PEMF Intensity

Intensity of pulsed electromagnetic fields -generated by PEMF devices- is a very important part of the specifications if you want to get effective therapy results. 

Magnetic field strength or magnetic field intensity is defined in Tesla (symbol T) and named after the famous scientist Nikola Tesla. another name is "magnetic flux density" or "magnetic induction". Electromagnetic field strength was previously expressed in Gauss (symbol G) which numbers are 10.000 times larger than Tesla. 

Because intensity is probably the most important parameter for effective PEMF therapy devices, and because micro Tesla and milli Tesla are very often confused (milli is a factor 1000 x larger than micro), you can see here a table showing the differences between these values. Some manufacturers on purpose write mTesla in order to confuse costumers, but the correct scientific way of using symbols is mT for milli Tesla and μT for micro Tesla.

Tesla values

In order to be effective for successful PEMF therapy the field strength of the pulsed electromagnetic signal must be sufficiently powerful to penetrate deep inside the cells and bones. This means that the applied intensity levels must be high enough or else only a minimal and superficial effect will occur.

Two Japanese scientists discovered in 1956 the piezo electric effect of bones. By mechanically bending a bone and at the same time measuring the electrical voltage between two electrodes attached to the bone, they proved that electrical properties exist inside bones. 

An example of the piezo electric effect is your own alarm clock. Your clock contains a tiny crystal which is covered at both sides with an electrical conductor. When your clock reaches the wake-up time, an electrical voltage is applied to the electrical conductors of the crystal causing small mechanical movements, resulting in the wake-up sound you hear.

When the pulsed electromagnetic field penetrates through bone the opposite effect takes place. The pulsed electromagnetic effect causes small mechanical movements, resulting in small electrical currents inside the bones and cells. These electrical microcurrents cause the beneficial effects inside the body, and if the intensities of the pulsing magnetic fields are too low to penetrate deep inside the body, no effect will take place!

PEMF piezo-electric effect in bones

The only way showing that the pulsed magnetic fields completely penetrate the body is to check if it is still possible to detect a pulsing magnetic field at the opposite side of the body. E.g. if the field is applied at the back it must be possible to show its existence still at the chest and the other way around else it will not be able to penetrate deep enough into the body! 

The human body is unable to feel the magnetic pulses themselves but only the effects they cause However it is easy to detect a sufficiently strong pulsed magnetic field by taking a static magnet into your hand and hold it above the applicator containing the coils. Now you can clearly feel the pulses in your hand with the same pulse repetition rate (frequency) generated by the device. This effect happens because the pulsed magnetic fields distort the static magnetic field of the magnet you hold in your hand, which results in the pulses you can now feel in your hand.

Earth magnetic fields? Some companies talk about the intensity of the earth magnetic field? They are joking, right?

Claiming that weak natural magnetic fields work better than stronger fields is misleading and pure scientific nonsense. 

Need some proof? The geomagnetic field strength varies over the surface of the earth. The intensity of the magnetic field over South America has a minimum strength of 22 micro Tesla and reaches a maximum of 67 micro Tesla over the south of Australia. A device generating only 70 micro Tesla can NEVER work as manufacturers of those devices say they do!

Potential customers become afraid because of misquotations of statements by the World Health Organization that indicates magnetic field strengths for continuous magnetic fields, like those radiated by power lines. Claims are made by people having no idea about the differences between a continuous magnetic field and a pulsed electromagnetic field and the only things they have in common are the words "electromagnetic fields"!

Geomagnetic field

Devices generating only micro Tesla fileds intensity probably have the same effect like the field intensity generated by your fridge or blender probably only offering a placebo effect.

PEMF devices generating these low micro Tesla intensity fields require sensitive electronic magnetic field measurement detectors to show that any magnetic field is actually generated because for the field cannot even be detected otherwise! Low intensity magnetic field strengths cannot penetrate through the body more than just an inch as will be explained here under. 

Electromagnetic intensity decreases very fast over distance, according to the "Inverse Square Law". The further away from the coil, the faster the decrease of the pulsed magnetic field intensity: by the square of the distance! 

Having a specific electromagnetic field intensity at the surface of the coil (red in the picture), the pulsed magnetic field intensity drops fast as you move away. Increase of the distance by a factor of 2 means that the field intensity drops by a factor of 4. If the distance is 3 times greater then the intensity of the field decreases by a factor of 9. If the distance is 4 times greater the field intensity drops by a factor of 16!

Inverse square law

This is clearly shown when we look at the picture: The PEMF pulses pass through the lowest yellow area closest to the coil. When we double the distance from the coil only 25% of the field intensity is left now passing through a similar yellow area. Double the distance again and you can clearly see how little of the original intensity passes through a similar yellow area at the top of the picture (not more than 11%).

In order to obtain effective PEMF therapy it is important to have enough PEMF intensity starting at the coil surface else or it will do hardly anything deep inside the body!  

Therefore all different Parmeds systems generate create PEMF intensities up to the milli Tesla range. Of course this requires superior engineering design compared to the other low intensity PEMF devices that are only able to generate low micro Tesla levels. 

It is a fact that because of thousands of customers around the globe with more than two million successful therapy sessions, our devices have proven to be extremely effective!

The Parmeds PEMF Super models is controlled by an external computer (PC or laptop) and with this software the user is able to define the intensities for the field strengths himself, down into the micro Tesla range if the system is used only for very superficial therapy applications

To precisely measure the Tesla values of the Parmeds PEMF devices special measuring equipment is used. 

A so called Hall effect sensor is used invensted by Edwin Hall an American physicist. 

The Parmeds devices are measured by such a laser calibrated Hall effect sensor before shipping and you will know that to receive a system on which intensity you can rely.

The electrical voltage which is generated by the Hall sensor is measured and visualized on an instrument called oscilloscope. This way the correct pulse forms and the Tesla values are measured.

Hall sensor for PEMF measurements