Lilin Du

Publication Date


Document Type


First Advisor

Liu, Lichuan, 1945-

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Electrical Engineering


Noise control; Acoustic impedance; Incubators (Pediatrics)


Preterm infants are often admitted into neonatal intensive care unit (NICU) to increase their survival rate. However, fragile infants are exposed to ambient noise from medical equipment and human activities. High intensities of noise have been involved with numerous advanced health effects in infants. There is a growing concern that a mechanism can be used to cancel noise both inside and outside the incubator. More and more researches show that communication between parents and infants from an early stage accelerates the maturation of infants and has good influence on infants' self-esteem and socialization. This causes the need for a medium that transfers the information between parents and neonates while infants are still protected in a safe environment. Since impulsive noise is a main portion in real-time NICU noise, an effective and stable method should be conducted to solve the problem. However, the traditional algorithm in active noise control (ANC) system has high chance to diverge when impulsive noise occurs. In this thesis, based on three major problems in the existing ANC system, a wireless communication integrated hybrid ANC (WCHANC) system with impulsive noise cancellation for infant incubator is proposed. My main contributions are: 1) The hybrid active noise control (HANC) system implemented in this thesis can cancel both inside and outside noise. 2) The wireless communication function is integrated to the main HANC system in order to transfer speech signals between parents and infants. 3) An alternative Kalman filter is proposed to reduce the impulsive noise. Real-time experiment results for WCHANC show that the proposed system can dramatically reduce the noise level inside infant incubators while providing two-way communication between parents and infants. Simulations for the proposed Kalman filter algorithm show that it can effectively track and cancel the impulsive noise.


Advisors: Lichuan Liu.||Committee members: Veysel Demir; Donald S. Zinger.||Includes bibliographical references.||Includes illustrations.


xi, 81 pages




Northern Illinois University

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