| 摘要 |
A system, method, and apparatus for providing variable expiratory pressure comprises an expiratory chamber in operable communication with an expiratory pathway; a valve within the expiratory chamber wherein the valve comprises an orifice; and a control module configured to alter an area of the orifice wherein the area of the orifice is altered to vary backpressure in the expiratory pathway over the course of expiration. |
