ultrasound Flashcards
what is ultrasound
deep heating modality used for thermal and non-thermal effects
applying high frequency AC to a piezoelectric crystal - reverse piezoelectric effect
generation of ultrasound
piezoelectric material expands and contracts in response to AC
crystal expands = compresses plate = spaced out waves
crystal contracts = rarefies plate =
how is the ultrasound wave created
alternating compression-refraction from the expansion and contraction of the crystal = US wave
where in the body is ultrasound used
heating of tissues c high collagen content - tendons, ligaments, joint capsules and fascia
not ideal for muscles
compare US to superficial heating agents
heats smaller and deeper areas
thermal effects of US
inc MTR
reduce pain and spasm
inc NCV, BF, tissue extensibility
non-thermal effects of US
inc CM permeability, intracellular Ca ions, macrophage activity, protein synthesis
= wound healing
indications for continuous/thermal
before stretching of shortened short tissues
reduction of pain
indications for pulsed/non-thermal
accelerate tissue healing - ulcers, skin incisions, tendon injuries, bone fractures
phono/sonophoresis - localized transcutaneous drug delivery
compare 3 MHz and 1 MHz
penetration is lower in 3 MHz bcs attenciates but can achieve higher temperatures
depth of penetration of 3 MHz
1-2 cm
depth of penetration of 1MHz
up to 5 cm
discuss duty cycle for thermal effects
100% duty cycle bcs continous
discuss duty cycle for non-thermal effects
usually starts at 20% duty cycle tas inc as u progress treatment gang 100
what is duty cycle
pulse duration/pulse period
how to we determine the intensity of warmth applied
from patient feedback
what is BNR
ratio of spatial peak intensity to the spatial average intensity
spatial average - 1.5 W/cm^2
peal - 9 W/cm^2 - can cause burns kaya moving technique
parameters for shortened soft tissues using 3 MHz
3 MHz x 0.5-1 W/cm^2 x 5-10 mins.
parameters for shortened soft tissues using 1 MHz
1 MHz x 1.5-2.5 W/cm^2 x 5-10 mins.
parameters for painful areas using 3 MHz
3 MHz x 0.5 W/cm^2 x 3-10 mins.
parameters for painful areas using 1 MHz
1 MHz x 3.0 W/cm^2 x 3-10 mins.
parameters for wound healing
3 MHz x 0.5-1 W/cm^2 x 20% duty cycle x 3-10 mins.
parameters for acute tendon and ligamental repair
1/3 MHz x 0.5-1 W/cm^2 x duty cycle x 5-10 mins.
accelerate healing
parameters for chronic tendon and ligamental repair
high enough intensity to increase temp, continous mode
address tissue shortening
parameters for bone fractures
very low dose
1.5 MHz x 0.15 W/cm^2 x 20% duty cycle x 15-20 mins.
parameters for CTS
1 MHz x 0.5-1 W/cm^2 x pulsed 1:4 x 5-15 mins.
parameters for phonophoresis
3 MHz x 0.5-1 W/cm^2 x 20% duty cycle x 5-10 mins.
discuss the significance of ERA
5-10 mins : 2x ERA
so if era is 10 cm^2 and area to be treated is 20 cm^2 = 5-10 mins
when is US duration increased
lower intensity/frequency
area larger than 2x ERA
heating effects are deisred
methods of appli
direct - moving technique - 2-8 cm/sec
glove or balloon technique - pag di flat surface
underwater treatment - distal ex, circumferential
contra for US
malignant tumor
pregnancy
CNS tissue
joint cement or plastic parts of arthroplasty
pacemaker
thrombophlebitis
eyes
reproductive organs
precautions for US
acute inflammation - dapat pulsed
epiphyseal plates
fractures - vv low dose dapat
breast implants
temp and appli of non thermal
37.5°C - acute injury, edema healing
temp and appli of mild thermal
38.5°C - subacute injury, hematoma
temp and appli of mod thermal
39.5°C - chronic inflammation, pain, trigger points
temp and appli of vigorous
41.5°C - stretch collagen
