Currently, there are 2 ultrasound systems housed in our Ultrasound Imaging Laboratory • System A has 32 channels. It use
Posted: Sun May 15, 2022 8:10 pm
Currently, there are 2 ultrasound systems housed in our Ultrasound Imaging Laboratory • System A has 32 channels. It uses a linear array that operates at a central frequency of 5 MHz and has a 50% fractional bandwidth. The size of the array is 4 cm and the total number of elements is 128 (each element width is 0.12 mm). System B has 64 channels. It uses a linear array that operates at a central frequency of 14 MHz and has a 80% fractional bandwidth. The size of the array is 4 cm and the total number of elements is 256 (each element width is 0.12 mm). Note: For calculation of the wavelength, please use c = 1540 m/s.
a) (6 points) Compare the performance of these 2 systems in terms of axial resolution and optimal lateral resolution at a typical imaging depth of 4 cm.
b) (6 points) Sketch the far field polar power density pattern for System B (please assume that you are using the maximum allowable number of elements given the hardware constraints).
c) (4 points) List 2 potential advantages of System A with respect to System B and 2 potential advantages of System B with respect to System A. Please, clearly justify your answers.
d) (6 points) Consider the radiation pattern of System B. Qualitatively describe how the pattern would change if each of the following modification was made independently in the array (all other parameters stay as specified): i) the wavelength was decreased. ii) the spacing between elements was decreased. iii) the total number of elements was decreased.
a) (6 points) Compare the performance of these 2 systems in terms of axial resolution and optimal lateral resolution at a typical imaging depth of 4 cm.
b) (6 points) Sketch the far field polar power density pattern for System B (please assume that you are using the maximum allowable number of elements given the hardware constraints).
c) (4 points) List 2 potential advantages of System A with respect to System B and 2 potential advantages of System B with respect to System A. Please, clearly justify your answers.
d) (6 points) Consider the radiation pattern of System B. Qualitatively describe how the pattern would change if each of the following modification was made independently in the array (all other parameters stay as specified): i) the wavelength was decreased. ii) the spacing between elements was decreased. iii) the total number of elements was decreased.