A prosthetic valve (100) comprising a plurality of leaflets (130), each leaflet comprising a leaflet first side region and a leaflet second side opposite to the leaflet first side region Each leaflet defines a leaflet base (134) and a leaflet free end (142) opposite the leaflet base, each leaflet first side region comprising: The leaflet second side region of the adjacent leaflet is connected by a seam (136), and each leaflet base of each of the plurality of leaflets defines an opening, and at least one of the leaflet first side region The prosthetic valve, wherein the first portion has a first thickness, the second side region has a second thickness, and the first thickness is greater than the second thickness. The leaflet second side region of the leaflet first moves toward the open position before the leaflet first side region, and the leaflet first side region is in front of the leaflet second side region. These leaflets move asymmetrically in that they move first towards the closed position. In the fully open position, the leaflet first side region is less open than the leaflet second side region. The asymmetrical opening and the final opening position produce a spiral flow. A controlled leaflet asymmetric movement reduces the closed volume. [Selection] Figure 1B複数の弁尖（１３０）を含む人工弁（１００）であって、それぞれの弁尖は、弁尖第一側部領域と、弁尖第一側部領域の反対側の弁尖第二側部領域とを画定し、それぞれの弁尖は、弁尖基部（１３４）と、弁尖基部の反対側の弁尖自由端（１４２）とを画定し、それぞれの弁尖第一側部領域は、隣接する弁尖の弁尖第二側部領域と継ぎ目（１３６）で連結しており、複数の弁尖のそれぞれの弁尖基部は共に開口部を画定し、弁尖第一側部領域の少なくとも第一の部分は第一の厚みを有し、第二側部領域は第二の厚みを有し、第一の厚みは第二の厚みよりも厚い、人工弁。弁尖の弁尖第二側部領域は、弁尖第一側部領域の前に開放位置へ向かって最初に動き、弁尖第一側部領域は、弁尖第二側部領域の前に閉鎖位置へ向かって最初に動くという点で、これらの弁尖は非対称に動く。全開位置において、弁尖第一側部領域は弁尖第二側部領域より開きが小さい。非対称の開放及び最終的な開放位置は螺旋流を生ずる。制御された弁尖の非対称の動きは閉鎖体積を低減する。【選択図】図１Ｂ
