A Color Doppler Processing Engine with an Adaptive Clutter Filter for Portable Ultrasound Imaging Devices

This paper presents an optimized color Doppler processing engine for portable ultrasound devices. The imaging performance is improved by the proposed adaptive clutter filter that separates the clutter from the blood signal in the frequency-eigenvalue space. The adaptive clutter filter provides high attenuation on clutter and also reserves the low-velocity blood flow. Compared to the conventional eigenvalue-based and frequency-based clutter filters, this work achieves 2.5-to-17.5dB and 1-to-12.5dB improvements, respectively, in blood-to-clutter ratio (BCR) based on an in vivo dataset with 16 images. The blood-tissue discriminator is re-arranged and integrated with the clutter filter to further enhance the imaging performance with less computational complexity. The computational complexity is reduced by 48-78% by leveraging the reduced processed area. Randomized spatial down-sampling is adopted to further reduce the processing time. An overall reduction of 60% in processing time is achieved. This work provides a promising solution to color Doppler imaging for portable ultrasound devices.