WO2020014786A1

WO2020014786A1 - Fluoresence imaging apparatus and method

Info

Publication number: WO2020014786A1
Application number: PCT/CA2019/050990
Authority: WO
Inventors: Thomas Bernard KERBER
Original assignee: Kerber Thomas Bernard
Priority date: 2018-07-17
Filing date: 2019-07-17
Publication date: 2020-01-23

Abstract

An imaging method and apparatus is provided for detection and visualization of cutaneous and subcutaneous infections and other conditions. Red or yellow-green light is directed to a biological target structure or area comprising an accumulation of a fluorescable biomarker, such as protoporphyrin IX. Fluoresced light in the red range is then detected by an image sensor, optionally further filtered with a red light filter, to generate a representative image of the target or structure. An apparatus for illuminating the target structure or area includes an illumination apparatus mountable to a smartphone or other electronic device comprising an image sensor and one or more sets of light sources, such as light-emitting diodes, at selected wavelengths arranged in a pattern around a lens directing the fluoresced light to the image sensor.

Description

FLUORESENCE IMAGING APPARATUS AND METHOD

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of United States Provisional Application No. 62/699,723 filed on July 17, 2018, the entirety of which is incorporated herein by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to producing an image on a display screen, and more particularly to methods of and apparatus for producing an image of a portion of a patient’s body on a display screen using a fluorescable biomarker.

BACKGROUND OF THE INVENTION

[0003] Fluorescence imaging is a known technique for detection and visualization of biological processes and/or structures. Typically, a fluorescing agent is administered to a subject to produce fluorescence in response to illumination. The fluorescing agent may comprise a fluorescent compound such as a fluorophore, or a pro-agent that is metabolized to produce a fluorescent compound. The fluorescent compound, whether directly administered or whether synthesized as a result of administration of a pro-agent, is referred to as a fluorescable biomarker. Once an appropriately selected fluorescing agent is administered, the fluorescent compound may accumulate at a target structure or area in a patient. When illuminated with light of a suitable wavelength, the fluorescent compound absorbs the illuminated light and emits light at one or more response frequencies, thus facilitating visualization of the target structure or location. In many cases the emitted wavelengths are in the visible spectrum, and it is possible to detect the fluorescence using an image sensor such as found in a digital camera.

[0004] One example of a fluorescing agent is 5-aminolevulinic acid (5-ALA) or methyl aminolevulinate (MAL), or collectively ALA, which results in production of an intracellular photosynthesizer, protoporphyrin IX (PplX). PplX has known light absorption and emission characteristics, and is further known to accumulate at higher levels in cancer cells than in surrounding tissue. However, prior art system and methods of fluorescent imaging are constrained in the selection of absorption and detection wavelengths.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Novel features believed to be characteristic of the present invention, as to its structure, organization, use and method of operation, will be better understood from the following drawings in which presently preferred embodiments of the invention are illustrated by way of example. It will be understood by those skilled in the art, however, that these drawings are for the purpose of illustration and description only, and are not intended as a definition of the limits of the invention. In the accompanying drawings:

[0006] FIG. 1 is a set of photographs of a healthy breast (a) and a breast infected with mastitis (b), generated with red light after administration of ALA;

[0007] FIG. 2 is a set of photographs of the nose of a patient diagnosed with mucocutaneous leishmaniasis, generated with red light after administration of ALA prior to treatment (a) and after beginning photodynamic therapy treatment (b);

[0008] FIG. 3 is a set of photographs depicting a leishmaniasis lesion in full-spectrum light (a), and images of the lesion area generated using red light after administration of ALA approximately four hours later (b) and after further administration of ALA about four days later

(c);

[0009] FIG. 4 is a set of photographs depicting a leishmaniasis lesion in full-spectrum light (a), and images of the lesion area generated using red light after administration of ALA approximately five hours later (b), after further administration of ALA about four days later (c), and after further administration of ALA about six days later (d);

[00010] FIG. 5 is a front view of an illumination and detection apparatus for imaging a target area; [00011] FIG. 6 is a cutaway side view of the apparatus of FIG. 5;

[00012] FIG. 7 is a rear view of the apparatus of FIG. 5; and,

[00013] FIG. 8 is a flowchart illustrating a high-level process for generating an image using the apparatus of FIG. 5.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[00014] As mentioned above, the use of ALA in the detection of cancer is known. 5-ALA, administered to a patient, results in increased accumulation of PplX at a cancerous tumor. PplX is known to fluoresce in response to illumination, with certain absorption peaks corresponding to emission peaks. For example, PplX is characterized by a significant absorption peak around 407 nm (blue), and smaller peaks around 505 nm (cyan), 535 nm (green), 580 nm (yellow- green), and 635 nm (red). Responsive emissions peak around 635 nm (red) and 705 nm (near- infrared). Consequently, blue light excitation is often suggested in the prior art because of its higher absorption, and because it is easier to discriminate from emitted red or near-infrared light. However, excitation by longer wavelengths may be preferred, because longer wavelengths penetrate further below the skin surface, enabling visualization of more of a target structure or location. Accordingly, in the prior art, when red light excitation is used, wavelengths around the stronger 635 nm emission peak are filtered out.

[00015] However, surprisingly it has been discovered that use of red light (e g., from about 620 nm to about 655 nm) or yellow-green light (e.g., from about 530 nm to about 580 nm) to excite accumulated PplX from the administration of ALA, coupled with detection of emitted red light (e.g., below 650 nm) is sufficient to perform a qualitative assessment of the extent of cutaneous and subcutaneous conditions such as infection (bacterial, parasitic, and/or fungal) and cancerous or precancerous conditions, and other biological structures in which PplX may accumulate at higher concentrations than in neighboring tissue. This permits detection of these conditions to be carried out using simple, low-cost apparatus that is easily deployable to developing countries and requiring minimal technical training Further, the emitted light from a target structure or area can be easily captured by a conventional, CCD (charged-couple device) or less expensive CMOS (complementary metal-oxide-semiconductor) image sensor, and superimposed over a white-light or broader-spectrum image of the same target structure or area and displayed to a clinician or the patient for diagnosis or education.

[00016] FIGS. 1 and 2 are sets of photographs comprising red-light images of lesions in patients diagnosed with mastitis (FIG. 1 ) and mucocutaneous leishmaniasis (FIG. 2), dosed with 5-ALA. FIGS. 3 and 4 are sets of photographs comprising white-light and red-light images of lesions in patients diagnosed with cutaneous leishmanaisis, both pre-treatment and subsequently dosed with 5-ALA. Generally, it was found that fluoresced light captured as a result of illumination by 635 nm light correlated to prior diagnosis

[00017] In FIG. 1 , a patient diagnosed with mastitis in one breast was administered a topical 5-ALA at 20% by weight on the affected breast in Lubriderm® skin lotion on the affected area, and further received a 10 mg/kg oral dose of 5-ALA. Subsequently, healthy breast tissue (not treated with the topical ALA) was subject to illumination by 635 nm light, photographed in (a) At the same time, the affected breast was also illuminated with 635 nm light and photographed (b). As can be seen by comparing the two photographs, the affected breast revealed infection via fluorescence at the infection site. The infection was estimated to be located about 2 to 3 cm below the skin surface, based on typical progress of mastitis.

[00018] The photographs of FIG. 2 depict the nose of a patient diagnosed with mucocutaneous leishmaniasis No anomalies were visually present on the skin surface (no lesions, scarring, etc ). Again, the patient was administered a 10 mg/kg oral dose of 5-ALA. The affected area was subject to 635 nm light and photographed at the start of treatment (a). Later, after initial photodynamic therapy using 5-ALA, the patient received the same dosages and the affected area was again illuminated with 635 nm light (b). As can be seen from a comparison of the two photographs, the fluorescence pattern was altered in dimension. [00019] FIG. 3 depicts a lesion in a first patient, photographed with surrounding tissue first in white (e.g., broad or full-spectrum) light (a). A topical 5-ALA at 20% by weight in Lubriderm® skin lotion, was applied to the affected area and the patient additionally received a 10 mg/kg oral dose of 5-ALA so that PplX may accumulate in other areas affected by leishmaniasis that had not yet ulcerated and were thus not visually detectable. The patient was kept out of the sun to allow the topical 5-ALA to be absorbed. The affected area and its surrounding tissue was then exposed to 635 nm illumination about four hours after initial administration of 5-ALA, which was captured (b). The patient returned for the same treatment about four days later and was again exposed to 635 nm illumination, which was captured (c). As can be seen from a comparison of photographs (b) and (c), the intensity of the captured light is reduced, and a visual inspection showed that healing had started, likely as a result of photodynamic therapy treatment

[00020] FIG. 4 depicts a lesion in a second patient, again photographed with surrounding tissue first in white light (a). The same treatment was given to this patient to the primary lesion near the center of the image, while no topical treatment was applied to the satellite inflammation in the lower left-hand corner of the image. The patient was first exposed to 635 nm illumination about five hours after initial administration of 5-ALA (b). The patient returned for the same treatment about four days later and was again exposed to 635 nm illumination (c), and again a further two days later (d) (a total of six days from (b)). As can be seen in a comparison of (b) to (d), additional fluorescence can be seen between the original wound and inflamed areas.

[00021] In all cases, illumination was provided by red light emitting diodes (LEDs) emitting at about a 635 nm wavelength at a fluence rate (at the skin surface) of about 140 J/cm² over 900 seconds exposure. It was estimated that fluence at a 2 mm depth into skin was about 20% of the surface fluence rate. 635 nm images were captured using a CMOS camera in an inexpensive smartphone (Alcatel® Pixi 4 (6), TCL Communication Technology Holdings Limited, Guangdong, China) and two 75-micron thicknesses of a dye-coated polyethylene terephthalate color effect lighting filter in #106 Primary Red from Rosco Laboratories, Inc., Stamford, CT, USA.

[00022] While it may be expected that reflection of impinging red light on the patient’s skin would combine with emitted red light, rendering it difficult to discern the fluorescence from the accumulated PplX, it was found that a useful representative image could still be formed from the red light resulting from illumination of the patient’s skin surface. The captured red light is believed to be emitted light in the 635 nm range. It is expected that the target structure or area in which PplX has accumulated may be illuminated with yellow-green light (e g , in the range from about 530 nm to about 580 nm) and emitted red light may be successfully captured to provide a similarly useful image representative of the target structure or area It will also be appreciated that where red light of about the same wavelength is used for both excitation and detection, the same color filter may be employed to both generate light of the desired wavelength for excitation, and to filter extraneous light during detection, simplifying the construction of an illumination/detection apparatus. It will be appreciated by those skilled in the art that the disclosed detection methodology and the apparatus discussed below may be effective for detection of any condition that can be distinguished by a naturally-occurring or induced elevation of PplX or a similar fluorescable biomarker in a target structure or area, including, but not necessarily limited to, fungal infections (such as, but not limited to, Trichophyton rubrum and Candida albicans), viral infections (such as, but not limited to, human papillomavirus); parasitic infections (such as, but not limited to, Leishmania (leishmaniasis) and Plasmodium (malaria)); bacterial infections (such as, but not limited to, methicillin-resistant Staphylococcus aureus (MRSA)); lesions and cancerous and pre-cancerous conditions, including tumors and actinic keratosis.

[00023] Excitation and detection may be carried out using a single portable, dual-purpose apparatus, or alternatively by providing an illumination apparatus that can be mounted to a general-purpose electronic device provided with an image sensor, such as a smartphone. The latter is depicted in FIGS. 5-7 with an illumination apparatus 100 mounted on a digital electronic device 184 (in this example, a smartphone), but it will be appreciated by those skilled in the art that with suitable modification, the illumination apparatus 100 and the necessary components of the digital electronic device 184 (e.g., image sensor, microprocessor, display screen) may be combined in a unitary structure. Briefly, an image sensor is capable of capturing images in different light conditions (e g , white light or broader-spectrum light, as well as in selective wavelength illumination conditions). LEDs of selected wavelength surround an optical lens of an image sensor on a face of the illumination apparatus to direct evenly distributed light to a target structure or region containing a fluorescable biomarker. Captured images under different lighting conditions can be stored in memory of the apparatus and displayed on an optional display screen on a reverse face of the apparatus, and/or optionally downloaded via a port or wireless connection (not depicted in the accompanying drawings). Further, in some implementations, an image processing component (e.g., in the digital electronic device 184) may be configured to generate a composite image from a broader-spectrum light image and a selective wavelength image that can be presented to the user of the apparatus (or downloaded) to assist in diagnosis and/or education.

[00024] The configuration and operation of the example combined apparatus 100 and 184 will be described with reference to FIGS. 5-7 and the high-level flowchart of FIG. 8. The apparatus 100 comprises a housing 1 1 1 , having a front 1 1 1f, a back 1 1 1 b, a through-passage 1 12 for an optical lens 180, and an annular light shade 1 13 around the front of the optical lens 180. The optical lens may be a very wide angle (a.k.a. fisheye) lens. The apparatus 100 further comprises one or more light sources, such as LEDs, of yellow-green light 150yg in the wavelength range from about 530 nm to about 580 nm and a source of red light 150r in the wavelength range from about 620 nm to about 655 nm.

[00025] A fan 1 14 and a heat sink 1 15 are provided for cooling the LEDs 150. The apparatus 100 also comprises an electronic circuit 1 18 for driving the various electrical and electronic components. An electronic control interface 1 19 for controlling the LEDs is disposed on the housing 1 1 1 on a face opposing the face on which the LEDs are mounted. Control can include turning each set of LEDs on and off independently or together, as well as altering the brightness of the LEDs since it may be desirable to adjust the intensity of the illumination. The apparatus 100 mounts to a digital electronic device 184, such as a smartphone 184, such that the optical lens 180 is aligned with the image sensor (e.g., a rear-facing CCD or CMOS camera) of the digital electronic device 184, and the electronic control interface 1 19 remains accessible, as can be seen in FIG. 7. The other face of the digital electronic device 184 (e.g. , the face bearing a touchscreen, or display screen and keyboard) sufficiently exposed to permit the operator to control the digital electronic device 184. The optical lens 180 focuses received light onto the image sensor 182 to create a captured image representative of the target structure or object. It has been found that the use of smart phone is highly desirable since many apps are available to permit control of the camera function of suitable smart phones. The general configuration of a smartphone will be understood by those skilled in the art and includes at least one microprocessor and a display screen, as well as the image sensor. The digital electronic device 184 may alternatively be a conventional digital camera (not specifically shown). It should also be understood that the digital electronic device 184 may be used to produce and save either or both of still images and or moving images. A clip-type frame 187, is used to retain the digital electronic device 184 in place with respect to the illumination apparatus 100. Customized adapters (not specifically shown) could also be used in conjunction with the clip-type frame 187. It should be noted that the digital electronic device 184 may also have its own built-in a supplemental lens 180a.

[00026] As an initial step S1 , a fluorescing agent is administered to a patient or other subject. The fluorescing agent may be the types of agents generally described above; as noted above, in the examples of FIGS. 1 -4, ALA was employed. Depending on the method of administration, some delay may be required before the fluorescing agent reaches the target structure or area, particularly if the fluorescing agent is administered internally. After some time, a fluorescable biomarker is expected to accumulate in the target structure or area. The amount of time required will depend on factors such as the fluorescing agent, the mechanism of action of the fluorescence, and the dosage amount. [00027] Subsequently, illumination at a desired wavelength or set of wavelengths is generated at S2. In the example apparatus of FIGS. 5-7, the apparatus 100 is configured to generate either yellow-green light, red light, or both using yellow-green LEDs 150yg or red LEDs 150r, for use in exciting ALA. Yellow-green light is preferably in the wavelength range around about 530 nm to about 580 nm, or more narrowly in the wavelength range from about 560 nm to about 575 nm, or even more narrowly in the wavelength range from about 565 nm to about 570 nm. Red light is preferably in the wavelength range around 620 nm to about 655 nm, or more narrowly in the wavelength range from about 630 nm to about 640 nm, or even more narrowly in the wavelength range from about 633 nm to about 637 nm. While in the example apparatus of FIG. 5, the selective wavelength light is generated using LEDs, in some implementations a broader-spectrum source (e.g., a white light source) may be used, with appropriate color filters disposed in front of the white light to pass through only the selected wavelength range. It will be appreciated by those skilled in the art that different wavelength sources may be employed, depending on the fluorescable biomarker that is to be excited, and its characteristic absorption spectrum.

[00028] In the example of FIG. 5, and as can also be seen in the cutaway view of FIG. 6, LEDs of two different colors are arranged in one or more rings around the lens 180 of the image sensor 182. The yellow-green LEDs 150yg are arranged in an inner circumferential ring of light emitting diodes, while the red light emitting diodes 150r are arranged in an outer circumferential ring of light emitting diodes that is disposed circumferentially around the inner ring of yellow- green light emitting diodes 150yg. The inner circumferential ring of yellow-green light emitting diodes 150yg and the outer circumferential ring of red light emitting diodes 150r are separated one from the other by an annular light barrier 158. As one example, the yellow-green LEDs may be Luxeon Z™ 568 nm LEDs from Lumileds Holding B.V. , Schipol, Netherlands, and LEDs of each color may produce a light intensity of about 50 mW/cm² to about 1000 mW/cm² in a light pattern on surface area of about 30 cm², and may draw an electrical power of about 40 watts to about 100 watts. It is understood by those skilled in the art that LEDs specified to emit light at a given wavelength are subject to manufacturing tolerances; thus, it is generally expected that LEDs of a selected color will emit light at within a selected narrow band of wavelengths around a target wavelength.

[00029] The apparatus may be controllable by an operator to illuminate only one ring of LEDs, the other, or both concurrently. In addition, other colors of LEDs may be added or substituted for the red or yellow-green LEDs, and of course if illumination at only one target wavelength is required, only a single circle of LEDs may be provided, or multiple concentric rings of LEDs of the same color may be provided. Further, while in the example of FIG. 5 the rings of red and yellow-green LEDs are arranged concentrically, in other implementations LEDs of different colors may be positioned in alternating positions around the ring or rings.

[00030] Optionally, a clear uncolored window 159 may be disposed in front of the LEDs 150 for protection. Additionally or alternatively, a yellow-green light filter 191 may be disposed in front of the yellow-green LEDs 150yg in order to filter out any small amounts of red light that might emanate from the yellow-green LEDS. The annular light barrier 158 precludes light from the yellow-green LEDs 150yg from directly shining outwardly past the yellow-green light filter 191 and therefore must pass through the yellow-green light filter 191 .

[00031] At step S3, the generated light in the selected wavelength(s) is directed to the target structure or area, in this example a patient's skin. It is expected that where the target structure is subcutaneous, the light will penetrate subcutaneously to reach the target structure. The light directed to the target structure or area will excite the fluorescable biomarkers in the region of impingement or penetration, thus inducing fluorescence.

[00032] Next, at step S4, a selective-wavelength image is captured from light resulting from the illumination of step S3, using the image sensor 182. The selective-wavelength image will comprise resultant light, resulting from the illumination of the target structure or area, and may therefore include emitted light from the fluorescable biomarker at the target structure or area, and potentially some reflected light. As noted above, the image sensor 182 may be a CCD or CMOS image sensor. [00033] A further step, not shown in FIG. 8, may be that of filtering the light fluoresced by the target structure or area. For example, a red light optical filter 190 may be positioned in behind the optical lens 180 to pass light in the wavelength range of about 600 nm to 900 nm, and even more favorably passes light in the wavelength range of about 600 nm to 650 nm. The optional red light filter 190 is mounted in sliding engagement between the back end of the optical lens 180 and the camera lens 180a of the smart phone 184. The red light filter 190 may be slid into place, as indicated by arrow“A”, and out of place, as indicated by arrow Ί3” Accordingly, the red light filter 190 may be selectively employed as required, in the event that the red light passing through the optical lens 180 contains contaminants, or in other words undesirable wavelengths of light.

[00034] In some implementations, multiple selective-wavelength images may be captured at step S4. For example, a first image may be captured while the yellow-green LEDs are on and the red LEDs are off, and a further image may be captured when the yellow-green LEDs are off and the red LEDs are on. Still other images of other selected wavelengths may be captured if the appropriate light source is provided on the illumination apparatus 100. As different wavelengths penetrate skin to different depths, multiple images of the same target structure or area can be generated at different penetration depths. Each of these images will be representative of the fluorescence of light at different depths. The approximate depth of penetration of each of the wavelengths of light into human tissue may be pre-determined by previous measurement.

[00035] Next, at S5 the selective wavelength illumination is discontinued and a broader spectrum light is directed to the same target structure or area. The broader spectrum light may be white light, either from a light source provided on the illumination apparatus 100 (not shown in the figures), or from an external source such a flash or ambient lighting (e.g., normal room conditions or sunlight). A second image is captured at step S6, preferably while the combined apparatus is in the same approximate position with respect to the target structure or area, and preferably without the use of any filters interposed between the optical lens 180 and the camera lens 180a. It will be appreciated that steps of the method of FIG. 8 may be carried out in different orders while still achieving the intended effect; for example, steps S2 to S4 may follow steps S5 and S6. Digital files representing the captured images may be stored in memory of the digital electronic device 184.

[00036] Subsequently, at step S7, representative images may be generated and viewed separately on the display screen of the digital electronic device 184, but in some implementations, a composite image is generated to produce a single representative image from both the first and second captured images. This composite image can be considered as an amalgamation of a partial image from the first captured image and a partial image from the second captured image, such that one is superimposed over the other while in alignment. Optionally, the alpha channel of one of the captured images may be altered to provide transparency when it is merged with the other captured image. Still further, optionally the operator may manipulate the relative position and/or scaling of the two captured images to bring them into assignment when viewed on the display screen. In this manner, the relative position of the target structure or area identifiable by the selective wavelengths in the first captured image, can be determined by the operator with respect to the visually recognizable features of the second captured image.

[00037] Thus, the above examples and embodiments provide an apparatus, comprising at least one light source for generating light in a narrow wavelength band for direction toward a target structure or area comprising an accumulation of a fluorescable biomarker; an optical lens for receiving resultant light and directing the resultant light to an image sensor, the resultant light comprising fluoresced light emitted by the fluorescable biomarker resulting from illumination of the target structure or area; wherein the at least one light source comprises a plurality of light emitting diodes surrounding said optical lens.

[00038] In one aspect, the plurality of light emitting diodes comprises a first set of light emitting diodes emitting light having a wavelength from about 530 nm to about 580 nm, or from about 620 nm to about 655 nm.

[00039] In another aspect, the plurality of light emitting diodes is arranged in a circle around the optical lens.

[00040] In another aspect, the plurality of light emitting diodes further comprises a second set of light emitting diodes emitting light in a different wavelength range, for example having a wavelength from about 530 nm to about 580 nm, or from about 620 nm to about 655 nm.

[00041] In another aspect, the first set of light emitting diodes is arranged in a circle around the optical lens and the second set of light emitting diodes is arranged in a circle around the optical lens.

[00042] In another aspect, the apparatus further comprises a red light filter to pass only red light of the resultant light to the image sensor.

[00043] In still a further aspect, the apparatus is configured to be mounted on a smartphone comprising the image sensor, a microprocessor, and a display screen.

[00044] In another aspect, the apparatus further comprises the image sensor, microprocessor, and a display screen.

[00045] In another aspect, the microprocessor is configured to generate a composite image from a first and a second image captured by the image sensor, where the first image comprises an image generated from the resultant light and the second image comprises a broader spectrum image of the target structure or area.

[00046] There is also provided an imaging method, comprising: directing red light having a wavelength range from about 620 nm to about 655 nm, and preferably from about 630 nm to about 640 nm, to a target structure or area comprising an accumulation of a fluorescable biomarker; capturing resultant light by an image sensor, the resultant light comprising fluoresced red light emitted by the fluorescable biomarker resulting from illumination of the target structure or area; and generating and displaying an image from the resultant light.

[00047] In another aspect, the red light directed to the target structure or area comprises about 635 nm light.

[00048] There is also provided an imaging method, comprising: directing yellow-green light having a wavelength range from about 530 nm to about 580 nm, and preferably from about 560 nm to about 575 nm, to a target structure or area comprising an accumulation of a fluorescable biomarker; capturing resultant light by an image sensor, the resultant light comprising fluoresced red light emitted by the fluorescable biomarker resulting from illumination of the target structure or area; and generating and displaying an image from the resultant light.

[00049] In another aspect, the yellow-green light directed to the target structure or area comprises about 568 nm light.

[00050] In the imaging methods described above, a further aspect is filtering the resultant light prior to capturing the resultant light by an image sensor to pass only red light to the image sensor.

[00051] In one aspect, the fluoresced red light has a wavelength from about 620 nm to about 655 nm, and preferably from about 630 to about 640 nm.

[00052] In another aspect, the fluorescable biomarker comprises protoporphyrin IX.

[00053] In still another aspect, the target structure or area comprises a cancerous or pre- cancerous condition.

[00054] In another aspect, the target structure or area comprises an infection. The invention may comprise a leishmaniasis lesion or leishmaniasis-infected area or a mastitis infection.

[00055] In another aspect, the resultant light is filtered prior to capturing the resultant light by an image sensor to pass only red light to the image sensor.

[00056] The examples and embodiments are presented only by way of example and are not meant to limit the scope of the subject matter described herein. Each example embodiment presented above may be combined, in whole or in part, with the other examples. Some steps or acts in a process or method may be reordered or omitted, and features and aspects described in respect of one embodiment may be incorporated into other described embodiments. Further, variations of these examples will be apparent to those in the art and are considered to be within the scope of the subject matter described and claimed herein.

[00057] The data employed by the systems, devices, and methods described herein may be stored in one or more data stores. The data stores can be of many different types of storage devices and programming constructs, such as RAM, ROM, flash memory, programming data structures, programming variables, and so forth. Code adapted to provide the systems and methods described above may be provided on many different types of computer-readable media including computer storage mechanisms (e.g., CD-ROM, diskette, RAM, flash memory, computer hard drive, etc.) that contain instructions for use in execution by one or more processors to perform the operations described herein The media on which the code may be provided is generally considered to be non-transitory or physical.

[00058] Use of any particular term should not be construed as limiting the scope or requiring experimentation to implement the claimed subject matter or embodiments described herein. Any suggestion of substitutability of the data processing systems or environments for other implementation means should not be construed as an admission that the invention(s) described herein are abstract, or that the data processing systems or their components are non- essential to the invention(s) described herein.

Claims

CLAIMS:

1. An apparatus, comprising: at least one light source for generating light in a narrow wavelength band for direction toward a target structure or area comprising an accumulation of a fluorescable biomarker; an optical lens for receiving resultant light and directing the resultant light to an image sensor, the resultant light comprising fluoresced light emitted by the fluorescable biomarker resulting from illumination of the target structure or area; wherein the at least one light source comprises a plurality of light emitting diodes surrounding said optical lens.

2. The apparatus of claim 1 , wherein the plurality of light emitting diodes comprises a first set of light emitting diodes emitting light having a wavelength from about 530 nm to about 580 nm.

3. The apparatus of claim 1 , wherein the plurality of light emitting diodes comprises a first set of light emitting diodes emitting light having a wavelength from about 620 nm to about 655 nm.

4. The apparatus of any one or claims 1 to 3, wherein the plurality of light emitting diodes is arranged in a circle around the optical lens.

5. The apparatus of claim 3, wherein the plurality of light emitting diodes further comprises a second set of light emitting diodes emitting light having a wavelength from about 530 nm to about 580 nm.

6. The apparatus of claim 5, wherein the first set of light emitting diodes is arranged in a circle around the optical lens and the second set of light emitting diodes is arranged in a circle around the optical lens.

7. The apparatus of any one of claims 1 to 6, further comprising a red light filter to pass only red light of the resultant light to the image sensor.

8. The apparatus of any one of claims 1 to 7, wherein the apparatus is configured to be mounted on a smartphone comprising the image sensor, a microprocessor, and a display screen.

9. The apparatus of any one of claims 1 to 7, further comprising the image sensor, microprocessor, and a display screen.

10. The apparatus of either claim 8 or 9, wherein the microprocessor is configured to generate a composite image from a first and a second image captured by the image sensor, where the first image comprises an image generated from the resultant light and the second image comprises a broader spectrum image of the target structure or area.

1 1. An imaging method, comprising: directing red light having a wavelength range from about 620 nm to about 655 nm to a target structure or area comprising an accumulation of a fluorescable biomarker; capturing resultant light by an image sensor, the resultant light comprising fluoresced red light emitted by the fluorescable biomarker resulting from illumination of the target structure or area; and generating and displaying an image from the resultant light.

12. The imaging method of claim 1 1 , wherein the red light directed to the target structure or area has a wavelength range from about 630 nm to about 640 nm.

13 The imaging method of claim 12, wherein the red light directed to the target structure or area comprises about 635 nm light.

14. The imaging method of any one of claims 1 1 to 13, further comprising filtering the resultant light prior to capturing the resultant light by an image sensor to pass only red light to the image sensor.

15. The imaging method of claim 14, wherein the fluoresced red light has a wavelength from about 620 nm to about 655 nm.

16. The imaging method of claim 15, wherein the fluoresced red light has a wavelength from about 630 to about 640 nm.

17. The imaging method of any one of claims 1 1 to 16, wherein the fluorescable biomarker comprises protoporphyrin IX.

18. The imaging method of claim 17, wherein the target structure or area comprises a cancerous or pre-cancerous condition.

19. The imaging method of claim 17, wherein the target structure or area comprises an infection.

20. The imaging method of claim 19, wherein the target structure or area comprises a leishmaniasis lesion or leishmaniasis-infected area.

21. The imaging method of claim 19, wherein the target structure or area comprises a mastitis infection.

22. An imaging method, comprising: directing yellow-green light having a wavelength range from about 530 nm to about 580 nm to a target structure or area comprising an accumulation of a fluorescable biomarker; capturing resultant light by an image sensor, the resultant light comprising fluoresced red light emitted by the fluorescable biomarker resulting from illumination of the target structure or area; and generating and displaying an image from the resultant light.

23. The imaging method of claim 22, wherein the yellow-green light directed to the target structure or area has a wavelength range from about 560 nm to about 575 nm.

24. The imaging method of claim 23, wherein the yellow-green light directed to the target structure or area comprises about 568 nm light.

25. The imaging method of any one of claims 22 to 24, further comprising filtering the resultant light prior to capturing the resultant light by an image sensor to pass only red light to the image sensor.

26. The imaging method of claim 25, wherein the fluoresced red light has a wavelength from about 620 nm to about 655 nm.

27. The imaging method of claim 26, wherein the fluoresced red light has a wavelength from about 630 to about 640 nm.

28. The imaging method of any one of claims 22 to 27, wherein the fluorescable biomarker comprises protoporphyrin IX.

29. The imaging method of claim 28, wherein the target structure or area comprises a cancerous or pre-cancerous condition.

30. The imaging method of claim 28, wherein the target structure or area comprises an infection.

31 The imaging method of claim 30, wherein the target structure or area comprises a leishmaniasis lesion or leishmaniasis-infected area.

32. The imaging method of claim 30, wherein the target structure or area comprises a mastitis infection.