Patent attributes
A valve body circumscribes a longitudinal axis and defines a lumen along the axis. Upstream arms are coupled to the valve body, and extend radially outward from the valve body to respective arm-tips. Downstream legs are coupled to the valve body, and extend radially outward from the valve body and toward the plurality of arms. A flexible pouch extends radially outward from the valve body. The arms and the legs narrow the pouch therebetween to form a narrowed portion of the pouch, thereby defining, in an interior space of the pouch: (a) an inner portion, radially inward from the narrowed portion, and in fluid communication with the lumen, and (b) an outer portion, radially outward from the narrowed portion, and in fluid communication with the inner portion via the narrowed portion. Other embodiments are also described.