Typically, intensity is set somewhere between 0.5 W/cm 2 and 2.0 W/cm 2. Intensity must be set with frequency in mind, as the thermal effect of the chosen intensity will depend on the frequency; with greater thermal changes noted when 3MHz is used.
Full Answer
What is the intensity of UltraSound required at the target tissue?
In a similar way to the pulse ratio decision, the intensity of ultrasound required at the target tissue will vary with the tissue state. The more acute the lesion, the less strong the ultrasound needs to be in order to achieve/maintain the tissue excitement.
How much surface dose do I need for a deep ultrasound?
There IS a need to increase the surface dose to allow for loss of ultrasound at depth, and using the tables above, it is estimated that the required surface dose will need to be 0.75 W/cm2 (though of course this will depend on the size of the patient – it is not a universal formula)
What is the appropriate ultrasound intensity for the anterior capsule lesion?
Ultrasound treatment of a chronic lesion of the anterior capsule of the shoulder (glenohumeral joint. The lesion is chronic, thus an intensity of 0.5 W/cm2 should be sufficient to treat the lesion There IS a need to increase the surface dose to allow for loss of ultrasound at depth, and using the tables above,...
What is the frequency of therapeutic ultrasound?
The frequency of therapeutic ultrasound can be set from 1MHz to 3MHz, depending on the structures you wish to target. At 1 MHz, the ultrasonic waves penetrate deeper into the soft-tissue; while at 3MHz the effects are limited to more superficial structures.
When do you use 1 MHz or 3 MHz ultrasound?
Therefore, 1-MHz continuous ultrasound, with a half-value depth of approximately 2.3 cm, is frequently used to treat deep tissues that are approximately 2.3 to 5 cm deep. With its smaller half-value depth, 3-MHz ultrasound is frequently used to heat tissues that are more superficial, from 0.8 to 1.6 cm deep.
What is the range of intensities for most therapeutic ultrasounds?
These procedures generally use high frequency ultrasound (1–10 MHz) and a range of intensities (0–20 W/cm2). The acoustic energy is focused on the tissue of interest to agitate its matrix and make it more permeable for therapeutic drugs.
Is 1 MHz stronger than 3 MHz?
3 MHz should be used when the tissues targeted are within 2.5 cm. [8] 3 MHz is a much more efficient frequency in regards to heating because it heats roughly 3x faster than 1 MHz. [3] 1 MHz should be used when wanting to affect deeper tissues. That would be considered up to 5 cm deep.
What is the frequency of ultrasound treatment?
Therapeutic ultrasound has a frequency range of 0.75–3 MHz, with most machines set at a frequency of 1 or 3 MHz. Low‐frequency ultrasound waves have greater depth of penetration but are less focused.
What is intensity in ultrasound?
Intensity is the rate at which energy passes through the unit area and is an important quantity when discussing bioeffects and safety. The average intensity is equal to the power of an ultrasound beam, normally expressed in mW, divided by the cross-sectional area of the beam, expressed in cm2.
How is ultrasound intensity calculated?
The intensity I of the ultrasonic wave is determined from the temperature increase measured at the rear side of an absorber. 3.1.
How do you do therapeutic ultrasound?
0:5616:04Therapeutic Ultrasound-How it works and when to use it!! (Correction ...YouTubeStart of suggested clipEnd of suggested clipAnd into the tendons those deep tissues. This actually sends a sound wave that's a little bit deeperMoreAnd into the tendons those deep tissues. This actually sends a sound wave that's a little bit deeper to help heat those tissues. That are deeper than you would get with a hot pack.
What is the intensity W cm2 of a typical ultrasound beam?
Intensity: For acute conditions we start with the intensity of 0.5 W/cm2, and for chronic conditions 0.8 - 1.0 W/cm2 is used. Later it is increased according to the patient's reaction (the positive step method). The ultrasound intensity must not exceed 2.0 W/cm2 in continuous mode and 3.0 W/cm2 in pulse mode.
What is ultrasound therapy in physiotherapy?
Ultrasound physical therapy is a branch of ultrasound, alongside diagnostic ultrasound and pregnancy imaging. It's used to detect and treat various musculoskeletal issues you may have including pain, tissue injury, and muscle spasms.
How do you explain therapeutic ultrasound to a patient?
0:5916:14Therapeutic Ultrasound EXPLAINED | Use, Parameters, & Real ExampleYouTubeStart of suggested clipEnd of suggested clipOkay what would be our goal for them if they had muscle tightness well we of course want the musclesMoreOkay what would be our goal for them if they had muscle tightness well we of course want the muscles to relax. Right along the same lines if the patient has pain in a particular.
When do you use pulsed vs continuous ultrasound?
Results. Pulsed US (PUS) is more effective in both pain relief and function improvement when compared with the control group; but for continuous US (CUS), there is only a significant difference in pain relief in comparison with the control group.
What frequency is ultrasound?
The frequency of therapeutic ultrasound can be set from 1MHz to 3MHz, depending on the structures you wish to target. At 1 MHz, the ultrasonic waves penetrate deeper into the soft-tissue; while at 3MHz the effects are limited to more superficial structures.
How long has ultrasound been used in physical therapy?
Ultrasound has been used in physical therapy as a treatment to relieve aches and pains for nearly 70 years. But does ultrasound work?
Why is pulsed ultrasound considered nonthermal?
Because pulsed ultrasound interrupts the soundwave generation, the intensity output overtime is lower; resulting in non-thermal effects. Thermal v. Non-Thermal. Assuming for a moment that ultrasound is a well proven intervention for the patient or condition you have in mind, how do you know if you should be using ultrasound for thermal ...
What is duty cycle ultrasound?
Duty cycle is the total amount of treatment time which the ultrasound is actually ON for. This is where pulsed vs. continuous ultrasound comes into play. By setting the machine to, say 50%, you’re creating parameters in which the ultrasound will be alternatingly turned on and off, with a total “on time” accounting for 50% of the total treatment time. Continuous (100% duty cycle) ultrasound is what you want if you’re seeking thermal effects. Because pulsed ultrasound interrupts the soundwave generation, the intensity output overtime is lower; resulting in non-thermal effects.
What happens when sound waves are absorbed by the soft tissue?
When the alternating compressions and rarefactions are absorbed by the soft-tissue in the body, the mechanical energy of the sound waves (vibrations) is proposed to result in increased tissue temperature, increased localized blood flow, increased tissue extensibility, and accelerated metabolism through increased cellular permeability.
When was the systematic review of ultrasound done?
Systematic Reviews on Ultrasound. A systematic review of the effectiveness of ultrasound on musculoskeletal disorders done in 1999 by Van Der Windt, et al found that the evidence “did not support the existence of clinically important or statistically significant differences in favour of ultrasound therapy”.
Is ultrasound a good modality?
As it stands, this is the way I see it…at best, ultrasound is a moderately effective modality in treating a select few conditions if the parameters are set just right. At worst, since the potential risks and side effects are minimal, it is a waste of time for both you and your patient.
Ultrasound Waves
FREQUENCY – the number of times a particle experiences a complete compression/rarefaction cycle in 1 second. Typically 1 or 3 MHz.
Ultrasound Waveform
The Ultrasound beam is not uniform and changes in its nature with distance from the transducer. The US beam nearest the treatment head is called the NEAR field, the INTERFERENCE field or the Frenzel zone. The behaviour of the US in this field is far from regular, with areas of significant interference.
Thermal Effects of US
In thermal mode, US will be most effective in heating the dense collagenous tissues and will require a relatively high intensity, preferably in continuous mode to achieve this effect.
What frequency is ultrasound used for?
Low power ultrasound of about 1 MHz fre quency has been widely applied since the 1950s for physical therapy in conditions such as tendinitis or bursitis.
What are the biological effects of ultrasound?
Other potential mechanisms for biological effects of ultrasound include the direct action of the compressional, tensile, and shear stresses. In addition, second-order phenomena, which depend on transmitted ultrasound energy, include radiation pressure, forces on particles and acoustic streaming.
How many lithotripters are there in the USA?
Over 50 lithotripter devices have been on the USA market. Fluoroscopy is used for targeting the acoustic focus on the stone in the USA, although some lithotripters have B-mode ultrasound for targeting. The first lithotripters were electrohydraulic, using an underwater spark source and a reflector.
What is HIFU used for?
HIFU application in therapy and treatment of disease is one of the more active areas of research and development among all the non-ionizing-energy modalities such as radiofrequency, lasers, and microwaves. For example, HIFU is under investigation for therapeutic modulation of nerve conductance (Foley et al. 2008).
What is ultrasound assisted liposuction?
Another procedure, ultrasound assisted liposuction, is widely used in cosmetic surgery for the purpose of removing excessive fat tissue (Mann et al. 2008). The mechanism of action apparently involves cavitational fat cell break up with removal of the fat emulsion by suction through the probe.
When was ultrasound first used in physical therapy?
Physical Therapy. Unfocused beams of ultrasound for physical therapy were the first clinical application, dating to the 1950s , which often has been referred to simply as “therapeutic ultrasound” (Robertson and Baker, 2001). This modality now typically has a base unit for generating an electrical signal and a hand-held transducer.
How long does a flat transducer therapy last?
Therapy involves multiple treatments of 20 min each day by applying the large flat transducer to the site of injury and continuing treatment for periods of months. Although the process appears to be safe and effective, the therapy is slow and its use is predominantly limited to management of non-healing fractures.
What is therapeutic ultrasound?
Therapeutic ultrasound is a treatment modality commonly used in physical therapy. It is used to provide deep heating to soft tissues in the body. These tissues include muscles, tendons, joints, and ligaments.
What are the contraindications for ultrasound?
There are some instances where you should not use ultrasound at all. These contraindications to ultrasound may include: 1 Over open wounds 2 Over metastatic lesions or any active area of cancer 3 Over areas of decreased sensation 4 Over parts of the body with metal implants, like in a total knee replacement of lumbar fusion 5 Near or over a pacemaker 6 Pregnancy 7 Around the eyes, breasts, or sexual organs 8 Over fractured bones 9 Near or over an implanted electrical stimulation device 10 Over active epiphyses in children 11 Over an area of acute infection
How does ultrasound work?
Ultrasound is performed with a machine that has an ultrasound transducer (sound head). A small amount of gel is applied to the particular body part; then your physical therapist slowly moves the sound head in a small circular direction on your body.
Why is ultrasound used in the body?
Ultrasound is often used to provide deep heating to soft tissue structures in the body. Deep heating tendons, muscles, or ligaments increases circulation to those tissues, which is thought to help the healing process. Increasing tissue temperature with ultrasound is also used to help decrease pain.
Is ultrasound a passive treatment?
Many people argue that ultrasound can have a negative effect on your physical therapy by needlessly prolonging your care. Ultrasound is a passive treatment .
Can ultrasound be used for rotator cuff tears?
Generally speaking, any soft-tissue injury in the body may be a candidate for ultrasound therapy. Your physical therapist may use ultrasound for low back pain, neck pain, rota tor cuff te ars, knee meniscus tears, or ankle sprains.
Can a physical therapist use ultrasound?
Your physical therapist may use ultrasound to help improve your condition. If so, be sure to ask about the need for ultrasound and possible risks. Also, be sure that you are also performing an active self-care exercise program in the PT clinic and at home. If you are actively engaged in your rehabilitation, you can ensure that you have a safe and rapid recovery back to normal function.
Why is ultrasound not used during the inflammatory, proliferative and repair phases?
The application of ultrasound during the inflammatory, proliferative and repair phases is not of value because it changes the normal sequence of events, but because it has the capacity to stimulate or enhance these normal events and thus increase the efficiency of the repair phases.
What is the therapeutic effect of ultrasound?
One of the therapeutic effects for which ultrasound has been used is in relation to tissue healing. It is suggested that the application of US to injured tissues will, amongst other things, speed the rate of healing & enhance the quality of the repair.
What is pulsed ultrasound?
Pulsed Ultrasound. Most machines offer the facility for pulsed US output, and for many clinicians, this is a preferable mode of treatment. Until recently, the pulse duration (the time during which the machine is on) was almost exclusively 2ms (2 thousandths of a second) with a variable off period.
What is ultrasound energy?
Ultrasound (US) is a form of mechanical energy (not electrical), and therefore, strictly speaking, not really electrotherapy at all, but does fall into the Electro Physical Agents grouping. Mechanical vibration at increasing frequencies is known as Sound Energy. The normal human sound range is from 16 Hz to something approaching 15-20,000 Hz (in children and young adults). Beyond this upper limit, the mechanical vibration is known as ultrasound. The frequencies used in therapy are typically between 1.0 and 3.0 MHz (1 MHz = 1 million cycles per second).
How does ultrasound help healing?
It is suggested that the application of US to injured tissues will, amongst other things, speed the rate of hea ling & enhance the quality of the repair. The following information is intended to provide a summary of some of the essential research in this field together with some possible mechanisms through which US treatments may achieve these changes. It is not intended to be a complete explanation of these phenomena or a comprehensive review of the current literature. It may, none the less, provide some useful basic information for clinical application.
What is the pattern of energy absorption?
The absorption of US energy follows an exponential pattern - i.e. more energy is absorbed in the superficial tissues than in the deep tissues. In order for energy to have an effect it must be absorbed, and at some point this must be considered in relation to the US dosages applied to achieve certain effects.
What determines the impedance of a tissue?
All materials (tissues) will present an impedance to the passage of sound waves. The specific impedance of a tissue will be determined by its density and elasticity. In order for the maximal transmission of energy from one medium to another, the impedance of the two media needs to be as similar as possible.