809 results about "Thermal damage" patented technology

A method for treating obstructive sleep disorders includes accessing the interior of the tongue through an incision made in the skin in the vicinity of the jaw of a patient; advancing an instrument through the incision into the interior of the tongue; and removing an amount of tissue from the interior of the base of the tongue with the instrument. The present invention includes forming a cavity or plurality of channels in the tongue. The cavity may be collapsed using a suture, fastener or bioadhesive. An emplaced suture may be provided to hold the cavity in a collapsed position thereby reducing the degree of obstruction. Additionally, thermal energy may be applied to the tissue surface immediately surrounding the channels to cause thermal damage to the tissue surface, thereby creating hemostasis and stiffening the surrounding tissue structure.

A bipolar electrosurgical instrument having a pair of relatively moveable jaws, each of which includes a tissue contacting surface. The tissue contacting surfaces of the jaws are in face-to-face relation with one another, and adjacent each of the tissue contacting surfaces are first and second spaced-apart electrodes that are adapted for connection to the opposite terminals of a bipolar RF generator so as to generator a current flow between the electrodes. The first and second electrodes of one jaw are in offset opposed relation, respectively, with the first and second electrodes of the other jaw. A cutting portion is provided between the jaws. The cutting portion is moveable to provide the instrument with a scissors-like capability or a grasper-like capability, depending on the position of the cutting portion. A tissue dam is included on at least one jaw to help contain tissue within the desired coagulation area, and thereby help contain current density between the electrodes, thereby decreasing lateral tissue thermal damage and increasing hemostasis.

The present invention provides systems, apparatus and methods for selectively applying electrical energy to body tissue in order to incise, dissect, harvest or transect tissues or an organ of a patient. The electrosurgical systems and methods are useful, inter alia, for accessing, dissecting, and transecting a graft blood vessel, such as the internal mammary arteries (IMA) or the saphenous vein, for use in a by-pass procedure. A method of the present invention comprises positioning an electrosurgical probe adjacent the target tissue so that one or more active electrode(s) are brought into at least partial contact or close proximity with a target site in the presence of an electrically conductive fluid. A high frequency voltage is then applied between the active electrode and one or more return electrode(s). During application of the high frequency voltage, the electrosurgical probe may be translated, reciprocated, or otherwise manipulated such that the active electrode is moved with respect to the tissue. The present invention volumetrically removes the tissue at the point of incision, dissection, or transection in a cool ablation process that minimizes thermal damage to surrounding, non-target tissue.

An electrosurgical electrode and electrosurgical generator system utilizing the same are disclosed capable of controlling or limiting the current per arc in real-time during an electrosurgical procedure. The conductive electrosurgical electrode is configured for being connected to an electrosurgical generator system and has a non-conductive, porous ceramic coating that “pinches” or splits the arc current generated by the electrosurgical generator system into the smaller diameter pores of the coating, effectively keeping the same current and voltage, but creating several smaller diameter arcs from one larger diameter arc. This has the effect of separating the arc current, effectively increasing the current frequency, resulting in a finer cut or other surgical effect. That is, the non-conductive, porous ceramic coating enables a low frequency current to achieve surgical results indicative of a high frequency current, while minimizing or preventing thermal damage to adjacent tissue.

The present invention provides improved methods and apparatus for skin treatment and tissue remodeling. The apparatus includes an array of needles that penetrate the skin and serve as electrodes to deliver radio frequency current or other electrical or optical energy into the tissue being treated, causing thermal damage in controlled patterns. The damaged regions promote beneficial results such as uniform skin tightening by stimulation of wound healing and collagen growth.

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.

A system for effective NOx and particulate matter control in a diesel or other lean burn internal combustion engine is presented. The system includes a urea-based SCR catalyst having an oxidation catalyst coupled upstream of it and a particulate filter coupled downstream of the SCR catalyst. This system configuration results in improved NOx conversion due to fast SCR catalyst warm-up and higher operating temperatures. Additionally, placing the particulate filter last in this system configuration reduces tailpipe ammonia emissions as well as prevents any thermal damage to the SCR catalyst due to the particulate filter regeneration.

A new method for the ablation of undesirable tissue such as cells of a cancerous or non-cancerous tumor is disclosed. It involves the placement of electrodes into or near the vicinity of the undesirable tissue through the application of electrical pulses causing irreversible electroporation of the cells throughout the entire area of the undesirable tissue. The electric pulses irreversibly permeate the cell membranes, thereby invoking cell death. The irreversibly permeabilized cells are left in situ and are removed by the body immune system. The amount of tissue ablation achievable through the use of irreversible electroporation without inducing thermal damage is considerable.

This invention relates to the treatment of a patient's lung, for example, a lung exhibiting chronic obstructive pulmonary disease (COPD) and in particular to methods and devices for affecting lung volume reduction, preferably for achieving acute or immediate lung volume reduction following treatment. The lung volume reduction is effected by delivering a condensable vapor at a temperature above body temperature to the desired regions of the patient's lung to damage tissue therein. Blood flow and air flow to the damaged tissue region is essentially terminated, rendering the target region non-functional. Alternative energy sources may be used to effect the thermal damage to the lung tissue.

A method for treating obstructive sleep disorders includes accessing the interior of the tongue through a sublingual incision; advancing an instrument through the incision into the interior of the tongue; and instantaneously removing an amount of tissue from the interior of the base of the tongue with the instrument. The present invention includes forming a cavity or plurality of channels in the tongue. The cavity may be collapsed using a suture, fastener or bioadhesive. An emplaced suture may be provided to hold the cavity in a collapsed position thereby reducing the degree of obstruction. Additionally, thermal energy may be applied to the tissue surface immediately surrounding the channels to cause thermal damage to the tissue surface, thereby creating hemostasis and stiffening the surrounding tissue structure.

This invention relates to the working end of a medical instrument that applies energy to tissue. In one embodiment, the instrument has a microfluidic tissue-engaging surface fabricated by soft lithography means together with optional superlattice cooling means that allows for very precise control of energy application, for example in neurosurgery applications. The tissue-engaging surface can eject a high-heat content vapor into the engaged tissue for treating tissue, while the superlattice cooling structure can prevent collateral thermal damage. Also, the superlattice cooling structure can be used to localize heat at a selected depth in tissue and prevent surface ablation. Also, the superlattice cooling structure can be used to prevent tissue sticking to a thermal energy delivery surface. In another embodiment, the tissue-engaging surface can be used in a jaw structure for sealing tissue together with hydrojet means for transecting the tissue.

A thermal interface material includes a mechanically compliant vertically aligned nanofiber film and a binder material for joining the nanofibers of the film to the surfaces of two substrates. Preferably, the binder material comprises a non-hydrocarbon-based material such as a metallic eutectic with a melting temperature below a nanofiber thermal damage threshold temperature of the film. The film is grown on a substrate which is then bonded to another substrate by the binder material in an adhesion process that may include pressure and heat. Alternatively, the film may be released from the substrate to produce a stand-alone thermal tape which may later be placed between two substrates and bonded.

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.

This invention relates to a novel surgical device scalable to small dimensions for thermally-mediated treatments or thermoplasties of targeted tissue volumes. An exemplary embodiment is adapted for fusing, sealing or welding tissue. The instruments and techniques utilize a thermal energy delivery means, for example an electrical energy source, to instantly elevate the temperature of a biocompatible fluid media within an electrically insulated instrument portion. The altered media which may then be a gas is characterized by a (i) a high heat content, and (ii) a high exit velocity from the working end, both of which characteristics are controlled to hydrate tissue and at the same time denature proteins to fuse, seal, weld or cause any other thermally-mediated treatment of an engaged tissue volume—while causing limited collateral thermal damage and while totally eliminating electrical current flow the engaged tissue volume. The system can further utilize a piezoelectric material that carried fluid channels to apply compressive forces to the fluid eject the fluid from the working end of make it require less electrical energy to convert it to a gas.

The present invention includes a device and a method for preventing injury of the esophagus during thermal ablation of the left atrium. The device has an esophageal probe with a balloon tip for insertion into the esophagus of a patient. During usage, coolant passes into the esophageal probe and then fills its balloon. The coolant, when circulating through the balloon and an external cooling machine, protects the esophageal tissue in contact with the esophageal probe from thermal damage during ablation of the posterior wall of the left atrium of the heart, or other procedure.

Body lumens such as blood vessels are selectively occluded by applying radiofrequency voltage to a vaso-occlusive coil (100) at the target site (TS) and generating a thermal reaction to induce fibrogenic occlusion of the blood vessel (BV) around the vaso-occlusive coil. The radiofrequency current is usually sufficient to induce thermal damage to the luminal wall and to coagulate the surrounding blood, thereby initiating clotting and subsequent fibrosis to permanently occlude the lumen. The invention also includes a method for endoluminally deploying the vaso-occlusive coil and preventing migration of the coil from of the target site.

Methods for treating a tissue site. Introducing at least first and second mono-polar electrodes to a tissue site of the patient. Positioning the at least first and second mono-polar electrodes at or near the tissue site. Applying an electric field in a controlled manner to the tissue site in an amount sufficient to produce electroporation of cells at the tissue site and below an amount that causes thermal damage to a majority of the tissue site.

Described herein are methods and apparatus for cutting a material including biological tissue. The apparatus has a cutting electrode with an elongate cutting portion. A voltage pulse waveform (typically comprising repeated bursts of minipulses) having a low or very low duty-cycle is applied to the cutting electrode to cut the tissue or other material by producing a vapor cavity around the cutting portion of the electrode and ionizing a gas inside the vapor cavity to produce a plasma. A low duty cycle cutting waveform may prevent heat accumulation in the tissue, reducing collateral thermal damage. The duration of the burst of minipulses typically ranges from 10 μs to 100 μs, and the rep rate typically ranges from 1 KHz to 10 Hz, as necessary. The apparatus and method of invention may cut biological tissue while decreasing bleeding and maintaining a very shallow zone of thermal damage.

Methods and systems for heating a body tissue region adjacent a body lumen with diseased and healthy portions using selective accumulation of energy in the artery tissue with or without knowledge of tissue topography. The method includes positioning an energy delivery portion of a catheter body within the lumen adjacent the body tissue region to be heated, determining a pulse characteristic in response to a thermal property of a first tissue type and applying pulsed energy with the pulse characteristic from the energy delivery portion so as to therapeutically treat the second tissue type within the body tissue region by drawing heat from the first tissue type at a rate that avoids significant thermal damage to the first tissue type while building-up heat in the second tissue type. The system includes an elongate flexible catheter body having a proximal end and a distal end with an axis therebetween, an energy delivery portion proximate the distal end, an energy source coupled to the energy delivery portion and a processor coupled to the energy source, the processor configured to control a pulse characteristic of pulsed energy transmitted from the energy source to the energy delivery portion so as to therapeutically treat the second tissue type within the body tissue region by drawing heat from the first tissue type at a rate that avoids significant thermal damage to the first tissue type while building-up heat in the second tissue type.

A method for treating obstructive sleep disorders includes accessing the interior of the tongue through a sublingual incision; advancing an instrument through the incision into the interior of the tongue; and instantaneously removing an amount of tissue from the interior of the base of the tongue with the instrument. The present invention includes forming a cavity or plurality of channels in the tongue. The cavity may be collapsed using a suture, fastener or bioadhesive. An emplaced suture may be provided to hold the cavity in a collapsed position thereby reducing the degree of obstruction. Additionally, thermal energy may be applied to the tissue surface immediately surrounding the channels to cause thermal damage to the tissue surface, thereby creating hemostasis and stiffening the surrounding tissue structure.

A system is provided for reducing restenosis. A catheter apparatus is provided with at least first and second mono-polar electrodes positioned at an inflatable balloon. The balloon is sized to be positioned and expanded at a restenosis site. A voltage pulse generator is coupled to the first and second mono-polar electrodes. The voltage pulse generator is configured to apply an electric field, in a controlled manner, to the restenosis site in an amount sufficient to produce electroporation of the restenosis site, and below an amount that causes thermal damage to the restenosis site.

A method of depositing various materials onto heat-sensitive targets. Heat-sensitive targets are generally defined as targets that have thermal damage thresholds that are lower than the temperature required to process a deposited material. The invention uses precursor solutions and / or particle or colloidal suspensions, along with optional pre-deposition treatment and / or post-deposition treatment to lower the laser power required to drive the deposit to its final state. The present invention uses Maskless Mesoscale Material Deposition (M3D™) to perform direct deposition of material onto the target in a precise, highly localized fashion. Features with linewidths as small as 4 microns may be deposited, with little or no material waste. A laser is preferably used to heat the material to process it to obtain the desired state, for example by chemical decomposition, sintering, polymerization, and the like. This laser processing may be performed in an ambient environment with laser powers of less than 100 milliwatts.

An apparatus and method for creating drug-filled pockets within muscle tissue, such as myocardium of the heart for increasing angiogenesis. More particularly, the apparatus has an excising assembly with a dilator tip for penetrating and advancing through the surface and body of a muscle or organ, such as the heart. Preferably, the dilator tip has a low level laser optical fiber emission to ease the passage of the excising assembly and provide thermal damage which also stimulates angiogenesis. More preferably, the dilator tip also disperses a pharmacologically active substance as the apparatus is passed through the tissue and / or creates pockets. The excising assembly is connected to a hand-held control device from which the operator pushes a switch to activate a punching mechanism within the excising assembly. The punching mechanism cuts a discrete piece of muscle tissue and traps it within the excising assembly leaving a pocket in the remaining muscle tissue. The excising assembly may also optionally release a bolus of the pharmacologically active substance into the pocket so created. Most preferably, there is a timing mechanism to measure the contraction of the heart, and the timing mechanism is synchronized with the operator's switch on the hand-held device to ensure that the punching occurs at maximum contraction of systole. A measurement guide determines how much excised tissue is trapped in the reservoir of the excising assembly. At a threshold level of filling, the surgeon will remove the excising assembly from the hand-held control device and open the punching mechanism for release of tissue. More preferably, the threshold level of filling will automatically turn off the switch to the punching mechanism to indicate to the surgeon the need to empty the excising assembly of tissue.

A method for controlled removal of surface tissue layer portions with a non-contact energy delivery modality that applies electrical energy to the targeted tissue surface to cause electrochemical ablation. The system provides (i) a UV energy source for irradiating a beam path through a selected neutral gas environment overlying the targeted tissue thereby creating an ionized gas volume (i.e., a conductive non-equilibrium plasma), and (ii) an electrical source for creating an intense electrical field in the ionized gas volume to thereby apply energy to the targeted surface layer to cause volatilization and removal of the surface layer in a plasma-mediated ablation. The ultrafast plasma creation events are repeated at a high repetition rate to ablate surface layer portions in a controlled manner. Each ultrafast plasma creation event is of such a high intensity and such a brief duration that thermal energy is not transferred to the tissue thus preventing collateral thermal damage to regions adjacent to the targeted site.

A method of depositing various materials onto heat-sensitive targets, particularly oxygen-sensitive materials. Heat-sensitive targets are generally defined as targets that have thermal damage thresholds that are lower than the temperature required to process a deposited material. The invention uses precursor solutions and / or particle or colloidal suspensions, along with optional pre-deposition treatment and / or post-deposition treatment to lower the laser power required to drive the deposit to its final state. The present invention uses Maskless Mesoscale Material Deposition (M3D™) to perform direct deposition of material onto the target in a precise, highly localized fashion. Features with linewidths as small as 4 microns may be deposited, with little or no material waste. A laser is preferably used to heat the material to process it to obtain the desired state, for example by chemical decomposition, sintering, polymerization, and the like. This laser processing may be performed in an ambient environment with laser powers of less than 100 milliwatts. Cover gases and / or forming gases may be used during thermal processing to change the material properties, for example by preventing oxidation.

Selective occlusion of a blood vessel is achieved by selectively damaging endothelial cells at a target location in the blood vessel, resulting in the formation of a fibrin clot proximate to the damaged endothelial cells. Additional fibrinogen can then be introduced into the blood vessel if occlusion is not achieved, as the fibrinogen is converted to fibrin by enzymes released by the exposed thrombogenic tissue and activated platelets. Endothelial cells are selectively damaged using thermal effects induced by ultrasound, by mechanical effects induced by ultrasound, or by mechanical effects produced by a tool introduced into the blood vessel (such as a catheter-based tool). A particularly preferred technique for selectively damaging endothelial cells involves introducing an ultrasound activatable agent into the blood vessel, and causing cavitation in that agent using pulses of high-intensity focused ultrasound having a duration insufficient to induce thermal damage in adjacent perivascular tissue.