Ultra-high Frame Rate or Ultrafast Imaging/Acquisition
The ultrafast (very high frame rate) imaging capability offered by the Vantage platform has enabled many major innovations in biomedical ultrasound research.A key advantage of ultrafast ultrasound imaging is the ability to provide effective temporal sampling of real-time dynamic processes, allowing fast motion tracking and analysis of dynamic systems, not possible using conventional imaging technologies.
Conventionally, phased array imaging in NDT examines static objects. Additional information useful for inspections may be gained from observing the dynamics of features inside. For example, analysis of the hysteresis, conditioning and slow dynamics of contact interfaces has led to the understanding of non-classical dynamic elastic nonlinearity. Leveraging the ultrafast imaging capability of Vantage systems, a recent joint research by Verasonics and Tohoku University aims to push the phased array technology towards that direction.
Presented in [3,4] is an example of ultrafast ultrasound imaging applied in NDT for closed crack characterization. Very high frame rate images were acquired to capture the fast dynamic of a fatigue crack in response to a 7 kHz pump wave. The figures below show two selected frames, where image intensity varies around the tip of the crack, considered due to the periodical fatigue crack opening and closing at 7 kHz. Looking at the intensity variation over time, hysteresis and slow dynamics are likely observed around the crack tip during and immediately after the external pump. Research is on-going to extract the phase information from the dynamic. Statistical analysis will be applied (to the highly temporal- and spatial- resolved ultrafast data) to gain new information.
It is expected that ultrafast imaging/acquisition will benefit other applications, where high-speed production line inspections, fast 3D imaging and weak signal detection, etc., are required.