At first glance, the pulse shapes of Physio and SCENAR are really looking very similar. However, after careful analysis, we can see some significant differences, which definitely shows that Physio is absolutely not a SCENAR!
Moreover, it is clearly visible both with and without the electrode-skin contact.
He who has eyes, let him see.
Notice that changing energy in SCENAR causes the change of amplitude, whereas in Physio it doesn’t! (the amplitude in Physio starts to decrease only with energy less than 56).
That means that the effective energy control range is only from 1 to 56!
Now, for those looking for details, you can find the description of stimuli shapes differences below.
- 1. Physio’s stimulus shape with minimal energy and with no load is given on Fig.1(a) in its regular look, and on Fig1(b) it is shown 10 times stretched.
On SCENAR device we adjusted the energy so that the duration of the first pulse stage match Physio’s duration ((1 + 3/5) * 10 = 16µs) on the null line level. This was achieved with energy set on 12. SCENAR stimulus’ form with that energy level and with no load is presented on Fig.1(c) in its regular look, and on Fig.1(d) it is shown 10 times stretched.
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No load
On the stretched oscillograms we can clearly see the difference between Physio and SCENAR – the slope of the first pulse (shown with red line) of the stimulus’ second stage is different in more than 3 times! The shapes of this pulse are also significantly different, whether the further damping oscillations are looking similar in both cases. It is not possible to say which stimulus’ form is better, but the very fact of difference is obvious.
- 2. Now, let’s compare the stimuli shapes with the load. We used the load L1, which is used for SCENAR tuning and control check (its scheme is provided in every Operating manual of SCENAR device). We also change the polarity of oscillograph connection in order to receive the oscillograms with the same polarity given in Physio’s Operating manual).
For both devices we set the maximum energy (250 for SCENAR and 99 for Physio) – see Fig.2. Here we can see some major differences:
- the shape of the first stage (the left half of the screen) in case of SCENAR is almost complete trapeze along the entire stage duration, whereas in case of Physio the trapeze part is less than half of the first stage’s duration (150µs out of 400);
- the amplitude of the second stage’s first pulse (these oscillograms show the negative impulse headed downwards) is 132V versus 82V – see the results of automatic measurements (hereinafter the amplitude of the first pulse of the second stage is called Amplitude). Not only the stimuli shapes are obviously different, but the Amplitude differs by 1.5 times (energy differs at least by 2.5 times!). Of course, the maximum energy is not used on the regular treatment basis, but in some cases we need to use the maximum influence! Physio cannot provide it at all.
Now let’s decrease the duration of the first stage by 100µs for both devices (energy of 200 and 84, respectively) – Fig.3.
- the shape of the first stage remained the same for both devices (trapeze for SCENAR and plummeting trapeze for Physio);
- the Amplitude is 120V vs 80V, therefore, in case of SCENAR the decrease of energy from 250 to 200 – i.e., 1/5 of the control range – leads to Amplitude decrease of 12V, but decreasing Physio’s energy by 15/99 = 1/7 of the control range almost doesn’t change the Amplitude!
Let’s decrease the duration of the first stages again by 100µs for both devices (energy of 150 and 67, respectively –Fig.4.
- the shape of the first stage remained the same for both devices (trapeze for SCENAR and plummeting trapeze for Physio);
- the Amplitude is 100V vs 80 V, therefore, in case of SCENAR the decrease of energy from 200 to 150 – i.e., 1/5 of the control range – leads to Amplitude decrease of 20V, when decreasing Physio’s energy by 17/99 = 1/6 of the control range has no effect on the Amplitude again!
Again, let’s decrease the duration of the first stage for both devices by 100µs (energy 100 and 56, respectively) – Fig.5.
- the shape the first stage for both devices became almost the same (SCENAR has a bit smaller amplitude of the pulse’s first stage than Physio);
- the Amplitude is 100V vs 80 V, therefore, in case of SCENAR the decrease of energy from 150 to 100 – i.e., 1/5 of the control range – leads to another Amplitude decrease of 28V, when decreasing Physio’s energy by 11/99 = 1/6 of the control range finally leads to Amplitude decrease of 4V.
Thus, changing the energy of SCENAR from 250 to 100 (150/250 = 3/5 = 0.6 of the range) changes the Amplitude by (132-72) = 60V or almost in half. For Physio, changing energy from 99 to 56 (43/99 = 0,43 of the range) changes the Amplitude only by 4-6V! Thus, almost half of the energy regulation range does not change the treatment energy, but just changes the shape of the first stage’s pulse a little!
Moreover, the manufacturer shows it himself in the User’s Manual:
Thus, I hope I made it obvious that the stimuli shape of SCENAR and PhysioKey is different.
Author of the material: Michael Unakafov.
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