| 主权项 |
1. A suction device, comprising:
an outer tube having an inlet at a first outer end, an opening at a proximal end of the outer tube to receive an inner suction tube, and a wall with an inner surface and an outer surface; an inner suction tube to be located within the outer tube, the inner suction tube having an inlet at a first inner end corresponding to the first outer end of the outer tube, an outlet at a proximal end of the inner suction tube, and a wall with an inner surface and an outer surface, the inner suction tube having a smaller diameter than the outer tube, wherein the wall of the inner suction tube includes no openings other than the inlet at the first inner end and the outlet; wherein the inlet of the inner suction tube, when the device is fully assembled, is offset by a distance from the inlet of the outer tube such that the inlet of the inner suction tube is recessed within the outer tube; wherein the outer surface of the wall of the inner suction tube is spaced from the inner surface of the wall of the outer tube; wherein when a suction pressure is applied to the outlet at the proximal end of the inner suction tube and the first outer end of the outer tube contacts a fluid, a first vacuum is formed in a space directly between a proximal portion of the outer surface of the wall of the inner suction tube and a proximal portion of the inner surface of the wall of the outer tube, and a second vacuum is formed within the inner suction tube; wherein the wall of the outer tube includes no openings other than the inlet at the first outer end and the opening at the proximal end of the outer tube to receive the inner suction tube. |
