Transducer of ultrasound machine
A device that converts one form of energy to another
Piezoelectric crystal: a crystal that produces (+) and (-) electrical charges when it contracts or expands
Crystal of quartz, barium titanate, lead zirconate, or titanate housed within transducer
Reverse (indirect) piezoelectric effect: occurs when an alternating current is passed through a crystal resulting in contraction & expansion of the crystal
US is produced through the reverse piezoelectric effect
Vibration of crystal results in high-frequency sound waves
Fresnal zone (near field) – area of the ultrasound beam on the transducer used for therapeutic purposes
Longitudinal waves – molecular displacement is along direction in which waves travel (bungee cord)
Compression – regions of high molecular density (molecules in high pressure areas compress)
Rarefraction – regions of low molecular density (molecules in low pressure areas expand)
Transverse waves – molecular displacement in direction perpendicular to wave (guitar string)
Influences on the Transmission of Energy:-
Reflection – occurs when the wave can’t pass through the next density
Refraction – is the bending of waves as a result of a change in the speed of a wave as it enters a medium with a different density
Absorption – occurs by the tissue collecting the wave’s energy
Decrease in a wave’s intensity resulting from absorption, reflection, & refraction
as the frequency of US is because of molecular friction the waves must overcome in order to pass through tissues
US penetrates through tissue high in water content & is absorbed in dense tissues high in protein
Absorption = Frequency (3 MHz) , and
Penetration = Absorption (1 MHz) , so
Penetration = Frequency + Absorption (1 MHz)
Tissues water content = low absorption rate (fat)
Tissues protein content = high absorption rate (peripheral nerve, bone)
Muscle is in between both
Spatial Average Temporal Peak Intensity (SATP): average intensity during the “on” time of the pulse
Output meter displays the SATP intensity
Spatial Peak Intensity (SPI): max. output (power) produced within an ultrasound beam
Spatial Average Temporal Average Intensity (SATA) or Temporal (time) Average Intensity:
Power of US energy delivered to tissues over a given period of time
Only meaningful for Pulsed US
SAI x Duty Cycles
Ratio between the spatial peak intensity (SPI) to the average output as reported on the unit’s meter
The lower the BNR, the more uniform the beam is
A BNR greater than 8:1 is unsafe
Because of the existence of high-intensity areas in the beam (hot spots), it is necessary to keep the US head moving
Soft tissue healing & repair
Joint contractures & scar tissue
Muscle spasm,Neuroma,Trigger areas,Warts
|
|
|
|
|
|
|
Related posts
read moreUltrasound in Medicine
Ultrasound is simply sound that has a very high frequency.
Humans are not able to hear ultrasound, though some animals can hear them.
Sounds with frequencies above 20 000 hertz are called ultrasounds.Ultrasound is used for examining soft tissue inside the body.
Parts of the body that may be examined include muscles and unborn babies.
Blood flow can also be monitored using ultrasound.Modern ultrasound equipment can produce 3D images The images so far have been of static images, ultrasound captures movement.
This baby is so pleased to see you it’s waving!Ultrasound is very safe. There is no firm evidence that it does any harm to the body (or the baby in the case of pregnancy scans).
X-rays are potentially dangerous, particularly to young children and pregnant women (they damage the unborn baby).Medical ultrasound systems use very high frequencies – several megahertz (mega means million or 106).
A sound is a wave it has all the usual wave properties (reflection, refraction, diffraction). Ultrasound imaging makes use of the fact that sound can be reflected.
The idea is just like that used in radar and sonar.
A thin layer of jelly is placed between the probe and the skin to make sure all the sound enters the body.
The probe contains a transmitter and a receiver.
A pulse of ultrasound is sent out by the transmitter.
The pulse is reflected from a surface and returns to the receiver.The ultrasound machine measures how long it takes for the pulse to return
Colour enhancement to show blood flow
Digital files for examination on computers
Millions of sound waves are transmitted every second.
As the waves reflected at different times, the computer in the ultrasound machine calculates how far the wave travelled before being reflected (using d=vt).
Using this information the computer builds up an image of the inside of the patient.
Ultrasound is sound with a frequency above 20 000 Hz. If you have just said that it is a sound we cannot hear, that is not quite accurate enough.
Ultrasound can be used for examining soft tissue inside the body. For example, muscle, the heart and unborn babies.
The following are ultrasound frequencies:
23 000 Hz, 36 kHz, 4 MHz, 0.58 MHz, 600 000 Hz
Ultrasound does not have any damaging effect on the body. It is entirely safe to use, even on very young foetuses. X-rays are harmful, particularly on young and unborn children.
Most of the problems involving ultrasound need you to use v=d/t or v=fl
Things to look out for:
Units- time will often be in milliseconds (ms). Take care not to get this confused with metres per second (m/s or ms-1). and distances may be in mm or cm
There will often be an echo (or reflection involved. This means that you will need to think carefully about the times and distances involved.
|
|
|
|
|
|
|
|
Related posts
read moreUltrasound Imaging System
The Ultrasound Machine A basic ultrasound machine has the following parts: Transducer probe – probe that sends and receives the sound waves Central processing unit (CPU) – computer that does all of the calculations and contains the electrical power supplies for itself and the transducer probe Transducer pulse controls – changes the amplitude, frequency and duration of the pulses emitted from the transducer probe Display – displays the image from the ultrasound data processed by the CPU Keyboard/cursor – inputs data and takes measurements from the display Disk storage device (hard, floppy, CD) – stores the acquired images Printer – prints the image from the displayed data
The basic functional components of an ultrasound imaging system are shown below. THE ULTRASOUND IMAGING SYSTEM
Modern ultrasound systems use digital computer electronics to control most of the functions in the imaging process. Transducer Pulse Generator Amplification Scan Generator Scan Converter Image Processor Display We will now consider some of these functions in more detail and how they contribute to image formation.
|
|
|
|
|
|
|
|
Related posts
read morePRINCIPLE AND APPLICATION OF ULTRASOUND IN VETERINARY PRACTICE
INTRODUCTION : INTRODUCTION Ultrasonography is the second most commonly used imaging format Important part of specialty areas in clinical veterinary medicine – internal medicine – gynaecology and obstretics – surgery – cardiology – gastro – enterology – orthopaedics and – ophthalmology Insights into basic anatomy and physiological processes Almost all organs and tissues are now accessible Minimally invasive imaging method Least hazards
WHAT IS ULTRASOUND? : WHAT IS ULTRASOUND? Ultrasound or ultrasonography is a medical imaging technique that uses high frequency sound waves and their echoes.
Ultrasound : Ultrasound Ultrasound is defined as sound waves of frequencies greater than 20,000 Hz. Frequency range of 1-10MHz (max.20MHz) used in medical and veterinary diagnostics No disturbance to animals at employed diagnostic frequencies A sound wave travels in a pulse and when it is reflected back it becomes and echo. It is the pulse echo principle, which is used for ultrasound imaging. No propagation in vacuum and poor transmission in gases Generated by piezoelectric materials.
Principle : Principle A pulse is generated by one or more piezoelectric crystals in an ultrasound transducer. When these crystals are stimulated electrically it changes its shape and produces sound waves of particular frequencies. The frequency of a transducer is determined by the times the crystals expands and contracts per second. In an ultrasound scanner the crystal is shocked by a short pulse of electricity to vibrate.
Basic Ultrasound Machine : Basic Ultrasound Machine Components – Central Processing Unit (CPU) – Transducer probe – Transducer Pulse Controls: – Display – Keyboard/Cursor – Disk Storage – Printers
As the transducer is placed in close contact with the body surface through a coupling medium, it undergoes continuous modification that occurs through three processes Absorption, Reflection And scattering.
Absorption: : Absorption: It occurs when the energy in the sound beam is absorbed by the tissues thereby converting it into heat. Absorption process forms the basis of therapeutic ultrasound.
Reflection : Reflection It is the redirection of a portion of the ultrasound beam back towards the source. The reflection gives rise to echo and forms the basis of diagnostic ultrasound. These echoes are converted by piezoelectric effect into electric signals that are displayed onto on oscilloscope screen.
Scattering : Scattering It occurs when the beam encounters an interface that is irregular and smaller than the sound beam. The portion of the beam that interacts with this interface is scattered in all the directions. Two closely related phenomenons occur, refraction and diffraction of which refraction is a common cause of artifacts.
Echo quantification : Echo quantification For displaying this echo amplitude information, different modes are used.
Display Modes : A-mode (amplitude) : Display Modes : A-mode (amplitude) Reflective surfaces are displayed as vertical spikes with different amplitudes along baseline Application: Echo-encephalography Echo-ophthalmography Pregnancy diagnosis (previously).
B-mode (brightness) : B-mode (brightness) Returning echoes are displayed as dots with varying brightness on the monitor Brightness or grey scale.
2-D Brightness mode: – Assembles numerous 1-D scan in to 2-D US image – Echoes traced along vertical line.
Interfaces that are stationary- are seen in straight line Interfaces that re in motion –are seen as wiggly line.
Real Time Mode : Real Time Mode Static organs: Slow frame rate & high scan line density Cardiological scans: Higher frame rate.
3-D ultrasound – ultrasound waves are directed from multiple angles – waves are reflected back and captured, providing very detailed 3-dimensional images of the baby 4-D ultrasound – the process of streaming 3-D images into live, real-time video of the baby. This allows viewers to see real-time motion.
Triangular or pie shaped (Sector) Use: Echocardiography,Sonography of intra pelvic & intra thoracic organs, brain, eyes, testes & joints.
Rectangular linear (Linear) Use: Sonography of abdominal organs (extra thoracic) Sonography of superficial structure (skin, mammary gland, joints and tendons).
Trapezoid convex (Curved array) Use: Abdominal ultrasonography Pregnancy diagnosis.
Endorectal Transducer : Endorectal Transducer Transducer with attached biopsy guide system and inserted needle Provide advantage of US beam offset by 45 degree.
Scanning procedure: : Scanning procedure: Ultrasonography involves considerable cooperation between the patient and the sonologist. The transducer must be in close contact with the patients skin to have minimum attenuation of the sound beam. In Vety. Patients it requires clipping of hair and cleaning of skin. There should not be any air between the transducer and skin, as it will completely block the beam. So good contact is provided by application of mineral oil or an aqueous gel between the transducer and contact surface. Any coupling medium should be applied liberally. Both gas and bone acts as a barrier to ultrasound beam as these reflect the beam. Therefore, a proper acoustic window should be formed to visualize the organ.
|
|
|
|
|
|
|
|
Related posts
read moreSkin Care Ultrasonic machine
If you have questions about the beauty of your face like this:-
How can care my face?
What are the methodes adopted by women to care the face beauty?
Home Ultrasonic Facial Machines
How Do Ultrasonic Facial Massage Machines Work?
Is Ultrasonic Facial Treatment Safe?
The Benefits Of Ultrasonic Skin Care Treatment
Then read these information. It may help you to do some care of your face beauty with the help of ultrasoinic machines.
There are many Ultrasonic facial machines whaich are used by sophisticated sound wave technology to penetrate deep below the surface of the skin promoting cellular renewal and repair, toning muscles, increasing blood circulation, encouraging lymphatic drainage, combating puffiness and swelling and improving skin care product penetration. Ultrasound may be used on most parts of the body, including the face, neck, arms, breasts, stomach, waist, hips, buttocks, and legs and can now be used in the comfort of your own home.
Home Ultrasonic Facial Machines
How Do Ultrasonic Facial Massage Machines Work?
Is Ultrasonic Facial Treatment Safe?
The Benefits Of Ultrasonic Skin Care Treatment
transducers can be used on Ultrasonic Cavitation Body Slimmer and Fat Reduction Beauty Machine, ultrasonic massager is Provided, and other beautifiers and devices, such as IPL stimulator and electric potential mattress layover, Facial Massager, Ligtwave treatment transducer for beatuy equipment, it can be used in tinnitus for ears, varices, congestion, swelling of bump Also supply item PCB, with sweeping, adjustale power controller functions.
Ultrasonic Cleaning Transducer – Double Frequency (HNC-8SE-3828/40)
Ultrasonic Transducer 40Khz, 50W (HNC-4AH-3540)
Ultrasonic Cleaning Transducer (HNC-4SS-130)
Ultrasonic Transducer (HNC-4SH-3828)
Have you ever read a medical journal called Ultrasound in Medicine and Biology? You could have read a fascinating article about how ultrasound skin therapy that rejuvenates skin for both young and old. Why so much hype about ultrasound skin care?
How to Use Facial Massager ? Step by Step
Galvanic Treatment with Facial Massagers
Ultrasonic Skin Therapy
Care and Maintenance of Your Galvanic Ultrasound Machine
Botox or Galvanic Treatment with Facial Massagers?
History of Design
How does Ultrasound Facial Therapy Improves Your Skin?
How does The Ultrasonic Wave Reduce your Wrinkles, Pimples & Acne?
How to Achieve Youthful Healthy Skin with Vitamins?
|
|
|
|
|
|
|
|