Principle of electronic measuring instrument for vital capacity
The volume of the gas that is blown out of the body is the volume of the water that is expelled from the barrel, the volume of the empty part of the barrel. Although it is cheaper and easier to implement than the hundreds of thousands of precision spirometry, the drawback is that it is not accurate enough, intelligent, and can not display and broadcast voice.
In plastic bucket filled with water after the upside down in the water, blowing through the catheter into the barrel, the barrel bottom up by gas water discharge, water flow and water by gravity automatic downward drop principle, can measure the vital capacity.
The principle of the electronic measuring instrument for vital capacity is that the vital capacity is the maximum expiratory volume after a deep inspiration. Because the body's exhaled gas density is lighter than water, it will rise in water, so you can use the "drainage" method of making simple spirometry.
