Abstract: A ophthalmic fixation apparatus includes a case housing with an interior area to hold a power source, the case housing further having a switch to activate a first fixation element and a second fixation element; one or more straps extending from the case housing; a first flexible conduit extending from the case housing and to facilitate direction of the first fixation element; and a second flexible conduit extending from the case housing and to facilitate direction of the second fixation element; the ophthalmic apparatus is for use during an eye exam to keep the patient's attention and maintain a still eye for examination.

Abstract: Pumps for noncontact tonometry are provided. In one embodiment, a pump for noncontact tonometry includes a compression pump, a compression chamber, a first pressure sensor in communication with the compression chamber, a surge chamber, and a valve separating the compression chamber and surge chamber. The compression pump compresses a first volume of gas into the compression chamber. When the first pressure sensor detects a threshold pressure in the compression chamber, the valve opens and releases the gas into a surge chamber, where it combines with a gas residing in the surge chamber to form a puff of gas that escapes from the surge chamber through a flow-limiting nozzle. The components of the pump, which relies on passive rather than active components to create the controlled puff, can be assembled to have a profile that is portable and fit for home use.

Abstract: A spatially compact, lightweight positioning system for guiding an operator in positioning an ophthalmic instrument relative to an eye of a test subject has first and second light sources and an area detector spaced apart from a measurement axis of the instrument and from each other for providing positioning images which may be evaluated relative to stored calibration image information to determine current position of the instrument relative to the eye. The first and second light sources may fit within a lateral distance less than or equal to 25 mm. First and second illumination axes associated with the light sources may reside in a horizontal plane containing the measurement axis, and an observation axis of the area detector may reside in a vertical plane containing the measurement axis. The light sources and the area detector may be intersected by a plane which is normal to the measurement axis.

Abstract: This invention provides for a method and an EMDU used to dispense precise quantities of liquids with an image sensor being capable of providing feedback to the user as to both, when an eye is properly aligned with the EMDU, and to detect and track the quantity of the dose administered on to the eye.

Abstract: Described is a system, method and apparatus for measuring a vibrational response in an eye for determination of ocular parameters such as intraocular pressure, corneal elasticity and scleral pressure. The method comprises positioning an air jet nozzle to direct an excitation stimulus at a single frequency to the apex of the eye along the optical axis of the eye; positioning a sensor to direct incident light at a fixed position of the eye distinct from the apex of the eye; exciting vibration in the eye with the excitation stimulus; directing incident light from the sensor to the fixed position of the eye; and detecting backscatter light from the eye with the sensor, to measure the vibrational response. Algorithms are used to calculate the ocular pressure from the vibrational response of the cornea or sclera. The method does not require contact with the eye, and is reliable and accurate.

Abstract: A corneal dynamic model algorithm and system using the same is provided, comprising an ophthalmotonometer and a calculating unit. The calculating unit comprises the algorithm for calculating the corneal dynamic model. The algorithm comprises: reading an actual corneal deformation from the ophthalmotonometer; substituting a young's modulus initial value and a damping coefficient initial value into a mathematical equation for getting a calculated corneal deformation; determining whether error amount between the calculated deformation and the actual deformation is a minimum or not; and getting a young's modulus and a damping coefficient.

Abstract: A fiber reinforced polymer material lid or cover for a utility vault made from an unsaturated polyester thermosetting resin matrix, glass fiber reinforcement, an inorganic filler and an ultraviolet inhibitor. The lid or cover has a flat textured upper surface having a plurality of bosses having different heights extending above the upper surface and a bottom surface having an outer perimeter rim with a recessed interior cavity having a number of continuous support ribs extending through the recessed interior cavity from opposite sides of the outer perimeter of the rim to transfer load placed on the lid or cover and minimize deflection under the load to the outer perimeter rim.

Abstract: This invention provides for a method and an EMDU used to dispense precise quantities of liquids with an image sensor being capable of providing feedback to the user as to both, when an eye is properly aligned with the EMDU, and to detect and track the quantity of the dose administered on to the eye.

Abstract: The present invention provides an acoustic wave intraocular pressure detecting device and a method thereof, which uses a driver to generate a vibration wave on the skin or bones. The energy of the vibration wave is transmitted to the orbital bones via the skin and the skeletons. A standing wave of the basin effect is generated on the eyeball inside the orbital bones. The standing wave vibrates the eyeball or the cornea to generate an acoustic wave signal with a resonance frequency. The eyeball or the cornea emits the acoustic wave outwardly. A receiver receives the acoustic wave and converts the acoustic wave into an intraocular pressure (IOP) value.

Abstract: An ophthalmic apparatus for measuring an ocular function in a non-contact manner, comprising two or more independent Z alignment detection systems for projecting an alignment light to an eye to be examined and detects a Z alignment position of the eye based on a reflection light from the eye and a control unit for controlling an alignment, wherein the Z alignment detection systems are adapted to have different magnifications, wherein the Z alignment detection systems project the reflection light from the eye to a common photodetection element and the control unit is adapted to execute a coarse Z alignment based on a signal obtained by a Z alignment detection system with a low magnification among the signals obtained from the photodetection element and to execute a precise Z alignment based on a signal obtained by a Z alignment detection system with a high magnification.

Abstract: A non-contact type tonometer includes: a measurement unit including a first measuring unit for measuring an eye pressure of an examinee's eye in a non-contact manner and a second measuring unit for measuring a corneal thickness of the examinee's eye in a non-contact manner; a moving mechanism for causing relative movement of the measurement unit with respect to the examinee's eye; a drive controller for driving the moving mechanism for aligning the measurement unit; and a setting switch controller for switching an alignment reference on the cornea used for aligning the measurement unit between first and second alignment references. The first alignment reference is a reference for measuring the eye pressure with the first measuring unit and the second alignment reference is a reference for measuring the corneal thickness with the second measuring unit and set closer to a corneal rear surface than the first alignment reference.

Abstract: The optical apparatus includes an optical measurement module, a central processing module, and an air-puff module. The air-puff module is used for generating an air pressure to a surface of the cornea according a blow pattern to cause a deformation of the cornea. The optical measurement module includes a first unit and a second unit. The first unit is used for measuring an intraocular pressure (IOP) of the eye according to the deformation of the cornea. The second unit is used for measuring properties of the cornea in an optical interference way. The central processing module is coupled to the first unit and the second unit and used for receiving and processing the intraocular pressure and the properties of the cornea to provide a result.

Abstract: An ophthalmic image processing apparatus includes: a storage unit configured to store a fundus image and a first partial image, the first partial image being a partial image photographed for a part of the fundus image and having a higher resolution than the fundus image; and a display control unit configured to combine the first partial image with respect to an image region on the fundus image corresponding to the first partial image, and to display a combined image of the fundus image and the first partial image on a display medium.

Abstract: An excessive amount of pressurized air is inhibited from being blown to an eye of a patient during measurement of a corneal shape deformation amount. In a non-contact tonometer having a piston, a driving unit to drive the piston, a fluid ejection unit to blow air pressurized by driving the piston toward a cornea of an eye to be inspected, and an intraocular pressure measuring unit to detect a deformed state of the cornea and measure an intraocular pressure, there are provided a piston displacement restricting unit that restricts a displacement amount when the piston pressurizes the air, and a changing unit to change the displacement amount to be restricted by the piston displacement restricting unit.

Abstract: In an ophthalmic instrument that directs a fluid pulse at a cornea to cause reversible deformation of the cornea and monitors the corneal deformation to generate a deformation signal, the shape of the deformation signal is analyzed with respect to deformation signal data from a statistical population of eyes to calculate a deformation signal score indicating a degree of probability that the deformation signal corresponds in shape to a normal deformation signal for normal eyes in the population. In calculating the deformation signal score, significant geometrical signal parameters are calculated and combined. The deformation signal score may be used as a basis to keep or discard intraocular pressure measurements in a non-contact tonometer, and/or as a basis to conduct further diagnostic screening.

Abstract: Non-tactile and non-evasive tonometer utilizing air flow with a definite amount of pressure to the eye and a mechanism to deflate the thin foil set that is placed near to eye ball such that re-bounded air hits on it. The mechanism involves acquiring or capturing then the images of the known pattern marking on thin foils both before and after deflating process due to rebounded air. On evaluating the deformation of the pattern appearing in the images obtained before and after air flow and calibrating the deformation with respect to size, translation, rotation and scaling parameters due the different pressure level that hits the eye ball and that rebounds on to thin foils, we arrive at a scheme of measuring the intraocular pressure of human eye. This intraocular pressure is used as a parameter for the ophthalmologist to diagnose glaucoma impairment of human beings.

Abstract: An ophthalmic apparatus comprises an imaging unit configured to capture an anterior eye part image of an eye to be examined, a measuring unit configured to measure unique information of the eye, a calculation unit configured to calculate variations of a plurality of pieces of unique information measured by the measuring unit, and a display control unit configured to cause a display unit to display a plurality of anterior eye part images respectively corresponding to the plurality of pieces of unique information when variations calculated by the calculation unit satisfy a predetermined condition.

Abstract: The invention relates to an ophthalmic analysis system for measuring the intraocular pressure in an eye comprising an actuating device for contact-free deformation of the cornea, an observation system with which the deformation of the cornea can be observed and recorded, an analysis device with which the intraocular pressure can be deduced from the image information of the observation system, wherein split images of at least parts of the undeformed and/or deformed cornea can be recorded using the observation system.

Abstract: A method for measuring corneal elastic constant and viscosity constant comprises steps of: ejecting compressed air toward a cornea of a live eye ball and measuring air pressure thereof; emitting infrared rays during an air ejecting period, for measuring corneal deformation caused by the compressed air applied to the cornea; and calculating an elastic constant and a viscosity constant of the cornea based on Kelvin-Voigt model by utilizing the corneal deformation measured via the infrared rays and the measured air pressure during the air ejecting period. One advantage of the present invention is to aid preliminary detection in eye diseases.

Abstract: Provided is a non-contact tonometer capable of inhibiting unnecessary air discharge against an eye to be inspected. The non-contact tonometer includes: a corneal shape deforming unit for pressurizing air in a cylinder using a piston provided in the cylinder and puffing the air through an opening in the cylinder toward a cornea of an eye to be inspected so as to deform the cornea; a piston control unit for controlling operation of the piston; and an eye pressure measurement unit for detecting a state of deformation of the cornea so as to measure an eye pressure of the eye to be inspected. The piston includes: an air ejecting portion provided on the opening side in the cylinder; and a piston drive portion connected to the piston control unit independently of the air ejecting portion.

Abstract: A tool for calibrating a non-contact tonometer (NCT) comprises a body having a mating feature configured for removably mounting the body on the nosepiece or on the measurement head of the NCT, a pressure sensor carried by the body and arranged to receive an air pulse discharged by the NCT to provide a pressure signal in response to the air pulse, and a radiation emitter carried by the body, wherein the radiation emitter provides a pseudo-applanation event when the pressure signal reaches a predetermined level that is detectable by the NCT as though an actual corneal applanation had taken place. In one embodiment, the mating feature includes a mounting orifice for receiving a portion of the nosepiece. In another embodiment, the mating feature includes a pair of mounting pins sized for receipt by a corresponding pair of mounting holes in the measurement head of the NCT.

Abstract: An excessive amount of pressurized air is inhibited from being blown to an eye of a patient during measurement of a corneal shape deformation amount. In a non-contact tonometer having a piston, a driving unit to drive the piston, a fluid election unit to blow air pressurized by driving the piston toward a cornea of an eye to be inspected, and an interocular pressure measuring unit to detect a deformed state of the cornea and measure an interocular pressure, there are provided a piston displacement restricting unit that restricts a displacement amount when the piston pressurizes the air, and a changing unit to change the displacement amount to be restricted by the piston displacement restricting unit.

Abstract: In a non-contact tonometer, puffing of air unnecessary for measurement of an eye to be inspected after driving of a solenoid is stopped is suppressed. In the non-contact tonometer including a corneal shape change unit configured to change the shape of the cornea by pressurizing and supplying a gas in a cylinder by a piston, and an eye pressure measuring unit configured to measure the eye pressure from the state of the shape change of the cornea, an opening portion configured to be formed in the outer wall of the cylinder and decide the internal volume of the cylinder when pressurizing the gas, and a pressurized gas volume change unit configured to change a position where the opening portion can connect the inside of the cylinder with the outside, and change the internal volume of the cylinder when pressurizing the gas.

Abstract: A non-contact ophthalmologic apparatus includes: a storage unit for storing measurement results of an intraocular pressure of an eye to be inspected as statistical data; a condition determination unit for determining a measurement range of an intraocular pressure value based on the statistical data; and a control condition determination unit for determining, based on the measurement range determined by the condition determination unit, a control condition of a fluid ejection unit for ejecting air toward the eye to be inspected. Thus, it is possible to eliminate a need to eject high-pressure air even in the first measurement of the intraocular pressure of the eye to be inspected, thereby alleviating a burden on a subject.

Abstract: Non-tactile and non-evasive tonometer utilizing air flow with a definite amount of pressure to the eye and a mechanism to deflate the thin foil set that is placed near to eye ball such that re-bounded air hits on it. The mechanism involves acquiring or capturing then the images of the known pattern marking on thin foils both before and after deflating process due to rebounded air. On evaluating the deformation of the pattern appearing in the images obtained before and after air flow and calibrating the deformation with respect to size, translation, rotation and scaling parameters due the different pressure level that hits the eye ball and that rebounds on to thin foils, we arrive at a scheme of measuring the intraocular pressure of human eye. This intraocular pressure is used as a parameter for the ophthalmologist to diagnose glaucoma impairment of human beings.

Abstract: A portable non-contact tonometer (2) for measuring Intra-Ocular Pressure (IOP) of subject's eye is presented. Tonometer (2) is designed to be operated by the subject himself. It is housed in a hand-held case (4) which contains compressed air source (40), eye alignment detectors (12, 14), cornea applanation detector system (8, 10), a pressure sensor (32) and optical system for presenting gaze target (48). The animated gaze target (48) advantageously draws subject's attention to itself and keeps his eye (62) in alignment long enough for the measurement to take place, while optionally displaying system status and operating instructions. An audio annunciation system (16) guides the subject in the operation of the tonometer and prepares him for the actual procedure. The timing of the air puff is randomized to prevent subject's conditioning. The overall operation of the tonometer is controlled by a built-in microprocessor (50) system.

Abstract: An ophthalmic instrument that discharges a fluid pulse to deform the cornea of a test subject is improved by reducing the working distance between a nosepiece or a discharge tube from which the fluid pulse is discharged and the eye of the test subject. The invention improves measurement repeatability and patient comfort.

Abstract: In a contactless tonometer having a mechanism of puffing compressed air by moving a piston in a cylinder, puffing of unnecessary air against the eye to be inspected is suppressed. An apparatus includes a corneal shape changing unit configured to change a shape of a cornea of an eye to be inspected by compressing air in a cylinder by using a piston, and puffing the compressed air from the nozzle to the cornea, a piston control unit configured to control operation of the piston, and an intraocular pressure measurement unit configured to measure an intraocular pressure of the eye by detecting a state of a changed shape of the cornea. This apparatus includes a piston volume changing unit configured to change an initial volume when the piston compresses the air in the cylinder.

Abstract: The invention relates to an ophthalmological analysis method for measuring an intraocular pressure in an eye with an analysis system consisting of an actuating device, wherein the actuating device causes a puff of air to be applied to the eye in such manner that the cornea is deformed, an observation system with which the deformation of the cornea is observed and recorded, wherein sectional images of the cornea when it is deformed and not deformed are created with the observation device, and an analysis device with which the intraocular pressure is derived from the sectional images of the cornea, wherein a structural characteristic and/or material characteristic of the cornea is derived from the sectional images of the cornea in the analysis device, wherein a stress of the cornea is derived as a structural characteristic and/or material characteristic, wherein stresses in the corneal material are rendered visible.

Abstract: The invention relates to an ophthalmological analysis method for measuring an intraocular pressure in an eye with an analysis system consisting of an actuating device with which a cornea of the eye is deformed in contactless manner, wherein the actuating device causes a puff of air to be applied to the eye in such manner that the cornea is deformed, an observation system with which the deformation of the cornea is observed and recorded, wherein sectional images of the cornea when it is deformed and not deformed are created with the observation device, and an analysis device with which the intraocular pressure is derived from the sectional images of the cornea, wherein a material characteristic of the cornea is derived from the sectional images of the cornea in the analysis device, wherein a stiffness of the cornea is derived as a material characteristic.

Abstract: The invention relates to an opthalmological analysis method for measuring an intraocular pressure in an eye with an analysis system consisting of an actuating device, wherein the actuating device causes a puff of air to be applied to the eye in such manner that the cornea is deformed, an observation system with which the deformation of the cornea is observed and recorded, wherein sectional images of the cornea when it is deformed and not deformed are created with the observation device, and an analysis device with which the intraocular pressure is derived from the sectional images of the cornea, wherein a material characteristic of the cornea is derived from the sectional images of the cornea in the analysis device, wherein a diameter d1 of a first applanation area of the cornea and a diameter dn of a deformation area of the cornea is derived as a material characteristic.

Abstract: A non-contact tonometer of the present invention quantitatively measures characteristic vibration of the cornea of an eyeball and measures a true ocular pressure utilizing this vibration, and comprises: an air flow spray unit (200) spraying an air flow (F) to a cornea (C) of an eye (E) to be examined and deforming the cornea; a cornea deformation amount measurement unit (300) measuring deformation of the cornea caused by the air flow spray unit along with elapsed time from the start of the air flow spray; a Fourier analysis unit (401) performing Fourier analysis on a relationship between a deformation amount of the cornea obtained by a cornea deformation detection unit and the elapsed time; an eyeball tissue characteristic frequency operation unit (402) obtaining an characteristic frequency of each constituent tissue of the eyeball based on a Fourier analysis result obtained by the Fourier analysis unit; and an ocular pressure operation unit (403) calculating an ocular pressure based on the characteristic fre

Abstract: The invention relates to an illumination system (10) and an illumination method for an opthalmological analysis apparatus, in particular an analysis apparatus for measuring an intraocular pressure in an eye, wherein the analysis apparatus includes an actuation device (11) with which a puff of air for deforming a cornea (14) can be applied to the eye (12) in the direction of an optical axis (15) of the eye, wherein the illumination system includes at least one illumination device (23) with which the cornea of the eye can be illuminated by a slit light in such a way that a sectional image (27) can be generated in an illumination plane coinciding with the optical axis, wherein the illumination device is formed so that an illuminating beam path (28) of the illumination device oriented towards the eye is arranged at an angle ? relative to the optical axis (15).

Abstract: Devices, systems, and methods interface a cassette with an eye treatment system console to provide coupling between the console and an eye treatment probe. The console may receive the cassette using a driven axial translation linkage that inhibits rotation of the cassette. The cassette may facilitate accurately positioning of a pressure sensor relative to a the console by allowing sliding movement between the sensor and a cassette body. Multiple peristaltic drives may be mounted to the console so that their rotors rotate about a common axis. An integrated mount structure may support and/or position components of the console which will interface with cassette, and an axially compressible vacuum connector of the console seal to a tapered vacuum coupler of the cassette.

Abstract: An air-puff type intraocular pressure measuring device includes an optical measuring unit and a puffing unit. The optical measuring unit includes an imaging optical path having a perforated lens and an image sensor capable of receiving an eyeball image via the perforated lens for eyeball alignment; a measuring optical path having a measuring element for transmitting a measuring signal and receiving a reflected signal via the perforated lens to derive an intraocular pressure value; and a beam splitter for the image sensor and the measuring element to respectively form a first and a second path having different axial directions. The puffing unit is connected to the optical measuring unit for puffing air through the perforated lens against an eyeball. The puffing unit has a puffing path located coaxially on the second path of the measuring optical path, so that measuring errors caused by parts-related tolerances are effectively reduced.

Abstract: An ophthalmological analysis method measures an intraocular pressure in an eye using an analysis system. The analysis system includes an actuation device, with which a cornea of the eye is deformed contactlessly. The actuation device applies a puff of air to the eye to deform the cornea. A monitoring system monitors the deformation of the cornea and records sectional images of the undeformed and deformed cornea. An analysis device derives an intraocular pressure from the sectional images of the cornea, wherein the recorded sectional images of the deformed cornea are corrected relative to a recorded sectional image of the undeformed cornea, the intraocular pressure being derived under consideration of the correction.

Abstract: An ophthalmic apparatus comprises an imaging unit configured to capture an anterior eye part image of an eye to be examined, a measuring unit configured to measure unique information of the eye, a calculation unit configured to calculate variations of a plurality of pieces of unique information measured by the measuring unit, and a display control unit configured to cause a display unit to display a plurality of anterior eye part images respectively corresponding to the plurality of pieces of unique information when variations calculated by the calculation unit satisfy a predetermined condition.

Abstract: An ophthalmic instrument that discharges a fluid pulse to deform the cornea of a test subject is improved by reducing the working distance between a nosepiece or a discharge tube from which the fluid pulse is discharged and the eye of the test subject. The invention improves measurement repeatability and patient comfort.

Abstract: A self-operated non-contact tonometer for measuring the intra-ocular pressure of an eye, projecting light into the eye and measuring the reflected light as affected by mechanical distortion. The cornea is distorted by delivering a pneumatic pulse. The tonometer consists mainly of an electro-optical unit mountable on the head of a user and a control unit. The control unit of the tonometer includes a display and optionally an audio device for instructing the user. The electro-optical unit employs a tubular wave guide, a light detector, and a reflector for deflecting a light beam to the eye and for eliminating a part of the reflected light reaching the detector. The aligning of the tonometer with the head of the user is optionally assisted by a reticle.

Abstract: The invention relates to an ophthalmic analysis system for measuring the intraocular pressure in an eye comprising an actuating device for contact-free deformation of the cornea, an observation system with which the deformation of the cornea can be observed and recorded, an analysis device with which the intraocular pressure can be deduced from the image information of the observation system, wherein split images of at least parts of the undeformed and/or deformed cornea can be recorded using the observation system.

Abstract: The invention relates to an ophthalmological analysis method for measuring an intraocular pressure in an eye with an analysis system consisting of an actuating device, wherein the actuating device causes a puff of air to be applied to the eye in such manner that the cornea is deformed, an observation system with which the deformation of the cornea is observed and recorded, wherein sectional images of the cornea when it is deformed and not deformed are created with the observation device, and an analysis device with which the intraocular pressure is derived from the sectional images of the cornea, wherein a structural characteristic and/or material characteristic of the cornea is derived from the sectional images of the cornea in the analysis device, wherein a stress of the cornea is derived as a structural characteristic and/or material characteristic, wherein stresses in the corneal material are rendered visible.

Abstract: The invention relates to an ophthalmological analysis method for measuring an intraocular pressure in an eye with an analysis system consisting of an actuating device, wherein the actuating device causes a puff of air to be applied to the eye in such manner that the cornea is deformed, an observation system with which the deformation of the cornea is observed and recorded, wherein sectional images of the cornea when it is deformed and not deformed are created with the observation device, and an analysis device with which the intraocular pressure is derived from the sectional images of the cornea, wherein a material characteristic of the cornea is derived from the sectional images of the cornea in the analysis device, wherein a diameter d1 of a first applanation area of the cornea and a diameter dn of a deformation area of the cornea is derived as a material characteristic.

Abstract: The invention relates to an ophthalmological analysis method for measuring an intraocular pressure in an eye with an analysis system consisting of an actuating device with which a cornea of the eye is deformed in contactless manner, wherein the actuating device causes a puff of air to be applied to the eye in such manner that the cornea is deformed, an observation system with which the deformation of the cornea is observed and recorded, wherein sectional images of the cornea when it is deformed and not deformed are created with the observation device, and an analysis device with which the intraocular pressure is derived from the sectional images of the cornea, wherein a material characteristic of the cornea is derived from the sectional images of the cornea in the analysis device, wherein a stiffness of the cornea is derived as a material characteristic.

Abstract: In an ophthalmic instrument that directs a fluid pulse at a cornea to cause reversible deformation of the cornea and monitors the corneal deformation to generate a deformation signal, the shape of the deformation signal is analyzed with respect to deformation signal data from a statistical population of eyes to calculate a deformation signal score indicating a degree of probability that the deformation signal corresponds in shape to a normal deformation signal for normal eyes in the population. In calculating the deformation signal score, significant geometrical signal parameters are calculated and combined. The deformation signal score may be used as a basis to keep or discard intraocular pressure measurements in a non-contact tonometer, and/or as a basis to conduct further diagnostic screening.

Abstract: A non-contact tonometer of the present invention quantitatively measures characteristic vibration of the cornea of an eyeball and measures a true ocular pressure utilizing this vibration, and comprises: an air flow spray unit (200) spraying an air flow (F) to a cornea (C) of an eye (E) to be examined and deforming the cornea; a cornea deformation amount measurement unit (300) measuring deformation of the cornea caused by the air flow spray unit along with elapsed time from the start of the air flow spray; a Fourier analysis unit (401) performing Fourier analysis on a relationship between a deformation amount of the cornea obtained by a cornea deformation detection unit and the elapsed time; an eyeball tissue characteristic frequency operation unit (402) obtaining an characteristic frequency of each constituent tissue of the eyeball based on a Fourier analysis result obtained by the Fourier analysis unit; and an ocular pressure operation unit (403) calculating an ocular pressure based on the characteristic fre

Abstract: This invention is a system, an apparatus and a method for measuring biomechanical properties of cornea and the intraocular pressure in vivo. More than one dimensional topographic information of the cornea is recorded and analyzed before and during the fluid discharge and converted to the stress-strain relationship and other cornea parameters, for example the cornea thickness and radius of curvature, etc. The deformation of cornea is initiated by a non-contact fluid discharge whose profile is predetermined and monitored in real time. Utilizing this non-contact topographer, the true intraocular pressure can be derived from the response of the cornea due to the impact of fluid discharge and the corneal topographic parameters. One embodiment of this invention includes the use of a multiple color strobe light/multiple detector system to record the corneal topographic deformation due to the impact of fluid discharge.

Abstract: A method and apparatus for measuring corneal resistance to deformation use an empirically derived function wherein an inward applanation pressure P1 and an outward applanation pressure P2 obtained during a corneal deformation cycle caused by a fluid pulse are separately weighted so as to minimize dependence of the calculated corneal resistance factor (CRF) on intraocular pressure. In one embodiment, the function is optimized, at least in part, to maximize statistical correlation between the calculated corneal resistance factor (CRF) and central corneal thickness.

Abstract: A portable non-contact tonometer (2) for measuring Intra-Ocular Pressure (IOP) of subject's eye is presented. In its preferred embodiment tonometer (2) is designed to be operated by the subject himself. It is housed in a hand-held case (4) which contains compressed air source (40), eye alignment detectors (12, 14), cornea applanation detector system (8, 10), a pressure sensor (32) and optical system for presenting gaze target (48). The animated gaze target (48) advantageously draws subject's attention to itself and keeps his eye (62) in alignment long enough for the measurement to take place, while optionally displaying system status and operating instructions. An audio annunciation system (16) guides the subject in the operation of the tonometer and prepares him for the actual procedure. The timing of the air puff is randomized to prevent subject's conditioning. The overall operation of the tonometer is controlled by a built-in microprocessor (50) system.

Abstract: A method for direct indication of the IOP level without requiring an additional pressure transducer being introduced into the irrigation path. The method of the present invention estimates resistance ratio for a particular setup, and thus does not assume a typical value; the estimation is performed in a pre-operational configuration that is the closest possible to the surgical configuration.

Abstract: A tonometer for measuring intraocular pressure of an examinee's eye in a non-contact manner, comprises: an arithmetic part for calculating the intraocular pressure; a fluid blowing unit for blowing a fluid at a cornea of the examinee's eye through a nozzle; a projecting optical system for projecting light onto an anterior segment of the examinee's eye through the nozzle, the system including a light source and a condensing lens; and an imaging optical system for imaging a cross-sectional image of the anterior segment, the system including an imaging lens and an imaging elements.