JP2007301215A - Intracranial pressure diagnostic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intracranial pressure diagnostic apparatus which is not susceptible to diagnostic experience to allow examination of beat in retina central vein and objective diagnosis of a rise in intracranial pressure. <P>SOLUTION: The intracranial pressure diagnostic apparatus comprises an eyeground irradiating system 5 for irradiating the eyegrounds of a subject 1, an imaging optical system 7 for using reflection light from the eyegrounds to form the image of a retina central vein on a photoelectric detector, and a beat detector 36 for using a time course change in the image of the retina central vein based on the signal from the photoelectric detector to detect the beat in the retina central vein. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an intracranial pressure diagnostic apparatus for diagnosing the presence or absence of increased intracranial pressure based on the presence or absence of pulsation of the central retinal vein of the fundus of a subject's eye.

  Conventionally, in order to measure the intracranial pressure, there is no choice but to measure the internal pressure by opening a hole in the skull openly or by inserting an injection needle into the spinal cord arachnoid from the back of the waist. . However, these methods have a high risk, and a method for diagnosing internal pressure noninvasively has been desired. On the other hand, it is known that pulsation of central retinal vein is observed in people with normal intracranial pressure, but pulsation of central retinal vein is not observed in people with abnormally high intracranial pressure. . Therefore, the fundus of a patient is observed with a direct-view mirror, the pulsation of the central retinal vein is observed, and the presence or absence of increased intracranial pressure is detected by the presence or absence of this pulsation.

  However, observing the central retinal vein and examining the presence or absence of pulsation with a direct-image mirror requires experience, making it difficult to make an objective diagnosis regardless of experience. It was.

  In view of such circumstances, the present invention makes it possible to examine the presence or absence of pulsation of the central retinal vein without being affected by the experience of diagnosis, and to enable objective diagnosis of increased intracranial pressure.

  The present invention relates to a fundus illumination system for illuminating the subject's fundus, an imaging optical system for forming a central retinal vein image on a photoelectric detector by reflected light from the fundus, and a signal from the photoelectric detector. The intracranial pressure diagnostic apparatus includes a pulsation detecting unit that detects pulsation of the central retinal vein based on temporal changes of the central retinal vein image, and the illumination luminous flux for illuminating the fundus of the eye to be examined is near infrared light An imaging device for capturing a fundus image having a wider field of view than the fundus image formed on the photoelectric detector, and displaying a fundus image based on a signal from the imaging device Intracranial pressure diagnosis apparatus having display means for performing intracranial pressure diagnosis having a movable fixation target for guiding the line of sight of an eye to guide an image of a central retinal vein on the photoelectric detector The pulsation detecting unit is related to the apparatus, and the central retinal vein image brightness Intracranial pressure diagnostic apparatus for detecting pulsation of central retinal vein based on amount of change in blood pressure, and further, a signal from an electrocardiogram measuring apparatus or a pulse wave sensor is input to the pulsation detecting unit It is related to.

  According to the present invention, the fundus illumination system for illuminating the fundus of the eye to be examined, the imaging optical system for forming a central retinal vein image on the photoelectric detector by the reflected light from the fundus, and the photoelectric detector And a pulsation detecting unit that detects pulsation of the central retinal vein based on temporal changes in the central retinal vein image based on the signal of The pulsation of the vein can be detected, and an accurate intracranial pressure diagnosis can be performed.

  According to the present invention, since the illumination light beam for illuminating the fundus of the subject's eye is near infrared light, the subject does not feel dazzled and the burden on the subject is small.

  According to the invention, there is provided an imaging device for capturing a fundus image having a wider field of view than the fundus image formed on the photoelectric detector, and for displaying the fundus image based on a signal from the imaging device. Since the display means is provided, the examination site can be easily specified.

  Further, according to the present invention, since the movable fixation target for guiding the line of sight of the eye to be examined is guided on the photoelectric detector, the examination site is appropriately positioned in the image. This makes it easy to adjust the direction of the visual field of the eye to be examined.

  According to the present invention, the pulsation detecting unit detects the pulsation of the central retinal vein based on the change amount of the central retinal image luminance, and therefore, when the physical change due to the pulsation of the central retinal vein cannot be captured. However, recoil can be detected reliably.

  Furthermore, according to the present invention, since the signal from the electrocardiogram measuring device or the pulse wave sensor is input to the pulsation detection unit, the causal relationship between the pulsation detection result and the pulse wave can be specified, and the test result It exhibits excellent effects such as improved certainty.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  In FIG. 1, reference numeral 1 denotes an eye to be examined, and 2 denotes an intracranial pressure diagnostic apparatus.

  The intracranial pressure diagnostic apparatus 2 mainly includes an optical system 3 and a signal processing unit 4.

  The optical system 3 will be described.

  The optical system 3 has a main optical axis 9, and a fundus illumination system 5, a first fundus imaging system 6, a second fundus imaging system 7, and a fixation target projection system 8 are associated with the main optical axis 9. Is provided.

  The fundus illumination system 5 will be described.

  A perforated mirror 11 is disposed on the main optical axis 9, and the main optical axis 9 matches the hole center of the perforated mirror 11. An illumination light source 13 using a heating element such as tungsten as a light source on the first branch optical axis 12 branched by the perforated mirror 11, an infrared filter 14 that transmits only near-infrared light at 720 nm, a capacitor A lens 15, a ring-shaped aperture 16, and a relay lens 17 are disposed, and an objective lens 18 is disposed on the main optical axis 9 between the perforated mirror 11 and the eye 1 to be examined.

  The fundus illumination system 5 illuminates one fundus of the eye to be examined with near infrared light in the vicinity of 720 nm.

  The first fundus imaging system 6 will be described.

  On the main optical axis 9 that has passed through the perforated mirror 11, a focusing lens 21, an imaging lens 22, a half mirror 23, and a first imaging device 24 that are movable along the main optical axis 9 are disposed. The first fundus imaging system 6 is configured by the objective lens 18, the focusing lens 21, the imaging lens 22, and the first imaging device 24. The first fundus imaging system 6 is the eye 1 to be examined. A fundus image is formed on a light receiving unit (photoelectric detector) (not shown) of the first imaging device 24 for observation by reflected light from the fundus. The first imaging device 24 outputs an image signal to a monitor 35 described later.

  The fixation target projection system 8 will be described.

  The half mirror 23 branches the main optical axis 9 into a second branch optical axis 25. The second branch optical axis 25 has a field lens 26 and a dichroic mirror that reflects near infrared light near 720 nm through visible light. 27, a relay lens 28, and a fixation target 29 are disposed.

  The fixation target 29 is constituted by a minute LED or the like, and can move two-dimensionally in a plane perpendicular to the second branch optical axis 25.

  The fixation target projection system 8 includes the objective lens 18, the focusing lens 21, the imaging lens 22, the half mirror 23, the field lens 26, the relay lens 28, and the fixation target 29. The eye 1 is gazeed at the eye 1 to be examined, and the line of sight of the eye 1 is guided in a desired direction.

  The second fundus imaging system 7 will be described.

  The dichroic mirror 27 further branches the second branch optical axis 25 into a third branch optical axis 31, and an imaging lens 32 and a measurement imaging device 33 are disposed on the third branch optical axis 31. .

  The second fundus imaging system 7 includes the objective lens 18, the focusing lens 21, the imaging lens 22, the half mirror 23, the field lens 26, the dichroic mirror 27, the imaging lens 32, and the measurement lens. The imaging device 33 is configured to enlarge a fundus image by reflected light from the fundus and form an image on a light receiving unit (photoelectric detector) of the measurement imaging device 33. The measurement imaging device 33 outputs an image signal to the arithmetic processing unit 36 described later.

  The signal processing unit 4 will be described.

  The signal processing unit 4 mainly includes the monitor 35, the arithmetic processing unit 36, an electrocardiogram measurement device 37, a pulse wave sensor 38, an operation unit 39, and the like. The arithmetic processing unit 36 includes the measurement imaging device. 33 is inputted with the heart pulsation signal from the electrocardiogram measuring device 37 for detecting the heart pulsation of the subject, or is attached to the finger, arm or the like of the subject. A pulse wave signal from the pulse wave sensor 38 is input. The operation unit 39 is, for example, a keyboard or a mouse, and the examiner inputs operations and instructions necessary for measurement to the intracranial pressure diagnostic apparatus 2 from the operation unit 39.

  The operation will be described below.

  The illumination light source 13 is turned on to illuminate the fundus of the eye 1 to be examined. Near-infrared light is used as light used as illumination light so that the subject does not feel dazzling. The examiner observes the fundus image displayed on the monitor 35 and adjusts the position of the focusing lens 21 so that the fundus image of the eye 1 to be examined is the first imaging device 24 and the measurement imaging device 33. To be imaged.

  The fundus image displayed on the monitor 35 is, for example, as shown in FIG.

  Further, the fixation target 29 is turned on to cause the eye 1 to gaze at the fixation target 29 and guide the line of sight in a predetermined direction. For example, the line of sight of the eye 1 is guided so that the optic disc edge 41 of the fundus image is at the center of the display screen.

  A central retinal vein 42 and a central retinal artery 43 appear from the optic disc margin 41, and the second fundus imaging system 7 includes the central retinal region 42 of the optic disc 41 in particular. Magnify and image. The enlargement may be performed optically, or may be performed electronically by image processing, or may be performed by combining optical and image processing.

  On the monitor 35, an index 44 indicating a range in which the measurement imaging device 33 captures an image is displayed. The examiner switches the display of the monitor 35 from the captured image of the first imaging device 24 to the image captured by the measurement imaging device 33, and the imaging location of the measurement imaging device 33 indicated by the index 44 is: The position of the fixation target 29 is adjusted so as to be the central retinal vein 42 portion. FIG. 3 shows an example of an image captured by the measurement imaging device 33.

  When intracranial pressure increases, the pulsation of the central retinal vein 42 disappears or cannot be observed. Therefore, the increase in intracranial pressure is determined by the presence or absence of pulsation of the central retinal vein 42, and the presence or absence of pulsation can be determined by the amount of blood cells flowing through the central retinal vein 42.

  The change in the amount of blood cells flowing through the central retinal vein 42 also appears as a change in luminance of the central retinal vein 42. In the present invention, this luminance change is detected to detect the presence or absence of pulsation of the central retinal vein 42.

  In order to effectively detect a change in luminance of the central retinal vein 42, a wavelength at which venous blood flow (oxygenated hemoglobin) is easily reflected is used as light for illuminating the fundus of the eye to be examined. The wavelengths at which venous blood flow (oxygenated hemoglobin) is likely to be reflected are 415 nm to 430 nm, 540 nm to 570 nm, so use light in these wavelength ranges, or use near infrared light as close to visible light as possible. It is preferable to do. When using near-infrared light, the dichroic mirror 27 is selected to reflect near-infrared light near 720 nm.

  When an imaging location by the measurement imaging device 33 is set, an image between 3 to 4 seconds, that is, 3 to 4 pulse waves is captured at a predetermined time interval, for example, approximately 0.1 second interval. The image signal is stored in the storage unit 45 of the arithmetic processing unit 36.

  The arithmetic processing unit 36 compares the stored images with time and detects a temporal change in luminance.

  FIG. 4 exemplifies the luminance change of the central retinal vein 42. The presence / absence and strength of pulsation correspond to the presence / absence and strength of the luminance change H.

  The arithmetic processing unit 36 detects the luminance change H from the acquired image of the central retinal vein 42, displays the detection result on the monitor 35, and whether the luminance change H is larger or smaller than a predetermined amount, or Whether or not there is a possibility of an increase in intracranial pressure is determined based on whether or not the luminance change H has been detected. If the luminance change H is smaller than a predetermined amount, or if the luminance change H cannot be detected, the intracranial pressure A display warning is given to the monitor 35 that there is a high possibility of enhancement.

  Whether or not the pulsation of the central retinal vein 42 is caused by pulsation when imaging is performed by the measurement imaging device 33 in synchronization with the pulsation from the electrocardiogram measurement device 37 or the pulse wave sensor 38. Thus, the determination of the presence or absence of the pulsation of the central retinal vein 42 is more reliable.

  In the above embodiment, the low-magnification first imaging device for observing a fundus image in a wide range and the high-magnification measurement imaging device for detecting recoil of the central retinal vein 42 are provided. Observation and measurement may be performed by a single imaging device. In this case, the optical system for forming the fundus image may be a variable magnification optical system so that a high magnification narrow field fundus image and a low magnification wide field fundus image can be obtained by optical magnification. The optical system may have a low magnification and obtain a fundus image having a high magnification and a narrow field of view by electronic magnification.

  Further, as a means for detecting the luminance change of the central retinal vein 42, it is possible to detect only the total light quantity of incident light instead of a measurement imaging device that acquires an image. The photoelectric element may be used.

It is a schematic block diagram which shows embodiment of this invention. It is a figure which shows the fundus image for observation obtained in this embodiment. It is a figure which shows the fundus image for a measurement obtained in this embodiment. It is a diagram which shows the luminance change of the retinal central vein used as the object of a measurement.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Eye to be examined 2 Intracranial pressure diagnostic apparatus 3 Optical system 4 Signal processing part 5 Fundus illumination system 6 First fundus imaging system 7 Second fundus imaging system 8 Fixation target projection system 9 Main optical axis 11 Perforated mirror 13 Illumination light source DESCRIPTION OF SYMBOLS 21 Focusing lens 23 Half mirror 24 1st imaging device 27 Dichroic mirror 29 Fixation target 33 Measuring imaging device 35 Monitor 36 Operation processing part 37 Electrocardiogram measuring device 38 Pulse wave sensor

Claims (6)

  A fundus illumination system for illuminating the fundus of the eye to be examined, an imaging optical system for forming a central retinal vein image on the photoelectric detector by reflected light from the fundus, and a retinal center based on a signal from the photoelectric detector An intracranial pressure diagnostic apparatus, comprising: a pulsation detecting unit that detects pulsation of a central retinal vein from a temporal change of a vein image.   2. The intracranial pressure diagnostic apparatus according to claim 1, wherein the illumination light beam for illuminating the fundus of the subject's eye is near infrared light.   2. An image pickup device for picking up a fundus image having a wider field of view than the fundus image formed on the photoelectric detector, and display means for displaying the fundus image based on a signal from the image pickup device. Intracranial pressure diagnostic device.   2. The intracranial pressure diagnostic apparatus according to claim 1, further comprising a movable fixation target for guiding the line of sight of the eye to guide the image of the central retinal vein on the photoelectric detector.   The intracranial pressure diagnosis apparatus according to claim 1, wherein the pulsation detecting unit detects a pulsation of the central retinal vein based on a change amount of central retinal vein image brightness.   The intracranial pressure diagnosis apparatus according to claim 1, wherein a signal from an electrocardiogram measurement device or a pulse wave sensor is input to the pulsation detection unit.

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