Desenvolvimento de um sistema de aquisição de sinais vibratórios das pregas vocais

Abstract

The propose of this study is to develop a signal acquisition system to be used in a low cost vocal dosimeter prototype. This clinical tool enables the monitoring and recording of vocal fold vibratory signals data in a noninvasive way. The dosimeter can be divided into three systems: acquisition, storage and signal processing. The acquisition system, the focus of this project, uses an accelerometer that is fixed to the skin of the neck, below the larynx, to measure the vibration of the vocal folds and a microcontroller to control the process through the communication protocol. The development of this system was performed by testing and comparing the components available for the operation. In the first tests, the microcontroller ATmega 328 (Arduino nano) and the accelerometer ADXL345, with the communications protocols I2C and SPI were used. Despite the efficiency of SPI over I2C, arduino did not allow it to reach the maximum output rate allowed by the sensor. The test using the PIC18F4550 and ADXL345 in SPI, as well as how to enable a signal quality analysis, which is also collected at maximum rate, in order to compare the microcontrollers as well as their processing capacities. Finally, the PIC18F4550 would be used with the KX122-1037 sensor also in SPI, which will be a more promising combination due to the processing capacity and performance of the accelerometer.