If it's an Auto machine, you don't have to do anything. because the machine automatically adjusts the air pressure But if using as a manual model, you have to try to adjust the air pressure by yourself by 1 cmH2O, then download the results from the machine to see if the AHI value is more than 5 or not. If not more, try to reduce the pressure again and check the value. AHI Keep watching this until the AHI value starts to exceed 5, then stop adjusting the voltage. In addition, if adjusting the air pressure down to the lowest pressure of 4 cmH2O and finding that the AHI value is not more than 5, it can be considered to stop using the machine.