- #1
enc08
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Hi,
Please refer to the attached image.
T1 and T2 are ultrasound transducers. The focal point of the transducers is 2cm into the liver tissue.
Q) A pulse is emitted from both transducers at the same time. Calculate the difference in arrival time at the focal point.
I seem to be getting the wrong answer. This is what I'm doing:
The arrival time from T2 is: [tex]t_{T2} = 1cm/1450 + 2cm/1540 = 19.9us[/tex]
From this we can calculate an equivalent average speed across both tissue:
[tex]c_{equiv} = 3cm/19.9us = 1508.8m/s[/tex]
Using this we'll calculate the arrival time for T1
[tex]t_{T1} = \sqrt{(9.6mm)^2 + (3cm)^2}/c_{equiv} = 20.9us[/tex]
Thus the difference in arrival time is [tex]1us[/tex]
However the answer sheet indicates [tex]0.4us[/tex]
Thanks for your input.
Please refer to the attached image.
T1 and T2 are ultrasound transducers. The focal point of the transducers is 2cm into the liver tissue.
Q) A pulse is emitted from both transducers at the same time. Calculate the difference in arrival time at the focal point.
I seem to be getting the wrong answer. This is what I'm doing:
The arrival time from T2 is: [tex]t_{T2} = 1cm/1450 + 2cm/1540 = 19.9us[/tex]
From this we can calculate an equivalent average speed across both tissue:
[tex]c_{equiv} = 3cm/19.9us = 1508.8m/s[/tex]
Using this we'll calculate the arrival time for T1
[tex]t_{T1} = \sqrt{(9.6mm)^2 + (3cm)^2}/c_{equiv} = 20.9us[/tex]
Thus the difference in arrival time is [tex]1us[/tex]
However the answer sheet indicates [tex]0.4us[/tex]
Thanks for your input.