physics safety & infection control setting up the machine
DESCRIPTION
Physics Safety & Infection Control Setting Up The Machine. H. Gee MD, FRCOG (teaching materials provided by David Cole, Lecturer at City University, Birmingham). Sound. WAVELENGTH . +. LOW PRESSURE REGION. HIGH PRESSURE REGION. = ONE CYCLE. A sound wave. wavelength. Excess pressure. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/1.jpg)
PhysicsSafety & Infection ControlSetting Up The Machine
H. Gee MD, FRCOG
(teaching materials provided by David Cole, Lecturer at City
University, Birmingham)
![Page 2: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/2.jpg)
Sound
HIGH PRESSURE REGIONLOW PRESSURE REGION+
= ONE CYCLE
WAVELENGTH
![Page 3: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/3.jpg)
A sound wave
wavelength
amplitude
Excess pressure
![Page 4: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/4.jpg)
Amplitude & Frequency
• Frequency– Pitch
• Amplitude– Loudness
• the strength of the sound.• The maximum change in
pressure due to the soundwave
![Page 5: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/5.jpg)
Ultrasound
![Page 6: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/6.jpg)
Ultrasound
• High Frequency Sound
• > 20 KHz (above the audible range)
• Short Wavelength
• Resolution Wavelength
• 3.5 MHz - Wavelength = .44 mm
• Frequency Penetration
![Page 7: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/7.jpg)
Spatial Resolution
• The ability to display two small structures situated close together as separate images
objects Image resolved
Image unresolved
![Page 8: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/8.jpg)
Piezo-electric effect
• Sound Electricity
Piezo-electric crystal
![Page 9: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/9.jpg)
Inverse piezo-electric effect
• Electricity SoundPiezo-electric crystal
![Page 10: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/10.jpg)
Ultrasound transducer
ECHOECHO
PULSE
CONVERTS ELECTRICITY INTO SOUND
CONVERTS SOUND INTO ELECTRICITY
PIEZO ELECTRIC CRYSTAL
![Page 11: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/11.jpg)
Pulse echo techniquemultiple reflectors
![Page 12: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/12.jpg)
Imaging Principles
![Page 13: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/13.jpg)
Imaging Principles
![Page 14: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/14.jpg)
How the image is How the image is producedproduced
![Page 15: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/15.jpg)
• Sound
• Ultrasound
• Piezo-electric effect
• Pulse-echo technique
• Imaging principles
• Resolution
Summary
![Page 16: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/16.jpg)
Infection Control
![Page 17: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/17.jpg)
Setting up the Machine
• Two Parts– Monitor (may be done automatically)
• Contrast• Brightness
• Grey Scale on Screen – ALL GRADATIONS
– Imaging System
![Page 18: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/18.jpg)
![Page 19: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/19.jpg)
Equipment Controls
• Probe selection
• Mode selection 2D, Doppler, Colour
• Gain, TGC, Power
• Depth and Zoom Scan angle (field size)
• Focus
• Measurement, freeze
• (Examination selection post processing)
![Page 20: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/20.jpg)
Probe selection
• This control is used to select from the probes available
• For example– Curvilinear general– Transvaginal– Linear array for small parts
![Page 21: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/21.jpg)
Mode selection 2D, Doppler, Colour
• 2D is normally selected automatically for all examinations and the other modalities are selected when required during the examination.
![Page 22: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/22.jpg)
Making the image darker or brighter
• Power
• Gain,
• Time Gain Compensation
![Page 23: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/23.jpg)
Safety
• Cavitation• Heating
• Frequency• Duration• Intensity
• Power
![Page 24: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/24.jpg)
Power (Output) increased
BRIGHTER IMAGE
Safety implicationsSet power to 35%Use gain to control brightness
![Page 25: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/25.jpg)
Power reduced
DARKER IMAGE
![Page 26: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/26.jpg)
Gain• Controls image brightness by amplifying
echo signals
• Completely safe
• Increased image noise
![Page 27: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/27.jpg)
Gain
INCREASE IN GAINMORE NOISE
![Page 28: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/28.jpg)
Time gain compensation Time gain compensation (TGC)(TGC)
![Page 29: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/29.jpg)
Time gain compensation Time gain compensation (TGC)(TGC)
![Page 30: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/30.jpg)
Time gain compensation Time gain compensation (TGC)(TGC)
TGC correctTGC correct
![Page 31: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/31.jpg)
Changing the field size
• The following controls change the size of the field of view– Depth
– Zoom
– (Scan angle)
![Page 32: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/32.jpg)
Freeze
• Measurement• Image recording
![Page 33: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/33.jpg)
Measurement=
+ +
•Electronic callipers
•Linear
•Circumference / area
•Ellipse / trace
•Volume measurement
•Organ specific
•Embedded charts
![Page 34: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/34.jpg)
Summary
• Probe selection
• Mode selection 2D, Doppler, Colour
• Depth and Zoom Scan angle (field size)
• Gain, TGC, Power
• Focus
• Measurement, freeze (& cine loop)
• (Examination selection post processing)
![Page 35: Physics Safety & Infection Control Setting Up The Machine](https://reader036.vdocuments.net/reader036/viewer/2022062322/56814660550346895db3834f/html5/thumbnails/35.jpg)
Important Controls
• Power (output, acoustic)• Gain• Time gain compensation (TGC)• Freeze• Electronic calipers