Hospitals are densely populated with patients, and the environment of hospitals is most likely to be polluted by pathogenic microorganisms, thus providing external conditions for the spread of diseases and promoting the occurrence of nosocomial infections. And hospital cleaning, disinfection, sterilization is a very important link to prevent and control hospital infection. It includes the clean of the environment inside and outside hospital ward, disinfect, the disinfect of utensils of diagnosis and treatment, apparatus and instruments, medicamenti, disinfect, and the measure such as the disinfect isolation of contact infectious disease patient and final disinfect. In order to prevent the occurrence of nosocomial infection, we must take comprehensive measures to ensure that every time disinfection, sterilization, isolation to meet the predetermined requirements, in order to prevent and control the occurrence of nosocomial infection. The application of disinfection and sterilization equipment can greatly reduce the chance of hospital infection. Thus, doctors, patients and their families can work and be treated safely in hospitals. The following introduces several commonly used hospital disinfection and sterilization equipment, so that medical staff and maintenance personnel understand.

1. Ultraviolet sterilization and disinfection

Ultraviolet ray refers to the solar rays with A wavelength between 200nm and 380nm, including three categories: 1. UV-A wavelength is

The wavelength of UV-B is 280nm~315nm, and the wavelength of UV-C is 200nm~280nm. About 13% of the solar rays reaching the earth's surface (290nm~2000nm) are ultraviolet, of which UV-A accounts for 97%, UV-B accounts for 3%, and UV-C is close to zero. The only damage to human skin is UV-A and UV-B. UV-C ultraviolet lamp made by special technology is used for disinfection and sterilization. What has bactericidal effect is UV-C wave ultraviolet ray, about 254nm ultraviolet ray is the best. Ultraviolet rays can kill all kinds of microorganisms, including bacterial propagules, buds, mycobacteria, viruses, fungi, rickettsiae and mycoplasma, etc., with a broad spectrum.

UV ultraviolet C wave principle of sterilization by ultraviolet irradiation of bacteria, viruses and other organisms, to damage the DNA in the body (DNA Lead to the key and chain rupture, crosslinking and photochemical products, etc., between stocks which changed the biological activity of DNA, the microbe itself cannot copy, make its immediate death or loss of ability to reproduce. Ultraviolet lamp tube is an artificial low-pressure mercury quartz lamp tube, the tube is injected with 0.4~0.6kPa argon gas and mercury drops, the tube ends with tungsten wire made of spiral electrode. After electrification, argon gas ionizes first, and then shocks mercury to ionize, emitting ultraviolet light. After 5~7min by the ultraviolet radiation of the air, in order to make oxygen produce ozone, so the disinfection time should be lighted 5~7min after the timing. When used for disinfection of articles, such as the selection of 30W ultraviolet lamp, the effective irradiation distance is 25~60cm, the time is 25~30min(articles to spread out or hang up, expand the irradiation surface). When using ultraviolet disinfection, attention should be paid to the protection of the eyes and skin. When irradiating, the patient should not look directly at the ultraviolet light source. Wearing sunglasses or using gauze to cover his eyes. Cover the limbs with a sheet to avoid ophthalmitis or erythema.

2. Ozone sterilization

Ozone at room temperature, atmospheric pressure molecular structure is not stable, quickly decomposed into oxygen (O2) and a single oxygen atom (O); The latter has a very strong activity, has a strong oxidation effect on bacteria, will kill it, the excess oxygen atoms will recombine to become ordinary oxygen atoms (O2), there is no toxic residue, so it is called non-pollution disinfectant. It not only to all sorts of bacteria (include hepatitis virus, coliform bacillus, green thick bacillus and miscellany bacillus to wait) have extremely strong killing ability, and very effective also to killing mycin. The process of ozone sterilization belongs to biochemical oxidation reaction, ozone sterilization has the following three forms: (1) ozone oxygen decomposes the glucose oxidase necessary for the oxidation of glucose inside the bacteria; (2) directly interact with bacteria and viruses, destroy their cell walls, DNA and RNA, decompose proteins, lipids and polysaccharides and other macromolecular polymers, so that the metabolic growth and reproduction process of bacteria is destroyed; (3) permeable membrane organization, invades the membrane on the outer membrane of lipoprotein and internal fat polysaccharide, permeability of distortion in the cells, leading to the dissolution of cell death, and death bacteria in the body of the genetic, parasitic species, parasitic virus particles, phage, branches of the original body and pyrogen (such as bacteria, endotoxin virus metabolites) dissolve degeneration. Thus, ozone sterilization is bacteriolytic and does not kill healthy cells. The ozone sterilizer is composed of a tubular ozone generator. The C-type integral high pressure power supply provides the ozone generator with stable high pressure. When the disinfector works, the ozone generator uses air as raw material to produce high concentration ozone, and makes use of the strong oxidation of ozone to realize the disinfection of air. Ozone disinfection has no dead corner, after the end of disinfection ozone will automatically decompose into oxygen, no residual, no side effects.

3. Ethylene oxide sterilization

Ethylene oxide is a simple epoxy compound, the liquid is colorless and transparent, has the aromatic ether flavor, is highly toxic. Inhalation of large amounts of ethylene oxide can cause respiratory irritation, dizziness, weakness, nausea, neurotoxic reactions, etc. Liquid ethylene oxide can cause skin irritation, dermatitis, and blisters. Eye contact with ethylene oxide can cause serious eye injury, and high concentration of gas splashing can cause serious eye irritation and injury. The ethylene oxide gas is placed in an airtight container. The disinfection chamber is a double-walled shell with a jacket in the middle to ensure the heating effect of the disinfection chamber. Put the items into the disinfection cabinet, close the door of the disinfection cabinet, and the steam humidifying system heats the temperature in the chamber to 40~60.C. The vacuum exhaust system discharges the pressure in the chamber from 1 atmosphere to about 21kPa. Ethylene oxide safety perforation system will be ethylene oxide gas cylinder puncture, ethylene oxide leakage into the pressure chamber, the amount of 1kg/m3. In the case of optimal relative temperature (60~80%), the sterilized air from the air filtration system can act for 6~12 hours when 42.C is sterilized for 150min and 55.C for 60min. After sterilization, the ventilation and exhaust system discharges carbon dioxide and water vapor into the atmosphere. Open the cabinet door, take out the items, disinfection is complete. The control and printing system controls the completion of the setting procedure, and the printing system records the procedure. The safety system provides the safety of temperature, pressure and toxic gas emissions for ethylene oxide disinfection procedures. The equipment is especially suitable for the articles that cannot withstand high heat and warm heat, such as precision instruments, electronic instruments, optical instruments, heart-lung machines, pacemaker, books and documents, etc., without damage and corrosion and other side effects. After sterilizing the remaining ethylene oxide gas, the ethylene oxide is converted to safe carbon dioxide and water (steam) by catalytic heating. EO+ oxygen carbon dioxide + water (steam) Figure 3 ethylene oxide sterilization principle structure diagram

4. Pre-vacuum high pressure steam sterilization

There is a pretreatment stage before steam entry, that is, the negative pressure inside the cabinet is pumped to 2.6KPa (about 98% air exclusion). The temperature of the pre-vacuum high-pressure steam sterilizer can reach 132~135. C. It has the advantages of fast sterilization cycle and high efficiency. It only takes 8~10min to complete the whole sterilization cycle, which saves manpower, time and energy. The cold air elimination is more reliable and thorough; The packaging and emission requirements of the goods are wide, and the characteristics of the goods are not easy to oxidize damage under the vacuum state. But the equipment cost maintenance cost is high, high requirements for the sealing of the cabinet, leakage per minute shall not make the negative pressure rise value more than 0.13KPa. Small volume effect exists, that is, the sterilization effect is poor if the items to be sterilized are placed too little. The effect of small volume is mainly due to the smaller the volume of the article, the more residual air in the cabinet, the greater the blocking effect on the steam contact with the article, the bottled liquid is not sterilized by this method. The equipment is suitable for high temperature, high pressure, not afraid of moisture, such as dressings, surgical instruments, medicines, bacterial culture media, etc. The general procedure for pre-vacuum high-pressure steam sterilization and disinfection is the general procedure for pre-vacuum high-pressure steam sterilization and disinfection boiler. The first three times of vacuuming-steam injection are carried out through the vacuum exhaust system and steam generator, the purpose is to remove the residual air in the disinfected items and ensure the disinfection effect. It is generally discharged to 80mbar. After that, a large amount of steam is injected into the double pressure chamber to ensure its constant pressure and temperature. During the period of heating and disinfection, vacuum is taken for better penetration. During disinfection, the temperature is maintained at 134.C and 3500mbar for disinfection for 8~10min. The vacuum is then vented to a negative pressure and the sterilized item is dried with hot, dry air. The air filtration system enters sterile air to restore to one atmosphere of pressure and disinfection is complete. The control and printing system controls the completion of the setting procedure, and the printing system records the procedure. The safety system ensures the safety of parameters such as temperature and pressure for the high-pressure steam disinfection process. Chemical gas sterilization, etc. The sterilization speed is fast, which can greatly improve the utilization rate of the sterilized instruments, and facilitate the operation in the hospital. It greatly reduces the injury to the medical instrument and effectively prolongs the service life of the instrument. At the same time, there is no drug residue in the sterilized device, and there is no harm to the medical staff. Due to the renewal of its sterilization principle, it has entered the ranks of green environmental protection. Plasma is a physical concept, a special state of matter that exists in nature (i.e. the fourth mass after solids, liquids and gases). The plasma low temperature sterilization system uses hydrogen peroxide liquid as the sterilization medium. Under the vacuum condition, the hydrogen peroxide liquid is input into the sterilization chamber after ultrasonic atomization, and the natural diffusion is uniform. The plasma excitation source and the mixing system feed the radio frequency electromagnetic wave (13.56MHz) into the plasma excitation electrode on the sterilization chamber wall to make the hydrogen peroxide gas molecules produce continuous glow discharge, forming a material state in which ions with negative charge and equal amount of positive charge coexist with each other. When the ionization rate and recombination rate reach a balance, This stable state of matter is called plasma. The formed plasma contains a large number of reactive oxygen ions, high-energy free groups and other components, easy to oxidize with bacteria, mold, spores and viruses in the protein and nucleic acid substances and denaturation, so that all kinds of microorganisms die, to achieve the purpose of sterilization of all kinds of equipment. The control and printing system controls the completion of the setting procedure, and the printing system records the procedure. Safety systems provide security for plasma disinfection procedures. The equipment is suitable for the stainless steel, titanium, aluminum and other metal materials and ceramics, glass, silicon rubber, polyethylene, ptfe, nylon, silicone non-metallic materials, such as medical equipment and medical electronic equipment, devices, wires, electrodes, battery, optical fiber soft hard endoscope, surgical instruments, metal non-metal surgical instruments, electrodes, craniocerebral drill, breathing masks, probes, Expander, lead wire, mechanical and electrical apparatus, all kinds of laboratory non-heat resistant apparatus, etc.