Transverse oscillation vector velocity estimation using a phased array transducer

The Transverse Oscillation method has shown its commercial feasibility, providing the user with 2D velocity information. Todays implementation on commercial ultrasound platforms only support linear array transducers and are limited in depth. Extending the implementation to a phased array transducer, vector velocity echocardiography will become possible. This paper describes the general modification made on the BK Medical 2202 Pro Focus UltraView using a 64 element phased array transducer and the simulations and measurements performed. The results show that velocities can be obtained at depths even greater than 100 mm. Tests at depths of 72 mm and 82 mm with a peak velocity of 0.5 m/s, showed a relative mean bias B̃_vx that varied from 0% and to 21% and a relative mean standard deviation σ̃_vx that varied from 18% and to 51%. The investigation showed an increasing bias with respect to depth, which leaves room for optimization. Despite the bias, the method has shown to work and produce reliable results, and 2D velocity estimates are provided within the entire color-box down to a depth of more than 100 mm making vector velocity imaging possible in the entire heart.