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 N
L
×N
E
-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 N
L
elevational parallel beamformers each with (N
E
/2)-channel and the output of which is fed to a (N
L
/2)-channel lateral beamformer. We tested and compared the proposed and existing array designs through numerical PSF simulations.