Non contact tonometer

摘要

PPROBLEM TO BE SOLVED: To provide a contactless ophthalmotonometer capable of reducing unnecessary contact noises. PSOLUTION: In the contactless ophthalmotonometer, gas in a cylinder is compressed by a piston, the compressed gas is blown against an object's eye cornea, and intraocular pressures is measured by detecting a deformation state of the cornea. The contactless ophthalmotonometer is provided with: a piston having a gas passage linked to the air compression chamber and a gas release chamber in the cylinder; a rod which is connected to the piston so that it can move in an axial direction on the gas passage and has a drive valve for opening/closing the gas passage at its tip; an energizing means for energizing the drive valve and the piston in the direction in which the gas passage is closed; and a driving means which is driven by supply of drive current and moves the piston by moving the rod in the direction in which the gas in the cylinder is compressed. When the rod is driven at an initial position or in the direction in which the gas is compressed, it is in a state that the gas passage is closed by the drive valve; when the rod returns to the initial position, the gas passage is open. PCOPYRIGHT: (C)2009,JPO&INPIT