Monitoring device for a sterilization container

Abstract

Monitoring device for a sterilization container (1) with a control element (9) which is displaceably mounted on a sterilization container (1) between a rest position and an active position and which is displaced from the rest position to the active position during a sterilization process, wherein the monitoring device comprises a feed element (19) which is at least partially made of a shape-memory alloy and has a conversion temperature that is above the ambient temperature and close to the sterilization temperature, wherein the feed element (19) displaces the control element (9) from the rest position to the active position by means of a shape conversion when the feed element (19) is heated to a temperature above the conversion temperature, and wherein a retention device (12, 21) is provided which enables the control element (9) to be displaced from the rest position to the active position.a displacement in the opposite direction from the active position to the rest position, however, is prevented, wherein the retaining device (12, 21) is releasable, characterized in that a spring element (24) acts on the control element (9), which acts on the control element (9) with a restoring force that displaces it from the active position to the rest position, such that the control element (9) can be displaced from the active position to the rest position after active release of the retaining device (12, 21).

Description

[0001] The invention relates to a monitoring device for a sterilization container with a control element which is displaceably mounted on a sterilization container between a rest position and an active position and which is displaced from the rest position to the active position after a sterilization process, wherein the monitoring device comprises a feed element which consists at least partially of a shape-memory alloy and has a conversion temperature which is above the ambient temperature and close to the sterilization temperature, which feed element displaces the control element from the rest position to the active position by means of a shape conversion when the feed element is heated to a temperature above the conversion temperature, and wherein a retention device is provided which enables the control element to be displaced from the rest position to the active position.However, a movement in the opposite direction from the active position to the resting position is prevented, whereby the retaining device is releasable.

[0002] Sterilization containers, which typically consist of a tub-shaped base and a tightly fitting lid, hold instruments and other items that are sterilized at elevated temperatures and then stored sterilely within the container. It is important that, after the sterilization process, it can be verified that the sterilization process has taken place and whether the container has been opened unintentionally or has remained closed.

[0003] It is known to provide a monitoring device on a sterilization container with a movable control element, for example, a bimetallic element, which, at the elevated temperature of the sterilization process, moves from a rest position to an active position, which is retained after sterilization. This active position indicates that sterilization has taken place. However, with known monitoring devices, it is difficult to ensure that the control element remains in its active position after sterilization, even if the sterilization container is set down hard or subjected to other movements. Furthermore, in many cases, a relatively large volume is required for the monitoring device, which negatively impacts the overall size of the sterilization container.

[0004] A sterilization container with a generic monitoring device is described in EP 0 412 571 A2.

[0005] US Patent 4,539,929 describes a monitoring device in which a control element is movable by means of a feed element that is deformable depending on the temperature and is made, for example, of a bimetal.

[0006] The object of the invention is to design a monitoring device of the generic type in such a way that the operational reliability of the monitoring device is improved and that at the same time a simplification of the design is possible.

[0007] This problem is solved in a monitoring device of the type described above according to the invention by the fact that a spring element acts on the control element, which exerts a restoring force on the control element, shifting it from the active position to the rest position, so that the control element can be shifted from the active position to the rest position after active release of the retaining device.

[0008] The design of the monitoring device according to the invention counteracts unintentional manipulation of the display status with high forces and minimal attack surfaces.

[0009] Shape memory alloys are known alloys that undergo a microstructural change when a certain temperature, the transformation temperature, is exceeded. This change is associated with a change in the shape of an object made from this shape memory alloy. For example, components made from a shape memory alloy that have two angled arm sections can change the angle of inclination between these arm sections when the transformation temperature is exceeded—in one direction when the transformation temperature is exceeded and in the opposite direction when the transformation temperature is not reached. Shape memory alloys can be alloys with the following compositions, for example: Nickel-titanium copper-zinc Copper-zinc-aluminum Copper-aluminum-nickel Iron-nickel-aluminum.

[0010] The shape changes of the shape-memory alloys can be used to generate a displacement force for the control element when the transformation temperature is exceeded, which moves it from its rest position to its active position. Such a displacement therefore only occurs when the transformation temperature has been exceeded, that is, when the temperature increase necessary for sterilization has acted upon the sterilization container.

[0011] However, the sterilization temperature is only one of many parameters relevant for ensuring sterility. The indicator alone cannot therefore guarantee a successful sterilization process. Rather, it is necessary to monitor the process with regard to other parameters as well, and in case of a malfunction, the sterilization indicator must be reset by opening the container. A crucial parameter, however, is reaching the sterilization temperature, and this is monitored by the design according to the invention.

[0012] The conversion temperature can be slightly below the sterilization temperature; in this case, the control element moves to the rest position at a temperature just below the sterilization temperature. However, to ensure that the sterilization temperature has been reached, the conversion temperature must be slightly above the sterilization temperature. Only when the sterilization temperature is actually reached and exceeded will the control element move to the active position. It is advantageous if the conversion temperature lies within a relatively narrow temperature range, so that the deviation of the temperature at which the control element moves to the active position from the sterilization temperature is minimal. This is described below as "close to the sterilization temperature."

[0013] The inclusion of a retention device ensures that, after the control element is moved from its rest position to the active position, it remains in the active position and is therefore not unintentionally pushed back to the rest position, even if the sterilization container is moved abruptly or handled. The retention device must be actively engaged to allow the control element to return to its rest position, which is not possible during normal handling of the sterilization container. This ensures that the position of the control element clearly indicates that a sterilization process has taken place.

[0014] The control element can serve solely as an indicator or, according to a preferred embodiment, be connected to an indicator that provides different readings in the control element's rest position and active position. Alternatively, the retaining device can contribute to the secure closure of the sterilization container, for example, by acting as a lock or a locking mechanism that prevents opening. Only when the retaining device is actively removed from the active position is it possible to open the sterilization container. This ensures maximum security that the sterilization container has not been unintentionally opened after sterilization.

[0015] The feed element can be a separate component, which is held, for example, on the sterilization container and, in the event of deformation due to temperature increase, moves the control element from the rest position to the active position.

[0016] In a particularly preferred embodiment, the feed element is part of the control element. The control element can consist entirely of a shape memory alloy or have an active feed section that forms the feed element and is also made of a shape memory alloy.

[0017] It is advantageous that a spring element acts on the control element, exerting a restoring force on the control element that moves it from the active position to the rest position. The movement of the control element from the rest position to the active position thus occurs against the action of this spring element, and when the retaining device is actively released, the control element is moved back from the active position to the rest position by the spring element itself.

[0018] In a preferred embodiment of the invention, the retaining device comprises locking projections on the control element and / or the sterilization container, and at least one of the locking projections has a sliding surface by which, when the control element is moved from the rest position to the active position, the locking projections slide against each other and thus move past each other until, after this past movement, the locking projections engage behind each other and thereby prevent the control element from moving back from the active position to the rest position. It is advantageous if the control element, with its locking projection, is spring-loaded against the locking projection on the sterilization container.

[0019] In a preferred embodiment, the control element is arranged in a housing which is located on the sterilization container.

[0020] It is advantageous for the housing to be in the form of a plate that lies flat against a wall of the sterilization container. This allows for a very flat housing design, which can be inserted into a card holder in a wall of the sterilization container, similar to a card. Such cards are used on sterilization containers to record or display data about the contents, the sterilization process, etc. By using a flat, plate-shaped housing resembling such a card, the housing can be used instead of a card-shaped data carrier, or it can be attached to the sterilization container in a similar manner, for example, to the side wall of the tub-shaped lower part of a sterilization container.

[0021] It is particularly advantageous if the control element is designed as a wire- or band-shaped spring element. Such spring elements can be very narrow and yet exert relatively high spring forces. This design is especially beneficial when the control element is housed in a flat, plate-shaped casing, which, due to the wire- or band-shaped design of the spring element, can be made very narrow, thus protruding only slightly when in contact with a wall of the sterilization container.

[0022] In a preferred embodiment, it is provided that a locking projection is formed by bending in such a control element, which, together with a locking projection on the sterilization container, forms part of the retention device.

[0023] Furthermore, it is advantageous if the control element is supported on opposite sides of the housing, thereby pressing the locking protrusions against each other in a spring-like manner. Thus, in a control element designed as a spring element, the inherent elasticity is utilized to press the locking protrusions on the control element on the one hand and on the sterilization container or the housing on the other hand in a spring-like manner against each other.

[0024] In a preferred embodiment, it is provided that the control element is supported with one end against an end surface of the housing and that, during the transformation of the shape memory alloy when the transformation temperature is exceeded, this end moves away from the other parts of the control element and thereby moves it into the active position.

[0025] In particular, the control element may be provided with an actuating section, the actuation of which releases the retaining device. This could, for example, be an extension of the control element that, in the active position, protrudes from a housing that receives the control element. In this way, it is possible to manually release the retaining device by moving the actuating section and thereby push the control element back into its rest position.

[0026] In particular, the actuating section can be arranged on the sterilization container in such a way that when the sterilization container is opened by moving a closing element of the sterilization container into its open position, the closing element actuates the actuating section. For example, a closing element in the form of a pivoting tab can be arranged on the lid of a sterilization container. When this closing element pivots from the closed position to the open position, it can move the actuating section of the control element, thereby releasing the retaining device and initiating the return movement of the control element to its rest position. Until this point, the control element remains securely in the active position; only the intentional opening of the sterilization container inevitably leads to the return movement of the control element to its rest position.

[0027] The following description of a preferred embodiment of the invention, in conjunction with the drawing, serves for further explanation. The drawing shows: Fig. 1: A perspective view of part of a sterilization container with a tub-shaped base and a lid, a locking device and a monitoring device; Fig. 2: A top view of the monitoring device of the sterilization container of the Fig. 1 in the direction of arrow A in Fig. 1 with the control element in a rest position; Fig. 3: a view similar Fig. 2 with the control element in an active position; Fig. 4: a view similar Fig. 3 with a feed element deformed after cooling of the control element and Fig. 5: a view similar Fig. 4 with the control element during the movement into the rest position.

[0028] The in Fig. The sterilization container 1 shown comprises a tub-shaped lower part 2 with substantially vertical side walls 3 and a lid 4 placed on top of it, which tightly seals the interior of the sterilization container 1 by means of a seal not shown in the drawing.

[0029] In this closed position, the lid 4 is closed by a pivotally attached locking tab 5, which must be pivoted upwards about a horizontal axis to open and remove the lid 4. In the Fig. In the downward-swinged position shown in 1, the locking tab 5 closes the lid 4 and presses it tightly against the lower part 2.

[0030] Next to the locking tab 5, a rectangular, flat, plate-shaped housing 6 is arranged on a side wall of the lower part 2, enclosing a substantially rectangular interior space 7. This interior space is open on one narrow side via an opening 8 towards the locking tab 5; this opening 8 is less wide than the interior space 7 is high. The interior space 7 is closed on the opposite side.

[0031] In Fig. 1. The interior space 7 is also open towards the front, but this is not absolutely necessary; the interior space 7 could also be closed. Furthermore, it would be possible to place a card-shaped data carrier on the interior space 7, which could, for example, be held in a suitable slot holder.

[0032] A control element 9, consisting of a spring wire or a narrow spring band and featuring various bends, is arranged within the interior space 7. A V-shaped deformation 11 adjoins a horizontal, straight actuating section 10, forming a downwardly projecting detent projection 12. This projection is inclined relative to the horizontal actuating section 10 such that the flank 13 of the detent projection 12 adjoining the actuating section 10 extends downwards at an angle of approximately 45° to the horizontal defined by the actuating section 10, while the flank 14 facing away from the actuating section 10 forms an angle of less than 90° to the horizontal defined by the actuating section 10, but extending in the opposite direction to the flank 13.

[0033] From the upper end of the flank 14, the control element 9 extends upwards in a straight spring section 15 and from there downwards in another straight spring section 16. The two spring sections 15 and 16 form an obtuse angle. At the point where the spring sections 15 and 16 meet, the control element 9 rests against the upper surface 17 of the interior 7, and at the lower end of the spring section 16, it rests against the lower surface 18 of the interior 7. At the free end of the spring section 16, a feed section 19 projects at an angle from the spring section 16. At room temperature, this feed section runs vertically within the housing 6, i.e., parallel to the rear wall 20 of the interior 7 opposite the opening 8. Fig. 2).

[0034] The control element 9 consists of an elastic metal, for example, a shape memory alloy or spring steel. However, in any case, in the area of ​​the transition between the spring section 16 and the feed section 19, the control element 9 is made of a shape memory alloy and is designed such that, at room temperature and at temperatures below a transformation temperature, the feed section 19 runs parallel to the rear wall 20 as described. The feed section 19 forms an acute angle with the straight spring section 16.

[0035] However, when the transformation temperature is exceeded, a structural rearrangement of the shape memory alloy material occurs, and this causes the feed section 19 to pivot relative to the spring section 16; after this pivoting, the feed section 19 and the spring section 16 enclose an angle that is significantly greater than 90° ( Fig. 3).

[0036] The composition of the shape-memory alloy is selected such that the transformation temperature is either slightly below the sterilization temperature or slightly above it, preferably slightly above it. It is common practice to heat the contents of a sterilization container 1 to a temperature of 134°C using conventional sterilization methods. At this temperature, the desired germicidal effect is achieved with a high degree of reliability, and the transformation temperature lies within this range.

[0037] When this temperature is reached, the feed section 19 pivots relative to the spring section 16 and thereby moves the control element 9 from a rest position in which the feed section 19 rests against the rear wall 20 ( Fig. 2), into an active position in which the feed section 19 only rests against the rear wall 20 with its free end ( Fig. 3) In this process, the actuating section 10, which in the rest position is completely immersed in the interior 7, is pushed outwards through the opening 8.

[0038] On the underside 18 of the interior 7, a locking projection 21 is arranged, projecting upwards into the interior. On its side facing the opening 8, this projection has a flank 22 that is angled slightly less than 90° (for example, 80°) relative to the underside 18. The flank 23 of the locking projection 21 facing away from the opening 8 is inclined more steeply relative to the underside 18, for example, at an angle of 45°. This more steeply inclined flank 23 forms a sliding surface for the flank 13 of the locking projection 12 facing the opening 8, while the steeper flank 22 of the locking projection 21 forms a retaining surface that interacts with the flank 14 of the locking projection 12 facing away from the opening 8.

[0039] The control element 9, which is designed as a spring element, is inserted into the interior 7 under tension, such that the control element 9 is elastically compressed by contact with the upper surface 17 and the lower surface 18 of the interior 7. This causes the detent projection 12 to also be elastically pressed downwards against the lower surface 18 and can only be pushed past the detent projection 21 by deforming the control element 9 against this spring force, thereby lifting the detent projection 12 from the lower surface 18 of the interior 7.

[0040] When the control element 9 is advanced from the rest position to the active position, the detent projection 12 slides onto the detent projection 21. This sliding is enabled by the contact of the flank 13 of the detent projection 12 with the flank 23 of the detent projection 21 and occurs against an elastic deformation of the control element 9. This allows the detent projection 12 to slide along the detent projection 21 until, upon reaching the active position, it is pressed back against the underside 18 behind the detent projection 21 by the spring action of the control element 9. Fig. 3) In this position, the control element 9 cannot be pushed back into the rest position because the detent projection 12 with its flank 14 abuts the flank 22 of the detent projection 21 and prevents a return movement.

[0041] In this position, the locking projection 12 is held by the spring action of the control element 9; in addition, a spring element 24 projecting downwards into the interior 7 is mounted on the upper side 17 of the interior 7, which, in the rest position of the control element 9, projects essentially vertically downwards into the interior 7 and thus runs essentially parallel to the rear wall 20 ( Fig. 2) and which rests with its free end against the upper end of the flank 14 of the detent projection 12. When the control element 9 is moved, this spring element 24 pivots towards the opening 8 and exerts a force on the control element 9, attempting to move the control element 9 from the active position to the rest position. However, this movement is prevented by the detent projection 12 bearing against the detent projection 21.

[0042] However, a displacement can be made possible if the actuating section 10 is raised in the opening 8 until the lower end of the detent projection 12 is positioned above the upper end of the detent projection 21 ( Fig. 5), so that the detent projection 12 can slide along the detent projection 21. Such a return movement of the control element 9 towards the rest position is effected by the spring element 24, which, when relaxed, moves the control element 9 back into the rest position.

[0043] Naturally, for the control element 9 to return to its rest position, it must cool below the conversion temperature, thus allowing the feed section 19 to return to its initial position parallel to the rear wall 20. Therefore, the control element 9 can only return to its rest position once the sterilization process is complete and the temperature in the area of ​​the control element 9 is below the conversion temperature again.

[0044] This results in, starting from the in Fig. In the resting position shown in section 2, the following procedure is used when sterilizing the items arranged in the sterilization container: • Starting from the rest position, the control element 9 remains in the rest position until the conversion temperature is reached, which is just below or preferably above the sterilization temperature. • When the conversion temperature is exceeded, the feed section 19 is pivoted relative to the spring section 16, moving the control element 9 into the active position, whereby the detent projection 12 slides onto and past the detent projection 21 until it engages behind it ( Fig. 3). • Cooling of the control element 9 after completion of the sterilization process and return of the feed section 19 to the starting position parallel to the rear wall 20 ( Fig. 4). • The control element 9 normally remains in this position, thus providing proof that the temperature required for sterilization has been reached.

[0045] To make the position of the control element visible, an indicator element 25 can be arranged on the control element, for example, in the area of ​​the transition between the spring sections 15 and 16. When the control element 9 is moved from its rest position to its active position, the indicator element 25 changes its position relative to the housing 6, and this change can be visible from the outside. For example, the indicator element 25 can be two-colored and covered by a window located in a cover that closes off the interior 7 at the front. In one position, only the portion of the indicator element 25 with one color is visible through the window; in a second position, the portion with a different color is visible. In this way, a user can immediately see from the color visible behind the window the position of the indicator element 25 and thus also the position of the control element 9.

[0046] The control element 9 can be pushed back into its rest position by lifting the actuating section 10 in the opening 8. In principle, this can be done manually by the user.

[0047] The safety of the monitoring device is improved if the actuating section 10 cannot be operated uncontrollably by the user, but only, for example, by the locking tab 5 of the sterilization container 1. As long as this tab is in a closed position, it can cover the actuating section 10, preventing manual operation. As soon as the locking tab 5 pivots into the open position, it can either release the actuating section 10 for manual operation or, by moving the locking tab 5 itself, lift the actuating section 10 in the opening 8, thereby initiating the return movement of the control element 9. This provides maximum security against uncontrolled opening of the sterilization container 1. If, after a sterilization process, the control element 9 is in its rest position, it is then clear that the sterilization container 1 has been opened.

[0048] The described construction can be housed in a very flat casing, so that this casing protrudes very little from the side wall of the sterilization container 1. The monitoring device ensures reliable monitoring, and the control element 9 is secured against unintentional movement into its rest position. Even relatively large forces prevent retraction due to the engagement of the locking projections 12 and 21, unless the actuating section 10 is actuated. Actuating the actuating section 10, in turn, requires relatively little force, and the control element is then automatically returned to its rest position by the spring element 24, thus greatly simplifying the actuation process.

Claims

[1] Monitoring device for a sterilization container (1) with a control element (9) which is displaceably mounted on a sterilization container (1) between a rest position and an active position and which is displaced from the rest position to the active position during a sterilization process, wherein the monitoring device comprises a feed element (19) which is at least partially made of a shape memory alloy and has a conversion temperature which is above the ambient temperature and close to the sterilization temperature, wherein the feed element (19) displaces the control element (9) from the rest position to the active position by means of a shape conversion when the feed element (19) is heated to a temperature above the conversion temperature, and wherein a retention device (12, 21) is provided which enables the control element (9) to be displaced from the rest position to the active position,a displacement in the opposite direction from the active position to the rest position, however, is prevented, whereby the retaining device (12, 21) is releasable, characterized by , that a spring element (24) acts on the control element (9), which applies a restoring force to the control element (9) such that it moves from the active position to the rest position, that the control element (9) can be moved from the active position to the rest position after active release of the retaining device (12, 21). [2] Monitoring device according to claim 1, characterized by , that the feed element (19) is part of the control element (9). [3] Monitoring device according to any of the preceding claims, characterized by, that the retaining device comprises locking projections (12, 21) on the control element (9) and / or on the sterilization container (6), that at least one of the locking projections (12, 21) has a sliding surface (13, 23) by which, when the control element (9) is moved from the rest position to the active position, the locking projections (12, 21) slide onto each other and therefore move past each other until, after this past movement, the locking projections (12, 21) engage behind each other and thereby prevent a return movement of the control element (9) from the active position to the rest position. [4] Monitoring device according to claim 3, characterized by , that the control element (9) with its locking projection (12) is pressed springily against the locking projection (21) on the sterilization container (1). [5] Monitoring device according to any of the preceding claims, characterized by , that the control element (9) carries a display element (25). [6] Monitoring device according to any of the preceding claims, characterized by , that the control element (9) is arranged in a housing (6) which is arranged on the sterilization container (1). [7] Monitoring device according to claim 6, characterized by , that the housing (6) has the form of a plate which lies flat against a wall (3) of the sterilization container (1). [8] Monitoring device according to any of the preceding claims, characterized by , that the control element (9) is designed as a wire- or band-shaped spring element. [9] Monitoring device according to claim 8, characterized by , that in the control element (9) a locking projection (12) is formed by bends, which together with a locking projection (21) on the sterilization container (1) is part of the retention device. [10] Monitoring device according to claim 9, characterized by, that the control element (9) is supported on opposite sides (17, 18) of the housing (6) and thereby springs the detent projections (12, 21) against each other. [11] Monitoring device according to one of claims 8 to 10, characterized by , that the control element (9) is supported with one end against an end surface (20) of the housing (6) and that during the transformation of the shape memory alloy, when the transformation temperature is exceeded, this end moves away from the other parts of the control element (9) and thereby moves it into the active position. [12] Monitoring device according to any of the preceding claims, characterized by , that the control element (9) has an actuating section (10) which, when actuated, releases the restraint device. [13] Monitoring device according to claim 12, characterized by, that the actuating section (10) is arranged on the sterilization container (1) such that when the sterilization container (1) is opened by moving a closing element (5) of the sterilization container (1) into its open position, the closing element (5) actuates the actuating section (10).

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