Abstract:
Disclosed herein is a telescoping bipolar electrode (1) having an inner electrode (4) with an outer diameter (D4), length and outer side surface, such that up to the entire side surface is covered with an insulation sheath (5), which alternatively is fixed to the inner electrode (4) or is lengthwise adjustable with respect thereto, the inner electrode (4) and insulation sheath (5) together being slidably mounted within the inner space of an outer electrode (2) having an inner diameter greater than that of the inner electrode and its insulation sheath, an outer diameter (D2), thickness, length and an outer side surface area, the outer electrode (2) also having an insulation sheath (3) around its outer diameter (D2), covering up to the entire side surface area of the outer electrode (2), with the insulation sheath (3) around the outer electrode (2) being alternatively fixed to the outer electrode (2) or lengthwise adjustable with respect thereto. The bipolar electrode (1) is capable of being inserted into the human body through a body cavity or through the lumen of a vessel. At least one of the outer and inner electrodes is supplied with radio frequency energy from an external source (10). The bipolar electrode (1) is utilized to cut, desiccate or ablate neoplasms (12) in the body. In an alternative embodiment, the bipolar electrode (1) is configured such that the two component electrodes (2, 4) are arranged externally parallel to one another and are telescopically slidable relative to one another.
Abstract:
An electrosurgical generator (11) control responds to tissue impedance between active and return electrodes (12 and 13) during desiccation. Active and return generator leads supply energy (25) and a user control (16) sets the level of energy (25) desired for electrosurgery. Voltage and current sensing circuits (19) respond to high frequency energy (25) in the leads to signal voltage and current in the leads. A multiplier (21) receives the signals to calculate power. A clock (23) sets units of time during which power calculation. An integrator (24) calculates the energy (25) supplied through the leads per time unit. The user control (16) sets a reference signal (26) for the energy (25) level desired. A correlation circuit (27) receives the energy (30) calculations from the integrator (24) and the reference signal (26) and provides a feedback signal (28) to indicate when the energy (25) calculation equals the user control (16) setting for altering the generator supply of energy (25) to the leads. A counter (38) assesses the number of packets of energy (40) delivered against a setting of the user control (16) and the total energy (25) delivered is a function of multiple packet sequences containing pulses wherein the time between the pulses is controlled by the user control (16). The method uses the automatic control (10) in measuring impedance during tissue desiccation and altering the output of an electrosurgical generator (11).
Abstract:
An apparatus (10) and method to find leakage due to tissue load or transients at the start or end of electrosurgery. Active and return electrodes (11 and 16) between a patient and an ESU (13) pass RF energy sensed by inductive transformers (17 and 19). A circuit finds leakage at more than two thousand times per second; that frequency depends on the phase shift (23) between voltage and current. Software and feedback (26) manage RMS voltage to reduce the peak voltage of the output wave or increase the crest factor by pulse width modulation of the RF drive. Phase shift (23) changes of the active and return current signals (18 and 20) and peak voltage and current are found. The phase angle theta is compared to a threshold and if greater than the frequency at which the differences (22) between the active and return current signals (18 and 20) are examined is increased. The differences (22) between the active and return current signals (18 and 20) are examined and if greater than a maximum for leakage while the mode selected is in coagulation then the pulse width of the RF drive is reduced to hold voltage wave-form peaks at a predetermined value while the RMS voltage is reduced to lower the leakage to a maximum or the frequency at which the leakage current is calculated is held to a maximum level until the phase angle theta is smaller than the threshold. If the difference (22) is greater than a maximum for leakage while the mode is cut or bipolar then the Vrms is reduced to a maximum level or the level remains high until the phase angle theta is smaller than a threshold. The crest factor is increased by reducing the duty cycle or the pulse width of the output wave shape.
Abstract:
A circuit, for monitoring and controlling parameters of an electrosurgical unit (10), ESU, relative to load and the RF energy, has a load responsive output sensing circuit (11) that measures the ESU load. A signal modifier (12) attached to the sensing circuit (11) enhances the signals measured and transmits them to a buffer (13). An analog to digital converter (18), A/D, digitizes the signals and samples wave pulse train at about eight million samples per second. A data memory (21) stores the digitized signals. An RF drive clock (27) connects to the ESU output; a sample clock (19) uses phase shifting to interrogate the input signals to a processor (20), DSP, at a greater sampling rate of frequency than without. The DSP receives the stored signals from the data memory (21) and processes them while monitoring and calculating ESU parameters measured, i.e. voltage, current, power, load impedance, leakage current, peak to peak voltage, peak to peak current, spectral content and/or crest factor of the RF wave pulse train energy to use as controlling feedback to either a high voltage power supply in the ESU, regulating the RF drive pulses or both. A method monitors and controls the ESU relative to load and has the steps of collecting parameters with the ESU output sensing circuit (11) responsive to loads; enhancing signals with the signal modifier (12); transmitting signals to the buffer (13); converting signals with the A/D converter (18); storing signals in the data memory (21); receiving signals in the DSP, and processing, monitoring and controlling signals by repeatedly measuring ESU output parameters.
Abstract:
An ultrasonic and electrosurgical handpiece (10) housing (11) has an axis, a distal end (12), a proximal end (13) and a passage (14) defined by an inside wall (40). A piezo stack (26) has elements (16) carried along a plane (17) generally transverse to the axis. A retainer (18) for the elements (16) has distal, intermediate and proximal portions (21). The distal portion (19) has a fastener (22); the proximal portion (21) has a threaded shoulder bolt (24). The stack (26) about the shoulder has an energy input (29) and a reference output (30) positioned axially apart from one another. An insulating sleeve (31) about the bolt is between central openings of the elements (16) and the bolt. A pair of insulators (32) about the bolt has the stack (26) therebetween; one insulator (32) is between the plane (17) and the stack (26) and the other is near the threads. The intermediate portion (20) attaches to the housing (11) at the plane (17) with decoupling and sealing. An irrigation channel (44) conveys fluid. The drive energy input (29), the feedback signal and the reference outputs (30) are insulated by the sleeve (31) and pair from the bolt. A washer (34) against the insulator (32) and about the threads applies axial but not torsion to the insulator (32) when a clamping nut (35) on the threads holds components on the bolt. The clamping nut (35) is in circuit with electrosurgical energy as the reference return for electrosurgery. A tool (36) fastens to a connector (37) for transmitting axial vibrations in the form of a predefined stroke at a tip (38) thereof.
Abstract:
An electrosurgical bipolar cutting apparatus comprising a handpiece (1) to which is connected a first active electrode and a second return electrode having exposed distal ends (6, 7) which define a tip for electrosurgically cutting tissue at an operational site on a patient, which tip is structured so that both distal ends simultaneously contact said tissue and wherein the active electrode has a higher tissue to electrode impedance than the return electrode.
Abstract:
An electrical circuit system (1) which provides electrical energy to a surgical apparatus having ultrasonic fragmentation, aspiration and electrosurgical coagulation capabilities, which system also includes an impedance sensing network (10) and automatic feedback power output control to reduce RF power output as load impedance increases, thereby reducing RF leakage current.