Noncontact type tonometer
AssigneeTopcon Corporation
InventorMineki Hayafuji
Life of this patent
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Abstract
A noncontact type tonometer capable of accurately measuring intraocular pressure of a subject's eye even if the intraocular pressure is much higher than normal. The noncontact type tonometer comprises a fluid discharging device for discharging fluid toward a cornea of the eye, a corneal transfiguration detecting portion for detecting the corneal transfiguration, a pressure detecting portion for detecting discharge pressure of the fluid, and a delay circuit for determining the precise moment for stopping the operation of the fluid discharging means according to the discharge pressure detected by the pressure detecting means.
Claims2
A noncontact type tonometer comprising:
- means for discharging fluid toward a cornea of a subject's eye;
- means for detecting discharge pressure of the fluid and for generating a discharge pressure signal;
- means for detecting transfiguration of the cornea and for generating a corneal transfiguration signal;
- means for generating a corneal transfiguration reference signal;
- means for comparing the corneal transfiguration signal with the corneal transfiguration reference signal and for generating a coincidence signal before applanation of the cornea when the corneal transfiguration signal coincides with the corneal transfiguration reference signal;
- means for generating a driving signal in response to the discharge pressure signal, the corneal transfiguration signal, and the corneal transfiguration reference signal;
- means for determining when to stop operation of the means for discharging fluid after calculating a delay time according to the discharge pressure signal and the coincidence signal and for generating a stop signal;
- and means for controlling the means for discharging fluid according to the driving signal and the stop signal.
A noncontact type tonometer comprising:
- means for discharging fluid toward a cornea of a subject's eye;
- means for detecting discharge pressure of the fluid and for generating a fluid discharge pressure signal:
- means for detecting transfiguration of the cornea and for generating a corneal transfiguration signal;
- means for generating a corneal transfiguration reference signal;
- means for comparing the corneal transfiguration signal with the corneal transfiguration reference signal and for generating a coincidence signal before applanation of the cornea when the corneal transfiguration signal coincides with the corneal transfiguration reference signal;
- means for generating a driving signal in response to the discharge pressure signal, the corneal transfiguration signal, and the corneal transfiguration reference signal
- a timer for counting elapsed time of the driving signal and for generating a delay time signal;
- means for determining when to stop operation of the means for discharging fluid according to the delay time signal and the coincidence signal and for generating a stop signal:
- and
- means for controlling the means for discharging fluid according to the driving signal and the stop signal.
Dependencies are inferred from the claim text.