A dual measurement tonometer for simultaneously measuring intraocular pressures of eyes using an air pulse

Abstract

Disclosed is a dual measurement tonometer (100, 200) for measuring intraocular pressure (IOP) values of a first eye (122A, 204) and a second eye (122B) of a user (120) within a pre-defined time period. The dual measurement tonometer comprises a first air pulse generator (APG) (102A) and a second APG (102B) aligned with the first and second eye, respectively, the first and second APGs positioned on opposite sides of a frame (104); at least one corneal oscillation measurement sensor (106, 208) (COMS) operatively coupled to the first and second APGs; a controller (108) communicatively coupled to the COMS and the first and second APGs. The controller is configured to: determine first set of operational parameters of each of the first and second APGs; control the first and second APGs to send, within a pre-defined time period, a first excitation air pulse (126, 202) towards the eyes; measure, within the pre-defined time period, a first signal (206) related to corneal oscillations of the eyes, caused by the first excitation air pulse, using the COMS; determine the IOP values from the measured first signals.

Description

[0001] A DUAL MEASUREMENT TONOMETER FOR SIMULTANEOUSLY MEASURING INTRAOCULAR PRESSURES OF EYES USING AN AIR PULSE

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to dual measurement tonometers for simultaneously measuring intraocular pressures of eyes using air pulses. Moreover, the present disclosure relates to methods for simultaneously measuring intraocular pressures of eyes using air pulses.

[0004] BACKGROUND

[0005] A tonometer is an instrument for measuring the intraocular pressure of an eye. However, conventional tonometer can measure intraocular pressure of only one eye at a time. For measuring the intraocular pressures of both eyes of a person, an operator or healthcare professional has to measure the intraocular pressure of one eye first then move the conventional tonometer from that eye to the other eye for measuring the intraocular pressure thereof. Thus, level of manual effort utilized is amplified. Moreover, the intraocular pressure of eyes may be influenced by, for example, different phases of cardiac cycle (namely systolic and diastolic phases) as well as various physiological characteristics (such as blood pressure, posture during measurement, corneal properties of eyes, movement) of the person. Moreover, when measuring the first eye and the second eye at different moments of time, the influences on the measurements or eye conditions may vary. The time difference in measurement of IOP may yield different and incomparable intraocular pressure values for both the eyes which leads to lack of accuracy.

[0006] Therefore, in light of the foregoing discussion, there exists a need to overcome the aforementioned drawbacks. SUMMARY

[0007] The aim of the present disclosure is to provide a dual measurement tonometer and a method to measure intraocular pressure (IOP) of both eyes simultaneously to avoid errors in IOP measurement caused due to measuring IOP at different moments of time or due to other physiological characteristics affecting the IOP, for example, systolic and diastolic phases a cardiac cycle. The aim of the present disclosure is achieved by a dual measurement tonometer and a method for measuring intraocular pressures values of a first eye and a second eye of a user within a predefined time period, as defined in the appended independent claims to which reference is made to. Advantageous features are set out in the appended dependent claims.

[0008] Throughout the description and claims of this specification, the words "comprise" , "include", "have", and "contain" and variations of these words, for example "comprising" and "comprises" , mean "including but not limited to", and do not exclude other components, items, integers or steps not explicitly disclosed also to be present. Moreover, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0009] BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1A is an illustration of a schematic diagram of a dual measurement tonometer for measuring intraocular pressure values of a first eye and a second eye of a user within a pre-defined time period, when in use, in accordance with an embodiment of the present disclosure;

[0011] FIGs. IB is an illustration of a schematic diagram illustrating movement of a first air pulse generator and a second air pulse generator of the dual measurement tonometer of FIG. 1A relative to each other, when in use, in accordance with an embodiment of the present disclosure;

[0012] FIG. 2A is an illustration of an implementation of a dual measurement tonometer for measuring an intraocular pressure value of an eye, in accordance with an embodiment of the present disclosure;

[0013] FIG. 2B is an illustration of a graphical representation of the IOP value as a function of oscillation frequency, in accordance with an embodiment of the present disclosure;

[0014] FIG. 2C and 2D are illustrations of a graphical representation of the IOP value as a function of time, in accordance with an embodiment of the present disclosure; and

[0015] FIG. 3 is an illustration of a flowchart depicting steps of a method for measuring intraocular pressure values of a first eye and a second eye of a user within a pre-defined time period, in accordance with an embodiment of the present disclosure.

[0016] DETAILED DESCRIPTION OF EMBODIMENTS

[0017] The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practising the present disclosure are also possible.

[0018] In a first aspect, the present disclosure provides a dual measurement tonometer for measuring intraocular pressure values of a first eye and a second eye of a user within a pre-defined time period, the dual measurement tonometer comprising: a first air pulse generator and a second air pulse generator positioned on opposite sides of a frame, wherein when in use the first air pulse generator is aligned with the first eye and the second air pulse generator is aligned with the second eye; at least one corneal oscillation measurement sensor operatively coupled to the first air pulse generator and the second air pulse generator; a controller communicatively coupled to the at least one corneal oscillation measurement sensor, the first air pulse generator and the second air pulse generator, the controller configured to: determine a first set of operational parameters of each of the first air pulse generator and the second air pulse generator; control the first air pulse generator and the second air pulse generator to send, within the pre-defined time period, a first excitation air pulse towards a cornea of the first eye and the second eye, respectively; measure, within the pre-defined time period, a first signal related to corneal oscillations of the first eye and the second eye, caused by the sent first excitation air pulse with the at least one corneal oscillation measurement sensor; and determine the intraocular pressure values for the first eye and the second eye from the measured first signals.

[0019] The aforementioned dual measurement tonometer is configured to measure the intraocular pressure values of both eyes (e.g., the first eye (left eye) and the second (right eye)) of the user within a predefined time period by accounting for any external or physiological variabilities. For example, when a patient sits in a chair, his / her eye pressure may drop up to 5 mm Hg within 1-2 minutes of sitting in the chair. It may be appreciated that moving a measuring device or tonometer from one eye to the other can take time, and therefore, the latter eye of said patient may show a lower intraocular pressure compared to the first eye. In order for the IOP of the two eyes to be comparable in terms of said external variables of posture change, the aforementioned dual measurement tonometer, due to its unique construction, can account for such errors (caused by external or physiological variables) by measuring the intraocular pressure values for both eyes simultaneously and thereby enhancing accuracy of measurement.

[0020] In a second aspect, the present disclosure provides a method for measuring intraocular pressure values of a first eye and a second eye of a user within a pre-defined time period, the method comprising: aligning a first air pulse generator with the first eye and a second air pulse generator with the second eye; determining a first set of operational parameters of each of the first air pulse generator and the second air pulse generator; controlling the first air pulse generator and the second air pulse generator to send, within the pre-defined time period, a first excitation air pulse towards a cornea of the first eye and the second eye, respectively; measuring, within the pre-defined time period, a first signal related to corneal oscillations of the first eye and the second eye, caused by the sent first excitation air pulse with the at least one corneal oscillation measurement sensor; and determining the intraocular pressure values for the first eye and the second eye from the measured first signals.

[0021] The aforementioned method enables satisfactory operation of the dual measurement tonometer during measurement. Moreover, the method allows minimization of measurement duration thus reducing discomfort of the user. Furthermore, the method allows minimization of human effort, thereby enhancing operational experience of an operator and limiting the errors caused by the operator. Throughout the description, the term "dual measurement tonometer" refers a device for measuring intraocular pressure (IOP) values of the first eye and the second eye of the user, simultaneously. The term "first eye" refers to either of a left eye or right eye of the user. The term "second eye" refers to the right eye when the first eye is the left eye, and vice-versa. Moreover, the dual measurement tonometer within the predefined time period sends pulses of air, namely the first excitation air pulse, to impact both the first eye and the second eye of the user, respectively, and measures the IOP values thereof, simultaneously or within a pre-defined time period. Throughout the description the term "IOP value" of an eye refers to a value of a fluid pressures inside the eye, exerted by the aqueous humor filling the anterior chamber of the eye.

[0022] Throughout the description the term "user" refers to at least one of a patient experiencing an ocular condition, or an individual experiencing symptoms of such ocular conditions and who is being subjected to IOP measurement.

[0023] The term "operator" used throughout the description refers to a healthcare professional, an ophthalmologist, or any such person skilled in art. Optionally, the user may be the operator of the dual measurement tonometer.

[0024] The term "cornea" refers to the transparent outer surface membrane of an eye, namely the first eye and the second eye. The term "corneal oscillations" refers to deformation or displacement in the cornea of the first eye and in the cornea of the second eye, caused due to the impact from the first excitation pulse.

[0025] Throughout the description, the term "pre-defined time period" refers to an optimum time period for measuring IOP of the first eye and the second eye of the user, taking various physiological factors into account. The term "physiological factors" may refer to phases of cardiac cycle namely a systolic cycle and a diastolic cycle, a posture, a position of the user, corneal properties of both eyes of the user, and other physiological factors affecting IOP.

[0026] Optionally, the pre-defined time period may range from 0 to 10 seconds. Optionally, the pre-defined time period may range from 0, 1, 2, 3, 4, 5, 6 ,7 8 or 9 seconds up to 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 seconds. For example, the pre-defined time period may refer to sending the first excitation air pulse during 0 to 5 seconds which is the time period for opening time of the first and second eyes between eye blinks (assuming the user is opening the first and second eyes at the same time). In another example, the pre-defined time period may be no longer than 0.1- 0.200 seconds (considering corneal reflex or blink reflex of the first and the second eyes, i.e. when the first excitation air pulse impacts the first eye then eyelids of the first eye will move involuntary following eyelids of the second eye within 0.1-0.2 seconds). In yet another example, the predefined time period is less than l / 5th of time taken for a single phase of cardiac cycle (composed of systolic and diastolic phases) since diastolic IOP can differ from systolic IOP. The term "systolic phase" refers to a contraction of ventricles of a heart. A time period for systolic phase may be 0.1 to 0.3 seconds. The term "diastolic phase" refers to a relaxation of the ventricles of the heart. A time period for diastolic phase may be 0.5 to 0.7 seconds. In that regard the difference between measurement from the first eye and the second eye cannot exceed 0.7 sec in some embodiment. Since the IOP values of the first eye and the second eye, differ during the systolic phase and diastolic phase, the measurement of IOP values will be incomparable when the measurements for the first eye and the second eye, are not done in the same phase (systolic or diastolic phase) of a cardiac cycle. For example, when the IOP for first eye is measured during a systolic phase, and the IOP for second eye is measured in a diastolic phase, or vice versa, then the measured IOP values are incomparable and thereby estimation of a final value of IOP for the user may differ even up to 5 mmHg of actual IOP value of the user. However, since it is not possible to know at which cycle the measurement has been done, it is best to do the measurement for both eyes simultaneously, i.e., within the pre-defined time period, in order to get comparable results (i.e., IOP values) for both first and second eyes for accurate measurement of IOP for the user.

[0027] Throughout the description the term "simultaneously" refers to the predefined time period within which the pulses of air, namely the first excitation air pulse is sent towards the first eye and the second eye of the user from the dual measurement tonometer.

[0028] The dual measurement tonometer comprises the first air pulse generator and the second air pulse generator. The terms "first air pulse generator" and "second air pulse generator" refer to components of the dual measurement tonometer which are configured to generate compressed or pressured pulses of air, namely the first excitation air pulse, which are directed towards the first eye and the second eye, respectively, simultaneously or within pre-defined time period. The first and second air pulse generators are arranged on the frame of the dual measurement tonometer, next to each other, directed towards the first eye and the second eye. In this regard, the first air pulse generator is aligned with the first eye, and the second air pulse generator is aligned with the second eye, when the dual measurement tonometer is in use. The first and second air pulse generators are designed to discharge the first excitation air pulse therefrom a stream or flow of the first excitation air pulse is directed onto a corneal surface of the first and second eyes when measuring the IOP.

[0029] Throughout the description the term "frame" refers to an assembly of rigid elements and flexible / movable elements capable of supporting the first air pulse generator, and the second air pulse generator, and other components of the dual measurement tonometer thereon. The term "central axis" of the frame refers to a horizontal axis of reference across a length of the frame. In this regard, the length of the frame ranges from 3 to 25cm. The length can be in a range from 3 cm, 5 cm, 7 cm, 9 cm, 11 cm, 13 cm, 15 cm, 17 cm, 19 cm, 21 cm, or 23 cm to 5 cm, 7 cm, 9 cm, 11 cm, 13 cm, 15 cm, 17 cm, 19 cm, 21 cm, 23 cm, or 25 cm.

[0030] In an embodiment, optionally, the first air pulse generator is aligned with a first optical axis of the first eye and the second air pulse generator is aligned with a second optical axis of the second eye, wherein the first and the second optical axes are axes of reference through pupils of the first and second eyes towards the dual measurement tonometer, when the user is in a state of staring straight ahead.

[0031] In an embodiment, optionally, the first air pulse generator may be aligned with peripheral region of the corneal surface (with respect to a conjunctiva of the first eye) or a central region (with respect to the pupil of the first eye) of the first eye, while the second air pulse generator may be aligned with peripheral region (with respect to a conjunctiva of the second eye) or a central region of the corneal surface (with respect to the pupil of the second eye) of the corneal surface of the second eye. It may be appreciated that the alignment of the first air pulse generator and / or the second air pulse generator with the peripheral region of the corneal surface of the first eye and / or the second eye, respectively, is due to a skewness in the corresponding first eye and / or the second eye, namely a first "skewed" eye and / or a second "skewed" eye, respectively. The term "skewness" used herein refers to an anatomical asymmetry or irregularity in an eye, such as corneal asymmetry, astigmatism. In an example, when the first eye may be skewed while the second eye is normal. Then the alignment of the first air pulse generators is performed with respect to peripheral region of the corneal surface for the skewed first eye, and the alignment of the second air pulse generators is performed with respect to central region of the corneal surface of the normal second eye. In another example, when both the first eye and the second eye are skewed, then both the first and second air pulse generators are aligned with the peripheral region of the corneal surfaces of the first and second eyes, respectively. In yet another example, when both the first and second eyes are normal then both the first and second air pulse generators are aligned with the central region of the corneal surfaces of the first and second eyes, respectively. A technical advantage of aligning the first air pulse generator and the second air pulse generator to any of the peripheral region or the central regions of the first and second eyes, is overcoming physiological constraint of the user which may affect the IOP measurement, while still being able to measure the IOP values of the user simultaneously or within the pre-defined time period.

[0032] Optionally, the first air pulse generator and the second pulse generator each may comprise a pressure chamber, a nozzle having an exit aperture, and a control valve or a piston. In one embodiment, the pressure chamber is coupled with the nozzle and the control valve. In another embodiment, the pressure chamber is coupled with the nozzle and the piston.

[0033] Herein, the term "pressure chamber" refers to an enclosure within the first and second air pulse generators where compressed air is stored before being released. The pressure chamber is designed to maintain a consistent level of air pressure. The pressure chamber may comprise a pressure generation means configured to generate the first excitation air pulse at a specific pressure level within the pressure chamber, which can be controlled and adjusted based on requirement. Optionally, the pressure chambers of the first air pulse generator and the second air pulse generator, may comprise an air compressor configured to generate compressed or pressured pulses of air, namely the first excitation air pulse. The air compressor may be at least one of: a reciprocating air compressor, a rotary screw air compressor, a centrifugal air compressor, and any suitable pressure generation means. In this regard, the pressure chamber of the first air pulse generator is configured to generate the first excitation air pulse which is sent towards the first eye to impact the cornea of the first eye, via the nozzle of the first air pulse generator. Similarly, simultaneously or within the predefined time period, the pressure chamber of the second air pulse generator is configured to generate the first excitation air pulse which is sent towards the second eye to impact the cornea of the second eye, via the nozzle of the second air pulse generator.

[0034] Throughout the description, the term "first excitation air pulse" refers to a controlled burst of pressured / compressed air directed towards the cornea of the first eye and the cornea of the second eye of the user. The first excitation air pulse impacts the cornea of the first eye and the cornea of the second eye simultaneously to induce corneal oscillations thereof and subsequently IOP values for the first eye and the second eye are determined, based on such corneal oscillations.

[0035] Moreover, the control valves of the first air pulse generator and the second air pulse generator, may be configured to regulate release of the first excitation air pulse generated in the pressure chambers of the first air pulse generator and the second air pulse generator. In this regard, the controllable valve is configured to open and close to release air within the first and second air pulse generators as the first excitation air pulse. The control valves of the first air pulse generator and the second air pulse generator, may be at least one of: a solenoid valve, a diaphragm valve, a check valve, a pressure relief valve, and any such suitable valves which are capable of swift opening and closing. In an embodiment, the control valves of the first air pulse generator and the second air pulse generator, may be of different types. In another embodiment, the control valves of both the first air pulse generator and the second air pulse generator, may be of same type. Herein, the term "nozzle" refers to an outlet that directs the first excitation air pulse. Moreover, the nozzles of the first air pulse generator and the second air pulse generator, each may comprise a first end coupled with the pressure chamber of the first air pulse generator and the second air pulse generator, and a second end having the exit aperture. The exit aperture refers to an opening via which the first excitation air pulse leaves or escapes the first air pulse generator and the second air pulse generator via the nozzle. Optionally, the exit aperture may be of at least one of: a circular shape, a rectangular shape, a triangular shape, a square shape, a pentagonal shape, a quadrilateral shape, a hexagonal shape, an octagonal shape. Optionally, the nozzles of the first air pulse generator and the second air pulse generator, are designed in a manner where the first end has a wider diameter than the second end. Optionally, the diameter of the second end having the exit aperture is adjustable. The nozzles of the first air pulse generator and the second air pulse generator, are configured to send the first excitation air pulse generated in the pressure chamber in a controlled manner via the exit aperture. In this regard, when the dual measurement tonometer is aligned with the cornea, the first excitation air pulse is directed from the exit aperture towards the cornea to exert an optimum force thereon to cause corneal oscillations thereof.

[0036] Optionally, the first air pulse generator and the second pulse generator may comprise a common pressure chamber arranged on the frame of the dual measurement tonometer. In this regard, the common pressure chamber may be coupled with the nozzle of the first air pulse generator and the nozzle of the second air pulse generator, both, to send the first excitation air pulse towards the first eye and the second eye. In this regard, the common pressure chamber sends the first excitation air pulse towards the first eye via the nozzle of the first air pulse generator, and simultaneously sends the first excitation air pulse towards the second eye via the nozzle of the second air pulse generator. Moreover, the dual measurement tonometer comprises the at least one corneal oscillation measurement sensor. The at least one corneal oscillation measurement sensor is operatively coupled to the first air pulse generator and the second air pulse generator. The term "corneal oscillation measurement sensor" refers to a sensing and a measurement unit of the dual measurement tonometer capable of measuring the corneal oscillations in the cornea of the first eye and the cornea of the second eye. Herein, the corneal oscillation measurement sensor measures the displacement of the corneal surface of the first and second eyes in response to the first excitation air pulse. Herein, the response is at least one of: a change in position of the corneal surface of the first and second eye relative to a reference point, an oscillation frequency of the corneal surface, an extent of deformations, recovery from said deformations.

[0037] Moreover, the dual measurement tonometer comprises the controller. The controller is communicatively coupled to the at least one corneal oscillation measurement sensor, the first air pulse generator and the second air pulse generator. The term "controller" as used herein refers to a computational device that is operable for controlling the overall operation of the tonometer for IOP value measurement. In an example, the controller may be any one of an embedded microcontroller, a microprocessor, a field-programmable gate array (FPGA), digital signal processor (DSP), an application-specific integrated circuit (ASIC), a programmable logic circuits, an on-the chip control system, and any other suitable control module. The controller may be implemented as an internal component of the tonometer, an external component of the tonometer, or a combination thereof.

[0038] The controller is configured to determine the first set of operational parameters for the first air pulse generator, and the first set of operational parameters for the second air pulse generator. The term "first set of operational parameters" refers to characteristics of each of the first excitation air pulse generator and the second excitation air pulse generator. Moreover, the controller is configured to adjust various regulators of each of the first air pulse generator and the second air pulse generator based on the determined the first set of operational parameters. The term "regulators" as used herein refer to electrical or electromechanical components of the first air pulse generator and the second air pulse generator which can be regulated or adjusted by the controller, to modify one or more operational parameters from amongst the first set of operational parameters of the first air pulse generator and the second air pulse generator. The regulators may be implemented as a pressure value regulator of the pressure chambers, a movement control regulator for the control valves or pistons, a diameter adjustment regulator for exit apertures of nozzles, and so forth.

[0039] Optionally, the first set of operational parameters comprises at least one of: a pressure of air in a pressure chamber of each of the first air pulse generator and the second air pulse generator; an opening speed of a control valve of each of the first air pulse generator and the second air pulse generator; a closing speed of the control valve; a velocity of the first excitation air pulse; and a duration between a start of opening to an end of closing of the control valve, wherein the control valve controls release of the first excitation air pulse from the pressure chamber towards the cornea of the first eye and the second eye; or a speed of a piston movement of the first air pulse generator and the second air pulse generator; and a length of the piston movement, wherein the piston movement towards a first direction generates the first excitation air pulse to be sent from the first air pulse generator towards the cornea of first eye and from the second air pulse generator towards the cornea of the second eye.

[0040] In this regard, the first set of operational parameters may include, but do not limit to, characteristics of the pressure chamber, the nozzle and the control valve or the piston. For example, the first set of operational parameters is an inner diameter of the exit aperture. In this regard, the first set of operational parameters is adjusted by adjusting a size of exit aperture of the nozzle. Similarly, the first set of operational parameters may be adjusted by either regulating a timing of sending the first excitation air pulse from the first and the second air pulse generators, or by regulating the pressure of air in the pressure chambers therein.

[0041] In this regard, the pressure of air in the pressure chambers of the first and the second air pulse generator is relative to structural and operational characteristics of the air compressor therein. For example, the pressure of air in the pressure chamber ranges from 0.5 to 5 bars. As an example, the pressure may range from 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0 or 4.5 bars up to 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5 or 5.0 bars. However, the pressure of air exiting the exit aperture of the nozzle may be same or different based on the exit aperture cross-section, the velocity of the first excitation air pulse, and a mass flow rate of the first excitation air pulse. Notably, the first excitation air pulse exerts a specific force on the cornea of the first eye and the cornea of the second eye which results in the corneal oscillation thereon. The said force is relative to the pressure of air in the pressure chamber of the first and the second air pulse generator.

[0042] Notably, the said force is also relative to the velocity of the first excitation air pulse sent towards the first and the second eye. It may be appreciated that, the pressure of air in the pressure chambers of the first air pulse generator and the second air pulse generator, and the velocity at which the first excitation air pulse is sent towards the first eye and the second eye are determining factors regulating the force of the first excitation air pulse and the corneal oscillations occurring on the corneas of the first and the second eyes. By determining the optimum value of the first set of operational parameters indicating the pressure (in the pressure chambers of the first and second air pulse generator) and the velocity of the first excitation air pulse, a corneal oscillation of desirable oscillation characteristics may be observed. Thereby leading to an accurate IOP measurement.

[0043] It may be appreciated that the opening and closing speeds of the control valve and the duration between thereof may influence the first excitation air pulse. The "opening speed" of the control valve refers to the speed at which the control valve opens, the "closing speed" of the control valve refers to the speed at which the control valve closes, and the "duration" refers to the time period for which the control valve remains open. Notably, the opening and closing speeds and the duration therebetween determine an amount and consistency of the first excitation air pulse which exits the pressure chamber. Specifically, a faster opening speed ensures a rapid build-up of the pressure, leading to a more forceful and immediate impact on the cornea of the user, which is crucial for initiating consistent oscillations. A slower opening speed, on the other hand, might allow for a more controlled release of pressure, preventing abrupt changes that could dampen the oscillation which might be beneficial in some type of measurements. Optionally, the opening speed and the closing speed may be same or different. By regulating the opening speed and closing speed of the control valve, a duration of application of the first excitation air pulse on the corneas of the first eye and the second eye may be varied. For example, the first excitation air pulse may be a short pulse or may be a long pulse. Notably, the duration of application of the first excitation air pulse may be determined by the operator of the dual measurement tonometer, depending on various properties of the corneas of the first eye and / or the second eye. Notably, the term "properties of cornea" as used herein refers to an elasticity, rigidity, curvature, shape, thickness, corneal hysteresis, of the corneas of the first eye and the second eye. Notably, the properties of the cornea of each of the first and second eye are different, thus, by controlling the opening and closing speed of the control valve, the operator and or the controller can manipulate the dual measurement tonometer to send the short or long pulse of the first excitation air pulse for an effective and personalized IOP value measurement. Optionally, the opening speed and closing speed of the control valve ranges from 0.5 to 15msec (opening) and 0.25 to 3msec (time of closing). As an example, the opening speed may range from 0.5, 1.0, 2.0, 3.0, 5.0, 7.5, 10.0 or 12.5 ms up to 1.0, 2.0, 3.0, 5.0, 7.5, 10.0, 12.5 or 15.0 ms, and the closing speed may range from 0.25, 0.5, 1.0, 1.5, 2.0 or 2.5 ms up to 0.5, 1.0, 1.5, 2.0, 2.5 or 3.0 ms. Preferably closing should take place in less than 3msec to ensure good oscillations after the air pulse and prevent residual air to interfere with the measurement. A technical effect of manipulation of the duration of first excitation air pulse is to exert an optimum force on the first eye and second eye based on the preference and / or requirement of the user for the desired measurement. The opening speed refers to the time duration required to transition the valve from a closed state to an open state. The closing speed refers to the time duration required to transition the valve from an open state to a closed state.

[0044] Moreover, by adjusting the duration for which the control valve remains open, an amount of the first excitation air pulse may be regulated, to regulate a distribution of the force of the first excitation air pulse on the corneas of the first eye and the second eye for obtaining the consistent and predictable corneal oscillation thereof. Optionally, the duration between the opening and the closing of the control valve ranges from 1 to 15msec. The duration can be for example from 1 msec, 2 msec, 3 msec, 4 msec, 5 msec, 6 msec, 7 msec, 8 msec, 9 msec, 10 msec, 11 msec, 12 msec, 13 msec, 14 msec, to 1 msec, 2 msec, 3 msec, 4 msec, 5 msec, 6 msec, 7 msec, 8 msec, 9 msec, 10 msec, 11 msec, 12 msec, 13 msec, 14 msec, 15 msec. For example, a short duration between the opening and closing of the control valve produces a short first excitation air pulse, and vice versa. A technical effect of adjusting the duration of the opening of the control valve is an effective and consistent corneal oscillation owing to uniform distribution of the force of the first excitation air pulse on the corneas of the first eye and the second eye.

[0045] Optionally, either of the first air pulse generator and the second air pulse generator may use the control valve or the piston to regulate the exit of the first excitation air pulse. When the first air pulse generator and the second air pulse generator may use the piston to regulate the exit of the first excitation air pulse, in such cases the first set of operational parameters is adjusted by adjusting the speed and length of the piston movement. The piston movement in the first direction sends the first excitation air pulse towards the first eye and the second eye, within the pre-defined time period. Herein, the term "first direction" refers to the direction towards the eye. It may be appreciated that the piston is at an initial position in a second direction, opposite to the first direction, when the pressure chambers of the first air pulse generator and the second air pulse generator, have an initial amount of air of a given pressure therein. When the piston (of the first air pulse generator or of the second air pulse generator) is moved from the initial position thereof in the first direction, by a given length and / or speed, a given volume of air exits the exit aperture of the nozzle as the first excitation air pulse. For example, a smaller length of the piston movement may produce a short air pulse as compared to a longer length of the piston movement that can produce a long air pulse. Moreover, controlling the piston speed allows for precise adjustment of the pulse's rise time, which directly affects the initial impact force on the cornea. A faster piston speed results in a quicker rise time, delivering a sharper, more immediate force, while a slower speed provides a gentler, more gradual application of force.

[0046] Moreover, by adjusting the length of the piston movement, the velocity of the first excitation air pulse may be modified. For example, by increasing the length of the piston movement, the velocity of the first excitation air pulse may be increased as a displacement volume of the air through the exit aperture of the nozzle is increased. The term "displacement volume" used herein refers to the amount of air in the first excitation air pulse that is sent out for each piston movement. Furthermore, by adjusting the speed of piston movement, the velocity of the first excitation air pulse is modified. For example, by increasing the speed of the piston movement, the velocity of the first excitation air pulse may be increased.

[0047] It may also be appreciated that, one or more operational parameters from amongst the first set of operational parameters may be changed alone or in any suitable combination to produce the desired force of the first excitation air pulse at the cornea of the first eye and the cornea of the second eye. For example, if the pressure of air is to be maintained, then the opening and closing speed of the control valve and / or velocity of the first excitation air pulse may be changed to produce the desired force at the cornea of the first eye and the cornea of the second eye. Beneficially, the combination of operational parameter control and real-time feedback provides a technical effect of improved accuracy and reliability, especially for patients with abnormal corneal properties.

[0048] Moreover, the at least one corneal oscillation sensor simultaneously measures the first signal related to the corneal oscillations of the first eye and the second eye. The term "first signal" as used herein refers to a signal containing information related to the various characteristics of the corneal oscillations, such as the oscillation frequency, an amplitude, a damping factor, a duration, a decay factor, and a peak-to-peak ratio of the corneal oscillations caused by the first excitation air pulse. The at least one corneal oscillation sensor is configured to utilize at least one of a plurality of detection techniques, such as confocal microscopy, chromatic aberration, optical coherence tomography (OCT), laser displacement sensor or ultrasound, to capture and analyse the first signal corresponding to the corneal oscillations of the first eye and the second eye. Subsequently, the controller is configured to receive the first signal measured from the at least one corneal oscillation sensor to determine the value of IOP value of the user.

[0049] Moreover, the IOP values for the eyes of the user, namely the first eye and the second eye, are determined. In this regard, the controller is configured to analyze the first signal received to determine information related to the various characteristics of the corneal oscillations. Notably, the corneal oscillations are relative to the properties of cornea (such as elasticity, rigidity, curvature, shape, thickness, corneal hysteresis, of the corneas) and IOP of the eyes of the user, namely the first eye and the second eye. Based on the analysis of the corneal oscillations and the various characteristics of the corneal oscillations the controller is configured to determine the IOP values of the first eye and the second eye.

[0050] Optionally, the controller is configured to: determine, from the first signal, an oscillation frequency of the corneal oscillations; and calculate, from the oscillation frequency, the intraocular pressure value.

[0051] In this regard, the first signal measured by the at least one corneal oscillation sensor may be used to determine information on the oscillation frequency of the corneal oscillations. The term "oscillation frequency" used herein refers to a measure of how often a corneal oscillation occurs in a given time period. It quantifies the rate of corneal oscillation and is crucial for understanding and analyzing periodic motions in various physical systems. The controller upon receiving the first signal, determines the oscillation frequency which is utilized to compute the IOP of the eye. Beneficially, the oscillation frequency provides information on the duration of one complete cycle and the number of cycles per unit time. Moreover, the oscillation frequency is relevant when analyzing the temporal variations, such as patterns or repeatability of a certain value of IOP. It will be appreciated that by linking the oscillation frequency to the calculation of IOP value, the dual measurement tonometer employs a more fundamental and sensitive parameter for pressure determination. This method enhances the accuracy and objectivity of IOP measurement, as it is less susceptible to confounding factors such as corneal thickness, hydration, or operator technique, which can affect traditional applanation or indentation methods. Therefore, analysis of the oscillation frequency can reveal subtle biomechanical changes in the cornea, offering additional clinical information beyond simple pressure values, such as corneal rigidity or viscoelastic properties.

[0052] Optionally, the dual measurement tonometer further comprising at least one distance measurement sensor, wherein the controller is further configured to: process sensor data collected by the at least one distance measurement sensor to determine a distance between the first eye and the second eye; and control a controllable distance adjustment means, arranged on the frame, such that a separation distance between the first air pulse generator and the second air pulse generator becomes equal to the distance between the first eye and the second eye.

[0053] In this regard, the controller also receives the sensor data from the at least one distance measurement sensor. The term "distance measurement sensor" refers to a sensor configured to collect the information on a distance between the first eye and the second eye of the user and to transmit the information collected as the sensor data to the controller for further processing. The term "sensor data" used herein refers to information related to the distance (G) between the first eye and the second eye of the user. The sensor data may comprise linear and angular values pertaining to relative positions of each of the first eye and the second eye with respect to a position of the at least one distance measurement sensor, and / or relative positions of the first eye and the second eye with respect to each other. Optionally, the at least one distance measurement sensor may be arranged on the frame of the dual measurement tonometer along the axis parallel to the central axis, at a mid-section of the frame. More optionally, the at least one distance measurement sensor may be arranged on the frame of the dual measurement tonometer along the axis parallel to the central axis, at a first side aligned with the first eye of the user or the second side aligned with the second eye of the user. Beneficially, the distance measurement sensor arranged in the dual measurement tonometer enables the dual measurement tonometer to automatically and precisely detect the distance (G) between the first eye and the second eye of the user, which can vary significantly between individuals. The detection of the distance eliminates the need for manual measurement or estimation, thereby reducing the risk of human error and ensures that the dual measurement tonometer is optimally configured for each user. The at least one distance measurement sensor may compensate for small head movements or misalignments during setup, further improving the robustness and repeatability of the measurement process.

[0054] Upon receiving the sensor data, the controller determines the distance between the first eye and the second eye, by analyzing the sensor data, and optionally, guides, for example a controllable distance adjusting means, to adjust distance (D) between the first and second air pulse generators based on the distance (G) between the first and second eyes. A technical effect of the automatic determination of the distance (G) and the adjustment of the distance (D) is that the air pulse generators can be positioned with high precision to match the user's unique anatomy. This precise alignment facilitates accurate and reproducible intraocular pressure (IOP) measurements, as even small misalignments can lead to significant measurement errors or variability. By adjusting the distance (D) between the first and second air pulse generators based on the distance (G) between the first and second eyes, an optimum alignment of the dual measurement tonometer, with respect to the first and second eyes of the user is achieved. Thereby, a technical effect of accurately sending the first excitation air pulse towards the first and second eyes of the user is achieved. Specifically, automatic determination of the distance (G) and the adjustment of the distance ensure that each air pulse is delivered perpendicularly and centrally to the corneal apex of each eye. It not only improves the accuracy of the IOP measurement but also reduces the need for repeated measurements, thereby minimizing patient discomfort and increasing throughput in busy clinical environments. Furthermore, the automated adjustment process can adapt in real time to changes in user position, providing a dynamic and responsive measurement system.

[0055] Therefore, the combination of the distance measurement sensor and automatic adjustment provides a technical effect of improved accuracy, repeatability, and reduced operator dependency, which is not achieved by manual alignment alone. Moreover, automatic adjustment compensates for changes that can affect eye position during measurement, e.g., user's movement, changes in posture, and so on, ensuring consistent alignment throughout the measurement process.

[0056] Further optionally the dual measurement tonometer which comprises at least one distance measurement sensor the distance (G) between the first eye and the second eye can be used to control a controllable air nozzle direction adjustment means to control direction of the first excitation air pulse and / or direction of the second excitation air pulse towards respective eye. Direction adjustment means can be turntable air nozzles with actuators or those can be guiding elements arranged in front of nozzles or a like. The direction adjustment means can be implemented in addition or instead of distance adjustment means. It will be appreciated that the direction adjustment means allows the dual measurement tonometer to compensate for asymmetrical facial features or nonstandard eye positions, ensuring that the first excitation air pulse and / or the second excitation air pulse pulse is optimally directed at the corneal apex, regardless of user anatomy. Purpose of both (and combination of) is to provide, in a controlled manner, air impulse to both eyes (essentially) at the same time and in a same way. Additionally, the use of the least one distance measurement sensor to control the controllable air nozzle direction adjustment means allows for individualized targeting of each eye, which is particularly beneficial in cases where the first eye and the second eye is not symmetrically positioned or where the patient has unique facial features. The individualized targeting ensures that the force and angle of the air pulse are optimized for each eye, leading to more reliable corneal deformation and oscillation responses, and thus more accurate IOP readings.

[0057] Optionally, the at least one distance measurement sensor is a camera, a depth sensor, or a gaze-tracking camera. In this regard, the at least one distance measurement sensor measures the distance of the first and second air pulse generator from the first eye and second eye respectively, for proper alignment of the first and second air pulse generator with the first and the second eye, respectively. For an example, the depth sensor may be utilized to estimate the distance between the first and the second eye by sending a near infrared light from a light source such as a light emitting diode (LED) towards the first eye and the second eye and analyzing a reflection. In another example, the camera can be utilized for measuring the distance between the first eye and the second eye, by utilizing a stereoscopic effect to capture multiple images of the first and second eyes. In this regard, the distance between the first and the second eye is calculated based on any disparity in position between the corresponding points in the multiple images. The camera allows the tonometer to accurately detect the positions of the first eye and the second eye, even in the presence of minor head movements or variations in user anatomy. The camera-based approach supports image processing algorithms, such as facial landmark detection and pupil localization, which further enhance the precision of interocular distance measurement. For another example, the gaze-tracking camera may be utilized to estimate the distance between the first and the second eye. The gaze-tracking camera provides safety and quality control feature, as it can detect and compensate for loss of fixation or involuntary eye movements. For example, the depth sensor enables the tonometer to determine the depth of the first eye and the second eye relative to the distance measurement sensor and to achieve the optimal alignment in all three spatial dimensions, reducing parallax errors and ensuring that the air pulse is delivered perpendicularly to the corneal surface. The obtained information on the distance between the first and the second eye is utilized to align the first and the second air pulse generator with the first and the second eye, respectively.

[0058] Moreover, based on the distance (between the first eye and the second eye) determined, the controller is configured to manipulate a separation distance between the first air pulse generator and the second air pulse generator, by utilizing a controllable distance adjustment means arranged on the frame. The controllable distance adjustment means is controlled until the separation distance becomes equal to the distance between the first eye and the second eye. Thereby achieving a technical effect where the first air pulse generator and the second air pulse generator can be accurately aligned with the first eye and the second eye. Additionally, the non-contact nature of the aforementioned sensors improves hygiene and patient comfort, as there is no need for physical contact or invasive positioning aids, which is particularly advantageous in high-throughput or pediatric settings.

[0059] The "distance adjustment means" used herein refers to an electromechanical (thus "controllable distance adjustment means", controllable by the controller) or mechanical arrangement that, when in use, is capable of adjusting a placement the first air pulse generator and the second air pulse generator on the frame.

[0060] In this regard, the controllable distance adjustment means, when in use, causes the first air pulse generator and the second air pulse generator to move in a specific direction covering a pre-defined distance on the frame, each time the controllable distance adjustment means moves. The term "specific direction" used herein refers to a direction with respect to the mid-section of the frame, either a direction away from the mid-section or a direction towards the mid-section. The term "pre-defined distance" as used herein refers to a distance on the frame covered by the first and the second air pulse generators, with respect to a movement of the controllable distance adjustment means, when moved towards or away from each other. In this regard, the term "movement of the controllable distance adjustment means" as used herein pertains to any one of: clicks, and turns depending on an implementation of the controllable distance adjustment means. The term "clicks" used herein refers to a forward click, or a backward click corresponding to moving towards or away from the mid-section of the frame, respectively. The term "turns" used herein refers to a clockwise turn or an anti-clockwise turn corresponding to moving towards or away from the mid-section of the frame respectively or vice versa.

[0061] Optionally, the controllable distance adjustment means is electro- mechanically movable by at least one of: a stepper, an electrical motor. Such controllable distance adjustment means is operated by the controller based on the sensor data from the at least one distance sensor. In this regard, the controller may generate trigger pulses to dictate an operation of the stepper and / or the electrical motor, thereby regulating a movement of the controllable distance adjustment means. Notably, the stepper is a device with regulated movements capable of making instant stops thereby enhancing accuracy in adjustment of the controllable distance adjustment means. Notably, the electrical motors may be a servo motor, a brushless de (BLDC) motor or any such suitable motor capable of instant stopping. The term "trigger pulses" used herein refers to electrical signals such as a voltage pulse for operation (such as rotate clockwise, rotate anti-clockwise, stop rotation, speed regulation) of the stepper and / or the electrical motor. Moreover, the stepper motor enables highly precise, incremental positioning, allowing the controller to set the separation distance between the first and the second air pulse generators with fine granularity and repeatability. Such precision ensures that the first and the second air pulse generator is optimally aligned with the first eye and the second eye, respectively. Furthermore, the electrical motor offers smooth, rapid, and programmable movement, enabling the controller to adapt to the users with varying interocular distances and to make real-time adjustments in response to the sensor data or the user movement. The technical effect of regulated and accurate movement control of the first and the second air pulse generators is achieved by utilizing the controllable distance adjustment means to align the first and the second air pulse generators with the first and the second eyes, respectively. Additionally, the use of stepper and electrical motors supports long-term durability and low maintenance requirements, as these components are robust and designed for extended operational lifespans.

[0062] Optionally, the controllable distance adjustment means is implemented as at least one of: linear actuators, piezoelectric actuators, gear assemblies, screw assemblies. In this regard, the controllable distance adjustment means may be sensitive to trigger pulse and quick to react as per trigger pulses received from the controller. The controllable distance adjustment means implemented as at least one of: linear actuators, piezoelectric actuators, gear assemblies, screw assemblies are configured to move according to the trigger pulses which can causes the first air pulse generator and the second air pulse generator to move in the specific direction covering the pre-defined distance on the frame, each time the controllable distance adjustment means moves. The term "linear actuators" refers to devices that move linearly between two positions on the frame. It will be appreciated that the use of linear actuators enables precise, rapid, and repeatable adjustment of the separation distance between the air pulse generators. The linear actuators can be controlled electronically to achieve fine positional accuracy, which ensures that the first and the second air pulse generators are optimally aligned with the user's eyes during measurement. Moreover, electronically controlled actuators allow for fully automated adjustment, eliminating the need for manual intervention and reducing the risk of misalignment that can occur with the manual or fixed systems. The term "piezoelectric actuators" refers to devices that utilize electroactive material such as zirconate titanate (PZT) to move the first and the second air pulse generator on the frame. Moreover, the piezoelectric actuators provide greater precision, with the ability to make sub-micron adjustments in real time. This is particularly advantageous for fine-tuning the alignment after coarse positioning, compensating for small user movements, and maintaining optimal geometry throughout the measurement process. The piezoelectric actuators are compact, silent, and energy-efficient, contributing to a more comfortable and user- friendly experience. The term "gear assemblies" refers to a systematic arrangement of gears (parallel axis gears, non-parallel gears, intersecting axis gears, non-intersecting gears), shafts, bearings, casing or any such components, which when in a combined operation provide desired movement of the first and the second air pulse generator on the frame. The term "screw assemblies" refers to an arrangement of various parts that when in operation move rotationally and cause the first and the second air pulse generators to move linearly on the frame. It will be appreciated that the gear assemblies and the screw assemblies are designed for long-term use with minimal wear to the controllable distance adjustment means, offering a significant advantage over less robust manual adjustment mechanisms. Furthermore, the ability of gear and screw assemblies to hold position without continuous power reduces energy consumption and ensures that the system remains safe and stable even in the event of a power interruption. The technical effect achieved is a precise movement of the first air pulse generator and the second air pulse generator on the frame to properly align the first air pulse generator and the second air pulse generator with respect to the first eye and the second eye. Additionally, a faster and more accurate setup reduces patient discomfort and increases throughput in clinical environments, addressing limitations in the prior art where manual adjustment can be time-consuming and less precise.

[0063] Beneficially, the integration of the controllable distance adjustment means with the distance measurement sensor and controller creates a closed-loop system that optimizes alignment in real-time to achieve a specific level of precision.

[0064] Optionally, the first air pulse generator and the second air pulse generator align with the first eye and the second eye by mechanically moving a distance adjusting means by an operator of the dual measurement tonometer. The term "distance adjusting means" used herein refers to a mechanical means adjustable manually to perform turn, slide, push, pull or any such mechanical movements on the first and the second air pulse generators to change the placement of the first and the second air pulse generators on the frame. Herein, the distance adjusting means is operated manually by an operator of the dual measurement tonometer. In this regard, the operator utilizes the distance adjusting means to move the first and the second air pulse generators on the frame to align the first air pulse generator and the second air pulse generator to align with the first eye and the second eye respectively, based on physiological factors of the user such as facial feature of the user. Moreover, the operator-guided adjustment is advantageous for the users with atypical facial structures, pediatric patients, or those with physical limitations, where automatically moving the distance adjusting means may not be performed optimally. On the other hand, the manual mechanism is inherently robust and reliable, requiring no power or complex electronics, which ensures continued operation in resource-limited or field settings. Furthermore, simplicity of the manual movement of the distance adjusting means reduces the risk of mechanical failure and lowers maintenance requirements, while also making the device more cost- effective and accessible. A technical effect of flexible adjustment based on physiological factors of the user, is to enhance the accuracy of alignment of the dual measurement tonometer.

[0065] Optionally, the distance adjusting means is implemented as an actuator, a slider, screws, gears, knobs. In this regard, the distance adjusting means implemented as the actuator may also be a hydraulic actuator which can minimize friction to provide smooth movement of the first and the second air pulse generator and enables smooth, controlled movement, reducing the risk of sudden shifts or misalignment that could compromise measurement accuracy. The distance adjusting means implemented as the slider may allow sliding movement of the first and second air pulse generators on the frame towards the mid-section of the frame or away from the mid-section of the frame, by a conveyor movement, a chain movement, or any such suitable arrangement. The hydraulic actuators and precision sliders ensure smooth, low-friction movement of the first and the second air pulse generators on the frame, reducing the risk of abrupt shifts and enhancing measurement accuracy of the dual measurement tonometer. The distance adjusting means implemented as the gears and / or knobs may be operated to convert a rotational movement of the distance adjusting means into sliding movement of the first and second air pulse generators on the frame towards the mid-section of the frame or away from the mid-section of the frame with each turn or click of the knob. Moreover, the gears and screws convert small inputs by the operator into precise linear movement, allowing for fine-tuning of the first and the second air pulse generator positions. Optionally, the operator may also utilize a dedicated interface which sends an electrical pulse to the distance adjusting means which is configured to convert the received electrical pulse into mechanical movement of the first and second air pulse generators on the frame. The technical effect of providing autonomy to adjust to user's physiology on basis of on-site situation is achieved. Optionally, the manual adjustment and automatic adjustment of the position / placement of the first and the second air pulse generators may be carried out in combination to reduce energy consumption of the dual measurement tonometer. Furthermore, modularity and versatility of the distance adjusting means enhance reliability of the dual measurement tonometer, reduces maintenance requirements, and improves ergonomics for the operator.

[0066] Optionally, the frame further comprises a face support for at least partly aligning the first air pulse generator with the first eye and the second air pulse generator with the second eye. In this regard, the face support may be of non-abrasive, skin friendly material such as clinical silicon. Notably, the face support may contact at least one part of the user's face, for example, the face support may contact a bridge of a nose of the user while the dual measurement tonometer is set up for measuring IOP of the user. Therefore, the face support made up of non-abrasive, skin friendly material leads to minimal of discomfort to the user when the dual measurement tonometer is in use. The technical effect achieved is minimized error in initial alignment of the first air pulse generator with the first eye and the second air pulse generator with the second eye, due to reduced intervention on part of an operator.

[0067] Optionally, the frame comprises a slot adapted to: receive the first air pulse generator and the second air pulse generator therein; and allow movement of the first air pulse generator and the second air pulse generator relative to each other, along a central axis of the frame, to align the first air pulse generator and the second air pulse generator to the corresponding first eye and the second eye.

[0068] In this regard, the first and the second air pulse generator placed into the slot of the frame are adjustable by utilizing the controllable distance adjustment means or the distance adjusting means. As the first and the second air pulse generators are flexible and can be moved along the central axis of the frame, an accurate alignment of the first air pulse generator with the first eye and the second air pulse generator with the second eye is achieved. The slot may be configured to accommodate any necessary means such as the actuator, the slider, the screws, the gears, the knobs or the linear actuators, the piezoelectric actuators, the gear assemblies, the screw assemblies or any other such arrangement. Optionally, the slot may also have provision to take out faulty first air pulse generator or / and the second air pulse generator. The technical effect is achieving accurate alignment of the first and the second air pulse generators.

[0069] Optionally, the at least one corneal oscillation measurement sensor comprises a first corneal oscillation measurement sensor, and wherein the first corneal oscillation measurement sensor is arranged on the frame between the first air pulse generator and the second air pulse generator, and directed towards the first eye and the second eye, respectively. In this regard, the term "first corneal oscillation measurement sensor" refers to a common sensing and measuring unit that is configured to measure the corneal oscillations in both the first and the second eyes, caused by the impact of the first excitation air pulse. The first corneal oscillation measurement sensor may be operatively coupled to both the first air pulse generator and the second air pulse generator. The first corneal oscillation measurement sensor may be arranged on the mid-section of the frame. In an embodiment, first corneal oscillation measurement sensor may be arranged in on the frame in an optimum measuring position. For example, the common corneal oscillation measurement sensor may be arranged on an axis parallel to a vertical axis passing through the mid-section of the frame, by utilizing at least one attachment mean. It will be appreciated that positioning the single corneal oscillation measurement sensor centrally between the first and the second air pulse generator provides a compact and symmetrical design that enhances portability and suitability for space-constrained clinical environments. The technical effect of making the frame less bulky is to reduce user discomfort as well as easy operation by the operator. Moreover, by utilizing the common corneal oscillation measurement sensor, overall power consumption in operation of the dual measurement tonometer is reduced. Furthermore, the accuracy of measurement of the various characteristics of the corneal oscillations is enhanced by utilizing the common corneal oscillation measurement sensor, which is configured to capture the first signals from the first eye and the second eye. Moreover, the first corneal oscillation measurement sensor enables simultaneous or rapid sequential measurement of the first eye and the second eye without the need to reposition or recalibrate multiple sensors, thereby increasing measurement throughput and reducing the total time required for bilateral intraocular pressure assessment. This configuration also minimizes parallax and alignment errors that can occur with offset or asymmetrical sensor arrangements. Furthermore, by utilizing the first corneal oscillation measurement sensor, the number of components is minimized, resulting in lower manufacturing costs of the dual measurement tonometer.

[0070] Optionally, the first corneal oscillation measurement sensor is directed towards the first eye and the second eye in turns, wherein the first corneal oscillation measurement sensor is coupled to a turning mechanism configured to change orientation of the first corneal oscillation measurement sensor, and wherein the controller is configured to actuate the turning mechanism to: turn the first corneal oscillation measurement sensor towards the first eye, at a first time, for measuring the first signal from the first eye; and turn the first corneal oscillation measurement sensor towards the second eye, at a second time, for measuring the first signal from the second eye, wherein, a time period between the first time and the second time lies in a range of 0.1 to 2 seconds.

[0071] In this regard, the first corneal oscillation measurement sensor is directed towards the first eye and the second eye in turns, by means of the turning mechanism coupled with the first corneal oscillation measurement sensor. The term "turning mechanism" refers to an arrangement of movable components like gears, shafts, chains, belts or any such components capable of changing direction of movement (horizontal to vertical or vice versa) as well as type of movement (rotational to linear or vice versa). Moreover, the turning mechanism is actuated for controlling movement of the first corneal oscillation measurement sensor by turning the first corneal oscillation measurement sensor towards the first eye, at the first time. The term "first time" is a time period for which the first corneal oscillation measurement sensor faces the first eye for measuring the first signal from the first eye. The controller, thereafter, utilizes the turning mechanism to turn the first corneal oscillation measurement sensor towards the second eye, at the second time. The term "second time" refers to a time period for which the first corneal oscillation measurement sensor faces the second eye for measuring the first signal from the second eye. It will be appreciated that by switching the orientation of the first corneal oscillation measurement sensor between the first eye and the second eye, the dual measurement tonometer is able to capture corneal response data from both eyes in a near-simultaneous manner. This minimizes the impact of physiological variations (such as changes in blood pressure or tear film thickness) that can occur over longer measurement intervals, leading to more accurate and comparable intraocular pressure (IOP) readings. The technical effect is achieving accurate and reliable measurement of the first signals from the first and the second eyes corresponding to the first excitation air pulse sent towards the first eye and the second eye. Optionally, the time period between the first and the second times is within a range of 0.1 to 2 seconds. For example, the said time period may be from 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 seconds up to 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2.0 seconds. Optionally, the controller utilizes the first corneal oscillation sensor to measure the first signals for both the first eye and the second eye within the pre-defined time period. Swift and smooth operation of turning mechanism enables measurement of the first signals for both the first eye and the second eye accurately and thereby leading to reliable IOP measurement. Additionally, the given range of the time period is short enough to minimize physiological variations between measurements of the first signals for the first eye and the second eye, yet long enough to allow for accurate and complete capture of the first signals. Furthermore, the use of the turning mechanism to quickly switch the first corneal oscillation measurement sensor orientation between the first eye and the second eye, combined with the controller's precise timing and coordination, enables a level of performance of the dual measurement tonometer that is not achievable without the said alternating measurement approach. Optionally, the at least one corneal oscillation measurement sensor comprises a first corneal oscillation measurement sensor and a second corneal oscillation measurement sensor. In this regard, the dual measurement tonometer may comprise the first corneal oscillation measurement sensor and the second corneal oscillation measurement sensor operatively coupled with the controller, as well as the first air pulse generator and the second air pulse generator, respectively. The first corneal oscillation measurement sensor and the second corneal oscillation measurement sensor are configured to measure the corneal oscillations in the first and the second eye, respectively.

[0072] Optionally, the first corneal oscillation measurement sensor may be arranged on the frame aligning with the first eye and the first air pulse generator, along the central axis of the frame, or along an axis parallel to the central axis of the frame. Optionally, both the first and the second corneal oscillation measurement sensors may be adjacent to each other arranged on the mid-section of the frame, along the central axis of the frame, or along an axis parallel to the central axis of the frame. Optionally, the first and the second corneal oscillation measurement sensors may be arranged opposite to each other on the frame with respect to an axis perpendicular to the central axis of the frame. More optionally, the first and the second corneal oscillation measurement sensors may be arranged angularly on the frame with respect to the axis perpendicular to the central axis of the frame. The technical effect of optimized design balance and rapid and prompt measurement of the first signals corresponding to the corneal oscillations is achieved.

[0073] Optionally, the first corneal oscillation measurement sensor is arranged in front of the first eye such that the first corneal oscillation measurement sensor is concentric with the first air pulse generator, and the second corneal oscillation measurement sensor is arranged in front of the second eye such that the first corneal oscillation measurement sensor is concentric with the second air pulse generator. In this regard, the first corneal oscillation measurement sensor and the second corneal oscillation measurement sensor arranged in front of the first eye and the second eye respectively, may have a common center on the central axis of the frame, thereby leading to compact design. The technical effect of enhanced operational efficiency is achieved due to distinct range of measurements with respect to each other. Additionally, the concentric alignment of the first and the second corneal oscillation measurement sensor with the first and the second air pulse generator, respectively, minimizes off-axis errors and maximizes the signal-to-noise ratio of the measurement, leading to more accurate and reliable intraocular pressure (IOP) readings. Moreover, the concentric arrangement ensures that the corneal response is measured at the optimal location, maximizing signal quality and minimizing the influence of external factor. Furthermore, the concentric arrangement eliminates any time delay between measurements of the two eyes.

[0074] In an embodiment, the at least one corneal oscillation measurement sensor is a first confocal chromatic sensor or a second confocal chromatic sensor, optionally, the at least one corneal oscillation measurement sensor is a displacement sensor. In this regard, the first confocal chromatic sensor or the second confocal chromatic sensor is configured to measure both the distance between the first eye and the second eye, and the first signals corresponding to corneal oscillation of the first eye and the second eye. The first confocal chromatic sensor and the second confocal chromatic sensor typically emit a light pulse, covering a large area of the corneas of both the first and the second eye, for accurate measurement of the change in corneas, namely corneal oscillation, by using the corresponding first signals, during IOP value measurement. Moreover, the at least one corneal oscillation measurement sensor is the displacement sensor which is configured to measure the displacement or changes in the corneas of the first eye and the second eye corresponding to the impact of the first excitation air pulse. The displacement sensor may be an ultrasound sensor, an infrared sensor, a light sensor or a third confocal chromatic sensor. It will be appreciated that the first confocal chromatic sensor or the second confocal chromatic sensor offers noncontact, high-resolution, and highly sensitive measurement of the corneal displacement, enabling the detection of minute corneal oscillations with sub-micron accuracy. The displacement sensor such as ultrasound, infrared sensor, or light sensor, provide additional flexibility in the corneal oscillation measurement, allowing the dual measurement tonometer to adapt to different patient needs and clinical environments. The displacement sensor is able to operate at high speeds and with minimal physical contact, improving patient comfort and reducing the risk of infection which is essential for repeated measurements or sensitive patient populations. Moreover, the dual measurement tonometer can utilize different sensor types (optical, ultrasound, infrared) depending on clinical requirements, increasing its applicability across a wide range of patients and use cases. The technical effect of rapid and accurate measurement of the first signal corresponding to the first excitation air pulse for the first and the second eyes, is achieved.

[0075] Optionally, the dual measurement tonometer further comprising an output device, communicably coupled to the controller, for providing information related to at least one of: the alignment of the first air pulse generator with the first eye and the second air pulse generator with the second eye; a completion of the determination intraocular pressure values for each eye; the determined intraocular pressure values for each eye.

[0076] In this regard, the term output device used herein pertains to a device, component or part of the dual measurement tonometer, which is configured to receive information related to: the alignment of the first air pulse generator with the first eye and the second air pulse generator with the second eye on basis of the sensor data, the first signal corresponding to the corneal oscillations of the first and the second eye, as well as a result of the IOP determination. The output device provides a visual, and / or auditory information during the IOP measurement process which corresponds to alignment of the first and second air pulse generators with the first and second eyes, final estimated value of IOP for a person. Thus, manual efforts in alignment of the dual measurement tonometer as well as calculation of IOP is greatly reduced. It will be appreciated that the information related to the completion of the determination intraocular pressure values for each eye is immediately provided to the output device by way of a notification (such as audio alert, visual alert and the like), thereby, reducing waiting time and allowing for faster patient processing. Thereby leading to technical effect of smooth, easy, and accurate operation of the dual measurement tonometer by the operator and / or the user. The output device is able to provide step-by-step prompts or warnings, making the output device more accessible to new users and reducing the need for extensive training. Moreover, automated display or announcement of IOP values minimizes the risk of manual data entry errors and ensures that results are accurately communicated to the operator or user.

[0077] Optionally, the output device is implemented as a display, the controller is configured to display thereat a mark corresponding to each of the first eye and the second eye on the display for aligning the first air pulse generator with the first eye and the second air pulse generator with the second eye. In this regard, the controller is configured to display the mark for each of the first eye and the second eye which may be in form of a blink of light, or a text or any other suitable visual representation. For example, when the first air pulse generator is not aligned with the first eye and the second air pulse generator is not aligned with the second eye, then the display may show a red light continuously. When the first air pulse generator is properly aligned with the first eye and the second air pulse generator is properly aligned with the second eye, then the light is changed from red to green indicating that alignment is accurately achieved, and the first excitation air pulse may be sent towards the eye. For another example, there may be separate light for each of first and second eye, when both turns green they indicate that the alignment of the first air pulse generator with the first eye and the second air pulse generator with the second eye is achieved. For another example, the display may indicate a text saying, 'measurement complete' or 'IOP value is...' when the determination of IOP is completed thus advantageously providing ease of operation for the operators. It will be appreciated that by displaying the mark at the display for aligning the first air pulse generator with the first eye and the second air pulse generator with the second eye to the operator, the dual measurement tonometer significantly reduces the risk of misalignment. Optionally, the user of visual effects, such as color changes or blinking lights, enables the operator to quickly and confidently achieve optimal positioning, even in busy or low-light clinical environments. Beneficially, displaying the mark at the display enables accurate adjustment of various components of the dual measurement tonometer as well as accurate measurement of IOP.

[0078] Optionally, the output device is implemented as an alarm module, the controller is configured to actuate the alarm module to sound an alarm to notify an operator of the dual measurement tonometer. In this regard, the alarm module may sound the alarm when the first air pulse generator is properly aligned with the first eye and the second air pulse generator is properly aligned with the second eye, when the IOP measurement starts, when IOP determination is completed. It will be appreciated that implementation of the output device as an alarm module ensures that the operator is promptly informed of critical events during the measurement process, even if their attention is divided or if they are not directly observing the display. The alarm module is particularly beneficial in busy clinical environments, where visual cues alone may be insufficient. The alarm module facilitates preventing procedural errors by alerting the operator if alignment is not achieved, if the measurement is about to begin, or if the process is complete, thereby reducing the risk of missed or invalid measurements. The alarm module can also be configured to provide different tones or patterns for different events, further enhancing clarity. The technical advantage of ease of operation and enhanced operational experience for the operators is achieved.

[0079] Optionally, the controller is configured to control timing between sending of the first excitation air pulse towards the first eye and sending the first excitation air pulse towards the second eye to not exceed, for example 10 sec. In this regard, when the user positioned in a sitting posture in sitting arrangement such as a chair, due to physiological factors the IOP value may drop up to a specific range. The said specific range is up to 5 mmHg. The said drop or decline can occur in 1 minute or less. Therefore, a second measurement of IOP values of any of the first eye or the second eye within an optimum time period of a first measurement of any of the first eye or the second eye. The term first measurement and second measurement refer to a measurement initiation instance of time. The optimum time period is within 5 seconds after the first measurement. Measuring the IOP of the first eye and the second eye within the optimum time period eliminates error in IOP measurement due movement of the patient Thereby, achieving the technical effect of accurate IOP value measurement. Moreover, the said time limit ensures that the first eye and the second eye is measured under nearly identical physiological conditions, reducing the influence of systemic factors (such as cardiac cycle, posture changes that can affect IOP over short periods of time) on the measurement. This is especially critical for patients with conditions that cause rapid fluctuations in the IOP, such as glaucoma or ocular hypertension. Shorter measurement times reduce patient discomfort and improve compliance, especially for those who are anxious or sensitive to the procedure. Moreover, the combination of precise timing and rapid signal acquisition provides a technical effect of improved accuracy and reliability, especially for patients with conditions that cause rapid IOP fluctuations.

[0080] Optionally, the controller is configured to measure each of the first signals related to the corneal oscillations of the first eye and the second eye, caused by the sent first excitation air pulse with the at least one corneal oscillation measurement sensor within a time period not exceeding duration of corneal oscillations (such as few milliseconds to few tens of milliseconds) from the sending of the first excitation air pulse. In this regard, the first signal corresponds to the corneal oscillations caused by the impact of the first excitation air pulse on the cornea of the first and the second eye. However, the corneal oscillations are subjected to damping over a period of time after the impact. The said period of time may be of the range of 0 to 10-50 msec of the impact. Therefore, a strength of the first signal is maximum within the time period not exceeding 10-50 msec. The controller is configured to measure the first signal utilizing the at least one corneal oscillation measurement sensor within a time period not exceeding 10-50 msec from the sending of the first excitation air pulse. It will be appreciated that capturing the first signals within the undamped phase (i.e., time not exceeding the 10-50 msec) ensures that the corneal oscillations reflect the immediate biomechanical properties of the cornea, leading to more precise and reproducible IOP measurement. By avoiding the first signals acquisition during the damped or recovery phases, the controller minimizes the impact of noise, patient movement, or secondary physiological changes in the IOP measurement. Thus, the technical effect of accurately measuring first signal comprising information on various characteristics of the corneal oscillations, is achieved. According to embodiments the time period would not exceed 10, 15, 20, 25, 30, 35, 40, or 45 milliseconds up to 15, 20, 25, 30, 35, 40, 45, or 50 milliseconds (msec). The present disclosure also relates to the method as described above. Various embodiments and variants disclosed above, with respect to the aforementioned dual measurement tonometer, apply mutatis mutandis to the method.

[0081] DETAILED DESCRIPTION OF THE DRAWINGS

[0082] Referring to FIG. 1A, illustrated is a schematic diagram of a dual measurement tonometer 100 for measuring intraocular pressure values of a first eye 122A and a second eye 122B of a user 120 within a predefined time period, when in use, in accordance with an embodiment of the present disclosure. The dual measurement tonometer 100 comprises a first air pulse generator 102A and a second air pulse generator 102B positioned on opposite sides of a frame 104 of the dual measurement tonometer 100 arranged along a central axis A-A'. The first air pulse generator 102A and the second air pulse generator 102B are separated by a separation distance D therebetween. When in use, the first air pulse generator 102A is aligned with the first eye 122A and the second air pulse generator 102B is aligned with the second eye 122B. The dual measurement tonometer 100 also comprises at least one corneal oscillation measurement sensor 106 operatively coupled to the first air pulse generator 102A and the second air pulse generator 102B, and a controller 108 communicatively coupled to the at least one corneal oscillation measurement sensor 106, the first air pulse generator 102A and the second air pulse generator 102B. The controller 108 is configured to determine a first set of operational parameters of each of the first air pulse generator 102A and the second air pulse generator 102B; to control the first air pulse generator 102A and the second air pulse generator 102B; to send within a pre-defined time period, a first excitation air pulse 126 towards a cornea 124 of the first eye 122A and the second eye 122B respectively; to measure within the pre-defined time period, a first signal related to corneal oscillations of the first eye 122A and the second eye 122B, caused by the sent first excitation air pulse 126 with the at least one corneal oscillation measurement sensor 106; and to determine the intraocular pressure values for the first eye 122A and the second eye 122B from the measured first signals. As shown, the first air pulse generator 102A and the second air pulse generator 102B both include pressure chamber(s) 110 and control valve 112. As shown, the dual measurement tonometer 100 further comprises an output device 114 coupled to the controller 108. The output device 114 may be implemented as a display or an alarm module.

[0083] Moreover, the frame 104 comprises a slot 116 adapted to: receive the first air pulse generator 102A and the second air pulse generator 102B therein; and allow movement of the first air pulse generator 102A and the second air pulse generator 102B relative to each other, along the central axis A-A' of the frame, to align the first air pulse generator 102A and the second air pulse generator 102B to the corresponding first eye 122A and the second eye 122B. A controllable distance adjustment means 118 is arranged on the frame 104 to adjust the separation distance D between the first air pulse generator 102A and the second air pulse generator 102B.

[0084] As shown, the first air pulse generator 102A and the second air pulse generator 102B are aligned with respect to the first eye 122A and the second eye 122B respectively. As shown, the dual measurement tonometer 100 further comprises at least one distance measurement sensor 128 communicably coupled with the controller 108, to measure a distance G between the first eye 122A and the second eye 122B. A controllable distance adjustment means 118 is arranged on the frame 104 to adjust the separation distance D between the first air pulse generator 102A and the second air pulse generator 102B. The controllable distance adjustment means 118 is configured to equate the separation distance D with the distance G between the first eye 122A and the second eye 122B. The first excitation air pulse 126 is sent towards the first eye 122A and the second eye 122B from the first air pulse generator 102A and the second air pulse generator 102B respectively.

[0085] Referring to FIG. IB, illustrated is a schematic diagram illustrating movement of the first air pulse generator 102A and the second air pulse generator 102B of the dual measurement tonometer 100 relative to each other. The first air pulse generator 102A and the second air pulse generator 102B are controlled to move relative to each other, in direction of dashed arrows, along the central axis A-A' of the frame 104. The controller 108, upon receiving information from any of: at least one corneal oscillation measurement sensor 106 and the at least one distance measurement sensor 128, is configured to estimate the distance G between the first eye 122A and the second eye 122B. Thereafter, the controllable distance adjustment means 118 is utilized to adjust the separation distance D between the first air pulse generator 102A and the second air pulse generator 102B, by moving the first air pulse generator 102A and the second air pulse generator 102B in the slot 116 of the frame 104. The controllable distance adjustment means 118 is operated until the separation distance D becomes equal to the distance G.

[0086] FIGs. 1A-1B are merely examples, which should not unduly limit the scope of the claims herein. A person skilled in the art will recognize many variations, alternatives, and modifications of embodiments of the present disclosure.

[0087] Referring to FIG. 2A, illustrated is a schematic diagram of an implementation of a dual measurement tonometer 200 for measuring an intraocular pressure value of an eye 204, in accordance with an embodiment of the present disclosure. Herein the dual measurement tonometer 200 is configured to produce corneal oscillation in the first (or second) eye 204 and measure a first signal 206 corresponding thereto for further intraocular pressure value measurement. The first excitation air pulse 202 interacts (shown by a double-sided arrow) with the first (or second) eye 204 which offers resistance in response to a force exerted by the first excitation air pulse 202. As shown, a first excitation air pulse 202 from a first (or second) air pulse generator of the dual measurement tonometer is sent towards the first (or second) eye 204 which results in corneal oscillation thereof, depicted as a first signal 206 related to corneal oscillations. A corneal oscillation measurement sensor 208 measures the first signal 206 for further intraocular pressure value measurement.

[0088] Referring to FIG. 2B, illustrated is a graphical representation of an intraocular pressure value as a function of oscillation frequency, in accordance with an embodiment of the present disclosure. As shown, the intraocular pressure values are plotted on the X-axis against the oscillation frequency on the Y-axis. As shown, with an increase in the corneal frequency, the intraocular pressure values also increase.

[0089] Referring to FIG. 2C, illustrated is a graphical representation of an intraocular pressure value as a function of time. In the experiment, an intraocular pressure value was measured several times after the person sat down (at time 0). It can be seen that the intraocular pressure value dropped from 15mmHg to lOmmHg as function of time due (120 sec later in lOmmHg) due to person being more relaxed for example. This demonstrates importance of measuring both eyes essentially at the same time as if the first eye would be measured directly after sitting down and second, say 1-2 minute later the values from left and right eye would appear different but actually those would be same. In essence values from left and right eye cannot be compared in relative terms if the measurements are done time wise at different moment of times.

[0090] FIG 2D is an illustration of how IOP changes as a function of time (in sync with cardiac cycle). It can be seen that pulse-to-pulse amplitude 264 can be in range of 5mmHg. This further demonstrates importance of measuring IOP from both eyes substantially at the same time. Delay of half a second in given example between measuring left and right eye would result to readings which are not comparable. It would not be possible to say if the difference (if present) is due to actual differences of IOP between left and right eye or is it artifact created due to measuring it at different time moments.

[0091] FIGs. 2A-2D are merely examples, which should not unduly limit the scope of the claims herein. A person skilled in the art will recognize many variations, alternatives, and modifications of embodiments of the present disclosure.

[0092] Referring FIG. 3, illustrated is a flowchart 300 depicting steps of a method for measuring intraocular pressure values of a first eye and a second eye of a user within a pre-defined time period, in accordance with an embodiment of the present disclosure. At step 302, a first air pulse generator is aligned with the first eye and a second air pulse generator is aligned with the second eye. At step 304, a first set of operational parameters of each of the first air pulse generator and the second air pulse generator is determined. At step 306, the first air pulse generator and the second air pulse generator are controlled to send, within the predefined time period, a first excitation air pulse towards a cornea of the first eye and the second eye, respectively. At step 308, a first signal related to corneal oscillations of the first eye and the second eye, caused by the sent first excitation air pulse with the at least one corneal oscillation measurement sensor, is measured within the pre-defined time period. At step 310, the intraocular pressure values for the first eye and the second eye are determined from the measured first signals.

[0093] The aforementioned steps are only illustrative and other alternatives can also be provided where one or more steps are added, one or more steps are removed, or one or more steps are provided in a different sequence without departing from the scope of the claims herein.

Claims

CLAIMS1. A dual measurement tonometer (100, 200) for measuring intraocular pressure values of a first eye (122A, 204) and a second eye (122B) of a user (120) within a pre-defined time period, the dual measurement tonometer comprising: a first air pulse generator (102A) and a second air pulse generator (102B) positioned on opposite sides of a frame (104), wherein when in use the first air pulse generator (102A) is aligned with the first eye and the second air pulse generator (102B) is aligned with the second eye; at least one corneal oscillation measurement sensor (106, 208) operatively coupled to the first air pulse generator and the second air pulse generator; a controller (108) communicatively coupled to the at least one corneal oscillation measurement sensor, the first air pulse generator and the second air pulse generator, the controller configured to: determine a first set of operational parameters of each of the first air pulse generator and the second air pulse generator; control the first air pulse generator and the second air pulse generator to send, within the pre-defined time period, a first excitation air pulse (126, 202) towards a cornea (124) of the first eye and the second eye, respectively; measure, within the pre-defined time period, a first signal (206) related to corneal oscillations of the first eye and the second eye, caused by the sent first excitation air pulse with the at least one corneal oscillation measurement sensor; and determine the intraocular pressure values for the first eye and the second eye from the measured first signals.

2. The dual measurement tonometer (100, 200) according to claim 1, further comprising at least one distance measurement sensor (128), wherein the controller (108) is further configured to: process sensor data collected by the at least one distance measurement sensor to determine a distance (G) between the first eye (122A, 204) and the second eye (122B); and control a controllable distance adjustment means (118), arranged on the frame (104), such that a separation distance (D) between the first air pulse generator (102A) and the second air pulse generator (102B) becomes equal to the distance between the first eye and the second eye.

3. The dual measurement tonometer (100, 200) according to claim 2, wherein the controllable distance adjustment means (118) is electro- mechanically movable by at least one of: a stepper, an electrical motor.

4. The dual measurement tonometer (100, 200) according to claim 3, wherein the controllable distance adjustment means (118) is implemented as at least one of: linear actuators, piezoelectric actuators, gear assemblies, screw assemblies.

5. The dual measurement tonometer according to claim 1, further comprising at least one distance measurement sensor (128), wherein the controller (108) is further configured to: process sensor data collected by the at least one distance measurement sensor to determine a distance (G) between the first eye (122A, 204) and the second eye (122B); and control a controllable air nozzle direction adjustment means to control direction of the first excitation air pulse and / or direction of the second excitation air pulse towards respective eye.

6. The dual measurement tonometer (100, 200) according to claim 2- 5, wherein the at least one distance measurement sensor (128) is a camera, a depth sensor, or a gaze-tracking camera.

7. The dual measurement tonometer (100, 200) according to any of the preceding claims, wherein the frame (104) further comprises a face support for at least partly aligning the first air pulse generator (102A) with the first eye (122A, 204) and the second air pulse generator (102B) with the second eye (122B).

8. The dual measurement tonometer (100, 200) according to claim 1, wherein the first air pulse generator (102A) and the second air pulse generator (102B) align with the first eye (122A, 204) and the second eye (122B) by mechanically moving a distance adjusting means (118) by an operator of the dual measurement tonometer.

9. The dual measurement tonometer (100, 200) according to claim 8, wherein the distance adjusting means (118) is implemented as an actuator, a slider, screws, gears, knobs.

10. The dual measurement tonometer (100, 200) according to any of the preceding claims, wherein the frame (104) comprises a slot (116) adapted to: receive the first air pulse generator (102A) and the second air pulse generator (102B) therein; and allow movement of the first air pulse generator (102A) and the second air pulse generator (102B) relative to each other, along a central axis (A-A') of the frame, to align the first air pulse generator (102A) and the second air pulse generator (102B) to the corresponding first eye (122A, 204) and the second eye (122B).

11. The dual measurement tonometer (100, 200) according to any of the preceding claims, wherein the at least one corneal oscillationmeasurement sensor (106, 208) comprises a first corneal oscillation measurement sensor, and wherein the first corneal oscillation measurement sensor is arranged on the frame (104) between the first air pulse generator (102A) and the second air pulse generator (102B), and directed towards the first eye (122A, 204) and the second eye (122B), respectively.

12. The dual measurement tonometer (100, 200) according to claim 11, wherein the first corneal oscillation measurement sensor (106, 208) is directed towards the first eye (122A, 204) and the second eye (122B) in turns, wherein the first corneal oscillation measurement sensor is coupled to a turning mechanism configured to change orientation of the first corneal oscillation measurement sensor, and wherein the controller is configured to actuate the turning mechanism to: turn the first corneal oscillation measurement sensor towards the first eye (122A), at a first time, for measuring the first signal from the first eye; and turn the first corneal oscillation measurement sensor towards the second eye (122B), at a second time, for measuring the first signal from the second eye, wherein, a time period between the first time and the second time lies in a range of 0.1 to 2 seconds.

13. The dual measurement tonometer (100, 200) according to any of the preceding claims 1-10, wherein the at least one corneal oscillation measurement sensor (106, 208) comprises a first corneal oscillation measurement sensor and a second corneal oscillation measurement sensor.

14. The dual measurement tonometer (100, 200) according to claims 13, wherein the first corneal oscillation measurement sensor is arranged in front of the first eye (122A, 204) such that the first corneal oscillation measurement sensor is concentric with the first air pulse generator(102A), and the second corneal oscillation measurement sensor is arranged in front of the second eye (122B) such that the first corneal oscillation measurement sensor is concentric with the second air pulse generator (102B).

15. The dual measurement tonometer (100, 200) according to any of the preceding claims, wherein the at least one corneal oscillation measurement sensor (106, 208) is a first confocal chromatic sensor or a second confocal chromatic sensor, optionally, the at least one corneal oscillation measurement sensor is a displacement sensor.

16. The dual measurement tonometer (100, 200) according to any of the preceding claims, further comprising an output device (114), communicably coupled to the controller (108), for providing information related to at least one of: the alignment of the first air pulse generator (102A) with the first eye (122A, 204) and the second air pulse generator (102B) with the second eye (122B); a completion of the determination intraocular pressure values for each eye; the determined intraocular pressure values for each eye.

17. The dual measurement tonometer (100, 200) according to claim 16, wherein the output device (114) is implemented as a display, the controller (108) is configured to display thereat a mark (142) corresponding to each of the first eye (122A, 204) and the second eye (122B) on the display for aligning the first air pulse generator (102A) with the first eye and the second air pulse generator (102B) with the second eye.

18. The dual measurement tonometer (100, 200) according to any of the preceding claims, wherein the output device (114) is implemented as an alarm module, the controller (108) is configured to actuate the alarmmodule to sound an alarm to notify an operator of the dual measurement tonometer.

19. The dual measurement tonometer (100, 200) according to any of the preceding claims, wherein the first set of operational parameters comprises at least one of: a pressure of air in a pressure chamber (110) of each of the first air pulse generator (102A) and the second air pulse generator (102B); an opening speed of a control valve (112) of each of the first air pulse generator (102A) and the second air pulse generator (102B); a closing speed of the control valve; a velocity of the first excitation air pulse (126, 202); and a duration between a start of opening to an end of closing of the control valve, wherein the control valve controls release of the first excitation air pulse from the pressure chamber towards the cornea (124) of the first eye (122A, 204) and the second eye (122B); or a speed of a piston movement of the first air pulse generator and the second air pulse generator; and a length of the piston movement, wherein the piston movement towards a first direction generates the first excitation air pulse to be sent from the first air pulse generator towards the cornea of first eye and from the second air pulse generator towards the cornea of the second eye.

20. The dual measurement tonometer (100, 200) according to any of the preceding claims, wherein the controller (108) is configured to: determine, from the first signal, an oscillation frequency of the corneal oscillations; andcalculate, from the oscillation frequency, the intraocular pressure value.

21. The dual measurement tonometer (100, 200) according to any of the preceding claims, wherein the controller (108) is configured to control timing between sending of the first excitation air pulse (202) towards the first eye (122A, 203) and sending the first excitation air pulse towards the second eye (122B) to not exceed 5 sec.

22. The dual measurement tonometer (100, 200) according to claim 20, wherein the controller (108) is configured to measure each of the first signals (206) related to the corneal oscillations of the first eye (204) and the second eye, caused by the sent first excitation air pulse (126, 202) with the at least one corneal oscillation measurement sensor (106, 208) within a time period not exceeding 50 msec from the sending of the first excitation air pulse.

23. A method for measuring intraocular pressure values of a first eye (122A, 204) and a second eye (122B) of a user (120) within a pre-defined time period, the method comprising: aligning a first air pulse generator (102A) with the first eye and a second air pulse generator (102B) with the second eye; determining a first set of operational parameters of each of the first air pulse generator and the second air pulse generator; controlling the first air pulse generator and the second air pulse generator to send, within the pre-defined time period, a first excitation air pulse (126, 202) towards a cornea (124) of the first eye and the second eye, respectively; measuring, within the pre-defined time period, a first signal (206) related to corneal oscillations of the first eye and the second eye, caused by the sent first excitation air pulse with at least one corneal oscillation measurement sensor (106, 208); anddetermining the intraocular pressure values for the first eye and the second eye from the measured first signals.

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