U.S. patent application number 14/971032 was filed with the patent office on 2017-04-20 for adaptive optical objective inspection instrument for optic nerve function.
The applicant listed for this patent is THE INSTITUTE OF OPTICS AND ELECTRONICS, THE CHINESE ACADEMY OF SCIENCES. Invention is credited to YUN DAI, Yudong Zhang, Haoxin Zhao.
Application Number | 20170105640 14/971032 |
Document ID | / |
Family ID | 54890549 |
Filed Date | 2017-04-20 |
United States Patent
Application |
20170105640 |
Kind Code |
A1 |
DAI; YUN ; et al. |
April 20, 2017 |
ADAPTIVE OPTICAL OBJECTIVE INSPECTION INSTRUMENT FOR OPTIC NERVE
FUNCTION
Abstract
An adaptive optical objective inspection instrument for optic
nerve function comprises: a sub-system for measuring wave
aberration of human's eyes, including a near infrared beacon light
source, an intermediate optical system, a wavefront corrector and a
wavefront sensor, configured to measure and obtain wave aberration
of testee's eyes, the intermediate optical system arranged along an
optical path between the near infrared beacon light source and the
wavefront sensor, and the wavefront corrector arranged in the
optical path of the intermediate optical system; a sub-system for
correcting wave aberration of human's eyes, including the
intermediate optical system, the wavefront corrector and a control
unit, the control unit configured to drive and control the
wavefront corrector to correct the wave aberration of testee's eyes
according to the measured wave aberration; and a sub-system for
inspecting optic nerve function, including a visual stimulus
display and a system for collecting visual evoked potential
signal.
Inventors: |
DAI; YUN; (Chengdu, CN)
; Zhao; Haoxin; (Chengdu, CN) ; Zhang; Yudong;
(Chengdu, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
THE INSTITUTE OF OPTICS AND ELECTRONICS, THE CHINESE ACADEMY OF
SCIENCES |
Chengdu |
|
CN |
|
|
Family ID: |
54890549 |
Appl. No.: |
14/971032 |
Filed: |
December 16, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 26/06 20130101;
A61B 5/0496 20130101; G01J 9/00 20130101; G02B 27/0068 20130101;
A61B 3/0025 20130101; G01J 1/00 20130101; A61B 3/1015 20130101;
A61B 3/0041 20130101; A61B 5/04001 20130101; A61B 5/04842 20130101;
A61B 3/14 20130101 |
International
Class: |
A61B 5/04 20060101
A61B005/04; G02B 27/00 20060101 G02B027/00; A61B 3/14 20060101
A61B003/14; A61B 3/10 20060101 A61B003/10; A61B 3/00 20060101
A61B003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 19, 2015 |
CN |
201510679438.1 |
Claims
1. An adaptive optical objective inspection instrument for optic
nerve function comprising: a sub-system for measuring wave
aberration of human's eyes, including a near infrared beacon light
source, an intermediate optical system, a wavefront corrector and a
wavefront sensor, configured to measure and obtain wave aberration
of human's eyes of testee, the intermediate optical system being
arranged along an optical path between the near infrared beacon
light source and the wavefront sensor, and the wavefront corrector
being arranged in the optical path of the intermediate optical
system; a sub-system for correcting wave aberration of human's
eyes, including the intermediate optical system, the wavefront
corrector and a control unit, the control unit configured to drive
and control the wavefront corrector to correct the wave aberration
of human's eyes of the testee according to the measured wave
aberration of human's eyes of the testee; and a sub-system for
objectively inspecting optic nerve function, including a visual
stimulus displaying unit and a system for collecting visual evoked
potential signal, wherein the testee observes a visual stimulation
displayed on the visual stimulus displaying unit through the
intermediate optical system and the wavefront corrector, and the
visual evoked potential signal at a dermal surface of the head is
recorded through the system for collecting visual evoked potential
signal.
2. The adaptive optical objective inspection instrument for optic
nerve function according to claim 1, wherein an objective
inspection and estimation for the visual nerve are selected from
the visual evoked potential by flashing or image.
3. The adaptive optical objective inspection instrument for optic
nerve function according to claim 1, wherein the wavefront
corrector is selected from the group consisting of a deformable
mirror, a liquid crystal wavefront corrector, a micromachined
membrane deformable mirror, micro electromechanical deformable
mirror, a bimorph deformable reflective mirror and a liquid
deformable mirror.
4. The adaptive optical objective inspection instrument for optic
nerve function according to claim 1, wherein the wavefront sensor
is a Hartmann wavefront sensor based on a micro lens array, a
Hartmann wavefront sensor based on a micro grating array, a
curvature wavefront sensor or a pyramid wavefront sensor.
5. The adaptive optical objective inspection instrument for optic
nerve function according to claim 1, wherein the visual stimulus
displaying unit is selected from the group consisting of a CRT
display, a commercial projector, a liquid crystal display, a plasma
display, electroluminescent display and an organic light-emitting
display.
6. The adaptive optical objective inspection instrument for optic
nerve function according to claim 1, wherein the video processing
circuit combines an R channel signal and a B channel signal in a
common video output and implements a gray scale of 14 bits or
more.
7. The adaptive optical objective inspection instrument for optic
nerve function according to claim 1, wherein the intermediate
optical system comprises a collimator mirror, a first reflective
mirror, a first spectroscope, a first light beam matching
telescope, a second light beam matching telescope, a second
reflective mirror and second spectroscope arranged in turn in a
light path between the near infrared beacon light source and the
wavefront sensor; and the wavefront corrector is arranged in a
light path between the first light beam matching telescope and the
second light beam matching telescope.
8. The adaptive optical objective inspection instrument for optic
nerve function according to claim 1, wherein the wave aberration of
human's eyes is calculated based on an actual light spot signal
received by the wavefront sensor and a light spot signal generated
by incidence of a standard plane wave and functioning as a
referencing data.
9. The adaptive optical objective inspection instrument for optic
nerve function according to claim 1, wherein the subsystem for
objectively inspecting optic nerve function further comprises a
video processing circuit, the video processing circuit is visually
stimulated by flashing or image having a different spatial
frequencies and different contrast, and the stimulation is
displayed on the visual stimulus displaying unit; and comparing and
analyzing the recorded visual evoked potential signal to
objectively inspect and evaluate the optic nerve function.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to an adaptive optical
objective inspection instrument for optic nerve function by
measuring and correcting aberration of human's eyes through an
adaptive optical system as well as visually stimulating a retina by
flashing or an image in such a situation.
BACKGROUND
[0002] A visual evoked potential (VEP) is also called as a visual
evoked reaction, which is an electrical reaction of an visual
center of an occipital lobe recorded in the dermal surface of the
head when the retina is stimulated by flashing or an image and then
the signal is delivered along an optic pathway. It mainly reflects
a transfer function from a ganglion cell of the retina to the
visual cortex. The 17.sup.th region of the visual cortex in the
cerebral cortex mainly receives projection of nerve fibers within
10 degree in the central retina 100, and the projection region is
nearest to the scalp surface, so most of information about the VEP
is originated from macula lutea region. The VEP not only reflects a
function of a visual cortex of the occipital lobe, but also reflect
a function of a transfer channel from the macula lutea region of
the retina and a ganglion cell of the macula lutea region to the
visual cortex. VEP is an important method for objectively
evaluating and inspecting the visual nerve function (cf. Yingfu
PAN, Clinical evoked potential, Edition 2, People's medical
publishing house).
[0003] The Visual evoked potential is an electrical reaction of the
occipital lobe of the cerebral cortex on the visual stimulation and
represents a potential change caused by the stimulation received by
the retina and conducted to the cortex of the occipital lobe
through the visual pathway. As can be seen from a mechanism for
generating the visual evoked potential, no matter which of the
visual evoked potential, it is the most import that the retina
receives visual stimulation and the stimulation on the retina has
to be projected through the dioptric system of the human's eyes.
Thus, the quality of an optical system of the human's eyes will
directly affect the quality of the stimulation projected onto the
retina. For the transfer of the visual stimulation to the retina,
except for diffraction generated by the pupil of the human's eyes
which is incapable of being avoiding, the optical aberration is the
most important influential factor. It is well known for the people
that the optical system of the human's eyes is not an ideal optical
system. Except for the low-order aberrations such as defocus and
astigmatism, there are many high order aberrations having more
complex shape (e.g. spherical aberration, trefoil aberration and so
on). Furthermore, the aberration of the human's eyes is not
stationary and dynamically varies with time (D. R. Williams, &
Hofer, H. Formation and Acquisition of the Retinal Image. In: J. S.
W. Leo M. Chalupa (Ed.), The Visual Neurosciences, the MIT Press,
Cambridge, Mass., London, England, 2003). The existing VEP
inspection only corrects the low order aberration of human's eyes
by ametropia compensation of the lens, and a correction lens with a
high degree of separation can't accurately compensate the low order
aberration. The existence of the residual low order aberration and
the high order aberration of the human's eyes less affect the VEP
inspection at a lower spatial frequency. However, when an image
with a higher spatial frequency is utilized to stimulate for the
VEP inspection, and an abnormal phenomenon is found, it can't be
determined wither there is abnormal for the visual pathway and
perhaps it is caused by the optical aberration of the testee which
is not corrected ("Electrophysiological research on the effects of
optical-induced ametropia on transfer of visual signal and response
of visual signals in the visual cortex", Master degree thesis of
Laiqing Xie, Tianjin Medical University, 2009). Therefore, when the
VEP is utilized to evaluate the visual nerve function and to
objectively inspect eyesight of human's eyes, the influence of the
human's eyes aberration on the projection of the visual stimulation
to the retina within the eye ground has to be eliminated so as to
obtain an accurate result for the VEP inspection.
SUMMARY
[0004] One aspect of the present disclosure provides an adaptive
optical objective inspection instrument for optic nerve function
comprising: a sub-system for measuring wave aberration of human's
eyes, including a near infrared beacon light source, an
intermediate optical system, a wavefront corrector and a wavefront
sensor, configured to measure and obtain wave aberration of human's
eyes of testee, the intermediate optical system being arranged
along an optical path between the near infrared beacon light source
and the wavefront sensor, and the wavefront corrector being
arranged in the optical path of the intermediate optical system; a
sub-system for correcting wave aberration of human's eyes,
including the intermediate optical system, the wavefront corrector
and a control unit, the control unit configured to drive and
control the wavefront corrector to correct the wave aberration of
human's eyes of the testee according to the measured wave
aberration of human's eyes of the testee; and a sub-system for
objectively inspecting optic nerve function, including a visual
stimulus displaying unit and a system for collecting visual evoked
potential signal, wherein the testee observes a visual stimulation
displayed on the stimulus displaying unit through the intermediate
optical system and the wavefront corrector, and the visual evoked
potential signal at a dermal surface of the head is recorded
through the system for collecting visual evoked potential
signal.
[0005] Alternatively, the wavefront corrector is selected from a
deformable mirror, a liquid crystal wavefront corrector, a
micromachined membrane deformable mirror, micro electromechanical
deformable mirror, a bimorph deformable reflective mirror and a
liquid deformable mirror.
[0006] Alternatively, the wavefront sensor is selected from a
Hartmann wavefront sensor based on a micro lens array, a Hartmann
wavefront sensor based on a micrograting array, a curvature
wavefront sensor or a pyramid wavefront sensor.
[0007] Alternatively, the stimulus displaying unit is selected from
a CRT display, a commercial projector, a liquid crystal display, a
plasma display, electroluminescent display and an organic
light-emitting display.
[0008] Alternatively, the video processing circuit combines an R
channel signal and a B channel signal in a common video output and
implements a gray scale of 14 bits or more.
[0009] Alternatively, the intermediate optical system comprises a
collimator mirror, a first reflective mirror, a first spectroscope,
a first light beam matching telescope, a second light beam matching
telescope, a second reflective mirror and second spectroscope
arranged in turn in a light path between the near infrared beacon
light source and the wavefront sensor; and the wavefront corrector
is arranged in a light path between the first light beam matching
telescope and the second light beam matching telescope.
[0010] Alternatively, the wave aberration of human's eyes is
calculated based on an actual light spot signal received by the
wavefront sensor and a light spot signal generated by incidence of
a standard plane wave and functioning as a referencing data.
[0011] Alternatively, the subsystem for objectively inspecting
optic nerve function further comprises a video processing circuit,
the video processing circuit is visually stimulated by flashing or
image having a different spatial frequencies and different
contrast, and the stimulation is displayed on the visual stimulus
displaying unit; and the recorded visual evoked potential signal is
contrasted and analyzed to objectively inspect and evaluate the
optic nerve function.
[0012] As compared with the prior art, the present disclosure
firstly apply an adaptive optical correction of human's eyes
aberration to VEP inspection. With respect to the existing VEP
inspection, the present system measures and corrects low order and
high order optical aberrations of human's eyes by the adaptive
optical system. In such a situation, the retina is visually
stimulated by flashing or image so as to eliminate influence of the
low order and high order optical aberrations of human's eyes on the
visual evoked potential, thereby eliminate the projection of the
visual stimulation onto the retina in an eye ground. Finally, the
accuracy of the objective inspection and evaluation on the visual
nerve function may be enhanced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The above and other objects, features and advantages of the
present disclosure would be apparent by illustrating the optional
embodiments of the present disclosure in conjunction with the
following figures, in which:
[0014] FIG. 1 is a principle block diagram of the configuration of
the present disclosure.
[0015] FIG. 2 is a schematic view of the influence of the human's
eyes optical aberrations on a visual evoked potential signal of an
image.
[0016] FIG. 3a is a schematic view of the configuration of a
Hartmann wavefront sensor based on a micro lens array.
[0017] FIG. 3b is a schematic view of a principle of the Hartmann
wavefront sensor based on a micro lens array.
DETAILED DESCRIPTION
[0018] In order to definitely illustrate implementations of the
present disclosure, the alternative embodiments of the present
disclosure will be described in detail by referring to FIG. 1.
During description, unnecessary details and functions are omitted
for confuse the understanding of the present disclosure.
[0019] FIG. 1 is a principle block diagram of the configuration of
the present disclosure.
[0020] As shown in FIG. 1, the adaptive optical objective
inspection instrument for optic nerve function according to the
present disclosure comprises a near infrared beacon light source 1,
a collimator mirror 2, a first reflective mirror 3, a first
spectroscope 4, a first light beam matching telescope 6, a
wavefront corrector 7, a second light beam matching telescope 8, a
second reflective mirror 9, a second spectroscope 10,a wavefront
sensor 11, a control computer 12, a high voltage amplifier 13, a
third reflective mirror 14, an optical imaging system 15, a visual
stimulus displaying unit 16, a video processing circuit 17, a VEP
signal collecting unit 18 and a data processing computer 19. The
testee is indicated by a reference sign of "5".
[0021] The adaptive optical objective inspection instrument for
optic nerve function according to the present disclosure comprises
three sub-systems: a sub-system for measuring wave aberration of
human's eyes, a sub-system for correcting wave aberration of
human's eyes and a VEP sub-system for collecting and analyzing
signals.
[0022] In the sub-system for measuring wave aberration of human's
eyes, a light emitted from the near infrared beacon light source 1
is collimated by the collimator mirror 2, reflected by the first
reflective mirror 3 and the first spectroscope 4 into a pupil of
human's eyes 5; the light reflected by the human's eyes 5 passes
through the first spectroscope 4 and the first light beam matching
telescope 6 and is reflected by the wavefront corrector 7, passes
through the second light beam matching telescope 8 and is reflected
by the second reflective mirror 9 and the second spectroscope 10
into the wavefront sensor 11; the wavefront sensor 11 delivers the
received light spot signal to the control computer 12 to be
processed to wave aberration of human's eyes.
[0023] The wavefront corrector 11 may be a Hartmann wavefront
sensor based on a micro lens array, a Hartmann wavefront sensor
based on a micro grating array, a curvature wavefront sensor or a
pyramid wavefront sensor. Herein, the Hartmann wavefront sensor
based on micro lens array is taken as an example to illustrate its
principle for measuring. As shown in FIG. 3a, the Hartmann
wavefront sensor based on micro lens array is constituted of a
micro lens array 11-1 and a photo detector (such as a CCD detector)
11-2, in which the photo detector 11-2 is located at a focal plane
of the micro lens array 11-1.
[0024] The principle of the Hartmann wavefront sensor based on
micro lens array is shown as follows: an incidence light passes
through the micro lens array 11-1 to form a light spot array on its
focal plane so that the whole aperture of the light beam is
uniformly divided. A light spot array generated by incidence of the
standard plane wave is saved as a referencing data. When a
wavefront having a certain aberration is incidence, the inclination
of local wavefront on the respective microlens leads to position
shift of the light spot on the focal plane of the micro lens
array.
[0025] The light spot signal received by the photo detector 11-2
may be processed by the computer utilizing a centroid algorithm as
follows. The position (x.sub.i, y.sub.i) of the light spot is
calculated by the formula {circle around (1)} so as to detect
information about the wave plane of the full aperture:
x i = m = 1 M n = 1 N x nm I nm m = 1 M n = 1 N I nm , y i = m = 1
M n = 1 N y nm I nm m = 1 M n = 1 N I nm 1 ##EQU00001##
[0026] in which, m=1.about.M, n=1.about.N, showing that the
sub-aperture is mapped into the corresponding pixel regions on the
photo detector 11-2, I.sub.nm represents signals received by the
(n,m).sup.th pixel on the photo detector 11-2, and x.sub.nm and
y.sub.nm represent x coordinate and y coordinate of the
(n,m).sup.th pixel, respectively.
[0027] Then, a slope g.sub.xi, g.sub.yi of wave aberration of the
incidence wavefront is calculated according to the formula {circle
around (2)}:
g xi = .DELTA. x .lamda. f = x i - x o .lamda. f , g yi = .DELTA. y
.lamda. f = y i - y o .lamda. f 2 ##EQU00002##
[0028] in which, (x.sub.0, y.sub.0) represents a reference position
of the center of the light spot obtained by standardizing the
Hartmann sensor for an ideal plane wave; when the Hartmann sensor
detects wavefront aberration, the center of the light sport shifts
to (x.sub.i, y.sub.i), in which .lamda. is a wavelength of the
incidence light and f is a focal length of the microlens. Thus, the
Hartmann wavefront sensor detects signal and the schematic view of
its principle is shown in FIG. 3b.
[0029] In the sub-system for correcting wave aberration of human's
eyes, the control computer 12 utilizes a direct slop method to
obtain a control voltage for the wavefront corrector 7 according to
a slope data of wave aberration of human's eyes. Such a control
voltage is amplified by the high voltage amplifier 13 to drive the
wavefront corrector 7 to generate a corresponding change so as to
correct the wave aberration of human's eyes.
[0030] After the correction of the wave aberration of human's eyes
is completed, the VEP signal may be collected and analyzed. A VEP
measuring software installed in the computer 12 generates visual
stimulation by a flash or an image having different spatial
frequencies and different contrasts, to be processed by the video
processing circuit 17 and then displayed on the visual stimulus
displaying unit 16. The testee observes the visual stimulation
presented on the visual stimulus displaying unit 16 through the
first spectroscope 4, the light beam matching telescope 6, the
wavefront corrector 7, the light beam matching telescope 8, the
second reflective mirror 9, the second spectroscope 10, the third
reflective mirror 14 and the imaging lens 15; the visual evoked
potential signal at the dermal surface of the head is recorded
through the VEP signal collection unit 18 and input to the data
processing computer 19. Thus, by comparing and analyzing the
recorded visual evoked potential signal, the optic nerve function
may be objectively inspect and evaluated.
[0031] The wavefront corrector 7 may be selected from a deformable
reflective mirror, a liquid crystal wavefront corrector, a
micromachined membrane deformable mirror, a micro electromechanical
deformable mirror, a bimorph deformable mirror, a liquid deformable
mirror.
[0032] The wavefront sensor 11 may be selected from a Hartmann
wavefront sensor based on a micro lens array, a Hartmann wavefront
sensor based on a micro grating array (cf. Chinese invention patent
ZL03126431.X), a curvature wavefront sensor or a pyramid wavefront
sensor.
[0033] The visual stimulus displaying unit 16 may be selected from
a CRT display, a commercial projector, a color liquid crystal
display, a plasma display, electroluminescent display and an
organic light-emitting display.
[0034] The video processing circuit 17 may combine an R channel
signal and a B channel signal in a common video output and
implements a gray scale of 14 bits (16384 steps) or more so as to
meet the requirement of fine adjustment of contrast for the visual
stimulation. For example, the video processing circuit 17 may
utilizes a particular circuit disclosed by a Chinese Utility Patent
ZL02220968.9.
[0035] FIG. 2 is a schematic view of the influence of the human's
eyes optical aberrations on a visual evoked potential signal of an
image. The influence of human's eyes aberration on the VEP signal
is indirectly validated by Laiqing Xie, Tianjin Medical University,
superposing spherical lens with astigmatism. The present disclosure
eliminates influence of the low order and high order optical
aberrations of human's eyes on the visual evoked potential, thereby
eliminate the projection of the visual stimulation onto the retina
in an eye ground, by the adaptive optical system measuring and
correcting the human's eyes aberration, so as to enhance the
accuracy of the objective inspection and evaluation on the visual
nerve function.
[0036] According to embodiments of the present disclosure, the
adaptive optical system measures and corrects aberrations of
human's eyes. In such a situation, the retina is visually
stimulated by flashing or image so as to eliminate influence of the
low order and high order optical aberrations of human's eyes on the
visual evoked potential, thereby eliminate the projection of the
visual stimulation onto the retina in an eye ground. Finally, the
accuracy of the objective inspection and evaluation on the visual
nerve function may be enhanced.
[0037] The present invention has been illustrated in conjunction
with the alternative embodiments. It should be understood for those
skilled in the art that there are various alternation, substitution
and addition without deviating from the spirit and scope of the
present invention. Thus, the scope of the present invention is not
limited to the specific embodiments as mentioned above, but is
defined by the accompany claims.
* * * * *