1684 results about "Energy delivery" 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 (i) a first surface conductive portion or a variably resistive matrix of a temperature-sensitive resistive material or a pressure-sensitive resistive material, and (ii) a second surface portion coupled to a fixed resistive material that coupled in series or parallel to a voltage source together with the first portion. In use, the engagement plane will apply active Rf energy to ohmically heat the captured tissue until the point in time that a controller senses an electrical parameter of the tissue such as impedance. Thereafter, the controller switches energy delivery to the second surface portion that is resistively heated to thereby apply energy to tissue by conductive heat transfer.

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 medical device and technique for creating thermal welds in engaged tissue that provides very high compressive forces. In one exemplary embodiment, at least one jaw of the instrument defines a tissue engagement plane carrying first and second surface portions that comprise (i) an electrically conductive material and (ii) a positive temperature coefficient (PTC) material having a selected increased resistance that differs at each selected increased temperature over a targeted treatment range. One type of PTC material is a doped ceramic that can be engineered to exhibit a selected positively sloped temperature-resistance curve over about 37° C. to 100° C. The 70° C. to 100° C. range can bracket a targeted “thermal treatment range” at which tissue welded can be accomplished. The engineered resistance of the PTC matrix at the upper end of the temperature range will terminate current flow through the matrix. In one mode of operation, the engagement plane cause ohmic heating within tissue from Rf energy delivery tissue PTC matrix is heated to exceed the treatment range. Thereafter, energy density in the engaged tissue will be modulated as the conductivity of the second portion hovers within the targeted treatment range to thereby provide optical tissue heating for purposes of tissue welding.

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 system has an electrosurgical generator and a bipolar electrosurgical instrument, the generator being arranged to perform a treatment cycle in which radio frequency energy is delivered to the instrument as an amplitude-modulated radio frequency power signal in the form of a succession of pulses characterized by successive pulses of progressively increasing pulse width and progressively decreasing pulse amplitude. There are periods of at least 100 milliseconds between successive pulses, and the treatment cycle begins with a predetermined pulse mark-to-space ratio. Energy delivery between pulses is substantially zero. Each burst is of sufficiently high power to form vapor bubbles within tissue being treated and the time between successive pulses is sufficiently long to permit condensation of the vapor.

An electrosurgical system has an electrosurgical generator and a bipolar electrosurgical instrument, the generator being arranged to perform a treatment cycle in which radio frequency energy is delivered to the instrument as an amplitude-modulated radio frequency power signal in the form of a succession of pulses characterized by periods of a least 100 milliseconds between successive pulses and by a predetermined pulse mark-to-space ratio. Energy delivery between pulses is substantially zero and the mark-to-space ratio is typically 1:4 or less. Each burst is of sufficiently high power to form vapor bubbles within tissue being treated and the time between successive pulses is sufficiently long to permit condensation of the vapor. The treatment cycles may each include an initial period and a subsequent period, the pulse duty cycle being increased or energy being delivered continuously in the subsequent period in order that tissue coagulation can be achieved quickly despite increasing tissue impedance.

An embodiment of the invention provides a method for detecting and treating a tumor using tissue localized volumetric impedance measurement. The method includes providing an impedance measurement apparatus having a plurality of resilient members deployable with curvature and configured to sample tissue impedance through a plurality of conductive pathways. The apparatus is configured to be coupled to at least one of an energy delivery device, a power supply, a switching device or logic resources. The apparatus is then positioned at a selected tissue site and the impedance array deployed to define a sample volume. The impedance array is then utilized to make impedance measurements through a plurality of conductive pathways. Information from the impedance measurements is then utilized to determine a tissue condition of the sample volume. Energy is then delivered from the energy delivery device to ablate or necrose at least a portion of the tumor.

An embodiment of the invention provides a tissue biopsy and treatment apparatus that comprises an elongated delivery device that is positionable in tissue and includes a lumen. A sensor array having a plurality of resilient members is deployable from the elongated delivery device. At least one of the plurality of resilient members is positionable in the elongated delivery device in a compacted state and deployable with curvature into tissue from the elongated delivery device in a deployed state. At least one of the plurality of resilient members includes at least one of a sensor, a tissue piercing distal end or a lumen. The sensor array has a geometric configuration adapted to volumetrically sample tissue at a tissue site to differentiate or identify tissue at the target tissue site. At least one energy delivery device is coupled to one of the sensor array, at least one of the plurality of resilient members or the elongated delivery device.

A method and apparatus for calculating current lost through a patient during a treatment of a patient using an electromagnetic energy delivery system is disclosed. The system generates electromagnetic energy, contacts a skin surface of the patient, transfers the electromagnetic energy to tissue beneath the surface of the skin, detects a value of at least one characteristic of the electromagnetic energy utilizing synchronous undersampling, and calculates the current lost through the patient. The characteristic measured may be a value of current of the electromagnet energy. An adjustable matching network may be utilized to maximize power to the tissue of the patient. Values of the impedance of the matching network may be utilized to determine the electromagnetic energy delivered to the tissue of the patient. A current correction factor is determined from the impedance of the matching network and utilized to calculate the current lost through the patient.

Various embodiments provide compositions that exhibit positive temperature coefficient of resistance (PTCR) properties for use in thermal interactions with tissue—including thermal sensing and I2R current-limiting interactions. Embodiments also provide tissue-engaging surfaces having PTCR materials that provide very fast switching times between low resistance and high, current-limiting resistance. One embodiment provides a matrix for an electrosurgical energy delivery surface comprising a PTCR material and a heat exchange material disposed within an interior of the matrix. The PTCR material has a substantially conductive state and a substantially non-conductive state. The heat exchange material has a structure configured to have an omni-directional thermal diffusivity for exchanging heat with the PTCR material to cause rapid switching of the PTCR material between the conductive state and non-conductive state. Preferably, the structure comprises a graphite foam having an open cell configuration. The matrix can be carried by tissue contacting surfaces of various electrosurgical devices.

A system and method manage delivery of energy from a distribution network to one or more sites. Each site has at least one device coupled to the distribution network. The at least one device controllably consumes energy. The system includes a node and a control system. The node is coupled to the at least one device for sensing and controlling energy delivered to the device. A control system is coupled to the node and distribution network for delivery to the node at least one characteristic of the distribution network. The node controls the supply of energy to the device as a function of the at least one characteristic.

An end effector assembly adapted to couple to an electrosurgical instrument, the end effector assembly including a pair of opposing jaw members pivotably attached about a pivot member and moveable from a first spaced position to a second grasping position. Each jaw member includes a jaw housing and a seal plate formed on an inner surface of the jaw member including at least two seal plate segments extending along a substantial portion of the length of the jaw members. An insulating member is positioned between adjacent seal plate segments and configured to provide electrical isolation between adjacent seal plate segments. Each sealing plate segment is adapted to selectively connect to an electrosurgical energy source and form part of an electrosurgical energy delivery circuit.

A system for efficient delivery of radio frequency (RF) energy to cardiac tissue with an ablation catheter used in catheter ablation, with new concepts regarding the interaction between RF energy and biological tissue. In addition, new insights into methods for coagulum reduction during RF ablation will be presented, and a quantitative model for ascertaining the propensity for coagulum formation during RF ablation will be introduced. Effective practical techniques a represented for multichannel simultaneous RF energy delivery with real-time calculation of the Coagulum Index, which estimates the probability of coagulum formation. This information is used in a feedback and control algorithm which effectively reduces the probability of coagulum formation during ablation. For each ablation channel, electrical coupling delivers an RF electrical current through an ablation electrode of the ablation catheter and a temperature sensor is positioned relative to the ablation electrode for measuring the temperature of cardiac tissue in contact with the ablation electrode. A current sensor is provided within each channel circuitry for measuring the current delivered through said electrical coupling and an information processor and RF output controller coupled to said temperature sensor and said current sensor for estimating the likelihood of coagulum formation. When this functionality is propagated simultaneously through multiple ablation channels, the resulting linear or curvilinear lesion is deeper with less gaps. Hence, the clinical result is improved due to improved lesion integrity.

A method and apparatus for calculating current lost through a patient during a treatment of a patient using an electromagnetic energy delivery system is disclosed. The system generates electromagnetic energy, contacts a skin surface of the patient, transfers the electromagnetic energy to tissue beneath the surface of the skin, detects a value of at least one characteristic of the electromagnetic energy utilizing synchronous undersampling, and calculates the current lost through the patient. The characteristic measured may be a value of current of the electromagnet energy. An adjustable matching network may be utilized to maximize power to the tissue of the patient. Values of the impedance of the matching network may be utilized to determine the electromagnetic energy delivered to the tissue of the patient. A current correction factor is determined from the impedance of the matching network and utilized to calculate the current lost through the patient.

A medical probe assembly, system, and methods for the use thereof to treat tissue are described. The system optionally comprises an energy source, two internally-cooled probe assemblies, and one or more cooling devices to provide cooling to at least one of the probe assemblies. The probe assemblies may be configured in a bipolar mode, whereby current flows preferentially between the probe assemblies. The probe assemblies and system described herein are particularly useful to deliver radio frequency energy to a patient's body. RF energy delivery may be used for various applications, including the treatment of pain, tumor ablation and cardiac ablation.

A radio frequency tissue ablation system with a radio frequency generator, the generator comprising a radio frequency source, at least four independently controllable radio frequency outputs, a user interface and a controller configured to delivery radio frequency energy from the radio frequency source to the radio frequency outputs in one of at least two different output configurations in response to a configuration selection made through the user.

A receptacle assembly for use in connecting an energy source to an energy delivering device is described herein. The receptacle assembly includes a face plate defining an aperture. The receptacle also includes an adapter assembly including an adapter plate, supporting a terminal that is operatively connected to the energy source. Additionally, the receptacle includes a spacer member interposed between an inner surface of the aperture of the face plate and an outer surface of the adapter plate, wherein the spacer member permits omni-directional movement of the adapter plate and terminal relative to the face plate.

Apparatus and methods are provided for thermally and / or mechanically treating tissue, such as valvular structures, to reconfigure or shrink the tissue in a controlled manner. Mechanical clips are implanted over the leaflets of a valve, e.g., in the heart, either alone or after thermal treatment to cause the valve to close more tightly. The clips are delivered by a catheter and may be configured to traverse directly over the valve itself or to lie partially over the periphery of the valve to prevent obstruction of the valve channel. The clips can be coated with drugs or a radiopaque coating. Alternatively, individual anchors with a tensioning element, like a suture, may be used to approximate the valves towards each other. The catheter can also incorporate sensors or energy delivery devices, e.g., transducers, on its distal end.

Semi-autonomously executed routines accomplish the primary functions of electrosurgical energy delivery on a responsive basis for power control purposes and to adapt the delivered output waveform to perform new and better surgical procedures. The routines include and output voltage and output current sampling routine, a control routine for establishing the width of drive pulses used to create the output waveform, a pattern generation routine for establishing the pattern of drive pulses to be delivered in one mode cycle established by a selected mode of operation, a pattern delivery routine for repeatedly delivering sequences of the mode cycle pattern of drive pulses, and a power supply control routine for varying the voltage of the drive pulses in coordination with varying the width of the drive pulses.

Methods and systems are provided for achieving delivery of power wirelessly using a highly beam-formed array of radio frequency (RF) transmitters as a source and a spatially beam-formed array of receivers that collect the impinged RF power and feed a multistage RF to direct current (RF-DC) conversion circuit that, for example, increases output voltage by doubling the voltage at each stage, while power delivery remains constant. One or more embodiments may provide energy wirelessly and—unlike conventional systems where the power flux density may be too low for applications where an energy density (specific energy) on the order of several mega-Joules per kilogram (MJ / Kg) is desired—may provide sufficient power flux density for many practical applications.

An intelligent network demand control system provides a system and method for controlling demand in an energy delivery system. Various embodiments of the intelligent network demand control system employs a transceiver network with a plurality transceivers coupled to meters and appliances residing at a plurality of customer premises. Control room operators instruct a customer premises (CP) energy management controller to implement a reduction in system demand. A demand reduction control signal is relayed out to a predefined group of transceivers to bring their respective controlled generators on line. The predefined transceivers, identified by their identification codes, are specified in the demand reduction control signal. The actual demand reduction is metered and relayed back to the CP energy management controller. In some embodiments, the total demand reduction is aggregated into a single number and then communicated to the operators.

A system and method for efficient delivery of radio frequency (RF) energy includes a backplane. At least a single channel card is removably coupled to the backplane for controlling the amount of RF power delivered through a single channel via an electrical coupling to at least one ablation electrode or a catheter. The at least one channel card provides a gradual increase in RF power calculated in real-time during an initial ramp-up phase, and to limit the delivery of RF power through the electrical coupling based on a received temperature of cardiac tissue in contact with the at least one ablation electrode, thereby reducing the likelihood coagulum formation.

An electrode sealing assembly is designed for use with an electrosurgical instrument for sealing tissue and includes first and second jaw members each having an insulative housing and being movable from a first position in spaced relation relative to one another to at least one second position for grasping tissue therebetween. Each of the jaw members includes an electrically conductive sealing member disposed within the respective insulative housing. At least one of the insulative housings includes at least one tissue engaging surface configured to extend beyond the electrically conductive sealing member of one of the jaw members. The tissue engaging surface of the insulative housing cooperates with the opposing insulative housing of the opposing jaw member to both pinch and spread tissue when the jaw members are moved to the second position to decrease extraneous energy transmittance to tissue surrounding the jaw members.

An apparatus for cooling a skin surface includes a support structure coupled to an electromagnetic energy delivery device. The electromagnetic energy delivery device is configured to be coupled to an electromagnetic energy source. A cooling member is coupled to the electromagnetic energy delivery device and is configured to create a reverse thermal gradient through a skin surface. A memory is coupled to the electromagnetic energy delivery device and is positioned at the support structure or the electromagnetic energy delivery device. The memory is configured to store information to facilitate operation of at least one of the cooling member, and the electromagnetic energy source. Resources are coupled to the cooling member to permit different levels of cooling at different times of treatment.

A patient-worn energy delivery apparatus for imparting electrical therapy to the body of a patient responsive to an occurrence of a treatable condition includes a voltage converter for converting electrical energy from an initial voltage to a final voltage, and a defibrillator electrically coupled between the converter and the patient and having an energy reservoir for receiving the electrical energy. The defibrillator produces preshaped electrical pulses such as defibrillation pulses and cardioversion pulses. The apparatus additionally includes an energy delivery controller electrically coupled to the patient and the converter and the defibrillator. The controller causes the converter to provide the electrical energy to the defibrillator at a specific charging rate in response to an energy level in the reservoir. The apparatus may include a plurality of electrodes interposed between the defibrillator and the patient and each electrode preferably has an impedance reducing means contained therein. One embodiment of the apparatus may include a H-bridge to produce a positive-going pulse segment and the negative-going pulse segment within the biphasic exponential signals. The apparatus periodically measures the energy as it is being delivered to the patient and can pre-emptively stop or truncate the pulse in the event an error condition is detected, such as an overvoltage condition or if the energy level approaches a predetermined level. The electrical components which store and release the energy minimize the size and expense of the apparatus, while isolating the microcomputer from the high energy levels as the therapeutic pulse is delivered.