Abstract:
A slide stainer and a method for operating the slide carrier is disclosed. The slide stainer includes a slide carrier that carries one or more laboratory slides; a vessel that is capable of carrying fluid for staining the laboratory slides and that is sized to accommodate the laboratory slides; a slide transporter that moves the slide carrier into and out of the vessel; and a spring loaded pin that engages with a surface of the slide stainer to limit free-fall translation of the slide carrier in an event of a power loss. Additionally, during an agitation phase of a slide staining process, the slide transporter is configured to translate the slide carrier in an upward direction to a pre-determined height that is set by a user of the slide stainer, and the slide transporter translates the slide carrier in a downward direction back into the vessel.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to an apparatus for staining laboratory slides. 
       BACKGROUND OF THE INVENTION 
       [0002]    Laboratories routinely stain biological tissue specimens deposited on laboratory slides for subsequent pathologic examination to detect and/or monitor tissue abnormalities. Automated tissue staining systems allow batch staining of large numbers of slides containing tissue specimens for subsequent examination. In the course of a staining process, the tissue specimens are exposed to a series of well-defined processing steps that ultimately produces a properly stained specimen for examination. Automation of the staining process significantly reduces the time required to stain tissue specimens, reduces the incidence of human error and allows processing parameters to be altered in an efficient manner. Improvements to slide staining systems are continually sought in the interest of reliability, performance, speed and cost. 
       SUMMARY OF THE INVENTION 
       [0003]    According to one aspect of the invention, a slide stainer assembly is disclosed. The slide stainer includes a slide carrier that is configured to carry one or more laboratory slides; a vessel that is capable of carrying fluid for staining the one or more laboratory slides and sized to accommodate the one or more laboratory slides; a slide transporter that is configured to move the slide carrier into and out of the vessel; and a spring loaded pin that engages with a surface of the slide stainer to limit free-fall vertical translation of the slide carrier in an event of a power loss. 
         [0004]    According to another aspect of the invention, a method of operating a slide stainer is disclosed. The method includes the steps of: translating a slide carrier, which is configured to carry one or more laboratory slides, in a vertical direction with respect to a vessel that is capable of carrying fluid for staining the one or more laboratory slides; and engaging a spring loaded pin with a surface of the slide stainer to limit free fall vertical translation of the slide carrier in an event of a power loss. 
         [0005]    According to another aspect of the invention, a slide stainer includes a slide carrier that is configured to carry one or more laboratory slides; a vessel that is capable of carrying fluid for staining the one or more laboratory slides and sized to accommodate the one or more laboratory slides; a user interface for entering instructions to operate the slide stainer; and a slide transporter that is configured to move the slide carrier in and out of the vessel, and, during an agitation phase of a slide staining process, the slide transporter is configured to repeatedly (i) translate the slide carrier in an upward direction out of the vessel to a pre-determined height that is set by a user using the user interface, and (ii) translate the slide carrier in a downward direction back into the vessel. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The invention is best understood from the following detailed description when read in connection with the accompanying drawings. It is emphasized that, according to common practice, the various features of the drawings are shown schematically and may not be to scale. Included in the drawings are the following figures: 
           [0007]      FIG. 1  depicts a perspective view of a slide stainer according to one exemplary embodiment of the invention wherein a portion of the housing cover is shown in an open configuration to reveal the interior compartment of the slide stainer. 
           [0008]      FIG. 2A  depicts a top plan view of the slide stainer of  FIG. 1  (housing cover omitted in its entirety), wherein the moveable arm is depicted in one radial position. 
           [0009]      FIG. 2B  depicts a top plan view of the slide stainer of  FIG. 1  (housing cover omitted in its entirety), wherein the moveable arm is depicted in another radial position. 
           [0010]      FIG. 3A  depicts a side elevation view of the slide stainer of  FIG. 1  (housing cover omitted in its entirety and part of the housing is cut-away), wherein the moveable arm is depicted in a raised position. 
           [0011]      FIG. 3B  depicts a side elevation view of the slide stainer of  FIG. 1  (housing cover omitted in its entirety and part of the housing is cut-away), wherein the moveable arm is depicted in a lowered position. 
           [0012]      FIG. 4  depicts a perspective view of the slide transporter of the slide stainer of  FIG. 1 . 
           [0013]      FIG. 5  depicts another perspective view of the slide transporter of  FIG. 4 , with the top plate of the slide transporter omitted to reveal the mechanism that accomplishes rotation of the moveable arm. 
           [0014]      FIG. 6  is a flow chart depicting an exemplary method for operating the slide stainer. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    The invention will next be illustrated with reference to the figures. Such figures are intended to be illustrative rather than limiting and are included herewith to facilitate explanation of the present invention. In the figures, like item numbers refer to like elements throughout. When a plurality of similar elements are present, a single reference numeral may be assigned to the plurality of similar elements with a small letter designation referring to specific elements. When referring to the elements collectively or to a non-specific element, the small letter designation may be omitted. 
         [0016]      FIG. 1  depicts a perspective view of a slide stainer  10  according to one exemplary embodiment of the invention. In that figure, a portion of the two-piece top cover  13  of the housing  11  of the slide stainer  10  is shown in an open configuration (i.e., one piece of the two-piece cover  13  is rotated) to reveal the interior compartment  15  of the slide stainer  10 . 
         [0017]    The slide stainer  10  includes twenty-two (22) slide processing stations  12   a  through  12   v , one (1) slide unloading station  12   w , and one (1) slide loading station  12   x . Each slide processing station  12   a - 12   v  in the illustrated embodiment includes a vessel  14  that may be filled with either a reagent for staining the slides of a single slide carrier assembly  20 , or a rinsing medium, such as water, for rinsing the slides of a single slide carrier assembly  20 . The slide unloading station  12   w  and the slide loading station  12   x  each includes a vessel  14  that is configured to hold a single slide carrier assembly  20 . 
         [0018]    It should be understood that any station  12  may be a staining station, a heating/drying station, a rinsing station or other type of station. Accordingly, the slide stainer  10  is not limited to the particular configuration shown. Moreover, the vessels  14  associated with stations  12   a - 12   x  may be removable from the housing  11  of the slide stainer  10 , such that the stations  12  within the slide stainer  10  may be reconfigured to the operator&#39;s requirements. 
         [0019]    As best shown in  FIG. 3A , each slide carrier assembly  20  includes a slide carrier  22  and a plurality of laboratory slides  24  releasably mounted to slide carrier  22 . A laboratory specimen (not shown) is mounted to each laboratory slide  24 . Two (2) slide carrier assemblies  20   a  and  20   b  are illustrated in the exemplary embodiment depicted in  FIGS. 1-2B . It will be understood by those skilled in the art from the description herein that the slide stainer  10  may interface with as many as twenty-four (24) slide carrier assemblies  20 . 
         [0020]    The slide stainer  10  includes an electronics control unit (ECU)  25  including a processor and controller (see  FIG. 5 ). The ECU  25  is connected to all of the motors, solenoids and sensors that are described herein. The slide stainer  10  also includes a user interface including a user display  26  and a user keypad  27  for programming the ECU  25  of the slide stainer  10 . The user interface is integrated with the housing  11  of the slide stainer  10 . 
         [0021]    The slide stainer  10  includes a slide transporter  18  that is configured to translate and rotate in order to transport a slide carrier assembly  20  from one station  12  to another station  12 . The slide transporter  18  moves the slide carrier assemblies  20  in an upward direction and out of their respective vessels  14 , then rotates the slide carrier assemblies  20  in either a clockwise or counterclockwise direction toward the adjacent vessels  14 , and then moves the slide carrier assemblies  20  in a downward direction to position the slide carrier assemblies  20  into the adjacent vessels  14 . 
         [0022]    The slide transporter  18  includes a moveable arm  19  that is configured to rotate in both a clockwise and a counterclockwise direction (compare  FIGS. 2A and 2B ).  FIG. 2A  depicts a top plan view of the slide stainer of  FIG. 1  (top cover  13  omitted in its entirety), wherein the moveable arm  19  is positioned above station  12   a .  FIG. 2B  depicts the moveable arm  19  of the slide transporter  18  rotated in a clockwise direction with respect to its position in  FIG. 2A  such that the moveable arm  19  is positioned above station  12   c.    
         [0023]    The slide transporter  18  is also configured to translate the moveable arm  19  in a vertical direction (compare  FIGS. 3A and 3B ).  FIG. 3A  depicts the moveable arm  19  in a raised position, where the distance between the arm  19  and the top surface of the stations  20  is designated by height h 0 . At height h 0 , the slide carrier assembly  20   b  that is coupled to the moveable arm  19  is positioned above the stations  12  such that the carrier assembly  20   b  is not positioned in a vessel  14  of a station  12 .  FIG. 3B  depicts the moveable arm  19  in a lowered position, where the distance between the arm  19  and the top surface of the stations  20  is designated by height h 1 . At height h 1 , the slide carrier assembly  20   b  that is coupled to the moveable arm  19  is positioned in a vessel  14  of a station  12 . 
         [0024]    The slide transporter  18  can be programmed to maintain the moveable arm  19  at any desired height between height h 1  and height h 0 . An operator of the slide stainer  10  can select from multiple heights for the moveable arm  19  during an agitation phase of the slide staining process. More particularly, during the agitation phase of the slide staining process, the slide stainer  10  moves the arm  19  up and down to repeatedly dunk the slides  24  in their respective vessels  14 , thereby agitating the reagent in the respective vessels  14 . The operator may change the vertical height ‘h’ at which the arm  19  travels to tailor the intensity of the agitation phase. 
         [0025]    The moveable arm  19  includes means for releasably carrying a single slide carrier assembly  20 . The releasable slide carrying means of the moveable arm  19  may be brackets  23   a  (see  FIG. 3A ) having recesses that are configured to releasably engage posts  23   b  that extend from the sides of the slide carrier assembly  20 . The releasably carrying means may also be in the form of a slot, fastener, surface, recess, protrusion, magnet, or pin, for example. 
         [0026]    Referring now to the basic operation of the slide stainer  10 , an operator of the slide stainer  10  manually loads a slide carrier assembly  20  into the load station  12   x . The slide transporter  18  sequentially transports the slide carrier assembly  20  from the load station  12   x  to one or more stations  12   a - 12   w  under the control of the ECU  25 . The operator then manually removes a processed slide carrier assembly  20  from the unload station  12   w.    
         [0027]    The operation of the slide transporter  18  will now be described in greater detail.  FIG. 4  depicts a perspective view of the slide transporter  18  of the slide stainer  10  of  FIG. 1 .  FIG. 5  depicts another perspective view of the slide transporter  18  of  FIG. 4 , with the top plate  29  omitted. As will be described in greater detail hereinafter, an arrangement of motors, gears, belts and sensors are configured for rotating and translating the moveable arm  19  to any desired position. 
         [0028]    As best shown in  FIG. 4 , to accomplish vertical translation of the moveable arm  19  along vertical axis ‘A,’ the slide transporter  18  includes a motor  30  having a rotatable output shaft  30 ′. A belt pulley  31  is connected to the rotatable output shaft  30 ′ of the motor  30 . A belt  32  is attached to the belt pulley  31  and another belt pulley  33 . A bracket  34  is attached to the belt  32  by a fastener  41  such that the bracket  34  moves along with the belt  32 . The bracket  34  is indirectly fixed to the moveable arm  19  such that the moveable arm  19  translates along with the bracket  34 . 
         [0029]    More particularly, the bracket  34  is fixedly attached to another bracket  46 , and the bracket  46  is fixedly attached to a lower plate  42 . The lower plate  42  is fixedly attached to the top plate  29 . The arm  19  is fixedly attached to the bottom side of the top plate  29  by fasteners  40 . Thus, the brackets  34  and  46 , the plates  42  and  29  and the arm  19  all simultaneously translate together in a vertical direction (i.e., along axis A). The plates  29  and  42  translate along the length of a fixed post  43  (compare  FIGS. 3A and 3B ). 
         [0030]    In operation, rotation of the output shaft  30 ′ of the motor  30  causes rotation of the belt pulley  31 , which causes rotation of the belt  32 . The bracket  34  translates in a vertical direction as the belt  32  rotates. The moveable arm  19  translates in a vertical direction along with the bracket  34 . Thus, rotation of the output shaft  30 ′ of the motor  30  causes translation of the moveable arm  19  in a vertical direction. The output shaft  30 ′ can rotate in a counterclockwise direction (taken from the perspective of  FIG. 4 ) to raise the arm  19 , or the output shaft  30 ′ can rotate in a counterclockwise direction to lower the arm  19 . 
         [0031]    Although not shown, a sensor monitors the movement of the output shaft  30 ′, the belt  32 , the arm  19 , the bracket  34  and/or the bracket  46  and transmits a corresponding signal to the ECU  25 . The sensor may be a hall sensor or a rotary encoder. The ECU  25  monitors that signal to determine when the moveable arm  19  has reached its intended vertical position. Once the arm  19  has reached its intended vertical position, the ECU  25  deactivates the motor  30 . Those skilled in the art will recognize that numerous ways exist to monitor the vertical position of the arm  19 . 
         [0032]    As best shown in  FIGS. 4 and 5 , to accomplish rotation of the moveable arm  19  about the axis of rotation ‘A,’ the slide transporter  18  includes a motor  35  having a rotatable output shaft  35 ′. A belt pulley  36  is connected to the rotatable output shaft  35 ′ of the motor  35 . A belt  37  is attached to the belt pulley  36  and another belt pulley  38 . The belt pulley  38  is fixedly attached to the top plate  29  (see  FIG. 4 ). The top plate  29  is fixedly attached to the arm  19  by fasteners  40  (see  FIG. 4 ). 
         [0033]    In operation, rotation of the output shaft  35 ′ of the motor  35  causes rotation of the belt pulley  36 , which causes rotation of the belt  37 , which causes rotation of the belt pulley  38 , which causes rotation of the top plate  29 , which causes rotation of the moveable arm  19 . Thus, rotation of the output shaft  35 ′ of the motor  35  ultimately causes rotation of the moveable arm  19 . The output shaft  35 ′ can rotate in either a counterclockwise direction to rotate the arm  19  in a counterclockwise direction, or rotate in a clockwise direction to rotate the arm  19  in a clockwise direction. 
         [0034]    A sensor  45 , such as a hall sensor, an optical sensor, or a rotary encoder, for example, monitors the movement of the belt pulley  38  and transmits a corresponding signal to the ECU  25 . The ECU  25  monitors that signal to determine when the moveable arm  19  has reached its intended rotational position. Once the arm  19  has reached its intended rotational position, the ECU  25  deactivates the motor  35 . Those skilled in the art will recognize that numerous ways exist to monitor the rotational position of the arm  19 . 
         [0035]    Referring now to  FIGS. 3A ,  3 B and  4 , an elongated slot  48  is formed at the top end of the bracket  46 , and a recess  50  is formed at the bottom end of the bracket  46 . The recess  50  extends between a top edge  50 ′ and a bottom edge  51  of the bracket  46 . As will be described later, the recess  50  interacts with a pin  52 . 
         [0036]    The pin  52  includes an internal compression spring that biases the pin  52  in an outward direction toward the bracket  46 . The pin  52  is also actuated by a solenoid  54  that cooperates with the pin  52 . The solenoid  54  is, however, an optional component of the slide stainer  10 . Upon activating the solenoid  54 , the magnetic field produced by the solenoid  54  draws the spring-loaded pin  52  inward (i.e., toward the solenoid  54  and away from the bracket  46 ) to a retracted position against the bias of its internal compression spring. Once deactivated or in the event of a power loss, the magnetic field is severed and the compression spring of the spring-loaded pin  52  biases the pin  52  outward (i.e., away from the solenoid  54  and toward the bracket  46 ) to an extended position. 
         [0037]    In operation, when the moveable arm  19  is translated in a downward vertical direction and approaches height h 1 , the solenoid  54  may be deactivated to conserve power, which causes the pin  52  to spring forward toward the bracket  46  and through the elongated slot  48  under the force of the compression spring to the extended position. 
         [0038]    When the moveable arm  19  is translated in an upward vertical direction and approaches height h 0  (see  FIG. 3A ), the solenoid  54  is deactivated thereby releasing the pin  52  to both conserve power and prepare for a potential power loss. Consequently, the pin  52  springs forward under the force of the compression spring (not shown) toward the bracket  46  to the extended position. The extended pin  52  either approaches or bears upon the top edge  50 ′ of the recess  50 . Thus, in the event of a power loss, the engagement between the extended pin  52  and the top edge  50 ′ of the recess  50  prevents the arm  19  and all of the components that are either directly or indirectly connected to the arm  19  from free-falling in a downward vertical direction under gravity. 
         [0039]    While some conventional slide stainers employ a leadscrew to accomplish safe vertical translation of the slide carriers, such leadscrews can be expensive and may require significant torque from a motor. This invention offers a cost-effective way to accomplish safe vertical translation of the slide carriers while preventing damage to the slide stainer in the event of a power outage. 
         [0040]      FIG. 6  is a flow chart depicting an exemplary method of operating the slide stainer  10 . At step  100 , the solenoid  54  is activated to retract the spring-loaded pin  52  thereby disengaging the pin  52 . At step  102 , the slide carrier  20  is translated in a vertical direction with respect to the vessel  14 . In the course of step  102 , the belt  32  that is indirectly attached to the slide carrier  20  translates the slide carrier  20  in a vertical direction, as described previously. 
         [0041]    At step  104 , the solenoid  54  that cooperates with the spring-loaded pin  52  is deactivated causing the spring-loaded pin  52  to extend under its own spring force into the recess  50  of the bracket  46 . In an event of a power loss, the spring loaded pin  52  would ultimately engage with a surface (e.g., edge  50 ′) of the slide stainer  10  to limit free fall vertical translation of the slide carrier  20 . 
         [0042]    While exemplary embodiments of the invention have been shown and described herein, it will be understood that such embodiments are provided by way of example only. Numerous variations, changes and substitutions will occur to those skilled in the art without departing from the spirit of the invention. For example, the spring-loaded pin  52  may be positioned on the bracket  46  (or other translating component of the slide stainer  10 ) and the slot  46  and/or the recess  50  may be defined on a fixed component of the slide stainer  10  to achieve the same result. Accordingly, it is intended that the appended claims cover all such variations as fall within the spirit and scope of the invention.