Laying-up of sterile instruments in the operating theatre: equal or superior protection by using a horizontal unidirectional air flow system

Abstract

SummaryBackground: A system for the preparation of sterilized instruments with unidirectional horizontal air flow (UDHF) has several advantages over a unidirectional down-flow system (UDDF). The advantages are based on the installation of the system being more flexible and easier to use, no cooling of the air flow being necessary and less air being needed for circulation, resulting in reduced energy use.

Numerical and experimental analysis of airborne particles control in an operating theater

“…The SIMPLE algorithm has been used for the pressureevelocity coupling. The diffusion terms are discretized with a central- difference scheme while a second-order upwind scheme is used for the convective terms [28]. Adaptive wall-functions, the so called (enhanced wall treatment [32]) have been employed.…”

“…On the contrary only few works have dealt with the application of CFD simulations to national standard performance tests on air contamination control [23e27]. Traversari et al [28] have evaluated the airborne bacterial contamination in an OT by comparing two air diffusion systems, i.e. a unidirectional horizontal flow (UDHF), and a unidirectional downward flow (UDDF), partly using the procedure described in standard DIN 1946-4 [27].…”

Mobile ultra-clean unidirectional airflow screen reduces air contamination in a simulated setting for intra-vitreal injection

“…As a result, the head position of the patient is not consequential, as the particles, like gas particles, are diffusely and evenly spread in the room. [ 13 , 14 ] A setup was arranged in which particles were emitted on one side of the OR, and particles were measured at 3 sites: (1) at the instrument table, (2) at the operative site, and (3) at the other side of the patient, representing the background measurement (Fig. 1 ).…”

The Effect of Operating Lamps on the Protected Area of a Unidirectional Down Flow (UDF) System

“…The DP is defined as the logarithm of the quotient (ratio) of the number of particles with a size of 0.5 µm or larger in the protected area compared to the number of particles of this size in the periphery. This corresponds to the following Equation 1 (Traversari et al, 2013).…”

“…The small water droplets (2–4 µm) emitted by the machine vaporize relatively fast (a few seconds) and the mineral residues of the evaporated tap water remain airborne as solid particles (Hinds, 1999; Porstendörfer, Gebhart, & Röbig, 1977; Rodes, Smith, Crouse, & Ramachandran, 1990). The particles in this study were emitted at a height of 1.5 m (average neck height; Traversari et al, 2013). It is assumed that most particles are produced by the staff at that height.…”