Premature infants in the Neonatal Intensive Care Unit (NICU) are at risk for hearing impairment, cognitive development abnormalities, and even intraventricular hemorrhaging due to high noise levels. Nearly 400,000 babies are admitted into the NICU in the United States each year, and this number is only growing. Up to 10% of these preterm infants are diagnosed with hearing impairment in comparison to only .1% for the general pediatric population. Between noises from the CPAP machine and other life sustaining devices along with external human noise in the NICU, sound levels average around 62 dB and can reach up to 120 dB. However, the American Academy of Pediatrics recommends noise levels should be lower than 45 dB. Current incubators on the market do not address this noise issue. 

The team’s solution is to create an adjustable foam insert that can be fitted to any incubator and used for sound absorption. The foam would line the edges of the incubator to reduce resonance and allow for neonatologists to still have full vision of the inside of the incubator. Additionally, the team’s design contains a bottom piece that perfectly fits a Z-flow device so that the infants can be positioned for maximum health. This bottom piece is also made of foam for extra sound absorption. This design was modeled in Solidworks and various geometries were tested to improve the design’s effectiveness. Two foams were tested and a statistical t-test was used to determine the better foam. The two foams used from the manufacturer Acoustical Surfaces Inc. were the Sound Silencer ARPRO foam and the Flat Faced Melamine Foam. The ARPRO foam performed better in this statistical comparison for noise reduction. Furthermore, in comparison to having no foam present in the chamber, the noise level was reduced by over 15 dB. The combination of this foam along with an Active Noise Control system would significantly reduce noise levels to below the acceptable limit. The team proposes to introduce a multi-channel Active Noise Control system along with the adjustable foam insert. This system would consist of one reference microphone that picks up noise, two error microphones to sense residual noise, and two loudspeakers to generate the “anti noise” signal. This Active Noise Control system is already proven to significantly reduce noise levels, and the loudspeakers are placed near the babies’ heads so that there is no wave amplification. Ultimately, this foam insert was found to reduce noise levels to approximately the 45 decibels which was recommended by the American Academy of Pediatrics.


Usage of Foam to Reduce Noise Levels in NICU Incubators

Division / Sponsors: 
Aerospace, Bioengineering, Applied Mechanics, Design Engineering Division, Advanced Energy Systems, Manufacturing Engineering Division, Noise Control and Acoustics, Nondestructive Evaluation, Diagnosis, and Prognosis (NDPD), Nuclear Engineering Division, Process Industries Division, Fluids Engineering, Heat Transfer, Materials, Microelectromechanical Systems, Safety Engineering and Risk Analysis, Computers & Information in Engineering


Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2020/volume/84478

IMECE2020 - Virtual Conference

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.