RU2758868C1 - System for intraoperative detection and recognition of neurovascular structures in the volume of biological tissue - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to the field of medicine, medical and technical technologies, namely to intraoperative diagnostics and functional diagnostics, and can be used to detect and recognize local inhomogeneities that differ in optical properties from the surrounding biological tissues in the field of research. The system for intraoperative detection and recognition of neurovascular structures in the volume of biological tissue, includes: an optical-surgical device for probing biological tissues and surgical manipulations, made on the basis of branches; a block of positional and/or force control of an optical-surgical device, including a position sensor and/or a force sensor or a force-moment sensor, made with the ability to control the movement and/or the force of pressing the working end of the optical-surgical device to the biological tissue; a signal conversion unit, made with the ability to form direct and receive reverse optical signals of subsurface probing of biological tissue; a control and processing unit made with the possibility of generating control signals for the synchronized operation of the conversion unit and the position control unit, as well as with the possibility of processing received signals from these blocks, displaying diagnostic information and storing the received data. The signal conversion unit is designed with the possibility of generating radiation for reflective diffusion spectroscopy with a time resolution at least at two wavelengths (λ_i, i=1..K, K≥2) from the range of 650-950 nm. The opto-surgical device is made with the possibility of subsurface contact probing of biological tissue to a maximum depth of at least 5 mm, and is equipped with at least two groups of optical fibers for supplying a direct optical signal of subsurface probing of biological tissue, and at least one fiber-optic cord for receiving the return signal. Optical fibers and a fiber-optic cord, each, if there are more than one, are output at one end to the working end of the device, and the other end is connected to the signal conversion unit. Groups of optical fibers on the working end are located along separate mismatched semi-axes directed from the fiber bundle. Each group of optical fibers consists of at least two subgroups. Each subgroup is designed to provide a signal at least at two wavelengths (λ_i, i=1..K, K≥2) from the specified range. The optical fibers of each subgroup are located at a distance of no more than 1 mm from each other, and each subgroup is located at a certain distance (r_j, j=1..M, M≥2) from the receiving fiber bundle along the corresponding half-axis. The control unit is designed with the possibility of forming a feature vector for detecting and recognizing neurovascular structures based on signals received from the conversion unit and the position control unit, which are used to judge the presence of certain neurovascular structures in the volume of biological tissue, tissue saturation and local blood filling, including the presence or absence of tissue hypoxia.

EFFECT: obtaining reliable data on the presence of nerves, large and small arteries and veins in the volume of biological tissue at a maximum depth of at least 5 mm during operations.

7 cl, 1 tbl, 11 dwg

Description

The technical field to which the invention relates

The invention relates to the field of medicine and medical and technical technologies, namely to intraoperative diagnostics and functional diagnostics, and is intended to detect and recognize local heterogeneities that differ in optical properties from the surrounding biological tissues in the field of research. It is possible to use the invention for various types of surgical intervention or invasive manipulations, as well as for probing through intact skin. In particular, the invention can be used in neurosurgery for the detection and recognition of neurovascular structures, arterial and venous vessels and nerves, in the volume of biological tissue during operations to remove a brain tumor, including the endoscopic transnasal method.

State of the art

The task of detecting and recognizing neurovascular structures is especially relevant in neurosurgery when performing operations to remove neoplasms. The problematic of the current methods of resection of tumors of the base of the skull with the endoscopic transnasal method is the complexity of the operation itself. Pathological tissue is removed with endoscopic instrumentation through the sinuses of the nose piecewise, several millimeters each. During the operation, there is a high risk of damage to neurovascular structures located in the volume of tumor tissue. Damage to the cranial nerve leads to a loss of muscle functionality associated with the injured nerve, loss of important physiological functions, a significant deterioration in the quality of life; damage to an arterial vessel - to instant death.

To minimize damage to neurovascular structures, as well as to increase the degree of radicality of tumor tissue resection, modern methods and technical means of diagnostics and imaging are applicable, such as magnetic resonance imaging (MRI), X-ray computed tomography (CT), positron emission tomography (PET), magnetic resonance spectroscopy, single-photon emission computed tomography (SPECT), radiography and angiography. The listed diagnostic methods and the corresponding technical means allow preoperative diagnostics, providing information on the individual anatomical (vascularization), physiological (blood flow velocity, perfusion) and metabolic characteristics of the patient's tissues and organs. For the preoperative determination of the location of nerves in the tumor, a system of diffusion tensor tractography is also used [Yoshino M., Kin T., Ito A., Saito T., Nakagawa D., Ino K., Saito N. Feasibility of diffusion tensor tractography for preoperative prediction of the location of the facial and vestibulocochlear nerves in relation to vestibular schwannoma // Acta Neurochirurgica. - 2015. - 157 (6), P. 939-946]. A significant drawback of these preoperative diagnostic systems is the impossibility of their use for local neuronavigation during surgical interventions. For differentiation of tissues and cells, assessment of their functional activity and local hemodynamics, optical systems are applicable that implement the possibility of research using Raman spectroscopy in vivo [Cordero E., Latka I., Matthus Ch., Schie IW, Popp J. In-vivo Raman Spectroscopy: from basics to applications // J. Biomed. Opt. - 2018. - 23 (7), 071210-1-23, doi: 10.1117 / 1.JBO.23.7.071210], broadband [Wisotzky EL, Uecker, Arens Ph., Dommerich S., Hilsmann A., Eisert P. Intraoperative hyperspectral determination of human tissue properties // J. Biomed. Opt. - 2018. - 23 (9), 091409- (1-8), doi: 10.1117 / 1.JBO.23.9.091409] and narrowband [Gono K., Obi T., Yamaguchi M., et al. Appearance of enhanced tissue features in narrow-band endoscopic imaging // J. Biomed. Opt. - 2004. - 9 (3), 568-577] spectroscopy, multispectral imaging [Bolton FJ, Bernat AS, Bar-Am K., Levitz D., and Jacques S. Portable, low-cost multispectral imaging system: design, development , validation, and utilization // J. Biomed. Opt. - 2018. - 23 (12), 121612, doi: 10.1117 / 1.JBO.23.12.121612], fluorescence spectroscopy and visualization [Bachmann L., Zezell DM, Adriana da Costa Ribeiro, and Gomes L., Siuiti A. Fluorescence Spectroscopy of Biological Tissues-A Review // Applied Spectroscopy Reviews. 2006. 41: 575-590, doi: 10.1080 / 05704920600929498; Sun Y., Hatami N., Yee M., et al. Fluorescence lifetime imaging microscopy for brain tumor image-guided surgery // Journal of Biomedical Optics. - 2010 .-- 15 (5), 056022; Pogue B.W., Gibbs-Strauss S.L., Valdes P.A., Samkoe K.S., Roberts D.W., and Paulsen K.D. Review of Neurosurgical Fluorescence Imaging Methodologies // IEEE J. of Selected Topics in Quantum Electronics. - 2010. - Vol. 16, No. 3, doi: 10.1109 / JSTQE.2009.2034541], optoacoustic (photoacoustic) imaging [Ovsepian S.V., Olefir I., Westmeyer G., Razansky D., and Ntziachristos V. Pushing the boundaries of neuroimaging with optoacoustics // Neuron. - 2017 .-- 96, p. 966-988] and multimodal combined solutions. However, the use of these optical systems has a number of limitations, such as a shallow probing depth (up to 1.5 mm), the absence of standard methods of application in clinical practice, or technical solutions applicable in situ for neurosurgery with endoscopic transnasal access.

Known use of ultrasound Doppler (USDG) systems for intraoperative identification of blood vessels [Sharipov OI and others. Experience in the use of intraoperative ultrasound Doppler in endoscopic transsphenoidal surgery // Journal of Neurosurgery Issues named after NN Burdenko. - 2016. - T. 80. - No. 2. - S. 15-20]. The presence of a vessel in the volume of biological tissue is determined by the speed and direction of blood flow in the vessel. To scan the operating field, a combined device with a movable working part is used, which makes it possible to locate the vessels in different directions. The presence of an arterial vessel, its depth relative to the tumor surface is assessed using the monitor in the M-Mode window. The limitations of ultrasonic scanning systems are associated with the low mobility of ultrasonic sensors in a small operating field and with the difficulty of detecting neural structures in the tissue volume. The system of ultrasound imaging of nerves and vessels, presented in [Smistad E., Johansen K.F., Iversen D.H., Reinertsen I. Highlighting nerves and blood vessels for ultrasound-guided axillary nerve block procedures using neural networks // J. Med. Imag. - 2018. - Vol. 5.No. 4. P. 044004], is not intended for a small operating field with limited access, for example, endonasal neurosurgery. The identification of neurovascular structures using an ultrasound imaging system is carried out by analyzing the obtained images that are difficult to uniquely interpret.

For the identification of cranial nerves, the use of trigger electromyography (t-EMG, t-EMG) and spontaneous electromyography (free run EMG, f-EMG) systems is known [Thirumala P. D., Mohanraj S. K., Habeych M., et al. Value of Free-Run Electromyographic Monitoring of Extraocular Cranial Nerves during Expanded Endonasal Surgery (EES) of the Skull Base // Journal of Neurological Surgery Reports. 2013. 74: R1, doi: 10.1055 / s-0033-1346975]. Neurophysiological identification of the cranial nerves several times reduces the frequency of their damage, and as a result, improves the quality of life of patients. However, the t-EMG system only identifies motor and mixed nerves. The main disadvantages of t-EMG systems also include a wide area of current propagation through electrically conductive tissues, which can lead to excitation of distant nerve structures and a false response to stimulation, and the need to register the response to stimulation with additional measuring tools outside the area of nerve localization. A modern alternative to electrical nerve stimulation is optical infrared (IR) stimulation [Cayce J. M., Wells J. D., Malphrus J. D., et al. Infrared neural stimulation of human spinal nerve roots in vivo // Neurophotonics. - 2015 .-- 2 (1). - P. 015007; Wells J., Konrad P., Kao C. et al. Pulsed laser versus electrical energy for peripheral nerve stimulation // Journal of Neuroscience Methods. 2007. 163 (2). - P. 326-337], which does not require direct contact with the stimulated nerve and has a local effect. However, such systems of IR stimulation are currently under development, and their significant limitations are the ability to detect a nerve only when it is surfaced and the need to use additional means to record the response. Optical systems for reflective diffusion and fluorescence spectroscopy [Balthasar A., Desjardins A.E., M. van der Voort, et al. Optical Detection of Peripheral Nerves: An in Vivo Human Study // Regional anesthesia and pain medicine. - 2012. - Vol. 37, No. 3, p. 277-82; Langhout G.C., Kuhlmann K.F.D., Schreuder P. In Vivo Nerve Identification in Head and Neck Surgery Using Diffuse Reflectance Spectroscopy // Laryngoscope Investigative Otolaryngology. - 2018. - 3. - P. 349-355] allow intraoperative differentiation of tissues by composition, for example, by the concentrations of hemoglobin and lipids. However, these systems are used to identify superficially located tissues and structures, including nerves. analysis of deep tissue layers is unrealizable. Modern systems of spatially modulated diffusion imaging (the so-called SFDI [Gioux S., Mazhar A., Cuccia DJ Spatial frequency domain imaging in 2019: principles, applications, and perspectives // J. Biomed. Opt. - 2019. - 24 (7) , 071613, doi: 10.1117 / 1.JBO.24.7.071613]) provide a non-contact quantitative assessment of the optical parameters of biological tissues, absorption coefficient and transport scattering coefficient, but for a small surface layer no more than 2-2.5 mm, which is insufficient for conditions carrying out neurosurgical operations to remove a tumor.

Closest to the claimed system is the system of intraoperative detection and recognition of neurovascular structures in the volume of biological tissue [Safonov LP, Orlova VG, Shkarubo AN. Study of neurovascular structures using phase-modulation spectrophotometry [Electronic resource] / // Optics and Spectroscopy. - 2019. -vol. 126. No. 6. - S. 822-833. (DOI: 10.21883 / OS.2019.06.47778.58-19). English version: Safonova LP, Orlova VG, Shkarubo AN The neurovascular structures research by phase modulation spectrophotometry // Optics and Spectroscopy, 2019, Vol. 126, No. 6, pp. 745-757 (https://rdcu.be/bM7sz)], consisting of a time-resolved spectrometer, a personal computer with specialized software, and a linear optical fiber sensor for reflective diffusion spectroscopy with 6 mm and 9 mm source-receiver spacing, with with the help of which subsurface probing of the investigated volume of biological tissue is carried out to a depth of 2-5 mm, the first wavelength (λ ₁ <806 nm, λ ₁ = 692 nm) and the second wavelength (λ ₂ > 806 nm, λ ₂ = 834 nm) from red and / or near infrared (KBIR) range based on the phase-modulation or otherwise frequency approach (FD - frequency domain) spectroscopic method with time resolution. Using the prototype system, the values of the optical parameters are determined: the absorption coefficients for the first wavelength μ _a (λ ₁ ) and for the second wavelength μ _a (λ ₂ ), corrected for the water content per unit volume of biological tissue, and transport scattering coefficients μ _s '(λ ₁ ) for the first wavelength and μ _s ' (λ ₂ ) for the second wavelength. These optical parameters are used to evaluate the derived parameters in the form of ratios, and / or physiological parameters, such as tissue saturation (S _t O ₂ ), the concentration of total hemoglobin ([tHb]) per unit of the investigated volume of biological tissue and the index of pulse hemodynamic fluctuations of this volume ... Criteria are used for comparing the derived derivatives and physiological parameters with threshold values for the detection and recognition of neurovascular structures, nerves, arterial and venous vessels, taking into account the preoperative and diagnostic information about the features of the microcirculatory blood filling of the investigated volume and its morphological structure at the cellular level.

However, this prototype system is characterized by a limited field of view due to the use of highly directional sensing, implemented by a fiber optic sensor of a linear configuration, not invariance to the location of neurovascular structures, if they are present in the studied volume of biological tissue, and, as a consequence, uneven sensitivity to neurovascular structures with insignificant displacements of the optical fiber. sensor. In addition, when detecting and recognizing neurovascular structures, the prototype system does not take into account the informative pulse and respiratory components of hemodynamic processes occurring in the studied volume of biological tissue. A significant drawback of the known system is the uncontrolled pressing force of the fiber optic sensor to the surface of the investigated volume of biological tissue, which leads to the presence of motor artifacts in measurements caused by hand tremor and / or uncontrolled clamping of biological tissue at the time of contact probing of the investigated volume and, as a consequence, to distortion obtained data due to changes in structural and optical parameters and a decrease in the efficiency of detection and recognition of neurovascular structures. The disadvantage is also the lack of assessments, qualitative and / or quantitative, of the type of arterial or venous vessel when it is detected in the investigated volume of biological tissue. In addition, this system does not allow to control the presence of possible spasm of the arterial vessels of the studied volume of biological tissue or the feeding large artery and the degree of ischemia of the tissues supplied by them during the operation, which can lead to a significant decrease in the efficiency and quality of the performed operation.

A technical problem is the development of a system that eliminates the disadvantages listed above that are characteristic of analogues.

Disclosure of invention

The technical result of the invention consists in obtaining reliable data on the presence of nerves, large and small arteries and veins in the volume of biological tissue at a maximum depth of at least 5 mm during operations.

The claimed system is universal, can be used both for neurosurgical operations of open or endoscopic, including transnasal access, and other types of surgical interventions to remove a tumor, as well as in plastic and reconstructive surgery and, in addition, to identify and recognize neurovascular structures through intact skin, to assess the state of the tissues of the internal environment of the body during surgical interventions, and invasive diagnostic procedures of the laparoscopic type, as well as to study damaged tissues with an assessment of the depth of damage and at all stages of their treatment and recovery, for example, with burns and frostbite.

The use of the claimed system increases the efficiency of intraoperative detection and recognition of neurovascular structures, which reduces the risks of their accidental damage during the surgical intervention, and as a consequence, improves the quality of medical care. The system allows for quantitative diagnostics of the state of various tissues of the body: at different depths (up to 10 cm) with the required depth resolution, the required sensitivity to structural inhomogeneities, over the probing area (mapping area from several mm ² to several tens of cm ² ), to carry out an objective quantitative assessment of the adequacy of therapeutic procedures and measures and the quality of treatment at all stages.

The specified technical result is achieved by the fact that the system for intraoperative detection and recognition of neurovascular structures in the volume of biological tissue includes:

- an optical-surgical device for probing biological tissues and surgical manipulations, made on the basis of branches;

- a positional and / or force control unit of an optical-surgical device (position control unit), including a position sensor and / or a force sensor or a force-torque sensor configured to control the position / movement and / or pressing force of the working end of the optical-surgical device to the biological fabrics;

- signal conversion unit, configured to generate direct and receive reverse optical signals from subsurface probing of biological tissue;

- a control and processing unit (hereinafter referred to as the control unit), configured to generate control signals for synchronized operation of the conversion unit and the position control unit, and also with the ability to process received signals from said units, display diagnostic information and store the received data,

wherein

the signal conversion unit is configured to generate radiation for reflective diffusion spectroscopy with a time resolution of at least two wavelengths (λ _i , i = 1 ... K, K≥2) from the range of 650-950 nm;

the optical-surgical device is made with the possibility of subsurface contact sensing of biological tissue to a maximum depth of at least 5 mm, and is equipped with at least two groups of optical fibers for supplying a direct optical signal of subsurface sensing of biological tissue, and at least one optical fiber bundle for receiving a return signal; optical fibers and optical fiber bundle (each, if there is more than one), one end is brought out to the working end of the device, and the other end is connected to the signal conversion unit, while the groups of optical fibers at the working end are located along separate mismatched semi-axes directed from the optical fiber bundle; each group of optical fibers consists of at least two subgroups, each of which is designed to supply a signal at least at two wavelengths (λ _i , i = 1 ... K, K≥2) from the specified range, the optical fibers of each subgroup are located at each other from another at a distance of not more than 1 mm, and each subgroup - at a certain distance (r _j , j = 1 ... M, M≥2) from the receiving fiber-optic bundle along the corresponding semiaxis;

the control unit is configured to generate a vector of features for the detection and recognition of neurovascular structures based on signals received from the conversion unit and the position control unit, which are used to judge the presence of certain neurovascular structures in the volume of biological tissue, tissue saturation and local blood filling, including on the presence or absence of tissue hypoxia.

A variant of the system implementation is possible, in which, for the formation of a vector of features (for the detection and recognition of neurovascular structures), the signal conversion unit is _{configured to register signals of intensities of backscattered radiation for each wavelength λ i} and each r _j with subsequent processing in the control unit and the formation of parameters vector of features for the detection and recognition of neurovascular structures:

- absorption coefficient (s) μ _a (λ _i ) and transport (s) scattering coefficient (s) μ _s ' (λ _i ) for each group of optical fibers and each optical fiber bundle, which determine the concentration of total hemoglobin ([tHb]) in unit of the investigated volume of biological tissue and tissue saturation (S _t O ₂ ) - the degree of oxygen saturation of blood in the vessels of the investigated tissue volume, as well as the tangent of the slope of the transport scattering coefficient from the wavelength (D _s ),

- the amplitudes of the pulse (Ap) and respiratory (Ar) oscillations and their ratio Ap / d = Ap / Ar for each pair (λ _i , r _j ), and / or

, крупному венозному сосуду

, или функциональной тканевой единице в размерах исследуемого объема биологической ткани

,- vector of the form (), which is a set of values characterizing the shape of the pulse wave corresponding to a large or small arterial vessel

, a large venous vessel

, or a functional tissue unit in the size of the investigated volume of biological tissue

,

and for each subgroup of sources, for at least two wavelengths from the specified range, the local amplitude of pulse fluctuations in the concentration of total hemoglobin (Δ [tHb] p) is determined,

while the listed parameters are measured in a static mode, in which the pressure of the fiber-optic sensor P on the surface of the investigated volume of biological tissue is P ≤ 0.2 mm Hg.

, определяющийся тремя переменными {N, AvCor_k, DI_m}_i,j , гдеA variant of the system implementation is possible, in which the control unit generates the vector of the pulse waveform

defined by three variables {N, AvCor _k , DI _m } _{i, j} , where

N is the number of components of the Fourier spectrum of the autocorrelation function of the pulse component of the recorded intensity of backscattered radiation, the amplitude of which is not less than 0.2 rel. Units;

AvCor _k , k = 1 ... N are the amplitudes of these components of the Fourier spectrum of the autocorrelation function;

- среднее за период регистрации абсолютное значение локальных минимумов производной пульсовой составляющей регистрируемой интенсивности обратно рассеянного излучения по времени с шагом 0,2±0,003 с;

- the average over the registration period the absolute value of the local minima of the derivative of the pulse component of the recorded intensity of backscattered radiation in time with a step of 0.2 ± 0.003 s;

in this case, the shape of the pulse wave is determined as corresponding to a functional tissue unit in the dimensions of the investigated volume of biological tissue when the following values of the shape vector are obtained:

=

: N = 1; 0,6 ≤ AvCor₁ ≤ 1;

, -

=

: N = 1; 0.6 ≤ AvCor ₁ ≤ 1;

, -

as corresponding to a large artery in the investigated volume of biological tissue when obtaining the following values of the shape vector:

=

: N = 1; 0,8 ≤ AvCor₁ ≤ 1; DI_m > 4DIm₀, -

=

: N = 1; 0.8 ≤ AvCor ₁ ≤ 1; DI _m > 4DIm ₀ , -

as corresponding to a large vein in the investigated volume of biological tissue when the following values of the shape vector are obtained:

=

: N = 1 или N = 2; AvCor_k < 0,6, k = 1...N; DI_m < DIm₀, -

=

: N = 1 or N = 2; AvCor _k <0.6, k = 1 ... N; DI _m <DIm ₀ , -

where DI _m0 is the threshold value of DI _m , determined for a functional tissue unit in the size of the investigated volume of biological tissue.

A variant of the system is possible, in which the control unit is configured to form conclusions about the presence of certain neurovascular structures when receiving the following sets of measured parameters:

=

; Δ[tHb]_п > (Δ[tHb]_п)₀} (1) - о наличии в исследуемом объеме биологической ткани крупной артерии;- for {D _s >0;[tHb]> [tHb] ₀ ; S _t O ₂ > (S _t O ₂ ) ₀ ; A / d> (A / d) ₀ ;

=

; Δ [tHb] _n > (Δ [tHb] _n ) ₀ } (1) - about the presence of a large artery in the studied volume of biological tissue;

=

; Δ[tHb]_п ≤ (Δ[tHb]_п)₀} (2) - о наличии в исследуемом объеме биологической ткани крупной вены;- for {D _s >0;[tHb]> [tHb] ₀ ; S _t O ₂ ≤ (S _t O ₂ ) ₀ or S _t O ₂ > (S _t O ₂ ) ₀ ; A / d <(A / d) ₀ ;

=

; Δ [tHb] _n ≤ (Δ [tHb] _n ) ₀ } (2) - about the presence of a large vein in the studied volume of biological tissue;

=

; Δ[tHb]_п < (Δ[tHb]_п)₀} (3) - о наличии в исследуемом объеме биологической ткани нерва диаметром от 1,5 мм и более;- for {D _s0 <D _s <0; [tHb] ≤ [tHb] ₀ ; S _t O ₂ ≤ (S _t O ₂ ) ₀ ; A / d ≤ (A / d) ₀ ;

=

; Δ [tHb] _n <(Δ [tHb] _n ) ₀ } (3) - on the presence of a nerve with a diameter of 1.5 mm or more in the studied volume of biological tissue;

=

; Δ[tHb]_п ≥ (Δ[tHb]_п)₀} (4) - о наличии в исследуемом объеме биологической ткани, по меньшей мере, одной малой артерии;- for {D _s ≤ D _s0 ; [tHb] ≥ [tHb] ₀ ; S _t O ₂ ≥ (S _t O ₂ ) ₀ ; A / d ≥ (A / d) ₀ ;

=

; Δ [tHb] _n ≥ (Δ [tHb] _n ) ₀ } (4) - the presence of at least one small artery in the investigated volume of biological tissue;

=

; Δ[tHb]_п > (Δ[tHb]_п)₀} (5) - о наличии в исследуемом объеме биологической ткани части крупной артерии, когда объем цельной крови сосуда в исследуемом объеме биологической ткани не приводит к Δμ_s'(λ) > 0;- for {D _s0 <D _s <0;[tHb]> [tHb] ₀ ; S _t O ₂ ≥ (S _t O ₂ ) ₀ ; A / d> (A / d) ₀ ;

=

; Δ [tHb] _n > (Δ [tHb] _n ) ₀ } (5) - about the presence in the investigated volume of biological tissue of a part of a large artery, when the volume of whole blood of the vessel in the investigated volume of biological tissue does not lead to Δμ _s '(λ)>0;

=

; Δ[tHb]_п ≤ (Δ[tHb]_п)₀} (6) - о наличии в исследуемом объеме биологической ткани, по меньшей мере, одной малой вены,- for {D _s0 ≤ D _s <0; [tHb] ≥ [tHb] ₀ ; S _t O ₂ ≤ (S _t O ₂ ) ₀ ; A / d ≤ (A / d) ₀ ;

=

; Δ [tHb] _n ≤ (Δ [tHb] _n ) ₀ } (6) - about the presence in the investigated volume of biological tissue of at least one small vein,

и Δ[tHb]п определяют, по меньшей мере, для одной подгруппы излучателей этой группы.where [tHb]₀, D_s0, (S_tO₂)₀, (A / d)₀, (Δ [tHb]_NS)₀ - threshold values of the above parameters, measured for a functional tissue unit in the dimensions of the investigated volume of biological tissue. Parameter values D_s, [tHb] and S_tO₂ for each group of optical fibers at the working end of the optical-surgical device and each receiving fiber-optic bundle or, at least, the only one, and A / d,

and Δ [tHb] n is determined for at least one subgroup of emitters of this group.

There is a variant of the system implementation, in which the position control unit and the control unit are made with the ability to measure parameters, detect and recognize neurovascular structures in a static mode, in which the controlled pressure P of the opto-surgical device on the surface of the investigated volume of biological tissue is P ≤ 0.2 mm Hg, and in a dynamic mode with an increase in the pressure of the optical-surgical device on the surface of the investigated volume of biological tissue at a given constant velocity V _L ≤ 10 mm / min with a change in force from 0 to F _max , corresponding to the maximum allowable for the investigated biological tissue pressure level P _max = F _max / S, taking into account the contact area S of the working end of the diagnostic optical-surgical device with the surface of the investigated volume of biological tissue, where P _max takes values from 70 mm Hg. for brain tissue up to 200 mm Hg for tissues of the lower extremities, or with a two-stage change in pressure P from 0 to 20 mm Hg. and from 20 mm Hg. up to P _max .

A possible embodiment of the system, in which the control unit is configured to determine the state of spasm of arterial vessels of the investigated volume of biological tissue or a feeding large artery by obtaining the following sets of measured parameters {D _s0 ≤ D _s <0; [tHb] <[tHb] ₀ ; S _t O ₂ <(S _t O ₂ ) ₀ ; Ap / d = 0 (in the absence of pulse fluctuations)} (7).

A variant of the implementation of the system is possible, in which the optical-surgical device contains a branching unit for jaws, to regulate the spatial position of the jaws relative to the investigated surface of biological tissue and relative to each other, made with the possibility of control from the side of the position control unit and from the side of the control unit, (using signals feedback generated during regulation and sent to the position control and control units) and / or contains a docking unit with a positional and / or force control unit for automated regulation of the spatial position of the jaws relative to the investigated surface of biological tissue and relative to each other, made with the ability to control with from the side of the position control unit and from the side of the control unit by special control signals.

Thus, the claimed system eliminates the following disadvantages inherent in the closest solution known from the prior art:

- non-use or incomplete use of the informative pulse and respiratory components of hemodynamic processes occurring in the studied volume of biological tissue for the detection and recognition of neurovascular structures;

- uncontrolled positioning and / or uncontrolled pressing force of the fiber-optic sensor to the surface of the investigated volume of biological tissue, which leads to the presence of motor artifacts in measurements caused by hand tremor and / or uncontrolled clamping of biological tissue at the time of contact probing of the investigated volume and, as a consequence, to distortion of the obtained data due to changes in structural and optical parameters and a decrease in the efficiency of detection and recognition of neurovascular structures;

- lack of assessments, qualitative and / or quantitative, of the type of arterial or venous vessel when it is detected in the investigated volume of biological tissue;

- limited field of view of the fiber optic sensor used in the prototype, its non-invariance to the location of neurovascular structures when they are present in the studied volume of biological tissue and, as a result, uneven sensitivity to neurovascular structures with minor displacements of the fiber optic sensor;

- lack of control over the possible spasm of the arterial vessels of the studied volume of biological tissue or the feeding large artery and the degree of ischemia of the tissues supplied by them, especially nerve tissues, hypoxia and damage to which during the operation lead to irreversible consequences for the patient, which does not allow us to speak of the effectiveness and quality of the operation performed ,

- limited functionality of the prototype, low efficiency of detection and recognition of neurovascular structures.

In contrast to the closest solution, the claimed system implements:

- application of methods of multiple-scale analysis of the recorded intensity of backscattered radiation and the formation of a complex characteristic of pulse and respiratory oscillations, which determines the presence or absence of pronounced pulse oscillations, the presence or absence of respiratory oscillations in the investigated volume of biological tissue, the pulse waveform corresponding to a large artery, a small artery , forced pulse fluctuations of the venous volume or functional tissue unit;

- expanding the set of criteria for the detection and recognition of neurovascular structures: large and small arterial and venous vessels and nerves, taking into account preoperative and intraoperative diagnostic information and taking into account a priori physiological information;

- implementation of the possibility of implementation in conditions of automated control of positioning and / or pressing force of the used fiber-optic sensor to the surface of the investigated volume of biological tissue, using a position control unit equipped with displacement and / or force sensors, in two modes: static and dynamic;

- formation and application of an extended set of criteria for the detection and recognition of neurovascular structures based on spectroscopic measurements in the static mode of automated control of positioning and / or pressing force;

- the possibility of carrying out a two-stage dynamic mode to confirm or detect: at the first stage - the presence of a venous vessel in the investigated volume of biological tissue; at the second stage - additional confirmation of the presence of an arterial vessel already detected in a static mode or detection and recognition of an arterial vessel of a deeper occurrence, not detected in a static mode, assessing the caliber of an arterial vessel by the pressure in the vessel;

- the possibility of additional confirmation that the studied area of biological tissue is a site with a microvasculature without neurovascular inclusions: vessels, such as arteries and veins, and nerves;

- ensuring the uniformity of probing of the investigated volume of biological tissue and the invariance of the method to the location of neurovascular structures, if they are present in the investigated volume, through the use of at least two groups of emitters in the optical-surgical device and the application of methods of multiple-scale analysis to the intensity recorded for each source back scattered radiation for the isolation and analysis of respiratory and pulse oscillations;

- ensuring control of the presence of possible spasm of arterial vessels of the studied volume of biological tissue or a feeding large artery and the degree of ischemia of the biological tissues supplied by them according to deviations of the controlled physiological parameters from their initial values recorded intraoperatively towards pronounced tissue hypoxia.

The above distinctive features of the claimed system lead to the achievement of the following advantages over the closest technical solution:

- to increase the efficiency of recognition of neurovascular structures by analyzing a complex of significant parameters in static and, if necessary, in dynamic modes, and obtaining a wider range of criteria that ensure the determination of incl. type of structure, due to the automated control of positioning and / or pressing force of the used optical-surgical device to the surface of the investigated volume of biological tissue, which ensures the absence of uninformative motor artifacts and distortions of optical parameters, ensures the stability and reproducibility of the parameters by which a decision is made based on the relevant criteria , by increasing the uniformity of probing of the investigated volume of biological tissue and the invariance of the result to the location of neurovascular structures;

- to increase the versatility by increasing the depth of detection and recognition of arterial vessels with a controlled automated indentation of an optical-surgical device into the tissue under study without increasing its dimensions and dimensions of the investigated area, by ensuring the invariance of the method to the location of neurovascular structures in the investigated volume of biological tissue by using not less than two groups of emitters of an optical-surgical device and analysis of the intensity of backscattered radiation for each source;

- to expand the functionality of the system on a unified methodological basis by controlling possible spasm of arterial vessels of the investigated volume of biological tissue or a feeding large artery and the degree of ischemia of the biological tissues supplied by them using the proposed vector of signs and the corresponding criteria for assessing spasm and ischemization;

- improving the quality of medical care due to the reduction or prevention of cases of damage to neurovascular structures and sudden uncontrolled spasm of large arteries in case of accidental sharp mechanical impact on them, which are not uncommon in neurosurgical practice.

The diagnostic algorithm (method) implemented using the proposed system has no restrictions if the spatial resolution and the minimum probed volume are consistent with the characteristic dimensions of neurovascular structures to be detected and recognized, and changes in optical parameters that are significant for the detection and recognition of neurovascular structures are at least 2 times exceed the corresponding noise performance.

Brief Description of Drawings

The invention is illustrated by illustrative material, where in FIG. 1 is a block diagram of an embodiment of the system; in fig. 2 shows a longitudinal section of an optical-surgical device (a), a top view of a variant of the working end of circular jaws (b), a cross-section of an optical-surgical device with groups of optical fibers and / or a fiber-optic bundle (c), a variant of an element of the branching unit - in section (G); in fig. 3 shows individual examples of layouts on the working end of the opto-surgical device of groups and subgroups of emitters relative to the receiver; in fig. 4 shows an embodiment of the working end of a small-sized optical-surgical device with a sector arrangement of the receiver and emitters in a closed state (a), a device in the biological tissue sensing mode with open branches (b) and a sectional view of the working end surface of a sector type (c); in fig. 5 shows options for the design of the working end of the optical-surgical device, in cross-section, when the sounding uniformity is ensured by an increase in the number of point sources (a) and / or receivers (b), the presence of a ruler or matrix of receivers (c) or an increase in the number of sliding jaws (d) ; in fig. 6 shows the structure of a conversion unit for realizing time-resolved reflective diffusion spectroscopy; in fig. 7 shows the experimental layout of the system; in fig. 8 shows the object of study (a): blood vessels, nerves, soft tissues of a human hand, and the results (b) of correct detection and recognition of neurovascular structures relative to soft tissues, muscle and skin-fat, according to optical parameters measured by time-resolved spectroscopy with the implementation of the ability to change the depth of tissue sounding; in fig. 9 shows a possible view of information display on the monitor screen of the control and display unit; in fig. 10 shows the results obtained with the force-torque sensor of the position control unit.

Table 1 shows examples of recognition of neurovascular structures using the system and by the parameters of the prototype based on the criterion values of the parameters corresponding to the functional tissue unit.

Implementation of the invention

For a more unambiguous understanding of the essence of the claimed invention, below are the basic terms and definitions used in the framework of the present description.

A functional tissue unit (FUU) in the size of the investigated volume of biological tissue is a complex of specialized tissue cells, cells and a non-cellular component of connective tissue, blood and lymphatic microvessels, endings of nerve fibers and the smallest arterial and venous vessels with diameters less than 0.5 mm. The basis of PTU of a certain organ or tissue is the microcirculatory-tissue system, the morphofunctional features of which are considered in detail by the authors of the work [Krupatkin A.I., Sidorov V.V. Functional diagnostics of the state of microcirculatory-tissue systems: Fluctuations, information, nonlinearity. 2nd edition. - M .: LENAND, 2016. - 496 p.]. Functional tissue units of different organs have differences at the structural and functional levels: histological differences at the level of cells of different tissues, differences in the connective tissue structure, in the structure of the microvascular network and at the level of blood vessels are larger (with a diameter of more than 250 μm) vessels of the microcirculatory level (with a diameter of 3 μm - 250 μm). As a result of these differences, FTE have different physical properties: optical, acoustic, electrical. The optical parameters of the FTU determined in this way, the absorption coefficients and the transport scattering coefficients at different wavelengths, are characterized by high biological variability. Therefore, the development of methods for detecting and recognizing in the volume of FTU such structures as nerves and whole blood in vessels, which have a significantly lower biological variability of morphofunctional and physical properties, requires a preliminary assessment and consideration of the measured parameters of the FTU in the applied criteria.

Taking into account the functionality of the applied time-resolved spectroscopy method for FTU in the size of a relatively small investigated volume of biological tissue with the specified maximum probing depth of at least 5 mm, the ratio between the vessel caliber and its size is taken as follows:

- a large vessel, artery or vein is defined as a vessel with a diameter of 2.0 mm or more;

- a small vessel, artery or vein, has a diameter of 0.5 mm to 2.0 mm;

recognizable nerves with a diameter of 1.5-5 mm and above.

In the framework of the present invention, studies were carried out for a human hand from the hand to the middle of the forearm. The functional tissue unit was the volume of tissue on the outer side of the middle of the forearm, the obtained values of the parameters D _s0 , [tHb] ₀ , (S _t O ₂ ) ₀ , (A / d) ₀ , DI _m0 and (Δ [tHb] _n ) ₀ were as thresholds.

The possibility of performing the functions of the claimed system is demonstrated using a device, the generalized block diagram of which is shown in Fig. 1 and FIG. 6. The scheme includes the following structural units:

подхода (TD, time domain), содержащий 1.1 - радиочастотный генератор, 1.2 - блок формирования излучения с мультиплексированием по времени для зондирования биологической ткани, как минимум, на двух длинах волн, 1.3 - блок приема излучения, рассеянного в исследуемой биологической ткани (5) в обратном направлении, 1.4 - блок аналоговой обработки сигнала, регистрируемого блоком приема излучения (1.3);1 - signal conversion unit that implements the method of diffusion spectroscopy with time resolution based on the frequency approach (FD, frequency domain), or

approach (TD, time domain), containing 1.1 - a radio frequency generator, 1.2 - a radiation formation unit with time multiplexing for sensing biological tissue at least at two wavelengths, 1.3 - a unit for receiving radiation scattered in the biological tissue under study (5) in the opposite direction, 1.4 - block for analog processing of the signal recorded by the unit for receiving radiation (1.3);

2 - an optical-surgical device for reflective diffusion spectroscopy, with the help of which the subsurface mapping of the investigated volume of biological tissue is carried out with the required number of wavelengths of the indicated red and near infrared (KBIR) range to the required depth with the required spatial resolution, having the required technical version containing ( fig. 2): 2.1 - branches, 2.2 - working end. 2.3 - branching unit for jaws, 2.4 - fiber optic groups and / or fiber optic bundle;

3 - position control unit for positioning the optical-surgical device relative to the biological tissue under study, equipped with a force sensor or force-torque sensor 3.1 and a displacement sensor 3.2 and having a attachment point for the optical-surgical device 3.3;

4 - control unit for structural elements 1-3 of the system, including a microcontroller unit for control and digital signal processing 4.1 and a personal computer with software and a unit for displaying and storing information 4.2;

5 - investigated biological tissue;

6 - video recorder for illumination and registration of the image of the operating space, the surface of the investigated volume of biological tissue.

The device shown in FIG. 1 is operated by an operator (and / or physician).

The design of the optical-surgical device 2 is determined by the medical task, the type of access to the investigated volume of biological tissue 5, the size of the operating field available for probing, the properties of the investigated volume of biological tissue (dimensions, surface shape, biomechanical and optical properties), the required number of probing wavelengths of the KBIK range, required sounding depth, required sensitivity and required spatial resolution. An example of the design of an optical-surgical device for reflective diffusion spectroscopy and the implementation of system functions is shown in Fig. 2, the indicated positions of the main elements are deciphered above. The literature also presents options for the implementation of optical sensors that can be upgraded and used when implementing the claimed system [Utzinger U., Richards-Kortum R.R. Fiber optic probes for biomedical optical spectroscopy // Journal of Biomedical Optics. - 2003. - Vol. 8. - No. 1. - P. 121-147].

For intraoperative detection and recognition of neurovascular structures in the volume of biological tissue, an optical-surgical device 2 for reflective diffusion spectroscopy carries out subsurface probing of the volume of biological tissue 5 under investigation, for example, tumor.

Subsurface sounding of the investigated volume of biological tissue 5 is carried out on the basis of a spectroscopic method with a time resolution to a maximum depth of at least 5 mm, at least the first wavelength (λ ₁ ) and the second wavelength (λ ₂ ), λ ₁ <λ ₂ , from KBIK range from 650 nm to 950 nm, such that the standard requirements for the selection of wavelengths for reflective diffusion spectroscopy are provided:

- the depth of sensing biological tissue z at the same distance r between the sources and the receiver at different wavelengths should not differ significantly [Choi J.H., Wolf M., Toronov V., et al. Noninvasive determination of the optical properties of adult brain: near-infrared spectroscopy approach // Journal of Biomedical Optics. - 2004, vol. 9, No. 1, p. 221-229]:

;

;

- physiologically significant minimum changes in [HbO ₂ ] and [HHb] should be distinguishable during measurements, and the errors in determination of [HbO ₂ ] and [HHb] should be minimal at the selected wavelengths, taking into account the noise characteristics of the measuring instrument used. Recommended combinations of wavelengths used in spectroscopy of biological tissues for the range 650-950 nm are given in [Scholkmann F., Kleiser S., Metz AJ, Zimmermann R., Pavia JM, Wolf U., Wolf M. Review on continuous wave functional near-infrared spectroscopy and imaging instrumentation and methodology // NeuroImage. - 2014, vol. 85, Part 1, p. 6-27].

The specified criteria when choosing two wavelengths, for example, correspond to 690 ± 10 nm and 830 ± 10 nm.

The spectroscopic method with time resolution and the options for its technical implementation in the form of frequency (FD) or time (TD) approaches are discussed in detail, respectively, in [Optical biomedical diagnostics. In 2 volumes.Vol. 1 / Per. from English ed. V.V. Tuchin. - M .: Fizmatlit, 2007 .-- 560 p .; Wolf, M., Ferrari, M., Quaresima, V. Progress of near-infrared spectroscopy and topography for brain and muscle clinical applications // Journal of Biomedical Optics. - 2007, vol. 12, No. 6, p. 062104 (1-14); Fantini S., Franceschini M.A., and Gratton E. Semi-infinite-geometry boundary problem for light migration in highly scattering media: a frequency-domain study in the diffusion approximation // Journal of Optical Society of America. - 1994. Vol. 11.N 10.p. 2128; Fantini, S., Franceschini, M.A., Maier, J.S., et.al. Frequency-domain multichannel optical detector for non-invasive tissue spectroscopy and oximetry // Optical engineering. - 1995, Vol. 34, No. 1, p. 32-42; US6,216,021 B1] - for FD and [Optical Biomedical Diagnostics. In 2 volumes.Vol. 1 / Per. from English ed. V.V. Tuchina. - M .: Fizmatlit, 2007 .-- 560 p .; Wolf, M., Ferrari, M., Quaresima, V. Progress of near-infrared spectroscopy and topography for brain and muscle clinical applications // Journal of Biomedical Optics. - 2007, vol. 12, No. 6, p. 062104 (1-14); Torricelli, A., Contini, D., Pifferi, A., et.al. Time domain functional NIRS imaging for human brain mapping // NeuroImage. - 2014, Vol. 85, p. 28-50] - for TD.

Before using the optical-surgical device, depending on the technical implementation of the method, it may be necessary to calibrate the sensor in accordance with the operating instructions for the spectrometer under conditions of the required illumination level of the operating field, acceptable for the implementation of the proposed method, and on blocks with known optical properties close to optical properties of the investigated volume of biological tissue, such as for brain tissue, μ _a ~ 0.1 (cm ^-1 ) and μ _s ' ~ 10 (cm ^-1 ). The permissible level of illumination depends on the design of the optical-surgical device, the calibration conditions, the type of the receiver for radiation diffusely scattered in the opposite direction, and the hardware-software implementation of the method.

In the process of probing the investigated volume of biological tissue 5, the parameters of backscattered radiation are recorded, corresponding to the spectroscopic method with time resolution, with a sampling frequency of at least 20 Hz. For the frequency approach, such parameters are the average intensity level, modulation amplitude and phase shift of the recorded modulated signal with respect to the reference signal [Optical biomedical diagnostics. In 2 volumes.Vol. 1 / Per. from English ed. V.V. Tuchin. - M .: Fizmatlit, 2007 .-- 560 p .; Wolf, M., Ferrari, M., Quaresima, V. Progress of near-infrared spectroscopy and topography for brain and muscle clinical applications // Journal of Biomedical Optics. - 2007, vol. 12, No. 6, p. 062104 (1-14); Fantini S., Franceschini MA, and Gratton E. Semi-infinite-geometry boundary problem for light migration in highly scattering media: a frequency-domain study in the diffusion approximation // Journal of Optical Society of America. - 1994. Vol. 11.N 10.p. 2128; Fantini, S., Franceschini, MA, Maier, JS, et.al. Frequency-domain multichannel optical detector for non-invasive tissue spectroscopy and oximetry // Optical engineering. - 1995, Vol. 34, No. 1, p. 32-42; US 6,216,021 Bl]. Determine the values of optical parameters, at least for two wavelengths of the QBIR range: absorption coefficients for the first wavelength μ _a (λ ₁ ) and for the second wavelength μ _a (λ ₂ ), λ ₁ <λ ₂ , corrected for water content per unit volume of biological tissue (5), and transport scattering coefficients μ _s '(λ ₁ ) for the first wavelength and μ _s ' (λ ₂ ) for the second wavelength, assuming that the main absorbers of radiation in the CIRC range in the investigated volume of biological tissue are are water, oxygenated and deoxygenated hemoglobin. The determination of optical parameters is carried out with a spectrometer (1) with a time resolution, for example, with a phase-modulation frequency mode (frequency domain, FD), as in "OxiplexTS" (ISS, Inc., USA), with specialized software, such as “OxiTS”, which calculates optical parameters, absorption coefficients μ _a (λ ₁ ) and μ _a (λ ₂ ) and transport scattering coefficients μ _s '(λ ₁ ) and μ _s ' (λ ₂ ), based on the parameters of backscattered radiation and equations known from the literature [Optical biomedical diagnostics. In 2 volumes.Vol. 1 / Per. from English ed. V.V. Tuchina. - M .: Fizmatlit, 2007 .-- 560 p .; Fantini S., Franceschini MA, and Gratton E. Semi-infinite-geometry boundary problem for light migration in highly scattering media: a frequency-domain study in the diffusion approximation // Journal of Optical Society of America. - 1994. Vol. 11.N 10.p. 2128; Fantini, S., Franceschini, MA, Maier, JS, et.al. Frequency-domain multichannel optical detector for non-invasive tissue spectroscopy and oximetry // Optical engineering. - 1995, Vol. 34, No. 1, p. 32-42; US 6,216,021 Bl]. Additional examples of spectrometers implementing the time-resolved approach are given in [Optical Biomedical Diagnostics. In 2 volumes.Vol. 1 / Per. from English ed. V.V. Tuchina. - M .: Fizmatlit, 2007 .-- 560 p .; Wolf, M., Ferrari, M., Quaresima, V. Progress of near-infrared spectroscopy and topography for brain and muscle clinical applications // Journal of Biomedical Optics. - 2007, vol. 12, No. 6, p. 062104 (1-14); Torricelli, A., Contini, D., Pifferi, A., et.al. Time domain functional NIRS imaging for human brain mapping // NeuroImage. - 2014, Vol. 85, p. 28-50; Spichtig S., Hornung R., Brown DW, Haensse D., and Wolf M. Multifrequency frequency-domain spectrometer for tissue analysis // Review of scientific instruments. - 2009, Vol. 80, p. 024301 (1-7)]. A list of spectrometers providing the measurement of the absolute values of the optical parameters μ _a and μ _s ' at least at two wavelengths is presented in [Wolf, M., Ferrari, M., Quaresima, V. Progress of near-infrared spectroscopy and topography for brain and muscle clinical applications // Journal of Biomedical Optics. - 2007, vol. 12, No. 6, p. 062104 (1-14)].

и по известным соотношениям, представленным в [Сафонова Л.П., Орлова В.Г., Шкарубо А.Н. Исследование нейроваскулярных структур с помощью фазово-модуляционной спектрофотометрии [Электронный ресурс]/ //Оптика и спектроскопия. - 2019. -том 126. №6. - С. 822-833. (DOI: 10.21883/OS.2019.06.47778.58-19). Версия на английском языке: Safonova L.P., Orlova V.G., Shkarubo A.N. The neurovascular structures research by phase modulation spectrophotometry // Optics and Spectroscopy, 2019, Vol. 126, No. 6, pp. 745-757 (https://rdcu.be/bM7sz); Оптическая биомедицинская диагностика. В 2 т. Т. 1 / Пер. с англ. под ред. В. В. Тучина. - М.: Физматлит, 2007. - 560 с.], рассчитывают физиологические параметры, такие как концентрации оксигенированного гемоглобина ([HbO₂]), дезоксигенированного гемоглобина ([HHb]) и общего гемоглобина ([tHb] = [HbO₂] + [HHb]) в единице исследуемого объема биологической ткани и тканевая сатурация (S_tO₂ = 100*[HbO₂] / [tHb]).Based on the indicated optical parameters in the control and processing unit (4), the derived parameter (D _s ) is estimated in the form of the ratio

and according to the known ratios presented in [Safonov LP, Orlova VG, Shkarubo AN. Study of neurovascular structures using phase-modulation spectrophotometry [Electronic resource] / // Optics and Spectroscopy. - 2019. -vol. 126. No. 6. - S. 822-833. (DOI: 10.21883 / OS.2019.06.47778.58-19). English version: Safonova LP, Orlova VG, Shkarubo AN The neurovascular structures research by phase modulation spectrophotometry // Optics and Spectroscopy, 2019, Vol. 126, No. 6, pp. 745-757 (https://rdcu.be/bM7sz); Optical biomedical diagnostics. In 2 volumes.Vol. 1 / Per. from English ed. V.V. Tuchin. - M .: Fizmatlit, 2007. - 560 p.], Calculate the physiological parameters, such as the concentration of oxygenated hemoglobin ([HbO ₂ ]), deoxygenated hemoglobin ([HHb]) and total hemoglobin ([tHb] = [HbO ₂ ] + [HHb]) per unit of the investigated volume of biological tissue and tissue saturation (S _t O ₂ = 100 * [HbO ₂ ] / [tHb]).

Registration and calculation of parameters is carried out in an automated mode by means of software installed on a personal computer, such as, for example, “OxiTS” for the “OxiplexTS” spectrometer.

In the general case of using at least two probing wavelengths λ _i , i = 1,2, ..., n, physiological parameters are evaluated by the measured absorption coefficients:

, (1)

, (1)

- молярные коэффициенты экстинкции, мкМ^-1⋅ см^-1;

- соответствующие концентрации, мкМ=мкмоль/л, основных учитываемых биологических хромофоров: воды, оксигенированного (HbO₂) и дезоксигенированного (HHb) гемоглобина, липидов и др. В случае двух зондирующих длин волн λ₁ и λ₂, λ₁ < λ₂, предполагают процент водонасыщения исследуемого объема биологической ткани (70-80%), пренебрегают вкладом липидов, если λ₂ < 900 нм, и на основании соотношения (1) по измеренным значениям μ_a с поправкой на содержание воды оценивают [HbO₂] и [HHb], [tHb]=[HbO₂]+[HHb] и S_tO₂=([HbO₂]/[tHb])⋅100%. Применение трех и более зондирующих длин волн позволяет повысить точность оценки физиологических параметров [tHb] и S_tO₂, но существенно повышает сложность и стоимость технической реализации. Ошибка при учете концентрации воды в диапазоне водонасыщения ткани от 70 до 80% не превышает десятых долей процента, в широком диапазоне водонасыщения от 50 до 90% максимальная ошибка - менее 2%.where

- molar extinction coefficients, μM ^-1 ⋅ cm ^-1 ;

- appropriate concentration, M = mol / l, basic accounted biological chromophores: water, oxygenated (HbO ₂₎ and deoxygenated (HHb) hemoglobin, lipids, etc. In the case of two probe wavelengths λ ₁ and λ _2, λ ₁ <λ _2. , assume the percentage of water saturation of the investigated volume of biological tissue (70-80%), neglect the contribution of lipids, if λ ₂ <900 nm, and based on relationship (1), according to the measured values of μ _a corrected for the water content, [HbO ₂ ] and [ HHb], [tHb] = [HbO ₂ ] + [HHb] and S _t O ₂ = ([HbO ₂ ] / [tHb]) 100%. The use of three or more probing wavelengths makes it possible to increase the accuracy of evaluating the physiological parameters [tHb] and S _t O ₂ , but significantly increases the complexity and cost of technical implementation. The error when taking into account the concentration of water in the range of tissue water saturation from 70 to 80% does not exceed tenths of a percent, in a wide range of water saturation from 50 to 90% the maximum error is less than 2%.

играет ключевую роль в обнаружении крупных сосудов и нервов. При наличии измеренных значений μ_s' на трех и более длинах волн D_s оценивают как тангенс угла линейного наклона аппроксимирующей зависимости μ_s'(λ) в силу специфики уменьшения μ_s' биологических тканей с увеличением λ [Оптическая биомедицинская диагностика. В 2 т. Т. 1 / Пер. с англ. под ред. В.В. Тучина. - М.: Физматлит, 2007. - 560 с.; Jacques S. L. Topical Review. Optical properties of biological tissues: a review // Phys. Med. Biol. - 2013, Vol. 58, p. R37-R61].Derived parameter D _s , cm ^-1 / μm,

plays a key role in the detection of large vessels and nerves. In the presence of measured values of μ _s ' at three or more wavelengths, D _{s is} estimated as the tangent of the linear slope of the approximating dependence μ _s ' (λ) due to the specific decrease in μ _s ' of biological tissues with increasing λ [Optical biomedical diagnostics. In 2 volumes.Vol. 1 / Per. from English ed. V.V. Tuchina. - M .: Fizmatlit, 2007 .-- 560 p .; Jacques SL Topical Review. Optical properties of biological tissues: a review // Phys. Med. Biol. - 2013, Vol. 58, p. R37-R61].

For a large blood vessel in the studied volume of biological tissue, Δμ _s '> 0 or D _s > 0, which is determined by a significant difference in the values of the anisotropy factor of most soft biological tissues (muscle, brain tissue, etc.), which are in the range from 0.7 to 0 , 95 from the values of the anisotropy factor for whole blood 0.997-0.999, and a change in the nature of the propagation of probing radiation in the investigated volume of biological tissue [Optical biomedical diagnostics. In 2 volumes.Vol. 1 / Per. from English ed. V.V. Tuchin. - M .: Fizmatlit, 2007. - 560 p.].

_{The values of the parameters D s} , S _t O ₂ and [tHb] used for the detection and recognition of neurovascular structures according to the appropriate criteria are determined by averaging over a registration period of at least 15 s.

Methods of multiple-scale analysis are applied to the recorded signal of the intensity of backscattered radiation, for example, to the average level or amplitude of modulation in the case of using spectroscopy with a frequency mode, to all wavelengths and distances from the emitters to the receiver realized using an optical-surgical device. Wavelet decomposition of the signal and subsequent Fourier analysis of the selected frequency components are performed [Krupatkin A.I., Sidorov V.V. Functional diagnostics of the state of microcirculatory-tissue systems: Fluctuations, information, nonlinearity. Ed. 2nd. - M .: LENAND, 2016. - 496, C. 167-229] with the allocation of the maximum peaks corresponding to the pulse (0.8-3.0 Hz) and respiratory (0.2-0.4 Hz) ranges.

), представляющий собой набор значений, характеризующих форму пульсовой волны, соответствующую крупному или малому артериальному сосуду

, крупному венозному сосуду

, или функциональной тканевой единице в размерах исследуемого объема биологической ткани

. В одном из вариантов осуществления изобретения вектор формы пульсовых колебаний

определяют тремя переменными {N, AvCor_k, DI_m}_i,j , гдеThus, a characteristic of the presence or absence of pronounced pulse oscillations, the presence or absence of respiratory oscillations in the investigated volume of biological tissue is formed, and the amplitudes of pulse (Ap) and respiratory (Ap) oscillations are determined, and their ratio Ap / d = Ap / Ar. Define a vector of the form (

), which is a set of values characterizing the pulse waveform corresponding to a large or small arterial vessel

, a large venous vessel

, or a functional tissue unit in the size of the investigated volume of biological tissue

... In one embodiment, the pulse waveform vector

are determined by three variables {N, AvCor _k , DI _m } _{i, j} , where

N is the number of components of the Fourier spectrum of the autocorrelation function of the pulse component of the recorded intensity of backscattered radiation, the amplitude of which is not less than 0.2 rel. Units;

AvCor _k , k = 1 ... N are the amplitudes of these components of the Fourier spectrum of the autocorrelation function;

- среднее за период регистрации абсолютное значение локальных минимумов производной пульсовой составляющей регистрируемой интенсивности обратно рассеянного излучения по времени с шагом 0,2±0,003 с.

- the average over the registration period the absolute value of the local minima of the derivative of the pulse component of the recorded intensity of backscattered radiation in time with a step of 0.2 ± 0.003 s.

In this case, the shape of the pulse wave is determined as corresponding to the functional tissue unit of the investigated biological tissue in the dimensions of the investigated volume when the following values of the shape vector are obtained:

=

: N = 1; 0,6 ≤ AvCor₁ ≤ 1;

;

=

: N = 1; 0.6 ≤ AvCor ₁ ≤ 1;

;

- as corresponding to a large artery in the investigated volume of biological tissue when obtaining the following values of the shape vector:

=

: N = 1; 0,6 ≤ AvCor₁ ≤ 1; DI_m > 4DIm₀;

=

: N = 1; 0.6 ≤ AvCor ₁ ≤ 1; DI _m > 4DIm ₀ ;

- as corresponding to a large vein in the investigated volume of biological tissue when the following values of the shape vector are obtained:

=

: N = 1 или N = 2; AvCor_k < 0,6, k = 1...N; DI_m < DIm₀,

=

: N = 1 or N = 2; AvCor _k <0.6, k = 1 ... N; DI _m <DIm ₀ ,

where DI _m0 is the threshold value of DI _m , determined for a functional tissue unit in the size of the investigated volume of biological tissue.

The pulse waveforms corresponding to a large artery, a small artery and forced pulse fluctuations of the venous blood volume with a pronounced dicrotic phase and doubling of the oscillation frequency or weakly expressed forced pulse fluctuations of the microcirculatory blood volume can be determined qualitatively in accordance with the publications [Human Physiology. In 3 volumes. T. 2. Per. from English / Ed. R. Schmidt and G. Tevs. - M .: Mir, 1996. - S. 556-559, 626-639; Lelyuk V.G., Lelyuk S.E. Cerebral circulation and blood pressure. - M .: Realnoe Vremya, 2004. - 304 p.].

In one embodiment of the invention, the local amplitude of the pulse fluctuations in the total hemoglobin concentration (Δ [tHb] _p ) is determined for each subgroup of sources and the corresponding distance (r) from the receiver, at least two wavelengths from the specified range. In this case, Δ [tHb] _p is determined by the recorded signals of the intensity of backscattered radiation I (λ _i ) using the known relations: modified Bouguer-Lambert-Beer law [Optical biomedical diagnostics. In 2 volumes.Vol. 1 / Per. from English ed. V.V. Tuchina. - M .: Fizmatlit, 2007. - 560 p.], Expressions for the total absorption coefficient at each wavelength, taking into account the corresponding number of analyzed chromophores, the calculation formula for the differential length factor (DPF) based on those measured in static mode for the corresponding group of optical emitters parameters μ _a (λ _i ) and μ _s ' (λ _i ) and formulas for determining the concentrations of oxygenated and deoxygenated hemoglobin by μ _a (λ _i ):

,

,

и

соответственно максимальное и минимальное значение интенсивности обратно рассеянного излучения, соответствующее пульсовому изменению.where

and

respectively, the maximum and minimum value of the intensity of the backscattered radiation corresponding to the pulse change.

In this case, the listed parameters are measured in a static mode, in which the pressure of the opto-surgical device P on the surface of the investigated volume of biological tissue is P ≤ 0.2 mm Hg.

The conclusion about the presence of certain neurovascular structures is made by obtaining the following sets of measured parameters:

=

; Δ[tHb]_п > (Δ[tHb]_п)₀} (1) - о наличии в исследуемом объеме биологической ткани крупной артерии;- for {D _s >0;[tHb]> [tHb] ₀ ; S _t O ₂ > (S _t O ₂ ) ₀ ; A / d> (A / d) ₀ ;

=

; Δ [tHb] _n > (Δ [tHb] _n ) ₀ } (1) - about the presence of a large artery in the studied volume of biological tissue;

=

; Δ[tHb]_п ≤ (Δ[tHb]_п)₀} (2) - о наличии в исследуемом объеме биологической ткани крупной вены;- for {D _s >0;[tHb]> [tHb] ₀ ; S _t O ₂ ≤ (S _t O ₂ ) ₀ or S _t O ₂ > (S _t O ₂ ) ₀ ; A / d <(A / d) ₀ ;

=

; Δ [tHb] _n ≤ (Δ [tHb] _n ) ₀ } (2) - about the presence of a large vein in the studied volume of biological tissue;

=

; Δ[tHb]_п < (Δ[tHb]_п)₀} (3) - о наличии в исследуемом объеме биологической ткани нерва диаметром от 1,5 мм и более;- for {D _s0 <D _s <0; [tHb] ≤ [tHb] ₀ ; S _t O ₂ ≤ (S _t O ₂ ) ₀ ; A / d ≤ (A / d) ₀ ;

=

; Δ [tHb] _n <(Δ [tHb] _n ) ₀ } (3) - on the presence of a nerve with a diameter of 1.5 mm or more in the studied volume of biological tissue;

=

; Δ[tHb]_п ≥ (Δ[tHb]_п)₀} (4) - о наличии в исследуемом объеме биологической ткани, по меньшей мере, одной малой артерии;- for {D _s ≤ D _s0 ; [tHb] ≥ [tHb] ₀ ; S _t O ₂ ≥ (S _t O ₂ ) ₀ ; A / d ≥ (A / d) ₀ ;

=

; Δ [tHb] _n ≥ (Δ [tHb] _n ) ₀ } (4) - the presence of at least one small artery in the investigated volume of biological tissue;

=

; Δ[tHb]_п > (Δ[tHb]_п)₀} (5) - о наличии в исследуемом объеме биологической ткани части крупной артерии, когда объем цельной крови сосуда в исследуемом объеме биологической ткани не приводит к изменениям Δμ_s'(λ) > 0;- for {D _s0 <D _s <0;[tHb]> [tHb] ₀ ; S _t O ₂ ≥ (S _t O ₂ ) ₀ ; A / d> (A / d) ₀ ;

=

; Δ [tHb] _p > (Δ [tHb] _p ) ₀ } (5) - about the presence in the investigated volume of biological tissue of a part of a large artery, when the volume of whole blood of the vessel in the investigated volume of biological tissue does not lead to changes in Δμ _s ' (λ) >0;

=

; Δ[tHb]_п ≤ (Δ[tHb]_п)₀} (6) - о наличии в исследуемом объеме биологической ткани, по меньшей мере, одной малой вены,- for {D _s0 ≤ D _s <0;[tHb]> [tHb] ₀ ; S _t O ₂ ≤ (S _t O ₂ ) ₀ ; A / d ≤ (A / d) ₀ ;

=

; Δ [tHb] _p ≤ (Δ [tHb] _p ) ₀ } (6) - about the presence of at least one small vein in the studied volume of biological tissue,

where [tHb] ₀ , D _s0 , (S _t O ₂ ) ₀ , (A / d) ₀ , (Δ [tHb] _p ) ₀ are the threshold values of the above parameters, measured for a functional tissue unit in the dimensions of the investigated volume of biological tissue,

moreover, the values of the parameters D _s , [tHb] and S _t O _{2 are} determined for each group of emitters and the corresponding receiver.

и Δ[tHb]_п хотя бы для одной подгруппы излучателей этой группы.To recognize the neurovascular structure in the investigated volume of biological tissue, it is necessary and sufficient to fulfill the criteria for D _s , [tHb] and S _t O _{2 for} at least one group of emitters and the corresponding receiver and fulfill the criteria for A / d,

and Δ [tHb] _{п for} at least one subgroup of emitters of this group.

The value of D _s0 depends on the type, composition and structure of the biological tissue under study, for example, the type, composition and structure of tumor tissue. The threshold value [tHb] ₀ for the tissue under study without nerves and large vessels is assessed by the known dependencies [Safonova LP, Orlova VG, Shkarubo AN. Study of neurovascular structures using phase-modulation spectrophotometry [Electronic resource] // Optics and Spectroscopy. - 2019. -vol. 126. No. 6. - S. 822-833. (DOI: 10.21883 / OS.2019.06.47778.58-19). English version: Safonova LP, Orlova VG, Shkarubo AN The neurovascular structures research by phase modulation spectrophotometry // Optics and Spectroscopy, 2019, Vol. 126, No. 6, pp. 745-757 (https://rdcu.be/bM7sz); Optical biomedical diagnostics. In 2 volumes.Vol. 1 / Per. from English ed. V.V. Tuchina. - M .: Fizmatlit, 2007. - P. 468] through blood filling or volumetric blood flow corresponding to the physiological norm or taking into account the increased perfusion of biological tissue, for example, tumor, which is detected at the stage of preoperative diagnosis, for example, using X-ray computed tomography. The values of the parameters [tHb] ₀ and D _s0 <0, corresponding to the type of biological tissue under study in terms of cellular composition and structure and the nature of blood supply at the microcirculatory level, but without neurovascular inclusions, can be estimated from the data of spectroscopic measurements with time resolution immediately at the beginning of the operation on the studied biological tissue, for example, to be excised, and / or with the involvement of a priori / preoperative diagnostic information about the biological tissue under study.

The presence of nerve in the volume of the biological tissue is characterized by small values [tHb] and StO ₂ compared with the same values of typical volume of tissue without nerves and large vessels that determined by the characteristic structure and molecular nerve composition with a high content of lipids (about 70%). In the presence of a nerve, D _s takes values D _s0 <D _s <0 in comparison with the value of D _s0 for the studied tissue, for example, pituitary adenoma, tumor tissue, the structure of adipose tissue is characterized by D _s0 <0 values close to zero.

The proposed criteria for the detection and recognition of neurovascular structures in the investigated volume of biological tissue are invariant to the choice of the approach (time or frequency) spectroscopic method with time resolution and are available for interpretation and analysis, since reflect physiological processes in the investigated volume of biological tissue.

The system is carried out with automated control of positioning and / or pressing force of the used optical-surgical device (2) to the surface of the investigated volume of biological tissue (5), using a positioning device (3) equipped with force sensors (3.1) and displacement (3.2) and a node attachments (3.3) of the opto-surgical device. It happens in the following way. The opto-surgical device is inserted and rigidly fixed in the attachment point (3.3) of the positioning unit (3), in which the force (3.1) and displacement (3.2) sensors are embedded. Registration and display of the current values of force and displacement occurs using the control unit (4) and the corresponding software. Examples of positioning devices are devices used in neurosurgery [Chan S., Conti F., Salisbury K., Blevins N.H. Virtual Reality Simulation in Neurosurgery: Technologies and Evolution // Neurosurgery. - 2013. - Vol. 72: A154-A164] or universal collaborative robots such as desktop mini-manipulators [Industrial robots catalog. Desktop minibots [Electronic resource] Access mode: http://robotforum.ru/promyishlennyie-robotyi.html]. Force and displacement sensors (force-torque sensors) used in similar positioning devices [Force-torque sensors. ForceKit from Weiss-Robotics. [Electronic resource] Access mode: http://ant-company.ru/catalog/forcesensor/forcekit/] are applicable for the implementation of the proposed system.

At the same time, the dependence of the pressing force (F) on the movement of the optical-surgical device (x) and the pressing force on time (t) with a sampling frequency of at least 20 Hz in two modes is determined and controlled:

1) static, when the pressing force corresponds to zero or minimum pressure (P ≤ 0.2 mm Hg) of the sensor on the surface of the investigated volume of biological tissue, taking into account the contact surface area (S), or

2) dynamic, when the method of pressing the optical-surgical device into the investigated volume of biological tissue at a given constant speed (V _L ≤ 10 mm / min) is implemented when the force changes from 0 to F _max , corresponding to the maximum allowable pressure level for the biological tissue under study (P _max = F _max / S, mm Hg), or with a two-stage pressure change from 0 to 20 mm Hg. and from 20 mm Hg. up to P _max .

и Δ[tHb]_п.In the static mode, on the basis of spectroscopic measurements, an extended set of criteria for the detection and recognition of neurovascular structures is formed and applied based on the parameters D _s , [tHb], S _t O ₂ , A / d,

and Δ [tHb] _p .

Then, two-stage measurements are performed in dynamic mode. At the first stage, the initial loading is carried out, increasing the pressing force of the optical-surgical device to the surface of the investigated volume of biological tissue from 0 to 20 mm Hg. with a given constant speed V _L. At the same time, when the criteria for the detection of a venous vessel in a static mode are fulfilled and in the presence of a relatively sharp, more than 25%, decrease in the parameters μ _a (λ _i ) and [tHb] at the first stage of loading, reflecting a decrease in the blood filling of the studied volume of biological tissue, and when respiratory fluctuations in the recorded signals additionally confirm the presence of a large venous vessel in the investigated volume of biological tissue.

At the second stage of the dynamic mode, further loading is carried out at a given constant speed V _L up to the maximum allowable pressure P _max for the studied biological tissue, where P _max takes values from 70 mm Hg. for brain tissue up to 200 mm Hg for the tissues of the lower extremities, which is determined by the localization of arterial vessels of the investigated volume of biological tissue in relation to the heart and the magnitude of the pressure in them, taking into account the hydrostatic pressure [Lelyuk V.G., Lelyuk S.E. Cerebral circulation and blood pressure. - M .: Realnoe Vremya, 2004. - 304 p.].

The registration of the dependences of the pressing force (F) on the movement of the optical-surgical device (x) and the pressing force (F) on time (t) with a sampling frequency of at least 20 Hz is carried out, on the basis of which the presence of an arterial vessel is detected at a depth greater than the maximum sounding depth in a static mode, and also estimate the size of the vessel by the value of the pressure in the vessel. The conclusion about the presence of an arterial vessel at a depth greater than the maximum sounding depth in a static mode is made when detecting pulse fluctuations of the force F (t) with a maximum in the heart rate range from 0.8 to 3.0 Hz using methods of multiple-scale analysis of discrete signals in real time, including windowed Fourier transform and wavelet transform. The pressure value (P) of the arterial vessel is determined by the formula P = F / S, where F is the value of the pressing force of the optical-surgical device at time t _to , corresponding to the end of the pulse oscillations or F _max , if the pulse oscillations have not stopped, S is the contact area an optical-surgical device with the surface of the investigated volume of biological tissue. When receiving a value of 70≤P≤90 mm Hg. make a conclusion about the presence of a small artery at a depth greater than the maximum sounding depth in a static mode; when receiving P> 90 mm Hg. conclude that there is a large artery at a depth greater than the maximum sounding depth in static mode.

_{With a decrease in the parameters μ a} (λ _i ) and [tHb] at the first and second stages of the two-stage dynamic regime, which characterize the blood filling of the studied volume of biological tissue, by less than 25% compared to the values obtained in the static regime for all groups of sources, in addition confirm the absence of large vessels in the study area of biological tissue.

One of the simplest designs of the working end (Fig. 2, a, b) of the optical-surgical device 2, which satisfies the condition of increasing the sounding uniformity in comparison with the prototype, is a sector version with one receiver and eight sources (Fig. 3, Fig. 4, c), which implements two linear versions of the minimum configuration - two distances from the receiver to the subgroups of emitters and two wavelengths from the QBIR range in each subgroup. In the closed state, the sensor has minimum dimensions for input into the operating field (Fig. 2, a, Fig. 4, a), in working condition with divorced branches (Fig. 4, b) it provides the required depth of probing of the investigated volume. The permissible range of jaws opening angles is determined by the design of the opto-surgical device with the required access to the operating field, taking into account the size of the operating space. The opening angle determines the size of the probed volume of biological tissue.

A separate linear version of the placement of the receivers and the source at the end of the optical-surgical device, corresponding to the prototype [Safonova LP, Orlova VG, Shkarubo AN. Study of neurovascular structures using phase-modulation spectrophotometry [Electronic resource] / // Optics and Spectroscopy. - 2019. - Volume 126. No. 6. - S. 822-833. (DOI: 10.21883 / OS.2019.06.47778.58-19). English version: Safonova L.P., Orlova V.G., Shkarubo A.N. The neurovascular structures research by phase modulation spectrophotometry // Optics and Spectroscopy, 2019, Vol. 126, No. 6, pp. 745-757 (https://rdcu.be/bM7sz)], does not ensure the uniformity of probing of the investigated volume and is not feasible for endoscopic transnasal neurosurgery due to the use of a sensor with large dimensions, two and a half times exceeding the permissible ones, for example, for endonasal neurosurgery , where the maximum transverse diameter does not exceed 6 mm, and the lack of the possibility of using sliding jaws with sources and receivers of optical radiation.

More complex variants of the design of the working end of the optical-surgical device are presented in Fig. 5, where the sounding uniformity is provided by an increase in the number of sources (Fig. 5, a) and / or receivers (Fig. 5, b), the presence of a line of receivers (Fig. 5, c) or an increase in the number of sliding jaws (Fig. 5, d) ... Distributed rather than point sources with uniform illumination of the investigated volume do not provide spatial resolution and spatial sensitivity to neurovascular structures in the investigated volume.

The invariance of the method to the location of neurovascular structures, if they are present in the investigated volume of biological tissue, is ensured by subsurface mapping of the investigated volume, which assumes the distribution over the surface of the working end of the optical-surgical device (2) of the sources of probing radiation of the used wavelengths of the CIRC range and receivers of the backscattered in biological tissue radiation to increase or ensure the uniformity of probing of the investigated volume and spatial sensitivity to neurovascular structures, the maximum possible for the used technical implementation of the KBIR spectroscopy method with time resolution with a certain number of sources of wavelengths λ _i , i = 1 ... N, N≥2 and the required number of subgroups emitters with distances r _j , j = 1 ... M, M≥2, from the receiver, providing the maximum sounding depth, not less than 5 mm, for each group of emitters.

Examples of layouts of groups and subgroups of emitters relative to the receiver are shown in Fig. 3 and FIG. 5.

The spatial resolution and sensitivity of the system are determined by the value of the minimum required for the implementation of the spectroscopic method with time resolution [Optical biomedical diagnostics. In 2 volumes.Vol. 1 / Per. from English ed. V.V. Tuchina. - M .: Fizmatlit, 2007 .-- 560 p., Ch. 3, Ch. 7] of the investigated volume of biological tissue, provided at a distance from the emitters to the receiver of at least 5 mm, and the number of measurement channels of the spectrometer.

In addition, the claimed system allows you to control the presence of possible spasm of large arteries and the degree of ischemia of the biological tissues supplied by them by deviations of the controlled physiological parameters from their initial values recorded intraoperatively towards pronounced tissue hypoxia, S _t O ₂ <(S _t O ₂ ) ₀ , and decreased blood flow [tHb] <[tHb] ₀ . For this, the same device (2) for reflection diffusion spectroscopy with the required frequency monitors in a static mode the areas of an organ or tissue to be monitored for possible ischemia due to spasm of arterial vessels of the studied volume or the main artery supplying them, a decrease in local blood flow and tissue saturation to critical level and below. The recorded values of S _t O ₂ and [tHb] should not be less than the critical values for biological tissues: S _t O ₂ ≤ 55%, which is determined by the ratio between the supply of oxygen by the blood, adequate to the consumption of oxygen in the tissues [Human physiology. In 3 volumes. T.2. Per. from English / Ed. R. Schmidt and G. Tevs. - M .: Mir, 1996. - S. 556-559, 626-639]; the critical value [tHb] is determined by the level of blood flow that is acceptable for the tissue under study; for the assessment, you can use the well-known ratios [Optical biomedical diagnostics. In 2 volumes.Vol. 1 / Per. from English ed. V.V. Tuchina. - M .: Fizmatlit, 2007 .-- 560 p .; Human physiology. In 3 volumes. T. 2. Per. from English / Ed. R. Schmidt and G. Tevs. - M .: Mir, 1996. - S. 556-559, 626-639].

When implementing the method with the number of wavelengths more than two, it is preferable to fulfill the following conditions: 1) at least two of the applied wavelengths must meet the criterion λ ₁ <806 nm and λ ₂ > 806 nm if the above requirements for the sounding depth and the accuracy of the determination of the determined concentrations are met biological chromophores; 2) λ ₃ = (930 ± 5) nm, which corresponds to the spectral absorption peak of lipids, the assessment of the concentration of which will be an additional criterion for the detection and recognition of nerves; 3) one of the wavelengths can be selected from the range of 900-950 nm, in addition to λ ₃ ~ 930 nm, which will allow to quantify the concentration of water in the investigated volume of biological tissue, improve the accuracy of determining the concentrations of oxygenated and deoxygenated hemoglobin, lipids, water and others detectable chromophores (for example, cytochrome oxidase, collagen, myoglobin, etc.) depending on the practical application of the method and the total number of used wavelengths other than those indicated; 4) other wavelengths can be selected from the range 650-950 different from those already selected.

The possibility of using the developed system, as well as the achievement of the technical result, is demonstrated in the data presented below.

Studies of neurovascular structures were carried out using a spectrophotometric device "OxiplexTS" (ISS, Inc., USA) with a two-wavelength (692 nm and 834 nm) phase-modulation measurement mode (FD-mode) (Fig. 7) using the minimum sector configuration of the optical -surgical device with a diameter of 12 mm and a working distance from the emitters to the receiver of 6 mm and 9 mm, manufactured by LLC STC Fiber Optic Devices (Moscow, RF).

In order to detect and recognize large venous and arterial vessels, areas with different anatomy of the vascular bed and nerves on the arm and forearm of volunteers were examined in vivo (Fig. 8, a). For the skin and soft muscle tissues of the hand, the maximum pressing force F _max does not exceed 10 N.

To verify the results obtained in the recognition of large vessels, the method of ultrasound Doppler ultrasonography of vessels was used simultaneously with spectroscopy. Verification of the presence of a nerve in the investigated volume was performed using ultrasound imaging of the investigated limb.

Automated control of the movements of the opto-surgical device and the pressing force was carried out using the Instron force-moment unit (Fig. 7, b) with simultaneous registration of spectroscopic data using the OxiplexTS (Fig. 7, c) on the subject's arm and forearm.

The results of the application of multiple-scale analysis, wavelet transform and spectral Fourier analysis to isolate and analyze the pulse and respiratory components in the backscattered radiation intensity signals recorded for individual sources are shown in Fig. nine.

Examples of pulse waveform analysis and determination of the corresponding waveform vectors are presented in Table 1.

,

и Δ[tHb]п позволяет, в отличие от прототипа, распознавать малые артерии и вены и наличие малого объема крови крупной артерии в исследуемом объеме биологической ткани, а также состояние спазмирования артерий в исследуемом объеме или спазмирования питающей магистральной артерии.The performance, significance and effectiveness of the introduced set of indicators and criteria for the detection and recognition of arteries, veins and nerves are confirmed by the research results presented in Table 1. Examples of recognition are given for the proposed method in comparison with the prototype. The threshold values correspond to the functional tissue unit of the investigated tissue volume of the outer surface of the middle of the forearm. Expansion of the feature vector with parameters

,

and Δ [tHb] n allows, in contrast to the prototype, to recognize small arteries and veins and the presence of a small blood volume of a large artery in the investigated volume of biological tissue, as well as the state of spasm of arteries in the investigated volume or spasm of the supplying main artery.

The effectiveness of the control of displacements and the pressing force in the process of a dynamic measurement mode is demonstrated by the results presented in Fig. 10. For the investigated area with a large venous vessel, an ulnar vein (with a diameter of more than 2 mm) at the stage of static measurements, the condition D _s <0 was not fulfilled. At the first stage of the dynamic measurement mode, under loading from 0 to 20 mm Hg. the presence of a large vein with a low pressure in the vessel (less than 20 mm Hg) is detected, as evidenced by a decrease in the parameters μ _a (692), μ _a (834) and [tHb], characterizing the blood filling of the studied volume of biological tissue, more than by 25% of the values in the static measurement mode. At the second stage of loading in the dynamic mode, the presence of a large artery - ulnar - in the area under study is detected, which is confirmed by the appearance of pulsations of the pressing force F (t), which persist up to F _max , which corresponds to a pressure in the vessel of more than 90 mm Hg. In this case, the changes in μ _s '(834) and μ _s ' (692) corresponded to D _s > 0.

An increase in the sensitivity of a sectoral opto-surgical device to local inhomogeneities of the investigated volume of biological tissue in comparison with the linear sensor of the prototype is confirmed by different local dynamics (pulse and respiratory) for emitters of different subgroups and by the results of measurements carried out on inhomogeneous phantoms of biological tissues with inclusions imitating large vessels according to optical parameters.

Thus, the conducted studies have demonstrated the possibility of implementing the invention with the achievement of the claimed result.

Claims (37)

1. A system for intraoperative detection and recognition of neurovascular structures in the volume of biological tissue, including: - an optical-surgical device for probing biological tissues and surgical manipulations, made on the basis of branches; - a unit for positional and / or force control of an optical-surgical device, including a position sensor and / or a force sensor or a force-torque sensor, configured to control the movement and / or force of pressing the working end of the optical-surgical device to biological tissue; - signal conversion unit, configured to generate direct and receive reverse optical signals from subsurface probing of biological tissue; - a control and processing unit capable of generating control signals for synchronized operation of the conversion unit and the position control unit, as well as with the ability to process received signals from said units, display diagnostic information and store the received data, wherein the signal conversion unit is configured to generate radiation for reflective diffusion spectroscopy with a time resolution at least at two wavelengths (λ _i , i = 1 ... K, K≥2) from the range of 650-950 nm; the optical-surgical device is made with the possibility of subsurface contact sensing of biological tissue to a maximum depth of at least 5 mm and is equipped with at least two groups of optical fibers for supplying a direct optical signal of subsurface sensing of biological tissue and at least one optical fiber bundle for receiving a return signal; optical fibers and a fiber optic bundle, each, if there is more than one, are brought out to the working end of the device at one end, and connected to the signal conversion unit at the other end, while the groups of optical fibers at the working end are located along separate mismatched semiaxes directed from the fiber optic bundle; each group of optical fibers consists of at least two subgroups, each of which is designed to supply a signal at least two wavelengths (λ _i , i = 1 ... K, K≥2) from the specified range, the optical fibers of each subgroup are located from each other on a distance of not more than 1 mm, and each subgroup - at a certain distance (r _j , j = 1 ... M, M≥2) from the receiving fiber-optic bundle along the corresponding semiaxis; the control unit is configured to generate a vector of signs for the detection and recognition of neurovascular structures based on signals received from the conversion unit and the position control unit, which are used to judge the presence of certain neurovascular structures in the volume of biological tissue, tissue saturation and local blood filling, including on the presence or absence of tissue hypoxia. 2. The system according to claim 1, characterized in that for the formation of a vector of features for the detection and recognition of neurovascular structures, the signal conversion unit is configured to register signals of intensities of backscattered radiation for each wavelength λ _i and each r _j with subsequent processing in the control unit and the formation of the parameters of the feature vector for the detection and recognition of neurovascular structures: - absorption coefficient (s) μ _a (λ _i ) and transport (s) scattering coefficient (s) μ _s ' (λ _i ) for each group of optical fibers and each optical fiber bundle, which determine the concentration of total hemoglobin ([tHb]) in unit of the investigated volume of biological tissue and tissue saturation (S _t O ₂ ) - the degree of oxygen saturation of blood in the vessels of the investigated tissue volume, as well as the tangent of the slope of the transport scattering coefficient from the wavelength (D _s ), - amplitudes of pulse (Ap) and respiratory (A) oscillations and their ratio A _{p / d} = Ap / A for each pair (λ _i , r _j ), and / or - vectors of the form (

), which is a set of values characterizing the pulse waveform corresponding to a large or small arterial vessel

, a large venous vessel

, or a functional tissue unit in the size of the investigated volume of biological tissue

, and for each subgroup of sources for at least two wavelengths from the specified range - with the ability to determine the local amplitude of pulse fluctuations in the concentration of total hemoglobin (Δ [tHb] _p ). 3. The system according to claim 1, characterized in that the control unit is configured to generate a vector of the pulse waveform

defined by three variables {N, AvCor _k , DI _m } _{i, j} , where N is the number of components of the Fourier spectrum of the autocorrelation function of the pulse component of the recorded intensity of backscattered radiation, the amplitude of which is not less than 0.2 rel. Units; AvCor _k , k = 1 ... N are the amplitudes of these components of the Fourier spectrum of the autocorrelation function;

- the average over the registration period the absolute value of the local minima of the derivative of the pulse component of the recorded intensity of backscattered radiation in time with a step of 0.2 ± 0.003 s; in this case, the shape of the pulse wave is determined as corresponding to a functional tissue unit in the dimensions of the investigated volume of biological tissue when the following values of the shape vector are obtained:

=

: N = 1; 0.6 ≤ AvCor ₁ ≤ 1;

, - as corresponding to a large artery in the investigated volume of biological tissue when obtaining the following values of the shape vector:

=

: N = 1; 0.6 ≤ AvCor ₁ ≤ 1; DI _m > 4DIm ₀ , - as corresponding to a large vein in the investigated volume of biological tissue when the following values of the shape vector are obtained:

=

: N = 1 or N = 2; AvCor _k <0.6, k = 1 ... N; DI _m <DIm ₀ , where DI _m0 is the threshold value of DI _m , determined for a functional tissue unit in the size of the investigated volume of biological tissue. 4. The system according to claim 1, characterized in that the control unit is configured to form conclusions about the presence of certain neurovascular structures when receiving the following sets of measured parameters: - for {D _s >0;[tHb]> [tHb] ₀ ; S _t O ₂ > (S _t O ₂ ) ₀ ; A / d> (A / d) ₀ ;

=

; Δ [tHb] _n > (Δ [tHb] _n ) ₀ } (1) - about the presence of a large artery in the studied volume of biological tissue; - for {D _s >0;[tHb]> [tHb] ₀ ; S _t O ₂ ≤ (S _t O ₂ ) ₀ or S _t O ₂ > (S _t O ₂ ) ₀ ; A / d <(A / d) ₀ ;

=

; Δ [tHb] _p ≤ (Δ [tHb] _p ) ₀ } (2) - about the presence of a large vein in the studied volume of biological tissue; - for {D _s0 <D _s <0; [tHb] ≤ [tHb] ₀ ; S _t O ₂ ≤ (S _t O ₂ ) ₀ ; A / d ≤ (A / d) ₀ ;

=

; Δ [tHb] _n <(Δ [tHb] _n ) ₀ } (3) - on the presence of a nerve with a diameter of 1.5 mm or more in the studied volume of biological tissue; - for {D _s ≤ D _s0 ; [tHb] ≥ [tHb] ₀ ; S _t O ₂ ≥ (S _t O ₂ ) ₀ ; A / d ≥ (A / d) ₀ ;

=

; Δ [tHb] _n ≥ (Δ [tHb] _n ) ₀ } (4) - the presence of at least one small artery in the investigated volume of biological tissue; - for {D _s0 <D _s <0;[tHb]> [tHb] ₀ ; S _t O ₂ ≥ (S _t O ₂ ) ₀ ; A / d> (A / d) ₀ ;

=

; Δ [tHb] _p > (Δ [tHb] _p ) ₀ } (5) - about the presence in the investigated volume of biological tissue of a part of a large artery, when the volume of whole blood of the vessel in the investigated volume of biological tissue does not lead to changes in Δμ _s ' (λ) >0; - for {D _s0 ≤ D _s <0; [tHb] ≥ [tHb] ₀ ; S _t O ₂ ≤ (S _t O ₂ ) ₀ ; A / d ≤ (A / d) ₀ ;

=

; Δ [tHb] _p ≤ (Δ [tHb] _p ) ₀ } (6) - about the presence of at least one small vein in the studied volume of biological tissue, where [tHb] ₀ , D _s0 , (S _t O ₂ ) ₀ , (A / d) ₀ , (Δ [tHb] _p ) ₀ are the threshold values of the above parameters, measured for a functional tissue unit in the dimensions of the investigated volume of biological tissue, moreover, the values of the parameters D _s , [tHb] and S _t O _{2 are} determined for each group of optical fibers at the working end of the optical-surgical device and each receiving fiber-optic bundle or at least a single one, and A / d,

and Δ [tHb] _n is determined for at least one subgroup of emitters of this group. 5. The system according to claim 1, characterized in that the position control unit and the control unit are configured to measure parameters, detect and recognize neurovascular structures in a static mode, in which the controlled pressure P of the optical-surgical device on the surface of the investigated volume of biological tissue is P ≤ 0.2 mm Hg, and in a dynamic mode with an increase in the pressure of the optical-surgical device on the surface of the investigated volume of biological tissue at a given constant velocity V _L ≤ 10 mm / min with a change in force from 0 to F _max , corresponding to the maximum allowable for the investigated biological tissue, the pressure level P _max = F _max / S, taking into account the contact area S of the working end of the diagnostic optical-surgical device with the surface of the investigated volume of biological tissue, where P _max takes values from 70 mm Hg. for brain tissue up to 200 mm Hg for tissues of the lower extremities, or with a two-stage change in pressure P from 0 to 20 mm Hg. and from 20 mm Hg. up to P _max . 6. The system according to claim 1, characterized in that the control unit is configured to determine the state of spasm of arterial vessels of the investigated volume of biological tissue or a large feeding artery by obtaining the following sets of measured parameters {D _s0 ≤ D _s <0; [tHb] <[tHb] ₀ ; S _t O ₂ <(S _t O ₂ ) ₀ ; Ap / d = 0 (in the absence of pulse fluctuations)}. 7. The system according to claim 1, characterized in that the optical-surgical device comprises a jaw dilution unit for adjusting the spatial position of the jaws relative to the investigated surface of biological tissue and relative to each other, and / or comprises a docking unit with a positional and / or force control unit for automated regulation of the spatial position of the branches relative to the investigated surface of biological tissue and relative to each other, made with the possibility of control from the side of the position control unit and from the side of the control unit according to special control signals.

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