Wireless Integrated Microsystems Cochlear Team

Team Members

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

Outline

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

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

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

Introduction

The Human Ear– Outer ear– Middle ear– Inner ear

Cochlea

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

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

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

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

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

Demos: Tone Demo

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Goal– Show site addressing and current amplitude by

driving the appropriate LEDs represented on a graphical interface

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

Demos: Tone DemoLabVIEW Interface I – Piano Demo

Sends Amplitude and Frequency– Command Words– Sound generation

Individual KeysClose Encounter

Buttons LED Array Output

Control

Demos: Tone DemoLabVIEW Interface: Led Array

Get Processed Data

Simulate Hybrid Chip

Shows a representation of the electrode stimuli

Display biphasic signal

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)

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

Demos: DSP Demo

• CIS Algorithm Block Diagram

• Implemented in hardware in the DSP

of the WIMS Microcontroller

Demos: DSP Demo

Equations used for the sound filtering.

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

•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

Demos: DSP Demo

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

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.

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

WDEMO

INTERFACE– Open– Preview– Convert– Analyze– Graph

LabVIEW Interface II: DSP Demo

LabVIEW Interface II: DSP Demo

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

Final Results

Bidirectional Communication– PC generates data– MCU process the data– PC displays output

Data Recovery Among Interfaces

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.

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

Questions