Investigation of MEMS as accelerometer sensor in an Implantable Centrifugal Blood Pump prototype

Abstract

Microelectromechanical systems (MEMS) accelerometers have applications in many fields based on the measurement of Cartesian components of the gravitational acceleration vector. Miniaturized MEMS have low power consumption and adequate response to dynamic acceleration. In order to detect thrombus inside blood pumps, an experimental setup was assembled with the MEMS accelerometer sensor (ADXL335, Analog Devices, Norwood). This detector should contribute to a recent study of fault diagnosis in an Implantable Centrifugal Blood Pump (ICBP) using vibrational analysis for detection of thrombus adhered in the pump’s rotor. This work proposes to verify the performance of the experimental data acquisition system developed with the MEMS accelerometer sensor in the vibrational analysis of ICBP. For this, a comparison between the vibrational spectra obtained by the MEMS acquisition system and the commercial type Vaibro® Vibrational Analyzer and Field Balancer (Rozh—VaibroSmart CH1 model) is made. Tests were carried out with different pump speeds in a mock loop, at this stage, without thrombus simulation. The vibrational spectra were plotted on graphs for analysis of their harmonic components, based on the fast Fourier transform. The spectral features for each speed of the pump rotor are compared and discussed. The experiment shows that the MEMS accelerometer sensor has better efficiency in detecting harmonics in the range from $$\approx $$ 50 to $$\approx $$ 150 Hz, at speeds greater than 1200 rpm, suggesting that MEMS can detect thrombi in ICBP.