Kowa Company Limited

Yazaki Corporation

Tohoku University

Satoshi Shimada

Takuya Hara

Toru Nakazawa

Shinji Tsuchiya

Yoshikatsu Suzumura

Shigeru Takimoto

Takeshi Hasegawa

Shin Tanaka

Masayoshi Oouchi

In examining a patient for progression of glaucoma, a perimeter capable of appropriately assessing visual field progression in a short period of time, therefore lessening the physical burden of testing on the examinee.

Perimeter for testing for progression of Glaucoma

In a perimetry to be conducted, designating an inspection region through a region designator, a perimeter is configured to set a required time of the perimetry (upper limit time) through an upper limit condition setter and to determine total number or positions of stimulus presentation spots based upon the upper limit time. In such a configuration, an examinee knows the time to finish the inspection, and is able to highly keep his (her) concentration in comparison with a case where the required time is not known, thereby improving precision of the inspection.

Perimeter

Through the present invention, a perimetry result is obtained for a position on a retina surface designated as a position to be tested. As illustrated in the drawing, 'the position of a ganglion cell (RGC)' and 'the position of a photoreceptor cell (C) for sending information to the ganglion cell (RGC)' are offset on the retina surface (macular part). Here, when position (P) is designated as a test position for testing the functioning of a ganglion cell at position (P), the perimeter of the present invention finds &#x201c;the position (P) of the photoreceptor cell for sending information to the ganglion cell at position (P),&#x201d; presents a visual target at position (P) rather than position (P), and tests a visual field. The information of the visual target is sent to the ganglion cell at position (P), and the functioning of the ganglion cell can therefore be tested. The test result is correlated with the position (P) and displayed, and the ganglion cell at the designated position (P) can be therefore be tested.

In a perimetry to be conducted, designating an inspection region through a region designator, stimuli are presented to regions separated in an up/down direction, an oblique direction and a right/left direction from the inspection region ('the spaced region') in addition to the designated inspection region. At the result, examinees are not able to predict to which of both regions, the inspection region and the spaced region the stimuli are presented, thereby obtaining correct inspection results that do not receive a prediction of the examinees.

The perimeter (), which has a perimetry means () that measures the visual field of a test eye and outputs the results thereof as measurement results (MR), is configured by comprising: a measurement database memory () wherein multiple measurement results of previous visual field measurements are stored as a measurement database (MDB) in a form that is divided into a database (DB) pertaining to normal eyes and a database (DB) pertaining to eyes with glaucoma; a means () for assessing whether or not the measurement results (MR) for the test eye can be used as measurement results for normal eyes; and a means () that, when it is determined that the measurement results can be used as measurement results for normal eyes, adds the measurement results to the database (DB) pertaining to normal eyes along with database search attribute data (data such as the subject's age, sex, race, visual acuity, refractive index, diagnosis, residence, date and time of examination, etc.).

A visual field examination system measures the visual field of an eye. Quantitative information of a 3D retinal layer structure is acquired by detecting a range in which a peak of a retinal reflectance distribution obtained by OCT scanning is lost. A position of the fovea of the eye fundus is identified based on the acquired information. A location of a range in which the peak of the retinal reflectance distribution is lost is specified in a 2D fundus image based on the position of the fovea, and the specified location is marked on a region of the 2D fundus image. A position of the marked region is detected, and a visual inspection field region is generated based on the detection. Visual field examination points of the visual inspection field region are presented to the eye through a visual field dome for carrying out visual field examination of the eye.

Visual field examination system

In a perimeter having means for measuring a visual field of an eye to be examined, means for monitoring fixation state and means for lighting the eye to be examined with a brightness necessary for monitoring the fixation state of the eye to be examined and means for correcting visibility, means for correcting visibility is provided so as to be freely moved between a set position corresponding to a measurement position of the eye to be examined and a stored position retracted to an outer periphery of a projection member. Such a perimeter further has means for detecting whether means for correcting visibility is at the set position or the stored position and an illustration controller for changing brightness of the illumination onto the eye to be examined through the means for lighting according to the detected position of means for correcting visibility.

A virtual sensitivity value which is obtained, variously changing a pupil diameter is measured in advance for many examinees, and volume of correction which is necessary at the time when the sensitivity value is corrected into one in a standard pupil diameter is stored as correction volume database. An apparatus has measurement means for measuring the pupil diameter of the eye to be examined, computing means for computing a shape parameter rate of the measured pupil diameter to the standard pupil diameter, and judgment means for computing volume of correction by referring to the correction volume database from the shape parameter rate and correcting the virtual sensitivity value obtained by measurement of the eye to be examined and for judging a sensitivity step of the eye to be examined.

Ophthalmic apparatus

A perimeter performs a kinetic visual field examination on the basis of a response as to whether a subject visually recognizes a displayed stimulus for kinetic visual field examination. The stimulus is displayed a series of times on an inner surface of a visual field dome. An operation is performed in which the subject is made aware of an operating sound of the perimeter while no stimulus is actually displayed. The operation is performed at a predetermined frequency during the display times of the stimulus, and a duration of the operation is determined in accordance with a response time by the subject to the displayed stimulus. The reliability of the kinetic visual field examination is evaluated on the basis of the response of the subject in the performed operation.

It is easy to perceive a stimulus in a central portion of a visual field rather than in a peripheral portion thereof, and it is easy to perceive the stimulus for a younger examinee rather than for an older examinee even if the stimulus having the same luminance is indicated. In the perimeter according to the invention, the stimuli are indicated at various positions of a visual field dome, and the luminance of the stimulus is gradually raised before obtaining a response from an examinee through an operation switch. A value of the luminance of the indicated stimulus is set according to the position of the indicated stimulus and an age of the examinee, and the measurement accuracy is correct, thereby.

Perimeter has input means for inputting identification data of an examinee and a kind of perimetry to be conducted, means for judging whether or not the examinee has already received the perimetry, means to read examinee measurement information, means to judge whether or not a kind of inputted perimetry is different from the past perimetry, means to compute and determine initial stimulus luminance of the perimetry to be conducted from now on as a value equal to the sensitivity which is shown in sensitivity distribution data or closer thereto from the sensitivity distribution data of the past perimetry if different kind is judged, and means for starting the perimetry with the determined initial stimulus luminance.

A Perimeter is provided for designating a perimetry point for an eye to be examined with a fundus image of the eye which has already been provided so as to compensate the individual variation in the position of a blind spot to the maculalutea.

A method of predicting a displacement range of a wire harness, includes the steps of: designing a basic route of the wire harness; fixing the wire harness at least two different fixing points on the basic route; computing a displacement range of the wire harness between the fixing points, based on a length of the basic route between the fixing points including a dimensional tolerance, fixing positions and fixing directions of the wire harness at the fixing points, and a minimum bending radius of the wire harness; and displaying the displacement range of the wire harness in three dimensions.

Growing community of inventors

Hamamatsu, Japan

Satoshi Shimada