Disposable protection system for capacitive radiofrequency delivery devices

Abstract

A disposable device designed to enhance the safety of capacitive radiofrequency treatment is described, which can prevent risks arising from lesions present on the dielectric surface of the insulated electrodes or on the stratum corneum of the skin, risks arising from the use of technology that was on the market before the requirement for non-cytotoxic certification (ISO10993:2018) of parts applied to patients, as well as the risk of contamination of parts applied in treatments previously performed on other patients.

Description

[Technical Field]

[0001] The present invention relates to the field of capacitive radiofrequency delivery devices useful for stimulating skin repair and regeneration. [Background technology]

[0002] Capacitive radiofrequency (RF) is known in the art for its ability to regenerate skin, i.e., promote the growth and rebuilding of skin layers that have become physiologically degraded due to chronological aging or as a result of trauma, wounds, and already healed injuries (abrasions, post-surgical scars, acne, burns), as well as for regenerating muscle fibers in sports medicine.

[0003] During the 21st century, capacitive radiofrequency has become established in the field of aesthetic medicine and aestheticians, becoming one of the most popular anti-aging therapies, and in the field of sports medicine it is of course the treatment of choice in the sequelae of muscle injuries and tendonitis.

[0004] Capacitive radiofrequency waves are known to perform their regenerative function by acting on the skin in a manner similar to that of a capacitor. To achieve this, two opposing conductors coated with an insulator are required. In aesthetic and sports medicine applications, insulated electrodes are used, consisting of a conductor through which the radiofrequency waves generated by a specific device are transmitted. The conductor is completely covered with an insulating material (e.g., plastic, glass, or resin). Such insulated electrodes are applied to intact skin, where the dermis has low electrical resistance and therefore functions as a conductor, while the highly resistive stratum corneum is an insulator. This combination therefore allows the concept of a capacitor to be applied to the skin, where ionic exchange is activated in relation to the charge present in the insulated electrode.

[0005] As shown in Figure 1, capacitive RF is based on the concept of a capacitor, where the central conductive core 51 of the insulated electrode 50 and the dermis 54 act as the conductors, and the dielectric coating 52 and stratum corneum 53 act as the electrical insulators. The integrity of the electrical insulators 52 and 53 is essential for the safe delivery of capacitive RF.

[0006] Capacitive radiofrequency has been associated with rare side effects such as burns, possibly due to either the loss of the insulating electrode cover or damage to the stratum corneum; moreover, the creation of safety standards has mandated the guarantee that the components applied to the patient, in this case the insulated electrodes, are non-cytotoxic, without forgetting the need to ensure maximum hygiene during treatment, a requirement that has become particularly acute since the COVID-19 pandemic.

[0007] We know that even a slight surface fracture of the insulation covering an insulated electrode can expose the patient to the risk of direct RF discharge. If the integrity of the insulating cover is lost, delivery becomes resistive rather than capacitive, no longer distributed over the electrode's surface, but can instead be concentrated in the fractured area. This, of course, can lead to a variety of consequences, ranging from intense redness and erythema to skin burns, similar to the action of electrocautery. Thus, in Figure 2, we consider an insulated electrode 50 consisting of a core (possibly of different sizes, shapes, and radii) made of metal or other conductive material 51, covered by insulating material 52 with a surface fracture point 55. In this case, the conductor 51 contacts the stratum corneum 53, determining a RF discharge 56 directed toward the skin (53, 54), resulting in cauterization 57.

[0008] Similarly, the safety of treatment can be compromised by imperfections in the stratum corneum. Indeed, lesions in the stratum corneum determine local changes in the resistance of the insulating dermis, increasing the concentration of ionic charges in the skin directly beneath such lesions and exposing the patient to a greater or less severe risk of burns. We know that charges actually move according to a clear rationale. If there is a negative charge in the insulated electrode, all ions with opposite charges present in the skin, such as Na+ and K+, tend to be attracted to the electrode, while ions with the same charge, such as Cl-, tend to recede. The opposite is true for positive charges in the insulated electrode. The attractive force, which is exerted evenly across the entire surface of an intact shielded electrode, is concentrated; in contrast, the electrical resistance in this area is low or zero, thereby reducing the integrity of the stratum corneum. Therefore, the risk of the concentration of intradermal ionic charges becoming greater than the resistance of an incompletely intact stratum corneum is well known, potentially damaging the stratum corneum itself from the inside, leading to first-degree burns and subsequent hypotrophic scars. In Figure 3, we consider an insulated electrode 50 consisting of a conductor 51 temporarily supplied with a negative charge, coated with an insulating material 52, and placed in contact with the stratum corneum 53. On the left side of the diagram, we consider a lesion 58 in the stratum corneum, which reduces its thickness and proportionally reduces its electrical resistance. As a result of this lesion, an oppositely charged molecule, e.g., sodium (Na + ) and potassium (K + ) are attracted to the skin, and they tend to concentrate where they find less resistance. This results in the results shown on the right side of the diagram: first a thermal injury, then the formation of an atrophic scar 59.

[0009] Another major risk arising from the application of capacitive RF is posed by the nature and quality of the insulation used to cover the insulated electrodes. The latest edition of ISO 10993 analyzes the risk of cytotoxicity in components applied to patients, in this case insulated electrodes, and provides higher safety standards than previously provided (ISO 10993-1:2018 Biological Evaluation of Medical Devices, Part 1: Evaluation and Testing in the Risk Management Process). The insulating materials typically used to create the outer shield of insulated electrodes (resins and plastics) generally do not qualify as non-cytotoxic and therefore may accelerate cell death in the skin they come into contact with, which is precisely counterproductive to the skin regeneration that capacitive RF is intended to achieve.

[0010] While manufacturers of capacitive RF delivery devices are able to source ISO 10993 certified materials, there is still a risk of using previously commercially available insulated electrodes, whereby newer versions of insulated electrodes may not be available, for example, due to models of capacitive RF generators and insulated electrodes that are outdated, discontinued, or manufactured by companies that are no longer on the market.

[0011] Finally, there is a small risk of contamination of the shield electrode as a result of application to a previous patient. The nature of the shield electrode's cover prevents it from being sterilized in an autoclave, as both the resin and plastic materials melt. In these cases, the use of alcohol-based disinfectants is not recommended, so regular disinfection of the electrode is also not easy. Residues on the surface of the insulated electrode expose the patient to the risk of irreversible hardening of the skin capillaries, with obvious aesthetic (ectasia, couperose, capillary fragility, etc.) and functional consequences.

[0012] It is well known that in electronic devices, failure of just one of the two opposing inner insulators of a capacitor, which in this case corresponds to the insulating electrode cover or the stratum corneum, can result in an internal discharge from one conductor to the other, which can even lead to the explosion of the capacitor.

[0013] Indeed, in medicine, the failure of just one of the two insulators (dielectric cover of the electrode and the stratum corneum) exposes one to the same risk of discharge from one conductor to the other, resulting in the skin damage mentioned above. It should be noted that although the reported risks are rare, they are known in the scientific literature and various publications describe the damage caused to skin tissue without questioning its cause and accept them as a statistically likely event.

[0014] For further confirmation, please note that the capacitive radiofrequency delivery device user manual reports: 1. Treatment should not be performed with a shield electrode that is not completely intact. 2. If the shield electrode is not completely intact, it should be replaced with a similar one. 3. Treatment should not be performed on skin tissue that is not completely intact.

[0015] In fact, the problem of failure of only one of the two insulators is known in the art, but currently the only solution available is to discard any electrode that is not fully intact or that does not provide treatment of the stratum corneum, even if it is only partially damaged.

[0016] Therefore, it is currently not possible to apply capacitive radiofrequency waves to damaged skin tissue, such as ulcers, fistulas, sores, etc.

[0017] The objective of the present invention is to provide a system that improves the safety of capacitive RF delivery devices to comply with the requirements of the ISO 10993 standard, avoids the disposal of damaged electrodes, avoids contamination of electrodes when applied sequentially to different patients, and allows for the application of capacitive RF to non-intact skin tissue.

[0018] (Definitions and Abbreviations) RF: Radio frequency [Prior art documents] [Patent documents]

[0019] [Patent Document 1] International Publication No. 2007 / 096009 [Patent Document 2] International Publication No. 2019 / 049105 Summary of the Invention

[0020] The present invention solves the above problems by providing a specially adapted insulating protective shield made of a non-cytotoxic dielectric material and configured to be interposed between the insulated electrodes of a capacitive RF delivery device and the skin surface of a patient being treated.

[0021] Surprisingly, the shielding subject matter of the present invention makes it possible to eliminate the risks arising from capacitive radiofrequency treatments performed on patients with a non-intact stratum corneum using insulated electrodes that are not completely intact, and the risks arising from employing insulated electrodes that may be cytotoxic, i.e. not certified according to the ISO 10993 standard, as well as the risks of contamination arising from applying a shielding electrode to a previously treated patient.

[0022] The shielding objective of the present invention is to restore the integrity of the insulating electrodes and the stratum corneum, ensuring that the applied components are non-cytotoxic and free of contamination resulting from treatments administered to previous patients.

[0023] Surprisingly, the protective insulating shield of the present invention allows for capacitive RF to be used to treat and therefore heal ulcers that cannot be healed by any type of medical treatment.

[0024] In one aspect, the present invention relates to the above-mentioned protective insulating shield for medical use in treating damaged and non-intact skin tissue, preferably selected from the group consisting of ulcers, sores and fistulas, by applying capacitive RF. [Brief explanation of the drawings]

[0025] [Figure 1] 10 shows a schematic representation of a capacitor between an insulated electrode and the patient's skin. [Figure 2] 1 illustrates diagrammatically the risks arising from the use of an insulated electrode 50 that is not completely intact. [Figure 3] 1 illustrates schematically the risks arising from an intact stratum corneum. [Figure 4] The disposable protective shield according to the invention is shown in two possible embodiments: (A) as a cover cap that conforms to the shape of the electrode 50, and (B) as an insulating sheet or membrane. [Figure 5] 1 illustrates the use of a cover cap 60 a according to the present invention to cover the insulated electrode 50 and to be interposed between the electrode 50 and the skin 53 to restore the integrity of the insulator 52 and / or the skin 53 . [Figure 6] Illustrated is the use of an insulating film 60b according to the present invention in the form of an insulating sheet or film interposed between the electrode 50 and the skin 53 to restore the integrity of the insulator 52 and / or the skin 53. [Figure 7] A protective cap 60a made of PVC according to that described in Example 1 is shown. [Figure 8] 1 shows a capacitive electrode 50 with a protective cap 60a according to the present invention. [Figure 9] Shown are (A) a non-healing ulcer, (B or C) application of capacitive RF using electrodes covered with a cover cap 60a according to the present invention, and (D) a healed ulcer. DETAILED DESCRIPTION OF THE INVENTION

[0026] The protective insulating shield of the present invention is preferably disposable.

[0027] The protective insulating shield of the present invention may have a thickness of 0.01 to 20 mm, preferably 0.1 to 5 mm.

[0028] The protective insulating shield of the present invention preferably has a minimum electrical resistance of at least 500 ohms.

[0029] The protective shield can be made in rigid, semi-rigid or flexible form, and is generally thermoformed or injection molded, milled or molded, and can be made of any dielectric material, so long as it is non-cytotoxic, i.e., ISO 10993 certified, preferably PVC or polyoxymethylene (POM; Delrin®), polysulfone (PSU; Udel®), polyphenylsulfone (PPSU; Radel®, Tecason®), polyetheretherketone (PEEK; Ketron®), or other non-cytotoxic dielectric materials.

[0030] One embodiment of the insulating protective shield of the present invention is in the form of a cover cap 60a (FIG. 4A) specifically adapted to the shape of the insulated electrode 50, in which the cover 60a is thermoformed, injection molded, milled, or otherwise formed to have a three-dimensional structure that completely surrounds the surface of the insulated electrode 50 that is intended to contact the patient's skin.

[0031] According to another embodiment, the insulating protective shield may be in the form of a film, membrane, or dielectric sheet 60b (FIG. 4B) that is applied to the patient's stratum corneum 53, with the insulated electrodes sliding over the shield 60b.

[0032] The use of the protective shield of the present invention in capacitive RF applications is compatible with the conventional use of conductive gel as an interspace of conductive and lubricious material between the electrode covered by cap 60a and the skin, or between the electrode covered by membrane 60b and the skin.

[0033] 5 and 6, it can be seen that both in the case of fracture 55 of the insulator 52 of the insulated electrode 50 and in the case of alteration 58 of the stratum corneum 53, the function of the protective insulating shield 60a / b can be restored to full electrical insulation and prevent the aforementioned risk of discharge to the skin by the insulated electrode and the concentration of ionic charges in the skin.

[0034] The insulating shield must be able to interpose itself between the insulated electrode and the patient's skin, thus eliminating both the risks arising from fractures 55 of the insulating coating 52 and from damage 58 of the stratum corneum 53, thus ensuring a completely intact and efficient shield on both the insulated electrode side and the skin side, and is preferably a disposable cover, thus preventing both the risks of contamination from previous applications and from contact with potentially cytotoxic shielded electrodes, i.e. electrodes manufactured before the new version of ISO 10993.

[0035] The protective shield of the present invention can be used in combination with any capacitive RF delivery device for cosmetic or medical purposes. Preferably, for purposes of the present invention, the capacitive RF delivery device is as described in WO 2007 / 096009 or WO 2019 / 049105.

[0036] In one aspect, the invention relates to a method for cosmetic treatment to promote skin regeneration, sports medicine treatment, or medical treatment of skin lesions, said method comprising interposing a protective shield as described above between the insulated electrodes of a capacitive RF delivery device and the area of ​​the patient's skin to be treated.

[0037] Preferably, the method of the present invention includes using a conductive gel as a gap between the cap and the patient's skin when a protective shield in the form of a cap 60a is used, or between the electrode and the shield when a protective shield in the form of a film, membrane, or dielectric plane 60b is used.

[0038] Preferably, the method provides for a protective shield in the form of a cap 60a, if used, to slide the shield electrode over the patient's skin in the area to be treated, or a protective shield in the form of a film, membrane, or dielectric plane 60b, if used, to be placed over the patient's skin in the area to be treated.

[0039] The present invention can be better understood in light of the following examples.

[0040] (Experimental part) "Example 1" - Insulated electrode cover / cap The protective cap 60a can be made of transparent, non-cytotoxic PVC, which is molded using a mold made of aluminum or other material with a reversed double impression and softened at temperatures ranging from 50 to 200°C. The resulting cap has a thickness ranging from 0.3 to 0.5 millimeters, allowing for considerable elasticity to ensure optimal adhesion to the electrode (see Figures 6 and 7). Alternatively, the cap can be made of Delrin®, Udel® polysulfone, Radel®, Ketron®, Tecason®, or other non-cytotoxic dielectric material and hollowed or molded on a lathe or with other machine tools. The resulting cap has a thickness ranging from 0.3 to 2 millimeters.

[0041] "Example 2" - Protective film The protective film 60b can be made of transparent, non-cytotoxic PVC, which is formed using a mold made of aluminum or other material with a double-impression inverse, and softens at temperatures ranging from 50 to 200°C. The resulting cap has a thickness ranging from 0.3 to 0.5 millimeters, resulting in significant elasticity and flexibility, allowing the film to conform to the contours of the skin surface and provide continuity of stimulation to the skin via the shield electrode. Alternatively, the film can be made of Delrin®, Udel® polysulfone, Radel®, Ketron®, Tecason®, or other non-cytotoxic dielectric material, with a thickness ranging from 0.3 to 2 millimeters, formed using a mold or other mechanical solution, or cut with a laser or milling cutter, providing rigidity that allows it to mold and flatten over skin surfaces that tend to stick to the film.

[0042] (ulcer treatment) The cap of Example 1 has proven highly effective in treating ulcers, successfully enabling a capacitor effect by artificially restoring the electrical insulation that would otherwise be provided by an intact stratum corneum. This result is superior to any other treatment available in the prior art, leading to precise and complete re-epithelialization of chronic ulcers (see Figure 8). The solution offered by the cap to the problem of lack of stratum corneum integrity in the case of pressure sores, ulcers, and fistulas makes it possible to extend the typical regenerative power of capacitive radiofrequency to specific areas of these applications that were not previously possible.

[0043] The ulcer had not improved and instead continued to worsen until it became chronic, despite prior treatment with every treatment known in the art for 18 months prior to treatment with the cap of Example 1.

Claims

1. A capacitive RF delivery device having insulated electrodes (50) for treating the skin of a patient, comprising:

1. A capacitive RF delivery device comprising an insulating protective shield (60a / 60b) made of a non-cytotoxic dielectric material, the insulating protective shield (60a / 60b) configured and specifically adapted as a gap between the insulated electrodes (50) of the capacitive RF delivery device and the skin surface (53, 54) of a patient to be treated.

2. A capacitive RF delivery device as described in claim 1, characterized in that the protective shield is disposable.

3. A capacitive RF delivery device as described in claim 1 or 2, wherein the protective shield has a thickness of 0.01 to 20 mm, preferably 0.1 to 5 mm.

4. A capacitive RF delivery device as described in any one of claims 1 to 3, wherein the protective shield is in a rigid, semi-rigid, or flexible form.

5. A capacitive RF delivery device as described in any one of claims 1 to 4, wherein the protective shield is thermoformed or injection molded, milled or molded.

6. A capacitive RF delivery device as described in any one of claims 1 to 5, wherein the protective shield is made of PVC or polyoxymethylene (POM), polysulfone (PSU), polyphenylsulfone (PPSU), polyetheretherketone (PEEK).

7. A capacitive RF delivery device as described in any one of claims 1 to 6, wherein the protective shield is in the form of a cover cap (60a) specifically adapted to the shape of the insulated electrode (50).

8. A capacitive RF delivery device as described in any one of claims 1 to 6, wherein the protective shield is in the form of a film, membrane, or dielectric sheet (60b) applied onto the patient's skin surface (53).

Images