Ultrasound - Physical Therapy And Applications

Generally speaking, the term ultrasound is applied to all the sound waves with the frequency above the frequency detectable by the human ear (above 20 kHz). In medicine, the ultrasound employed is anywhere in the range between 1 MHz and 20 MHz.

The high-frequency sound waves are emitted and their echoes received by means of a transducer probe - a probe generally consisting of a piezoelectric crystal that can convert electrical energy into mechanical energy (sound waves) and emit it. It is used in, but not limited to, medical diagnostic ultrasonography, ultrasonic cleaning, disintegration, healing by means of therapeutic ultrasound, in welding and as a means of communication.

The medical ultrasonography is generally used to observe the internal organs: the heart, the liver and the abdominal organs and any changes that may occur in these organs. It is also widely employed in imaging the fetus during the pregnancy where the development of the fetus is tracked and it can also help determine the sex of the baby.

In ultrasound cleaning, frequencies between 20kHz and 40 kHz are generally employed. Here, the ultrasound is used in cleaning of jewelry, lenses and other optical devices, medical instruments and even to remove the mineral deposits from the teeth (use in dentistry).

The use in ultrasound disintegration is reflected in the probe producing series of alternating high and low-pressure sound waves. During the low-pressure stage, small vacuum bubbles are created in the specimen and these burst during the high-pressure stage. Common application of the technique is in breaking down of hard or biological materials, such as cellular structures, when there is a need for isolation and analysis of intracellular material.

In ultrasound welding, the high-frequency sounds are applied to make a permanent, solid-state weld between two pieces of materials. In ultrasound welding, the materials can be dissimilar and no other means of joining them is necessary (glues, bolts, etc.). The ultrasound is applied only after the pieces of material have been joined by means of contact and pressure, to assure even contact before the welding stage begins.

Ultrasounds also have possible use in communications. Namely, a graphene probe would be employed to produce or detect the ultrasound waves. This technology has been proposed in underwater communication, since radio-waves generally do not travel well through liquids.

Although they have a wide array of possible uses, the ultrasounds are not harmless though. Occupational exposure to long term ultrasound operating at energy levels higher than 120 dB may lead to hearing loss. Nevertheless, the use in medicine, industry, communications and warfare makes the ultrasound one of the best techniques available today.

Electromagnetic Radiation Found in Low Frequency Devices

Electromagnetic radiation is the radiation produced by electronic particles moving through the air in oscillating waves. It surrounds computers, mobile devices, satellites, appliances, power lines, and radios - anything that requires a signal or electrical surge to operate. While no dose of radiation is good to be exposed to, there are varying degrees of danger characterized within the electromagnetic spectrum according to frequency. Low-frequency radiation appearing in radio waves, microwaves and infrared waves present one set of health concerns, while higher frequency radiation, such as ultraviolet (UV), x-rays and gamma rays present another.

The length of the wave defines the amount of radiation that is produced. Longer wavelengths are less intense and emit lower levels of electromagnetic radiation. Shorter waves oscillate more quickly and therefore diffuse greater levels of electromagnetic radiation.

Most people come across low-frequency waves in their daily lives. This is because low-frequency electromagnetic radiation blankets everyday devices, such as laptops, cellphones, tablets, hair dryers, televisions, and microwaves.

For instance, according to the Mail Online, mobile phone users check their cell phone an average of 150 times per day, which works out to about once every six-and-a-half minutes. The frequency in which mobile users are talking on the phone, checking their email, updating social networks and playing games on their device is quite high and can directly affect their exposure to electromagnetic radiation.

Cell phone use in the United States has increased by six times in the last ten years, and users report having a hard time going without their phone throughout the day. An article in the San Francisco Chronicle reports a study in which 83% of respondents said cell phones have made life easier, with the Internet in second place at 76%. As the use of the devices continues to climb, there is an increased vulnerability to electromagnetic radiation.

In addition to cell phones, worldwide Internet use has also increased since it can be accessed on smartphones, laptops, desktop computers and tablet devices emitting highly similar radiation as cell phones. The exposure to these electromagnetic waves is not ideal. Although the electromagnetic radiation produced is on the lower side on the electromagnetic spectrum, it still presents heath dangers.

To avoid any risk associated with low-frequency electromagnetic radiation, there are some ways to minimize exposure. Cutting back on the use of mobile phones and laptop computers can help reduce exposure times for the user. Other ways to lower the risk of low-frequency radiation exposure is by turning a device off and storing it away when not using it or by investing in a state of the art laptop shield, which you can find through online retail specialists.

How electromagnetic radiation affects us?

Have you ever wondered about the high-tech world we live in, where things work wirelessly? We often wonder what will appear in the next years to be used as often as cell phones. How safe are electromagnetic radiation in the environment? How bad are they for human cells? How did harm they produce? How many radiations are we exposed daily, being surrounded by so many devices that produce electromagnetic radiation?

Do not you remember that when you were children, adults said not to get too close to the TV? The reason was the TV, as also the computer, emits all kinds of electromagnetic radiation, including microwaves, radio waves, ultraviolet, X-rays, infrared, electrical and magnetic fields of low frequency. But the truth is that the most dangerous is to stand behind the TV, where most of the radiation can escape.

However, computer or TV is not the only source of electromagnetic radiation in homes and offices. Particularly sunlight and X-rays can cause some principal activities of free radicals. Free radicals are unbalanced molecules fragments that appear in the body through normal breathing and digestive processes. Scientists have found that an excess of free radicals in the human body can lead to decreased immunity and cells function, which results in aging, heart disease, cancer and other degenerative diseases.

Some vitamins and minerals classified as antioxidants reduce free radical activity and protect cells from premature aging. The antioxidants can include vitamin C, vitamin E (in seeds and nuts), beta carotene (carrots) and selenium.

There are many ways that we are exposed to electromagnetic radiation, including power cords of appliances. Stronger magnetic fields and the highest devices come in much lower electricity interfering with our bodies. Magnetic fields induce weak electric fields on electrical conductors - our bodies are conductors. This process, called induction, is one of the ways in which such fields can affect body chemistry.

Creates static electricity and an increased average of positive ion charge, which is not good for human health. We must balance our environment by adding a positive ionization, which will make us to feel better and to limit the action of positive ions. Also, the chemicals from photocopiers, electronic equipment, plastics, etc., can lead to our poor health.