Research on magnetic fields and the living body has become very active in recent years and a lot of literature has been published on the subject. One of these, using animals, confirmed the theory that electric current is generated by electromagnetic induction when a magnetic field is applied to the bloodstream.
Then, by placing the human chest between the poles of an electromagnet or by generating a pulse between two poles by using electrodes fixed to the skin, electromotive force was determined by the blood flow across the magnetic field. This was termed Magnetoheography. It was the first time the electric change occurring when a magnetic field was applied to the human body was confirmed.
Many similar studies were conducted in 1964, 1966 and 1969 with squirrel monkeys. Those studies, using a 100-kilogauss field from a super-conductive electromagnet, showed an electromotive force similar to previous experiments on the human body.
From these experimental results, it is now clear that in the case of both human beings and animals, electromotive force is generated by the external application of a magnetic field to the body.
A magnetic field, although weak, is formed around the human body by the active current within the body. This field changes as the active current changes. The purpose of magnetocardiography and magnetoencephalography is to record the change of this field from outside the body and to utilise these findings for diagnosis. This recording is very difficult to make as an instrument capable of measuring very low gauss is necessary for external recording.
On the other hand, the earth’s magnetic field has a magnetic flux density much stronger than that emanating from the human body. Therefore, even a small change in the earth’s field will affect the human body. This may even affect the active current within the human body, and we can imagine that this could be the cause of disorder or change in the body.
As the earth’s magnetic field is to some extent always working on the body, and as the body fluid is always in motion even when the body is at rest, electromotive force is constantiy being generated by electromagnetic induction. Also, when a man is in motion, he moves across the magnetic field and, like a conductive material moving across a magnetic field, it is also possible to generate electromotive force. For these reasons, the electromotive force generated when a man moves East-West and North-South will be different, the speed of motion also causing a difference.
Scientists worldwide believe that the effectiveness of a magnetic field applied to the human body depends on:
• Strength of the field
• Uniformity of the field
• Direction
• Range of the field
• Operational time
• Position on the body to which the field is applied.
When the point of application of the magnetic field and the point where the effect is felt do not coincide, for example when magnetic bracelets and rings to cure shoulder stiffness are used, it is referred to as the Remote Effect of the magnetic field. However, when patch-on-the-skin type devices are directly applied to the area in which the symptoms are felt, the effect is referred to as the Local Effect of the magnetic field. Magnetic fields can function in both ways.
Magnetic fields can be roughly divided into two types – the Stationary and the Varying Field. The latter is further divided into Alternating, Pulsating, Rotating and Travelling fields.
In Japan, magneto-therapeutic devices are registered under the Drug Regulations Act of 1961. It is now legal to manufacture and sell magneto-therapeutic devices as they have been officially approved. As a result, devices like the magnetic wristband, magnetic ring, magnetic stomach belt, magnetic mattress, magnetic necklace, magnetic arch plate, magnetic patch-on-the-skin device, among others, are not only marketed in Japan but also all over the world.
Generally, as a thumb rule, magneto-therapeutic devices should have the following features:
• They can be easily used
• They can be used for long hours continuously
• The user can adjust the hours of usage to the subjective symptoms
• No serious side effects occur.
With the new magnetic materials, the desired magnetic flux density can be achieved with a sn all size and the user can also wear them as an item of jewellery.
However, for effective treatment, a magnetic field with a flux density of over 500 gauss must be applied.