2. Wireless Integrated Microsystems Cochlear Team

3. Team Members Feliut Guzman Wilmarie Rios Luis Calderon Guillermo Martinez Michael Ortiz Esteban Valentin Abigail Fuentes Debbie Ruperto Axel Claudio

4. Outline Introduction Cochlear Implants WIMS Cochlear Implant UPRM Work Demos Final Results Acknowledgements Questions

5. Introduction WIMS - Wireless Integrated MicroSystems – Engineering Research Center National Science Foundation (NSF) Core Institutions University of Michigan, Ann Arbor – leading institution Michigan State University Michigan Technological University Collaborating Institutions University of Puerto Rico, Mayagüez Campus Praire View University Tulane University Howard University University of Utah

6. Introduction Merge – Micropower circuits – Wireless interfaces – Biomedical and environmental sensors and subsystems Create microsystems with persuasive impact on society for next two decades – WIMS Cochlear Implant

7. Introduction The Human Ear – Outer ear – Middle ear – Inner ear Cochlea

8. Cochlear Implants Medical devices that bypass damaged structures in the inner ear Stimulate directly auditory nerve to allow deaf individuals to learn to hear and interpret sounds and speech For patients who have an injury at the cilium level in the cochlea

9. Cochlear Implants Electrodes formed from a bundle of wires – Fed into the snail-shaped cochlea of the inner ear Different auditory nerve fibers are stimulated at different places in the cochlea Different electrodes are stimulated depending on the frequency of the signal

10. WIMS Cochlear Implant WIMS – Development of cochlear implant based on thin-film electrodes Direct stimulation of the auditory nerve Cochlear Implant design – Allow a simpler insertion for surgeons – Minimize damage to healthy ear tissue Current implants – Anywhere from 16 to 22 stimulating sites along its length WIMS implant – Expected host up to 128 stimulating sites

11. UPRM Work University of Puerto Rico at Mayagüez – Development of software for the microcontroller developed by WIMS WIMS Board is under development Testing Methods – Demos Tone Demo DSP Demo

12. UPRM Work WIMS Board is still under development. Code needs to be tested. We will demonstrate the functionality of the implant using two demonstrations – Tone Demo Demonstrate input and output of the system – DSP Demo Demonstrate processing in the system

13. Demos: Tone Demo Array Transmitter Array Electronics 16-bits (ampl & address) Microcontroller 8-bits (ampl & freq) Telemetry ChipProcessor RF Goal – Show site addressing and current amplitude by driving the appropriate LEDs represented on a graphical interface

14. Demos: Tone Demo WIMS board emulated in SiLabs 8051 board – Modules Telemetry Chip Tone Demo C Code LabVIEW Intefaces – Piano Demo – LED Array Hybrid Chip Simulation

15. Demos: Tone Demo LabVIEW Interface I – Piano Demo Sends Amplitude and Frequency – Command Words – Sound generation Individual Keys Close Encounter Buttons LED Array Output Control

16. Demos: Tone Demo LabVIEW Interface: Led Array Get Processed Data Simulate Hybrid Chip Shows a representation of the electrode stimuli Display biphasic signal

17. Demos: DSP Demo DSP – Specialized microprocessor designed for Signal processing algorithms Reduced power consumption and space requirements of the system WIMS DSP – Fully integrated, low power DSP core – Performs Continuous Interleaved Sampling (CIS algorithm)

18. Demos: DSP Demo Functionality – The WIMS DSP receives data from the chip’s analog to digital converter – Signal is compressed reducing it’s dynamic range – Sends the processed signal to the hybrid chip – Stimulates Electrodes. – By stimulating one electrode at the time Allows better speech spectrum and speech understanding

19. Demos: DSP Demo CIS Algorithm Block Diagram Implemented in hardware in the DSP of the WIMS Microcontroller

20. Demos: DSP Demo Equations used for the sound filtering.

21. Demos: DSP Demo Goal – Implementation of an emulator for digital signal processor of the WIMS microcontroller System Behavior – Signals from LabVIEW interface sent throught ADC – Data Processed by emulator – Processed Data is sent to LED Array interface

22. DSP must be initialized ADC receives analog input. 16-bit command word generated. Command word sent to Hybrid Chip Lab VIEW interface to simulate electrode stimulation. Demos: DSP Demo

23. Process – Receive data from the ADC – Filters this signal – Process using the CIS algorithm – Send a calculated signal containing the amplitude and channel thru the SPI – Signal goes to the Hybrid Chip Creation of stimuli for the electrodes inside the cochlea

24. LabVIEW Interface I: DSP Demo Description – The interface named values.vi is used to send the coefficients values to the MCU. Coefficients – values that are used to initialize the DSP.

25. LabVIEW Interface I: DSP Demo Tasks – Send coefficients values to MCU’s USART through the Data Acquisition Board. Data to be sent in the same format used in the WIMS Telemetry Chip. – Synchronize the interface with the microcontroller's USART Guarantee data is being transmitted and received correctly. – Test interface functionality

26. WDEMO INTERFACE – Open – Preview – Convert – Analyze – Graph LabVIEW Interface II: DSP Demo

27. Works in conjunction with Matlab Out.wav File Datastream.txt File If Analyzed the data is displayed. Data can also be plotted on the interface. Goal – Work with DAQ and ADC – Communicate with MCU

28. Final Results Bidirectional Communication – PC generates data – MCU process the data – PC displays output Data Recovery Among Interfaces

29. Acknowledgements Nayda Santiago, Ph. D. David Ortiz, M.S. Student UPRM Jamie Hetke, System Integrator Eric Marsman, Ph.D. Student UMich Amir Sodagar, Ph. D. Ken Wise, Ph. D.

30. References Craig Steinger-Online 8051/8052 Microcontroller Tutorial: Architecture, Assembly Language, and Hardware Interfacing Eric D. Marsman, A DSP Architecture for Cochlear Implants; 8051 Data sheets

31. Questions