Noise control engineering on neonatal incubators

Abstract

Neonatal incubators provide suitable environmental conditions for premature newborns and allow for medical treatment such as medication and monitoring of vital functions such as blood pressure. The incubator includes several system components such as a control system, an oxygen supply, a scale or flaps and drawers for patient care and storage of medical material, respectively. These system components generate noise such as monitoring alarms, noise of the oxygen supply, or noise due to opening and closing of flaps during medical treatments. The noise leads to a significantly increased sound exposure inside the incubator. Increased sound exposure is known to cause distress and to increase the risk of acute or chronic diseases in the preterm neonate. This paper presents acoustic measurements on an incubator in a neonatal intensive care unit. Several vibration and acoustic measurements are performed inside the incubator as well as in the surrounding environment in order to characterize typical acoustic scenes from everyday life on the neonatal intensive care unit. Based on the measurement results, the scenes are categorized in terms of sound exposure. This forms the basis for a future design for acoustics of the incubator.

Noise and Critical Sound Levels During Non-Invasive Ventilation of a Preterm Infant in the Incubator

“…Our results are also consistent with previous reports showing attenuation of numerous noise sources generated in the NICU inside an incubator, reducing continuous sound exposure [5,15,23,27]. Other sound sources such as phone ringing, music boxes on top of the incubator, remote alarms in other rooms, con-versations, using disinfectant dispensers, or opening windows did not produce any relevant variation in sound pressure level at the incubator microphone [2]. In contrast, in our measurements, the sound pressure level of noise generated by handling the incubator itself was mostly higher in the child environment than in the room.…”

“…Four wired ¼" microphones (MI17, ROGA-Instruments, Nentershausen, Germany) were positioned for the analysis of sound pressure levels inside (three microphones) and outside a neonatal incubator (one microphone). After the interim analysis showed that the three incubator microphones had qualitatively similar sound pressure levels (SPL) [2], only the microphone positioned closest to the neonate's head and the room microphone were used for further evaluation. Particular attention was paid to the placement of the microphones in order to represent the respective sound fields: the incubator microphone was pushed through one of the grommets of the incubator and positioned about 15 cm above the head and the room microphone about 25 cm above the lid of the incubator.…”

“…Particular attention was paid to the placement of the microphones in order to represent the respective sound fields: the incubator microphone was pushed through one of the grommets of the incubator and positioned about 15 cm above the head and the room microphone about 25 cm above the lid of the incubator. For further details on the measurement setup, including the choice of a suitable microphone position, data acquisition, and processing, see Adams et al [2] and Supplementary Fig. S1.…”