Patent ID: 7785322

Claim:
A tissue treatment system comprising: a radio frequency (r.f.) generator; a treatment instrument connectible to the generator and to a source of ionisable gas and operable to produce a plasma jet at a nozzle of the instrument when supplied with the ionisable gas and energised by the generator; and a calibration device that comprises: a target element having a target surface area; a transducer arranged to produce an electrical signal indicative of a temperature change of the target element within the target surface area; a receptacle for locating the nozzle of the instrument in juxtaposition with the target surface area whereby, in operation of the instrument when the nozzle is in the receptacle, the plasma jet is incident upon the target surface area to cause the transducer to generate a calibration signal for adjusting the energy output of the generator; and an output connected to the generator for coupling the calibration signal to the generator; wherein the generator includes an energy output adjuster for adjusting the r.f. energy output of the generator, the adjuster being configured to adjust the r.f. energy output in response to the calibration signal.