METHOD FOR DELIVERING THE FLUID FORMULATION AS A SPRAY OR A JET OF DROPLETS TO A TARGET AREA ON AN EYE

Abstract

A package (1) for a fluid formulation (2) to be delivered as a spray or a jet of droplets to an eye (4), comprising an enclosed container (5) a storage recess (6) containing a fluid formulation (2); and a delivery recess (7), adjacent to the storage recess (6). The storage recess (6) and the delivery recess (7) are separated by a fluid barrier (8). Package (1) further comprises a matrix of holes (9), for generating the spray and/or jet of droplets, the matrix of holes (9) opening into the delivery recess (7). The storage recess (6) is configured to expel, by application of an impulse thereto, a dose of fluid formulation (2). The matrix of holes (9) is configured to steer the spray and/or jet of droplets to the target area (3) on the eye (4). Also provided is a device (20) for delivery of the fluid formulation, and a method for delivering the fluid formulation (2) as a spray or a jet of droplets to an eye (4) of a user.

Claims

1. Method for delivering a fluid formulation (2) as a spray or a jet of droplets to a target area (3) on an eye (4) of a user (16) by a device (20), wherein the device (20) comprises extraction means (30, 31, 32, 33, 34, 35, 36, 37, 38, 39) for extracting the fluid formulation (2) from an enclosed container (5) lodged in, or coupled to, the device (20); comprising the steps of: sending out a beam of light to the user's eye (4); detecting a corresponding beam of light reflected therefrom; determining that the device (20) is within an appropriate distance range from the eye (4) and/or aligned with the target area (3) on the user's eye (4), or with a pupil thereof; determining that an eye blink cycle is occurring, based on a rate of change in the intensity of the reflected beam of light; determining an eye opening phase of the eye blink cycle; during the eye opening phase, transmitting a delivery activation signal to the extraction means (30, 31, 32, 33, 34, 35, 36, 37, 38, 39); delivering the fluid formulation (2) as a spray or a jet of droplets to the target area (3) of the eye (4) within a predefined time from the end of the eye opening phase.

2. The method of claim 1, wherein determining that the device (20) is within an appropriate distance range from the eye (4) comprises the steps of: measuring a value of the reflected beam of light; if the value of the reflected beam of light is lower than a first minimum intensity threshold value (D), assuming the device is not within an appropriate distance range from the eye and not proceeding to the next step of determining a rate of change in the reflected beam of light; if the value of the reflected beam of light is higher than the first minimum intensity threshold value (D), determining if the value of the reflected beam of light maintains above the first minimum intensity threshold value (D) for a time longer than a minimum time threshold (F); if the value of the reflected beam of light does not maintain above the first minimum intensity threshold value (D) for a time longer than the minimum time threshold (F), not proceeding to the next step of determining a rate of change in the reflected beam of light; if the value of the reflected beam of light maintains above the first minimum intensity threshold value (D) for a time longer than the minimum time threshold (F), then determining a rate of change in the reflected beam of light.

3. The method of claim 1, wherein determining that an eye blink cycle is occurring comprises the step of determining an eye closing phase, followed by a step of determining an eye opening phase, wherein determining the eye closing phase comprises the steps of: measuring the current value of the reflected beam of light; measuring the minimum value of the reflected beam of light within a refresh time equal to the maximum length of time within minimum and maximum values of the reflected beam of light are updated; calculating a difference between the current value and the minimum value of the reflected beam of light as above measured and establishing that the difference is at least a threshold value (C); determining that the rate of positive change is higher than a minimum positive gradient threshold (A).

4. The method of claim 3, wherein determining the eye opening phase of the eye blink cycle comprises the steps of: measuring the current the value of the reflected beam of light; measuring the maximum value of the reflected beam of light within a refresh time equal to the maximum length of time within which minimum and maximum values of the reflected beam of light are updated; calculating a difference between the current value and the maximum value of the reflected beam of light as above measured and establishing that the difference is at least a threshold value (C); determining that the rate of negative change is higher than a minimum negative gradient threshold (B); verifying that the conditions above are met within a preset maximum blink time (E) from the eye closing phase.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0096] The package, the device and the method according to the invention are described in more detail herein below by way of exemplary embodiments and with reference to the attached drawings, in which:

[0097] FIG. 1 shows a section view of an embodiment of a package according to the present invention;

[0098] FIG. 2 shows a schematic view of three exemplary target areas on an eye, to which the spray and/or jet of droplets created by the package of FIG. 1 can be steered;

[0099] FIG. 3 shows a lateral view of a first embodiment of a device according to the present invention, adapted to lodge the package of FIG. 1, as it is employed by a user for delivering a spray or a jet of droplets to a target area of his eye;

[0100] FIG. 4 shows a frontal view of the device of FIG. 3, displaying an outlet of the device for letting the spray or the jet of droplets out of the device, aligned with a target area on the user's eye;

[0101] FIG. 5 shows a lateral view of a storage recess of the package of FIG. 1 which progressively collapses by folding into itself under a pressure impulse imparted by a firing member of the device of FIG. 3;

[0102] FIG. 6 shows a schematic manufacturing line for the package of FIG. 1;

[0103] FIG. 7 is a schematic representation of internal components of a device according to an embodiment of the present invention;

[0104] FIG. 8a is a perspective, partially cut away view of the device of FIG. 3;

[0105] FIG. 8b is a lateral perspective view of the device of FIG. 3, including a removable cap for the closing thereof;

[0106] FIG. 9 is an illustration of a sequence of steps to prepare the device of FIG. 3 for later use, including the steps of lodging a package comprising multiple doses of fluid formulation on position control means of the device; placing a removable eyecup on top of the position control means; and closing the device with a removable cap;

[0107] FIG. 10a shows a lateral view of a second embodiment of a device according to the present invention, adapted to lodge the package of FIG. 1, as it is employed by a user for delivering a spray or a jet of droplets to a target area of his eye;

[0108] FIG. 10b is a lateral perspective view of the device of FIG. 10a, including a removable cap for the closing thereof;

[0109] FIG. 11 is an illustration of a sequence of steps to prepare the device of FIG. 10a for later use, including opening a hinged eyecup for accessing position control means of the device, lodging a package comprising multiple doses of fluid formulation on the position control means; closing the hinged eyecup and placing a removable cap on top to close the device therewith;

[0110] FIG. 12 is an exploded perspective view of impulse applying means and of position control means of the device of either FIG. 3 or of FIG. 10a, the impulse applying means comprising a cam mechanism and a motor coupled thereto;

[0111] FIG. 13 is a sequence of three angular positions of the cam mechanism of FIG. 12, respectively a rest angular position, a fired angular position and an intermediate angular position between the fired angular position and the rest angular position;

[0112] FIG. 14 is a diagram of the force of a spring of a piston assembly of the cam mechanism of FIG. 12 in relation to angular positions of the cam mechanism, including the angular positions of FIG. 13;

[0113] FIG. 15 is an illustration of the interaction of a driver segment and a follower segment of the cam mechanism of FIG. 12, in the three angular positions of FIG. 13;

[0114] FIG. 16 is a schematic illustration of registering means for placing the device of either FIG. 3 or of FIG. 10a at an appropriate distance from the eye and/or for aligning the device, or an outlet thereof, with the target area on a user's eye;

[0115] FIG. 17 is a diagram exemplifying the value of a reflected beam of light as measured by a reflectance proximity sensor means of a device according to the present invention, relative to a baseline value of the sensor means, during use of the device to detect an eye blink cycle; and

[0116] FIG. 18 is a schematic representation of a subset of steps of a method for delivering a fluid formulation according to the present invention, including a step of determining that a device according to the present invention is within an appropriate distance range from an eye and a step of determining that an eye blink cycle is occurring, based on a rate of change in the intensity of the reflected beam of light of FIG. 17.

DESCRIPTION OF EMBODIMENTS

[0117] In the following description certain terms are used for reasons of convenience and are not intended to limit the invention. The terms “right”, “left”, “up”, “down”, “under” and “above” refer to directions in the figures. The terminology comprises the explicitly mentioned terms as well as their derivations and terms with a similar meaning. Also, spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper”, “proximal”, “distal”, and the like, may be used to describe one element's or feature's relationship to another element or feature as illustrated in the figures. These spatially relative terms are intended to encompass different positions and orientations of the devices in use or operation in addition to the position and orientation shown in the figures. For example, if a device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be “above” or “over” the other elements or features. Thus, the exemplary term “below” can encompass both positions and orientations of above and below. The devices may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein interpreted accordingly. Likewise, descriptions of movement along and around various axes include various special device positions and orientations.

[0118] To avoid repetition in the figures and the descriptions of the various aspects and illustrative embodiments, it should be understood that many features are common to many aspects and embodiments. Omission of an aspect from a description or figure does not imply that the aspect is missing from embodiments that incorporate that aspect. Instead, the aspect may have been omitted for clarity and to avoid prolix description. In this context, the following applies to the rest of this description: If, in order to clarify the drawings, a figure contains reference signs which are not explained in the directly associated part of the description, then it is referred to previous or following description sections. Further, for reason of lucidity, if in a drawing not all features of a part are provided with reference signs it is referred to other drawings showing the same part. Like numbers in two or more figures represent the same or similar elements.

[0119] With reference to FIG. 1 and to FIG. 2, a package 1 according to the present invention contains a fluid formulation 2 to be delivered as a spray or a jet of droplets to a target area 3 on an eye 4. The package 1 contains an enclosed container 5 comprising a storage recess 6 containing the fluid formulation 2; and a delivery recess 7, adjacent to the storage recess 6. The package 1 takes substantially the form of a blister package. The storage 6 is substantially a blister cavity. A matrix of holes 9 for generating the spray and/or jet of droplets is provided on the enclosed container 5. Specifically, the holes 9 open into the delivery recess 7.

[0120] The matrix of holes 9 is configured to steer the spray and/or jet of droplets to the target area 3 on the eye 4.

[0121] The enclosed container 5 comprises a base element 10, which is cold formed to embed the storage recess 6; and a cover element 11, attached at least in part to the base element 10, closing the storage recess 6. The base element 10 and the cover element 11 further cooperate to create the delivery recess 7.

[0122] The delivery recess 7 is substantially an expansible pocket, which is created by affixing the base element 10 to the cover element 11 in a way that they are close in contact but not attached over the delivery recess area.

[0123] The enclosed container 5 comprises a permanent seal 13 between the base element 10 and the cover element 11. The permanent seal 13 is created along the outer periphery of the storage recess 6 and of the delivery recess 7.

[0124] During storage of the fluid formulation 2 in the storage recess 6, the storage recess 6 and the delivery recess 7 are separated by a fluid barrier which takes the form of a frangible seal 8. The frangible seal 8 is positioned between the base element 10 and the cover element 11.

[0125] When the package 1 is used for delivering the fluid formulation 2, the storage recess 6 is configured to expel a dose of fluid formulation 2 beyond the frangible seal 8 to the delivery recess 7. The frangible seal 8 breaks upon application of a specific pressure impulse, applied to the storage recess 6 by a device 20 according to the present invention, thus providing the desired fluid expulsion force.

[0126] As the delivery recess 7 fills with fluid formulation 2, the expansible pocket of the delivery recess 7 channels the fluid formulation 2 to the holes 9 for spray or jet delivery.

[0127] FIG. 3 shows a first embodiment of a device 20 according to the present invention, adapted to lodge the package 1, as it is employed by a user 16 for delivering a spray or a jet of droplets to a target area 3 of his eye 4.

[0128] In FIG. 4, an outlet 22 of the device 20 of FIG. 3, adapted to let the spray or the jet of droplets out of the device 20, is displayed in alignment with a target area 3 on the user's eye 4.

[0129] The device 20 imparts the pressure impulse to the storage recess 6 in order to create the spray or jet of droplets out of the package 1.

[0130] FIG. 5 shows how the storage recess 6 of the package 1, once impacted, progressively collapses by folding into itself under a pressure impulse imparted by a firing member 35 of the device 20. Thus, the force required to crush the storage recess 6 is reduced and the residual volume of fluid formulation 2 remaining in the storage recess 6 after use is minimised. Approximately, the diameter of the firing member 35 equals the diameter of the storage recess 6, less four wall thicknesses of package material.

[0131] The base element 10 and the cover element 11 are made of aluminium laminate material. The laminate material is structured in a way that the inner walls 12 of the enclosed container 5 are created by a layer of polyethylene which contacts the fluid formulation 2.

[0132] In FIG. 6, a schematic manufacturing line for the package 1 according to the present invention is shown. The package 1 is manufactured out of two rolls of cover element 11 and base element 10. The matrix of holes 9 is created on the cover element 11 by a femtosecond laser 100. As already mentioned, such a high speed laser increases throughput and allows for a low cost per blister package 1. The high speed laser also vaporises material which reduces the risk of particulates and thermal damage during drilling.

[0133] The base element 10 is first sterilised, then cold formed to create the storage recess 6. A registration is added to both the base element 10 and the cover element 11 in order to match the relative position and orientation, such that the superimposition of cover element 11 on base element 10 is executed as desired. The formed storage recess 6 is thus filled with the required volume of fluid formulation 2.

[0134] Once the cover element 11 has also been made sterile, base element 10 and cover element 11 are brought together and affixed so as to form delivery recess 7. Seals 8 and 13 are then created between the base element 10 and the cover element 11. More specifically, after the frangible seal 8 is first created around the storage recess 6, the permanent seal 13 is created along the outer periphery of the storage recess 6 and of the delivery recess 7. The permanent seal 13 and the frangible seal 8 are heat seals, created ultrasonically.

[0135] In case of a fluid formulation 2 that is oxygen sensitive, the storage recess 5 can further comprise a volume 14 (FIG. 1) of five to ten microliters of an inert gas, such as nitrogen.

[0136] The package 1 manufactured as above described is subsequently cut.

[0137] As mentioned, the unified system, or platform, for delivery of several topical ocular drug formulations according to the present invention comprises a device 20 configured to prompt the spray or jet of fluid formulation droplets out of the package 1 therein lodged.

[0138] The device 20 exemplified in FIG. 3 is further portrayed in FIG. 8a, FIG. 8b and FIG. 9. Relative to such first embodiment, the device 20 is adapted to lodge a package 1 comprising a plurality of enclosed containers 5, namely four enclosed containers 5, for a daily dosing regimen consisting of two daily doses for each eye.

[0139] The device 20 comprises an external case, or shell, 21 and an outlet 22.

[0140] Internal to the case 21, a position control means comprises indexing means such as a turntable 40. Turntable 40 is provided for lodging the package 1 and for feeding in succession each of the enclosed containers 5 to a dosage station wherein a dose of fluid formulation 2 is expelled out of the enclosed container 5 to create a spray or a jet of droplets.

[0141] As portrayed in FIG. 9, the package 1 is substantially shaped as an oblong profiled disk 15 comprising the plurality of enclosed containers 5 on two extremity lobes. The special design of the package 1 allows also for improved manipulation by a user 16. The enclosed containers 5 are packed to each other on a common support of the disk and are arranged on the disk 15 so that each respective matrix of holes 9 is oriented substantially towards the center of the disk 15. The holes 9 are therefore as close as possible to the central axis of the device 20, or to the center of the outlet 22.

[0142] The impulse applying means of device 20, apt to apply a pressure impulse to a storage recess 6 of an enclosed container 5 positioned at a dosage station, comprises a cam mechanism and a motor 30 coupled thereto. The cam mechanism comprises a piston assembly comprising a driver segment 33 and a follower segment 34 resiliently biased by way of a contrast spring 37 packed therebetween.

[0143] The motor 30, mounted on a motor chassis, drives a motor spur gear 31 which in turn engages a drive spur gear 32. Drive spur gear 32 rotatively drives the cam mechanism. The exact functioning of the cam mechanism and of the turntable 40 will be described in the following, with reference to FIG. 12.

[0144] A printed circuit board 60 mechanically supports and electrically connects electronic components of an electronic circuitry of the device 20. With reference to the scheme of FIG. 7, the electronic circuitry can comprise a memory storage means, a controller, or processor, 62 for processing electric signals, sensors to deliver detection electric signals to the processor 62, wireless communication circuitry such as a Bluetooth modem. Communication circuitry can be used for communication with a mobile hand-held communication device provided with an application program executable thereon. The electronic circuitry can further comprise a display for visual information, a speaker as acoustic output element, a clock, a haptic motor for providing the device user 16 with feedback haptic sensations data transmission and/or reception.

[0145] A reflectance proximity sensor means 61, coupled to the controller 62, is configured to determine an eye blink cycle of the user 16, in order to allow effective delivery of the fluid formulation 2 during an eye opening phase of the eye blink cycle.

[0146] Battery 64 powers the electronic circuitry of the device 20. The driving function of the motor 30, as well as other functions incorporated in the device 20, is supported by the battery 64. Battery 64 can be rechargeable and its lifespan can be managed by a power management module to be maximized.

[0147] Device 20 comprises registering means for placing the device 20 at an appropriate distance from the eye 4 and/or for aligning the device 20, or its outlet 22, with the target area 3 on a user's eye 4. Relative to the embodiment of FIGS. 3, 8a, 8b and 9, the registering means comprises a removable telescopic eyecup means 23. Eyecup 23 is configured to stably rest on anatomical features surrounding the eye 4 of a user 16. To this purpose, eyecup 23 comprises two independently extractable/retractable telescopic extensions 24, 25. The eyecup 23 can be secured to the case 21, or removed therefrom, by a snap-fit engagement mechanism or similar. In order to ease a manual removal from the case 21 and a fastening thereto, the eyecup 23 can comprise grip means 29, such as spaced apart grooves providing ridges therebetween.

[0148] The outlet 22, as well as the telescopic extensions 24, 25 and the reflectance proximity sensor means 61 can be protected by way of a removable cap 200.

[0149] The turntable 40 is further provided with a profiled indexing bar 45 which functions as an indexing aid for positioning the package 1 in the delivery device 20 relative to the impulse applying means. In particular, the disk 15 and the indexing bar 45 have mutually complementary profile shapes so that they come in form-locking engagement when the disk 15 is fitted to the indexing bar 45 on the turntable 40. For loading the package 1 on the turntable 40, the cap 200 and the eyecup 23 are removed.

[0150] FIGS. 10a, 10b and 11 are relative to a second embodiment of the device 20 according to the present invention. Whereas the impulse applying means is substantially the same as for the first embodiment above described, the indexing means and the registering means are in part differently conceived. As for the general structure, same numbers as in the first embodiment of device 20 apply to same components.

[0151] As shown in FIG. 11, the turntable 40 is set in a profiled well 46 matching the shape of the package 1 and creating an oriented accommodation space. The package 1 is, analogously to the former embodiment, a profiled disk 15 comprising a plurality of enclosed containers 5. The package 1 is thus fittable into the profiled well 46 in two possible positions which are 180° apart.

[0152] The package 1 can be loaded thanks to a hinged eyecup 26, which allows access to the turntable 40 and is openable by way of a latch 28.

[0153] Relative to the embodiment of FIGS. 10a, 10b and 11, the registering means comprises a hinged eyecup means 26 provided with a compliant contact portion 27 configured to conform to anatomical features surrounding the eye 4 of a user 16.

[0154] For better handling by a user 16, the case 21 can comprise grip means 29, such as spaced apart rounded corrugations.

[0155] FIG. 12 clarifies on the structure of the cam mechanism and on the position control means provided in both of the above described embodiments of device 20 according to the present invention.

[0156] The cam mechanism comprises a substantially circular cam portion 38 having a circumferential profile 39 and a piston assembly. The piston assembly is resiliently biased against the profiled cam portion 38 and rotatively coupled to the profiled cam portion 38 by the motor 30.

[0157] The piston assembly comprises a driver segment 33 and a follower segment 34 which are mutually slidably engaged, to move relative to each other along a longitudinal axis A-A of the piston assembly. The driver segment 33 and the follower segment 34 are also resiliently biased by way of a contrast spring 37 packed therebetween, which makes the follower segment 34 abut against the cam portion 38.

[0158] The follower segment 34 comprises a follower member 36 and the firing member 35. The follower member 36 abuts against and follows the profile 39 of the cam portion 38. The profile 39 comprises a firing cliff.

[0159] Driven in rotation by the motor 30, through engaging gear 31 and gear 32 carrying the driver segment 33, the follower segment 34 rotatively contacts, by the follower member 36, the cam portion 38 on its profile 39. Thus, with reference to FIGS. 13, 14 and 15, the impulse applying means sequentially pass from a reset angular position I to a fired angular position II.

[0160] More specifically, in the fired angular position II of the piston assembly relative to the profiled cam portion 38, the spring 37 is fully extended and the follower member 36 goes off the firing cliff of the profile 39. Consequently, the firing member 35 of the piston assembly axially advances and applies a pressure impulse on an enclosed container 5 of the package 1 positioned at a dosage station. When the follower member 36 goes off the firing cliff of the profile 39, the movement and the consequent noise are dampened by the progressive crushing of the enclosed container 5. This ensures that the user 16 does not experience unpleasant noises or abrupt tactile sensations.

[0161] In the reset angular position I of the piston assembly relative to the profiled cam portion 38, the spring 37 is compressed and the follower member 36 comes to rest on the profile 39 keeping above the firing cliff by a given angular distance. Consequently, the firing member 35 of the piston assembly is completely retracted and automatically brought to a reset position for a subsequent firing.

[0162] Substantially between angular positions III of the piston assembly relative to the profiled cam portion 38 wherein, after firing, the spring 37 has been newly fully compressed and the firing member 35 is retracted, up to the reset angular position I, the turntable 40 comes to be rotatively coupled to the motor 30 of the impulse applying means and is thereby driven in rotation to bring a next enclosed container 5 to the dosage station.

[0163] In fact, with special reference to FIGS. 12 and 15, over angular positions III where the piston assembly comes to be fully retracted and the spring is fully compressed, a Geneva wheel 42 axially approaches motor spur gear 31 to an extent that pins 43 of the motor spur gear 31 come in engagement with slots 44 of the Geneva wheel 42. Thus, the Geneva wheel 42 communicates the rotation of the motor 30 to the turntable 40 by way of an indexing shaft 41.

[0164] With reference to FIG. 14, for instance, the follower member 36, when in the configuration corresponding to the first reset angular position I, remains about 12° before the first fired angular position II. If the first fired angular position II is assumed at 0°, then the first reset angular position I can correspond to −12°. Advantageously, such a small angular offset allows for a prompt activation of the impulse applying means once the delivery of the fluid formulation is needed, while ensuring that no accidental delivery happens as a result of external shocks to the device 20.

[0165] After the firing, progressively the piston assembly is retracted and the spring 37 is compressed, up to about 80° when the piston assembly is fully retracted and the spring 37 is fully compressed. Just about when the spring 37 comes to exert its maximum compression force, the turntable 40 is put in rotation and indexing is activated, substantially between 78° and up to the next, second reset angular position I happening around 168°. The piston assembly is then ready for a successive, second firing, at an angular position II corresponding to 180°.

[0166] FIG. 14 exemplifies almost a full rotation of the cam mechanism by 360°.

[0167] FIG. 16 shows an example of registering means comprising an offset viewing orifice 50 substantially aligned with the central axis of the outlet 22 of the device 20; and a backplate 51 comprising visual cues 52. The offset viewing orifice 50 and the backplate 51 are configured so that at an appropriate distance and/or in an aligned state the visual cues 52 are visible through the offset viewing orifice 50 in a predefined pattern and a predefined relation thereto. In particular, on the backplate 51 are three dots 52 surrounded by a circle of a different colour 54. The user 16 is instructed to ensure that all three dots 52 are visible just on the edge of the viewing orifice 50, to ensure that the device 20 is positioned on the correct axis, that is the device 20, or its outlet 22, is aligned with the target area 3 on his eye 4. This could be also be achieved differently, e.g. with two circular shapes or two triangular shapes. If the differently coloured circle 54 encircling dots 52 is visible through the viewing orifice 50, this is an indication to the user 16 that the device 20 has been brought too close to his eye 4.

[0168] The offset viewing orifice 50 is integrated in a front plate 53 which comprises further visual cues for aligning the device 20 horizontally, such as an arrow 55.

[0169] As mentioned, in order to allow effective delivery of the fluid formulation 2 during an eye opening phase of the eye blink cycle, a reflectance proximity sensor means 61, coupled to the controller 62, is employed to determine an eye blink cycle of the user 16.

[0170] In FIG. 17, a diagram exemplifies the value of a reflected beam of infrared light as measured by a reflectance proximity sensor means 61 of the device 20, relative to a baseline value of the sensor means, during use of the device 20 to detect an eye blink cycle. Threshold values A, B, C, D, E and F are explained below.

[0171] FIG. 18 is a schematic representation of a subset of steps of a method for delivering a fluid formulation according to the present invention, as implemented by a corresponding algorithm. Shown are a step of determining that a device 20 is within an appropriate distance range from an eye and a step of determining that an eye blink cycle is occurring, based on a rate of change in the intensity of the reflected beam of light as shown in FIG. 17. The method is based on threshold values A, B, C, D, E and F as shown in FIG. 17.

[0172] The method for delivering a fluid formulation 2 according to the present invention comprises steps of sending out a beam of light to the user's eye 4 by an emitter unit of the reflectance proximity sensor means 61 and detecting a corresponding beam of light reflected therefrom by a receiver unit of the reflectance proximity sensor means 61.

[0173] Thereafter, it is determined if the device 20 is in position, that is within an appropriate distance range from the eye 4 and/or aligned with the target area 3 on the user's eye 4, or with a pupil thereof. For this purpose, as shown in FIG. 17, the method comprises a step of measuring a value of the reflected beam of light. If the value of the reflected beam of light is lower than a first minimum intensity threshold value D, the algorithm assumes the device is not within an appropriate distance range from the eye and does not proceed to the next step of determining a rate of change in the reflected beam of light. If, instead, the value of the reflected beam of light is higher than the first minimum intensity threshold value D, it is determined if the value of the reflected beam of light maintains above the first minimum intensity threshold value D for a time longer than a minimum time threshold F. If the value of the reflected beam of light does not maintain above the first minimum intensity threshold value D for a time longer than the minimum time threshold F, the algorithm does not proceed to the next step of determining a rate of change in the reflected beam of light. If, on the contrary, the value of the reflected beam of light maintains above the first minimum intensity threshold value D for a time longer than the minimum time threshold F, then the algorithm assumes that the device 20 is in position, with the user's eye 4 open.

[0174] Under these conditions, the algorithm then determines that an eye blink cycle is occurring, based on a rate of change in the intensity of the reflected beam of light. Determining that an eye blink cycle is occurring comprises the step of determining an eye closing phase, followed by a step of determining an eye opening phase.

[0175] Determining the eye closing phase comprises the steps of measuring the current the value of the reflected beam of light; measuring the minimum value of the reflected beam of light within a refresh time equal to the maximum length of time within minimum and maximum values of the reflected beam of light are updated; and calculating a difference between the current value and the minimum value of the reflected beam of light as above measured to establish that the difference is at least a threshold value C. The algorithm finally concludes that an eye closing phase is happening if it also determines that the rate of positive change is higher than a minimum positive gradient threshold A.

[0176] Determining the eye opening phase of the eye blink cycle comprises the steps of measuring the current the value of the reflected beam of light; measuring the maximum value of the reflected beam of light within a refresh time equal to the maximum length of time within which minimum and maximum values of the reflected beam of light are updated; and calculating a difference between the current value and the maximum value of the reflected beam of light as above measured to establish that the difference is at least a threshold value C.

[0177] The algorithm finally concludes that an eye opening phase is happening if it also determines that the rate of negative change is higher than a minimum negative gradient threshold B; combined with verifying that the conditions above are met within a preset maximum blink time E from the eye closing phase. If this is the case, then the algorithm assumes that the blink cycle is actually consequently happening and that the eye is currently open as a result of an eye opening phase. During the eye opening phase, a delivery activation signal is transmitted to the impulse applying means and the delivery is instructed of the fluid formulation 2 as a spray or a jet of droplets to the target area 3 of the eye 4 within a predefined time from the end of the eye opening phase.

[0178] If an eye opening phase cannot be confirmed, then the algorithm assumes the eye had not originally closed and reassess if the device 20 is in position as above described.

[0179] This description and the accompanying drawings that illustrate aspects and embodiments of the present invention should not be taken as limiting the claims defining the protected invention. In other words, while the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. Various mechanical, compositional, structural, electrical, and operational changes may be made without departing from the spirit and scope of this description and the claims. In some instances, well-known circuits, structures and techniques have not been shown in detail in order not to obscure the invention. Thus, it will be understood that changes and modifications may be made by those of ordinary skill within the scope and spirit of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below.

[0180] The disclosure also covers all further features shown in the FIGS. individually although they may not have been described in the afore or following description. Also, single alternatives of the embodiments described in the figures and the description and single alternatives of features thereof can be disclaimed from the subject matter of the invention or from disclosed subject matter. The disclosure comprises subject matter consisting of the features defined in the claims or the exemplary embodiments as well as subject matter comprising said features.

[0181] Furthermore, in the claims the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single unit or step may fulfil the functions of several features recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. The terms “essentially”, “about”, “approximately” and the like in connection with an attribute or a value particularly also define exactly the attribute or exactly the value, respectively. The term “about” in the context of a given numerate value or range refers to a value or range that is, e.g., within 20%, within 10%, within 5%, or within 2% of the given value or range. Components described as coupled or connected may be electrically or mechanically directly coupled, or they may be indirectly coupled via one or more intermediate components. Any reference signs in the claims should not be construed as limiting the scope.