Term
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Definition
a high frequency sound wave generated by applying an electrical current to a crystal designed to resonate with the frequency of the applied electrical field |
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Term
what type of energy is ultrasound |
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Definition
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Term
what is conversion energy |
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Definition
taking one form of energy and turning it into another |
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Term
what happens when we apply electrical energy to a crystal? |
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Definition
it vibrates, putting out sound energy |
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Term
what was the original inspiration for US? |
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Definition
WWII and sonar: putting sound energy into the water to look for submarines |
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Term
what is the differene between sonar and ultrasound |
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Definition
in sonar, you listen for the return of the sound that bounces off a submarine. In PT/therapeutic ultrasound, you only dispense sound and don't listen for the return |
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Term
what is the frequency range of human hearing |
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Definition
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Term
what is the frequency of middle C |
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Definition
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Term
what is the frequency range of US |
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Definition
1 million to 3 million Hz |
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Term
what is required for the generation of sound waves |
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Definition
a medium for them to travel through |
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Term
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Definition
a crystal that converts electricity into sound waves |
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Term
what is the Piezo-Electric effect |
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Definition
If I deform a crystal, it will produce electrical energy |
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Term
what is the Reverse Piezo Electric Effect |
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Definition
applying electrical energy causes a crystal to change shape |
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Term
describe how an US head works |
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Definition
Run electricity through coaxial cable into US head. Piece (resonating coil) in the head gets electrified. Piece presses against crystal. Electrical energy causes crystal to vibrate/change shape. Crystal expands/contracts based on frequency we apply to it. US passes through front plate of US head. |
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Term
describe what makes up the frequency of the crystal |
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Definition
compression/rarefaction cycles/second |
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Term
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Definition
amount of energy being delivered by the unit = amount of energy/time |
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Term
what is the unit of power |
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Definition
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Term
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Definition
power/surface area of the device |
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Term
what is the unit of intensity |
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Definition
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Term
what is the WHO limit of intensity for US |
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Definition
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Term
what are crystals in older units made of |
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Definition
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Term
what are crystals in newer units made of |
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Definition
synthetics: Plumbium Zirconium Titinate (PZT) or Barium Titinate |
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Term
what can happen if you don't have gel/a medium on the US head |
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Definition
you can get a standing wave that oscillates and fractures the crystal |
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Term
what is the longest amount of time that you can hold the US up off the person |
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Definition
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Term
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Definition
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Term
what is effective radiating area |
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Definition
area of transducer from which US is generated = size of the ultrasound head |
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Term
do crystals produce an even vibration? |
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Definition
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Term
what is spatial peak intensity |
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Definition
highest point of beam on the sound head |
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Term
what is the spatial average intensity |
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Definition
US beam or output averaged over the surface area of the US head |
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Term
are spatial peak intensities and spatial average intensities used for continuous or pulsed US |
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Definition
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Term
for continuous US, does the power meter read spatial peak intensity or spatial average intensity? |
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Definition
spatial average intensity |
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Term
what are the units of spatial average intensity |
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Definition
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Term
what is beam non-uniformity ratio |
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Definition
ratio of spatial peak intensity to spatial average intensity |
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Term
what does beam non-uniformity ratio indicate |
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Definition
how smooth or evenly distributed the beam is |
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Term
what is the FDA limit of the beam non-uniformity ratio |
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Definition
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Term
what is a very good beam non-uniformity ratio |
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Definition
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Term
what is a benefit of having a 2:1 beam non-uniformity ratio? |
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Definition
very good crystals make a very smooth beam. Can slow down movement of the head without worrying about safety |
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Term
what is a disadvantage of having a 2:1 beam non-uniformity ratio |
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Definition
these devices are rare and very expensive |
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Term
if you're using WHO's upper limit of intensity and FDA's upper limit for beam non-uniformity ratio, what's the highest power you can have? |
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Definition
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Term
how do you calculate the spatial peak intensity |
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Definition
SAI x beam non-uniformity ratio |
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Term
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Definition
the proportion of time the US is on to the total time |
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Term
why might you want to know what the SPI is? |
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Definition
to know what the hottest point of the beam is |
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Term
if the duty cycle is on 1:5, how much of the time in percentage is the US on |
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Definition
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Term
what is the usual duty cycle |
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Definition
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Term
what does the duty cycle help with |
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Definition
helps prevent getting too much energy applied |
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Term
are spatial average temporal averages and spatial average temporal pulses used with continuous or pulsed machines |
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Definition
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Term
what is the spatial average temporal peak? |
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Definition
the spatial average intensity when the machine is pulsed "on." |
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Term
what is spatial average temporal average |
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Definition
the spatial average temporal pulse averaged over the entire pulse. |
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Term
how can you calculate spatial average temporal average? |
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Definition
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Term
for pulsed US, what does the meter reading show? |
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Definition
Spatial Average Temporal Peak |
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Term
what measure shows the actual energy delivered to the tissue over time? |
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Definition
spatial average temporal average |
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Term
what is the duty cycle for a machine that pulses on for 2ms and then off for 8ms? |
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Definition
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Term
if the machine says that the SATP is 1W/cm^2, and we are using a 20% duty cycle, what is the SATA or the energy that is actually being delivered to the tissue? |
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Definition
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Term
what does the sound field look like? |
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Definition
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Term
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Definition
first half of the hour glass of the sound field near the transducer |
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Term
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Definition
2nd half of the hour glass shape of the sound field away from the transducer |
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Term
does US work in near field or far field |
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Definition
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Term
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Definition
conversion of mechanical energy into heat |
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Term
do all tissues absorb sonic energy in the same way |
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Definition
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Term
how does high collagen content relate to absorption |
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Definition
high collagen content leads to high absorption |
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Term
what determins absorption |
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Definition
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Term
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Definition
redirection of an incident beam |
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Term
what is acoustical impedance |
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Definition
a tissue's opposition to the passage of soundwaves |
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Term
where is reflection highest |
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Definition
between tissues with greatest acoustical impedance differences |
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Term
what can you do to avoid reflection |
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Definition
be sure that the head of the US is aimed at the tissue you want to treat |
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Term
how much reflection occurs between air-skin |
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Definition
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Term
how much reflection occurs between soft tissue-bone? |
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Definition
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Term
how much reflection occurs between transducer-medium |
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Definition
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Term
how can you eliminate acoustical impedance from air-skin? |
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Definition
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Term
if someone complains of deep ache with US, what is happening |
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Definition
energy is reflecting off bone |
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Term
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Definition
re-direction of a wave at an interface |
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Term
what is the difference between refraction and reflection |
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Definition
reflection stays in the first medium; refraction goes into the 2nd medium, just not at the angle you want |
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Term
why do we want to try to reduce reflection and refraction? |
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Definition
so that we get the greatest absorption that we can |
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Term
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Definition
decrease of US intensity as it goes through the tissue |
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Term
what 3 things cause attenuation |
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Definition
reflection, refraction, absorption |
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Term
how much of the energy that goes into the tissue is absorbed |
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Definition
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Term
what happens to the energy that goes into tissue that is not absorbed? |
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Definition
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Term
how does high collagen content relate to attenuation? |
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Definition
high collagen = high attenuation |
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Term
how does frequency affect absorption |
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Definition
high frequency increases absorption |
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Term
how does frequency affect attenuation? |
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Definition
high frequency increases attenuation |
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Term
if you get the US past the tissue interface, does bone absorb US well? |
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Definition
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Term
where does most absorption occur? |
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Definition
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Term
why is there not a lot of absorption of US in bone? |
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Definition
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Term
what determines the depth that US energy will go |
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Definition
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Term
does increasing amplitude make the US go deeper |
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Definition
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Term
what does increasing amplitude do |
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Definition
gives you more power/energy within the depth you choose to work at |
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Term
what frequency is required to have most energy absorbed in 5cm |
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Definition
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Term
what frequency is required to have most energy absorbed in 2.5cm |
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Definition
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Term
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Definition
formation or growth of gas-filled bubbles generated by the US vibration |
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Term
what is stable cavitation |
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Definition
oscillation of bubbles without bursting |
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Term
what is stable cavitation used for |
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Definition
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Term
what does stable cavitation vibration do |
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Definition
affects the cell membrane |
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Term
when are you at risk for unstable cavitation |
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Definition
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Term
what happens in unstable cavitation |
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Definition
bubbles increase in size and burst |
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Term
what are the results of unstable cavitation |
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Definition
increased pressure, temperature; tissue destruction; free radical production (goldfish story) |
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Term
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Definition
eddying produced around a vibrating object |
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Term
what is acoustic streaming |
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Definition
circular flow of fluids, like a latte steamer. Mixes up the fluid in the tissue. |
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Term
how does acoustic streaming compare to microstreaming |
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Definition
acoustic streaming is larger in scale than microstreaming |
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Term
what does acoustic streaming do |
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Definition
alters cellular activity by moving fluid around. Helps get nutrition to cells |
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Term
what are some non-thermal effects of US |
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Definition
increased cell membrane permeability, increased intracellular calcium, histamine release, increased macrophage response |
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Term
why is it good to have increased cell membrane permeability |
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Definition
can move things into/out of cell more easily |
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Term
why is it good to have increased intracellular calcium |
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Definition
helps you get a better muscle contraction |
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Term
why is it good to have histamine release |
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Definition
changes chemical composition in the area; causes mast cells to send out chemical signals to start inflammatory/healing |
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Term
why is it good to have an increased macrophage response |
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Definition
macrophages help clean up the area |
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Term
when do non-thermal US effects occur? |
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Definition
always, whenever you use US |
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Term
does low energy US have more non-thermal or thermal effects |
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Definition
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Term
does high energy US have more thermal or non-thermal effects |
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Definition
more thermal effects, but non-thermal effects are still occurring |
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Term
is it possible to get only non-thermal effects |
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Definition
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Term
is it possible to get only thermal effects |
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Definition
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Term
what are the thermal effects of US |
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Definition
same as superficial heating, denatures collagen bonds, improved blood flow, periosteal pain |
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Term
how US heating different from superficial heating |
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Definition
smaller specific, deeper areas |
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Term
why is it good to denature collagen bonds |
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Definition
allows us to reform collagen into the direction we want it to go |
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Term
what 3 factors affect heating |
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Definition
collagen content, frequency, intensity |
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Term
what are some tissues with high collagen content |
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Definition
tendon, ligament, capsule, fascia |
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Term
what is an absorption coefficient |
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Definition
the amount of absorption by a tissue |
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Term
how does the rate of temperature increase relate to absorption coefficient |
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Definition
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Term
how does collagen content relate to temperature increase |
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Definition
the higher the collagen, the greater the temperature increase because it absorbs more |
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Term
how does frequency relate to rate of heating |
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Definition
higher frequency = higher rate of heating |
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Term
do high or low frequencies travel farther |
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Definition
low frequencies travel farther (think of subwoofer in a car) |
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Term
to have the same heating results, what will you need to change and now if you want to increase frequency? |
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Definition
If you are going to increase frequency, you need to decrease intensity and/or duration. |
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Term
do non-thermal effects occur at low or high temperature changes? |
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Definition
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Term
if we increase temperature by 1C, is that a thermal or a non-thermal effect |
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Definition
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Term
what are the effects of increasint temp by 1C |
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Definition
increased metabolism and healing |
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Term
what are the effects of increasing temp by 2-3C |
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Definition
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Term
if we increase temp by 4C, is that a thermal or non-thermal effect? |
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Definition
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Term
what is the effect of increasing temp by 4C? |
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Definition
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Term
at what temperature are we getting thermal effects |
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Definition
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Term
how long do you have after using US to stretch someone and take advantage of the thermal range |
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Definition
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Term
why is it good to stretch someone during US |
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Definition
that way, you're sure to be stretching them as soon as they're in the thermal range |
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Term
do you get a faster rise into the thermal range using 3MHz or 1MHz? |
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Definition
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Term
what are indications for US/conditions for which you would treat with US? |
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Definition
soft tissue shortening, tendon injuries, tendon calcification, pain, plantar warts, dermal ulcers |
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Term
how does US help with soft tissue shortening |
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Definition
helps to try to lengthen tissue |
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Term
how does US help with tendon injuries |
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Definition
lengthen tissues, promote healing |
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Term
how does US help with tendon calcification |
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Definition
helps with calcium deposit resorption |
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Term
how does US help with pain |
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Definition
used to address the cause of pain |
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Term
what are draper's indications for US |
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Definition
acute/post acute, soft tissue healing/repair, scar, joint contracture, chronic inflammation, increase collagen extensibility, reduce muscle spasm, pain modulation, increase protein synthesis, tissue regeneration, bone healing, non-union fractures, inflammation with myositis ossificans (resorb extra bone growth), plantar warts, trigger points |
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Term
what are the basic indications for US |
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Definition
healing, pain, muscle spasm, connective tissue changes, blood flow changes |
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Term
what are the purposes of phonophoresis |
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Definition
facilitates transdermal delivery; increases pores in stratum corneum so that molecule can move through the tissue |
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Term
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Definition
sound energy that changes the epidermis to the point that medicinal molecules can get through |
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Term
what medicine is typically used with phonophoresis |
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Definition
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Term
does phonophoresis work, according to research? |
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Definition
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Term
what medicines are transferred well with phonophoresis |
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Definition
lidex gel, theragesic cream, mineral oil |
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Term
when doing phonophoresis, what should you do first? |
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Definition
regular US, so that the medicine doesn't block the US |
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Term
what are contraindications for US |
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Definition
tumors, pregnancy, CNS, joint cement/plastic, pacemakers, thrombophlebitis, eyes, reproductive organs |
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Term
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Definition
increasing blood flow increases tumor growth |
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Term
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Definition
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Term
when not to use US over spinal cord |
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Definition
if person has had a laminectomy or other exposure of CNS |
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Term
why no US over joint cement/plastic |
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Definition
US can break up cement. Plastic absorbs US and will heat up |
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Term
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Definition
plastic casing, metal parts |
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Term
where can you not use US for someone with pacemaker |
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Definition
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Term
what are precautions for US |
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Definition
acute inflammation, epiphyseal plates, fractures, breast implants |
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Term
why is acute inflammation only a precaution for US |
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Definition
you can still use non-thermal US |
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Term
why are fractures only precautions for US |
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Definition
US can create pain, but can also be used to help heal fractures |
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Term
what are adverse effects of US |
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Definition
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Term
what is blood cell stasis |
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Definition
red blood cells form into bands, capillary circulation stops. |
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Term
is blood cell stasis common |
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Definition
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Term
when does blood cell stasis happen |
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Definition
if you use high energy for a long time |
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Term
what are US treatment choices you can make |
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Definition
frequency, duty cycle, intensity, duration |
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Term
how to determine duty cycle |
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Definition
choose based on the effect that you want. Can be continuous or pulsed. |
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Term
what does intensity determine? |
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Definition
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Term
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Definition
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Term
what 3 things combine to get dose level |
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Definition
frequency, intensity, duration |
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Term
what are techniques for application of US |
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Definition
direct contact: moving, stationary; underwater; balloon (plastic glove filled with water) |
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Term
is it possible to get a thermal change using pulsed US? |
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Definition
yes, but you have to do it for a long duration at a high intensity |
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Term
is it possible to get nonthermal changes using continuous US? |
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Definition
yes, if you do it for a short duration at a low intensity |
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Term
when would you use direct contact, stationary as an US technique? |
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Definition
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Term
what tissue has the highest absorption coefficient? |
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Definition
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Term
after bone, what tissue has the highest absorption coefficient? |
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Definition
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Term
close to cartilage, what tissue has the 3rd highest absorption coefficient? |
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Definition
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Term
which tissue has the lowest absorption coefficient? |
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Definition
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Term
why to use continuous vs. pulsed US |
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Definition
use continuous for more thermal effects, use pulsed for more nonthermal effects (though both effects can be acquired using both applications) |
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Term
how to determine size of US head |
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Definition
choose based on the size of area to be treated. |
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Term
how does the ERA relate to the size of the US head |
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Definition
the ERA (actual surface of the crystal that delivers the energy) is always smaller than the area of the US head. |
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Term
how big should your treatment area be in relation to ERA? |
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Definition
all treatments should be contained within an area only 2x size of the ERA |
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Term
what frequency to use if target is deeper than 1 inch? |
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Definition
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|
Term
what frequency to use if target is less than 1 inch deep? |
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Definition
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|
Term
what to do if your US head is smaller than the area you want to treat |
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Definition
either increase intensity, increase duration, or do more than 1 consecutive treatment (which will still take more time) |
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Term
if using water as US medium, what must you do? |
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Definition
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|
Term
how to achieve thermal effects using 1MHz continuous? |
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Definition
5-10 minutes at 1-2W/cm^2 |
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Term
how to achieve thermal effects using 3MHz continuous? |
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Definition
3-5 minutes at 1-1.5W/cm^2 |
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Term
how to achieve nonthermal effects at 1MHz continuous |
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Definition
5-10 minutes at .25-.7W/cm^2 |
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Term
how to achieve nonthermal effects at 3MHz continuous |
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Definition
5 minutes at .25-.7W/cm^2 |
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Term
how to achieve nonthermal effects at 1MHz 20% pulsed |
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Definition
5-10 minutes at 1-2W/cm^2, SATA =.2-.4W/cm^2 |
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Term
how to achieve nonthermal effects using 3MHz pulsed |
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Definition
3-5 minutes at 1-1.5W/cm^2, SATA = .2-.3W/cm^2 |
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