title: A spark counter as a control unit of a radio frequency surgery device.
abstract: A new approach in radio frequency (rf) electrosurgery, used for tissue treatment, is achieved by using a new process control method. An external control unit allows a commonly available rf-generator to automatically supply the appropriate power for differing tissue types, thus ensuring best cutting quality. The sparks, generated during the scalpel electrode interaction with the tissue, appear statistically distributed. The spark rate depends on various factors and is monotonic with the supplied electrical power. This allows it to be used as the controlled variable in the cutting process. The ac current passing through the tissue is evaluated by an external control unit using an analyzation algorithm to determine the number of sparks. The external unit is comprised of a system, which measures the spark rate, and a subsequent proportional integral (P.I.) controller. The functionality of the control method as well as the electrical circuitry is verified through cuts with different degrees of carbonization and cuts through tissue heterojunctions.
authors.affiliation: SIMEC, Dresden, Germany. Helmut-Dr.Wurzer@hl.siemens.de
authors.forename: H
authors.initials: H
authors.lastname: Wurzer
authors.forename: R
authors.initials: R
authors.lastname: Maeckel
authors.forename: J
authors.initials: J
authors.lastname: Lademann
authors.forename: H
authors.initials: H
authors.lastname: Audring
authors.forename: H D
authors.initials: HD
authors.lastname: Liess
mesh_terms: D000273:Adipose Tissue / Q000601:surgery; D000818:Animals; D004553:Electric Conductivity; D004566:Electrodes; D004598:Electrosurgery / Q000295:instrumentation*; D004867:Equipment Design; D066298:In Vitro Techniques; D018482:Muscle, Skeletal / Q000601:surgery; D013552:Swine