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Ultrasound
Beginnings in the 1880s when Pierre Curie Beginnings in the 1880s when Pierre Curie introduced simple echo sounding introduced simple echo sounding methods. methods.
1913 discovery of SONAR 1913 discovery of SONAR --(Sound (Sound Navigating and Ranging)Navigating and Ranging)
First introduced to medical world in 1950sFirst introduced to medical world in 1950s
History
Dog whistleDog whistle Bets and dolphins communication and Bets and dolphins communication and
orientationorientation SonarSonar SubmarineSubmarine--boat communication boat communication
Applications
UltrasoundUltrasound--welding (for plastic)welding (for plastic) Materials testingMaterials testing Multiphase flow measurementMultiphase flow measurement
Applications
Disinfection of instruments Disinfection of instruments
ImagingImaging Detection of tumors (Oncology)Detection of tumors (Oncology) AssesmentAssesment of the development of fetus of the development of fetus
(OB/GYN)(OB/GYN) Evaluation of blood flow (Cardiology)Evaluation of blood flow (Cardiology) InsertionsInsertions
TherapyTherapy
Medical Applications
Frequency Range
Low bass notes Animals
Medical and destructive
Diagnostic
Physics
REFLECTED WAVEINCIDENT WAVE
MEDIA 1 - water
MEDIA 2 - air
TRANSMITTED WAVE
http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=16
Same frequency in both materialshttp://interactagram.com/physics/optics/refraction/
Indices of Refraction
Animation:http://health.howstuffworks.com/adam-200128.htm
Principle
Principle
Transducer
Transducer
Transducer
Transducer
Distance equal to less than a wavelength for the minimum interference and reduced grating lobes
Transducer
Transducer
CRC Press - Biomedical Technology and Devices Handbook
CRC Press - Biomedical Technology and Devices Handbook
Transducer
CRC Press - Biomedical Technology and Devices Handbook
Transducer
Transducer
9.19
Images
A-Mode
V
t
Images
B-Mode
DLigne US Ligne US
(analogique) (Vidéo)
Images
B-Mode: Normal Imaging
CRC Press - Biomedical Technology and Devices Handbook
Images
Images
M-Mode (Motion-mode imaging)Image line is a function of time
Examples:• Heart valves• Cross-section of a carotid artery
Images
M-Mode (Motion-mode imaging)
Images
M-Mode (Motion-mode imaging)
Images
Doppler Mode
Images
Doppler Mode
http://www.kettering.edu/~drussell/Demos/doppler/doppler.html
Images
Doppler Mode
Images
Doppler Mode - Flow track
Images
Doppler Mode - Flow track
Images
3D Imaging (4D + time)
ImagesFrame Rate
The size of an area in a scene that is The size of an area in a scene that is represented by one pixel in the imagerepresented by one pixel in the image
Lower resolution leads to data reduction!Lower resolution leads to data reduction!
Resolution
Tradeoff between resolution and attenuation Tradeoff between resolution and attenuation ↑↑higher frequency higher frequency ↓↓shorter wavelength shorter wavelength ↑↑ higher attenuationhigher attenuation
Power loss:Power loss:
Typical Ultrasound Frequencies: Typical Ultrasound Frequencies: Deep Body Deep Body 1.5 to 3.0 MHz1.5 to 3.0 MHzSuperficial Structures Superficial Structures 5.0 to 10.0 MHz5.0 to 10.0 MHz
Resolution
MHz cmdB 1
Amplification
Gain compensation as fuction of the deep
Amplification lineAmplification line
Echo 1 Echo 2
1dB / 1MHz / 1cm
Reflection coefficient
Rmuscle/blood=1,63 - 1,561,63 + 1,56
Muscle 1,63Blood 1,56FatFat 1,421,42
2)
0,00079 0,079%
(
Air 0,0004
Total reflection
1,63 - 0,00041,63 + 0,0004
Rair/muscle = )( 2
0,99887 99,88%
Gel
No gel with gel
Ultrasound at high energy can be used to Ultrasound at high energy can be used to ablate (kill) tissue.ablate (kill) tissue.
Cavitation (bubble formation)Cavitation (bubble formation)
Temperature increase is limited to 1Temperature increase is limited to 1ºº C for C for safety.safety.
Safety
Block Diagram
Block Diagram
RF AMPLIFIER FM DEMODULATOR AMPLIFIER SIGNAL PROCESSING
RECEPTOR
TRANSMITTER OSCILLATOR
BODY
SPEAKER DISPLAY
Block Diagram
Block Diagram
Cell Phone Ecography
Gathering data with the phones and sending it where specialists can analyze the image
Cost: $2,000 (goal of $500)
Therapy
Therapy
Phacoemulsification
Phacoemulsification - Videos
Kidney Stones
A biplane xA biplane x--ray apparatus is used to make sure the stone is at the focal poiray apparatus is used to make sure the stone is at the focal point of sparknt of spark--generated shock generated shock waves from the ellipsoidal reflector.waves from the ellipsoidal reflector.
Kidney Stones - Shock Wave Lithotripsy
http://www.umm.edu/patiented/articles/kidney_stones_animation_000475.htmhttp://hcd2.bupa.co.uk/fact_sheets/html/Kidney_stones.html
Kidney Stones
UreteroscopyPercutaneous Nephrolithotomy
Disinfection of Instruments
Experience