DOUBLE DECK VENOUS FILETER

摘要

A double-layer deck venous filter includes an upper layer screen and a lower layer screen (1, 2). The upper layer screen (1) is connected to the lower layer screen (2) through a connecting rod (3) disposed in the middle of the screens (1, 2). Each of the upper layer screen (1) and the lower layer screen (2) consists of several filter threads (4, 5) which are led from the center of the screens (1, 2) and are unidirectional and collateral. The shape of the filter threads (4, 5) is chrysanthemumpetal, and the filter threads (4, 5) are radiated from the center of the screens (1, 2) to the peripheral of the screens (1, 2). The filter threads (4) of the upper layer screen (1) are denser than the filter threads (5) of the lower layer screen (2). The filter threads (5) of the lower layer screen (2) are sparse to filter off big thrombus, and the upper layer screen (1) comes into use gridding screen with small density, or the filter threads (4) of the upper layer screen (1) are dense, in order to filter off small thrombus.