Provided herein is a method for use in medical applications that permits (1) affordable three-dimensional imaging of
blood flow using a low-profile easily-attached
transducer pad, (2) real-time blood-flow vector velocity, and (3) long-term unattended Doppler-
ultrasound monitoring in
spite of motion of the patient or pad. The pad and associated processor collects and Doppler processes
ultrasound blood velocity data in a three dimensional region through the use of a planar
phased array of piezoelectric elements. The invention locks onto and tracks the points in three-dimensional space that produce the locally maximum
blood velocity signals. The integrated coordinates of points acquired by the accurate tracking process is used to form a three-dimensional map of blood vessels and provide a display that can be used to select multiple points of interest for expanded data collection and for long term continuous and unattended
blood flow monitoring. The three dimensional map allows for the calculation of vector velocity from measured radial Doppler.A
thinned array (greater than half-
wavelength element spacing of the
transducer array) is used to make a device of the present invention inexpensive and allow the pad to have a low profile (fewer connecting cables for a given spatial resolution). The full aperture is used for transmit and receive so that there is no loss of sensitivity (
signal-to-
noise ratio) or
dynamic range. Utilizing more elements (extending the physical array) without increasing the number of active elements increases the angular
field of view. A further increase is obtained by utilizing a convex non-planar surface.