Apparatus and method for sterilizing and drying medical filters

Abstract

The present invention relates to a device for disinfecting and drying filters, in particular medical filters such as dialyzers, and a method for disinfecting and drying filters. The device comprises a pressure chamber and a holder for at least one filter, the pressure chamber having at least one inlet and an outlet. To optimize the disinfection and drying of filters, in particular medical filters, the invention provides that the pressure chamber is divided into a first chamber and a second chamber, and the filter can be placed in the holder such that the inlet opening of the filter is arranged in the first chamber and the outlet opening of the filter is arranged in the second chamber.

Description

Technical Field

[0001] The invention relates to a device for sterilizing and drying medical filters, such as dialyzers, wherein the device comprises a pressure chamber having at least one inlet and an outlet and a holder for at least one filter, and a method for sterilizing and drying filters. Background Art

[0002] Dialyzers, in particular hollow fiber dialyzers, in which hollow fibers through which blood flows form a filter membrane, are particularly suitable for use in medical filters according to the present invention. These dialyzers are used in hemodialysis. The hollow fiber dialyzer comprises at least one hollow fiber module, through which blood can be guided from a blood inlet opening to a blood outlet opening. The blood inlet opening and the blood outlet opening define a blood chamber. The dialyzer also has an inlet opening and an outlet opening for the dialysis liquid. The dialysis liquid flushes the hollow fibers from all sides, wherein the substances to be filtered from the blood pass from the blood into the dialysis liquid via the hollow fiber membranes.

[0003] Since the blood compartment of the dialyzer is in direct blood contact with the patient's blood, the dialyzer must be sterile.

[0004] Disinfection methods for dialyzers are based on the use or application of gamma radiation, electron radiation, ethylene oxide (EtO) and hot steam, for example. In these methods, radiation, heat and toxicity are factors that kill microorganisms.

[0005] In medical technology, autoclaves are used for steam sterilization of medical items. Sterilization is achieved by expelling air, applying hot steam for a specified period of time, and then drying. Disinfection kills bacteria and microorganisms that pose a health risk. A disadvantage of sterilizing dialyzers in autoclaves is that drying the hydrophilic hollow fibers after hot steam sterilization is difficult and time-consuming.

[0006] AT 351 172 discloses a sterilization device for infusion solutions or the like filled in containers, the housing of which comprises a heating chamber, a sterilization chamber, and a cooling chamber.

[0007] DE 11 2005 002 948 T5 describes a hydrogen peroxide steam sterilizer and a sterilization method using the hydrogen peroxide steam sterilizer. Summary of the Invention

[0008] The object of the present invention is to optimize the sterilization and drying of filters, in particular medical filters.

[0009] This object is achieved in that the pressure chamber is divided into a first chamber and a second chamber, and the filter can be inserted into the holder such that the inlet opening of the filter is arranged in the first chamber and the outlet opening of the filter is arranged in the second chamber.

[0010] The first chamber and the second chamber can be pressurized with a pressure between 0 and 10 bar.

[0011] Advantageously, a filter, such as a dialyzer, can be placed in a holder of the device. Here, the blood inlet opening and the inlet opening for the dialysis fluid are arranged in the first chamber, while the blood outlet opening and the outlet opening for the dialysis fluid are arranged in the second chamber. The same applies to other filters or medical filters. The inlet of the chamber allows not only the removal of residual air but also the addition of hot steam or dry air. If both chambers are operated simultaneously, sterilization using, for example, a vacuum-steam method is also possible.

[0012] However, it is also advantageous to allow hot steam to enter the first chamber through the inlet for steam sterilization. This creates an overpressure in the first chamber. A pressure differential is generated between the first and second chambers. This pressure differential can be small, allowing the steam to flow slowly through the filter. For example, the pressure differential is 100 mbar at a steam temperature of 123°C. Due to the pressure differential between the two chambers, hot steam flows from the blood inlet / dialysis fluid inlet opening through the blood and dialysate chambers of the dialyzer to the blood outlet / dialysis fluid outlet opening, initially displacing any air. The dialyzer is then sterilized by applying hot steam for a predetermined time. After exiting through the blood outlet / dialysis fluid outlet opening, the hot steam can be discharged from the second chamber via the outlet. The same applies to other filters or medical filters. A combination of a vacuum steam method with a continuous steam flow through the medical filter is also possible. The temperature range for steam sterilization can be between 10 and 180°C. The duration of steam sterilization can be, for example, between 5 and 180 minutes.

[0013] The filter can be dried by evacuating both chambers several times simultaneously and then filling them with dry gas.

[0014] Advantageously, hot air can be introduced into the first chamber via the inlet in order to dry the dialyzer after steam sterilization. A pressure difference is generated between the first chamber and the second chamber. The hot air then flows through the blood chamber and the dialysate chamber of the dialyzer, thereby drying the hollow fibers. Moisture is absorbed by the hot air. After being discharged through the blood discharge opening / dialysate discharge opening, the hot air can be discharged from the second chamber via the outlet. Particularly advantageously, the dialyzer can thus be dried in less than half an hour, particularly advantageously within 20 minutes. The same applies to other filters or medical filters. The device can be operated in both horizontal and vertical orientations.

[0015] In this case, the pressure chamber is expediently divided into a first chamber and a second chamber by a partition wall.

[0016] Advantageously, provision is made here for the position of the partition wall to be movable.

[0017] The size of the first chamber and the second chamber can be varied by means of a movable separating wall.

[0018] One solution of the present invention is that the first chamber is larger than the second chamber.

[0019] Particularly advantageously, a larger area of ​​the dialyzer can be arranged in the first chamber. This allows the dialyzer to be heated from outside during the inflow of steam, thereby facilitating disinfection. Drying can also be accelerated by flowing hot air into the first chamber, which can also heat the outside of the filter and thus accelerate the drying process. The same applies to other filters or medical filters.

[0020] A further embodiment of the invention consists in that means for exerting a force on the filter located in the holder are provided in the region of the holder.

[0021] In particular, dialyzers with a housing made of polypropylene expand during steam sterilization. By applying force to the dialyzer during steam sterilization, the dialyzer's expansion can be limited. The dialyzer's expansion is limited to less than 5 mm, preferably less than 2 mm, and particularly preferably less than 1 mm. Advantageously, this allows for fluctuations in the hollow fiber bundle during steam sterilization. The force applied can be adjusted based on the fluctuations in the dialyzer and hollow fibers to be sterilized.

[0022] An advantageous embodiment of the invention provides that a spring element or a pressure cylinder is provided for exerting a force on the filter located in the holder.

[0023] The force can be applied to the filter particularly easily by means of a spring element or a pressure cylinder.

[0024] Another embodiment of the present invention is that the device comprises a water outlet for condensed water in the bottom of each of the first chamber and the second chamber.

[0025] Advantageously, the condensed steam can be led out of the pressure chamber via the water outlet.For example, a condensate separator can be provided in both chambers.

[0026] Another embodiment of the present invention is that the first chamber and the second chamber are connected to each other via a valve.

[0027] When steam is introduced for steam sterilization, the first and second chambers can be connected via an open valve. The steam can thus be distributed throughout the pressure chamber and penetrate the filter through all openings. For example, when drying the filter, the valve can be closed to allow hot air to flow through the filter due to the pressure difference between the first and second chambers.

[0028] In this case, the housing of the pressure chamber is expediently heatable.

[0029] By heating the housing of the pressure chamber, condensation of steam on the housing wall during steam sterilization is advantageously prevented or the amount of condensation is reduced.

[0030] Finally, according to the invention, the device comprises an emitter for introducing radiation energy into the filter.

[0031] The filter can be dried rapidly by introducing radiation energy into the filter. The radiation may be, for example, microwave radiation or infrared radiation.

[0032] The object is also achieved by a method for sterilizing and drying filters, in particular medical filters. The method comprises the following steps:

[0033] ●Place the filter into the holder,

[0034] · Close the pressure chamber of the equipment,

[0035] Periodic vacuuming and steaming in both chambers for initial air removal,

[0036] introducing hot air into the first chamber and passing the hot air through the filter for a predetermined time for excess air removal,

[0037] Loading both chambers with hot steam for a predetermined period of time,

[0038] By flowing hot air into the first chamber and / or the second chamber and passing the hot air through the filter, hot steam is forced out through the outlet in the first chamber and / or the second chamber until complete drying.

[0039] The object is also achieved by a method comprising the following steps:

[0040] Place the filter into the holder,

[0041] ●The pressure chamber of the closed device,

[0042] introducing hot steam into the first chamber and / or the second chamber via the inlet in order to remove the air located in the filter,

[0043] Passing hot steam through the filter for a predetermined period of time,

[0044] The hot steam is removed through an outlet in the second chamber by displacement of air,

[0045] Hot air is introduced into the first chamber and / or the second chamber and is passed through the filter until it is completely dry.

[0046] The object is also achieved by a method comprising the following steps:

[0047] Place the filter into the holder,

[0048] ●The pressure chamber of the closed device,

[0049] Periodic vacuuming and steaming in both chambers for air removal,

[0050] Loading both chambers with hot steam for a predetermined period of time,

[0051] by causing hot air to flow into the first chamber and / or the second chamber, forcing the hot steam out through an outlet in the first chamber and / or the second chamber,

[0052] Hot air is flowed into the first chamber and / or the second chamber and is passed through the filter until it is completely dry.

[0053] The three methods mentioned above are each implemented using the device according to the present invention.

[0054] In a preferred embodiment of the method, the filter is a medical filter, in particular a dialyzer, and the blood chamber of the medical filter, in particular a dialyzer, is sealed with a steam-permeable and microbiologically impermeable membrane prior to the disinfection process. Hot steam first flows through the hollow fibers of the medical filter, in particular the dialyzer, which are then exposed to the hot steam for a predetermined period of time and subsequently to hot air.

[0055] As a membrane that is vapor-permeable and impermeable to pathogens, such as microorganisms, for example, DuPont's A medical filter, in particular a blood chamber of a dialyzer, is sealed pyrogen-tightly by a vapor-permeable and microbiologically impermeable membrane. Advantageously, the blood inlet and blood outlet openings of the medical filter, in particular a dialyzer, do not need to be sterilely packaged again in the device after sterilization.

[0056] The steam-permeable and microorganism-impermeable membrane can be, for example, a 0.2 μm thick membrane sheet made of a pyrogen-tight film.

[0057] In this case, it is expedient for the dialyzer to keep the inlet and outlet openings for the dialysis fluid closed during the disinfection.

[0058] Advantageously, this facilitates the flow through the blood chamber of the dialyzer. The inlet opening and the outlet opening for the dialysis fluid can be closed, for example, with a cover.

[0059] Finally, it is within the scope of the invention that the filter is dried by inputting energy or by radiation. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Below with the aid of accompanying drawings, an embodiment of the present invention will be described in more detail.Here, the filter is a dialyzer.

[0061] Figure 1 A cross-sectional view of the device according to the invention is shown with an inserted dialyzer. DETAILED DESCRIPTION

[0062] Figure 1 A schematic diagram of an embodiment of an apparatus 1 according to the present invention with a dialyzer 2 inserted is shown. The apparatus comprises a cylindrical pressure chamber 3 having at least one inlet 4 and an outlet 5. Steam or hot air can be introduced into the pressure chamber 3 via the inlet 4. Residual air can also be removed from the chamber by means of a vacuum pump. Steam or hot air can be discharged from the pressure chamber 3 via the outlet 5. The pressure chamber 3 is divided into a first chamber 7 and a second chamber 8 arranged vertically one above the other by a movable separating wall 9. The size of the first chamber 7 and the second chamber 8 can be varied due to the mobility of the separating wall 9. The first chamber 7 and the second chamber 8 are connected by a valve 12 in the separating wall 9. The pressure chamber 3 can be opened and closed by a closing device 21. A water outlet 11 for condensed water is located at the bottom of the apparatus 1.

[0063] A support 6 for inserting the dialyzer 2 to be sterilized is located within the pressure chamber. The support has a spring element 10 for applying force to the dialyzer 2 in order to limit the expansion of the dialyzer housing 20 during steam sterilization and subsequent drying. The blood inlet opening 13 and the blood outlet opening 14 of the blood chamber of the dialyzer 2 are accommodated in the center of the support 6. The blood chamber of the dialyzer 2 is formed by hollow fibers 18. The dialyzer's dialysate chamber 19 is located between the inlet opening 16 and the outlet opening 17 for the dialysis fluid. The blood inlet opening 13 and the blood outlet opening 14 of the dialyzer's blood chamber are sealed by a steam-permeable and microbially impermeable membrane 15. Steam and air can penetrate through the steam-permeable and microbially impermeable membrane 15, but health-threatening pathogens cannot penetrate into the blood chamber of the dialyzer.

[0064] To sterilize the dialyzer 2, first a steam-permeable and microbiologically impermeable membrane 15, such as DuPont's The blood chamber of the dialyzer 2 is sealed. To this end, a steam-permeable and microbially impermeable membrane 15 is attached to the blood inlet opening 13 and the blood outlet opening 14, for example, by heat welding. In the next step, the dialyzer 2 is placed in the holder 6 and the pressure chamber 3 of the apparatus 1 is sealed. Steam is then introduced into the first chamber 7 via the inlet 4. Due to the pressure difference between the first chamber 7 and the second chamber 8, the hollow fibers of the dialyzer 2 are flowed through by steam, and the air contained in the hollow fibers is removed. The dialyzer 2 is then flowed through with steam for a predetermined period of time, for example, 15 minutes, thereby being disinfected. Hot steam is removed from the pressure chamber 3 via the outlet 5 in the second chamber 8. To dry the dialyzer, hot air is introduced into the first chamber 7 via the inlet 4. Due to the pressure difference between the first chamber 7 and the second chamber 8, the hot air flows through the hollow fibers of the dialyzer 2, whereby moisture is absorbed by the hot air. The hot air is removed from the pressure chamber 3 via the outlet 5 in the second chamber 8.

Claims

1. A device (1) for sterilizing and drying medical filters, wherein: The device (1) comprises a pressure chamber (3) and a holder (6) for at least one filter (2), the pressure chamber having at least one inlet (4) and an outlet (5), characterized in that the pressure chamber is divided into a first chamber (7) and a second chamber (8), the filter (2) being insertable into the holder (6) such that the inlet opening (13, 16) of the filter (2) is arranged in the first chamber (7) and the outlet opening (14, 17) of the filter (2) is arranged in the second chamber (8).

2. The device (1) according to claim 1, characterized in that The pressure chamber is divided into a first chamber (7) and a second chamber (8) by a separation wall (9).

3. The device according to claim 2, characterized in that The position of the separation wall (9) is movable.

4. The device (1) according to any one of claims 1 to 3, characterized in that The first chamber (7) is larger than the second chamber (8).

5. The device (1) according to any one of claims 1 to 3, characterized in that Means for exerting a force on the filter (2) located in the holder are provided in the region of the holder (6).

6. The device (1) according to claim 5, characterized in that A spring element (10) or a pressure cylinder is provided for exerting force on the filter located in the holder (6).

7. The device (1) according to any one of claims 1 to 3, characterized in that The device (1) has a water outlet (11) for condensed water in the bottom of the first chamber (7) and in the bottom of the second chamber (8).

8. The device (1) according to any one of claims 1 to 3, characterized in that The first chamber (7) and the second chamber (8) are connected to each other via a valve (12).

9. The device (1) according to any one of claims 1 to 3, characterized in that The housing of the pressure chamber (3) can be heated.

10. The device (1) according to any one of claims 1 to 3, characterized in that The device (1) has an emitter for introducing radiant energy into a filter.

11. The device (1) according to any one of claims 1 to 3, characterized in that The medical filter is a dialyzer.

12. A method for sterilizing and drying a filter (2) using the device (1) according to any one of claims 1 to 11, comprising the following steps: ●Place the filter (2) into the bracket (6), a pressure chamber (3) of a closed device (1), ● Periodic vacuuming and steaming in both chambers for initial air removal, introducing hot air into the first chamber (7) and passing the hot air through the filter (2) for a predetermined time for excess air removal, ● loading both chambers with hot steam during a predetermined time, ●By allowing hot air to flow into the first chamber (7) and / or the second chamber (8) and passing the hot air through the filter (2), hot steam is expelled through the outlet (5) in the first chamber (7) and / or the second chamber (8) until complete drying.

13. A method for sterilizing and drying a filter (2) using the device (1) according to any one of claims 1 to 11, comprising the following steps: ●Place the filter (2) into the bracket (6), a pressure chamber (3) of a closed device (1), introducing hot steam into the first chamber (7) and / or the second chamber (8) via the inlet (4) in order to remove the air located in the filter (2), - passing hot steam through the filter (2) for a predetermined period of time, The hot steam is removed through the outlet (5) in the second chamber (8) by displacement of the air, • Hot air is introduced into the first chamber (7) and / or the second chamber (8) and is passed through the filter until it is completely dry.

14. A method for sterilizing and drying a filter (2) using the device (1) according to any one of claims 1 to 11, comprising the following steps: Place the filter (2) into the bracket (6), a pressure chamber (3) of a closed device (1), Periodic vacuuming and steaming of both chambers for air removal, Loading both chambers with hot steam for a predetermined period of time, by causing hot air to flow into the first chamber (7) and / or the second chamber (8), forcing the hot steam out through the outlet (5) in the first chamber (7) and / or the second chamber (8), Hot air is flowed into the first chamber (7) and / or the second chamber (8) and is passed through the filter (2) until it is completely dried.

15. The method according to any one of claims 12 to 14, characterized in that The filter (2) is a medical filter, and the blood chamber of the medical filter is sealed with a steam-permeable and microorganism-impermeable membrane before the hot steam is introduced.

16. The method according to any one of claims 12 to 14, characterized in that The filter (2) is dried by energy input or by radiation.

17. The method according to claim 15, characterized in that The medical filter is a dialyzer.

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