Circuit for radiofrequency devices applicable to living tissues and device containing same

• US 8,465,483 B2
• Filed: 05/26/2008
• Issued: 06/18/2013
• Est. Priority Date: 06/20/2007
• Status: Active Grant

• Current Assignee: INDIBA, S.A.
• Original Assignee: INDIBA, S.A.
• Inventors: Buisan Escartin, Jorge, Lario Garcia, Javier, Calbet Benach, Jos
• Primary Examiner(s): Dvorak, Linda
• Assistant Examiner(s): Ram, Jocelyn D
• Application Number:
  US12/665,180
• Publication Number:
  US 20100198213A1
• Time in Patent Office: 1,849 Days
• Field of Search: 606/32, 606/34, 606/41
• US Class Current: 606/34
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• CPC Class Codes: A61B 2018/128 generating two or more frequencies
• CPC Class Codes: A61B 2018/1293 having means to prevent interference
• CPC Class Codes: H03H 7/0115 comprising only inductors and capacitors H03H7/075, H03H7/09, H03H7/12, H03H7/13 take precedence
• CPC Class Codes: H03H 7/175 Series LC in series path H03H7/1783 takes precedence
• CPC Class Codes: H03H 7/1775 Parallel LC in shunt or branch path H03H7/1791 takes precedence

Abstract

The supply circuit for the electrodes comprises a series resonant filter and a parallel resonant filter, tuned to admit the fundamental signal of the input signal and simultaneously and exponentially attenuate the remaining harmonics by increasing the frequency thereof, in such a way that the input signal with harmonics only passes the fundamental signal without attenuation to the output, while the harmonics causing interferences are increasingly attenuated as their frequency is raised.

Claims

1. A circuit for supplying output electrodes of a radiofrequency device applicable to living tissues, said circuit comprising:

a transformer having a primary winding, a secondary winding, and a turn ratio of 1;

N, where N is a real number;

a resonant serial filter connected to the primary winding of the transformer having an inductor L_S1 connected in series with a capacitor C_S1; and

a resonant parallel filter connected to the secondary winding of the transformer having an inductor L_p connected in parallel with a capacitor C_P;

wherein the resonant serial filter and the resonant parallel filter allow a fundamental signal of an input signal, which includes harmonics, to simultaneously pass through and exponentially attenuate the harmonics as a frequency of said harmonics increases, and

wherein an output frequency of said circuit is varied such that a combined impedance of a plurality of output electrodes connected to the circuit, and living tissue in contact with the output electrodes matches an impedance of the circuit.

2. The circuit of claim 1, wherein the inductor L_P of the resonant parallel filter is the parasitic inductance of the secondary winding of the transformer.

3. The circuit of claim 1 including anti-stimulus capacitors C_S2—

_CAP, C<sub>S2—

RES</sub> at each output electrode, each of said anti-stimulus capacitors C<sub>S2—

CAP</sub>, C<sub>S2—

RES</sub> having a corresponding inductor L_S2-CAP, L_S2-RES connected in series, the inductors L_S2-CAP, L_S2-RES having values that resonate at a fundamental frequency of the input signal.

4. The circuit of claim 1, wherein the inductor L_S1 and the capacitor C_S1 of the resonant serial filter have a first impedance to the fundamental frequency of the input signal and a second impedance to the harmonics of the input signal, the first impedance being lower than the second impedance.

5. The circuit of claim 1, wherein the inductor L_P and the capacitor C_p of the resonant parallel filter have a first impedance to the fundamental frequency of the input signal and a second impedance to the harmonics of the input signal, the first impedance being higher than the second impedance.

6. The circuit of claim 1, wherein the radiofrequency device is a diathermy device.

7. The circuit of claim 1, wherein the radiofrequency device is an electroscalpel device.