Center for Health-Related Aerosol Studies, Department of Environmental Health, College of Medicine, University of Cincinnati, Cincinnati, OH, USA.
Department of Civil and Architectural Engineering and Construction Management, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, OH, USA.
Ann Work Expo Health. 2018 Jul 6;62(6):742-753. doi: 10.1093/annweh/wxy026.
A low-cost real-time Respirator Seal Integrity Monitor (ReSIM) was recently developed to monitor a respirator's actual performance at a workplace. The objective of this study was to evaluate the capability of the new ReSIM prototype in manikin-based laboratory experiments to rapidly detect induced leakage of a half-mask elastomeric respirator.
Two phases of testing were conducted in this study. First, the accuracy of ReSIM measuring an aerosol concentration was assessed by comparing the outputs of ReSIM against a reference optical aerosol spectrometer (OAS) in a flow-through set-up. Second, the capability to detect a leak was tested using a manikin-based set-up to simulate leaks into a functional respirator.
The regression curve of ReSIM versus OAS had an R2 of 0.936, indicating its high accuracy within the targeted particle size range of 0.5-2 µm. The ReSIM provided a leak detection sensitivity (probability of correctly identifying intervals with the true leak) of 98.4% when challenged with a combustion aerosol, compared to 71.8% when challenged with a NaCl aerosol. Its specificity (probability of identifying intervals without a leak) was 99.8% after adjusting for persistent false positives for both types of challenge aerosol.
The ReSIM prototype not only can estimate the particle concentration with high accuracy but also can rapidly detect respirator faceseal leakage in real time with sufficient sensitivity and specificity. In addition, it can trigger an alarm when the faceseal integrity is compromised.
最近开发了一种低成本的实时呼吸防护器密封完整性监测器（ReSIM），用于监测工作场所呼吸防护器的实际性能。本研究的目的是评估新型 ReSIM 原型在基于人体模型的实验室实验中检测半面罩弹性呼吸防护器诱导泄漏的能力。
本研究进行了两个阶段的测试。首先，通过在流动装置中比较 ReSIM 与参考光学气溶胶光谱仪（OAS）的输出，评估 ReSIM 测量气溶胶浓度的准确性。其次，使用基于人体模型的装置测试检测泄漏的能力，以模拟功能性呼吸防护器中的泄漏。
ReSIM 与 OAS 的回归曲线 R2 为 0.936，表明其在目标粒径范围 0.5-2 µm 内具有很高的准确性。ReSIM 在使用燃烧气溶胶进行测试时，泄漏检测灵敏度（正确识别存在真实泄漏的时间段的概率）为 98.4%，而在使用 NaCl 气溶胶进行测试时为 71.8%。调整两种类型的挑战气溶胶的持续假阳性后，其特异性（识别无泄漏时间段的概率）为 99.8%。
ReSIM 原型不仅可以高精度地估计颗粒浓度，还可以实时快速检测呼吸防护器的面部密封泄漏，具有足够的灵敏度和特异性。此外，当面部密封完整性受到损害时，它可以触发警报。
