Patent Application
20080236621
The present invention relates to the washing and sterilization of medical instruments, and to an apparatus for achieving both washing and sterilization.
After use reusable medical instruments must be both washed and then sterilized before they can be reused. They are placed into a container at the point of use and then transported to the hospital central supply area for further processing. Typically, washing is performed either by hand using a detergent and mechanical scrubbing devices such as brushes, are in a machine which typically directs jets of detergent laid in water at the device to effect cleaning. The devices are contaminated with potentially dangerous pathogens which require the personnel performing such cleaning to wear appropriate protective gear such as gloves, gowns, masks etc.
After the device has been washed it is decontaminated, which typically comprises a brief contact with a decontaminating agent such as bleach or steam sufficient to kill the most dangerous pathogens such as hepatitis. The instruments may then be safely handled for inspection and processed for sterilization. This typically involves each instrument being packaged in a semi-permeable pouch permeable to a sterilizing agent yet impermeable to microorganisms, or by being packaged into a tray which is then wrapped in CSR wrap which is semi-permeable. It is then placed into and processed in a sterilizer such as a steam sterilizer or a hydrogen peroxide gas plasma sterilizer such as the STERRAD Sterilizer available from Advanced Sterilization Products Division Ethicon, Inc., Irvine, Calif. Such a sterilizer is depicted in U.S. Pat. No. 6,365,102, which is hereby incorporated by reference.
The two-step cleaning and sterilization procedure introduces complexities into the preparation of instruments for reuse. The instruments require packaging between the cleaning and the sterilization steps into a packaging which will preserve their sterility after the sterilization procedure is completed. Such packaging cannot be applied prior to the washing step as it is incompatible with the transmission of the cleaning fluids and it would contain and prevent the removal of the foreign matter which washed off of the instrument. The personnel require protective garb when handling the contaminated instruments, and this presents an issue for the hospital as they typically then must provide a special area for such handling and provide additional air conditioning to such area to compensate for the extra garb worn by the personnel. The present invention overcomes these and other limitations by providing a method and mechanism for both washing and sterilizing the medical instruments.
A method according to the present invention provides for cleaning and sterilizing a device. The method comprises the steps of: a) placing the device into a container; b) placing the container into a washing/sterilization apparatus; c) the washing/sterilization apparatus washing the device by applying a washing fluid to an interior of the container to wash the device; d) after washing the device, and without removing the device from the washing/sterilization apparatus, the washing/sterilization apparatus packaging the device in a bacteria impermeable package; e) the washing/sterilization apparatus sterilizing the device by exposing the device to a sterilizing vapor; and f) removing the device while it remains in the package whereby to preserve its sterility until use.
In one aspect of the invention, step e) occurs prior to step d) and step d) further includes the step of sterilizing the package. In a different aspect of the invention, step e) occurs after step d) and the package comprises a material permeable to the sterilizing vapors.
Preferably, the washing/sterilization apparatus further comprises a control system which controls the steps c), d) and e).
In one aspect of the invention, the package comprises the container and a lid and the step of packaging the device comprises sealing the lid to the container. In a different aspect of the invention, the package comprises a pouch and wherein the step of packaging comprises the washing/sterilization apparatus inserting the container into the pouch and then sealing the pouch closed. The container can comprise an open top tray. In one aspect of the invention, step e) occurs prior to step d) and step d) further includes the step of sterilizing the pouch. In a different aspect of the invention, step e) occurs after step d) and the pouch comprises a material permeable to the sterilizing vapors.
Preferably, the sterilizing vapors comprise hydrogen peroxide.
Preferably, step e) occurs within a chamber and a vacuum is applied to the chamber prior to exposing the device to the sterilizing vapor.
An apparatus according to the present invention provides for cleaning and sterilizing a device, the apparatus comprises a chamber and a container adapted to receive the device. A washing fluid distribution system connects to the chamber whereby to apply washing fluid to the device within the chamber. A source of sterilizing vapor connects to the chamber whereby to apply sterilizing vapor to the device within the chamber to sterilize the device. A packaging means is provided within the chamber for packaging the device within a microorganism impermeable package whereby to maintain sterility of the device after its removal from the chamber.
In one aspect of the invention, the packaging means comprises a mechanism for fitting a lid to the container. Preferably, the mechanism comprises one or more arms connected to the lid whereby the lid can be raised and lowered by the arms.
In another aspect of the invention, the package comprises a pouch and the packaging means comprises an actuator for pushing the container into the pouch through an opening therein and a sealing member to push the pouch closed at the opening and seal it closed. Preferably, the sealing member is a heat sealing iron.
Preferably, a vacuum pump connects to the chamber for drawing a vacuum thereon.
Preferably, the sterilizing vapor comprises hydrogen peroxide.
In one aspect of the invention, the washing fluid distribution system further comprises spray nozzles for spraying the washing fluid onto the device.
Preferably, a computer control system connects to the washing fluid distribution system, the source of sterilizing vapor and the packaging means and is programmed to first engage the washing fluid distribution system to wash the device and then engage the source of sterilizing vapor to sterilize the device. In one aspect of the invention, the package is permeable to the sterilizing vapor and the computer control system is programmed to engage the packaging means to package the device prior to engaging the source of sterilizing vapor to sterilize the device. In another aspect of the invention, the computer control system is programmed to engage the packaging means to package the device after it has been sterilized.
a and 1b are side elevation views of a container according to the present invention.
a and 2b are cut-away side elevation views of a chamber according to the present invention receiving the container of
a is a side elevation view of an alternative container according to the present invention.
b is an end elevation view of the container of
c is a side elevation view of the container of
a and 5b are cut-away side elevation views of a chamber according to the present invention receiving the container of
a and 6b are side elevation views of a container according to the present invention.
a and 7b are side elevation views of a container according to the present invention.
c is a side elevation view of a chamber for receiving the container of
a is a side elevation view of a container according to the present invention.
b is a cut away side elevation view of a chamber according to the present invention receiving two of the containers of
a and 10b is a cut away side elevation view of a chamber according to the present invention receiving the container of
a and 1b show a container 10 for receiving one or more medical instruments 12. The container comprises a bottom 14 and upstanding sidewalls 16. A lid 18 fits to the top of the sidewalls 16 to seal the container 10. The bottom 14 is sloped and has a drain 20 with a closure valve 22. A grid 24 rests slightly above the bottom 14 and supports one or more instrument receiving baskets 26. Both the grid 24 and baskets 26 are preferably formed from a mesh having large enough holes to freely pass cleaning solution and may be formed of stainless steel, aluminum, polyethylene, polypropylene, or styrene, TEFLON polytetrafluoroethylene and other suitable materials. Several bosses 28 project from a lower surface 30 of the lid 18 and engage with meeting channels 32 in the sidewalls 16 to help position the lid 18 correctly. First and second valved openings 34 and 36 enter the container 10 through one of the sidewalls 16. Also, brackets 38 on the lid 18 are provided for machine grasping.
Turning now also to
Turning now also to
The cleaning and sterilization starts with placing contaminated devices in a container. Preferably, this occurs at the point of use, such as in an operating room. The container may be filled with soaking fluid to prevent contaminates on the devices from drying and becoming more difficult to remove. The soaking fluid may comprise a liquid solution of cleaning and/or sterilization chemicals, or more preferably a foam of comprising an enzymatic cleaner or hydrogen peroxide. After the container is sealed, the contaminants and pathogens are sealed inside and the container may be transported by personnel not wearing protective gloves, garments etc.
The container is then inserted into the chamber 40 and the chamber 40 is sealed. The chamber 40 may be heated to enhance the cleaning and sterilization process. Preferably, the chamber is heated to 30° C. to 60° C. The lifting rods 42 lift the lid 18. The soaking fluid may be used for further cleaning or drained. Preferably, it is drained and rinsed by opening the drain 22 and flowing water in through the opening 34. The drain 22 is then closed and the container 10 is filled with a cleaning solution comprising water and concentrated cleaning fluid from the reservoir 74. This is re-circulated by the pump 66. If the additional agitation of the agitators 52 and ultrasound transducers 54 is required then the drain 22 is left open and the chamber 40 also filled with cleaning solution. By separating the lid from container, it exposes one most likely contaminated area between the lid 18 and container 10 for cleaning and sterilization. Rinsing fluid is then used to remove the cleaning chemicals. The rinsing fluid may be city water, DI water or distilled water.
Next, germicide is admitted to the chamber 40. The germicide may be introduced as liquid, mist, vapor, or gas to treat the devices, container and chamber. The germicide may comprise hydrogen peroxide, peracetic acid, performic acid, or ozone. The sterilization process may be hydrogen peroxide vapor from pre-treated liquid peroxide or solid peroxide complex. It may be steam or ethylene oxide. Preferably, the sterilization process comprises admitting heated air through inlet 58 to dry the chamber 40 and its contents followed by sealing the chamber and lowering the pressure via the vacuum pump 78 to below 1 torr whereupon a 59% hydrogen peroxide solution is vaporized into the chamber 40 and left in contact with for a sufficient period of time to effect sterilization of the container 10 and the instruments 12 therein. After the sterilization is completed, the lid 18 and drain 20 are all closed and the container is ready to be removed from the chamber 40. The sterility of the instruments 12 is maintained by the sealed container 10.
a, 4b and 4c show an alternative container 100. It comprises a removable lid 102 and removable bottom 104 each with locating bosses 106 as in the previous container. Flanges 108 are provided on two opposing sidewalls 109. Turning also now to
a and 6b show an alternate version of a container 120. It has a lid 122 which attaches to the container 120 via a hinge 124. The hinge 124 helps ensure that the lid 122 will be properly positioned upon the container 120 when it is pushed into the closed position.
a, 7b and 7c show a container 126 having a lid 128 attached via a hinge 130 and a bottom 132 attached via a hinge 134. Flanges 136 along its side portions function to hold the container similar to the flanges 108 of the container 100 of
Turning also to
After the washing cycle the partition 188 is opened, the basket 192 is pushed via an actuator 208 into the sterilization section 186 and the partition 188 closed. In the sterilization section 186 a sterilization process employing steam or vapor phase chemical sterilization is carried out. Preferably, it involves a vapor phase hydrogen peroxide process via vaporizing a liquid peroxide solution or releasing hydrogen peroxide from a solid peroxide complex as previously described. After the process is complete the cover 196 is lowered onto the bottom 194 to seal the container 190 and maintain the sterility of the instruments therein.
Optionally, semi-permeable filters 210 can be provided on the container 190 to allow a vapor phase sterilization process to be carried out with the cover 196 sealed to the bottom 194. Further, the container 190 having a cover 196 which leaves the basket 192 open during both cleaning and sterilization can be employed with any of the previously described chambers.
With separated washing 184 and sterilization sections 186, the system 182 can be operated as a washer and a sterilizer simultaneously, or an integrated washer/sterilizer and can be adapted to many cleaning, disinfecting and sterilization techniques. The packaging may be performed between cleaning and sterilization or after sterilization. Optionally, the packaging area and sterilization area can be separated with a removable divider. If packaging is not required, then the sterilization process may only occur in the sterilization area. Optionally, the packaging area may be located on the same level as the cleaning area and sterilization area. The packaging area may be located between cleaning area and sterilization area, or after the sterilization area. The packaging can be performed with container, pouch or wrap. The following examples represent a few of the many possible processes.
Step 1: Loading a load in wire basket or tray into the right-most cleaning area
Step 2: Cleaning the load in the cleaning area. Optionally, this step may include detergent, surfactant, enzyme, cleaning chemical, spray, agitation, or ultrasound.
Step 3: Rinsing the load with water. Preferably, the water is distilled water, or DI water.
Step 4: Treating load with liquid hydrogen peroxide. Preferably, the liquid is in the form of mist.
Step 5: Moving load into the middle packaging area.
Step 6: Sliding load into an open gas permeable pouch and sealing the pouch. Optionally, the packaging may be a container with gas permeable barrier or CSR wrap.
Step 7: Moving load into the right-most sterilization area
Step 8: Reducing the pressure to below the vapor pressure of hydrogen peroxide.
Step 9: Sterilizing the load with vaporized peroxide. Optionally, the process further comprises exciting the atmosphere into plasma to complete the process.
Step 1: Loading a load in wire basket or tray into the right-most cleaning area.
Step 2: Cleaning the load in the cleaning area. Optionally, this step may include detergent, surfactant, enzyme, cleaning chemical, spray, agitation, or ultrasound.
Step 3: Rinsing the load with water. Preferably, the water is distilled water, or DI water.
Step 4: Moving the load into the middle packaging area.
Step 5: Sliding the load into an open gas permeable pouch and sealing the pouch. Optionally, the packaging may be a container with a gas permeable barrier or CSR wrap.
Step 6: Moving the load into the right-most sterilization area.
Step 7: Sterilizing the load.
Step 1: Loading a load in wire basket or tray into the cleaning area.
Step 2: Cleaning the load in the cleaning area. Optionally, this step may include detergent, surfactant, enzyme, cleaning chemical, spray, agitation, or ultrasound.
Step 3: Rinsing the load with water. Preferably, the water is distilled water, or DI water.
Step 4: Moving the load into the sterilization area.
Step 5: Sterilizing the load.
Step 6: Moving the load into the packaging area.
Step 7: Packaging the load with sterile pouch, container or CSR wrap.
Step 1: Placing a load into a container with lid.
Step 2: Loading the container into the integrated washer/sterilizer 182. Optionally, the washer/sterilizer can be a washer/decontaminator or washer/disinfector.
Step 3; Opening the lid. Optionally, the bottom can be opened.
Step 4: Cleaning the load, container and lid. Optionally, this step may include detergent, surfactant, enzyme, cleaning chemical, spray, agitation, or ultrasound.
Step 5: Rinsing the load, container, and lid with water. Preferably, the water is distilled water, or DI water.
Step 6: Sterilizing the load, container and lid.
Step 7: Closing the container.
Step 1: Placing a load into a container with lid.
Step 2: Soaking the load with soaking fluid. Optionally, the soaking fluid may include detergent, surfactant, enzyme, or peroxide. The soaking fluid may be liquid or foam. Optionally, the container has a soaking indicator to indicate the proper soaking of load (both the soaking fluid is deep enough to cover the instruments and that the time period is sufficient).
Step 3: Loading the container into the integrated washer/sterilizer. Optionally, the washer/sterilizer can be a washer/decontaminator or washer/disinfector.
Step 4; Opening the lid. Optionally, the bottom can be opened.
Step 5: If necessary, further cleaning the load, container and lid. Optionally, this step may include detergent, surfactant, enzyme, cleaning chemical, spray, agitation, ultrasound, or defoaming agent.
Step 6: Rinsing the load, container, and lid with water. Preferably, the water is distilled water, or DI water.
Step 7: If necessary, further decontaminating, disinfecting, or sterilizing the load, container and lid.
Step 8: If necessary closing the container.
A simple use for the containers, such as the container 10, and systems and chambers, such as chamber 40 as shown in
While the invention has been particularly described in connection with specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and that the scope of the appended claims should be construed as broadly as the prior art will permit.
