Contraceptive for men in form of implanted mechanical filter - is positioned in vas deferens and removes sperm from seminal fluid

摘要

The filter consists of a mass of fine granules, of a suitable size to hold back the sperm but not the whole seminal fluid. The granules are placed in a container which could hold them in either of two positions, one making the7 effective as a filter, the other not. By moving them from the one position to the other, the possibility of conception could be restored, when desired. Alternatively, the implant can include a rotary valve, by which the seminal flow could be selectively directed through the filter.