Abstract:
The present invention relates to a sealing device for closing an introduction aperture, the sealing device comprising a fixed support and a shutter mounted movably in translation relative to the support between an extended position and a final retracted position, wherein the sealing device is in a final retracted configuration and wherein the shutter closes introduction aperture. The device includes locking means for preventing any movement of the shutter when it is in the final retracted position. The sealing device further comprises an intermediate retracted configuration, wherein the shutter is at least partly retracted. The sealing device also comprises motion guiding means for guiding the movement of the shutter and designed so that the extension of the shutter is required to move the shutter from the intermediate retracted position to the final retracted position.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a sealing device for use in a cartridge. 
     BACKGROUND OF THE INVENTION 
     Advanced biotechnology research is nowadays focusing on multiplexed biological assays, which require high reproducibility and reliability. Recently, a cartridge for automated medical diagnostics, as described in WO 2007/004103, has proved to be a promising yet simple and practical solution. Such a cartridge usually contains all necessary equipment and reagents to run said diagnostic assays on a biological sample. The equipment in particular comprises various reagent compartments and a preparation chamber wherein a sample to be analyzed can be introduced and contacted with said reagents contained in the compartments. To allow the introduction of the biological sample in the preparation chamber, the latter usually comprises an introduction aperture through which the biological sample can be introduced by the user via a swab. 
     Preferably, the introduction aperture must be sealed once the biological sample has been introduced in the preparation chamber in order to avoid leakages and/or contaminations. Usually, a closure device is designated to insure a tamper-proof sealing of the preparation chamber during and/or after the diagnostic assays, meaning that the preparation chamber cannot be reopened by the user under normal use conditions. Thus, this prevents any direct contamination of the user or of the biological material contained in the preparation chamber and vice-versa. A cartridge that is sealed in such a tamper-proof manner will also ensure that the introduction opening will not be untimely reopened while the assay is running, which would invalidate the result of the biological assays due to possible contaminations of the preparation chamber. 
     A typical closure device existing in the art comprises a support and a closure element mounted movably in translation relative to the support between an extended position and a retracted position wherein the closure device is in a retracted configuration and wherein the closure element closes said aperture. The typical closure device further includes locking means for preventing movement of, the closure element once the latter is placed in the retracted position. 
     A cartridge equipped with this closure device presents however disadvantages: 
     The classical closure device may close untimely before the introduction of a biological sample which could render the cartridge unusable. One will understand that a user may easily and inadvertently close the introduction aperture by simply pushing the closure element prior to introducing the biological sample. The untimely closure may also occur during the packaging and/or transport of the cartridge. 
     The present invention aims to remedy all or part of the disadvantages mentioned above. 
     SUMMARY OF THE INVENTION 
     The present invention fulfills these objectives and provides a sealing device for closing an introduction aperture, the sealing device comprising a fixed support and a shutter mounted movably in translation relative to the support between an extended position and a final retracted position, wherein when the shutter is in said final retracted position the sealing device is in a final retracted configuration and the shutter closes said introduction aperture, the device further including locking means for preventing any movement of the shutter when it is in the final retracted position, the sealing device being characterized in that it comprises an intermediate retracted configuration, wherein the shutter is at least partly retracted when the sealing device is in said intermediate retracted position, the sealing device being further characterized in that it comprises motion guiding means for guiding the movement of the shutter and designated so that the extension of the shutter is required to move the shutter from, the intermediate retracted position to the final retracted position 
     Thus, the sealing device according to the present invention comprises an intermediate retracted position and motion guiding means to prevent the untimely closure. It is advantageous to store or carry a cartridge equipped with the sealing device according to the invention placed in its intermediate configuration. Said motion guiding means prevent the move of the shutter from the intermediate retracted position to the final retracted position by a direct thrust. The motion guiding means are such that they impose the shutter to be moved from the intermediate retracted position to the final retracted position by a motion that comprises its extension from the intermediate retracted position to an extended position. Then, once extended, the shutter can be retracted towards the final retracted position. Thus, a user cannot move inadvertently the shutter from the intermediate retracted position to the final retracted position by a simple pushing motion on the shutter. The fact that the shutter must first be moved to an extended position before being retracted implies an intentional action of the user. 
     According to an embodiment of the present invention, the sealing device comprises switching means designed to shunt the movement of the shutter, when the shutter is being extended, so as to prevent the return of the shutter in the intermediate configuration. Advantageously, the switching means are designed to prevent the return in the intermediate retracted position when the shutter has been extended beyond a switching position. The switching means prevent the user from pushing the shutter back into the intermediate retracted position, when it has been extended beyond the switching position. Thus, the user does not have to worry about whether the shutter has been pushed back in the final retracted position and not in the first retracted position. 
     According to an embodiment of the present invention, the sealing device further comprises retaining means designed to prevent the extension of the shutter beyond the extended position. 
     In a preferred embodiment, the retaining means comprise a second limit stop. The retaining means prevent the separation of the shutter from the fixed support. The limit stop allows maintaining the shutter and the support assembled together and thus avoids the operator having to reinsert the extended shutter in the fixed support. 
     According to an embodiment of the present invention, the motion guiding means comprise at least a guide-pin, at least a deformable tongue and at least a guide groove cooperating together. Advantageously, the switching means comprise a deformable tongue and a first guide groove, said first guide groove being designated to cause an elastic deformation of said tongue in a third switching portion of said first guide groove comprising said switching position. 
     According to a possibility of the invention the sealing device comprises cutting means designed to cut a swab inserted in the introduction aperture when the shutter is moved towards the final retracted position. Thus, the cutting means allow the user to work safely and minimize the contamination of the swab comprising the sample, as the cutting means cut automatically the swab. Advantageously, the cutting means comprise at least a cutting edge mounted in a cutting slot and lying in the plane of the second plate of the shutter. 
     According to an embodiment of the present invention, the shutter and/or the support comprise or are made of polycarbonate. 
     According to an embodiment of the present invention, the shutter closes the introduction aperture when the sealing device is in the intermediate retracted configuration. Thus, the shutter ensure optimal storage conditions of the cartridge and in particular helps maintain a conditioned atmosphere during the storage and prevents the introduction of contaminants in the cartridge before the introduction of the biological sample. 
     The present invention also relates to a cartridge for performing medical assays comprising a sealing device according to the present invention. 
     The present invention is further illustrated by the following detailed description set forth in view of the appended drawings, which represent an exemplary and explanatory embodiment of a sealing device not restrictive of the invention, wherein: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a bottom perspective view of the fixed support according to the present invention; 
         FIG. 2  illustrates a top perspective view of the closure device according to the present invention; 
         FIG. 3  illustrates a partial bottom perspective view of the sealing device in the intermediate retracted configuration; 
         FIG. 4  illustrates a view similar to the  FIG. 3  wherein the sealing device is in the extended configuration; 
         FIG. 5  illustrates a view similar to the  FIG. 3  wherein the sealing device is in the final retracted configuration; 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In order to avoid leakages and contaminations, a sealing device according to the present invention is designed to close an introduction aperture  1  provided in a diagnostic cartridge for introducing a biological sample. The sealing device comprises a fixed support  2 , shown in the  FIG. 1 , and a shutter  3 , shown in the  FIG. 2 , designed to be movably mounted in translation on the fixed support  2 . The sealing device further comprises motion guiding means, designed to guide the movement of the shutter  3  on the fixed support  2  when the shutter  3  is being extended. 
     The fixed support  2 , illustrated in the  FIG. 1 , comprises a first plate  4  having a substantially rectangular shape and delineating the introduction aperture  1 . The first plate  4  is provided with two cylindrical guide-pins  5  at one of its ends that corresponds to the width of the plate  4 . The two guide-pins  5  are symmetrically located with respect to the longitudinal axis of the first plate  4  and extend in a direction substantially perpendicular to the plane of the first plate  4 , so as to protrude from a first contacting side  6  of said first plate  4 . The guide-pins  5  are respectively located at the end of two tongues  7  which are elastically deformable. Each tongue  7  is positioned in a slot  8  of the first plate  4  and extends in a direction substantially parallel to the longitudinal axis A of said first plate  4 . Advantageously the first plate  4  comprises at least two tips  9  elastically deformable located on the edge of the insertion aperture  1 , said tips  9  defining a gap  10  between them adapted to pinch a swab. 
     The shutter  3 , shown in the  FIG. 2 , comprises a second plate  11  substantially rectangular and designed to cover totally or partially the insertion aperture  1 , depending of the relative positions of the shutter  3  and the fixed support  2 . The shutter  3  further comprises a prehension handle  12  substantially rectangular in shape and which length corresponds substantially to the width of the second plate  11 . The prehension handle  12  extends substantially perpendicularly from one of the edges defining the width of the second plate  11 , and is intended to be grasped by the user and is intended to enable the user to move the shutter  3 . The second plate  11  of the shutter  3  comprises on a second contacting side  13  two pairs of guide grooves, each pair comprising a first guide groove  14  and a second guide groove  15 . Each first and second guide groove  14 ,  15  extends in a direction substantially parallel to the longitudinal axis B, shown in  FIG. 2 , of the second plate  11  and is disposed along an edge  16  forming the length of the shutter  3 . Each first guide groove  14  extends between a first limit stop  17 , located near the prehension handle  12 , and a switching position  18  distant from the prehension handle  12 . The first guide groove  14  comprises three portions  19 ,  20 ,  21  which extend successively from the first limit stop  17  to the switching position  18 . The said first portion  19  comprises at one of its end the first limit stop  17  and is curved in such a way to form a boss  22 . The second portion  20 , substantially straight, is followed by a third switching portion  21  extending to the switching position  18 . The third switching portion  21  is curved towards the longitudinal axis B of the second plate  11 . The third switching portion  21  opens onto a linking area  23 . The linking area  23  comprises advantageously retaining means formed by a second limit stop  24  arranged facing the switching position  18 . Each second guide groove  15  comprises three parts  25 ,  26 ,  27  of guide groove which extend successively from the switching position  18  towards the prehension handle  12 . The first part  25  is curved toward the prehension handle  12  and towards the nearest edge forming the length of the second plate  11 . The second part  26  extends the first part  25  and is substantially straight, extending between the nearest edge  16  of the second plate  11  and the first guide groove  14 . The second portion  20  and the second part  26  of a given guide groove pair, are substantially parallel to each other. The third part  27  forms an extension of the second part  26  and extends perpendicularly to the longitudinal axis B of the second plate  11 , between the first limit stop  17  of the first guide groove  14  and the prehension handle  12 . Walls of the third part  27  form a second and third limit stop  28 ,  29 . Advantageously, the shutter  3  further comprises cutting means. The cutting means comprises a cutting edge  30  disposed in a cutting slot  31  located at the opposite end of the prehension handle  12 . The cutting edge  30  lies in the plane of the second plate  11  of the shutter  3 . 
     The motion guiding means of the sealing device comprise the cylindrical guide-pins  5 , the tongues  7  and the first and second guide grooves  14 ,  15 . 
     The motion guiding means are designed so that the shutter  3  is moved along a first path between the intermediate retracted position and the extended position and along a second path between the extended position and the final retracted position. The switching means induce an elastic deformation of at least a part of the motion guiding means during the switching from the first path to the second path. 
     The shutter  3  and the support  2  are made of polycarbonate. 
     In working order, the shutter  3  is mounted on the fixed support  2  so that the first contacting side  6  of the fixed support  2  is positioned facing the second contacting side  13  of the shutter  3 , so that each guide-pin  5  is inserted in a first guide groove  14 . When the guide-pins  5  are in contact with a first limit stop  17 , the sealing device is in an intermediate retracted configuration as shown in the  FIG. 3 . The displacement of the shutter  3  by the operator induces the movement of each guide-pin  5  in a first guide groove  14  and/or in a second guide groove  15 . Each first limit stop  17  blocks guide-pins  5  and prevents the operator from pushing the shutter  3  in the direction opposite to the direction indicated by the arrow C shown in the  FIGS. 3 to 5 . From the intermediate retracted position and in order to open the insertion aperture  1 , the operator has to pull the shutter  3  to move the guide-pins  5  along the first portion  19  of the guide groove  14 , in the direction indicated by the arrow C. The boss  22  is designed to prevent the movement of the guide-pins  5  without the intervention of the operator. Indeed, the orientation and the form of the boss  22  as well as the form and orientation of the tongues  7  are chosen in order to require the deformation of the tongues  7 , therefore requiring the operator to increase its effort while pulling the shutter  3  from the intermediate retracted position. When the operator continues to pull the shutter  3  in the direction indicated by the arrow C, the guide-pins  5  come out into the second portion  20  of the first guide groove  14 . The operator, when continuing to pull the shutter  3 , further induces the displacement of the guide-pins  5  from the second portion  20  to the third switching portion  21 . The form of the third switching portion  21  and the movement of the guide-pins  5  in the third switching portion  21  bring the guide-pins  5  closer to the longitudinal axis A of the plate  11  and induce a deformation of the tongues  7 , when the shutter  3  is displaced and until the guide-pins  5  arrive in the switching position  18 . The movement of the guide-pins  5  in the first portion  19 , in the second portion  20  and in the third switching position  18  is possible in the direction indicated by the arrow C or in the in the opposite direction. When the guide-pins  5  are moved in the direction indicated by the arrow C, beyond the switching position  18 , the guide-pins  5  come out into the linking area  23  and the tongues  7  spring back to their initial form immediately after the switching position  18  is gone past. The initial form of the tongues  7  is chosen in such a way that each guide-pin  5  is facing the first part  25  of the second guide groove  15 , in the linking area  23 , when the tongues  7  are not bent. Immediately after the switching position is gone past when the guide-pins  5  are moved in the direction indicated by the arrow C, the sealing device is in the deployed configuration as shown in the  FIG. 4 . The guide-pins  5  can be moved within the linking area  23  in the direction indicated by the arrow C or in the opposite direction. Advantageously, the second limit stop  24  of the linking area  23  blocks the guide-pins  5  and prevents the operator from pulling the shutter  3  further and prevents from moving the guide-pins  5  beyond the linking area  23 . Thus, the shutter  3  cannot be disassembled from the fixed support  2  by pulling it. In the extended position, the operator may insert through the insertion aperture  1  of the sealing device a swab comprising a biological sample to be analyzed. To proceed to do the assays on the sample in the proper conditions, the shutter  3  must be locked. The operator must therefore push the shutter  3  in the direction opposite to the direction indicated by the arrow C. In doing so, the operator leads the cylindrical guide-pins  5  to leave the linking area  23  and to enter the second guide groove  15  past the switching position  18 . Indeed, considering the form of the tongues  7  and the forms of the guide groove  14 ,  15 , the guide-pins  5  cannot enter the third switching portion  21  of the first guide groove  14 . The first part  25  is curved and forces the operator to increase its effort while pushing the shutter  3  in the direction opposite to the direction indicated by the arrow C as the guide-pins  5  move along the first part  25  and the tongues  7  are being bent. The movement of the cylindrical guide-pins  5  in the first and second parts  26 ,  27  is possible in the direction indicated by the arrow C as well as in the opposite direction. The form of the tongues  7  and the forms and positions of the first and second parts  25 ,  26  are chosen so that the tongues  7  are bent when the guide-pins  5  are in the first and second parts  25 ,  26 . When the operator continues to push the shutter  3 , the guide-pins  5  enter the third part  27  which causes the tongues to spring back to their initial form immediately. When the guide-pins  5  are in the third part  27 , the second and third limit stop  28 ,  29  form locking means and block the guide-pins  5  in order to prevent the shutter  3  from being moved. In this configuration, the sealing device is in the final retracted configuration as shown in the  FIG. 5 . The sealing device in the final retracted position is locked and cannot be deployed, preventing from contaminations and leaks during the biological assays. Advantageously, when the swab is inserted inside the insertion aperture  1  and maintained by the tips  9 , the cutting means are designated so that the swab is introduced inside the cutting slot  31  in order to be cut by the cutting edge  30  during the movement of the shutter  3  towards the final retracted position. 
     Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and example be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.