Abstract:
Ablationskatheter (12) zur Ablation biologischen Gewebes, mit mindestens einer optischen Faser (14) zum Transport von Laserlicht entlang des Ablationskatheters (12) und mindestens einem Auskoppelbereich (18) zum Auskoppeln des von der optischen Faser (14) transportierten Laserlichts aus dem Katheter, wobei eine Sensorik dazu ausgebildet ist, Parameter, aus denen der Ablationserfolg ermittelt werden kann, kontinuierlich zu erfassen.
Abstract:
A bipolar electrosurgical fusion/sealer and dissector is provided that is arranged to simultaneously fuse and cut tissue captured between jaws of the instrument. The jaws include particularly positioned, shaped and/or oriented electrodes along with a compressible landing pad to perform the simultaneous fusion and cutting of tissue. An electrosurgical generator is arranged to supply RF energy through the instrument and monitors a phase angle of the supplied RF energy and adjusts or terminates the supplied RF energy based on the monitored phase angle to optimally fuse and dissect the tissue.
Abstract:
In part, the disclosure relates to an electromagnetic current displacement apparatus that includes one or more magnetic field sources and an alternating current source. The apparatus includes current delivery electrodes that may be part of a cuff, a hand held device, or individual electrode pads suitable for temporary fixation to skin. In one embodiment, an alternating current is transcutaneously delivered using skin contacting electrodes sized and arranged to avoid hotspots and provide a uniform delivery of the current. In turn, current attractors and repulsors can be arranged on the skin or in a suitable device to push or pull sections of the current that is disposed below such elements. Magnetic fields can be applied and focused to the regions through which the current passes, effectively pushing the current deeper into a target region below the surface of the skin.
Abstract:
A method of assessing a tissue ablation treatment, including positioning a medical device adjacent a target tissue; the medical device measuring a first impedance magnitude at a first frequency with the medical device; measuring a first impedance phase at a second frequency with the medical device; ablating at least a portion of the target tissue with the medical device; measuring at second impedance magnitude at a third frequency with the medical device; measuring a second impedance phase at a fourth frequency with the medical device; comparing at least one of (i) the first and second impedance magnitudes and (ii) the first and second impedance phases; and providing an indication of the efficacy of the ablation treatment based at least in part on the comparison.
Abstract:
An electrosurgical instrument includes jaws (102, 104) having an electrode configuration (103a, 103b, 105b) utilized to electrically modify tissue in contact with one or more electrodes. The instrument is removably connectable to an electrosurgical unit via an electrosurgical connector extending from the instrument and a receptacle on the electrosurgical unit. The electrosurgical instrument is rotatable without disrupting the electrical connection to the electrodes of the jaws. One or more of the electrodes is retractable. The electrosurgical unit and instrument optimally seals and/or cuts tissue based on identifying the tissue and monitoring the modification of the tissue by the application of radio frequency energy.
Abstract:
The invention concerns a system for producing specific field distributions in a defined volume or region. The system comprises an array of electromagnetic field generating elements each with an integrated sensor for measuring the phase and amplitude of the current flowing in a metallic element (antenna or coil) or field in a slot based element, a measurement device to enable measurement of both phase and amplitude of the electrical signals from the sensors with sufficient dynamic range for quantification of the signal, a multi channel radio frequency power source with individually controllable amplitude and phase to excite each of the electromagnetic field generating elements, and a feedback controller enabling controlled adjustment of the amplitude and phase of the radio frequency power source based on the signals from the sensors. The system controls the outputs of a multi channel radio frequency power source such that the current in a metallic or the field in a slot based electromagnetic field generating elements provide the desired electromagnetic field values and the superposition of the fields produced by each electromagnetic field generating element produces said specific electromagnetic field distribution in said defined volume or region. As the signal picked up by each sensor is directly related to the phase and amplitude of the current or field in the associated electromagnetic field generating element and hence the electromagnetic field generated by the array elements, where the current or field measured is the sum of both the applied (from the radio frequency power source) and secondary excitations from mutual coupling and reflections hence the measured value represents the ideal excitation in the absence of mutual coupling, reflections and mismatch. The feedback controller modifies the direct excitation such that the total excitation is the ideal array excitation without coupling or mismatch. The invention implicitly corrects for the coupling and mismatch without explicit knowledge of, and calculation based on, the mutual coupling and mismatch, termed the coupling matrix, such that changes in the coupling matrix due to presence of objects or changes thereof are inherently taken into account. Additionally, by sequentially exciting each element in turn the invention can directly determine the exact mutual coupling matrix of the array even in the presence of variations in source impedance and undefined cable lengths such that initial excitation amplitudes and phases can be calculated to allow rapid adjustment to the desired values. A particular application of interest is in radio frequency hyperthermia applicator systems.
Abstract:
An electrosurgical device includes a plurality of electrodes arranged to form a tissue treatment surface and a power supply. The power supply is configured to deliver a first drive signal with a first phase to at least a first one of the plurality of electrodes and a second drive signal with a second phase to at least a second one of the plurality of electrodes such that an electric field extends from the tissue treatment surface, where the first phase and the second phase are different. The power supply is further configured to receive an input from an operator of the electrosurgical device, and adjust the first phase or the second phase such that an aspect of the electric field extending from the tissue treatment surface changes in response to the input from the operator.
Abstract:
An electrode catheter and a method for assessing electrode-tissue contact and coupling are disclosed. An exemplary electrode catheter comprises an electrode adapted to apply electrical energy. A measurement circuit is adapted to measure impedance between the electrode and ground as the electrode approaches a target tissue. A processor determines a contact and coupling condition for the target tissue based at least in part on reactance of the impedance measured by the measurement circuit. In another exemplary embodiment, the electrode catheter determines the contact and coupling condition based at least in part on a phase angle of the impedance.
Abstract:
An electrode catheter and a method for assessing electrode-tissue contact and coupling are disclosed. An exemplary electrode catheter comprises an electrode adapted to apply electrical energy. A measurement circuit is adapted to measure impedance between the electrode and ground as the electrode approaches a target tissue. A processor determines a contact and coupling condition for the target tissue based at least in part on reactance of the impedance measured by the measurement circuit. In another exemplary embodiment, the electrode catheter determines the contact and coupling condition based at least in part on a phase angle of the impedance.
Abstract:
A method and apparatus for carrying our thermal ablation of target tissue is disclosed. The apparatus includes an RF ablation device having a multi-electrode electrode assembly designed to be deployed in target tissue, defining a selected-volume tissue region to be ablated, and having infusion channels for infusing a liquid into the target tissue during the ablation process. A control unit in the apparatus is operably connected to an RF energy source, for controlling the RF power level supplied to the electrodes, and to an infusion device, for controlling the rate of infusion of a liquid through the device into the tissue. During both electrode deployment and tissue ablation, impedance and or temperature measurements made within the tissue are used to control the RF source and infusion device, for optimizing the time and extent of tissue ablation.