FIELD: medicine.SUBSTANCE: group of inventions relates to medical equipment. In the method, the mouthpiece contains an intake tube an oxidizing filter body having an inlet and an outlet with an inner diameter between 9.6 mm and 18 mm a first filter, located near the inlet of the oxidizing filter body, and a second filter, located near the outlet of the oxidizing filter body. Filter particles are arranged between the first and second filters and include CaSO, including a solid porous substrate impregnated with sodium permanganate. Further, a connector connects the intake tube to the inlet of the oxidizing filter body. And the outlet tube is connected to the outlet of the oxidizing filter body. Said oxidizing filter body, the first and second filters and the filter particles give a flow resistance of less than 4 cm HO. Said sensor is connected to receive exhaled breath coming from the inlet tube through the outlet tube, wherein the sensor displays the output data. Said pressure sensor is connected to the outlet of the oxidizing filter body and has an outlet, an electronics unit connected to the pressure sensor output to calculate the pressure measurement and a display connected to receive and display a breath pressure measurement such that the subject can respond by adjusting the exhalation force to maintain a stable pressure and flow rate within plus or minus 10%. Disclosed is a method for adjusting the exhalation force to maintain a stable pressure and flow rate.EFFECT: technical result consists in simplifying the measurement of nitric oxide by providing a low counter pressure.18 cl, 8 dwgГруппа изобретений относится к медицинской технике. Мундштук содержит впускную трубку корпус окислительного фильтра, имеющий впуск и выпуск, имеющий внутренний диаметр между 9,6 мм и 18 мм первый фильтр, расположенный вблизи с впуском корпуса окислительного фильтра, и второй фильтр, расположенный вблизи с выпуском корпуса окислительного фильтра. Фильтрующие частицы упакованы между
