms may include lookup tables. Therefore, computational effort can be saved. Specifically, lookup tables save processing time because retrieving values ​​from memory is generally faster than performing calculations or input / output operations. Specifically, linearization algorithms may include a single lookup table. Specifically, linearization algorithms may include a single lookup table, up to and unless the shape and structure of the coil are consistent.

[0021] The lookup table describes the strength of the output signal of each inductive sensor as a function of the horizontal distance between the reference object and the corresponding inductive sensor, parallel to the transport plane. Therefore, as the sample container carrier approaches the inductive sensor, the output signal increases as the horizontal distance decreases, while the vertical distance perpendicular to the transport plane can be assumed to remain constant.

[0022] The evaluation unit can be further configured to compensate for the presence of conductive objects in the sensing region of at least one of the inductive sensors. During operation, it may be necessary for the inductive sensor to work with conductive objects (such as fixed conductive objects) near its antenna. By measuring the output value from the antenna, the presence of objects affecting the antenna's readout can be detected and quantified.

[0023] The evaluation unit can be configured to compensate for the presence of conductive objects in the sensing region by measuring the output signal of the corresponding inductive sensor during a period when no sample container carrier is present in the sensing region of at least one of the inductive sensors. By measuring the output value from the antenna when no sample container carrier (target) is present on the surface, the presence of objects affecting antenna readout can be detected and quantified.

[0024] The evaluation unit can be configured to compensate for the presence of a conductive object in the sensing region as an offset if the output signal value of the measured output signal of the corresponding inductive sensor is lower than a predetermined threshold during a period when no sample container carrier is present in the sensing region of at least one of the inductive sensors. If the measured value is not too high, compensation can be made by treating it as a nonlinear but deterministic offset.

[0025] The evaluation unit can be configured to compensate for the presence of a conductive object in the sensing area as an error if the output signal value of the measured output signal of the corresponding inductive sensor is higher than a predetermined threshold when the sample container carrier is not present in the sensing area of ​​at least one of the inductive sensors. On the other hand, if the measured interference is too high and cannot be handled, the system will detect that the performance exceeds specifications, which may cause errors and avoid using antennas subject to external interference.

[0026] The evaluation unit can be further configured to detect changes in the conductivity of the sample container carrier by periodically measuring the maximum output signal value of the inductive sensor. Since calibration is performed by measuring the maximum value of a reference object, the antenna can detect changes in the single-holder target caused by wear or damage by periodically measuring the maximum signal strength. An error can be detected if the maximum value generated by the conductive target exceeds specifications (the target is defective or the distance to the antenna exceeds specifications due to wear / tolerance). By periodically performing checks, the system can monitor changes in the sensed target measurement over time. Predictive maintenance is possible by observing patterns leading to failure before a sensor readout failure actually occurs.

[0027] The sample container carrier can be a single sample container carrier.

[0028] According to a second aspect, this disclosure provides a method for operating a laboratory sample dispensing system in accordance with the above details. The method includes:

[0029] - Provide multiple sample container carriers on the transfer plane.

[0030] - Move the sample container carrier along the corresponding conveyor path.

[0031] - Receive an output signal from at least one of the inductive sensors.

[0032] - The output signal is linearized using a linearization algorithm, and

[0033] The distance between at least one of the sample container carriers and at least one of the inductive sensors is determined based on the linearized output signal value.

[0034] The method may further include determining the direction of movement of at least one of the sample container carriers and at least one of the inductive sensors based on at least two different output signal values ​​of the linearized output signal, the at least two different output signal values ​​indicating two different distances between at least one of the sample container carriers and at least one of the inductive sensors.

[0035] The method may further include determining the separation of a sensing area of ​​at least one of the sample container carriers from that of one of the inductive sensors and the proximity of a sensing area of ​​at least one of the sample container carriers from that of an adjacent inductive sensor.

[0036] The method may also include tracking the movement of at least one of the sample container carriers from a starting position on the transport plane to a final destination on the transport plane.

[0037] The method may also include compensating for the presence of a conductive object in the sensing region of at least one of the inductive sensors.

[0038] The method may also include compensating for the presence of a conductive object in the sensing region by measuring the output signal of the respective inductive sensor during a period when the sample container carrier is not present in the sensing region of at least one of the inductive sensors.

[0039] The method may further include compensating for the presence of a conductive object in the sensing region as an offset if the output signal value of the measured output signal of the corresponding inductive sensor is lower than a predetermined threshold during a period when no sample container carrier is present in the sensing region of at least one of the inductive sensors.

[0040] The method may further include compensating for the presence of a conductive object in the sensing region as an error if the output signal value of the measured output signal of the corresponding inductive sensor is higher than a predetermined threshold during a period when no sample container carrier is present in the sensing region of at least one of the inductive sensors.

[0041] The method may also include detecting changes in the conductivity of the sample container carrier by periodically measuring the maximum output signal value of the output signal of the inductive sensor.

[0042] As used herein, the term "laboratory sample dispensing system" is a broad term and is given a common and customary meaning to those skilled in the art, and is not limited to a specific or customary meaning. Specifically, the term may refer to, but is not limited to, a part or apparatus of a laboratory automation system that allows for the dispensing of sample container carriers to target destinations within the laboratory automation system. Laboratory sample dispensing systems are used in laboratory automation systems that include multiple laboratory stations, such as pre-analytical stations, analytical stations, and / or post-analytical stations. Laboratory sample dispensing systems can be used to dispense sample containers between laboratory stations and other equipment.

[0043] As used herein, the term "sample container carrier" is a broad term and is given a common and customary meaning to those skilled in the art, and is not limited to a specific or customary meaning. Specifically, the term may refer to, but is not limited to, any device configured to hold one or more laboratory diagnostic containers or instruments and supply them via a conveyor or transport line. Thus, a sample container carrier may be configured as a single-container carrier suitable for receiving a single laboratory diagnostic container or as a support suitable for receiving multiple containers. Without any limitation, specific embodiments are described with reference to a so-called test tube holder. This test tube holder holds a single test tube containing a sample or reagent and transports the test tube via a conveyor or transport line to different modules of an automated laboratory system, such as an automated sample testing system. The test tube holder includes a housing with a spring for securing the test tube, a test tube support body housing, and a bottom cover housing. The housing with the spring for securing the test tube has a columnar structure with a central hole punched to allow insertion of the test tube, and a spring portion disposed within an upwardly extending protrusion. It should be noted that the spring-loaded housing is typically cylindrical, but it can have any shape as long as the housing can vertically hold the test tubes via equidistant or equiangularly spaced spring portions, and the external shape of the housing can be a polygonal cylinder. The main body housing of the test tube holder has a cylindrical shape and is preferably equipped with a cavity portion. The cavity portion houses a tag with a unique ID number, weights for stable transport of the test tubes, etc. Furthermore, the outer diameter of the main body housing and the bottom cover housing of the test tube holder is larger than the outer diameter of the test tube to be transported and smaller than the width of the transport line. It should be noted that the shape of the main body housing and the bottom cover housing of the test tube holder can be, for example, polygonal. Even in that case, the maximum length in the cross-sectional direction is preferably smaller than the width of the conveyor or transport line. A specific test tube holder that can be used with the present invention is described in EP 2 902 790 A1, the contents of which regarding the design or construction of the container carrier are incorporated herein by reference. The sample container is typically made of transparent plastic or glass material and has an opening on the top side. The sample container can hold samples, such as blood samples or other medical samples.

[0044] As used herein, the term "magnetically activated device" is a broad term and is given a common and conventional meaning to those skilled in the art, and is not limited to a specific or customary meaning. Specifically, the term may refer to, but is not limited to, any device, element, or component that incorporates magnetic properties. A magnetically activated device may be a magnet, such as a permanent magnet.

[0045] As used herein, the term "conductive component" is a broad term and is given a common and conventional meaning to those skilled in the art, and is not limited to a specific or customary meaning. Specifically, the term may refer to, but is not limited to, any device, element, or component that incorporates conductive properties. Conductivity, or specific conductivity, is the reciprocal of resistivity. It represents a material's ability to conduct electric current. High conductivity indicates that the material readily allows current to flow. Conductive components may be metallic components such as copper foil.

[0046] As used herein, the term "transfer plane" is a broad term and is given a common and conventional meaning to those skilled in the art, and is not limited to a specific or customary meaning. Specifically, the term may refer to, but is not limited to, any plane configured to support a sample container carrier. A plane is a flat two-dimensional surface. A plane is a two-dimensional simulation of points (zero-dimensional), lines (one-dimensional), and three-dimensional space.

[0047] As used herein, the term "electromagnetic actuator" is a broad term and is given a common and conventional meaning to those skilled in the art, and is not limited to a specific or customary meaning. Specifically, the term can refer to, but is not limited to, any actuator that has an electromagnet. An actuator is a component of a machine responsible for moving and controlling a mechanism or system, for example, by opening a valve. Simply put, an actuator is a "propeller." In the present case, the actuator moves the sample container carrier on top of a transfer plane by applying a magnetic force to the sample container carrier. An actuator requires a control signal and energy. The energy of the control signal is relatively low and can be voltage or current, pneumatic or hydraulic pressure, or even human power. Its primary energy source can be current, hydraulic fluid pressure, or pneumatic pressure. When a control signal is received, the actuator responds by converting the energy of the source into mechanical motion. An electromagnet is a magnet that generates a magnetic field through an electric current. Electromagnets typically consist of a wire wound into a coil. The current flowing through the wire generates a magnetic field, which is concentrated in a hole, representing the center of the coil. When the current is turned off, the magnetic field disappears. The coils are typically wound around a core made of a ferromagnet or ferromagnetic material such as iron; the core concentrates the magnetic flux, creating a more powerful magnet. The main advantage of electromagnets compared to permanent magnets is that the magnetic field can be rapidly changed by controlling the amount of current in the windings.

[0048] As used herein, the term "inductive sensor" is a broad term and is given a common and conventional meaning to those skilled in the art, and is not limited to a particular or customary meaning. Specifically, the term can refer to, but is not limited to, a sensor based on an inductor used as a sensing coil that generates an output signal based on induced eddy currents from a conductive surface. Specifically, inductive sensing technology utilizes a capacitor and an inductor to form an LC resonator, also known as an LC tank circuit. This circuit can be used to detect the presence of a conductive object within an alternating electromagnetic field. Whenever a conductor interacts with an alternating electromagnetic field, eddy currents are induced on the conductor's surface. Lenz's law states that the induced current will flow in the opposite direction to the magnetic field, thus measurably weakening the originally generated magnetic field. This effectively reduces the inductance of the resonant circuit, and therefore lowers the resonant frequency, as the resonant frequency changes whenever the inductor is affected. This change is proportional to the distance of the metal surface target relative to the sensing coil (antenna).

[0049] As used herein, the term "control unit" is a broad term and is given a common and conventional meaning to those skilled in the art, and is not limited to a specific or customary meaning. Specifically, the term may refer to, but is not limited to, any device configured to control components of a laboratory sample dispensing system. More specifically, the term may refer to any embedded system within a laboratory sample dispensing system that controls one or more electrical components or modules within the laboratory sample dispensing system.

[0050] As used herein, the term "evaluation unit" is a broad term and is given a common and conventional meaning to those skilled in the art, and is not limited to a specific or customary meaning. Specifically, the term may refer to, but is not limited to, any device configured to provide additional functionality, such as frequency filtering or computational functions. Therefore, an evaluation unit eliminates the need for additional hardware such as a computer or logic module. Typically, multiple sensors can be connected to a single evaluation unit.

[0051] As used herein, the terms "linearize" or "linearize" are broad terms and are given a common and conventional meaning to those skilled in the art, and are not limited to any particular or custom-defined meaning. Specifically, the term may refer to, but is not limited to, finding a linear approximation of a function at a given point. Linearization allows the use of tools designed for studying linear systems to analyze the behavior of nonlinear functions near a given point. A linear approximation of a function is a first-order Taylor expansion around the target point. Specifically, the term may refer to the transformation from a nonlinear function or nonlinear graph to a linear function or linear graph.

[0052] As used herein, the term "algorithm" is a broad term and is given a common and conventional meaning to those skilled in the art, and is not limited to a specific or custom-defined meaning. Specifically, the term can refer to, but is not limited to, a well-defined, finite sequence of computer-implementable instructions typically used to solve a class of problems or perform computations. Algorithms are always well-defined and used as specifications for performing computations, data processing, automated reasoning, and other tasks. As an efficient method, algorithms can be expressed in a well-defined formal language within finite space and time to compute functions. Starting from an initial state and initial input (which may be empty), the instructions describe a computation that, when executed, proceeds through a finite number of well-defined successive states, eventually producing an "output" and terminating in a final terminal state. The transition from one state to another is not necessarily deterministic; some algorithms (called stochastic algorithms) incorporate random inputs.

[0053] As used herein, the term "output signal" is a broad term and is given a common and conventional meaning to those skilled in the art, and is not limited to a specific or customary meaning. Specifically, the term may refer to, but is not limited to, signals from electronic systems.

[0054] As used herein, the term "sensing area" is a broad term and is given a common and conventional meaning to those skilled in the art, and is not limited to a specific or customary meaning. Specifically, the term may refer to, but is not limited to, the spatial range in which a sensor can effectively sense or detect an object.

[0055] As used herein, the term "inductor" is a broad term and is given a common and conventional meaning to those skilled in the art, and is not limited to a specific or customary meaning. Specifically, the term can refer to, but is not limited to, a passive, two-terminal electrical component that stores energy in a magnetic field when an electric current flows through it. An inductor typically consists of insulated wire wound into a coil around a magnetic core. When the current flowing through an inductor changes, the time-varying magnetic field induces an electromotive force (EMF) (voltage) in the conductor, as described by Faraday's law of induction. According to Lenz's law, the polarity (direction) of the induced voltage is opposite to the change in current that produces it. Therefore, inductors resist any change in the current flowing through them. An inductor is characterized by its inductance, which is the ratio of the rate of change of voltage to the rate of change of current. Inductors are also called coils, chokes, or reactors.

[0056] As used herein, the term "capacitor" is a broad term and is given a common and conventional meaning to those skilled in the art, and is not limited to a particular or customary meaning. Specifically, the term may refer to, but is not limited to, a device that stores electrical energy in an electric field. A capacitor is a passive electronic component with two terminals. The effect of a capacitor is called capacitance. A capacitor is a component designed to add capacitance to a circuit when some capacitance exists between any two close electrical conductors in the circuit. Unlike a resistor, an ideal capacitor does not dissipate energy, although real-world capacitors do dissipate a small amount of energy. (See Non-ideal Behavior) When a potential (voltage) is applied across the terminals of a capacitor, such as when a capacitor is connected across a battery, an electric field is generated across the dielectric, causing a net positive charge to accumulate on one plate and a net negative charge on the other. No current actually flows through the dielectric. However, charge flows through the source circuit. If this condition is maintained long enough, the current through the source circuit stops. If a time-varying voltage is applied across the leads of a capacitor, a continuous current flows through the source circuit due to the charging and discharging cycles of the capacitor.

[0057] As used herein, the term “lookup table” is a broad term and is given a common and conventional meaning to those skilled in the art, and is not limited to a particular or custom meaning. Specifically, the term may refer to, but is not limited to, arrays that are computed at runtime instead of arrays that are indexed by simpler array operations. The savings in processing time can be significant, as retrieving values ​​from memory is generally faster than performing computations or input / output operations. [1] These tables may be pre-computed and stored in static program memory, computed (or “prefetched”) as part of the program initialization phase (memorization), or even stored in application platform-specific hardware. Lookup tables are also widely used to validate input values ​​by matching them against a list of valid (or invalid) items in an array, and in some programming languages, lookup tables may include pointer functions (or offsets of labels) to process matching inputs. FPGAs also widely use reconfigurable, hardware-implemented lookup tables to provide programmable hardware functionality.

[0058] This document further discloses and proposes a computer program including computer-executable instructions that, when executed on a computer or computer network, are used to perform the method according to the invention in one or more embodiments disclosed herein. Specifically, the computer program may be stored on a computer-readable data carrier and / or a computer-readable storage medium.

[0059] As used herein, the terms "computer-readable data carrier" and "computer-readable storage medium" can specifically refer to non-transitory data storage devices, such as hardware storage media having computer-executable instructions stored thereon. Computer-readable data carriers or storage media can specifically be or may include storage media such as random access memory (RAM) and / or read-only memory (ROM).

[0060] Therefore, specifically, one, more, or even all of the method steps a) to d) as indicated above can be performed by using a computer or computer network, preferably by using a computer program.

[0061] This document further discloses and proposes a computer program product with program code tools so that, when executed on a computer or computer network, the method according to the invention is performed in one or more embodiments appended herein. Specifically, the program code tools may be stored on a computer-readable data carrier and / or a computer-readable storage medium.

[0062] This document further discloses and proposes a data bearer having a data structure stored thereon, which, after being loaded into a computer or computer network, such as after being loaded into the working memory or main memory of the computer or computer network, can perform methods according to one or more embodiments disclosed herein.

[0063] This document further discloses and proposes a computer program product having program code tools stored on a machine-readable carrier, so that when the program is executed on a computer or computer network, it performs methods according to one or more embodiments disclosed herein. As used herein, a computer program product refers to a program that is a tradable product. The product can generally exist in any format (such as paper format) or reside on a computer-readable data carrier and / or computer-readable storage medium. Specifically, the computer program product may be distributed on a data network.

[0064] This document further discloses and proposes a modulated data signal containing instructions readable by a computer system or computer network for performing a method according to one or more embodiments disclosed herein.

[0065] Referring to the computer implementation aspects of the present invention, one or more method steps, or even all method steps, of the methods according to one or more embodiments disclosed herein can be performed using a computer or computer network. Therefore, generally speaking, any method steps including providing and / or processing data can be performed using a computer or computer network. Generally, these method steps can include any method steps other than those typically requiring manual operation (such as providing samples and / or performing certain aspects of actual measurements).

[0066] Specifically, this article further discloses the following:

[0067] - A computer or computer network including at least one processor, wherein the processor is adapted to perform a method according to one of the embodiments described in this specification.

[0068] - A computer-loadable data structure, which is adapted to perform a method according to one of the embodiments described in this specification when the data structure is executed on a computer.

[0069] - A computer program, wherein the computer program is adapted, when executed on a computer, to perform a method according to one of the embodiments described in this specification.

[0070] - A computer program, including program tools for performing, when executed on a computer or on a computer network, a method according to one of the embodiments described in this specification.

[0071] - A computer program comprising program means according to the foregoing embodiments, wherein the program means are stored on a computer-readable storage medium.

[0072] - A storage medium on which a data structure is stored and wherein the data structure is adapted to perform a method according to one of the embodiments described herein after being loaded into the main memory and / or working memory of a computer or computer network.

[0073] - A computer program product having program code tools, wherein the program code tools may be stored or stored on a storage medium for performing a method according to one of the embodiments described in this specification when the program code tools are executed on a computer or computer network.

[0074] In summary, and without excluding further possible embodiments, the following embodiments are conceivable:

[0075] Example 1: A laboratory sample dispensing system, comprising:

[0076] - A plurality of sample container carriers, each adapted to carry one or more sample containers, each sample container carrier including at least one magnetostrictive activation device and at least one conductive member.

[0077] - A transfer plane adapted to support the sample container carrier.

[0078] - A plurality of electromagnetic actuators are fixedly arranged below the transfer plane, the electromagnetic actuators being adapted to move the sample container carrier on top of the transfer plane by applying a magnetic force to the sample container carrier.

[0079] - Multiple inductive sensors, distributed above the transmission plane.

[0080] - A control unit configured to control the movement of a sample container carrier on top of a transfer plane using signals provided by an inductive sensor by driving an electromagnetic actuator, such that the sample container carrier moves along a corresponding transfer path, and

[0081] - An evaluation unit configured to linearize the output signal received from at least one of the inductive sensors by means of a linearization algorithm, wherein the evaluation unit is further configured to determine, in particular, the distance, between at least one of the sample container carriers and at least one of the inductive sensors based on the output signal value of the linearized output signal.

[0082] Example 2: The laboratory sample dispensing system according to the foregoing embodiments, wherein the evaluation unit is further configured to determine the movement direction of at least one of the sample container carriers and at least one of the inductive sensors based on at least two different output signal values ​​of the linearized output signal, the at least two different output signal values ​​indicating two different distances between at least one of the sample container carriers and at least one of the inductive sensors.

[0083] Example 3: A laboratory sample dispensing system according to any of the foregoing embodiments, wherein the evaluation unit is further configured to determine the departure of a sensing area of ​​at least one relative inductive sensor in the sample container carrier and the proximity of a sensing area of ​​at least one relative adjacent inductive sensor in the sample container carrier.

[0084] Example 4: A laboratory sample dispensing system according to any of the foregoing embodiments, wherein the evaluation unit is further configured to track the movement of at least one of the sample container carriers from a starting position on the transfer plane to a final destination on the transfer plane.

[0085] Example 5: A laboratory sample dispensing system according to any of the foregoing embodiments, wherein each of the inductive sensors includes at least one inductor and at least one capacitor, the at least one inductor and the at least one capacitor being arranged in a channel.

[0086] Example 6: A laboratory sample dispensing system according to the foregoing examples, wherein an inductor is arranged below the conveying plane.

[0087] Example 7: A laboratory sample dispensing system according to the foregoing embodiments, wherein the inductors are arranged parallel to the transfer plane.

[0088] Example 8: A laboratory sample dispensing system according to any of the foregoing embodiments, wherein the linearization algorithm includes a lookup table.

[0089] Example 9: A laboratory sample dispensing system according to the foregoing embodiments, wherein a lookup table describes the strength of the output signal of each inductive sensor as a function of the horizontal distance parallel to the transfer plane between the reference object and the corresponding inductive sensor.

[0090] Example 10: A laboratory sample dispensing system according to any of the foregoing embodiments, wherein the evaluation unit is further configured to compensate for the presence of a conductive object in the sensing region of at least one of the inductive sensors.

[0091] Example 11: A laboratory sample dispensing system according to the foregoing embodiments, wherein the evaluation unit is configured to compensate for the presence of a conductive object in the sensing region by measuring the output signal of the corresponding inductive sensor during a period when a sample container carrier is absent in the sensing region of at least one of the inductive sensors.

[0092] Example 12: The laboratory sample dispensing system according to the foregoing embodiments, wherein the evaluation unit is configured to compensate for the presence of a conductive object in the sensing area as an offset if the output signal value of the measured output signal of the corresponding inductive sensor is lower than a predetermined threshold during a period when no sample container carrier is present in the sensing area of ​​at least one of the inductive sensors.

[0093] Example 13: The laboratory sample dispensing system according to Example 11, wherein the evaluation unit is configured to compensate for the presence of a conductive object in the sensing area as an error if the output signal value of the measured output signal of the corresponding inductive sensor is higher than a predetermined threshold during a period when no sample container carrier is present in the sensing area of ​​at least one of the inductive sensors.

[0094] Example 14: A laboratory sample dispensing system according to any of the foregoing embodiments, wherein the evaluation unit is further configured to detect changes in the conductivity of the sample container carrier by periodically measuring the maximum output signal value of the output signal of an inductive sensor.

[0095] Example 15: A laboratory sample dispensing system according to any of the foregoing embodiments, wherein the sample container carrier is a single sample container carrier.

[0096] Example 16: A method for operating a laboratory sample dispensing system according to any of the foregoing embodiments, the method comprising:

[0097] - Provide multiple sample container carriers on the transfer plane.

[0098] - Move the sample container carrier along the corresponding conveyor path.

[0099] - Receive an output signal from at least one of the inductive sensors.

[0100] - The output signal is linearized using a linearization algorithm, and

[0101] The distance between at least one of the sample container carriers and at least one of the inductive sensors is determined based on the output signal value of the linearized output signal.

[0102] Example 17: The method according to the foregoing embodiments further includes determining the movement direction of at least one of the sample container carriers and at least one of the inductive sensors based on at least two different output signal values ​​of the linearized output signal, the at least two different output signal values ​​indicating two different distances between at least one of the sample container carriers and at least one of the inductive sensors.

[0103] Example 18: The method according to Example 16 or 17 further includes determining the separation of a sensing area of ​​at least one relative to one of the inductive sensors in the sample container carrier and the proximity of a sensing area of ​​at least one relative to an adjacent inductive sensor in the sample container carrier.

[0104] Example 19: The method according to any one of Examples 16 to 18 further includes tracking the movement of at least one of the sample container carriers from a starting position on the transport plane to a final destination on the transport plane.

[0105] Example 20: The method according to any one of Examples 16 to 19 further includes compensating for the presence of a conductive object in the sensing region of at least one of the inductive sensors.

[0106] Example 21: The method according to the foregoing embodiments further includes compensating for the presence of a conductive object in the sensing region by measuring the output signal of the corresponding inductive sensor during a period when the sample container carrier is not present in the sensing region of at least one of the inductive sensors.

[0107] Example 22: The method according to the foregoing embodiments further includes compensating for the presence of a conductive object in the sensing region as an offset if the output signal value of the measured output signal of the corresponding inductive sensor is lower than a predetermined threshold during a period when no sample container carrier is present in the sensing region of at least one of the inductive sensors.

[0108] Example 23: The method according to Example 21 further includes compensating for the presence of a conductive object in the sensing area as an error if the output signal value of the measured output signal of the corresponding inductive sensor is higher than a predetermined threshold during a period when no sample container carrier is present in the sensing area of ​​at least one of the inductive sensors.

[0109] Example 24: The method according to any one of Examples 16 to 23 above further includes detecting changes in the conductivity of the sample container carrier by periodically measuring the maximum output signal value of the output signal of the inductive sensor. Attached Figure Description

[0110] Further optional features and embodiments will be disclosed in more detail in the following description of the embodiments, preferably in conjunction with the dependent claims. As those skilled in the art will recognize, the various optional features may be implemented in an isolated manner and in any feasible combination. The scope of the invention is not limited to the preferred embodiments. Embodiments are schematically depicted in the accompanying drawings. In these drawings, the same reference numerals refer to the same or functionally comparable elements.

[0111] In the attached image:

[0112] Figure 1 shows a laboratory sample dispensing system;

[0113] Figure 2 shows the components of an inductive sensor;

[0114] Figure 3 illustrates the operating principle of an inductive sensor;

[0115] Figure 4 shows a flowchart of a method for detecting the movement of a sample container carrier;

[0116] Figure 5 illustrates a method for calibrating an inductive sensor;

[0117] Figure 6 illustrates a method for compensating for conductive objects in the sensing region of an inductive sensor;

[0118] Figure 7 illustrates another method for compensating for conductive objects in the sensing region of an inductive sensor;

[0119] Figure 8 illustrates a method for compensating for changes in the conductivity of conductive objects in the sensing region of an inductive sensor.

[0120] Figure 9 This is a cross-section of the output signal of an example of the coils of six inductive sensors along one axis of the transmission plane;

[0121] Figure 10 This is a cross-section of the output signal of an example of the coils of six inductive sensors along an axis of the transmission plane after offset calibration.

[0122] Figure 11 This is a cross-section of the output signal of an example of the coils of six inductive sensors along one axis of the transmission plane after scaling and calibration.

[0123] Figure 12 It is a reference lookup table;

[0124] Figure 13 This is an example of the output signal of the coil or inductor of an inductive sensor along an axis of the transmission plane after scaling, calibration and linearization of the distance;

[0125] Figure 14 This is an example of the output signal of the coil or inductor of an inductive sensor along an axis of the transmission plane after scaling, calibration, and linearization of the distance; and

[0126] Figure 15 This is an example of the output signal of the coil or inductor of an inductive sensor along an axis of the transmission plane after scaling, calibration, and linearization of the distance. Detailed Implementation

[0127] Figure 1 illustrates a laboratory sample dispensing system 100. The laboratory sample dispensing system 100 may be part of a laboratory automation system (not shown in detail) that includes one or more laboratory stations. Such laboratory stations may be, for example, pre-analytical stations, analytical stations, and / or post-analytical stations. For example, they may perform tasks such as analyzing samples, centrifuging samples, etc.

[0128] The laboratory sample dispensing system 100 includes a transfer plane 110 under which a plurality of electromagnetic actuators 120 are arranged. Each electromagnetic actuator 120 has a corresponding ferromagnetic core 122. The electromagnetic actuators 120 may be arranged in a grid pattern including intersecting lines or rows.

[0129] The laboratory sample dispensing system 100 also includes multiple sample container carriers 130. It should be noted that, for clarity, only one exemplary sample container carrier 130 is shown in Figure 1. The sample container carrier 130 is configured to carry a sample container 132, which may be implemented as a tube. Each sample container carrier 130 includes a magnetostrictive activation device 134, such as a permanent magnet. These permanent magnets are contained within the sample container carrier 130. Each sample container carrier 130 also includes at least one conductive member 136. The conductive member 136 may be disposed at or near the bottom of the sample container carrier 130. The conductive member 136 may be made of metal. For example, the conductive member 136 is implemented as a copper foil disposed at or near the bottom of the sample container carrier 130.

[0130] The laboratory sample dispensing system 100 also includes a plurality of inductive sensors 140 distributed above the transfer plane 110. As shown in FIG1, the inductive sensors 140 are arranged at logical locations defined by the intersections of the electromagnetic actuators 120. FIG2 shows the components of the inductive sensor 140. The inductive sensor 140 includes at least one inductor 142 serving as a detector coil and at least one capacitor 144 serving as part of an oscillator 146. Furthermore, the inductive sensor 140 includes a demodulator 148, a trigger 150, and an output terminal 152.

[0131] Figure 3 illustrates the operating principle of the inductive sensor 140. The inductor 142 can be multiple insulated magnetic turns wound around a high-permeability magnetic core (such as a ferrite ceramic rod or coil), and this winding may or may not have a feedback tap a number of turns away from one end of the overall winding. The inductor is connected to a capacitor 144 to form a tank circuit. It should be noted that, for clarity, the capacitor 144 is not shown in Figure 3. Combined with a voltage or current gain device such as a transistor or operational amplifier, this forms an oscillator 146 as a tuned frequency oscillator. When power is applied, the resulting oscillation is a high-frequency alternating current in the inductor 142, which has a constantly changing magnetic field 154 that induces eddy currents 156 in a near-side (target) conductor (such as the conductive member 136 of the sample container carrier 130). The closer the target and the greater its conductivity (e.g., metals are good conductors), the greater the induced eddy current 156, and the greater the influence of the resulting reverse magnetic field 158 on the amplitude and frequency of the oscillation. The amplitude of the oscillation decreases with increasing load in a non-magnetic conductor such as aluminum because the induced field in the target is opposite to the source induced field, thus reducing the net inductive impedance and therefore tuning the oscillation frequency higher. However, if the target is a high-permeability material (such as iron), the amplitude is less affected because high permeability increases the coil inductance, thus reducing the oscillation frequency. Changes in oscillation amplitude can be detected using a simple amplitude modulation detector (such as a diode) that passes a peak voltage value to a small filter to produce a reflected DC voltage value, while frequency changes can be detected using one of several frequency discriminator circuits (such as a phase-locked loop detector) to see the direction and amount of frequency shift. The magnitude of the amplitude or frequency change can be used to limit the proximity distance of the sensor from on to off, and vice versa. In other words, the slot circuit can be used to detect the presence of conductive objects (such as conductive members 136) within the generated AC electromagnetic field 154. Whenever the conductor interacts with the generated alternating electromagnetic field 154, eddy currents 156 are induced on the conductor's surface. Lenz's law states that the induced current will flow in the opposite direction to the magnetic field, thereby measurably weakening the originally generated magnetic field 154. This effectively reduces the inductance of the resonant circuit, and thus lowers the resonant frequency. This change is proportional to the distance of the metal surface (target) relative to the inductor 142, which serves as a sensing coil or antenna. The inductor 142 may be arranged below the transmission plane 110. Specifically, the inductor 142 may be arranged parallel to the transmission plane 110. In other words, the central axis of the wire or coil wound around the inductor 142 is arranged perpendicular to the transmission plane 110.

[0132] As further shown in Figure 1, the laboratory sample dispensing system 100 also includes a control unit 160 adapted to drive electromagnetic actuators 120 to move sample container carriers 130 along corresponding transport paths. For this purpose, each sample container carrier 130 includes a magnetostrictive activation device 134, such as a permanent magnet. The control unit 160 uses an output signal provided by an inductive sensor 140 to control the movement of the sample container carrier 130 on top of the transport plane 110. The control unit 160 receives the output signal from the inductive sensor 140 to determine the position of the sample container carrier 130 on the transport plane. The inductive sensor 140 senses changes in the generated magnetic field.

[0133] The laboratory sample dispensing system 100 also includes an evaluation unit 170. The evaluation unit 170 is configured to linearize the output signal received from at least one of the inductive sensors 140 using a linearization algorithm. The evaluation unit 170 is further configured to determine, based on the linearized output signal value, at least the distance between at least one of the sample container carriers 130 and at least one of the inductive sensors 140. Furthermore, the control unit 160 can determine the position of the sample container carrier 130 on the transfer plane based on the linearized output signal value. The linearization algorithm includes a lookup table. The lookup table describes the strength of the output signal of each inductive sensor 140 as a function of the horizontal distance between a reference object and the corresponding inductive sensor 140 parallel to the transfer plane 110, as will be described in further detail below.

[0134] Evaluation unit 170 is further configured to determine the direction of movement of at least one of the sample container carriers 130 and at least one of the inductive sensors 140 based on at least two different output signal values ​​of the linearized output signal, the at least two different output signal values ​​indicating two different distances between at least one of the sample container carriers 130 and at least one of the inductive sensors 140. Evaluation unit 170 is further configured to determine the departure of at least one of the sample container carriers 130 from the sensing area of ​​one of the inductive sensors 140 and the approach of at least one of the sample container carriers 130 from the sensing area of ​​an adjacent inductive sensor 140. Evaluation unit 170 is further configured to track the movement of at least one of the sample container carriers 130 from a starting position on the transport plane 110 to a final destination on the transport plane 110. In this respect, it should be noted that the starting position and / or final destination may be defined by control unit 160. Evaluation unit 170 and control unit 160 communicate with each other.

[0135] Figure 4 illustrates a flowchart of a method for detecting movement of a sample container carrier 130. The method includes linearizing the output signal of an inductive sensor 140, as will be described in further detail below. In step S10, at the beginning, the inductive sensor 140 is initialized, and the evaluation unit 170 obtains sensor values. In a subsequent step S12, the inductive sensor 140 provides nonlinear sensor values ​​as an output signal. In a subsequent step S14, the evaluation unit 170 linearizes the sensor values ​​using a lookup table as part of a linearization algorithm. In a subsequent step S16, the evaluation unit 170 determines and / or provides the orientation and initial position of the sample container carrier 130. In a subsequent step S18, the control unit 160 selects an appropriate path for the sample container carrier 130, and the evaluation unit 170 sets the sensor values ​​based on the current position. In a subsequent step S20, the evaluation unit 170 increments the linearized distance from the current inductive sensor 140. In subsequent step S22, the evaluation unit determines whether the linearization value of the current inductive sensor 140 exceeds a threshold such as 18 mm. If the linearization value of the current inductive sensor 140 exceeds the threshold, the method proceeds to step S24. In step S24, the evaluation unit 170 changes or switches to the coil or inductor 142 of the next or adjacent inductive sensor 140. Subsequently, the method returns to step S20. If the linearization value of the current inductive sensor 140 does not exceed the threshold in step S22, the method proceeds to step S26. In step S26, the evaluation unit determines whether the linearization value of the current inductive sensor 140 exceeds another threshold such as 5 mm, and whether the new or current sensor value is less than the previous or old sensor value. If the linearization value of the current inductive sensor 140 is not less than another threshold and the new or current sensor value is not less than the previous or old sensor value, the method returns to step S20. If the linearization value of the current inductive sensor 140 is less than another threshold and the new or current sensor value is less than the previous or old sensor value, the method proceeds to step S28. In step S28, the evaluation unit 170 becomes the opposite side of the coil of the inductive sensor 140 or the inductor 142. Subsequently, the method returns to step S20.

[0136] Figure 5 illustrates a method for calibrating inductive sensors 140. Four inductive sensors 140 are shown as an example only. Each inductive coil or inductor 142 exhibits different behavior and generates different signals for a phase-conductive target at the same distance, as shown in the left portion of Figure 5. This problem makes it difficult to correlate and integrate information in a system where the target moves above different inductors 142 used as antennas. During the fabrication of the transmission plane 110, all inductive sensors 140 are calibrated using a reference object 180, thereby defining a specific output signal between the reference object 180 and each sensor coil or inductor 142 at a predetermined vertical distance 182, as shown in the middle portion of Figure 5. The vertical distance 182 is a distance perpendicular to the transmission plane 110 and can be adjusted appropriately. This calibration during fabrication forms a lookup table describing the strength of the position signal as a function of the horizontal distance between the reference object 180 and the sensing coil or inductor 142 parallel to the transmission plane 110. Calibration results in standardized common behavior for the inductive sensor 140, as shown in the right portion of Figure 5. Specifically, the calibration shown in Figure 5 is relative to a horizontal distance, as described in WO 2011 / 138448 A1 or US 2016 / 0069715 A1, which takes into account vertical distance. Specifically, a single lookup table can be created applicable to all sensor coils 142, as will be described in further detail below.

[0137] Figure 6 illustrates a method for compensating for conductive objects 190 in the sensing region of an inductive sensor 140. Four inductive sensors 140 are shown as an example only. During operation, it may be necessary for an inductive sensor 140 to work with conductive objects 190 present near the inductor, as shown in the left portion of Figure 6. The presence of conductive objects 190 affecting the reading of inductor 142 can be detected and quantified by measuring the output value from the inductor 140 when there is no sample container carrier 130 on the transfer plane 110, as shown in the middle portion of Figure 6. The evaluation unit 170 is configured to compensate for the presence of conductive objects 190 in the sensing region as an offset if the measured output signal value of the corresponding inductive sensor 140 is below a predetermined threshold when the sample container carrier 130 is absent in the sensing region of at least one of the inductive sensors 140, as shown in the right portion of Figure 6. In other words, if the measured value is not too high, it can be compensated for by treating it as a non-linear but deterministic offset.

[0138] Figure 7 illustrates another method for compensating for conductive objects 190 in the sensing region of inductive sensor 140. Hereinafter, only the differences from Figure 6 will be described, and similar structural components are indicated by similar reference numerals. During operation, it may be necessary for inductive sensor 140 to work with conductive objects 190 present near the inductor, as shown in the left portion of Figure 7. The presence of conductive objects 190 affecting the reading of inductor 142 can be detected and quantified by measuring the output value from inductor 140 when there is no sample container carrier 130 on the transfer plane 110, as shown in the middle portion of Figure 7. Evaluation unit 170 is configured to compensate for the presence of conductive objects 190 in the sensing region as an error if the measured output signal value of the corresponding inductive sensor 140 is higher than a predetermined threshold when the sample container carrier 130 is absent in the sensing region of at least one of the inductive sensors 140. In other words, compared to Figure 6, on the other hand, if the measured interference is too high and cannot be handled, the evaluation unit 170 will detect that the performance of the corresponding inductive sensor 140 is out of specification, and may cause errors and avoid using the inductive sensor 140 which is subject to external interference.

[0139] Figure 8 illustrates a method for compensating for changes in the conductivity of a conductive object 190 in the sensing region of an inductive sensor 140. Only a single inductive sensor 140 is shown as an example. The evaluation unit 170 is further configured to detect changes in the conductivity of the sample container carrier 130 by periodically measuring the maximum output signal value of the output signal of the inductive sensor 140. Since the calibration described above is performed by measuring the maximum value of a reference object, the inductive sensor 140 can detect changes in the sample container carrier 130 caused by wear or damage by periodically measuring the maximum signal strength. An error can be detected if the maximum value generated by the sample container carrier 130 exceeds specifications, i.e., the sample container carrier 130 is defective (as shown in the lower right portion of Figure 8), or if the distance to the inductor 142 of the inductive sensor 140 exceeds specifications due to wear / tolerance (as shown in the upper right portion of Figure 8). By performing periodic checks, the evaluation unit 170 can monitor changes in the measurements of the sample container carrier 130 over time. Predictive maintenance is possible by observing patterns that lead to failure before sensor read failures actually occur.

[0140] The linearization of the output signal of the inductive sensor 140 and the creation of the lookup table will be described in further detail below. It should be noted that Figures 9 through 11 also illustrate the details of the calibration process.

[0141] As mentioned above, the transport plane 110 includes a plurality of inductive sensors 140. Therefore, the transport plane 110 may also be referred to as a sensor plate. The transport plane 110 defines a two-dimensional plane, also referred to hereinafter as the XY plane. The array of inductive sensors 140 involves the problem of obtaining accurate distances in the XY plane because, without the calibration and linearization algorithms applied in this invention, each inductive sensor 140 provides different output signals for the practically same horizontal distance. To solve this problem, multiple steps are involved that guide the current system to provide improved resolution (such as 1 / 10 mm resolution) on a 25 cm x 25 cm sensor plate with 36 sensing coils (6 along the x-axis and 6 along the y-axis).

[0142] Figure 9 shows a cross-section of the output signals of an example of the coils of six inductive sensors 140 along one axis of the transport plane 110. The X-axis represents the length of the sensor plate along the axis of the transport plane 110 or the cross-section. The Y-axis represents the LDC (inductance count) of the inductor 142 or sensor coil. Furthermore, the output signals 192 (graphed) of the inductors 142 or coils of the inductive sensors 140 are shown, and these output signals are obtained as a circular metal target (such as reference object 180 or laboratory sample carrier 130) moves over the inductors or coils. The peak 194 of the output signal 192 indicates the presence of a metal target above the center of the inductor 142 or coil. For ease of understanding, it can be assumed that the metal target is positioned above each coil and moves over each coil in the XY plane of the sensor plate. As can be seen from Figure 9, the output signal 192 of each inductor 142 is at a different minimum, making the evaluation of the corresponding output signal tricky. For this purpose, a so-called offset calibration is performed.

[0143] Figure 10 shows a cross-section of the output signal 192 of an example of the coils of six inductive sensors 140 along one axis of the transport plane 110 after offset calibration. Hereinafter, only the differences from Figure 9 will be described, and similar structural components or features will be indicated by similar reference numerals. To obtain any measurement structure from the inductors 142 or coils, the inductors 142 or coils are calibrated such that all coils exhibit the same minimum value. In the example shown, the selected minimum LDC value is 100, but essentially any value greater than 0 is acceptable to avoid difficulties caused by signal noise. Therefore, the offset 196 of the inductors 142 or coils can be seen in Figure 10, and the output signals 192 are all at the same basic level. To create a single lookup table for all inductors 142 or coils, a so-called scaling calibration is subsequently performed.

[0144] Figure 11 shows a cross-section of an example output signal 192 of the coils of six inductive sensors 140 along one axis of the transport plane 110 after scaling calibration. In the following text, only the differences from Figure 10 are described, and similar structural elements or features are indicated by similar reference numerals. Starting with Figure 10, where the output signals 192 of all coils are at the same basic level, a multiplier factor is applied to the output signal 192 of each coil. This multiplier factor can scale the output signal 192 of each coil to a reference value based on measurements from a reference coil, which may be outside or inside the transport plane 110. In the example shown, the multiplier factor is 869, but it can be any number based essentially on the characteristics of the coil used as a reference (e.g., the shape of the coil). This reference is important because the reference lookup table is also generated from this reference coil. During the calibration process at manufacturing time, the multiplier factor is stored in memory (such as the EEPROM of the sensor board). Figure 11 shows the normalized coil behavior in response to movement of a metallic target after scaling calibration. Following this step, the coil's output signal 192 is at the same reference offset and scale, and a reference lookup table is used to linearize the nonlinear coil response. This reference lookup table is created based on measurements from the reference coil mentioned above.

[0145] Figure 12 shows the reference lookup table. The X-axis of the table represents the LDC count, and the Y-axis represents the distance value from the center of inductor 142 or the coil, given in 0.1 mm steps. Graph 198 shows the measurement results for the reference coil. For any offset-calibrated and scale-calibrated coil, the 0.1 mm distance value can be calculated or viewed from this lookup table. This is valid for any sensor board with similar frequency characteristics. The lookup table is valid for all hardware manufactured within tolerances until and unless there are significant changes in the hardware (such as changes in capacitor or coil design). Although the nonlinearity of the output signal 192 of the coil does have some impact on accuracy, it has been found to be well below 0.1 mm resolution. With the help of the lookup table, the nonlinear output signal of inductor 142 can be linearized, i.e., converted into a linear graph.

[0146] Figures 13 and 14 show an example output signal 192 of the coil or inductor 142 of an inductive sensor 140 along an axis of the transport plane 110 after scaling calibration and linearization distance 200. Hereinafter, only differences from Figure 10 will be described, and similar structural members or features will be indicated by similar reference numerals. The X-axis represents the length of the transport plane 110 or the sensor plate along its axis. The left Y-axis represents the LDC (inductance count) of the inductor 142 or sensor coil. The right Y-axis indicates the linearization distance along the axis of the sensor plate or transport plane 110. As can be seen from Figures 13 and 14, the output signal 192 is at its maximum value when the metal target is located at the center of the coil or inductor 142, representing the zero-crossing region. Furthermore, the maximum value of the linearization distance 200 is located midway between the centers of two adjacent coils or inductors 142, representing the coil-to-coil crossing region.

[0147] As can be seen from Figures 13 and 14, one of the problems with the inductive sensor 140 is the symmetrical response of the coils in the XY plane in a multi-coil system. This complicates the use of such a sensor, and the present invention provides a novel solution with minimal variables. To address this problem, the algorithm for evaluating the output signal 192 uses known information such as the position of the coils on the sensor plate or the direction of movement of the metal target on the surface of the sensor plate.

[0148] Figure 15 shows an example output signal 192 of the coil or inductor 142 of the inductive sensor 140 along one axis of the transport plane 110 after scaling calibration and linearization distance 200. In the following description, only the differences from Figures 13 and 14 are shown, and similar structural components or features are indicated by similar reference numerals. To further illustrate the linearization algorithm, an example of two coils or inductors 142 arranged along one axis (X-axis or Y-axis) can be assumed. A metal target is located at the center of coil 1 and moves toward coil 2, as shown in Figure 15. It must be noted that the direction or manner of movement is given by the control unit 160. In other words, the control unit 160 defines the target movement path for the metal target. Coil 1 is located 30 mm from the boundary of the sensor plate. Therefore, the starting position (SP) is 30 mm, and as the metal target moves further, the distance from the center of coil 1 (LT[LDC]) is increased from the lookup table (such as shown in Figure 12) to the CP (center position) based on the LDC value. (coilx) ]). Not to mention, CP changes when the metal target starts from another coil. For the current sensing solution design, coil 1 (i.e., the outer coil at the boundary of the sensing plate) is located at a starting position equal to 30mm from the edge of the plate, and the distance increases according to the coil number (i.e., Given the distance from the center of the coil to the boundary Distance = Distance from the center of the outer coil to the sensor boundary + (Coil number - 1) * Distance between the centers of the two coils Since the distance between adjacent coils is 40mm for the current sensing solution design, the distance from the center of coil number 2 to the boundary can be calculated using the above formula, as follows:

[0149] 30 mm + (2-1)*40 mm = 70 mm.

[0150] When the metal target moves from the center of coil 1 from its initial position, the distance from the sensor plate boundary is calculated as D = CP. (coil 1) + LT[LDC (coil1) It is important to note that this calculation is based on the assumption that the movement of the metal target from coil 1 towards coil 6 is considered positive movement. When the metal target crosses the coil into the coil crossing area (18mm, derived experimentally, where it has been found that the second coil has sufficient signal to jump to the other coil), the algorithm then checks the point where the metal target crosses coil 1 to coil 2. When the algorithm detects that the metal target has crossed into the other coil, it begins to use the LDC value of that other coil (i.e., coil number 2 in this example). When the algorithm begins to use the LDC value of coil 2 from the lookup table, the formula used to calculate the distance from the sensor boundary becomes D = CP (coil2) -LT[LDC (coil2)Now, when the metal target approaches the zero-crossing region (the middle of the coil), the algorithm anticipates a zero-crossing point. When the target moves above the zero-crossing point of coil 2, the algorithm modifies the formula, recalculating the distance as D = CP using the right side of the output signal 192 of coil 2. (coil2) + LT[LDC (coil2) The input to the lookup table is [coil 3 through coil 6]. This loop continues for other coils (e.g., coils 3 through 6). The same algorithm applies to all coil pairs along the XY plane. This is a method that provides a single lookup table for all coils. Figure 15 shows the linearization algorithm graphically for better understanding. It is also worth noting that the coil coordinates are fixed. Furthermore, for clarification, many filtering steps are not mentioned here.

[0151] The linearization algorithm according to the invention is based on the fact that the direction of movement of the metal target is known. Furthermore, the starting position and length of the movement (in terms of the logical position number) are known. The direction of drive, initial position, and length are controlled by the control software of the control unit 160, which is also responsible for the target's path on the drive surface. Specifically, the initial position is known and the presence of the metal target can be detected by checking the LDC value of the coil; that is, if the LDC value of the coil is higher than a certain value, it means that a metal target exists at the logical position of that coil. Now, the target can be moved blindly to the center of the logical position. Now the target is centered on the logical position. In the algorithm mentioned above, the direction and length of the target's drive are used. The algorithm only requires information about whether the starting position of the movement is at a zero-crossing point (the top of the symmetry) as input.

[0152] List of reference numerals

[0153] 100 Laboratory Sample Dispensing System

[0154] 110 Transmission Plane

[0155] 120 Electromagnetic Actuator

[0156] 122 Ferromagnetic Core

[0157] 130 Sample container carrier

[0158] 132 Sample Container

[0159] 134 Magnetostrictive Activation Device

[0160] 136 Conductive components

[0161] 140 Inductive Sensor

[0162] 142 Inductor

[0163] 144 capacitor

[0164] 146 Oscillator

[0165] 148 Demodulator

[0166] 150 trigger

[0167] 152 Output Terminal

[0168] 154 Electromagnetic Field

[0169] 156 Vortex

[0170] 158 Magnetic Field

[0171] 160 Control Unit

[0172] 170 Evaluation Units

[0173] 180 Reference Objects

[0174] 182 vertical distance

[0175] 190 Conductive objects

[0176] 192 Output signal

[0177] 194 peaks

[0178] 196 offset

[0179] 198 Figures

[0180] 200 linearized distance

[0181] S10 Initialize the sensor and obtain sensor values

[0182] S12 Nonlinear Sensor Value

[0183] S14 Linearize sensor values ​​using a lookup table

[0184] S16 Determine / provide direction and initial position

[0185] S18 Select an appropriate path and set a value based on the current location.

[0186] S20 Increases the linearized distance from the current sensor.

[0187] Is the linearized sensor value of S22 greater than the threshold / distance?

[0188] S24 becomes the next sensor inductor coil.

[0189] S26 Is the linearized sensor value less than the threshold / distance? Is the new value less than the old value?

[0190] S28 becomes the other side of the symmetry.

Claims

1. A laboratory sample dispensing system (100), comprising: - A plurality of sample container carriers (130), each of the plurality of sample container carriers being adapted to carry one or more sample containers (132), each sample container carrier (130) including at least one magnetostrictive activation device (134) and at least one conductive member (136), - A transfer plane (110) adapted to support the sample container carrier (130). - A plurality of electromagnetic actuators (120) are fixedly arranged below the transfer plane (110), the electromagnetic actuators (120) being adapted to move the sample container carrier (130) on top of the transfer plane (110) by applying a magnetic force to the sample container carrier (130). - Multiple inductive sensors (140) are distributed above the transmission plane (110). - A control unit (160) configured to control the movement of the sample container carrier (130) on the top of the transfer plane (110) by driving the electromagnetic actuator (120) using the output signal provided by the inductive sensor (140), such that the sample container carrier (130) moves along a corresponding transfer path, and - An evaluation unit (170) configured to linearize the output signal received from at least one of the inductive sensors (140) using a linearization algorithm, wherein the evaluation unit (170) is further configured to determine, based on the output signal value of the linearized output signal, at least the distance between at least one of the sample container carriers (130) and at least one of the inductive sensors (140). The evaluation unit (170) is further configured to determine the movement direction of at least one of the sample container carriers (130) and at least one of the inductive sensors (140) based on at least two different output signal values ​​of the linearized output signal, the at least two different output signal values ​​indicating two different distances between at least one of the sample container carriers (130) and at least one of the inductive sensors (140).

2. The laboratory sample dispensing system (100) according to claim 1, wherein the evaluation unit (170) is further configured to determine the departure of at least one of the sample container carriers (130) from the sensing area of ​​one of the inductive sensors (140) and the proximity of at least one of the sample container carriers (130) from the sensing area of ​​an adjacent inductive sensor (140).

3. The laboratory sample dispensing system (100) according to claim 1 or 2, wherein the evaluation unit (170) is further configured to track the movement of at least one of the sample container carriers (130) from a starting position on the transfer plane (110) to a final destination on the transfer plane (110).

4. The laboratory sample dispensing system (100) according to claim 1 or 2, wherein each of the inductive sensors (140) comprises at least one inductor (142) and at least one capacitor (144), the at least one inductor and the at least one capacitor being arranged in a channel.

5. The laboratory sample dispensing system (100) according to claim 4, wherein the inductor (142) is arranged below the transfer plane (110).

6. The laboratory sample dispensing system (100) according to claim 5, wherein the inductor (142) is arranged parallel to the transfer plane (110).

7. The laboratory sample dispensing system (100) according to claim 1 or 2, wherein the linearization algorithm includes a lookup table.

8. The laboratory sample dispensing system (100) according to claim 7, wherein the lookup table describes the intensity of the output signal of each inductive sensor (140) as a function of the horizontal distance between the reference object (180) and the corresponding inductive sensor (140) parallel to the transfer plane (110).

9. The laboratory sample dispensing system (100) according to claim 1 or 2, wherein the evaluation unit (170) is further configured to compensate for the presence of a conductive object (190) in the sensing region of at least one of the inductive sensors (140).

10. The laboratory sample dispensing system (100) according to claim 9, wherein the evaluation unit (170) is configured to compensate for the presence of a conductive object (190) in the sensing region by measuring the output signal of the corresponding inductive sensor (140) during a period when a sample container carrier (130) is absent in the sensing region of at least one of the inductive sensors (140).

11. The laboratory sample dispensing system (100) according to claim 10, wherein the evaluation unit (170) is configured to compensate for the presence of the conductive object (190) in the sensing area as an offset if the output signal value of the measured output signal of the corresponding inductive sensor (140) is lower than a predetermined threshold during a period when a sample container carrier (130) is not present in the sensing area of ​​at least one of the inductive sensors (140).

12. The laboratory sample dispensing system (100) according to claim 10, wherein the evaluation unit (170) is configured to compensate for the presence of the conductive object (190) in the sensing area as an error if the output signal value of the measured output signal of the corresponding inductive sensor (140) is higher than a predetermined threshold during a period when a sample container carrier (130) is not present in the sensing area of ​​at least one of the inductive sensors (140).

13. The laboratory sample dispensing system (100) according to claim 1 or 2, wherein the evaluation unit (170) is further configured to detect changes in the conductivity of the sample container carrier (130) by periodically measuring the maximum output signal value of the output signal of the inductive sensor (140).

14. The laboratory sample dispensing system (100) according to claim 1, wherein the distance between at least one of the sample container carriers (130) and at least one of the inductive sensors (140) is a horizontal distance.

15. A method for operating a laboratory sample dispensing system (100) according to any of the preceding claims, the method comprising: - A plurality of sample container carriers (130) are provided on the transfer plane (110), - Move the sample container carrier (130) along the corresponding conveying path. - Receive an output signal from at least one of the inductive sensors. - The output signal is linearized using a linearization algorithm. - Based on the output signal value of the linearized output signal, determine at least the distance between at least one of the sample container carriers (130) and at least one of the inductive sensors (140), and - The direction of movement of at least one of the sample container carriers (130) and at least one of the inductive sensors (140) is determined based on at least two different output signal values ​​of the linearized output signal, the at least two different output signal values ​​indicating two different distances between at least one of the sample container carriers (130) and at least one of the inductive sensors (140).

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