Abstract:
A sensor device ( 45 ) for calibrating a staining device ( 20 ) has a coupling unit ( 46 ) which is configured to be attachable to a transport device ( 22 ) of the staining device ( 20 ). A sensor unit ( 48 ) of the sensor device ( 45 ) is adapted to detect the presence of components of the staining device ( 20 ).

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority of German patent application number 10 2010 036 317.0 filed Jul. 9, 2010, the entire disclosure of which is incorporated by reference herein. 
     FIELD OF THE INVENTION 
     The present invention relates to a sensor device for calibrating a staining device and to a staining device. The staining device includes a transport device by means of which sample baskets can be moved to different components within the staining device. Moreover, the present invention relates to a method for calibrating the staining device. 
     BACKGROUND OF THE INVENTION 
     Samples, in particular tissue samples to be examined using a microscope, are routinely stained using staining devices, so that structures of the samples can be better seen in the microscopic image than in the case of unstained samples. For sample staining, a staining device includes two or more containers in which identical, similar or different process media are stored. The samples to be stained are immersed in the process media, where they remain for residence times which are dependent on the process step, the process medium, and on the sample to be stained. Once the predetermined residence time has elapsed, the samples are withdrawn from the container and transferred to the next container by means of a transport system. Depending on the staining method and/or the sample, the samples are in this manner successively immersed in a plurality of containers filled with process media. Moreover, the samples may be dried before, between or after the aforementioned steps, using an oven. For example, moist sections of paraffin-embedded tissue samples placed on slides may be dried in the oven, thereby evaporating the moisture and partially melting the paraffin, which improves the adherence of the tissue samples to the slides. 
     The containers and the oven, if provided, are positioned within the staining device during assembly thereof. After that, the containers and/or the oven may be replaced, for example, for purposes of repair. Moreover, optional components, such as the oven, cuvettes, or additional containers, may be added later. Further, the transport device, its attachment and suspension arrangement, as well as a lifting device of the transport device have manufacturing tolerances. In order for the staining operation to function properly after replacement or installation of components and despite the tolerances, the staining device is calibrated. During calibration, the exact positions of the containers and the oven in the staining device are determined, taking into account the tolerances, and stored in a processing unit. The staining process and, in particular, the transport system of the staining device can then be controlled by the processing unit. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a sensor device for calibrating a staining device, a staining device, and a method for calibrating the staining device, which will allow easy calibration of the staining device. 
     This object is achieved by the features of the independent claims. Advantageous embodiments are set forth in the dependent claims. 
     A first aspect of the present invention resides in a sensor device for calibrating a staining device. The sensor device includes a coupling unit and a sensor unit. The coupling unit is configured to be attachable to a transport device of the staining device. The sensor unit is adapted to detect the presence of components of the staining device. The sensor device is also able to determine the positions of such components. 
     In order to calibrate the staining device, the sensor device can be attached to the transport device in place of a sample basket for holding samples. The sensor device can then be moved to different components of the staining device. Once the sensor device detects the presence of a component, the position of corresponding component can be determined based on the known current position of the transport system. The positions of the individual components may be stored, so that they are precisely known during further operation of the staining device. 
     In a specific embodiment, the sensor unit operates using acoustic, optical or tactile sensing techniques. In other words, the sensor unit includes a device for generating sound waves, such as ultrasound, and a sensor for receiving sound waves reflected from the components, or the sensor unit includes a laser and a photosensitive element capable of detecting laser beams reflected from the components, or the sensor unit includes touch-sensitive elements which, upon contact with components of the staining device, cause corresponding output signals to be produced in the sensor unit. The device for generating sound waves and/or the sensor for receiving the sound waves include, for example, a piezoelectric ceramic material or a piezoelectric plastic material. 
     In another embodiment, the sensor unit includes a base element, a sensor lever, and a sensor circuit. The sensor lever is fixedly secured to the base element. The sensor unit may be configured in the manner of a control stick or joystick, so that movement of the sensor lever can be detected in a similar way as that of a joystick. The position of the sensor lever can be detected by the sensor circuit. When the sensor lever hits the components of the staining device as the sensor device is moved, then this can be detected by the sensor circuit, for example by way of microswitches of the sensor circuit which are acted upon by the sensor lever. 
     Alternatively, the sensor unit may be capable of detecting a force acting on the sensor lever. For example, the sensor lever may be provided with one or more strain gauges capable of detecting bending of the sensor lever. Such bending deformations are then reflected in the output signal of the sensor unit, and indicate contact of the sensor lever with one of the components, in particular with a wall of the corresponding component. 
     Since the current position of the transport system, and thus the position of the sensor device, are known at all times, the positions of the components can be determined based on the output signals of the sensor unit. These positions can then be stored. After that, the positions of the components are known. 
     A second aspect of the present invention resides in the staining device, which includes the transport device to which the sensor device is attached. The staining device further includes a plurality of components disposed in different locations within the staining device. A calibration unit is capable of driving the transport device to move the sensor device to the different locations of the staining device. The components of the staining device include, for example, a plurality of containers which are filled, or at least fillable, with process media for processing the samples. Moreover, the components may include an oven for drying the samples, or cuvettes, in particular heated cuvettes. The positions of the containers and/or of the oven can be determined by means of the sensor device, so that the sample baskets can be precisely placed into the containers containing the process media, or into the oven, during subsequent operation. 
     A third aspect of the present invention resides in a method for calibrating the staining device. For this purpose, the sensor device is attached to the transport device of the staining device. The transport device moves the sensor device to different locations within the staining device. The sensor device is used to detect where predetermined components of the staining device are located within the staining device. 
     In a specific embodiment, the transport device moves the sensor device over and/or through the staining device in such a manner that the sensor lever of the sensor device successively hits the different components and/or hits the same components repeatedly, thereby influencing an output signal of the sensor unit. In particular, the sensor unit detects the current position of the sensor lever, which changes upon contact with the components, or the force exerted on the sensor lever upon contact with the components. The arrangement of the components within the staining device is determined based on the output signal of the sensor unit and the current position of the sensor device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the present invention are described in more detail below with reference to the schematic drawings, in which: 
         FIG. 1  is a side view of a staining device; 
         FIG. 2  is a perspective view showing a sensor device and a sample basket of the staining device; 
         FIG. 3  is a plan view of the staining device; 
         FIG. 4  is a view of the staining device shown in  FIG. 3 , illustrating the path of movement of a lifting device of the staining device; and 
         FIG. 5  is a flow chart of a program for calibrating the staining device. 
     
    
    
     Elements having the same design or function are identified by the same reference numerals throughout the figures. 
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a schematic side view of a staining device  20 . Staining device  20  is suitable for staining samples, in particular tissue samples, for subsequent examination under a microscope. Staining device  20  includes a transport device  22  having a lifting device  24 . Attached to lifting device  24  is a sample basket  26 , which is partially located in a first container  30 . Besides first container  30 , staining device  20  includes additional components or modules, in particular an oven  28  and a second container  32 , a third container  34 , a fourth container  36 , and a fifth container  38 . Containers  30 ,  32 ,  34 ,  36 ,  38  are filled with different process media for cleaning and staining the samples in sample basket  26 . Sample basket  26  can be successively immersed in oven  28  and/or in containers  30 ,  32 ,  34 ,  36 ,  38  by means of transport device  22 , in particular by lifting device  24 . 
       FIG. 2  shows, by way of example, one of containers  30 ,  32 ,  34 ,  36 ,  38 , which has a handle  40  secured thereto. By means of handle  40 , sample basket  26  can be lifted, removed from or placed into staining device  20 . A holder  42  is mounted to lifting device  24  (not shown in  FIG. 2 ). Holder  42  is fixedly connected to a coupling member  44 . Coupling member  44  is configured such that sample basket  26  can be attached thereto. To this end, coupling member  44  includes, for example, one or more latch means which may cooperate with corresponding mating latch means on the sample basket. However, a sensor device  45  is attached to coupling member  44  in place of sample basket  26 . 
     Sensor device  45  includes a sensor unit  48  and a coupling unit  46  for attachment to coupling member  44  of transport device  22 . Coupling unit  46  includes means, such as latch means, by which coupling unit  46  can be fixedly secured to coupling member  44 . Sensor unit  48  includes a sensor lever  50 , which is fixedly secured to a base element  49  of sensor unit  48 . Sensor unit  48  further includes a sensor circuit  47  by means of which a position of sensor lever  50  or a force acting on sensor lever  50  can be detected. As an alternative to sensor lever  50 , which allows tactile sensing of the position of the components, it is also possible to provide a sensor which operates using optical or acoustic sensing techniques. For example, an optical sensor unit may be provided, for example, in the form of a laser and a photosensitive sensor element for detecting the laser beam reflected from the components. An acoustic sensor unit may be provided, for example, in the form of an ultrasound source and a piezoelectric ceramic or plastic material for detecting the sound waves reflected by the components of the staining device. 
       FIG. 3  shows a plan view of a staining device  20 , showing that a sixth container  60 , a seventh container  62 , an empty receiving space  64  for a further container, an eighth container  66  and a ninth container  68  are arranged in staining device  20 . Containers  30  through  38  and  60  through  68  are placed into staining device  20  during assembly thereof. In order to facilitate emptying, cleaning, and servicing of containers  30  through  38  and  60  through  68 , said containers can be removed from and replaced into staining device  20 . To this end, staining device  20  has provided therein a plurality of receiving spaces; specifically, one receiving space for each of containers  30  through  38  and  60  through  68 . An empty receiving space  64  is not occupied. Further, ninth container  68  is somewhat displaced toward fifth container  38  within staining device  20 . Fourth container  36  is slightly rotated out of position within staining device  20 , and second container  32  is somewhat displaced toward third container  34 . The irregular arrangement of containers  30  through  38  and  60  through  68  within staining device  20  may be due, for example, to manufacturing tolerances, particularly of the receiving spaces, or to the negligence of a user. 
     Transport device  22 , its attachment and suspension arrangement and/or its lifting device  24 , may also have manufacturing tolerances, so that transport devices  22  of different staining devices of identical design may be located at slightly different positions within staining device  20 . Moreover, the motion amplitudes of different transport devices  22  of identical design may differ for identical control inputs. 
     In order for staining device  20  to function properly despite inaccurately positioned containers  30  through  38  and  60  through  68  and/or despite the manufacturing tolerances, the staining device is calibrated with the aid of sensor device  45 . To this end, lifting device  24  carrying sensor device  45  is moved over the components of staining device  20  along a path  70  shown in  FIG. 4 , and specifically in such a way that sensor lever  50  of sensor device  45  repeatedly hits the individual components. Alternatively, sensor device  45  may also be moved along a different path through staining device  20 . 
       FIG. 5  shows a flow chart of a program for calibrating staining device  20 . The program is preferably started in a step S 2 , in which variables are initialized if necessary. 
     In a step S 4 , sensor device  45  is attached to transport device  22 , specifically to lifting device  24 . 
     In a step S 6 , lifting device  24  is moved through staining device  20  along the predetermined path  70 , and specifically in such a way that sensor lever  50  hits the individual components of staining device  20 . During this process, sensor device  45  can be moved vertically to some extent, so that once it has hit one of the components, it may be lifted, moved further, and lowered again in order for it to hit the next component. 
     The exact position of lifting device  24 , and thus that of sensor device  45 , can be detected at all times with the aid of calibration unit  23 . Further, the exact positions of sensor device  45  on lifting device  24  and of sensor lever  50  on sensor device  45  are known. Thus, based on an output signal of sensor unit  48  of sensor device  45 , calibration unit  23  can precisely determine where sensor lever  50  hits the components of staining device  20 , so that the exact positions of the components within staining device  20  can be determined as a function of the output signal of sensor unit  48  and the current position of sensor device  45 . 
     In a step S 8 , the output signals of sensor unit  48  are stored or, when the output signal exhibits an amplitude which indicates that sensor lever  50  has hit [a component], the current position of sensor lever  50 , and thus that of the component hit, are stored. Each time sensor lever  50  hits one of the components, the coordinates at which sensor lever  50  is located at the time of contact are stored. 
     In a step S 10 , the positions of the components are determined. In other words, the exact positions and/or orientations of the components are determined based on the locations where sensor lever  50  has hit the components and based on the known dimensions of the components. 
     In a step S 12 , the determined positions are stored, so that sample basket or baskets  26  can be precisely moved to the individual components of staining device  20  during the operation of staining device  20 . 
     In a step S 14 , the program for calibrating staining device  20  may be terminated. Preferably, the program is executed each time a component of staining device  20  has been replaced or repaired. 
     The present invention is not limited to the exemplary embodiments described herein. For example, staining device  20  may contain a greater or lesser number of components, the positions of which are detectable with the aid of sensor device  45 . Further, a plurality of sample baskets  26  may be moved simultaneously within staining device  20 , or sensor device  45  may be moved simultaneously with a sample basket  26 , for example by means of an additional lifting device  24 . 
     LIST OF REFERENCE NUMERALS 
     
         
         
           
               20  staining device 
               22  transport device 
               23  calibration unit 
               24  lifting device 
               26  sample basket 
               28  oven 
               30  first container 
               32  second container 
               34  third container 
               36  fourth container 
               38  fifth container 
               40  handle 
               42  holder 
               44  coupling member 
               45  sensor device 
               46  coupling unit 
               47  sensor circuit 
               48  sensor unit 
               49  base element 
               50  sensor lever 
               60  sixth container 
               62  seventh container 
               64  receiving space 
               66  eighth container 
               68  ninth container 
               70  path of movement 
             S 2 -S 14  steps two through fourteen