TECHNICAL FIELD

The present invention relates to medical devices and apparatuses. More in particular, the invention relates to improvements to devices and apparatuses for removing adipose layers.

BACKGROUND ART

Nowadays, in the aesthetical treatment field the techniques for selective removal of adipose tissue have great significance. To this end, various methods have been developed over the years, some of which are based on invasive surgery. In less recent times, a treatment called liposuction was widely used, allowing to eliminate fat portions through suction, wherein small cannulas are inserted through tiny cuts (some mm wide) in the skin achieving the adipose tissue to be removed or reduced and sucking fat. The suction may be performed manually by means of syringes, or using suitable sucking devices. In some cases, the suction may be combined with local application of ultrasounds, vibrations, or water jets in order better to liquefy fat.

As it is an invasive surgery, local or general anesthesia is used, based on the amount and distribution of the adipose tissue to be removed.

In some cases, in order to liquefy the adipose tissues a lipolysis treatment is performed, wherein liquids (for example soy lecithin) are injected into the adipose layers to be removed, the liquids being suitable to cause adipocytes lysis, i.e. the destruction of the cell membranes and therefore the liquefaction of adipocytes. The biological material resulting from lipolysis is then gradually absorbed by the organism.

More recently, laser-assisted liposuction techniques have been developed, wherein the adipocytes are sucked by means of a sucking cannula after having liquefied the fat by means of laser energy conveyed in the tissues by means of an optical fiber introduced through a cannula. In some cases, laser-assisted adipocytes lipolysis is performed and then the resulting biological material is metabolized by the organism instead of being removed by suction.

Methods and devices for laser-assisted lipolysis are disclosed in U.S. Pat. No. 6,206,873.

An alternative method uses cooling by means of plates surrounding folds of abdominal tissue constituted by derma and subcutaneous fat. The exposure to cooling for a certain time causes adipocytes damages and, thus, the cell death of subcutaneous fat tissue. The fat is then gradually eliminated by the organism.

Already in less recent times, methods have been proposed for adipocytes lipolysis by means of percutaneous energy delivery. U.S. Pat. No. 5,143,063 discloses, for example, an energy delivery device to be applied to the skin. The energy passes through the derma, achieves the underlying fat layers and causes adipocytes destruction. In this prior art document the use of different energy forms is disclosed, for example ultrasounds or microwave electromagnetic energy.

WO-A-96/40369 discloses an apparatus and a handpiece for fat removal through microwaves. The handpiece has a matrix of antennas generating converging microwave beams in order to achieve a desired temperature in the subcutaneous adipose layers.

EP-A-2767308 (corresponding to US-A) discloses devices and systems for microwave energy delivery in order to remove subcutaneous adipose layers. In an embodiment described in EP-A-2767308, a horn antenna is provided with an inner conductor of small diameter and a horn-shaped outer conductor of increasing diameter, ending with an edge whose diameter is more than tenfold greater than the diameter of the inner conductor. The horn-shaped outer conductor protrudes, with respect to the inner conductor, by a multiple of the inner conductor diameter.

These known devices for percutaneous delivery of radiant energy have the advantage of allowing substantially non-invasive treatments, but they are not particularly effective.

There is therefore the need for providing devices and apparatuses allowing lipolysis treatments that are non-invasive but effective.

Subcutaneous fat accumulations is also present in subjects affected by cellulite. Cellulite is a topographical alteration of the skin associated with depressions or introflexions, frequent in the pelvic and abdominal area, hips, buttocks and thighs. The typical unsightly appearance of cellulite is known as the “orange peel” effect, as the skin is covered in small indentations or dimples that resemble the skin of an orange. Orange peel skin consists of a series of fat accumulations (fat lobules) surrounded by bands of fibrous connective tissue (interlobular septa), present under the skin, which are also visible to the naked eye as they push up toward the outer skin layer causing a “bulging” effect.

SUMMARY OF THE INVENTION

According to a first aspect, a device for delivering radiofrequency energy is provided, comprising an outer conductor and an inner conductor arranged approximately coaxial with each other, wherein the outer conductor surrounds the inner conductor, so as to form an open-ended coaxial line. The open-ended coaxial line is connected, through a coaxial cable, for example, to a radiofrequency generator, typically a radiofrequency electromagnetic field generator. When connected to the radiofrequency generator, the outer conductor and the inner conductor, arranged and configured so as to form the open-ended coaxial line, generate an electromagnetic field with lines of force extending from a front surface of the inner conductor to a front surface of the outer conductor. When the open-ended coaxial line interfaces with the skin surface of a patient to be treated, the electromagnetic field spreads therefrom. By putting the delivery device into contact with the skin area where the underlying adipose layer shall be eliminated or removed (through a mechanism comprising adipocytes lysis and/or destruction by triggering of the apoptosis mechanism), an electric field propagates in the tissues below the area where the delivery device has been applied to the skin, according to lines of force extending approximately orthogonally with respect to the tissue layers, i.e. approximately orthogonally to the interface surfaces between epidermis and adipose layer, as well as between adipose layer and muscle tissue.

Consequently, the current crosses sequentially, i.e. serially, the various layers, causing greater heat dissipation and therefore greater heating in the tissues having more resistivity. These tissues are indeed the adipose layers, where, consequently, the transformation of electric energy into thermal energy is concentrated, with consequent localized temperature increase.

Practically, the delivery device may have an energy delivery window arranged in front of the outer conductor and the inner conductor. The delivery window may be embodied by a plate of a dielectric material which is transparent to the electromagnetic radiation frequency used for these applications. Advantageously, the used material is preferably also a good thermal conductor.

The window may be cooled, for instance by a coolant, which is dielectric in order to low electric losses and a good thermal conductor, and which flows along the inner surface of the closing plate, in order to avoid the risk of burns, as well as any feeling of localized overheating. In fact, the passage of radiofrequency energy through epidermis and derma causes therein heat production due to the transformation of electromagnetic energy into thermal energy and the consequent heating of the crossed tissues. The cooled window into contact with the epidermis removes heat and keeps the tissue temperature within acceptable values.

According to a further aspect, the invention also relates to a radiofrequency energy delivering apparatus, comprising a radiofrequency generator, a connector and a delivery device as described above.

According to a further aspect, a method is described for removing adipose layers, comprising the following steps:

applying a delivery device of the type described above to an epidermis portion, below which the adipose layers to be eliminated or reduced are located;

by means of the delivery device generating a radiofrequency electromagnetic field in a tissue volume below the epidermis portion, which has lines of force that extend approximately orthogonally with respect to the epidermis and that sequentially cross the epidermis, the derma and the adipose tissue below the derma.

In this way, a current flow is generated by the electromagnetic field, causing localized heating of the adipose tissue up to a temperature sufficient to cause the immediate lysis of some adipocytes and/or the subsequent destruction, through the apoptosis mechanism, of at least part of the adipocytes forming the adipose tissue.

Further advantageous features and embodiments of the delivery device, of the apparatus using it, and of the method according to the invention are described hereafter with reference to the attached drawing, which shows a non-limiting practical embodiment of the invention, and in the attached claims, forming an integral part of the present description.

