Apparatus and methods for the destruction of adipose tissue
View Patent ↗Methods and apparatus are described for modifying unwanted tissue for cosmetic reasons. The methods provide a non-invasive manner to perform body contouring by destroying adipose tissue while simultaneously causing collagen contraction in a single procedure so that as destroyed tissue is removed from a treatment volume, the volume shrinks gradually to maintain the skin tone of the treatment area.
1. A method of modifying adipose tissue in a patient using high intensity focused ultrasound, the method comprising the steps of:
determining a volume of adipose tissue to be treated;
identifying a corresponding surface area of skin over said volume of adipose tissue;
marking the patient's skin to create a plurality of guide markers at a predetermined spacing on the patient's skin within the surface area;
moving a HIFU therapy transducer successively from guide marker to guide marker on said surface area of skin; and
applying therapeutic ultrasound energy into said volume of adipose tissue at a power and for a time at each of said guide markers, wherein the power and time of applying said energy and the spacing of said guide markers are selected such that a plurality of necrosed tissue cells and denatured collagen fibrils are produced within a plurality of adjacent treatment cells covering substantially all of the treatment volume.
2. The method as described in claim 1 , wherein moving the HIFU therapy transducer is performed in a raster scan pattern.
3. The method as described in claim 1 , wherein the plurality of cells form a contiguous lesion field.
4. The method as described in claim 1 , wherein the moving the transducer is done in a continuous motion.
5. The method as described in claim 1 , wherein the moving the transducer is done in a discontinuous motion.
6. The method as described in claim 1 wherein moving the HIFU transducer is done while applying therapeutic ultrasound energy.
7. The method as described in claim 1 , wherein moving the HIFU transducer is done when the transducer is not applying ultrasound energy.
8. The method as described in claim 1 , wherein the applying of therapeutic ultrasound energy raises the temperature of the focal zone to at least 46° C.
9. The method as described in claim 1 , wherein the applying of therapeutic ultrasound energy raises the temperature of the adipose tissue to at least 56° C. for at least one second.
10. The method of claim 1 , wherein the thermal energy may be measured as an energy flux (EF) and determined by the relationship:
[(p)×(l/v)×(dc)×(nl)]/(sa)
wherein
p=power,
l=line length,
v=velocity,
dc=duty cycle,
nl=number of lines
and
sa=scanned area.
11. The method of claim 10 , wherein the energy flux is between 35 J/cm 2 and 460 J/cm 2 .