Center for Wireless Integrated MicroSystems (WIMS)Center for Wireless Integrated MicroSystems (WIMS)

Code for Cochlear Implant with Low-Power ConstraintsLuis Calderón, Axel Claudio, Jomayra Marrero, Guillermo Martínez, Wilmarie Ríos, Debbie Ruperto, Feliut Guzmán, Esteban Valentín,

Abigail Fuentes, Michael OrtizUndergraduate Students

Nayda G. SantiagoFaculty Advisor

Electrical and Computer Engineering DepartmentUniversity of Puerto Rico, Mayagüez Campus

Introduction Description Site Addressing DemoDeafness is an issue that affects between 9 and 22 of every 1000 people in the United States. Cochlear implant technology has emerged as an alternative for non-hearing patients. As time goes on cochlear implant, technology has been improved. The Center for Wireless Integrated Microsystems (WIMS) is developing a neural prosthesis for the human cochlea since August 2005 with the collaboration of University of Puerto Rico at Mayagüez.

Given the current status of WIMS board, emulation into the 8051 allows the design, implementation and testing of software update codes and LabVIEW Interfaces. The two microcontroller’s are low power consuming, and have most of the peripherals needed to send and receive data.

A simple tone sequence is sent to the MCU from a LabVIEW interface. The amplitude and frequency of the sound is sent and the MCU uses such data to generate the Command Word, needed by the Hybrid Chip simulation

Future Work•Test Working Code in the WIMS Cochlear board

•Optimize Tested Code for Low power Consumption

Up to date, new algorithms are being implemented, more sophisticated and less power consuming circuits are being used to extend the life time of the battery. Software will run on hardware designed by WIMS, which is still under development. As an alternative to test and debug the logic of the software, an 8051 MCU is being used. WIMS board will be emulated using such microcontroller, thus it is required to take into account the hardware constraints on the real WIMS system.

The 8051 made by SiLabs has more memory that the WIMS MCU, enough to allow the emulation of some of the missing components that are part WIMS board. The main goal is to create working code that generates the desired output, depending for which demo is being implemented for. There are two demos for the Neural Prosthesis Testbed: Site Addressing Demo and DSP Demo.

in order to activate the electrode stimuli. This is implemented at the output of the MCU where another LabVIEW interface will represent the electrode stimuli in a LED Array Interface. The input is provided by a simulation of a Piano keyboard, it consists of the common keys and two buttons that play a predefine sequence of key strikes. The MCU must do the same error checking schemes used the WIMS board to prevent the data to be lost after being received and after sending it as output. All communication is done using a Data Acquisition boards. These that allow communication of LabVIEW interfaces with the outside world.

Integrated System

For the final system, two LabVIEW interfaces are to be implemented in such a way a communication between two computers is done. One is responsible to send input (depending on the type of demo) and the one that is going to receive the output, by means of the microprocessor. WIMS board receives data from Telemetry chip. The former ensures the data is received correctly, and sends it to the MCU. Processing is done, and the output is received by the end interface. A last inspection is done to confirm information is sent as effectively. In 8051 MCU, the telemetry module will be software implemented, and bidirectional communication between the PC and the MCU will be used to ensure a good data transfer. Moreover, it is used at the output of the MCU to display the correct output.

DSP DemoWIMS microcontroller has an internal custom made DSP, designed by Eric Marsman, Ph. D. The Continuous Interleaved Sampling Algorithm is hard coded in such. DSP requires to be initialized before starting to process the data received from the ADC.

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.

Once initialized, the MCU goes to sleep mode until another process wakes it up. The purpose of the 8051 emulation is to understand its behavior and to test the LabVIEW interfaces that communicates with it.

LabVIEW Interface(Tone Demo, DSP Demo)

LED ArrayInterface

UART SPI

8051 MCU

TelemetryModule

Command Word

Generator or DSP Module