Friberg B E, Friberg S, Burman L G
Department of Orthopedics, Northern University Hospital, Umeå, Sweden.
Acta Orthop Scand. 1996 Dec;67(6):578-82. doi: 10.3109/17453679608997760.
We evaluated a novel concept of High Efficiency Particulate Air (HEPA)-filtered vertical Laminar Air Flow (LAF) for operating room ventilation, designed to be used without side-walls. The LAF-unit has a central zone with an airflow of 0.4 m/s and a peripheral zone with an airflow of 0.2 m/s. The design provides an exponential downflow of air resembling an upside-down trumpet mouth and it was claimed to prevent entrainment of peripheral contaminated air. The unit was evaluated with regard to elimination of particles with focus on bacteria-carrying particles (colony-forming units = cfu) during rigidly standardized sham operations. Three different lengths of walls/enclosures (short-ending 2.0 m, medium 1.0 m and long 0.2 m above the floor) were tested. It provided a high degree of bacteriological cleanliness (0.05-4 cfu/m3 of air and 7-64 cfu/m2/h surface contamination) and its efficiency was proved to be independent of the length of the enclosures. We conclude that the novel zoned ultraclean vertical LAF unit is versatile, as it allows for omitting long side-walls, without compromising bacteriological safety.
我们评估了一种用于手术室通风的新型高效空气过滤器（HEPA）过滤垂直层流空气（LAF）概念，其设计无需侧壁即可使用。LAF单元有一个中心区域，气流速度为0.4米/秒，还有一个周边区域，气流速度为0.2米/秒。该设计提供了一种类似倒喇叭口的指数向下气流，据称可防止周边受污染空气的夹带。在严格标准化的模拟手术过程中，对该单元进行了评估，重点关注携带细菌颗粒（菌落形成单位=cfu）的颗粒消除情况。测试了三种不同长度的墙壁/围护结构（短的在地面以上2.0米处结束，中等的1.0米，长的0.2米）。它提供了高度的细菌清洁度（空气0.05 - 4 cfu/m³，表面污染7 - 64 cfu/m²/h），并且其效率被证明与围护结构的长度无关。我们得出结论，新型分区超净垂直LAF单元具有通用性，因为它允许省略长侧壁，而不影响细菌安全性。
