AuDXPro – OAE hearing screening

26 October 2016

Otoacoustic Emission (OAE) is a sound which is generated by outer hair cells inside the cochlea. Almost all humans with normal OAEs have normal hearing (except for patients with “auditory neuropathy” for whom OAEs are normal but ABR is abnormal). Strict correlation between correct hearing and OAE was used as a base for developing a simple, non-invasive test for hearing defects. By measuring OAE, hearing loss can be assessed. There are two classes of Otoacoustic Emissions: spontaneous and evoked. Only for evoked OAE correlation with hearing is high (observed in almost all humans with regular hearing), so only evoked can be used for clinical applications. There are two different methodologies for evoked OAE: transient-evoked OAEs (TEOAEs) – evoked using a click and distortion product OAEs (DPOAEs) – evoked using a pair of primary tones with particular intensity (usually either 65 – 55 dB or 65 for both).

Features:

Portable DPOAE and/or TEOAE hearing screening device dedicated for testing all ages and featuring a large color display and user friendly software.

Powered by DSP processor from Analog Devices
Real-time system
User interaction via GUI – large color display, enhanced operation and data viewing
Easy to navigate between OAE type and protocols
Generating stimulation and collecting response from ear
Fast, accurate results – as fast as 10 seconds per ear
Objective test – no patient response needed
Automatic Pass/Refer result provided – no interpretation required
Labels printer driver implementation
Variety of communication interfaces (USB, 1-wire, IrDA, RS232)

Example screens:

Application layer

Stimuli generation – building sound pattern and generating acoustic stimulation
Response processing – collecting, processing and analyzing response from an ear
Patient database – managing requests, patients and results data
User interface – utilizing GUI components to visualize test process, patient and test results, etc…
Labels printing – printing labels including patient data and test results

Operating System layer

RTOS Core – custom, real time operating system created for hearing assessment AuDXPro system
Memory management – memory allocation and data access management, support for program memory paging (overlays)
Power management – managing energy consumption and controlling charging battery process
File system – files management
GUI subsystem – library of PC style controls for embedded LCD (windows, edit boxes, list boxes, buttons, etc.)
Software update – managing firmware updates and configuration files
Data synchronization – receiving test requests (including patient info) from PC side and sending results back
System clock & calendar – system clock and calendar support

Drivers layer

USB Host, USB Device, RS232, IrDA, 1-Wire, I2C – bunch of drivers providing support for communication buses and interfaces allowing interactions with external devices
Flash, EEPROM – Flash and EEPROM external memory drivers
LCD – support for graphical LCD
Printer – driver providing support for wide range of thermal printers
AC97 Codec – hardware driver for A/D and D/A converter
Battery – battery management
Buttons – support for casing buttons