252 results about "Tissue volume" patented technology

A working end of a surgical instrument that carries first and second jaws for delivering energy to tissue. In a preferred embodiment, at least one jaw of the working end defines a tissue-engagement plane that contacts the targeted tissue. The cross-section of the engagement plane reveals that it defines a surface conductive portion that overlies a variably resistive matrix of a temperature-sensitive resistive material or a pressure-sensitive resistive material. An interior of the jaw carries a conductive material or electrode that is coupled to an Rf source and controller. In an exemplary embodiment, the variably resistive matrix can comprise a positive temperature coefficient (PTC) material, such as a ceramic, that is engineered to exhibit a dramatically increasing resistance (i.e., several orders of magnitude) above a specific temperature of the material. In use, the engagement plane will apply active Rf energy to captured tissue until the point in time that the variably resistive matrix is heated to its selected switching range. Thereafter, current flow from the conductive electrode through the engagement surface will be terminated due to the exponential increase in the resistance of variably resistive matrix to provide instant and automatic reduction of Rf energy application. Further, the variably resistive matrix can effectively function as a resistive electrode to thereafter conduct thermal energy to the engaged tissue volume. Thus, the jaw structure can automatically modulate the application of energy to tissue between active Rf heating and passive conductive heating of captured tissue to maintain a target temperature level.

An electrosurgical working end for automatic modulation of active Rf density in a targeted tissue volume. The working end of the probe of the present invention defines a tissue-engagement surface of an elastomeric material with conductive elements that extend therethrough. In one embodiment, the expansion of the elastomeric material can de-couple the conductive elements from an interior electrode based temperature to modulate current flow. In another embodiment, the elastomeric material can couple and de-couple the conductive elements from an interior electrode based engagement pressure to modulate current flow.

An electrosurgical working end and method for sealing and transecting tissue are provided. An exemplary electrosurgical working end has openable-closeable first and second jaws for progressively clamping a selected tissue volume. A method of the invention comprises applying electrosurgical energy to the tissue in either a first mode or a second mode based on the degree of jaw closure.

An electrosurgical instrument that allows precise modulation of active Rf density in an engaged tissue volume. The working end of the instrument has a tissue-contacting surface of a conductive-resistive matrix that is variably resistive depending on its temperature. The matrix comprises a positive temperature coefficient (PTC) polymeric material hat exhibits very large increases in resistivity as any local portion increases beyond a selected temperature. In a method of use, the polymeric PTC material senses the temperature of engaged tissue in a manner akin to pixel-by-pixel sensing and thereby changes its resistance in a corresponding pixel-by-pixel manner. The instrument further carries cooling means to cause accelerated thermal relaxation of the PTC matrix during use to make the engagement surface highly responsive to temperature changes that in turn alter the matrix between being electrically conductive and electrically resistive.

Method for carrying out the recovery of an intact volume of tissue wherein a delivery cannula tip is positioned in confronting adjacency with the volume of tissue to be recovered. The electrosurgical generator employed to form an arc at a capture component extending from the tip is configured having a resistance-power profile which permits recovery of the specimen without excessive thermal artifact while providing sufficient power to sustain a cutting arc. For the recovery procedure, a local anesthetic employing a diluent which exhibits a higher resistivity is utilized and the method for deploying the capture component involves an intermittent formation of a cutting arc with capture component actuation interspersed with pauses of duration effective to evacuate any accumulation or pockets of local anesthetic solution encountered by the cutting electrodes.

Method for carrying out the recovery of an intact volume of tissue wherein a delivery cannula tip is positioned in confronting adjacency with the volume of tissue to be recovered. The electrosurgical generator employed to form an arc at a capture component extending from the tip is configured having a resistance-power profile which permits recovery of the specimen without excessive thermal artifact while providing sufficient power to sustain a cutting arc. For the recovery procedure, a local anesthetic employing a diluent which exhibits a higher resistivity is utilized and the method for deploying the capture component involves an intermittent formation of a cutting arc with capture component actuation interspersed with pauses of duration effective to evacuate any accumulation or pockets of local anesthetic solution encountered by the cutting electrodes.

This invention relates to the destruction of pathological volumes or target structures such as cancerous tumors or aberrant functional target tissue volumes by direct thermal destruction. In the case of a tumor, the destruction is implemented in one embodiment of the invention by percutaneous insertion of one or more radiofrequency probes into the tumor and raising the temperature of the tumor volume by connection of these probes to a radiofrequency generator outside of the body so that the isotherm of tissue destruction enshrouds the tumor. The ablation isotherm may be predetermined and graded by proper choice of electrode geometry and radiofrequency (rf) power applied to the electrode with or without temperature monitoring of the ablation process. Preplanning of the rf electrode insertion can be done by imaging of the tumor by various imaging modalities and selecting the appropriate electrode tip size and temperature to satisfactorily destroy the tumor volume. Computation of the correct three-dimensional position of the electrode may be done as part of the method, and the planning and control of the process may be done using graphic displays of the imaging data and the rf ablation parameters. Specific electrode geometries with adjustable tip lengths are included in the invention to optimize the electrodes to the predetermined image tumor size.

An instrument for thermally-mediated therapies in targeted tissue volumes or for volumetric removal of tissue. In one embodiment, the instrument has an interior chamber that includes a diffuser structure for diffusing a biocompatible conductive fluid that is introduced under high pressure. The interior chamber further includes surfaces of opposing polarity electrodes for vaporizing the small cross-section diffused fluid flows created within a diffuser structure. In one embodiment, the diffuser structure includes a negative temperature coefficient of resistance material between the opposing polarity surfaces. The NTCR structure can self-adjust the lengths of current paths between the opposing polarities to insure complete vaporization of the volume of flow of conductive fluid. The non-ionized vapor phase media is ejected from a working surface of the instrument and a controlled vapor-to-liquid phase change in an interface with tissue applies thermal energy substantially equal to the heat of vaporization to ablate tissue. In another embodiment, the instrument provides voltage means for converting the non-ionized vapor phase media into an ionized media or plasma for applying energy to body structure.

A device and a method to provide a more reliable and accurate measurement of hematocrit (Hct) by noninvasive means. The changes in the intensities of light of multiple wavelengths transmitted through or reflected light from the tissue location are recorded immediately before and after occluding the flow of venous blood from the tissue location with an occlusion device positioned near the tissue location. As the venous return stops and the incoming arterial blood expands the blood vessels, the light intensities measured within a particular band of near-infrared wavelengths decrease in proportion to the volume of hemoglobin in the tissue location; those intensities measured within a separate band of wavelengths in which water absorbs respond to the difference between the water fractions within the blood and the displaced tissue volume. A mathematical algorithm applied to the time-varying intensities yields a quantitative estimate of the absolute concentration of hemoglobin in the blood. To compensate for the effect of the unknown fraction of water in the extravascular tissue on the Hct measurement, the tissue water fraction is determined before the occlusion cycle begins by measuring the diffuse transmittance or reflectance spectra of the tissue at selected wavelengths.

An embodiment of a method of the invention provides a method for welding tissue comprising providing a tissue welding device having first and second tissue engaging surfaces with at least one surface including an electrode surface that defines a plurality of surface portions having different resistances to electrical current flow therethrough. A target tissue volume is engaged with the tissue engaging surfaces. Rf energy is delivered to the target volume to create a substantially even temperature distribution across at least a portion of the target tissue volume to substantially uniformly weld at least a portion of the target tissue volume.

A stent for treating ocular hypertension by providing means for enhancing outflows of aqueous humor from the anterior chamber. An exemplary stent is fabricated of a shape memory polymer (SMP) that can withstand very large reversible inelastic strains for storing energy in a temporary reduced cross-sectional shape. In one embodiment, the stent in a temporary shape is introduced into a targeted tissue volume in and about the eye's aqueous outflow pathways. Following minimally invasive implantation of the stent, body temperature or another stimulus causes the stent to move from its temporary shape to its memory shape thereby releasing stored energy to retract the tissue to open flow pathways or increase tissue permeability. In another embodiment, the SMP stent body has interior flow passageways to provide addition fluid outflow means. In several embodiments, the stent can be of a shape memory alloy material.

An optical sampling interface system is disclosed that minimizes and compensates for errors that result from sampling variations and measurement site state fluctuations. Embodiments of the invention use a guide that does at least one of, induce the formation of a tissue meniscus, minimize interference due to surface irregularities, control variation in the volume of tissue sampled, use a two-part guide system, use a guide that controls rotation of a sample probe and allows z-axis movement of the probe, use a separate base module and sample module in conjunction with a guide, and use a guide that controls rotation. Optional components include an occlusive element and a coupling fluid.

A surgical instrument for thermally-mediated therapies in targeted tissue volumes and for causing thermal effects in polymer tissue-contacting members. In one embodiment, the instrument has a working end with an interior chamber that is supplied with a biocompatible liquid. An energy source causes a liquid-to-vapor phase change within the interior of the instrument. The vapor phase media then is ejected from the working surface of the instrument, and a controlled vapor-to-liquid phase change in an interface with tissue applies thermal energy substantially equal to the heat of vaporization to ablate tissue. The vapor-to-liquid phase transitions, or internal energy releases, can be provided about thin-film flexible structures for engaging body lumens and cavities. An exemplary embodiment can be used for shrinking, sealing, welding or creating lesions in tissue—while causing limited collateral thermal damage and while totally eliminating electrical current flow in the engaged tissue.

Devices and methods for utilizing electromagnetic radiation and other forms of energy to treat a volume of tissue at depth are described. In one aspect, a device modulates the flux incident on surface tissue to control and vary the depth in the tissue at which an effective dose of radiant energy is delivered and, thereby, treat a specific volume of tissue. The methods and devices disclosed are used to perform various treatments, including treatments to relieve pain and promote healing of tissue.

A method for photoselective vaporization of prostate tissue includes delivering laser radiation to the treatment area on the tissue, via an optical fiber for example, wherein the laser radiation has a wavelength and irradiance in the treatment area on the surface of the tissue sufficient because vaporization of a substantially greater volume of tissue than a volume of residual coagulated tissue caused by the laser radiation. The laser radiation is generated using a neodymium doped solid-state laser, including optics producing a second or higher harmonic output with greater than 60 watts average output power. The delivered laser radiation has a wavelength for example in a range of about 200 nm to about 650 nm, and has an average irradiance in the treatment area greater than about 10 kilowatts / cm2, in a spot size of at least 0.05 mm2.

Computer aided visualization and diagnosis by volume analysis of optical coherence tomography (OCT) angiographic data. In one embodiment, such analysis comprises acquiring an OCT dataset using a processor in conjunction with an imaging system; evaluating the dataset, with the processor, for flow information using amplitude or phase information; generating a matrix of voxel values, with the processor, representing flow occurring in vessels in the volume of tissue; performing volume rendering of these values, the volume rendering comprising deriving three dimensional position and vector information of the vessels with the processor; displaying the volume rendering information on a computer monitor; and assessing the vascularity, vascular density, and vascular flow parameters as derived from the volume rendered images.

The present invention provides a method and apparatus for assessing ventricular function on a chronic basis using a plurality of electrodes disposed on or about a left ventricle and / or a right ventricle—and optionally, at least one mechanical or metabolic sensor—all operatively electrically coupled to an implantable medical device. The plurality of electrodes are preferably spaced-apart so that at least one electrode is disposed electrical communication with a discrete volume of ventricular tissue. In one embodiment, the discrete volume of tissue is defined by multiple longitudinal and axial planes as known and used in the medical arts. Thus, according to the present invention, at least one electrode couples to appropriate sensing circuitry and essentially provides a localized electrogram (EGM) that, when compared to other EGMs, provides for configurable, localized delivery of therapeutic pacing stimulus, diverse impedance-sensing vectors, various diagnostic information regarding myocardial function and / or anti-tachycardia pacing.

An electrosurgical working end for instant and automatic modulation of active Rf density in a targeted tissue volume. The working end of the probe of the present invention defines a tissue-engagement plane that is adapted to contact the targeted tissue. The cross-section energy delivery apparatus comprises (i) a conductive surface engagement plane for tissue contact, (ii) a substrate comprising a medial conductive matrix of a temperature sensitive resistive material; and (iii) an inner or core conductive material (electrode) that is coupled to an Rf source and controller. Of particular interest, the medial conductive matrix comprises a positive temperature coefficient (PTC) that exhibits very large increases in resistivity as it increases beyond a selected temperature, which is described as a switching range. The PTC material is selected and fabricated to define a switching range that approximates a particular thermally-mediated therapy. In a method of use, it can be understood that the engagement plane will apply active Rf energy to the engaged the tissue temperature elevates the medial PTC conductive layer to its switching range. Thereafter, Rf current flow from the core conductive to the engagement surface will be instantly modulated to maintain tissue temperature at the switching range. Moreover, the conductive matrix effectively functions as a resistive electrode to thereafter passively conduct thermal energy to the engaged tissue above its switching range. Thus, the working end can modulate the energy application to tissue between active Rf heating and passive conductive heating of the targeted tissue to maintain a targeted temperature level.

Methods and devices for ablating portions of a tissue volume with electromagnetic radiation (EMR) to produce lattices of EMR-treated ablation islets in the tissue are disclosed, including lattices of micro-holes, micro-grooves, and other structures. Also, methods and devices for using the ablated islets are disclosed, including to deliver chromophores, filler, drugs and other substances to the tissue volume.

An anatomical space access device having an elongate body; an insertion tip at a distal end of the elongate body; an anatomical space sensor disposed at the distal end of the elongate body, the sensor being adapted to sense a parameter identifying an anatomical space other than a vasculature space and to generate a signal; and an indicator operatively connected to the sensor to receive the signal and to indicate access of the sensor to the anatomical space. The invention also provides a method for providing access to an anatomical space outside of a vasculature space, including the following steps: inserting a distal end of an instrument through a tissue volume into the anatomical space outside of a vasculature space, the instrument comprising an anatomical space sensor; and generating a location indication of the anatomical space sensor.

A method and system for gating therapeutic or diagnostic energy to a tissue volume of a medical patient during a selected portion of the patient's respiratory cycle, to thereby diminish inaccuracies in the assumed spatial position of the tissue volume arising from displacements induced by the patient's respiration. The gases flowing to and from the patient's lungs are monitored to provide quasi-continuous measurements as a function of time, of (a) flow rate, (b) pressure, (c) patient lung volume and (d) carbon dioxide concentration. The measurements are utilized to trigger the time period during which the energy is gated on, at the beginning of the selected portion of the respiration cycle; and the time period during which the energy is gated on, is terminated at the end of the selected portion of the respiration cycle.

Methods and devices for ablating portions of a tissue volume with electromagnetic radiation (EMR) to produce lattices of EMR-treated ablation islets in the tissue are disclosed, including lattices of micro-holes, micro-grooves, and other structures. Also, methods and devices for using the ablated islets are disclosed, including to deliver chromophores, filler, drugs and other substances to the tissue volume.

A laser can produce pulses of light energy to eject a volume of the tissue, and the energy can be delivered to a treatment site through a waveguide, such as a fiber optic waveguide. The incident laser energy can be absorbed within a volume of the target tissue with a tissue penetration depth and pulse direction such that the propagation of the energy from the tissue volume is inhibited and such that the target tissue within the volume reaches the spinodal threshold of decomposition and ejects the volume, for example without substantial damage to tissue adjacent the ejected volume.

A medical instrument coupled to first and second energy means and a computer controller for the controlled volumetric removal of thin tissue layers. The system provides a source for introducing a gas to controllably form and capture transient gas volumes in a microchannel structure at the working surface of the instrument that interfaces with a targeted tissue site. Each of the microchannel features of the working surface carries an electrode element coupled to the electrical source. The energy may be applied to the targeted site in either of two modes of operation, depending in part on voltage and repetition rate of energy delivery. In one mode of energy application, electrical potential is selected to cause an intense electrical arc across the transient ionized gas volumes to cause an energy-tissue interaction characterized by tissue vaporization. In another preferred mode of energy delivery, the system applies selected levels of energy to the targeted site by means of an energetic plasma at the instrument working surface to cause molecular volatilization of surface macromolecules thus resulting in material removal. Both modes of operation limit collateral thermal damage to tissue volumes adjacent to the targeted site. Another preferred embodiment provides and an ultrasound source or other vibrational source coupled to the working end to cause cavitation in fluid about the working end.

A computer assisted, minimally invasive method and apparatus for surgically removing abnormal tissue from a patient, for example, from a breast, are disclosed. The method involves imaging of the breast to locate the abnormal tissue, and determining a volume encapsulating the abnormal tissue and including a margin of healthy tissue. Based on the volume, a sequence of movements of a surgical instrument for tissue removal device is planned, so as to predictably excise the desired volume of tissue.

Methods and devices for ablating portions of a tissue volume with electromagnetic radiation (EMR) to produce lattices of EMR-treated ablation islets in the tissue are disclosed, including lattices of micro-holes, micro-grooves, and other structures. Also, methods and devices for using the ablated islets are disclosed, including to deliver chromophores, filler, drugs and other substances to the tissue volume.

A method and apparatus are provided for dermatological treatment by focusing ultrasound energy in a volume of tissue below the dermis to obtain selective heating and thermal damage of certain portions of the volume while sparing other portions of the treatment volume from thermal damage. Selective heating of fibrous septae can be achieved while relatively sparing surrounding fatty tissue, which can lead to some shrinkage of the fibrous septae and reduction in the appearance of wrinkles. The matrix of hair follicles can also be selectively heated to provide relatively safe temporary or permanent hair removal. The superficial musculoaponeurotic system can also be selectively heated to obtain a tightening of the overlying skin.