JP2013190381A - Sterilization performance predicting system and sterilization performance predicting program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve prediction accuracy of a bacteria survival state in an evaluation object space where chemical spraying is carried out.SOLUTION: A sterilization performance predicting system includes: a database for storing relationships between an accumulated agent adhesion depositing amount obtained by performing numerical analysis for a sampling place within an experiment space where an agent is sprayed from a first agent spraying source, and a bacteria survival state obtained by actually performing an experiment at the sampling space; and controlling means that calculates an accumulated drug adhesion amount by applying the numerical analysis for an evaluation place within an evaluation object space sprayed with an agent from a second agent spraying source, and that, based on the calculated accumulated agent adhesion amount and the database, calculates the bacteria survival state at the evaluation place.

Description

  The present invention relates to a sterilization performance prediction system and a sterilization performance prediction program capable of predicting a bacteria survival state when a medicine is sprayed in an evaluation target space.

  Medical facilities and food production facilities are required to have a high level of in-facility environment including countermeasures against microorganisms. In addition, measures against microbes such as viruses and bacteria are required for hospital infections, pandemics, bioterrorism, and the like. As such a measure, it is necessary to estimate the sterilization performance to what extent viruses and bacteria can be sterilized when a drug is sprayed.

  Patent Document 1 discloses a method for preparing a sterilization performance evaluation surface having a dry evaluation surface to which evaluation bacteria are attached, and a sterilization performance evaluation method using the same. Patent Document 2 discloses a sprayed drug concentration detection method for estimating a spraying state of a drug by agricultural chemicals or liquid fertilizer sprayed on a farm field or a disinfectant liquid sprayed on a house or a breeding facility.

  In addition, in the non-patent document 1, the present applicant evaluates the sterilization performance by comparing the distribution state of the drug obtained by numerical calculation and a biological indicator (hereinafter referred to as “BI”) as an indicator bacterium. Is going. An index CT value (C: concentration × T: action time) of bactericidal power is used for the state of spraying of the medicine. In particular, in this non-patent document, a drug balance equation based on room air is solved to obtain a CT value that assumes instantaneous uniform diffusion of the drug (simple method), and the diffusion equation of the drug in the flow field is analyzed by CFD analysis. The CT value is calculated in two ways (the detailed method) for obtaining a local CT value such as the BI installation position, and the sterilization performance is evaluated by comparing with the success or failure of sterilization in the BI.

  Non-Patent Document 2 analyzes the particle deposition mechanism of fine particles in a clean room with respect to a control target site such as a silicon wafer, and studies on the construction of the particle deposition model.

JP 2005-83803 A JP 2009-133768 A

"Countermeasures against microorganisms using chlorinated chemicals (5th report) Relation between biological indicators and CT value", Koichi Izawa and three others, 28th Air Cleaner and Contamination Control Research Conference, July 5, 2011 "Modeling of suspended particulate deposition in a rectifying clean room", Shuji Fujii et al., Architectural Institute of Japan Planning Report, No. 397, pp. 30-37, March 1989

The evaluation of the sterilization performance proposed by the applicants in Non-Patent Document 1 is based on the CT value obtained by numerical calculation and the success or failure of sterilization obtained by installing BI in the laboratory and spraying the drug. It was just a comparison. By the way, such an evaluation of the sterilization performance needs to predict in advance how much sterilization can be performed not only in the laboratory but also in the space where the drug is actually sprayed. In particular, a business operator that sprays a medicine needs to inform the client in advance of the cost of spraying, which range, and how much sterilization is performed (sanitization performance). Needless to say, the more accurate the relationship between the cost and the sterilization performance is, the better.

  In addition, evaluation of drug dispersion in Non-Patent Document 1 is performed using uniform diffusion CT values or local CT values. The uniform diffusion CT value and the local CT value are calculated based on the concentration of the drug (chlorine) floating in the air in the vicinity where the BI (indicator bacterium) is installed and the elapsed time after spraying the drug. Further, in the evaluation of drug dispersion in Non-Patent Document 1, uniform diffusion CT values and local CT values are calculated by excluding the amount of drug that has settled out of the air due to gravity. It has been difficult to match the evaluation of such drug spraying with the association with the actual sterilization performance.

  The present invention proposes a system capable of predicting the sterilization performance when a drug is sprayed, and in particular, by using a new index of accumulated drug adhesion amount, more accurate sterilization with respect to drug spraying. The present invention proposes a sterilization performance prediction system capable of calculating performance (bacteria survival state).

The sterilization performance prediction system according to the present invention,
A storage means for storing the database, and a control means;
The database performs an actual experiment at the sampling position and the accumulated drug adhesion amount obtained by performing numerical analysis on the sampling position in the experimental space where the drug is sprayed from the first drug spraying source. Memorize the relationship with the bacterial survival status obtained in
The control means includes
For the evaluation position in the evaluation target space where the medicine is sprayed from the second medicine spraying source, the integrated medicine adhesion amount is calculated by numerical analysis, and the evaluation is performed based on the calculated cumulative medicine adhesion amount and the database. It is characterized by calculating the bacterial survival state at the position.

Furthermore, in the sterilization performance prediction system according to the present invention,
The integrated drug adhesion amount calculated by the control means is calculated based on the local air drug concentration obtained by the computational fluid dynamics analysis, the deposition rate of the drug, the effective area of the evaluation position, and the action time. It is characterized by the amount of accumulated drug deposition.

Furthermore, the sterilization performance prediction system according to the present invention,
Differentiating the deposition rate of the drug used to calculate the cumulative drug deposition amount on the floor surface of the evaluation space and the deposition rate of the drug used to calculate the cumulative drug deposition amount on the wall surface of the evaluation space It is characterized by.

Furthermore, in the sterilization performance prediction system according to the present invention,
The deposition rate of the drug used on the floor surface of the evaluation space is a value corresponding to the particle diameter of the drug.

Furthermore, in the sterilization performance prediction system according to the present invention,
The integrated drug adhesion amount calculated by the control means is a local air drug concentration obtained by numerical fluid dynamics analysis, an air velocity near the evaluation position, an adsorption coefficient, an effective area of the evaluation position, It is an integrated drug adsorption amount calculated based on the action time.

Furthermore, in the sterilization performance prediction system according to the present invention,
The control means uses either the accumulated drug deposition amount or the accumulated drug adsorption amount as the accumulated drug adhesion amount, depending on the form of the drug sprayed by the second drug spray source.

Furthermore, in the sterilization performance prediction system according to the present invention,
The storage means has a different database for each bacterial species,
The said control means calculates the said microbe survival state using the database according to the microbe type | mold used as evaluation object.

Furthermore, in the sterilization performance prediction system according to the present invention,
The storage means has a different database for each medicine to be spread,
The said control means calculates the said microbe survival state using the database according to the said chemical | medical agent spread with a 2nd chemical | medical agent spray source.

Furthermore, in the sterilization performance prediction system according to the present invention,
The bacterium survival state stored in the database and the bacterium survival state calculated by the control means are a reduced number of bacteria.

In addition, the sterilization performance prediction program according to the present invention,
Based on the database stored in the storage means, a sterilization performance prediction program capable of calculating the bacteria survival state calculation process by a computer,
The database performs an actual experiment at the sampling position and the accumulated drug adhesion amount obtained by performing numerical analysis on the sampling position in the experimental space where the drug is sprayed from the first drug spraying source. Memorize the relationship with the bacterial survival status obtained in
The bacteria state calculation process calculates an integrated drug adhesion amount by numerical analysis for an evaluation position in an evaluation target space where the drug is distributed by a second drug distribution source, and calculates the calculated integrated drug adhesion amount and the Based on the database, the bacteria survival state at the evaluation position is calculated.

  According to the sterilization performance prediction system of the present invention, the integrated drug adhesion amount at the evaluation position in the evaluation target space where the drug is dispersed is calculated, and the relationship between the cumulative drug adhesion amount stored in the database and the bacteria survival state is applied. By doing so, it is possible to predict the bacterial survival state at the evaluation position in the evaluation target space. In particular, by using a new index of the accumulated drug adhesion amount, it is possible to more accurately calculate (predict) the bacteria survival state at the evaluation position in the evaluation target space.

  Furthermore, in the sterilization performance prediction system of the present invention, the accumulated drug adhesion amount is based on the local air drug concentration obtained by the computational fluid dynamics analysis, the drug deposition rate, the effective area of the evaluation position, and the action time. The calculated integrated drug deposition amount is used. When the drug is sprayed in the form of mist, by using this accumulated drug deposition amount as the accumulated drug adhesion amount, the amount of drug adhering to the evaluation position such as the floor surface can be calculated more accurately, It becomes possible to improve the prediction accuracy.

  Furthermore, when the medicine is sprayed in the form of a mist, the deposition rate for calculating each cumulative drug deposition amount using the cumulative drug deposition amount on the floor surface of the evaluation target space and the cumulative drug deposition amount on the wall surface of the evaluation target space. To improve prediction accuracy. In addition, when it is necessary to evaluate also on the ceiling, it may be different from the deposition rate used on the floor surface in the calculation of the cumulative amount of medicine deposited on the ceiling. Further, in the calculation of the accumulated drug deposition amount, it is possible to perform more accurate prediction by setting the drug deposition rate to a value corresponding to the drug particle diameter.

Furthermore, in the sterilization performance prediction system of the present invention, as the integrated drug adhesion amount, the local air drug concentration obtained by computational fluid dynamics analysis, the air velocity near the evaluation position, the adsorption coefficient, and the effective area of the evaluation position And the integrated drug adsorption amount calculated based on the action time is used.
When the drug is sprayed in the form of gas, by using this accumulated drug adsorption amount as the accumulated drug adhesion amount, the amount of drug adhering to the evaluation position can be calculated more accurately, and the bacteria survival state at the evaluation position can be calculated Thus, it is possible to improve the accuracy of predicting the bacterial survival state.

  Furthermore, in the sterilization performance prediction system of the present invention, either the accumulated drug deposition amount or the accumulated drug adsorption amount is used as the accumulated drug adhesion amount depending on the form of the drug sprayed by the second drug spray source. . For example, if the drug is sprayed in the form of a mist, use the integrated drug deposition amount. If the drug is sprayed in the form of a gas, use the cumulative drug adsorption amount to adhere to the evaluation position. It is possible to accurately calculate the amount of the medicine to be taken in consideration of the form of spraying.

  Furthermore, the sterilization performance prediction system of the present invention has a different database for each microbial species, and predicts using a database of microbial species to be sterilized in the evaluation target space, thereby further accurate microbial survival. It is possible to calculate the state.

  Furthermore, in the sterilization performance prediction system of the present invention, a different database is provided for each drug to be sprayed, and prediction is made by using a database of drugs actually sprayed in the evaluation target space, so that more accurate bacteria survival can be achieved. It is possible to calculate the state.

  Furthermore, in the sterilization performance prediction system of the present invention, the bacterium survival state memorized in the database and the bacterium survival state calculated by the control means are used as the reduced number of bacteria to grasp a more precise bacterium survival state. It becomes possible to do. For convenience, the survival state of the bacteria may be determined as success or failure of sterilization, that is, whether all the bacteria have been killed.

  The sterilization performance prediction system of the present invention can also be realized by a computer such as a personal computer or a workstation. Therefore, it is also possible to provide a computer as a program (sterilization performance prediction program) that incorporates the functions of the above-described sterilization performance prediction system.

Plan view of the experimental space used in the embodiment of the present invention The block diagram which shows the support | carrier which hold | maintains BI which concerns on embodiment of this invention The figure for demonstrating the BI test (simple method) which concerns on embodiment of this invention The figure for demonstrating the BI test (detailed method) which concerns on embodiment of this invention The block diagram which shows the structure of the microbe elimination performance prediction system which concerns on embodiment of this invention. The figure which shows the various parameters used by the CFD analysis which concerns on embodiment of this invention The graph which shows the accumulation amount of chemical | medical agent deposition obtained by the CFD analysis which concerns on embodiment of this invention The graph which shows the number of living bacteria obtained by the experiment which concerns on embodiment of this invention

The sterilization performance prediction system according to the present invention will be described with reference to the drawings. FIG. 1 is a plan view of an experimental space used in the embodiment of the present invention. This experimental space is a space for conducting a BI test for constructing a database storing the relationship between the accumulated amount of adhered drug and the survival state of the bacteria,
1 to BI # 5, a biological indicator (hereinafter, “
BI ”) is installed.

BI # 1 to BI # 5 are BI # 1 (on the table), BI # 2 (table floor below), BI # 3 (window side corner floor), BI # 4 (wall side corner floor), BI, respectively. Installed at sampling position # 5 (wall). FIG. 2 is a block diagram showing a carrier for holding a BI according to an embodiment of the present invention. FIG. 2A is a perspective view of the carrier 10, and FIG. 2B is a depression 1 of the carrier 10.
FIG. The carrier 10 has a flat plate shape made of a resin such as glass or polyester, and a recess 11 for holding the BI is formed at the center thereof.

In the BI test of the present embodiment, wet is adopted, and a microbial solution (BI) containing a predetermined number of bacteria is dropped into the depression 11. In addition to this wet BI test, it is also possible to employ a dry method using dry bacteria (BI). In the ISO standard, it is a standard for guaranteeing sterilization that the number of 10 ⁶ bacteria is killed, and about 10 ⁶ bacteria were dropped into the depression 11 in accordance with this standard. As the bacterial species used for BI, various selections such as spore bacteria, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and the like can be selected. In addition, it is preferable to associate the used microbial species with the database to be constructed. When calculating the bacteria survival state in the later evaluation target space, it is possible to perform highly accurate prediction by using a database of the same type of bacteria.

  Further, in the experimental space shown in FIG. 1, an air conditioning system having two inlets and eight outlets near the ceiling is installed. In the center of the experimental space, a drug spray source for spraying a drug for sterilization (referred to as “first drug spray source” in the present invention) is installed. In this embodiment, the spraying apparatus which has a spraying form which sprays a chemical | medical agent in mist form is used. In addition to such a spraying form, it is possible to use a medicine spraying source having a spraying form in which the medicine is sprayed in a gas state depending on the medicine used or the purpose. In addition, stirring fans (fans) are installed at two locations in the room to diffuse the sprayed medicine. A chlorinated drug was used as a drug used in the BI test. As other chemicals to be used, hydrogen peroxide water, hypochlorous acid water, ozone, peracetic acid, chlorine dioxide, and the like can be used. As for this drug, it is preferable to associate the drug used in the database in the same manner as the above-mentioned bacterial species. When calculating the bacterial survival state in the evaluation target space, it is possible to increase the accuracy of prediction by using a database of the same or the same kind of drugs.

  In the BI test, after spraying the drug in such an experimental space for a predetermined time, BI # 1 to BI # 5 installed at the sampling position are collected, and the survival state of the bacteria is confirmed. In order to confirm the survival state of the bacteria, it is conceivable to adopt a simple method for confirming whether or not the bacteria have been killed by the collected BI and a detailed method for confirming the number of bacteria reduced. When a database is constructed using the detailed method, it is possible to calculate the reduced number of bacteria as the bacteria survival state in the evaluation target space.

  FIG. 3 is a diagram for explaining the BI test (simple method). The bacterial solution collected from the depression 11 of the carrier 10 collected from the experimental space is placed in the liquid medium 12 and cultured in an incubator. After culturing, the success or failure of sterilization is determined by the turbidity of the liquid medium 12. When the liquid medium becomes turbid as shown in (a), it is determined that there are proliferating bacteria, that is, “positive” in which the bacteria at the place where the BI is installed are not killed. On the other hand, when the liquid medium is transparent as shown in (a), it is determined that all the bacteria are killed, that is, “negative”. In this way, data for constructing a database is acquired by performing negative / positive determination on BI # 1 to BI # 5 installed at each sampling position in the experimental space.

  FIG. 4 is a diagram for explaining the BI test (detailed method). In this detailed method, the number of bacteria is compared with respect to two types of BI acquired at the same sampling position. One is a BI in which a drug is sprayed in the experimental space, and the other is a BI that is not sprayed with a drug. The bacterial solution collected from the depression 11 is diluted and applied to the plate agar medium 13. By culturing the flat plate agar medium 13 in an incubator, the bacteria on the agar grow to form colonies. While counting colonies, the number of bacteria present in the bacterial solution in the depression 11 is calculated by considering the dilution factor.

In the detailed method, it is possible to obtain the reduced number of bacteria by calculating the number of bacteria for each of the case where the medicine is applied and the case where the medicine is not applied. That is, it is conceivable that the number of bacteria decreases under conditions other than the drug with the passage of time. BI without a drug is for obtaining a more accurate reduction number of bacteria in consideration of such conditions. That is, the population parameter for reducing the number of bacteria, rather than the original 10 ⁶ charged into the a culture, a number of surviving bacteria in BI without drug (A number), the bacteria in BI of there agents from A number By subtracting the number of survivors (B), the number of reduced bacteria (A-B) is calculated. The reduced number of bacteria obtained by such a detailed method is used as data for constructing a database.

  On the other hand, for the construction of the database, the accumulated drug adhesion amount at each sampling position of BI # 1 to BI # 5 is required in the BI test in the experimental space. This integrated drug adhesion amount can be obtained not by experiment but by numerical analysis. Since this numerical analysis is calculated in the same manner as the integrated drug adhesion amount in the evaluation target space calculated by the sterilization performance prediction system described later, here, in the sterilization performance prediction system, A case where the integrated drug adhesion amount is calculated will be described. Note that the calculation of the accumulated drug adhesion amount for database construction is not necessarily performed by the sterilization performance prediction system.

  FIG. 5 is a block diagram showing the configuration of the sterilization performance prediction system according to the embodiment of the present invention. The sterilization performance prediction system of this embodiment can use a general information processing apparatus such as a personal computer or a workstation. The sterilization performance prediction system 20 of the present embodiment includes a CPU 21, a hard disk 22, a RAM 23, and an interface 24.

The hard disk 22 functioning as a storage means stores a program for calculating the integrated drug adhesion amount at the sampling position. This program performs CFD analysis using Computational Fluid Dynamics (CFD), and it is possible to determine the spraying status of drugs sprayed in the space using parameters that define the space. It is. As the spraying situation, local drug concentration C [μg / m ³ ] in various places in the space
To seek.

  FIG. 6 shows a table showing various parameters used in the CFD analysis according to the embodiment of the present invention. The parameter is provided with six categories such as “evaluation space”, “medicine”, “medicine spray source”, “stirring fan”, “air conditioning system”, and “sterilization system operation schedule”. Parameters corresponding to the various conditions used in the BI test described above are input to the input means 25, and a local drug concentration C corresponding to the sampling position where BI # 1 to BI # 5 is installed is determined by a program for performing CFD analysis. Calculated. Among these parameters, main parameters for changing the local drug concentration C are “evaluation space”, “drug injection speed”, “drug spraying source”, “position of the air-conditioning system (inlet), air volume”, “Spray time”. It is preferable to calculate the local drug concentration C at the sampling position using at least these main parameters. In addition, for calculating the local drug concentration C, other parameters that vary the spread state of the drug may be employed in addition to the parameters listed in FIG.

In the present embodiment, the accumulated drug adhesion amount is calculated using the calculated local drug concentration C. This accumulated drug adhesion amount is an index indicating the amount of drug adhering to the floor, wall surface, ceiling surface, etc. By using this accumulated drug adhesion amount, it is compared with the conventional evaluation using the amount of drug floating in the space. Thus, it is possible to improve the evaluation accuracy. When using this integrated drug adhesion amount, the calculation method of the integrated drug adhesion amount differs depending on the spraying form of the drug. It is known that the medicine is sprayed in the form of mist by applying ultrasonic waves, two-fluid nozzles, high pressure, etc., and that the medicine is sprayed in the form of gas using a hot plate, cylinder, etc. It has been. The form of adhesion differs between the mist form and the gas form mainly due to the difference in the particle size of the sprayed drug.

  In the present embodiment, paying attention to such a difference in the mist and gas adhesion modes, the calculation method of the integrated drug adhesion amount is made different. Specifically, when the drug is sprayed in the form of a mist according to the spraying form of the drug, the cumulative drug deposition amount W considering the influence of gravity is used. In addition, when the drug is sprayed in the form of gas, the integrated drug adsorption amount X considering the action between the drug and the surface to which the drug adheres is used. By taking into account such a difference in the adhesion form, the accuracy of the accumulated drug adhesion amount is improved.

  First, the accumulated drug adhesion amount (accumulated drug deposition amount W) when the drug is sprayed in the form of mist will be described. Four forces of “thermophoretic force”, “gravity”, “electrostatic force”, and “inertial force” act on the mist. The trajectory of the dispersed mist is determined by the combined vector of these four forces. “Thermophoretic force” is caused by molecular diffusion, and the smaller the mist particle size, the greater the influence on movement. The “gravity” has a greater influence on movement as the particle size of the mist increases. The “electrostatic force” works only when the mist is a charged particle. “Inertial force” is the effect of wind power. However, the action is reduced by the boundary layer formed on the BI surface.

  As described above, the four forces acting on the mist are shown. The most important factors that determine the orbit of the mist are “thermophoretic force” and “gravity”. In particular, when the object to be attached is a floor surface, the influence by “gravity” is the main. It is expected that the construction of the database for predicting the sterilization performance in this embodiment and the prediction of the sterilization performance are mainly performed on the floor surface. Therefore, when evaluating the floor surface, it is possible to calculate the accumulated drug deposition amount W with high accuracy by considering the trajectory due to “gravity”.

A method of calculating the accumulated drug deposition amount W in consideration of this “gravity” will be described. Accumulated drug deposition amount W [μg] is based on local drug concentration C calculated by CFD analysis, drug deposition rate V ₁ [m / s] mainly due to gravity, and indicator bacteria used in BI The effective area S [m ² ] and the operation time t [h] or [s] are calculated (integrated). The deposition speed V _{1 on the} floor surface is a value corresponding to the particle size of the sprayed medicine since the speed at which the sprayed medicine falls due to gravity is the main component. This deposition speed V ₁ can be obtained by a calculation formula described in Non-Patent Document 2. For example, in the case of the drug used in the BI test of this embodiment (the state at the time of spraying is mist), the particle size is 3 [μm], and the deposition rate V ₁ is 2.86 × 10 ⁻⁴ [m / s]. Is calculated and set as The effective area S is an area where the indicator bacteria BI are exposed to the air, and in the case of the present embodiment, the effective area S is a value corresponding to the area of the depression 11 of the carrier 10 described in FIG. The action time t is the time when BI is exposed to the air sprayed with the medicine.

Cumulative drug deposition of W with respect to the floor or table surface, such as a BI # 1~BI # 4 in FIG. 1, is calculated using the deposition rate V ₁ this gravity is mainly. On the other hand, with respect to the wall surface, such as a BI # 5 shown in FIG. 1, the deposition rate V ₂ which does not consider the effect of gravity is used. This deposition rate V ₂ is a rate mainly composed of “thermophoretic force” due to molecular diffusion as described above. When sprayed in the mist form as described above, it is possible to improve the calculation accuracy of the integrated drug deposition amount W by using the deposition speeds V ₁ and V ₂ in consideration of the direction of the surface to be attached. When calculating the cumulative drug deposition amount with respect to the ceiling, the cumulative drug deposition amount W is accurately calculated by using the same deposition rate V ₂ as that of the wall surface or the deposition rate V ₃ having a similar value. It is possible.

When the medicine is sprayed in the form of mist, the integrated medicine deposition amount W corresponding to the sampling position is calculated by performing such calculation. FIG. 7 shows a graph showing the accumulated drug deposition amount at each sampling position in the BI test described in FIG. In this BI test, the drug is sprayed in a mist form. In the graph, the graph indicated by Ave is the average value of the accumulated drug deposition amount W in the experimental space.

  On the other hand, FIG. 8 is a graph showing the survival number of bacteria at the sampling position obtained in the BI test (detailed method) described in FIG. In the graph, the graph indicated by Ave is the number of surviving bacteria B in BI # 1 to BI # 5. Separately, it is possible to calculate the reduced number of bacteria by subtracting B from the survival number (A) of bacteria in BI without a drug at each sampling position tested.

  As can be seen from the graph of FIG. 8, it can be seen that the bacteria have been killed in BI # 1 (on the table) and BI # 2 (under the table). On the other hand, it can be seen that bacteria remain in BI # 3 to BI # 5. In addition, when this BI test is conducted by a simple method, it can be expected that BI # 1 and BI # 2 are negative, and BI # 3 to BI # 5 are positive.

  Next, the accumulated drug adhesion amount (accumulated drug deposition amount X) when the drug is sprayed in a gas form will be described. When the sprayed medicine is gaseous, the adsorption of the medicine is mainly caused by the energy interaction between the adsorbate (here, the medicine) and the adsorbent (here, the indicator fungus BI). In the case of spraying in a gas form, it is not necessary to consider the difference in the calculation method depending on the orientation of the adhesion surface such as a floor surface, a wall surface, a ceiling surface, etc., as in the mist form described above.

The integrated drug adsorption amount X [μg] is expressed as the drug adsorption coefficient Y, the air flow velocity [m / s] near the position where the drug adheres, and BI with respect to the local drug concentration C calculated by the CFD analysis. It is obtained by calculating (integrating) the effective area S [m ² ] of the indicator bacteria used and the action time t [h] or [s]. The air velocity [m / s] can be calculated by CFD analysis when the local drug concentration C is calculated. The effective area S is an area where the indicator bacteria BI are exposed to the air, and in the case of the present embodiment, the effective area S is a value corresponding to the area of the depression 11 of the carrier 10 described in FIG. The action time t is the time when BI is exposed to the air sprayed with the medicine.

  The deposition adsorption Y is an index determined by the combination of the adsorbate (here, the drug) and the adsorbent (here, the indicator fungus BI). The adsorption coefficient Y can be obtained by using molecular dynamics calculation disclosed in Japanese Patent Application Laid-Open No. 2011-7620 (chemical contaminant contamination evaluation method).

  The database of the present embodiment is created based on the relationship between the accumulated amount of attached medicine and the bacteria survival state (the number of bacteria reduced or the success or failure of sterilization) for each sampling position. For example, in a database created by using a simple method, it is possible to calculate a threshold value of the cumulative amount of drug adhesion for sterilization. In addition, in a database created using the detailed method, the relationship between the cumulative amount of adhered drug and the number of bacteria reduced is stored as it is for each sampling position, or based on the obtained data It is conceivable that the relationship between the accumulated drug adhesion amount and the number of bacteria reduced is graphed or mathematically expressed. As described above, the database preferably stores the medicine used and the bacterial species used in BI in association with each other. When predicting the bacterial survival state for the evaluation target space, it is possible to improve the prediction accuracy of the bacterial survival state by using a database of the same or the same type of drugs and bacterial species.

  In the sterilization performance prediction system according to the present embodiment, the evaluation set in the evaluation target space different from the experimental space based on the database that stores the relationship between the accumulated amount of adhered drug and the bacterium survival state created in this way. Prediction of the sterilization performance is executed by calculating the bacterium survival state at the position.

  The sterilization performance prediction system can be performed by the system 20 that calculates the integrated drug adhesion amount in the experimental space described with reference to FIG. As described above, the system 20 has a program for calculating the integrated drug adhesion amount. When used as a sterilization performance prediction system, first, an accumulated drug adhesion amount at an evaluation position appropriately set in the evaluation target space is calculated using this program. As the accumulated drug adhesion amount, either an accumulated drug deposition amount (in the case of mist) or an accumulated drug adsorption amount (in the case of gas) is calculated according to the spraying form of the drug. As in the case of the experiment space, the evaluation target space is calculated using various parameters shown in FIG. At that time, a drug spray source for spraying the drug in the evaluation target space is the “second drug spray source” in the present invention.

  Further, the program for realizing the sterilization performance prediction system calculates the survival state of the bacterium at the evaluation position by referring to the accumulated drug adhesion amount calculated for the evaluation position and the database stored in the hard disk 22. As described above, this database stores the relationship between the bacterial survival state obtained in the BI test performed in the experimental space and the accumulated drug adhesion amount obtained by numerical analysis with respect to the experimental space. The bacteria survival state at the evaluation position is calculated by acquiring or calculating the bacteria survival state in the database corresponding to the integrated drug adhesion amount at the evaluation position. At that time, it is preferable to prepare a plurality of databases corresponding to the drug and the bacterial species, and to use the database corresponding to the drug and the bacterial species used in the evaluation target space in order to improve the prediction accuracy.

  For example, when the simple method is taken in the BI test, the threshold value of the accumulated drug adhesion amount for sterilization is stored in the database. Therefore, when the cumulative amount of adhered drug calculated for the evaluation position reaches this threshold, the sterilized state in which all bacteria have been killed (negative), and when the threshold has not been reached, the bacteria remain (positive) ) Can be determined. On the other hand, when the detailed method is adopted in the BI test, the database stores the relationship between the accumulated drug adhesion amount and the reduced number of bacteria. By using this relationship, it is possible to calculate the reduction number of bacteria according to the accumulated amount of adhered medicine calculated for the evaluation position.

  The bacteria survival state calculated in this way can be output as visual information from the monitor 26 or the printer 27 in the sterilization prediction system 20 shown in FIG. At that time, as in the experimental space of FIG. 1, it is possible to help understanding by displaying the bacteria survival state on the sketch of the space. In addition, by providing the evaluation positions adjacent to each other (for example, at intervals of several centimeters), it is possible to display the distribution of the bacteria survival state in the evaluation space. In that case, it is easy to understand by displaying a three-dimensional graph or a distribution map according to a difference in color, density, etc. on a sketch of the evaluation space.

  Such a sterilization prediction system is effective when performing sterilization that meets the needs of the evaluation client by changing various parameters in the evaluation target space. When actually spraying medicines on the evaluation target space, by using this sterilization prediction performance system in advance, the range that can be sterilized at the evaluation position, the number of bacteria reduced, etc. can be presented to the evaluation requester It becomes possible. In addition, it is possible to arbitrarily change the drug spraying conditions (such as “medicine”, “medicine spraying source”, “sterilization system operation schedule” in the parameters shown in FIG. 6) in the evaluation target space. Prior to sterilization, it is possible to propose sterilization tailored to the client's needs. In addition, it is possible to propose by comparing the cost of sterilization with the sterilization performance.

  Note that the present invention is not limited to these embodiments, and embodiments configured by appropriately combining the configurations of the respective embodiments also fall within the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Carrier, 11 ... Dimple, 12 ... Liquid medium, 13 ... Flat plate agar, 20 ... Information processing system (computer), 21 ... CPU (central processing unit), 22 ... Hard disk (storage means), 23 ... RAM (temporary) Storage means), 24 ... interface, 25 ... input means, 26 ... monitor, 27 ... printer

Claims (10)

A storage means for storing the database, and a control means;
The database performs an actual experiment at the sampling position and the accumulated drug adhesion amount obtained by performing numerical analysis on the sampling position in the experimental space where the drug is sprayed from the first drug spraying source. Memorize the relationship with the bacterial survival status obtained in
The control means includes
For the evaluation position in the evaluation target space where the medicine is sprayed from the second medicine spraying source, the integrated medicine adhesion amount is calculated by numerical analysis, and the evaluation is performed based on the calculated cumulative medicine adhesion amount and the database. A sterilization performance prediction system characterized by calculating a bacterium survival state at a position. The integrated drug adhesion amount calculated by the control means is calculated based on the local air drug concentration obtained by the computational fluid dynamics analysis, the deposition rate of the drug, the effective area of the evaluation position, and the action time. The sterilization performance prediction system according to claim 1, wherein the system is an accumulated amount of accumulated drug. Differentiating the deposition rate of the drug used to calculate the cumulative drug deposition amount on the floor surface of the evaluation space and the deposition rate of the drug used to calculate the cumulative drug deposition amount on the wall surface of the evaluation space The sterilization performance prediction system according to claim 2. The sterilization performance prediction system according to claim 2 or 3, wherein the deposition rate of the drug used on the floor surface of the evaluation space is a value corresponding to a particle diameter of the drug. The integrated drug adhesion amount calculated by the control means is a local air drug concentration obtained by numerical fluid dynamics analysis, an air velocity near the evaluation position, an adsorption coefficient, an effective area of the evaluation position, The sterilization performance prediction system according to claim 1, which is an integrated drug adsorption amount calculated based on an action time. The control means uses either an accumulated drug deposition amount or an accumulated drug adsorption amount as the accumulated drug adhesion amount, depending on the form of the drug sprayed by the second drug spray source. The sterilization performance prediction system according to any one of claims 1 to 5. The storage means has a different database for each bacterial species,
The sterilization performance prediction according to any one of claims 1 to 6, wherein the control means calculates the survival state of the bacterium using a database corresponding to the bacterium species to be evaluated. system. The storage means has a different database for each medicine to be spread,
The said control means calculates the said microbe survival state using the database according to the said chemical | medical agent disperse | distributed with a 2nd chemical | medical agent spray source, The any one of Claims 1-7 characterized by the above-mentioned. Sterilization performance prediction system. 9. The bacterium survival state stored in the database and the bacterium survival state calculated by the control means are a reduced number of bacteria. 9. Sterilization performance prediction system. Based on the database stored in the storage means, a sterilization performance prediction program capable of calculating the bacteria survival state calculation process by a computer,
The database performs an actual experiment at the sampling position and the accumulated drug adhesion amount obtained by performing numerical analysis on the sampling position in the experimental space where the drug is sprayed from the first drug spraying source. Memorize the relationship with the bacterial survival status obtained in
The bacteria state calculation process calculates an integrated drug adhesion amount by numerical analysis for an evaluation position in an evaluation target space where the drug is distributed by a second drug distribution source, and calculates the calculated integrated drug adhesion amount and the A sterilization performance prediction program characterized by calculating a bacterium survival state at the evaluation position based on a database.

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