12.2.2.3 Shape of the electrical stimulation wave
When the stimulation current has vertically reached an intensity higher than the rheobase, how should it
develop in order to oer maximum comfort?
With minimum intensity, it must provide in time 𝑡 the quantity of electrical charges
𝑄 = 𝑖𝑡 + required to trigger the action potential.
Since 𝑄 = 𝐼.𝑡., it is clear that the rectangle is the wave shape capable of providing the quantity of charges 𝑄
with minimum intensity 𝐼 (Fig. 3).
Fig. 3
Comparison of dierent electrical pulse shapes of equal duration, established
vertically and providing the same quantity of electrical charges, which correspond
graphically to identical areas.
In order to create the same quantity of charges with pulses with shapes other than rectangular, higher
intensities must be used, which are as a result even less comfortable for the patient.