Clinical blood flow measurements using diffraction-grating transducers

Changing the phase or frequency of the signal driving a diffraction-grating transducer produces beams at known, multiple angles; these multiple angle beams can be used to make angle-independent Doppler measurements. This paper addresses three questions in developing a diffraction-grating instrument for measuring blood flow: how efficient and broadband can these transducers be, how close can such transducers be placed to blood vessels, and can the Doppler spectrum shape be used to determine the velocity profile.