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Smart Split Neck Seals for Respiratory Protection


Current respiratory protection neck seal systems do not incorporate smart sensing technologies. Current neck seal systems are simply basic circular rubber cut-outs and are required to be constructed of one continuous piece of material. Many wearers find traditional neck seals to be uncomfortable. Respiratory protection systems utilized for fixed wing aircraft pilots (e.g. JSAM-FW, AR-5, and AERP), as well as escape purposes (e.g. JSCESM and NIOSH CBRN escape hoods) utilize neck seals as a primary protective barrier. These one piece neck seals may only be donned by pulling the system over the head and down onto the neck. This donning methodology limitation greatly impacts the overall system design, its ability to be worn concurrent with other forms of head-borne PPE, and wearer acceptance. Innovative technology is needed that can allow for a smart split neck seal design that allows for donning versatility, improved comfort, and the provision of user feedback regarding seal performance. Application of smart technology to a neck seal will provide an additional option for wearers with facial hair and/or spectacles (optical correction), would assist in avoiding seal collisions with concurrently worn headgear (e.g. helmet chin straps), and would allow for optional overlapping neck seal wrap designs as opposed to the current continuous neck seal that must be donned over the head. Sensor technology that would continually assess the integrity of the seal but does not require the presence of a specific threat challenge is desired. This sensor would help balance comfort with protection in ensuring that a hermetic neck seal is maintained around the entire circumference of the neck while concurrently ensuring the pressures at the neck are not excessive leading to discomfort. Many types of flexible electronics and pressure-sensitive devices have been constructed from thin films, micro-electromechanical systems (MEMS), and nanowires. However, none have been demonstrated to work in a respiratory protective mask seal system. The current effort would develop not only a novel split neck seal design but also an innovative sensor technology to enhance the sealing of the respiratory protective mask. The sensor would ensure the mask seal maintains proper pressure with the neck skin surface to prevent breakage of the mask seal. In addition, the sensors would be utilized to ensure that both sections of the two piece seal design adequately adhere to one another to form a continuous hermetic sealing surface. The resultant system must be hygienic, durable, and easy to clean. The sensor should be able to be integrated with the seal of the mask, should be lightweight, and should not impact the flexibility or extensibility of the sealing surface. The system must be able to withstand a large range of temperature and environmental extremes and must be resistant to chemical, biological, and non-traditional threat agents. Lastly, the split neck seal system with the seal sensor should not add more than thirty dollars to the cost of the system in which it is intended to be integrated. PHASE I: Investigate material sealing methodologies (e.g. ferrofluids, advanced closure systems, etc.) that would allow for the development of a split neck seal design with a hermetic closure. Identify seal performance and wearer comfort metrics for the neck while wearing a full facepiece respirator that seals to the neck. Identify appropriate sensor technology for the proposed split seal design. Demonstrate that selected material sealing technology provides a hermetic seal to the geometry of the neck (e.g., on a headform) and to itself (as a neck closure). A negative pressure between 10 to 15 cmH2O shall be applied to the neck seal and maintained for 30 sec with less than a 2.5 cmH2O drop in pressure. PHASE II: Refine seal performance and develop sensor. Develop sensor technology identified in Phase I. Provide a functioning prototype sensor. The developed sensors should detect a seal performance change of less than or equal to 2% within a time period of 0.2 seconds (e.g. for a pressure sensor, detect a pressure change of less than or equal to 2% of the identified pressures). Apply the developed sensors to actual neck seal geometries to demonstrate performance. Concepts for a split seal design, seal performance indicator, and for electronic user adjustable and automatic fit control shall be demonstrated. Demonstrate the technology can quickly identify repeated seal breaks occurring in the same region. Develop ability to store baseline pressures acquired during a successful fit test. Develop and demonstrate indicator technology to warn user of seal breaks and/or differences in fit from the baseline. Provide a capability for visualization of the potential leak location. Provide pre-production prototype of both face and neck seal respirators with embedded Smart Seal technology. Provide a means for self-calibration of the sensor and seal technology. Demonstrate the flexibility of the existing sealing surface does not change by more than 2% due to the sensor technology. Total weight of the sensors, housing, and electronics including power source should not exceed 50 g. Demonstrate that the system can be electronically adjusted by the wearer to improve fit and that an automatic fit control option is provided and these controls are capable for achieving suitable fit and fit adjustment during simulated workplace protection factor testing. PHASE III: Complete system refinement. Optimize fabrication process to demonstrate large-scale production capabilities. Demonstrate ability of the technology to be incorporated into a full facepiece respirator prototype. Demonstrate the technology is durable and suitable for military combat applications. PHASE III DUAL USE APPLICATIONS: Potential alternative applications include industrial, international, and commercial respiratory protection systems as well as protective clothing seals and closures.
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