Current Research Projects
Integrated Design of Hospital Wards for a Safe and Sustainable Patient Environment.
Funder: EPSRC, duration: 5 years, value: £1.03M
Redesigning healthcare building infrastructure to minimize infection risk, meet demanding government carbon reduction targets and create a safe and comfortable environment for patients and staff is one of the biggest challenges currently facing the NHS. Hospital acquired infection remains at the forefront of the Department of Health agenda. Targets to halve MRSA and cut C Diff by 30% by 2011, together with increasing awareness that the environment influences the risk of transmission have put infection control at the heart of hospital building programs. Building related energy use is also an increasing concern for the NHS, with the national carbon reduction targets of 20% by 2010 and 60% by 2050 almost certain to be demanded of hospitals. These two issues present a major design conflict. Improving ventilation to increase patient comfort and reduce infection while at the same time reducing the need for mechanical building services to cut energy use is a huge undertaking.
This research programme will tackle these design challenges from an integrated building services and pathogen control perspective. The aim is to develop robust design methodologies and an interactive computational based modelling environment that can used to evaluate and optimise hospital building design strategies from several different perspectives; energy use, infection risk and thermal comfort as well as patient safety and cost implications. A series of targeted projects, initially focusing on ward design and ventilation design strategy, is being used to develop these design tools and at the same time establish specific evidence-based solutions that address critical issues in existing outdated hospital wards. This will create the knowledge base necessary to establish the best designs for both refurbished and new build accommodation and meet both the immediate and long-term energy and infection targets.
The programme will involve collaboration with a number of industry, academic and healthcare partners
Principal Investigator: Dr Cath Noakes
Development of Computational Models to Design Upper-Room Ultraviolet Germicidal Irradiation Air Disinfection Systems in Hospital Environments
Funder: EPSRC, duration: 3 years, value: £256K
Ultraviolet Germicidal Irradiation (UVGI) irradiation has been known for many years to have a lethal effect on microorganisms. It is routinely used in water disinfection and can be a viable method of reducing airborne pathogens in indoor environments to decrease the risk of cross transmission of infection. Despite recommendations for use in high risk healthcare environments such as tuberculosis (TB) wards, the application of UVGI remains limited due to lack of evidence gained directly in clinical settings. However two major clinical studies that are about to be published will prove the effectiveness of UVGI devices against TB transmission and thus a significant increase in the future demand for UVGI air disinfection is anticipated. To translate these clinical based research findings into successful control strategies tailored to the needs of a particular healthcare environment, robust guidance on designing safe and effective UVGI air disinfection systems is now needed.
This project aims to address this need by developing a design tool for simulating the behaviour of upper room air disinfection devices in realistic hospital environments, and guidance documents to enable hospital managers, architects and engineers to (a) determine if UVGI disinfection is suitable for a particular environment and (b) to ensure any UVGI installations are both effective and safe. The proposed study will use computational fluid dynamics (CFD) simulations to carry out a parametric study quantifying the factors that influence the performance of a UV device to produce an empirical model of UVGI disinfection within a ventilation design model. The model will quantify the mean effectiveness, as well as stochastic variations, and provide an output in terms of UV device performance and relative risk of infection for ward occupants. This will enable better design and specification of UVGI systems without the use of resource intensive CFD models. Parametric studies using CFD models and the new design tool will then be used to draft three design guidance documents; suitability of upper-room UVGI systems in healthcare environments, safe installation and operation of UVGI systems, and optimising UVGI system design to minimise airborne infection risk.
Principal Investigator: Dr Cath Noakes
Design and Performance of Isolation Rooms.
Funder: Department of Health
This project focuses on the design and performance of isolation rooms for hospital environments. The study includes infection risk modelling, CFD modelling of isolation room airflows, experimental studies comparing tracer techniques to bioaerosols in the Leeds aerobiology chamber and experimental studies in full scale mock-up rooms to assess steady state and transient behaviour against particles and tracer gases. Applications include assessment of the PPVL isolation room which is described in HBN 4 supplement 1, and is now the recommended design for most isolation rooms in UK hospitals
Principal Investigator (Leeds): Dr Cath Noakes
Co Investigators: Dr Andy Sleigh, Dr Louise Fletcher
Partners: BSRIA, Malcolm Thomas
Development of modelling tools for evaluating large water distribution networks.
Funder: KTP (TSB), duration: 3 years, project value: £170K
This project aims to develop and implement computational tools for effectively visualising and analysing the connectivity and resilience of a large water distribution network. The focus is on the application of network theory to examine network properties without the computational or geographical constraints present in hydraulic or GIS based tools
Principal Investigator: Dr Cath Noakes
Co Investigators: Dr Andy Sleigh, Prof Ed Stentiford
Industry Partner: Yorkshire Water
KTP Associate:
Development of Ultra-Violet Sterilization Products for the Ventilation Industry
Funder: KTP, duration: 2.25 years, project value: £120K
This project aims to develop a state-of-the-art range of industry leading 'airside' ultra-violet sterilisation products for the H&V industry and establish an R&D function
Principal Investigator: Dr Andy Sleigh
Co Investigators: Dr Louise Fletcher, Dr Cath Noakes, Prof Duncan Mara
Industry Partner: Mansfield Pollard Ltd
KTP Associate:Azael Capetillo
Recently Completed PhD Projects
PhD title : CFD Modelling of Pathogen Transport due to Human Activity
Health-care Associated Infection is a major concern with 1 in 11 patients affected each year. With the evidence that some pathogens may be transported by an airborne route fluid modelling tools, such as Computational Fluid Dynamics (CFD), are increasingly used to aid understanding of the transport mechanisms of infection. There are shortcomings in modelling techniques,for example models tend to only consider respiratory infections that are released from a single point, such as a person coughing. However there is substantial evidence that certain pathogens, such as MRSA, may be released from the skin during regular routine activities (e.g. undressing, walking).
This thesis develops the methodology for representation of releases of pathogens through human activity so that they are more fully representative of reality. The study undertook both laboratory and field work in hospitals to monitor activity and aerosol production and then developed several models to represent the production and transport of the aerosols and subsequent infection risk.
The full thesis may be downloaded here in pdf format.
Below are some publications that were derived from work undertaken during the research for this thesis:
- Roberts K., et al., (2006). "Bioaerosol production on a respiratory ward." Indoor and Built Environment 15(1): 35-40)
- Hathway E.A., et al., (2008). "Bioaerosol production from routine activities within a hospital ward." Proceeding of Indoor Air 2008, Copenhagen
- Hathway et al (2007) (Hathway E.A. et al "CFD Modelling of Transient Pathogen Release in Indoor Environments due to Human Activity". Proceedings of Roomvent. Helsinki. Finland
- Hathway E.A. et al., (2008) "CFD Modelling of a Hospital Ward: Assessing risk from bacteria produced from respiratory and activity sources." Proceeding of Indoor Air 2008, Copenhagen
The work for this thesis was undertaken with support from Arup
Researcher, Supervisors and Collaborators: Abigail Hathway , Dr Andy Sleigh , Dr Cath Noakes and Arup
Funded by: EPSRC
PhD title: The aerial dissemination of Clostridium difficile in the clinical environment
This thesis investigated the aerial dissemination of Clostridium difficile (C. difficile) in the clinical environment and the contribution that this transmission route made to contamination levels. It describes evidence for the aerial dissemination of C. difficile. This evidence may offer some assistance in helping to explain why Clostridium difficile infection (CDI) is so persistent within hospitals and so difficult to eradicate. The findings reinforce concerns that current C. difficile control measures may be inadequate and they suggest that improved ward ventilation and ultraviolet germicidal irradiation (UVGI) systems may help to reduce the spread of CDI in healthcare facilities.
The full thesis may be downloaded here in pdf format.
The work for this thesis was undertaken in conjunction with Arup
Below are some publications that were derived from work undertaken during the research for this thesis:
- Roberts, K., Hathway, A., Fletcher, L., Beggs, C., Elliott, M., Sleigh, P.A., Bioaerosol production on a respiratory ward. Indoor and Built Environment, 2006. 15: p. 35-40.
- Roberts, K., Smith, C., Snelling, A., Kerr, K., Banfield, K., Sleigh, P.A., Beggs, C., Aerial Dissemination of Clostridium difficile spores. BMC Infectious Diseases, 2008. 8, pp1-7.
Supervisors and Collaborators: Katherine Roberts, Dr Andy Sleigh, Dr Louise Fletcher, Prof Kevin Kerr, Harrogate District HospitalProf. Clive Beggs, University of Bradford and Arup