Solid-state SL-IVUS arrays based on non-uniform aperture sampling

We propose new reconfigurable ring and cylindrical array designs using non-uniform (Fresnel) aperture sampling with identical differential delays between adjacent elements which reduces the beamformer complexity. For side-looking intravascular ultrasound (SL-IVUS), the image plane is scanned through stepping the active subarray which is reformed in each step. A ring array with such sampling leads to a simplified phased array beamformer with N/2 identical differential delays. The same logic applies to a two-dimensional (2-D) array with NL×NE-elements over a cylindrical patch. The 2-D beamformer becomes separable along the elevation and the lateral dimensions and possesses the delay symmetry in both dimensions. Consequently, the overall phased array beamforming can be realized by using NL elevational parallel beamformers each with (NE/2)-channel and the output of which is fed to a (NL/2)-channel lateral beamformer. We tested and compared the proposed and existing array designs through numerical PSF simulations.