Patent ID: 7867191

Claim:
An irrigation/aspiration apparatus which supplies an irrigation liquid from an irrigation bottle positioned at a given height to a patient's eye via an irrigation tube and a handpiece connected to the irrigation tube, and aspirates the supplied irrigation liquid with eliminated tissue inside the eye via the handpiece and an aspiration tube connected to the handpiece, the apparatus comprising: a pump for generating aspiration pressure inside the aspiration tube; a chamber, which is arranged on a channel of the irrigation tube from the irrigation bottle to the handpiece, for storing air and the irrigation liquid; a first control valve, which is arranged on a channel of the irrigation tube from the chamber to the handpiece; a vent tube for connecting the chamber with the aspiration tube on the handpiece side with respect to the pump; a second control valve, which is arranged on a channel of the vent tube; a leading vent, which is positioned at a lower portion inside the chamber, for leading the irrigation liquid into the chamber from the irrigation tube on the irrigation bottle side; an outflow hole, which is positioned at the lower portion inside the chamber or on the channel of the vent tube, for flowing the irrigation liquid into the irrigation tube on the handpiece side from the chamber; an outflow pipe extended in an up-and-down direction inside the chamber, of which an inflow hole through which the air and the irrigation liquid inside the chamber flow into the outflow pipe is positioned higher than the leading vent and is disposed to leave a given space at an upper portion inside the chamber, and to which the vent tube is connected; an opening that is formed on a wall of the outflow pipe, is arranged at a position higher than the leading vent and lower than the inflow hole, has a narrow width that is set such that the opening is closed by surface tension of the irrigation liquid during a time from when a liquid level of the irrigation liquid inside the chamber rises by leading the irrigation liquid from the leading vent to when the liquid level of the irrigation liquid reaches the inflow hole, and acts as a path of the irrigation liquid after the irrigation liquid flows into the outflow pipe from the inflow hole by a further rise of the liquid level of the irrigation liquid; and a control part that controls driving of each of the pump, the first control valve, and the second control valve such that the irrigation tube, the aspiration tube, and the vent tube are filled with the irrigation liquid and the chamber is filled with the irrigation liquid leaving a given space, wherein the air inside the given space inside the chamber filled with the irrigation liquid is compressed corresponding to a height of the irrigation bottle.