RU2506049C1 - Device for diagnosing skin cancer - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medical equipment, namely to examinations with diagnostic purposes, and can be applied in dermatology and oncology. Device for skin cancer diagnostics includes laser and PC, as well as optic system, consisting of fibre-optic probe, which includes transmitting optic fibre with formed on distal end transmission Bragg grating-light filter, adjusted to laser wave length, and length, receiving optic fibre with formed in it notch-filter in form of Bragg grating, blocking laser radiation, optic fibre splitter, to each outlet channel of which connected is its own Bragg grating, adjusted to transmission of a particular wavelength of spectrum of combination dispersion and connected optically to its own photoreceiver or a series of photoreceivers with parallel access, whose outlets are connected with card of PC data collection. Detachable metal figured washer, permitting disinfection or replacement in case if patients change, is installed on the butt end of fibre-optic probe.

EFFECT: invention makes it possible to solve problems of diagnostics of skin malignant neoplasm boundaries in carrying out operations and medicinal impact, and endoscopic examinations.

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Description

The invention relates to medical equipment, namely to research for diagnostic purposes, and can be used in dermatology and oncology in solving the problems of diagnosing the boundaries of malignant neoplasms on the skin during operations and medical treatments, endoscopic examinations, as well as in instrumentation in the manufacture of medical equipment.

Raman spectroscopy (Raman spectroscopy) is widely used in biological research, starting with the study of purified biological substances and ending with studies at the level of individual cells. This technique has some characteristics that make it particularly suitable for in vivo and in vitro skin studies (D. Lucassen et al. In vivo infrared absorption and Raman spectroscopy of human skin. In: Optical biomedical diagnostics. B 2 vol. 2 / Transl. From English under the editorship of V.V. Tuchin. - M: FIZMATLIT, 2007. - P.124-153). Raman spectroscopy provides detailed information on the molecular composition and molecular structures of the skin. In addition, since molecular vibrations are directly affected by the microenvironment of functional groups, the vibrational spectrum carries information about the intermolecular interaction. Moreover, all this information can be extracted in a completely non-invasive manner, since Raman spectra can be recorded directly on the skin. In cases where you need to track any changes, this gives a particularly great advantage compared to the existing technique requiring the removal of skin material, for example by tearing with adhesive tape. An important advantage of Raman spectroscopy is that not only superficial but also deeper layers of the skin can be investigated. However, the device for obtaining Raman spectra described in the aforementioned article includes a spectrometer and a CCD camera, and its operation provides for the formation and recording of the entire Raman spectrum in a given wavelength range and its processing, thereby reducing the speed of obtaining a diagnostic result.

In contrast to diffuse scattering, Raman scattering of optical radiation is characterized by a shift in the radiation frequency with respect to the incident radiation frequency. Moreover, this shift is associated with the oscillation frequency of the scattering molecule. Considering that each chemical substance has its own unique microscopic structure, which also differs in its own vibrational frequencies, the spectral analysis of Raman scattering makes it possible to unambiguously judge the chemical substance in the observation (scattering) region. Tumor cells are characterized by the presence of a certain set of peaks of Raman scattering intensity at the selected frequency shifts, which form a certain signature. A characteristic signature of the skin lesions is formed due to phosphodiester O-P-O DNA vibrations (788 cm ^-1 ), proline vibrations and the main C-C band of protein vibrations (850 and 950 cm ^-1 ), molecular collagen vibrations (1268 and 1312 cm ^-1 ) and phenylalanine (1003 cm ^-1 ), and for melanoma, intensity peaks are additionally observed in the regions of 1650 and 1450 cm ^-1 , corresponding to vibrations of the methylene group CH ₂ (Gniadecka M. et all. Melanoma Diagnosis by Raman Spectroscopy and Neural Networks: Structure Alterations in Proteins and Lipids in Intact Cancer Tissue. // J Invest Dermatol, 2004. - No. 122. - P. 443-449).

A well-known clinical tool for combined Raman spectroscopy - optical coherence tomography of skin cancer, described in the article Patil C.A. et all. A Clinical Instrument for Combined Raman Spectroscopy-Optical Coherence Tomography of Skin Cancers. // Lasers in Surgery and Medicine. - 2011. - No. 43. - P.143-151. In it, the Raman channel is made in the form of a probe, consisting of discrete traditional optical elements: lenses, mirrors, and light filters; Raman spectrum is formed by a spectrograph; recorded by a CCD camera; analyzed and stored in the PC. The authors themselves note the low efficiency of obtaining spectroscopic information, and the large dimensions and mass of the CR probe necessitated its placement on a mechanical arm.

The closest technical solution is the device proposed in the article Larraona-Puy M. et all. Development of Raman microspectroscopy for automated detection and imaging of basal cell carcinoma. // Journal of Biomedical Optics. - 2009 .-- Vol.14 (5). - No. 054031. - P. 1-10, in which, in addition, statistical studies have convincingly substantiated a method for diagnosing skin cancer using basal cell carcinoma as an example by multivariate analysis of intensity ratios of Raman spectral peaks. The device contains a laser exciting the Raman spectra, two interference notch filters for suppressing the exciting radiation in the scattered analyzed radiation, a spectrograph, a CCD detector, and a PC.

The proposed device has drawbacks consisting in low speed due to sequential processing of the entire Raman spectrum, complexity and cumbersome design, the presence of optical elements that require very precise alignment, which necessitates the use of additional vibration isolation and degrades the consumer properties of the device.

The objectives of the invention are to increase the speed of the device, simplifying the design and reducing its size.

These problems are solved due to the fact that in the device for diagnosing skin cancer by Raman spectroscopy, which includes a laser with an optical fiber radiation output, a transmitting fiber with a transmitting Bragg grating-optical filter configured at the laser wavelength and a lens, a receiving optical fiber with the notch filter formed in it in the form of a Bragg grating, a fiber optic splitter, to each output channel of which its own fiber optic bragg is connected This grating is configured to transmit a specific wavelength of the Raman spectrum and is optically coupled to its own photodetector or a line of photodetectors with parallel access, the outputs of which are connected to a PC data acquisition board. The transmitting and receiving optical fibers are combined into a probe whose interchangeable metal washer determines the distance to the scattering surface, shields the distal end of the probe from external exposure and allows disinfection or replacement when changing patients.

The use of an optical fiber probe and receiving optical fibers with Bragg gratings, light filters and photodetectors with parallel access allows us to simplify the design of the device, reduce its dimensions and increase speed. In addition, the proposed solution does not require additional adjustments and can work in conditions of external shock and vibration external loads, does not require additional vibration isolation.

The drawing shows a diagram of a device for diagnosing skin cancer by Raman spectroscopy. A transverse set of lines across the optical axis of the optical fiber is the Bragg gratings formed in the optical fiber.

The device comprises an optical fiber probe 1, for example, a piece of a metal tube, into which a transmitting 2 and a receiving 3 optical fiber are glued. A lens 5 is formed on the distal end of the transmitting optical fiber 4 facing the diagnostic object and, in the optical fiber itself, a Bragg transmission grating-filter 6 tuned to laser radiation 7, and near the distal end of the receiving optical fiber 3, a notch filter grating 8 is formed in it , preventing the penetration of elastically scattered laser radiation into the receiving channel. The distance to the diagnostic object is determined by the thickness of the removable curly metal washer 9, the other purpose of which is to shield the input end of the receiving fiber from external illumination, and when removable, it allows disinfection or replacement when switching from the diagnosis of one patient to the diagnosis of another. At the other end, the receiving optical fiber is optically connected to the splitter 10. Optical fibers 11 - 19 are terminated to the output of the splitter 10, ending with Bragg grating-filters 20, the maximum transmission spectrum of each of which is configured to transmit Raman radiation at one of the diagnostic wavelengths. The outputs of the optical fibers 11-19 are optically connected to their own photodetectors or a line of photodetectors with parallel access 21, the outputs of which are connected to the data acquisition board 22 of the PC 23.

In accordance with a method for diagnosing skin cancer based on the ratio of the peaks of Raman scattering (Larraona-Puy M. et all. Development of Raman microspectroscopy for automated detection and imaging of basal cell carcinoma. // Journal of Biomedical Optics. - 2009. - Vol. 14 (5). - No. 054031. - P.1-10, Gniadecka M. et all. Melanoma Diagnosis by Raman Spectroscopy and Neural Networks: Structure Alterations in Proteins and Lipids in Intact Cancer Tissue, J Invest Dermatol, 2004. No. 122 , P. 443-449), the maximum transmission spectrum of each of the Bragg gratings-filters 20 formed in the optical fibers 11-19 is selected by the frequency shifts relative to the central laser radiation wavelength of 7 maxima Oxide components of the Raman spectrum of the skin. So the wavelength of the maximum of the transmission spectrum of the Bragg grating-filter of optical fiber 11 should be shifted in the long-wave direction relative to the wavelength of the laser 7 by 788 cm ^-1 in the frequency representation, for optical fiber 12 - by 850 cm ^-1 , for 13 - by 950 cm ^{- 1} , for 14 - at 1003 cm ^-1 , for 15 - at 1093 cm ^-1 , for 16 - at 1268 cm ^-1 , for 17 - at 1312 cm ^-1 , for 18 - at 1450 cm ^-1 , for 19 - at 1650 cm ^-1 . These spectral bands include all the main (strong) peaks of Raman intensity for all forms of cancer.

The device operates as follows. The optical fiber probe 1 with a removable curly washer 9 is applied to the diagnosed area of the skin 4 of the patient. On command from the PC 23, the laser 7 is turned on, and its radiation propagating through the transmitting optical fiber 2 is focused by the lens 5 formed at its distal end to the skin surface 4 or its subsurface layer selected for diagnostic reasons. The radiation scattered by the diagnosed object 4 falls on the distal end of the receiving optical fiber 3. The elastic-scattered component of this radiation is suppressed by the Bragg grating — notch filter 8 formed in the receiving fiber 3. The Raman-scattered radiation through the splitter 10 enters the optical fibers 11-19 ending in the Bragg gratings 20 filters, the maximum transmission spectrum of each of which is configured to transmit Raman scattered radiation at one of the diagnostic wavelengths.

From the output ends of each of the optical fibers 11-19, the radiation with intensities I778 cm ^-1 , I850 cm ^-1 , I950 cm ^-1 , I1003 cm ^-1 , I1093 cm ^-1 , I1268 cm ^-1 , I1312 cm ^-1 , I1450 cm ^{- 1} , I1650 cm ^-1 gets on its photodetector 21 and then, being converted into an electric signal proportional to the intensity of the corresponding spectral component of Raman scattered radiation, in the form of an electric signal through nine parallel channels it goes to the data acquisition board 22 and then to the PC 23. PC 23 calculates the intensity ratios in each of the channels that form comfort signature of the Kyrgyz Republic, which is used to qualify a diagnostic area of the skin. So, in accordance with the classifier proposed in the article Larraona-Puy M. et all. Development of Raman microspectroscopy for automated detection and imaging of basal cell carcinoma. // Journal of Biomedical Optics. - 2009 .-- Vol.14 (5). - No. 054031. - P.1-10, to identify basal cell carcinoma, it is sufficient to use the following relationships

r ₁ = I778 cm ^-1 / I1003 cm ^-1 ;

r ₂ = I850 cm ^-1 / I1003 cm ^-1 ;

r ₃ = I950 cm ^-1 / I1003 cm ^-1 ;

r ₄ = I1093 cm ^-1 / I1003 cm ^-1 ;

r ₅ = I1312 cm ^-1 / I1268 cm ^-1 .

To identify melanoma in accordance with (Gniadecka M. et all. Melanoma Diagnosis by Raman Spectroscopy and Neural Networks: Structure Alterations in Proteins and Lipids in Intact Cancer Tissue. // J Invest Dermatol, 2004. - No. 122. - P. 443- 449.) it is necessary to additionally use the ratio r _{6 of the} detected radiation in the channels 18 and 19 corresponding to the Raman scattering bands of 1650 cm ^-1 and 1450 cm ^-1 :

r ₆ = I1650 cm ^-1 / I1450 cm ^-1 .

Claims (1)

A device for diagnosing skin cancer, including a laser, an optical system and a PC, characterized the fact that the optical system consists of an optical fiber probe, including a transmitting optical fiber with a transmitting Bragg grating-optical filter configured at the laser wavelength at the distal end, and a lens, a receiving optical fiber with a notch filter formed in it by the laser radiation in the form of a Bragg grating, fiber splitter, each output channel of which has its own fiber-optic Bragg grating, configured to transmit a specific wavelength of the spectrum scattering and optically coupled to its own photodetector or a line of photodetectors with parallel access, the outputs of which are connected to a PC data acquisition board, a removable metal figured washer is installed at the end of the fiber optic probe, which allows disinfection or replacement when changing patients.

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