JPH10201714A - Ophthalmic diagnostic system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate an ease of operating turning an image rotator by measuring a width in a part at where a detection field crosses a blood vessel by tracking the primary movement of the blood vessel to irradiate the measured luminous flux always onto a measuring position on the fundus and by displaying a value corresponded to the measured width at the part at where it crosses a blood vessel. SOLUTION: This system takes a luminous flux, via a pair of mirrors 64a, 64b, passing through the measured receiving luminous fluxes out of a luminous flux measured on the pupil Ep of a subject's eye, taken out of a blood vessel receiving luminous flux and received into the primary source CCD61, which is then received by the photo-multipliers 65a, 65b. Both the measuring/tracking lights have a part of light scattered/reflected at the fundus Ea transmit the band path mirror 32, which is then lead to the fundus observation optical system behind the hole-opened mirror 31. The tracking light is then imaged as a bar- type indicator on the scale board 35, while the measuring light, as a spot image at the center of the indicator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmologic diagnosis apparatus for irradiating a fundus of an eye to be examined with a light beam and measuring its ophthalmologic characteristics.

[0002]

2. Description of the Related Art Conventionally, an ophthalmologic diagnostic apparatus for irradiating a measurement light beam such as a laser beam into an eye to measure characteristics of an eye to be examined includes a fundus blood flow meter and a laser flare cell meter.
The fundus blood flow meter measures the blood flow in the fundus blood vessels that can be directly observed noninvasively, and various fundus blood flow meters utilizing the Doppler principle and the speckle phenomenon have been devised.

In such a fundus blood flow meter, the movement of the fundus is tracked in order to constantly irradiate the measurement light beam to the measurement position on the fundus. As described in JP-A-63-288133, the motion of two blood vessels is detected,
One for two-dimensional tracking;
As described in Japanese Patent No. 3733, there is a device that detects a movement of a blood vessel in a direction perpendicular to a running direction and performs one-dimensional tracking.

In a general fundus blood flow meter, even if the fundus moves in the direction of blood vessel movement, the blood flow measurement is hardly affected, so that the operation is easier and the configuration is simpler. Has been put to practical use.

[0005]

[Problems to be solved by the invention]

(1) However, as in the conventional example described above, in an ophthalmic diagnostic apparatus that performs one-dimensional tracking, an image rotator or the like is rotated so that the direction in which the motion of a blood vessel is detected is perpendicular to the running direction of the blood vessel. Must be
There is a problem that operation is troublesome.

(2) In a fundus blood flow meter that measures blood flow in a fundus blood vessel, the blood flow velocity, the blood flow rate, and the like are calculated on the assumption that the blood flows in a direction perpendicular to the direction in which the movement of the blood vessel is detected. Therefore, there is a problem that the rotational alignment accuracy of the image rotator or the like affects the measurement result.

A first object of the present invention is to solve the above problem (1).
It is an object of the present invention to provide an ophthalmologic diagnosis apparatus that eliminates the need for complicated operations for rotating an image rotator or the like.

A second object of the present invention is to solve the above problem (2).
It is an object of the present invention to provide an ophthalmic diagnosis apparatus in which the rotational alignment accuracy of an image rotator or the like does not affect the measurement result.

[0009]

An ophthalmic diagnostic apparatus according to the present invention for achieving the above object has an irradiating means for irradiating a fundus of a subject's eye with a measuring light beam for measuring characteristics of the subject's eye. In the apparatus, a detection unit that detects a one-dimensional movement of a blood vessel on the fundus, a blood vessel detection unit that enables the detection unit to relatively rotate with respect to the blood vessel, and a portion where the detection unit intersects with the blood vessel Cross-width measuring means for measuring the width of the blood vessel, tracking means for tracking the one-dimensional movement of the blood vessel and constantly irradiating the measurement light beam to a measurement position on the fundus, and corresponding to the width of a portion intersecting the blood vessel. Display means for displaying the values before the measurement of the characteristics of the eye to be examined.

An ophthalmologic diagnostic apparatus according to the present invention is an ophthalmic diagnostic apparatus having an irradiating means for irradiating a fundus of a subject's eye with a measurement light beam for measuring characteristics of the subject's eye. A detection unit that detects the movement of the blood vessel, a blood vessel detection unit that can relatively rotate the detection unit with respect to the blood vessel, an intersection width measurement unit that measures the width of the intersection of the detection unit and the blood vessel, Tracking means for tracking the one-dimensional movement of the blood vessel and constantly irradiating the measurement light beam to a measurement position on the fundus; and automatically rotating the detection unit before measuring the characteristics of the eye to be inspected with respect to the blood vessel, optimally. And a driving means for converting the data.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 shows a perspective view of the first embodiment,
A stage fixing part 2 and a television monitor 3 are mounted on a base 1, and a stage movable part 4 and a chin support 5, which are movable back and forth and right and left, are fixed to the stage fixing part 2. A measuring head 6 is mounted on the stage movable section 4, and an operation rod 7, a switch 8, an operation ring 9, a measurement mode selection switch 10, and a display LED 11 are fixed to the examiner. The measurement head 6 includes an operation knob 12, a focus knob 13, and an image rotator knob 1 as fixation target moving means.
4 are provided.

FIG. 2 is a structural view of the main body of the fundus blood flow meter built in the measuring head 6 and is arranged at a position facing the eye E from an observation light source 21 such as a tungsten lamp that emits white light. A condenser lens 23, for example, a field lens 24 with a band-pass filter that transmits only light in the yellow range, and a pupil Ep of the eye E to be examined are provided on the illumination optical path to the objective lens 22. A ring slit 25, a light shielding member 26 provided at a position substantially conjugate with the crystalline lens of the eye E, a relay lens 27, and a fixation target display element movable along an optical path, as shown in FIG. Liquid crystal panel 2 on which dot patterns Q are lined up
8, a relay lens 29, a light-blocking member 30 provided conjugate with the vicinity of the cornea of the eye E, a perforated mirror 31, and a band-pass mirror 32 that transmits light in the yellow range and almost reflects other light beams are sequentially arranged. Thus, an illumination optical system is configured.

The ring slit 25 and the light shielding member 2
Reference numerals 6 and 30 are provided for separating the fundus illumination light and the fundus observation light in the anterior segment of the eye E to be examined, and their shapes do not matter as long as they form a necessary light-shielding region.

A fundus observation optical system is provided behind the perforated mirror 31. The focusing lens 33, the relay lens 34, and the scale plate 3 are movable along the optical path.
5. An optical path switching mirror 36 and an eyepiece 37, which can be inserted and removed in the optical path, are sequentially arranged to reach the examiner's eye e. A television relay lens 38 and a CCD camera 39 are arranged on the optical path in the reflection direction when the optical path switching mirror 36 is inserted in the optical path, and the output of the CCD camera 39 is connected to the television monitor 3. .

An image rotator 40 and a galvanometric mirror 41 polished on both sides having a rotation axis perpendicular to the paper are provided on the optical path in the reflection direction of the band-pass mirror 32.
Is disposed in the direction of reflection of the lower reflection surface 41a of the galvanometric mirror 41. The second direction is movable along the optical path.
Focus lens 42 is disposed on the upper reflective surface 41b.
A lens 43 and a focus unit 44 that can move along the optical path are disposed in the reflection direction. The front focal plane of the lens 43 has a conjugate relationship with the pupil Ep of the eye E, and the galvanometric mirror 41 is disposed on this focal plane.

Above the galvanometric mirror 41, an optical path length compensating meniscus 45, a black spot plate 46 having a light shielding portion in the optical path, and a concave mirror 47 are arranged, and are reflected by the lower reflecting surface 41a of the galvanometric mirror 41. A relay optical system that guides a light beam that passes through the upper surface to the upper reflecting surface 41b of the galvanometric mirror 41 is configured.
The optical path length compensating meniscus 45 is used to correct the position of the upper reflecting surface 41b and the lower reflecting surface 41a of the galvanometric mirror 41 in the vertical direction in the drawing caused by the mirror thickness. Rotator 40
It works only in the light path toward.

In the focus unit 44, a dichroic mirror 48 and a condenser lens 49 are sequentially arranged on the same optical path as the lens 43, and the dichroic mirror 4
A mask 50 and a mirror 51 are arranged on the optical path in the reflection direction of 8, and the focus unit 44 can move integrally in the direction indicated by the arrow. Also,
On the optical path in the incident direction of the lens 49, a fixed mirror 52,
An optical path switching mirror 53 that can be retracted from the optical path is disposed in parallel, and a collimator lens 54 and a measuring semiconductor laser light source 55 that emits coherent, for example, red light are arranged on the optical path in the incident direction of the optical path switching mirror 53. I have.
Further, on the optical path in the incident direction of the mirror 51, a beam expander 56 composed of a cylindrical lens or the like and a tracking light source 57 that emits, for example, high-luminance green light different from other light sources are arranged.

A second focusing lens 42, a dichroic mirror 58, a field lens 59, a magnifying lens 60, a one-dimensional CCD 61 with an image intensifier are provided on the optical path in the reflection direction of the lower reflection surface 41a of the galvanometric mirror 41. Are sequentially arranged to form a blood vessel detection system. Also, the dichroic mirror 58
An imaging lens 62, a confocal stop 63, and mirror pairs 64a and 64b provided substantially conjugate with the pupil Ep of the eye E to be examined are arranged on the optical path in the reflection direction of
The photomultipliers 65a,
65b is arranged, and a light receiving optical system for measurement is configured. For convenience of illustration, all the optical paths are shown on the same plane, but the reflected optical paths of the mirror pairs 64a and 64b, the measuring optical path in the emission direction of the tracking light source 57, and the optical path from the semiconductor laser light source 55 to the mask 50 are Each is perpendicular to the paper.

Further, a system control unit 66 for controlling the entire apparatus is provided.
Switch 8, measurement mode selection switch 10, operation knob 1
2. The outputs of the photomultipliers 65a and 65b and the left / right movement detecting means 67 are connected respectively. One-dimensional CC
The output of D61 is connected to a blood vessel detection circuit 68, and the output of the blood vessel detection circuit 68 is connected to a system control unit 66 and a control circuit 69 that controls the galvanometric mirror 41,
The output of the system controller 66 is connected to the display LED 11, the transmissive liquid crystal panel 28, the optical path switching mirror 53, and the control circuit 69, respectively.

FIG. 4 shows the arrangement of each light beam on the pupil Ep of the eye E to be examined. I denotes an image of the ring slit 25 in a region illuminated by yellow illumination light, O denotes a fundus observation light beam, and The image of the opening, V is the measurement / vessel received light beam, the image of the effective portion of the upper and lower reflection surfaces 41b, 41a of the galvanometric mirror 41, Da and Db are the two measured received light beams and the images of the mirror pair 64a, 64b, respectively. is there. Further, P1 and P1 ′ are the incident positions of the measuring light, and indicate the positions of the measuring light selected by switching the optical path switching mirror 53, and a region M indicated by a chain line is the lower reflecting surface 41 of the galvanometric mirror 41.
It is an image of a.

At the time of measurement, the examiner first fixes the subject's face on the chin support 5 and selects a measurement mode for measuring, for example, blood vessels near the nipple by using the measurement mode selection switch 10. The left and right positions of the stage movable base 3 are detected by the left and right movement detecting means 67 to determine whether the subject's eye E is a left eye or a right eye, and signals from the left and right movement detecting means 67 and the measurement mode selection switch 10 are used for system control. It is sent to the unit 66. In response to these signals, a predetermined dot pattern Q predetermined on the transmission type liquid crystal plate 28 is displayed as a fixation target, and the observation light source 21 is turned on.

The white light emitted from the observation light source 21 passes through the condenser lens 23, and only the yellow wavelength light is transmitted by the field lens 24 with the band-pass filter, and passes through the ring slit 25, the light shielding member 26, and the relay lens 27. The transmissive liquid crystal panel 28 is illuminated from behind, and the relay lens 2
9, only the light in the yellow range is reflected by the perforated mirror 31 through the light-shielding member 30, passes through the band-pass mirror 32, passes through the objective lens 22, and passes through the objective lens 22 onto the pupil Ep of the eye E to be examined. After forming an image once as I, the fundus Ea is illuminated almost uniformly.

At this time, one of the dot patterns Q is displayed on the transmissive liquid crystal plate 28, this is projected on the fundus oculi Ea of the eye E by illumination light, and presented to the eye E as a target image. You. The examiner can operate the operation knob 12 to send a signal to the system control unit 66, change the position of the presented dot pattern Q, and guide the eye E to be examined.

The reflected light from the fundus oculi Ea returns along the same optical path and is taken out of the pupil Ep as a fundus oculi observation light beam O, and the opening at the center of the perforated mirror 31 and the focusing lens 3
3. After passing through the relay lens 34 and forming an eye fundus image Ea 'on the scale plate 35 as shown in FIG. 5, the light reaches the optical path switching mirror 36. Here, when the optical path switching mirror 36 is retracted from the optical path, the eyepiece 37 is moved by the examiner's eye e.
When the optical path switching mirror 36 is inserted in the optical path, the fundus image Ea 'formed on the scale plate 35 is converted into a CCD camera by the television relay lens 38. The image is re-imaged on 39 and displayed on the television monitor 3.

The examiner can use the eyepiece 37 or the television monitor 3
By operating the operating rod 7 and the operating ring 9 while observing the fundus image Ea ′, the stage movable section 4 is slid in the XZ plane and in the Y direction to perform positioning with respect to the eye E to be examined. At this time, it is preferable to adopt an observation method according to the purpose. In the case of observation with the eyepiece 37, since the resolution is generally higher and the sensitivity is higher than that of the television monitor 3 or the like,
It is suitable for the case of reading and diagnosing minute changes in the fundus oculi Ea.

On the other hand, in the case of observation with the television monitor 3, since the field of view is not restricted, the fatigue of the examiner can be reduced, and the output of the CCD camera 39 is connected to an external video tape recorder or video printer. By
Since it is possible to electronically record the change of the measurement site on the fundus image Ea ', it is extremely effective clinically.

Next, the measuring semiconductor laser light source 55 and the tracking light source 57 are turned on. The measurement light emitted from the semiconductor laser light source 55 is collimated by the collimator lens 54, and when the optical path switching mirror 53 is inserted in the optical path, the measurement light is reflected by the optical path switching mirror 53 and the fixed mirror 52, respectively. When the optical path switching mirror 53 is retracted from the optical path, the light passes directly through the upper part of the condensing lens 49 and the dichroic mirror 48, and is converged with the center of the opening of the mask 50 by the condensing lens 49. An image is formed in a spot shape at a conjugate position.

The beam diameter of the tracking light emitted from the tracking light source 57 is expanded by the beam expander 56 at different magnifications in the vertical and horizontal directions, and after being reflected by the mirror 51, it is shaped into a desired shape by the shaping mask 50. ,
The light is reflected by the dichroic mirror 48 and is superimposed on the measurement light.

The superimposed measurement light and tracking light pass through the lens 43, are reflected once by the upper reflection surface 41b of the galvanometric mirror 41, and after passing through the black spot plate 46,
The light is reflected by the concave mirror 47, passes through the black spot plate 46 and the meniscus 45 for correcting the optical path length, and is returned to the galvanometric mirror 41. Here, the galvanometric mirror 41
Is disposed at a position conjugate with the pupil Ep of the eye E, so that the image of the galvanometric mirror 41 has a shape indicated by a broken line M in FIG.

Further, the concave mirror 47, the black spot plate 46, and the meniscus 45 for correcting the optical path length are arranged concentrically on the optical path, and together reduce the upper reflecting surface 41b and the lower reflecting surface 41a of the galvanometric mirror 41 by -1. Is provided with the function of a relay system that forms an image on the optical path switching mirror 53 by inserting and retracting the optical path switching mirror 53 into the optical path.
4 are reflected at positions P1 and P1 'in FIG. 4 on the back side of FIG.
As a result, the image rotator 4 is returned to the position P 2 ′ without being reflected by the galvanometric mirror 41.
Go to zero. Then, both light beams deflected toward the objective lens 22 by the band-pass mirror 32 via the image rotator 40 are radiated to the fundus oculi Ea of the eye E through the objective lens 22.

As described above, the measurement light and the tracking light are:
When the light is reflected in the upper reflecting surface 41b of the galvanometric mirror 41 and returned again, the light is incident on the galvanometric mirror 41 while being decentered from the optical axis of the objective lens 22, and passes from the position P1 to the position P2 on the pupil Ep. The light beam becomes the spot image P, and the light beam passing from the position P1 'to the position P2' forms an image as a spot image P ', and thereafter irradiates the fundus oculi Ea in a point-like manner.

The light beam scattered and reflected by the fundus oculi Ea is collected again by the objective lens 22, reflected by the band-pass mirror 32, passed through the image rotator 40, and
The measurement light and the tracking light are reflected by the lower reflection surface 41 a of the galvanometric mirror 41, pass through the focus lens 42, and are separated by the dichroic mirror 58.

The tracking light is a dichroic mirror 5
8, and is formed on the one-dimensional CCD 61 by the field lens 59 and the imaging lens 60 as a blood vessel image Ev 'which is larger than the fundus image Ea' by the fundus observation optical system.
On the other hand, the measuring light is reflected by the dichroic mirror 58 and passes through the opening of the confocal stop 63 to the mirror pair 64a, 64a.
4b, respectively, and each of the photomultipliers 65
a and 65b.

At this time, due to the spectral characteristics of the bandpass mirror 32, the illumination light from the observation light source 21
Since it does not reach 61 and the imaging range is set narrow, harmful flare light is unlikely to be mixed. As a result, only the blood vessel image Ev 'by the tracking light is captured on the one-dimensional CCD 61. In addition, since blood hemoglobin and melanin on pigment epithelium have significantly different spectral reflectances in the green wavelength range, it is possible to capture a blood vessel image Ev 'with good contrast by using green tracking light. Become.

The light beam received by the one-dimensional CCD 61 is a light beam extracted from the measured / blood vessel received light beam V on the pupil Ep of the eye E to be examined, and the mirror pair 64a, 64b is derived from this light beam.
The light beams passing through the measured light beams Da and Db are taken out by means of, and are received by the photomultipliers 65a and 65b. The reason why the measurement / blood vessel received light beam V is larger than that of the fundus observation light beam O is that the one-dimensional CCD 61 uses the CC of the fundus observation optical system.
Since the imaging magnification of the fundus oculi Ea is larger than that of the D camera 39,
This is because it is difficult to secure the image plane illuminance on the one-dimensional CCD 61. On the other hand, the influence of the flare light generated in the anterior segment of the eye E due to the increase of the light flux is not a problem because the blood vessel image receiving optical system has a smaller image receiving range. Although the distance between the measured light beams Da and Db on the pupil Ep directly affects the resolution of blood flow velocity measurement, the distance between the measured light beams Da and Db is sufficiently secured by increasing the measurement / blood vessel light beam V. It becomes possible.

Further, the fundus by measuring light and tracking light
Part of the scattered reflected light at Ea passes through the band-pass mirror 32 and is guided to the fundus observation optical system behind the perforated mirror 31, and the tracking light forms an image as a bar-shaped indicator T on the scale plate 35, The measurement light forms a spot image at the center of the indicator T. As shown in FIG. 5, these images are observed together with the fundus image Ea ′ via the eyepiece 37 or the television monitor 3 and the optotype image F projected on the fundus oculi Ea of the eye E by illumination light. At this time, a spot image (not shown) is superimposed on the center of the indicator T, and the center of the indicator T falls within a scale S of a perfect circle prepared in advance on the scale plate 35 projected on the fundus oculi Ea. By rotating the switch 8, the indicator T can be moved one-dimensionally.

The examiner rotates and adjusts the focus knob 13 to focus the fundus image Ea '. Focus knob 13
Is rotated, the transmission type liquid crystal plate 28, the focusing lenses 33 and 42, and the focus unit 44 move along the optical path in conjunction with each other by a driving unit (not shown), and the fundus image Ea '
Is focused, the transmission type liquid crystal panel 28 and the scale panel 3
5. The one-dimensional CCD 61 and the confocal stop 63 are simultaneously placed on the fundus Ea.
Is conjugate to

The function of the confocal stop 63 is to focus on a desired blood vessel Ev. Referring to FIG. 6, the light beam from the semiconductor laser light source 55 for measurement enters the mirror 71 from below, The light is reflected in the direction and irradiates the measurement site K1 of the blood vessel Ev on the fundus oculi Ea to be measured.
The reflected light at the measurement site K1 passes through an opening 72 having the same function of determining the light receiving direction as the mirror pair 64a, 64b, is conjugated to the measurement site K1 by the lens 73, and
4 and a photomultiplier 65 (not shown)
a and 65b. On the other hand, the reflection point at the measurement site K2 of the blood vessel Ev in the choroid behind the measurement site K1 travels along the optical path shown by the dotted line, and is imaged by the lens 73 similarly to the light beam reflected at the measurement site K1 shown by the solid line. But a small hole 74
Multiplier 65 because it cannot pass through
No light is received at a and 65b.

The confocal stop 63 having the same function as the small hole 74 is provided, and the photomultipliers 65a and 65b receive only the reflected light from the blood vessel Ev at a specific depth. The operator can set the depth of the blood vessel Ev to be measured while watching the focus state on the fundus image Ea ′ shown in FIG. 5, and focus the fundus image Ea ′.

After the focusing is completed in this manner, if necessary, the examiner operates the operation knob 12 to move the optotype image F, guide the line of sight of the eye E, and change the observation area. Then, the blood vessel Ev to be measured is moved into the circle S of the scale plate 35. Then, as shown in FIG. 7, the image rotator 40 is operated by the image rotator knob 14 to rotate the indicator T so that the indicator T is perpendicular to the running direction of the blood vessel Ev to be measured.

At this time, since the fundus oculi observation light has not passed through the image rotator 40, it is recognized that only the indicator T rotates. Therefore, the pupil Ep shown in FIG.
The image of each optical member above is also rotated by the same angle in the same direction around the origin, and is a straight line connecting the centers of the measured received light beams Da and Db and a straight line connecting the centers of the spot images P and P ′. The axis corresponds to the running direction of the blood vessel Ev. Since the blood flow velocity is obtained from the interference signal between the scattered reflected light from the blood vessel wall and the scattered reflected light in the blood, even if the fundus Ea moves in the X-axis direction during the measurement, the blood vessel Ev moves in the X-axis direction. If they are almost parallel, the measurement result will not be affected.

On the other hand, when the fundus oculi Ea moves in the Y-axis direction orthogonal to the X-axis, the luminous flux from the semiconductor laser light source 55 for measurement deviates from the blood vessel Ev at the measurement site, and the measured value becomes unstable. However, in this case, the movement amount of the blood vessel Ev needs to be detected only in the Y-axis direction.
Detection system and galvanometric mirror 41 behind 8
Performs this one-way tracking.

In this embodiment, the elements of the one-dimensional CCD 61 are arranged in the longitudinal direction of the tracking light.
The fundus image Ea 'indicated by the indicator T is enlarged and captured on the CD 61. At this time, since the green tracking light is absorbed by the blood vessel, the signal SG of the one-dimensional CCD 61 has a shape in which the intersection of the indicator T and the blood vessel Ev is depressed as shown in FIG. Blood vessel detection circuit 68
Detects the width of the intersecting portion by comparing the signal SG of the one-dimensional CCD 61 with the reference signal SO, sends a value proportional to the detected width to the system control unit 66, and displays it on the display LED 11.

The examiner operates the image rotator 40 to rotate the indicator T while looking at the value displayed on the display LED 11 using the image rotator knob 14 so that the value displayed on the display LED 11 is minimized. To be. At this time, the indicator T is most perpendicular to the traveling direction of the blood vessel Ev to be measured, that is, the direction for detecting the one-dimensional movement of the blood vessel is most perpendicular to the traveling direction of the blood vessel Ev. The width of the portion where the detected indicator T and the blood vessel Ev intersect has a value more correctly corresponding to the blood vessel diameter.

After the angle adjustment is completed, the switch 8 is rotated to move the indicator T in the direction shown by the arrow as shown in FIG. 9 so that the spot image superimposed on the tracking light coincides with the measurement site. Select the measurement site. After the measurement site is determined, the switch 8 is pressed to input the start of tracking.

When a tracking start command is input from the switch 8 to the control circuit 69 via the system control unit 66, the blood vessel detection circuit 68 generates a one-dimensional image of the blood vessel image Ev ′ based on the received light signal of the one-dimensional CCD 61. The movement amount from the reference position is calculated. Then, the galvanometric mirror 41 is driven by the control circuit 69 on the basis of the amount of movement, so that the image receiving position of the blood vessel image Ev ′ on the one-dimensional CCD 61 is controlled to be constant.

After the examiner confirms the start of tracking,
The switch 8 is further pushed in, and the measurement is started with the second-stage switch. Optical path switching mirror 53 by system controller 66
Is inserted into the optical path, and firstly, the light flux incident from the position of the spot image P on the pupil Ep of the subject's eye E is received by the photomultipliers 65a and 65b, and the received light signal is taken into the system control unit 66, and the maximum frequency Shift | Δfmax1
|, | Δfmax2 | Here, | Δfmax1
| And | Δfmax2 | are photomultipliers 65, respectively.
a, Processing results of output signals from 65b.

At this time, the incident light flux is a spot image P
, And is provided at a position that is sufficiently displaced with respect to the measured received light beams Da and Db.
Is obtained by Vmax = {λ / (n · α)} · || Δfmax1 | − | Δfmax2 || (1), but depending on the position of the blood vessel Ev on the fundus oculi Ea, the true blood flow velocity Vmax = {λ / (n · α)} · || Δfmax1 | + | Δfmax2 || (2) in some cases. Here, λ is the wavelength of the measurement light beam, n is the refractive index of the measurement site, and α is the angle between the measurement light beam and the received light beam.

In this embodiment, provisional measurement is first performed in this state, and after calculating the maximum speed Vmax according to the above equation (1), the system control unit 66 retreats the optical path switching mirror 53 from the optical path, and The measurement is performed by irradiating a light beam from the position of the spot image P ′ on the pupil Ep of E.

The position of the spot image P 'on the pupil Ep is shown in FIG.
As shown in the figure, the light spots are arranged so that they pass through the center of the other spot image P and have a center on a straight line parallel to the straight line connecting the centers of the measured light beams Da and Db. The distance between P and P 'is selected to be larger than the distance between the centers of the measured light beams Da and Db, and that the straight line connecting the midpoints of the two straight lines is orthogonal to the straight line connecting the centers.

After switching the position of the incident light from the spot image P to the spot image P 'thus selected, the system controller 66 returns to the two photomultipliers 65a and 65a again.
5b, the maximum frequency shifts | fmaxl '| and | fmax2' | are calculated, and the maximum speed Vmax 'is calculated according to equation (1). The system control unit 66 compares the two maximum velocities Vmax and Vmax ′ to determine an appropriate incident direction of the light flux for obtaining the true maximum flow velocity, and switches the optical path in an appropriate state based on this information. Then, control is performed so that the main measurement is continuously performed while repeating the calculation of the maximum speed Vmax or Vmax 'at appropriate time intervals.

The blood flow maximum speed thus obtained is displayed on the display LED 11, and the measurement of the blood vessel on the right side of the nipple is completed. If necessary, the blood flow rate can be calculated and displayed using the measured blood vessel diameter value.

FIG. 10 is a block diagram of a fundus blood flow meter according to the second embodiment. A motor 80 for rotating and driving the image rotator 40 is provided, and the output of the system control unit 66 is also connected to the motor 80. I have. Other configurations are the same as those in FIG.

After completing the focusing in the same manner as in the first embodiment, the examiner operates the operation knob 12 to obtain the optotype image F.
Is moved to guide the line of sight of the eye E to change the observation region, and the blood vessel Ev to be measured is moved into the circle S of the scale plate 35. Then, switch 8 is pressed to start tracking. When a tracking start command is input from the switch 8 to the control circuit 69 via the system control unit 66, the control is performed so that the image receiving position of the blood vessel image Ev ′ on the one-dimensional CCD 61 becomes constant. At this time, the blood vessel detection circuit 68 detects the width of the part where the signal SG of the one-dimensional CCD 61 shown in FIG. 8 falls, that is, the width of the part where the indicator T and the blood vessel Ev intersect, and calculates a value proportional to the detected width. This is sent to the control unit 66.

The control unit 66 sends an output to the motor 80 to drive the image rotator 40, and while rotating the indicator T, compares the width of the intersection between the detected indicator T and the blood vessel Ev. Automatic control is performed to stop the rotation of the image rotator 40 when it becomes narrow.
At this time, the indicator T is perpendicular to the traveling direction of the blood vessel Ev to be measured, that is, the direction for detecting one-dimensional movement of the blood vessel is perpendicular to the traveling direction of the blood vessel Ev. The width of the portion where T intersects the blood vessel Ev has a value that more correctly corresponds to the blood vessel diameter.

After the rotation of the image rotator 40 is stopped, the examiner pushes the switch 8 and starts the measurement with the switch of the second stage.

[0057]

As described above, the ophthalmologic diagnosis apparatus according to the present invention can determine whether or not the angle between the direction in which the movement of the blood vessel is detected and the running direction of the blood vessel is nearly vertical while looking at the display. Rotational alignment of the rotator and the like is facilitated, and rotational alignment accuracy is improved, and measurement accuracy is improved.

Further, the ophthalmic diagnostic apparatus according to the present invention automatically controls the angle between the direction in which the movement of the blood vessel is detected and the running direction of the blood vessel to be substantially perpendicular, so that the rotation of the image rotator or the like can be adjusted. This eliminates the necessity of performing, and improves the accuracy of rotation alignment, and improves the measurement accuracy of blood flow velocity, blood flow, and the like.

[Brief description of the drawings]

FIG. 1 is a perspective view of a first embodiment.

FIG. 2 is a configuration diagram of a measuring head.

FIG. 3 is an explanatory diagram of a dot pattern.

FIG. 4 is an explanatory diagram of a light beam arrangement on a pupil.

FIG. 5 is an explanatory diagram of a fundus image.

FIG. 6 is an explanatory diagram of a confocal stop.

FIG. 7 is an explanatory diagram of rotation of an indicator.

FIG. 8 is an explanatory diagram of signals of a one-dimensional CCD.

FIG. 9 is an explanatory diagram of movement of an indicator T.

FIG. 10 is a configuration diagram of a second embodiment.

[Explanation of symbols]

 2 Stage fixed part 3 TV monitor 4 Stage movable part 6 Measuring head 7 Operation stick 8 Switch 11 Display LED 12 Operation knob 13 Focus knob 14 Image rotator knob 21 Observation light source 28 Transmissive liquid crystal plate 39 CCD camera 40 Image rotator 41 Galvano Metric mirror 53 Optical path switching mirror 55 Semiconductor laser light source 57 Tracking light source 61 One-dimensional CCD 63 Confocal stop 65a, 65b Photomultiplier 66 System control unit 69 Control circuit 80 Motor

Claims (4)

[Claims] 1. An ophthalmologic diagnosis apparatus having an irradiation unit for irradiating a fundus of a subject's eye with a measurement light beam for measuring characteristics of the subject's eye, wherein the detection unit detects a one-dimensional movement of a blood vessel on the fundus. A blood vessel detecting means for relatively rotating the detecting part with respect to the blood vessel, an intersection width measuring means for measuring a width of a portion where the detecting part intersects with the blood vessel, and a one-dimensional movement tracking of the blood vessel Tracking means for constantly irradiating the measurement light beam to the measurement position on the fundus, and display means for displaying a value corresponding to the width of the portion intersecting with the blood vessel before measuring the characteristics of the eye to be examined. Ophthalmological diagnostic device. 2. The ophthalmologic diagnosis apparatus according to claim 1, further comprising a light receiving unit that receives a reflected light beam of the measurement light beam from the fundus, and measuring a blood flow state of the fundus from a signal of the light receiving unit. 3. An ophthalmic diagnostic apparatus having an irradiating means for irradiating a fundus of a subject's eye with a measurement light beam for measuring characteristics of the subject's eye, wherein the detecting section detects a one-dimensional movement of a blood vessel on the fundus. A blood vessel detecting means for relatively rotating the detecting part with respect to the blood vessel, an intersection width measuring means for measuring a width of a portion where the detecting part intersects with the blood vessel, and a one-dimensional movement tracking of the blood vessel Tracking means for constantly irradiating the measurement light beam to the measurement position on the fundus, and driving means for automatically rotating and optimizing the detection unit before measuring the characteristics of the subject's eye with respect to the blood vessel. Ophthalmic diagnosis device characterized by the following. 4. The ophthalmologic diagnosis apparatus according to claim 3, further comprising a light receiving unit for receiving a reflected light beam of the measurement light beam from the fundus, and measuring a blood flow state of the fundus from a signal of the light receiving unit.