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WO2025026807A1 - Œil test à pression ajustable pour des tonomètres - Google Patents

Œil test à pression ajustable pour des tonomètres Download PDF

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Publication number
WO2025026807A1
WO2025026807A1 PCT/EP2024/070821 EP2024070821W WO2025026807A1 WO 2025026807 A1 WO2025026807 A1 WO 2025026807A1 EP 2024070821 W EP2024070821 W EP 2024070821W WO 2025026807 A1 WO2025026807 A1 WO 2025026807A1
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WO
WIPO (PCT)
Prior art keywords
pressure
cornea
test eye
adjustable test
film
Prior art date
Legal status (The legal status 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 status listed.)
Pending
Application number
PCT/EP2024/070821
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German (de)
English (en)
Inventor
Martin Hacker
Lukas Rothmann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Carl Zeiss Meditec AG
Original Assignee
Carl Zeiss Meditec AG
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
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Publication of WO2025026807A1 publication Critical patent/WO2025026807A1/fr
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Classifications

    • 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
    • A61B3/0016—Operational features thereof
    • A61B3/0025—Operational features thereof characterised by electronic signal processing, e.g. eye models
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09B—EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
    • G09B23/00—Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes
    • G09B23/28—Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes for medicine
    • G09B23/30—Anatomical models
    • 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
    • A61B3/16—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions for measuring intraocular pressure, e.g. tonometers
    • A61B3/165—Non-contacting tonometers

Definitions

  • the present invention relates to a pressure-adjustable test eye for tonometers, in particular for contact-free tonometers.
  • Test eyes are essentially used to regularly check and/or calibrate medical devices for their correct function.
  • a tonometer is used to measure the intraocular pressure (IOP).
  • IOP intraocular pressure
  • An increase above the normal value is usually one of the most important, but not the only, risk factor for glaucoma.
  • Lowering the IOP, for example through medication (eye drops or drug depot implants) or surgical interventions, is the most important therapeutic measure for treating glaucoma, which is why tonometric monitoring of the IOP is an important tool for managing therapy.
  • glaucoma can also be present when the intraocular pressure is within the normal range mentioned above (normal pressure glaucoma), and increased intraocular pressure outside the normal range (hypertension) only gives rise to suspicion of a disease.
  • Glaucoma also known as glaucoma, is a group of eye diseases of various causes that result in irreversible damage to the nerve fibers of the optic nerve. As the disease progresses, this becomes noticeable at the point where the optic nerve exits as increasing hollowing (excavation) or fading and atrophy of the optic nerve head (papilla). This results in characteristic visual field defects (scotomas), which in extreme cases can lead to blindness in the affected eye.
  • IOP intraocular pressure
  • the stated intraocular pressure (IOP) is the relative pressure of the inside of the eye, particularly the aqueous humor, in relation to the atmospheric air pressure. If this relative pressure is significantly increased, for example, the eye becomes noticeably hard, which is why ophthalmologists used palpation to at least qualitatively assess the intraocular pressure before tonometers were available.
  • absolute pressures such as those determined by intraocularly implanted pressure sensors, must be distinguished from this IOP if they are not related to the prevailing atmospheric air pressure.
  • Tonometers for determining intraocular pressure are important diagnostic devices in ophthalmology, especially for the detection of ocular hypertension as a major risk factor for glaucoma and for therapy monitoring, but also in emergency medicine for the detection of high intracranial pressures that are transmitted to the eye.
  • Tonometers as medical devices, should be regularly checked for correct functioning and/or must be calibrated. Unfortunately, this is a difficult task, as the pressure-dependent interaction of an eye with the respective tonometer is complex and different pressure levels must be tested. This is a largely unsolved problem, especially for dynamic measuring, contact-free tonometers, such as airpuff or rebound tonometers or the shock wave tonometer described in [1].
  • US 2014/0323843 A1 describes a tool for calibrating a non-contact tonometer (NCT).
  • the tonometer calibration tool consists of a non-contact tonometer, which is placed in front of an air outlet channel of a non-contact tonometer. Tonometer's positionable "electronic eye” with a pressure sensor to receive the air pulse and a transmitter to provide a pseudo-applanation event.
  • the electronic eye is used to simulate the reaction of an eye that is to be measured tonometrically without contact by imitating a pressure-dependent deflection of a light reflex on a "cornea" that is dynamically deformed by an air puff.
  • the light beam is not actually deflected, but a similar light signal is generated depending on the air puff, which is detected by the air-puff tonometer instead of the deflected light beam.
  • artificial anterior chambers are known that can be used for surgical manipulation of corneas or for training purposes.
  • the chamber is a special device that allows a donor's corneoscleral tissue cap to be positioned anatomically with the epithelial side up.
  • the chamber is used to support the donor tissue and maintain adequate pressure while lamellar dissection or full-thickness trephination is performed on the donor tissue.
  • the present invention is based on the object of providing a test eye to enable intraocular pressure-dependent measurements, in particular for dynamically measuring, contact-free tonometry methods.
  • the test eye should be used to generate measurement signals that are as close to reality as possible in order to be able to carry out regular functional tests and/or calibrations.
  • the film simulating the cornea has a flat or curved surface, the central, mechanically excitable region of which has an area between 500 and 8000 mm 2 .
  • the film simulating the cornea has a homogeneous, isotropic structure and is transparent and elastic.
  • the inner and outer sides of the film are smooth and contain no mechanical disturbances, so that a low optical and acoustic scattering effect is achieved.
  • the film simulating the cornea consists of PVC, TPU or PE, in particular PE-LD.
  • the property modification includes a variation of the curvature and/or a variation of the thickness and/or a variation of the elasticity of the film simulating the cornea.
  • a damping element is present directly under the film simulating the cornea, which is designed and arranged in such a way that the central, mechanically excitable area has a minimum distance from the damping element of 10 to 2000pm, in particular 500 to 800pm.
  • the film and the damping element located directly underneath gradually approach each other, whereby the approach decreases particularly preferably from the inside to the outside.
  • the test eye is arranged for measurements so that the base element is aligned horizontally and the film simulating the cornea points upwards or downwards.
  • the property modification of the film simulating the cornea in such a way that the test eye is not unacceptably deformed by gravity under measurement conditions.
  • the proposed pressure-adjustable test eye is intended for tonometers, in particular for non-contact tonometers, in order to generate measurement signals that are as close to reality as possible in order to perform regular functional tests and/or calibrations.
  • the proposed pressure-adjustable test eye is not only applicable for tonometry, but also for elastography or elastometry, for example to enable the pre- and postoperative evaluation of corneas.
  • Figure 1 a pressure-adjustable test eye with a flat foil
  • Figure 2 a pressure-adjustable test eye with a curved foil
  • Figure 3 a pressure-adjustable test eye with a foil with varied
  • Curvature, Figure 4 a pressure-adjustable test eye with a foil of varying thickness
  • Figure 5 a pressure-adjustable test eye with a damping element arranged under the foil and
  • Figure 6 a pressure-adjustable test eye with a foil with varying curvature, varying thickness and a damping element.
  • the proposed pressure-adjustable test eye for tonometers in particular for contact-free tonometers, consists of a base element with a pressure source, to the edge of which a film simulating the cornea is attached, the resulting cavity being filled with liquid or gas.
  • the film simulating the cornea has gradually varying conduction properties for mechanical waves, starting from a central, mechanically excitable area.
  • a film is used to simulate the cornea which is self-supporting and has a certain residual rigidity.
  • the central, mechanically excitable area is the area of the foil that is to be stimulated by a tonometer to be tested, for example by an air blast, in order to generate measurement signals that are as realistic as possible.
  • Water, silicone oil or similar can be used as a liquid for the cavity. It is also possible to fill the test eye partially or completely with gas, for example to test the measuring conditions in a partially gas-filled patient eye. Gas fillings, for example with the very dense but non-toxic sulphur hexafluoride, are used in the treatment of retinal detachments, among other things. Since sulphur hexafluoride is chemically inert, it can also be used in a test eye.
  • the film that simulates the cornea is referred to below as just the film.
  • the base element holding the film is plate-shaped or cylindrical, with its diameter being larger than its height.
  • the base element also has at least one pressure sensor to detect the pressure setting of the test eye.
  • the pressure sensor is advantageously designed in such a way that it can carry out a relative pressure measurement to the atmospheric ambient pressure, for example by means of a can or membrane barometer that is measurably deformed by the pressure difference between the test eye fluid and the ambient pressure.
  • an absolute measuring pressure sensor for example as a temperature-compensated, miniaturized MEMS or piezoresistive sensor
  • a second pressure sensor is then required to determine the atmospheric ambient pressure as a reference value.
  • Another variant is to pair these two sensors in a pressure sensor module that emits a differential electrical measurement signal for the relative pressure in the test eye.
  • Figure 1 shows a first pressure-adjustable test eye consisting of a cylindrical base element 1.1 with a pressure source 2, to the edge of which a flat film 3.1 is attached.
  • the resulting cavity 4 is filled with liquid or gas, which is indicated by the hatching.
  • Pressure sensors are not shown for the sake of clarity.
  • Figure 2 shows a second pressure-adjustable test eye consisting of a flat base element 1.2 with a pressure source 2, to the edge of which a curved film 3.2 is attached.
  • the resulting cavity 4 is filled with liquid or gas, which is expressed by the hatching.
  • Preferred further developments and advantageous embodiments essentially concern the film attached to the edge of the base element.
  • the film simulating the cornea has a flat or curved surface. This can, for example, have the shape of a sphere or an ellipsoid.
  • the central, mechanically excitable region of the film particularly preferably has an area of between 500 and 8000mm 2 .
  • the film simulating the cornea has a homogeneous, isotropic structure that is preferably transparent and elastic. It is particularly advantageous if the film is also optically reflective, with a degree of reflection between 0.1 and 10%. This average reflectivity should be related to vertically incident, non-polarized light. Changes in reflectivity can be achieved by suitable surface coatings. Alternatively, reductions in film rear-side reflections can also be reduced by introducing dyes that absorb the measuring radiation on the way to the rear of the film and back.
  • the inner and outer sides of the film are smooth and contain no mechanical disturbances, so that a low optical and acoustic scattering effect is achieved.
  • the film simulating the cornea consists of PVC, TPU or PE, in particular PE-LD.
  • This Materials have proven to be particularly suitable for generating measurement signals that are as realistic as possible.
  • PE-VLD high density
  • PE-LD low density
  • PE-MD low density
  • PE-HD from “very low density”, “low density”, “medium density”, “linear low density” to “high density”.
  • the further preferred developments relate to the design of the gradually varying conduction properties of the film for mechanical waves by property modification.
  • the property modification includes a variation in the curvature and/or a variation in the thickness and/or a variation in the elasticity of the film simulating the cornea.
  • Property modification of the film is understood here to mean, for example, deep-drawing the film during the manufacturing process, whereby the curvature is flattened somewhat in the center.
  • Figure 3 shows a third pressure-adjustable test eye consisting of a flat base element 1.2 with a pressure source 2, to the edge of which a curved foil 3.3 is attached.
  • the resulting cavity 4 is also filled with liquid or gas, which is expressed by the hatching.
  • the gradually varying conduction properties for mechanical waves were generated by varying the curvature of the curved foil 3.3.
  • Figure 4 shows a fourth pressure-adjustable test eye consisting of a flat base element 1.2 with a pressure source 2, to the edge of which a curved foil 3.4 is attached.
  • the resulting cavity 4 is also filled with liquid or gas, which is again expressed by the hatching.
  • the gradually varying conduction properties for mechanical waves in this variant were generated by varying the thickness of the curved foil 3.4.
  • the film has a thickness in the range between 10 and 1000 pm.
  • the film has a modulus of elasticity in the range from 0.2 to 1000 MPa, in particular in the range below 10 MPa.
  • a damping element is present directly under the film simulating the cornea, which is designed and arranged such that the central, mechanically excitable area has a minimum distance from the damping element of 10 to 2000pm, in particular 500 to 800pm.
  • a possibility for pressure equalization can be provided in the damping element.
  • Figure 5 shows a fifth pressure-adjustable test eye consisting of a flat base element 1.2 with a pressure source 2, to the edge of which a curved film 3.5 is attached.
  • the resulting cavity 4 is also filled with liquid or gas, which is expressed by the hatching.
  • a damping element 5 with a pressure compensation element in the form of an opening 5.1 is arranged under the curved film 3.5.
  • the film and the damping element located immediately underneath it gradually approach each other, with the approach particularly preferably decreasing from the inside to the outside.
  • Figure 6 shows a sixth pressure-adjustable test eye consisting of a planar base element 1.2 with a pressure source 2, a curved foil 3.6 is attached to the edge.
  • the resulting cavity 4 is again filled with liquid or gas, which is indicated by the hatching.
  • a damping element 5 is also arranged under the curved foil 3.6.
  • the gradually varying conduction properties for mechanical waves in this variant were generated by varying the thickness and curvature of the curved foil 3.6 and the varying distance of the damping element.
  • a sufficiently slow, gradual approach between the film and the damping element in the peripheral direction is required, whereby a defined distance must be maintained in order to avoid signal interference.
  • the damping element can also be designed in such a way that the film and the damping element touch or are connected outside the central, mechanically excitable area.
  • the film and the damping element preferably have different mechanical properties.
  • the damping element arranged directly beneath the film simulating the cornea can be integrated into the base element.
  • the foil is located at a defined distance from the damping element or gradually approaches it in a peripheral direction until contact occurs. This creates a gradual coupling between the foil and the damping element, which results in a more realistic signal attenuation of the signals generated during contact-free tonometry.
  • the test eye for measurements is arranged so that that the base element is aligned horizontally and the film simulating the cornea points upwards or downwards. It is also possible to modify the properties of the film simulating the cornea in such a way that the test eye is not unacceptably deformed by gravity under measurement conditions.
  • the film could be locally stiffened or pre-formed in such a way that the desired shape of the test eye is still ensured in the end, despite the additional deformation caused by gravity that occurs under measurement conditions.
  • the present invention provides a test eye that enables measurements dependent on the intraocular pressure, in particular for dynamically measuring, contact-free tonometry methods.
  • the test eye generates realistic measurement signals in order to be able to carry out regular functional tests and/or calibrations.
  • test eye described comes very close to the behavior of the human eye, particularly in the area of the anterior chamber (cornea, iris and limbus) in terms of mechanical excitation and vibration behavior.
  • the interaction of the foil and the damping element makes it possible to simulate the slight reflection of surface waves at the edge of the cornea of the real eye.
  • the proposed pressure-adjustable test eye is intended for tonometers, especially for non-contact tonometers, but can also be used for elastography or elastometry.

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  • Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
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Abstract

La présente solution se rapporte à un œil test à pression ajustable pour des tonomètres, en particulier pour des tonomètres sans contact. L'œil test à pression ajustable proposé pour des tonomètres est composé d'un élément de base avec une source de pression, élément de base au bord duquel un film, simulant la cornée, est fixé, la cavité résultante étant remplie de liquide ou de gaz. Selon l'invention, le film simulant la cornée présente, à partir d'une région centrale excitable mécaniquement, des propriétés conductrices progressivement variables pour des ondes mécaniques. Pour une simulation de la cornée, on utilise un film autoportant et présentant une certaine rigidité résiduelle. L'œil test à pression ajustable est destiné à des tonomètres, en particulier des tonomètres sans contact, afin de générer les signaux de mesure les plus réalistes possibles, afin de pouvoir réaliser des tests et/ou des étalonnages réguliers de fonctions. Toutefois, l'œil test à pression ajustable peut également être utilisé en élastographie ou en élastométrie afin, par exemple, de permettre la réalisation d'une évaluation préopératoire et postopératoire des cornées.
PCT/EP2024/070821 2023-08-03 2024-07-23 Œil test à pression ajustable pour des tonomètres Pending WO2025026807A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102023207473.7 2023-08-03
DE102023207473.7A DE102023207473A1 (de) 2023-08-03 2023-08-03 Druckeinstellbares Testauge für Tonometer

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WO2025026807A1 true WO2025026807A1 (fr) 2025-02-06

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102023208852A1 (de) 2023-09-12 2025-03-13 Carl Zeiss Meditec Ag Dockingstation für ein handgehaltenes Biometer

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140323843A1 (en) 2011-10-21 2014-10-30 Reichert, Inc. Tonometer calibration tool
KR20210061861A (ko) * 2019-11-20 2021-05-28 주식회사 휴비츠 토노미터용 모델 아이
JP2021132671A (ja) * 2020-02-21 2021-09-13 株式会社トプコン 眼圧調整装置及び模型眼システム

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201814554U (zh) 2010-09-03 2011-05-04 四川中测辐射科技有限公司 非接触式眼压计检测标准装置
SK1462020A3 (sk) 2020-12-30 2021-04-28 Slovenska Technicka Univerzita V Bratislave Etalónové zariadenie na metrologickú kontrolu bezkontaktných očných tonometrov a umelá očná rohovka na účely kalibrácií oftalmologických veličín pre toto zariadenie

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140323843A1 (en) 2011-10-21 2014-10-30 Reichert, Inc. Tonometer calibration tool
KR20210061861A (ko) * 2019-11-20 2021-05-28 주식회사 휴비츠 토노미터용 모델 아이
JP2021132671A (ja) * 2020-02-21 2021-09-13 株式会社トプコン 眼圧調整装置及び模型眼システム

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