CN110710953A

CN110710953A - Skin tumor early screening device based on fluorescence imaging and use method

Info

Publication number: CN110710953A
Application number: CN201910850252.6A
Authority: CN
Inventors: 郑伟波; 王少伟; 刘清权; 潘婧月; 孙浩; 陆卫; 张涛
Original assignee: Shanghai Institute of Technical Physics of CAS
Current assignee: Shanghai Institute of Technical Physics of CAS
Priority date: 2019-09-10
Filing date: 2019-09-10
Publication date: 2020-01-21

Abstract

The invention discloses a skin tumor early screening device based on fluorescence imaging and a using method thereof. The invention has the advantages that: the coaxial light is used for lighting, and the excitation light path and the fluorescence receiving light path are integrated into the same optical axis, so that the structure of the device is simplified, and the volume and the weight of the device are reduced. As long as the excitation light of the device is irradiated on the skin coated with the 5-aminolevulinic acid and the photographing and imaging are carried out, the skin condition can be quickly diagnosed through the fluorescence imaging condition of the skin, the tumor can be clearly imaged and accurately positioned, and important technical support and scientific basis are provided for quick and early diagnosis of clinical skin canceration.

Description

Skin tumor early screening device based on fluorescence imaging and use method

Technical Field

The invention belongs to the technical field of medical detection, and particularly relates to a skin tumor early screening device based on fluorescence imaging and a using method thereof.

Skin tumors are located in the superficial layers of the body and are clinically composed of two major classes, melanoma (MM) and non-melanoma (NMSC). Early screening should be considered for both non-melanoma and melanoma tumors, and if early tumors or precancerous lesions can be diagnosed and treated in time, the progression of skin tumors in most patients can be controlled.

The diagnostic methods for skin tumor include histopathological biopsy and various skin imaging methods. Histopathological biopsy is the current gold standard for skin cancer diagnosis. However, histopathological biopsy is very limited, e.g., traumatic, leaves scars and risks infection; pain, time consuming, high cost; only biopsy site information can be provided; some hospitals are limited by the condition that histopathological biopsy cannot be performed; the quantitative detection can not be carried out. For early stage skin tumor, the tissue pathological biopsy cannot be sampled and applied in a large scale. Because the early skin tumor focus has unobvious characteristics and is a multiple disease, the early skin tumor focus cannot be accurately positioned, and the histopathological biopsy of each suspected early skin tumor focus is not feasible. Therefore, the most effective means is to match with auxiliary means such as skin image to locate the focus and use the image information to make rapid diagnosis.

The existing skin image means are numerous, each skin image can reflect partial characteristics of skin tumor, but the skin image has certain limitation in the positioning aspect of the skin tumor. In the aspect of reflecting the characteristics of the skin tumor, the skin mirror can amplify the skin tumor part to reflect the color and texture characteristics which are difficult to be identified by naked eyes; the reflection type confocal microscope can highlight the scale characteristics of skin tumor cells, and the high-frequency ultrasonic can highlight the depth information of tumors on the skin surface. However, the characteristics of the early skin tumor are not obvious and are not easily distinguished from the normal skin, so that the common skin mirror cannot accurately distinguish the early skin tumor part from the normal skin, the fields of view of the reflective confocal microscope and the high-frequency ultrasonic probe are small, all suspected tumor parts cannot be rapidly checked on a large scale, and the current skin auxiliary imaging means still has a blank in the positioning aspect of the early skin tumor.

Research shows that the metabolism of skin tumor is often abnormal to normal tissue, and early skin tumor can be distinguished from normal tissue by specific fluorescent mark of tumor metabolite. The medical fluorescence diagnosis technology is divided into autofluorescence and photosensitizer-mediated fluorescence detection. Autofluorescence is the fluorescence generated by tissue itself, and the most common detection method is to detect vitiligo, skin fungal infection, acne and psoriasis by Wood lamp with wavelength of 320nm-400 nm. The photosensitizer-mediated fluorescence detection is a detection mode that utilizes a special photosensitizer drug to excite fluorescence, and is also called photodynamic diagnosis (PDD). It is applied to the focus of skin with a specific photosensitizer, which is then concentrated in high concentration inside the tumor, and irradiated with a specific wavelength to produce fluorescence at the tumor site, so that the tumor boundary can be diagnosed according to the fluorescence boundary.

Disclosure of Invention

The invention discloses a skin tumor early screening device based on a fluorescence imaging excitation light and fluorescence receiving coaxial light path and a using method thereof.

The invention adopts the photodynamic diagnosis principle to position the tumor, and 5-aminolevulinic acid (5-aminolevulinic acid, 5-ALA) is selected as an external application fluorescence induction reagent. 5-ALA is a porphyrin synthesis precursor, 5-ALA has no photosensitive property, but 5-ALA can be polymerized in mitochondria to form protoporphyrin IX (PpIX) with photosensitive property. Protoporphyrin is a trace metabolite during heme synthesis, can be accumulated in a tumor at a high concentration, can emit near-infrared fluorescence under the excitation of near ultraviolet light, has the advantages of deeper penetrating power, lower tissue background and the like, and can be used as a photodynamic fluorescent substance. Therefore, the skin tumor can be positioned in a fluorescence manner by externally applying 5-ALA on the skin tumor focus to promote in vivo cells to synthesize protoporphyrin, so that the protoporphyrin is gathered at the tumor focus and then exciting the fluorescence of the protoporphyrin by using a light source. Under the excitation light, the protoporphyrin solution generates fluorescence with a peak position near 635nm, and has a small peak at 700nm, and the brick red color is shown on the surface of the skin.

The invention discloses a skin tumor early screening device based on fluorescence imaging, which comprises a convex lens 1, a light source optical filter 2, an excitation light source 3, a beam splitting sheet 4, a fluorescence optical filter 5 and an image sensor 6, wherein light emitted by the excitation light source 3 passes through the light source optical filter 2, is reflected by the beam splitting sheet 4, penetrates through the convex lens 1, irradiates the surface of an object to be detected and excites the fluorescence of the surface of the object to be detected, the fluorescence of the surface of the object to be detected sequentially passes through the convex lens 1, the beam splitting sheet 4 and the fluorescence optical filter 5 and is received by the image sensor 6, the excitation light source 3 is a coaxial light source, and the light path of the excitation light reflected by the beam splitting sheet 4 is coaxial with the light path of the receiving light reaching the.

The image sensor 6 is a CCD chip or a CMOS chip responding to a visible-near infrared band, and is used to acquire a fluorescence signal excited by the skin surface or an optical signal reflected by the skin surface.

The excitation light source 3 is a blue light source, a near ultraviolet source or an ultraviolet source, and is used for exciting fluorescence on the surface of the skin, as long as the wavelength of the light source is shorter than that of the fluorescence.

The light source optical filter 2 comprises a low-pass optical filter, a band-pass optical filter and a narrow-band optical filter, signals of the ultraviolet to blue light part of the excitation light source 3 can penetrate through the light source optical filter 2, and it is ensured that only light in the wave band of the excitation light source can penetrate through the light filter, but light in the fluorescence wave band cannot penetrate through the light filter.

The fluorescence filter 5 comprises a high-pass filter, a band-pass filter and a narrow-band filter, and a fluorescence signal of the object to be detected can penetrate through the fluorescence filter 5 so as to ensure that light in the wave band of the excitation light source cannot penetrate through to interfere with the collection of fluorescence.

After passing through the light source filter 2 and the fluorescent filter 5, the excitation light source 3 signal cannot be sensed by the image sensor 6.

When the light source filter 2 is removed, the light emitted from the excitation light source 3 passes through the beam splitter 4 and the fluorescence filter 5, and is filtered out completely and cannot reach the image sensor 6, then the light source filter 2 can be removed.

Optionally, the beam splitting sheet 4 is a dichroic filter for reflecting the excitation light source, and the fluorescence signal of the object to be detected can pass through the dichroic filter.

When the beam splitting sheet 4 is a dichroic filter and the fluorescent filter 5 is removed, if the signal of the excitation light source 3 is transmitted through the light source filter 2, and then is completely reflected to the skin to be measured by the dichroic filter and does not reach the image sensor 6, the fluorescent filter 5 can be removed.

When the beam splitting sheet 4 selects the dichroic filter and the light source filter 2 and the fluorescent filter 5 are removed at the same time, the signal of the excitation light source 3 is directly and completely reflected to the skin to be measured by the dichroic filter, and then the light source filter 2 and the fluorescent filter 5 can be removed at the same time.

Preferably, the excitation light source 3 is located near the focal length of the convex lens 1, and the positions of the excitation light source 3 and the convex lens 1 are adjustable, so as to adjust the light intensity irradiated on the surface of the object to be measured and the definition of the image.

A method of using a fluorescence imaging based early skin tumor screening device, comprising the steps of:

1) preparing skin to be tested: 5-aminolevulinic acid (5-ALA) with the concentration of 5-15% is externally applied on the skin to be detected for 1-3 hours in a dark place.

2) Fluorescence imaging: the fluorescence imaging device is opened, the skin to be detected is irradiated with the fluorescence image, and the fluorescence image is obtained, so that whether the skin tumor exists or not can be quickly judged and accurately positioned according to whether the brick red area exists in the fluorescence image or not.

After the fluorescence imaging device is turned on, light output by an excitation light source 3 is reflected by the light source optical filter 2 and the beam splitting sheet 4, then is uniformly irradiated to the surface of an object to be detected through the convex lens 1, so as to excite a fluorescence signal of the object to be detected, and fluorescence emitted by the object to be detected passes through the convex lens 1, the beam splitting sheet 4 and the fluorescence optical filter 5 in sequence, and is collected and output by the image sensor 6.

The invention has the innovativeness and advantages that the beam splitting sheet and the specific optical filter are combined to integrate the excitation light source into the device camera device to form a coaxial light path, thereby greatly simplifying the structure, providing uniform illumination and reducing the volume of the equipment; meanwhile, optical filters are added in the light source and the fluorescence, so that invalid stray light signals are filtered, and the contrast of a fluorescence image is improved; and only one LED is used for lighting, so that the power consumption of the whole device is reduced. In addition, the structure is simple, the size is small, and the device can be integrated with other diagnoses such as ultrasound and the like to realize multi-mode joint diagnosis, so that the accuracy of skin tumor diagnosis is further obviously improved.

The following further description is made in conjunction with the accompanying drawings and the detailed description.

Drawings

Fig. 1 is a schematic structural diagram of a skin tumor early-stage screening device based on fluorescence imaging in an embodiment of the present invention.

Fig. 2 is a graph of the filter transmission spectrum and the light intensity in the first embodiment of the present invention, in which the solid black line is the light intensity of the mercury lamp, the dotted line is the fluorescence intensity of protoporphyrin PpIX, the dotted line is the low pass filter transmission spectrum, and the dotted line is the high pass filter transmission spectrum.

FIG. 3 is a graph of the transmittance spectrum and the intensity of the filter in the second embodiment of the present invention, in which the solid black line is the intensity of the LED, the dotted line is the PpIX fluorescence intensity, and the dotted line is the high pass filter transmittance graph.

FIG. 4 is a graph of the filter transmission spectrum and intensity of light in the third embodiment of the present invention, in which the solid black line is the intensity of the mercury lamp, the dotted line is the PpIX fluorescence intensity, the dotted line is the low pass filter transmittance, and the dotted line is the transmittance at 45 ° for the dichroic filter.

Fig. 5 is a graph of the transmission spectrum and the light intensity of the filter in the fourth embodiment of the present invention, in which the solid black line is the light intensity of the LED, the dotted line is the light intensity of PpIX fluorescence, and the dotted line is a 45 ° transmittance graph of the dichroic filter.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments, but not all embodiments, of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

1. Skin tumor early screening device based on fluorescence imaging

The first embodiment is as follows:

in this example, we show a skin tumor early stage screening device based on fluorescence imaging, which is made of high and low pass filters and a beam splitter, and a mercury lamp is used as an excitation light source.

A skin tumor early screening device based on fluorescence imaging is assembled as shown in figure 1 and comprises a convex lens 1, a low-pass filter 2, a mercury lamp light source 3, a beam splitting sheet 4, a high-pass filter 5 and an image sensor 6. Here, the low-pass filter is used as a light source filter, the high-pass filter is used as a fluorescent filter, and the mercury lamp is used as an excitation light source. The device has a volume of only 116cm³(3.5×3.5×9.5cm³) The weight is about 150g, and the power consumption is 1.5W.

Wherein, the convex lens is a lens with a focal length of 3.76cm, and the position of the convex lens can be adjusted up and down; the excitation light source is a mercury lamp, and the position of the mercury lamp is at the focal length of the convex lens and can be adjusted left and right; the image sensor is an MT9P031 COMS chip.

Fig. 2 shows graphs of low pass filter transmittance, high pass filter transmittance, mercury lamp intensity, protoporphyrin PpIX fluorescence intensity, where the solid black line is the mercury lamp intensity, the dotted line is the protoporphyrin PpIX fluorescence intensity, the dotted line is the low pass filter transmittance graph, and the dotted line is the high pass filter transmittance graph. It can be seen that the low pass filter can filter out the light above 480nm by passing through the blue-violet light emitted by the mercury lamp light source, while the high pass filter can filter out the light below 500nm by passing through the PpIX fluorescence, so that the signal of the excitation light source will not be detected by the image sensor to interfere with the fluorescence signal of the skin.

Example two:

in this embodiment, we show a skin tumor early screening device based on fluorescence imaging, which is manufactured by using a high-pass filter and a beam splitter, wherein the light source is 405nm led light source.

A skin tumor early screening device based on fluorescence imaging is assembled as shown in figure 1, but an LED light source is selected as an excitation light source, so that a low-pass filter 2 is removed, and the device comprises a convex lens 1, an LED light source 3, a beam splitting sheet 4, a high-pass filter 5 and an image sensor 6. Here, the low-pass filter serves as a light source filter and the high-pass filter serves as a fluorescence filter. The device has a volume of only 116cm³(3.5×3.5× 9.5cm³) The weight is about 150g, and the power consumption is 1.5W.

Wherein, the convex lens is a lens with a focal length of 3.76cm, and the position of the convex lens can be adjusted up and down; the excitation light source is 405nm LED light source, and the position of the excitation light source is at the focal length of the convex lens and can be adjusted left and right; the image sensor is an MT9P031 COMS chip.

The high pass filter transmittance, LED light source intensity, protoporphyrin fluorescence intensity plot is shown in fig. 3, where the solid black line is the LED intensity, the dotted line is the PpIX fluorescence intensity, and the dotted line is the high pass filter transmittance plot. It can be seen that the high pass filter filters the light emitted by the light source and transmits the fluorescent light PpIX.

Example three:

in this example, we show a fluorescence imaging-based skin tumor early-stage screening device using a low-pass filter and a dichromatic photo, wherein the light source is a mercury lamp.

A skin tumor early screening device based on fluorescence imaging is assembled as shown in figure 1, a dichroic film is selected to replace a beam splitting film, so that a high-pass filter 5 is removed, and the device comprises a convex lens 1, a low-pass filter 2, a mercury lamp light source 3, a dichromatic picture 4 and an image sensor 6. Here, the low-pass filter serves as a light source filter and the high-pass filter serves as a fluorescence filter. The device has a volume of only 116cm³(3.5×3.5× 9.5cm³) The weight is about 150g, and the power consumption is 1.5W.

Wherein, the convex lens is a lens with a focal length of 3.76cm, and the position of the convex lens can be adjusted up and down; the excitation light source is a mercury lamp light source, and the position of the mercury lamp light source is at the focal length of the convex lens and can be adjusted left and right; the image sensor is an MT9P031 COMS chip.

FIG. 4 shows graphs of low pass filter transmittance, 45 DEG angle transmittance of dichromatic picture, mercury lamp intensity, protoporphyrin fluorescence intensity, where the solid black line is the mercury lamp intensity, the dotted line is PpIX fluorescence intensity, the dotted line is the low pass filter transmittance graph, and the dotted line is the transmittance graph of the dichroic picture at 45 deg. It can be seen that the light of the mercury lamp light source above 480nm is intercepted by the low pass filter, while the high pass filter reflects light below 500nm, and above 500 nm.

Example four:

in this embodiment, we show a skin tumor early screening device based on fluorescence imaging, which is made of dichroic filters, wherein the light source is 405nm led light source.

A skin tumor early screening device based on fluorescence imaging uses an LED light source as an excitation light source, uses a dichroic sheet to replace a beam splitting sheet, removes a low-pass filter 2 and a high-pass filter 5, and comprises a convex lens 1, an LED light source 3, a dichroic sheet 4 and an image sensor 6. The volume is only 116cm³(3.5 ×3.5×9.5cm³) The weight is about 150g, and the power consumption is 1.5W.

The dichroic plate transmittance, LED light source intensity, protoporphyrin fluorescence intensity are plotted in fig. 5, where the solid black line is the LED intensity, the dotted line is the PpIX fluorescence intensity, and the dotted line is the dichroic plate 45 ° transmittance plot. It can be seen that the dichroic plate reflects the excitation light and transmits the PpIX fluorescence.

2. Use method of skin tumor early screening device based on fluorescence imaging

1) Preparation of test object

Two hairless female SKH-1 mice were selected, one of which was a squamous cell carcinoma primary tumor mouse and the other was a normal mouse as a control group. The mice were anesthetized and placed in a dark room, and a small, visually invisible tumor skin area of the primary tumor mice was removed and the corresponding control mice were coated with 10% 5-aminolevulinic acid (5-ALA) for 2 hours.

2) Tumor fluorescence imaging

And turning off all external light sources, placing the mouse under the device of the second embodiment of the invention, turning on an LED light source in the device, and displaying a fluorescent image through a computer. The result shows that the fluorescence image of the normal mouse presents dark red and has no abnormal phenomenon; the fluorescence image of the primary tumor mouse had a clear bright red spot, an early squamous cell carcinoma tumor. Experiments show that the skin tumor screening device can quickly and accurately diagnose the skin tumor and realize accurate positioning.

Claims

1. The utility model provides a skin tumour early stage screening device based on fluorescence imaging, includes convex lens (1), light source light filter (2), excitation light source (3), beam splitting piece (4), fluorescence filter (5), image sensor (6), its characterized in that:

light emitted by the excitation light source (3) passes through the light source optical filter (2), is reflected by the beam splitting sheet (4), passes through the convex lens (1), then irradiates the surface of the object to be detected and excites fluorescence on the surface of the object to be detected, and the fluorescence on the surface of the object to be detected is received by the image sensor (6) after sequentially passing through the convex lens (1), the beam splitting sheet (4) and the fluorescence optical filter (5);

the excitation light source (3) is a blue light source, a near ultraviolet light source or an ultraviolet light source;

the light source optical filter (2) comprises a low-pass optical filter, a band-pass optical filter and a narrow-band optical filter, and transmits light source signals from ultraviolet light to a blue light waveband;

the fluorescent filter (5) comprises a high-pass filter, a band-pass filter and a narrow-band filter, and transmits fluorescent signals from red light to near infrared bands.

2. The device for early screening of skin tumor based on fluorescence imaging as claimed in claim 1, wherein the light source filter (2) can be removed from the device if the excitation light source (3) is LED light source or laser light source.

3. The device for the early screening of skin tumors based on fluorescence imaging as claimed in claim 1, wherein if the beam splitter (4) is dichroic filter, the fluorescence filter (5) can be removed from the device.

4. Use of the fluorescence imaging-based early skin tumor screening device according to claim 1, comprising the steps of:

1) preparing a substance to be tested: 5-aminolevulinic acid with the concentration of 5-15% is externally applied on the skin to be detected for 1-3 hours in a dark place;

2) fluorescence imaging: and opening the fluorescence imaging device, irradiating the skin to be detected, acquiring a fluorescence image, and quickly judging whether skin tumor exists and accurately positioning by judging whether a brick red area exists in the fluorescence image.