130 results about "Vascular tissue" patented technology

The present invention discloses a focal learning-based method for intelligent CT angiography imaging. (1) Acquiring NCCT images and their corresponding real CTA images; (2) Constructing an adversarial network model comprising a generator, a corrector, and a discriminator; (3) Formulating a joint focal learning loss function for the generator-corrector pair and a separate loss function for the discriminator; (4) Training the adversarial network model using the training set, and validating the trained model using the validation set; (5) Identifying the generator with the best test performance by virtue to the test set. The invention establishes a joint focal learning loss function, which allows the generator to create synthetic CTA images that more effectively emphasize target areas, like vascular tissues. Furthermore, a corrector is incorporated into the invention to facilitate improved registration and alignment between NCCT images and CTA images.

The utility model discloses a closing clip capable of preventing tissue from being torn, and belongs to the field of medical hemostatic clips. The closing clamp capable of preventing the tissue from being torn comprises a first clamping arm and a second clamping arm, the near ends of the first clamping arm and the second clamping arm are connected through a connecting part, and the far end of the first clamping arm and the far end of the second clamping arm are respectively provided with a locking structure which can be buckled and locked together. The clamping faces of the first clamping arm and the second clamping arm are each divided into an anti-skid tooth face and a clamping smooth face in the width direction, and the anti-skid tooth face and the clamping smooth face of the first clamping arm and the anti-skid tooth face and the clamping smooth face of the second clamping arm are arranged in a one-to-one correspondence mode or in a crossed correspondence mode. According to the utility model, the clamping surfaces of the two clamping arms of the closing clamp are divided into the anti-slip tooth surfaces and the clamping smooth surfaces, so that the clamping pressure of the closing clamp on vascular tissues during closing is reduced, unnecessary damage to the tissues in the process of closing the tissues is effectively avoided, and hemostasis failure caused by tearing of the vascular tissues is prevented.

The invention belongs to the technical field of agricultural biology, and particularly relates to a sisal hemp Aux / IAA gene and application of protein of the sisal hemp Aux / IAA gene in plants. The sisal hemp Aux / IAA gene provided by the invention comprises a first SNP (Single Nucleotide Polymorphism) site or a second SNP site. Research finds that the Aux / IAA gene can increase the number of the vascular tissues of the plant, construct a plant model related to the vascular tissues and cultivate the multi-vascular tissue plant; the first SNP site or the second SNP site on the gene is significantly related to the number of vascular bundles of sisal hemp leaves, and can be used for screening and cultivating multi-vascular tissue plants, thereby providing a theoretical basis and gene resources for genetic breeding.

The present invention provides an artificial dura mater and a preparation method thereof, and relates to the technical field of medical repair materials. The artificial dura mater is mainly composed of a degradable repair membrane layer and an anti-seepage protective layer composited on the degradable repair membrane layer, wherein: the degradable repair membrane layer is composited by a plurality of fiber-oriented sheets, and the orientation direction of the oriented fibers in the fiber-oriented sheets is consistent. The oriented fibers with the same orientation direction are conducive to the attachment of cells, have high biocompatibility, and have good repair and regeneration effects; at the same time, the patch composited by fiber-oriented sheets with different orientation directions in the present application has better mechanical strength. In addition, the anti-seepage protective layer can play a good anti-seepage role, and can also prevent fibroblasts, muscles, and vascular tissue cells from growing into the artificial dura mater to cause adhesion. Therefore, the artificial dura mater of the present application has the advantages of high biocompatibility, good mechanical strength, and excellent anti-seepage and adhesion performance.

The invention relates to an antibacterial anti-inflammatory blood vessel promoting time sequence microneedle and a preparation method thereof. The microneedle comprises a first microneedle mold, a second microneedle mold and a third microneedle mold which are arranged in sequence, the first microneedle mold is filled with a carrier material A, an antibacterial component and / or a traditional Chinese medicine component A; the second microneedle mold is filled with a carrier material B, an anti-inflammatory component and / or a traditional Chinese medicine component B; and the third microneedle mold is filled with a carrier material C and / or a vascular tissue regeneration promoting component. A good microenvironment is provided for tissue regeneration, the microneedle sequentially resists bacteria, resists inflammation and promotes vascular tissue regeneration, the microneedle conforming to the time sequence is beneficial to tissue regeneration, and the microneedle has a good application prospect.

The invention discloses an image processing method and device, electronic equipment and a storage medium, and relates to the technical field of image processing. The method comprises the steps that a first RGB image formed by reflection of emergent light of an endoscope illumination light source on tissue blood vessels of a patient is obtained, and the illumination light source comprises a narrow-band amber light source and a narrow-band red light source; decomposing an R channel of the first RGB image to obtain a first component image taking narrowband red light as a main response component and a second component image taking narrowband amber light as a main response component; based on the light splitting mapping matrix, performing mapping processing on the first component image and the second component image to obtain a second RGB image; and based on the color adjustment matrix, color enhancement is performed on the second RGB image to obtain a target RGB image, and the target RGB image is used for performing observation processing on tissue blood vessels. In this way, the independent response images of the narrow-band light source can be processed respectively, and the effect of enhancing the vascular tissue is achieved.

The invention discloses a preparation method of vascular tissue-derived extracellular vesicles, and belongs to the field of cytobiology. According to the preparation method of the extracellular vesicles, the artery blood vessel tissue is directly subjected to enzymolysis through collagenase, the extracellular vesicles are obtained by combining low-speed centrifugation and ultra-speed centrifugation methods and utilizing a differential centrifugation mode, and the technical blank of obtaining the extracellular vesicles from the blood vessel tissue is filled. Experimental results show that the extracellular vesicles can be successfully prepared from collagenase I, collagenase II, collagenase IV, collagenase V or collagenase IV combined with elastin, the prepared extracellular vesicles are different in particle size, form, yield, protein quantity, purity and the like, and the quality of the extracellular vesicles obtained by enzymolysis of collagenase IV combined with elastin is optimal. The extracellular vesicles are extracted from vascular tissues with normal physiological characteristics for the first time, a new source is provided for preparation of the extracellular vesicles, and the extracellular vesicles have great significance in expanding application of the extracellular vesicles.

The invention provides a blood vessel supporting device, a conveying device and a blood vessel supporting system, and relates to the technical field of medical instruments.The blood vessel supporting device comprises a supporting ring and anchoring thorns, the supporting ring has the elastic deformation capacity, and a through hole is formed in the supporting ring; the anchoring thorn comprises a main thorn used for puncturing the through hole outwards from the interior of the supporting ring, a limiting part is arranged on the outer wall of the main thorn, and the limiting part has a compression reset function; the supporting ring in the blood vessel supporting device has the elastic deformation capacity, and cannot excessively extrude blood vessel tissue to cause undercut, so that the problem of damage to blood vessels due to long-time use is avoided; moreover, the anchoring thorns which are clamped with the supporting ring and pierce into the blood vessel are arranged, the supporting ring can be prevented from shifting under the anchoring effect of the anchoring thorns, and the situation that the anastomotic stoma bleeding due to shifting of the supporting ring is avoided.

The utility model provides a catheter assembly and an intravascular ultrasonic imaging device. The catheter assembly is used for at least movably collecting ultrasonic echo signals of vascular tissue. The catheter assembly comprises a shell, an ultrasonic transducer, a displacement sensor and a driving part. A containing cavity is formed in the shell. The ultrasonic transducer is arranged in the containing cavity and used for transmitting ultrasonic pulses to the vascular tissue and receiving ultrasonic echo signals formed by reflection of the vascular tissue. The displacement sensor is arranged in the containing cavity and used for obtaining position information in the moving process when the shell moves in the vascular tissue. The two ends of the driving part are connected with the ultrasonic transducer and the displacement sensor correspondingly, and the driving part is used for driving the ultrasonic transducer to rotate in the circumferential direction. Therefore, the structure of the intravascular ultrasonic imaging device is effectively simplified while the signal acquisition effect of the catheter assembly is ensured.

The invention discloses vascular tissue closing forceps capable of being adjusted at any angle, and relates to the field of medical equipment, and the vascular tissue closing forceps comprise a right hand-held part, a left hand-held part, a traction rod, a hinge connecting piece, a long catheter, an outer U-shaped head, a driving mechanism, a forceps head, a screwing head, a perforating seat, an inner U-shaped head, a forceps head regulation and control steel wire and a lateral rotation regulation and control steel wire. The blood vessel fixator has the advantages that the two driving mechanisms are used for driving the connected outer U-shaped head and the connected inner U-shaped head to be in a lateral rotation state, the forceps heads at the ends of the blood vessel fixator can be adjusted at any angle, and the sight blocking area of the structural part of the blood vessel fixator is laterally moved out through the forceps heads; and the barrier-free property of a blood vessel fixing operation visual field area is ensured.

A method of implementing changes in deoxyhemoglobin concentration, the method comprising: targeting a sequence of partial pressures of oxygen in arterial blood (PaCh) values in a subject using a sequential gas delivery device in a periodic input pattern; measuring a blood-oxygen level dependent (BOLD) signal in a voxel of the subject's brain using a magnetic resonance imaging device while targeting the sequence of values; comparing the pattern to the signal; and determining a vascular tissue characteristic (vessel type, vessel orientation, or pathological condition) for the voxel based on the comparison.

The invention discloses a plant vascular tissue specific expression promoter ProVNS11 and application thereof, belongs to the technical field of plant genetic engineering, and provides a plant vascular tissue specific expression promoter ProVNS11, and the nucleotide sequence of the plant vascular tissue specific expression promoter ProVNS11 is as shown in SEQ ID NO. 1. The poplar vascular tissue specific expression promoter ProVNS11 provided by the invention can be effectively and specifically expressed in the poplar vascular tissue, can specifically play the function of an exogenous gene expression product in a specific tissue, and regulates and controls the continuous expression of an exogenous gene in the plant vascular tissue.

Systems and methods of predicting microcalcification activity in a vascular vessel comprising either an artery or a vein, comprising the steps of: (a) measuring patient data comprising one or more of: the existence of and / or quantity of coronary plaques or visible markers of disease in a vascular tissue sample; the existence of and / or quantity of healthy tissue in the vascular tissue sample; one or more features that define an abnormal hemodynamic environment in a vessel; one or more geometric features that are associated with vascular remodeling and which influence hemodynamics in a vessel, and / or one or more material properties that influence vascular hemodynamics; and (b) calculating the microcalcification activity in the vessel as a function of the measurements taken in Step (a).

The invention belongs to the technical field of artificial blood vessels, and provides a composite modified double-layer structure small-caliber artificial blood vessel which comprises an inner layer and an outer layer, the inner layer comprises a mixture of zwitterionic polyurethane and polycaprolactone, the outer layer comprises polycaprolactone, zwitterionic polyurethane contains zwitterionic sulfonic acid negative ions and ammonium positive ions, and the zwitterionic sulfonic acid negative ions and the ammonium positive ions are different. Inner and outer layers of the artificial blood vessel are modified by heparin; the invention further provides a preparation method of the artificial blood vessel, the double-layer artificial blood vessel with a zwitterionic polyurethane and polycaprolactone blend as an inner layer and polycaprolactone as an outer layer is prepared through electrostatic spinning, and heparin is used for surface modification of the double-layer artificial blood vessel. The size of the small-caliber artificial blood vessel can be effectively controlled, and the prepared small-caliber antithrombotic artificial blood vessel has excellent biocompatibility, tensile property, protein adsorption resistance and antithrombotic property and can be used for vascular tissue repair or replacement.

The utility model belongs to the technical field of medical instruments, and particularly relates to a novel brain protection device which comprises a catheter, a balloon conducting tube and a filter screen traction wire are arranged in the catheter, the filter screen traction wire slides in the catheter, one end of the filter screen traction wire is fixedly connected with a filter screen, the filter screen is embedded in the catheter, and the other end of the filter screen traction wire is fixedly connected with the balloon conducting tube. The filter screen is arranged on the balloon conducting tube in a sleeving manner, and the filter screen moves on the balloon conducting tube; through traction of the arranged filter screen traction wire, the filter screen moves to the outside of the catheter and opens in a blood vessel, falling calcified vascular tissue fragments are comprehensively intercepted and filtered, the filter screen traction wire is pulled outwards, the filter screen can be collected into the catheter, the filtered calcified vascular tissue fragments are wrapped, and the calcified vascular tissue fragments are taken out along with the brain protection device. And valve calcification fragments are prevented from blocking brain blood vessels.

The invention relates to a turbine disc cavity imitated venous valve type sealing structure and a design method thereof, an axial sealing gap simulates human body vein vascular tissue, and a sealing structure assembly is located in the axial sealing gap where a disc cavity is connected with a main flow channel and comprises two rows of imitated venous valve teeth on the static disc side and two rows of imitated venous valve teeth on the rotary disc side. Furthermore, the two groups of sealing structures are matched with each other, so that the gap is gradually shrunk outwards in the radial direction, a large amount of invading gas at the joint of the disc cavity and the main flow channel is blocked, and the gas is rectified by a vortex structure and enters the main flow channel again. By means of the modeling design of the sealing assembly, fluid, namely high-temperature fuel gas, is prevented from flowing into the disc cavity in the radial direction while the fluid is guided to flow outwards in the radial direction, mixing of high-temperature invasion fuel gas and sealing cold air is enhanced, the sealing cooling efficiency of the connecting area of the disc cavity and the main flow channel is improved, and the high-temperature heat load borne by the position is reduced; and the method is of great significance to safe operation of the whole gas turbine.

An imaging sensor includes a radiation sensor. An imaging controller is configured to: (i) generate an imaging-datastream based on the sensed phenomena and (ii) transmit, to a central controller, the imaging-datastream. The central controller is configured to: receive the imaging-datastream; generate, from the imaging-datastream, a high-contrast videostream in which surgical tools and vascular tissue is represented with a dark color and in which surrounding tissue is represented with a light color, the dark color being darker than the light color; and transmit, to an augmented-reality controller, the high-contrast videostream. The augmented-reality controller is configured to: (i) receive the high-contrast videostream and (ii) instruct a head-worn display to render the high-contrast videostream such that the surgical tools and vascular tissue is rendered with the dark color. The head-worn display is configured to render the high-contrast videostream such that the surgical tools and vascular tissue is rendered with the dark color.

The present invention relates to the field of medical image processing technology, and more specifically to a method, system, and storage medium for vascular tissue segmentation based on MR images. The method comprises the following steps: enhancing vascular information in MR images using a Canny operator to obtain an MR-enhanced image; constructing a first segmentation model and a second segmentation model based on the MR image and the MR-enhanced image, respectively, using a UNet network; guiding the training of the first segmentation model using the second segmentation model, and using the output of the trained first segmentation model as the vascular tissue segmentation result in the MR image. The present invention can guide the segmentation results on low-resolution images to learn from the segmentation results on high-resolution images, thereby obtaining high-precision segmentation results directly on low-resolution images without increasing the data processing process and model complexity of the segmentation process, thereby improving the efficiency of accurate vascular tissue segmentation.

The present disclosure provides a method for evaluating a seedling plant character of a transgenic poplar and use of an overexpressed pagEXPA1 gene in promoting xylem development of the poplar, relating to the technical field of forest wood character determination. The method for evaluating the seedling plant character of the transgenic poplar in the present disclosure includes the following steps: S1. detecting whether or not a foreign gene is integrated into a poplar genome through PCR; S2. detecting the expression level of the foreign gene in the poplar; S3. conducting a microstructural analysis on stem vascular tissues of the transgenic poplar; and S4. separating fibers, ducts, and sieve-tube cells through fiber isolation, and staining the isolated fibers to observe the morphology and structure of the fibers, ducts, and sieve-tube cells.

The invention relates to the technical field of interventional medical treatment, and discloses a magneto-optical positioning assisted catheter wall contact risk monitoring system and method.The method comprises the steps that initial three-dimensional position data and actual magnetic field signals of a catheter are collected, and the initial three-dimensional position data are calibrated based on the actual magnetic field signals and a preset magnetic field reference signal range; a contact force signal of the wall surface of the catheter and the vascular tissue and temperature data in the catheter are collected, and the contact force signal is corrected based on the temperature data and a preset reference temperature interval; acquiring wall surface image data of the front end and the lateral direction of the catheter, extracting image features, and establishing a spatial geometrical relationship between the wall surface of the catheter and vascular tissue; according to the final three-dimensional position data of the catheter and the mapping result of the spatial geometrical relationship, judging the contact risk level of the wall surface of the catheter and the vascular tissue; and outputting warning information and sending a motion compensation control instruction based on the risk level. According to the invention, real-time monitoring and accurate intervention of the contact risk of the wall surface of the catheter can be realized.

An apparatus is configured to provide hemostasis with tissue removal in order to inhibit one or more of blood loss or tissue drainage. In many embodiments, a nozzle releases a liquid jet in a liquid medium in order to provide cavitation and a plurality of shedding pulses. The liquid jet, its cavitation and the plurality of shedding pulses can affect vascular tissue in order to promote clotting in order to inhibit bleeding. In many embodiments, vessels of the vascular tissue are affected at a distance from a region where cavitation of the water jet contacts the tissue. In many embodiments, the cavitation and plurality of shedding pules are related to a pulsatile shear wave propagating along the blood vessel that is related to clot promoting changes of the blood vessel.

The invention relates to a gene PagBES1 for regulating and controlling poplar wood yield and wood fiber length and application of the gene PagBES1, and belongs to the technical field of plant genetic engineering. The nucleotide sequence is shown as a sequence 3 in a sequence table, and the amino acid sequence is shown as a sequence 4 in the sequence table. The PagBES1 gene is transferred into the poplar, compared with a wild type, the plant height of the PagBES1 activated and expressed transgenic poplar is remarkably increased, the ground stem is remarkably thickened, the number of cell layers of stem vascular tissues is remarkably increased, the length and width of wood fibers are remarkably increased, secondary cell walls are remarkably deposited and thickened, and the phenotype of the PagBES1 inhibited and expressed transgenic poplar is opposite to the phenotype of the PagBES1 inhibited and expressed transgenic poplar. Therefore, the PagBES1 gene is a key regulatory gene for regulating the generation of poplar wood, and has important application value in the fields of forest gene engineering and clonal forestry.

The invention relates to the technical field of medical image processing, in particular to a preoperative image segmentation method and system based on hybrid supervision enhancement, and the method comprises the following steps: constructing an organ tissue segmentation model by using a Unet network, and constructing a vascular tissue segmentation model by using the Unet network; setting a supervision enhancement module, and combining the organ tissue segmentation model and the vascular tissue segmentation model into a teacher model; a student model is constructed by using an FCN network, and a preoperative image segmentation model is obtained through mixed supervised learning of a teacher model and the student model. For preoperative three-dimensional medical image segmentation, a mixed supervision segmentation model is provided, a supervision enhancement mode is adopted when a teacher model is constructed, it can be guaranteed that the teacher model accurately segments each organization, and a lightweight model structure is obtained based on a teacher-student multi-fine-grained feature learning strategy; and a student model capable of precisely segmenting each organization can be realized, so that the segmentation precision and the segmentation efficiency coexist.

The present invention discloses a plant vascular tissue-specific expression promoter ProAPL and its application, belonging to the technical field of plant genetic engineering. A plant vascular tissue-specific expression promoter ProAPL is provided, and the nucleotide sequence of the vascular tissue-specific expression promoter ProAPL is as shown in SEQ ID NO.1. The present invention provides the poplar vascular tissue-specific expression promoter ProAPL, which can effectively express specifically in the poplar vascular tissue, can specifically exert the function of the exogenous gene expression product in a specific tissue, and regulate the continuous expression of the exogenous gene in the plant vascular tissue.

The application belongs to the technical field of frozen section, and particularly relates to an animal blood vessel tissue frozen embedding and sectioning and spatial transcriptome sequencing method. In the first aspect, the application provides an animal blood vessel tissue frozen embedding method, wherein a first buffer is used to replace blood in an animal body; a blood vessel is peeled off and surrounding tissues are removed; a perfusion liquid is used to perfuse the blood vessel to obtain a perfused blood vessel, the perfusion liquid comprising OCT and a second buffer; and a plurality of perfused blood vessels are embedded in the same OCT embedding block and then rapidly frozen. The blood vessel is peeled off from the tissue and embedded alone, and a plurality of blood vessels in each embedding block are laid flat after sectioning to ensure that the chip surface is covered with sufficient blood vessel structures, thereby solving the problems of small volume of blood vessel tissue, small number of cells, small amount of RNA and difficulty in spatial transcriptome sequencing and the like.

The invention discloses an ultrasonic controlled-release drug balloon catheter which comprises a balloon with the outer surface coated with a drug coating and a catheter penetrating through the balloon, and the drug coating comprises a drug carrying layer, a hydrophilic layer located between the outer surface of the balloon and the drug carrying layer and an ultrasonic response layer located on the outer surface of the drug carrying layer; the ultrasonic response layer comprises the following components: at least one of PDMS (Polydimethylsiloxane), P (AAA) and P (NIPAM-co-AM); and an ultrasonic transducer is arranged on the catheter in the balloon. According to the ultrasonic controlled-release medicine balloon catheter, a'sandwich 'design of'hydrophilic bottom layer-medicine carrying layer-ultrasonic response layer' is adopted for the medicine coating on the surface of the balloon, and ultrasonic transducers with two or more frequencies are further arranged on the catheter in the balloon, so that the loss of the medicine coating in the conveying process can be avoided; transfer of the medicine from the balloon to the blood vessel at the treatment position is increased, the medicine can deeply permeate into the vascular tissue, vascular stenosis can be effectively inhibited for a long time, and the medicine utilization rate is effectively increased.

The invention discloses a vascular specific VND gene promoter and application of the vascular specific VND gene promoter in driving expression of xylan hydrolase in plants. The invention provides a DNA fragment. The DNA fragment is any one of the following: 1) the nucleotide sequence of the DNA fragment is sequence 1; and 2) a nucleic acid sequence which has more than 90% of homology with the nucleic acid sequence shown in 1) and has the same function. Experiments prove that a SbNAC31 gene promoter specifically expressed by a vascular tissue is connected with CDS of a xylan hydrolase gene SbXyl, and a vector with the fusion gene is used for converting a sorghum xylan hydrolase function deletion mutant, so that the growth and development defects of the mutant are made up; meanwhile, the excellent lignocellulose quality (high feed quality) of the mutant is reserved.

Disclosed in the present invention are a long-acting functionalized double-layer bionic small-caliber vascular prosthesis, and a preparation method therefor and use thereof. The preparation method therefor comprises: separately synthesizing degradable polyurethane elastomers PCHU-DSeSe and PCHU-DTA using a three-step solution polymerization method, and carrying out near-field direct-writing electrospinning of PCHU-DSeSe on a stainless steel mandrel with an axial groove to obtain an axially oriented fibrous vascular inner layer; assembling the axially oriented fibrous vascular inner layer together with the mandrel into a polytetrafluoroethylene mold having radially oriented patterns on the inner wall of the housing; rapidly casting a PCHU-DTA / DMSO solution into the mold for phase separation to obtain a vascular outer layer of an axis-aligned topological microstructure, and carrying out freeze-drying to obtain the long-acting functionalized double-layer bionic small-caliber vascular prosthesis. The long-acting functionalized double-layer bionic small-caliber vascular prosthesis has the functions of continuous release of DSS, NO and H2S, and in-situ dynamic regulation and repair of a vascular tissue microenvironment, can be used for arteriovenous fistula creation, and coronary artery and peripheral vascular bypass therapy, and thus has good application prospects.

The present invention relates to the field of neuroscience, and proposes a method and system for realizing the cause identification of ischemic stroke based on neuroimaging, wherein the method comprises: obtaining a patient's brain nerve image, including CT and MRI scan images, diagnosing and analyzing the stroke patient, extracting the vascular load value by identifying the vascular tissue and the high-density sign of the cerebral artery in the CT scan image, identifying the thrombus pore through the MRI scan image, extracting the thrombus morphological characteristics, calculating the thrombus shape coefficient, combining the vascular load value and the thrombus shape coefficient, determining the abnormal area in the brain nerve image, identifying the ischemic area, and detecting the damaged nerve tissue, and finally, using the cause identification network to classify the lesions of the damaged nerve tissue, correlating the cause of stroke with the clinical index, and generating a cause report. The present invention can improve the accuracy of the cause identification of ischemic stroke.

A system including an elongate shaft configured to be placed into an access lumen of an access catheter having a side access port that communicates with the access lumen, the shaft including a dilator catheter lumen extending therethrough and a distal portion including a tapered distal tip, the distal portion configured to be passed out of the side access port, a puncture device including an elongate shaft including a distal end configured to penetrate through vascular tissue, a first engagement feature carried by the dilator catheter, and a second engagement feature carried by the puncture device, wherein the second engagement feature is configured to engage the first engagement feature at a first relative longitudinal position between the dilator catheter and the puncture device at which the distal end of the shaft of the puncture device is fully exposed from the dilator catheter and is located at a preconfigured amount of extension out of the dilator catheter lumen.