660 results about "Calcification" patented technology

The present invention provides methods for treating tissue to inhibit post-implant calcification of a biological tissue. In one method of this invention, a tissue is immersed in or otherwise contacted with a pretreated glutaraldehyde solution, i.e., a heat-treated or pH-adjusted glutaraldehyde solution. The tissue may be partially fixed with glutaraldehyde prior to, after, or concurrently with the step of contacting the tissue with the pretreated gluteraldehyde. Contact with the pretreated gluteraldehyde produces free amine groups on the tissue, which are subsequently blocked by contacting the crosslinked tissue with a blocking agent. In another embodiment, a tissue is contacted with either a non-pretreated glutaraldehyde or a pH-adjusted glutaraldehyde solution for a period of time sufficient to crosslink the tissue. The crosslinked tissue is then treated with a reducing agent that reduces aldehyde and carboxylic acid groups on the fixed tissue.

The present invention provides processes for fixation of biological tissue and / or post-fixation treatment of such tissue that result in modified tissues with reduced susceptibility to in vitro calcification when used in prosthetic devices. The invention also relates to calcification resistant biological tissue and to methods of using such tissue.

Systems and methods that facilitate the presentation and assessment of selected features in projection and / or reconstructed breast images, such as calcifications that meet selected criteria of size, shape, presence in selected slice images, distribution of pixels that could be indicative of calcification relative to other pixels or of other image features of clinical interest.

Methods for treating xenogenic tissue for implantation into a human body including in-situ polymerization of a hydrogel polymer in tissue, and tissue treated according to those methods, where the polymerization takes place in tissue that has not been fixed with glutaraldehyde. The polymerization may only fill the tissue, bind the polymer to the tissue, or cross-link the tissue through the polymer, depending on the embodiment. One method includes free radical polymerization of a first vinylic compound, and can include cross-linking through use of a second compound having at least two vinyl groups. Another method utilizes nucleophilic addition polymerization of two compounds, one of which can include PEG and can further include hydrolytically degradable regions. In one embodiment, applicants believe the in-situ polymerization inhibits calcification, and that the polymerization of tissue un-fixed by glutaraldehyde allows for improved penetration of the polymer. The methods find one use in the treatment of porcine heart valve tissue, intended to extend the useful life of the valves by inhibiting calcification. The incorporation of degradable hydrogel regions may initially fill the tissue and reduce any initial inflammatory response, but allow for later infiltration by cells to remodel the tissue.

A device for fracturing calcifications in heart valves including a catheter (12, 22, 42) configured for percutaneous delivery to a heart valve, an fracture-producing element (14, 26, 46, 64, 66,82, 124, 152) disposed at a distal portion of the catheter and operative to vibrate and mechanically fracture calcifications when brought into contact with a calcification at a leaflet of the heart valve, and an energy source (34, 47, 79, 98, 152) operative to vibrate the fracture-producing element so that the fracture-producing element fractures the calcification without necessarily removing the calcification from the leaflet. The device may further comprise a valvuloplasty balloon (30), an embolic protection net (56) and a protective sleeve (110, 130).

A method for processing biological tissue used in biological prostheses includes providing a tissue procurement solution formed from a phosphate buffered saline (PBS) solution and a chelating agent. The tissue is transferred from the tissue procurement solution and undergoes chemical fixation. The fixed tissue is then immersed in a series of fresh bioburden reduction process (BRP) solutions to extract phospholipids. The tissue procurement solution reduces the bioburden on the stored tissue and preserves tissue architecture by minimizing tissue swelling. The tissue procurement solution further reduces calcium from the incoming water and / or tissue, and inhibits enzymes that digest the collagen matrix. The serial immersion of the tissue in the fresh bioburden solutions ensures optimal extraction of phospholipids thereby mitigating subsequent calcification of the tissue.

A method for processing biological tissue used in biological prostheses includes providing a tissue procurement solution formed from a phosphate buffered saline (PBS) solution and a chelating agent. The tissue is transferred from the tissue procurement solution and undergoes chemical fixation. The fixed tissue is then immersed in a series of fresh bioburden reduction process (BRP) solutions to extract phospholipids. The tissue procurement solution reduces the bioburden on the stored tissue and preserves tissue architecture by minimizing tissue swelling. The tissue procurement solution further reduces calcium from the incoming water and / or tissue, and inhibits enzymes that digest the collagen matrix. The serial immersion of the tissue in the fresh bioburden solutions ensures optimal extraction of phospholipids thereby mitigating subsequent calcification of the tissue.

A device for fracturing calcifications in heart valves characterised by a stabilizer assembly and an impactor assembly assembled on and deployed by a delivery system, wherein said delivery system is operable to cause relative motion between said impactor assembly and said stabilizer assembly with sufficient energy so as to fracture a calcification located in tissue which is sandwiched between said stabilizer assembly and said impactor assembly, wherein said impactor assembly and said stabilizer assembly have shaped impact delivery portions of which the footprint on the valve leaflets is shaped in accordance with a shape of desired fracture sites.

The present invention relates to methods for inhibiting stenosis, obstruction, or calcification of a valve following implantation of a valve prosthesis which may involve disposing a coating composition on an elastical stent and securing the valve prosthesis which may have a collapsible elastical valve mounted on the elastical stent such that the elastical stent may be in contact with the valve.

The invention discloses a method of vanadium slag direct entering high temperature roasting furnace calcify roasting, that is, high calcium vanadium slag or ordinary vanadium slag and lime or limestone are mixed uniformly without the gradual heating up process from low temperature to high temperature, the mixture enters into the roasting furnace of more than 600 DEG C for calcified roasting., the vanadium of the vanadium slag is changed into vanadium acid calcium, vanadium of the roasting clinker is dissolved into the solution under the leaching function of sulphuric acid solution, vanadium oxide and the like vanadium products are further made. The invention needs no gradual heating up process from low temperature to high temperature of the prior sodium treatment roasting, thereby reducing roasting time, improving productivity of unit and reducing production cost.

Bioprosthetic tissues are treated by immersing or otherwise contacting fixed, unfixed or partially fixed tissue with a glutaraldehyde solution that has previously been heat-treated or pH adjusted prior to its contact with the tissue. The prior heat treating or pH adjustment of the glutaraldehyde solution causes its free aldehyde concentration to decrease by about 25% or more, preferably by as much as 50%, and allows a “stabilized” glutaraldehyde solution to be obtained at the desired concentration and pH for an optimal fixation of the tissue at high or low temperature. This treatment results in a decrease in the tissue's propensity to calcify after being implanted within the body of a human or animal patient. The heat-treated or pH adjusted glutaraldehyde solution may, in some cases, also be used as a terminal sterilization solution such that the calcification-decreasing treatment with the previously treated glutaraldehyde and a terminal sterilization may be carried out simultaneously and / or in a single container.

Methods for decellularizing mammalian tissue for use in transplantation and tissue engineering. The invention includes methods for simultaneous application of an ionic detergent and a nonionic detergent for a long time period, which may exceed five days. One method utilizes SDS as the ionic detergent and Triton-X 100 as the nonionic detergent. A long rinse step follows, which may also exceed five days in length. This long duration, simultaneous extraction with two detergents produced tissue showing stress-strain curves and DSC data similar to that of fresh, unprocessed tissue. The processed tissue is largely devoid of cells, has the underlying structure essentially intact, and also shows a significantly improved inflammatory response relative to fresh tissue, even without glutaraldehyde fixation. Significantly reduced in situ calcification has also been demonstrated relative to glutaraldehyde fixed tissue. Applicants believe the ionic and non-ionic detergents may act synergistically to bind protein to the ionic detergent and may remove an ionic detergent-protein complex from the tissue using the non-ionic detergent. The present methods find one exemplary use in decellularizing porcine heart valve leaflet and wall tissue for use in transplantation.

Non-glutaraldehyde fixation of an organ or a prosthesis for implantation in a mammal is based upon carbodiimide treatment. A solution containing a sterilizing agent, such as EDC, in combination with a coupling enhancer, such as Sulfo-NHS, and a high concentration of a diamine cross linking agent is used. As a result, only minimal surface reduction occurs during fixation, and the resultant products show a dramatic increase in resistance to calcification.

An objective of the present invention is to overcome a problem that there is an inverse relationship between the decellularization rate and the strength of tissue. This problem was solved by immersing tissue in a solution containing a non-micellar amphipathic molecule (e.g., a 1,2-epoxide polymer). Thus, the present invention provides decellularized tissue, in which the cell survival rate of the tissue is less than a level at which calcification or an immune reaction is elicited in an organism and the tissue damage rate of the tissue is suppressed to a level which permits clinical applications. Tissue prepared by the above-described treatment preferably retains a certain level of tissue strength. Further, the tissue of the present invention has an effect of performing cell replacement.

Apparatus and methods for spatially resolved Raman detection of calcification in tissues are disclosed. A region of soft non-arterial biological tissue is illuminated with monochromatic light. A spatially organized first area of calcified tissue is then detected in the region by detecting a Raman shifted light signal. The Raman shifted light signal is spatially resolved in at least one direction.

Methods for the conditioning of bioprosthetic material employ bovine pericardial membrane. A laser directed at the fibrous surface of the membrane and moved relative thereto reduces the thickness of the membrane to a specific uniform thickness and smoothes the surface. The wavelength, power and pulse rate of the laser are selected which will smooth the fibrous surface as well as ablate the surface to the appropriate thickness. Alternatively, a dermatome is used to remove a layer of material from the fibrous surface of the membrane. Thinning may also employ compression. Stepwise compression with cross-linking to stabilize the membrane is used to avoid damaging the membrane through inelastic compression. Rather, the membrane is bound in the elastic compressed state through addition cross-linking. The foregoing several thinning techniques may be employed together to achieve strong thin membranes. The finally thinned membrane may then be treated by capping of calcification nucleation sites and borohydride reduction. The leaflets may be formed to have more than one region of uniform thickness, such as a thicker peripheral sewing region.

The present invention relates to methods for inhibiting stenosis, obstruction, or calcification of a valve following implantation of a valve prosthesis which may involve disposing a coating composition on an elastical stent or valve leaflet. The valve prosthesis is mounted on the elastical stent such that the elastical stent is in contact with the valve.

A treatment for bioprosthetic tissue used in implants or for assembled bioprosthetic heart valves to reduce in vivo calcification is disclosed. The method includes preconditioning, pre-stressing, or pre-damaging fixed bioprosthetic tissue in a manner that mimics the damage associated with post-implant use, while, and / or subsequently applying a calcification mitigant such as a capping agent or a linking agent to the damaged tissue. The capping agent suppresses the formation of binding sites in the tissue that are exposed or generated by the damage process (service stress) and otherwise would, upon implant, attract calcium, phosphate, immunogenic factors, or other precursors to calcification. The linking agent will act as an elastic reinforcement or shock-absorbing spring element in the tissue structure at the site of damage from the pre-stressing. In one method, tissue leaflets in assembled bioprosthetic heart valves are preconditioned by simulating actual flow conditions for a predetermined number of cycles, during or after which the valve is exposed to the capping agent.

A method of treating a biological tissue including contacting the biological tissue with an aqueous sterilizing solution, and maintaining the aqueous sterilizing solution at a temperature of about 50° C. for a time period of about 1 to 2 days. The method of treating a biological tissue may be utilized as a terminal sterilization step in a method for fixation of biological tissues, and bioprosthetic devices may be prepared by such fixation method. The fixation method may include the steps of A) fixing the tissue, B) treating the tissue with a mixture of i) a denaturant, ii) a surfactant and iii) a crosslinking agent, C) fabricating or forming the bioprosthesis (e.g., forming the tissue and attaching any non-biological components thereto) and D) subjecting the bioprosthesis to the terminal sterilization method. The aqueous sterilizing solution may be glutaraldehyde of about 0.625 weight percent buffered to a pH of about 7.4.

A method of detecting breast masses and calcifications in digitized images, includes providing a plurality of 2-dimensional (2D) digital X-ray projectional breast images acquired from different viewing angles, extracting candidate lesions and 2D features from said 2D projectional images, computing spicularity characteristics of said candidate lesions, including location, periodicity, and amplitude, applying learning algorithms to said candidate lesions to predict a probability of malignancy of said lesion, receiving from said learning algorithm a probability map of detections for each breast image, said detections comprising associating pixels with a probability of being associated with a malignancy, creating a synthetic 2D slice for each X-ray image wherein malignant regions are indicated by ellipses on a non-malignant background, and constructing a synthetic 3-dimensional (3D) image volume from said 2D synthetic slices.

A breast imaging system leverages the combined strengths of two-dimensional and three-dimensional imaging to provide a breast cancer screening with improved sensitivity, specificity and patient dosing. A tomosynthesis system supports the acquisition of three-dimensional images at a dosage lower than that used to acquire a two-dimensional image. The low-dose three-dimensional image may be used for mass detection, while the two-dimensional image may be used for calcification detection. Obtaining tomosynthesis data at low dose provides a number of advantages in addition to mass detection including the reduction in scan time and wear and tear on the x-ray tube. Such an arrangement provides a breast cancer screening system with high sensitivity and specificity and reduced patient dosing.

Systems and methods that facilitate the presentation and assessment of selected features in projection and / or reconstructed breast images, such as calcifications that meet selected criteria of size, shape, presence in selected slice images, distribution of pixels that could be indicative of calcification relative to other pixels or of other image features of clinical interest.

The invention provides methods and compositions that include a nutraceutical supplement, antibiotic, and metal chelating agent that is administered to a patient to treat or prevent pathological calcification and or plaque formation as associated with Nanobacteria Calcifying Nano-Particles and / or diseases caused there-from, The method includes the administration of a therapeutically effective nutraceutical supplement, tetracycline HCL, and ethylenediaminetetraacetic acid calcium di-sodium salt to a patient in order to prevent and treat calcific disease.

New methods of ultrasound imaging are presented that provide images with reduced reverberation noise and images of nonlinear scattering and propagation parameters of the object, and estimation of corrections for wave front aberrations produced by spatial variations in the ultrasound propagation velocity. The methods are based on processing of the received signal from transmitted dual frequency band ultrasound pulse complexes with overlapping high and low frequency pulses. The high frequency pulse is used for the image reconstruction and the low frequency pulse is used to manipulate the nonlinear scattering and / or propagation properties of the high frequency pulse. A 1st method uses the scattered signal from a single dual band pulse complex for filtering in the fast time (depth time) to provide a signal with suppression of reverberation noise and with 1st harmonic sensitivity and increased spatial resolution. In other methods two or more dual band pulse complexes are transmitted where the frequency and / or the phase and / or the amplitude of the low frequency pulse vary for each transmitted pulse complex. Through filtering in the pulse number coordinate and corrections of nonlinear propagation delays and optionally also amplitudes, a linear back scattering signal with suppressed pulse reverberation noise, a nonlinear back scattering signal, and quantitative nonlinear scattering and forward propagation parameters are extracted. The reverberation suppressed signals are further useful for estimation of corrections of wave front aberrations, and especially useful with broad transmit beams for multiple parallel receive beams. Approximate estimates of aberration corrections are given. The nonlinear signal is useful for imaging of differences in tissue properties, such as micro-calcifications, in-growth of fibrous tissue or foam cells, or micro gas bubbles as found with decompression or injected as ultrasound contrast agent.

Disclosed herein shock wave catheters comprising one or more shock wave electrodes for cracking calcifications located within blood vessels. In some variations, a shock wave catheter has first and second shock wave electrodes each circumferentially disposed over the outer surface of the catheter. In certain variations, the first electrode has a recess and the second electrode has a protrusion that is received by the recess and a spark gap is located along the separation between the recess and the protrusion. The second electrode can also have a recess that receives a protrusion from a third shock wave electrode, where the separation between the second and third electrodes along the separation between the recess and the protrusion forms a second spark gap. A shock wave can be initiated across these spark gaps when a voltage is applied over the electrodes.

A device is configured to monitor a cardiovascular property of a subject. The device obtains measurement data from a primary pressure wave sensor arranged to detect pressure waves in an extracorporeal fluid circuit in fluid communication with the cardiovascular system of the subject. The device has a signal processor configured to generate a time-dependent monitoring signal based on the measurement data, such that the monitoring signal comprises a sequence of heart pulses, wherein each heart pulse represents a pressure wave originating from a heart beat in the subject; determine beat classification data for each heart pulse in the monitoring signal; and calculate, based at least partly on the beat classification data, a parameter value indicative of the cardiovascular property. The beat classification data may distinguish between heart pulses originating from normal heart beats and heart pulses originating from ectopic heart beats. The cardiovascular property may be an arterial status of the cardiovascular system, a degree of calcification in the cardiovascular system, a status of a blood vessel access used for connecting the extracorporeal fluid circuit to the cardiovascular system, a heart rate variability, a heart rate, a heart rate turbulence, an ectopic beat count, or an origin of ectopic beats. The device may be attached to or part of a dialysis machine.

A method includes estimating structure models for a voxel(s) of a spectral image based on a noise model, fitting structure models to a 3D neighborhood about the voxel(s), selecting one of the structure models for the voxel(s) based on the fittings and predetermined model selection criteria, and de-noising the voxel(s) based on the selected structure model, producing a set of de-noised spectral images. Another method includes generating a virtual contrast enhanced intermediate image for each energy image of a set of spectral images corresponding to different energy ranges based on de-noised spectral images, decomposed de-noised spectral images, an iodine map, and a contrast enhancement factor; and generating final virtual contrast enhanced images by incorporating a simulated partial volume effect with the intermediate virtual contrast enhanced images. Also described herein are approaches for generating a virtual non-contrasted image, a bone and calcification segmentation map, and an iodine map for multi-energy imaging studies.