AU2021107649A4

AU2021107649A4 - Skin examination device

Info

Publication number: AU2021107649A4
Application number: AU2021107649A
Authority: AU
Inventors: Kar Gay Lim
Original assignee: Macquarie Medical Systems Pty Ltd
Current assignee: Macquarie Medical Systems Pty Ltd
Priority date: 2021-08-24
Filing date: 2021-08-24
Publication date: 2022-02-03
Anticipated expiration: 2029-08-24
Also published as: AU2021107649B4; CN117858660A; AU2023100013A4

Abstract

The invention relates to a skin examination device and method of using the skin examination device. The skin examination device comprises a housing, a light emitting and dispersing means, an image capturing means and a power supply. Activation of the devices emits light within the device whereby a significant amount of light is dispersed and then projected on to a skin site. 10 20 A 22 15 A Fiiur

Description

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TITLE "SKIN EXAMINATION DEVICE" FIELD OF THE INVENTION

[0001] The present invention relates to a skin examination device. In particular, a skin examination device utilising diffused light.

BACKGROUND

[0002] Skin is a vital organ of the human body and often requires examination for disease and damage. In particular, Melanoma (skin cancer) is a high risk disease that can spread rapidly to other organs if it is not identified and diagnose at an early stage.

[0003] According to official Australian government organisation, Cancer Australia, it's the third most commonly diagnosed cancer in 2020 and at least 2 in 3 Australians will be diagnosed with skin cancer before the age of 70. Similarly, according to Skin Cancer Foundation of America, it's estimated that 207,390 cases will be diagnosed in the USA in 2021, and 7,180 (4,600 male, 2,580 female) will die of melanoma in 2021.

[0004] The standard method of detecting skin diseases, such as Melanoma, is usually a physical examination, followed by biopsy when a particular area of the skin is determined to be suspicious by the medical doctor. The usual instruments used by doctors for a physical skin examination are hand held magnifying instruments known as dermoscopes. Additionally, epiluminescence microscopy (ELM) of pigmented lesions of the skin is nowadays a well-established method for the early detection of skin cancer, also for the differential diagnosis of pigmented skin lesions.

[0005] The human skin has an oily surface that reflects light. When taking images of the skin with traditional illuminating devices, the reflection of light by the oily surface will obscure the cells structures underneath in the final image. A known traditional method of reducing this reflection, called the oil immersion method, is to apply oils on the skin and press a glass surface to the surface of the skin. This method can usually produce good images except in situations where the use of oil immersion method is neither suitable nor useful. For example, wounds and significantly curved areas of skin.

[0006] Known in the art is a handheld skin examination device of Australian patent AU 199538975 (and the associated the patent family). This patent utilises cross polarisation of light. An illuminating light source is filtered by a linear polariser so that the incident light source is polarised in one fixed angle. As the light enters the skin, it gets dispersed inside the epidermal layer and changes the angle of polarisation. The light that is reflected off the skin will directly be filtered by the second polariser which is perpendicular to the first polariser. The on-board imaging system will detect only those images beneath the reflective layer of the skin.

[0007] The cross polarisation illumination method has the following disadvantages: • Illuminations and image quality - A typical linear polariser filters up to 75% of the light passing through. Thus, the cross polarisation method requires very a high intensity of light source in order to be effective as the amount of light that finally pass through to the camera is less than 10% of the original intensity. This can result in low contrasts and shadowy imaging because of light absorption within the epidermal layer. As a result, some conditions of the skin may not be fully captured and biopsies are prescribed to confirm the skin condition. Therefore, some doctors still use the traditional oil immersion method as the images tend to be brighter and higher contrast.

• Depth of field of focus in the skin layers - The device of Australian patent AU 199538975 uses long focal length lenses and has a limited depth of field of around 0.2mm. The software controlling the camera needs to shift the focus control to 0.2mm into the skin to avoid focusing on the epidermal layer. This has been found to be insufficient to fully cover the depth required to identify structures underneath the 0.2mm layer. As with typical camera lenses, the depth of field can be control by the aperture F stop of the camera. The smaller the aperture, the larger the depth of field.

However, due to the heavy loss of light, it is not practical to use a smaller aperture camera to increase the depth of field.

Further, the long focal length also means the focus field is not flat, so the software controlling the camera operation needs to zoom in further to remove the corners of the actual images. In order to provide different magnifications for different skin conditions, multiple adapters are required to provide the user to attain 30x, 50x, and 80x magnification.

• Resolutions and colour quality - Due to the use older analogue video image capturing hardware, the colour spectrum coverage of the signal is poor and some colours are not fully reproduced after the analogue to digital conversion process. This usually means the type of display monitors used by a user will require more vivid display characteristics. Most laptop LCD displays tend to produce dull images thus making diagnosis more difficult.

[0008] The present invention attempts to overcome at least in part the aforementioned disadvantages of previous skin examination devices.

SUMMARY OF THE INVENTION

[0009] In accordance with a first aspect of the present invention there is provided a device for examination of a skin site comprising: a housing with a central axis perpendicular to the skin site; a light emitting and dispersing means arranged within the housing; an image capturing means arranged within the housing; a power supply; wherein the housing incorporates a substantially planar plate of transparent plastic or glass material which contacts the skin site, wherein light is radiated from the light emitting and dispersing means to the skin site in a radiated light path, and wherein light is reflected from the skin site to the image capturing means in a reflected light path.

[0010] In a preferred embodiment, the device further comprises a first polariser arranged in the radiated light path between the light emitting and dispersing means and the skin site.

[0011] In a preferred embodiment, the device further comprises a distortion correction lens arranged in the reflected light path between the skin site and the image capturing means.

[0012] In a preferred embodiment, the device further comprises a second polariser arranged in the reflected light path between the skin site and the image capturing means. More preferably, the second polariser arranged in the reflected light path between the distortion correction lens and the image capturing means.

[0013] In a preferred embodiment, the second polariser polarises light in an orientation perpendicular to an orientation that the first polariser polarises light.

[0014] In a preferred embodiment, the light emitting and dispersing means is a substantially flat annular disk oriented perpendicular to the central axis of the device.

[0015] In a preferred embodiment, a surface of the light emitting and dispersing means facing the skin site is reflective.

[0016] In a preferred embodiment, the light emitting and dispersing means has a plurality of light emitting elements arranged on the perimeter of the annular disk.

[0017] In a preferred embodiment, the light emitting elements are arranged equidistant to each other.

[0018] In a preferred embodiment, the light emitting elements are oriented to emit light on to the reflective surface.

[0019] In a preferred embodiment, the light emitting elements are light emitting diodes.

[0020] In a preferred embodiment, the light emitting elements have a 1200 dispersion angle on a plane perpendicular to the reflective surface.

[0021] In a preferred embodiment, the reflected light path traverses the central axis and passes through the centre of the light emitting and dispersing means.

[0022] In a preferred embodiment, an inner surface of the housing adjacent the plate is reflective.

[0023] In a preferred embodiment, the reflective surface of the light emitting and dispersing means is uneven.

[0024] In a preferred embodiment, the reflective surface of the light emitting and dispersing means has a regular pattern of ridges.

[0025] In a preferred embodiment, the image capturing means is a digital camera.

[0026] In a preferred embodiment, the power supply is external and power is provided to the device through a cord.

[0027] In an alternative embodiment, the power supply is internal and comprises an internal battery.

[0028] In a preferred embodiment, the device further comprises a control means.

[0029] In a preferred embodiment, the control means is adapted to signal the image capturing means to capture an image.

[0030] In a preferred embodiment, the device is connected to an external computer.

[0031] In a preferred embodiment, the housing is dustproof.

[0032] In a preferred embodiment, the housing is splashproof More preferably, the housing is waterproof

[0033] In a preferred embodiment, the device further comprises a handle affixed to or incorporated with the housing.

[0034] In a preferred embodiment, the light emitting and dispersing means is a printed circuit board.

[0035] In accordance with a second aspect of the present invention there is provided a method of examining skin using a device according to the first aspect of the invention, whereby the method comprises the steps of: selecting a skin site, positioning the device such that the substantially planar plate contacts the skin site, activating the device so as to emit light within the device whereby a significant amount of light is dispersed within the device, and projecting the light on to the skin site; whereby light reflected from the skin site travels the reflected light path to the image capturing means which captures image data.

[0036] In a preferred embodiment, light is polarised by a first polariser prior to being projected on to the skin site.

[0037] In a preferred embodiment, light in the reflected light path passes through a distortion correction lens prior to reaching the image capturing means.

[0038] In a preferred embodiment, light in the reflected light path is polarised by a second polariser prior to reaching the image capturing means.

[0039] In a preferred embodiment, the image capturing means transmits the image data to an external computer.

[0040] In a preferred embodiment, the image data is modified using software.

BRIEF DESCRIPTION OF DRAWINGS

[0041] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

[0042] Figure 1 is a perspective view of a device for examination of a skin site in accordance with an embodiment of the present invention.

[0043] Figure 2 is an exploded view of the embodiment of the device depicted in Figure 1.

[0044] Figure 3 is an exploded view of a component module of the device depicted in Figure 1.

[0045] Figure 4 is a cross-sectional view A-A of the device depicted in Figure 1.

[0046] Figure 5 is a cross-sectional detail view B of the device depicted in Figure 1.

[0047] Figure 6 is an image taken of an Irritated mildly Dysplastic Junctional Melanocytic Naevus taken with a device in accordance with Australian patent AU 199538975.

[0048] Figure 7 is an image taken of an Irritated mildly Dysplastic Junctional Melanocytic Naevus taken with a device in accordance with the present invention.

[0049] Figure 8 is an image taken of a Nodular Basal Cell Carcinoma taken with a device in accordance with Australian patent AU 199538975.

[0050] Figure 9 is an image taken of a Nodular Basal Cell Carcinoma with a device in accordance with the present invention.

[0051] Figure 10 is an image taken of a Basal Cell Carcinoma taken with a device in accordance with Australian patent AU 199538975.

[0052] Figure 11 is an image taken of a Basal Cell Carcinoma with a device in accordance with the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0053] In accordance with a first aspect of the present invention there is provided a device for examination of a skin site comprising: a housing with a central axis perpendicular to the skin site; a light emitting and dispersing means arranged within the housing; an image capturing means arranged within the housing; a power supply; wherein the housing incorporates a substantially planar plate of transparent plastic or glass material which contacts the skin site, wherein light is radiated from the light emitting and dispersing means to the skin site in a radiated light path, and wherein light is reflected from the skin site to the image capturing means in a reflected light path.

[0054] Traditional devices that project light directly on to a skin site have to adjust to accommodate or counteract the significant proportion of the light which is reflected back to the imaging means.

[0055] The device of the present invention specifically diffuses the light prior to projection on to the skin site, thus reducing the reflected light allowing the image capturing means to capture an image without extreme differences in light intensities and lessening the requirements for image correction. The decrease in directly reflected light creates a corresponding increase of visibility of subsurface cell structures.

[0056] It is not necessary that 100% of the light be diffused in this manner, as some direct light is not undesirable. In some cases, some direct light may allow for a brighter and clearer image.

[0057] For imagery capture at such short distances using a device that shines the full intensity of light directly at a skin site commonly results in local hot-spots and uneven illumination intensity which is detrimental to the quality of the final image. The present invention addresses this detriment by utilising a dispersed light which has been diffused and/scattered by the light emitting and dispersing means. The diffused light enters the skin at obtuse angles decreasing the frequency of direct reflection from the skin surface, evenly illuminating the skin and allowing sub-surface cell structures to be perceived more clearly.

[0058] The plate flattens the skin site thus allowing for reproducible image capturing which can be compared against one another. The plate may stretch or smooth out the skin site for inspection.

[0059] There may be a wall, border or skirt structure around the substantially planar plate that prevents external light from entering the area of the skin site and distorting the results of the examination.

[0060] For the reasons of hygiene and cleaning, glass, and in particular a scratch proof, tough, hardened mineral glass, is preferred as the material for the plate. The plate also prevents foreign bodies from entering the device.

[0061] The housing is preferably dustproof and waterproof to prevent damage to the internal components and to maintain a consistent image capturing environment.

[0062] The power supply provides power for the light emission, image capturing and any control systems the device may have.

[0063] In an alternative embodiment the image capturing device may accommodate manual observation of the skin site, similar to a microscope, rather than purely relying on digital or analogue image capsuling.

[0064] The device may further comprise a distortion correction lens arranged in the reflected light path between the skin site and the image capturing means.

[0065] Traditional lens design requires compound lenses working in combination to correct distortions and optical aberrations such as chromatic aberrations, barrel distortions and pin cushioning. Distortions and aberrations typically arise from the spherical structure of the lenses. To reduce the chromatic and shape distortions, lens designers require precision tooling to shape aspherical lenses.

[0066] The preferred lens for the present invention is a droplet liquid lens which has similar properties to an aspherical lens. This allows a single lens element to replace complex lens design for small microscopy cameras such as pin-hole cameras.

[0067] By shifting a droplet liquid lens' focal distance away from a camera sensor, the result is close to microscopy quality, but suffers the fish-eye effect or very heavy barrel distortion. The barrel distortion can typically result in misdiagnosis in dermoscopy because the shape of the mole or skin condition can become distorted. By placing a second aspherical achromatic lens in front of the droplet liquid lens can induce a pin-cushion effect which may reduce or cancel out the fish-eye/barrel distortion of the droplet liquid lens. The liquid lens is required to be unfocused to compensate the additional focal length of the second lens. The final result is a very low distortion skin imaging system now suitable for dermoscopy

[0068] The device may further comprise a first polariser arranged in the radiated light path between the light emitting and dispersing means and the skin site.

[0069] The device may further comprise a second polariser arranged in the reflected light path between the skin site and the image capturing means. Preferably, the second polariser arranged in the reflected light path between the distortion correction lens and the image capturing means.

[0070] The second polariser may polarise light in an orientation perpendicular to an orientation that the first polariser polarises light. The utilisation of a pair of opposing polarising elements benefits the quality of the captured image as the cross-polarisation reduces the amount of light that is directly reflected from the skin surface, thus allowing for the subsurface details to be observed more clearly. Reflected light that has linear polarisation and can be filtered out by a second polariser.

[0071] The first or second polariser may be rotatable such that the cross-polarisation effect may be adjusted.

[0072] The light emitting and dispersing means may be a substantially flat annular disk of printed circuit broad oriented perpendicular to the central axis of the device.

[0073] A surface of the light emitting and dispersing means facing the skin site may be reflective. In a preferred embodiment, the surface is rendered reflective with a mesh-like uneven coating. The mesh-like coating may form a regular pattern.

[0074] The light emitting and dispersing means may incorporate a plurality of light emitting elements.

[0075] The light emitting elements may be light emitting diodes connected to the circuitry of the printed circuit board.

[0076] The light emitting elements may be arranged in a manner to provide uniform distribution of light. For example, arranged on a circular perimeter equidistant to each other.

[0077] The power supply may be external and/or internal to the device. The device may incorporate a battery.

[0078] The device may incorporate a handle for manual operation or a frame for static operation.

[0079] The device may be connected to an external computer via a cable or wireless connection. The external computer may provide power to the device as an external power supply.

[0080] The device may incorporate a control means, such as a button or touchpad that when activated signals the device to capture an image.

[0081] The light emitting elements may activate upon the device receiving power or light activation may be controlled through a control system. The device may be signalled to capture an image remotely from an external computer or similar system. The light emitting elements may be controlled modally to allow for adjustable light levels, sequenced activation and other similar requirements within the scope of understanding of a person skilled in the art.

[0082] A device in accordance with the present invention may accommodate an oil immersion method as previously described.

[0083] Referring to Figures 1 to 5, there is shown an embodiment of a device (10) for examination of a skin site in accordance with a first aspect of the present invention that is adapted for handheld use. The device (10) comprises a housing (20) with a central axis (15). The housing is constructed from three components: a back housing component (20a), a front housing component (20b) and a head housing piece (20c). The housing (20) is dustproof and waterproof

[0084] The housing (20) has a handle at a proximal end of the device (10), and substantially cylindrical head at a distal end of the device (10) which contains a component module (12). On one end of the head is a truncated hemisphere shape with a substantially planar plate (22) of transparent plastic or glass material perpendicular to and centred on the central axis (15) at the most distal end. In use, the planar plate (22) contacts with the skin site, flattening the area.

[0085] A component module (12) is located within the housing (20), within the head of the device (10) and centred on the central axis (15). The component module (12) comprises: a light emitting and dispersing means (30), a digital camera (40), a distortion correction lens (60), a first polariser (70), and a second polariser (80). The light emitting and dispersing means (30), the digital camera (40), the distortion correction lens (60), the first polariser (70), and the second polariser (80) are all centred on the central axis (15).

[0086] In use, light is radiated from the light emitting and dispersing means (30) to the skin site in a radiated light path, and light is reflected from the skin site to the digital camera (40) in a reflected light path. The reflected light path traverses the central axis and passes through the centre of the light emitting and dispersing means.

[0087] The first polariser (70) is arranged in the radiated light path between the light emitting and dispersing means (30) and the skin site.

[0088] The distortion correction lens (60) is arranged in the reflected light path between the skin site and the digital camera (40).

[0089] The second polariser (80) is arranged in the reflected light path between the distortion correction lens and the digital camera (40).

[0090] The light emitting and dispersing means (30) is a printed circuit board with a substantially flat annular disk shape oriented perpendicular to the central axis (15) of the device (10). A surface (34) of the light emitting and dispersing means (30) facing the skin site is reflective and has a regular pattern of ridges (36) which render the surface uneven. A plurality of light emitting diodes (32) are arranged equidistant to each other on the perimeter light emitting and dispersing means (30). The light emitting diodes (32) are oriented to emit light on to the surface (34). The light emitting diodes (32) have a 1200 dispersion angle on a plane perpendicular to the surface (34).

[0091] An inner surface (24) of the housing (20c) adjacent the plate (22) is reflective. This increases the quantity of dispersed light which can be projected by the device (10), and thus aids in the efficiency of the device (10).

[0092] In figure 5 light beams X and Y are shown to be emitted from the light emitting element (32) through the plate (22). Light beam X travels directly from the light emitting element (32) and light beam Y reflects off of an inner surface (24) of the housing (20c).

[0093] The second polariser polarises (80) light in an orientation perpendicular to an orientation that the first polariser (70) polarises light.

[0094] The device (10) is connected to an external computer by a USB cable connection (50). The cable connection (50) transfers imaging data from the device (10) to the external computer. Additionally, power is supplied to the device (10) via the cable connection (50) from the external computer. The light emitting diodes (32) are automatically turned on when the device is supplied with power.

[0095] The device (10) further comprises a control means in the form of a button (90) on the back of the head of the housing (20). When depressed, the button signals the digital camera (40) to take an image.

[0096] The Figures depict additional structural features of the housing (20) and the component module (12), such as gaskets, screw thread and fastening points that would be within the consideration of a person skilled in the art.

[0097] In accordance with a second aspect of the present invention there is provided a method of examining skin using a device according to the first aspect of the invention, whereby the method comprises the steps of: selecting a skin site, positioning the device such that the substantially planar plate contacts the skin site, activating the device so as to emit light within the device whereby a significant amount of light is dispersed within the device, and projecting the light on to the skin site; whereby light reflected from the skin site travels the reflected light path to the image capturing means which captures image data.

[0098] Most of the light is diffusely reflected at the stratum corneum. Some light is reflected by deeper parts of the epidermis. Further, some light is typically absorbed.

[0099] Light may be polarised by a first polariser prior to being projected on to the skin site.

[00100] Light in the reflected light path may pass through a distortion correction lens prior to reaching the image capturing means.

[0100] Light in the reflected light path maybe polarised by a second polariser prior to reaching the image capturing means.

[0101] The image capturing means may transmit the image data to an external computer.

[0102] The image data may be recorded, reviewed, compared and monitored for changes over time. These actions may be performed using software by the external computer.

[0103] The image data may modified using software. This may clear up defects or aberrations in an image, identify areas of note, and/or perform other functions that would benefit a diagnosis.

[0104] Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.

[0105] Figures 6 to 11 are comparison images of a range of skin conditions between images taken with a device in accordance with Australian patent AU 199538975 and a device in accordance with the present invention respectively. Comparison images were taken of the same patient on the same day.

[0106] Figures 6 and 7 are images taken of an Irritated mildly Dysplastic Junctional Melanocytic Naevus. The image taken by a device in accordance with the present invention is capable of showing where the hair enters and a more distinct net like structure.

[0107] Figures 8 and 9 are images taken of a Nodular Basal Cell Carcinoma. In the image taken by a device in accordance with the present invention more blood vessels can be identified underneath the skin surface and and the distinct BCC structure can be seen more clearly.

[0108] Figures 10 and 11 is an image taken of a Basal Cell Carcinoma. The image taken by a device in accordance with the present invention shows clearer blood vessels and structures underneath the skin.

Claims

1. A device for examination of a skin site comprising: a housing with a central axis perpendicular to the skin site, a light emitting and dispersing means arranged within the housing an image capturing means arranged within the housing, and

a power supply; wherein the housing incorporates a substantially planar plate of transparent plastic or glass material which contacts the skin site; wherein light is radiated from the light emitting and dispersing means to the skin site in a radiated light path; wherein light is reflected from the skin site to the image capturing means in a reflected light path; and wherein, the device further comprises a distortion correction lens arranged in the reflected light path between the skin site and the image capturing means.

2. A device of claim1 wherein, the device further comprises a first polariser arranged in the radiated light path between the light emitting and dispersing means and the skin site.

3. A device of any of the p ceding claims wherein, the device further comprises a second polariser arranged in the reflected light path between the skin site and the image capturing means, the second polariser being arranged in the reflected light path between the distortion correction lens and the image capturing means, and wherein the second polariser polarises light in an orientation perpendicular to an orientation that the first polariser polarises light.

4. A device of any of the preceding claims wherein, the light emitting and dispersing means is a substantially flat annular disk oriented perpendicular to the central axis of the device, and the light emitting and dispersing means has a plurality of light emitting elements arranged on the perimeter of the annular disk, whemin the light emitting elements are arranged equidistant to each other.

5. A device of any of the preceding claims wherein, a surface of the light emitting and dispersing means facing the skin site is reflective.

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