Continuous Wave Dental Doppler Ultrasound System for Measuring Pulp Blood Flow

In this paper, we present a continuous wave dental Doppler ultrasound system (DDUS), in which 22-MHz ultrasonic probes are utilized. It is an optimized efficacy in terms of monitoring a slow pulp blood flow (PBF) in point of dental diagnostic applications. The proposed DDUS consists of a dual elements transducer, a two-channel (one for transmission and the other for reception) probe system, and a laptop. The probe system performs analog front-end processing that performs ultrasonic transmission and reception, low noise amplification (LNA), quadrature demodulation (QDM), low pass filtering (LPF), and analog-to-digital conversion (ADC). The laptop, on the other hand, performs mid/back-end processing such as decimation, log compression, clutter filtering/noise reduction, and data analysis represented by spectrum/spectrogram. To increase the signal-to-noise ratio (SNR), the clutter filtering/noise reduction is implemented by Hankel singular value decomposition (SVD). The results are displayed as Doppler spectrum and spectrogram and are provided in real-time via the developed DDUS customized graphical user interface (GUI).