Quantitative ultrasound system for the characterization of animal blood plasma

Abstract

This paper presents the implementation of a quantitative system of assessment by ultrasound, which allows the acoustic characterization of animal blood plasma, with potential applications in hematic biometric techniques. The system comprises a unidimensional electronic controller with step size 1 mm which enables the acoustic inspection of blood samples using an ultrasonic field incident with central frequency of 5MHz in pulse echo mode. Additionally, the implemented system incorporates the development of computer algorithms in Matlab allowing digital signal processing of ultrasonic backscattered signals, based on the estimation of acoustic parameters such as speed of sound and spectral energy loss, using the logarithmic power spectral density subtraction in the bandwidth of the transducer (1MHz @ -3dB). Estimating acoustic parameters from blood samples centrifuged to 3398 rpm were correlated with density values, pH and concentration of platelets. The results showed that samples with densities between 1.040 g/ml-1.051 g/ml and variations of platelet concentrations between 45×103/mm3-138×103/mm3, showed variations in sound velocity between 1335 m/s-1572 m/s. Moreover, measurements showed a sound attenuation subtle difference variations between 0.21dB/cm to 2.73 dB/cm. Finally quantitative ultrasound system shows that the estimate of velocity profiles acoustic propagation enables infer variations of platelet concentration at room temperature with potential applications in the quality assessment of blood plasma.