What is Time-of-flight?

• Total time someone is sitting on an airplane.

• Time needed for a pulse to travel to the transducer.

• Time needed for a pulse to travel to the reflector.

• Time needed for a pulse to travel to and from the transducer AND the reflector.

What is the AKA for Time-of-flight?

• Go-Return Time

• Distance Traveled

• Time Travel

• Time-Distance Traveled

When Time-of-flight is known, we can determine the distance.

• False

• True

What is Time-of-flight directly related to?

• Nothing

• How deep a continuous wave is.

• How long a roundtrip in an airplane is.

• How deep a sound pulse travels.

What is Time-of-flight affected by?

• How fast the wind is.

• If the pulse is traveling deep.

• If the pulse is traveling shallow.

• If the pulse is traveling deep AND shallow.

What is the average speed of sound in soft tissue?

• 1,540

• 1.54 mm/us

• 1.54 m/s

• 1,540 mm/us

What is the equation for depth?

P.S they just have the = sign because the full equation will get cut off.

•  $=\frac{1.54\ \frac{mm}{\mu s}\times goreturntime\ \left(\mu s\right)}{2}$ 

•  $=\frac{1.54\ \frac{mm}{\mu s}\times goreturntime\ \left(\mu s\right)}{4}$ 

•  $=\frac{1.54\ \frac{m}{s}\times goreturntime\ \left(\mu s\right)}{2}$ 

•  $=\frac{1.52\ \frac{mm}{\mu s}\times goreturntime\ \left(\mu s\right)}{2}$ 

What is the 13 microsecond rule?

• For every 13(m/s) of go-return time, the object creating the reflection is 1cm deeper in the body.

• For every 13(us) of go-return time, the object creating the reflection is 10 cm deeper in the body.

• For every 13(us) of go-return time, the object creating the reflection is 1 cm deeper in the body.

• For every 13(us) of go-return time, the object creating the reflection is 11 cm deeper in the body.

Fill in blank A and B.

• A = 20in & B= 30in

• A = 10cm & B= 20cm

• A = 11cm & B= 20cm

• A = 10m & B= 20m

Since a pulse travels to the reflector and back to the transducer the total distance a pulse travels is twice the reflector depth.

• True

• False