82 results about "Tissue density" patented technology

A coaxial cable apparatus which transmits radio frequency (RF) energy for the ablation of biological tissues has inner and outer coaxial conductors extending from a proximal portion to a distal portion. An RF antenna is disposed at the distal portion of the cable and transmits RF energy for ablation of a tissue region to be treated. At least one ultrasonic transducer is also disposed at the distal portion of the cable to direct ultrasonic frequency energy to a tissue region. The ultrasonic transducer detects reflected ultrasonic signals from the tissue region and provides a signal output which varies dependent on the density of tissue over the monitored tissue region. The reflected ultrasonic signal can be monitored before, during, and after ablation treatment.

A surgical instrument for assessing tissue characteristics such as tissue density and volume is disclosed. The surgical instrument is hand-held and includes transducers adapted for emitting and/or receiving acoustic signals. The surgical instrument utilizes pulse-echo to determine tissue characteristics. The surgical instrument may be utilized to determine such things as the size of a lesion and whether the lesion has been completely removed or filled with graft material.

A hybrid calibration method uses an calibration phantom (exterior reference) scanned simultaneously with the patient, and one or more known tissues of the subject (interior reference) to create a hybrid calibration reference that improves the measurement of tissue densities throughout the body. In addition, the calibration method is used to quantitatively define boundaries of tissue and organs for more accurate measurements of lengths, areas and volumes. Another aspect of the invention uses the calibrated images to quantitatively preset absolute window/levels for filming and image display, which provides standardized viewing for diagnostic purposes.

A three-dimensional (3-D) culture “Petri-dish” for research in regenerative medicine, biotechnology and clinical translation is described. This 3-D perfusion culture dish is to advance in vitro culture tools from static 2-D to dynamic 3-D perfusion culture. Interwoven hollow fiber capillary membranes divide the “Petri-dish” culture space into a controllable 3-D pattern of different compartments, serving the functions of the organ's larger vasculature. These physically active scaffolds, which can be suitable for cell adhesion or cell aggregate immobilization, offer a supply of cells with high-performance mass exchange including gas supply and under perfusion conditions. In contrast to static and discontinuous medium supply, a dynamic culture can be achieved with continuous or alternating medium supply and integral oxygenation. They provide a more physiologic supply in the cell macro environment, including homeostasis of oxygen, pH, nutrition, soluble factors, and gradients of metabolites for the cells. Also, medium perfusion can be achieved. Consequently the invention was made for cultures at tissue density, especially stem cells and support cells, which strive to create their own stem cell niche.

An implantable sensor for detecting changes in tissue density is disclosed. The implantable sensor includes a transducer adapted for detecting indicators of tissue density. The implantable sensor includes memory for storing data corresponding to the tissue density indicators detected by the sensor. A telemetry circuit is configured for transmitting the tissue density data outside of the body.

The present invention is a thorax phantom that enables simulation of tumor motion within a tissue equivalent material. The system consists of a tissue equivalent epoxy phantom representing a 15 cm axial section of the human thorax that includes simplified spine and lung anatomies. Within the phantom are thru rods of similar tissue density. The rods are attached to a computer-controlled actuator that facilitates both linear and rotational motion of the rods within the phantom. A plurality of tumor targets and radiation detectors can be placed within the rods at various locations thereby enabling the simulation of respiratory and cardiac induced tumor motions within the phantom and assessment of the effects of these motions on image acquisitions, treatment planning and radiation treatment delivery.

A method for classifying tissue density of a breast includes obtaining mammography image data and segmenting the mammography image to identify the region representing the breast tissue. A plurality of regions within the breast tissue region are identified for obtaining image features therefrom. A plurality of image features are computed from the identified plurality of regions. The breast tissue density is classified using the computed plurality of image features.

The invention relates to a structure of a grinding material composited with a novel high-shrinkage engineering ceramic binder for the preparation of a grinding wheel and a preparation method thereof. The preparation method is characterized in that: the high-strength high-shrinkage engineering ceramic binder which is prepared from clay, feldspar, boracic glass, bentonite and manganite is composited with the mixed grinding material, the opacifying effect of the boracic glass promotes the glass nucleation, fluxing agents bentonite and manganite powder promote the preparation of the high-strengthhigh-shrinkage engineering ceramic structure, and the ceramic binder for the steel ball grinding wheel is prepared through carrying out cold-press high-pressure molding, and sintering at a certain temperature. Compared with market products, the strength, the combination degree, the elastic modulus and the linear velocity in usage of the steel ball grinding wheel are greatly improved, the geometric dimension of the steel ball grinding wheel is stable, the steel ball grinding wheel which has a high strength, a high hardness and a uniform tissue density and has the advantages of large grinding ratio, high fineness and no workpiece burning under high speed grinding conditions is a special grinding wheel for a novel high efficiency steel ball. So the steel ball grinding wheel can be widely applied to the mechanical steel ball manufacturing industry and is easy to be automated in the industry.

The invention discloses a process for quickly manufacturing a removable partial denture bracket by laser, which mainly comprises the following steps: acquiring a three-dimensional part model of a tooth jaw of a patient, adding an indented thin-wall support to the model, layering and dispersing to generate laser processing numerical control instructions, and paving powder on a preheated and insulated metal substrate; and then using a continuous YAG or fiber laser with the beam quality M<2> is smaller than 1.1 to melt metal or alloy powder in a special granularity range layer by layer by using optimized powder paving thickness, falling height of a forming cylinder and a laser processing technique under a focusing light spot of 10 to 100 mu m, and finishing melting, accumulating and processing of the whole part; and finally carrying out tempering heat treatment on the formed part, to obtain the removable partial deture bracket, which combines metallurgy and has a tissue density close to 100 percent. The process can overcome the difficulty of the prior art, and directly manufacture the removable partial denture bracket which has the advantages of high precision and high surface smoothness, no deformation and excellent mechanical property.

The invention relates to a steel blank grinding abrasion wheel adopting microcrystal ceramic bonding agents, which is in a structure made of polycrystalline solid materials with the coexistence of glass and crystals and adopts the bonding agents of clay, feldspar, boron-containing microcrystal glass, pyrophyllite and soapstone to be made into high-intensity and low-shrinkage engineering ceramic bonding agents, good performance of the glass and the ceramics such as high mechnical intensity, wear resistance, corrosion resistance and the like are integrated, then, the glass and the ceramics are combined with mixed grinding materials, a molding pressing method is adopted for the high-pressure double-side pressing process forming, the low-temperature firing is adopted, the positive pressure reducing atmosphere heat simulation crystallization is adopted at the 800 DEG C heat insulation section, and the mixed grinding material and micro porous glass phase high-intensity microcrystal engineering ceramic composite structure is formed, so the intensity and the bonding degree of the steel blank grinding abrasion wheel are greatly improved, the use linear speed of the abrasion wheel is accelerated, and the safety factor is high. The steel blank grinding abrasion wheel belongs to the novel efficient special steel blank grinding abrasion wheel with the characteristics that the intensity andthe hardness are high, the tissue density is uniform, the grinding ratio is great under the condition of high-speed grinding, workpieces can not be damaged through firing, and the automation of iron and steel industries is easy to realize.

The invention provides a shear wave viscoelasticity imaging method and system. The method includes the steps that a CT value of tissue is obtained; according to a tissue mark, body model CT value and body model density value relation information corresponding to the tissue mark is obtained; a tissue density value corresponding to the CT value of the tissue is determined; shear waves are stimulated inside the tissue, ultrasonic waves are generated in the tissue through an ultrasonic transducer, and an ultrasonic wave return signal is received; according to the ultrasonic wave return signal, a propagation characteristic parameter of the shear waves in the tissue is obtained, and according to the propagation characteristic parameter and the tissue density value, the viscoelasticity parameter of the tissue is obtained; according to the viscoelasticity parameter, a shear wave viscoelasticity image of the tissue is formed. In this way, the effect of viscoelasticity parameter detection is improved, and more reliable references are provided for pathology judgment on the tissue by a doctor according to the shear wave viscoelasticity image of the tissue.

A system and method enable calibration of CT scanners without using water phantoms. Tissue densities are expressed in either the Hounsfield Scale units (HU) referenced back to water or the proposed Gram Scale units (GU) with voxel intensities expressed in true density units. The fully automatic software-only method requires no interactions with the images. Routine calibration of CT scanners with water phantoms can be eliminated. The method further provides accurate calibrations that are patient, scanner, and scan specific and are repeatable over long time durations. The calibrations are based on the uniquely defined intensity of voxels with equal contributions of two tissues types. This calibration point is immune to the many variables found in ROI histogram measurements of mean, mode, SD or other measures of voxel intensities. The disclosed CT scanner system provides consistent CT image voxel intensities of the various tissues across a great variety of patients.

The invention belongs to the technical field of metallurgy, and particularly relates to a process for controlling center porosity of a large and round continuous casting billet. The process comprises steps as follows: qualified molten steel in tundish is injected into a mold through a four-slitting sided cyclone submerged nozzle; mold fluxes are added, and the depth of the submerged nozzle of the mold is controlled to range from 110 mm to 130 mm; a mold liquid level automatic control system is used for stabilizing a mold liquid level and a pulling rate, and the superheat degree of the molten steel in the tundish is stabilized; the secondary cooling speed of a casting billet is controlled; and M-EMS (mold electromagnetic stirring) and F-EMS (final electromagnetic stirring) parameters are optimized. With the adoption of the process, the large and round billet is produced, melting of the mold fluxes is facilitated, the temperature gradient from a billet shell to molten steel at the core part of the casting billet can be reduced, the overheat degree of the molten steel in the center is decreased, the isometric crystal proportion of the casting billet is increased, the tissue density of the casting billet is increased, and the grade of the center porosity of the large and round continuous casting billet can be controlled.

The invention discloses a transmission planetary gear carrier with a support shaft. The transmission planetary gear carrier comprises a support plate, a hollow cover plate parallel to the support plate and supporting legs connected with the support plate and the hollow cover plate, wherein the support plate and the hollow cover plate are correspondingly provided with multiple gear holes for small gears to be installed, the middle of the support plate penetrates the hollow cover plate and is provided with the support shaft, and the support plate and the support shaft form an integral structure. A production process of the transmission planetary gear carrier comprises the steps of (a) forming the support plate disc portion and a support shaft rod through warm-cold forging, forming the support plate and the support shaft through spline machining and rolling and performing carburizing treatment; (b) forming the hollow cover plate and the supporting legs through machining; (c) welding the hollow cover plate, the supporting legs and the support plate. The defect brought by assembly during classified manufacture of the planetary gear carrier and the support shaft in the prior art in a friction welding or press-fitting mode is overcome, the cutting-milling machining frequency and machining step number are decreased, the production efficiency is high, the production cost is low, the product quality is stable, the internal tissue density is high, the comprehensive mechanical performance is good, and the service life is long.

The invention discloses a metal mould casting method of a cylinder cover. The method comprises the following steps: preparing a sand core; putting an aluminum alloy molten ingot in a melting furnace to be melt to a liquid, and obtaining a clean aluminum liquid through an aluminum liquid treatment step; installing a mould on a casting machine, preheating the mould and heating the metal mould to 200-350 DEG C; eliminating rusts and impurities on the forming surface of the mould by a jetting tool, and spraying an anti-sticking aluminum metal cavity coating; putting the sand core in the metal mould and assembling the mould; injecting the aluminum liquid into a metal mould cup; cooling to form a solid state cylinder cover cast within a time T; and opening the mould to take out a cast product, sequentially removing sprue and dead head of the cast, removing the sand cover in the cavity, polishing and finishing and carrying out surface shot blasting treatment to obtain a product cast of the cylinder cover. The cast of the cylinder cover obtained by the method disclosed by the invention is high in tissue density, good in quality and high in yield, so that the defects of easily generating pores, shrinking and insufficiently pouring are effectively avoided.

The invention discloses a cascade grinding wheel slice and a production method thereof. The cascade grinding wheel slice comprises abrasive layers and reinforcing layers, which are stacked alternately. The reinforcing layers are fiberglass mesh discs, located in even layers, and the abrasive layers are located in odd layers. The abrasive layers are made from white corundum, fused alumina zirconia, brown aluminum oxide, semi-friable aluminum oxide, phenolic resin liquid, phenolic resin powder, cryolite powder, pyrite powder and gypsum powder. The use of hot-forming process for production promotes prepolymerization of resin bond, increases tissue density and improves cutting ratio. In addition, compounding of the resin liquid and the resin powder improves wetting and bonding performance of resin for abrasives, so that revolving strength of the grinding wheel slice is increased and burst in rotation at normal linear speed is avoided.

The invention relates to a layered compression molding method and device for a grinding wheel ring. The layered compression molding method for the grinding wheel ring includes the following steps that firstly, a molding material of the grinding wheel ring is divided into at least two parts, and the vertical height of a downward-pressing head is adjusted through a driving mechanism; secondly, the first part of the molding material is put into the portion between an inner mold ring and an outer mold ring, and the first part of the molding material is compressed in two directions; thirdly, an upward-pressing head moves upwards and is reset, the downward-pressing head is driven by the driving mechanism to move downwards, then the second part of the molding material is put into the portion between the inner mold ring and the outer mold ring, the second part of the molding material is compressed in two directions through cooperation of the upward-pressing head, the downward-pressing head and a first reverse compression mechanism, and then the third step is repeated until the nth part of the molding material is compressed, and all the parts of the molding material compressed in two directions jointly form a blank of the grinding wheel ring. According to the layered compression molding method and device for the grinding wheel ring, layered compression molding can be achieved on the grinding wheel ring, and then the difference of tissue densities of all positions of the grinding wheel ring is reduced.

A system and method for reshaping and altering the cornea of an eye employs a laser beam for two different purposes. For one, the laser beam is configured to perform Laser Induced Optical Breakdown (LIOB) on selected tissue in the stroma of the cornea. This generally weakens the stromal tissue and allows intraocular pressure and bio-mechanical forces in the eye to reshape the cornea. For the other, the laser beam is configured to cause Permanent Structural Change (PSC) on selected tissue in the stroma of the cornea. This alters the tissue density of the selected PSC stromal tissue to change its refractive index. In combination, the LIOB and PSC provide for corrected vision.