Sterilization method and apparatus.

(54) Title: STERILIZATION METHOD WITH HYDROGEN PEROXIDE.

(54) Title: STERILIZATION METHOD AND APPARATUS.

(57) Summary

A method is described for measuring hydrogen peroxide gas in an evacuated sterilization chamber. The method includes the steps of continuously monitoring a pressure in the sterilization chamber; connecting a path of known volume to the evacuated chamber to evacuate the path; seal the way; bonding the evacuated pathway to a supply of hydrogen peroxide solution for a period of time sufficient to extract the hydrogen peroxide solution and fill the pathway; seal the way; and repeating those steps until an increase in the preselected pressure is detected in the sterilization chamber. The increase in pressure is preferably 19 Torr. The known volume of the regulatory pathway is preferably between 75 pL and 15 pL to control unwanted condensation of hydrogen peroxide in the sterilization chamber. Costly peroxide concentration measurement systems are replaced by an inexpensive and inexpensive pressure sensor for hydrogen peroxide concentration control.

(57) Abstract

A method of sterilizing an article by sequentially exposing the article to hydrogen peroxide and ozone is disclosed. The article is exposed under vacuum first to an evaporated aqueous solution of hydrogen peroxide and subsequently to an ozone containing gas. The exposure is carried out without reducing the water vapor contained of the sterilization atmosphere, the water vapor contained being derived from the aqueous solvent of the hydrogen peroxide solution and from the decomposition of the hydrogen peroxide into water and oxygen. The complete sterilization process is carried out while the chamber remains sealed and without removal of any component of the sterilization atmosphere. For this purpose, the chamber is initially evacuated to a first vacuum pressure sufficient to cause evaporation of the aqueous hydrogen peroxide at the temperature of the chamber atmosphere. The chamber is then sealed for the remainder of the sterilization process and during all sterilant injection cycles. Keeping the chamber sealed and maintaining the hydrogen peroxide and its decomposition products in the chamber for the subsequent ozone sterilization step results in a synergistic increase in the sterilization efficiency and allows for the use of much lower sterilant amounts and sterilization cycle times than would be expected from using hydrogen peroxide and ozone ¡n combination.

Mexican Institute of Industrial Property

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PATENT TITLE NO. 345910

Owner (s): TSO3 INC

Address: 2505 Avenue Dalton, G1P 3S5, Quebec, Quebec, CANADA

Name: HYDROGEN PEROXIDE STERILIZATION METHOD.

Classification: lnt.CI.8: A61L2 / 20

Inventor (s): SIMON ROBITAILLE; SYIVIE DUFRESNE: JEAN-MARTIN VALLIERES; CYNTHIA

MARTEL; HELENE LEBLOND; NANCY DASSIE; MARIE-CHRISTINE GAGNE; KARINE MARTEL: CLAUDIA BEDARD: BRUNO TREMBLAY

REQUEST

Number: International filing date:

MX / a / 2013/002682 September 29, 2010;

Divisional Patent Number: 337243

PRIORITY

Country: Date: Number:

US September 30, 2009 61 / 247,197

Validity: Twenty years

Expiration Date: September 29, 2030

The reference patent is granted on the basis of articles 1, 2 ° V, 6 ° fraction ΠΙ, and 68 of the Industrial Property Law.

In accordance with Article 23 of the Industrial Property Law, this patent has a non-extendable twenty-year term, counted from the filing date of the international application and will be subject to the attachment of 'to tanH to keep the rights. ^::, .. í

Whoever signs this title does so based on the provisions of articles β * fractions lll and 7 bis 2 of the Industrial Property Law (Official Gazette of the Federation (DOF) 06/27/1991, amended BF &lt;8 / 08/1994, 25/10/1996, 26/12/1997, 17/05/1999, 26/01/2004, 16/06/2005, ^ 5/01/20 ^, 06/05 / 2009,06 / 01/2010, 06/18/2010, fWÚW5ÓfT'27701 / 2012 and 04/09/2012); Articles 1¾ 3 'fraction V subsection a). 4^or and 12th sections l and MI of the Regulations of the Mexican Institute of Industrial Property (DOF 14/12/1999, amended on 07/01/2002, 07/15/2004, 07/09/2004 and 09/07/2007); Articles 1 ·, 3 », 4 ·, 5^or fraedton V InefSo a), 16 fractions fy til and 30 of the Organic Statute of the Mexican Institute of Industrial Property (DOF 12/27/1999, amended on 10/10/2002, 07/29/2004, 08/04/2004 and 09/13/2007); 1^or, 3^orand 5th subsection a) of the Agreement that delegates powers to the Deputy General Directors, Coordinator, Divisional Directors, Heads of Regional Offices, Divisional Deputy Directors, Departmental Coordinators and other subordinates of the Mexican Institute of Industrial Property. (DOF 12/15/1999, amended on 02/04/2000, 07/29/2004, 08/04/2004 and 09/13/2007).

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PEROXIDE STERILIZATION METHOD

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CROSS REFERENCE WITH RELATED REQUESTS

This application claims priority of the Application for

Provisional US Patent No., Serial No. 61 / 247,197, filed September 30, 2009 and entitled Sterilization Method And Apparatus, and is a continuation of a US Application Serial No. 12 / 893,742, filed on September 29, 2010 and entitled METHOD AND APPARATUS OF ₁₀ STERILIZATION, the contents of which are incorporated in this application, in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to sterilization methods and apparatus. More particularly, the present invention relates to a sterilization process using gaseous vacuum biocides.

BACKGROUND OF THE INVENTION

Sterilization is the destruction of any virus, bacteria, fungus or other microorganism, whether in a vegetative state or in an inactive spore and is defined by a reduction of 10-⁶ the level of bacteria. Conventional sterile processing procedures for medical instruments involve elevated temperatures (such as steam and

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dehydrated heat units) or productxxfi ^ -xpiijai &amp; eHB— ethylene oxide gas, hydrogen peroxide, or ozone).

Sterilization methods and apparatus using gaseous sterilants are known. Sterilizers that use hydrogen peroxide as the sterilant are widely used. Hydrogen peroxide is generally supplied as an aqueous solution and evaporated prior to injection into a sterilization chamber of the sterilizer, by heating from the solution, or by applying a vacuum to the chamber.₁₀ sterilization, or both. After evaporation of the solution, the sterilization atmosphere in the sterilization chamber includes hydrogen peroxide gas and water vapor. It is a disadvantage of this process that water vapor tends to condense on items in the chamber while sterilization continues. The resulting layer of water condensate on the items to be sterilized interferes with the sterilizing action of hydrogen peroxide. Various apparatus and process modifications have been developed to address this problem, all of which are aimed at limiting the relative humidity in the sterilization atmosphere during the sterilization process. However, these modifications invariably increase operating cost and / or sterilization cycle times.

Sterilization processes that use so much ³ IMPI

INSTITUTO MEXICANO J *. OF THE PROPERTY

INDUSTRIAL hydrogen peroxide as ozone gas have been used, but with unsatisfactory results especially with regard to the sterilization of items with long internal lumens, such as gastroscopes and colonoscopes, and with regard to sterilization cost and cycle times. Although ozone based processes are satisfactory with respect to sterilizing items with long lumens, material compatibility poses a problem. Hydrogen peroxide based processes are generally unsatisfactory in terms of sterilizing long lumens. Unwanted condensation of hydrogen peroxide on the article to be sterilized reduces the efficiency of sterilization. Reliable control of the hydrogen peroxide concentration in the sterilization chamber is important. Expensive systems are generally used to quantify the concentration of hydrogen peroxide in the chamber.

Therefore, a method and apparatus is desired to address at least one of the disadvantages of known sterilization processes using gaseous sterilants.

BRIEF DESCRIPTION OF THE INVENTION

It is an object of the present invention to avoid or mitigate at least one disadvantage of prior sterilization processes using gaseous sterilants.

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In a first aspect, a method is provided for measuring hydrogen peroxide gas in an evacuated sterilization chamber, to control the concentration of hydrogen peroxide in the chamber. The method includes the steps of continuously monitoring a pressure in the sterilization chamber; joining a path of known volume to the evacuated chamber to evacuate the path; they seal the way; binding the evacuated pathway to a supply of hydrogen peroxide solution for a period of time sufficient to draw the hydrogen peroxide solution in and fill the pathway with the hydrogen peroxide solution; seal the pathway, - and repeating those steps until a preselected pressure rise in the sterilization chamber is detected. The concentration of the hydrogen peroxide vapor in the chamber is controlled in a repeatable manner by simply monitoring for a desired pressure rise.

In a second aspect, the increase in pressure is 19Torr.

In a third aspect, the known volume of the regulatory pathway is between 75 pL and 15 pL to control unwanted condensation of hydrogen peroxide in the sterilization chamber.

In a fourth aspect, the volume of the regulatory pathway is between 15 pL and 35 pL.

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In a fifth aspect, it is between 15 pL and 20 pL.

the volume of the regulatory pathway

In the method of this disclosure, expensive peroxide concentration measurement systems are replaced by an inexpensive pressure sensor for monitoring the hydrogen peroxide concentration.

Other aspects and features of the present invention will become apparent to those skilled in the art upon review of the following description of the ₁₀ specific modalities of this description together with the accompanying figures.

BRIEF DESCRIPTION OF THE FIGURES

The modalities of the present apparatus, systems and methods will now be described only by way of example with regard to the attached figures, where:

Figure 1 shows a schematic diagram of an apparatus in accordance with the description, the illustrated parts of the apparatus listed in Table III;

Figure 2 shows a schematic diagram of a hydrogen peroxide delivery system in accordance with the description, the illustrated parts of the system listed in Table III ;;

Figure 3 is a flow chart of a preferred sterilization method in accordance with the description;

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* WPI INSTITUTO MEXICANO DE LA PROPERTY INDUSTRIA!

Figure 4 is a graph illustrating an exemplary first sterilization cycle in accordance with the description;

Figure 5 is a graph illustrating an exemplary second sterilization cycle in accordance with the description;

Figure 6 is a graph illustrating an exemplary third sterilization cycle in accordance with the description;

Figure 7 shows an exemplary embodiment of a hydrogen peroxide supply unit in accordance with the description;

Figure 8 shows an exemplary embodiment of a hydrogen peroxide reservoir, metering and evaporation unit in accordance with the description;

Figure 9 (comprising Figure 9a to Figure 9c) is a schematic diagram of a control system for an apparatus according to the description;

Figure 10a is a perspective view of a sterilizing container according to the description;

Figure 10b is a cross-sectional view of the container of

FIGURE, 10a;

Figure 10c is a side elevation view of the container of Figure 10a; and

Figure 10 is an enlarged detail B of the container shown in Figure 10b.

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DETAILED DESCRIPTION OF THE PREFERRED MODE

In general terms, the present application provides a method for sterilizing an article in a gaseous sterilizing atmosphere by sequentially adding evaporated hydrogen peroxide and particularly with a method for measuring hydrogen peroxide vapor in an evacuated chamber. Preferably, the measurement is controlled by monitoring an increase in the preselected pressure in the chamber. Furthermore, by controlling not only₁₀ the total concentration of the hydrogen peroxide in the chamber, but also the individual aliquots injected, the condensation of hydrogen peroxide in the sterilization chamber at a preselected temperature can be controlled.

The method includes the steps of continuously monitoring a pressure in the sterilization chamber; connecting a path of known volume to the evacuated chamber to evacuate the path; seal the way; binding the evacuated pathway to a supply of hydrogen peroxide solution for a period of time sufficient to extract the hydrogen peroxide solution and fill the pathway with the hydrogen peroxide solution; seal the way; and repeating those steps until the increase in preset pressure is detected in the sterilization chamber. The concentration of the hydrogen peroxide vapor in the chamber

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It is controlled in a repeatable manner by monitoring obtaining a desired increase in pressure.

By maintaining the sterilization chamber at a vacuum pressure below the pressure where the hydrogen peroxide will boil at the preselected temperature and evaporating and injecting successive pulses of hydrogen peroxide until a desired pressure rise is achieved, the concentration of hydrogen peroxide in the chamber can be controlled as well as the unwanted condensation of the hydrogen peroxide at the preselected temperature.

As will be mentioned later, hydrogen peroxide solution injected into the sterilization chamber in a vapor form condenses on the article to be sterilized. However, the condensation of hydrogen peroxide interferes with the sterilization of long lumens, since the hydrogen peroxide is removed from the vapor phase during condensation. Thus, for hydrogen peroxide to penetrate long lumens, hydrogen peroxide should be kept in the vapor phase as much as possible and condensation to be avoided during hydrogen peroxide injection. This is achieved in accordance with the present disclosure by controlling the volume of the individual hydrogen peroxide injection pulses. In one embodiment, the volume of each pulse of peroxide

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MEXICAN INSTITUTE OF. ! A RUOMEDAL INDUSTRIAL hydrogen is less than 75 pL. In another mode, the VülUWéh 'of each pulse of hydrogen peroxide is less than 35 pL. In another embodiment, the volume of each pulse of hydrogen peroxide is less than 20 pL.

As will be mentioned later, hydrogen peroxide solution injected into the sterilization chamber in a vapor form condenses on the article to be sterilized. However, the condensation of hydrogen peroxide interferes with the sterilization of long lumens, since the hydrogen peroxide is removed from the vapor phase during condensation. Thus, for hydrogen peroxide to penetrate long lumens, hydrogen peroxide should be kept in the vapor phase as much as possible and condensation to be avoided during hydrogen peroxide injection. This is achieved in accordance with the present disclosure by controlling the volume of the individual hydrogen peroxide injection pulses. In one embodiment , the volume of each pulse of hydrogen peroxide is less than 75 pL. In another embodiment, the volume of each pulse of hydrogen peroxide is less than 35 pL. In another embodiment, the volume of each pulse of hydrogen peroxide is less than 20 pL.

This method of controlling hydrogen peroxide concentration can be used in a sterilization method as illustrated in the flow chart in Figure 3 and the

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Cycle graphs of FIGs 4 through 6, where an item is sterilized by sequentially exposing it to hydrogen peroxide and ozone. The article is preferably exposed under vacuum first to evaporated aqueous hydrogen peroxide solution and subsequently to a gas containing ozone. Exposure to evaporated hydrogen peroxide is accomplished by controlling unwanted condensation of hydrogen peroxide. Preferably, the exposure is carried out without reducing the water vapor content of the atmosphere of ₁₀ sterilization, the content of water vapor that is derived from the aqueous solvent of the hydrogen peroxide solution and from the decomposition of hydrogen peroxide into water and oxygen. Most preferably, the entire sterilization process is accomplished while the chamber remains sealed and without removing any components from the sterilization atmosphere. For this purpose, the chamber is initially evacuated at a first vacuum pressure sufficient to cause evaporation of the aqueous hydrogen peroxide at the temperature of the chamber atmosphere. The chamber is then sealed and the hydrogen peroxide and ozone containing gas are sequentially added to the chamber and held in the chamber for a preselected exposure time. All the elimination of any component in the sterilization atmosphere is stopped during the addition of the sterilants and for the duration of the exposure time.

The aqueous hydrogen peroxide solution is evaporated and directly injected into the sterilization chamber without any measures to reduce the water vapor content. The inventors of the present application have surprisingly discovered that the amount of sterilants used and the length of the sterilization cycle can be considerably reduced, when any steps to reduce the content of steam in the chamber are omitted and the sterilization step of hydrogen peroxide is examined in more detail by an ozone sterilization step, since the water vapor generated during the hydrogen peroxide sterilization stage can be used sufficiently to moisten the atmosphere in the chamber to improve the ozone sterilization stage. Much lower amounts of hydrogen peroxide and ozone can be used than in prior art processes using the same sterilants, sterilization while still being achieved complete. Also, the required amounts of the sterilants according to the present invention are less than what would be expected from simply using two steriliants in the same cycle. Thus, keeping the chamber sealed throughout all sterilization steps without any measure to control humidity in the sterilization atmosphere appears to result in a synergistic effect.

A sterilizer according to the description as shown

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INSTITUTO MLXlCANí nt Ι.Α ΗΟΡΙΕΟΑΓ iNnUSTtlAL

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schematically illustrated in Figure 1 generally works in the following manner. An item to be sterilized (not shown) is placed in a sterilization chamber 10 and the chamber is sealed. A vacuum is applied to chamber 10. The evaporated hydrogen peroxide solution is supplied into the sterilization chamber 10 of an administration unit 30 (see Figure 8), of which less than will be mentioned in detail. Evaporated hydrogen peroxide supplied into the chamber provides sterilization ₁₀ part of the article. The medical grade oxygen is subjected in an ozone generator 22 to an electric field, which converts the oxygen into the gas-containing ozone. The gas-containing ozone is then fed into chamber 10, which has been moistened by the injection of the evaporated hydrogen peroxide solution and the decomposition of hydrogen peroxide into free radicals (hydroxyl), water and oxygen. The ozone containing gas completes the sterilization of the item. Remaining sterilizing gases are subsequently decomposed into water and oxygen using a 52 catalyst.

The only residues kept at the end of the sterilization cycle are clean, oxygenic water.

The ozone sterilization method of the invention is preferably carried out at room temperature and thus does not require substantially any aeration or cooling of sterilized items so that they can be used.

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immediately following the sterilization cycle. Furthermore, used gases diffuse more quickly into long lumens to be sterilized, reducing the cycle times required for sterilization. This allows hospitals to reduce the cost of maintaining expensive medical device inventories. The sterilization method of the invention offers several additional advantages. This does not produce any toxic waste, does not require the handling of dangerous gas cylinders, and does not pose any threat to the environment or the health of the user. Stainless steel instruments and heat sensitive instruments can undergo treatment simultaneously, which for some users will avoid the need for two separate sterilizers.

The preferred sterilization apparatus according to the disclosure as schematically illustrated in Figure 1 includes a sterilization chamber 10 which can be sealed to contain a vacuum. This is accomplished with an access door 12, which can be selectively opened for access into the chamber and which seals the chamber in the closed condition. The apparatus further includes an ozone generator 22 for supplying gas containing the ozone to the sterilization chamber, a hydrogen peroxide supply unit 30 for supplying the evaporated hydrogen peroxide to the sterilization chamber 10, and a vacuum pump. 40 (CM-005-052 TS03, Inc.). Vacuum pump

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INSTTTUTC MEX1CANC I HEARD THE INDUSTRIAL PROMROAD

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0 It is used for requesting a sufficient vacuum to the sterilization chamber 10 to increase the penetration of sterilization gas and to be able to generate the evaporated hydrogen peroxide solution at a temperature below the temperature within the sterilization chamber. The vacuum pump 40 in the preferred embodiment has the ability to produce a sufficient vacuum in the sterilization chamber to lower the boiling temperature of water in the chamber below the current temperature of the atmosphere in the chamber. ₁₀ camera. In the preferred apparatus, the vacuum pump is capable of producing a vacuum of ITorr (1.33mbar). The ozone produced in the ozone generator 22 is destroyed in an ozone catalyst 52 to which the ozone-containing gas is fed downstream through the sterilization chamber 10 or directly from the ozone generator 22 through the valve. auxiliary bypass tube 29b. Ozone catalyst 52 (AM-004-001, TS03 Inc.) is connected in series after vacuum pump 40 to prevent ozone gas from escaping into the environment. Decomposition material

0 ozone in the preferred catalyst 52 is carulite. For economic and practical reasons, it is preferred to use a catalyst for the decomposition of ozone in spent sterilization gas from the sterilization chamber 10. The catalyst destroys hydrogen peroxide and ozone on contact and transforms it back to oxygen. and water with¹⁵ I hfi PI

INSTITUTO MEXICANO DE LA HOMEDAI INDUSTRIA! —- a certain amount of heat that is produced. Catalysts of this type and their manufacture are known to those skilled in the ozone generator art and do not have to be described in detail here. Furthermore, other means of destroying ozone and hydrogen peroxide contained in sterilization gas will be readily apparent to one of ordinary skill in the art. For example, gas can be heated for a preselected period of time to a temperature where the sterilizing decomposition is accelerated, for example, to 300 ° C for a period of 3 seconds.

The hydrogen peroxide supply unit 30 includes a tank 220 (AM-213-010, TSO3 Inc.), a dosing unit 240, and an evaporator unit 260 (FM-213003, TSO3 Inc.) directly connected to the sterilization chamber 10 through a conduit 280. (AM-213-003, TSO3 Inc.) The tank 220 is equipped with a level sensor 222 to always ensure a sufficiently high level of hydrogen peroxide for the execution of another sterilization cycle. A hydrogen peroxide solution (359%) is supplied to the reservoir of a hydrogen peroxide supply unit 200 (see Figure 7), less than will be mentioned in more detail. The hydrogen peroxide solution is supplied in supply unit 200 from a sealed bottle 180 (see Figure 7). The evaporated hydrogen peroxide solution produced in the

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evaporator unit 260 directly enters the sterilization chamber 10 without intermediate flow restriction or valve. The evaporator unit is preferably equipped with a heating device (not shown) that maintains the temperature of the hydrogen peroxide solution high enough to achieve a higher evaporation rate and prevent freezing of the solution.

Ozone generator 22 (OZ, model 14a, TSO3 Inc.) is of the corona discharge type and is cooled to decrease the rate of ozone decomposition, all of which are known in the art. The generation of ozone is associated with the loss of energy in the form of heat. Since heat accelerates the decomposition of ozone into oxygen, this should be removed as soon as possible by cooling the ozone generator 22. The ozone generator in the apparatus is kept at the relatively low temperature of 3 to 6 ° C by a cooling system 60, which is an indirect cooling system with recirculation of water for cooling, or a direct cooling system with a air cooling unit or a refrigeration unit for cooling (not shown). The refrigeration system is preferably kept at a temperature of 3 to 6 ° C. In the preferred embodiment, the refrigeration system is maintained at 4 ° C so that gas containing the ozone generated by the

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generator 22 is in an ambient temperature of approximately 20 to 35 ° C. Thus, gas that contains ozone and signs the sterilization chamber for humidification and sterilization is kept at ambient temperatures of 20 to 35 ° C. This means that ozone decomposition is minimized and the sterilization process is the most efficient. The ozone generator 22 is preferably supplied with medical grade oxygen. Oxygen can also be supplied directly to the sterilization chamber 10 through the oxygen supply valve 21. The apparatus can be connected to a wall, the oxygen exhaust valve common in hospitals or to an oxygen cylinder or to any other source capable of supplying the quality required and flow. The oxygen supply to the generator 22 occurs through a filter 23, a pressure regulator 24, a flow meter 25 and a closed valve oxygen 26. The generator is protected against oxygen over pressure by a safety pressure switch 27. The oxygenic mixture due to ozone generated by the generator 22 concerns the sterilization chamber 10 through a flow regulator orifice 28 and a valve mix supply solenoid 29a. The mixture can also be directly supplied to ozone catalyst 52 via an auxiliary bypass tube solenoid valve 29b (optional). In a preferred embodiment where a sterilization chamber of the

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IMPI

INSTITUTO MEXICANA. DE LA FROPISBAf · INniíST «l * i.

125 liter volume is used, the pressure regulator 24 and the regulator valve 28 preferably control the oxygen intake at a pressure of about 13.8 kPa (2 psig) and a flow rate of about 1.5 liters per minute. However, it will be readily apparent to the skilled person that other flow rates can be used depending on the make and model of the ozone generator 22 and the size of the sterilization chamber.

The vacuum in the sterilization chamber 10 occurs ₁₀ via the vacuum pump 40 and the sterilization chamber drain valve 44.

Valves 29a and 29b are Teflon solenoid valves (CM-900-156, TSO3 Inc.) Valve 26 and vacuum valve 44 are solenoid valves (CM-015-004, TSO3 Inc.).

The preferred ozone generator used in the process and apparatus of the invention is a generator of the corona discharge type, which is known to the person skilled in the art and does not have to be further described here.

Functioning

A preferred sterilization method according to the invention includes the general steps that follow as illustrated by the flow chart of Figure 3. Items to be sterilized, such as medical instruments, can be placed directly into the sterilization chamber, but

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they are preferably sealed in sterile packaging containers, sterile coats or sachets such as generally used in the hospital environment and then placed in the sterilization chamber. Various different types of such containers or sachets are known to those skilled in the art and do not have to be described further herein.

After the insert of the item to be sterilized has been placed in the sterilization chamber at step 320, the sterilization chamber door is closed and the chamber sealed at step 34 0 and a vacuum is applied to the chamber. sterilization in step 350 until a first pressure of lTorr (1.33 mbar) is reached in the chamber. The sterilization chamber walls have preferably been preheated in a heating stage 310 to a temperature of 40 ° C. The evaporated hydrogen peroxide solution is admitted to the sterilization chamber in the humidification stage 360 ​​to partially sterilize and moisten the chamber contents. The injection of evaporated hydrogen peroxide solution is stopped once a pressure increase of 19 Torr has been achieved in the chamber. The chamber can be kept sealed for a first exposure period 370 (preferably 2 minutes) during which the hydrogen peroxide at least partially decomposes into free radicals, water and oxygen. Preferably, this exposure period also

INSTITUTO MEXICANO DI LA PROPIKDAD INDUSTRIAL can be omitted. A gas-containing ozone, "preferably the form of a mixture of the dehydrated ozone and oxygen, is then supplied to the chamber at the ozone injection stage 380 and the chamber kept sealed for a second preselected exposure period 390. No humidification of the gas-containing ozone is carried out, or even necessary, since the chamber atmosphere has been humidified by the hydrogen peroxide solution. Between the vacuum request, before the evaporation stage of₁₀ hydrogen peroxide, and the end of the second exposure period, all removal of any component from the sterilizing atmosphere is interrupted so that none of the components from the atmosphere is removed before the end of the second exposure period. The steps of the vacuum application, injection of hydrogen peroxide with the first period of exposure and injection of ozone gas with the second period of exposure, are preferably repeated at least once, the number of repetitions that are determined in the step 3 95 based on the cycle previously selected in step 330. To remove all remaining sterilants from the sterilization chamber 10 after the sterilization cycle is completed a ventilation phase 400 is started, which preferably includes multiple cycles of evacuating the chamber and flushing with oxygen. After the ventilation phase 400, the

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INSTITUTO MEXICANO DE LA PHOMOAl INCJSTXIAI

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The door is unlocked in step 410 and the sterilized items can be obtained from the chamber. The temperature of the floor and door of the chamber and of the evaporator unit are preferably controlled throughout the sterilization process.

In an exemplary sterilization apparatus in accordance with the description, the user has the option of multiple different sterilization cycles. In a preferred method, the user can choose at the selection stage₁₀ cycle 330 of the process between three cycles having the respective characteristics shown in Table 1 and mentioned below.

Table I

<td>Cycle Phases</td><td>Cycle 1</td><td>Cycle 2</td><td>Cycle 3</td>

<td>Empty</td><td>1 Torr</td><td>1 Torr</td><td>1 Torr</td>

<td>Humidification with 50% H202 solution</td><td>20 Ton</td><td>20 Torr</td><td>20 Torr</td>

<td>Humidification plateau (optional)</td><td>2 min</td><td>2 min</td><td>2 min</td>

<td>03 Injection</td><td>2 mg / 1</td><td>10mg / l</td><td>3mg / l</td>

<td>Exposition</td><td>5 min</td><td>5 min</td><td>10 minutes</td>

<td>Number of repetition (ones)</td><td> 2</td><td> 2</td><td> 4</td>

<td>Approximate Duration of</td><td>46 min</td><td>56 min</td><td>100 min</td>

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Cycle

Cycle 1-Surface sterilization of devices that have low compatibility with ozone, articulated devices and short-circuit flexible endoscopes (1 mm x 85 cm). (Except. Chambers, cables, shovels, forceps, bronchoscopes, ureteroscopes).

Cycle 2-Surface devices with high compatibility with ozone, articulated instruments and rigid endoscopes (1 mm x 50 cm).

Cycle 3-Sterilizable instruments with cycle # 1 and formed into complex endoscopes (Except gastroscopes, colonoscopes).

Although it is preferred to operate the present sterilization process using a 50% hydrogen peroxide solution, the process can be operated with solutions including the 3% to 50% hydrogen peroxide. Exemplary conditions for the process when run with 3%, 30% and 50% hydrogen peroxide solution is as follows.

Table II

<td>% H202</td><td>Maximum pressure Injection (Torr)</td><td>Dose of ozone (mg / L)</td><td>Number of repetitions</td><td>Time of Conditioning</td>

<td> 3</td><td> 44-54</td><td> 25-50</td><td> 2-8</td><td>2 hours</td>

<td> 30</td><td> 30-44</td><td> 5-25</td><td> 2-6</td><td>2 hours</td>

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<td> 50</td><td> 17-21 (20)</td><td> 2-10</td><td> 2-4 -*</td><td>IThr ”” ”” ”'</td>

The maximum injection pressure is the pressure where the injection of the evaporated hydrogen peroxide solution is stopped. The conditioning time period represents a period of time after the chamber sealing and before the vacuum request where the items to be sterilized are kept in the sterilization chamber and gradually warm from room temperature due to the chamber walls, floor and door₁₀ they heat up to about 40 ° C. This heating of the load in the chamber is required to prevent excessive condensation of water in the load on injection of the evaporated hydrogen peroxide solution. The risk of condensation increases with decreasing concentrations of₅ hydrogen peroxide. .

Once the user has selected one of the three cycles, the user ends the sterilization chamber door and pushes the boot. The sterilizer control system (see Figure 9) then goes, under the control of a running built-in software, to begin the sterilization process according to the selected cycle and using preselected parameters for the selected cycle. There is no preconditioning of the sterilization load. The cycle begins with the generation of a vacuum in the sterilization chamber of approximately lTprr

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(1.33mbar). An evaporated peroxide solution is subsequently injected into the chamber through the evaporator unit to partially sterilize and wet the load. Before entering the evaporator unit, the hydrogen peroxide solution passes through the dosing unit 24 0 shown in Figure 8. The dosing unit 240 is directly connected with the evaporator unit 260 and thus subjected at present vacuum pressure in the chamber. Dosing unit 240 includes low block 241 having a known, fixed volume line (not shown) and connected by inlet valve 242 at a 5 'end of the line to the hydrogen peroxide reservoir 220 and by an exhaust valve 243 at one end in direction 3¹ from the path to the evaporator unit 260. The flow of hydrogen peroxide solution through the dosing unit 24 0 can be exactly controlled via the valves 242, 243, which are oppositely switched and non-overlapping so that one valve is always closed when the other is available and both valves are never open at the same time. In this way, the path is evacuated when the exhaust valve 243 is available and the inlet valve 242 is closed, filled with the hydrogen peroxide solution when the exhaust valve 243 is closed and the inlet valve 242 is available and evacuated again when the valve

<img file="MX345910B_D0028.tif" />

Exhaust valve 243 is again open and inlet valve 242 is closed again. Since the exact volume of the pathway is known, the amount of hydrogen peroxide solution delivered per valve cycle is known and the total amount of hydrogen peroxide can be calculated based on the number of valve switching cycles. The number of times and the frequency that valves 242, 243 open and close are controlled and monitored by the apparatus software and can be used to determine the amount of hydrogen peroxide solution withdrawn from the reservoir and calculate the theoretically remaining amount of solution in the reservoir, based on the total amount aspirated from the supply bottle and the measured amount. The inventors of the present apparatus and method have found that, contrary to common general knowledge the exact amount of evaporated hydrogen peroxide supplied to the chamber is not critical. On the contrary, the inventors of the present application have surprisingly discovered that the most reliable determinant of the sterilization efficiency of hydrogen peroxide vapor is the pressure in the chamber. The sterilization efficiency is dependent on the level of saturation of the sterilization atmosphere with hydrogen peroxide. However, the saturation level cannot be reliably calculated from the amount of solution injected, as this greatly depends on the charge in the chamber and the adsorption characteristics of the materials in the charge. The level of saturation is however directly proportional to the pressure in the chamber. Therefore, the level of saturation in the chamber can be determined solely on the basis of chamber pressure rather than by measuring the flow or amount of the hydrogen peroxide solution injected into the chamber. As a result, the number of valve switching cycles during the hydrogen peroxide injection step 360 in a mode of the₁₀ The present invention is totally dependent on the pressure to be reached in chamber 10 at the completion of the hydrogen peroxide injection. In a preferred embodiment, a 50% aqueous hydrogen peroxide solution is used and the pressure rise to be achieved in the chamber is 19Torr. An optional sampling time of 2 5 minutes follows the scope of the predetermined pressure rise of 19Torr. Then a dose of the dehydrated ozone containing gas is injected followed by a second exposure time. The ozone dose depends on the 20 cycle selected by the user. When the desired number of repetitions of the first and second partial sterilization stages is achieved, the ventilation of the sterilization chamber 10 is carried out by evacuating and filling the chamber 3 times with oxygen in order to remove 25 residual ozone sterilizers. and peroxide

<img file="MX345910B_D0029.tif" />

hydrogen.

In order to determine whether a variation in the volume of hydrogen peroxide injected by each pulsation during the conditioning phase has an undesirable effect on the sterilization efficiency and the amount of condensation observed on the load, requesting the sterilization tests carried out with different injection pulse amounts. Theoretically, the injection / evaporation rate of hydrogen peroxide could have an undesirable effect on sterilization efficiency. Injecting a much more spacious volume during each pulse, the solution is pushed into the chamber faster, and the time period for the liquid to evaporate is decreased. The possibility of having more condensation on the instrument or on the packaging material is therefore greater. Condensation that is too pronounced would be expected to form two problems. First, the pronounced condensation could limit the ability of ozone to reach the spores on the surface of the instruments. Second, the hydrogen peroxide liquid can get trapped in the packaging material, which is risky for people who handle the sterilized load afterwards. If the amount of trapped hydrogen peroxide liquid is too spacious, the ventilation of the chamber and packaging at the end of the sterilization cycle may not be enough, to

INSTITUTO MEXICANO Ϊ DS LA PROPIEDAD ^VINDUSTRIAL

<img file="MX345910B_D0030.tif" />

remove all traces of hydrogen peroxide condensate.

When the pressure in the sterilization chamber is lowered to less than atmospheric pressure, any liquid present or injected into the chamber will boil at a lower temperature than atmospheric conditions. In the above-described embodiment of the present process, the pressure in the chamber is first lowered and then a volume of hydrogen peroxide is injected in the form of vapor. The volume₁₀ Total hydrogen peroxide used is injected in small increments. During injection, the pressure in the chamber increases until a final pressure of 20Torr (ITorr initial pressure + 19Torr pressure increase) is reached. Hydrogen peroxide evaporates at a higher temperature than water (the boiling point of 50% hydrogen peroxide is 114 ° C, and the boiling point of water is 100 ° C). Therefore, the condensate will be more concentrated in the hydrogen peroxide than the initial solution entering the chamber. · This phenomenon is observed with an ultraviolet lamp placed in the chamber. Even if the pressure in the chamber increases, the concentration of hydrogen peroxide in the vapor read by the UV lamp decreases. Also, the concentration of the first hydrogen peroxide droplet (lOTorr) is titrated. The liquid is found to be hydrogen peroxide

<img file="MX345910B_D0031.tif" />

IMPI

INSTITUTO MEX1CAN · DELAMOMEOAi. indu «t» i ·· concentrated to approximately 85%. However, the condensation of hydrogen peroxide interferes with the sterilization of long lumens, as the hydrogen peroxide is removed from the vapor phase during condensation. Thus, for hydrogen peroxide to penetrate long lumens, hydrogen peroxide should be kept in the vapor phase as much as possible and its condensation avoided during hydrogen peroxide injection.

At a pressure of approximately 10 Torr, a layer of ₁₀ Microcondensation from hydrogen peroxide appeared on targets in the chamber. The thickness of the microcondensation is calculated to be only a few coarse molecules, but it can aid sterilization, as it is known that hydrogen peroxide can sterilize in a vapor form as well as in a liquid form. Also, ozone is more soluble in hydrogen peroxide and can form radicals directly on the surface, where the spores are found.

In order to inject a high volume immediately, a valve separated by the Teflon tubing is used instead of the normally used microvalve (AM-213-001, TSO3 Inc.). The length of tubing is determined by the volume to be injected. Since the volume contained in the valve is significant, two sizes of valves are used. The first 25 type (TS03 #: CM-900-157) with a 0.062 hole, is used

INSTITUTO MBXICANO di la MtortíDAn rwurru * i for a volume up to 1.5mL. The second type of Nentuno. with an orifice of 0.156, (CM-900-156, TSO3 Inc.), it is used for a volume up to 3.5mL. The roomier valve size also helps push the roomy liquid volume into the chamber. For the 35pL volume, Burket 7616 micropump (CM-113001, TS03 Inc.) is used. For the 23 L volume, a more spacious, specially crafted block is used.

Two cycles are used for this experiment. To analyze sterility, Cycle 1 (hemicycle) is used, where the stage₁₀ Injection conditioning phase is modified with a variation in volume and pulse for each attempt, as previously described. Regarding the condensation effect, Cycle 3, comprising four phases, is used. This cycle is selected because a greater quantity of hydrogen peroxide is injected for the cycle, making it the worst case. A third party performs a test for sterility testing. The lumens (Teflon 1 mm x 80 cm) are inoculated using the wire method according to MCB-09-A07. After exposure to a Cycle 1 hemicycle, the sterility of each lumen is determined according to Rev 7 MCB-09A04 by quantitative recovery using the ultrasound method followed by filtration.

A burette is plugged into the valve system in order to accurately determine the injected volume. This volume 25 is then divided into the pulse quantity. The three cycles

I · - · ~ ---- F γ, - ιυ _κ- II

<img file="MX345910B_D0032.tif" />

TSO3 are analyzed with a special load that represents an average load for these three cycles. Charging is always at room temperature at the beginning of the cycle. An ultraviolet lamp is also installed in the used sterilizer. This allowed analysis of the hydrogen peroxide vapor during the conditioning phase.

Sterility is verified with Teflon wires (1 mm x 80 cm) inserted into the tubing, and analyzed in a Cycle 1 hemicycle. The first volume injected by each pulsed during the conditioning phase is 1.5mL. In case of an adequate result for sterile efficacy, the volume would double. If the result is not satisfactory, then half the volume would be analyzed. Since the result for the test using 1.5mL per pulse is adequate, the test is repeated with 2.5mL and 3.4mL. Testing is stopped at 3.4mL injection because only two pulses are needed to reach the desired 18Torr pressure. The normal conditioning phase stopped at 19Torr, but to ensure the pressure is not exceeded, the microvalve is used between 18 to 19Torr.

Sterility is achieved with 3.4mL (all tests are zero for spore count). Thus, Applicant found that variations in pulse volume have no effect on sterilization efficiency. However, it is noticed during sterility

INSTITUTO MEXICANO DE LA PMOPIIDAD INDUSTRIAL, which analyzes that condensation, is found exactly where the hydrogen peroxide is injected into the chamber. Therefore, more tests are carried out in order to determine the maximum volume that could be injected by each pulse without 5 condensation.

The first volume injected is again 1.5mL. Condensation is present on the charge with the injection site. The quantity of liquid condensate quantified is similar to that observed with a 3.4mL injection pulse. The₁₀ pulse amount is gradually decreased then reducing the. amount injected in half each time until no more condensation is visible. At 75 L, the condensation is again similar to this with a pulse injection of 3.4mL. A significant reduction in accumulated condensation is observed less at a pulse volume of 75 L. At 35 L, condensation is still visible, but much reduced. At 23 L, almost no condensation is visible. At a pulse volume of 16 L absolutely no condensation is observed. Condensation is found to occur in volumes of 20 pulses above 20 L. Thus, to control the amount of the unwanted condensation of hydrogen peroxide, it is preferred to use a pulse injection volume of less than 75 L, more preferably less than 35L, more preferably about 20L.

In an exemplary process in accordance with the description, the chamber walls of size are maintained at a temperature of 40 ° C while the charging temperature can vary between 20 ° C and 25 ° C. The concentration of the hydrogen peroxide solution used is preferably 50%, but concentrations as low as 3% and as high as 59% can be used. The pressure achieved inside the chamber is a function of the concentration of hydrogen peroxide used (see Table II). Although the pressure achieved is the same for each cycle mentioned above, the volume of hydrogen peroxide solution required depends on the concentration of the solution, the type of charge in the chamber and the hydrogen peroxide adsorption capacity of the charge. The level of humidification in the sterilizing atmosphere prior to ozone injection can be adjusted using different concentrations of the hydrogen peroxide solution.

The ozone dose varies between 2mg / l for cycle # 1 and 10mg / l for cycle # 2 and its exposure time varies between 5 minutes for cycle # 1 and 10 minutes for cycle # 3.

The amounts of ozone used in prior art sterilization processes employing moistened ozone as the sterilization gas are generally about 85mg / l. Using hydrogen peroxide for partial sterilization as well as humidification of the load before ozone injection allows a significant reduction in the amount of ozone required to achieve sterilization (SAL 101 below at a dose between 2mg / l and 10mg / l, depending on the selected cycle. This reduction is much higher than would be expected from just the fact that hydrogen peroxide and ozone are used in the same sterilization cycle.

In effect, the evaporated hydrogen peroxide solution injected into the chamber is not sufficient to achieve sterilization, although a 4 logarithmic reduction in spores has been observed. However, the addition of only a very minor amount of ozone in the range of 1-10mg of ozone per liter of the sterilization atmosphere results in full and complete sterilization at the level required under the Safety Assurance Level standards. from the United States Food and Drug Administration or worldwide standards, such as ISO (SAL 10-6). Such complete sterilization could not be achieved using only the injection of evaporated hydrogen peroxide solution, independent of the amount of hydrogen peroxide solution used and the concentration of the solution. Furthermore, high concentrations of hydrogen peroxide reduce compatibility with some instruments. Furthermore, a longer period of time after hydrogen peroxide injection, for example 3 minutes instead of 2 minutes, does not enhance the sterilization efficiency. In fact, the period of time after the injection of

<img file="MX345910B_D0033.tif" />

INSTITUTO MSXIC.ANC OS LA nOHEPAl) INDUSTÍIAI

<img file="MX345910B_D0034.tif" />

hydrogen peroxide appears to have no effect on sterilization efficiency. Still, adding only the minor amount of ozone as mentioned above surprisingly leads to complete sterilization.

During evacuation stage 350 (see Figure 3), oxygen supply valves 21 and 26, mix supply valve 29a, and auxiliary mix bypass tube valve 29b are closed and chamber drain valve 44 it opens. The sterilization chamber 10 is evacuated at a vacuum pressure of approximately 1 Torr (1.33 mbar). Once this pressure is reached, which is determined via a pressure sensor 13 in the sterilization chamber, the chamber drain valve 44 is closed and the dosing unit 240 activated to supply the hydrogen peroxide solution of the evaporator unit 260 where the solution is evaporated and subsequently flows freely into the sterilization chamber 10. Once a pressure rise of 19 Torr is reached in the sterilization chamber 10, as determined by the pressure sensor 13, the dosage unit 240 is deactivated and the supply of hydrogen peroxide solution from the evaporator 260 is stopped. The chamber can be kept sealed so that no injection of any substance occurs during a first exposure period that follows 370, which can last for 2 minutes.

<img file="MX345910B_D0035.tif" />

However, that exposure period is completely optional. Shortly before the end of the hydrogen peroxide injection stage 360, (usually about 2 to 6 minutes) The ozone generator is activated to ensure a supply of ozone containing gas. The flow of the oxygen / ozone mixture leaving the ozone generator is controlled at all times by the regulator orifice 28 capable of withstanding vacuum and adjusting the flow to between 1 and 3 liters per minute. Activation of the ozone generator 22 ₁₀ includes supply valve opening 26 and auxiliary mixing bypass tube valve 29b. Supply valve 26 allows oxygen to enter the generator. The oxygenic ozone mixture produced by the generator is then guided directly into ozone catalyst 52 through auxiliary mixing bypass tube valve 29b. After completion of step 370, the oxygen ozone mixture produced by the generator 22 is guided into the sterilization chamber 10 by opening the mixture supply valve 29a and closing the auxiliary mixture bypass tube valve 29b. The oxygen-ozone mixture enters chamber 10 until the desired ozone concentration according to the selected cycle is reached in the chamber. The period of time required for this stage is dependent on the flow rate and concentration of ozone gas in the mixture 25 (preferably 160 to 200mg / l NTP), as determined

<img file="MX345910B_D0036.tif" />

by an ozone monitor 15 of a type known in the art. Once the desired concentration is reached, the mixture supply valve 29a is closed to seal the sterilization chamber and where to keep the ozone / oxygen gas mixture in the chamber under vacuum.

Once the supply of sterilization gas (the mixture of oxygen and ozone gas) in the chamber is stopped, the generator 22 is stopped and the oxygen supply valve 26 is closed. The camera stays₁₀ sealed for an exposure period of 5-10 minutes, depending on the sterilization cycle selected by the user. Also dependent on the selected cycle, steps 350 to 390 is repeated 1 to more 3 times before sterilization is complete. This configuration conformed to Security Assurance Level 10-6 (SAL 10 - 6) standards.

To remove all remaining hydrogen peroxide, ozone, and moisture in the sterilization chamber 10 after complete sterilization, the vent stage 400 is engaged. The vent phase begins after the past exposure period 390. The chamber drain valve 44 is opened and a vacuum is applied down at approximately 6.5 mbar. Once the vacuum pressure of 6.5 mbar is obtained, the drainage valve 44 ends and the oxygen supply valve 21 open, admitting 25 oxygen in the sterilization chamber 10. Once the

<img file="MX345910B_D0037.tif" />

Atmospheric pressure is reached, the oxygen supply valve 21 is closed, the sterilization chamber drain valve 44 is opened, and vacuum is reapplied until a pressure of 1.3 mbar is reached. This last ventilation cycle, down to 1.3 mbar, is repeated once for a total of three ventilation cycles. Once atmospheric pressure is reached after the last cycle, the sterilization chamber door mechanism is activated in step 410 to allow access to the contents. ₁₀ of the sterilization chamber. The ventilation phase has two functions. First, to remove all sterilizing residues in the sterilization chamber before opening the access door, and second, to dry the sterilized material by evaporation when vacuum pressure is applied. Of course, different vacuum pressures, cycle times and number of repetitions can be used, while the desired sterilizing removal and drying are achieved.

Sterilants and gas-containing moisture 20 evacuated from sterilization chamber 10 are passed over catalyst 52 prior to gassing to atmosphere to ensure complete decomposition of the sterilants. Catalyst 52 is used during only two portions of the sterilization cycle, activation of generator 22 (with valves 26 and 29b) and evacuation of the

<img file="MX345910B_D0038.tif" />

sterilization chamber 10. During the start-up phase of the generator 22, the auxiliary mixing bypass tube valve 29b opens and the ozone is guided through the catalyst 52. Once the start-up phase of the generator 5 22 is complete , the auxiliary bypass tube valve 29b ends. During ventilation of the sterilization chamber 10, the sterilization chamber drain valve 44 is opened and the ozone containing the sterilization spent gas is guided to the catalyst 52. A ₁₀ Once the evacuation of the sterilization chamber 10 is completed, the drain valve 44 closes. The ozone circulation is ensured by the vacuum pump 40. The catalyst 52 can be located in the 5 'direction or in the 3' direction of the vacuum pump 40.

Indeed, at 20 ° C, water is boiled up to an absolute pressure of 23.3 mbar and at 35 ° C, water is boiled up to an absolute pressure of 56.3 mbar. The vacuum in the sterilization chamber is preferably set at a pressure where the boiling temperature of water is decreased below the temperature in the sterilization chamber. That boiling temperature can be so low that the temperature of the hydrogen peroxide solution in the evaporator unit would drop rapidly and, depending on the energy available from the surrounding structure, 25 it can freeze if no power supply is • α

INSTITUTE OE LA MIOfWAl INDUSTRIAL ----- provides. The energy required to evaporate the hydrogen peroxide solution is obtained from many sources. This is obtained primarily from the main body of the evaporator unit 260, which is in the form of an aluminum block provided with a heater configuration (not shown). The evaporation process can also cool the humidifier to a PT where moisture condenses on the sterilization chamber walls. This is avoided by heating the chamber walls sufficiently to keep them at least room temperature, preferably 40 ° C. This is accomplished with a heater configuration (not illustrated), which will be readily apparent to the person of skill in the art.

The evaporated hydrogen peroxide solution injected into the chamber increases the relative humidity in the sterilization chamber. This humidification considerably improves the efficiency of the ozone sterilization stage. Oxygen / ozone-containing sterilization gas is injected into the humidified sterilization chamber at a temperature close to ambient. Gas containing ozone is not heated before injection.

Hydrogen peroxide has its limitations in terms of sterilizing medical instruments. H202 is the least stable when they make contact with metal, as for the example, stainless steel. This problem is aggravated at low pressures, where chemical reactions are

<img file="MX345910B_D0039.tif" />

accelerated. Therefore, the composition of hydrogen peroxide will be accelerated under vacuum, limiting the period of time available to sterilize the long metal tubing. Furthermore, the diffusion of H202 is limited since it is not a gas. The hydrogen peroxide would reach the end of the long pipe via diffusion, but by that time its concentration will have decreased, due to accelerated decomposition, to a level where it is no longer sufficient for sterilization.

₁₀ Applicants have discovered, as described above, that these problems cannot only be overcome by adding sterilizing gas, such as ozone, but that humidifying the chamber by decomposition of hydrogen peroxide into free radicals improves sterilizing gas efficiency. Furthermore, the applicants have surprisingly discovered that ozone can be advantageously replaced by nitrogen monoxide, or nitric oxide. Applicants discovered that water and oxygen generated during the decomposition of hydrogen peroxide also improves the efficiency of nitric oxide.

Nitrogen monoxide (or nitric oxide) is known to be the cell toxicant in low concentrations. In the presence of water and oxygen, NO reacts to form nitrogen dioxide, NO2, which is also very toxic. In the absence of oxygen, NO does not form NO2, but reacts to

<img file="MX345910B_D0040.tif" />

<img file="MX345910B_D0041.tif" />

INSTITUTE MSX! CAN &lt;DE LA PROHIBA U INDUSTRIAL form nitric acid, which is very -Ωοττηπτνη to other materials.

2N0 + 3 H202-> 2HNO3 + 2 H20 (1)

N02 + H202-> 2HNO3 (2)

The problem of nitric acid formation is minimized by mixing nitric oxide with hydrogen peroxide instead of water, since the required NO concentration after hydrogen peroxide preconditioning is very low. H202 treatment, weaken the layer₁₀ of spore, and hydrogen peroxide and nitric oxide, when mixed together, form free radicals, similar to the reaction of ozone when mixed with hydrogen peroxide.

HO + Η202-> H20 + H02. (3)

H02 + NO-> HO + N02 (4)

HO + N0-> HONO (5)

Those radicals will react quickly with all organic substances, oxidizing them. The oxidation rate will be on the order of 109, instead of 101 for NO or 20 03 alone.

Applicants discussed the effectiveness of substituting ozone gas originally discussed for another gas, such as oxygen and nitric oxide. The test evaluated sterile efficacy in inoculated devices. The inoculated wires are inserted into the tubing and then into sachets. The sachets

<img file="MX345910B_D0042.tif" />

<img file="MX345910B_D0043.tif" />

INSTITUTO MEXICANO DE LA PROPIEDAt INDUSTRIAL are also placed on top of the ^ Trarispurce '35 load in the sterilization chamber. This area is considered the PT of the least effective part of the chamber.

EXAMPLES

The same charges are used for the three series of tests carried out: ozone, oxygenic oxide and nitric. The length, diameter, material, and type of tubing are different for each cycle and are described in Table 3.

₁₀ The inoculated lumens are placed in a special load that represents an average load for the three cycles.

Table 3: Length, diameter and pipe material for each cycle

<td>Number of cycle</td><td>Diameter (mm)</td><td>Length (cm)</td><td>Material</td>

<td>Cycle 1</td><td> 1</td><td> 80</td><td>Teflon</td>

<td>Cyc 2</td><td> 1</td><td> 50</td><td>Steel stainless</td>

<td>Cycle 3</td><td> 1</td><td> 110</td><td>Teflon</td>

The lumens used to evaluate sterile efficacy are inoculated according to protocol Rev MCB-09-A07 9. The wire method is used. The wires are inoculated with 10 L of a

g. stearothermophilus ATCC 7953 spore suspension of

<img file="MX345910B_D0044.tif" />

<img file="MX345910B_D0045.tif" />

INSTITUID MEXICANO

OF THE MOPIEDAL · INDUSTIIAL

1.0x106 to 2.5x106 CFU / 10pL. The inoculated wires are left to dry overnight under normal room conditions.

The test loads are exposed to one chamber of each cycle. For the experiment with oxygen and nitrogen oxide, ozone is replaced by gas to be analyzed. A burette is also plugged into the valve system in order to accurately determine the H202 volume injected. After exposure, the sterility of each lumen is determined₁₀ according to Rev 7 MCB-09-A04 by quantitative recovery using the ultrasound method followed by filtration.

Ozone

The sterile efficacy reference value in the inoculated lumens used in each cycle is established using hydrogen peroxide alone. Cycles using hydrogen peroxide and ozone are performed to compare the effectiveness of oxygen and nitrogen oxide to ozone.

Oxygen

Oxygen is injected into the chamber using the same system as that used for ozone. The ozone generator is turned off. Nitric oxide

However, it is NOT injected directly into the chamber

<img file="MX345910B_D0046.tif" />

INDUSTWIAI of an independent NO cylinder (Praxair). A 0.156 orifice Neptune valve (CM-900-156, TSO3 Inc.), separated by a Teflon tube is used for this injection. By doing so, gas is forced into the chamber.

All testing is conducted outside to limit potential accidental spill hazards. A NO detector is used. A long tube is plugged into the catalyst converter unit, to allow the NO to be removed far from the configuration. A calculation is carried out₁₀ out (see below) to determine the number of valve injections required to obtain a concentration of 2mg / L.

Valve volume: 3.3mL (Volume calculated in R-1937)

NO NTP Density: 1.25g / L

Sterilization chamber volume: 125L Desired final concentration: 2mg / L NONE Pressure: 3 psig

Corrected volume: 3300 x ((14.7 + 3) /14.7) = 3973.2 L

Mass to be injected: 0.002 g / L x 125L = 0.25gno

Mass injected per injection: 1.25g / L x 0.003974 L = 4.9665 X10-3 g / injection

Number of injections required: 0.25gno / 4.9665 X10-3 g / injection = 50 injections

Two lenses are located on the camera, one on the bottom rear 25, and the other on the rear

<img file="MX345910B_D0047.tif" />

⁴⁶ ϊΜΡΙ top. These are exactly aligned one up to Ha An ultraviolet light lense emitted from a tungsten source, and another lense connects to an ultraviolet light detector. This configuration allowed the quantification of the hydrogen peroxide vapor in the chamber.

Hydrogen peroxide has some inactivating activity against G. stearothermophilus spores. However, the percentage of sterility achieved in lumens is not sufficient for use alone, especially for long, rigid flexible lumens. The results for hydrogen peroxide and other gases mixed with hydrogen peroxide are summarized in Table 4.

Table 4. The percentage of sterility for three TSO3 cyclizes with the different sterilizing agent mixed with the hydrogen peroxide.

<td rowspan="2">Used sterilizing agent</td><td colspan="3">Sterile lumens</td>

<td>Cycle 1</td><td>Cycle 2</td><td>Cycle 3</td>

<td>H202</td><td> 50%</td><td> 12.5%</td><td> 16%</td>

<td>H202 + 03</td><td> 77%</td><td> 50%</td><td> 77%</td>

<td>H202 + 02</td><td> 11%</td><td> 0%</td><td> 77%</td>

<td>H202 + NO</td><td> 100%</td><td> 66%</td><td> 66%</td>

In the case of oxygen mixed with hydrogen peroxide, the concentrations equivalent to the dose give

<img file="MX345910B_D0048.tif" />

MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY

<img file="MX345910B_D0049.tif" />

ozone is used in each cycle, in other words T — 2 mg. of 02 / ΈΓ for cycle 1, 10mg / l for cycle 2, and finally 3mg / l for cycle 3. Oxygen hindered the efficiency of the process in Cycles 1 and 2 compared with hydrogen peroxide alone or mixed with ozone . In Cycle 3, the efficiency of the process with oxygen or ozone is equivalent. Consequently, oxygen is found to be ineffective in replacing ozone.

Although nitric oxide is a known disinfection agent, it is never mixed with hydrogen peroxide, since the mixture can be the explosive in high concentrations. To minimize the danger of explosion, the NONE concentration is limited to 2mg / l for three cycles of a first series of tests. Sterility is achieved for some samples in all cycles so the nitrogen monoxide concentration is not increased further. The results are very conclusive, that is, better than or similar to ozone mixed with hydrogen peroxide.

Even if no controls are carried out to verify the inactivation of G. stearothermophilus spores by NO in this study, it is shown in multiple studies that the rate of inactivation of NO is low. When NOT injected into a sterilization chamber and combined with humid air, it does NOT react with oxygen at a predictable rate to form NO2, which is lethal to G spores.

«IMPI

MEXICAN INSTITUTE ^IHDf LARHOMIOAt

INDUSTRY!

stearothermophilus. When it is NOT injected eg -a- sterilization without oxygen atoms present, NO does not form N02, and the spores are not sterilized (http://www.mddionline.com/article/sterilizing-combination- 5 products-using-oxides -nitrogen). Based on data from Noxilizer's sterilization process editor, at 5.12mg / l N02, the D-value is only 0.3 minutes. At 3mg / l, the value of D is approximately 1.9 minutes.

In this experiment, the amount of NO injected is ₁₀ 2mg / l. Taking into account that all NO molecules are transformed into NO2, a D-value of 1.9 minutes for a concentration of 2mg / l of NO2, only 2.5 log of spores would have been inactivated by N02. This less than 6 log present in inoculated devices. In reality, the rate of change from NO to NO2 is probably not 100%, and the D-value is more than 1.9 5 minutes. Thus the number of spores inactivated by NO alone is probably more than about 1 log.

The substitution of ozone by another gas is analyzed in three cycles of the present process. Injection of hydrogen peroxide is carried out as usual. Two gases are analyzed. The first, oxygen, did not achieve conclusive results. Sterility is not achieved in two of the three cycles.

Nitric oxide is also tested. The results show complete sterility in three cycles. The

<img file="MX345910B_D0050.tif" />

<img file="MX345910B_D0051.tif" />

concentration used for all tests is low. Only 2mg / l is injected for all three tests. The use of these chemicals could be considered in the future. However, significant changes to the sterilizer will have to be made to accommodate this. Since N02 is formed during cycles, only compatible materials could also be used, protective equipment, similar for example NO detector would have to be considered.

Other sterilizing gases that can interact with hydrogen peroxide to continue free radical formation could be used to replace ozone, such as chloride dioxide.

On the other hand, many different molecules can have the same effect as hydrogen peroxide on ozone. Some ions can also have the catalytic effect of hydrogen peroxide on ozone. The Co2 +, Ni2 +, Cu2 +, Mn2 +, Zn2 +, 2 + Cr2 + and Fe2 +, Ti2 + ions enhance the decomposition of ozone. All the transition metals that can form a molecule with oxygen will break down ozone. The positive ions will try to become neutral by obtaining an oxygen atom from the ozone molecule. The ozone molecule is more or less stable and will easily provide the oxygen atom. Water with an alkaline pH will be richer in hydroxyl ions. Hydroxyl ions break ozone down to atomic oxygen. Those oxygenic atoms can form hydroxyl radicals ^ »- ~ deS ^. Therefore, any molecule that can be used to make the solution pH alkaline will promote ozone decomposition. Suitable examples are NaOH or KOH.

Another source of hydroxyl radicals is all solvents that contain an alcohol group. Those solvents will provide OH ions and promote ozone dilution. In the same vein, the format and humic substances can start the chain towards root formation. Some acids can also be used, such as acetic acid and paraacetic acid. Ozone is more soluble and stable in the acid solution will be able to react longer and be more concentrated. Any molecule that contains carbonate, bromine, phosphate, or sulfate group will also break down ozone.

As shown in FIGS. 2 and 7, the delivery unit 200 includes a bottle holder unit 202 for receiving a sealed hydrogen peroxide solution bottle 180. The support unit has a bottle seat 204 where the bottle 180 is conveniently received. Flask 180, which will be mentioned in more detail further under, is held in seat 204 by gravity alone. Support unit 202 is rotatably mounted on pivot 203 for movement between an open position as illustrated in

<img file="MX345910B_D0052.tif" />

Figure 7, that the bottle 180 can be placed, in. or removed from the support unit and a closed position where the support unit is completely inside the sterilizer cabinet (not shown) and a 205 cover of the support unit closes all access to the support unit from outside the cabinet . When the support unit 202 is in the closed position, a pneumatically actuated drainage configuration 207, including a needle pulse, in this embodiment a vertically oriented pneumatic cylinder 208, and a drainage needle 209 mounted on the cylinder rod 210, is activated to drain all of the hydrogen peroxide solution from the 180 flask. This is accomplished by activating cylinder 208 to force needle 209 through the vial seal until the needle tip reaches the bottom of vial 180. Needle 209 is fluidically connected to reservoir 240 (see Figure 8) and the Solution is drawn from flask 180 and into reservoir 240 using the vacuum generated by vacuum pump 44 with which reservoir 240 can be fluidly connected via conduit 211 and valve 212 (see Figure 1). Once the contents of bottle 180 have been aspirated, the support unit can be opened and the bottle removed, or the empty bottle can be kept in the support unit until a refill of reservoir 240 is required. Reservoir 240 is provided with a 242 level sensor that provides

<img file="MX345910B_D0053.tif" />

industrial a signal to the control system to the liquid level in the tank. Based on the signal received from sensor 242, the control system notifies the user if the amount of liquid in reservoir 240 is insufficient for the execution of the cycle selected by the user.

In an alternate embodiment, the hydrogen peroxide supply system does not include a reservoir. Instead, the flask 180 itself is cooled (CS-01) to prevent the rapid degradation of the aqueous hydrogen peroxide. A sensor (S14) measures the amount of solution kept in the bottle. When the solution reaches a 1st preselected level, a warning Wrath appears on the screen and when a lower preselected level, 2nd is reached, the software generated message to the operator specifies that only one more sterilization cycle # 1 or # 2 can be executed with the remaining solution in the bottle. The operator will then have to recharge the delivery system with a fresh, filled bottle.

As shown in FIGs 10a to 10d, the bottle 180 has a conical bottom 182 to ensure complete drainage of all liquid in the bottle, thus reducing the danger of drops or contamination in disposal of a drained bottle. In order to ensure that the bottle 180 remains well upright, a holder 184 is attached to the lower end of the bottle. Bracket 184 includes a concave shape

<img file="MX345910B_D0054.tif" />

<img file="MX345910B_D0055.tif" />

INSTITUTE M £ XICAN &lt;

DF LA raCMFDAl INDUSTRIAL upturned 185 with tight snap closure tn¹¹ Circumferential iMr'aufee 186 on the outer wall of vial 187. Needle 209 is aligned with the lowest PT on the bottom of vial and can be moved in the vial, through the vial seal, until it reaches the Lower PT on the bottle.

Mechanical, electronic or other control structures and functions are provided to ensure needle contact with the bottle bottom by preventing penetration of the bottle bottom. A sensor₁₀ Pressure is preferably incorporated into the corresponding needle pulse and / or needle holder (not shown).

Control system

The sterilization apparatus is preferably controlled by the Reaction Scheme presented in the electrical block diagram (Figure 9 and Process Flow Diagram (Figure 3). The control system is built around a PLC (Programmable Logic Controller) shelf. This shelf contains a power supply (107), a 20 CPU unit (108), a Device Network Transceiver (109), a 32 x 24 volt direct current x individual input module (110), 16 x 120VAC input module. individual output (111) and finally 16 individual output module transistor (112), an RS232C communication module. All those 25 modules are stacked together by a joining system

<img file="MX345910B_D0056.tif" />

intrinsic that contains data and bus of.i ^ iÍxecciQn.QG.,. ,

Device Network is an industrial serial communications protocol largely used in industry for instrumentation and control. In this sterilization apparatus, the Device Network transceiver (109) is used to communicate in full duplex, the data between the CPU (109) and the 15-bit A / D converter (106), a D converter / A of 15 bits (125) and both Digital Temperature Interconnects (120), (121).

The PLC CPU has three RS232 ports. One is used receive and send data to the Touch Screen Terminal (118), the other is used send data to a thermal printer (119) and the last port is used as a service port where a personal computer (Personal Computer) can be connected to communicate with the PLC CPU (108) to load the control protocol program. (Check Protocol Program is not in scope of this document).

The Touch Screen terminal (118) is located in front of the sterilizer next to the thermal printer (119). The Touch Screen Terminal and Thermal Printer constitutes a User Interface terminal.

Power needed for: Thermal Printer (119), Device Network Link, (109), (106), (120), (121), (125), Chamber Pressure Sensor (104) electronic oxygen regulator (126) and individual data input PLC (lll) and

<img file="MX345910B_D0057.tif" />

Individual outputs (112 is provided by DC Power (103).

The Chamber Pressure Sensor (104) and Ozone Monitor (105) have a conventional 0 to 10VDC output signal. The electronic Oxygen Regulator has an output of 0 to 5 VDC. All signals are sent to a 15 bit A / D converter. All converted signals are sent to the CPU over the Device network on the digital link for processing.

The input power (of 100) of the sterilizer is a three wire 208 to 240 VAC single phase type without the neutral. The input power is filtered to prevent RFI from taking place (101). Power is distributed by the power distribution buss (102) to various electrical systems of the sterilizer apparatus.

A cooling system (60) is used to cool the ozone generator. This system includes the cooling unit (114) and the cooling circulation pump pump (113). The temperature of the coolant in the generator is sensed by an RTD located in the generator. The temperature is sent to the CPU (108) by the Device Network system (109) (120) (121). The refrigerant circulation pump (113) and cooling unit (114) are controlled by contactor switches activated by PLC outputs (111) which in turn are controlled by the software protocol. All the

MSKICARK INSTITUTE OF THE ΜΟΗΕΟΑΙ 'NDllSTSl The input and output required to achieve control of, refrigeration system is listed on the electrical block diagram as: Circulation Pump Pump Relay, Refrigeration System Relay, Pump Overload Sensor 5 circulation system, Refrigeration System Overload system, Refrigerant Low pressure and Refrigerant Flow Switch.

The vacuum control system includes the vacuum pump 40 and a pressure sensor 104. The startup and runs of ₁₀ completion of the vacuum pump are monitored according to the control protocol. All the input and output required for the vacuum system are listed in the diagram: Vacuum Pump contactor switch, Vacuum Pump not running sensor, Vacuum Pump Overload sensor, Vacuum to Chamber Valve ( 44), Air Presses Valve (18) and Oxygen to Chamber Valve (21). The pressure sensor output is converted by the 15-bit A / D converter (106) and sent to the CPU over the Digital Link Device Network (109). The pressure sensor also has two individual outputs that indicate to the CPU (108) the following conditions: Chamber Pressure Sensor Failure Chamber Pressure Sensor Heater and Temperature. Those two signals are listed on the electrical block diagram as PLC data input.

The chamber door actuator system

INSTITUTO MEXICANO DE LA EROP1EDAL INDUSTRIAL sterilization includes an electrical impulse ^ eX ™ screw and four inductive sensors that allow the detection of the door closing and the immobilized or unlocked position of the actuator as part of the control protocol. The doorway system is also used in the alarm condition management protocol to ensure user safety. All input and output required to achieve the door actuator system are listed on the electrical block diagram as: Immobilize Door Relay, Unlock Door Relay, Lower Sensor Door closed (S2), Upper Sensor Door closed (51 ), Sensor Door Immobilized (S4) and Sensor Door Unlocked (S3).

The Ozone power supply 116 includes a full wave rectifier, an oscillator circuit, and a high voltage transformer. The output of the transformer is connected to the ozone generator (22). The power supply (116) is mounted as a resonator using the non-ideal characteristics of the high voltage transformer. The CPU that 108 controls the ozone production and ensures via ozone 104 and Electronic oxygen regulator (126) monitor, that the desired concentration for sterilization is achieved and maintained throughout the sterilization cycle. All the input and output required by the Ozone Generation System are listed in the diagram as: Oxygen Supply Valve (26), Ozone to Valve

<img file="MX345910B_D0058.tif" />

(29a), Catalytic rbe Valve Ozone Weir (29b), Zeroing Ozone Monitor), High Voltage Backup Relay, High Voltage Current Limiter, High Voltage Ozone Overload Sensor Rectifier High Temperature Sensor , Ozone monitor failure.

The oxygen supply system is a unit called the Electronic Oxygen Pressure Regulator. A proportional valve (26) that also shuts off the oxygen is controlled by an integrated PID circuit that converts an analog signal from an absolute pressure sensor (27). The PID then sends the current proper duty cycle to the proportional valve (26). With orifice 28 this system constitutes an oxygen flow regulator. The mechanical regulator 24 is used as a first stage regulator to decrease oxygen pressure from 60 psi to 10 psi. The electronic regulator also provides the alarm condition protocol to ensure user protection. Data input used for the alarm condition is listed on the electrical block diagram as: High Pressure Oxygen Sensor and Low Pressure Oxygen Sensor. Also, the electronic oxygen pressure regulator provided 0 to 5VDC analog readout output by the ND converter 106 minimum device network network.

The control system is provided with a user interface 118. In the preferred embodiment, this interface

<img file="MX345910B_D0059.tif" />

IMPI

INSTITUTO MBXICAHO DE LA ΡΛΟΛΧΟαι includes a liquid crystal display sensTbl ^ ~ '^ - ~' Touch ^ (LCD) screen 118, a printer 119 for performance reports and a communication port 153 (Serial RS-232) user permission to receive and transmit the information necessary for the use of the device. It will be readily apparent to the person skilled in the art that other types of user interfaces can be used, such as touch sensitive pads, keyboards, or the like, and other types of communication interfaces. Thermal printer status enters₁₀ They appear on the electrical block diagram as: Printer Off Process Sensor and Document Printer.

H202 distribution system control processing

At this time, two configurations of an H202 distribution system are possible. The control system could be used for both systems. The first system represented in the present application in Figure 7 and Figure 8 is mainly a bottle of H202 (180) rinsed in a thermoregulated tank (240) Figure 8. This first system will be described in terms of FIG.s 7,8,9 and 2. All the input and output sensors described in the following appear in the control system input and output list listed in Figure 9. When the strerilizer is first initialized, the door 12 is closed and the closed position is detected by

<img file="MX345910B_D0060.tif" />

<img file="MX345910B_D0061.tif" />

iNSTmrro mewcan, Df -A ÍKOPIF.OA »INDUSTRIAL switch S7. Neither vial is attached to the support unit by (S6), the puncture needle is also retracted into position by cylinder PA 01 (208). S8 and S9 provide sensing to the up and down position of the cylinder (208). Also, the actuator PA 02 is retracted into the support unit unlocked position. The user is invited by the message on the screen (118) to open the door (205) and insert a bottle H202 in the support unit. So when the bottle is detected by S6, another message on the screen (118) invites the user to close the door (205) which is detected by S7. The software control is carried out by the CPU (108) and condition sensors. The bottle is set by gravity on a rotating base (209). The CPU starts engine M 02 to rotate the bottle 180. A barcode reader 01 (Figure 2,) (122) Figure 9 reads a barcode on the vial. The CPU verifies the expiration date of the bottle and if the bottle is past its expiration date, the door 205 remains unlocked and a message on the strainer (118) invites the user to change the bottle for the other. If the date is correct, the CPU ends M of motor 02 and immobilizes the door (205) by activating the PA 02 (Figure 2). Then the CPU operates the cylinder (208) for the needle 209 to pierce the sealed cap of the vial until S9 senses the needle in the down position. Then the bottle is completely emptied into the

<img file="MX345910B_D0062.tif" />

reservoir 240 by suction provided through valve (212) and pump vacuum (40). The door (205) remains immobilized until all of the H202 in the reservoir has been used. Level sensors S10 and Sil provide the necessary conditions to the CPU to estimate if another flask is needed. If so, the needle is retracted from the bottle and the door (205) is unlocked and the user is invited by a message on the screen (118) to replace the bottle H202.

₁₀ Description of the alternate and distribution system

H202 preferred

The distribution system that follows does not include the cooled reservoir (240). Instead, the H202 remains in the bottle (180). S10 and Sil level detectors are removed and replaced by an ultrasonic level detector when the sensor is deflected by a spring against the container to one side of the flask near the bottom and used as a low level detector to indicate to the CPU an empty jar. Since this sensor is spring loaded, this adds too much friction on the bottle to use motor M 02. Therefore, the user is invited by a message on the screen (118) to manually rotate the bottle until the code of bars is read by (DEGREE IN SCIENCE 01) Figure 9 of Figure 2 or (122). If the bottle is not out of date, the user is invited to close the door (205) and the

<img file="MX345910B_D0063.tif" />

CPU immobilizes the bottle holder unit compartment and operates (208) to prick down the needle. In a preferred embodiment, the support unit H202 is thermoregulated by a Peltier cell unit. An RTD attached to the bracket unit and connected to the temperature interconnect (121) sends data to the CPU (108) over the Device Network network and the CPU controls the PID function the amount of power being applies to the Peltier cell unit. The Peltier unit is supplied by the 12VDC (121) power supply used also for the air compressor activating the pneumatic system composed of SV-15, SV-16, actuators (PA 02 and PA 01) in Figure 2. Between each cycle , the process connected between the H202 bottle (180) and the micro valve module (240) will be purged by SV20. Near the module inlet (240) a foam optical detector snapped on process H202 will indicate full process replenishment with no air in the process.

To that PT both the H202 distribution systems can supply the micro valve module (240). The micro valves (SV-18 and SV19) interact for a predetermined duty cycle program in an on-board micro-controller circuit that generates the appropriate moment pulses for both micro-valves. That electronic circuit is activated by a signal from the CPU (108) called H202 repeatedly step on the regulator point FIGURE 9.

<img file="MX345910B_D0064.tif" />

Under software control, an appropriate amount of H202 is allowed into the humidifier manifold (260, Figl). This distributor is thermoregulated by the CPU (108) using RTD data (TT-04, Figure 1) and controlling the heater HTR-01 (Figure 1) by the PID function. Then the H202 is vaporized in the distributor (260) and the vapor is sent to the chamber under vacuum through the pipe (280, Figure 1).

In the foregoing description, for purposes of explanation, the various details are set forth in order to provide a careful understanding of the embodiments of the invention. However, it will be apparent to one skilled in the art that these specific details are not required in order to practice the invention. In other cases, well known sterilizer structures and circuits are shown in block diagram or symbol form so as not to obscure the invention. For example, specific details are not provided as to whether certain parts of the sterilizer controls are implemented as a software routine, hardware circuit, firmware, or a combination thereof.

The above-described embodiments of the invention are intended to be examples only. Modifications, modifications, and variations can be made to the particular modalities by those skilled in the art without departing from the scope of the invention, which is defined

<img file="MX345910B_D0065.tif" />

solely by the appended claims »u eibLcrr

TABLE III

Oxygen circuit

<td>FTR-01</td><td>Oxygen Inlet Filter</td>

<td>RG-01</td><td>Oxygen Pressure Regulator</td>

<td>SV-OI</td><td>Oxygen supply valve</td>

<td>FS-01</td><td>Oxygen Pressure Switch</td>

<td>FI-01</td><td>Oxygen Flow Indicator</td>

<td>SV-05</td><td>Oxygen Chamber Valve</td>

Ozone circuit

<td></td><td>Ozone generator</td>

<td>TT-01</td><td>Generator Cooling Ozone or Transmitter temperatures</td>

<td>AOZ-OI</td><td>Ozone monitor</td>

<td></td><td>Orifice (used to regulate the ozone flowing into the chamber)</td>

<td>SV-02</td><td>Ozone Chamber Valve</td>

<td>SV-04</td><td>Discharge Ozone Valve (Auxiliary Bypass Tube)</td>

Air circuit

<td>AC 01</td><td>Air compressor</td>

<td>IN - 01</td><td>Compressed air tank</td>

<td>PS-03</td><td>Th pressure for compressor</td>

<img file="MX345910B_D0066.tif" />

INSTITUTO mex; can &lt;'oe LA MORIDA · iNnumiAL

<img file="MX345910B_D0067.tif" />

<td></td><td></td>

<td></td><td>d -L X. L »·</td>

<td>RG-03</td><td>Air pressure regulator</td>

<td>Pl-03</td><td>Air Pressure Indicator</td>

<td>FTR-03</td><td>Air intake filter</td>

⁵ Aluminum block

<td>TT-04</td><td>Temperature Transmitter Aluminum block</td><td>of</td>

<td>1-ITR-OI</td><td colspan="2">Heating element</td>

STERIZONE Solution Circuit

<td>SV-17</td><td>H202 fill valve</td>

<td>SV-21</td><td>H202 vent valve</td>

<td>SV-18</td><td>H202 inlet valve</td>

<td>S 7- 9H</td><td>202 exhaust valve valve</td>

<td>SV-20</td><td>[H202 purge valve]</td>

TABLE III, continued

STERIZONE Solution Delivery System

<td></td><td>S6</td><td>The sensor (detects the absence of</td>

<td></td><td></td><td>presence of STERIZONE Solution container</td>

<td> 20</td><td></td><td>state)</td>

<td></td><td>S7</td><td>Sensor (detects open end of</td>

<td></td><td></td><td>STERIZONE Solution compartment status)</td>

<td></td><td>S8</td><td>The sensor (detects PA 01 position</td>

<td></td><td></td><td>higher)</td>

<td> 25</td><td>S9</td><td>The sensor (detects the FA 01 position</td>

<img file="MX345910B_D0068.tif" />

IMPI

MEXICAN INSTITUTE

OF THE COPUDA C

<td></td><td>lower) </td><td></td>

<td>S12</td><td colspan="2">Sensor (detects STERIZONE Solution compartment immobilized unlocked state)</td>

<td>S13</td><td colspan="2">Sensor (detects STERIZONE Solution compartment access from an open and closed condition)</td>

<td>S14</td><td colspan="2">The sensor (detects the lower level of H202 in the jar)</td>

<td>S15</td><td>The sensor (detects the presence of of air in the process</td><td>the bubble</td>

<td>SV-15</td><td>Air pilot valve for puncture actuators</td><td>the needle</td>

<td></td><td colspan="2">PM-900-014</td>

<td>SV-16</td><td>Air pilot valve Solution compartment immobilizes the actuator</td><td>for him STERIZONE</td>

<td>B-01</td><td>Candle shape bottom a STERIZONE Solution bottle</td><td>measure</td>

<td>DEGREE IN SCIENCE 01</td><td>Barcode scanner for</td><td>jar</td>

<td>PA 01</td><td colspan="2">Pneumatic actuator for vial puncture</td>

<td>FA 02</td><td colspan="2">Fneumatic actuator for STERIZONE Solution compartment fixation lock</td>

IMPI

INSTITUTO MEXICANO DS LA PROPERTY INDUSTRIAL

<td rowspan="2">PA 03</td><td></td>

<td>to focus</td>

<td>M 02</td><td>The electric motor that will spin the flask for code scan bars</td>

<td>CS-01</td><td>Cooling system or flask</td>

<td>VS - 02</td><td>Vacuum switch (to fill and bleed process H202)</td>

<td>Camera of sterilization</td><td>YES</td>

<td>Door switch Higher Closed</td><td>S2</td>

<td>Door switch lower Closed</td><td>S4</td>

<td>Door switch Immobilized</td><td>S3</td>

<td>Door switch Unlocked</td><td>PT 01</td>

<td>Camera</td><td>VS - 01</td>

<img file="MX345910B_D0069.tif" />

<img file="MX345910B_D0070.tif" />

<td></td><td>Transmitter Fressure</td><td>of</td><td colspan="3"> ' ’ —————</td>

<td> 5</td><td>switch Empty camera.</td><td>of of</td><td colspan="3">TT-03,5,6.</td>

<td></td><td colspan="2">Transmitters Of temperature Of camera</td><td colspan="3"></td>

<td></td><td colspan="2">TT-07</td><td colspan="3">Chamber Door Temperature Transmitter</td>

<td> 10</td><td>Circuit empty</td><td>to the</td><td colspan="3">SV-06</td>

<td></td><td>Valve Empty camera</td><td>of of</td><td colspan="3">M 01</td>

<td> 15</td><td colspan="2">Vacuum Fump Series signaling state</td><td colspan="3">M 01</td>

<td></td><td colspan="2">CAT 01</td><td>Pump contactor switch</td><td>empty</td><td></td>

<td> 20</td><td colspan="2">Catalyst</td><td colspan="3">Circuit Drying Catalyst</td>

<td></td><td colspan="2">FTR-02</td><td colspan="3">Muffler</td>

<td></td><td colspan="2">SV-11</td><td>Air to Catalyst Valve Catalyst Dryer)</td><td>(Valve</td><td>of</td>

TABLE III, continued

<img file="MX345910B_D0071.tif" />

<td>ΡΜ-900-002</td><td></td>

<td colspan="2">Refrigeration Circuit</td>

<td>FS-02</td><td>Refrigerant Flow Switch</td>

<td>M 05</td><td>Circulation pump series status signaling</td>

<td>M 05</td><td>Circulation pump overhead Circulation pump contactor switch</td>

<td></td><td></td>

<td>FS-02</td><td>Compressor Decreases Pressure Switch</td>

<td>M 06</td><td>Compressor status signaling series</td>

<td>M 06</td><td>Compressor contactor switch</td>

<td></td><td>Overload compressor</td>

IMPI

INSTITUTO MEXICANO • f THE INDUSTRIAL PKOPltDAD

<img file="MX345910B_D0072.tif" />