Body-mountable multi-spot laser indirect ophthalmoscope (LIO) system

Abstract

An optical module for a multi-spot Laser Indirect Ophthalmoscope (LIO) system, the optical module comprising: a housing, a fiber-optic input port for receiving at least one light beam via an optical fiber along an input direction, a scanning mirror, and an output aperture for directing at least one output beam along an output beam direction.

Description

[0001] Body-mountable multi-spot Laser Indirect Ophthalmoscope (LIO) system

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to a laser apparatus for ophthalmic treatment, in particular a body mounted multi-spot laser indirect ophthalmoscope (LIO) system.

[0004] BACKGROUND OF THE INVENTION

[0005] Laser-based ophthalmic treatment, such as laser photocoagulation, is a well-established practice within ophthalmology for treating diseases such as glaucoma, diabetic retinopathy, wet age-related macular degeneration (AMD), and other retinal diseases.

[0006] Ophthalmologists are medical specialists dealing with diagnosing and treating the eyes of patients. Some of these treatments involve delivering laser energy to the patient’s eye. In these treatments, doctors regularly set and update parameters for the laser energy to be delivered. These parameters can include power, exposure duration, repeat interval, among other examples.

[0007] Commonly, slit lamps and slit lamp adapters are used for delivering laser energy to the patient’s eye. In these systems, the patients sit up in an examination chair, rest their chin on a chin rest, and place their forehead against a forehead band, both of which keep the patient’s head in place during the procedure. However, some patients are unable to sit at a slit lamp due to the patient’s age, size, or health condition, among other factors.

[0008] A laser indirect ophthalmoscope (LIO) is a head-mounted device, worn by the doctor to deliver laser energy into a patient’s eye. During procedures that use the LIO, the doctor typically moves around the patient to deliver the laser energy to the desired portions of the retina, where the patient is usually in a supine position. For example, US 2019 I 0290121 discloses a body-mounted laser-indirect ophthalmoscope (LIO) system for delivering laser energy into the eye of a patient. This prior art system includes a wearable assembly which secures a control unit, laser module, and / or power module (including a battery) to the body of the user. The control unit receives activation signals and parameter information from an activation unit, e.g. a mobile computing device, and controls the laser energy emitted by the laser module based on the parameter information.

[0009] Photothermal ophthalmic therapy typically involves directing a treatment beam, in particular a treatment laser beam, onto a location on a structure in the subject's eye, in particular the retina. In this respect, it is often desirable to direct the laser energy to multiple locations within a target area of the retina. Photothermal ophthalmic treatment may be performed point-by-point (single spot delivery), where each individual dose of radiation is directed and delivered to a selected target position on the structure to be treated. The treatment beam may be individually directed to the respective selected treatment positions by a physician. To this end, an aiming laser beam at a visible wavelength different from the treatment wavelength, is typically used in conjunction with, in particular prior to, a treatment laser beam. The aiming laser beam, sometimes also referred to as a pilot beam, indicates the treatment location on the retina or other structure, which is subsequently to be treated by the treatment laser beam. Each dose at each treatment location is individually initiated by the physician, e.g. by activating a foot switch.

[0010] Point-by-point (single spot) treatment tends to be a lengthy procedure, in particular when a large number of treatment locations are needed. This increases treatment costs, may cause physician fatigue as well as discomfort for the patient being treated. Ultimately, this may cause a prematurely terminated treatment, in which case the patient is left undertreated or needs to return at a later date to finish treatment.

[0011] Several approaches have been suggested in an attempt to reduce treatment times. One such approach involves multi-spot treatment (pattern Laser treatment) where the aiming beam is controlled to indicate multiple treatment locations and where the physician can activate a sequence of doses, which are then automatically directed to multiple treatment locations.

[0012] US 2023 / 0414412 discloses an apparatus for photothermal ophthalmic treatment comprising: a treatment light source for producing a treatment beam, a scanning module configured for delivering the treatment beam onto separate treatment locations within a treatment target area on a structure of a subject's eye, an aiming light source for producing an aiming beam, wherein the scanning module is configured for delivering the aiming beam to create a visible outline pattern on the structure of the subject's eye, the visible outline pattern being indicative of a periphery of said treatment target area, wherein the visible outline pattern includes one or more pattern elements, each pattern element perceivable as moving along the periphery.

[0013] Compared to single-spot treatment, multi-spot treatment often requires a more complicated optical system, in particular because a multi-spot system needs to be able to automatically direct an output beam to multiple treatment spots. This should be done in quick succession, accurately and reliably. The more complex optical design normally renders such a system to be large in size and heavy. However, in particular in the context of LIO systems, a compact and light-weight design is important to make the system suitable for head-mounting such that the ophthalmologist can wear the LIO system over longer periods of time without experiencing fatigue.

[0014] SUMMARY In view of the above, it remains desirable to provide a multi-spot LIO system that mitigates one or more of the disadvantages of prior art systems or that at least can serve as an alternative.

[0015] According to a first aspect, disclosed herein are embodiments of an optical module for a multi-spot Laser Indirect Ophthalmoscope (LIO) system, the optical module comprising:

[0016] - a housing,

[0017] - a fiber-optic input port for receiving at least one light beam via an optical fiber along an input direction,

[0018] - a scanning mirror, and

[0019] - an output aperture for directing at least one output beam along an output beam direction.

[0020] The housing may accommodate the input port, the scanning mirror, and the output aperture. It will be appreciated that the housing may accommodate additional components. In some embodiments, the housing has an output end and an input end, opposite the output end, wherein the output aperture is located at the output end, and wherein the fiber-optic input port is configured such that, when the optical module is attached to a head-worn assembly of an LIO system, a fiber-optic cable connected to the fiber-optic input port extends upwardly from the housing of the optical module. The fiber-optic input port may be arranged at the output end or at a side of the housing, e.g. a side extending between the input end and the output end. Accordingly, despite the presence of a scanning mirror in the optical module, the beam path within the optical module can be made very compact such that the optical module as a whole can be made compact, in particular such that the optical module has an elongated shape having a relatively small width, thereby making it more suitable for mounting to a head-worn assembly. Moreover, the fiber-optic cable can be led to another position of the head-worn assembly in a manner that reduces the risk of the fiber-optic cable being damaged when the ophthalmologist moves around. In addition, the upward direction of the fiber-optic cable allows the cable to be led to the back of the head-worn assembly such that a headband can easily be adjusted to the head of the doctor.

[0021] In some embodiments, the input direction and the output beam direction are codirectional with each other, i.e. point in the same general direction. In particular, they may both be directed in a downward direction when the optical module is attached to a head-worn assembly of an LIO system. The input direction and the output beam direction may be parallel with each other or define an acute angle between them. Preferably, the acute angle is between 0° and 45°, such as between 1 ° and 45°, preferably between 10° and 40°, more preferably between 20° and 40°, such as between 30° and 40°.

[0022] In some embodiments, the housing has a height, a width and a depth, the height being defined between the input end and the output end, and the width and depth being defined along respective directions orthogonal to the direction defined between the input end and the output end, wherein the depth and the width are each smaller than the height, i.e. the optical module has an elongate shape making it suitable for head-mounting. In some embodiments, the height is between 50 mm and 100 mm, such as between 60 mm and 90 mm, such as between 70 mm and 90 mm. The width and the depth may each be less than 70% of the height, preferably less than 60 % of the height. For example, the width may be between 30 mm and 50 mm, such as between 35 mm and 45 mm. The depth may be between 30 mm and 60 mm, such as between 50 mm and 50 mm.

[0023] In some embodiments, the optical module is configured, when mounted to a head-worn assembly of an LIO system, to output the at least one output beam along a downward output beam direction. In some embodiments, the optical module is configured, when mounted to a head-worn assembly of an LIO system, to output the at least one output beam along an output beam direction towards a bending mirror mounted to the head-worn assembly and external to the housing of the optical module. The bending mirror may be configured to redirect the output beam towards and eye of a subject to be treated, i.e. away from the ophthalmologist wearing the head-worn assembly. The bending mirror may be semi-transparent to allow a portion of light received from the eye of the subject to be treated to be viewed by the ophthalmologist through the bending mirror.

[0024] The scanning mirror is configured to reflect incident light, in particular the received light, and to selectively direct the reflected light along respective directions, e.g. according to a predetermined scanning pattern, in particular a 2D scanning pattern. To this end, the optical module may comprise a mirror controller configured to control the scanning operation of the scanning mirror. The mirror controller may be configured to receive a control signal indicative of a desired scan pattern, e.g. a predetermined or user- selected scan pattern, and to control the scanning operation based on the desired scan pattern. The scanning mirror may thus allow the optical module to automatically direct the output beam towards respective target locations on the retina of the eye of a subject to be treated so as to provide a multispot treatment. The optical module may be configured to consecutively direct the output beam towards respective target locations one at a time and in a sequential order. The scanning mirror may be a MEMS mirror, thereby providing a particular compact design. Alternatively, the scanning mirror may be another suitable scanning mirror, such as a scanning galvo mirror.

[0025] In some embodiments, the optical module further comprises a redirecting mirror in addition to, and separate from, the scanning mirror, thereby providing a folded beam path which allows for a particularly compact beam path and a particularly compact optical module. In particular, in some embodiments, the scanning mirror and the redirecting mirror are configured to direct the at least one received light beam along a z-shaped beam path between the fiber-optic input port and the output aperture, the z-shaped beam path being defined by the input direction, an intermediate beam path and the output beam direction, the intermediate beam path extending between the scanning mirror and the redirecting mirror. Moreover, in some embodiments, the scanning mirror is configured to direct the at least one light beam along an intermediate beam path to the redirecting mirror, and the redirecting mirror is configured to direct at least a reflected portion of the at least one light beam along the output beam direction through the output aperture. The intermediate beam path and the output beam direction may define an acute angle between them, the acute angle being between 1 ° and 45°, such as between 10° and 40°, such as between 20° and 30°. Alternatively, or additionally, the input direction and the intermediate beam path may define an acute angle between them, the acute angle being between 1 ° and 45°, such as between 10° and 40°, such as between 20° and 30°. The small angles reduce the polarization dependence of the optical system and facilitate a compact design. The z-shaped beam path allows the large components, in particular the scanning mirror and the redirecting mirror, to be displaced along the longitudinal direction of the optical module, i.e. along the direction between the output end and the input end of the optical module. This in turn allows the optical module to be compact in the lateral directions, orthogonal to the longitudinal directions.

[0026] In some embodiments, the z-shaped beam path is a three-dimensional beam path in more than a single plane so as to allow for a particularly compact arrangement of the optical components of the optical module. In particular, in some embodiments, the input direction and the intermediate beam path together define a first plane, and the intermediate beam path and the output beam direction together define a second plane, wherein the first and second planes are non-parallel relative to each other. In particular, the first plane may define a first normal vector of the first plane, and the second plane may define a second normal vector of the second plane, wherein the angle between the first and second normal vectors is 30° or more.

[0027] The optical module may comprise a collimating lens for collimating the input light received at the input port and for directing the collimated input light as a collimated input beam towards the scanning mirror. In some embodiments, the optical module further comprises a focusing lens arranged along an intermediate beam path between the scanning mirror and the redirecting mirror. Accordingly, the focusing lens may cause the light beam to converge towards the redirecting mirror. In some embodiments, rather than focusing the light beam onto the redirecting mirror, the focusing lens may define a virtual image plane that does not coincide with the redirecting mirror. The virtual image plane may correspond to a virtual image of the end facet of the optical fiber that delivers the input light at the input port. In particular, in some embodiments, the focusing lens defines a virtual image plane at a position along the output beam direction between the redirecting mirror and the output aperture, thereby causing the light beam to have a small beam waist around the location of the virtual plane so that the focusing lens and the redirected light beam along the output beam direction can be arranged next to each other in a very compact manner.

[0028] In some embodiments, the optical module comprises an output lens. The output lens may define the output aperture of the optical module. Alternatively, the output aperture may be defined by another suitable component of the optical module. The output lens may be configured to provide the output beam as a focused beam or as a collimated beam, in particular so as to deliver the output beam at a desired spot size and working distance. The output lens is typically a relatively large component. In embodiments using the z-shaped beam path described herein, the output lens, the scanning mirror and the redirecting mirror may be conveniently distributed along the longitudinal direction of the optical module in a spacesaving configuration. In particular, the output lens, the scanning mirror and the redirecting mirror may be arranged at respective distances from the output end of the housing.

[0029] In some embodiments, the optical module comprises a mirror controller for controlling the scanning mirror, thereby providing a reliable and robust optical module, e.g. by reducing or even eliminating the need for high-speed control signals, which may be susceptible to noise or signal interferences, to be transmitted between an external control unit and the optical module. It will be appreciated, however, that the mirror controller may be configured to control the scanning mirror responsive to control signals received from an external module, e.g. so as to trigger initiation of the scanning operation and / or so as to select a scan pattern. However, such control signals may be implemented as digital signals that do not need to be transmitted at a high rate corresponding to the scanning rate of the scanning mirror. The mirror controller may be embodied as any suitable digital and / or analogue control circuit.

[0030] In some embodiments, the optical module comprises a data communication interface for communicating with a control circuit of the LIO system, e.g. with a laser module and / or with another control unit. The communication interface may be a wireless or a wire communication interface.

[0031] In some embodiments, the optical module comprises a power input for receiving operating power from a power source of the LIO system, e.g. from or via a laser module and / or directly from another power source, thereby avoiding the need for integrating a power source into the optical module.

[0032] When the optical module receives the control signals, the light beam and the operating power from a single control unit, e.g. from a laser module, the optical fiber for transmitting the light beam and the electrical transmission lines for transmitting control signals and operating power may be combined into a single, combined fiber-optic and electronic cable connecting the control unit and the optical module. The fiber-optic cable may thus be a combined fiber-optic and electrical cable that accommodates an optical fiber and one or more electrical transmission lines. In some embodiments, the laser module may receive signals, e.g. sensor signals, from the optical module. Transmission lines for such sensor signals may also be provided by said combined cable or otherwise.

[0033] In some embodiments, the optical module further comprises at least one detector for detecting at least one property of the received at least one light beam. The detector may detect said at least property at a suitable position along the beam path through the optical module, e.g. by detecting the at least one property of the received at least one light beam after being reflected by the scanning mirror. The at least one detector may comprise a photodetector for measuring a quantity indicative, or at least related, to the power of the received at least one light beam, in particular of the received at least one light beam after being reflected by the scanning mirror. The quantity indicative of the power may be the power or a related quantity dependent on the power, e.g. the intensity, luminous flux or the like. Accordingly, the at least one property may include the power of the received at least one light beam, in particular of the received at least one light beam after being reflected by the scanning mirror, or a quantity that depends on or is indicative of said power. By measuring the power, or a related quantity, of the received light beam, the integrity of the fiber-optic connection may be monitored, and a defective or degraded fiber-optic connection may reliably be detected, thereby providing a reliable and robust LIO system. The fiberintegrity monitoring may be performed by the optical module itself or by an external control unit. Accordingly, in some embodiments, the optical module further comprises a fiber-integrity monitoring circuit configured to receive information indicative of the detected property and to use the received information to perform integrity monitoring of the optical fiber, and / or wherein the optical module is further configured to output a signal indicative of the detected property to an external fiber-integrity monitoring circuit for detecting integrity of the optical fiber.

[0034] Alternatively, or additionally, to the detection of the power of the light beam, the at least one detector may detect the beam direction of the light beam after being redirected by the scanning mirror. Accordingly, in some embodiments, the at least one detector comprises a beam direction detector for detecting a beam direction of the received at least one light beam after being reflected by the scanning mirror and / or a beam position detector for detecting a beam position of the received at least one light beam after being reflected by the scanning mirror. The beam direction of the light beam after being redirected by the scanning mirror may conveniently be detected by a beam position detector that detects the position of the light beam coming from the scanning mirror and impinging on a detection area of the beam position detector. Accordingly, in some embodiments, the beam direction detector comprises a beam position detector configured to detect a beam position of the at least one received light beam after being reflected by the scanning mirror. When the beam position detector is arranged to receive at least partially focused light from the focusing lens, in particular when the beam position detector is located at a position at or close to the virtual image plane of the focusing lens, an accurate position detection is facilitated. The position detector may be a position-sensitive photodetector (PSD), a two- dimensional CMOS / CCD detector, a quadrant photodetector, or the like.

[0035] In some embodiments, the photodetector and the beam position detector are provided as a combined position-sensitive photodetector configured to measure the power and beam position of the at least one received light beam after being reflected by the scanning mirror, thereby providing a comprehensive monitoring system with only a few components and in a compact and light-weight manner. The detected beam directions may be used to monitor operation of the scanning mirror. To this end, in some embodiments, the optical module further comprises a scanning mirror monitoring circuit configured to receive information indicative of the detected beam direction and / or beam position and to use the received information to perform fault detection of the scanning mirror and / or wherein the optical module is configured to output a signal to an external scanning mirror monitoring circuit for performing fault detection of the scanning mirror. For example, fault detection may comprise a comparison of a detected pattern of beam positions with a target pattern, in particular the predetermined pattern the scanning mirror has been controlled to perform. If the deviation between the detected pattern and the target pattern exceeds an acceptable level, the scanning mirror monitoring circuit may issue a corresponding alert signal.

[0036] The at least one light beam may include a treatment beam having a treatment beam wavelength and a treatment beam power. The treatment beam wavelength and the treatment beam power may be selected to be suitable for optical treatment of a subject's eye, in particular of the retina of a subject’s eye, e.g. by photocoagulation or photothermal treatment. Alternatively, or additionally, the at least one light beam may include an aiming beam having an aiming beam wavelength and an aiming beam power. The aiming beam wavelength and the aiming beam power may be selected such that the aiming beam is visible to a human observer and preferably such that the aiming beam does not have a therapeutic or even detrimental effect on the subject's eye. In particular, the aiming beam wavelength may be different from the treatment beam wavelength and / or the aiming beam power may be lower than the treatment beam power.

[0037] In some embodiments, the treatment beam power is between 10 mW - 3 W. In some embodiments, the aiming beam power is between 0.1 pW and 5 mW. In some embodiments, the treatment beam wavelength is between 512-580 nm, preferably between 512-535 nm. The treatment beam wavelength may be defined as the wavelength at which most optical power of the treatment beam is emitted. The Full Width Half Maximum (FWHM) spectral width of the diode laser output is typically 2-4 nm.

[0038] The optical module may be configured to receive the treatment beam and the aiming beam at the fiber-optic input port via the same optical fiber. The optical module may be configured to receive the treatment beam and the aiming beam at the fiber-optic input port concurrently or one at a time, e.g. alternatingly. To this end, a laser module separate from the optical module may be configured to selectively feed the treatment beam or the aiming beam into the optical module via the optical fiber.

[0039] In some embodiments, the detector for detecting the beam direction and / or the beam position is configured to detect respective beam directions and / or beam positions of each of the treatment beam and the aiming beam. In particular, when the optical module receives the aiming and treatment beam one at a time, the detector for detecting the beam direction and / or beam position does not need to be able to detect whether it currently receives the aiming or the treatment beam, as the optical module may receive that information as a control signal from the laser module(s) providing the treatment and aiming beams.

[0040] In some embodiments, the redirecting mirror is a partially reflecting and partially transmitting redirecting mirror, wherein the scanning mirror is configured to direct the light beam along an intermediate beam path to the redirecting mirror, and wherein the redirecting mirror is configured to direct a reflected portion of the light beam along the output beam direction through the output aperture, and to direct a transmitted portion of the light beam to the at least one detector. A partially reflecting and partially transmitting mirror will also be referred to as a partial mirror. Accordingly, the detector may be positioned behind the redirecting mirror, when seen from the scanning mirror, thereby providing a compact arrangement. Moreover, in embodiments with a focusing lens arranged between the scanning mirror and the redirecting mirror, the detector receives an at least partially focused beam, thereby providing an accurate detection. The wavelength-selective reflectance and transmittance properties of the redirecting mirror may be provided by a suitable coating of the redirecting mirror.

[0041] In some embodiments, the transmittance of the redirecting mirror is wavelength-dependent, in particular such that the wavelength-dependent transmittance is higher at the aiming beam wavelength than at the treatment beam wavelength, e.g. at least 10 times higher, such as at least 50 times higher. Accordingly, even when the aiming beam power is much smaller than the treatment beam power, the difference of the optical power transmitted by the redirecting mirror and received at the detector positioned behind the redirecting mirror is less pronounced. Accordingly, the detector does not need a large range of possible gain settings while still being able to detect both the treatment and the aiming beam.

[0042] The present disclosure relates to different aspects including the optical module described above and in the following, corresponding apparatus, systems, methods, and / or products, each yielding one or more of the benefits and advantages described in connection with the first mentioned aspect, and each having one or more embodiments corresponding to the embodiments described in connection with the first mentioned aspect and / or disclosed in the appended claims.

[0043] In particular, according to one aspect, the present disclosure relates to a multi-spot laser indirect ophthalmoscope (LIO) system, comprising:

[0044] - a head-worn assembly,

[0045] - an embodiment of the optical module described above and in the following, - a laser module for creating at least one light beam, and

[0046] - an optical fiber configured to feed the created light beam from the laser module to the fiber-optic input port of the optical module, wherein the optical module is attached or attachable to the head-worn assembly such that the optical module is positioned in front of a user's forehead when the head-worn assembly is worn by the user.

[0047] The optical module may be attached to the head-worn assembly such that the optical module is positioned in front of the user's head when the user wears the head-worn assembly. The optical module may be integrated with, or otherwise permanently attached to, the head-worn assembly, or it may be removable / detachably attached. The laser module may be or include a control unit for controlling operation of the optical module. Accordingly, the laser module may be communicatively coupled to the optical module. Alternatively, the control of the optical module may be implemented by a control unit separate from the laser module.

[0048] In some embodiments, the laser module comprises a detector for detecting at least one property of the at least one light beam created by the laser module. In some embodiments, the system further comprises a fiberintegrity monitoring circuit configured to monitor integrity of the optical fiber based on information about the detected at least one property of the at least one light beam created by the laser module and further based on information about the detected at least one property of the at least one light beam received by the optical module, in particular of the at least one light beam received by the optical module and reflected by the scanning mirror. As described herein, the at least one property may include a quantity indicative of the power of the created light beam and of the received or reflected light beam, respectively. The fiber-integrity monitoring circuit may be provided as part of the laser module, of the optical module or of a control unit different from the laser module and different from the optical module. The fiber-integrity monitoring circuit may e.g. monitor a difference or ratio between the power or other suitable quantity of the light beam created by the laser module and of the light beam received at the optical module, e.g. after having been reflected by the scanning mirror. For example, if the difference or ratio changes, e.g. beyond a predetermined threshold, the fiber-integrity circuit may output an alert signal indicative of a possible degradation of the optical fiber.

[0049] In some embodiments, the laser module is attached or attachable to the head-worn assembly. In other embodiments, the laser module may be mounted to a belt or be otherwise wearable by the user, thereby increasing the mobility of the user when operating the LIO system. In yet further embodiments, the laser module may be provided as a desk-top unit or otherwise.

[0050] In some embodiments, the laser module or a separate control unit is configured to forward a scanning control signal for controlling the scanning mirror of the optical module to sequentially direct the output beam towards multiple treatment sites.

[0051] In some embodiments, the laser module or a separate control unit is configured to receive a detector signal from the at least one detector of the optical module.

[0052] In some embodiments, the laser module includes a power output for providing operating power to the optical module. Accordingly, the laser module may include a power source or be configured to receive operating power from an external power supply. Alternatively, the optical module may receive operating power directly from a separate power supply unit.

[0053] In some embodiments, the laser module comprises:

[0054] - a treatment light source configured to generate a treatment beam having a treatment beam wavelength and a treatment beam power; - an aiming light source configured to generate an aiming beam having an aiming beam wavelength different from the treatment beam wavelength and having an aiming beam power lower than the treatment beam power.

[0055] The laser module may be configured to emit a high-power treatment beam, e.g. a green or yellow treatment beam, and to direct the treatment beam to the optical module via a fiber-optic connection, in particular via the fiberoptic cable. The optical module then directs the treatment beam, via a bending mirror, through the pupil of the patient and focused on the retina. The treatment beam power is sufficiently high to cause changes on the retina. During a treatment session, the doctor is viewing the retina so that he / she can aim the treatment beam at appropriate locations, in particular to cause automatic multi-spot delivery of laser energy to the target region on the retina.

[0056] In some embodiments, the system comprises a safety circuit configured to detect, based at least in part on the property detected by the at least one detector of the optical module, a fault condition of the optical fiber and / or of the scanning mirror, and to prevent emission of at least one light beam, in particular a treatment beam, responsive to the detected fault condition. The safety circuit may comprise a fiber-integrity monitoring circuit and / or a scanning mirror monitoring circuit as described herein or otherwise. In some embodiments, the safety circuit is configured to prevent emission of the at least one light beam, in particular the treatment beam, within a reaction time of no more than 10 ms, such as no more than 5 ms, such as no more than 3 ms, from detection of the fault condition.

[0057] In some embodiments, the treatment light source comprises one or more direct diode lasers for generating the treatment beam. By making use of direct diode lasers instead of solid-state lasers, the laser apparatus can be made more compact, robust and reliable. Details of embodiments described above with respect to the first aspect, are also relevant and can be combined with, this second aspect.

[0058] BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The above and other aspects will be apparent and elucidated from the embodiments described in the following with reference to the drawing in which:

[0060] FIG. 1 schematically illustrates a multi-spot LIO system according to one embodiment.

[0061] FIG. 2 schematically illustrates the optical components of an optical module for a multi-spot LIO system according to one embodiment.

[0062] FIG. 3 schematically illustrates the 3D z-shaped beam path of an optical module for a multi-spot LIO system according to one embodiment.

[0063] FIGs. 4A-B schematically illustrate an optical module for a multi-spot LIO system according to one embodiment.

[0064] FIG. 5 schematically illustrates the transmission properties of a redirecting mirror of an optical module for a multi-spot LIO system according to one embodiment.

[0065] FIG. 6 schematically illustrate use of the sensor signals from a positionsensitive photodetector for monitoring the optical fiber and the scanning mirror of an embodiment of a multi-spot LIO system.

[0066] DETAILED DESCRIPTION

[0067] FIG. 1 schematically illustrates a body-mounted multi-spot LIO system according to one embodiment. The LIO system, generally designated by reference numeral 1 , includes a wearable assembly, which secures the body-mounted LIO system to the user’s body via one or more wearable objects such as a head-worn assembly 30, a utility belt, or a backpack, among other examples. In the illustrated example, the wearable assembly comprises only a head-worn assembly 30, which is worn on the user’s head 2. Typically, the user is a physician, in particular an ophthalmologist. In other embodiments the wearable assembly may include additional wearable components, such as a belt, a backpack, or the like.

[0068] The body-mounted LIO includes an indirect ophthalmoscope 60, which is an optical device for examining the inside of the eye of the patient system. The indirect ophthalmoscope 60 includes an illumination unit (not explicitly shown) for providing white light and an optical system allowing the user to view the retina of a patient, typically through a hand-held lens (not shown). The indirect ophthalmoscope may be a binocular indirect ophthalmoscope or otherwise. The optical system of the indirect ophthalmoscope 60 includes a semi-transparent bending mirror 61 .

[0069] The head-worn assembly 30 may be provided as a headband, headset, or other type of head-mountable device. The LIO system further comprises a laser module 20, and an optical module 10.

[0070] In the present example, the laser module 20 is mounted to the head-worn assembly 30, in particular such that the laser module at the back of the user's head when the user wears the head-worn assembly. This arrangement provides a convenient, weight balanced wearable system. In other embodiments, the laser module may otherwise be worn by the user, e.g. at a belt or otherwise, or provided as a separate, non-wearable unit, e.g. a unit for placement on a desk, shelve, cart, movable arm, or the like. The laser module 20 comprises one or more laser sources 210 and a control unit 220. The control unit 220 may be configured for controlling operation of the laser sources and, optionally, for controlling some or all of the operations of the optical module 10. It will be appreciated that other embodiments may include a separate control unit, external to the laser module. Such a separate control unit may be provided as a wearable control unit, a handheld control unit or otherwise. Accordingly, some or all of the control functions may be performed by a separate control unit or by the laser module or by a combination of the laser module and a separate control unit.

[0071] In the present embodiment, the one or more laser sources 210 include a treatment laser source 211 and an aiming light source 212, different from the treatment laser source. Each of the treatment laser source and the aiming light source may be provided as respective direct diode laser, each configured to emit laser light at a respective wavelength and power. While the use of direct diode lasers provides a particularly compact and lightweight implementation, it will be appreciated that other forms of light sources may be used to create the treatment light and / or the aiming light. Examples of other light sources for creating the treatment laser light include other types of lasers, such as solid-state lasers. Examples of other types of light sources for creating an aiming beam include high-power LEDs, and / or the like.

[0072] It will be appreciated that the laser module may include further optical elements, e.g. a beam combiner, one or more lenses, one or more filters, and / or the like.

[0073] The laser module 20 is connected to the optical module 10 via a fiber-optic cable 50 which includes one or more optical fibers for feeding the created treatment light and the created aiming light to the optical module. The laser module may be configured to selectively emit the treatment light and the aiming light one at a time. In some embodiments the laser module may also be capable of feeding the treatment light and the aiming light to the optical module concurrently.

[0074] The fiber-optic cable 50 may further include one or more wired electrical signalling lines for communicating electrical control signals and / or sensor signals between the laser module and the optical module, i.e. the fiber-optic cable may be a combined fiber-optic and electrical cable. Alternatively, the control signals and / or the sensor signals may be communicated wirelessly via a suitable wireless communication protocol or via a separate cable. Yet alternatively, in embodiments including a separate control unit, separate from the laser module 20, the system may include wired and / or wireless control and / or sensor connections between the control unit and the optical module and / or between the control unit and the laser module.

[0075] The laser module 20 may further be connected to a user-actuatable actuator 40, e.g. a foot switch or other form of user-activatable switch for allowing the user to initiate emission of the treatment beam to a multi-spot pattern, or otherwise. In particular, activation of the user-actuatable actuator by the user may trigger automatic delivery of laser energy to multiple treatment spots on the retina as defined by a predetermined, e.g. user-selected, scan pattern. Accordingly, the ophthalmologist does not have to individually aim at the individual spots and initiate delivery of laser energy to the selected individual spot. Instead, the ophthalmologist may aim the system at a target region, e.g. by means of an aiming beam, and initiate automatic delivery of laser energy to multiple spots according to the scan pattern, e.g. by a single actuation of the user-actuatable actuator or otherwise. Additionally, or alternatively, the LIO system may include a user device, e.g. a suitably programmed tablet computer, for providing a user interface that allows the user to adjust various control parameters, e.g. desired power levels, treatment durations, treatment patterns etc.

[0076] The laser module 20 may further be connected to a power source 41 , e.g. a rechargeable battery or another suitable power source. In the present embodiment, the power source 41 is integrated into the actuator 40 so as to provide a compact design that uses only few cables between the various units. However, other embodiments may use a separate power source, or a power source integrated into the laser module or the like. The fiber-optic cable 50 may further include an electrical power line for feeding operating power from the laser module 20 to the optical module. Alternatively, the optical module 10 may include its one power source, e.g. a rechargeable battery or be connected to a separate power source.

[0077] The optical module 10 is attached to the head-worn assembly 30. The optical module may be permanently attached to the head-worn assembly, e.g. integrated into the head-worn assembly, or it may be removably attached to the head-worn assembly. The optical module may be integrated with indirect ophthalmoscope 60 or provided as a separate module, e.g. attachable to the indirect ophthalmoscope or otherwise.

[0078] Various embodiments of the LIO system disclosed herein are multi-spot LIO systems that are configured to deliver the treatment laser energy as a treatment beam that is directed towards a predetermined two-dimensional pattern of treatment locations, e.g. in the form of spots. The pattern of spots may be selected, in particular selected by the ophthalmologist, based on the pathology or treatment for the patient. Some embodiments may deliver treatment laser energy in a pulse train such as discrete pulses known as micropulses or microsecond pulses, e.g. such that each pulse has a duration ranging from 10-1000 microseconds (ps). The multi-spot LIO system may further deliver an aiming beam, e.g. before and / or during delivery of the treatment beam, so as to form a visible aiming pattern on the retina, e.g. in the form of a visible outline pattern that indicates the outline of a treatment target area on the retina, or otherwise.

[0079] Accordingly, as described in more detail below, the optical module 10 receives input light, in particular the treatment light and the aiming light, from the laser module 20 via the fiber-optic cable 50. The optical module 10 is operable to deliver patterned laser energy to the retina of an eye of a patient, in particular to a multi-spot pattern of treatment spots. The optical module may be configured to selectively deliver an aiming laser beam and a treatment laser beam. Each of the aiming laser beam and the treatment laser beam may be scanned by the optical module across a part of the retina so as to deliver respective scanned aiming and treatment patterns, respectively.

[0080] To this end, as will be described in greater detail below, the optical module 10 comprises a scanning mirror (not shown in FIG. 1 ) and an optical system for sequentially directing the received input light via the bending mirror 61 to respective locations so as to form the two-dimensional pattern of treatment locations and / or so as to form the visible aiming pattern on the retina of the patient to be treated.

[0081] FIG. 2 schematically illustrates the main optical components of an optical module for a multi-spot LIO system according to one embodiment, e.g. of the optical module of the LIO system of FIG. 1 , or of another embodiment of a multi-spot LIO system.

[0082] The optical module, generally designated by reference numeral 10, comprises a housing 190 for accommodating various optical components of the optical module.

[0083] The optical module 10 comprises an input port 110 attachable to an optical fiber 111 , e.g. an optical fiber of a fiber-optic cable, for receiving the input light 181 , in particular the treatment beam and the aiming beam.

[0084] The optical module further comprises a collimating lens 120, a scanning mirror 130, a focusing lens 140, a redirecting mirror 150, position-sensitive photodetector 160, and an output lens 170, all accommodated by the housing 190.

[0085] The collimating lens 120 collimates the received input light 181 and directs the collimated light 182 onto the scanning mirror 130.

[0086] The scanning mirror 130 is preferably a two-dimensional (2D) MEMS mirror for scanning the reflected beam 183 in a two-dimensional pattern. In alternative embodiments, another type of scanning mirror may be used, e.g. a galvo scanning mirror. In FIG. 2 the scanning mirror 130 is schematically shown in two orientations - one orientation is shown by solid lines while the other orientation is shown as dashed lines - resulting in two downstream beam paths, which are also illustrated by solid and dashed lines, respectively. It will be appreciated that the scanning mirror will typically be operable to provide more than two distinct beam directions, e.g. more than 4, such as more than 10, such as more than 50, or even more distinct beam directions, for creating predetermined beam patterns, e.g. patterns of multiple illuminated spots or otherwise. In some embodiments, the scanning mirror may vary the scanning speed, e.g. so as to slow down or even intermittently stop its movement when reaching each of the treatment spots, e.g. so as to deliver a suitable amount of laser energy to each treatment spot. In some embodiments, the laser module may be configured to selectively enable and disable emission of the treatment beam or the aiming beam while the scanning mirror moves between the designated treatment spots. The scanning mirror 130 comprises a mirror controller that controls the two-dimensional scanning operation of the mirror 130. The mirror controller may be operable based on control signals received from an external laser module and / or from another external control unit.

[0087] The focusing lens 140 is arranged to re-focus the collimated and reflected light beam 183 coming from the scanning mirror onto a virtual image location 187.

[0088] The redirecting mirror 150 receives the light beam 184 from the focusing lens 140 and reflects a major portion of the light beam 184 towards the output lens 170 such that the virtual image location 187 is located between the redirecting mirror 150 and the output lens 170. The output lens 170 receives the reflected portion 186 of the light beam from the redirecting mirror 150 and creates a focused output beam 188. The redirecting mirror is a partially reflecting and partially transmitting mirror which reflects a major portion of the incoming light 184 as a reflected beam 186 and which allows a minor portion 185 of the incoming light to be transmitted. The position-sensitive photodetector 160 is arranged such that it receives the transmitted portion 185, i.e. the redirecting mirror 150 is positioned between the focusing lens 140 and the position-sensitive photodetector 160.

[0089] The position-sensitive photodetector 160 is configured to measure the power of the transmitted portion 185 of the light beam and to detect the position of the transmitted portion 185 of the light beam, i.e. the positionsensitive photodetector 160 provides a sensor signal that is indicative of the power of the received light after being reflected by the scanning mirror 130 and that is also indicative of the current scanning direction, i.e. of the direction and the corresponding beam position of the output beam 188. The sensor signal is thus also indicative of the direction of the output beam and, hence, the position at which the output beam (i.e. the treatment beam and / or the aiming beam) impinges on the retina of the subject to be treated. The sensor signals from the position-sensitive photodetector may be forwarded to a control circuit of the optical module, e.g. the mirror controller 131 , and / or to an external control unit, e.g. to the laser module that provides the incoming light.

[0090] Generally, the beam path between the input port 110 and the output lens is folded twice, thus resulting in a z-shaped beam path. The beam path is defined by the input direction along which the input light 181 is received, by the intermediate beam path of the reflected light 183 between the scanning mirror and the redirecting mirror 150, and by the output beam direction along which the output beam 188 is emitted. The z-shaped beam path is created by the scanning mirror 130 and the redirecting mirror 150. As is illustrated in FIG. 3, the z-shaped beam path does not lie in a single plane. Preferably, the input direction of the incoming light 181 and the output beam direction of the output beam 188 are substantially codirectional, i.e. generally directed along the same or similar direction. In some embodiments, the input direction and the output beam direction may be parallel with each other, alternatively they may define an acute angle. The acute angle may be between 0° and 45°, such as between 1 ° and 45°, preferably between 10° and 40°, more preferably between 20° and 40°, such as between 30° and 40°. The z-shaped arrangement where the relatively large components, i.e. the scanning mirror and the photodetector 160 with the redirecting mirror 150 act as beam reflectors provide a very compact design.

[0091] Moreover, as the virtual image location 187 is positioned between the redirecting mirror 150 and the output lens 170, the focusing lens can conveniently be placed without obstructing the beam path between the redirecting mirror 150 and the output lens 170. Moreover, as the beam diameter is decreasing after the focus lens 140, the beam diameter is small at the position-sensitive detector, which is helpful to keep the optical components small.

[0092] Preferably, the output lens 170 has a large diameter to allow for a large beam diameter at the output lens. The z-shaped arrangement with the focusing lens 140 allows the output lens to be positioned such that the large beam does not interfere with the scanning mirror 130. In particular, the scanning mirror may be displaced from the output lens when seen along the output beam direction where the scanning mirror is closer to the redirecting mirror than the output lens.

[0093] The above arrangement of optical components provides a compact and light-weight design while the input port and the output lens are conveniently positioned such that the output beam can be directed downwards towards the bending mirror of the LIO system when the optical module is attached 1 to the head-worn assembly of the LIO system, while the input port allows the fiber-optic cable to feed the incoming light along a downward direction. The fiber-optic cable can thus be led between the laser module and the optical module without interfering with the user's field of view or otherwise impairing use of the system.

[0094] FIG. 3 schematically illustrates the three-dimensional (3D) z-shaped beam path of an optical module for an LIO system according to one embodiment. In particular, FIG. 3 shows the optical components of an optical module according to one embodiment, e.g. of the optical module of FIG. 2. The optical module comprises an input port 110, a collimating lens 120, a scanning mirror 130, a focussing lens 140, a redirecting mirror 150, a position-sensitive photodetector 160 and an output lens 170, all as described in connection with FIG. 2. Also illustrated in FIG. 3 is the bending mirror 61 that redirects the output beam 188 from the optical module as a patient-facing beam 189 (i.e. as a treatment beam or as an aiming beam towards the eye of the patient.

[0095] As illustrated in FIG. 3, the input direction of the incoming light beam 181 and the intermediate beam path of the reflected beam 183 from the scanning mirror 130 define a first plane having a normal vector V1. The intermediate beam path of the reflected beam 183 and the output beam direction of the beam reflected by the redirecting mirror 150 define a second plane having a second normal vector V2. In the present and various other embodiments, the normal vectors of the first and second planes are not parallel with each other. They may define an angle between the first and second normal vectors of 30° or more.

[0096] Generally, during operation, various embodiments of the optical module collimate divergent light received at the input port via an optical fiber. The collimated light is directed to the scanning mirror. The collimated light is reflected and steered by the scanning mirror. The reflected light is re- focused so as to create a virtual image of the fiber output facet at a reimaging location. Converging (or otherwise partly focused) light reaches the redirecting mirror. The converging light reaches the redirecting mirror slightly out of focus, i.e. the redirecting mirror is displaced from the virtual image location. The redirecting mirror is a partial mirror that reflects a main beam towards the output lens and that transmits a small portion of light transmitted towards the position-sensitive photodetector. The transmitted portion hits the position-sensitive detector close to focus, i.e. with a high sensitivity and such that the spot size on the photo-sensitive detector can easily be adjusted by adjusting the location of the position-sensitive detector. The main beam converges and then diverges towards the output lens, which images the virtual image onto a target spot at a desired working distance.

[0097] Various embodiments of the optical module provide a convenient entry location and / or direction of the optical fiber and a convenient exit location / direction of the output beam when the optical module is mounted to a head-worn assembly of an LIO system.

[0098] Moreover, the beam diameters can be kept small on the scanning mirror and on the focusing lens.

[0099] Moreover, the beam is decreasing in diameter after the focusing lens, which is advantageous to provide a compact design of the position-sensitive detector and the redirecting mirror. The focal length of the focusing lens may be chosen such that beam diameter is small when the beam, after being reflected by the redirecting mirror, passes next to the re-focus lens, thereby allowing a compact design.

[0100] The output beam should preferably be relatively large at the output lens. The twice-folded, z-shaped beam path allows the large output lens to be located behind the scanning mirror (when seen from the input end of the optical module) in order to prevent overlapping of the scanning mirror and the focus lens.

[0101] The redirecting mirror of various embodiments of the optical module has multiple functions, including: operating as a folding mirror, performing beam sampling, and performing balancing of treatment and alignment laser power. By having multiple functionalities, the number of optical elements can be reduced, thereby allowing a compact design. The folding function facilitates realization of a compact design. The beam sampling function facilitates the ability to pick-off a small portion of light for position sensing. The balancing improves the position sensing, since the same sensor can be used for the treatment laser and the much weaker alignment laser.

[0102] Various embodiments of the optical module comprise a housing that accommodates the optical components of the optical module. In some embodiments, the housing comprises an outer cover and an inner support structure to which the optical components are mounted. An embodiment of such a housing will now be described with reference to FIGs 4A-B.

[0103] FIGs. 4A-B shows an embodiment of the optical module 10 mounted to an indirect ophthalmoscope 60 having a bending mirror 61 for directing an output beam 188 from the optical module as a patient-facing beam 189 towards the retina of an eye of a subject to be treated. The optical module 10 may e.g. be the optical module described in connection with any of the previous figures and the indirect ophthalmoscopy may be the indirect ophthalmoscope of FIG.1 .

[0104] In particular, FIG. 4A shows the optical module 10 including its outer cover 196, which accommodates and protects the components of the optical module. The outer cover 196 of the optical module 10 has a downward facing output end 191 defining an output aperture 193 for outputting the output beam towards the bending mirror 61 of the indirect ophthalmoscope 60. The outer cover defines an input end 192, opposite the output end. The fiber-optic cable 50 enters the outer housing at or near the input end 192 and along a downward entry direction. The optical module 10 is elongated along the longitudinal direction defined between the output end 193 and the input end 192. The optical module 10 has a depth defined in a direction facing towards the forehead of the user, and the optical module has a width defined in a direction orthogonal to the height and depth. The directions of the height, depth and width are illustrated by arrows H, D, and W, respectively. In some embodiments, the height of the optical module is larger than the width and larger than the depth, where the height, width and depth are defined by the overall height, width and depth, respectively, of the outer cover 196. In particular, in some embodiments, the height is between 50 mm and 100 mm, such as between 60 mm and 90 mm, such as between 70 mm and 90 mm. The width and the depth may each be less than 70% of the height, preferably less than 60 % of the height. For example, the width may be between 30 mm and 50 mm, such as between 35 mm and 45 mm. The depth may be between 30 mm and 60 mm, such as between 50 mm and 50 mm. The outer cover 196 may be made from plastic or from another suitable material.

[0105] FIG. 4B schematically illustrates the optical module with its outer cover having been removed for the purpose of illustration. As can best be seen in FIG. 4B, the optical module 10 comprises an inner support structure 195 to which the optical components of the optical module 10 are mounted. In particular, the input port 1 10 of the optical module is located at a side wall at the upper portion of the support structure 195, while the output lens 170 is mounted at the bottom of the support structure. The scanning mirror 130 is mounted at an intermediate position.

[0106] As previously discussed, in various embodiments, e.g. in the embodiments described with reference to the previous figures, the optical module comprises a redirecting mirror, which may be a partially reflecting and partially transmitting mirror. The redirecting mirror reflects a major portion of the incident light and transmits a minor portion of the incident light toward a position-sensitive detector. The incident light may either be the treatment beam or the aiming beam, which typically has a much lower power than the treatment beam. When the position-sensitive photodetector is to detect both the treatment and the aiming beam, the detector needs to have suitable gain settings to be able to detect the aiming beam while not saturating when detecting the treatment beam. The inventors have realized that these requirements may be relaxed when the transmission properties of the redirecting mirror are carefully selected, e.g. by carefully selecting a suitable coating of the redirecting mirror. The selection is based on the observation that the wavelength of the aiming beam is typically different from the wavelength of the treatment beam. Accordingly, in some embodiments, the redirecting mirror is configured to allow a first fraction of incident light at the aiming beam wavelength to pass and to let a second fraction, smaller than the first fraction, of incident light at the treatment beam wavelength pass. That way, the relative magnitudes of the portions of the aiming and treatment beam that reach the detector become more similar.

[0107] FIG. 5 schematically illustrates the transmission properties of a redirecting mirror of an optical module for a multi-spot LIO system according to one embodiment. In the present embodiment, the aiming beam has an aiming beam wavelength in the red portion of the visible spectrum between 610 nm and 650 nm and the treatment beam has a treatment beam wavelength in the green portion of the visible spectrum between 512 nm and 535 nm. As can be seen from the simulated transmission spectrum of FIG. 5 for the two polarisation directions (S and P) of light, the redirection mirror selectively transmits light at the treatment beam wavelength and at wavelength in the red portion of the visible spectrum. The transmission at the red portion of the visible spectrum is about two orders of magnitude higher than the transmission at the treatment beam wavelength. The redirecting mirror is placed in front of the position-sensitive detector. Because of the high sensitivity of the sensor, only a small portion of the laser light is transmitted through the partial mirror to reach the detector. The high reflectivity maintains high optical efficiency of the system.

[0108] The inventors have found that the reflectivity / transmission profile of the coating of the redirecting mirror can be tailored such that a single sensor can be used for position monitoring for both the aiming beam and the treatment beam. In addition, the same sensor can be used for power monitoring for both aiming beam and treatment beam. In one embodiment, a single sensor can be used for measuring all four parameters, namely power and position of each of the aiming and treatment beams.

[0109] The optical power of the aiming beam is typically 50 - 1000 times lower than the optical power of the treatment beam. Also, an LIO system typically only turns on one of the two laser beams at the time. In order to use a single sensor for both beams, the power of aiming beam and the power of the treatment beam should preferably be balanced, i.e. the “pick-off ratio” (i.e. the fraction of the transmitted portion) should differ for the two beams, preferably by a factor of e.g. 50 - 1000. In this way, the sensor response from the aiming beam and the treatment beam can be balanced, such that the sensor can be used with a single gain setting for all measurements. This simplifies the electronics design, reduces the cost, and improves signal-to- noise ratio.

[0110] To realise this reflectivity / transmission profile of the coating, the reflectivity may be selected to be very high (to maintain high optical efficiency), and the transmission of the aiming beam is preferably about two orders of magnitude higher than for the treatment beam. In one embodiment, the coating provides 99.9% reflectivity for the treatment beam (i.e. 0.1 % transmission) and 90% reflectivity for the aiming beam (i.e. 10% transmission). FIG. 6 schematically illustrate use of the sensor signals from a positionsensitive photodetector for monitoring the optical fiber and the scanning mirror of an embodiment of a multi-spot LIO system, e.g. the system of FIG. 1 or another system having an optical module as described with reference to the previous figures, or otherwise.

[0111] In the example of FIG. 6, LIO system comprises a laser module 20 and an optical module 10, e.g. as described in connection with the previous figures. The laser module 20 comprises a laser source 210 and a laser controller 220, while the optical module comprises a position-sensitive photodetector 160, all as described in connection with the previous embodiments. The laser source 210 provides a laser beam, in particular a treatment beam, which is forwarded to the optical module 10, via a fiber-optic cable 50, also as described in connection with the previous embodiments. The laser module 20 further includes a safety circuit 230, which may include a fiberintegrity monitoring circuit 231 and a scanning mirror monitoring circuit 232. While shown as a separate block in FIG. 6, it will be appreciated that the safety circuit may be implemented as a sperate circuit or it may be implemented partly or completely integrated into the laser controller 220, or otherwise. Similarly, fiber-integrity monitoring circuit and the scanning mirror monitoring circuit may be implemented as separate circuits or as a combined circuit. The safety circuit may be implemented at least in part as a digital processing circuit.

[0112] The fiber-integrity monitoring circuit 231 may receive information about the laser output power from the laser source 210 of the laser module 20, e.g. of the aiming beam power and / or of the treatment beam power. To this end, the laser module 20 may comprise a photodetector for measuring the power of the created laser light, or the laser module may determine the power of the created laser beam in another way. The fiber-integrity monitoring circuit 231 may further receive a sensor signal from the position-sensitive photodetector 160 of the optical module 10. The fiber-integrity monitoring circuit may thus determine how much the laser beam has been attenuated between the laser source and the position-sensitive detector. If the attenuation changes over time and / or deviates from a predetermined acceptable range, the fiber-integrity circuit may output an alert signal indicating that the optical fiber or another component in the beam path, e.g. the scanning mirror, has been damaged or otherwise been degraded.

[0113] The scanning mirror monitoring circuit 232 may receive information about the desired scanning pattern. For example, the scanning mirror of the optical module 10 may receive a control signal, which may be received by the optical module from a user device or from the laser module 20. The control signal may cause the scanning mirror to perform a scanning operation according to a selected scanning pattern. The scanning mirror monitoring circuit 232 may further receive a sensor signal from the position-sensitive photodetector 160 of the optical module 10. The sensor signal may be indicative of the detected positions of the light beam incident on the positionsensitive detector. The scanning mirror monitoring circuit 232 may thus detect deviations of the detected beam positions from the intended scanning pattern. Upon detection of such a deviation, in particular of a deviation exceeding an acceptable margin, the scanning mirror monitoring circuit 232 may issue an alert, as such a deviation may indicate a malfunction of the scanning mirror.

[0114] The safety circuit 230 may forward any alert signals generated by the fiberintegrity monitoring circuit or by the scanning mirror monitoring circuit to the laser controller 220, which may be configured to disable emission of at least the treatment beam responsive to receipt of such an alert signal. In some embodiments, the safety circuit is configured to prevent emission of at least the treatment beam within a reaction time of no more than 10 ms, such as no more than 5 ms, such as no more than 3 ms, from detection of the fault condition. It will be appreciated that alternative embodiments may implement only one of the above safety mechanisms and / or additional or alternative safety mechanisms. It may further be appreciated that the detection of fiberintegrity and / or the fault detection of the scanning mirror may alternatively be implemented by a corresponding safety circuit of the optical module or of a separate control unit.

[0115] In the apparatus claims enumerating several means, several of these means can be embodied by one and the same element, component, or item of hardware. The mere fact that certain measures are recited in mutually different dependent claims or described in different embodiments does not indicate that a combination of these measures cannot be used to advantage.

[0116] It should be emphasized that the term "comprises / comprising" when used in this specification is taken to specify the presence of stated features, elements, steps, or components but does not preclude the presence or addition of one or more other features, elements, steps, components or groups thereof.

[0117] Various aspects disclosed herein may be summarized by the following items:

[0118] Embodiment 1 : An optical module for a multi-spot Laser Indirect Ophthalmoscope (LIO) system, the optical module comprising:

[0119] - a housing,

[0120] - a fiber-optic input port for receiving at least one light beam via an optical fiber along an input direction,

[0121] - a scanning mirror, and

[0122] - an output aperture for directing at least one output beam along an output beam direction. Embodiment 2: The optical module according to embodiment 1 , wherein the housing has an output end and an input end, opposite the output end, wherein the output aperture is located at the output end, and wherein the fiber-optic input port is configured such that, when the optical module is attached to a head-worn assembly of an LIO system, a fiber-optic cable connected to the fiber-optic input port extends upwardly from the housing of the optical module.

[0123] Embodiment 3: The optical module according to embodiment 2, wherein the input direction and the output beam direction are codirectional with each other, in particular parallel with each other or defining an acute angle between them, the acute angle being between 0° and 45°, such as between 1 ° and 45°, preferably between 10° and 40°, more preferably between 20° and 40°, such as between 30° and 40°.

[0124] Embodiment 4: The optical module according to embodiment 2 or 3, wherein the housing has a height, a width and a depth, the height being defined between the input end and the output end, and the width and depth being defined along respective directions orthogonal to the direction defined between the input end and the output end, wherein the depth and the width are each smaller than the height.

[0125] Embodiment 5: The optical module according to any one of the preceding embodiments, configured, when mounted to a head-worn assembly of an LIO system, to output the at least one output beam along an output beam direction towards a bending mirror mounted to the head-worn assembly and external to the housing of the optical module.

[0126] Embodiment 6: The optical module according to any one of the preceding embodiments, configured, when mounted to a head-worn assembly of an LIO system, to output the at least one output beam along a downward output beam direction. Embodiment 7: The optical module according to any one of the preceding embodiments, further comprising a redirecting mirror.

[0127] Embodiment 8: The optical module according to embodiment 7, wherein the scanning mirror and the redirecting mirror are configured to direct the at least one received light beam along a z-shaped beam path between the fiber-optic input port and the output aperture, the z-shaped beam path being defined by the input direction, an intermediate beam path and the output beam direction, the intermediate beam path extending between the scanning mirror and the redirecting mirror.

[0128] Embodiment 9: The optical module according to embodiment 7 or 8, wherein the scanning mirror is configured to direct the at least one light beam along an intermediate beam path to the redirecting mirror, and the redirecting mirror is configured to direct at least a reflected portion of the at least one light beam along the output beam direction through the output aperture.

[0129] Embodiment 10: The optical module according to any one of embodiments 8 through 9, wherein the intermediate beam path and the output beam direction define an acute angle between them, the acute angle being between 1 ° and 45°, such as between 10° and 40°, such as between 20° and 30°.

[0130] Embodiment 11 : The optical module according to any one of embodiments 8 through 10, wherein the input direction and the intermediate beam path define an acute angle between them, the acute angle being between 1 ° and 45°, such as between 10° and 40°, such as between 20° and 30°.

[0131] Embodiment 12: The optical module according to any one of embodiments 8 through 11 , wherein the input direction and the intermediate beam path together define a first plane, wherein the intermediate beam path and the output beam direction together define a second plane, and wherein the first and second planes are non-parallel relative to each other.

[0132] Embodiment 13: The optical module according to embodiment 12, wherein the first plane defines a first normal vector of the first plane and the second plane defines a second normal vector of the second plane, and wherein the angle between the first and second normal vectors is more than 30°.

[0133] Embodiment 14: The optical module according to any one of embodiments 7 through 13, further comprising a focusing lens arranged along an intermediate beam path between the scanning mirror and the redirecting mirror.

[0134] Embodiment 15: The optical module according to embodiment 14, wherein the focusing lens defines a virtual image plane at a position along the output beam direction between the redirecting mirror and the output aperture.

[0135] Embodiment 16: The optical module according to any of the preceding embodiments, comprising an output lens defining the output aperture.

[0136] Embodiment 17: The optical module according to any of the preceding embodiments, comprising a mirror controller for controlling the scanning mirror.

[0137] Embodiment 18: The optical module according to any of the preceding embodiments, comprising a data communication interface for communicating with a control circuit of the LIO system.

[0138] Embodiment 19: The optical module according to any of the preceding embodiments, comprising a power input for receiving operating power from a control circuit of the LIO system.

[0139] Embodiment 20: The optical module according to any one of the preceding embodiments, further comprising at least one detector for detecting at least one property of the received at least one light beam, in particular of the received at least one light beam after being reflected by the scanning mirror.

[0140] Embodiment 21 : The optical module according to embodiment 20 wherein the at least one detector comprises a photodetector for measuring a power of the received at least one light beam, in particular of the received at least one light beam after being reflected by the scanning mirror, and wherein the at least one property includes the power of the received at least one light beam, in particular of the received at least one light beam after being reflected by the scanning mirror.

[0141] Embodiment 22: The optical module according to embodiment 20 or 21 , further comprising a fiber-integrity monitoring circuit configured to receive information indicative of the detected property and to use the received information to perform an integrity monitoring of the optical fiber, and / or wherein the optical module is further configured to output a signal indicative of the detected property to an external fiber-integrity monitoring circuit for detecting integrity of the optical fiber.

[0142] Embodiment 23: The optical module according to any one of embodiments 20 through 22, wherein the at least one detector comprises a beam direction detector for detecting a beam direction of the received at least one light beam after being reflected by the scanning mirror.

[0143] Embodiment 24: The optical module according to any one of embodiments 20 through 23, wherein the at least one detector comprises a beam position detector configured to detect a beam position of the at least one received light beam after being reflected by the scanning mirror.

[0144] Embodiment 25: The optical module according to embodiment 24, when directly or indirectly dependent on embodiment 21 , wherein the photodetector and the beam position detector are provided as a combined position-sensitive photodetector configured to measure the power and beam position of the at least one received light beam after being reflected by the scanning mirror.

[0145] Embodiment 26: The optical module according to any one of embodiments 23 through 25, further comprising a scanning mirror monitoring circuit configured to receive information indicative of the detected beam direction and / or beam position and to use the received information to perform fault detection of the scanning mirror and / or wherein the optical module is configured to output a signal to an external scanning mirror monitoring circuit for performing fault detection of the scanning mirror.

[0146] Embodiment 27: The optical module according to any one of embodiments 23 through 26, wherein the at least one light beam includes a treatment beam and an aiming beam, and wherein the detector for detecting the beam position and / or beam direction is configured to detect respective beam directions and / or beam positions of each of the treatment beam and the aiming beam.

[0147] Embodiment 28: The optical module according to any one of embodiments 20 through 27, when directly or indirectly dependent on embodiment 7, wherein the redirecting mirror is a partially reflecting and partially transmitting redirecting mirror, wherein the scanning mirror is configured to direct the light beam along an intermediate beam path to the redirecting mirror, and wherein the redirecting mirror is configured to redirect a reflected portion of the light beam along the output beam direction through the output aperture, and to direct a transmitted portion of the light beam to the at least one detector.

[0148] Embodiment 29: The optical module according to embodiment 28, wherein the transmittance of the redirecting mirror is wavelength-dependent, wherein the at least one light beam includes a treatment beam and an aiming beam, the treatment beam having a treatment beam power and a treatment beam wavelength, the aiming beam having an aiming beam wavelength different from the treatment beam wavelength and an aiming beam power lower than the treatment beam power, and wherein the wavelength-dependent transmittance is higher at the aiming beam wavelength than at the treatment beam wavelength.

[0149] Embodiment 30: A multi-spot Laser Indirect Ophthalmoscope (LIO) system, comprising:

[0150] - a head-worn assembly,

[0151] - the optical module according to any one of the preceding embodiments,

[0152] - a laser module for creating at least one light beam, and

[0153] - an optical fiber configured to feed the light beam to the fiber-optic input port of the optical module, wherein the optical module is attached or attachable to the head-worn assembly such that the optical module is positioned in front of a user's forehead when the head-worn assembly is worn by the user.

[0154] Embodiment 31 : The multi-spot LIO system according to embodiment 28, wherein the laser module comprises a detector for detecting at least one property of the at least one light beam created by the laser module, wherein the optical module is an optical module according to any one of embodiments 20 through 29, and wherein the system comprises a fiberintegrity monitoring circuit configured to monitor integrity of the optical fiber based on information about the detected at least one property of the at least one light beam created by the laser module and further based on information about the detected at least one property of the at least one light beam received by the optical module and / or of the at least one light beam received by the optical module and reflected by the scanning mirror. Embodiment 32: The multi-spot LIO system according to embodiment 30 or 31 , wherein the laser module is attached or attachable to the head-worn assembly.

[0155] Embodiment 33: The multi-spot LIO system according to any one of embodiments 30 through 32, wherein the laser module is communicatively coupled to the optical module.

[0156] Embodiment 34: The multi-spot LIO system according to embodiment 33, wherein the laser module is configured to forward a scanning control signal for controlling the scanning mirror of the optical module to sequentially direct the output beam towards multiple treatment sites.

[0157] Embodiment 35: The multi-spot LIO system according to embodiment 33 or 34, wherein the optical module is an optical module according to any one of embodiments 20 through 29, and wherein the laser module is configured to receive a detector signal from the at least one detector of the optical module.

[0158] Embodiment 36: The multi-spot LIO system according to any one of embodiments 30 through 35, wherein the laser module includes a control unit for controlling operation of the optical module.

[0159] Embodiment 37: The multi-spot LIO system according to any one of embodiments 30 through 36, wherein the laser module includes a power output for providing operating power to the optical module.

[0160] Embodiment 38: The multi-spot LIO system according to any one of embodiments 30 through 37, wherein the laser module includes a power source or is configured to receive operating power from an external power supply.

[0161] Embodiment 39: The multi-spot LIO system according to any one of embodiments 30 through 38, wherein the laser module comprises: - a treatment light source configured to generate a treatment beam having a treatment beam wavelength and a treatment beam power;

[0162] - an aiming light source configured to generate an aiming beam having an aiming beam wavelength different from the treatment beam wavelength, and having an aiming beam power lower than the treatment beam power.

[0163] Embodiment 40: The multi-spot LIO system according to embodiment 39, wherein the treatment beam power is between 10 mW - 3 W.

[0164] Embodiment 41 : The multi-spot LIO system according to embodiment 37 or 38, wherein the aiming beam power is between 0.1 pW and 5 mW.

[0165] Embodiment 42: The multi-spot LIO system according to any one of embodiments 30 through 41 , wherein the optical module is the optical module according to any one of embodiments 20 through 29 and wherein the system comprises a safety circuit configured to detect, based at least in part on the property detected by the at least one detector of the optical module, a fault condition of the optical fiber and / or of the scanning mirror, and to prevent emission of at least one light beam, in particular a treatment beam, responsive to the detected fault condition.

[0166] Embodiment 43: The multi-spot LIO system according to embodiment 42, wherein the safety circuit is configured to prevent emission of the at least one light beam within a reaction time of no more than 10 ms, such as no more than 5 ms, such as no more than 3 ms, from detection of the fault condition.

[0167] Embodiment 44: A scanning LIO system that includes a. a green direct diode to create treatment laser light and a red direct diode to create aiming laser light, which can be operated independently b. A fiber-optic cable that directs the treatment and aiming light to the optical module c. An optical module placed at the front of the LIO, receiving the laser light from the fiber-optic cable, this module controlling the position of the laser light, monitoring the position and delivering the laser light towards the eye of the patient d. A scanning mirror module, positioned in the optical module, such mirror being a MEMS mirror or 2 galvano mirrors, such scanning mirror module controlling the laser beam position in 2 dimensions e. A monitoring module for monitoring the laser beam position, positioned in the optical module after the scanning mirror module, where the monitoring system monitors the position of the treatment laser beam and the aiming laser beam f. A focusing element that shapes the laser beams to achieve a predetermined spot diameter at the patient’s retina.

[0168] Embodiment 45: A system as in embodiment 44, where the monitoring module also monitors the optical power.

[0169] Embodiment 46: A system as in embodiment 45, where the monitoring module comprises a partial mirror, a power monitor and position monitor.

[0170] Embodiment 47: A system as in embodiment 44, where the response speed and the electronics control of the monitoring module enables the LIO to shut-down the treatment laser beam faster than 5 ms, (or faster than 3 ms).

[0171] Embodiment 48: A system as in embodiment 44, where the sensor for monitoring the optical power is a single element that can monitor both of the treatment beam and the aiming beam. Embodiment 49: A system as in embodiment 44, where the sensor for monitoring the laser beam position is a single element that can monitor the position of both the treatment beam and the aiming beam.

[0172] Embodiment 50: A system as in the two previous embodiments, where a single sensing / monitoring element can monitor both the optical power and laser beam position for both the treatment beam and the aiming beam.

[0173] Embodiment 51 : A system as in embodiment 46, where the reflectivity and the transmission of the partial mirror is achieved by dielectric coating on at least one of the surfaces.

[0174] Embodiment 52: A system as in embodiment 51 , where the reflectivity of the partial mirror is designed such that the transmission for the aiming beam is more than 5 times higher than for the treatment beam.

[0175] Embodiment 53: A system as in embodiment 52, where the reflectivity of the partial mirror is designed such that the transmission for the aiming beam is more than 50 times higher than for the treatment beam.

[0176] Embodiment 54: A system as in any of the previous embodiments, where the optical design is made such that the laser beam is reflected 2 times before the focusing element.

[0177] Embodiment 55: A system as in any of the previous embodiment, where the output end of the optical fiber is oriented such that the direction of the light emitted from the optical fiber is substantially downwards.

Claims

CLAIMS:

1. An optical module for a multi-spot Laser Indirect Ophthalmoscope (LIO) system, the optical module comprising:- a housing,- a fiber-optic input port for receiving at least one light beam via an optical fiber along an input direction,- a scanning mirror, and- an output aperture for directing at least one output beam along an output beam direction.

2. The optical module according to claim 1 , further comprising at least one detector for detecting at least one property of the received at least one light beam, in particular of the received at least one light beam after being reflected by the scanning mirror.

3. The optical module according to claim 2 wherein the at least one detector comprises a photodetector for measuring a power of the received at least one light beam, in particular of the received at least one light beam after being reflected by the scanning mirror, and wherein the at least one property includes the power of the received at least one light beam, in particular of the received at least one light beam after being reflected by the scanning mirror.

4. The optical module according to claim 2 or 3, further comprising a fiberintegrity monitoring circuit configured to receive information indicative of the detected property and to use the received information to perform an integrity monitoring of the optical fiber, and / or wherein the optical module is further configured to output a signal indicative of the detected property to an external fiber-integrity monitoring circuit for detecting integrity of the optical fiber.

5. The optical module according to any one of claims 2 through 4, wherein the at least one detector comprises a beam direction detector for detecting a beam direction of the received at least one light beam after being reflected by the scanning mirror.

6. The optical module according to any one of claims 2 through 5, wherein the at least one detector comprises a beam position detector configured to detect a beam position of the at least one received light beam after being reflected by the scanning mirror.

7. The optical module according to claim 6, when directly or indirectly dependent on claim 3, wherein the photodetector and the beam position detector are provided as a combined position-sensitive photodetector configured to measure the power and beam position of the at least one received light beam after being reflected by the scanning mirror.

8. The optical module according to any one of claims 5 through 7, further comprising a scanning mirror monitoring circuit configured to receive information indicative of the detected beam direction and / or beam position and to use the received information to perform fault detection of the scanning mirror and / or wherein the optical module is configured to output a signal to an external scanning mirror monitoring circuit for performing fault detection of the scanning mirror.

9. The optical module according to any one of claims 5 through 8, wherein the at least one light beam includes a treatment beam and an aiming beam, and wherein the detector for detecting the beam position and / or beam direction is configured to detect respective beam directions and / or beam positions of each of the treatment beam and the aiming beam.

10. The optical module according to any one of the preceding claims, further comprising a redirecting mirror.

11. The optical module according to claim 10, when directly or indirectly dependent on any one of claims 2 through 9, wherein the redirecting mirror is a partially reflecting and partially transmitting redirecting mirror, wherein the scanning mirror is configured to direct the light beam along an intermediate beam path to the redirecting mirror, and wherein the redirecting mirror is configured to redirect a reflected portion of the light beam along the output beam direction through the output aperture, and to direct a transmitted portion of the light beam to the at least one detector.

12. The optical module according to claim 11 , wherein the transmittance of the redirecting mirror is wavelength-dependent, wherein the at least one light beam includes a treatment beam and an aiming beam, the treatment beam having a treatment beam power and a treatment beam wavelength, the aiming beam having an aiming beam wavelength different from the treatment beam wavelength and an aiming beam power lower than the treatment beam power, and wherein the wavelength-dependent transmittance is higher at the aiming beam wavelength than at the treatment beam wavelength.

13. The optical module according to any one of claims 10 through 12, wherein the scanning mirror and the redirecting mirror are configured to direct the at least one received light beam along a z-shaped beam path between the fiber-optic input port and the output aperture, the z-shaped beam path being defined by the input direction, an intermediate beam path and the output beam direction, the intermediate beam path extending between the scanning mirror and the redirecting mirror.

14. The optical module according to any one of claims 10 through 13, wherein the scanning mirror is configured to direct the at least one light beam along an intermediate beam path to the redirecting mirror, and the redirecting mirror is configured to direct at least a reflected portion of the atleast one light beam along the output beam direction through the output aperture.

15. The optical module according to any one of claims 13 through 14, wherein the intermediate beam path and the output beam direction define an acute angle between them, the acute angle being between 1 ° and 45°, such as between 10° and 40°, such as between 20° and 30°.

16. The optical module according to any one of claims 13 through 15, wherein the input direction and the intermediate beam path define an acute angle between them, the acute angle being between 1 ° and 45°, such as between 10° and 40°, such as between 20° and 30°.

17. The optical module according to any one of claims 13 through 16, wherein the input direction and the intermediate beam path together define a first plane, wherein the intermediate beam path and the output beam direction together define a second plane, and wherein the first and second planes are non-parallel relative to each other.

18. The optical module according to claim 17, wherein the first plane defines a first normal vector of the first plane and the second plane defines a second normal vector of the second plane, and wherein the angle between the first and second normal vectors is more than 30°.

19. The optical module according to any one of claims 10 through 18, further comprising a focusing lens arranged along an intermediate beam path between the scanning mirror and the redirecting mirror.

20. The optical module according to claim 19, wherein the focusing lens defines a virtual image plane at a position along the output beam direction between the redirecting mirror and the output aperture.

21. The optical module according to any one of the preceding claims, wherein the housing has an output end and an input end, opposite theoutput end, wherein the output aperture is located at the output end, and wherein the fiber-optic input port is configured such that, when the optical module is attached to a head-worn assembly of an LIO system, a fiber-optic cable connected to the fiber-optic input port extends upwardly from the housing of the optical module.

22. The optical module according to claim 21 , wherein the input direction and the output beam direction are codirectional with each other, in particular parallel with each other or defining an acute angle between them, the acute angle being between 0° and 45°, such as between 1 ° and 45°, preferably between 10° and 40°, more preferably between 20° and 40°, such as between 30° and 40°.

23. The optical module according to claim 21 or 22, wherein the housing has a height, a width and a depth, the height being defined between the input end and the output end, and the width and depth being defined along respective directions orthogonal to the direction defined between the input end and the output end, wherein the depth and the width are each smaller than the height.

24. The optical module according to any one of the preceding claims, configured, when mounted to a head-worn assembly of an LIO system, to output the at least one output beam along an output beam direction towards a bending mirror mounted to the head-worn assembly and external to the housing of the optical module.

25. The optical module according to any one of the preceding claims, configured, when mounted to a head-worn assembly of an LIO system, to output the at least one output beam along a downward output beam direction.

26. The optical module according to any of the preceding claims, comprising an output lens defining the output aperture.

27. The optical module according to any of the preceding claims, comprising a mirror controller for controlling the scanning mirror.

28. The optical module according to any of the preceding claims, comprising a data communication interface for communicating with a control circuit of the LIO system.

29. The optical module according to any of the preceding claims, comprising a power input for receiving operating power from a control circuit of the LIO system.

30. A multi-spot Laser Indirect Ophthalmoscope (LIO) system, comprising:- a head-worn assembly,- the optical module according to any one of the preceding claims,- a laser module for creating at least one light beam, and- an optical fiber configured to feed the light beam to the fiber-optic input port of the optical module, wherein the optical module is attached or attachable to the head-worn assembly such that the optical module is positioned in front of a user's forehead when the head-worn assembly is worn by the user.

31. The multi-spot LIO system according to claim 30, wherein the laser module comprises a detector for detecting at least one property of the at least one light beam created by the laser module, wherein the optical module is an optical module according to any one of claims 2 through 9, and wherein the system comprises a fiber-integrity monitoring circuit configured to monitor integrity of the optical fiber based on information about the detected at least one property of the at least one light beam created by the laser module and further based on information about the detected at least one property of the at least one light beam received by the optical moduleand / or of the at least one light beam received by the optical module and reflected by the scanning mirror.

32. The multi-spot LIO system according to claim 30 or 31 , wherein the laser module is attached or attachable to the head-worn assembly.

33. The multi-spot LIO system according to any one of claims 30 through 32, wherein the laser module is communicatively coupled to the optical module.

34. The multi-spot LIO system according to claim 33, wherein the laser module is configured to forward a scanning control signal for controlling the scanning mirror of the optical module to sequentially direct the output beam towards multiple treatment sites.

35. The multi-spot LIO system according to claim 33 or 34, wherein the optical module is an optical module according to any one of claims 2 through 9, and wherein the laser module is configured to receive a detector signal from the at least one detector of the optical module.

36. The multi-spot LIO system according to any one of claims 30 through35, wherein the laser module includes a control unit for controlling operation of the optical module.

37. The multi-spot LIO system according to any one of claims 30 through36, wherein the laser module includes a power output for providing operating power to the optical module.

38. The multi-spot LIO system according to any one of claims 30 through37, wherein the laser module includes a power source or is configured to receive operating power from an external power supply.

39. The multi-spot LIO system according to any one of claims 30 through38, wherein the laser module comprises:- a treatment light source configured to generate a treatment beam having a treatment beam wavelength and a treatment beam power;- an aiming light source configured to generate an aiming beam having an aiming beam wavelength different from the treatment beam wavelength, and having an aiming beam power lower than the treatment beam power.

40. The multi-spot LIO system according to claim 39, wherein the treatment beam power is between 10 mW - 3 W.

41. The multi-spot LIO system according to claim 39 or 40, wherein the aiming beam power is between 0.1 pW and 5 mW.

42. The multi-spot LIO system according to any one of claims 30 through 41 , wherein the optical module is the optical module according to any one of claims 2 through 9 and wherein the system comprises a safety circuit configured to detect, based at least in part on the property detected by the at least one detector of the optical module, a fault condition of the optical fiber and / or of the scanning mirror, and to prevent emission of at least one light beam, in particular a treatment beam, responsive to the detected fault condition.

43. The multi-spot LIO system according to claim 42, wherein the safety circuit is configured to prevent emission of the at least one light beam within a reaction time of no more than 10 ms, such as no more than 5 ms, such as no more than 3 ms, from detection of the fault condition.

44. A scanning LIO system that includes: a. a green direct diode to create treatment laser light and a red direct diode to create aiming laser light, which can be operated independently b. a fiber-optic cable that directs the treatment and aiming light to the optical modulec. an optical module placed at the front of the LIO, receiving the laser light from the fiber-optic cable, this module controlling the position of the laser light, monitoring the position and delivering the laser light towards the eye of the patient d. a scanning mirror module, positioned in the optical module, such mirror being a MEMS mirror or 2 galvano mirrors, such scanning mirror module controlling the laser beam position in 2 dimensions e. a monitoring module for monitoring the laser beam position, positioned in the optical module after the scanning mirror module, where the monitoring system monitors the position of the treatment laser beam and the aiming laser beam f. a focusing element that shapes the laser beams to achieve a predetermined spot diameter at the patient’s retina.

45. A system as in claim 44, where the monitoring module also monitors the optical power.

46. A system as in claim 45, where the monitoring module comprises a partial mirror, a power monitor and position monitor.

47. A system as in claim 46, where the reflectivity and the transmission of the partial mirror is achieved by dielectric coating on at least one of the surfaces.

48. A system as in claim 47, where the reflectivity of the partial mirror is designed such that the transmission for the aiming beam is more than 5 times higher than for the treatment beam.

49. A system as in claim 48, where the reflectivity of the partial mirror is designed such that the transmission for the aiming beam is more than 50 times higher than for the treatment beam.

50. A system as in any one of claims 46 through 49, where the partial mirror is a redirecting mirror.51 . A system as in any one of claims 44 through 50, where the response speed and the electronics control of the monitoring module enables the LIO to shut-down the treatment laser beam faster than 5 ms, (or faster than 3 ms).

52. A system as in any one of claims 44 through 51 , where the sensor for monitoring the optical power is a single element that can monitor both of the treatment beam and the aiming beam.

53. A system as in any one of claims 44 through 52, where the sensor for monitoring the laser beam position is a single element that can monitor the position of both the treatment beam and the aiming beam.

54. A system as in claim 52 or 53, where a single sensing / monitoring element can monitor both the optical power and laser beam position for both the treatment beam and the aiming beam.

55. A system as in any one of claims 44 through 54, where the optical design is made such that the laser beam is reflected 2 times before the focusing element.

56. A system as in any one of claims 44 through 55, where the output end of the optical fiber is oriented such that the direction of the light emitted from the optical fiber is substantially downwards.

Images