METHOD FOR INTRAOPERATIVE DETECTION AND RECOGNITION OF NEUROVASCULAR STRUCTURES IN THE VOLUME OF BIOLOGICAL TISSUE Russian patent published in 2020 - IPC A61B34/20 

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to intraoperative diagnostics and functional diagnostics, and is intended for intraoperative detection and recognition of neurovascular structures in the volume of biological tissue. Method comprises contacting subsurface probing the analyzed volume of biological tissue with optical radiation using a fiber-optic sensor for reflective diffusion spectroscopy, comprising a receiver and emitters on at least two wavelengths, (λ₁) and (λ₂), where λ₂>λ₁, selected from 650 to 950 nm for maximum depth of at least 5 mm. Reciprocal scattered radiation parameters and optical parameters, including absorption coefficient, are recorded in time-resolution mode for each wavelength μ_a(λ_i) and transport scattering coefficient μ_s'(λ_i), by which the concentration of total hemoglobin ([tHb]) is determined in a unit of the analyzed volume of biological tissue and tissue saturation (S_tO₂), as well as the tangent of the transport coefficient of scattering from wavelength (D_s). That is followed by detecting and recognizing neurovascular structures: nerves, arterial and venous vessels by comparing the obtained parameters with their threshold values, obtained on the basis of evaluation of preoperative and intraoperative diagnostic data. At that, probing of investigated volume of biological tissue is carried out by at least two groups of emitters and at least one receiver, where each of the emitters groups includes at least two subgroups, each of which contains emitters of at least two wavelengths from said range of values and is located at a separate distance from receiver r_j, j = 1..M, M≥2. At that intensity of backscattered radiation in investigated volume of biological tissue for each wavelength and each r_j additionally define: amplitudes of pulse (Ap) and respiratory (Ar) oscillations and their ratio Ap/r=Ap/Ad, vector of form which is a set of values characterizing pulse wave shape, corresponding to large or small arterial vessel large venous vessel or functional tissue unit in size of analyzed volume of biological tissue . For each subgroup of sources for at least two wavelengths from said range, local amplitude of pulse oscillations of concentration of total hemoglobin (Δ[tHb]_p). At that, listed parameters are measured in static mode, at which pressure of optical sensor P on surface of analyzed volume of biological tissue is P≤0.2 mm Hg. Conclusion on the presence of certain neurovascular structures is made by obtaining the sets of measured parameters.

EFFECT: method provides reliable data on the presence of nerves, large and small arteries and veins in the volume of biological tissue at a depth of at least 5 mm during operations by expanding the set of criteria for detecting and recognizing neurovascular structures, methods of multiple-scale analysis of recorded intensity of back scattered radiation and formation of complex characteristics of pulse and respiratory oscillations.

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