Establishment of evaluation method for disinfection efficacy of positive pressure bio-protective hood / 医疗卫生装备

Objective To establish a method for evaluating the disinfecting effect of positive-pressure protective hoods by testing the disinfecting effect of canine influenza virus(CIV)on the positive-pressure protective hood with 1％Virkon S disinfectant.Methods The neutralizer was selected considering the characteristics of 1％Virkon S disinfectant in accordance with"Disinfection technical specifications"(2002 edition),and the effectiveness of the neutralizer was verified by determining median tissue culture infectious dose(TTCID50)of different samples inoculated with canine renal cells;in the same environment the effects of viral vectors and environment on viral activity were detected by measuring the TCID50 at different time points when CIV acted on the positive pressure protective hood;the optimal disinfection time was determined by establishing a viral vector model and a viral infiltration and sampling method,combining the results of viral recovery rates by real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay and viral titer measurements by TCID50 and 50％egg infectious dose(EID50).Results The phosphate buffer solution of 0.1％lecithin,2％Tween 80 and 0.5％sodium thiosulfate could be used as a neutralizer for 1％Virkon S disinfectant;the viral vectors and environment had no effects on CIV activity at different time points;the average recover rate was 96.12％for the samples inoculated with canine renal cells and 95.98％for the chicken eggs,and 1％Virkon S disinfectant behaved the best 4 min after its action on CIV on the positive-pressure protective hood.Conclusion The method proposed for evaluating the disinfection effect of the positive-pressure protective hood is effective in establishing optimal disinfection conditions for the positive-pressure protective hood.[Chinese Medical Equipment Journal,2023,44(9):33-37]

Reuse process of positive pressure powered air-filter protective hoods / 浙江大学学报·医学版

OBJECTIVE@#To establish reuse process of positive pressure powered air-filter protective hoods during coronavirus disease 2019 (COVID-19) epidemic.@*METHODS@#The procedure of pretreatment, storage, recovery, cleaning, disinfection and sterilization process of positive pressure powered air-filter protective hoods, which were used in the treatment of COVID-19 infection patients was established in Central Sterile Supply Department of the hospital. The cleaning and disinfection effects of the protective hoods after treatment were examined by magnifying glass method, residual protein detection method, real-time PCR, and agar pour plate method.@*RESULTS@#Twenty five used protective hoods underwent totally 135 times of washing, disinfecting and sterilizing procedures. After washing, all the protein residue tests and COVID-19 nucleic acid tests showed negative results. After sterilizing, all the protective hoods met sterility requirement. All the tested protective hoods were undamaged after reprocessing.@*CONCLUSIONS@#The established reuse procedures for used positive pressure powered air-filter protective hoods are safe.

Effect of the microenvironment of powered air-purifying medical protective hood on the body's physiological parameters / 医疗卫生装备

Environmental physiological method adopted, the ergonomic experiment is to seek the best parameter of the protective hood structural size, on which the structure design of the protective hood will be based, through the analysis of the organic relationship between the microenvironment of power air-purifying medical protective hood and the body's physiological characteristics. The changes of such indexes due to different air currents are analyzed as the oxygen, carbon dioxide, temperature and humidity in the microenvironment. The changes of testees' physiological parameters and their responses to psychological loads and body strengths are paid attention to. The results show the hood can meet the testees' demands with proper air current.