Beamforming in acoustic tomography
Beamforming is a signal processing technique used with arrays of transmitters or receivers that control the directionality of a radiation pattern. When receiving a signal, the so called receive beamforming can increase the receiver sensitivity in the direction of wanted signals and decrease the sensitivity in the direction of interference and noise. When transmitting a signal, the so called transmit beamforming can increase the power along the chosen direction. Therefore, using beamforming we can enhance the signal in a particular direction and suppress noise and reﬂections coming from other directions.
Our patented beamforming method uses transmit and receive beamforming optimized by taking into account transducers’ characteristics. The method shows to be very efficient in inhomogeneous and absorbing media and it reduces many ultrasounds artifacts. We were the first ones to propose a beamforming technique in an acoustic tomogrpahy setup.
In the images below, we see a coronal slice of a breast the is scanned by an ultrasound tomography scanner. On the left image, the effect of a strong surface wave that is traveling on the surface of the breast is present (black region on the breast boundary). On the right image, we see that the effect of the surface wave disappeared. Moreover, the latter has as a positive consequence on the whole reconstruction, and not only in the region where the strong surface wave is present.