How Many Airborne Particles Emitted from a Nurse will Reach the Breathing Zone/Body Surface of the Patient in ISO Class-5 Single-Bed Hospital Protective Environments?—A Numerical Analysis

Figures & data

TABLE 1 Information on the four nurse–patient interaction scenarios

Case no.	Nurse–patient interaction scenarios	Dimensions of the simulated patient and nurse	Dimensions of the simulated protective environment	Dimensions of the air supply opening	Dimensions of the exhaust opening	Supply air velocity	Supply air temperature	Wall heat flux	Source of particle emissions

FIG. 1 Layout of the protective environment A: patient care area, B: bathroom, 1: air supply openings, 2: air return openings, 3: air exhaust, 4: toilet, 5: particle generator.

FIG. 2 Floor plan of the test points.

FIG. 3 Comparison of tested and simulated particle velocity at L1, L2, and L3. (a) L1 (Left: height of 0.8 m, Middle: height of 1.2 m, Right: height of 1.6 m). (b) L2 (Left: height of 0.8 m, Middle: height of 1.2 m, Right: height of 1.6 m). (c) L3 (Left: height of 0.8 m, Middle: height of 1.2 m, Right: height of 1.6 m).

FIG. 4 Comparison of the simulated and tested dimensionless particle concentration at (a) position P1, (b) position P2, (c) position P3, (d) position P4, (e) position P5. Dimensionless concentration is defined as the local concentration relative to the concentration at the outlet.

FIG. 5 The four simulated nurse–patient interaction scenarios.

FIG. 6 The velocity vector at plane x = 2.8 m. (Arrow length represents the magnitude of velocity, with scale indicated by the reference bar for 0.2 m/s.)

FIG. 7 The temperature distribution at plane x = 2.8 m.

FIG. 8 Particle dispersion near the patient's breathing zone when the nurse's body is the particle source.

FIG. 9 Particle dispersion near the patient's breathing zone when the nurse's head is the particle source.

FIG. 10 Percentage of particles entering the breathing zone and reaching the body surface of the patient in scenario 2. (a) Emitted from head; (b) Emitted from body.

FIG. 11 Percentage of particles reaching the patient's body surface area in scenario 4.