Mobile ultrafast ultrasound imaging system based on smartphone and tablet devices

Abstract

Mobile and cost effective ultrasound devices are used in point of care scenarios or the drama room. To reduce the costs of such devices we already presented the possibilities of consumer devices like the Apple iPad for full signal processing of raw data for ultrasound image generation. Emerging technologies like ultrafast ultrasound imaging result in new algorithms for example for shearwave elastography or vector velocity imaging but also enable the creation of a full image with only one excitation/reception event based on plane wave imaging. This way acquisition times and power consumption of ultrasound imaging can be reduced for low power mobile devices based on consumer electronics realizing the transition from FPGA or ASIC based beamforming into more flexible software beamforming. This is usually performed on a GPU utilizing massive parallel processing (like CUDA or OpenCL) but with the development of modern processors (A7, A8 and A8X) for its smartphones and tablets Apple introduced parallel GPU hardware and the framework “Metal” for advanced graphics and general purpose GPU processing for the iOS platform. We use it for medical signal reconstruction in the mobile plane wave beamforming and imaging on ultrasound channel data sets measured with our research systems “DiPhAS” in ultrafast imaging mode. We were able to integrate the beamforming reconstruction into our mobile ultrasound processing application on the iOS platform. The next step into realizing a mobile, fully software based ultrasound system was made. The beamforming can be performed at up to 62 Hz at reasonable image quality on iPad Air 2 hardware providing real time imaging including the post-processing of beamformed data into images (envelope detection and scan conversion).