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29 Cards in this Set
- Front
- Back
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The seven parameters |
1) period 2) frequency 3) amplitude 4) power 5) intensity 6) wavelength 7) speed |
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Period |
Not adjustable Seconds, microseconds, time Determined by source Value: 0.06-0.5 microseconds |
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Frequency |
Not adjustable Unit: hertz, per second Determined by: source Value: 2-15 MHz |
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Amplitude |
Adjustable Unit: pascals, cm, g/cm^3, dB Determined by: source Value: 1MPa-3MPa |
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Power |
Adjustable Unit: watts, dB Determined by: source Value: 4-9 mW |
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Intensity |
Adjustable Unit: watts/cm^2, dB Determined by: source Value: 0.01-300 W/cm^2 |
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Wavelength |
Not adjustable Units: mm, distance Determined by: both Value: 0.1-0.8 mm |
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Speed |
Not adjustable Units: m/s Determined by: medium Value: 1500-1600 m/s |
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Period and frequency |
Reciprocals Inversely |
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Frequency and wavelength |
Inversely |
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Stiffness and speed |
Directly related |
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Density and speed |
Inversely related |
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Stiff but not dense |
Fastest speed Example: bone |
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Stiff but not dense |
Fastest speed Example: bone |
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Parameters |
Describe features of sound wave |
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-Source of sound -medium |
-Ultrasound system -tissue |
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Frequency is important in sonography Bc.. |
It affects image quality |
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Infrasound |
Less than 20 Hz Cannot be heard by human ears |
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Audible sound |
Btw 20Hz-20kHz Humans can hear |
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Ultrasound |
20 kHz or more Humans cannot hear |
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Period x frequency = 1 |
Period x frequency = 1 |
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Bigness parameters |
Amplitude Power Intensity |
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Intensity formula |
Intensity (W/cm^2) = power (w)/area (cm^2) |
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Intensity and power |
Proportional |
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Intensity and amplitude |
Intensity is proportional to the waves amplitude squared |
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Wavelength formula |
Wavelength(mm) = 1.54 mm/microseconds divided by frequency (MHz) |
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The speed of sound |
1,540 m/s |
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L F S L B M T B |
500 1450 1540 1560 1560 1600 1700 3500 |
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Air Water Metals |
330m/s 1480m/s 2,000 to 7,000 m/s |
