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CN-113945725-B - Laboratory sample distribution system and method of operating the same

CN113945725BCN 113945725 BCN113945725 BCN 113945725BCN-113945725-B

Abstract

Laboratory sample distribution systems (100) are disclosed. Comprising a plurality of sample container carriers (130), each adapted to carry one or more sample containers (132), a transport plane (110), adapted to support the sample container carriers (130), a plurality of electromagnetic actuators (120), fixedly arranged below the transport plane (110), for moving the sample container carriers (130) by applying a magnetic force to the sample container carriers (130), a plurality of inductive sensors (140), distributed above the transport plane (110), a control unit (160), configured to control the movement of the sample container carriers (130) on top of the transport plane (110) by driving the electromagnetic actuators (120), and an evaluation unit (170), configured to linearize an 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 at least determine a distance between the at least one of the sample container carriers (130) and the at least one of the inductive sensors (140) based on an output signal value of the linearized output signal value.

Inventors

  • P. Tanotra
  • M. Andrews kivich

Assignees

  • 豪夫迈·罗氏有限公司
  • 豪夫迈·罗氏有限公司

Dates

Publication Date
20260421
Application Date
20210715
Priority Date
20200715

Claims (15)

  1. 1. A laboratory sample distribution system (100), comprising: a plurality of sample container carriers (130) each adapted to carry one or more sample containers (132), each sample container carrier (130) comprising at least one magnetically active device (134) and at least one electrically conductive member (136), A transport plane (110) adapted to support the sample container carrier (130), A plurality of electromagnetic actuators (120) fixedly arranged below the transport plane (110), the electromagnetic actuators (120) being adapted to move the sample container carrier (130) on top of the transport plane (110) by applying a magnetic force to the sample container carrier (130), A plurality of inductive sensors (140) distributed above the conveying plane (110), -A control unit (160) configured to control the movement of the sample container carrier (130) on top of the transport plane (110) using an output signal provided by the inductive sensor (140) by driving the electromagnetic actuator (120) such that the sample container carrier (130) moves along a corresponding transport path, and An evaluation unit (170) configured to linearize an 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 a distance between at least one of the sample container carriers (130) and at least one of the inductive sensors (140) based on an output signal value of the linearized output signal, Wherein the evaluation unit (170) is further configured to determine a 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 signals, the at least two different output signal values being indicative of two different distances between at least one of the sample container carriers (130) and at least one of the inductive sensors (140).
  2. 2. The laboratory sample distribution system (100) according to claim 1, wherein the evaluation unit (170) is further configured to determine a departure of at least one of the sample container carriers (130) from a sensing area of one of the inductive sensors (140) and a proximity of at least one of the sample container carriers (130) from a sensing area of an adjacent inductive sensor (140).
  3. 3. The laboratory sample distribution system (100) according to claim 1 or 2, wherein the evaluation unit (170) is further configured to track a 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).
  4. 4. The laboratory sample distribution system (100) according to claim 1 or 2, wherein the inductive sensors (140) each comprise at least one inductor (142) and at least one capacitor (144), the at least one inductor and the at least one capacitor being arranged as a tank circuit.
  5. 5. The laboratory sample distribution system (100) according to claim 4, wherein said inductor (142) is arranged below said transport plane (110).
  6. 6. The laboratory sample distribution system (100) according to claim 5, wherein said inductors (142) are arranged parallel to said transport plane (110).
  7. 7. The laboratory sample distribution system (100) according to claim 1 or 2, wherein said linearization algorithm comprises a look-up table.
  8. 8. The laboratory sample distribution system (100) according to claim 7, wherein the look-up table describes the intensity of the output signal of each inductive sensor (140) as a function of the horizontal distance between a reference object (180) and the respective inductive sensor (140) parallel to the transport plane (110).
  9. 9. The laboratory sample distribution 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 a sensing area of at least one of the inductive sensors (140).
  10. 10. The laboratory sample distribution system (100) according to claim 9, wherein the evaluation unit (170) is configured to compensate for the presence of conductive objects (190) in a sensing region of at least one of the inductive sensors (140) by measuring the output signal of the respective inductive sensor (140) during absence of a sample container carrier (130) in the sensing region.
  11. 11. The laboratory sample distribution 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 region of at least one of the inductive sensors (140) as an offset if an output signal value of the measured output signal of the respective inductive sensor (140) is below a predetermined threshold value during absence of a sample container carrier (130) in the sensing region.
  12. 12. The laboratory sample distribution 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 region of at least one of the inductive sensors (140) as an error if an output signal value of the measured output signal of the respective inductive sensor (140) during absence of a sample container carrier (130) in the sensing region is above a predetermined threshold.
  13. 13. The laboratory sample distribution system (100) according to claim 1 or 2, wherein the evaluation unit (170) is further configured to detect a change in the conductive properties of the sample container carrier (130) by periodically measuring a maximum output signal value of the output signal of the inductive sensor (140).
  14. 14. The laboratory sample distribution system (100) according to claim 1, wherein a distance between at least one of said sample container carriers (130) and at least one of said inductive sensors (140) is a horizontal distance.
  15. 15. A method for operating a laboratory sample distribution system (100) according to any preceding claim, the method comprising: providing a plurality of sample container carriers (130) on the transport plane (110), Moving the sample container carriers (130) along respective transport paths, Receiving an output signal from at least one of the inductive sensors, Linearizing the output signal by means of a linearization algorithm, -Determining at least a distance between at least one of the sample container carriers (130) and at least one of the inductive sensors (140) based on an output signal value of the linearized output signal, and -Determining a 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 being indicative of two different distances between at least one of the sample container carriers (130) and at least one of the inductive sensors (140).

Description

Laboratory sample distribution system and method of operating the same Technical Field The present invention relates to laboratory sample distribution systems. The invention also relates to a method for operating a laboratory sample distribution system. Background Laboratory sample distribution systems are used in laboratory automation systems that include a plurality of laboratory stations, such as pre-analysis stations, and/or post-analysis stations. Laboratory sample distribution systems may be used to distribute sample containers between laboratory stations and other equipment. The sample container is typically made of a transparent plastic material or a glass material and has an opening at the upper side. The sample container may hold a sample, such as a blood sample or other medical sample. A typical laboratory sample distribution system, calibration device and method for calibrating a magnetic sensor are disclosed in WO 2011/138448 A1 or US 2016/0069715A. As disclosed, the sample container carrier moves on a transport plane, wherein a plurality of electromagnetic actuators are arranged below the transport plane in order to drive the sample container carrier. For detecting the respective position of the sample container carrier, a plurality of magnetic sensors, for example hall sensors, are assigned above the transport plane. The detection of the position of the sample container carrier is not only crucial to ensure that the transport tasks are properly completed, but also to low-level implementation of the drive logic. However, hall sensors are greatly affected by the actuator coil magnetic field, requiring excessive power to operate and generating excessive heat. The hall sensor provides insufficient accuracy of position detection due to the dead zone on the surface of the transport plane of the sample distribution system. Another disadvantage of hall sensors is the high cost of including a large number of sensors, each of which requires a mechanical recess to be configured to accommodate the sensor in the drive surface. Thus, inductive sensors may be used as an alternative technique to position sensing. Inductive sensors are based on an inductor that acts as a sensing coil that generates an output signal based on induced eddy currents from a conductive surface. In particular, the inductive sensing technique utilizes a capacitor and an inductor to form an L-C resonator, also referred to as an L-C tank circuit. The circuit may be used to detect the presence of a conductive object within an alternating electromagnetic field. Eddy currents are induced on the conductor surface whenever the conductor interacts with an alternating magnetic field. Lenz's law states that induced currents will flow in a manner opposite to the magnetic field, thereby attenuating the originally generated magnetic field in a measurable manner. This effectively reduces the inductance of the resonant circuit and thus the resonant frequency, since the resonant frequency also changes whenever the inductance is affected. This change is proportional to the distance of the metal surface target relative to the sensing coil (antenna). However, the output signal is non-linear in that it is measured in a plane parallel to the transmission plane, rather than in a distance from the LC resonant circuit. It therefore provides only information about the distance between the antenna and the target, and not about the relative position, since the signal strength is symmetrical around the center of the sensing coil. Furthermore, the signal strength increases as the metal surface approaches the coil center during movement along the transport plane, but also as the vertical distance between the metal surface and the sensor coil perpendicular to the transport plane decreases due to wear and/or manufacturing tolerances. Disclosure of Invention Embodiments of the disclosed sample distribution system and method of operation thereof aim to overcome the above-described disadvantages and in particular to provide for appropriate determination of the position and direction of movement of the sample carrier. In other words, the disclosed sample dispensing system and method of operation thereof are directed to overcoming problems associated with the non-linear and symmetric behavior of inductive sensors. This problem is solved by a sample distribution system and a method for operating a sample distribution system having the features of the independent claims. Advantageous embodiments which can be realized in isolation or in any combination are listed in the dependent claims and throughout the description. As used hereinafter, the terms "having," "including," or "containing," or any grammatical variations thereof, are used in a non-exclusive manner. Thus, these terms may refer to either the absence of other features in an entity described in this context or the presence of one or more other features in addition to the features introduced by these terms. As an e