Systems and methods for creating an effect using microwave energy to specified tissue

• US 8,401,668 B2
• Filed: 09/27/2011
• Issued: 03/19/2013
• Est. Priority Date: 04/19/2007
• Status: Active Grant

• Current Assignee: miraDry, Inc. (Sientra Incorporated)
• Original Assignee: Miramar Labs, Inc. (Sientra Incorporated)
• Inventors: Deem, Mark E., Francis, Dan, Johnson, Jessi Ernest, Kim, Steven, Salamini, Alexey, Su, Ted, Smith, Peter, Hallock, Dan
• Primary Examiner(s): Lucchesi, Nicholas
• Assistant Examiner(s): Price, Nathan R
• Application Number:
  US13/246,341
• Publication Number:
  US 20120010609A1
• Time in Patent Office: 539 Days
• Field of Search: 607 96-102
• US Class Current: 607/101
• CPC Class Codes: A61B 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 2018/00005 Cooling or heating of the probe or tissue immediately surrounding the probe
• CPC Class Codes: A61B 2018/00023 closed, i.e. without wound contact by the fluid
• CPC Class Codes: A61B 2018/00029 open
• CPC Class Codes: A61B 2018/00041 Heating, e.g. defrosting
• CPC Class Codes: A61B 2018/00291 using suction
• CPC Class Codes: A61B 2018/0047 Upper parts of the skin, e.g. skin peeling or treatment of wrinkles
• CPC Class Codes: A61B 2018/00779 Power or energy
• CPC Class Codes: A61B 2018/0091 Handpieces of the surgical instrument or device
• CPC Class Codes: A61B 2018/1823 Generators therefor
• CPC Class Codes: A61B 90/37 Surgical systems with images on a monitor during operation
• CPC Class Codes: A61F 2007/0075 using a Peltier element, e.g. near the spot to be heated or cooled
• CPC Class Codes: A61N 2005/007 for cooling the patient
• CPC Class Codes: A61N 5/02 using microwaves
• CPC Class Codes: A61N 5/04 Radiators for near-field treatment

Abstract

Systems, methods and devices for creating an effect using microwave energy to specified tissue are disclosed. A system for the application of microwave energy to a tissue includes a signal generator adapted to generate a microwave signal having predetermined characteristics, an applicator connected to the generator and adapted to apply microwave energy to tissue. The applicator includes one or more microwave antennas and a tissue interface, a vacuum source connected to the tissue interface, a cooling source connected to the tissue interface, and a controller adapted to control the signal generator, the vacuum source, and the coolant source. The tissue includes a first layer and a second layer, the second layer below the first layer. The controller is configured so that the system delivers energy such that a peak power loss density profile is created in the second layer.

Claims

1. A method of creating a lesion in a dermal layer of skin wherein the skin has at least a dermal layer and a sub-dermal layer, the method comprising the steps of:

positioning a device adapted to radiate microwave energy adjacent an external surface of the skin;

radiating microwave energy having an electric field component which is substantially parallel to a region of the external surface of the skin above the dermal layer, wherein the microwave energy has a frequency which generates a standing wave pattern of microwave energy in the dermal layer, the standing wave pattern having a constructive interference peak in the dermal layer proximal to an interface between the dermal layer and the sub-dermal layer; and

heating a portion of the dermal region in close proximity to the interface using the radiated microwave energy to create the lesion.

2. The method of claim 1, wherein the microwave energy radiates in a TEM mode.

3. The method of claim 1, wherein the microwave energy has a frequency of approximately 5.8GHz.

4. The method of claim 1, wherein the microwave energy generates heat in the target tissue by dielectric heating.

5. The method of claim 2, wherein the electromagnetic energy radiates in a TE10 mode.

6. A method of heating a sweat gland located in or near an interface between a dermal layer and sub-dermal layer in skin, wherein the dermal layer consists of a first, upper dermal layer and a second, lower dermal layer, the upper dermal layer being adjacent a skin surface, the method comprising the steps of:

irradiating the upper dermal layer and the lower dermal layer through the skin surface with electromagnetic energy having predetermined frequency and electric field characteristics; and

generating a power loss density profile wherein the power loss density profile has a peak power loss density in the lower dermal layer.

7. The method of claim 6, wherein the power loss density is generated by a standing wave pattern of electromagnetic energy having a single peak in the lower dermal layer.

8. The method of claim 7, wherein the standing wave pattern is created by the reflection of at least a portion of the electromagnetic energy off of the interface.

9. The method of claim 8, wherein the standing wave pattern has a constructive interference peak in the lower dermal layer.

10. The method of claim 9, wherein the upper dermal layer is protected by cooling the outer surface of the skin.

11. The method of claim 10, wherein tissue, including sweat glands are heated by heat generated in the region of dermis having the peak power loss density.

12. The method of claim 11, wherein heating the sweat glands results in a reduction in the symptoms of hyperhidrosis.

13. A method of raising the temperature of at least a portion of a tissue structure located below an interface between a dermal layer and sub-dermal layer in skin, the dermal layer having an upper portion adjacent an external surface of the skin and a lower portion adjacent a sub-dermal region of the skin, the method comprising the steps of:

radiating the skin with microwave energy having a predetermined power, frequency and e-field orientation;

generating a peak energy density region in the lower portion of the dermal layer;

initiating a lesion in the peak energy density region by dielectric heating of tissue in the peak energy density region;

enlarging the lesion, wherein the lesion is enlarged, at least in part, by conduction of heat from the peak energy density region to surrounding tissue;

removing heat from the skin surface and at least a portion of the upper portion of the dermal layer; and

continuing to radiate the skin with the microwave energy for a time sufficient to extend the lesion past the interface and into the sub-dermal layer.

14. The method of claim 13, wherein the e-field component of the microwave energy is substantially parallel to at least a portion of the skin surface through which the e-field passes.

15. The method of claim 13, wherein the energy density region results from a standing wave pattern of microwave energy generated by reflection of at least a portion of the microwave energy off an interface between a dermal and hypodermal layer.

16. The method of claim 15, wherein the standing wave pattern has a constructive interference minimum in the first tissue layer.

17. The method of claim 13, wherein the frequency is between approximately 5 GHz and 6.5 GHz.

18. The method of claim 17, wherein the frequency is approximately 5.8 GHz.

19. The method of claim 13, wherein the tissue structure is a sweat gland.