374 results about "Tissues types" patented technology

Systems and methods for discriminating and locating tissues within a body involve applying a waveform signal to tissue between two electrodes and measuring the electrical characteristics of the signal transmitted through the tissue. At least one of the electrodes is constrained in area so that localized electrical characteristics of the tissue are measured. Such localized electrical characteristics are determined over a portion of a body of the subject by using an array of electrodes or electrodes that can be moved over the body. A controller may implement the process and perform calculations on the measured data to identify tissue types and locations within the measured area, and to present results in graphical form. Results may be combined with other tissue imaging technologies and with image-guided systems.

A connecting band for a highly flexible tissue-type heart valve having a stent with cusps and commissures that are permitted to move radially. The connecting band follows the cusps and commissures and extends outwardly. The valve is connected to the natural tissue along the undulating connecting band using conventional techniques, such as sutures. The connecting band may be a cloth-covered inner suture-permeable member and attaches to the underside of the valve at the cusps to provide support to the stent and to the outer side of the valve at the commissures. The connecting band includes commissure portions defining generally axial gaps that help permit flexing of the valve. The inner member may include one or more slits along the cusps to enhance flexibility. The inner member may further include a continuous outwardly projecting sewing ridge around its periphery which includes a series of ribs separated by grooves around the inflow edge of the cusps. The sewing ridge enables supra-annular implant of a valve constructed with the connecting band.

A highly flexible tissue-type heart valve is disclosed having a structural stent in a generally cylindrical configuration with cusps and commissures that are permitted to move radially. The stent commissures are constructed so that the cusps are pivotably or flexibly coupled together at the commissures to permit relative movement therebetween.

An automated method and/or system for identifying suspected lesions in a brain is provided. A processor (a) provides a magnetic resonance image (MRI) of a patient's head, including a plurality of slices of the patient's head, which MRI comprises a multispectral data set that can be displayed as an image of varying pixel intensities. The processor (b) identifies a brain area within each slice to provide a plurality of masked images of intracranial tissue. The processor (c) applies a segmentation technique to at least one of the masked images to classify the varying pixel intensities into separate groupings, which potentially correspond to different tissue types. The processor (d) refines the initial segmentation into the separate groupings of at least the first masked image obtained from step (c) using one or more knowledge rules that combine pixel intensities with spatial relationships of anatomical structures to locate one or more anatomical regions of the brain. The processor (e) identifies, if present, the one or more anatomical regions of the brain located in step (d) in other masked images obtained from step (c). The processor (f) further refines the resulting knowledge rule-refined images from steps (d) and (e) to locate suspected lesions in the brain.

A method and apparatus for recognizing tissue types measures at least two separate and distinct properties of a tissue specimen using a probe tip containing electrodes coupled to circuitry that applies a measuring current and obtains values of electrical properties of the tissue such as conductivity and potential difference. An algorithm then uses the values to determine the tissue's type and condition.

The invention relates to apparatus and methods for measuring local tissue impedance for subcutaneous tissue surrounding a needle tip inserted into a subject, impedance spectra and/or complex impedance values are determined. The invention applies a monopolar impedance measuring setup with a needle, a current-carrying electrode, an optional reference electrode. The setup is configured to eliminate contributions from the current-carrying electrode in order to measure local impedance of tissue in the close neighbourhood of the needle tip instead of an averaged value over the volume or current path between the needle and the electrode(s). The determined impedance can be correlated with either a tissue type or state, or with a position of the needle tip in the subject, and can thereby provide an insertion history to the operator in the form of impedance or corresponding tissue type as a function of insertion depth or time.

Improved, adaptable tissue-type heart valves and methods for their manufacture are disclosed wherein a dimensionally stable, pre-aligned tissue leaflet subassembly is formed and its peripheral edge clamped between and attached to an upper shaped wireform and a lower support stent. A variety of adaptable structural interfaces including suture rings, flanges, and conduits may be attached to the support stent with or without an outlet conduit disposed about the wireform to provide a tissue-type heart valve adaptable for use in either a natural heart or in mechanical pumping devices. The methods include forming individual leaflets with a template and using the template to attach the leaflets together to form a tissue leaflet subassembly. The template and leaflets include a straight edge terminating in oppositely directed tabs, and a curvilinear cusp edge extending opposite the straight edge. The template may include a guide slot in its straight edge and the assembly includes aligning two leaflet tabs with the template and passing sutures through the guide slot and through the leaflet tabs. The leaflet subassembly is mated to a wireform with the tabs extending through commissure posts of the wireform. A support stent having an upper surface matching the lower surface of the wireform sandwiches the edges of the leaflet subassembly therebetween. Separated tabs on the leaflet subassembly are passed through the wireform commissures and attached to adjacent stent commissures so as to induce clamping of the leaflet tabs between the stent commissures and wireform commissures upon a radially inward force being applied to the leaflets.

The invention provides isolated stem cells of non-embryonic origin that can be maintained in culture in the undifferentiated state or differentiated to form cells of multiple tissue types. Also provided are methods of isolation and culture, as well as therapeutic uses for the isolated cells in cardiac indications.

A surgical tool such as a liposuction cannula is equipped with a sensor at the tool tip. The sensor continuously analyzes the type of tissue in contact with the tip based on the electrical properties of the tissue. When encountering a tissue type that should not be disturbed, the action of the surgical tool is stopped automatically. When used for liposuction, the cannula is mechanically decoupled from the handle when the wrong type of tissue is detected thus minimizing the inertia of the part that needs to be stopped. Besides electrical sensing, other sensors, such as mechanical or ultrasonic, can be used at the tip of the surgical tool or cannula to differentiate between tissue types

A computer automated method that applies supervised pattern recognition to classify whether voxels in a medical image data set correspond to a tissue type of interest is described. The method comprises a user identifying examples of voxels which correspond to the tissue type of interest and examples of voxels which do not. Characterizing parameters, such as voxel value, local averages and local standard deviations of voxel value are then computed for the identified example voxels. From these characterizing parameters, one or more distinguishing parameters are identified. The distinguishing parameter are those parameters having values which depend on whether or not the voxel with which they are associated corresponds to the tissue type of interest. The distinguishing parameters are then computed for other voxels in the medical image data set, and these voxels are classified on the basis of the value of their distinguishing parameters. The approach allows tissue types which differ only slightly to be distinguished according to a user's wishes.

An improved holder, system and method for implanting a tissue-type prosthetic mitral heart valve that prevents suture looping and may also constrict the commissure posts of the valve. The holder may include two relatively movable plates, one of which attaches to the valve sewing on the inflow end of the valve ring and the other which attaches via sutures or similar expedient to the valve commissures on the outflow end. Separation of the plates places the sutures in tension and constricts the commissures. The sutures may be strands or filaments, or may be wider bands of flexible biocompatible material. If bands are used, they desirably cover the commissure post tips to further help prevent suture looping thereover. The flexible lengths of material extend directly between commissures of the valve, or may extending radially inward from each commissure to a central upstanding member. Desirably, a slide is created by the flexible lengths of material adjacent each commissure post, for example by crossing over suture filaments at or radially inward from the commissure posts. If an upstanding member is used, the lengths of suture extend axially beyond the commissure post tips to create a tent that wards off sutures that otherwise might loop around the tips during advancement of the valve along an array of pre-implanted sutures.

The present invention provides for a system, method, and device for analyzing, localizing and/or identifying tissue types. The method includes analyzing, localizing and/or identifying one or more tissue samples, characterized in that the method comprises: (a) generating gaseous tissue particles from a site in the one or more tissue samples, (b) transporting the gaseous tissue particles from the site to an analyser, (c) using the analyser for generating tissue-related data based on the gaseous tissue particles, and (d) analyzing, localizing and/or identifying the one or more tissue samples based on the tissue-related data. The invention can either be used in close conjunction with a surgical procedure, when one or more surgical tools are an integrated part of ionization, or as a separate mass spectrometric probe for the analysis of one or more tissue parts.