3D Localization of Scatterers with a Spiral-Shaped Acoustic Lens

Traditionally, single element transducers are used for localizing objects in 1D through A-mode scans, where only the echo envelope is used. Due to the transducer surface symmetry, A-mode scans performed for azimuthally or elevationally translated scatterers will produce the same 1D information, radial distance. The current study extends the previous work to investigate scatterer localization in 3D by breaking this surface symmetry with the attachment of a new acoustic lens to a single element transducer. In this work, an acoustic lens was 3D printed with a spiral-shaped pattern to partially block the ultrasound waves. When the ultrasound waves are blocked in an anisotropic manner, the symmetry of the transducer is broken. Therefore, the acoustic lens acts as a spatial filter and encodes the received echoes unambiguously, where it is possible to decode the received signals and extract directional information. With this technology, a single sensor can acquire multi-dimensional information with a single measurement.