shit bro might ask about ultrasound lab

Question 1

Aim of the work?

Answer 1

To know main principles of ultrasonography and doppler effect

+see relationship between measures
(in this case diameter, cross section area, velocity and blood flow)

Question 2

Frequency?

higher or lower than audible sound?

Difference in wavelength?

Answer 2

Everything above 20kHz
5-15 MHz

Much higher freq. then audible sound which is
20Hz - 20kHz

Shorter wavelength than normal

Question 3

Similarities audible sound and ultrasound?

Answer 3

Both are longitudinal and mechanical waves that needs a medium to propagate

Both have Reflection, Refraction, and Absorption

Question 4

How is ultrasound generated?

Answer 4

pizoelectric crystals- contract or expand depending on voltage applied.

same material to send, recieve etc

Question 5

(Not very important)

How is an ultrasonic wave detected?

Answer 5

Question 6

Loss of the intensity with distance caused by?

Attenuation

Answer 6

• reflection
• refraction
• scattering
• tissue absorption.
• spreading of the beam (inverse square law)
  Ultrasound weakens or attenuates rapidly by the inverse square law with distance from the
  transducer; therefore, structures closer to the transducer are better visualized.
  Many transducers have been adapted to get them close to the imaged structures

Question 7

US is used where in medical terms?

Answer 7

+
Abdominal examinations (structure of organs)
* bladder
* pancreas
* spleen
* stomach
* bowel
* liver

Question 8

What kind of probe did we use? The other kind of probe is for what?

Answer 8

Linear probe

Curvilinear probe is for when it requires a wider view etc belly button of a pregnant women

Question 9

Why do you apply gel to US

Answer 9

Air-tissue interfaces reflect all incidental ultrasound waves, preventing them from penetrating through the skin.

This gel reduces reflection from the
air to skin-surface , allowing more ultrasound waves to penetrate and providing better contrast in the images.

Question 10

Doppler ultrasound

Doppler shift – magnitude of change in frequency.

Answer 10

Used to measure the speed of
* flowing fluids (blood flow)
* moving objects (eg., heart valves)

Question 11

Explain Bernoullis principle

Answer 11

Fluid moves faster = it creates lower pressure

moves slower = it creates higher pressure.

Think about a garden hose: If you put your thumb over the end, the water speeds up because the space is smaller. This fast-moving water has lower pressure. If you take your thumb away, the water flows out slower and has higher pressure.

Question 12

Wtf is Poiseuille’s Law

Answer 12

Think about how water flows through a hose.

Poiseuille’s Law helps us understand how the thickness (viscosity) of the fluid, the size of the hose, and the pressure affect the flow of liquid.

Poiseuille’s Law says that the flow of a liquid through a tube depends on:

• The thickness of the liquid (thicker liquids flow slower).
• The size of the tube (wider tubes allow more flow).
• The pressure pushing the liquid (more pressure means faster flow)

Question 13

How did we detect velocity?

Answer 13

average of distolic and sistolic is our speed, thats why we used periods to get both the ups and downs.