JP2022044186A - Decontamination method and decontamination unit - Google Patents

Abstract

To provide a decontamination method advantageous for improving inactivation of endotoxin contaminating an object to be treated.SOLUTION: A decontamination method for inactivating endotoxin that contaminates objects to be treated contained in a chamber 11 comprises: a first decompression step S102 for reducing an inside of the chamber 11; after the first decompression step S102, a first vapor injection step S104 for injecting vapor generated from a first aqueous solution of hydrogen peroxide inside the chamber 11; after the first vapor injection step S104, an ozone injection step S107 for injecting an ozone gas inside the chamber 11; and after the ozone injection step S107, a second vapor injection step S109 for injecting vapor generated from a second aqueous solution of hydrogen peroxide inside the chamber 11. A concentration of the hydrogen peroxide contained in the second aqueous solution is below a concentration of hydrogen peroxide contained in the first aqueous solution.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a decontamination method and a decontamination device.

Medical devices used in surgery and treatment in hospitals that are reused are thoroughly washed to remove deposits such as blood and proteins, and then sterilized. On the other hand, even if bacteria and microorganisms are killed by the sterilization treatment, endotoxin constituting ribopolysaccharide may remain in the outer membrane of the bacteria and the like. Since endotoxin is a febrile substance, its inactivation is desired.

Patent Document 1 sterilizes the object to be treated and sterilizes the object to be treated by bringing the object to be treated corresponding to the above medical device into contact with a gas in which hydrogen peroxide and ozone are mixed in a chamber. Discloses technology related to decontamination methods that inactivate endotoxin that contaminates hydrogen peroxide.

Japanese Unexamined Patent Publication No. 2016-154835

According to the decontamination treatment disclosed in Patent Document 1, the desired inactivating effect of endotoxin can be obtained by adjusting the relative humidity in the chamber to suppress the occurrence of dew condensation inside. On the other hand, this decontamination treatment is carried out under substantially normal pressure conditions. Therefore, it is relatively easy to adjust the humidity during the decontamination process, but further improvement is required to obtain the desired inactivating effect of endotoxin depending on the shape and material of the medical device as the object to be treated. In some cases.

Therefore, it is an object of the present disclosure to provide a decontamination method and a decontamination apparatus which are advantageous for improving the inactivation of endotoxin that contaminates the object to be treated.

The first aspect of the present disclosure is a decontamination method for inactivating the endotoxin that contaminates the object to be treated contained in the chamber, after the first decompression step of decompressing the inside of the chamber and the first decompression step. A first steam injection step of injecting steam generated from a first aqueous solution of hydrogen peroxide into the inside of the chamber, an ozone injection step of injecting ozone gas into the inside of the chamber after the first steam injection step, and ozone. After the injection step, a second steam injection step of injecting steam generated from the second aqueous solution of hydrogen peroxide into the inside of the chamber is included, and the concentration of hydrogen peroxide contained in the second aqueous solution is the first. It is less than or equal to the concentration of hydrogen peroxide contained in the aqueous solution.

In the above decontamination method, the concentration of hydrogen peroxide contained in the first aqueous solution and the concentration of hydrogen peroxide contained in the second aqueous solution depend on the presence or absence of a lumen of the object to be treated or the material of the object to be treated. It may be specified based on. The above decontamination method may include an outside air injection step of injecting air or dry nitrogen gas into the inside of the chamber after the second steam injection step. The above-mentioned decontamination method may include a state-maintaining step of maintaining the state inside the chamber for a certain period of time after the outside air injection step. The series of steps from the first decompression step to the state holding step may be repeated a plurality of times. The above decontamination method is a first steam preparation step of injecting a first aqueous solution into the inside of an evaporator, evaporating and filling it to generate steam to be injected in the first steam injection step, and evaporating a second aqueous solution. It may include a second steam preparation step of injecting into the interior of the vessel, evaporating and filling it to produce the steam injected in the second steam injection step. In the ozone injection step, ozone gas may be injected into the chamber through the inside of the evaporator. The above decontamination method includes an aeration step of repeating exhausting the inside of the chamber and injecting air into the inside of the chamber a plurality of times to bring the inside of the chamber into a state where the object to be processed can be taken out. Then, the exhaust may be performed at least once while injecting air into the inside of the chamber.

A second aspect of the present disclosure is a decontamination apparatus, which communicates with a chamber, a chamber for accommodating an object to be treated, an exhaust unit for exhausting and reducing the pressure inside the chamber, and a chamber, and the hydrogen peroxide. An evaporator that evaporates and fills one aqueous solution, a second aqueous solution of hydrogen peroxide, or pure water, an ozone generator that communicates with the chamber to generate ozone gas, the operation of the exhaust unit, and the evaporator. A control unit for controlling the injection operation of steam or ozone gas generated by an ozone generator into the chamber is provided, and the control unit decompresses the inside of the chamber to the exhaust unit and then the inside of the chamber. Is injected with the steam generated from the first aqueous solution and then the ozone gas is injected, and after the ozone gas is injected, the steam generated from the pure water or the steam generated from the second aqueous solution is injected to prepare the object to be treated. Inactivates contaminating endotoxins.

According to the present disclosure, it is possible to provide a decontamination method and a decontamination apparatus which are advantageous for improving the inactivation of endotoxin that contaminates an object to be treated.

It is a schematic diagram which shows the structure of the decontamination apparatus which concerns on 1st Embodiment. It is a flowchart which shows the flow of the decontamination method which concerns on 1st Embodiment. It is a table which shows each processing mode carried out by the decontamination apparatus which concerns on 1st Embodiment. It is a graph which shows the pressure change in a chamber in 1st Embodiment. It is a flowchart which shows the flow of the decontamination method which concerns on 2nd Embodiment. It is a graph which shows the pressure change in the chamber in 2nd Embodiment.

Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings. Here, the dimensions, materials, and other specific numerical values shown in each embodiment are merely examples, and the present disclosure is not limited unless otherwise specified. Further, elements having substantially the same function and configuration are designated by the same reference numerals to omit duplicate explanations, and elements not directly related to the present disclosure are omitted from the illustration.

(First Embodiment)
FIG. 1 is a schematic view showing the configuration of the decontamination device 100 according to the first embodiment. The decontamination device 100 uses the treatment gas to sterilize the object to be treated and inactivate the endotoxin that contaminates the object to be treated. The substances constituting the processing gas used in this embodiment are mainly hydrogen peroxide (H ₂ O ₂ ) and ozone (O ₃ ). Endotoxin is a febrile substance that exists in the outer membrane of Gram-negative bacteria and contains lipopolysaccharide (hereinafter referred to as "LPS") as a component.

The object to be treated is assumed to be a medical device used for surgery or treatment in a hospital and in contact with a vascular system or sterile tissue. Such medical devices include, for example, heat-resistant steel products such as forceps, knives, and shear blades, stainless steel rigid endoscopes for laparoscopic surgery, and flexible endoscopes for bronchial and urinary surgery. And its accessories include non-heat resistant resin products such as power cables. Further, the object to be treated shall be housed in the chamber 11 of the decontamination device 100 in a state of being previously put in a sterilization bag or wrapped in a sterilization wrap in advance. Sterilization bags and sterilization wraps are non-woven fabrics mainly made of resins such as polyethylene, and because the mesh is fine, processing gas can pass through, but bacteria cannot.

The decontamination device 100 includes a chamber unit 10, a hydrogen peroxide supply unit 20, an ozone supply unit 30, an exhaust unit 40, an atmosphere introduction unit 50, and a control unit 60.

The chamber unit 10 includes a chamber 11 for accommodating an object to be processed and a peripheral configuration thereof. The chamber unit 10 includes a chamber 11 including a door 12, a first heater 13, and a first pressure gauge 14.

The chamber 11 is a container in which the object to be processed can be arranged and accommodated. The chamber 11 is made of stainless steel or an aluminum alloy and has a structure that can withstand vacuum and reduced pressure. Hereinafter, as an example, it is assumed that the internal volume of the chamber 11 is 100 L. The door 12 can be opened and closed with respect to the chamber 11. When the door 12 is closed and the inside of the chamber 11 is depressurized, the chamber 11 is sealed in order to suppress a vacuum leak and a leakage of the processing gas.

The first heater 13 is installed around the chamber 11 together with the heat insulating material, and keeps the temperature inside the chamber 11 constant during the decontamination process. The temperature of the chamber 11 is measured by a thermometer (not shown) installed in the chamber 11.

The first pressure gauge 14 is a vacuum gauge installed in the chamber 11 and measures the pressure inside the chamber 11.

The hydrogen peroxide supply unit 20 supplies hydrogen peroxide vapor to the chamber 11 during the decontamination process. In the present embodiment, the hydrogen peroxide supply unit 20 can individually supply steam generated from two aqueous solutions of hydrogen peroxide. Hereinafter, one aqueous solution of hydrogen peroxide is referred to as "first aqueous solution", and the other aqueous solution of hydrogen peroxide is referred to as "second aqueous solution". The concentration of hydrogen peroxide contained in the first aqueous solution and the concentration of hydrogen peroxide contained in the second aqueous solution will be described in detail below, but are based on the presence or absence of a lumen of the object to be treated and the material of the object to be treated. It is stipulated. The hydrogen peroxide supply unit 20 includes a bottle 21, an extraction pipe 22, a tube pump 23, a storage unit 24, an evaporator 26, and a second heater 29.

The bottle 21 contains an aqueous solution of hydrogen peroxide. The bottle 21 is also called a cartridge if it is used as a so-called disposable item. In this embodiment, since two aqueous solutions of hydrogen peroxide are used, there are a first bottle 21a containing the first aqueous solution and a second bottle 21b containing the second aqueous solution.

The extraction pipe 22 extracts an aqueous solution of hydrogen peroxide from the bottle 21 and supplies the extracted aqueous solution to the storage unit 24. In the present embodiment, there is a first extraction pipe 22a for extracting the first aqueous solution from the first bottle 21a and a second extraction pipe 22b for extracting the second aqueous solution from the second bottle 21b.

The tube pump 23 is installed in the middle of the extraction pipe 22, and sucks out an appropriate amount of an aqueous solution of hydrogen peroxide from the bottle 21. In the present embodiment, there is a first tube pump 23a installed in the middle of the first extraction pipe 22a and a second tube pump 23b installed in the middle of the second extraction pipe 22b. Further, although not shown, the extraction pipe 22 may be provided with, for example, an optical liquid level sensor. The tube pump 23 pumps up an aqueous solution of hydrogen peroxide until the liquid level sensor reacts, and when the liquid level sensor reacts, it stops once and then rotates by a predetermined rotation speed to supply a specified amount to the storage unit 24. ..

The storage unit 24 is connected to the extraction pipe 22 and temporarily stores a predetermined amount of hydrogen peroxide aqueous solution sucked up from the bottle 21 before being sent to the evaporator 26. As the storage unit 24, a translucent fluororesin tube or the like in which the amount of liquid inside can be seen can be adopted. Since the tube pump 23 can stably supply a fixed amount when it is driven under atmospheric pressure, the storage unit 24 may introduce the atmosphere through the first filter 25 so as to have an atmospheric pressure. The first filter 25 is, for example, a HEPA filter.

The evaporator 26 communicates with the storage unit 24 via the first supply pipe 27 and evaporates the aqueous solution of hydrogen peroxide introduced from the storage unit 24. The evaporator 26 is made of, for example, stainless steel so as to withstand the corrosion of hydrogen peroxide, and is depressurized at the same time as the chamber 11, so that it has a structure capable of withstanding vacuum and depressurization.

A first solenoid valve 70 is installed in the first supply pipe 27. When the first solenoid valve 70 is opened, the aqueous solution of hydrogen peroxide in the storage unit 24 is sucked toward the depressurized evaporator 26. At this time, since the storage unit 24 introduces the atmosphere through the first filter 25 and is under atmospheric pressure, the atmosphere is also sucked together with the aqueous solution of hydrogen peroxide. As a result, the hydrogen peroxide aqueous solution remaining in the storage unit 24 and the first supply pipe 27 is also sucked into the evaporator 26, so that the hydrogen peroxide vapor is quantitatively and stably sent into the chamber 11. ..

Further, the evaporator 26 communicates with the chamber 11 via a plurality of injection pipes 28. In the present embodiment, there are a first injection pipe 28a and a second injection pipe 28b installed diagonally to each other on the ceiling portion. A second solenoid valve 71 is installed in the first injection pipe 28a, and a third solenoid valve 72 is installed in the second injection pipe 28b. When the aqueous solution of hydrogen peroxide evaporates in the evaporator 26 and the pressure inside the evaporator 26 increases, the second solenoid valve 71 or the third solenoid valve 72 is opened for a certain period of time to obtain the aqueous solution of hydrogen hydrogen. Steam is injected into the chamber 11. By installing a plurality of injection pipes 28 in this way, the diffusion of steam inside the chamber 11 becomes more uniform. Further, the evaporator 26 is provided with a pressure sensor 39 for determining whether or not a specified amount of steam has been supplied from the storage unit 24 depending on whether or not the pressure is within a predetermined pressure range after the injection of steam. May be good.

The second heater 29 is installed around the evaporator 26 and keeps the temperature inside the evaporator 26 constant. The inside of the evaporator 26 is kept constant at a predetermined temperature, for example, between 65 and 120 ° C.

The ozone supply unit 30 supplies ozone gas to the chamber 11 during the decontamination process. In this embodiment, ozone gas is generated in the ozone supply unit 30. The ozone supply unit 30 includes an oxygen generator 31, an ozone generator 32, an ozone concentration meter 33, a buffer tank 34, and a second pressure gauge 35.

The oxygen generator 31 generates oxygen (O ₂ ), which is a raw material for ozone. As a method of the oxygen generator 31, for example, a PSA (Pressure Swing Adsorption) method can be adopted in which nitrogen in the air is adsorbed by an adsorbent such as zeolite to generate high-concentration oxygen. Specifically, the oxygen generator 31 may be a PSA device having a discharge pressure of about 0.03 to 0.08 MPa as a gauge pressure and a flow rate of about 1 to 4 L / min. A fourth solenoid valve 73 is installed in a pipe that connects the oxygen generator 31 and the ozone generator 32. By appropriately controlling the opening and closing of the fourth solenoid valve 73, the amount of oxygen supplied to the ozone generator 32 is adjusted.

The ozone generator 32 generates ozone gas from the oxygen generated by the oxygen generator 31. As a method of the ozone generator 32, for example, a silent discharge method that generates ozone by applying a high frequency high voltage to oxygen to discharge and decompose it can be adopted. In the ozone supply unit 30, as an example, there are two ozone generators 32. For example, the generation capacity of the ozone generator 32 is expressed as (2 g / hr × 2 units) = 4 g / hr. In this case, the ozone generator 32 operates for 1.5 minutes while receiving the supply of oxygen of 1 L / min, for example, to generate (4 g × 1.5 minutes / 60 minutes) = 0.1 g of ozone. be able to. The ozone generator 32 communicates with the buffer tank 34 via the second supply pipe 36.

The ozone densitometer 33 measures the concentration of the ozone gas generated by the ozone generator 32 in the second supply pipe 36. For example, it is assumed that the measured value of the ozone densitometer 33 when ozone gas is passed through the second supply pipe 36 for 1.5 minutes at a flow rate of 1 L / min is 70 g / m ³ . In this case, the amount of ozone generated corresponds to (1 L / min × 1.5 minutes × 70 g / 1000 L) = 0.105 g. Then, it is assumed that 0.105 g of ozone gas is injected into the chamber 11 having a volume of 100 L, and further air is introduced to reach atmospheric pressure. The ozone concentration in the chamber 11 at this time corresponds to a volume concentration of (0.105 g / 48 g × 22.4 L / 100 L × 1,000,000) = 490 ppm from the molecular weight 48 of ozone and 22.4 L of the standard gas.

A fifth solenoid valve 74 is installed between the ozone densitometer 33 and the buffer tank 34 in the second supply pipe 36. Further, the ozone densitometer 33 and the fifth solenoid valve 74 in the second supply pipe 36 may communicate with the exhaust unit 40 via the pipe system X including the sixth solenoid valve 75. That is, when the fifth solenoid valve 74 is closed and the sixth solenoid valve 75 is open, the ozone gas circulated from the ozone generator 32 is supplied to the exhaust unit 40 side.

The buffer tank 34 temporarily stores the ozone gas generated by the ozone generator 32 before sending it to the evaporator 26. The buffer tank 34 is made of, for example, stainless steel so as to withstand the corrosion of hydrogen peroxide, and has a structure capable of withstanding reduced pressure. Hereinafter, as an example, the volume of the buffer tank 34 is assumed to be 2 L. The buffer tank 34 communicates with the evaporator 26 via a third supply pipe 37. A seventh solenoid valve 76 is installed in the third supply pipe 37. If ozone gas is injected into the buffer tank 34 when the seventh solenoid valve 76 is closed, the pressure inside the buffer tank 34 temporarily increases.

The second pressure gauge 35 is a vacuum gauge installed in the buffer tank 34 and measures the pressure inside the buffer tank 34. The control unit 61 monitors the pressure inside the buffer tank 34 by using the second pressure gauge 35, so that ozone is injected into the buffer tank 34 to a predetermined pressure, or the second supply pipe 36 or the like is used. It is possible to check whether ozone leakage or clogging has occurred.

Further, in the present embodiment, the ozone gas supplied from the buffer tank 34 is not directly injected into the chamber 11, but is injected via the evaporator 26. That is, the port for introducing the processing gas into the chamber 11 is common to hydrogen peroxide and ozone gas.

As another embodiment, the ozone gas may be directly charged into the chamber 11 from the buffer tank 34 without passing through the evaporator 26. In this case, since the ozone gas is injected into the chamber 11 without passing through the evaporator 26, there is an advantage that the diffusion of the ozone gas in the chamber 11 is accelerated. Further, in this case, if the second solenoid valve 71 and the third solenoid valve 72 between the evaporator 26 and the chamber 11 are closed, there is an advantage that the ozone concentration in the chamber 11 becomes high.

By exhausting the atmosphere inside the chamber 11, the exhaust unit 40 decompresses the inside of the chamber 11 and discharges the gas existing inside the chamber 11 to the outside. Specifically, in order to improve the decontamination effect at the time of the decontamination treatment, the exhaust unit 40 removes excess gas from the chamber 11 and the object to be treated itself before the decontamination treatment, for example, 100 Pa or less. The inside of the chamber 11 is depressurized to a medium vacuum level. Further, the exhaust unit 40 removes the processing gas remaining in the chamber 11 and the object to be processed after the decontamination treatment. The exhaust unit 40 includes a vacuum pump 41, a catalyst tank, and a heater.

As the vacuum pump 41, for example, a dry pump such as a scroll pump compatible with medium vacuum or an oil rotary pump such as a rotary pump can be adopted. In this embodiment, the vacuum pump 41 is an oil rotary pump. The vacuum pump 41 and the chamber 11 communicate with each other via an exhaust pipe 38. An eighth solenoid valve 77 is installed in the exhaust pipe 38. For example, at the time of depressurization, when the pressure inside the chamber 11 reaches a predetermined value, the control unit 61 closes the eighth solenoid valve 77 and stops the operation of the vacuum pump 41.

The catalyst tank is made of, for example, stainless steel and contains a catalyst such as a pellet type or a honeycomb type. The catalyst, for example, contains manganese dioxide as a main component and decomposes hydrogen peroxide and ozone. In this embodiment, in consideration of decomposing the gas that may corrode the vacuum pump and maintaining an appropriate exhaust speed, there are two catalyst tanks, one on the upstream side and the other on the downstream side of the vacuum pump 41. It is installed in. The first catalyst tank 42 is a catalyst tank installed on the upstream side of the vacuum pump 41. The second catalyst tank 43 is a catalyst tank installed on the downstream side of the vacuum pump 41.

Here, as described above, the ozone supply unit 30 supplies ozone gas to the exhaust unit 40 via the piping system X by appropriately controlling the ozone generator 32, the fifth solenoid valve 74, and the sixth solenoid valve 75. It is possible.

The heater keeps the catalyst tank warm at, for example, 60 to 90 ° C. The third heater 44 keeps the first catalyst tank 42 warm. The fourth heater 45 keeps the second catalyst tank 43 warm.

The atmosphere introduction unit 50 introduces the atmosphere into the chamber 11. The atmosphere introduction unit 50 includes a second filter 51 and a plurality of introduction ports.

The second filter 51 prevents dust in the atmosphere from entering the inside of the chamber 11 when the atmosphere is introduced. As the second filter 51, for example, a HEPA filter, which is a fine-grained non-woven fabric filter, can be adopted.

The introduction port introduces the atmosphere introduced through the second filter 51 into the chamber 11. It is desirable that a plurality of introduction ports are installed at different positions in the chamber 11 in order to equalize the gas concentration inside the chamber 11 in accordance with the introduction of the atmosphere. In the present embodiment, as an example, there are two introduction ports, a first introduction port 52 and a second introduction port 53, which are installed diagonally to each other on the ceiling portion. A ninth solenoid valve 78 is installed in the first introduction port 52. A tenth solenoid valve 79 is installed in the second introduction port 53. By individually controlling the opening and closing of the ninth solenoid valve 78 or the tenth solenoid valve 79, the control unit 61 can introduce the atmosphere into the chamber 11 from different positions at appropriate timings.

The introduction port is not limited to the one provided directly to the chamber 11. As another embodiment, the introduction port may be continuous to the chamber 11 via, for example, the evaporator 26. Alternatively, the introduction port may be continuous to the chamber 11 via, for example, the buffer tank 34. Further, the introduction port may be continuous to the chamber 11 via both the evaporator 26 and the buffer tank 34, for example.

The control unit 60 controls the driving of the power system elements in each unit constituting the decontamination device 100 based on various operation commands. The control unit 60 includes a control unit 61 and a touch panel 62. The control unit 61 is electrically connected to various power system elements, measurement system elements, and the like. The control unit 61 controls the operation of various power system elements based on, for example, a command input via the touch panel 62, a control sequence held in advance, a detection signal from each sensor, or the like. The touch panel 62 is electrically connected to the control unit 61 and is used by the operator to input information and commands and to visually recognize the information presented from the device side.

Next, the flow of the decontamination method according to the present embodiment using the decontamination apparatus 100 will be described.

FIG. 2 is a flowchart showing the flow of the decontamination method according to the present embodiment. The decontamination treatment by the decontamination method according to the present embodiment is roughly classified into, for example, three steps. The first first step is a pretreatment step including the treatment mode selection step S101. The second step is a sterilization / decontamination step including each step from the first decompression step S102 to the second state holding step S111. The final third step is the aeration step S113.

First, before starting the processing mode selection step S101, an operator such as a hospital nurse arranges an object to be processed in the chamber 11 and closes the door 12 to seal the inside of the chamber 11. At this point, it is assumed that the power of the decontamination device 100 is already turned on and the warm-up operation or the like is completed.

In the decontamination process in the present embodiment, the operator can select the process mode according to the type of the object to be processed. The type of the object to be processed is classified, for example, from the shape and material of the object to be processed. In particular, the shape of the object to be treated may be classified according to the presence or absence of a lumen. The processing mode selection step S101 is a step of inputting the processing mode selected by the operator to the decontamination apparatus 100.

FIG. 3 is a table showing each processing mode that can be carried out by the decontamination apparatus 100. As the processing mode, for example, the following four modes may be set. The short mode is applied when the object to be treated is a medical device having no lumen. The medical device in this case is mainly surface-sterilized, for example, a steel product such as forceps. The standard mode is applied when the object to be treated is a resin medical device having a lumen. The long mode is applied when the object to be treated is a stainless steel medical device with a lumen. The medical device in this case is, for example, a rigid endoscope having a thin tube having an inner diameter of about 1 mm. Further, the endotoxin inactivation specialized mode is applied when the endotoxin inactivation rate is required to be 99.9% or more. The object to be treated in this case may be, for example, a resin medical device having a lumen, similar to the object to be treated applied in the standard mode.

For each treatment mode, for example, the treatment time in the subsequent steps, the injection amount of the aqueous solution of hydrogen peroxide, or the number of exposures is different. Here, in the column of the injection amount of the aqueous solution of hydrogen peroxide in the table in FIG. 3, the range in which the numerical value per pulse corresponding to one series of sterilization steps can be taken is described. In particular, the upper row shows the algebra related to the injection amount of the first aqueous solution, and the lower row shows the algebra related to the injection amount of the second aqueous solution.

The sterilization / decontamination step according to the present embodiment first includes a first decompression step S102, a first steam preparation step S103, a first steam injection step S104, and a first state holding step S105.

The first decompression step S102 is a step of exhausting excess gas contained in the object to be processed by depressurizing the inside of the chamber 11 to a certain degree of vacuum. After starting the vacuum pump 41, the control unit 61 opens the eighth solenoid valve 77 to reduce the pressure inside the chamber 11. At this time, the control unit 61 opens the second solenoid valve 71, the third solenoid valve 72, and the seventh solenoid valve 76, respectively, to reduce the pressure inside each of the evaporator 26 and the buffer tank 34 together with the chamber 11. Let me. The processing time in the table in FIG. 3 is calculated from the time when the depressurization starts at this time. The target pressure in the first decompression step S102 is 50 Pa or less. When the target pressure is reached, the control unit 61 closes the second solenoid valve 71, the third solenoid valve 72, the seventh solenoid valve 76, and the eighth solenoid valve 77, and stops the vacuum pump 41. The control unit 61 shifts to the first steam preparation step S103 after the first decompression step S102.

Here, when the processing mode is the long mode, the object to be processed is, for example, a thin tube made of stainless steel. Therefore, when the long mode is selected, the temperature of the object to be treated is raised in advance, and the pressure is maintained for a certain period of time, for example, about 2 minutes, so that the influence of dew condensation in the lumen is minimized. You may.

The first steam preparation step S103 is a step of generating steam of the first aqueous solution to be injected in the next first steam injection step S104. First, the control unit 61 rotates the first tube pump 23a to suck up the first aqueous solution from the first bottle 21a, and then injects a predetermined amount into the storage unit 24 in equal divisions. Here, the specified amount is the total input amount per pulse, and as shown in FIG. 3, it differs depending on the processing mode. For example, when the treatment mode is the short mode, the concentration of hydrogen peroxide contained in the first aqueous solution is a predetermined concentration (x1) between 30 and 60%, and the specified amount is between 1 and 4 ml. It is a predetermined amount (y1). For example, when the specified amount is divided into two and charged, the amount of the specified amount evenly divided is a predetermined amount (y1 / 2) between 0.5 and 2 ml, which is half of y1. Next, the control unit 61 opens the first solenoid valve 70 for a certain period of time, for example, 5 seconds. Since the inside of the evaporator 26 has already been depressurized, the first aqueous solution is instantly sucked into the evaporator 26. At this time, since the storage unit 24 communicates with the atmosphere through the first filter 25, when the air enters the storage unit 24, the first aqueous solution remaining in the storage unit 24, the first supply pipe 27, and the like is also an evaporator. It will be sent to 26. Next, the control unit 61 closes the first solenoid valve 70 and evaporates the first aqueous solution with the evaporator 26 for a certain period of time, for example, 5 seconds. At this time, the evaporator 26 is constantly heated at a predetermined temperature, for example, between 65 and 120 ° C. For example, when the amount of the first aqueous solution is adjusted so as to evaporate almost completely inside the evaporator 26 having a volume of 0.5 to 2 L and a pressure of 50 Pa, the saturated vapor pressure is applied. It is thought that the pressure will increase to a certain extent. The control unit 61 shifts to the first steam injection step S104 after the first steam preparation step S103.

The first steam injection step S104 is a step of injecting the steam of the first aqueous solution generated by the evaporator 26 into the inside of the chamber 11. First, the control unit 61 opens the second solenoid valve 71 and the third solenoid valve 72 for a certain period of time, for example, 10 seconds. As a result, the steam of the first aqueous solution is vigorously injected into the chamber 11 according to the pressure difference. At this time, when the object to be treated has a lumen in particular, the larger the pressure difference, the easier it is for the vapor to permeate into the inside of the lumen. Further, as described above, the steam is easily homogenized inside the chamber 11. Next, the control unit 61 closes the second solenoid valve 71 and the third solenoid valve 72. After that, the control unit 61 repeats the injection of the steam of the first aqueous solution in the same procedure according to the processing mode. For example, when the processing mode is the short mode, the vapor of a predetermined amount (y1) of the first aqueous solution between a predetermined concentration (x1) × 1 to 4 ml between 30 and 60% per pulse is evaporated 26. Will be injected into. At this time, if a large amount of the first aqueous solution is injected at one time, the saturated vapor pressure is reached inside the evaporator 26, and the first aqueous solution may not be sufficiently evaporated and may remain. Therefore, the control unit 61 may evaporate the first aqueous solution in two portions, for example, half each, and inject it into the chamber 11 each time. Here, the control unit 61 may inject the steam of the first aqueous solution into a plurality of times. The control unit 61 shifts to the first state holding step S105 after the first steam injection step S104.

The first state holding step S105 is a step of sterilizing the object to be treated and inactivating endotoxin by holding the vapor of the first aqueous solution in the chamber 11 for a certain period of time. The holding time at this time differs depending on the processing mode. The holding time in the short mode is, for example, 3 minutes. The holding time in the standard mode is, for example, 4 minutes. The holding time in the long mode is, for example, 6 minutes. That is, the holding time gradually increases in the order of short mode, standard mode, and long mode. On the other hand, the retention time in the endotoxin inactivation specialized mode may be the same as the retention time in the standard mode.

Next, the sterilization / decontamination step includes an ozone preparation step S106 and an ozone injection step S107.

The ozone preparation step S106 is a step of generating ozone gas to be injected in the next ozone injection step S107. The ozone preparation step S106 is not necessarily executed after waiting for the end of the first state holding step S105, but may be executed before the ozone injection step S107 is started, and ozone gas may be prepared. First, the control unit 61 opens the fourth solenoid valve 73 to supply oxygen having a concentration of, for example, 95% to the ozone generator 32. Here, the control unit 61 closes the fifth solenoid valve 74 and opens the sixth solenoid valve 75 for about several tens of seconds after driving the ozone generator 32, so that the oxygen and ozone concentrations are increased. Ozone gas may not be sent to the buffer tank 34 but may flow into the piping system of the first catalyst tank 42 until it becomes stable. Next, the control unit 61 closes the sixth solenoid valve 75 and opens the fifth solenoid valve 74, so that the buffer tank 34 is filled with ozone gas for a constant flow rate, a constant concentration, and a constant time. Next, the control unit 61 closes the fifth solenoid valve 74 and stops the drive of the ozone generator 32 after the filling of the buffer tank 34 with ozone gas is completed.

The ozone injection step S107 is a step of injecting the ozone gas generated in the ozone preparation step S106 into the chamber 11. The ozone injection step S107 is executed after the first state holding step S105 is completed. The control unit 61 opens the seventh solenoid valve 76, the second solenoid valve 71, and the third solenoid valve 72 for a certain period of time, for example, for 5 seconds, and injects ozone gas into the chamber 11. Here, the pressure inside the buffer tank 34 is, for example, a predetermined pressure having a maximum gauge pressure of about 0.03 to 0.08 MPa, or a predetermined pressure having an absolute pressure of about 0.13 to 0.18 MPa. Pressure. Therefore, it is assumed that the injection of ozone gas into the chamber 11 under reduced pressure having an absolute pressure of 3000 Pa or less is completed in about several seconds due to this pressure difference. That is, by adopting the buffer tank 34, the decontamination device 100 can efficiently inject a small amount of ozone into the chamber 11 and contribute to sterilization.

Next, the sterilization / decontamination step includes a second steam preparation step S108, a second steam injection step S109, an outside air injection step S110, and a second state holding step S111.

The second steam preparation step S108 is a step of generating steam of the second aqueous solution to be injected in the next second steam injection step S109. The second steam preparation step S108 is not necessarily executed after waiting for the completion of the ozone injection step S107, but is executed before the second steam injection step S109 is started, and the steam of the second aqueous solution is prepared. Just do it. The generation of the steam of the second aqueous solution may be performed in the same procedure as the generation of the steam of the first aqueous solution in the first steam preparation step S103.

First, the control unit 61 rotates the second tube pump 23b to suck up the second aqueous solution from the second bottle 21b, and then injects a predetermined amount into the storage unit 24 in equal divisions. For example, when the treatment mode is the short mode, the concentration of hydrogen peroxide contained in the second aqueous solution is a predetermined concentration (x2) between 0.1 and 10%, and the specified amount is 2 to 8 ml. It is a predetermined amount (y2) between. For example, when the specified amount is divided into two and charged, the amount of the specified amount evenly divided is a predetermined amount (y2 ÷ 2) between 1 and 4 ml, which is half of y2. Next, the control unit 61 opens the first solenoid valve 70 for a certain period of time, for example, 5 seconds. Since the inside of the evaporator 26 has already been depressurized, the second aqueous solution is instantly sucked into the evaporator 26. At this time, since the storage unit 24 communicates with the atmosphere through the first filter 25, when the air enters the storage unit 24, the second aqueous solution remaining in the storage unit 24, the first supply pipe 27, and the like is also an evaporator. It will be sent to 26. Next, the control unit 61 closes the first solenoid valve 70 and evaporates the second aqueous solution with the evaporator 26 for a certain period of time, for example, 5 seconds. At this time, the evaporator 26 is constantly heated at a predetermined temperature, for example, between 65 and 120 ° C. For example, when the amount of the second aqueous solution is adjusted so as to evaporate almost completely inside the evaporator 26 having a volume of 0.5 to 2 L and a pressure of 50 Pa, the saturated vapor pressure is applied. It is thought that the pressure will increase to a certain extent. The control unit 61 shifts to the second steam injection step S109 after the second steam preparation step S108.

The second steam injection step S109 is a step of injecting the steam of the second aqueous solution generated by the evaporator 26 into the chamber 11. Ozone gas alone is difficult to contribute to sterilization and endotoxin inactivation, but the addition of water increases the reactivity. It is considered that this is because OH radicals and the like are generated when ozone reacts with water or residual hydrogen peroxide on the surface of the bacterium, effectively destroying the cell wall of the bacterium. Therefore, in the present embodiment, the steam of the second aqueous solution is immediately injected into the inside of the chamber 11 after the injection of ozone gas is completed. Hydrogen peroxide in the steam injected into the chamber 11 invades bacterial cells from the cell wall destroyed by ozone and attacks the cell nucleus, improving the sterilization effect and endotoxin inactivation effect. It is presumed that it is.

When the concentration of hydrogen peroxide contained in the second aqueous solution is higher, the sterilizing effect and the inactivating effect of endotoxin are increased. In some cases, the treatment time can be shortened by increasing the concentration of hydrogen peroxide contained in the second aqueous solution in this way. Therefore, in the present embodiment, as an example, when the treatment mode is the long mode, the concentration of hydrogen peroxide contained in the second aqueous solution is 30 to 60%, which is equivalent to the concentration of hydrogen peroxide contained in the first aqueous solution. It is set to a predetermined value (x1) between. On the other hand, the input amount per pulse is a predetermined amount (y2) between 2 and 8 ml in the short mode and the standard mode, whereas it is a predetermined amount between 1 and 5 ml in the long mode. It can be set as low as (y3).

As described above, the second steam injection step S109 is executed immediately after the ozone injection step S107 is completed. The injection of the steam of the second aqueous solution may be performed in the same procedure as the injection of the steam of the first aqueous solution in the first steam injection step S104.

First, the control unit 61 opens the second solenoid valve 71 and the third solenoid valve 72 for a certain period of time, for example, 10 seconds, and injects the steam of the second aqueous solution into the chamber 11. Next, the control unit 61 closes the second solenoid valve 71 and the third solenoid valve 72. After that, the control unit 61 repeats the injection of the steam of the second aqueous solution in the same procedure according to the processing mode. Again, when the processing mode is the short mode, the control unit 61 evaporates the second aqueous solution in two portions, for example, half of y2 (2 to 8 ml), and injects the second aqueous solution into the chamber 11 each time. You may. Alternatively, the control unit 61 may further inject the steam of the second aqueous solution into a plurality of times. The control unit 61 shifts to the outside air injection step S110 after the second steam injection step S109.

The outside air injection step S110 is a step of injecting outside air, which is air or dry nitrogen gas, into the inside of the chamber 11. In the present embodiment, as an example, it is assumed that the outside air is the atmosphere. The outside air injection step S110 is executed immediately after the second steam injection step S109 is completed. By injecting air into the chamber 11, for example, hydrogen peroxide and ozone gas that have stagnated in the middle of the lumen of the object to be treated having a lumen are pushed in, resulting in sterilization and inactivation of endotoxin. Is further promoted. Further, by injecting air into the chamber 11, the concentration distribution of the gas existing in the chamber 11 becomes uniform, and sterilization and endotoxin inactivation are performed evenly. Further, when the atmosphere is injected into the chamber 11, the internal pressure rises and hydrogen peroxide in the vapor is slightly condensed on the surface of the object to be treated, so that the sterilization effect and the endotoxin inactivation effect can be obtained. improves. Condensation here is sometimes called microcondensation.

The control unit 61 injects the atmosphere into the chamber 11 via the atmosphere introduction unit 50. Specifically, the control unit 61 adjusts the injection amount of the atmosphere introduced through the second filter 51 by appropriately controlling the opening and closing of the ninth solenoid valve 78 and the tenth solenoid valve 79. At this time, the atmosphere is injected until a certain pressure is reached. In the present embodiment, the control unit 61 closes the ninth solenoid valve 78 and the tenth solenoid valve 79 after injecting the atmosphere until the pressure inside the chamber 11 reaches about 90 kPa, which is about 90% of the atmospheric pressure. .. This is because if the internal pressure and the external pressure of the chamber 11 become the same, gas may leak to the outside from the sealed portion of the door 12. The control unit 61 shifts to the second state holding step S111 after the outside air injection step S110.

As described above, the outside air injection step S110 is particularly effective when selecting a standard mode, a long mode, or an endotoxin inactivation specialized mode, which is applied when the object to be treated has a lumen. On the other hand, in the case of a short mode in which the object to be treated does not have a lumen and the surface of the object to be sterilized is mainly performed, if the desired sterilization effect and endotoxin inactivating effect can be obtained, From the viewpoint of simplifying the process contents, the outside air injection step S110 may not be executed.

The second state holding step S111 is a step of holding the internal state of the chamber 11 for a certain period of time after the outside air injection step S110 is completed. By maintaining the internal state of the chamber 11 for a certain period of time in this way, the sterilizing action and the endotoxin inactivating action as described in the outside air injection step S110 are further promoted. The holding time here differs depending on the processing mode. The holding time in the short mode is, for example, 2 minutes. The retention time in the standard mode or the endotoxin inactivation specialized mode is, for example, 3 minutes. The holding time in the long mode is, for example, 5 minutes.

The sterilization / decontamination step up to this point may be repeated as many times as necessary depending on the shape and material of the object to be treated, the required sterilization effect, or the endotoxin inactivation effect. Therefore, the control unit 61 determines whether or not it is necessary to repeat a series of sterilization / decontamination steps after the second state holding step S111 is completed (S112). One sterilization / decontamination step is counted as one exposure, and the number of exposures is hereinafter expressed as the number of pulses. Here, when the control unit 61 determines that a further sterilization / decontamination step is required (YES), the control unit 61 shifts to the first decompression step S102 and executes the second pulse sterilization / decontamination step. On the other hand, when the control unit 61 determines that a further sterilization / decontamination step is not required (NO), the control unit 61 shifts to the next aeration step S113.

Here, when focusing on the sterility effect, the required number of pulses is specified so that a sterility guarantee level (SAL < ^10-6 ) of ^10-6 or less is realized. note that. In order to achieve this level, it is a condition that 10 to ⁶ or more indicator bacteria are completely killed in the half-cycle sterilization / decontamination process corresponding to one pulse. In the present embodiment, as an example, two pulses are set as a full cycle in the short mode, the standard mode, and the long mode.

On the other hand, when focusing on the inactivating effect of endotoxin, the required number of pulses can be set as follows.

First, in order to finally verify the inactivating effect of endotoxin on the number of pulses, the following decontamination test was carried out using the decontamination device 100, and the inactivation rates obtained for each test condition were compared with each other. did. In each test, dried Escherichia coli killed bacteria were used as LPS, which is a bacterial cell. Specifically, a method of dissolving the cells in water, applying them evenly to a vial tube having a body diameter of φ40 mm so that the amount of the cells applied is 1 μg, and drying the cells is used for each production condition. Three samples were prepared. Then, after exposing the treatment gas under predetermined test conditions, the amount of endotoxin was quantitatively measured using a LAL (Limulus Amebocyte Lysate) reagent, and the inactivation rate was determined by comparing with the initial value.

Further, as a reference condition for carrying out the test, the volume of the chamber 11 is 100 L, and the chamber 11 is preheated to 50 ° C. Only the sample is previously stored in the chamber 11. The input amount of the first aqueous solution (hydrogen peroxide aqueous solution) is 45% × 2 ml per pulse. The net amount of hydrogen peroxide in this case is 1.05 g per pulse. The input amount of the second aqueous solution (hydrogen peroxide aqueous solution) is 3% × 5 ml per pulse. The net amount of hydrogen peroxide in this case is 0.15 g per pulse. The ozone injection amount is 0.1 g per pulse. The amount of ozone injected corresponds to 300 to 400 ppm at atmospheric pressure and room temperature. The processing time required for the sterilization / decontamination process per pulse is about 11 minutes.

Here, as the first decontamination test, the inactivation rates for each type of treated gas are compared. First, regarding the decontamination method according to the present embodiment in which hydrogen peroxide and ozone are used in combination as the treatment gas, when the decontamination test in which the above sterilization / decontamination steps are repeated for 6 pulses is performed three times, the decontamination is performed three times. In both the dyeing tests, the inactivation rate was 99.9% or more. On the other hand, as a comparative example, when a decontamination test was carried out once in which only hydrogen peroxide was used as the treatment gas and the sterilization / decontamination process using oxygen (O ₂ ) instead of ozone was repeated for 6 pulses. The inactivation rate was 94.6%. Similarly, as a comparative example, when a decontamination test in which only ozone is used as the treatment gas and purified water is used instead of hydrogen peroxide to repeat the sterilization / decontamination process for 6 pulses is performed once, the inactivation rate is high. It was 95.7%. As described above, it can be seen that the decontamination method using two types of treatment gas as in the present embodiment can obtain more endotoxin inactivating effect than the case of using either treatment gas.

Next, as a second decontamination test, in the decontamination method in the present embodiment, the inactivation rates for each number of pulses are compared. First, the inactivation rate when the decontamination test in which the sterilization / decontamination process was repeated for two pulses was carried out twice was in the range of 94.8 to 99.8%. Next, the inactivation rate when the decontamination test in which the sterilization / decontamination process was repeated for 4 pulses was performed twice was in the range of 96.9 to 99.9%. Further, the inactivation rate when the decontamination test in which the sterilization / decontamination process was repeated for 6 pulses was carried out three times was 99.9% or more as described above. That is, in the present embodiment, the inactivating effect of endotoxin can be further obtained by increasing the number of pulses. Further, in the present embodiment, under the above-mentioned reference conditions, by setting the number of pulses to 6 pulses or more, an inactivation rate of 99.9% or more corresponding to the so-called 3 log reduction can be obtained.

Therefore, in the present embodiment, as one of the processing modes, an endotoxin inactivation specialized mode for obtaining an endotoxin inactivation rate of 99.9% or more is prepared. In the endotoxin inactivation specialized mode, the number of pulses in the sterilization / decontamination step is preset to 6 pulses or more by referring to the above example. Therefore, when starting the decontamination process according to the present embodiment, as long as the operator selects the endotoxin inactivation specialized mode as the process mode, the decontamination device 100 can obtain an inactivation effect corresponding to the reduction of 3 logs. The decontamination process can be performed automatically. In the above example, in the case of a specific reference condition, an inactivation rate of 99.9% or more could be obtained with 6 pulses. That is, under another reference condition, if an inactivation rate of 99.9% or more can be obtained even if the number of pulses is 6 pulses or less, the number of pulses in the endotoxin inactivation specialized mode is 99.9%. The number of pulses may be set to 6 pulses or less so that the above inactivation rate can be obtained.

Returning to FIG. 2, in the aeration step S113, hydrogen peroxide and ozone as processing gases are removed by reducing the pressure inside the chamber 11 to a certain degree of vacuum, and then the atmosphere is injected to near atmospheric pressure for processing. This is the step of diluting the gas. In the present embodiment, the processing in the aeration step S113 is different depending on whether the processing mode is the short mode or the other mode.

First, the processing in the aeration step S113 when the processing mode is the short mode will be described. In the short mode, the contact time between the processing gas and the object to be processed is shorter than in other modes. Therefore, in order to shorten the processing time, the aeration step S113 in this case includes, for example, the following processing step.

First, after the second state holding step S111 is completed, the control unit 61 starts the vacuum pump 41 as quickly as possible, opens the eighth solenoid valve 77, and starts depressurizing the inside of the chamber 11. At the same time, the control unit 61 opens the second solenoid valve 71, the third solenoid valve 72, and the seventh solenoid valve 76 to discharge the residual gas inside the evaporator 26 and the buffer tank 34. In the short mode, depressurization is continued until the pressure inside the chamber 11 reaches, for example, 100 Pa. The discharged treatment gas passes through the first catalyst tank 42 and the second catalyst tank 43, so that hydrogen peroxide is decomposed into harmless water and oxygen, while ozone is decomposed into harmless oxygen. Then, it is exhausted to the outside of the decontamination device 100 at a concentration equal to or lower than the safety control value. Next, the control unit 61 closes the eighth solenoid valve 77 when the pressure inside the chamber 11 reaches a predetermined depressurizing pressure.

Next, the control unit 61 opens the ninth solenoid valve 78 and the tenth solenoid valve 79, and injects the atmosphere into the chamber 11 through the second filter 51. At the same time, the control unit 61 opens the second solenoid valve 71, the third solenoid valve 72, and the seventh solenoid valve 76, and injects air into the inside of the evaporator 26 and the buffer tank 34. The injected air diffuses and dilutes the gas remaining inside the chamber 11 and removes the object to be treated and the processing gas adhering to the inner surface of the chamber 11. Next, the control unit 61 closes the ninth solenoid valve 78 and the tenth solenoid valve 79 after injecting the atmosphere until the pressure inside the chamber 11 reaches about 90 kPa, which is about 90% of the atmospheric pressure.

Then, the control unit 61 repeats such depressurization and atmospheric injection a predetermined number of times. In the case of the short mode, for example, it may be repeated a total of three times. In the aeration step S113 in this case, assuming that the time required for depressurization is about 3 minutes and the time required for atmospheric injection is about 0.5 minutes, 3.5 minutes x 3 times = about 10.5 minutes is spent. Will be. The control unit 61 repeats depressurization and atmospheric injection a specified number of times, then returns the inside of the chamber 11 to atmospheric pressure by atmospheric injection, and ends the aeration step S113. The control unit 61 ends the decontamination process after the aeration step S113.

Second, the processing in the aeration step S113 when the processing mode is a mode other than the short mode will be described. In the treatment mode other than the short mode, the contact time between the treatment gas and the object to be processed is long, the amount of hydrogen peroxide adhering to the object to be processed, and the amount of hydrogen peroxide remaining inside the chamber 11 are large. do. Therefore, the aeration step S113 in this case includes, for example, the following processing steps.

First, the basic operation of depressurization and atmospheric injection is the same as when the processing mode is the short mode. However, the ultimate pressure at the time of depressurization is, for example, 100 Pa or less in the short mode, whereas in modes other than the short mode, the workpiece may contain a lumen, so that the conditions are stricter than in the short mode. For example, it is set to 50 Pa or less.

Next, after the first depressurization and atmospheric injection are completed, the control unit 61 continuously executes depressurization while injecting into the atmosphere. Specifically, the control unit 61 starts the vacuum pump 41, opens the eighth solenoid valve 77 to start depressurization, and then, for example, with a delay of about 2 seconds, the ninth solenoid valve 78 and the tenth solenoid valve 79. Is opened, and the air is injected through the second filter 51. Here, it is assumed that the timing for stopping the atmospheric injection at the time of injecting into the atmosphere after depressurization is when the pressure inside the chamber 11 becomes approximately 90 kPa or more. In this case, the timing for stopping the atmospheric injection at the time when the pressure is reduced while injecting into the atmosphere may be when the pressure inside the chamber 11 is approximately 90 kPa or less. By exhausting while injecting into the atmosphere in this way, the flow of the atmosphere is activated, and the treated object and the treated gas adhering to the inner surface of the chamber 11 are positively removed. In particular, during normal decontamination treatment, a fine-grained non-woven fabric such as a sterilizing bag or sterilizing wrap is wrapped or covered with the object to be treated, which is effective in removing the processing gas adhering to the non-woven fabric. .. The time for depressurizing while injecting into the atmosphere here is, for example, about 5 minutes.

Then, the control unit 61 further repeats the same operations as the first decompression and atmospheric injection. In this case, for example, it may be repeated twice.

In the aeration step S113 in this case, the time required for the first decompression and atmospheric injection is 3.5 minutes, the time required for decompression while injecting into the atmosphere is 5 minutes, and the time required for the second decompression and atmospheric injection is 5 minutes. 3.5 minutes x 2 = 7 minutes, which means that a total of 15.5 minutes will be spent. After that, the control unit 61 returns the inside of the chamber 11 to the atmospheric pressure by injecting air, and ends the aeration step S113. The control unit 61 ends the decontamination process after the aeration step S113.

In the aeration step S113, depressurization and atmospheric injection are repeated a plurality of times as described above. The larger the number of repetitions, the more effective it is for removing the residual processing gas, but the longer the processing time. Become. So, for example, when depressurizing and injecting into the atmosphere are repeated 5 times, the time is shorter than the time spent for repeating 2 out of 5 times, for example, 5 minutes shorter than (3 minutes x 2 times), which is 6 minutes. Minutes may be replaced with one dose of the next iteration. As a result, the processing gas remaining inside the chamber 11 can be exhausted more efficiently, and the time required for the aeration step S113 can be shortened.

The treatment time related to the decontamination treatment according to the present embodiment is generally as shown in the table shown in FIG. 3 for each treatment mode. After completion of the series of decontamination treatments, the operator removes the object to be processed from the chamber 11.

FIG. 4 is a graph showing a pressure change inside the chamber 11 in the decontamination method according to the present embodiment. In the example shown in FIG. 4, after depressurization, the steam of the first aqueous solution is injected into the chamber 11 at the timing T1 (first steam injection step S104) and held for the period H1 (first state holding step S105). ). Then, at timing T2, ozone gas is injected into the chamber 11 (ozone injection step S107). Subsequently, at timings T3 and T4, steam is injected into the chamber 11 (second steam injection step S109) and held for period H2 (second state holding step S111). Finally, the aeration step is performed from the timing T5.

Next, the decontamination method according to the present embodiment and the effect of the decontamination apparatus 100 capable of carrying out the decontamination method will be described.

The decontamination method according to the present embodiment inactivates endotoxin that contaminates the object to be treated contained in the chamber 11. The decontamination method is as follows: after the first decompression step S102 for depressurizing the inside of the chamber 11 and the first decompression step S102, the steam generated from the first aqueous solution of hydrogen peroxide is injected into the inside of the chamber 11. The steam injection step S104 is included. The decontamination method includes an ozone injection step S107 in which ozone gas is injected into the inside of the chamber 11 after the first steam injection step S104. Further, the decontamination method includes a second steam injection step S109 for injecting steam generated from the second aqueous solution of hydrogen peroxide into the chamber 11 after the ozone injection step S107. Here, the concentration of hydrogen peroxide contained in the second aqueous solution is equal to or lower than the concentration of hydrogen peroxide contained in the first aqueous solution.

On the other hand, the decontamination apparatus 100 according to the present embodiment includes a chamber 11 for accommodating an object to be processed, and an exhaust unit 40 for exhausting the inside of the chamber 11 to reduce the pressure. The decontamination device 100 communicates with the chamber 11 to evaporate and fill the first aqueous solution of hydrogen peroxide or the second aqueous solution of hydrogen peroxide, and the ozone that communicates with the chamber 11 to generate ozone gas. A generator 32 is provided. Further, the decontamination device 100 controls the operation of the exhaust unit 40 and the operation of injecting the steam generated by the evaporator 26 or the ozone gas generated by the ozone generator 32 into the chamber 11. To prepare for. Here, the concentration of hydrogen peroxide contained in the second aqueous solution is equal to or lower than the concentration of hydrogen peroxide contained in the first aqueous solution. Further, the control unit 61 decompresses the inside of the chamber 11 into the exhaust unit 40, then injects steam generated from the first aqueous solution into the inside of the chamber 11 and then injects ozone gas. Then, after injecting ozone gas, the control unit 61 injects steam generated from the second aqueous solution to inactivate endotoxin that contaminates the object to be treated.

In the present embodiment, the object to be treated is decontaminated using the steam of the first aqueous solution, and then decontaminated using ozone gas. At this time, in the present embodiment, after the ozone gas is injected into the inside of the chamber 11, the steam of the second aqueous solution is further injected. As a result, the reactivity of the ozone gas can be improved, so that the endotoxin inactivation efficiency is higher than that in the case of performing the decontamination treatment with the ozone gas alone.

Further, in the present embodiment, the inside of the chamber 11 is depressurized to a certain degree of vacuum before injecting the steam of the first aqueous solution. That is, the decontamination treatment in the present embodiment is performed under reduced pressure conditions. In this way, by reducing the pressure inside the chamber 11 before the steam of the first aqueous solution is injected, for example, excess gas contained in the object to be treated can be exhausted in advance, so that a series of decontamination can be performed. The overall processing time required for processing can be shortened.

Further, in the series of decontamination treatments in the present embodiment, the internal temperature of the chamber 11 is maintained at a low temperature of about 60 ° C. or lower. That is, according to the present embodiment, for example, a high temperature state (approximately 250 ° C.) as in the case of the conventional dry heat sterilization method is not required. Therefore, the decontamination device 100 can be simplified because it is not necessary to install a large-scale heating device for obtaining a high temperature state.

According to the present embodiment, since the endotoxin inactivation treatment is performed under reduced pressure conditions and at a low temperature as described above, the sterilization treatment of the object to be treated can also be performed at the same time.

Further, in the present embodiment, the injection of the steam of the first aqueous solution is positioned as the main decontamination treatment using hydrogen peroxide as the material of the treatment gas. On the other hand, the injection of steam of the second aqueous solution of hydrogen peroxide is positioned as an auxiliary treatment for improving the inactivation efficiency of endotoxin in the decontamination treatment by injecting ozone gas. Therefore, in the second steam injection step S109, especially when the steam of the second aqueous solution is injected, is the concentration of hydrogen peroxide contained in the aqueous solution lower in the second aqueous solution than in the first aqueous solution? , Or can be equivalent. Therefore, according to the present embodiment, even if both the first aqueous solution and the second aqueous solution are used, the amount of hydrogen peroxide used can be reduced as a whole of the decontamination treatment. Further, by reducing the amount of hydrogen peroxide used, as a result, the amount of hydrogen peroxide that may remain on the surface of the object to be treated or inside the chamber 11 can be proportionally reduced.

Therefore, according to the present embodiment, it is possible to provide a decontamination method and a decontamination apparatus 100 that are advantageous for improving the inactivation of endotoxin that contaminates the object to be treated.

Further, in the decontamination method according to the present embodiment, the concentration of hydrogen peroxide contained in the first aqueous solution and the concentration of hydrogen peroxide contained in the second aqueous solution are determined by the presence or absence of a lumen of the object to be treated or to be treated. It may be specified based on the material of the object.

In the above description, four treatment modes are exemplified depending on the presence or absence of a lumen of the object to be treated or the difference in the material of the object to be treated. For example, a resin-made thin tube can be mentioned as an object to be decontaminated in the standard mode or the endotoxin inactivation specialized mode. On the other hand, examples of the object to be decontaminated in the long mode include a thin tube made of stainless steel. Comparing these resin tubules with stainless steel tubules, it is generally more difficult to decontaminate stainless steel tubules than to decontaminate resin tubules. This is because, for example, hydrogen peroxide has a high reactivity with transition elements such as Fe, Mo or Cr contained in stainless steel, so that hydrogen peroxide is decomposed during the treatment and sufficient peroxidation to the inside of the capillary tube. This is because hydrogen is considered to be difficult to reach. Alternatively, since the stainless steel thin tube has higher thermal conductivity than the resin thin tube and is easily cooled in a reduced pressure environment, it is considered that hydrogen peroxide is likely to condense inside the thin tube and it is difficult for sufficient hydrogen peroxide to reach the inside. ..

On the other hand, according to the present embodiment, for example, when decontaminating a stainless steel capillary tube, the concentration of hydrogen peroxide contained in the second aqueous solution is excessively contained in the second aqueous solution in another treatment mode. It can be dealt with by making the concentration higher than that of hydrogen peroxide. However, even in this case, the concentration of hydrogen peroxide contained in the second aqueous solution does not exceed the concentration of hydrogen peroxide contained in the first aqueous solution. Alternatively, even if the concentration of hydrogen peroxide contained in the second aqueous solution is equal to the concentration of hydrogen peroxide contained in the first aqueous solution, the input amount of the second aqueous solution can be reduced. That is, when decontaminating a stainless steel capillary tube, the total amount of hydrogen peroxide used (concentration of hydrogen peroxide in the first and second aqueous solutions x hydrogen peroxide input) is higher than that of the conventional decontamination method. It may be possible to reduce the total value of the amount).

Further, the decontamination method according to the present embodiment may include an outside air injection step of injecting air or dry nitrogen gas into the inside of the chamber 11 after the second steam injection step.

According to such a decontamination method, when the object to be treated has a lumen in particular, the outside air is injected into the chamber 11 to remove hydrogen peroxide and ozone gas stagnant in the middle of the lumen. Since it can be pushed in, inactivation of endotoxin can be further promoted. Further, by injecting the atmosphere into the chamber 11, the concentration distribution of the gas existing in the chamber 11 becomes uniform, so that inactivation can be performed evenly. Further, when the atmosphere is injected into the chamber 11, the internal pressure rises and hydrogen peroxide in the vapor is slightly condensed on the surface of the object to be treated, so that the inactivating effect can be further improved. can. Here, when the outside air is particularly the atmosphere, the raw material cost of the gas to be injected is not incurred, and the configuration for injecting the atmosphere into the chamber 11 can be simplified, so that the decontamination device. It is possible to suppress an increase in the manufacturing cost of 100.

Further, the decontamination method according to the present embodiment may include a state maintaining step of maintaining the internal state of the chamber 11 for a certain period of time after the outside air injection step. The state holding step here corresponds to the second state holding step S111 described above.

According to such a decontamination method, the inactivating effect of endotoxin by the outside air injection step can be further promoted.

Further, in the decontamination method according to the present embodiment, a series of steps from the first decompression step S102 to the second state holding step S111 may be repeated a plurality of times.

According to such a decontamination method, it is possible to realize a desired inactivation rate when inactivating endotoxin. In the above example, by setting the number of pulses in the sterilization / decontamination step to 6 pulses, an inactivation rate of 99.9% or more can be obtained. That is, in this case, if the desired inactivation rate is 99.9%, it may be preset to repeat a series of steps from the first decompression step S102 to the second state holding step S111 six times.

Further, in the decontamination method according to the present embodiment, a first steam preparation step of injecting a first aqueous solution into the inside of the evaporator 26 to evaporate and fill it to generate steam to be injected in the first steam injection step S104. S103 may be included. Further, the decontamination method may include a second steam preparation step S108 in which a second aqueous solution is injected into the inside of the evaporator 26 to evaporate and fill it to generate steam to be injected in the second steam injection step S109. .. In this case, in the ozone injection step S107, ozone gas may pass through the inside of the evaporator 26 and be injected into the inside of the chamber 11.

According to such a decontamination method, when the aqueous solution of hydrogen peroxide evaporates in the evaporator 26 and the internal pressure increases, steam can be injected into the inside of the chamber 11. By injecting the steam in this way, the diffusion of the steam inside the chamber 11 can be made more uniform. In addition, hydrogen peroxide can be easily penetrated into the tube of the object to be treated having a lumen. That is, the amount of hydrogen peroxide used can be further reduced while maintaining the sterilization efficiency and the inactivation efficiency of endotoxin.

Further, according to such a decontamination method, ozone gas passes through the inside of the evaporator 26 and is injected into the inside of the chamber 11. Therefore, the hydrogen peroxide remaining in the evaporator 26 is pushed out to the chamber 11 by the ozone gas, so that the sterilization effect and the inactivating effect of endotoxin can be further improved. Further, regarding the introduction port installed in the chamber 11, the port into which hydrogen peroxide is introduced and the port in which ozone gas is introduced can be shared, so that the peripheral configuration of the chamber 11 can be simplified. ..

Further, the decontamination method according to the present embodiment may include an ozone preparation step S106 for filling the inside of the buffer tank 34 with ozone gas before the ozone injection step S107. In the ozone injection step S107, the ozone gas filled in the inside of the buffer tank 34 may be injected into the inside of the chamber 11.

According to such a decontamination method, when the pressure of the ozone gas increases in the buffer tank 34, the ozone gas can be injected into the inside of the chamber 11. By injecting the ozone gas in this way, the diffusion of the ozone gas inside the chamber 11 can be made more uniform. In addition, ozone can easily enter the inside of the tube of the object to be treated having a lumen. That is, the amount of ozone used can be further reduced while maintaining the sterilization efficiency and the inactivation efficiency of endotoxin.

Further, in the decontamination method according to the present embodiment, the exhaust inside the chamber 11 and the injection of air into the inside of the chamber 11 are repeated a plurality of times to bring the inside of the chamber 11 into a state where the object to be processed can be taken out. The aeration step S113 may be included. In the aeration step S113, exhaust may be performed while injecting air into the inside of the chamber 11 at least once.

According to such a decontamination method, the air flow inside the chamber 11 is activated by exhausting while injecting into the atmosphere, so that it is easy to remove the object to be treated and the processing gas adhering to the inner surface of the chamber 11. can do. Further, the time required for one process of exhausting while injecting into the atmosphere is shorter than that of one process of injecting into the atmosphere after depressurization, and as a result, the time required for the entire aeration step S113 can be shortened. ..

(Second Embodiment)
FIG. 5 is a flowchart showing the flow of the decontamination method according to the second embodiment. As described above, the object to be treated is housed in the chamber 11 of the decontamination device 100 in a state of being put in a sterilization bag or wrapped in a sterilization wrap when the decontamination treatment is performed. Then, in the first embodiment, after the processing mode selection step S101 is completed, the process proceeds to the first decompression step S102. On the other hand, in the present embodiment, ozone gas may be further injected into the inside of the chamber 11 between the processing mode selection step S101 and the first decompression step S102. Hereinafter, the ozone gas injection step performed during this period is referred to as a pre-ozone injection step in order to distinguish it from the ozone gas injection in the ozone injection step S107.

FIG. 6 is a graph showing a pressure change inside the chamber 11 in the present embodiment. First, in order to remove excess air from the inside of the chamber 11, the inside of the chamber 11 is decompressed to, for example, 100 Pa (pre-decompression step S201). In FIG. 6, the period in which the pre-decompression step S201 is carried out is referred to as H31. After the pre-decompression step S201, at timing T31, ozone gas may be injected into the chamber 11 (pre-ozone injection step S202) and retained for period H32. Here, the control by the control unit 61 when injecting ozone gas is the same as the control in the ozone injection step S107 described in the first embodiment. Prior to the pre-ozone injection step S202, there may be a pre-ozone preparation step similar to the ozone preparation step S106. Next, during the period H33, the inside of the chamber 11 is depressurized (first decompression step S102). After the first decompression step S102, the interior of chamber 11 may be retained for period H34. Next, at the timing T32, the steam of the first aqueous solution is injected into the chamber 11 (first steam injection step S104) and held for the period H35 (first state holding step S105). Next, ozone gas is injected into the chamber 11 at the timing T33 (ozone injection step S107). Subsequently, steam of pure water or a second aqueous solution is injected into the chamber 11 at the timing T34 (second steam injection step S109), and the atmosphere is continuously injected at the timing T35 (outside air injection step S110). Then, the inside of the chamber 11 is held during the period H36 (second state holding step S111). In the example shown in FIG. 6, the sterilization / decontamination process is repeated for 2 pulses. Therefore, the control unit 61 determines that the sterilization / decontamination step needs to be repeated in the determination step S112 (YES), and causes the second pulse sterilization / decontamination step to be repeated. When the sterilization / decontamination step of the second pulse is completed, the control unit 61 determines in the determination step S112 that the repetition of the sterilization / decontamination step is unnecessary (NO), and causes the aeration step S113 to be carried out.

As described above, the decontamination method according to the present embodiment may include a pre-ozone injection step S202 for injecting ozone gas into the inside of the chamber 11 before the first steam injection step S104.

Since ozone, which has a strong oxidizing action, easily reacts with all substances, the ozone gas injected in the ozone injection step S107 may be adsorbed on a non-woven fabric such as a sterile wrap and decomposed before reaching the object to be treated. possible. On the other hand, according to the decontamination method according to the present embodiment, the nonwoven fabric can be preliminarily blended with ozone gas in the pre-ozone injection step S202. As a result, the oxidation reaction on the surface of the non-woven fabric is saturated, so that the ozone gas injected in the ozone injection step S107 is less likely to react with the non-woven fabric, and it becomes easier to reach the object to be treated. Therefore, it is possible to suppress a decrease in the sterilizing effect or the inactivating effect of endotoxin.

Although some embodiments have been described, it is possible to modify or modify the embodiments based on the above disclosure contents. All components of the above embodiments, and all the features described in the claims, may be individually extracted and combined as long as they do not conflict with each other.

11 Chamber 26 Evaporator 32 Ozone generator 40 Exhaust unit 61 Control unit 100 Decontamination device

Claims (8)

It is a decontamination method that inactivates endotoxin that contaminates the object to be treated contained in the chamber.
The first decompression step of depressurizing the inside of the chamber and
After the first depressurization step, a first steam injection step of injecting steam generated from the first aqueous solution of hydrogen peroxide into the inside of the chamber,
After the first steam injection step, an ozone injection step of injecting ozone gas into the inside of the chamber and a
After the ozone injection step, a second steam injection step of injecting steam generated from a second aqueous solution of hydrogen peroxide into the inside of the chamber is included.
A decontamination method in which the concentration of hydrogen peroxide contained in the second aqueous solution is equal to or lower than the concentration of hydrogen peroxide contained in the first aqueous solution. The concentration of hydrogen peroxide contained in the first aqueous solution and the concentration of hydrogen peroxide contained in the second aqueous solution are defined based on the presence or absence of a lumen of the object to be treated or the material of the object to be treated. The decontamination method according to claim 1. The decontamination method according to claim 1 or 2, further comprising an outside air injection step of injecting air or dry nitrogen gas into the inside of the chamber after the second steam injection step. The decontamination method according to claim 3, further comprising a state-maintaining step of maintaining the internal state of the chamber for a certain period of time after the outside air injection step. The decontamination method according to claim 4, wherein the series of steps from the first depressurization step to the state holding step is repeated a plurality of times. The first steam preparation step of injecting the first aqueous solution into the inside of the evaporator, evaporating and filling it to generate the steam to be injected in the first steam injection step, and
A second steam preparation step of injecting the second aqueous solution into the inside of the evaporator, evaporating and filling it to generate steam to be injected in the second steam injection step, and a second steam preparation step.
Including
The decontamination method according to any one of claims 1 to 5, wherein in the ozone injection step, the ozone gas passes through the inside of the evaporator and is injected into the inside of the chamber. The aeration step of repeating the exhaust inside the chamber and injecting air into the inside of the chamber a plurality of times to bring the inside of the chamber into a state where the object to be processed can be taken out is included.
The decontamination method according to any one of claims 1 to 6, wherein in the aeration step, exhaust is performed while injecting air into the inside of the chamber at least once. A chamber for accommodating the object to be processed and
An exhaust unit that exhausts the inside of the chamber and decompresses it,
An evaporator that communicates with the chamber and evaporates and fills a first aqueous solution of hydrogen peroxide or a second aqueous solution of hydrogen peroxide.
An ozone generator that communicates with the chamber and generates ozone gas,
A control unit that controls the operation of the exhaust unit and the operation of injecting steam generated by the evaporator or ozone gas generated by the ozone generator into the chamber.
Equipped with
The concentration of hydrogen peroxide contained in the second aqueous solution is equal to or lower than the concentration of hydrogen peroxide contained in the first aqueous solution.
The control unit decompresses the inside of the chamber into the exhaust unit, injects steam generated from the first aqueous solution into the chamber, injects ozone gas, and then injects ozone gas, and then the control unit. A decontamination device that inactivates endotoxin that contaminates the object to be treated by injecting steam generated from the second aqueous solution.

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