WO2007073848A2 - Dispositif de mesure oculaire par diffusion de lumière dynamique - Google Patents

Dispositif de mesure oculaire par diffusion de lumière dynamique Download PDF

Info

Publication number
WO2007073848A2
WO2007073848A2 PCT/EP2006/011836 EP2006011836W WO2007073848A2 WO 2007073848 A2 WO2007073848 A2 WO 2007073848A2 EP 2006011836 W EP2006011836 W EP 2006011836W WO 2007073848 A2 WO2007073848 A2 WO 2007073848A2
Authority
WO
WIPO (PCT)
Prior art keywords
light
scattered
excitation light
detection
scattering
Prior art date
Application number
PCT/EP2006/011836
Other languages
German (de)
English (en)
Other versions
WO2007073848A3 (fr
Inventor
Franz Fankhauser
Original Assignee
Franz Fankhauser
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Franz Fankhauser filed Critical Franz Fankhauser
Publication of WO2007073848A2 publication Critical patent/WO2007073848A2/fr
Publication of WO2007073848A3 publication Critical patent/WO2007073848A3/fr

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/0059—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
    • A61B3/10—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
    • A61B3/12—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions for looking at the eye fundus, e.g. ophthalmoscopes

Definitions

  • the invention relates to an eye measuring device with the aid of dynamic light scattering according to the preamble of claim 1.
  • the dynamic light scattering is based on the optical interference spectroscopy with the aim to detect small frequency changes in the scattered light. Similar techniques are used to receive radio signals in the frequency domain (heterodyne principle). The following points must be emphasized:
  • the measurement of frequency changes in this area would with optical filters, such as monochromators, not realizable and even using the best Fabry-Perot interferometers very difficult.
  • Heterodyne optical interference means that both the scattered light and part of the non-scattered light interfere simultaneously on a sensor (photomultiplier).
  • the electrical output signal of the photomultiplier is then proportional to the interference frequency of the two beams.
  • Heterodyne detection is now routinely used to improve properties such as Eg speed - A -
  • Doppler velocity measurement is an example of heterodyne detection, whereby the frequency changes that result from the Doppler effect in the scattered light of moving particles are analyzed.
  • the discrimination of the excitation light relative to the scattered light is relevant.
  • a detection coupling-out mirror which is embodied transmissively for the scattered light and reflective for the excitation light, offers the possibility of significantly improved discrimination between scattered light and excitation light.
  • the excitation light is coupled via a reflection at the detection output mirror in the common beam axis of excitation light and scattered light.
  • excitation light which runs undesirably exactly along the path of the scattered light to be detected, is transmitted by the detection outcoupling mirror, thus it is thus not coupled into the common beam axis. Only scattered light can then run along the path of the scattered light to be detected, so that it is suppressed highly efficiently with respect to the excitation light.
  • An antireflection coating according to claim 2 improves the maximum scattered light signal.
  • such an antireflection layer improves the suppression of excitation light traveling on the scattered light path during the reflection at the detection outcoupling mirror. It is preferred if both sides of the detection coupling-out mirror carry an antireflection coating.
  • An excitation light selection mirror according to claim 3 can be designed with a coating equivalent to the coating of the detection coupling-out mirror. This reduces the effort in the production of Eye-measuring device, since the detection coupling-out mirror and the excitation light selection mirror can be used from the same coating batch.
  • a hollow beam according to claim 4 allows a highly efficient excitation, which is adapted to the optical geometry of the eye.
  • annular reflective coating according to claim 5 enables a defined and efficient generation of the hollow beam.
  • the annular reflection coating of at least one of the mirrors which generate the hollow beam can be designed with a non-sharp-edged transition between the highly reflective ring and the transversive central area.
  • Beam angle according to claim 6 allow a survey also rearward regions of the eye, in particular the retina.
  • a beam angle of 4.6 ° is preferred.
  • Scattering volumes according to claim 7 allow a good compromise between see the criticality of the adjustment and the maximum achievable scatter signal.
  • Fig. 1 shows schematically the beam guidance within an apparatus for eye measurement with the aid of dynamic light scattering
  • Fig. 2 shows the intensity course of the beam direction containing
  • FIG. 3 schematically shows the beam path of the excitation light beam and of a scattered light beam emanating from a scattering volume when the device according to FIG. 1 is used;
  • FIG. 4 shows an example of a correlation function of the scattered light measured with the device according to FIG. 1;
  • FIG. 5 shows the beam path of excitation light and scattered light in a further embodiment of an eye measuring device with the aid of dynamic light scattering.
  • Fig. 1 shows schematically the beam path within a generally designated 1 device for eye measurement using dynamic light scattering.
  • a radiation source 2 for generating scattering excitation light 3 is a helium-neon laser.
  • the emission from this first passes through a filter 4 and is then coupled via a laser-fiber coupler 5 in a monomode fiber 6.
  • An entrance surface of the mono-mode fiber 6 is ground by 6 °, so that disturbing back reflections in the radiation source 2 are prevented.
  • the monomode fiber 6 forces a Gaussian bundle cross-section of the scatter excitation light 3 after the exit of this from the monomode fiber 6 and a downstream collimator 7 with a focal length of 6.2 mm.
  • the scattered excitation light 3 is reflected by a mirror 8 which is coated in an annular manner for the scattered excitation light 3 in the region of the annular coating and thus deflected by 90 °. After the reflection at the annular layer of the mirror 8, the scattered excitation light 3 is thus present as a hollow bundle 9.
  • the transmitted by the mirror 8 central portion 10 of the scatter excitation light 3 is blocked in a defined manner.
  • the mirror 8 represents an excitation light selection mirror for selectively separating the scattered excitation light 3 used for the measurement, that is to say the hollow bundle 9, from other excitation light, that is to say from the fraction 10.
  • the hollow bundle 9 has an intensity distribution shown in FIG.
  • the x-scale in mm refers to a hollow bundle section which lies 88 mm behind the center of a focusing lens 1 1, which in its function is still to be described, in front of a scattering volume 12.
  • a slight increase in intensity 16 which does not apply to the light scattering measurements is distracting caused by diffraction at the coating edges of the reflective coating of the mirror 8. This diffraction effect can be reduced if instead of a level of reflectivity on the mirror 8 a gentler, z.
  • B. continuous, reflectivity transition between the reflective ring coating and surrounded by this central, transmissive region is selected.
  • the hollow bundle 9 After reflection on the mirror 8, the hollow bundle 9 is parallelized by a further lens 17 with a focal length of 120 mm. After the other lens 17, the hollow beam 9 is reflected by a detection output mirror 18.
  • the detection outcoupling mirror 18 is coated in a highly reflective manner in the same way as the mirror 8 in the region of the impinging hollow bundle 9. In the central area surrounded by this reflective coating, the detection output mirror 18 is highly transmissive to the scattered excitation light. Excitation light components 19 in the region of the intensity increase 16 produced by diffraction are therefore transmitted by the detection output mirror 18 and are subsequently blocked in a defined manner.
  • the scattering volume 12 lies in a retina 21 of an eye 22 to be measured, as shown in FIG.
  • the scattering volume 12 at other positions of the eye 22 gene gene, z. B.
  • An angle ⁇ s in air in front of the scattering volume 12 of the hollow bundle 9 to the beam axis 28, ie to the central excitation beam path, is 4.6 ° in the beam path for scattering at the scattering volume 12 in the retina 21. Other angles between 2 ° and 8 ° are possible, depending on the position of the scattering volume to be measured in the eye 22.
  • the scattering volume 12 has a size of 640 ⁇ m 3 in air. Other sizes between 50 and 800 microns 3 are possible.
  • scattered light 27 is generated by dynamic light scattering. The latter is only shown in the drawing, as far as it is actually detected with the eye-measuring device 1. In fact, the scattered light 27 is radiated in many spatial directions. The scattered light 27 leaves the eye through the eye lens 24 and the cornea 26 and passes through the focusing lens 11 centrally. Subsequently, the scattered light 27 is deflected in the deflection mirror 20 and subsequently passes through the detection output mirror 18.
  • the detection output coupling mirror 18 has an anti-reflection layer for the scattered light 27 centrally.
  • an excitation beam path of the scatter excitation light 3 and a detection beam path of the scattered light 27 extend along or parallel to a common beam axis 28.
  • the beams of the scattered excitation light 3 and the scattered light 27 are spaced apart from each other.
  • the scattered light 27 is coupled via a collimator 29 into a detection monomode fiber 30.
  • the collimator 29 has a focal length of 20 mm.
  • the scattered light 27 is directed onto a single-photon avalanche diode (SPAD) 31.
  • the latter has an internally stabilized high voltage supply and a dead time of 30 ns.
  • the measurement signal received by the SPAD 31 is from a digital correlator 32 according to the multiple-tau schemes known from the technical article by K. Shutzel "Noise in photon correlation data: I. Autocorrelation functions", Quantum Opt. 1990, 2: 287-305
  • a correlation curve g 2 ( ⁇ ) obtained as a function of a correlation delay time ⁇ is shown as measurement curve 33 in FIG. 4.
  • the correlation signal g 2 ( ⁇ ) of the scattered beam at a certain delay time, z. B. at the time ⁇ m , determined, with a measuring scattering volume 12 is measured.
  • the scattering volume 12 to be measured shifted towards a reference scattering volume spaced therefrom within the eye.
  • the reference scattering volume is chosen so that there with sufficient certainty healthy eye tissue is present.
  • the reference litter volume may also be in the other, healthy eye of a patient.
  • the correlation signal g 2 ( ⁇ ) is determined at the same delay time ⁇ m . Since ⁇ m is in a range that is sensitive to an anomaly of the eye, the two correlation signals are different if there is diseased eye tissue in the measured scattering volume.
  • the difference of the two correlation signals is formed. This difference is then significantly different from 0 if diseased ocular tissue is present in the measured scattering volume. This can be determined by evaluating the difference value, wherein an eye disease is then reported as soon as the difference absolute value is above a predetermined threshold.
  • Sensitivity refers to the ability of the dynamic light scattering on the eye to recognize a disease correctly, ie to respond positively to an actual anomaly of the eye. Selectivity refers to the ability of the measurement to actually identify healthy patients as healthy, ie to reject them positively in healthy patients. If an absolute threshold value of 0.05 is chosen for the difference between the correlation signals g 2 ( ⁇ m ), measured on the measured scattering volume and on the reference scattering volume, the sensitivity of the diagnostic method is 78%. The selectivity of the diagnostic procedure is then 72%.
  • AMD age-related macular degeneration
  • the eye measurement device 1 can be used for dynamic light scattering both in vitro and in vivo.
  • FIG. 5 shows a variant of the beam guidance in a further embodiment of an eye measurement device.
  • Components and reference quantities which correspond to those which have already been explained above with reference to FIGS. 1 to 4 bear the same reference numerals and will not be discussed again in detail.
  • the scattered excitation light 3 is not provided in the form of a hollow beam but in the form of an excitation light beam guided parallel to the beam axis 28 in front of the focusing lens 11.
  • the distance of the beam path of the scattered excitation light 3 from the beam axis 28, along which the scattered light 27 passes, is as large as the radius of the hollow beam 9 in the beam guidance according to FIGS. 1 to 4.

Abstract

L'invention concerne un dispositif (1) permettant d'effectuer des mesures oculaires par diffusion de lumière dynamique. Ledit dispositif (1) comprend une source de rayonnement (2) qui permet de produire une lumière d'excitation diffusée (3). Une unité de détection (29 à 32) est utilisée pour détecter de la lumière diffusée (27) émise par un volume de diffusion (12). Un faisceau d'excitation de la lumière d'excitation diffusée (3) et un faisceau de détection de la lumière diffusée (27) s'étendent parallèlement à un axe de rayonnement commun (28) dans une section de faisceau (18, 20 11, 12) adjacente au volume de diffusion (12). Un miroir d'extraction de détection (18) est utilisé pour extraire la lumière diffusée (27) du faisceau d'excitation. Ledit miroir d'extraction de détection (18) est perméable à la lumière diffusée (27) et réfléchit fortement la lumière d'excitation diffusée (3). Le dispositif de mesure oculaire de l'invention permet d'établir une distinction plus nette entre la lumière diffusée et la lumière d'excitation diffusée.
PCT/EP2006/011836 2005-12-15 2006-12-08 Dispositif de mesure oculaire par diffusion de lumière dynamique WO2007073848A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US75033605P 2005-12-15 2005-12-15
US60/750,336 2005-12-15

Publications (2)

Publication Number Publication Date
WO2007073848A2 true WO2007073848A2 (fr) 2007-07-05
WO2007073848A3 WO2007073848A3 (fr) 2007-11-29

Family

ID=38218332

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2006/011836 WO2007073848A2 (fr) 2005-12-15 2006-12-08 Dispositif de mesure oculaire par diffusion de lumière dynamique

Country Status (1)

Country Link
WO (1) WO2007073848A2 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106198395A (zh) * 2016-06-29 2016-12-07 中国科学院半导体研究所 一种雪崩二极管探测器光耦合系统及其测量方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5777719A (en) 1996-12-23 1998-07-07 University Of Rochester Method and apparatus for improving vision and the resolution of retinal images
WO2002030273A1 (fr) 2000-10-10 2002-04-18 University Of Rochester Determination de refraction oculaire a partir de donnees d'aberration de front d'ondes
US6499843B1 (en) 2000-09-13 2002-12-31 Bausch & Lomb Incorporated Customized vision correction method and business
WO2003092485A1 (fr) 2002-05-03 2003-11-13 University Of Rochester Procede de mesure de l'acuite visuelle pour la qualite de vision
US6659613B2 (en) 2000-03-27 2003-12-09 Board Of Regents, The University Of Texas System Methods and systems for measuring local scattering and aberration properties of optical media

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999058047A1 (fr) * 1998-05-09 1999-11-18 Velde Frans J Van De Ophtalmoscope laser a balayage pour microphotocoagulation, presentant un minimum d'aberrations optiques
US6438396B1 (en) * 1998-11-05 2002-08-20 Cytometrics, Inc. Method and apparatus for providing high contrast imaging

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5777719A (en) 1996-12-23 1998-07-07 University Of Rochester Method and apparatus for improving vision and the resolution of retinal images
US6659613B2 (en) 2000-03-27 2003-12-09 Board Of Regents, The University Of Texas System Methods and systems for measuring local scattering and aberration properties of optical media
US20040119942A1 (en) 2000-03-27 2004-06-24 Board Of Regents, The University Of Texas System, And Advanced Research And Technology Institute Methods and systems for measuring local scattering and aberration properties of optical media
US6499843B1 (en) 2000-09-13 2002-12-31 Bausch & Lomb Incorporated Customized vision correction method and business
WO2002030273A1 (fr) 2000-10-10 2002-04-18 University Of Rochester Determination de refraction oculaire a partir de donnees d'aberration de front d'ondes
WO2003092485A1 (fr) 2002-05-03 2003-11-13 University Of Rochester Procede de mesure de l'acuite visuelle pour la qualite de vision

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106198395A (zh) * 2016-06-29 2016-12-07 中国科学院半导体研究所 一种雪崩二极管探测器光耦合系统及其测量方法

Also Published As

Publication number Publication date
WO2007073848A3 (fr) 2007-11-29

Similar Documents

Publication Publication Date Title
EP0884580B1 (fr) Détecteur à fibres optiques pour la détection de la lumière diffusée ou de la lumière de fluorescence d'une suspension liquide
EP0822395B1 (fr) Procédé et dispositif de spectroscopie à corrélation d'émission Raman
DE60202027T2 (de) Multi-Photonen-Endoskop
DE102012007030B4 (de) Vorrichtung und Verfahren zur schnellen Aufnahme eines Absorptionsspektrums eines Fluids
EP3521810A1 (fr) Appareil d'analyse permettant de déterminer la fines poussières
EP2324389A1 (fr) Source de rayonnement térahertz et procédé pour générer un rayonnement térahertz
EP3056934A1 (fr) Tete de mesure d'un dispositif endoscopique et procede d'inspection et mesure d'un objet
WO2012119695A1 (fr) Système et procédé de tomographie à cohérence optique
EP1399771A2 (fr) Dispositif d'eclairage plat d'un champ d'objet
DE10350918B3 (de) Vorrichtung und Verfahren zur Messung der Transmission eines Objekts
DE10255022A1 (de) Resonatorverstärktes Absorptions-Spektrometer
DE102012004977B3 (de) Vorrichtung und Verfahren zum Messen eines Zielgases
DE19919091A1 (de) Anordnung zur Einstellung der Laserleistung und/oder der Pulslänge eines Kurzpulslasers in einem Mikroskop
WO2019086552A1 (fr) Capteur novateur pour spectroscopie raman
EP3270045B1 (fr) Systeme de mesure de concentrations de gaz
EP2163883B1 (fr) Appareil de mesure de grandeur de particules
WO2007073848A2 (fr) Dispositif de mesure oculaire par diffusion de lumière dynamique
DE102008064760B3 (de) Partikelgrößenmessgerät
EP1889040B1 (fr) Dispositif de mesure pour la determination du glucose non invasive par spectrometrie raman
DE102012106867B4 (de) Vorrichtung und Verfahren zur resonator-verstärkten optischen Absorptionsmessung an Proben mit kleinem Absorptionswirkungsquerschnitt
DE102018115420B4 (de) Vorrichtung und Verfahren zum Nachweisen eines Stoffes
DE102012201949B4 (de) Bestimmung der Geschwindigkeit eines bewegten Fluids unter Einsatz eines Fabry-Pérot-Interferometers
WO2018224468A1 (fr) Procédé de fourniture d'un signal de détection pour des objets à détecter
DE102008064666B4 (de) Partikelgrößenmessgerät
WO1998000734A1 (fr) Procede et dispositif de detection d'objets au moyen de rayonnements diffractes

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 06829436

Country of ref document: EP

Kind code of ref document: A2