The Dorma 500 is an economical pressure-adjusting automatic CPAP machine. It has all the necessary basic functions, such as a pressure reduction function at the beginning of the ramp (ramp) or a function to reduce resistance when exhaling (flex). The set comes with a humidifier ( humidifier) but without hot pipes to prevent condensation in the pipes.
The DreamStation Pro is a semi-automatic CPAP machine. That is, the machine will provide constant pressure throughout the night. but will automatically adjust the pressure up and down every 30 hours (or about 5 days) with the adjusted pressure not exceeding +/- 3 cmH2O
The DreamStation Pro is a newer version. And will have more functions and features than the Dorma, with all the functions of the DreamStation Auto, a model that automatically adjusts the pressure throughout the night.