JP2013081539A - Sterilization method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mechanism capable of sterilizing the lumen of a body to be sterilized by state change of hydrogen peroxide.SOLUTION: A sterilization method of sterilizing a lumen of the body to be sterilized which is stored in a sterilization chamber with hydrogen peroxide includes: a hydrogen peroxide diffusion stage of supplying vapor of hydrogen peroxide and diffusing the vapor of hydrogen peroxide into the sterilization chamber; a hydrogen peroxide coagulation stage of introducing the diffused vapor of the hydrogen peroxide into the lumen of the body to be sterilized and coagulating the vapor of hydrogen peroxide introduced into the lumen into a liquid; and a hydrogen peroxide vaporization stage of vaporizing the coagulated liquid of hydrogen peroxide.

Description

  The present invention relates to a sterilization method.

As a method of sterilizing medical instruments used in medical treatment, there is a method of sterilizing using hydrogen peroxide gas. If the object to be sterilized is, for example, scissors, the surface may be sterilized. However, if the object to be sterilized is an endoscope or an injection needle, the object to be sterilized has a complex-shaped lumen, so the lumen is also sterilized. There is a need to.
The following techniques are disclosed as techniques for sterilizing the lumen with hydrogen peroxide vapor.

  In the prior art document 1, in order to compress the sterilant vapor and push it into the article, the gas is introduced into the chamber and increased to a predetermined pressure up to atmospheric pressure, and the gas and sterilant vapor are predetermined time. Among them, a technique for remaining in the chamber is disclosed.

Japanese National Patent Publication No. 8-505787

As described in the prior art document 1, the sterilization effect of the lumen is limited only by sterilizing the lumen of the article to be sterilized by simply exposing it to a hydrogen peroxide gas (vapor).
It is an object of the present invention to provide a mechanism that can sterilize the lumen of an object to be sterilized by changing the state of hydrogen peroxide.

The present invention is a sterilization method for sterilizing a lumen of an object to be sterilized housed in a sterilization chamber capable of maintaining a pressure from a vacuum pressure to an atmospheric pressure with hydrogen peroxide, wherein the sterilization is maintained at a vacuum pressure. Hydrogen peroxide diffusion process for supplying hydrogen peroxide vapor so that the interior is at the first pressure and diffusing the hydrogen peroxide vapor in the sterilization chamber, and the sterilization chamber in which the hydrogen peroxide vapor is diffused By supplying the gas so that the atmospheric pressure becomes atmospheric pressure, the diffused hydrogen peroxide vapor is introduced into the lumen of the object to be sterilized, and the hydrogen peroxide vapor introduced into the lumen is converted into a liquid. And a hydrogen peroxide condensing step for condensing, and a hydrogen peroxide vaporizing step for vaporizing the liquid of the condensed hydrogen peroxide by reducing the pressure in the sterilization chamber which is the atmospheric pressure.
The hydrogen peroxide vaporization step is started when the atmospheric pressure is reached.

The hydrogen peroxide vaporization step is an initial step of a vacuum step of evacuating the inside of the sterilization chamber at the atmospheric pressure so as to remove hydrogen peroxide introduced into the lumen of the sterilized object. To do.
The hydrogen peroxide diffusion process or the vacuum process is repeated a predetermined number of times.
Further, the gas is air.
In the hydrogen peroxide diffusion step, hydrogen peroxide vapor is introduced up to a first pressure during a predetermined time.
In the hydrogen peroxide condensing step, the gas is introduced to atmospheric pressure at a predetermined pressure increase rate.

  According to the present invention, it is possible to provide a mechanism capable of sterilizing the lumen of an object to be sterilized by changing the state of hydrogen peroxide.

It is a figure which shows the hardware constitutions of a sterilizer. It is a figure which shows the flowchart in 1st Example of the sterilization method. It is a figure which shows the time change of the pressure in the sterilization room | chamber interior during the sterilization process in a 1st Example. It is a figure which shows the hardware constitutions of a sterilizer. It is a figure which shows the time change of the pressure in the sterilization room | chamber interior during the sterilization process in a 2nd Example. It is a figure which shows the flowchart in the 3rd Example of the sterilization method.

Referring to FIG.
FIG. 1 is a diagram showing a hardware configuration of a sterilization apparatus according to the present invention.
FIG. 1 is a cross-sectional view of a sterilization apparatus viewed from the side.
Reference numeral 10 denotes an article to be sterilized, which is a medical instrument stored in a sterilization chamber and sterilized. It is assumed that the object to be sterilized has a complex-shaped lumen.

Reference numeral 11 denotes a sterilization chamber, which is a casing having a volume of 76 liters for sterilizing medical instruments. The pressure inside the sterilization chamber is a sealed space in which pressure from atmospheric pressure to vacuum pressure can be maintained.
The temperature inside the sterilization chamber is maintained at 50 ° C. during the sterilization process.
Reference numeral 12 denotes a door of the sterilization chamber, which is a door through which an object to be sterilized is taken in and out of the sterilization chamber.
Reference numeral 21 denotes a vacuum pump, which can set the pressure inside the sterilization chamber to a vacuum pressure.

In the present invention, a scroll dry pump that does not use oil is employed. The reason for this is that when the oil rotary pump is used in the present invention, there is a problem that the oil mist is blown out in the operation near the atmospheric pressure. When vacuuming is performed near the atmospheric pressure, the pump It is necessary to slow down the rotation speed (increase the vacuuming time). The vacuum process cannot be completed in a short time.
Reference numeral 40 denotes a vaporization valve, which can open and close the conduction between the vaporization chamber and the sterilization chamber.
A vaporization chamber 30 vaporizes the hydrogen peroxide solution supplied from the hydrogen peroxide solution supply device.
Reference numeral 22 denotes an air release valve, which can open and close the connection between the sterilization chamber and the outside air (atmosphere).
Note that the gas supplied to the sterilization chamber may not be the air, but may be air.
A hydrogen peroxide solution supply device 50 supplies a hydrogen peroxide liquid to the vaporizing chamber.
The concentration of the hydrogen peroxide solution supplied by the hydrogen peroxide solution supply device is between 59 wt% and 98 wt%.
Reference numeral 60 denotes a pressure sensor, which measures the pressure inside the sterilization chamber.
<First embodiment>
FIG. 2 will be described.
FIG. 2 is an example of a sterilization method (sterilization step) for sterilizing the lumen of an object to be sterilized by the sterilization apparatus of the present invention.
In step S101, the inside of the sterilization chamber is maintained at a vacuum pressure by closing the atmosphere release valve and operating the vacuum pump (preliminary vacuum process).

  In step S102, it is determined whether or not step S103 has been executed a predetermined number of times (about four times) (determination step). That is, it is determined how many times the process has been repeated from step S103 to step S106. If it has been repeated a predetermined number of times, the process proceeds to the ventilation step of step S107.

  In step S103, the vacuum pump is stopped and the vaporization valve is opened, so that the hydrogen peroxide vapor prepared in advance in the vaporization chamber is supplied into the sterilization chamber, and the hydrogen peroxide vapor diffuses into the sterilization chamber (excessive). Hydrogen oxide diffusion process). The diffusion time is a predetermined time set in advance (between 60 seconds and 480 seconds). During the diffusion time, the pressure in the sterilization chamber increases, and when the predetermined time is reached, P1 (the first pressure) 1 pressure). In step S103, the air release valve remains closed. Steps S <b> 103 to 302 in FIG. 3 correspond to step S <b> 103.

  In step S104, a gas (atmosphere) is supplied from the outside of the sterilization chamber by opening the air release valve, and hydrogen peroxide vapor is introduced into the lumen of the object to be sterilized. The introduction time is a predetermined time set in advance (between 5 seconds and 10 seconds). During the introduction time, the pressure in the sterilization chamber rises rapidly, and P2 (a predetermined pressure at a predetermined time) The second pressure) is reached. In step S104, the vacuum pump remains stopped. Steps 302 to 303 in FIG. 3 correspond to step S104.

  Here, it is important that the hydrogen peroxide vapor is introduced into the deep part of the lumen and the hydrogen peroxide vapor introduced into the deep part of the lumen is once condensed in a liquid (hydrogen peroxide condensing step). In order to condense into a liquid, it is necessary to rapidly increase the pressure in the sterilization chamber to atmospheric pressure in a short time.

This rapid increase means that the pressure in the sterilization chamber, which was 1500 Pascals with a volume of 76 liters, is a short time of 5 seconds to 10 seconds at a predetermined pressure increase rate that reaches atmospheric pressure (P2). It is to supply the atmosphere abruptly.
In addition, the vaporization valve is closed to prepare hydrogen peroxide vapor in the vaporization chamber.
In step S105, it is determined whether the atmospheric pressure (P2), which is a predetermined pressure, has been reached by a pressure sensor that measures the pressure inside the sterilization chamber.

  In step S106, when the atmospheric pressure (P2) is reached, the air release valve is closed and the vacuum pump is operated to exhaust the inside of the sterilization chamber, which is atmospheric pressure. In the initial process of exhausting the interior of the sterilization chamber, as the pressure in the interior of the sterilization chamber decreases (decompression), hydrogen peroxide is condensed in the lumen of the object to be sterilized in step S104 and the lumen of the object to be sterilized is sterilized. This liquid is vaporized again (vaporized) in the lumen of the object to be sterilized (hydrogen peroxide vaporization step).

  In the present invention, the moment when the hydrogen peroxide liquid once condensed in the lumen of the object to be sterilized at the atmospheric pressure by the introduced gas is vaporized again into hydrogen peroxide vapor by decompression is considered to have the highest sterilization effect. This high sterilization effect does not obtain a high sterilization effect by leaving the hydrogen peroxide liquid once condensed in the deep part of the lumen in step S104 for a certain period of time. Since the liquid does not need to remain for a certain period, the vacuum process in step S106 can be started immediately.

  In other words, hydrogen peroxide vapor or liquid is left in the lumen of the object to be sterilized for a certain period of time, so that the sterilization effect is not enhanced. By executing using pressure change, a high sterilization effect can be obtained instantaneously.

  That is, according to the invention of the present application, it is not necessary to increase the sterilization effect by leaving the vapor or liquid of hydrogen peroxide in the lumen of the object to be sterilized for a certain period of time in the deep portion of the lumen. There is an effect that can be started.

  The vacuum time including the initial process is a predetermined time set in advance. During the vacuum time, the pressure in the sterilization chamber gradually decreases, and reaches a vacuum pressure P0 when the predetermined time is reached. Steps 303 to 304 in FIG. 3 correspond to step S106 (vacuum process).

By operating the vacuum pump, the inside of the sterilization chamber, which is at atmospheric pressure, is exhausted. The hydrogen peroxide solution that has been condensed into a liquid in step S104 and the surface of the object to be sterilized in the sterilization chamber, the hydrogen peroxide solution that has sterilized the lumen of the object to be sterilized, and vaporized again in step S106 The hydrogen peroxide vapor sterilized on the surface of the object to be sterilized in the sterilization chamber and the hydrogen peroxide vapor sterilized in the lumen of the object to be sterilized can be removed (recovered).
In step S107, the inside of the sterilization chamber is ventilated (ventilation process).
The sterilization process ends.
FIG. 3 will be described.
FIG. 3 is a diagram showing the time change <first embodiment> of the pressure in the sterilization chamber during the sterilization process for sterilizing the lumen of the object to be sterilized by the sterilization apparatus of the present invention.

  The pressure of P0 is a pressure after the atmosphere release valve and the vaporization valve are closed and the inside of the sterilization chamber is evacuated by a vacuum pump, and is between 20 Pascals and 100 Pascals and is a vacuum pressure.

The pressure of P1 is a pressure after the vapor of hydrogen peroxide is diffused into the sterilization chamber, and is between 1000 Pascals and 4000 Pascals (preferably 1500 Pascals).
The pressure of P2 is the pressure after supplying gas (atmosphere) to the inside of the sterilization chamber and the vapor of hydrogen peroxide condenses in the lumen, and is atmospheric pressure.
301 is a pressure (P0) before starting the hydrogen peroxide diffusion process of step S103.
302 is a pressure (P1) when the hydrogen peroxide diffusion process of step S103 is completed.
302 is the pressure (P1) before starting the hydrogen peroxide condensing process of step S104.
303 is a pressure (atmospheric pressure) when the hydrogen peroxide condensing process of step S104 is completed.
Reference numeral 303 denotes a pressure (atmospheric pressure) before starting the hydrogen peroxide vaporization process in step S106.
304 is a pressure (P0) when the vacuum process of step S106 is completed.
305 is a pressure (P0) before starting the ventilation process of step S107.
<Second embodiment>
FIG. 4 will be described.
FIG. 4 is a diagram showing a hardware configuration of the sterilization apparatus of the present invention.
The second embodiment is an embodiment in which a step of opening the vaporization chamber opening valve is further added between the hydrogen peroxide diffusion step and the hydrogen peroxide condensation step of <first embodiment>.
Reference numeral 70 denotes a vaporization chamber opening valve, which can open and close the conduction between the vaporization chamber and outside air (atmosphere).
FIG. 5 will be described.
FIG. 5 is a diagram showing the time variation <second embodiment> of the pressure in the sterilization chamber during the sterilization process for sterilizing the lumen of the object to be sterilized by the sterilization apparatus of the present invention.

  In the step of opening the vaporization chamber release valve, the vaporization chamber release valve 70 is opened for a predetermined time (15 seconds) before the hydrogen peroxide condensation step, so that the sterilization chamber is opened from the atmosphere release valve 22 in the hydrogen peroxide condensation step. This is a step of supplying the atmosphere from the vaporization chamber 30 to the sterilization chamber 11 before supplying the atmosphere to the abruptly.

  When the vaporizing chamber opening valve 70 and the vaporizing valve 40 shown in FIG. 4 are opened by adding a step of opening the vaporizing chamber opening valve to the first embodiment, the vaporizing chamber is also opened to the atmosphere. Is introduced into the sterilization chamber after passing through the vaporization chamber 30. One end of the vaporizing chamber opening valve 70 passes through a hepa filter (not shown) and then is connected to the atmosphere. When the vaporizing chamber opening valve 70 and the vaporizing valve 40 communicate with each other, the gas in the vaporizing chamber 30 is introduced into the sterilization chamber by atmospheric pressure. Is done. The introduction time is a predetermined time set in advance (time up to 15 seconds). At this time, the vaporization chamber 30 and the sterilization chamber 11 are already in communication in step 103 but cannot be moved due to the pressure difference. This has the effect of guiding the steam to the sterilization chamber using the passage of atmospheric pressure.

  Originally, since the density (concentration) of hydrogen peroxide vapor follows the atmospheric pressure, the vaporization chamber 30 and the sterilization chamber 11 have the same atmospheric pressure when the vaporization valve is open. Concentration) should be the same density in the vaporization chamber 30 and the sterilization chamber 11.

However, in actuality, since the vapor of hydrogen peroxide is attached to the surface (inner wall) of the vaporization chamber 30 that supplies the vapor of hydrogen peroxide to the sterilization chamber 11 and the vaporization valve 40, the vapor of the hydrogen peroxide that has adhered thereto A step of opening the vaporization chamber opening valve is necessary in order to uniformly diffuse the vapor of hydrogen peroxide that has been supplied and adhered. As a result, hydrogen peroxide vapor attached to the surface (inner wall) of the vaporization chamber 30 and the vaporization valve 40 is further supplied, and the density (concentration) of hydrogen peroxide vapor can be increased in the hydrogen peroxide condensation step.
Steps 501 to 502 in FIG. 5 are the same as the hydrogen peroxide diffusion step described in the first embodiment.
Steps 502 to 503 in FIG. 5 are steps for opening the vaporizing chamber opening valve.
Steps 503 to 504 in FIG. 5 are the same as the hydrogen peroxide condensing step described in the first embodiment.
Steps 504 to 505 in FIG. 5 are the same as the vacuum process described in the first embodiment.
<Third embodiment>
FIG. 6 will be described.
In the third embodiment, the hydrogen peroxide condensing step in the first embodiment is divided into two steps having different gas introduction rates.

In this way, the hydrogen peroxide condensation process is subdivided into two steps with different gas introduction speeds (pressure increase speeds), so that the optimum introduction speed to be introduced into the lumen and the optimum introduction speed to condense are obtained. There is an effect that it can be divided.
In step S201, the inside of the sterilization chamber is maintained at a vacuum pressure by closing the atmosphere release valve and operating the vacuum pump (preliminary vacuum process).

  In step S202, it is determined whether step S103 has been executed a predetermined number of times (about four times) set in advance (determination step). That is, it is determined how many times from step S203 to step S208 is repeated. If it has been repeated a predetermined number of times, the process proceeds to the ventilation step of step S209.

  In step S203, the vacuum pump is stopped and the vaporization valve is opened, so that the hydrogen peroxide vapor prepared in advance in the vaporization chamber is supplied into the sterilization chamber, and the hydrogen peroxide vapor diffuses into the sterilization chamber (excess). Hydrogen oxide diffusion process). The diffusion time is a predetermined time set in advance (between 60 seconds and 480 seconds). During the diffusion time, the pressure in the sterilization chamber increases, and when the predetermined time is reached, P1 (the first pressure) 1 pressure). In step S203, the air release valve remains closed.

  In step S204, gas (atmosphere) is supplied from the outside of the sterilization chamber to the inside of the sterilization chamber by opening the air release valve under the second condition, and hydrogen peroxide vapor is introduced into the lumen of the object to be sterilized. The introduction time is a predetermined time set in advance (between 5 seconds and 10 seconds). During the introduction time, the pressure in the sterilization chamber rises rapidly, and reaches a predetermined pressure P1 at a predetermined time. Reach. In step S206, the vacuum pump remains stopped.

  Here, it is important to introduce the hydrogen peroxide vapor into the deep part of the lumen (introduction step). In order to introduce the steam into the deep part of the lumen, the sterilization chamber pressure is set to a predetermined pressure for a long time. It is necessary to raise slowly.

This gradual rise means that the pressure inside the sterilization chamber, which was 1500 Pascals with a volume of 76 liters, reaches a predetermined pressure rise rate that reaches atmospheric pressure (P3) over a long period of 60 seconds (second condition). It is to supply air gently into the sterilization chamber.
In step S205, it is determined whether the atmospheric pressure (P3), which is a predetermined pressure, has been reached by a pressure sensor that measures the pressure in the sterilization chamber.

  In step S206, gas (atmosphere) is supplied from the outside of the sterilization chamber to the inside of the sterilization chamber by opening the air release valve under the first condition, and hydrogen peroxide vapor is introduced into the lumen of the object to be sterilized. The introduction time is a predetermined time set in advance (between 5 seconds and 10 seconds). During the introduction time, the pressure in the sterilization chamber rises rapidly, and reaches a predetermined pressure P2 at a predetermined time. Reach. In step S206, the vacuum pump remains stopped.

  Here, it is important to condense the hydrogen peroxide vapor introduced deep into the lumen into a liquid (condensation process). In order to condense the vapor into the liquid, the sterilization chamber pressure is reduced to atmospheric pressure in a short time. It is necessary to raise it rapidly.

This rapid increase is a predetermined pressure increase in which the pressure in the sterilization chamber, which was 4000 Pascals with a volume of 76 liters, reaches atmospheric pressure (P2) in a short time (first condition) of 5 to 10 seconds. The air is rapidly supplied into the sterilization chamber at a speed of
In step S207, it is determined whether the atmospheric pressure (P2), which is a predetermined pressure, has been reached by a pressure sensor that measures the pressure in the sterilization chamber.

  In step S208, when the atmospheric pressure (P2) is reached, the air release valve is closed and the vacuum pump is operated to exhaust the inside of the sterilization chamber, which is atmospheric pressure. In the initial process of exhausting the inside of the sterilization chamber, as the pressure inside the sterilization chamber decreases (decompression), hydrogen peroxide is condensed in the lumen of the object to be sterilized in step S206 and the lumen of the object to be sterilized This liquid is vaporized again (vaporized) in the lumen of the object to be sterilized (hydrogen peroxide vaporization step).

  The vacuum time including the initial process is a predetermined time set in advance. During the vacuum time, the pressure in the sterilization chamber gradually decreases, and reaches a vacuum pressure P0 when the predetermined time is reached (vacuum process). .

By operating the vacuum pump, the inside of the sterilization chamber, which is at atmospheric pressure, is exhausted. The hydrogen peroxide solution that sterilized the surface of the object to be sterilized in the sterilization chamber and the hydrogen peroxide solution that sterilized the lumen of the object to be sterilized, and vaporized again in step S208. The hydrogen peroxide vapor sterilized on the surface of the object to be sterilized in the sterilization chamber and the hydrogen peroxide vapor sterilized in the lumen of the object to be sterilized can be removed (recovered).
In step S209, the inside of the sterilization chamber is ventilated (ventilation process).

10 Material to be sterilized 11 Sterilization chamber 22 Air release valve 40 Vaporization valve

Claims (7)

A sterilization method for sterilizing a lumen of an object to be sterilized stored in a sterilization chamber capable of maintaining pressure from vacuum pressure to atmospheric pressure with hydrogen peroxide,
A hydrogen peroxide diffusion step of supplying hydrogen peroxide vapor so that the inside of the sterilization chamber maintained at a vacuum pressure becomes the first pressure, and diffusing the hydrogen peroxide vapor into the sterilization chamber;
By supplying gas so that the inside of the sterilization chamber where the hydrogen peroxide vapor has diffused is at atmospheric pressure, the diffused hydrogen peroxide vapor is introduced into the lumen of the object to be sterilized, and into the lumen. A hydrogen peroxide condensation process in which the introduced hydrogen peroxide vapor is condensed into a liquid;
Hydrogen peroxide vaporization step for vaporizing the condensed hydrogen peroxide liquid by reducing the pressure inside the sterilization chamber, which is the atmospheric pressure,
A sterilization method comprising:   The sterilization method according to claim 1, wherein the hydrogen peroxide vaporization step is started when the atmospheric pressure is reached.   The hydrogen peroxide vaporization step is an initial step of a vacuum step of evacuating the inside of the sterilization chamber at the atmospheric pressure in order to remove hydrogen peroxide introduced into the lumen of the sterilized object. The sterilization method according to claim 1 or 2.   The sterilization method according to claim 3, wherein the hydrogen peroxide diffusion step or the vacuum step is repeated a predetermined number of times.   The said gas is air | atmosphere, The any one of Claim 1 thru | or 4 characterized by the above-mentioned.   The sterilization method according to any one of claims 1 to 5, wherein in the hydrogen peroxide diffusion step, vapor of hydrogen peroxide is introduced up to a first pressure during a predetermined time.   The sterilization method according to any one of claims 1 to 6, wherein in the hydrogen peroxide condensing step, gas is introduced to atmospheric pressure at a predetermined pressure increase rate.

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