Optical attachment and method for emitting light

Abstract

An optical attachment (100,200) is disclosed for radiating light (116A,116B) toward a target (106). The optical attachment comprises a hollow body (108,202) of optical waveguide material, the hollow body having a through opening (110,204), an outer surface (112A,206A), an inner surface (112B,206B) opposite the outer surface, a first output facet, and a buttock facet (114B,208B) opposite the first output facet, the buttock facet being configured to receive light from one or more light sources (118A,118B) and guide the received light through the hollow body toward the first output facet. The first output facet is configured to radiate light toward the target when in use, forming a first illuminated image (102,302) of the first output facet on the target.

Description

Technical Field

[0001] The disclosure of the present application (hereinafter referred to as the present disclosure) relates to an optical attachment for emitting light toward a target. The present disclosure also relates to a method of emitting light toward a target. Background

[0002] Generally, organisms (such as humans) may suffer from eye diseases such as glaucoma, ocular hypertension, and retinal detachment. Such eye diseases can be determined by measuring at least one physiological characteristic of the eye using a tonometry method. The tonometry method is carried out using a dedicated device such as a tonometer to measure at least one physiological characteristic of the eye. An example of at least one physiological characteristic is the pressure inside the eye. If this pressure exceeds a predefined pressure range, the optic nerve of the eye may be damaged. This results in vision loss in the eye.

[0003] Existing techniques for measuring the physiological properties of the eye have certain limitations. In the conventional tonometry method, a tonometer is used to measure at least one physiological property of the patient's eye. This tonometer has a magnetic probe for measuring at least one physiological property. The magnetic probe has a round tip and there is a possibility that the operator may accidentally touch it when attaching or detaching it from the tonometer, increasing the risk of infection. Also, the magnetic eye probe needs to be placed at a predetermined distance from the eye and the specific area of the eye surface needs to be measured multiple times for accurate and precise measurement. However, if the position of the patient or the tonometer accidentally changes during the measurement of at least one physiological parameter, the magnetic probe may contact another area of the eyeball surface, resulting in inaccurate measurement results. Furthermore, it is important to perform the measurement at an appropriate distance (not too close and not too far) from the eyeball surface.

[0004] Therefore, based on the above discussion, there is a need to overcome the aforementioned drawbacks associated with the conventional tonometry method for measuring at least one physiological parameter of the eye. Summary

[0005] This disclosure aims to provide an optical attachment for emitting light toward a target. This disclosure also aims to provide a method for emitting light toward a target. The objective of this disclosure is to provide a solution that overcomes, at least partially, the problems encountered in the prior art.

[0006] In one aspect, embodiments of the present disclosure provide an optical attachment for emitting light toward a target. This optical attachment is A hollow body of optical waveguide material comprising a through-opening, an outer surface, an inner surface facing the outer surface, a first output facet, and a rear facet facing the first output facet; The buttock facet is configured to receive light from one or more light sources and direct the received light through the hollow body toward the first output facet; The first output facet is configured to emit light toward a target when in use, thereby forming a first illuminated image of the first output facet on the target.

[0007] In another aspect, embodiments of the present disclosure provide a method for determining the distance between the surface of the eyeball and a tonometer. This method includes using an optical attachment to form a first illuminated image of a first output facet of the optical attachment onto the surface of the eyeball. Embodiments of the present disclosure substantially eliminate, or at least partially eliminate, the aforementioned problems of the prior art, enabling an efficient and dedicated device for emitting light toward a target and for properly aligning the optical attachment toward the target.

[0008] Further aspects, advantages, features, and objectives of what is disclosed herein will be made clearer by the accompanying drawings and the detailed description of exemplary embodiments, as to be interpreted in conjunction with the accompanying claims.

[0009] It will also be understood that a feature of this disclosure is that it can be combined in various ways without departing from the scope defined by the attached claims. [Brief explanation of the drawing]

[0010] The above summary and the following detailed description of exemplary embodiments will be better understood in conjunction with the accompanying drawings. For illustrative purposes of this disclosure, exemplary configurations of this disclosure are shown in the drawings. However, this disclosure is not limited to the specific methods and apparatus disclosed herein. The scale of the drawings is not accurate. Similar elements are indicated by the same number whenever possible. Hereinafter, embodiments of the present disclosure will be described only as examples, with reference to the following drawings. [Figure 1] This is a schematic diagram illustrating the formation of a first and a second illumination image by an optical attachment according to a different embodiment of the present disclosure. [Figure 2] A perspective view and a front view of an optical attachment according to an embodiment of the present disclosure are shown. [Figure 3] This is a schematic diagram showing the formation of a first and second irradiation image on a target according to an embodiment of the present disclosure. [Figure 4] Figures 4A, 4B, and 4C show exemplary schematic diagrams illustrating the formation of a first and second illumination image on a target using an optical attachment, according to embodiments of the present disclosure. [Figure 5] Figures 5A and 5B are cross-sectional views of an optical attachment according to an embodiment of the present disclosure, in use and connected to a tonometer. [Figure 6] An optical attachment comprising a detachable tube according to an embodiment of the present disclosure is shown. [Figure 7] This flowchart shows the steps of a method for emitting light onto a target using an optical attachment having a hollow body of optical waveguide material, according to an embodiment of the present disclosure. [Figure 8] Figures 8A and 8B illustrate how the analogy of a convex mirror can be used according to embodiments of the present disclosure. [Figure 9] Figures 9A, 9B, and 9C show the effect of tonometer distance on the size of the reflected image. [Figure 10] This is a diagram illustrating the viewpoint of the person operating the tonometer. In the attached diagram, underlined numbers are used to represent the item at the location of that number or an item adjacent to that number. Ununderlined numbers are associated with the item identified by the line extending from that number. When a number is written without an underline and accompanied by an arrow, that number is used to identify the general item indicated by the arrow. Detailed description of the embodiment

[0011] The following detailed description illustrates embodiments of the disclosure and methods by which they may be implemented. While several forms for implementing the disclosure have been disclosed, those skilled in the art will recognize that other forms for implementing the disclosure are also possible.

[0012] According to a first aspect, embodiments of the present disclosure provide an optical attachment for emitting light toward a target. This optical attachment is A hollow body of optical waveguide material comprising a through-opening, an outer surface, an inner surface facing the outer surface, a first output facet, and a rear facet facing the first output facet; The buttock facet is configured to receive light from one or more light sources and direct the received light through the hollow body toward the first output facet; The first output facet is configured to emit light toward a target when in use, thereby forming a first illuminated image of the first output facet on the target.

[0013] In a second aspect, embodiments of the present disclosure provide a method for determining the distance between the surface of an eyeball and a tonometer. This method includes using an optical attachment according to the first aspect to form a first projection image of a first output facet of the optical attachment on the surface of the eyeball. The present disclosure provides the aforementioned optical attachment and the aforementioned method. According to embodiments of the present disclosure, the optical attachment is optically efficient due to a hollow optical waveguide material. The optical waveguide material provides an optical path for the emitted light. Thus, the optical attachment functions as an optical waveguide system, aligning the attachment at the required distance from the target. The required distance from the target is visually observable by a user of a measuring device (such as a tonometer). In one example, light forms a first projection image of a first output facet on the target (e.g., the surface of the eyeball). In some embodiments, the first output facet is sized such that the first projection image formed on the target matches the relative size of the details of the target. In some embodiments, the target is the surface of an eyeball, and the first output facet is annular. In this example, a first annular projection image is formed on the surface of the eyeball. The device is at an appropriate distance when the size of this first annular projection image is close to the pupil diameter, for example, approximately 0.8 to 1.2 times the pupil diameter. Advantageously, such optical attachments are easy to manufacture because they do not require advanced manufacturing processes. Optical attachments are simple, lightweight, robust, reliable, and easy to implement.

[0014] The shape of the hollow body is one of a hollow cylinder, a hollow frustum of a cone, or a frustum of a cone. In fact, in some embodiments, the hollow body is cylindrical and frustum of a cone, with a first output facet forming the first base of the frustum and a butt facet forming the second base of the frustum. The first base of the frustum has a first radius. The optical waveguide material of the hollow body allows light to pass through. Examples of optical waveguide materials include, but are not limited to, polypropylene, polycarbonate, and polymethyl methacrylate (PMMA). In some embodiments, the outer surface of the optical attachment faces outward, and the inner surface of the optical attachment faces inward toward the center of the hollow body. In some embodiments, the first output facet is a curved surface on the outside of the hollow body close to the target, and this curved surface is formed between the outer and inner surfaces. Here, the curved surface is either a convex or concave surface similar to the back surface of a hard contact lens. For example, the first radius of curvature of the first output facet may range from 3mm, 4mm, 5mm, 6mm, 7mm, 8mm to 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm. For example, it could be 4mm.

[0015] In some embodiments, the gluteal facet is a flat surface facing the first output facet and located distal to the target. This flat surface is formed between the outer and inner surfaces. The term "through-opening" refers to an opening located in the center of the hollow body and formed based on the shape of the inner surface. For example, the outer surface is angled from the gluteal facet toward the first output facet, and the outer surface of the hollow body is formed to taper toward the gluteal facet toward the first output facet. In another example, the outer surface is angled from the gluteal facet toward the first output facet, and the outer surface of the hollow body is formed to widen toward the gluteal facet toward the first output facet. In yet another example, the outer surface is angled from the gluteal facet toward the first output facet, and the outer surface of the hollow body is formed to be straight toward the gluteal facet toward the first output facet. Similarly, in one example, the inner surface is angled from the buttock facet towards the first output facet, and the inner surface of the hollow body is formed to taper from the buttock facet towards the first output facet. In another example, the inner surface is angled from the buttock facet towards the first output facet, and the inner surface of the hollow body is formed to widen from the buttock facet towards the first output facet. In yet another example, the inner surface is angled from the buttock facet towards the first output facet, and the inner surface of the hollow body is formed to be straight from the buttock facet towards the first output facet.

[0016] In some embodiments, the hollow body is configured to surround an eye probe that is incorporated into the tonometer. The term “tonometer” refers to an optical device used to measure intraocular pressure (IOP) of an eye when the target is the eye. Here, the term “optical device” refers to a device used to measure at least one characteristic of the eye, which may be intraocular pressure, tactile sensitivity, and similar physiological parameters relating to the eye. The term “eye probe” refers to an instrument used to measure intraocular pressure. For example, an eye probe consists of a magnetized steel wire shaft covered with a tip (e.g., a rounded tip). The tonometer is used to handle the movement of the eye probe resulting from its interaction with the eyeball and to accurately measure intraocular pressure. In some examples, the eye probe is detachably attached to the tonometer. In this case, the eye probe is disposable. That is, to reduce the risk of infection, disposable eye probes are discarded after a single use. In other examples, the eye probe is permanently fixed to the tonometer. In this case, the eye probe always maintains the same position relative to the tonometer, ensuring consistent and accurate measurements.

[0017] In some embodiments, the optical attachment is positioned on the tonometer using the buttock facets of its hollow body and is physically supported by the tonometer. The buttock facets of the optical attachment are either detachably or permanently attached to the tonometer. For example, if the optical attachment is detachably attached to the tonometer, it means that the optical attachment is removable. In this case, the optical attachment can be removed from the tonometer and used with another optical device. In another example, if the optical attachment is permanently attached to the tonometer, it means that the optical attachment cannot be removed from the tonometer.

[0018] In some embodiments, the hollow body is configured to surround the eye probe when not in use. The technical advantage of configuring the hollow body to surround the eye probe when not in use is to protect the eye probe from the external environment and maintain its sterility. Another technical advantage is to prevent accidental contact with the eye probe, which can be caused by involuntary blinking of the eyeball. Yet another technical effect is to protect the movement of the eye probe. In other words, the hollow body protects the eye probe when it undergoes rebound movement during intraocular pressure measurement, thereby making the rebound movement error-free.

[0019] In some embodiments, the optical attachment further includes a detachable tube configured to be housed within the through-opening. The detachable tube is configured to house the eye probe for attaching and detaching the eye probe to and from the tonometer. In this regard, the diameter of the detachable tube is smaller than the diameter of the inner surface of the first output facet. Also, the length of the detachable tube is greater than or equal to the length of the eye probe. Further, the length of the detachable tube is greater than the length of the optical attachment. The detachable tube is a hollow cylindrical tube for housing the eye probe. When attaching the eye probe to the tonometer, the detachable tube housing the eye probe is inserted into the through-opening of the optical attachment in order to attach the eye probe to the tonometer through the buttocks facet of the hollow body. Thereafter, when the eye probe is attached to the tonometer, the detachable tube is discharged, and the eye probe is surrounded by the hollow body of the optical attachment. That is, the combination of the optical attachment and the detachable tube functions as a fixed probe applicator for the eye probe, and the eye probe safely drops into the through-opening and is removably attached to the tonometer. When removing the eye probe from the tonometer, the detachable tube is inserted into the through-opening of the optical attachment. Thereafter, the eye probe is discharged into the detachable tube, and the detachable tube housing the eye probe is separated from the tonometer. The technical advantage of the detachable tube that houses the eye probe is to prevent the tip of the eye probe from accidentally contacting during handling of the tonometer when attaching or detaching the eye probe to and from the tonometer. Another technical effect is that different eye probes can be easily exchanged or a damaged or malfunctioning eye probe can be exchanged using the detachable tube without replacing the entire optical attachment. Advantageously, this improves the versatility of the tonometer, as well as the time efficiency and cost efficiency.

[0020] Throughout this specification, the term "light source" refers to an element that emits light. In other words, a light source emits light when it is operating. In some embodiments, the one or more light sources include one or more visible light-emitting diodes. In some embodiments, the one or more light sources are active light sources. This means that the one or more light sources provide light by emitting light themselves. The light can be visible light or near-infrared light. Examples of one or more light sources include light-emitting diodes (LEDs).

[0021] In some embodiments, the one or more light sources can operate to generate various colors of light and light patterns indicating different operating states of the tonometer. Here, different operating states of the optical device can include powering on the tonometer, attaching an eye probe to the tonometer, starting magnetization of the eye probe, ending magnetization of the eye probe, completion of preparation for intraocular pressure measurement by the tonometer, removing the eye probe from the tonometer, and the like. And it is not limited to these. The technical advantage of generating various colors of light and light patterns is to create various visual effects. For example, by generating a pulsating red color, it can indicate that the attachment of the eye probe to the tonometer is inappropriate, or display a green color when the eye probe is positioned at a predetermined distance for measurement implementation.

[0022] In some embodiments, the one or more light sources are electrically connected to a drive circuit. An electrical connection is provided between the one or more light sources and the drive circuit. In this regard, the drive circuit is responsible for controlling the operation of the one or more light sources. The "drive circuit" refers to an electronic circuit that controls various aspects related to the operation of the one or more light sources (for example, on / off of the one or more light sources, etc.). Here, various aspects of the operation can be controlled by controlling the voltage supplied to the drive circuit. The drive circuit receives an input signal from a control system. This control system can be user-defined, automatic, or a combination of both. For example, the drive circuit may be designed to supply a voltage to turn on two of the five light sources of an optical attachment.

[0023] In some embodiments, one or more light sources are spatially arranged on an optical device, and the light emitted from these light sources is received by a first output facet. Alternatively, in some embodiments, one or more light sources are spatially arranged on a buttock facet of a hollow body, and the light emitted from these light sources is received by a first output facet. The shapes of the outer and inner surfaces guide the received light through the hollow body to the first output facet. For example, if the outer and inner surfaces taper from the buttock facet to the first output facet, the received light is guided diagonally based on the taper angle of the outer and inner surfaces.

[0024] In some embodiments, one or more light sources may operate to generate stray light that interferes with the visibility of the eye probe when measuring at least one characteristic of the eye. Here, “stray light” refers to scattered light emitted from one or more light sources through the outer surface of the optical attachment. When the optical attachment is in use and the tonometer is used to measure at least one characteristic of the patient’s eye, this stray light is visualized as a blurred cone of light in front of the eye. This blurred cone of light interferes with the visibility of the tip of the eye probe (by contrast) so that the patient’s eye cannot see the probe (or the tip of the probe) clearly. In other words, the optical attachment acts as the patient’s gaze point while measuring at least one characteristic of the eye. The technical advantage of generating stray light is that the patient’s eyeball stabilizes as they gaze at the stray light, and the eye probe strikes the surface of the eyeball at a right angle, allowing for repeated measurements of at least one characteristic of the eye.

[0025] Throughout this specification, the term “first projection image” refers to the image of the first output facet formed on a target when light is emitted from the first output facet toward the target. In other words, when light received from one or more light sources is projected onto the target via the first output facet through the butt facet of the hollow body, the first projection image of the first output facet is formed on the target. In this regard, in use, the first projection image represents the circular shape of the first output facet. When an optical attachment is used, the formation of the first projection image provides an indicator that the optical attachment is at the required distance from the target. The technical advantage of forming the first projection image is that the first projection image can define whether the optical attachment is at a predetermined distance (i.e., a safe distance or working distance) from the target. For example, the first projection image may be an annular image. If this annular image is approximately the same size as the pupil (e.g., iris), it can be concluded that the device is at the appropriate distance.

[0026] The technical effect of the buttock facet configuration and the use of the first output facet is to achieve precise positioning of the optical attachment (i.e., optical device). In this regard, the buttock facet directs the received light to the target (e.g., the surface of the eyeball). The buttock facet makes it possible to generate a clear projection image on the target, for example, by creating an projection image on the eyeball. This allows medical professionals to visually confirm whether the optical attachment is correctly positioned based on the projection image. Thus, assistance to medical professionals is provided. A further benefit is that since the projection image is formed on the eyeball, medical professionals can determine the positioning of the optical attachment from the image formed on the eyeball.

[0027] In some embodiments, the inner surface has a stepped shape defining a first portion, a second portion, and a second output facet located between the first and second portions. The second output facet is parallel to the first output facet. The buttock facet is further configured to guide the received light through a hollow body towards a second output facet. The second output facet is configured to emit light toward the target so as to form a second illuminated image of the second output facet on the target when in use.

[0028] In this regard, the second output facet is a flat surface on the inside of the hollow body and is located between the first output facet and the gluteal facet. For example, the radius of the second output facet may be 0.5, 1, or 2 millimeters smaller than the radius of the first output facet. The angle of the first part may be the same as or different from the angle of the second part. In one example, the first part is angled from the gluteal facet toward the second output facet and tapers toward the gluteal facet. In another example, the first part is angled from the gluteal facet toward the second output facet and tapers toward the gluteal facet. In yet another example, the first part is angled from the gluteal facet toward the second output facet and is straight toward the gluteal facet. Similarly, in one example, the second portion is angled from the second output facet toward the first output facet and tapers toward the second output facet. In another example, the second portion is angled from the second output facet toward the first output facet and tapers toward the second output facet. In yet another example, the second portion is angled from the second output facet toward the first output facet and is straight toward the second output facet. In some embodiments, the diameter of the second output facet is smaller than the diameter of the first output facet. When the optical attachment is used, the second output facet receives light emitted from one or more light sources. The buttock facet is positioned so that the received light is guided through the hollow body to the second output facet and the first output facet.

[0029] In some embodiments, the "second projection image" refers to the image of the second output facet formed on the target when light is emitted from the second output facet toward the target. In other words, when light received from one or more light sources is projected onto the target via the buttock facet and then the second output facet, a second projection image of the second output facet is formed on the target. In this regard, when in use, the second projection image represents the circular shape of the second output facet. When using an optical attachment, clearly forming the second projection image provides an additional indicator of the required position of the optical attachment relative to the target. For example, the second projection image is annular in shape and has a smaller radius than the first projection image (annular in shape). The technical advantage of forming the second projection image is that the second projection image is smaller than the pupil and the first projection image is larger, meaning that the pupil can be seen between the first and second images. This makes distance measurement more accurate and improves alignment.

[0030] In some embodiments, when the target is the surface of the eyeball and the target is at a predetermined distance (D) from the first output facet, a first projected image having a second radius is formed on the surface of the eyeball. This second radius is 1.0 to 1.2 times the radius of the pupil. For example, if the radius of the pupil is 4 mm, the radius of the first projected image will be 4 mm to 1.2 × 4 = 4.8 mm. The second radius can be set in the range of 1.0, 1.05, 1.1, 1.15 times, up to a maximum of 1.2 times, of the pupil radius.

[0031] Furthermore, if the target is the eyeball and the distance between the surface of the pupil and the first output facet is the predetermined distance (D), the first projected image is formed on the outer diameter of the pupil. Here, "pupil" refers to the circular opening at the center of the iris of the eyeball. "Surface of the pupil" refers to the edge or boundary of this circular opening, located at the junction of the iris and the pupil. Here, the surface of the pupil is the part of the pupil visible from the front of the eyeball. "Outer diameter" refers to the widest part of the pupil at the junction of the iris and the pupil.

[0032] In some embodiments, when the target is at a predetermined distance (D) from the first output facet, a second projected image having a third radius is formed on the eyeball. Here, the third radius is 0.5 to 1.0 times the radius of the pupil. This makes the second image smaller than the pupil, providing an indicator of distance through the second image.

[0033] In some embodiments, when a first illumination image is formed on the outer diameter of the pupil and a second illumination image is formed on the inner diameter of the pupil, a double-ring pattern image is formed on the pupillary surface. The technical advantage of forming a double-ring pattern image is that, when the eyeball is at a predetermined distance (D) from the first output facet, the tip of the eye probe can be precisely aligned in two-dimensional (2D) coordinates, i.e., the X and Y coordinates. This facilitates the optical attachment to function as a rangefinder and alignment device.

[0034] In some embodiments, the first radius (r1) is expressed by the following formula: r1 = -r2 × (Df) / f Here, r² is the second radius, D is a predetermined distance, and f is half the radius of curvature of the eyeball surface. In this disclosure, the eyeball surface can be considered as a convex mirror with a focal length f. For example, the anterior-posterior diameter of an average adult eyeball is approximately 24 millimeters, so its radius is approximately 12 millimeters. This means that the focal length (f) of the eyeball, when treated as a convex mirror, is approximately half the radius of curvature, or approximately 6 mm. According to the mirror equation (see below), the focal length of a convex mirror is considered a negative value, so in this example, f is -6 mm.

[0035] According to the mirror formula (see Figures 8A and 8B): 1 / f = 1 / v + 1 / D Here, f is the focal length, v is the image distance (distance from the surface of the eyeball to the retina), and D is the distance of the first output facet. By rearranging the mirror formula, we can obtain the following equation. v = fD / (Df)

[0036] The magnification formula is as follows: m = -v / D = r² / r¹ Here, r1 is the first radius of the first facet (the radius of the first base of the frustum of the hollow body, i.e., the radius of the first facet when the first facet is circular), r2 is the radius of the first projected image, and m is the magnification.

[0037] The magnification m can be expressed in terms of r2 and r1 as follows: m = r² / r¹

[0038] Substituting the value of v obtained from the mirror formula into the magnification formula, m = -[fD / (Df)] / D = -f / (Df) This allows us to determine the magnification m using the focal length f and distance D.

[0039] To find the first radius r1, we rearrange the scaling formula and solve for r1. r1 = r2 / m Finally, substituting the new expression for m into this equation, we get the following: r1 = r2 / [-f / (Df)] = -r2 * (Df) / f This is the formula that expresses the radius (r1) of the first output facet in a convex mirror as a function of the second radius (r2), the object distance (D), and the focal length (f).

[0040] The size of a human pupil changes depending on various factors such as light intensity, emotional state, age, and certain substances. Regarding light conditions, pupil diameter typically varies from approximately 1.5 mm in very bright light to approximately 8 mm in darkness. The following are approximate values.

[0041] In bright light environments, the pupil may constrict to a diameter of approximately 1.5-2 mm. This is because the eye needs to limit the amount of light entering it to prevent damage and maintain vision.

[0042] Under normal lighting conditions, the pupil tends to be approximately 3-4 mm in diameter. This balance allows for focused vision while still taking in sufficient light.

[0043] In dim light or darkness, the pupil dilates to a diameter of approximately 7-8 mm. This dilation (enlargement) in low-light conditions allows more light to reach the retina, contributing to improved low-light vision.

[0044] In some embodiments, the predetermined distance (D) is the operating range of the tonometer from the first output facet to the surface of the eyeball. The tonometer uses a probe to acquire information such as intraocular pressure (by physical contact). The probe is usually positioned to move from a first position to a second position. For example, the probe is initially in the first position (inside the hollow body), and in the second position, when the tonometer is in use, the tip of the probe protrudes from the first output facet by a predetermined distance D toward the surface of the eyeball.

[0045] In some embodiments, this predetermined distance (D) is in the range of 4 to 8 millimeters. For example, the predetermined distance (D) may be from 4 mm or 5 mm to 6 mm, 7 mm, or 8 mm. Furthermore, in some embodiments, the predetermined distance (D) is in the range of 4 mm to 7 mm. Furthermore, in some embodiments, the predetermined distance (D) is in the range of 4 mm to 6 mm. As mentioned above, D depends, for example, on the type and reach of the tonometer probe.

[0046] In this regard, the first radius can be calculated using the above formula. r1 = -2mm * (6mm + 6mm) / (-6mm) = 4mm (when D = 6mm and pupil radius 2mm). In other words, 4 mm may be considered as the design criterion for the first radius. Depending on the embodiment, the optical illumination output of one or more light sources may be controlled to control the pupil size of the user's eye. Since pupil size changes with illumination conditions, this makes it possible to control the pupil size during measurement. For example, setting the illumination output to be brighter will reduce the pupil size. This makes it possible to control the size in order to obtain a reference distance on the eyeball (compared to the size of the first or second illuminated image). Control can be achieved, for example, by increasing or decreasing the current to the LED when using an LED. "Bright" refers to "daylight level brightness." "Dark" corresponds to a darkroom state.

[0047] This disclosure also relates to the methods described above. The various embodiments and modifications relating to the optical attachments described above also apply mutatis mutandis to these methods.

[0048] In one aspect, a method is provided for determining the distance between the surface of the eyeball and a tonometer. In this method, an optical attachment is used to form a first projection image of the first output facet of the optical attachment onto the surface of the eyeball. This optical attachment is as described above.

[0049] Depending on the embodiment, the tonometer may be moved toward the surface of the eyeball to observe the first radius of the first projected image relative to the pupillary radius. The effect of this is that it is easy for (for example, a physician) to visually confirm whether the device is at an appropriate distance. An appropriate distance refers to a state where the radius of the first projected image is approximately equal to the pupillary radius.

[0050] In some embodiments, the tonometer is at an appropriate distance when the first radius is in the range of 1.0 to 1.2 times the pupillary radius. This has the advantage that the image is formed on the upper part of the iris, making detection easier.

[0051] In some embodiments, the tonometer is used to measure the characteristics of the eye when it is at an appropriate distance. This ensures that the measurement is performed at an appropriate distance, thereby increasing the reliability of the measurement. [Detailed description of the drawing]

[0052] Referring to Figures 1A and 1B, schematic diagrams are shown illustrating the formation of a first illumination image 102 and a second illumination image 104 of an optical attachment 100 that emits light toward a target 106, according to different embodiments of the present disclosure. In the figures, the target 106 is the surface 107 of an eyeball 109. For simplicity, a cross-sectional view of the optical attachment 100 is shown. In Figures 1A and 1B, the optical attachment 100 comprises a hollow body 108 of optical waveguide material. The hollow body 108 has a through opening 110, an outer surface 112A, an inner surface 112B opposite the outer surface 112A, a first output facet 114A, and a back facet 114B opposite the first output facet 114A. The buttock facet 114B is configured to receive light from one or more light sources (indicated as 118A and 118B) and guide the received light through the hollow body 108 toward the first output facet 114A. When in use, the first output facet 114A is configured to emit light toward the target 106. This forms a first illuminated image 102 of the first output facet 114A on the target 106. The first output facet has a first radius r1.

[0053] In Figure 1B, the inner surface 112B has a stepped structure which defines a first portion 122A, a second portion 122B, and a second output facet 114C between the first portion 122A and the second portion 122B. The second output facet 114C is parallel to the first output facet 114A. The buttock facet 114B is further configured to guide the received light through the hollow body 108 toward the second output facet 114C. The second output facet 114C is configured to emit light toward the target 106 when in use, forming a second illuminated image 104 of the second output facet 114C on the target 106.

[0054] Figures 1A and 1B are for illustrative purposes only and do not unduly limit the scope of the claims of this application. Specific embodiments of the optical attachment 100 are provided as examples. Those skilled in the art will be able to recognize many variations, alternatives, and modifications of the embodiments of this disclosure.

[0055] Referring to Figure 2, a perspective view and a front view of an optical attachment 200 according to an embodiment of the present disclosure are shown. The optical attachment 200 comprises a hollow body 202 of optical waveguide material. The hollow body 202 has a through opening 204, an outer surface 206A, an inner surface 206B facing the outer surface 206A, a first output facet 208A, and a rear facet 208B facing the first output facet 208A.

[0056] Figure 2 is for illustrative purposes only and does not unduly limit the scope of the claims of this application. Specific embodiments of the optical attachment 200 are provided as examples. Those skilled in the art will be able to recognize many variations, alternatives, and modifications of the embodiments of this disclosure.

[0057] Referring to Figure 3, schematic diagrams of a first illumination image 302 and a second illumination image 304 formed on a target according to an embodiment of the present disclosure are shown. Here, the target is an eyeball 306. The first illumination image 302 is formed on the outer diameter of the pupil 308 of the eyeball 306. The second illumination image 304 is formed on the inner diameter of the pupil 308 of the eyeball 306.

[0058] Figure 3 is for illustrative purposes only and does not unduly limit the scope of the claims of this application. Those skilled in the art will be able to recognize many variations, alternatives, and modifications of the embodiments of this disclosure.

[0059] Referring to Figures 4A, 4B, and 4C, exemplary schematic diagrams are shown of forming a first illumination image 402 and a second illumination image 404 on a target using an optical attachment 406 according to embodiments of the present disclosure. In Figures 4A, 4B, and 4C, the target is an eyeball 408. In Figure 4A, the first illumination image 402 is unclear. That is, the first illumination image 402 is smaller than the pupil 410 (shown as a dotted circle) of the eyeball 408. This is because the distance D is too far. This occurs when the surface of the pupil 410 is not at a predetermined distance (D) from the first output facet of the optical attachment 406.

[0060] In Figure 4B, the first illuminated image 402 is slightly (1.1 times) larger than the pupil 410. This is because the optical attachment (or its output facet) is correctly positioned at a predetermined distance (D) from the surface of the eyeball.

[0061] Figure 4C shows the case where the eyeball 408 is too close, i.e., closer than the predetermined distance (D). As shown in the figure, the first illuminated image 402 is significantly larger than the pupil 410 (e.g., 1.5 times its radius). This indicates that the device is too close.

[0062] Figures 4A, 4B, and 4C are for illustrative purposes only and do not unduly limit the scope of the claims. Specific embodiments of the optical attachment 406 are provided as examples. Those skilled in the art will be able to recognize many variations, alternatives, and modifications of the embodiments of this disclosure.

[0063] Referring to Figures 5A and 5B, cross-sectional views of the optical attachment 500 mounted on the tonometer 580 are shown. The tonometer 580 includes a probe 582, which can be used to measure the characteristics of the eyeball 508. Figure 5A shows the first output facet of the optical attachment 500 at a predetermined distance D from the surface of the eyeball 508. As shown, a first illuminated image 502 is formed around the pupil 510. The probe 582 is located inside the hollow body of the optical device. When the distance is deemed appropriate (based on visual indicators), the probe can be moved from the internal position to the external position (measurement position), as shown in Figure 5B. In this figure, the probe contacts the surface of the eyeball and the characteristics of the eyeball are measured. In this way, it is possible to control that the measurement is performed within the operating range (in this example, the reach of the probe), i.e., within a predetermined distance.

[0064] Figure 5 is for illustrative purposes only and does not unduly limit the claims of this specification. Those skilled in the art will be able to recognize many variations, alternatives, and modifications of embodiments of this disclosure.

[0065] Referring to Figure 6, an optical attachment 600 with a removable tube 602 according to an embodiment of the present disclosure is shown. The optical attachment 600 is either removablely or permanently attached to the tonometer 604. The removable tube 602 is configured to be housed within a through-opening of the optical attachment 600. The removable tube 602 is configured to house an eye probe for attaching and detaching the eye probe from the tonometer 604.

[0066] Figure 6 is for illustrative purposes only and does not unduly limit the scope of the claims of this application. Those skilled in the art will be able to recognize many variations, alternatives, and modifications of the embodiments of this disclosure.

[0067] Referring to Figure 7, a flowchart is shown illustrating the steps of a method for radiating light toward a target using an optical attachment having a hollow body of optical waveguide material, according to an embodiment of the present disclosure. In step 702, light from one or more light sources is received by the butt facet of the hollow body. The hollow body further has a through opening, an outer surface, an inner surface opposite the outer surface, and a first output facet opposite the butt facet. In step 704, the light received through the hollow body is directed toward the first output facet. In step 706, the light from the first output facet is directed toward the target, forming a first illuminated image of the first output facet on the target. Figures 8A and 8B illustrate that the eyeball 808 can be considered as a convex mirror type object. In Figure 8A, an arrow with a height of first radius r1 (corresponding to the radius of the first output facet) is shown at a distance D=D1. A virtual image (arrow) inside the eyeball 808 is formed at a distance v from the surface of the eyeball. The height of this virtual image corresponds to the second radius r2. The focal point f of a convex mirror (a generalization of the eyeball) is shown. The focal point f is approximately half the radius of the eyeball. Figure 8B shows that the closer the arrow (optical attachment), the larger the image becomes. In Figure 8B, the given distance D is D2, which is smaller than D1.

[0068] Figure 9A shows a situation where the first output facet 914A, which emits light, is too close (2.5 mm) to the eyeball 908. This is indicated by the first projected image 912 being larger than the pupil 910. The solid and dashed lines represent rays that form a virtual image on the convex mirror-like surface of the eyeball. The X-axis represents the distance from the surface of the eyeball (in millimeters). In Figure 9A, it is located 2.5 mm from the surface.

[0069] In the tonometer shown in Figure 9B, the first output facet is at the correct (predetermined) distance of approximately 6 mm. In the figure, the radius of the first output facet is approximately 4 mm. This dimensional setting yields the current image size shown in Figure 9B for adult patients. The halo of light formed around the pupil has been found to be a good and reliable indicator for physicians operating the tonometer. In practice, if a physician can confirm that the first image matches the size of the pupil, they can safely operate the tonometer.

[0070] Figure 9C illustrates the situation when the tonometer (and therefore the first output facet) is too far away (more than 10 mm). The first illuminated image is smaller than the pupil.

[0071] Figure 10 shows an illustration of the eyeball 1008 as seen from the direction in which the tonometer is used. The first illuminated image 1010 is drawn as a grayscale circle. The pupil 1010 is shown as a solid black circle. The image in the upper left shows the case where the tonometer (and the first output facet of the device attached to the tonometer) is too far away. The first illuminated image is smaller than the pupil. The image in the upper right shows the case where the tonometer (and the first output facet of the device attached to the tonometer) is too close. The first illuminated image is larger than the pupil. The image in the lower left shows the case where the tonometer (and the first output facet of the device attached to the tonometer) is at the appropriate distance. The first illuminated image is the same size as the pupil. The image in the lower right shows the case where the tonometer (and the first output facet of the device attached to the tonometer) is too far away and off-center from the pupil. The first projected image is smaller than the pupil and does not have the same center as the pupil. In fact, this is an added benefit; that is, if the center of the first projected image coincides with the center of the pupil, the alignment is correct.

[0072] The steps described above are merely illustrative, and alternative steps may also be included. That is, one or more steps may be added, one or more steps may be omitted, or one or more steps may be performed in a different order without departing from the scope of the attached claims.

[0073] It is possible to modify the embodiments of this disclosure described above without departing from the scope defined by the attached claims. Expressions such as “includes,” “equip,” “incorporates,” “possesses,” and “is” used to describe and claim this disclosure are intended to be interpreted non-exclusively, that is, to allow for the existence of items, parts, or components not expressly described. The absence of explicit indication that an element is plural does not preclude the existence of multiple such elements.

Claims

1. An optical attachment for emitting light towards a target, Equipped with a hollow body of optical wave guide material, The hollow body has a through opening, an outer surface, an inner surface facing the outer surface, a first output facet, and a buttock facet facing the first output facet. The buttock facet is configured to receive light from one or more light sources and guide the received light through the hollow body toward the first output facet. The first output facet is configured to emit light toward the target so as to form a first illumination image of the first output facet on the target when in use. Optical attachment.

2. The optical attachment according to claim 1, wherein the hollow body is cylindrical and frustoconical, the first output facet forms the first base of the frustoconical, the butt facet forms the second base of the frustoconical, and the first base has a first radius.

3. The inner surface has a stepped shape defining a first portion, a second portion, and a second output facet located between the first portion and the second portion, wherein the second output facet is parallel to the first output facet. The buttock facet is further configured to guide the received light through the hollow body toward the second output facet, The second output facet is configured to emit light toward the target so as to form a second illumination image of the second output facet on the target when in use. The optical attachment according to claim 1 or 2.

4. The optical attachment according to any of the preceding claims, wherein when the target is the surface of an eyeball and the target is at a predetermined distance from the first output facet, the first projected image having a second radius is formed on the surface of the eyeball, wherein the second radius is 1.0 to 1.2 times the radius of the pupil of the eyeball.

5. The optical attachment according to claim 3 or 4, wherein when the target is at a predetermined distance from the first output facet, a second illuminated image having a third radius is formed on the eyeball, wherein the third radius is 0.5 to 1.0 times the radius of the pupil of the eyeball.

6. The optical attachment according to claim 4 or 5, wherein the predetermined distance (D) is the operating range of the tonometer from the first output facet to the surface of the eyeball.

7. The first radius (r1) is, r1=-r2×(D-f) / f The optical attachment according to any one of claims 2 to 6, wherein r2 is the second radius, D is the predetermined distance, and f is half the radius of curvature of the surface of the eyeball.

8. The optical attachment according to any one of claims 3 to 6, wherein the predetermined distance (D) is in the range of 4 millimeters to 8 millimeters.

9. The optical attachment according to any one of claims 3 to 8, wherein the first radius is in the range of 3 millimeters to 10 millimeters.

10. The optical attachment according to any of the preceding claims, wherein the hollow body is configured to surround the eye probe of the tonometer.

11. The optical attachment according to claim 10, comprising a removable tube configured to be housed within the through-opening, wherein the removable tube is configured to house the eye probe for attaching to and detaching the eye probe from the tonometer.

12. The optical attachment according to any of the preceding claims, wherein one or more light sources may operate to generate stray light that interferes with the visibility of the eye probe when measuring at least one characteristic of the eye.

13. An optical attachment according to any of the preceding claims, wherein the illumination output of one or more light sources is controlled to control the size of the pupil of the user's eye.

14. A method for determining the distance between the surface of an eyeball and a tonometer, comprising forming a first illuminated image of a first output facet of an optical attachment described in any one of claims 1 to 13 on the surface of the eyeball.

15. The method according to claim 14, comprising moving the tonometer toward the surface of the eyeball and observing the first radius of the first illuminated image relative to the pupillary radius.

16. The method according to claim 15, wherein the tonometer is at an appropriate distance when the first radius is between 1.0 and 1.2 times the pupillary radius.

17. The method according to claim 16, wherein the tonometer is used to measure the characteristics of the eye when it is at an appropriate distance.

Images