我国标准将洁净手术室分为四级 ,其中前三级要求在手术台上方集中布置送风口 ,这样做是为了保护关键区域 ,符合我国早就提出的局部净化和主流区理论。按主流区理论计算结果表明 ,这样布置送风口 ,将在同样换气次数下使手术台区洁净度提高一个级别 ,使主流区细菌浓度和周边区细菌浓度之比降到 0 .5以下 Our standard will clean the operating room is divided into four, of which the first three require centralized arrangement of the air outlet above the operating table, in order to protect the key areas, in line with our country has long been proposed partial purification and mainstream area theory. According to the calculation of the mainstream area theory results show that the arrangement of the outlet, will be the same number of ventilators to improve the cleanliness of the operating table area level, so that the concentration of bacteria in the mainstream area and the surrounding bacteria concentration ratio down to 0.5