Sherwood Services Ag

Covidien Ag

Raymond A Fredricks

William N Gregg

Thomas A Sturm

John Shanahan

John P Shanahan

A multiple RF return pad contact detection system is provided which is adaptive to different physiological characteristics of patients without being susceptible to electrosurgical current interference (e.g., interference or measurement interaction between components of the detection system). The detection system can measure or sense the contact resistance or impedance between the patient and pairs of RF return pads or return electrodes where multiple pairs of RF return pads are utilized due to the high current frequently needed during electrosurgery while eliminating or minimizing the risk of measurement interaction between the RF return pad pairs. The system allows for the independent and simultaneous measurement of the pad contact impedance for each pair of RF return pads. If the impedance of any pad pair is above a predetermined limit, the system turns off or reduces the electrosurgical output of the electrosurgical generator to prevent excess heating. The system eliminates or minimizes interference or measurement interaction between the pad pairs by providing a different signal source frequency for each pad contact pair, but a frequency which matches an associated series resonant network frequency. The current that flows in the series resonant network is a direct reflection or function of the pad impedance of the corresponding pad pair.

Multiple RF return pad contact detection system

A system and method for approaching the intervertebral disc through a percutaneous insertion from the back of a patient for thermal or electromagnetic treatment of an intervertebral disc, includes an elongated probe member having a guidable region adjacent its distal end with an undulating groove defined in its outer surface. The undulating groove is dimensioned to facilitate bending of the guidable region in at least one radial direction of movement relative to a longitudinal axis of the thermal probe. Preferably, the guidable region includes a plurality of undulating grooves, whereby adjacent undulating grooves are longitudinally spaced with respect to each other. The undulating grooves each define a sinusoidal configuration which may be arranged about an undulating axis extending in oblique relation to the longitudinal axis. The guidable region also includes a longitudinally extending backbone which resists bending of the guidable region in a radial direction of movement. The apparatus may also include a cannula to facilitate introduction of the thermal probe into the intervertebral disc. The cannula includes an arcuate end portion dimensioned to arrange the guidable region of the thermal probe at a desired orientation within the annulus fibrosis.

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Nashua, NH, United States of America

Raymond A Fredricks