ITEE Innovation Expo 2008 : Project Details

Wireless Electrodes for Neonatal Hearing Screening

Hearing screening for newborns before they leave the hospital or maternity centre is becoming a common practice. Early detection and intervention of hearing impairment are crucial for speech and language development. Auditory brainstem response (ABR), an auditory evoked potential that originates from the auditory nerve, is a commonly used, non-invasive and objective physiologic assessment method. Nowadays, wireless connectivity is extensively used in many areas, such as home entertainment, short range communication. If wireless ABR acquisition is possible, EM interference of the signal can be eliminated; isolation requirement for medical instrumentation design could be bypassed. Moreover, distributed system will enable ABRs from multiple subjects being acquired simultaneous with less manpower requirement. The challenges are: the ABR signal has very low SNR, requiring ensemble average to eliminate the noise. Being evoked potential, ABR acquisition must be synchronized perfectly across epochs. Secondly, high sampling frequency, over 30k samples per second, is required. This thesis suggests a successful engineering solution to such challenges. Current hardware and software settings enable 10bit ADC with up to 48k samples per second.