As the “connection hub” between the sterile and non-sterile environments in hospitals, the stability of the equipment performance of medical transfer Windows directly affects medical safety. To avoid the risk of cross-contamination caused by equipment failure, it is necessary to establish a systematic maintenance and care system. The specific methods can be divided into four major modules: daily maintenance, regular inspection, special maintenance of core components, and emergency handling. The following is a detailed explanation:
I. Daily cleaning and Disinfection: Basic protection is indispensable
Daily cleaning should follow the principle of “clean first, then disinfect”, and be carried out at least once a day. For areas with high usage frequency (such as ICU and infectious disease wards), the frequency should be increased to 2-3 times. The specific steps are as follows:
Surface cleaning: First, wipe the inner and outer walls of the transfer window, door frame, handle and observation window with a soft cloth dipped in neutral detergent (such as medical-specific multi-enzyme cleaner) to remove surface dust and stains. The gaps (such as door shafts and sealing strips) should be cleaned with a soft-bristled brush to prevent dirt accumulation and poor sealing.
Disinfection treatment: After cleaning, use medical disinfectants approved by the hospital (such as 75% alcohol, chlorine-containing disinfectants, and avoid using strongly corrosive reagents) to disinfect the inside and outside of the transfer window by spraying or wiping. Pay special attention to high-frequency contact areas such as the placement surface of items and the air outlet of the disinfection module. After disinfection, it should be left to stand for 15 to 30 minutes to ensure the disinfection effect and avoid the residue of disinfectant from affecting the subsequent transferred items.
Precautions: When cleaning and disinfecting, the power supply of the transfer window (except for the disinfection module) must be turned off to prevent the circuit from getting damp. The observation window glass should be cleaned with a special glass cleaner to prevent scratches that may affect the view. If contaminated items have been passed on (such as waste from infectious disease wards), immediate enhanced disinfection should be carried out. If necessary, disposable protective pads should be replaced (if the equipment is equipped).
Ii. Core Component Maintenance: Focus on key functional links
The core function of the transfer window relies on the disinfection system, air purification system and interlocking device. Special maintenance plans need to be formulated for these components:
(1) Maintenance of the disinfection system
Ultraviolet lamp tubes: As commonly used disinfection components, the appearance of the lamp tubes should be inspected once a week. If the lamp tubes are found to be blackened, aged at both ends or have a significant decrease in brightness, they should be replaced in time (the general service life is 800-1000 hours, and the usage time should be recorded). When replacing, gloves must be worn to avoid fingerprint contamination of the lamp tube and affecting the ultraviolet penetration rate. After each use, the dust on the surface of the lamp tube should be cleaned. A dry and soft cloth can be used to wipe it to ensure the intensity of ultraviolet radiation.
Ozone generator/hydrogen peroxide spray system: Check the generator’s sealing performance monthly. If ozone leakage occurs (which can be determined by odor or a dedicated detector) or if the spray is uneven, stop using it immediately and carry out maintenance. Regularly clean the impurities from the nozzles to prevent blockage and affect the disinfection effect. After using ozone for disinfection, it is necessary to ensure adequate ventilation and air exchange to prevent residual ozone from irritating personnel.
(2) Maintenance of the air purification system
High-efficiency air filters (HEPA) : Inspect the appearance of the filter once every three months. If the filter material is found to be damaged, there is severe dust accumulation, or the air velocity at the outlet is significantly reduced, it should be replaced in a timely manner (the specific replacement cycle can be adjusted according to the usage frequency; for example, in infectious disease wards, it should be shortened to two months). When replacing, strict aseptic operation must be followed to avoid contaminating the new filter. After replacement, the sealing performance of the filter needs to be checked to prevent air short circuits from causing purification failure.
Primary/medium efficiency filters: Clean once a month (washable type) or replace once every two months (non-washable type) to prevent filter material blockage, which may cause excessive load on the fan and affect the air circulation efficiency. When cleaning, gently rinse with clean water, dry thoroughly before installation. Do not use detergent or high-temperature drying.
(3) Maintenance of Interlocking and control systems
Interlocking device: Before opening the transfer window every day, the interlocking function of both doors needs to be tested (try opening both doors simultaneously; if they cannot be opened, the function is normal). If the interlock fails (for example, after one side door is closed, the other side door still cannot be opened), the mechanical structure of the door lock or the circuit connection should be inspected and repaired in time to prevent air convection pollution.
Control panel and circuit: Check weekly whether the buttons on the control panel are sensitive and whether the indicator lights are functioning properly. Clean the dust at the circuit terminal blocks every month to prevent moisture or short circuits. In case of problems such as display screen failure or inability to start the disinfection program, professional personnel should be contacted for maintenance. It is strictly prohibited for non-professionals to disassemble the circuit.
Iii. Regular testing and calibration: Ensure performance meets standards
In addition to daily maintenance, professional testing should be conducted periodically to ensure that the transfer window meets the hospital infection control standards.
Aseptic effect testing: Every six months, the hospital’s infection management department is entrusted to conduct microbial sampling and testing. Sterile culture dishes are placed in the transfer window to simulate the item transfer process and then cultured. If the colony count exceeds the standard (usually ≤5cfu per dish), problems with the disinfection system or filter need to be checked. After rectification, the test should be conducted again.
Wind speed and pressure difference detection: Every three months, use an anemometer to measure the wind speed at the outlet (HEPA systems typically require a wind speed of 0.25-0.5m/s), and use a differential pressure gauge to measure the pressure difference inside and outside the transfer window (the transfer window in sterile areas needs to maintain positive pressure, and the transfer window in infectious disease wards needs to maintain negative pressure). If the values do not meet the standards, adjust the fan parameters or replace the filter.
Electrical safety inspection: Every year, the hospital’s equipment department conducts electrical safety inspections, including items such as grounding resistance and insulation resistance, to prevent leakage risks and ensure compliance with safety standards for medical electrical equipment.
Iv. Special Scenarios and Emergency Response: Targeted Protection
Infectious disease ward transfer window: Due to the high risk of contact with pathogens, it needs to be disinfected once a day. Immediately after the transfer of waste, hydrogen peroxide spray disinfection should be carried out inside the transfer window. Replace the sealing ring of the negative pressure system monthly to prevent pathogen leakage. In the event of the transmission window of patient body fluid or blood contamination, it is necessary to immediately wipe and disinfect with a chlorine-containing disinfectant (concentration ≥1000mg/L), and wait for 30 minutes before conducting routine cleaning.
Operating room/ICU transfer window: Due to the frequent transfer of sterile instruments and drugs, the status of the filter and disinfection system needs to be checked daily to ensure aseptic transfer. In the event of a sudden malfunction of the transfer window (such as interruption of the disinfection process), the sterile items that have been placed inside need to be re-sterilized and cannot be used any longer. The equipment can be reactivated only after it has been repaired and tested as qualified.
Emergency shutdown procedure: In the event of a serious malfunction of the transfer window (such as filter damage or a large amount of ozone leakage), a “shutdown” sign should be immediately posted to guide personnel to use the backup transfer window. At the same time, record the fault time, cause and handling situation, and incorporate them into the equipment maintenance file to prevent the recurrence of faults.
V. Maintenance of Archives Management: Traceability and Optimization
Establish a dedicated maintenance file for each transfer window, recording the following information: equipment model, installation time, daily cleaning and disinfection records, component replacement time (such as lamp tubes, filters), regular inspection reports, fault handling records, etc. By analyzing the usage patterns of equipment through archives, the maintenance cycle can be optimized (for instance, if the transfer window in a certain area is frequently used, the filter replacement cycle can be shortened) to ensure that the maintenance work is more targeted.
