ANCFreq: A novel active noise cancellation frequency analyser for magnetic resonance imaging

Abstract

Various types of acoustic noise are produced during the operation of a Magnetic Resonance Imaging (MRI) system. The noise generated can go up to 131 dB, which is a major concern. The Occupational Health and Safety regulations, suggests that the continual exposure of noise above 90 dB for continuous period of 8 hours is dangerous for the hearer. Problems associated with acoustic noise for a patients and health care professionals include annoyance, verbal communication difficulties, heightened anxiety, temporary hearing loss and, in extreme cases, the potential for permanent hearing impairment. The MRI imaging utilises both high and the low sound level frequency for optimum imaging results. The current sound level meter does not allow "anti-phase noise control" features. Hence an expensive noise frequency analyzer with built-in sound level meter is required to carry out such noise control task. Identifying the specific noise frequency (especially at low frequency element below 1000 Hz) during MR imaging without missing the useful frequency components remains to be a challenge .