Development and Evaluation of a Body-Worn Dosimeter for Continuous and Impulsive Noise.

Noise exposure is encountered nearly everyday in both recreational and occupational settings, and can lead to a number of health concerns including hearing-loss, tinnitus, social-isolation and possibly dementia. Although guidelines exist to protect workers from noise, it remains a challenge to accurately quantify the noise exposure experienced by an individual due to the complexity and non-stationarity of noise sources. This is especially true for impulsive noise sources, such as weapons fire and industrial impact noise which are difficult to quantify due to technical challenges relating to sensor design and size, weight and power requirements. Because of this, personal noise dosimeters are often limited to a maximum 140 dB SPL and are not sufficient to measure impulse noise. This work details the design of a body-worn noise dosimeter (mNOISE) that processes both impulse and continuous noise ranging in level from 40 dBA-185 dBP (i.e. a quiet whisper to a shoulder fired rocket). Also detailed is the capability of the device to log the kurtosis of the sound pressure waveform in real-time, which is thought to be useful in characterizing complex noise exposures. Finally, we demonstrate the use of mNOISE in a military-flight noise environment. Clinical Relevance- On-body noise exposure monitoring can be used by audiologists industrial hygiene personnel and others to determine threshold of injury adequate hearing protection requirements and ultimately reduce permanent noise-induced hearing loss.

Creation of a human head phantom for testing of electroencephalography equipment and techniques.

We have designed and fabricated an anatomically accurate human head phantom that is capable of generating realistic electric scalp potential patterns. This phantom was developed for performance evaluation of new electroencephalography (EEG) caps, hardware, and measurement techniques that are designed for environments high in electromagnetic and mechanical noise. The phantom was fabricated using conductive composite materials that mimic the electrical and mechanical properties of scalp, skull, and brain. The phantom prototype was calibrated and testing was conducted using a 32-electrode EEG cap. Test results show that the phantom is able to generate diverse scalp potential patterns using a finite number of dipole antennas internal to the phantom. This phantom design could provide a valuable test platform for wearable EEG technology.