Electronic design comparison for obtaining the IPG at the wrist
Tutor / director / evaluatorCasas Piedrafita, Óscar
Document typeMaster thesis
Rights accessRestricted access - author's decision
In this project it has been analysed and compared the techniques of synchronous demodulation and synchronous sampling in order to demodulate the IPG signal acquired at the wrist. The study revealed that both methods performs the demodulation process correctly and allow visualizing the pulsating information which corresponds to the heart beats being the method of synchronous sampling the one which performs better. Furthermore it has been carried out a study about the localization, size and electrode number required in order to obtain a good IPG signal at the wrist. The study comes to the conclusion that the measurement has to be performed using 4 electrodes located at the inner part of the wrist with a size greater than 187 mm2. Finally, it has been developed a data acquisition system using the MCP3911 which is a low cost analogical to digital sigma delta converter (ΣΔ ADC) that is able to offer from 16 bits to 24 bits. This converter is controlled by the MSP430FG4618 which is a low cost and low consumption microcontroller. The result is a system able to acquire two data streams in parallel with a sampling frequency of 488 Hz if both channels are used or a sampling frequency of 976 Hz if just one channel is used. The data is sent to Labview which allows visualizing the streams of data and save them into a file ready to be processed by Matlab. This acquisition system can not only be used for acquiring IPG signals but signals of other typology.