Phototherapy system for treatment of hyperbilirubinemia

Abstract

A phototherapy system (100) including a light-emitting apparatus (110) comprising a plurality of light sources (114) positioned on a flexible substrate (112), the plurality of light sources (114) being configured to emit light having a peak intensity within a wavelength range from 430 nm to 490 nm and a photoluminescent layer (120) comprising a photoluminescent material positioned to be irradiated by the light-emitting apparatus (110) and emit light having a peak wavelength within a second range from 525 nm to 675 nm. A spectral power distribution (SPD) of light emitted from the phototherapy system (100) comprises an SPD peak intensity within the wavelength range from 430 nm to 490 nm that is greater than a local maximum intensity within a wavelength range from 490 nm to 700 nm.

Description

PHOTOTHERAPY SYSTEM FOR TREATMENT OF HYPERBILIRUBINEMIAField of the Invention

[0001] The present invention relates to phototherapy systems and methods for the treatment of hyperbilirubinemia.Background of the Invention

[0002] Past phototherapy systems for the treatment of hyperbilirubinemia or jaundice typically use a blue light source or sources emitting light at the spectral range corresponding to absorption spectra for bilirubin. Examples include blue LED arrays (see for example U.S. Patent No. 7,438,719), optical fiber guided blue light emitted from tapered fiber ends arrays, or a lightguide bed sheet with a tapered light scattering microstructures region (see for example U.S. Patent No. 11 ,577,093).

[0003] In recent years, due to the commercial availability of flexible blue LED sheets comprising a 2D blue LED chip / die array, some companies have converted such sheets into a blanket as a phototherapy system for the treatment of hyperbilirubinemia or jaundice (see for example, motifmedical.com / bilitouch-phototherapy-blanket). However, some individuals report a feeling of nausea or discomfort from prolonged exposure to blue light. As a solution to this issue, prior art included the use of a balancing color chosen for its ability to mitigate discomfort that may be caused by viewing the treatment color (see for example U.S. Patent No. 7,438,719).

[0004] Typically, the balancing color is produced by separate light source(s) such as yellow or white LEDs, and color mixing is achieved after the blue and yellow / white light beams have propagated a certain distance (typically about 1 foot) such that the beams have intermixed spatially to overlap each other with a desired illumination uniformity to meet certain hyperbilirubinemia phototherapy treatment standards such as IEC-60601-2- 50.

[0005] An issue with this approach is that there is the need for a certain beam propagation distance to spatially mix and relatively uniformly distribute the illumination light. Another issue is that even with this color mixing approach, there are still regions, especially those outside the specified treatment area that can have stronger than ideal blue component to cause discomfort to some care-provider during the treatment. In addition, this approach is only applicable to an overhead type of devices that are placed above the patient with sufficient distance between the device and the patient. Accordingly,there is a need in the art for a phototherapy device operable to emit illuminating light for the treatment of hyperbilirubinemia while also having a spectral power distribution that results in the perception of light emitted thereby that does not cause the types of nausea mentioned above and also does not require the significant distance between the emitting device and the patient. There are additional needs in the art for avoiding over-divergence of light that can occur with significant distances between the emitting device and the patient particularly when phosphors with generally omnidirectional or semispherical emission characteristics are utilized.Summary of the Invention

[0006] With the foregoing in mind, embodiments of the invention are directed to a phototherapy system for reducing bilirubin in neonates and other living individuals. One embodiment is directed to a phototherapy system comprising a light-emitting apparatus comprising a plurality of light sources positioned on a flexible substrate, the plurality of light sources being configured to emit light having a peak intensity within a wavelength range from 430 nm to 490 nm. and a photo luminescent layer comprising a photoluminescent material positioned to be irradiated by the light-emitting apparatus and emit light having a peak wavelength within a second range from 525 nm to 675 nm. A spectral power distribution (SPD) of light emitted from the phototherapy system comprises an SPD peak intensity within the wavelength range from 430 nm to 490 nm that is greater than a local maximum intensity within a wavelength range from 490 nm to 700 nm.

[0007] In some embodiments the SPD peak intensity may be a dominant wavelength of light emitted by the phototherapy system. The photoluminescent material is a phosphor material. In some embodiments, the photoluminescent material include a first phosphor type configured to emit light having a peak intensity within a first wavelength range centered at a first wavelength within a range from 490 nm to 700 nm and a second phosphor type configured to emit light having a peak intensity within a second wavelength range centered at a second wavelength within a range from 490 nm to 700 nm. The first wavelength may be nonequivalent to the second wavelength.

[0008] In some embodiments, the light emitted by the phototherapy system may have a spectral irradiance within the wavelength range from 430 nm to 490 nm of at least 30 μW / cm2 / nm at a designed skin irradiation distance. In some embodiments, the photoluminescent layer may be applied to a light-emitting surface of the light-emitting apparatus. In some embodiments, the photoluminescent layer is comprised by aremovable optic that is positionable in optical communication with the light-emitting apparatus and configured to be selectively removable from the phototherapy system.

[0009] In some embodiments, the system may further comprise a lens array positioned in optical communication with the photoluminescent layer, the lens array comprising a plurality of lenslets configured to at least one of collimate light emitted by the photoluminescent layer and reduce a divergence of light emitted by the photoluminescent layer. Each lenslet of the plurality of lenslets may be at least one of axially aligned with a light emission axis of a light source of the plurality of light sources, axially aligned with one of a plurality of light emission axes comprised by a light source of the plurality of light sources, and axially aligned with a composite axis positioned parallel to and equidistant from two or more light emission axes comprised by a light source of the plurality of light emitting elements. Each lenslet of the plurality of lenslets may comprise at least one prism structure. The photoluminescent layer may be applied to a light receiving surface of the lens array.

[0010] Furthermore, the lens array may be formed of a flexible material and the lens array may be configured to conform to a flexure of the light-emitting apparatus. The lens array may comprise a first set of lenslets positioned in a first surface configured to modify an angular distribution of light emitted from the photoluminescent layer and emit angularly redistributed light and a second set of lenslets positioned in a second surface configured to collimate the angularly redistributed light and emit substantially collimated light.

[0011] In some embodiments, the plurality of lenslets may be a plurality of Fresnel lenslets. The plurality of light sources may be distributed in a pattern on the flexible substrate and the plurality of Fresnel lenslets is distributed in a pattern in the lens array corresponding to the pattern of the plurality of light sources. The Fresnel lenslets may have one of a circular geometry, a square geometry, a hexagonal geometry, and a polygonal geometry configured to minimize space between adjacent Fresnel lenses.

[0012] In some embodiments, a portion of a field of light emitted by the phototherapy system may define a treatment area and a spatial power distribution of light emitted from the phototherapy system has a ratio of a minimum integrated irradiance within a bilirubin-effective wavelength range from 400 nm to 550 nm to a maximum integrated irradiance within the bilirubin-effective wavelength range that is greater than 40% within the treatment area.

[0013] Another embodiment of the invention is directed to a phototherapy system comprising a light-emitting apparatus comprising a plurality of light sources positioned ona flexible substrate, the plurality of light sources being configured to emit light having a peak intensity at a peak wavelength within a wavelength range from 430 nm to 490 nm and a lens array positioned in optical communication with the light emitting apparatus, the lens array comprising a plurality of lenslets configured to at least one of collimate light emitted by the light-emitting apparatus and reduce a divergence of light emitted by the light-emitting apparatus. A portion of a field of light emitted by the phototherapy system defines a treatment area. A spatial power distribution of light emitted from the phototherapy system has a ratio of a minimum integrated irradiance within a bilirubineffective wavelength range from 400 nm to 550 nm to a maximum integrated irradiance within the bilirubin-effective wavelength range that is greater than 40% within the treatment area. The peak intensity at the peak wavelength within the range from 430 nm to 490 nm may be a dominant wavelength of light emitted by the phototherapy system.

[0014] In further embodiments, each lenslet of the plurality of lenslets may be at least one of axially aligned with a light emission axis of a light source of the plurality of light sources, axially aligned with one of a plurality of light emission axes comprised by a light source of the plurality of light sources, and axially aligned with a composite axis positioned parallel to and equidistant from two or more light emission axes comprised by a light source of the plurality of light emitting elements. Each lenslet of the plurality of lenslets may comprise at least one prism structure. The lens array may be formed of a flexible material and configured to conform to a flexure of the light-emitting apparatus.

[0015] In some embodiments the lens array may comprise a first set of lenslets positioned in a first surface configured to modify an angular distribution of light emitted from the light-emitting apparatus and emit angularly redistributed light and a second set of lenslets positioned in a second surface configured to collimate the angularly redistributed light and emit collimated light.

[0016] In some embodiments, the plurality of light sources may be further configured to emit at least a second light having a peak intensity at a second peak wavelength within a second wavelength range from 500 nm to 700 nm. In some embodiments, the plurality of lenslets is a plurality of Fresnel lenslets. The plurality of light sources may be distributed in a pattern on the flexible substrate. The plurality of Fresnel lenslets may be distributed in a pattern in the lens array corresponding to the pattern of the plurality of light sources. The Fresnel lenslets may have one of a square geometry, a hexagonal geometry, and a polygonal geometry configured to minimize space between adjacent Fresnel lenses.

[0017] Another embodiment of the invention is directed to a phototherapy system comprising a light-emitting apparatus comprising a plurality of light sources, the plurality of light sources being configured to emit light having a peak intensity at a peak wavelength within a wavelength range from 430 nm to 490 nm, a photoluminescent layer comprising a photoluminescent material positioned to be irradiated by the light-emitting apparatus and emit light having a peak or dominant wavelength within a range from 525 nm to 675 nm, and a lens array positioned in optical communication with the photoluminescent layer, the lens array comprising a plurality of lenslets configured to at least one of collimate light emitted by the photoluminescent layer and reduce a divergence of light emitted by the photoluminescent layer. A spectral power distribution (SPD) of light emitted from the phototherapy system comprises an SPD peak intensity within a wavelength range from 430 nm to 490 nm that is greater than a local maximum intensity within a range from 490 nm to 700 nm.

[0018] In some embodiments, the SPD peak intensity may be a dominant wavelength of light emitted by the phototherapy system. The photoluminescent material may be a phosphor material. The phosphor material may comprises a first phosphor type configured to emit light having a peak or dominant intensity within a first wavelength range centered at a first wavelength within a range from 490 nm to 700 nm and a second phosphor type configured to emit light having a peak or dominant intensity within a second wavelength range centered at a second wavelength within a range from 490 nm to 700 nm. The first wavelength may be nonequivalent to the second wavelength.

[0019] In some embodiments, light emitted by the phototherapy system may have a spectral irradiance within the wavelength range from 430 nm to 490 nm of at least 30 μW / cm2 / nm at a designed skin irradiance distance.

[0020] In some embodiments, the photoluminescent layer may be applied to a light-emitting surface of the light-emitting apparatus and / or a light receiving surface of the lens array. The photoluminescent layer may be comprised by a removable optic that is positionable in optical communication with the light-emitting apparatus and configured to be selectively removable from the phototherapy system.

[0021] In some embodiments, each lenslet of the plurality of lenslets may be at least one of axially aligned with a light emission axis of a light source of the plurality of light sources, axially aligned with one of a plurality of light emission axes comprised by a light source of the plurality of light sources, and axially aligned with a composite axis positioned parallel to and equidistant from two or more light emission axes comprised bya light source of the plurality of light emitting elements. Each lenslet of the plurality of lenslets may comprise at least one prism structure.

[0022] In some embodiments, the lens array comprises a first set of lenslets positioned in a first surface configured to modify an angular distribution of light emitted from the photoluminescent layer and emit angularly redistributed light and a second set of lenslets positioned in a second surface configured to collimate the angularly redistributed light and emit substantially collimated light.

[0023] In some embodiments, the plurality of lenslets is a plurality of Fresnel lenslets. The plurality of light sources may be distributed in a pattern on a substrate an the plurality of Fresnel lenslets may be distributed in a pattern in the lens array corresponding to the pattern of the plurality of light sources. The Fresnel lenslets may have one of a square geometry, a hexagonal geometry, and a polygonal geometry configured to minimize space between adjacent Fresnel lenses.

[0024] In some embodiments, a portion of a field of light emitted by the phototherapy system defines a treatment area. A spatial power distribution of light emitted from the phototherapy system has a ratio of a minimum integrated irradiance within a bilirubin-effective wavelength range from 400 nm to 550 nm to a maximum integrated irradiance within the bilirubin-effective wavelength range that is greater than 40% within the treatment area.Brief Description of the Drawings

[0025] FIG. 1 is a side sectional view of a phototherapy system according to an embodiment of the invention.

[0026] FIG. 2 is a side sectional view of the phototherapy system according to the embodiment of FIG. 1 where the phototherapy system is flexed.

[0027] FIG. 3 is a graph illustrating the spectral power distribution of light emitted by a phototherapy system according to an embodiment of the invention.

[0028] FIG. 4 is a side sectional view of a phototherapy system according to an embodiment of the invention.

[0029] FIG. 5 is a partial perspective view of a lens array of the phototherapy system of FIG. 1 when flexed.

[0030] FIG. 6 is a partial view of the phototherapy system of FIG. 4 depicting the refraction of light emitted by the phototherapy system.

[0031] FIG. 7 is a partial perspective view of a lens array according to an embodiment of the invention.

[0032] FIG. 8 is a side sectional view of a phototherapy system according to an embodiment of the invention.

[0033] FIG. 9 is a side sectional view of a phototherapy system according to an embodiment of the invention.

[0034] FIG. 10 is an environmental view of a phototherapy system according to an embodiment of the invention being used in practice.Detailed Description of the Invention

[0035] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Those of ordinary skill in the art realize that the following descriptions of the embodiments of the present invention are illustrative and are not intended to be limiting in any way. Other embodiments of the present invention will readily suggest themselves to such skilled persons having the benefit of this disclosure. Like numbers refer to like elements throughout.

[0036] Although the following detailed description contains many specifics for the purposes of illustration, anyone of ordinary skill in the art will appreciate that many variations and alterations to the following details are within the scope of the invention. Accordingly, the following embodiments of the invention are set forth without any loss of generality to, and without imposing limitations upon, the invention.

[0037] In this detailed description of the present invention, a person skilled in the art should note that directional terms, such as “above,” “below,” “upper,” “lower,” and other like terms are used for the convenience of the reader in reference to the drawings. Also, a person skilled in the art should notice this description may contain other terminology to convey position, orientation, and direction without departing from the principles of the present invention.

[0038] Furthermore, in this detailed description, a person skilled in the art should note that quantitative qualifying terms such as “generally,” “substantially,” “mostly,” and other terms are used, in general, to mean that the referred to object, characteristic, orquality constitutes a majority of the subject of the reference. The meaning of any of these terms is dependent upon the context within which it is used, and the meaning may be expressly modified.

[0039] An embodiment of the invention, as shown and described by the various figures and accompanying text, provides a phototherapy system for the treatment of hyperbilirubinemia. In some embodiments, the spectral power distribution (SPD) of light emitted from a phototherapy system according to the embodiments may have a peak intensity within a wavelength range from 430 nm to 490 nm, within the blue light wavelength range. The SPD may further comprise a local maximum intensity within a wavelength range from 490 nm to 700 nm, outside the blue light wavelength range. The peak intensity within the blue light wavelength range may be greater than the peak intensity outside the blue wavelength range. Light emitted by the phototherapy system may have a spectral irradiance within the wavelength range from 430 nm to 490 nm of at least 30 μW / cm2 / nm at a designed skin irradiation distance. A portion of a field of light emitted by the phototherapy system may define a treatment area, i.e. the area within which skin of the patient is to be treated for hyperbilirubinemia. The SPD of light emitted from the phototherapy system may have a ratio of a minimum integrated irradiance within a bilirubin-effective wavelength range from 400 nm to 550 nm to a maximum integrated irradiance within the bilirubin-effective wavelength range that is greater than 40% within the treatment area.

[0040] Referring now to FIGS. 1-3, a phototherapy system 100 according to an embodiment of the invention is presented. The phototherapy system 100 may comprise a light-emitting apparatus 110. The light-emitting apparatus 110 may be configured to emit therapeutic light in the direction of a person to be treated. The light-emitting apparatus 110 may comprise a substrate 112 and a plurality of light-emitting elements / light sources 114 positioned on the substrate 112. The substrate 112 may be formed of a flexible material to permit flexure of the phototherapy system 100. Flexure of the phototherapy system as enabled by the substrate 112 is shown in FIG. 2. Examples of such materials may include polymeric materials. In some embodiments, the substrate 112 may be opaque to prevent light emitted from the plurality of light sources 114 from passing therethrough. In some embodiments, conductive material (not shown) may be applied to or embedded into the substrate 112 to electrically connect the plurality of light sources 114 to each other and / or to a controller / power source.

[0041] The plurality of light sources 114 may be any light-emitting element as is known in the art, including, but not limited to, light-emitting semiconductor devices, suchas light-emitting diodes (LEDs). Any type of LED as is known in the art is contemplated and included within the scope of the invention. In the present embodiment, the plurality of light sources 114 may be LEDs configured to emit blue light, i.e. light having a peak intensity within a wavelength range from 430 nm to 490 nm. In some embodiments, the plurality of light sources 114 may be further configured to emit light having a peak intensity at a second peak wavelength within a second wavelength range. In some embodiments, the second wavelength range may be from 500 nm to 700 nm.

[0042] The plurality of light sources 114 may be distributed on the substrate 112 in any manner, including patterned distribution, random distribution, semi-random distribution, and the like. Types of patterns may include, but are not limited to, arrays, offset arrays, and the like.

[0043] The phototherapy system 100 may further comprise a photo luminescent layer 120. In some embodiments, the photoluminescent layer 120 may be formed on, applied to, attached to, or otherwise positioned adjacent to a light-emitting surface of the light-emitting apparatus 110. In some embodiments, the photoluminescent layer 120 may be formed on, applied to, attached to, or otherwise positioned on an optical element that may be removably positionable adjacent to the light-emitting surface of the light-emitting apparatus 110. The photoluminescent layer 120 may be configured to conform to the flexure of the phototherapy system 100 as shown in FIG. 2.

[0044] The phototherapy system 100 may be employed in use-cases where additional refraction, collimation, or other changes to the distribution characteristics of light emitted by the light-emitting apparatus 110 is not required. Types of such use-cases include, but are not limited to, phototherapy bedding, phototherapy blankets, phototherapy clothing, or other scenarios where the phototherapy system 100 is positioned in close proximity to the patient.

[0045] The photoluminescent layer 120 may comprise a photoluminescent material. The photoluminescent material may be any photoluminescent material as is known in the art, including, but not limited to, phosphorescent materials and quantum dot materials. The photoluminescent material may be configured to absorb light emitted by the plurality of light sources 114 in a first wavelength range and emit light in a second wavelength range that is different from the first wavelength range. In some embodiments, the photoluminescent material may be configured to absorb light within a wavelength range from 430 nm to 490 nm or any subrange within those wavelengths. Furthermore, the photoluminescent material may be configured to emit light within a wavelength range from 490 nm to 700 nm or any subrange within those wavelengths. In the presentembodiment, the photoluminescent layer 120 may comprise a photo luminescent material configured to emit light within a wavelength range from 525 nm to 675 nm, or a narrower wavelength range therebetween. In some embodiments, the photoluminescent later may comprise first and second types of phosphor, the first phosphor type configured to emit light having a peak or dominant intensity within a first wavelength range centered at a first wavelength within a range from 490 nm to 700 nm, and a second phosphor type configured to emit light having a peak or dominant intensity within a second wavelength range centered at a second wavelength within a range from 490 nm to 700 nm. The first wavelength may be nonequivalent to the second wavelength.

[0046] The thickness of the photoluminescent layer 120 may impact the proportion of light emitted by the plurality of light sources 114 that is converted from the first wavelength range to the second wavelength range. Such thickness may be selected to accomplish the relative spectral peaks as described above in the first and second wavelength ranges, i.e. from 400 nm to 490 nm and from 490 nm to 700 nm. Referring now additionally to FIG. 3, a spectral power graph 300 showing a first spectral intensity peak 302 within the wavelength range from 400 nm to 490 nm and a second spectral intensity peak 304 within the wavelength range from 490 nm to 700 nm. In the present embodiment, the first peak 302 is centered at about 452 nm ± 5 nm and the second peak 304 is centered at about 545 nm ± 5 nm. In some embodiments, the first peak may have a full width at half maximum (FWHM) measurement of 15-16 nm. It is contemplated and included within the scope of the invention that the first and second peaks 302, 304 may be centered at any wavelength within the first and second ranges provided above. In some embodiments, the second peak 304 may be centered at about 580 nm.

[0047] Referring now to FIGS. 4-6, a phototherapy system 400 according to another embodiment of the invention is presented. Similar to the phototherapy system 100 of FIGS. 1-2, the phototherapy system 400 may comprise a light-emitting apparatus 410 comprising a flexible substrate 412 and a plurality of light sources 414 positioned on the substrate 412, the plurality of light sources 414 having the same emission characteristics of the plurality of light sources 114 of phototherapy system 100.

[0048] The phototherapy system 400 may further comprise a photoluminescent layer 420 comprising a photoluminescent material similar to that of the photoluminescent layer 120 of FIGS. 1-2. The phototherapy system 400 may further comprise a lens or structured optical element array 430. The lens or structured optical element array 430 may be positioned in optical communication with each of the light-emitting apparatus 410 and the photoluminescent layer 420. The lens or micro-structured optical element array430 may comprise a plurality of lenslets or micro-structured optical elements 432. Each lenslet or micro-structured optical element 432 may function as an independent lens or micro-structured light refraction or reflection element and be configured to refract light that passes therethrough. In some embodiments, each lenslet or micro-structured optical element 432 may comprise at least one prism structure, including the prism structure in a Fresnel lens, in a non-inverted pyramid or an inverted air pyramid, in a non-inverted pyramid or an inverted air pyramid, and in a non-inverted polygon cone or an inverted air polygon cone. Within each lenslet or micro-structured optical element, there may be multiple ordered or random prism structures, with each prism structure functioning to refract or reflect a light ray to a certain desired direction such that the overall illumination on a patient skin is made to be sufficiently uniform. As shown in FIG. 5, the lens or microstructured optical element array 430 may be formed of one or more flexible materials and be configured to conform to the flexure of the substrate 412 / light-emitting apparatus 410. The photoluminescent layer 420 may be applied to, attached to, or positioned on one or both of the light-emitting apparatus 410 or the lens or micro-structured optical element array 430.

[0049] As mentioned above, the plurality of light sources 414 may be distributed on the substrate 412 in any manner, including in a patterned distribution. In some embodiments, the plurality of lenslets or micro-structured optical elements 432 may be distributed in the lens or micro-structured optical element array 430 in a pattern that matches the pattern of distribution of the plurality of light sources 414. In some embodiments, the plurality of lenslets or micro-structured optical elements 432 may be distributed in a manner that does not match the pattern of distribution of the plurality of light sources 414.

[0050] Each lenslet or micro-structured optical element 432 may be aligned with a light emission axis 416 of a light source of the plurality of light sources 414 as shown in FIG.6. The light emission axes 416 may represent an axis about which light emitted by each light source may be approximately symmetrically distributed. Referring now to FIG. 6, refraction by the plurality of lenslets is presented. The lenslet 432 may be aligned with the light emission axis 416 of a light source 414 and refract light emitted thereby. In some embodiments, the lenslets or micro-structured optical elements 432 may collimate or redistribute or otherwise reduce the divergence of light passing therethrough.

[0051] The plurality of lenslets or micro-structured optical elements 432 may be any type of lens as is known in the art, including, but not limited to, Fresnel lenses. As shown in FIG. 7, the lens or micro-structured optical element array 430 may comprise theplurality of lenslets or micro-structured optical elements 432 in a patterned distribution. The plurality of lenslets or micro-structured optical elements may have any geometry as is known in the art, including, but not limited to, hexagons, circles, triangles, squares, rectangles, parallelograms, and any other polygonal geometry. In some embodiments, the geometry of the plurality of lenslets or micro-structured optical elements 432 may be selected to one or both of conform to the distribution of the plurality of light sources 414 or minimize the space between adjacent lenslets or micro-structured optical elements 432. In some embodiments, the plurality of lenslets or micro-structured optical elements 432 may be spaced apart to permit the plurality of lenslets or micro-structured optical elements 432 to be axially aligned with the plurality of light sources 414 as described above. The flexibility of the lens or micro-structured optical element array 430 is further shown in FIG. 7.

[0052] Referring now to FIG. 8, a phototherapy system 800 according to another embodiment of the invention is presented. The phototherapy system 800 comprises a light-emitting apparatus 810 comprising a substrate 812 and a plurality of light sources 814 positioned on the substrate 812. The phototherapy system 800 further comprises a photo luminescent layer 820 positioned adjacent to the light-emitting apparatus 810. The phototherapy system 800 may further comprise a lens or micro-structured optical element array 830 comprising a first surface 832 and a first set of lenslets or micro-structured optical elements 834 positioned in the first surface 832. The first plurality of lenslets or micro-structured optical elements 834 may be configured to modify an angular distribution of light 842 emitted from the photoluminescent layer 820 and emit angularly redistributed light 844. Such angularly redistributed light 844 may have redistributed divergence than light emitted by the photoluminescent layer 820. The lens or micro-structured optical element array 830 may further comprise a second set of lenslets or micro-structured optical elements 838 in a second surface 836 of the lens or micro-structured optical element array 830. The second set of lenslets or micro-structured optical elements 838 may be configured to collimate the angularly redistributed light 844 emitted from the first set of lenslets or micro-structured optical elements 834 and emit substantially collimated light 846, as shown in emitted light 840.

[0053] Referring now to FIG. 9, a phototherapy system 900 according to another embodiment of the invention is presented. The phototherapy system 900 comprises a light-emitting apparatus 910 including a substrate 912 and a plurality of light sources 914 configured to emit light having a spectral peak within a first wavelength range and positioned on the substrate 912. The phototherapy system 900 may further comprise afirst photoluminescent layer 920 comprising a first photoluminescent material. The first photoluminescent layer 920 may be positioned adjacent to the plurality of light sources 914. The first photoluminescent material may be operable to absorb light emitted by the plurality of light sources 914 having a wavelength within the first wavelength range and emit light having a spectral peak within a second wavelength range that is different from the first wavelength range.

[0054] The phototherapy system 900 may further comprise a second photoluminescent layer 922 comprising a second photoluminescent material. In the present embodiment, the second photoluminescent layer 922 is positioned adjacent to the first photoluminescent layer 920 such that the first photoluminescent layer 920 is positioned between the plurality of light sources 914 and the second photoluminescent layer 922. Different configurations of the positioning of the first and second photoluminescent layers 920, 922 are contemplated and included within the scope of the invention, including, but not limited to, the second photoluminescent layer 922 being positioned between, the plurality of light sources 914 and the first photoluminescent layer 920 and the first and second photoluminescent layers 920, 922 being interspersed, mixed, patterned, or otherwise both positioned adjacent to the plurality of light sources 914.

[0055] The second photoluminescent material may be operable to absorb light having a wavelength within one or both of the first wavelength range or the second wavelength range and emit light having a spectral peak within a third wavelength range that is different from the first wavelength range and the second wavelength range.

[0056] Referring now to FIG. 10, a phototherapy system 1000 for the treatment of hyperbilirubinemia is presented. The SPD of light emitted from a phototherapy system 1000 may have a peak intensity within a wavelength range from 430 nm to 490 nm, within the blue lightwavelength range. The SPD may further comprise a local maximum intensity within a wavelength range from 490 nm to 700 nm, outside the blue light wavelength range. The peak intensity within the blue light wavelength range may be greater than peak intensity outside the blue wavelength range. The phototherapy system 1000 may be positioned to emit light into a field of light 1002. A portion of a field of light 1002 emitted by the phototherapy system 1000 may define a treatment area 1004, such that the light emitted thereby irradiates objects at a target distance d where a patient to be irradiated the light is expected to be positioned for treatment of hyperbilirubinemia. Light emitted by the phototherapy system 1000 may have a spectral irradiance within the wavelength range from 430 nm to 490 nm, i.e. a bilirubin-effective wavelength range, of at least 30μW / cm2 / nm at distance d within the treatment area 1004. The SPD of light emitted from the phototherapy system 1000 may have a ratio of a minimum integrated irradiance within a bilirubin-effective wavelength range from 400 nm to 550 nm to a maximum integrated irradiance within the bilirubin-effective wavelength range that is greater than 40% within the treatment area.

[0057] Some of the illustrative aspects of the present invention may be advantageous in solving the problems herein described and other problems not discussed which are discoverable by a skilled artisan.

[0058] While the above description contains much specificity, these should not be construed as limitations on the scope of any embodiment, but as exemplifications of the presented embodiments thereof. Many other ramifications and variations are possible within the teachings of the various embodiments. While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best or only mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the description of the invention. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items.

Claims

What is claimed is:

1. A phototherapy system (100) comprising: a light-emitting apparatus (110) comprising a plurality of light sources (114) positioned on a flexible substrate (112), the plurality of light sources (114) being configured to emit light having a peak intensity within a wavelength range from 430 nm to 490 nm; and a photoluminescent layer (120) comprising a photoluminescent material positioned to be irradiated by the light-emitting apparatus (110) and emit light having a peak wavelength within a second range from 525 nm to 675 nm; wherein a spectral power distribution (SPD) of light emitted from the phototherapy system (100) comprises an SPD peak intensity within the wavelength range from 430 nm to 490 nm that is greater than a local maximum intensity within a wavelength range from 490 nm to 700 nm.

2. The phototherapy system (100) of claim 1 wherein the SPD peak intensity is a dominant wavelength of light emitted by the phototherapy system (100).

3. The phototherapy system (100) of one of claims 1 or 2 wherein the photoluminescent material is a phosphor material.

4. The phototherapy system (100) of claim 3 wherein the phosphor material comprises: a first phosphor type configured to emit light having a peak intensity within a first wavelength range centered at a first wavelength within a range from 490 nm to 700 nm; and a second phosphor type configured to emit light having a peak intensity within a second wavelength range centered at a second wavelength within a range from 490 nm to 700 nm; wherein the first wavelength is nonequivalent to the second wavelength.

5. The phototherapy system (100) of one of claims 1 -3 wherein the light emitted by the phototherapy system (100) has a spectral irradiance within the wavelength range from 430 nm to 490 nm of at least 30 μW / cm2 / nm at a designed skin irradiation distance.

6. The phototherapy system (100) of one of claims 1-3 or 5 wherein the photoluminescent layer (120) is applied to a light-emitting surface of the light-emitting apparatus (110).

7. The phototherapy system (100) of one of claims 1-3 or 5 or 6 wherein the photoluminescent layer (120) is comprised by a removable optic that is positionable in optical communication with the light-emitting apparatus (110) and configured to be selectively removable from the phototherapy system (100).

8. The phototherapy system (100) of one of claims 1-3 or 5-7 further comprising a lens array (430) positioned in optical communication with the photoluminescent layer (120), the lens array (430) comprising a plurality of lenslets (432) configured to at least one of collimate light emitted by the photoluminescent layer (120) and reduce a divergence of light emitted by the photoluminescent layer (120).

9. The phototherapy system (100) of claim 8 wherein each lenslet of the plurality of lenslets (432) is at least one of axially aligned with a light emission axis (416) of a light source of the plurality of light sources (114), axially aligned with one of a plurality of light emission axes comprised by a light source of the plurality of light sources (114), and axially aligned with a composite axis positioned parallel to and equidistant from two or more light emission axes comprised by a light source of the plurality of light emitting elements.

10. The phototherapy system (100) of claim 8 wherein each lenslet of the plurality of lenslets (432) comprise at least one prism structure.

11. The phototherapy system (100) of claim 8 wherein the photoluminescent layer (120) is applied to a light receiving surface of the lens array (430).

12. The phototherapy system (100) of claim 8 wherein: the lens array (430) is formed of a flexible material; and the lens array (430) is configured to conform to a flexure of the light-emitting apparatus (110).

13. The phototherapy system (100) of claim 8 wherein the lens array (430) comprises: a first set of lenslets positioned in a first surface configured to modify an angular distribution of light emitted from the photoluminescent layer (120) and emit angularly redistributed light; and a second set of lenslets positioned in a second surface configured to collimate the angularly redistributed light and emit substantially collimated light.

14. The phototherapy system (100) of claim 8 wherein the plurality of lenslets (432) is a plurality of Fresnel lenslets (432).

15. The phototherapy system (100) of claim 14 wherein: the plurality of light sources (114) is distributed in a pattern on the flexible substrate (112); and the plurality of Fresnel lenslets (432) is distributed in a pattern in the lens array (430) corresponding to the pattern of the plurality of light sources (114).

16. The phototherapy system (100) of claim 15 where the Fresnel lenslets have one of a circular geometry, a square geometry, a hexagonal geometry, and a polygonal geometry configured to minimize space between adjacent Fresnel lenses.

17. The phototherapy system (100) of claim 8 wherein: a portion of a field of light emitted by the phototherapy system (100) defines a treatment area; and a spatial power distribution of light emitted from the phototherapy system (100) has a ratio of a minimum integrated irradiance within a bilirubin-effective wavelength range from 400 nm to 550 nm to a maximum integrated irradiance within the bilirubineffective wavelength range that is greater than 40% within the treatment area.

18. A phototherapy system (100) comprising: a light-emitting apparatus (110) comprising a plurality of light sources (114) positioned on a flexible substrate (112), the plurality of light sources (114) being configured to emit light having a peak intensity at a peak wavelength within a wavelength range from 430 nm to 490 nm; anda lens array (430) positioned in optical communication with the light emitting apparatus, the lens array (430) comprising a plurality of lenslets (432) configured to at least one of collimate light emitted by the light-emitting apparatus (110) and reduce a divergence of light emitted by the light-emitting apparatus (110); wherein a portion of a field of light emitted by the phototherapy system (100) defines a treatment area; and wherein a spatial power distribution of light emitted from the phototherapy system (100) has a ratio of a minimum integrated irradiance within a bilirubin-effective wavelength range from 400 nm to 550 nm to a maximum integrated irradiance within the bilirubin-effective wavelength range that is greater than 40% within the treatment area.

19. The phototherapy system (100) of claim 18 wherein the peak intensity at the peak wavelength within the range from 430 nm to 490 nm is a dominant wavelength of light emitted by the phototherapy system (100).

20. The phototherapy system (100) of one of claims 18 or 19 wherein each lenslet of the plurality of lenslets (432) is at least one of axially aligned with a light emission axis (416) of a light source of the plurality of light sources (114), axially aligned with one of a plurality of light emission axes comprised by a light source of the plurality of light sources (114), and axially aligned with a composite axis positioned parallel to and equidistant from two or more light emission axes comprised by a light source of the plurality of light emitting elements.

21. The phototherapy system (100) of one of claims 18-20 wherein each lenslet of the plurality of lenslets (432) comprise at least one prism structure.

22. The phototherapy system (100) of one of claims 18-21 wherein: the lens array (430) is formed of a flexible material; and the lens array (430) is configured to conform to a flexure of the light-emitting apparatus (110).

23. The phototherapy system (100) of one of claims 18-22 wherein the lens array (430) comprises:a first set of lenslets positioned in a first surface configured to modify an angular distribution of light emitted from the light-emitting apparatus (110) and emit angularly redistributed light; and a second set of lenslets positioned in a second surface configured to collimate the angularly redistributed light and emit collimated light.

24. The phototherapy system (100) of one of claims 18-23 wherein the plurality of light sources (114) are further configured to emit at least a second light having a peak intensity at a second peak wavelength within a second wavelength range from 500 nm to 700 nm.

25. The phototherapy system (100) of one of claims 18-24 wherein the plurality of lenslets (432) is a plurality of Fresnel lenslets (432).

26. The phototherapy system (100) of claim 25 wherein: the plurality of light sources (114) is distributed in a pattern on the flexible substrate (112); and the plurality of Fresnel lenslets (432) is distributed in a pattern in the lens array (430) corresponding to the pattern of the plurality of light sources (114).

27. The phototherapy system (100) of claim 26 where the Fresnel lenslets have one of a square geometry, a hexagonal geometry, and a polygonal geometry configured to minimize space between adjacent Fresnel lenses.

28. A phototherapy system (100) comprising: a light-emitting apparatus (110) comprising a plurality of light sources (114), the plurality of light sources (114) being configured to emit light having a peak intensity at a peak wavelength within a wavelength range from 430 nm to 490 nm; a photoluminescent layer (120) comprising a photoluminescent material positioned to be irradiated by the light-emitting apparatus (110) and emit light having a peak or dominant wavelength within a range from 525 nm to 675 nm; and a lens array (430) positioned in optical communication with the photoluminescent layer (120), the lens array (430) comprising a plurality of lenslets (432) configured to at least one of collimate light emitted by the photoluminescent layer (120) and reduce a divergence of light emitted by the photoluminescent layer (120);wherein a spectral power distribution (SPD) of light emitted from the phototherapy system (100) comprises an SPD peak intensity within a wavelength range from 430 nm to 490 nm that is greater than a local maximum intensity within a range from 490 nm to 700 nm.

29. The phototherapy system (100) of claim 28 wherein the SPD peak intensity is a dominant wavelength of light emitted by the phototherapy system (100).

30. The phototherapy system (100) of one of claims 28 or 29 wherein the photoluminescent material is a phosphor material.

31. The phototherapy system (100) of claim 30 wherein the phosphor material comprises: a first phosphor type configured to emit light having a peak or dominant intensity within a first wavelength range centered at a first wavelength within a range from 490 nm to 700 nm; and a second phosphor type configured to emit light having a peak or dominant intensity within a second wavelength range centered at a second wavelength within a range from 490 nm to 700 nm; wherein the first wavelength is nonequivalent to the second wavelength.

32. The phototherapy system (100) of one of claims 28-30 wherein the light emitted by the phototherapy system (100) has a spectral irradiance within the wavelength range from 430 nm to 490 nm of at least 30 μW / cm2 / nm at a designed skin irradiance distance.

33. The phototherapy system (100) of one of claims 28-30 or 32 wherein the photoluminescent layer (120) is applied to a light-emitting surface of the light-emitting apparatus (110).

34. The phototherapy system (100) of one of claims 28-30 or 32 or 33 wherein the photoluminescent layer (120) is comprised by a removable optic that is positionable in optical communication with the light-emitting apparatus (110) and configured to be selectively removable from the phototherapy system (100).

35. The phototherapy system (100) of one of claims 28-30 or 32-34 wherein each lenslet of the plurality of lenslets (432) is at least one of axially aligned with a light emission axis (416) of a light source of the plurality of light sources (114), axially aligned with one of a plurality of light emission axes comprised by a light source of the plurality of light sources (114), and axially aligned with a composite axis positioned parallel to and equidistant from two or more light emission axes comprised by a light source of the plurality of light emitting elements.

36. The phototherapy system (100) of one of claims 28-30 or 32-35 wherein each lenslet of the plurality of lenslets (432) comprise at least one prism structure.

37. The phototherapy system (100) of one of claims 28-30 or 32-36 wherein the photoluminescent layer (120) is applied to a light receiving surface of the lens array (430).

38. The phototherapy system (100) of one of claims 28-30 or 32-37 wherein the lens array (430) comprises: a first set of lenslets positioned in a first surface configured to modify an angular distribution of light emitted from the photoluminescent layer (120) and emit angularly redistributed light; and a second set of lenslets positioned in a second surface configured to collimate the angularly redistributed light and emit substantially collimated light.

39. The phototherapy system (100) of one of claims 28-30 or 32-38 wherein the plurality of lenslets (432) is a plurality of Fresnel lenslets (432).

40. The phototherapy system (100) of claim 39 wherein: the plurality of light sources (114) is distributed in a pattern on a substrate; and the plurality of Fresnel lenslets (432) is distributed in a pattern in the lens array (430) corresponding to the pattern of the plurality of light sources (114).

41. The phototherapy system (100) of claim 40 where the Fresnel lenslets have one of a square geometry, a hexagonal geometry, and a polygonal geometry configured to minimize space between adjacent Fresnel lenses.

42. The phototherapy system (100) of one of claims 28-30 or 32-39 wherein: a portion of a field of light emitted by the phototherapy system (100) defines a treatment area; and a spatial power distribution of light emitted from the phototherapy system (100) has a ratio of a minimum integrated irradiance within a bilirubin-effective wavelength range from 400 nm to 550 nm to a maximum integrated irradiance within the bilirubineffective wavelength range that is greater than 40% within the treatment area.

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