Shortwave therapies (SWT) use electromagnetic fields (EMF) within the radio frequency (RF) range.

Alos known as pulsed electromagnetic energy (PEME), pulsed electromagnetic field (PEMF), pulsed high frequency electromagnetic energy (PHFE) or pulsed radiofrequency energy (PRFE).

All radio frequencies in the 10 -100 mhz range are called shortwave. Hence therapies using these frequencies are called shortwave treatments. If heating occurs then the term diathermy is used. So heating with radio frequencies in the 10-100 mhz range are called shortwave diathermy.

Lets get into some more detail:

Shortwave therapy uses electromagnetic fields. So what is an electromagnetic field?

Electromagnetic fields are a part of the electromagnetic spectrum.

Within this spectrum are a range of frequencies. These frequencies are used to describe the type of machine you are using. For instance ultrasound is a band of frequencies that are used to treat patients. Infrared another band and shortwave is simply another band which falls into the radio frequency part of the spectrum.

Shortwave is then just an amount of electromagnetic radiation (we use electricity to create magnetic fields) at the respective wavelength and photon energy.

The electromagnetic waves within this band have different characteristics, such as how they are produced, how they interact with matter and their practical applications.

Radio frequency energies occupy 1.0 x 104 Hz to 3.0 x 1011 Hz of the electromagnetic spectrum.

Radio frequency electromagnetic energy is produced by RF electrical circuits (normally coils of a thin metal, copper is frequently used) connected to some sort of plate/antennae.

The wave parameters wavelength and frequency are interconnected and are inversely related. The frequency of the wave is directly proportional to the energy the wave carries.

The RF frequencies used in modern clinical practice are within 30 kHz – 30 MHz.

Pulsed shortwave is where the radio frequency (RF) oscillations are gated (turned on and off) at a rate of pulses (cycles) per second (one cycle per second is known as a hertz (Hz)).

This then leads to a whole host of parameters (that can be adjusted to give overall output):

• Pulses per second (1000 per second is one kilohertz pulse rate – with a gated pulse width of 42 μs).
• Pulse packet frequency, for example 27.125 megahertz (MHz) of RF energy.
• Duty cycle (the percentage time the RF packet is on, as an example 4.2% ([0.042 ms X 1000 pulses divided by 1000 ms/s] X 100).
• The pulse packet form (shape) can be a square, triangle, sawtooth or sine wave.
• In some applications of pulse shortwave the times between pulses can be modulated.

There are two general categories of pulsed radiofrequency field therapies based on their mechanism of action: thermal and non-thermal (athermal).

Pulsed radiofrequency therapy technologies are described by several acronyms EMF (electromagnetic field), PEMF (pulsed electromagnetic fields), PRF (pulsed radiofrequency fields), and PRFE (pulsed radiofrequency energy).