Cross infection in a hospital ward and deposition of particles exhaled from a source patient

摘要

The cross infection in a hospital ward is studied. Deposition of particles exhaled from a source manikin is investigated in a full-scale hospital ward ventilated by downward directed ventilation. Deposition on vertical surfaces close to the source shows distribution of particles directed upwards in the room. Deposition at the four beds shows that particles smaller than 10 μm disperse evenly in the ward, indicating that particles smaller than this size are airborne. The influence of top and bottom extraction openings on dispersion of particles is investigated. Results show that vertical distribution in the room is not affected by the position of the return openings. Deposition of particles at the four beds gives some indication of a less wide spread of particles with the use of ceiling-mounted return openings, and thereby a better protection of patients compared with bottom return openings.