Testing the effectiveness of operating room ventilation with regard to removal of airborne bacteria

In this research the ability of the ventilation system in an operating room to keep the operating table and the instrument tables free from airborne bacteria has been evaluated in an experimental mock-up for different ventilation systems under various static circumstances. To accomplish this, the VDI 2167 particle test has been used as a basis. In this test particles are released on the floor and smoke concentrations are measured on the operating table. The VDI 2167 method was able to distinguish the different systems, but did not provide for a complete evaluation. The thermal balance in the room plays a major role in whether a laminar downflow system works and the VDI method does not incorporate this into the tests in an adequate manner. Moreover, the influence of surgical lighting is not included in the test method in an effective way

Assessment of the performance of the airflow in an operating theatre

Recently, a German draft standard that describes a method to assess the performance of an operating room ventilation system has been made available by the VDI [1]. To evaluate the VDI procedure and to assess practical problems, measurements have been performed in a full-scale mock-up of an operating theatre. In the design stage the VDI approach may also be useful for an objective design assessment. In that case the approach can be mimicked through the application of the Computational Fluid Dynamics (CFD) technique. In this paper the results of the full scale measurements and a comparison with numerical results will be presented. It is possible to use the VDI 2167 to evaluate the performance of a room in a reproducible manner. The CFD simulations underestimate the temperatures in the periphery of the room. A better prediction of these temperatures will lead to a better prediction of the particle concentration on the operating table

Performance based building and its application to the operating theatre

The paper introduces the concept of performance based building and presents a definition of this broad concept, with a focus on the indoor environment. The performance based approach is already known and applied for a longer period but has no general application yet in the indoor environment. Through a practical case, the ventilation system in an operating theatre, the applicability of the concept is verified. In order to proceed, the developed approach has been refined. The stakeholders are used to arrive at the various performance requirements for this case and the performance indicators that can be linked to them. Use of simulation tools in the design phase has specific attention. For one of the requirements, the minimization of the surgical site infection rate, the air quality in the operating theatre was investigated numerically with Computational Fluid Dynamics (CFD). The results for this specific case show that the performance based approach is applicable and open for assessment of innovative designs

Influence of the shape of surgical lights on the disturbance of the airflow

Operating room ventilation systems are used to keep the wound area of a patient free from airborne bacteria. Surgical lighting is one of the major disturbances in operating room ventilation systems. This paper describes results from a series of measurements that aim to qualify and quantify the influence of the shape of an operating lamp on the disturbance of the air flow around the lamp. Visualization and particle concentration measurements in combination with a fixed particle source are used to study the upward transport mechanism of particles underneath an operating lamp. Air velocity measurements are used to determine to quantify the size of the wake underneath the lamp. Several different shapes are used in this investigation. The results of the investigation are used to compare with the laminar flow indexes by Leenemann and Oostlander and to assess how well they describe the performance of a lamp with regard to keeping the air clean. The results from these experiments in the future will be applied for CFD validation

Healthy environments from a broad perspective : an overview of research performed at the unit Building Physics and Systems of Eindhoven University of Technology

The design and realization of a healthy indoor environment is a challenge that is investigated from different perspectives at the unit Building Physics and Systems (BPS; Faculty of Architecture, Building and Planning) of Eindhoven University of Technology. Performance requirements (for instance, with respect to air quality, thermal comfort and lighting) and performance based assessment methods are the point-of-departure, focusing at computational techniques supporting the design process. Different specific application fields such as dwellings, offices, schools, but also, operating theatres, churches, musea and multifunctional stadiums, underline the applied approach that is part of the research within the unit. In the design of healthy environments, the performance based design assessment is crucial in arriving at innovative design solutions and optimized indoor and outdoor environments. In this assessment computational support tools and experimental verification play an important role. However, assessing the right indicators in an objective way, applying the correct tools and correct application of these tools is not yet well established. Alongside, developments are still ongoing. The work performed in the unit by the different researchers relates to the research questions that can be derived from this notice. The paper gives an introduction to the Unit BPS and presents a brief overview of recent and ongoing research. An extensive list of references is provided for further reading and supports the conclusion that healthy environments can and should be addressed from a wide angle

Healthy environments from a broad perspective : an overview of research performed at the unit Building Physics and Systems of Eindhoven University of Technology

The design and realization of a healthy indoor environment is a challenge that is investigated from different perspectives at the unit Building Physics and Systems (BPS; Faculty of Architecture, Building and Planning) of Eindhoven University of Technology. Performance requirements (for instance, with respect to air quality, thermal comfort and lighting) and performance based assessment methods are the point-of-departure, focusing at computational techniques supporting the design process. Different specific application fields such as dwellings, offices, schools, but also, operating theatres, churches, musea and multifunctional stadiums, underline the applied approach that is part of the research within the unit. In the design of healthy environments, the performance based design assessment is crucial in arriving at innovative design solutions and optimized indoor and outdoor environments. In this assessment computational support tools and experimental verification play an important role. However, assessing the right indicators in an objective way, applying the correct tools and correct application of these tools is not yet well established. Alongside, developments are still ongoing. The work performed in the unit by the different researchers relates to the research questions that can be derived from this notice. The paper gives an introduction to the Unit BPS and presents a brief overview of recent and ongoing research. An extensive list of references is provided for further reading and supports the conclusion that healthy environments can and should be addressed from a wide angle

Testing the effectiveness of operating room ventilation with regard to removal of airborne bacteria

In this research the ability of the ventilation system in an operating room to keep the operating table and the instrument tables free from airborne bacteria has been evaluated in an experimental mock-up for different ventilation systems under various static circumstances. To accomplish this, the VDI 2167 particle test has been used as a basis. In this test particles are released on the floor and smoke concentrations are measured on the operating table. The VDI 2167 method was able to distinguish the different systems, but did not provide for a complete evaluation. The thermal balance in the room plays a major role in whether a laminar downflow system works and the VDI method does not incorporate this into the tests in an adequate manner. Moreover, the influence of surgical lighting is not included in the test method in an effective way

Een objectief oordeel - Ontwerp van een ventilatiesysteem voor een operatiekamer objectief beoordeeld

Aan de kwaliteit van de lucht en de luchtstroming in een operatiekamer worden hoge eisen gesteld. Enkele recente voorbeelden in de praktijk hebben laten zien dat hier soms drastische consequenties aan verbonden kunnen worden. In een lopend promotieonderzoek aan de Technische Universiteit Eindhoven wordt geprobeerd om de objectieve beoordeling van de kwaliteit van een ventilatiesysteem verder te onderbouwen, ook al in de ontwerpfase. In dit artikel wordt een korte toelichting gegeven op dit lopende onderzoek en worden enkele deelresultaten beschreven