Design and Experimental Validation of Miniature External Mechanical Vibrators Towards Clinical Ultrasound Shear Wave Elastography

Shear wave generation using external mechanical vibration (EMV)is promising for enabling shear wave elastography (SWE)imaging on low-cost platforms. In this paper, we present the design and experimental validation of miniature external mechanical vibrators with ergonomic form factor suitable for routine clinical practice: 5 % of their predecessor. The newly designed miniature actuator is able to magnetically attach to ultrasound probes and vibrate at 50 Hz with 2 mm peak-to-peak amplitude. Effective shear wave propagation with varying patterns was induced in elasticity phantoms using miniature shear wave actuators in three different configurations: one actuator in plane; two actuators in plane and two actuators cross plane. A commercial acoustic radiation force impulse (ARFI)based shear wave elastography technique was also used on elasticity phantoms as benchmark. Reconstructed stiffness values from EMV in all configurations were in agreement with the ARFI-based approach at 50 Hz shear wave propagation.