Method and Apparatus for Treatment of Adipose Tissue

Abstract

The invention provides methods and apparatuses (4) for the treatment of adipose tissue. The methods comprise application of ultrasound energy to a region of adipose tissue, and the apparatuses comprise at least one source of ultrasound energy (42a, 42b) configured to direct ultrasound energy through a skin surface into the subcutaneous adipose tissue. In one embodiment, a pressure gradient is created in the region generating relative movement between fat cell constituents having different densities. In another embodiment, a protrusion of skin and underlying adipose tissue containing is formed and ultrasound energy is radiated into the adipose tissue in the protrusion. In another embodiment, an RF electric field is generated inside a region of adipose tissue together with the ultrasound energy.

Description

FIELD OF THE INVENTION[0001]The invention relates to methods and apparatuses for the reduction of adipose (fat) tissue.LIST OF REFERENCES[0002]The following references are brought to facilitate description of the background of the present invention, and should not be construed as limiting the scope or patentabililty of the invention:U.S. Pat. No. 5,143,063[0003]U.S. Pat. No. 5,158,070[0004]US Patent Applications Nos. 2005 / 0154431 and 2004 / 0106867[0005]U.S. Pat. No. 6,607,498[0006]U.S. Pat. No. 6,113,558[0007]U.S. Pat. No. 6,889,090[0008]U.S. Pat. No. 5,871,524[0009]U.S. Pat. No. 6,662,054[0010]S. Gabriel, R. W. Lau, and C. Gabriel, Phys. Med. Biol. 41 (1996), pp 2251-2269[0011]Luc Fournier and Be'la Joo's, Physical review 67, 051908 (2003)[0012]Alster T. S. and Tanzi, E. L., The Journal of Cosmetic and Laser Therapy. 2005; 7: 81-85[0013]“Physical properties of tissue”, by Francis A. Duck, Academic Press Ltd., 1990, p. 138.[0014]“Physical properties of tissue”, by Francis A. Duck, Ac...

AI Technical Summary

Benefits of technology

[0041]For a non-plane wave, kPmax in equation 7 must be replaced by the more general pressure gradient, ΔP, in accordance with Euler's equation. It is known to use focusing of the ultrasound energy to generate very high power densities in a focal volume. It helps in two ways: first, it facilitates production of high power densities by an ultrasound transducer, and, second, it generates geometrical selectivity for the desired effect at the focal volume. However it should be noted that focusing, especially strong focusing, enhances the peak pressure substantially more than the pressure gradient. As a limiting example, a spherical transducer will generate at its center a very high peak pressure but zero pressure gradient, a manifestation of the fact that at the center the fluid is not moving. The focusing may be described physically as a superposition of plane waves. The pressure amplitude is a scalar, and at the focus the phases of the plane waves are identical, therefore the pressure at the focus is a scalar sum of the pressure amplitudes. However, the pressure gradient, and the displacement which is proportional to that gradient (by Euler's equation), are vectors, therefore their vector summed amplitude is always smaller than the sum of the magnitudes. More specifically, for strong focusing, the ultrasound radiation arrives at the focus from directions with large angular deviations, reducing the vector sum of the pressure gradient and of the fluid displacement. Therefore, according to the invention, it is preferred to limit the focusing in order to enhance the pressure gradient at the expense of the pressure amplitude at the focus, so that the selective effects on the fat cell will be obtained without the undesired effects associated with high pressure, such as cavitations.

Problems solved by technology

One method, liposuction, is a very aggressive invasive treatment requiring local or general anesthesia, and the subsequent healing process is very long and painful.

The main challenge with non-invasive treatment of fat tissue is to transfer the energy through the outer layers of the skin, and concentrating it to the required level in the fat tissue with minimal collateral damage to the skin layers and deeper body tissues.

This method of cell rupturing is also not selective for adipose tissue cells (adipocytes) because the adipocyte membrane is not weaker than that of other cells.

Under certain critical conditions, the bubbles collapse violently, generating in their vicinity shock waves and fluid jets that can destroy cells.

However, it is less efficient for treatment of the deeper adipose layers.

Typically the width of the cytoplasm is only a few micrometers and it is not uniform around the lipid vacuole.

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