7Disposable filter assembly. United States Patent, 5433764.
8Ventilator unit exhalation contamination control device.United States Patent, 4653493.
9Tablan OC, Anderson LJ, Aden NH, et al. Guideline for prevention of nosoconial pneumonia (CDC)[J]. Infect Control Hosp Epidemiol, 1994,15(4) : 587-627.
10Stoller JK, Orens DK, Fatica C, et al. Weekly versus daily changes of in-line suction catheters: impact on rates of ventilator-associated pneumonia and associated costs[J]. Respir Care, 2003,48 (5) :494- 499.