Miniaturization of external mechanical vibration for shear wave elastography imaging

Ultrasound shear wave elastography is increasingly used as a non-invasive and quantitative tissue elasticity characterization method. External mechanical vibration (EMV) is an alternative to acoustic radiation force (ARF) for shear wave generation, due to its potential for inducing larger local displacements using lower power. The physical space and mass required for incorporating mechanical vibration sources makes it challenging to integrate EMV into commercial ultrasound systems in a compact and ergonomic manner. In this paper we present the design of a miniature EMV-equipped ultrasound probe that is suitable for clinical tests. Custom vibration motors were designed and tested towards optimizing the 'volume-toshear-wave-amplitude' ratio. Then the mechanical design and integration of vibration motors into commercial ultrasound probes is introduced, where the spatial placement and housing of the motors is designed to improve the ergonomics of the device and the performance of the motors.