Summary
Highlights
The video starts by explaining that shortwave therapy uses an "entertained current," which originates from triodes. This current negates the damping of alternative current waves, resulting in a consistent amplitude (both positive and negative). All amplitudes in this alternating current are identical.
There are two presentation modalities: continuous and pulsed. The continuous modality produces permanent heating due to constant agitation in both displacement and conduction mechanisms. The pulsed modality, or interrupter mode, includes pauses or electrical silence, leading to periods of heating and non-heating. The overall heat generation is considerably reduced, and the frequency of interruptions influences the heat level; higher frequencies lead to more heat, approaching the continuous modality.
The heat produced results in different thermal doses, which must be controlled based on the patient's sensitivity. If the patient lacks good sensitivity in the treatment area, this therapy cannot be applied. The thermal doses are categorized as: Grade 1 (subliminal - no perceived heat), Grade 2 (mild heat - barely felt), Grade 3 (moderate heat - commonly used, produces noticeable physiological effects), Grade 4 (intense heat - causes sweating), and Grade 5 (burning - to be avoided at all costs).
In the continuous modality, thermal grades 1 to 4 can be used, depending on patient comfort and the desired dose for their pathology. In the pulsed modality, the average power can generate perceptible heat, often feeling like a Grade 2. If the average power does not generate perceptible heat, it's akin to a Grade 1 treatment.
Shortwave therapy involves two oscillating circuits: one produced by the equipment and another generated by the electrodes on the patient. For effective results, both circuits must operate at the same frequency. This synchronization is called the resonant circuit. A device called a 'sintonía' (tuning) mechanism ensures both circuits operate at the same frequency, producing an effective treatment. This tuning can be manual, adjusted with a rod, or automatic in more advanced devices. Most current devices feature manual tuning.