Lecture 1 Flashcards
What is a transducer?
A transducer can be any device that is capable of changing one from if energy into another
How is a transducer used in Ultrasound?
Ultrasound Transducer converts US energy into electrical voltage and vice versa
What is the Piezoelectric Effect?
Conversion of acoustic pressure energy into electrics energy, or electrics energy into acoustic pressure
What are the 2 classifications of the Piezoelectric Effect?
Direct Piezoelectric Effect and indirect Piezoelectric Effect
Direct Piezoelectric Effect
When acoustic pressure energy is applied to some materials, they will deform and create electrical energy
Sound —> transducer —> electricity
Indirect Piezoelectric Effect
When an electrical voltage is applied to some materials, they will deform and produce acoustic energy
Electricity —> transducer —> sound
Natural Piezoelectric materials
Amber
Tourmaline
Quartz
Rochelle Salt
Man made Piezoelectric materials
- Lead Zirconate Titanate
- Barium Titanate
- Lead Metaniobate
- Polyvinyldiene
Names for the Piezoelectric material within the probe
- Piezoelectric element
- Piezoelectric Crystal
- Piezoelectric Ceramic
- Active Element
What are the components of the transducer?
- Piezoelectric element
- marching layer
- plastic case
- electrical wire
- backing material (dampening material)
What is the matching layer?
- Placed in front of the Piezoelectric element
- has intermediate impedance in relation to crystal and tissue
- helps increase the amount of sound that is transmitted into tissue
T/F there can be multiple matching layers?
True
What is the ideal thickness of the matching layer?
1/4 (squiggly A with no line)
What is usually composed of aluminum powder in epoxy resin
The matching layer
