CONTINUOUS DRUG SOLUTION INJECTOR EQUIPPED WITH BALLOON

摘要

This invention relates to a continuous drug solution injector equipped with a balloon and used for injecting a drug solution filled in a balloon made of an elastic material into the human body within a predetermined period of time by utilizing the shrinking force of the balloon. A bottomed cylinder (3) is fitted slidably with its bottom facing outward into a tubular body (1) which is formed by connectong a drug solution charge portion (5) having a valve member and a drug solution discharge portion (6) having a drug solution discharge control portion through a flow path change-over valve (4) disposed at an intermediate portion. A plurality of holes (12 or 31) are bored in the tubular body or the cylinder. The peripheral edges of the balloon (2) are fixed air-tight to both the tubular body and the cylinder in such a manner as to encompass the junction between the tubular body and the cylinder as well as the holes. Thus the cylinder can slide relative to the tubular body with the aid of the elasticity of the balloon and the inner pressure of the drug solution when the balloon undergoes expansion and shrinkage, and the balloon can undergo expansion and shrinkage in substantially the same quantity in the direction of the center axis in a longitudinal direction and an axial direction vertical to the former, whereby the drug solution can be injected uniformly without intermission.