WO2018020434A1

WO2018020434A1 - Tissue tolerable plasma generator and method for the creation of protective film from the wound substrate

Info

Publication number: WO2018020434A1
Application number: PCT/IB2017/054534
Authority: WO
Inventors: Oleg Vladimirovich BORISSOV
Original assignee: BORISSOVA, Anastasiia Olegovna
Priority date: 2016-07-26
Filing date: 2017-07-26
Publication date: 2018-02-01

Abstract

The generator comprises at least a plasma nozzle (3) a housing (2), at the bottom of which a metal ring (8) resides which forms a second electrode. The nozzle is attached to a rotating axis (1 ) for creating an active area width exceeding the plasma jet's diameter.

Description

Tissue Tolerable Plasma generator and method for the creation of protective film from the wound substrate

Corresponding application

The present application claims priority to the eariier Swiss application N° CH 00961/16 filed on July 26, 2016 in the name of Oleg Vladimirovich Borissov and Anastasiia Olegovna Borissova, the content of this eariier application being included in its entirety by reference in the present application.

Purpose and / or technical field of the invention

The invention relates to a TTP ("Tissue Tolerable Plasma") generator, for example for use as a medical coagulator. Other uses may of course be envisaged with the present invention and this is only a non-limiting application example of the principles of the present invention.

Prior art and background of the invention

The emergence of new types of pathogenic bacteria and viruses has cost billions of dollars in the research and development of antibiotics.

However, their effectiveness is lost as microorganisms evolve and develop resistance to antibiotics. In addition, and in the continuing fight against such microorganisms, the use and role of plasma has become increasingly important. Plasma in this instance is an ionised, high temperature, gas made up of charged particles, free electrons, ions, chemical radicals, infrared, UV and RF radiation. In addition to the effectiveness of temperature and electromagnetic radiation, plasma components are able to penetrate the membrane of bacteria, thereby affecting its life systems and viruses. The disinfectant properties of plasma have been well researched and documented by microbiologists, with no resistance to plasma treatment having been so far

l determined where the release of properly dosed plasma has been applied to surfaces with any damage. In addition to its disinfectant properties, plasma also has a thermal effect which leads to instant coagulation in the case of bleeding. Medical coagulators with an indirect arc functioning under atmospheric pressure in a gaseous environment are known in the art. Coagulators with a direct arc between the electrode and the body of the patient are also known in the art.

Typically, a direct arc coagulator has a plasma jet diameter of about 1 mm, making it difficult to use on large surfaces.

A side effect of this principle is the presence of electric current in the patient's body.

Known indirect arc coagulators generate a high temperature plasma jet, preventing to approach the plasmatron at a distance less than the length of the plasma jet and create a plasma spot on the treated surface. In conclusion it is not a TTP generator.

For example, four main types of plasma generators are currently in use in the art:

1 . Corona discharge sterilizers

2. Dielectric barrier discharge sterilizers

3. Direct arc argon coagulators

4. Indirect arc coagulators

Corona discharge is applied only for the sterilization of dielectric materials and cannot be used in surgery. Their low efficiency has meant that Dielectric Barrier Discharge Sterilizers have only a limited application as they can only treat flat surfaces: it is essential that these generators function in parallel with the surface to be treated.

In medicine, the problems of coagulation and disinfection are addressed with direct and indirect arc coagulators.

The Direct Arc Argon Coagulator with a plasma torch diameter of about 3mm creates uncontrolled currents, which flow from the generator through the patient's body. This type likewise as lasers is used for coagulation on the blood vessels. The diameter of the treatment area precludes its application on large surfaces. Indirect Arc Coagulators currently in use have a plasma torch diameter of about 10mm. For the purposes of this analysis, the example used is the OpenAir plasmatron, or similar applications used by companies such as PlasmaTreat, Diener, AcXys, Advanced Machines.

Torches of this type are widely used in industry for the treatment of heat resistant materials, such as metals, that can withstand contact with the plasma thereby ensuring the activation and disinfection of surfaces before gluing and painting.

In medicine, however, the plasma torch cannot be applied directly to a patient's body as the source temperature of the torch is in the region of 3-4Ό00 C°; the torch can only be applied from a distance of between 30 and 100 mm. There are no particular benefits, as coagulation follows exposure to hot nitrogen oxide (NO), and not to the application of plasma to the surface. Furthermore, its use is limited by the small diameter of the torch.

Prior art publications showing plasma generating devices include

-) US 201 1220143 which discloses a device for treating an inner surface of a workpiece, with a radiation, with at least one generating unit for generating the radiation, with a drive unit for rotating the at least one generating unit about an axis of rotation, the at least one generating unit for emitting the generated radiation being configured with a preferential direction toward the surface to be treated. It comprises an arm for inserting the generating unit into the workpiece to be treated. This device is not used for medical applications and is intended to be introduced inside the piece to be treated.

-) US 6262386 discloses a plasma nozzle, in particular for pretreating surface, including a casing defining a nozzle channel which has an axis and a mouth and through which a working gas is passed, an electrode disposed coaxially in the nozzle channel, and a counter electrode surrounding the nozzle channel, wherein the mouth of the nozzle channel is angled relative to the axis thereof. -) US 6265690 discloses a plasma processing device for surfaces. This device comprises two or more plasma nozzles mounted on a rotating head to rotate the plasma jet. In order for the electric arc not to pass radially from the electrode pin to the surrounding wall of the casing of the electrode, it is entrained by a swirling gas flow and chanelled into the core of the gas vortex to that it passes from the electrode pin straight along the central axis of the vortex channel to the mouth of the nozzle. A focused plasma jet is thus formed towards the surface of the workpiece being treated. Each plasma nozzle is supplied with high voltage from a separate high voltage source which is essential for the functioning of the device. -) US 2010164353 discloses a wide area plasma jet apparatus with two plasma-generating devices with a nozzle that tilts from a center axis. When the two devices rotate around the center axis, the two plasma beams are obliquely ejected from the plasma nozzles.

-) US 2015303034 discloses a device with a first tubular electrode and a second tubular electrode. The first tubular electrode is disposed in the first chamber and has a second chamber. The second tubular electrode has a third chamber connected with the second chamber. The second tubular electrode can rotate in relative to the casing, and the second chamber and the third chamber are adapted for accommodating a plasma formed between the first tubular electrode and the second tubular electrode. A nozzle is configured to eject the plasma and forms an included angle with or is spaced a distance apart from a rotating axis of the second tubular electrode, and the gas ejection port is configured to eject a cold gas. More specifically, two tubular electrodes 120 and 130 are positioned coaxially: one under another. The gas is supplied via two independent channels (GC1 and GC) through many intake holes (IP1 ). The swirl of the gas flow is ensured by two generators (141 , 143)

Other prior art documents include US 6800336, WO 2006/136467, KR 101498392, US 2010096086, EP 1759829, US 2013199540,

Prior art publications showing wound treatment with plasma are disclosed in the following publications:

-) US 8267884 discloses apparatuses and methods for treating wounds with an instrument generating a low temperature, atmospheric pressure plasma.

-) WO 20151 10783 discloses a plasma-generating device for applying plasma to a human body. -) US 6475215 discloses a surgical apparatus adapted to emit a plurality of high-energy inert gas atoms in a stream for cutting, cauterizing or evaporating tissue.

-) US 2012022522 disclose volumetrically oscillating plasma flows. Description of the invention

An aim of the present invention is to provide an improved device over the systems and methods known in the art. Another purpose of the present invention is to create a TTP generator with an active area width exceeding the plasma jet's diameter. In the present context, a TTP generator is generally considered a plasma device with a rotating nozzle. This device allows for the treatment of sensitive tissues (e.g. living tissues) due to the next specific factors:

1 ) The voltage is supplied to the electrodes in the form of pulses. Pulse duration is considerably lower than its repetition interval (e.g. the pulse duration is 350 nanoseconds and the repetition interval is 20 milliseconds).

2) The plasma torch does not stand still but scan the surface ensuring that the average temperature on the surface is considerably lower than the plasma temperature. A further aim of the present invention is to provide a generator that does not generate any electric current when in use, typically in a patient's body when it is used as a coagulator.

The features defined in claim 1 solve these technical issues and particular embodiments are defined by the dependent claims.

Using the present invention, the treatment area becomes greater than the plasma jet's diameter, one has the possibility of generating a plasma spot directly on the surface, and uncontrolled electric current in the body of the patient is avoided. In an embodiment, the invention concerns a plasma generator comprising at least a plasma nozzle with an electrode, a housing comprising at its bottom of which a metal ring forming a second electrode, wherein the nozzle is attached to a rotating piece, the generator further comprising an air under pressure supply in said rotating piece for forming a vortex air flow in said piece, wherein the nozzle is rota table with respect to the housing for creating an active area width exceeding the plasma jet's diameter. The nozzle may by a single rotating nozzle or not. In an embodiment, the longitudinal axis of the piece containing the first electrode is parallel to the rotation axis of the piece forming an eccentric construction with the nozzle, or at least the plasma jet, being eccentred with respect to the rotation axis of the piece.

In an embodiment, the rotating piece is made of a high temperature dielectric, for example ceramic or quartz. Other suitable equivalent materials are possible.

In an embodiment, the housing is preferably made of a dielectric material. Other suitable equivalent materials are possible. In an embodiment, the housing comprises at least a bearing for supporting said rotating piece.

In an embodiment, the housing and the piece have a cylindrical shape, or at least some parts of the piece have a cylindrical shape.

In an embodiment, when in use, the rotating piece has a rotational speed of 100 rpm approximately. This speed may be varied according to circumstances.

In an embodiment, the invention concerns a system with a generator as defined herein. The system may be of any type, for example a medical system or other.

In an embodiment, the invention concerns the use of a generator or a system as defined herein. As an example, the use may be for the treatment of a wound, as a coagulator, as will be described later in the present specification. Other medical or non-medical uses may be of course envisaged. Detailed description of the invention

The invention will be explained in more detail using an exemplary embodiment which is not to be construed in a limiting manner and represented in the following drawings:

Figure 1 illustrates a schematic view of an embodiment of a Raster TTP generator according to the present invention.

Figure 2 illustrates an exemplary result of the use of the generator of figure 1.

As illustrated in figure 1 , the raster TTP generator designed for the treatment of

thermosensitive surfaces, for example the skin, comprises at least a housing 2, in which a rotating piece 1 is embedded through a hole with a plain bearing 5 to allow free rotation of the piece 1. The housing is made of a dielectric material.

The rotation of the piece 1 is preferably carried out by a motor, for example an electric motor via appropriate drive means.

According to an embodiment, the rotating piece 1 is made of a high temperature dielectric which includes a plasma chamber with an electrode 3.

The generator creates a high voltage pulse on a specific trajectory 6 from the first electrode 3 arcing to the second electrode 8, i.e. a meshed cap metal ring 8, or a metal ring.

Reference 9 illustrates a wire that connects the pulse generator through a sliding contact. Specifically a voltage is supplied to the electrodes via the wire 9 through the sliding contact from the pulse generator. Compressed air is supplied to the air chamber 10 through a standard rotating joint (not indicated on the figure) for example. The air compressor is not illustrated in the figure. A plasma jet 7 is propulsed externally by a compressed air vortex flow generated by rotating joint 4 and the air under pressure injected in the chamber 10, reference 1 1 indicating the plasma nozzle. The tension on the cable or wire 9 is generated by a graphite brush (not indicated on Figure

1 ).

As illustrated, the position of the electrode 3 is excentered with respect to the rotation axis of the piece 1 so that the treatment area is not a point but as illustrated in figure 2: it has a ring shape which is created by the rotation of the piece 1 and the excentered position.

The device according to the present invention, by rotation of the piece 1 , thus allows the treatment of a large surface. The surface treated may be varied depending on the distance between the axis of rotation and the electrode 3.

Figure 2 illustrates an example of the plasma trace 20 on an object (i.e. a patient being treated). Technical characteristics of the product, as non-limiting examples:

Rotation speed of the piece 1 : 100 rpm or another suitable value.

Non-limiting examples of dimensions are the following: D=50 mm, pulse duration = 350 nanoseconds, repetition rate = 25 KHz, the length of the plasma jet = 15-30 mm, pulse's amplitude = 35 KV, the distance between the central electrode and second electrode (metal ring) is about 35-40 mm.

According to an embodiment, the plasma torch diameter is up to 100mm which enables combining the direct impact of the plasma substance on a surface with the therapeutic effect of nitrogen oxide. The device according to the present invention may be a portable device, or a semi-portable device. This device may comprise a "revolver-shaped" handheld manipulator connected to a power supply, and may use compressed air as a source of air under pressure. Typically, the weight of the manipulator may be about 1 .5kg, and that of the generator unit about 5kg. Power requirements are 220 volts 50Hz; a fully portable version might even be powered by a lithium ion battery. Power consumption is about 300- 500 watts.

The device may be equipped with interchangeable heads, allowing changes in the diameter of the plasma torch from 15 to 100mm. Threaded means may be used to allow this head interchangeability, or other equivalent means. The application distance from the torch to a patient's body is about 10mm, while the length of the plasma jet is approximately 15mm. During application, the plasma torch is moved continuously over the treatment area. The depth of thermal coagulation depends of the speed at which the device is applied over the treatment area. The effects of application of the plasma torch at a distance of between 5 and 10mm from the treatment surface involve the plasma substance. An increase in distance to 20-30mm from the surface will involve only nitrogen oxide. The device is simple to operate. Once connected to a power supply and switched on, the machine is ready to use. The operator may then apply the torch to the surface to be treated. Large areas may be rapidly treated with the present invention.

Summary of the principal TTP advantages:

Table 1: Key advantages of the generator of the invention in comparison with competitors The generator according to the present invention has been developed mainly for medical purposes, particularly for the treatment of large burns, trophic ulcers and gangrene, or bleeding (for example from wounds, during surgery) of body parts or organs such as, but not limited thereto the liver for example. One has observed further beneficial effects of a plasma jet on skin surfaces where in addition to sterilization, a wound is sealed from environmental contamination by forming a protective bio film, thereby reducing the use of classic fabric bandages. The healing of wounds and restoration of biological tissue follow quickly. Specifically, a coating film is generated from the substrate of the wound surface itself using plasma jet. The plasma jet evaporates the liquid fraction of the wound.

The thickness of the film and therefore its permeability depends on the duration of plasma treatment.

A wound is simultaneously disinfected and the generated film is covered with an ozone layer that protects from the external contamination.

During the processing of a bleeding zone or wound, the blood is maintained on the surface of the wound under the dressing.

The tissue regeneration and healing proceed in a liquid medium.

The synthesized protective film formed by the present invention aims to replace traditional bandages. Contrary to the tissue bandages, the film does not absorb the liquid substrate thus accelerating the process of wound healing.

It is clear that the invention will be invaluable in a military context, where combat injuries are often susceptible to infection and which, in the absence of prompt medical attention, might lead to death or life-changing consequences. The use of a plasma coagulator as a first aid measure (stopping of bleeding, wound disinfection) does not require any special medical training. Furthermore, a promising area of application for the generator is against pathogenic cells (cancer) in microbiology. The device according to the invention also enables the disinfection and surface activation of implants having a low melting point, (for example, plastics); survival rates will be improved through increased adhesion.

The treatment of surfaces greater than 10mm in industry often involves the use of lines of single torches to cover a given width - for example, the treatment of bands with a width of 1000mm will involve the installation of 100 adjoining plasma torches each of which requires its own generator. The present invention may replace this cumbersome construction with two made-to-order plasma torches, each able to treat a width of 500mm, which would considerably reduce the cost of equipment. The plasma torches can be integrated into existing robotic lines for example.

The applications in the Food and Pharmaceutical industries of the present invention include the cleaning and sterilization of aluminum foils, instead of using chemical reagents. The industrial use of solvents is the cause of serious environmental damage: such solvents can often be substituted by plasma.

Of particular interest is the use of the device in areas of poor levels of health care, as these regions are often the source of epidemics which then spread in an uncontrolled fashion around the globe.

The embodiments of the invention described herein are given by way of examples that should not be regarded as limiting the scope of the invention. Equivalent means may be used and the embodiments may be combined.

The present specification is neither intended nor should be construed as being

representative of the full extent and scope of the present invention. The present invention is set forth in various levels of detail herein as well as in the attached drawings and in the detailed description of the invention and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of elements, components, etc. Additional aspects of the present invention will become more readily apparent from the detailed description, particularly when taken together with the drawings. Exemplary embodiments have been described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the systems and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will understand that the systems and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the present invention is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention. A number of problems with conventional methods and systems are noted herein and the methods and systems disclosed herein may address one or more of these problems. By describing these problems, no admission as to their knowledge in the art is intended. A person having ordinary skill in the art will appreciate that, although certain methods and systems are described herein, the scope of the present invention is not so limited.

Moreover, while this invention has been described in conjunction with a number of embodiments, it is evident that many alternatives, modifications and variations would be or are apparent to those of ordinary skill in the applicable arts. Accordingly, it is intended to embrace all such alternatives, modifications, equivalents and variations that are within the spirit and scope of this invention.

Claims

1 . A plasma generator comprising at least a plasma nozzle (1 1 ) with a first electrode (3), a housing (2) comprising at its bottom of which a metal ring (8) forming a second electrode (8), wherein the nozzle is attached to a rotating piece (1 ), said generator further comprising an air under pressure supply in said rotating piece for forming a vortex air flow in said piece, wherein the nozzle is rota table with respect to the housing (2) for creating an active area width exceeding the plasma jet's diameter.

2. The generator of claim 1 , wherein the longitudinal axis of the part containing the first electrode is parallel to the rotation axis of the piece.

3. The generator of claim 1 or 2, wherein the rotating piece (1 ) is made of a high temperature dielectric.

4. The generator as defined in one of the preceding claims, wherein the housing (2) is dielectric.

5. The generator as defined in one of the preceding claims, wherein the housing (2) comprises at least a bearing (5) for supporting said rotating piece (1 ).

6. The generator as defined in one of the preceding claims, wherein the housing (2) and the piece (1 ) have a cylindrical shape.

7. The generator as defined in one of the preceding claims, wherein the piece rotates at approximately 100 rpm when in use.

8. The generator as defined in the preceding claims, wherein it is portable or at least partially portable.

9. A system comprising a generator as defined in one of the preceding claims.

10. Use of a generator or a system as defined in one of the preceding claims.