Presenter: Artur M. KUCZAPSKI Automation and Applied Informatics Real-time Interfacing for Fault Detection and Auralization with MED-EL Cochlear Implant Processors Artur M. KUCZAPSKI, Gheorghe-Daniel ANDREESCU SACI 2016 Presenter: Artur M. KUCZAPSKI

Content Cochlear Implants Challenges Project Scope The I100 Detector Box Real-time signal capturing with Arduino DUE CI Signal Processing Software Real-time Auralization Conclusions

Microphone, Battery pack and Speech processor Cochlear Implants External Transmitter Receiver / Stimulator Cochlea Microphone, Battery pack and Speech processor Electrode array

Cochlear Implants Sound is divided in frequency bands (channel) One electrode per channel Electric impulses are modulated according to the envelope of each channel

Challenges First year after implantation is critical Complex fitting procedure Patients are mostly toddlers (1-3 years) Reduced communication Absolutely no feedback on hearing quality Hardware defects frequently not discovered in time Microphone characteristics Audio Signal processing chain Stimulation signals Lack of feedback during fittings No real perception how the sound quality changes upon fitting

Project Scope Create data acquisition platform for further research and developments Develop application to test CI Processor Integrity Proof of concept for real-time auralization

The I100 Detector Box Generate electrical stimulation pulses based on the information received from the CI external processor Simulate a cochlear implant during telemetry Testing and fault detection of external components of a MED-EL Cochlear Implant system Available to anyone

Real-time signal capturing with Arduino DUE Requirements 12 analog Channels (±10V) 10 - 20 µs impulses 100K Samples / Second / Channel 2.4 MB/Sec transfer to PC (16 bits / sample)

Real-time signal capturing with Arduino DUE 12 Analog I/O ports (0 – 3.3V / 12 bit) 1M Samples / Second (multiplexed) 83K Samples / Second / Channel Native USB Port up to 1.5MB/Sec Voltage adaptor Shield Using only resistors and capacitors 1:10 division / + 1.65 V shift 10K input impedance (similar to cochlea)

Real-time signal capturing with Arduino DUE

Real-time signal capturing with Arduino DUE Single Channel Recordings

Real-time signal capturing with Arduino DUE 12 Channel Recordings

CI Signal Processing Software Real-time display of recorded impulses Load fitting parameters from Med-El Maestro System data base User interface to manually adjust fitting parameters Converts fitting parameters into voltages Converts recorded stimulation intensities into perceived sound intensities Displays sound intensities for each channel

CI Signal Processing Software

Real-time Auralization Uses the recorded stimulation impulses Continuously computes the envelope of each channel maximum pulse amplitude of the last 5 ms Maps channel envelopes to sound levels using fitting data Modulated sine wave is generated for each channel The mix of the sine waves is replayed

Real-time Auralization

Real-time Auralization

Conclusions Real-time data acquisition platform: Software application: Records stimulation impulses generated by CI processors Easily accessible for researchers Important support for further projects Software application: Display stimulation impulses Map impulse amplitudes to sound levels using fitting data Used for CI Processor integrity checks Provides simple real-time auralization.