UUP ch4

what are the 5 parameters to describe pulsed sound?

• -period

  -frequency

  -amplitude

  -power

  -intensity

• -pulse repetition frequency

  -pulse duration

• -pulse repetition period

  -duty factor

  -spatial pulse length

• all of the above

what is pulsed sound?

• a pulse of ultrasound is a collection of cycles that travel together.

• a pulse of ultrasound is one singular cycle

• a repetitive cycle

Answer explanation

its multiple cycles that make up the wave form as a whole. similar to a train that has multiple carts, its still 1 train though. so a pulse is the train and cycles are the carts

what are the two components of a pulse?

• talking,

  transmit,

  "on" (time)

• receive,

  listening,

  "off"(time)

• loud,

  long,

  "off"(time)

Answer explanation

when the wave form is moving its "on" time when its flatlining its considered "off" time

what is pluse duration? and what are its units?

• its the length of a cycle

• units of time

  microseconds

  (μs)

• actual time from the start of a pulse to the end of that pulse

• units of length

  centimeters

  (cm)

Answer explanation

the first two red lines represent pulse duration

what is pulsed duration determined by? is it adjustable?

• determined by sound source ONLY

• determined by medium

  ONLY

• it can be adjusted by the sonographer

• Can't be adjusted

  (each transducer has its own fixed duration)

what are the characteristics of a long duration

• many cycles in the pulse

• individual cycles with long periods

• few cycles in the pulse

• individual cycles with short periods

Answer explanation

the top one is a long duration pulse, it has many wave patterns before it ends

what are the characteristics of a short duration pulse?

• few cycles in the pulse

• individual cycles with long periods

• many cycles in the pulse

• individual cycles with long periods

how is pulse duration related to the number of cycles in the pulse ?

• directly related

  when one goes up the other goes up

• inversely related when one goes down the other goes up

• not related

  they dont connect at all

Answer explanation

pulse duration= #cycles x period

how is pulse duration related to period

• directly related

  when one goes up the other goes up

• inversely related when one goes up the other goes down

• not related

Answer explanation

pulse duration= #cycles x period

how is pulse duration related to frequency

• directly related

  when one goes up the other goes up

• inversely related when one goes down the other goes up

• not related

Answer explanation

#cycles

pulse duration= -----------------

frequency(MHz)