102 results about "Blood vessel diameter" patented technology

Method for assessing the patency of a patient's blood vessel, advantageously during or after treatment of that vessel by an invasive procedure, comprising administering a fluorescent dye to the patient; obtaining at least one angiographic image of the vessel portion; and evaluating the at least one angiographic image to assess the patency of the vessel portion. Other related methods are contemplated, including methods for assessing perfusion in selected body tissue, methods for evaluating the potential of vessels for use in creation of AV fistulas, methods for determining the diameter of a vessel, and methods for locating a vessel located below the surface of a tissue.

A method has been described for deriving contour data in X-Ray images for vessels with differential absorption through applying a contour-finding algorithm on a shadow image and finding the vessel borders through segmentation based on image intensities. In particular, the method uses the following steps: finding a densitometric area of an above mentioned vessel, and displacing one or both of the borders inward until the densitometric measurement result between the borders after such displacing will start to change significantly. Furthermore, a specific procedure is introduced to automatically determine the conversion factor to equate the densitometrically based diameter to the contour based diameter of the vessel and to discriminate bifurcating or parallel vessels.

The invention discloses a method and a system for processing and analyzing a blood vessel image, and provides a quantitative method for correlational researches such as researches about geometric and three-dimensional network characteristics and laws of a blood vessel network. According to the technical scheme, the method includes the steps of firstly, inputting a three-dimensional blood vessel image to the system, then obtaining relevant various characteristic parameters through isotropic interpolation, area-of-interest extraction, appropriate threshold-value blood vessel segmentation, connected region extraction, small-region elimination, morphological processing, blood vessel network central line extraction and three-dimensional image reconstruction and visualization operation, and sending and displaying a result to a user, and the characteristic parameters comprise blood vessel areas, blood vessel sizes, blood vessel lengths, the blood vessel segment number, blood vessel diameters, blood vessel density distribution, the loop blood vessel number in the blood vessel network, loop relevant segment ratios, weighted average series and the like.

Provided herein are compositions and methods for preventing, ameliorating, and / or reducing tissue ischemia and / or tissue damage due to ischemia, increasing blood vessel diameter, blood flow and tissue perfusion in the presence of vascular disease including peripheral vascular disease, atherosclerotic vascular disease, coronary artery disease, stroke and influencing other conditions, by suppressing CD47 and / or blocking TSP1 and / or CD47 activity or interaction. Influencing the interaction of CD47-TSP1 in blood vessels allows for control of blood vessel diameter and blood flow, and permits modification of blood pressure and cardiac function. Under conditions of decreased blood flow, for instance through injury or atherosclerosis, blocking TSP1-CD47 interaction allows blood vessels to dilate and increases blood flow, tissue perfusion and tissue survival. This in turn reduces or prevents tissue necrosis and death. The therapeutics identified herein allow for precise regulation of blood flow to tissues and organs which need it, while substantially avoiding systemic complications. Methods and compositions described herein can be used to increase tissue survival under conditions of trauma and surgery, as well as conditions of chronic vascular disease. Also disclosed are methods for the treatment of elderly subjects using agents that affect TSP1 and CD47 and thereby affect tissue perfusion. Additionally, provided herein are compositions and methods for influencing blood coagulation, allowing for controlled increased or decreased blood clotting. Additionally, provided herein are compositions and methods for decreasing blood flow, as in the case of cancer through mimicking the effects of TSP1 and CD47 on blood vessel diameter and blood flow.

The invention provides a fundus retinal vessel recognition and quantification method, device and equipment and a storage medium, and the method comprises the steps: inputting an original fundus imageinto a pre-trained U-shaped convolutional neural network model for processing, and obtaining a target feature map; performing optic disk segmentation based on the target feature map; segmenting the original fundus image to obtain an arteriovenous blood vessel recognition result; carrying out region-of-interest positioning based on the optic disk segmentation result; extracting a blood vessel center line according to the arteriovenous blood vessel recognition result, detecting key points in the blood vessel center line, removing the key points to obtain a plurality of mutually independent bloodvessel sections, and correcting arteriovenous category information on each blood vessel section; and based on the extracted blood vessel center line, obtaining the blood vessel diameter of each bloodvessel section after category information correction, and then quantifying arteriovenous blood vessels in the region of interest. According to the embodiment of the invention, the fundus retina artery and vein vessel identification precision is improved, and the quantization precision is further improved.

The invention discloses a subcutaneous vein three-dimensional reconstruction method based on a hybrid matching strategy and aims to obtain the three-dimensional information of veins. The method includes the steps of firstly, using IUWT and Hessian matrix analysis to respectively obtain the blood vessel segmentation result and the related blood vessel feature image in each view; secondly, extracting and dividing blood vessel central lines through morphology and a blood vessel tracking algorithm to obtain the radius and blood vessel direction of each central line branch; thirdly, using epipolar constraint to calculate the candidate point set, of points in the central line branch of single view, in another view; respectively extracting SURF in the blood vessel similarity image of each view, completing SURF feature point matching, and using a Ransac method to calculate the homograph matrix among views; fifthly, using the layered matching strategy from part to whole to realize point-point matching between the blood vessel central lines of the views of two eyes according to the homograph matrix and the candidate matching point set, and completing the optimization of the homograph matrix during matching; sixthly, completing the three-dimensional reconstruction of the matching central line points according to the principle of triangular measuring, and recovering a three-dimensional blood vessel surface according to two-dimensional blood vessel diameter information.

The present invention relates to real-time monitoring of photodynamic tumor treating effect, and the photoacoustic blood vessel imaging method is that during laser irradiation of tumor tissue for photodynamic treatment, the photoacoustic chromatographic images of the tumor tissue before and after photodynamic action are compared and the blood vessel diameter change is reflected with the positive and negative peak-to-peak width of the photoacoustic blood vessel signals. The equipment for the real-time monitoring of photodynamic tumor treating effect includes laser generator assembly, acoustic signal acquiring assembly and computer successively connected electrically, as well as rotating scan mechanism connected electrically to the computer, sample fixing assembly and connected acoustic assembly. The present invention is sensitive and quick in real-time monitoring of photodynamic tumor treating effect.

The invention discloses a vascular endothelial function detecting device based on fingertip temperature change. The vascular endothelial function detecting device is used in the field of medical instruments and comprises a device main machine with a main control circuit board and a function module led out from the device main machine and connected with the main control circuit board. The function module comprises a blood blocking module for controlling of brachial artery blood flowing, a temperature measuring module for measuring fingertip temperature change and an oxyhemoglobin saturation measuring module for measuring fingertip oxygen content of blood. A complex algorithm using the fingertip temperature change to deduce blood vessel diameter change rate is built in the main control circuit board, complex processes of a measuring method achieve automation and intelligentization, detecting cost and device price are reduced, most people can achieve self-management of cardiovascular health state at home, monitoring cost is effectively reduced, operation process is simplified, support can be provided for families and primary hospitals to conduct cardiovascular disease early prevention and diagnosis, and the device has great significance for early prevention of cardiovascular diseases.

A puncture assistance system provides information on a collapse state of a blood vessel to be punctured, caused by pressing action of an ultrasonic probe, when ultrasonic images of the blood vessel are acquired. A puncture assistance system 10 includes: vascular diameter detecting means 18 for detecting a vascular diameter during acquisition of the ultrasonic images from an ultrasonic diagnostic device 11; puncture assistance information generating means 12 for generating puncture assistance information for determination of whether or not puncture is allowed to be performed based on a collapse state of a blood vessel B caused by pressing action of an ultrasonic probe 15 against skin S by comparing a current vascular diameter detected by the vascular diameter detecting means 18 with a standard vascular diameter stored in advance; and a monitor 19 that presents the puncture assistance information.

An occlusion catheter system for full or partial occlusion of a vessel having a vessel diameter includes a proximal catheter shaft having a proximal lumen and a hypotube positioned partially within the proximal lumen and spaced from the proximal catheter shaft. The catheter system also includes a distal catheter shaft attached to a distal end of the hypotube and an occlusion balloon connected at a proximal end to the proximal catheter shaft and at a distal end to the distal catheter shaft. The occlusion balloon is configured to define flow channels with inner surfaces of the vessel at folds in the occlusion balloon when the occlusion balloon is partially inflated and in engagement with the inner surfaces.

The invention relates to the technical field of medical image analysis, and discloses an ultrasonic image blood vessel diameter automatic measurement method, which comprises the following steps of obtaining a preprocessed ultrasonic image; obtaining a multi-threshold segmentation ultrasonic image according to the obtained pre-processed ultrasonic image; and automatically measuring the diameter ofthe blood vessel through ellipse fitting according to the obtained multi-threshold segmentation ultrasonic image. An ultrasonic image is enhanced, a large number of noise particles are distributed throughout the ultrasonic image, and by carrying out noise smoothing on the enhanced image, performing multi-threshold image segmentation on the smoothed image, and dividing the ultrasonic image into four different areas according to pixel gray values, due to the fact that the shape of the blood vessel is generally round, and the diseased blood vessel is generally oval, and by carrying out oval curvefitting on the segmented blood vessel area, the manual intervention is not needed in the whole algorithm, the automatic measurement of the diameter of the blood vessel in the ultrasonic image is achieved, and therefore an important clinical auxiliary diagnosis technology is provided for the PICC or CVC operation.

The invention belongs to the technical field of medical image processing, and discloses a fundus image retina blood vessel diameter automatic quantification method. The method comprises the followingsteps of using a two-step positioning method combining coarse positioning and fine positioning to automatically detect the visual disc; preprocessing the fundus image, including denoising and enhancement processing of the fundus image; separating the retinal blood vessel from the background of the fundus image by adopting a multi-scale analysis method, and reconstructing and eliminating pseudo blood vessels in segmentation by utilizing mathematical morphology; and measuring the diameter of the blood vessel by using a boundary method, and displaying a result. On the basis of fundus image features, the fundus image feature extraction method firstly detects the optic disc, then enhances the image contrast ratio, segments the retinal blood vessel, finally measures the size of the retinal bloodvessel diameter, displays the result on the system interface, provides reference for early prediction and auxiliary diagnosis of clinicians, saves manpower and improves the efficiency.

The invention discloses a cerebrovascular system function and brain recirculation dynamic analysis method, wherein iconographical index and tangential stress index for reflecting cerebrovascular atherosclerosis degree and arteria carotis blood vessel are added into the analytical method, these two indexes can perform early diagnosis and analysis to atherosclerosis and comprehensive analysis for the prevention and early stage diagnosis for cerebrovascular diseases. The invention also discloses the related analytic instrument based on the method for detecting blood vessel diameter by employing type B supersonic detection, which can improve detecting accuracy substantially.

The invention relates to the technical field of image recognition in the medical field, in particular to an esophageal cancer B3 type blood vessel recognition method based on a variable coefficient method, and the method comprises an image segmentation method, a clustering algorithm and the variable coefficient method. The image segmentation method is used for extracting a whole blood vessel image in the esophagus image; the clustering algorithm is used for performing data processing on all blood vessel diameters in the whole blood vessel graph and dividing the blood vessel into a plurality of classes according to the blood vessel diameters; the variable coefficient method is used for calculating the variable coefficient of each class; and obtaining a blood vessel diameter dispersion degree coefficient through the maximum class and minimum class variable coefficients, and further judging whether the B3 type blood vessel is contained or not according to the blood vessel diameter dispersion degree coefficient. According to the method, a clustering algorithm and a variable coefficient method are used to quantify the dispersion degree of the diameter of the capillary vessel, the dispersion degree of the diameter of the capillary vessel is quantified, whether the esophageal endoscopic image contains the B3-type blood vessel is determined, and an endoscopic physician can be assisted to improve the reliability and accuracy of esophageal cancer analysis and diagnosis.

The invention discloses a blood flow measurement method based on a Doppler blood flow spectrogram. The blood flow measurement method is characterized by comprising the following steps: directly using the Doppler blood flow spectrogram to calculate the blood flow, that is, performing normalization processing on the data of the Doppler blood flow spectrogram, accumulating a product of a gray value of a normalized blood flow spectrogram image with a corresponding speed value, and finally obtaining a correct blood flow measured value by system calibration. According to the method disclosed by the invention, the blood flow is measured by using the blood flow spectrogram and the blood flow distribution, thereby avoiding the measurement of the blood vessel diameters, reducing the measurement errors and improving the blood flow measurement accuracy; and by adoption of the method, when Doppler blood flow imaging is performed, the blood flow speed can be obtained directly, the size of the blood flow can also be displayed on an imaging instrument in real time, and thus the blood flow measurement method has a clinical application value.

The invention relates to the field of medical science and technology, and provides a hypertension risk prediction method, device and equipment and a medium. The method comprises the following steps: obtaining the individual information and a fundus image of a to-be-detected target; respectively inputting the fundus image into a preset arteriovenous segmentation model, an optic disk segmentation model and a lesion recognition model, and respectively extracting arteriovenous blood vessels, optic disk regions and fundus lesion features in the fundus image; quantifying the diameters of arteriovenous blood vessels in the optic disc area to obtain blood vessel diameter quantized values corresponding to the arteriovenous blood vessels respectively; using a machine learning regression method to construct a risk prediction model for predicting the hypertension of the target to be detected based on the blood vessel diameter quantized value, the fundus lesion features and the individual information; and inputting the fundus image corresponding to the to-be-detected target into the risk prediction model for detection to obtain a hypertension prediction result of the to-be-detected target. The risk prediction model is trained by adopting a plurality of variable factors, so that the accuracy of hypertension risk prediction is greatly improved.

The invention relates to an artificial intelligence electro-cardio lead doppler color ultrasonic all-in-one machine, and belongs to the field of medical apparatuses and instruments and medical engineering. The artificial intelligence electro-cardio lead doppler color ultrasonic all-in-one machine mainly structurally comprises an ultrasonic imaging module, a lead connector, an electro-cardio module, a prompting and alarm module, an artificial intelligence module, a PC processing module and a display module. The artificial intelligence electro-cardio lead doppler color ultrasonic all-in-one machine can prompt the blood vessel diameter, the blood vessel speed, the catheter implantation depth, the distance, away from the best position, of the head end of the catheter and other information in an artificial intelligence mode, and send out prompting languages similar to the proper blood vessel diameter, the proper blood flow speed, the catheter implanted depth, the distance away from the bestposition and the like. A medical worker can conveniently perform corresponding operations according to prompts and information. When the implanted catheter is excessively deep, when the machine enters the right atrium, sound or flashing light alarm can be triggered. The operation success rate of the catheter inside the vein can be effectively increased, the operation time is shortened, and the working efficiency of the medical worker is improved.

The invention relates to an ultrasonic blood pressure measurement apparatus and a blood pressure measurement method. In the ultrasonic blood pressure measurement apparatus (10) that measures a blood pressure by transmitting an ultrasonic wave toward a blood vessel and receiving a reflected wave, a storage unit (300) stores a [beta] blood-pressure calculation expression that is a first relationship between a vascular diameter (D) of the blood vessel and a blood pressure (P); a pulse wave velocity calculation unit (208) measures a pulse wave velocity (PWV) of the blood vessel; a [beta] blood-pressure calculation expression modifying unit (214) calculates a modified [beta] blood-pressure calculation expression that is a third relationship obtained by modifying the [beta] blood-pressure calculation expression using the pulse wave velocity (PWV); a vascular diameter measurement unit (206) configured to measure the vascular diameter (D) of the blood vessel using the ultrasonic wave; and a temporary blood pressure calculation unit (220) determines the blood pressure (P) according to the modified [beta] blood-pressure calculation expression.

The invention discloses a device and a method for estimating a blood flow velocity field of a blood vessel through transcranial ultrasound. The device mainly comprises a low-frequency ultrasonic transducer, a programmable ultrasonic platform and a computer. The method is characterized in that the low-frequency ultrasonic transducer is used for transmitting a plane wave attached with a linear frequency modulation signal for imaging; space-time filtering on the radio frequency data, positioning and tracking radiography microbubbles are performed to obtain a blood vessel structure diagram, and the diameter and position coordinates of the blood vessel are confirmed; and a traditional image cross-correlation algorithm and a fast Fourier transform algorithm are combined and applied to speed distribution estimation. The method can effectively overcome the weakening of the echo signal intensity caused by transcranial ultrasonic attenuation, can accurately determine the blood vessel position area under the condition that the imaging resolution of the low-frequency ultrasonic transducer is low, and is particularly suitable for estimating the blood flow velocity distribution of the transcranial ultrasonic small blood vessel.

The invention discloses an image fusion method for detecting peripheral vascular obstructive diseases. The method comprises: in a first part, using a near-infrared II-region fluorescent blood vessel imaging technology and a laser speckle blood flow imaging technology for obtaining two heterologous images; in a second part, using an image fusion method for carrying out operation on the two images output in the last step; wherein the third part is used for positioning a concerned blood vessel in the living blood vessel information image, calculating indexes for reflecting the health condition ofthe blood vessel, mainly the blood vessel diameter stenosis rate and the blood flow velocity, and finally detecting whether the blood vessel is blocked or not according to the indexes. The advantageinformation and complementary information of the static blood vessel image and the dynamic blood flow image are organically combined, the part and the condition of vascular occlusion lesion can be well displayed, and other reasons causing limb swelling or pain, such as hematoma, vein compression and the like, can be found out. The development condition of the disease of the patient can be effectively evaluated, and corresponding treatment is provided for clinic.

The disclosure relates to a braided implant, which is configured as a flow diverter for treating an aneurysm. The implant can include a braided mesh configured to maintain a substantially consistent target porosity over up to a 1 mm vessel diameter range over a predetermined length in a tapered vessel.

The invention relates to a manufacturing method of a coaxial electrostatic spinning magnetic anastomosed artificial blood vessel. The method comprises the following steps: 1) preparing a coaxial electrostatic spinning solution; and preparing two solutions: namely a heparin sodium solution and a poly L-lactide-caprolactone solution, wherein the heparin sodium solution is a core layer solution for coaxial electrostatic spinning, and the PLCL solution is a shell layer solution for coaxial electrostatic spinning; 2) carrying out 3D printing of an electrostatic spinning receiver: 2.1) carrying outCT angiography examination on a patient before an operation; 2.2) measuring the blood vessel length L and the blood vessel diameter D, which need to be replaced; 2.3) drawing a 3D model of an electrostatic spinning receiver by using SolidWorks software; and 2.4) manufacturing an electrostatic spinning receiver by using a 3D printer; and 3) manufacturing a coaxial electrostatic spinning magnetic anastomosed artificial blood vessel. The prepared magnetic anastomosed artificial blood vessel has a good microstructure, hydrophilicity and stable heparin slow release performance, and the blood compatibility, mechanical properties and animal in-vivo implantation experiments show that the magnetic anastomosed artificial blood vessel has the advantages that the anastomosis process is convenient andrapid, an anastomosed stoma is not narrow, and anticoagulant application is avoided.

In an ultrasonic blood pressure measurement apparatus that measures a blood pressure by transmitting an ultrasonic wave toward a blood vessel and receiving a reflected wave, a storage unit stores a β blood-pressure calculation expression that is a first relationship between a vascular diameter of the blood vessel and a blood pressure; a pulse wave velocity calculation unit measures a pulse wave velocity of the blood vessel; a β blood-pressure calculation expression modifying unit calculates a modified β blood-pressure calculation expression that is a third relationship obtained by modifying the β blood-pressure calculation expression using the pulse wave velocity; a vascular diameter measurement unit configured to measure the vascular diameter of the blood vessel using the ultrasonic wave; and a temporary blood pressure calculation unit determines the blood pressure according to the modified β blood-pressure calculation expression.

The invention discloses a drug balloon which comprises a balloon body, the outer surface of the balloon body is coated with a drug coating, the drug coating comprises a first component and a second component, the first component comprises polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), a photoinitiator and a first solvent, and the second component comprises a second solvent and a third solvent. The second component comprises a cell proliferation inhibition drug, a drug carrier and a second solvent; the cell proliferation inhibition drug is one or more of rapamycin, rapamycin and derivatives thereof, paclitaxel and derivatives thereof, the drug carrier is one or more of amphipathic high-molecular compounds, the balloon has the advantages of being good in balloon lubricity, low in drug delivery loss rate, high in bioavailability and the like, and compared with other similar products, the balloon has the advantages of being good in balloon lubricity, low in drug delivery loss rate, high in bioavailability and the like. The medicine is more suitable for patients with intracranial atherosclerosis with high intracranial blood vessel tortuosity degree and small narrow blood vessel diameter, and has a remarkable curative effect.

The invention provides an application of a pharmaceutical composition in the preparation of drugs for improving cerebral microcirculation dysfunction. The application uses an ischemia-reperfusion model which is established by the ligation of bilateral carotid arteries of a Mongolian gerbil, the dynamic cerebral microcirculation including cerebral blood flow, blood velocity, blood vessel diameter, generation of vascular endothelial peroxides, leukocyte adhesion and change of vascular permeability of the Mongolian gerbil is observed through a visual dynamic continuous system after the ligation of the bilateral carotid arteries, and a projecting and scanning electron microscope is further used for observing the changes of ultrastructures of small veins and capillaries for observation and research, thereby proving that Yangxueqingnao particles have the effects of treating and improving the cerebral microcirculation dysfunction caused by ischemia-reperfusion.

The invention discloses a blood vessel stent. The blood vessel stent includes a stent main body which is of a mesh-tube-shaped structure woven by metal wires, wherein the stent main body includes a first stent segment and a second stent segment which are connected in an axial direction, and the mesh density of the first stent segment is different from that of the second stent segment. By adoptingthe blood vessel stent, regarding phlebostenosis involving inferior vena cava and iliofemoral veins, naked segments are arranged so that therapeutic effects can be improved; regarding compressed parts, a dense mesh structure with larger mesh density is arranged so that support strength and anti-extrusion performance can be improved; regarding bent parts, a sparse mesh structure with smaller mesh density is arranged so that flexibility performance and adherence performance can be improved; and regarding blood vessel anatomic forms, a variable-diameter structure is arranged and can adapt to theblood vessel forms, and therefore the blood vessel stent is suitable for blood vessels of various diameters.

The invention discloses a small blood vessel diameter measuring scale, relating to the technical field of blood vessel measurement. The small blood vessel diameter measuring scale comprises a measuring scale body, wherein the length of the measuring scale body is 100mm, the width of the measuring scale body is 5mm, the thickness of the measuring scale body is 1.5mm, the measuring scale body is made of a stainless steel material, three levels of scales are arranged on the measuring scale body, the length of each first-level scale is 1.5mm, totally ten first-level scales are available, the intervals among the first-level scales are 1mm, the length of the second-level scale is 0.75mm, and one second-level scale is available, is positioned between the first first-level scale and the second first-level scale, and is 0.5mm away from each of the first-level scale and the second first-level scale; the length of each third-level scale is 0.3mm, the third-level scales are positioned between the first first-level scale and the second-level scale and between the second-level scale and the second first-level scale, totally eight third-level scales are available, the third-level scales are close to the first-level scales and the second-level scale, each third-level scale is 0.1mm away from the adjacent third-level scale, namely, the intervals among the adjacent third-level scales are 0.1mm. The small blood vessel diameter measuring scale is used for measuring small blood vessels, and can directly complete the measurement and reading under a lens, the operation can be completed through one-hand operation by one person, the small blood vessel diameter measuring scale is a stainless steel straight rule, has low requirements on the environment, and is convenient to clean and disinfect, and the influences of the external environment to the measurement are small.

The invention provides a curled multi-section developing thrombectomy stent system. The curled multi-section developing thrombectomy stent system comprises a stent, a push rod and a guide-in sheath, wherein the stent is curled, and the diameter of the stent can be automatically adjusted according to the diameter of a blood vessel, so the stent can be attached to thrombus and the blood vessel wall more easily, and the blood vessel is prevented from being damaged by the stent; the stent is connected with a stent far-end developing mark and a stent middle developing mark, and the stent middle developing mark is arranged according to a preset axial distance from the stent far-end developing mark; and the stent is fixedly connected with the push rod, and a near-end developing mark is arranged at a fixed joint. According to the invention, a doctor can better judge the unfolding state of the stent and the embedding state of the stent in the thrombus, and the effective length of the stent for capturing the thrombus and the position of the thrombus are effectively marked. The invention further discloses various connection modes of the stent and the push rod, and the connection strength and the conveying performance between the stent and the push rod can be improved.

An arterial-wall stiffness evaluation system of the present invention includes: a cuff to be attached to a part of a living body; a pressure sensor for detecting pressure in the cuff; a cuff-pressure control section for controlling the pressure in the cuff to be increased or decreased up to a predetermined value, based on a value detected by the pressure sensor; and a data processing section for calculating, based on pulse waves detected by the pressure sensor, pulse-wave amplitudes of cuff-pressure pulse waves and blood-pressure pulse waves, and for evaluating arterial-wall stiffness based on the pulse-wave amplitudes. The arterial-wall stiffness is evaluated by a pressure-diameter characteristic curve, which represents a relationship between vascular diameter and transmural pressure applied to a vascular wall, or by estimation from shapes and amplitudes of the detected pulse waves. Alternatively, the evaluation is performed by estimating, from the detected pulse waves, a differential function obtainable by differentiating a pressure-diameter characteristic curve with respect to a transmural pressure, or by use of an arctan or a sigmoid function. This allows anybody to easily evaluate blood vessel stiffness anytime with high accuracy even at home without any special knowledge.

The invention discloses a vein vascular stent, which comprises a stent body, the stent body is of a mesh tubular structure formed by weaving metal wires, the stent body comprises a first stent sectionand a second stent section which are connected in the axial direction, and the mesh density of the first stent section is different from that of the second stent section. According to the intravenousstent provided by the invention, the treatment effect can be improved for bare sections involving inferior vena cava and iliac femoral vein stenosis, and the supporting strength and extrusion resistance can be improved for a dense net structure with relatively high mesh density at a compression part; a sparse net structure with small mesh density is arranged at a bent part, so that the flexibility and the adherence performance can be improved; the variable-diameter structure can conform to the blood vessel form aiming at the blood vessel anatomical form, and the product is suitable for various blood vessel diameters.