Clinical vignette. Renal arteriovenous malformation in a quarter horse foal.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
R D Tucker
Publications and source records attributed to R D Tucker.
Capacitive coupled stray currents during laparoscopic and endoscopic electrosurgical procedures.
Capacitively coupled currents may not be appreciated during laparoscopic and endoscopic radiofrequency electrosurgery. Two specific problems are documented and quantified: coupling of current into metal trocar cannulas during laparoscopic surgery and coupling of current into a guide wire during endoscopic surgery. The examples can yield power levels in excess of 25 watts (laparoscopic) and 15 watts (endoscopic) on nearby metal conductors, which can in turn be dissipated into patient organs such as the bowel or the common bile duct. This capacitive coupling can be, in part, responsible for serious patient complications. Methods to minimize capacitive coupling, e.g., active electrode shielding, dispersive metal cannulas, sheathed guide wires, and bipolar active electrodes, are discussed for each example.
Electric Conductivity↗
Direct-current potentials created by arcing during monopolar radiofrequency electrosurgery.
Muscle and nerve stimulation during radiofrequency electrosurgery has been a well-known phenomenon for over 50 years. However, as electrosurgery expands into new procedures, such as tissue ablation in the heart, the mechanism of the potentially deleterious stimulation becomes more important. This article presents data showing that large DC currents are generated during electrosurgery and that these potentials increase with increasing sparking at the active electrode. The data also show DC potentials generated by various generators, different operation modes (cut, coagulation, fulguration), and operations on tissues of various impedances.
Electric Conductivity↗
A simple and inexpensive method for measuring electrosurgical variables.
A simple circuit that demodulates the high-frequency output of an electrosurgical generator to proportional DC values can be employed to monitor generator voltage and electrosurgical current. An example of the use of the circuit in a urologic application is given. Employing this monitoring circuit, quantitative comparisons of electrosurgical equipment and performances can be made.
Electricity↗
A miniature current probe for measuring electrosurgical currents.
The measurement of high-frequency electrosurgical currents at the surgical site is complicated by a generator output circuit isolated from ground, as well as radiation and displacement current losses along connecting wires. An inductive probe can accurately measure the actual electrosurgical current at the active electrode.
Animals↗