Consultancy work at Stanford India Biodesign

Sohum: Auditory Brainstem Response (ABR) based newborn hearing loss screening device for resource constrained settings

Stanford India Biodesign (AIIMS), with Nitin Sisodia and Pragun Goyal

Supported by the Department of Biotechnology, Government of India and Siemens Information Systems Ltd.

The Need

Every year around 100,000 babies are born with a hearing impairment in India alone. Rehabilitation and treatment should start within 3 months of birth to ensure that these children develop normal communication skills. Cost of screening devices, tendency to reuse single-use electrodes/probes, the skill required to administer a hearing screening test and long test times severely restrict the extent to which hearing-loss screening programs can be scaled in developing countries. As a result almost all cases of congenital hearing loss go undetected till the age of 2-3 years.

Our Approach

We are developing a ABR based hearing screening device that would empower semi-skilled health-care workers to perform hear-loss screening examinations in  noisy and harsh environments of vaccination camps.

We are incorporating several signal-processing based methods to significantly reduce the test duration and its immunity to noisy environment and smart industrial design to reduce maintenance costs, so that hearing screening programs can be operated on a scale similar to Polio, DPT vaccination programs.

Over the last 8 months (May’11 -Dec’11), we have developed several prototype of the ABR based hearing screening device that have successfully recorded ABR in adults. Our third prototype (current) is a fully stand-alone system suited for initial testing. We have been approved to conduct tests on humans for a clinical study at the All India Institute of Medical Sciences (AIIMS).

The current Prototype consists of

• Fully differential high CMRR (>100 dB) Analog front-end with instrumentation amplifiers, filters and analog gain stage.
• High Dynamic range ADC unit with programmable gain.
• A TI DSP for signal acquisition, signal preprocessing and detection algorithm implementation.

My Work

• Development of artifact rejection and signal pre-processing (SNR improvement) algorithm to prepare signal for detection.
• Development of ABR detection algorithm for hearing screening which is not affected by environmental and EMG noise level.
• Development of vanilla DSP firmware (C55x) to support standalone functionality with stimulus generation (audio), data collection (through ADC), data pre-processing (algorithm above) and data storage (flash).
• Study and analysis of various ways in which audiologist detect presence or absence of ABR to further improve the performance of detection algorithm above,
• End product development strategy for reducing overall design and engineering cost as well as end product cost by re-using existing mass market hardware and software blocks.

Patents Portfolio:

A System and apparatus for Auditory Evoked Potential (AEP) data acquisition for hearing screening
Indian provisional patent filed from Stanford India Biodesign (Nov, 2011).

Presentations
India MedTech Summit 2011
Sohum made its first public appearance and was highly appreciated at the 2011 MedTech Summit organized in collaboration with NIH in New Delhi on December 5, 2011.

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