PROBLEM TO BE SOLVED: To provide a mixing device, mixing tube, medical solution injection system, and medical solution mixing method capable of uniformly and highly efficiently mixing a plurality of types of medical solutions at a desired density in injection and, even when being a small amount of medical solution, capable of mixing it at high mixing efficiency.SOLUTION: The mixing device according to the present invention includes: a swirl-flow generation chamber 2 for generating a swirl flow； a first inflow port 14 that introduces a first medical solution to the swirl-flow generation chamber in a direction parallel to a central axis of the swirl flow； a second inflow port 15 that introduces a second medical solution to the swirl-flow generation chamber so as to generate, in the swirl-flow generation chamber, a swirl flow of the second medical solution having a specific gravity smaller than the specific gravity of the first medical solution； an outflow port 16 for flowing out mixed medical solution of the first medical solution and the second medical solution； and a constricted chamber 3 provided between the swirl-flow generation chamber and the outflow port and continuously constricted toward the outflow port.SELECTED DRAWING: Figure 10【課題】注入時において複数種類の薬液を所望する濃度で均一に効率よく混合でき、少量の薬液であっても高い混合効率で混合できるミキシングデバイス、ミキシングチューブ、薬液注入システム及び薬液の混合方法を提供する。【解決手段】本発明に係るミキシングデバイスは、旋回流を生成するための旋回流生成室２と、上記旋回流の中心軸と平行な方向で第１薬液を上記旋回流生成室に導入するための第１流入口１４と、上記第１薬液の比重より小さい比重を有する第２薬液の旋回流が上記旋回流生成室において生成されるように、上記第２薬液を上記旋回流生成室に導入するための第２流入口１５と、上記第１薬液と上記第２薬液との混合薬液が流出する流出口１６と、上記旋回流生成室と上記流出口との間に設けられ、上記流出口に向かって連続的に狭窄している空間を有する狭窄室３とを備える。【選択図】図１０
