Performance and Energy Efficiency of Low Irradiance Antimicrobial Blue Light for Continuous Decontamination Applications

多重耐药微生物的出现对公共卫生构成了重大风险，也给全球医疗保健系统带来了经济负担。抗菌405 nm蓝色HINS光是一种独特的感染控制方法，已被证明可以杀灭广泛的微生物物种，包括具有抗生素耐药性的微生物物种。由于其独特的安全特性，它已被开发用于被动净化技术，允许对占用环境进行连续消毒。该项目旨在通过调查其基本光化学灭活机制的各个方面，特别是关于其使用低辐照光子能量的操作，产生关于这种新兴感染控制技术的重要新信息。与具有众所周知的杀菌作用的紫外线不同，对405 nm光的抗菌特性的认识是一个相对较新的科学发现。该领域的大部分文献都集中在证明抗菌原理上，为了做到这一点，研究倾向于使用高功率光源（高达150 mW/cm 2），以实现更快的抗菌效果。然而，当将研究结果转化为设计为使用低辐照度水平的实际应用时，这具有局限性。这对于连续环境净化技术的应用特别重要，因为这些系统通常使用<0.5mW/cm 2的辐照度水平，以允许安全，24/7，由ROLEST小组产生的最新数据已经强调，当与高强度相比时，使用低辐照光子水平导致微生物灭活动力学的主要差异。光子能级样品的低辐照度照明显示出增强的抗微生物功效和显著提高的能量效率。随着行业对照明系统能效的需求不断增长，理解这一基本概念并利用这些知识开发低功耗、高能效抗菌照明系统的能力将具有重大的研究和商业意义。该项目的目的和目标将包括以下内容：-深入的科学和技术文献综述，以建立关于抗菌蓝光的基本作用和应用的现有知识，包括对这些研究中报告的辐照度水平和能源效率的综述。设计和建造一个用于抗菌和能效测试的台式低辐照度光系统。为此需要进行重大的技术开发，以确保使用适当的LED光源和光学组件;冷却/热管理;输出辐照度的可控性;以及操作员的安全。将对所建系统进行辐照度分析，以优化LED配置并确保低辐照度光分布的均匀性。将进行抗菌试验，以评价一组关键微生物对低辐照度光的敏感性。将建立一系列辐照水平和剂量的灭活动力学。待检测的关键微生物将包括ESKAPE病原体和病毒。将在临床和工业环境中常见的一系列相关表面（例如金属、聚合物、织物、玻璃）上评价去污效果。- 确定的一个关键因素是抗菌效力的最低阈值水平。成功去污所需的最低辐照度水平和暴露时间的知识将是开发实际感染控制应用的低能量系统的关键因素。- 还将对使用高辐照度光进行微生物灭活所需的能量进行比较，以量化能量和杀菌效率的改进。

The emergence of multi-drug resistant microbes presents both a major risk to public health and an economic burden on the global healthcare system. Antimicrobial 405nm blue HINS-light is a unique method of infection control that has been proven to inactivate a broad range of microbial species including those with antibiotic resistance. Due to its unique safety features, it has been developed for use as a passive decontamination technology which permits continuous disinfection of occupied environments. This project aims to generate important new information on this emerging infection control technology by investigating aspects of its fundamental photo-chemical inactivation mechanism, specifically with respect to its operation using low irradiance photon energy. Unlike ultraviolet light, which possesses well-known germicidal action, the recognition of the antimicrobial properties of 405nm light is a relatively recent scientific discovery. Much of the literature in the area has focused on proving the antimicrobial principles, and to do this, studies have tended to utilise high power light sources (up to 150mW/cm2) in order to achieve faster antimicrobial effects. This however, has limitations when translating the findings towards practical applications which are designed to use low irradiance levels. This is particularly significant for the application of the technology for continuous environmental decontamination, as these systems typically utilise irradiance levels of <0.5mW/cm2 in order to permit safe, 24/7, exposure of room occupants.Recent data generated by the ROLEST group has highlighted that use of low irradiance photon levels results in major differences in the microbial inactivation kinetics when compared with high intensity photon levels. Low irradiance illumination of samples demonstrated enhanced antimicrobial efficacy and significantly improved energy efficiency. With the growing industry demand for energy efficiency in lighting systems, the ability to understand this fundamental concept and utilise the knowledge to develop low power, energy efficient antimicrobial lighting systems, will be of significant research and commercial interest. The project aims and objectives will include the following: -An in-depth scientific and technical literature review to establish current knowledge on the fundamental action and application of antimicrobial blue light, including a review of the irradiance levels and energy efficiencies reported in these studies.-Design and build of a bench-top, low irradiance light system which will be used for antimicrobial and energy efficiency testing. Significant technical development will be required for this in order to ensure the use of appropriate LED sources and optical components; cooling/thermal management; controllability of output irradiance; and operator safety. Irradiance profiling of the built system will be conducted to optimise LED configurations and ensure uniformity of the low irradiance light distribution.-Antimicrobial testing will be conducted to evaluate a panel of key organisms for their susceptibility to low irradiance light. Inactivation kinetics for a range of irradiance levels and doses will be established. Key organisms to be tested will include ESKAPE pathogens and viruses. Decontamination efficacy will be evaluated on a range of relevant surfaces common within clinical and industrial environments (e.g. metals, polymers, fabrics, glass). - A key factor to be established will be the minimum threshold level for antimicrobial efficacy. Knowledge of the minimum irradiance levels and exposure times required for successful decontamination will be a key factor in the development of low energy systems for practical infection control applications. -Comparisons will also be made to the energies required for microbial inactivation using high irradiance light in order to quantify improvements in energy and germicidal efficiency.