Hirotaka Baba

Deformable regions of interest with multiple points for tissue tracking in echocardiography

&NA; By tracking echocardiography images more accurately and stably, we can better assess myocardial functions. In this paper, we propose a new tracking method with deformable Regions of Interest (ROIs) aiming at rational pattern matching. For this purpose we defined multiple tracking points for an ROI and regarded these points as nodes in the Meshfree Method to interpolate displacement fields. To avoid unreasonable distortion of the ROI caused by noise and perturbation in echo images, we introduced a stabilization technique based on a nonlinear strain energy function. Examples showed that the combination of our new tracking method and stabilization technique provides competitive and stable tracking. HighlightsA optical flow‐based method with deformable Regions Of Interests (ROIs) is proposed.We use the Meshfree Method to interpolate the displacement fields in ROIs.We propose a nonlinear strain energy‐based stabilization technique. Graphical abstract Figure. No caption available.

Clinical evaluation of real-time phase-aberration correction system [medical ultrasound]

We have developed a phase-aberration correction system that correlates signals in real time. In this paper we evaluate the clinical performance of the system in vivo. This system 1) constructs a cross-sectional image and, 2) calculates the correlation of signals at neighboring sensor elements. Both 1) and 2) are carried out in real time. The system was used for imaging of living tissue. First the beam was formed using initial focus delay settings and a real-time cross-sectional image was constructed. The correlation between neighboring signals was calculated simultaneously with the beam formation and the time difference between the pairs of signals was acquired. The time difference was then used to compensate for the initial delay. The image of the living tissue was substantially improved after the compensation. A further experiment is in progress to collect a statistically significant number of clinical results.