Systems and methods employing radiofrequency energy for skin treatment
This disclosure relates generally to electrosurgical methods and devices. In one embodiment, an electrosurgical device is provided suitable for applying phase controlled RF energy to a treatment site. The electrosurgical device comprises a multi-electrode electrosurgical probe electrically coupled to a plurality of RF generators. Also provided are methods of use of such an electrosurgical device, as well as other electrosurgical devices. The methods and devices disclosed herein find utility, for example, in the field of medicine.
1. A system for heating tissue below the surface of the skin, the system comprising:
a probe including a surface configured to contact the surface of the skin;
at least three electrodes provided along the surface;
a power source configured to supply power to the electrodes and deliver RF currents to the tissue below the surface of the skin via at least three of the electrodes; and
a phase control unit arranged to control a phase between the RF currents to create regions of elevated temperature below the surface of the skin, the elevated temperature being with respect to the surface of the skin.
2. The system of claim 1 , arranged to deliver a first RF current below a second RF current.
3. The system of claim 1 , wherein the phase control unit is arranged to control the elevated temperature by controlling the phase between the RF currents.
4. The system of claim 1 , arranged to heat a skin volume extending between 0.1-50 μm below the skin surface to between 1-4000 μm below the skin, respectively.
5. The system of claim 1 , further arranged to deliver at least a part of the RF currents perpendicularly to the skin surface.
6. The system of claim 1 , arranged to heat a narrow skin volume with respect to a size of the probe holding the electrodes.
7. The system of claim 1 , arranged to heat a skin volume comprising at least a dermis region.
8. The system of claim 1 , arranged to heat a skin volume comprising at least a hair follicle or a hair.
9. The system of claim 1 , arranged to heat a plurality of focal regions in the heated tissue.
10. The system of claim 1 , wherein the phase control unit comprises a feedback loop with respect to at least one measured parameter.
11. The system of claim 10 , wherein the at least one measured parameter comprises at least one of: electrical impedance and/or admittance of the skin tissue, the currents flowing between electrodes, electrical potentials between the electrodes, output voltages and phases of the at least one generator, and phase differentials between the generators, when the power source comprises two or more generators.
12. The system of claim 10 , wherein the phase control unit comprises a phase locked loop (PLL) element.
13. The system of claim 1 , wherein the at least three electrodes are linearly arranged.
14. The system of claim 13 , wherein the at least three electrodes comprise at least a first pair of electrodes between electrodes of a second pair of electrodes.
15. The system of claim 13 , wherein the at least three electrodes comprise at least two pairs of electrodes having a common electrode.
16. The system of claim 1 , further comprising a vibration unit arranged to controllably vibrate at least a part of the probe holding the electrodes.
17. The system of claim 1 , further comprising a cooling unit arranged to cool the skin surface.
18. The system of claim 1 , further comprising an additional energy source arranged to apply to the skin at least one of: coherent or incoherent visible light, infrared radiation, ultraviolet radiation, and ultrasound.
19. A method of heating tissue below the surface of the skin, comprising:
delivering RF currents to a skin target via at least three electrodes associated with a probe and receiving power from a power source, and
controlling a phase between the RF currents to create regions of elevated temperature below the surface of the skin, the elevated temperature being with respect to the surface of the skin.
20. The method of claim 19 , further comprising delivering a first RF current below a second RF current.
21. An electrosurgical system comprising:
an electrosurgical probe for applying at least a heat treatment to tissue of a patient below the surface of the skin, the probe being configured to contact the surface of the skin and comprising at least one substantially straight row of electrodes, the at least one row of electrodes including at least a first electrode, a second electrode, and a third electrode; and
a generator comprising a plurality of RF outputs and phase controlling circuitry for controlling the phase therebetween, wherein connection between the RF outputs and the electrodes is configured such that at least two electrode pairings are formed, the at least two electrode pairings including a first pair comprising the first and second electrodes, and the second pair comprising the first and third electrodes,
wherein the phase controlling circuitry is configured such that the RF outputs apply a respective RF electrical potential across each pairing at a phase, and
wherein the phase between pairings results in electrical currents being established between at least one of the pairings at an angle to the surface of the skin causing heating of the tissue below the surface of the skin.
22. The System according to claim 21 , wherein the angle is substantially perpendicular.
23. The electrosurgical system of claim 21 , wherein the electrodes in cross section are substantially rectangular, and wherein the electrodes are disposed on the treatment surface such that there is at least between about 0.01 mm and about 25 mm between the centers of any two electrodes.
24. The electrosurgical system of claim 21 , wherein the RF energy causes elevation of the temperature within columns of the tissue, the columns of tissue being substantially perpendicular to a surface of the tissue.
25. The electrosurgical system of claim 21 , further comprising a means for adjusting the electrical currents in the living tissue in response to a measured characteristic of the current in the living tissue.
26. The electrosurgical system of claim 25 , wherein the measured characteristic is selected from the magnitude, time-integration, first derivative with respect to time, and second derivative with respect to time.
27. An electrosurgical system comprising:
an electrosurgical probe for applying at least a heat treatment to tissue of a patient below the surface of the skin, the probe being configured to contact the surface of the skin and comprise at least one substantially straight row of electrodes, the at least one row of electrodes including a first pair of electrodes and a second pair of electrodes, wherein the second pair of electrodes is arranged along the row to sandwich the first pair of electrodes; and
a generator comprising at least first and second RF outputs and phase controlling circuitry;
wherein each RF output provides power to a respective pair of the first and second pair of electrodes, the phase controlling circuitry being configured for effecting a phase between the first and second RF outputs such that electrical currents are established between at least the second pair of electrodes which are at an angle to the surface of the skin, and
wherein the electrical currents result in heating of the tissue below the surface of the skin for treatment thereof.
28. The System according to claim 27 , wherein the angle is substantially perpendicular.
29. The electrosurgical system of claim 27 , wherein the electrodes in cross section are substantially rectangular, and wherein the electrodes are disposed on the treatment surface such that there is at least between about 0.01 mm and about 25 mm between the centers of any two electrodes.
30. The electrosurgical system of claim 27 , wherein the RF energy causes elevation of the temperature within columns of the tissue, the columns of tissue being substantially perpendicular to a surface of the tissue.
31. The electrosurgical system of claim 27 , further comprising a means for adjusting the electrical currents in the living tissue in response to a measured characteristic of the current in the living tissue.
32. The electrosurgical system of claim 31 , wherein the measured characteristic is selected from the magnitude, time-integration, first derivative with respect to time, and second derivative with respect to time.