About Radiowave Therapy

Physics of Radiowaves

Electromagnetic radiation

The term “radiation” simply refers to the emission and propagation of energy in the form of waves or particles.

Electromagnetic (EM) radiation is a radiation consisting of particles called photons that act in some respects like a wave. It is caused by an oscillating electric charge.

Electromagnetic spectrum

EM radiation is characterised by the frequency of the wave. The frequency is the number of full waves that travel past a point in a given time – this is the number of crests or equivalently the number of troughs. When the unit of time is a second the frequency is expressed in Hertz (abbreviation: Hz). Therefore a frequency of 434 MHz indicates a wave in which 434 million waves travel past a point in each second.

All EM waves travel at the same speed. This is a universal constant known as the velocity of light (c) and is approximately 300,000 km/sec (3 x 108 m/s) – the phase velocity.

The frequency and wavelength of a wave are inversely proportional to one another, to calculate one the speed of the wave is divided by the other. For example, in the case of 434 MHz this implies an in vacuo wavelength of 69.1 cm (less inside matter such as a patient’s body).

It includes the range of the EM spectrum: radiowaves, microwaves, infrared radiation, visible light, ultraviolet radiation, x-rays and gamma rays. The divisions between these parts of the spectrum reflect differences in how the energy is created or detected rather than specific phenomena. For example, gamma rays (those produced by a LINAC) are basically high energy x-rays.

EM radiation carries energy – each photon is an indivisible packet of energy (E) and the amount of this energy is proportional to its frequency. Photons have no mass but they still carry momentum (p), that is to say, they push things that they strike, albeit a very small push.

Ionising radiation

EM radiation is classified into ionising and non-ionising radiation, based on whether it is capable of ionising atoms and breaking chemical bonds. Radiation with energies in the ultraviolet (UV) band or higher is ionising. Radiowaves are not ionising – the only known biological effect they have on the human body is heating.

Radio frequency (RF) waves

Radiofrequency (RF) radiation is a portion of the EM spectrum between frequencies of 10 kHz up to infra-red (less than 300 GHz). It is a non-ionising form of radiation. Ultra-high frequency (UHF) is a band of the radio spectrum designated to be between the frequencies of 300 MHz and 3 GHz (3,000 MHz). The frequency of 434 MHz used in radiowave therapy is located towards the lower end of this band.

Radiowaves and humans

Dielectric losses

The amount of RF energy that is absorbed (deposited into) human body tissue and the rate at which the energy decreases with the depth of penetration depends on both the type of tissue that the energy passes through and on the frequency of the incident radiation. Radio frequencies below 4 MHz the body is essentially transparent to the energy. As the frequency is increased more energy is absorbed by the human body. At high frequencies (around 1 GHz or more) there is scattering. Increasing the frequency of electromagnetic energy still further the point is reached when the body reflects radiation (visible light).

Refraction

When electromagnetic radiation passes from one medium to another the direction, velocity and wavelength of the wave changes.

Safety of radiowaves

When radiofrequency waves enter the human body a portion of the energy is absorbed and causes molecules in the body to vibrate. On a macroscopic level these vibrations are what we experience and measure as heat (NIOSH 1987):

  • The extent of heating is primarily dependent on the water content of the tissue and the intensity and duration of the RF energy. Most parts of the body have sufficient blood supply to dissipate heat resulting from absorption of RF radiation.
  • Dr Holt is quite clear that radiowaves at the frequency of 434 MHz have a non-thermal effect on the physiology of cancer cells. The Institute research will investigate this factor in detail as one of its radiowave therapy projects.

Radiowaves and Cancer Cells

Dr Holt argues that radiowaves at the specific frequency of 434 MHz UHF have a non-thermal effect on the physiology of cancer cells, namely increased cell division or some changes in the electrochemistry of cells evidenced by resonance effects. There has been no systematic in-vitro research into these questions and these hypotheses will be addressed as part of the Institute research.

Increase in cell division

Dr Holt postulated that 434 MHz radiowaves increase the rate of cell division and that this will result in more cancer cells being starved of energy following the administration of GMI. The evidence for this is based on observation of cells pre and post exposure to radiowaves.

Resonance/fluorescence effect

Dr Holt claims to have observed differences in the power spectrum of the radiowave waveform emitted by cancer patients’ bodies during radiowave treatment, compared to the spectrum emanating from people without cancer. The power spectrum, or spectral density, describes the power contribution to a signal at various frequencies. This is measured by a spectrum analyzer (Figure 10).

Dr Holt supported this postulation with the observation that when a tumour decreased in size during the course of a treatment the power spectrum would gradually return to the “normal” unimodal shape.

Dr Holt attributed this difference to an electrical resonance effect in cancer cells when they are stimulated by RF energy, specifically at 434 MHz. In physics, resonance is the tendency for a system to oscillate with a high amplitude when excited by energy at a certain frequency. This frequency is known as the system’s natural frequency of vibration or resonant frequency. Resonance is a phenomenon found in many mechanical, acoustic and electric systems. This resonance would, he believed, lead to fluorescence, whereby the cancer cells re-radiated the input RF energy at a slightly different output frequency – 434±ε MHz. The interference between the input and output frequencies created the harmonics observed in the waveform. Fluorescence is a phenomenon in which EM energy (usually at UV wavelengths) is absorbed by a body and reradiated at a longer wavelength.

Dr Holt suggested that the resonance effect could be attributed to some change in the electrical conductivity of malignant cells, although this was not elucidated.

Figure 10: Changes in power spectrum. Top: patient without cancer, Middle and bottom: patients with cancer. (Holt, undated Ill. 15, 16 and 17 p. 37)

Measuring RF Dose

Irradiance

Irradiance, or power density, measures the amount of power incident on a unit surface area, for example a patch of human skin. It is measured in units of mW / cm2 or equivalently, after multiplying by a factor of ten, in units of W / m2.

Penetration depth

The effective penetration depth (λ) is defined to be the depth at which the irradiance (incident power per unit area) has been reduced to a value of about 37%, being the reciprocal of Euler’s constant (e). Hence at a depth of twice the penetration depth there is still about 13% of the incident power (Figure 11). Note that this is a graph of a mathematical function (exponential decay) and is not experimentally measured data.

Figure 11: Decrease in power with tissue depth in fat at 434 MHz assuming exponential decrease. The penetration depth is 15 cm, as reported by Ammann and Curto for 434 MHz in a test phantom.

Specific absorption rate (SAR)

The specific absorption rate (SAR) measures the time rate of absorption of electromagnetic energy by a body. It is measured in W / kg.

The SAR can be determined from the electric field strength E in the body or from the rate of temperature rise (Δt).

Absorbed dose

Absorbed dose refers to the energy deposited in a medium by radiation. It has the units of J/kg, which are given the name gray (Gy). In ionizing radiation the absorbed dose is multiplied by a factor to obtain an equivalent dose measuring the biological effect of the radiation.