Mónica Vázquez

Pulse generator for ultrasonic PZT and PVDF transducer arrays based on a Programmable System-on-Chip (PSoC)

This paper describes the design of a pulse generator to excite PZT and PVDF ultrasonic transducer arrays, based on the Programmable System-on-Chip (PSoC) module. In this module, using programmable logic different pulses were implemented, these pulses are required in ultrasonic applications, for multiple channels to excite PZT and PVDF transducer arrays. This module can operate with programmable frequencies from 3-74 MHz; its programming may be versatile covering a wide range of ultrasonic applications. It is ideal for low-power ultrasonic applications.

Simulation of a PVDF transducer array using the finite element method (FEM) to measure temperature gradients in a soft tissue

The objective of this work is to use the Finite Element Method (FEM) to simulate the performance of a PVDF transducer array to measure temperature gradients through the determination of phase shifts, i.e. time shifts of the waveform of the echo due to a change in the speed of propagation of ultrasound as a result of a change in temperature, they can be interpreted as phase shifts in the frequency domain. Making it possible to determine the change in temperature from the phase shifts; in a medium of propagation previously characterized.

Computation of systolic / diastolic flow indices for coronary bypass surgery

This paper describes a method to calculate the systolic/diastolic indices of the blood flow that pass through an artery or vein under test. The method analyzes the Doppler and the ECG signals, associating and synchronising them in order to calculate the indices. The maximum of the R and T waves, are calculated using a continuous wavelet transform. Simultaneously, the pseudo-instantaneous mean frequency is calculated from the Doppler blood flow signal. A projection of the R and T wave mark over the pseudo-instantaneous Doppler mean frequency curve is used for computing the indices. The paper shows preliminary results from real signals obtained from a carotid artery, an humeral artery and an aortic artery, demonstrating the effectiveness of the method. Further results will be obtained through a formal experimental protocol during coronary bypass surgery.