The present disclosure is generally related to medical sterilization container valves and more particularly is related to a medical sterilization container shape memory alloy valve.
Articles such as medical instruments and the like are usually sterilized in an autoclave in which the articles are exposed to high-pressure saturated steam for a relatively brief interval. Unless the articles are to be used immediately and in close proximity to the autoclave, it is desirable to sterilize the articles while they are inside a valved container as described, for example, in U.S. Pat. No. 4,748,003 and in U.S. Pat. No. 5,097,865.
During the sterilization process, the valves open under the influence of high-pressure steam in the autoclave exposing the contents of the container to the hot steam. At the end of the sterilization cycle, when the pressure in the autoclave outside the container is returned to normal, i.e. atmospheric pressure, the valves close so that when the container is removed from the autoclave, the now sterilized articles are maintained in a completely sealed sterile environment until they are needed.
The sterilization container described above has pressure-actuated valves in the top and bottom walls of the sterilization container. Each valve has a large valve opening and a closure therefor, the latter being supported by a bellows capsule mounted inside the container. A return spring mechanism normally maintains the valve closure in its closed position. However, when the pressure outside the container exceeds that within the container by a few pounds per square inch, the force on the valve closure exceeds that exerted by the return spring with the result that the valve closure opens sufficiently to allow high-pressure steam to enter the container. That steam collapses the bellows, which thereupon moves the valve closure to its fully open position. Both valves being open, high-pressure steam can sweep through the container and sterilize the articles therein.
When the pressure inside the autoclave returns to normal after completion of the sterilization cycle, the return spring moves the valve closure of each valve to its closed position thereby sealing the container. As also described, pressure equalization occurs through a special filter member mounted in the container wall so that a sterile environment at ambient pressure is maintained in the container until the container is opened to remove the articles therefrom.
The conventional valves do have certain drawbacks. First and foremost, the bellows capsule has a relatively small diameter in relation to the valve opening and a large length-to-diameter ratio, e.g. 1.3 in./1 in.=1.3. This means that when the valve member starts to open in response to a given pressure differential outside and inside the container and the bellows is collapsed lengthwise, there is a relatively large reduction in the volume of the bellows, i.e. in excess of 20%, and a correspondingly large increase in gas pressure inside the bellows which resists further opening of the valve member.
To avoid this problem, the bellows capsule in the prior value has to be evacuated. This necessitates the use of an elaborate return spring mechanism in order to overcome the increased back pressure and close the valve. Also, the requirement for a bellows that must be evacuated makes the valve somewhat more difficult and expensive to manufacture. In addition, sometimes a small leak may develop in the bellows so that air enters the bellows. Resultantly, during the next sterilization cycle, when the valve member begins to open, that air will be compressed, effectively increasing the spring constant of the bellows so that the valve member does not open as much for a given pressure differential outside and inside the container.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.
Embodiments of the present disclosure provide a system for a medical sterilization container valve. Briefly described, in architecture, one embodiment of the system, among others, can be implemented as follows. The medical sterilization container valve has a valve housing affixed to a medical sterilization container. A first valve portion is attached to the valve housing. A second valve portion is proximate to the first valve portion, wherein the second valve portion is movable between at least a first position and a second position. A shape metal alloy (SMA) device is connected with the second valve portion, wherein the SMA device moves the second valve portion between the first and second positions.
The present disclosure can also be viewed as providing a method of utilizing a valve within a medical sterilization container. In this regard, one embodiment of such a method, among others, can be broadly summarized by the following steps: affixing a valve housing to a medical sterilization container, wherein the valve housing has a first valve portion attached to the valve housing, and a second valve portion proximate to the first valve portion, wherein the second valve portion is movable between at least a first position where the first and second valve portions are in contact, and a second position where the first and second valve portions are not in contact; connecting a shape metal alloy (SMA) device into the second valve portion; and subjecting the SMA device to a thermal energy, thereby moving the second valve portion between the first and second positions with the SMA device.
The present disclosure can also be viewed as providing a system for sterilizing medical instruments and storing sterilized medical instruments. Briefly described, in architecture, one embodiment of the system, among others, can be implemented as follows. A medical sterilization container has a plurality of side walls and a cover, wherein the cover is openable to expose an interior portion of the medical sterilization container, wherein the interior portion is sized to house a quantity of medical instruments. A valve is positioned within the cover, wherein the valve has a valve housing, a first valve portion attached to the valve housing, and a second valve portion proximate to the first valve portion, wherein the second valve portion is movable between at least a first position and a second position. A shape metal alloy (SMA) device is connected with the second valve portion, wherein the SMA device moves the second valve portion between the first and second positions. An access path is positioned through the valve between an exterior of the medical sterilization container and the interior portion, wherein the access path is closed when the second valve portion is in the first position and open when the second valve portion is in the second position.
Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims.
Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
The valve 10 may be used with a medical sterilization container 30 having any size or shape. The medical sterilization container 30 is used to house medical instruments and other medical devices in between medical procedures. For example, the medical sterilization container 30 may be used to house operating or surgical devices during a sterilization process and until their use in an operation or surgical procedure. The sterilization processes that the medical sterilization container 30 is subjected to may include any type of chemical, pressure, heat, and/or energy-based sterilization process. Commonly, the sterilization process includes the use of an autoclave which subjects the medical sterilization container 30 to high temperatures, high pressures, and moist environments which may include a sterilization chemical. However, other sterilization processes may include the use of other devices or other sterilization techniques, such high-temperature environments and ultra-violet light screenings.
The valve 10 may be located within any part of the medical sterilization container 30. For example, as is shown in
The valve 10 includes a valve housing 20, which is positioned within a sidewall, the base 34, or a cover 32 of the medical sterilization container 30. For example, the valve housing 20 may be integrally mounted within a cover 32 of the medical sterilization container 30, as is shown. In this position, the valve 10 is positioned at an interface between an exterior of the medical sterilization container 30, such as any atmosphere external to the interior part of the medical sterilization container 30, and the interior portion 36 of the medical sterilization container 30. The valve 10 may be similarly located within any portion of the base 34, as may vary by design. The cover 32 may be removable from the base 34, thereby allowing access to the interior portion 36 to insert medical instruments or remove them therefrom. When the cover 32 is affixed to the base 34, the interior portion 36 may be substantially sealed from the external environment, whereby access to the interior portion 36 of the medical sterilization container 30 is through the valve 10, or another similar structure, such as a secondary valve.
The valve 10 may be assembled and connected to the medical sterilization container 30 in a number of ways. The valve 10 includes a valve housing 20, which is positioned within a portion of the medical sterilization container 30. The valve housing 20 includes a first valve housing structure 22 and a second valve housing structure 24 which may be affixed together around the medical sterilization container 30. In other words, a portion of the medical sterilization container 30 may be located between the first and second valve housing structures 22, 24. For example, as is shown in
The valve housing 20 may be constructed from any type of material, and may be configured or designed in a number of different ways, and may include a plurality of additional features. For example, either or both of the first and second valve housing structures 22, 24 may include a plurality of perforations 28, which allow for gas, moisture, or other materials to penetrate therethrough. These perforations 28, which may include any type of hole, aperture, or other opening, may also allow a sterilization material, such as steam, gas, a chemical, or a heated substance to pass from the exterior of medical sterilization container 30 to the interior portion 36 (
The valve 10 includes a first valve portion 40 and a second valve portion 50, both of which are substantially housed within the valve housing 20. Either one, or both of the first and second valve portions 40, 50 may be movable within the valve housing 20, which generally remains secured to the medical sterilization container 30. For example, most commonly, the first valve portion 40 will be affixed to the valve housing 20 such that it remains substantially stationary, relative to the valve housing 20. In
The second valve portion 50 may be located proximate to the first valve portion 40, such that the two structures may be moved to contact each other and moved away from contact with each other. Generally, the second valve portion 50 is movable within the valve housing 20, wherein the movement is controlled, at least in part, by the SMA device 60. For example, in
The movement of the second valve portion 50 may be between at least two positions: a first position where the second valve portion 50 is in contact with the first valve portion 40, and a second position where the second valve portion 50 is not in contact with the first valve portion 40. In other words, the second valve portion 50 may be moved between a closed valve position (first position) and an open valve position (second position). This movement allows the valve 10 to be open and thus allow material to pass from outside the medical sterilization container 30 to the interior portion 36 (
The movement of the second valve portion 50 is controlled, at least in part, with the SMA device 60, in that, the SMA device 60 moves the second valve portion 50 between the first and second positions. The SMA device 60 is connected to the second valve portion 50, which may include any type of connection, mechanical communication, or other direct or indirect physical contact. The SMA device 60 may also be in contact or mechanical communication with any other structures of the valve 10, including the first or second valve housing structures 22, 24. The SMA device 60 may have a plurality of designs and shapes, such as a biasing structure or spring, as is shown in
The SMA device 60 may be understood as a shape memory alloy structure, which may also include a smart metal, memory metal, memory alloy and smart alloy structure, that can take a position depending on a temperature. The SMA device 60 may function by returning to a remembered, original, or pre-deformed shape from a deformed shape. Often, the original shape is one given to the SMA device 60 when it was cold-forged, and thus corresponds to a cold temperature or low thermal energy of the SMA device 60. In contrast, the deformed shape may correspond to a heated temperature or high thermal energy within the SMA device 60. Therefore, in general terms, the SMA device 60 will be located in one position at a high temperature and another position at a low temperature. The specific temperature for each position may depend on the specific SMA device 60, and may include a variety of different temperatures, all of which are considered within the scope of this disclosure.
It is noted that any of the components of the valve 10 disclosed herein may be constructed from a variety of materials in a variety of methods. For example, the first and second valve portions 40, 50 may be constructed from rubbers, plastics, or other materials capable of forming a seal when in contact. The valve housing 20 may be constructed from a hardened plastic, metal, or other material that substantially resists deformation when subjected to different temperatures or humid environments. The SMA device 60 may be constructed from any material having SMA properties, including but not limited to copper-zinc-aluminum-nickel, copper-aluminum-nickel, and nickel-titanium (NiTi) alloys, as well as various combinations of zinc, copper, gold, and iron alloys.
This movement is controlled by the SMA device 60, and may function as is disclosed in the follow example. A quantity of medical instruments may be positioned within the medical sterilization container 30, which may be closed to substantially seal off the interior portion 36 (
As the medical sterilization container 30 heats up within the sterilization environment, the SMA device 60 within the valve 10 may also experience a rise in temperature due to the thermal condition within the sterilization environment. As the SMA device 60 approaches a specified temperature, such as 212° F., or any other predetermined temperature, the SMA device 60 may expand and move the second valve portion 50 away from the first valve portion 40. A valve stem 52 may be used to align the second valve portion 50 during movement. The SMA device 60 in this expanded position is shown in
When the sterilization process finishes, the temperature within the sterilization environment decreases, which lowers the temperature of the valve 10 and changes the thermal condition of the SMA device 60. When the SMA device achieves a certain temperature, it reforms to its original shape, thereby moving the second valve portion 50 into contact with the first valve portion 40. This contact between the first valve portion 40 and the second valve portion 50 creates a biologically impermeable seal between an interior portion 36 (
The valve 110 functions similarly to that described of the valve 10 of the first exemplary embodiment. The valve 110 may be located in a portion of the medical sterilization container 130, such as in a cover or a base. More than one valve 110 may be included, depending on the size of the container 130 or the intended use of the medical sterilization container 130. In use, the SMA device 160 may be compressed at a low temperature, such as at room temperature, which may force the valve 110 closed, as illustrated in
The valve stem 152 may have an engagement platform 154 connected to the valve stem 152. As is shown, a proximate end of the valve stem 152 may be connected to the second valve portion 150 and a distal end of the valve stem 152 is connected to the engagement platform 154. The valve stem 152 may extend through the second valve housing structure 124, such that the distal end is located external of the valve housing 120. The engagement platform 154 connected to the distal end may provide an abutment for the SMA device 160. For example, when the SMA device 160 is subjected to high temperatures, the SMA device 160 may expand between the engagement platform 154 and the second valve housing structure 124, thereby forcing the engagement platform 154 away from the second valve housing structure 124. This, in turn, moves the second valve portion 150 away from the first valve portion 140 to open the valve 110.
It is noted that the spring 162 may be used to counterbalance the SMA device 160, or bias the second valve portion 150 to contact the first valve portion 140 when the SMA device 160 is not subjected to a high temperature. For example, the spring 162 may be located within the valve housing 120 and surrounding the valve stem 152, whereas the SMA device 160 may be located external of the valve housing 120 and surrounding the valve stem 152. The spring 162 may bias the second valve portion 150 towards the first valve portion 140 during non-heated conditions, thereby retaining the valve 110 in the closed position. When the SMA device 160 is heated, it may provide a force that overcomes the force of the spring 162 to move the second valve portion 150 away from the first valve portion 140.
For example, at room temperature or another low temperature, the SMA device 360 may have a concave shape that allows the Second valve portion 350 to contact the first valve portion 340. When the temperature is raised, such as to above 212° F., the SMA device 360 may reverse shape to a convex shape, thereby opening the valve 310, as is illustrated in
As is shown by block 402, a valve housing is affixed to a medical sterilization container, wherein the valve housing has a first valve portion attached to the valve housing, and a second valve portion proximate to the first valve portion, wherein the second valve portion is movable between at least a first position where the first and second valve portions are in contact, and a second position where the first and second valve portions are not in contact. A shape metal alloy (SMA) device is connected to the second valve portion (block 404). The SMA device is subjected to a thermal energy, thereby moving the second valve portion between the first and second positions with the SMA device (block 406).
The method may also include a number of additional steps or processes, or any variation thereof. Accordingly, the method may include any of the features, functions, or characteristics described with respect to any of the embodiments herein. For example, moving the second valve portion between the first and second positions may include moving the second valve portion into the first position, thereby contacting the first valve portion with the second valve portion, thereby placing the valve in a closed position, and/or moving the second valve portion into the second position, thereby opening the valve by moving the second valve portion out of contact from the first valve portion. The SMA device may be, subjected to a variety of temperatures, and may actuate or engage based on any predetermined temperature. This may include subjecting the SMA device to medical sterilization process having a temperature above 212° F., which may open or close the valve.
In use, the valve within the medical sterilization container may be placed within a sterilizing environment or a sterilization device, wherein the second valve portion moves from the second position to the first positioned while in the sterilization device and while being subjected to a thermal change. The medical sterilization container with the valve house may be removed from within the sterilization device, wherein the second valve portion remains in the first position after removal from within the sterilization device. For example, the SMA device may be subjected to at least a first, a second, and a third temperature, wherein the second temperature is higher than the first and third temperatures. Accordingly, the first temperature may influence the SMA device to place the second valve portion in the first position, the second temperature may influence the SMA device to place the second valve portion in the second position, and the third temperature may influence the SMA device to place the second valve portion in the first position.
It should be emphasized that the above-described embodiments of the present disclosure, particularly, any “preferred” embodiments, are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the disclosure. Many variations and modifications may be made to the above-described embodiment(s) of the disclosure without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present disclosure and protected by the following claims.
This application claims benefit of U.S. Provisional Application Ser. No. 61/424,310, entitled, “Medical Sterilization Container Shape Memory Alloy (SMA) Valve” filed Dec. 17, 2010, the entire disclosure of which is incorporated herein by reference.
Number | Date | Country | |
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61424310 | Dec 2010 | US |