| 摘要 |
<p>A spirometer for measurement of both the rate and volume of expiratory breathing, and creating a graphic record of the same. The spirometer incorporates an expansible chamber of the piston type, fitted with a molded rolling rubber seal. A recording surface in the form of a card is attached to the piston and a pen is moved across the face of the card at a constant velocity as a subject breathes into the expansible chamber. There is obtained a plot of the volume of expiration flow as a function of time. A control system provides for automatic operation. An air filled chamber having a movable wall in common with the expansible chamber has air displaced therefrom upon expansion of the expansible chamber. A switch is provided responsive to flow of air from the air filled chamber for activating the recording surface.</p> |
