FI129790B

FI129790B - Measurement devices and methods for using measurement devices

Info

Publication number: FI129790B
Application number: FI20215811A
Authority: FI
Inventors: Mika Salkola
Original assignee: Icare Finland Oy
Priority date: 2021-07-16
Filing date: 2021-07-16
Publication date: 2022-08-31
Also published as: WO2023285729A1; FI20215811A1

Abstract

Disclosed is measurement device (100, 204) for measuring property of object (102, 400, 500), the measurement device having optical axis (104, 210), and comprising: body (106, 404) having proximal end (114) and distal end (116, 402), first optical element (108, 206), second optical element (110, 208) and measurement sensor (112, 202). When measurement device is in use, first optical element receives first beam (118) of light from object at first distance (d1) and translates said beam to second distance (d2) to provide first translated beam (120) of light; and second optical element receives the first translated beam at third distance (d3) and translates said beam to fourth distance (d4) to provide second translated beam (122) of light. Measurement sensor is dimensioned and arranged to fit partially in volume (200) defined by first optical element, second optical element, second distance, and third distance.

Description

MEASUREMENT DEVICES AND METHODS FOR USING MEASUREMENT DEVICES

TECHNICAL FIELD The present disclosure relates to measurement devices for measuring properties of objects. The present disclosure also relates to methods for using such measurement devices.

BACKGROUND Over the past few decades, measurement devices have gained popularity in various disciplines such as medicine, engineering, and the like. Particularly, in the medicine discipline, the measurement devices are often employed to view objects (such as eyes of patients), for example by medical professionals (such as optometrists, ophthalmologists, and the like), in order to measure parameters associated with the objects and/or to diagnose ailments associated with the objects. Sometimes, the measurement devices are also employed for imaging the objects. As an example, a tonometer may be employed to measure an intraocular pressure of an eye (namely, a fluid pressure inside the eye) of a patient by interacting with cornea of the eye to an indentation. As another N 20 example, a keratometer may be employed to measure a curvature of an N anterior surface of a cornea of an eye, for diagnosing an extent of 3 astigmatism in a patient. E However, existing measurement devices are not well-suited for viewing = the objects. This is because the existing measurement devices block 3 25 visibility (partially or completely) of the objects from a point of view of a viewing object (such as a user's eye, a camera, and the like). In such a case, inaccurate views of the objects are provided as a direct line of sight between the viewing object the objects gets obstructed. Consequently,

examinations, diagnosis, and/or imaging of the objects are unreliable and erroneous. Therefore, in light of the foregoing discussion, there exists a need to overcome the aforementioned drawbacks associated with existing measurement devices.

SUMMARY The present disclosure seeks to provide a measurement device for measuring a property of an object. The present disclosure also seeks to provide a method for using such a measurement device. An aim of the present disclosure is to provide a solution that overcomes at least partially the problems encountered in prior art. In one aspect, an embodiment of the present disclosure provides a measurement device for measuring a property of an object, the measurement device having an optical axis, the measurement device comprising: a body having a proximal end and a distal end; a first optical element arranged on the distal end, wherein the first optical element is aligned with the optical axis; a second optical element arranged on the proximal end, wherein the N 20 second optical element is aligned with the optical axis; and N a measurement sensor arranged at least partially in the body and is

O + implemented as a probe that is arranged on a probe base, wherein the

O r measurement sensor is arranged on the optical axis and in between the jami * first optical element and the second optical element and 0 = 25 a controller configured to control the probe for measuring the property of the object; wherein, when the measurement device is in use,

- the first optical element receives a first beam of light from the object, the first beam of light being received at a first distance from the optical axis, and the first optical element translates the first beam of light within itself to a second distance from the optical axis and provides a first translated beam of light from the first optical element, wherein the first distance is less than the second distance; and - the second optical element receives the first translated beam of light, the first translated beam of light being received at a third distance from the optical axis, and the second optical element translates the first translated beam of light within itself to a fourth distance from the optical axis and provides a second translated beam of light from the second optical element, wherein the fourth distance is less than the third distance; and wherein the measurement sensor is dimensioned and arranged to fit partially in a volume defined by the first optical element, the second optical element, the second distance, and the third distance.

In another aspect, an embodiment of the present disclosure provides a method for using a measurement device of the aforementioned aspect, the method comprising: - arranging an object in proximity of a distal end of a body of the N measurement device; N - viewing the object from a proximal end of the body; and = - controlling a s probe associated with a measurement sensor of the 7 measurement device for measuring a property of the object. = = 25 Embodiments of the present disclosure substantially eliminate or at least D partially address the aforementioned problems in the prior art, and ES enable accurate and reliable measurement of a property of an object by providing a complete and a distortion-free line of sight view of the object from a proximal end of a body of a measurement device.

Additional aspects, advantages, features and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative embodiments construed in conjunction with the appended claims that follow.

It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those skilled in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers. Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein: N 20 FIGs. 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, and 11 illustrate exemplary N implementations of a measurement device for measuring a property of = an object, in accordance with various embodiments of the present 7 disclosure; s FIG. 1) illustrates another view of the implementation of the 2 25 measuring device of FIG. 11, in accordance with an embodiment of the N present disclosure;

N

FIG. 2 illustrates a volume in which a measurement sensor of a measurement device is partially fit, in accordance with an embodiment of the present disclosure; FIG. 3A illustrates a given focusing element and a given optical 5 element, while FIG. 3B illustrates the given focusing element integrated with the given optical element, in accordance with an embodiment of the present disclosure; FIG. 4 illustrates different views of an object when the object is arranged at various distances from a distal end of a body of a measurement device, in accordance with an embodiment of the present disclosure; FIG. 5 illustrates different views of reflection of a front light from an object when the object is arranged at various distances from a distal end of a body of a measurement device, in accordance with an embodiment of the present disclosure; and FIG. 6 illustrates steps of a method for using a measurement device, in accordance with an embodiment of the present disclosure. In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined N number to the item. When a number is non-underlined and accompanied N by an associated arrow, the non-underlined number is used to identify a © general item at which the arrow is pointing.

O E 25 DETAILED DESCRIPTION OF EMBODIMENTS = The following detailed description illustrates embodiments of the present 5 disclosure and ways in which they can be implemented. Although some N 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.

In one aspect, an embodiment of the present disclosure provides a measurement device for measuring a property of an object, the measurement device having an optical axis, the measurement device comprising: a body having a proximal end and a distal end; a first optical element arranged on the distal end, wherein the first optical element is aligned with the optical axis; a second optical element arranged on the proximal end, wherein the second optical element is aligned with the optical axis; and a measurement sensor arranged at least partially in the body and is implemented as a probe that is arranged on a probe base , wherein the measurement sensor is arranged on the optical axis and in between the first optical element and the second optical element a controller configured to control the probe for measuring the property of the object; wherein, when the measurement device is in use, - the first optical element receives a first beam of light from the object, the first beam of light being received at a first distance from the optical axis, and the first optical element translates the first beam of light A 20 within itself to a second distance from the optical axis and provides a first O translated beam of light from the first optical element, wherein the first S distance is less than the second distance; and S - the second optical element receives the first translated beam of E light, the first translated beam of light being received at a third distance = 25 from the optical axis, and the second optical element translates the first D translated beam of light within itself to a fourth distance from the optical ES axis and provides a second translated beam of light from the second optical element, wherein the fourth distance is less than the third distance;

and wherein the measurement sensor is dimensioned and arranged to fit partially in a volume defined by the first optical element, the second optical element, the second distance, and the third distance.

In another aspect, an embodiment of the present disclosure provides a method for using a measurement device of the aforementioned aspect, the method comprising: - arranging an object in proximity of a distal end of a body of the measurement device; - viewing the object from a proximal end of the body; and - controlling a measurement sensor of the measurement device for measuring a property of the object.

The present disclosure provides the aforementioned measurement device for measuring a property of an object, and the aforementioned method for using the measurement device.

Herein, optical components of the measurement device are arranged in a manner that the first beam of light (received from the object) is reguisitely translated to go around the measurement sensor, thereby making the measurement sensor optically invisible (namely, cloaked) from a point of view of the proximal end of the body of measurement device.

In other words, despite being physically present along a line of sight between the proximal end and the object, N the measurement sensor does not optically obstruct the (line of sight) N view of the object at the proximal end.

Owing to such translations, the = first beam of light would not be blocked by the measurement sensor and 7 would be provided as the second translated beam of light which appears 2 25 to travel along the line of sight.

Beneficially, when a user uses the = measurement device, visibility of the object would not get obstructed and 5 the user would be able to see and/or capture a complete and distortion- N free view of the object from the proximal end.

Conseguently, examinations, diagnosis, and/or imaging of objects using the measurement device would be reliable and error-free. The method is fast, effective, reliable and can be performed easily. The measurement device is a specialized device for measuring the property of the object. It will be appreciated that the measurement device enables in accurate and real time measurement of the property of the object. Throughout the present disclosure, the term "property" refers to a physiological parameter associated with the object that is measured by the measurement device. Optionally, the object is a body part associated with an entity (for example, a person, an animal, or similar) wherein the property of the body part is to be measured by the measurement device. It will be appreciated that the measurement device is used by a user to view (namely, examine) the object. In a first example, the object may be an eye of a patient, the property may be an intraocular pressure of the eye, and the user may be a medical professional (such as an optometrist, an ophthalmologist, or similar). The property could also be a curvature of a cornea of an eye, a thickness of the cornea, a axial length of the eye, a depth of an anterior chamber of the eye, and the like. Throughout the present disclosure, the term "optical axis" refers to an imaginary line which passes through a geometrical centre of the N measurement device, and which defines a path along which light moves N through the measurement device. It will be appreciated that the optical = axis lies along a given geometrical direction. As an example, the optical 7 axis may be between an eye of the user of the measurement device and E 25 the object. Optionally, the optical axis is a rotational axis of the = measurement device. In other words, the measurement device can be 5 rotated (for example, through 360 degrees), about the optical axis.

N Throughout the present disclosure, the term "body" refers to a housing wherein at least some components (such as the first optical element, the second optical element, and the like) of the measurement device are arranged.

In other words, the body is adapted to (partially or fully) accommodate the components of the measurement device.

Some other components of the measurement device may be arranged partially or completely outside the body.

Notably, when the measurement device is in use, the proximal end of the body is located in proximity of (i.e., near) the user, whereas the distal end of the body is located away (i.e., far) from the user.

In use, the proximal end of the body is located away from the object, whereas the distal end of the body is located in proximity of the object.

It will be appreciated that the components of the measurement device could be arranged (namely, held or attached) in the body via adhesive means, mechanical means, magnetic means, and the like.

In one case, the components of the measurement device could be manufactured individually, and then these components could be assembled in the body.

In another case, the components of the measurement device could be manufactured as an integral part of the body.

Throughout the present disclosure, the term "optical element" refers to an optical component that is employed to pass a given beam of light incident thereupon in a requisite manner.

It will be appreciated that a given optical element is arranged along the optical axis.

It will also be N appreciated that the term "given optical element" encompasses any of: N the first optical element, the second optical element, optional optical © element(s) (such as a third optical element, and so forth). Optionally, the 7 25 given optical element is aligned with the optical axis in a manner that a E central axis of the given optical element is coincident with the optical axis. = In other words, the given optical element may be symmetrical about the = optical axis.

Notably, the first optical element is located near the object, N whereas the second optical element is located far from the object.

The first and second optical elements may be similar in terms of their implementation, shape and/or size, and may be arranged in a face-to- face manner with respect to each other, in the body.

Optionally, the given optical element is implemented as at least one of: a prism, a mirror, a lens, an optical waveguide, an optical fibre, a fibre optic plate.

In an example, the given optical element is implemented as two prisms.

The two prisms could be two circular prisms, two triangular prisms, two dove prisms, and the like.

In another example, the given optical element is implemented as two optical waveguides.

In yet another example, the first optical element and the second optical element are collectively implemented as two lenses and optical fibres.

In such a case, the optical fibres could be used for image transition (i.e., image translation), wherein a first lens amongst the two lenses may be used to project a beam of light from the object on a surface of a bundle of the optical fibres, and a second lens amongst the two lenses may be used to match the projected beam of light to the proximal end.

The optical fibres could be attached integrally, detachably, or in any other reguired manner, to the two lenses.

It will be appreciated that the given optical element could be implemented as any other suitable component(s) besides the ones listed hereinabove.

Throughout the present disclosure, the term "measurement sensor" N refers to a specialised component that, in operation, senses and O measures the property of the object.

Optionally, the measurement sensor N is arranged at least partially in the body.

Optionally, in this regard, the s measurement sensor is arranged in a manner that a distal end of the E 25 measurement sensor is located outside the body and away (i.e., far) from = the user, while a proximal end of the measurement sensor lies inside the D body and in proximity of (i.e., near) the user.

In use, the proximal end O of the measurement sensor is located away from the object, whereas the distal end of the measurement sensor is located in proximity of the object.

It will be appreciated that the measurement sensor is aligned with the optical axis in such a manner that a central axis of the measurement sensor is coincident with the optical axis i.e., the measurement sensor is symmetrically arranged about the optical axis.

Referring to the first example, the measurement sensor may be a probe-based sensor for sensing and measuring the intraocular pressure of the eye.

When the measurement device is in use, the first optical element receives the first beam of light from the object when the first beam of light is reflected by the object towards the first optical element.

A "beam" of light comprises a plurality of light rays.

The first beam of light is received at the first distance from the optical axis.

Throughout the present disclosure, the term "distance" refers to an offset between the given beam of light and the optical axis.

A given distance may be expressed in units of length, such as micrometres, millimetres, centimetres, or similar.

Optionally, the first distance is zero units.

In such a case, the first beam of light is received by the first optical element along the optical axis.

Alternatively, optionally, the first distance is greater than the distal end of the measurement sensor.

In such a case, the first beam of light and the optical axis have an offset that is greater than the distal end of the measurement sensor.

This allows for having a requisite space in the body for the measurement sensor to perform its operation.

N The first optical element translates the first beam of light within itself.

By O such translation, the first beam of light is geometrically transformed in a N manner that the first beam of light is moved from the first distance to the x second distance from the optical axis, for providing the first translated E 25 beam of light.

Geometric transformations occur due to occurrence of = reflection, refraction, and the like, when any beam of light is incident D upon any optical element.

Since the second distance is more than the O first distance, the first beam of light is moved away from the optical axis to provide the first translated beam of light.

It will be appreciated that a technical effect of the aforesaid translation of the first beam of light by the first optical element is that the first translated beam of light would not be blocked by the measurement sensor which otherwise (i.e., without the aforesaid translation) would have been blocked by the measurement sensor.

Optionally, the measurement device further comprises a third optical element that is arranged in between the first optical element and the second optical element and is aligned with the optical axis. The third optical element is employed for geometrical correction and/or colour correction in the measurement device. The third optical element implements the aforesaid correction(s) as it directs the first translated beam of light through itself towards the second optical element.

Next, the second optical element receives the first translated beam of light at the third distance from the optical axis. In an embodiment, the third distance is different from the second distance. In such a case, a direction of the first translated beam of light is oblique (i.e., not parallel or at an angle) to the optical axis. Optionally, the third distance is greater than the second distance. Alternatively, optionally, the third distance is smaller than the second distance. In another embodiment, the second distance is same as the third distance. In such a case, a direction of the first translated beam of light is parallel to the optical axis.

N The second optical element translates the first translated beam of light N within itself. By such translation, the first translated beam of light is = geometrically transformed in a manner that the first translated beam of 7 light is moved from the third distance to the fourth distance from the 2 25 optical axis, for providing the second translated beam of light. Since the = fourth distance is less than the third distance, the first translated beam 5 of light is moved towards the optical axis to provide the second translated N beam of light. Notably, the second translated beam of light constitutes a view of the object at the proximal end. It will be appreciated that a technical effect of the aforesaid translation of the first translated beam of light by the second optical element is that the second translated beam of light would appear to follow an original optical path of the first beam of light which is received from the object.

Beneficially, the translations provided by the first optical element and the second optical element enable the first beam of light to go around (i.e., bend around) the measurement sensor, thereby making the measurement sensor optically invisible (namely, cloaked) from a point of view of the proximal end of the body of the measurement device.

In other words, despite being physically present along a line of sight between the proximal end and the object, the measurement sensor does not optically obstruct the (line of sight) view of the object at the proximal end.

As an example, the translations make the measurement sensor nearly invisible to the user of measurement device at the proximal end.

Owing to the translations, the first beam of light received from the object would not be blocked by the measurement sensor and would be provided as the second translated beam of light at the proximal end.

Advantageously, this second translated beam of light appears to travel along a natural line of sight between the user and the object when the user uses the measurement device to view the object from the proximal end.

Notably, the measurement sensor is dimensioned and arranged to fit N partially in the volume defined by the first optical element, the second O optical element, the second distance, and the third distance.

A length of N the measurement sensor could be from few centimetres to tens of x centimetres.

Optionally, a length of the measurement sensor lies in a E 25 range of 0.4 centimetres to 25 centimetres.

The length of the = measurement sensor may be, for example, from 0.4, 0.7, 1, 1.5, 2, 3, 5, D 10 or 15 centimetres up to 2, 5, 10, 15, 20, or 25 centimetres.

Optionally, O a width of the measurement sensor lies in a range of 0.5 millimetres to 20 millimetres.

Optionally, a height of the measurement sensor is egual to the width of the measurement sensor.

Optionally, the volume lies in a range of 10 cubic millimetres to 100000 cubic millimetres.

In an example, when the third distance is same as the second distance, and the first and second optical elements have circular shapes, there is defined a cylindrical volume in the measurement device.

The measurement sensor may be dimensioned and arranged to fit partially in this cylindrical volume.

In another example, when the third distance is different from the second distance, and the first and second optical elements may have circular shapes, square shapes, or rectangular shapes, there is defined a conical frustum volume, a cubical volume, or a cuboidal volume, respectively, in the measurement device.

The measurement sensor may be dimensioned and arranged to fit partially in such a volume.

Optionally, a given optical element is arranged in a manner that a clear view of the object is provided at the proximal end only when the object is arranged at a predefined distance from the distal end.

In this regard, the phrase "clear view of the object" means that the object appears complete and distortion-free when viewed or imaged from the proximal end.

When the object is arranged at a distance that is greater than or smaller than the predefined distance, the object would appear incomplete and/or distorted when viewed or imaged from the proximal end.

As an example, when the object is arranged too near to or too far from the distal end, parts of the object may appear dislocated (namely, displaced) 3 and/or may be missing.

Thus, the clear view of the object would not be N provided at the proximal end.

The object is said to be arranged too near © to the distal end when a distance between the object and the distal end 7 25 is less than the predefined distance, whereas the object is said to be E arranged too far from the distal end when a distance between the object = and the distal end is more than the predefined distance.

Therefore, only = when the object is arranged at the predefined distance from the distal N end, the given optical element is arranged in the manner that the clear view of the object is provided (for example, to the user) at the proximal end.

In use, a reguisite alignment between the measurement device and the object can be made (for example, by the user) until the object is arranged at the predefined distance and the clear view of the object is provided at the proximal end. Beneficially, the requisite alignment between the measurement device and the object can be made conveniently without requiring any additional alignment means. Different arrangements of the given optical element would affect optical paths of the given beam of light when the given beam of light travels through the measurement device. Subsequently, this would yield clear views of the object at the proximal end for different predefined distances. Therefore, the given optical element is arranged according to the (required) predefined distance. Since a view of the object changes (at the proximal end) according to a change in a distance between the object and the distal end, the object may be imaged at the proximal end using distance- dependent imaging. Optionally, the measurement device further comprises: a first focusing element arranged on an optical path between the object and the first optical element; and a second focusing element arranged on an optical path between the second optical element and the proximal end, wherein the first focusing element and the second focusing element are arranged in a manner that a clear view of the object is provided at the N proximal end only when the object is arranged at a predefined distance N from the distal end.

O x The term "focusing element" refers to an optical component that is E 25 capable of focusing a given beam of light incident thereupon. Optionally, = the first focusing element focuses the first beam of light that is received D from the object towards the first optical element, whereas the second O focusing element focuses the second translated beam of light that is received from the second optical element towards the proximal end. It will be appreciated that the first and second focusing elements further enhances and ensures a requisite alignment between the measurement device and the object such that the clear view of the object is provided at the proximal end only when the object is arranged at the predefined distance from the distal end. Beneficially, in such a case, the first and second focusing elements serve as an alignment means for assisting in making the requisite alignment between the measurement device and the object. Examples of the given focusing element may include, but are not limited to, a lens, a mirror, a prism, an optical fiber, an optical fiber bundle. Optionally, a given focusing element is aligned with the optical axis in a manner that a central axis of the given focusing element is coincident with the optical axis. It will be appreciated that the term "given focusing element" encompasses any of: the first focusing element, the second focusing element. It will also be appreciated that the given focusing element is arranged according to the predefined distance, since its different arrangements would differently affect optical paths of the given beam of light when the given beam of light travels through the measurement device. Optionally, the predefined distance lies in a range of 4 millimetres to 8 millimetres. More optionally, the predefined distance lies in a range of 4.5 millimetres to 7.5 millimetres. As an example, the predefined distance may be from 4, 4.2, 4.4, 4.6, 4.8, 5, 5.5, 6, 6.5 or 7 millimetres up to 5, 3 6, 7, 7.5 or 8 millimetres. In an example, the predefined distance may be 6 millimetres.

O x Optionally, the first focusing element is integrated with the first optical E 25 elementand/or the second focusing element is integrated with the second = optical element. In this regard, the given focusing element is integrated D (i.e., combined) with the given optical element to yield a single integrated O optical element that performs operations of the given focusing element as well as the given optical element. It will be appreciated that such an integration of the given focusing element with the given optical element simplifies an arrangement of components in the measurement device. Moreover, when the given focusing element and the given optical element are integrated, they take up less space within the measurement device, as compared to their separate arrangement. This potentially saves space in the measurement device, thereby making the measurement device compact. In general, using integrated components helps in saving manufacturing costs and time. Optionally, the measurement device comprises only one of: the first focusing element, the second focusing element. The one of: the first focusing element, the second focusing element, is arranged in a manner that a clear view of the object is provided at the proximal end only when the object is arranged at a predefined distance from the distal end. As an example, the measurement device may comprise only the first focusing element. This also simplifies the arrangement of components in the measurement device and saves space in the measurement device. Optionally, the second optical element also receives a second beam of light corresponding to information that is to be displayed to the user of the measurement device, the second beam of light emanating from a first light source, and wherein the second optical element optically combines the second beam of light with the first translated beam of light to obtain N a first combined beam of light, further wherein the second optical element O translates the first combined beam of light within itself to the fourth N distance and provides a third translated beam of light from the second x optical element.

I 2 25 Optionally, the second optical element receives the second beam of light = from the first light source. The term "/ight source" refers to an element 5 from which a given beam of light emanates. Optionally, the first light N source is driven to display the information to the user of the measurement device. Optionally, the first light source is driven by a controller of the measurement device. The controller may be a microcontroller, a microprocessor, or similar.

Optionally, the first light source is implemented as at least one of: a light-emitting diode (LED), an organic light-emitting diode (OLED), an incandescent lamp, a fluorescent lamp, a laser.

Alternatively, optionally, the first light source is implemented as a display.

In this regard, the information is displayed at the display.

Examples of such a display include, but are not limited to, a Liquid Crystal Display (LCD), a Light-Emitting Diode (LED)-based display (for example, an Organic LED (OLED)-based display), and a Liquid Crystal on Silicon (LCoS)-based display.

Yet alternatively, optionally, the first light source is implemented as a projector.

Optionally, in this regard, the information is projected onto a projection screen arranged on an optical path between the projector and the second optical element.

Examples of such a projector include, but are not limited to, an LCD- based projector, an LED-based projector (for example, an OLED-based projector), an LCoS-based projector, a Digital Light Processing (DLP)-

based projector, and a laser projector.

Optionally, the information that is to be displayed to the user pertains to the object.

This facilitates the user to utilize the information for examining, diagnosing, studying or manipulating the object.

Optionally, in this regard, the information comprises values of the property of the object.

Such a value could be a historical value, a reference value, an 3 existing value, or similar.

In an example, the information that is displayed N to the user (for example, a medical professional) may be a value of an © intraocular pressure of an eye.

This value may, for example, be equal to 7 25 17.5 millimetres of mercury (mm Hg). Additionally, optionally, the E information comprises at least one of: instructions to use the = measurement device, peripheral information pertaining to the = measurement device.

Optionally, the controller of the measurement N device is communicably coupled to a computing device wirelessly, or in a wired manner, wherein a processor of the computing device is configured to provide a user with an interactive user interface for enabling the user to select whether or not the information is to be displayed to the user.

The controller then would enable or disable the first light source based on a user input.

The computing device can be, for example, a smartphone, a tablet, a laptop, a desktop-computer, a workstation, or similar.

It will be appreciated that optionally the second optical element serves as an optical combiner for combining the second beam of light and the first translated beam of light to obtain the first combined beam of light.

Optionally, when the second optical element translates the first combined beam of light, the first combined beam of light is geometrically transformed in a manner that the first combined beam of light is moved from the third distance to the fourth distance from the optical axis, for providing the third translated beam of light.

Since the fourth distance is less than the third distance, the first combined beam of light is moved towards the optical axis to provide the third translated beam of light.

It will be appreciated that the third translated beam of light optionally constitutes the view of the object and the information to be displayed to the user, at the proximal end.

Moreover, the information is displayed to the user without obstructing the view of the object at the proximal end.

For example, the information is displayed to the user on a side of the view of the object and not on a top of the view of the object.

Beneficially, 3 in such a case, the information could be easily displayed to the user along N with the view of the object, at the proximal end.

Moreover, employing © the second optical element as the optical combiner simplifies a setup 7 25 needed for providing the information in addition to the view of the object.

E It will be appreciated that since the information is displayed to the user = along with the view of the object, the user need not look away from = his/her existing viewpoint.

In particular, addition of said information onto N the view of the object is performed in a similar manner as performed in ahead-up display (HUD).

Optionally, the first optical element also receives a third beam of light emanating from a second light source, and wherein the first optical element optically combines the third beam of light with the first beam of light to obtain a second combined beam of light, the first optical element translates the second combined beam of light within itself to the second distance and provides a fourth translated beam of light from the first optical element, further wherein the second optical element receives the fourth translated beam of light at the third distance, translates the fourth translated beam of light within itself to the fourth distance, and provides a fifth translated beam of light from the second optical element.

Optionally, the second light source, in operation, provides the third beam of light required to illuminate the object.

The third beam of light serves as an additional light to illuminate the object in a requisite manner (for example, for examination of the object by the user). Optionally, the second light source is a natural light source and/or an artificial light source.

The natural light source can be the Sun, whereas the artificial light source can be a lamp (for example, an ear, nose, and throat (ENT) lamp), a display, a candle, and the like.

Optionally, the first optical element receives the first beam of light from N the object and the third beam of light from the second light source.

In O such a case, the third beam of light is directly optically combined with the N first beam without being incident upon the object.

Alternatively, x optionally, the first optical element receives the first beam of light and a E 25 reflection of the third beam of light from the object.

In such a case, the = third beam of light is incident upon the object and then, the third beam D of light is reflected from the object towards the first optical element.

O Therefore, the first optical element receives the reflection of the third beam of light from the object.

It will be appreciated that optionally the reflection of the third beam of light from the object is correctly viewed at the proximal end only when the object is arranged at the predefined distance from the distal end. When the object is arranged too near to or too far from the distal end, the reflection of the third beam of light is improperly provided at the proximal end.

The first optical element optionally serves as an optical combiner for effectively combining the first beam of light with the third beam of light to obtain the second combined beam of light. Optionally, when the first optical element translates the second combined beam of light, the second combined beam of light is geometrically transformed in a manner that the second combined beam of light is moved from the first distance to the second distance from the optical axis, for providing the fourth translated beam of light. Since the second distance is more than the first distance, the second combined beam of light is moved away from the optical axis to provide the fourth translated beam of light. The fourth translated beam of light is further translated by the second optical element when the fourth translated beam of light is incident thereupon. Optionally, when the first optical element translates the fourth translated beam of light, the fourth translated beam of light is geometrically transformed in a manner that the fourth translated beam of light is moved from the third distance to the fourth distance from the optical axis, for providing the fifth translated beam of light. Since the fourth distance is N less than the third distance, the fourth translated beam of light is moved N towards the optical axis to provide the fifth translated beam of light. It © will be appreciated that the fifth translated beam of light constitutes a 7 25 clear and a well-illuminated view of the object at the proximal end. = = Optionally, the measurement device is arranged on an optical path D between the object and at least one of: a camera, a microscope, a O magnifying device, an ophthalmology device, an eye of a user of the measurement device. It will be appreciated that at least one of the aforementioned viewing objects are utilized for viewing the object from the proximal end.

Optionally, the measurement device is arranged on an optical path between the object and a lens of the camera.

Examples of the camera may include, but are not limited to, a Red-Green-Blue (RGB) camera, monochrome camera, a Red-Green-Blue-Depth (RGB-D) camera, an infrared camera.

The camera may be a charge-coupled device (CCD)-based camera, a complementary metal-oxide-semiconductor (CMOS)-based camera, or similar.

Optionally, the measurement device is arranged on an optical path between the object and a lens of the microscope.

Examples of the microscope may include, but are not limited to, an ophthalmic microscope, a slit-lamp microscope, a specular microscope.

Optionally, the magnifying device is a magnifying lens or a magnifying mirror.

The term "ophthalmology device" refers to an ophthalmic device that is used for eye diagnosis by a medical professional (for example, such as an optometrist and/or an ophthalmologist). Optionally, a distance between the object and a given viewing object of the measurement device lies in a range of O millimetres to 200 millimetres.

The distance between the object and the given viewing object may, for example, be from 0, 5, 10, 20, 30, 50, 75, 100, 130 or 175 millimetres up to 15, 20, 50, 100, 150 or 200 millimetres.

As an example, the distance between the object and the given viewing object (such as, the eye of the user) may be 130 millimetres.

It will be appreciated that the measurement device could also be arranged on the 3 optical path between the object and other suitable viewing objects N besides the ones listed hereinabove. + 7 25 Optionally, the measurement device is one of: a tonometer, a E keratometer, a pachymeter, a biometer, an ophthalmoscope, a tear-film = analyser.

The "tonometer" is a device that measures an intraocular = pressure of an eye (namely, a fluid pressure inside the eye) by interacting N with cornea of the eye to an indentation.

Tonometer is generally used for glaucoma screening of patients.

The "keratometer" is a device that measures a curvature of an anterior surface of the cornea, for assessing an extent of astigmatism in patients.

The "pachymeter" is a device that measures a thickness of the cornea (usually, in micrometres), when an ultrasonic transducer embedded in the pachymeter touches the cornea.

The " biometer" is a device that measures a length of the eye, a depth of an anterior chamber of the eye, a curvature of the cornea, a width of the cornea, and the like.

The "ophthalmoscope" is a device that checks and measures interior surface of the eye, to diagnose retinal detachment or eye diseases such as glaucoma.

The keratometer and the ophthalmoscope may be used for standalone imaging of the eye, and may optionally require the third beam of light (emanating from the second light source) as the additional light to illuminate the object in a requisite manner.

The "tear-film analyser" is a device that measures tear-film thickness, evaporation and/or composition.

Disorders could be caused by several systemic or ocular diseases and are possible leading to dry eye symptoms.

The measurement sensor is implemented as a probe arranged on a probe base, and wherein the measurement device further comprises the controller configured to control the probe for measuring the property of the object.

The "probe" is a slender flexible element with a small bulbous tip that is arranged on the probe base.

The "probe base" is a holder for holding the probe in the measurement device.

Optionally, the probe is 3 located entirely outside the body, whereas the probe base is located N partially outside the body.

The small bulbus tip could be made of a 7 25 medical-grade plastic material.

Such a material is free from E carcinogenicity, toxicity, and resistive to corrosion.

The probe may be = designed for a single use to prevent the object from a microbiological = contamination and/or an infectious transmission.

Moreover, an insertion N of the probe in the probe base and a removal of the probe from the probe base could be easily performed (for example, by the user). Optionally, a type of probe used in the measurement device depends on a type of measurement device. Measurement devices measuring different types of properties of the object utilize different types of probes. Optionally, the controller is configured to control the probe based on a user input. The controller may receive the user input by at least one of: a press of a button, a touch input, a gesture input, or similar on the measurement device. It will be appreciated that the controller controls a movement of the probe based on the user input. Such a movement could be a translation, probe, a tilting, a rotation, or similar. Optionally, a length of the probe base lies in a range of 10 millimetres to 60 millimetres. The length of the probe base may be from 10, 15, 20, 30 or 45 millimetres up to 20, 35, 50, 55 or 60 millimetres. Optionally, a width of the probe base lies in a range of 3 millimetres to 20 millimetres. The width of the probe base may be from 3, 5, 10 or 15 millimetres up to 10, 12.5, 15, 17.5 or 20 millimetres. As an example, the length of the probe base and the width of the probe base may be 41 millimetres and 9 millimetres, respectively. In an example, the measurement device may be the tonometer, and the user may press the button (coupled to the controller) on the tonometer to measure the intraocular pressure of the eye. The controller may receive a signal that is indicative of pressing of the button, and may N generate a drive signal for moving the probe towards the eye. The drive O signal is sent to the probe, and upon receiving the drive signal, the probe N gently and momentarily presses a surface the eye to indent the cornea x of the eye, and then rebounds. A pressure with which the cornea pushes E 25 back the probe is measured as the intraocular pressure of the eye. The = intraocular pressure may be calculated from a signal representing velocity D with which the probe rebounded from the surface of an eye.

QA & The present disclosure also relates to the method as described above. Various embodiments and variants disclosed above, with respect to the aforementioned system, apply mutatis mutandis to the method.

Optionally, in the method, the object is arranged at a predefined distance from the distal end in order to provide a clear view of the object at the proximal end.

It will be appreciated that the object is arranged in the proximity of the distal end in a manner that a view of the object which is provided at the proximal end is similar to a line of sight view of the object from the viewing object (for example, the eye of the user). Notably, the measurement sensor is controlled (optionally, by the controller) when the measurement device is in use for measuring the property of the object.

The controller could (continuously or intermittently) control the measurement sensor based on the user input.

The controller can control the measurement sensor via an electrical signal, a pneumatic signal, or similar.

Optionally, the method further comprises: - obtaining information that is to be displayed to a user of the measurement device; - controlling a first light source to emit a second beam of light corresponding to the information towards a second optical element of the measurement device; and - viewing the information from the proximal end.

It will be appreciated that obtaining the information that is to be displayed N to the user encompasses generation of the information at the O measurement device, as well as receiving the information from an N external device.

The external device may be the computing device, a data x repository, or similar.

Optionally, the external device is communicably E 25 coupled to the measurement device wirelessly, or in a wired manner. = Optionally, the first light source is controlled by the controller.

In this D regard, the controller could enable or disable the first light source based O on the user input.

The information can be viewed by the user at the proximal end along with the view of the object.

The information is displayed in a manner that the view of the object would not be obstructed. Optionally, the method further comprises: - arranging a second light source to emit a third beam of light towards a first optical element of the measurement device; and - viewing the third beam of light from the proximal end. Optionally, when the second light source is the artificial light source, the second light source is arranged in a manner that the third beam of light is incident upon the first optical element. Alternatively, optionally, when the second light source is the natural light source, the measurement device is arranged in a manner that the third beam of light is incident upon the first optical element. Such arrangements (namely, adjustments) may be performed by the user. Notably, the third beam of light is a part of the second combined beam of light (which is eventually provided as the fifth translated beam of light at the proximal end). In this regard, the additional light of the third beam of light is provided along with the view of the object. Therefore, a clear and a well-illuminated view of the object is viewed from the proximal end. Optionally, the method further comprises arranging at the proximal end, at least one of: a camera, a microscope, a magnifying device, an N ophthalmology device, an eye of a user of the measurement device.

N

S DETAILED DESCRIPTION OF THE DRAWINGS + 7 Referring to FIGs. 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, and 11, illustrated are s exemplary implementations of a measurement device 100 for a 2 25 measuring a property of an object 102, in accordance with various N embodiments of the present disclosure. The measurement device 100 N has an optical axis 104. The measurement device 100 comprises a body 106, a first optical element 108, a second optical element 110, and a measurement sensor 112. The body 106 has a proximal end 114 and a distal end 116. The first optical element 108 is arranged on the distal end 116 and is aligned with the optical axis 104. The second optical element 110 is arranged on the proximal end 114 and is aligned with the optical axis 104. The measurement sensor 112 is arranged partially in the body 106, and is arranged on the optical axis 104 in between the first optical element 108 and the second optical element 110. The first optical element 108 receives a first beam 118 of light from the object 102 at a first distance d1 from the optical axis 104. The first optical element 108 translates the first beam 118 of light within itself to a second distance d2 from the optical axis 104 and provides a first translated beam 120 of light. The first distance d1 is less than the second distance d2. The second optical element 110 receives the first translated beam 120 of light at a third distance d3 from the optical axis 104. The second optical element 110 translates the first translated beam 120 of light within itself to a fourth distance d4 from the optical axis 104 and provides a second translated beam 122 of light. The fourth distance d4 is less than the third distance d3. Moreover, a viewing object 124 is arranged near the proximal end 114, for viewing the object 102. The measurement device 100 is arranged on an optical path between the object 102 and the viewing object 124. For sake of simplicity, in FIGs. 1B-11, all elements of the measurement device 100 of FIG. 1A are not 3 numbered.

QA = In FIG. 1B, the measurement device 100 further comprises a third optical 7 25 element 126 arranged in between the first optical element 108 and the E second optical element 110, and is aligned with the optical axis 104. = Herein, third optical element 126 is employed for geometrical correction 5 and/or colour correction in the measurement device 100.

N In FIG. 1C, the measurement device 100 further comprises a first focusing element 128, and a second focusing element 130. The first focusing element 128 is arranged on an optical path between the object 102 and the first optical element 108. The second focusing element 130 is arranged on an optical path between the second optical element 110 and the proximal end 114. In FIGs. 1A, 1B, and 1C, the viewing object 124 is, for example, a microscope. In FIG. 1D, the second optical element 110 also receives a second beam 132 of light (depicted as dashed arrows) corresponding to information that is to be displayed to a user (not shown) of the measurement device

100. The second beam 132 of light emanates from a first light source

134. The second optical element 110 optically combines the second beam 132 of light with the first translated beam 120 of light to obtain a first combined beam of light (not shown). The second optical element 110 translates the first combined beam of light within itself to the fourth distance d4 and provides a third translated beam 136 of light. Herein, the viewing object 124 is, for example, an eye of the user of the measurement device 100. In FIG. 1E, the first optical element 108 receives a third beam 138 of light emanating from a second light source 140, wherein the third beam 138 of light is directly received by the first element 108 from the second light source 140 without being incident upon the object 102, while in N FIG. 1F, the first optical element 108 receives a reflection of the third O beam 138 of light, wherein the third beam 138 of light is incident upon N and is reflected from the object 102 towards the first optical element s 108.

I 2 25 In FIGs. 1E and 1F, the first optical element 108 optically combines the S third beam 138 of light with the first beam 118 of light to obtain a second 5 combined beam of light (not shown). The first optical element 108 N translates the second combined beam of light within itself to the second distance d2, and provides a fourth translated beam 142 of light. The second optical element 110 receives the fourth translated beam 142 of light at the third distance d3, translates the fourth translated beam 142 of light within itself to the fourth distance d4, and provides a fifth translated beam 144 of light. Herein, the viewing object 124 is, for example, a camera. In FIG. 1F, the measurement device 100 also comprises the first focusing element 128, and the second focusing element 130. In FIG. 1G, the first optical element 108 and the second optical element 110 are implemented as dual optical waveguides. In FIG. 1H, the first optical element 108 and the second optical element 110 are collectively implemented as two lenses 146 and 148 and optical fibres 150, wherein the lens 146 projects the first beam 118 of light on a surface of a bundle of the optical fibres 150, and the lens 148 is employed to match the projected first beam 118 of light to the proximal end 114. In FIGs. 1G and 1H, the viewing object 124 is, for example, an ophthalmology device. In FIG. 11, the measurement device 100 is shown to comprise the third optical element 126 arranged in between the first optical element 108 and the second optical element 110, and a first focusing element 128. The first focusing element 128 can be considered to be part of the first optical element 108. The first focusing element 128 can be used to collimate light from an object or to adjust focal point for visual inspection. N Measurement sensor 112 is arranged on an optical axis of the O measurement device at least partially between the first and the second N optical elements. Referring to FIG. 1J, illustrated is another view of the s implementation of the measuring device 100 of FIG. 11, in accordance E 25 with an embodiment of the present disclosure. The view of FIG. 1J = represents how components of the measuring device 100 are spaced with D respect to each other.

QA & Referring to FIG. 2, illustrated is a volume 200 (depicted as a dotted two- dimensional frustum) in which a measurement sensor 202 of a measurement device 204 is partially fit, in accordance with an embodiment of the present disclosure. The measurement sensor 202 is dimensioned and arranged to fit partially in the volume 200 that is defined by a first optical element 206 of the measurement device 204, a second optical element 208 of the measurement device 204, a second distance d2 from an optical axis 210 of the measurement device 204, and a third distance d3 from the optical axis 210. The measurement sensor 202 is shown to be implemented as a probe 212 arranged on a probe base 214 (depicted as a dotted-hatched element), and wherein the measurement device 204 further comprises a controller 216 configured to control the probe 212 for measuring a property of an object (not shown). For example, the measurement device 204 may be a tonometer that measures an intraocular pressure of an eye. Referring to FIGs. 3A and 3B, FIG. 3A illustrates a given focusing element 302 (depicted, for example, as a convex lens) and a given optical element 304 (depicted, for example, as a dual prism), while FIG. 3B illustrates the given focusing element 302 integrated with the given optical element 304, in accordance with an embodiment of the present disclosure. In FIG. 3A, the given focusing element 302 and the given optical element 304 are employed as separate optical components in a measurement device (not shown). In FIG. 3B, the given focusing element 302 integrated with the given optical element 304 to yield a single N integrated optical component 306 in the measurement device.

N N Referring to FIG. 4, illustrated are different views Z1, Z2, and Z3 of an x object 400 when the object 400 is arranged at various distances from a E 25 distal end 402 of a body 404 of a measurement device (shown partially = for simplicity), in accordance with an embodiment of the present D disclosure. Only a part of the body 404 has been shown for simplicity. As O shown in a top view of the measurement device in use, the object 400 is arranged at a given distance D from the distal end 402. When the given distance D is egual to a predefined distance from the distal end 402, a clear view (i.e., a complete and a distortion-free view, depicted as the view Z1) of the object 400 is provided at a proximal end (not shown) of the body 404. When the given distance D is less than the predefined distance (i.e. when the object 400 is located too near to the distal end 402), a distorted view (depicted as the view Z2) of the object 400 is provided at the proximal end.

When the given distance D is greater than the predefined distance (i.e. when the object 400 is located too far from the distal end 402), another distorted view (depicted as the view Z3) of the object 400 is provided at the proximal end.

The predefined distance may, for example, be 6 millimetres.

Referring to FIG. 5, illustrated are different views Y1, Y2, and Y3 of reflection of a front light Y reflected from an object 500 when the object 500 is arranged at various distances from a distal end (not shown) of a body (not shown) of a measurement device (not shown), in accordance with an embodiment of the present disclosure.

When the object 500 is arranged at a predefined distance from the distal end, a correct view (depicted as the view Y1) of the reflection of the front light Y is provided at a proximal end (not shown) of the body.

When the object 500 is arranged at a distance that is less than the predefined distance from the distalend (i.e. when the object 500 is located too near to the distal end), a distorted view (depicted as the view Y2) of the reflection of the front 3 light Y is provided at the proximal end.

When the object 500 is arranged N at a distance that is greater than the predefined distance from the distal © end (i.e. when the object 500 is located too far from the distal end), 7 25 another distorted view (depicted as the view Y3) of the reflection of the E front light Y is provided at the proximal end.

The predefined distance 2 may, for example, be 6 millimetres.

O Referring to FIG. 6, illustrated are steps of a method for using a measurement device, in accordance with an embodiment of the present disclosure.

At step 602, an object is arranged in proximity of a distal end of a body of the measurement device. At 604, the object is viewed from a proximal end of the body. At step 606, a measurement sensor of the measurement device is controlled for measuring a property of the object. The steps 602, 604, and 606 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. Modifications to embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as "including", "comprising", "incorporating", "have", "is" used to describe and claim the present disclosure are intended to be construed in a non- exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural. Ql

N O N

N <Q +

O

I = 0

LO N O N

Claims

1. A measurement device (100, 204) for measuring a property of an object (102, 400, 500), the measurement device having an optical axis (104, 210), the measurement device comprising: a body (106, 404) having a proximal end (114) and a distal end (116, 402); a first optical element (108, 206) arranged on the distal end, wherein the first optical element is aligned with the optical axis; a second optical element (110, 208) arranged on the proximal end, wherein the second optical element is aligned with the optical axis, characterized in that the measurement device comprising: a measurement sensor (112, 202) arranged at least partially in the body and is implemented as a probe (212) that is arranged on a probe base (214), wherein the measurement sensor is arranged on the optical axis and in between the first optical element and the second optical element; and a controller (216) configured to control the probe (212) for measuring the property of the object (102, 400, 500); wherein, when the measurement device is in use, N 20 - the first optical element receives a first beam (118) of light from N the object, the first beam of light being received at a first distance (d1) S from the optical axis, and the first optical element translates the first S beam of light within itself to a second distance (d2) from the optical axis E and provides a first translated beam (120) of light from the first optical = 25 element, wherein the first distance is less than the second distance; and = - the second optical element receives the first translated beam of & light, the first translated beam of light being received at a third distance (d3) from the optical axis, and the second optical element translates the first translated beam of light within itself to a fourth distance (d4) from the optical axis and provides a second translated beam (122) of light from the second optical element, wherein the fourth distance is less than the third distance; and wherein the measurement sensor is dimensioned and arranged to fit partially in a volume (200) defined by the first optical element, the second optical element, the second distance, and the third distance.

2. A measurement device (100, 204) according to claim 1, wherein the object (102, 400, 500) is arranged, when in use, at a predefined distance from the distal end (116, 402) in order to provide a clear view of the object (102, 400, 500) at the proximal end (114) .

3. A measurement device (100, 204) according to claim 1 or 2, further comprising: a first focusing element (128) arranged on an optical path between the object (102, 400, 500) and the first optical element (108, 206); and a second focusing element (130) arranged on an optical path between the second optical element (110, 208) and the proximal end (114), wherein the first focusing element and the second focusing element are arranged in a manner that a clear view of the object is provided at the proximal end only when the object is arranged at a predefined distance 3 20 from the distal end (116, 402). ©

4. A measurement device (100, 204) according to claim 2 or 3, 7 wherein the first focusing element (128) is integrated with the first optical E element (108, 206) and/or the second focusing element (130) is 2 integrated with the second optical element (110, 208). O 25

5. A measurement device (100, 204) according to any of the preceding claims, wherein a given optical element (108, 110, 126, 206, 208, 304) is implemented as at least one of: a prism, a mirror, a lens

(146, 148), an optical waveguide, an optical fibre (150), a fibre optic plate.

6. A measurement device (100, 204) according to any of the preceding claims, wherein the second optical element (110, 208) also receives a second beam (132) of light corresponding to information that is to be displayed to a user of the measurement device, the second beam of light emanating from a first light source (134), and wherein the second optical element optically combines the second beam of light with the first translated beam (120) of light to obtain a first combined beam of light, further wherein the second optical element translates the first combined beam of light within itself to the fourth distance (d4) and provides a third translated beam (136) of light from the second optical element.

7. A measurement device (100, 204) according to any of the preceding claims, wherein the first optical element (108, 206) also receives a third beam (138) of light emanating from a second light source (140), and wherein the first optical element optically combines the third beam of light with the first beam (118) of light to obtain a second combined beam of light, the first optical element translates the second combined beam of light within itself to the second distance (d2) and provides a fourth translated beam (142) of light from the first optical N element,

S N further wherein the second optical element (110, 208) receives the fourth x translated beam of light at the third distance (d3), translates the fourth = translated beam of light within itself to the fourth distance (d4), and = 25 provides a fifth translated beam (144) of light from the second optical 2 element.

S N 8. A measurement device (100, 204) according to any of the preceding claims, wherein the measurement device is arranged on an optical path between the object (102, 400, 500) and at least one of: a camera, a microscope, a magnifying device, an ophthalmology device, an eye of a user of the measurement device.

9. A measurement device (100, 204) according to any of the preceding claims, wherein the measurement device is one of: a tonometer, a keratometer, a pachymeter, a biometer, an ophthalmoscope, a tear-film analyser.

10. A method for using a measurement device (100, 204) according to any of the claims 1-9, characterized in that the method comprising: - arranging an object (102, 400, 500) in proximity of a distal end (116, 402) of a body (106, 404) of the measurement device; - viewing the object from a proximal end (114) of the body; and - controlling a probe (212) associated with a measurement sensor (112, 202) of the measurement device for measuring a property of the object (102, 400, 500).

11. Amethodaccording to claim 10, wherein the object (102, 400, 500) is arranged at a predefined distance from the distal end (116, 402) in order to provide a clear view of the object at the proximal end (114).

12. A method according to claim 10 or 11, further comprising: N - obtaining information that is to be displayed to a user of the

O N 20 measurement device (100, 204);

N = - controlling a first light source (134) to emit a second beam (132) 7 of light corresponding to the information towards a second optical E element (110, 208) of the measurement device; and 2 - viewing the information from the proximal end (114).

N S 25

13. A method according to any of claims 10-12, further comprising:

- arranging a second light source (140) to emit a third beam (138) of light towards a first optical element (108, 206) of the measurement device (100, 204); and - viewing the third beam (138) of light from the proximal end (114).

14. A method according to any of claims 10-13, further comprising arranging at the proximal end (114), at least one of: a camera, a microscope, a magnifying device, an ophthalmology device, an eye of a user of the measurement device.

Ql

N

O

N

N <Q +

O

I = 0

LO

N

O

N