| 摘要 |
<p>The pump is used to apply suction to the skin and comprises a cylindrical body containing a piston. This is a fine fit in the cylinder and its end projects beyond the body to form a cap. The pump nozzle is placed against the skin and its body held in the hand, the thumb on the cap. The plunger is depressed to eject the air in the pump and then released. Skin contact prevents air entering the pump and the piston is returned under spring pressure to create the suction.</p> |
