Thank you dredger for reposting this here.
The history of my experience with the Samozdrav is as follows: a few good years ago, injured, I could not make immoderate physical effort, I saw the Samozdrav on the same site that you presented (Quant-essence), and the name "training device-sports simulator", had attracted my attention.
Of the 4 stages, I had reached about a month and a half, which corresponds to half of the second cycle of training with the breathing apparatus.
Having recovered what I had to recover physically, I left the machine behind. And I don't remember any negative or positive effects, because at that time I was really fit.
Since the years have passed, I now have a big lung weakness, and in one of my piles of boxes, I found the Samozdrav device a month ago, which I am using again, with a very specific purpose.
At the moment I don't have enough experience to say what it's worth.
It may be a cheaper and therefore more accessible option for those who cannot access the hyperbaric chamber, indeed!
The way the Samozdrav works according to the small bulletin provided is to create an active breathing environment with a slightly lower O2 level and a slightly higher CO2 level, this mixture breathed through the device allows the restoration of a normal CO2 level, thus soliciting the respiratory muscles by creating an inhalation/exhalation resistance.
When I say CO2 here, I mean the CO2 produced by our own breathing.
CO2 is a natural dilator of the blood vessels, its increase eliminates
HYPERTONIA and normalizes the blood irrigation of all the organs.
In this respect, when faced with a ravine, the HBOT transports you to the other side of the ravine, whereas the Samozdrav, when faced with the same ravine, advises you to step back in order to better jump.
In the same vain of idea in order to relieve respiratory problems:
Méthode de respiration Buteyko