TOOL FOR COLD PLASMA MEDICAL TREATMENT DEVICE AND CORRESPONDING DEVICE

Abstract

A tool for a medical plasma treatment device, the tool comprising at least one instrument (11) having a sheath (16) in which a channel (17) is formed, the channel being closed at its distal end and the sheath comprising at least one orifice (18) passing through a thickness of the sheath so as to open at one end into the channel and at a second end outside the sheath, the instrument further comprising at least one power electrode (12) and a dielectric screen (13), the power electrode being arranged inside the dielectric screen such that the distal end of the power electrode is covered by the dielectric screen, plasma generated in operation by the treatment device propagating out of the instrument through the orifice. A device comprising such a tool. FIGURE IN ABRIDGED ANALYSIS: Fig. 2

Description

Title of the invention: TOOL FOR COLD PLASMA MEDICAL TREATMENT DEVICE AND CORRESPONDING DEVICE

[0001] The invention relates to a tool for a medical plasma treatment device.

[0002] Such a tool can be used just as well on a (human) patient as on an (animal) experimental model.

[0003] Such a tool can be used in many branches of medicine such as, but not limited to, otorhinolaryngology, pulmonology, gastroenterology (upper and lower parts of the digestive system and, for example, the esophagus, stomach, pancreas, large intestine, small intestine, duodenum, bile duct, etc.), laparoscopy, gynecology (including obstetrics), orthopedics, etc.

[0004] Such a tool can be used for numerous medical applications such as, but not limited to, oncological applications (anti-tumor effect, for example), decontamination of fluids and / or natural cavities and / or cellular tissues and / or organs, combating stenosis (particularly in the bile ducts), combating atresia, aiding blood coagulation, chemical surface activation, coating, stimulation or regeneration of cellular tissues and / or organs, chemical functionalization, etc.

[0005] Such a tool can be implemented to apply plasma directly to a given area to be treated and / or indirectly via a liquid (solution, hydrogel, medical liquid, ...) applied to the area to be treated, the liquid being or having been previously treated with plasma.

[0006] The invention also relates to a device comprising such a tool.

[0007] BACKGROUND OF THE INVENTION

[0008] Plasma is considered a state of matter in the same way as liquid, solid and gas. This "fourth state" can be obtained by ionization of a gas subjected to an electric field or by heating it to a high temperature.

[0009] It has been observed that the action of a cold plasma (sometimes called non-thermal plasma or plasma out of thermodynamic equilibrium) on tumors such as cholangiocarcinoma makes it possible to reduce their volume and induce apoptosis of cancer cells.

[0010] As medicine increasingly turns towards targeted treatments, prototypes have been developed to generate plasma in long flexible tubes.

[0011] However, their insertion into an endoscope makes them dangerous. Indeed, the internal structure of a conventional endoscope has certain metallic walls; walls that can therefore conduct electric current and thus electrocute both the patient (or experimental model) and the operator. In summary, current prototypes do not allow for the generation of plasma in a catheter-type tool, itself inserted into an endoscope, while being safe for both the patient (or experimental model) and the operator.

[0012] SUBJECT OF THE INVENTION

[0013] One object of the invention is to provide a tool for a plasma medical treatment device that is more secure with respect to a patient and / or an experimental model and / or a practitioner.

[0014] An object of the invention is also to propose a medical treatment device incorporating such a tool. Summary of the invention

[0015] To achieve this goal, a tool is proposed for a medical plasma treatment device, the tool comprising at least one instrument which has a sheath in which a channel is formed, the channel being closed at its distal end and the sheath comprising at least one orifice passing through a thickness of the sheath so as to open at a first end into the channel and at a second end outside the sheath, the instrument further comprising at least one power electrode and a dielectric screen, the power electrode being arranged inside the dielectric screen so that the distal end of the power electrode is covered by the dielectric screen, a plasma generated in operation by the treatment device propagating out of the instrument via the orifice.

[0016] The inventors were able to observe that the instrument thus described allowed good isolation of the power supply electrode from an external environment, which made it possible to protect a patient (or experimental model) treated by such a tool as well as a practitioner manipulating the tool.

[0017] In particular, with this tool, the plasma treatment can be applied laterally to the instrument and no longer longitudinally as with prior art devices: the distal end of the sheath remains solid which provides more protection to a patient / experimental model / practitioner.

[0018] Optionally, the dielectric screen and the feed electrode are arranged in the channel so that at least one section of the feed electrode surrounded by the dielectric screen is opposite the orifice.

[0019] Optionally, a distance separating the distal end of the internal dielectric screen from the distal end of the channel is between 1 millimeter and 40 centimeters.

[0020] Optionally at least one orifice extends radially into the sheath.

[0021] Optionally, the sheath includes a plurality of orifices through the thickness of the sheath so as to open at a first end into the channel and at a second end outside the sheath.

[0022] Optionally, the orifices follow a circumferential direction of the sheath.

[0023] Optionally, the orifices form at least two series of spaced orifices axially to each other.

[0024] Optionally, the tool includes a guide cable.

[0025] Optionally, a channel is provided in the distal end of the sheath without opening into the orifice or the channel, the guide cable extending for part of its length in this channel.

[0026] Optionally, the distal end of the sheath is rounded and / or beveled.

[0027] Optionally, the sheath is made of or based on polytetrafluoroethene.

[0028] Optionally, wherein the dielectric screen and the feed electrode are arranged in the channel so that no section of the feed electrode surrounded by the internal dielectric screen is opposite at least one of the different orifices.

[0029] The invention also relates to a medical treatment device comprising an applicator in which at least one conduit is provided, a tool such as the one mentioned above, being arranged so that at least its instrument extends into said conduit.

[0030] Other features and advantages of the invention will become apparent from the following description of a particular, non-limiting embodiment of the invention.

[0031] Thereafter, and unless otherwise indicated, the intervals indicated should be understood with terminals closed. Brief description of the drawings

[0032] The invention will be better understood in the light of the following description with reference to the accompanying figures, among which:

[0033] [Fig.1] Fig.1 is a schematic view of a device according to a particular embodiment of the invention;

[0034] [Fig.2] Fig.2 is a perspective view of a medical device represented in [Fig.1],

[0035] [Fig.3] Fig.3 is a cross-sectional view, along an axial cutting plane, of the tool represented in [Fig.2],

[0036] [Fig.4] Fig.4 is a cross-sectional view, along a transverse cutting plane, of the sheath of the medical tool shown in [Fig.2],

[0037] [Fig. 5] Fig. 5 represents possible variants of the sheath of the tool illustrated in the [Fig.2],

[0038] [Fig.6] Fig.6 is a cross-sectional view, along an axial cutting plane, of a variant of the tool shown in [Fig.2]. DETAILED DESCRIPTION OF THE INVENTION

[0039] With reference to [Fig.1], the medical treatment device 1 according to a particular embodiment of the invention comprises an applicator which is here an endoscope 2 and for example a duodenoscope.

[0040] The endoscope 2 comprises at least one working conduit 3 passing through it from one end to the other between a proximal end 2a of the endoscope intended to be positioned outside the body 100 of a patient and a distal end 2b of the endoscope intended to be positioned inside the body 100 of the patient near an area to be treated. In the present case, the endoscope 2 comprises several working conduits.

[0041] Hereafter the term "proximal end" should be understood as the end arranged outside the patient or closest to the outside of the patient and the term "distal end" should be understood as the end arranged furthest inside the patient.

[0042] The endoscope 2 can be introduced into the patient via a natural or artificial cavity 101 of the patient.

[0043] In a manner known per se, the endoscope 2 is sufficiently flexible to be able to deform in order to follow, if necessary, the natural path of the cavity 101. The endoscope 2 has, for example, a diameter of 12 millimeters.

[0044] Furthermore, the device 1 includes a tool 10 capable of generating plasma, the tool 10 comprising at least one instrument 11 which is arranged in one of the conduits 3 of the endoscope 2. At least the instrument 11 is sufficiently flexible to be able to deform in order to follow if necessary the natural path of the cavity 101 and / or of a channel 102 extending said cavity and in which it circulates (bile duct, digestive tract ...).

[0045] The conduit 3 has a diameter, for example, between 1 and 66 millimeters, and for example between 2 and 10 millimeters, and for example between 4 and 4.5 millimeters. Optionally, the conduit 3 has a diameter of 4.2 millimeters (it being understood that this diameter must necessarily be large enough for the instrument 11 to be inserted into it and therefore necessarily greater than the external diameter of the instrument 11). In particular, the instrument 11 is not attached (in any case, not continuously, around its entire circumference) to the conduit 3.

[0046] The tool 10 here comprises a single instrument 11. The instrument 11 extends, for example, coaxially to the conduit 3 of the endoscope 2 in which it is arranged when the endoscope 2 (and therefore the instrument 11) extends in a straight line. of course, instrument 11 is also sufficiently flexible to be able to deform to follow the movement of the associated endoscope 2.

[0047] Instrument 11 is a tubular instrument.

[0048] The instrument 11 also extends axially along a general direction X.

[0049] The instrument 11 extends more particularly here so that one or its ends axial ends protrude from endoscope 2. The tubular instrument 11 extends more particularly here so that its two axial ends protrude from endoscope 2.

[0050] The distal end 11b of the instrument 11 thus extends out of the endoscope 2 (distal end side 2b of the endoscope 2) and the proximal end 1la of the instrument 11 extends out of the endoscope 2 (proximal end side 2a of the endoscope 2).

[0051] Device 1 further includes a plasma generation system which includes at least one electrical power supply source 4 and at least one gas supply source 5, each of said sources being connected to tool 10.

[0052] The electrical power supply 4 has, for example, the following parameters: - use of a direct current, alternating current (square wave, sinusoidal wave, triangular wave, sawtooth wave, etc.), pulsed voltage, and / or - use of a voltage with an amplitude between 12 volts and 12 kilovolts, and preferably between 1 kilovolt and 10 kilovolts, and preferably between 3 kilovolts and 7 kilovolts, and / or - use of a voltage with a frequency between 0 (not included) and 27.12 Megahertz and preferably between 100 Hertz and 100 kilohertz and which is preferably 5 kilohertz.

[0053] The gas supply source 5 has, for example, the following parameters: - use of a carrier gas chosen from helium, argon, neon, ..., and / or - use of a carrier gas at a flow rate between 0 and 10 liters per minute (under standard temperature and pressure conditions taken at 25 degrees Celsius and 1 bar - CSTP) and preferably between 0.1 and 1 liter per minute, and preferably 0.7 liters per minute, and / or - use of one or more secondary gases chosen from air, dihydrogen, dinitrogen, dioxygen, carbon dioxide, methane ..., and / or - use of at least one secondary gas at a flow rate between 0 and 10 liters per minute (as measured by standard temperature and pressure), and preferably between 0.01 and 1 liter per minute, and preferably 0.05 liters per minute, and / or - use of a continuous, static, turbulent flow regime...

[0054] The device 1 also includes a system for evacuating residual gas 6 not transformed into plasma and / or generated plasma present in tool 10 and / or instrument 11, the residual gas evacuation system also being connected to tool 10.

[0055] The device 1 can of course include one or more other additional elements such as, for example, a second source of electrical power supply 7 this time connected to the endoscope 2 or a micro-fluidic control device for the flow of the carrier and / or secondary gas injected into the instrument 11 and / or a grounding cable, etc.

[0056] With reference to figures 1 to 4, tool 10 will now be described.

[0057] The instrument 11 of said tool 10 comprises, from the inside out, at least the following layers: - a 12-gauge power supply electrode, - an internal dielectric screen 13, - a sheath 16.

[0058] The power supply electrode 12 is a polarized electrode. The power supply electrode 12 is made of an electrically conductive material and for example of a metal and for example based on or made of copper and / or aluminum.

[0059] Preferably, the feed electrode 12 is a simple wire. The feed electrode 12 is thus very simple in structure.

[0060] The external diameter of the feed electrode 12 is for example between 0.01 and 10 millimeters and for example between 0.01 and 5 millimeters, and for example between 0.05 and 0.35 millimeters and for example between 0.1 and 0.3 millimeters.

[0061] The power supply electrode 12 is directly connected to the electrical power supply 4. Consequently, its electrical potential is not floating and depends only on the electrical characteristics of the electrical power supply 4, which are known and perfectly controlled. As a result, the power supply electrode 12 is an electrode whose value is always known (and therefore not floating).

[0062] Thus, the risk of the plasma transitioning to a thermal arc regime is advantageously limited. The instrument is therefore very safe to use.

[0063] The internal dielectric screen 13 is for example shaped into a tube which is closed at its distal end or is a coating directly applied to the supply electrode 12, the coating then covering the distal end of the supply electrode 12 (the internal dielectric screen 13 then not having a definite shape until it is applied to the supply electrode 12).

[0064] In this way, the feed electrode 12 is entirely arranged inside the internal dielectric screen 13. In particular, the distal end of the feed electrode 12 is completely covered by the internal dielectric screen 13: the plasma cannot therefore come into contact with said supply electrode 12, nor with the area to be treated or the immediate environment of said area (tissue, biological fluid ...).

[0065] Thus, the power supply electrode 12 and the internal dielectric screen 13 are joined together.

[0066] When at least the distal end 11b of the instrument 11 extends straight, the distance L1 separating the distal end of the supply electrode 12 from the distal end of the internal dielectric screen 13 is for example between 1 nanometer and 10 centimeters, and is for example between 1 millimeter and 10 millimeters, and is for example 5 millimeters.

[0067] Thus, the risk of the plasma transitioning to a thermal arc regime is advantageously limited.

[0068] Preferably, only the proximal end of the power supply electrode 12 is not covered by the internal dielectric screen 13 (for its connection to the electrical power supply source 4).

[0069] The internal dielectric screen 13 is of course made of a dielectric material.

[0070] The internal dielectric screen 13 is for example made of a natural or artificial rubber. The internal dielectric screen 13 is for example made of plastic material (polyvinylidene fluoride, polytetrafluoroethylene, perfluoroalkoxy ...).

[0071] The external diameter of the internal dielectric screen 13 is for example between 0.01 and 20 millimeters, and for example between 0.5 and 3 millimeters and for example between 1 and 2 millimeters (it being understood that this diameter is also necessarily greater than that of the supply electrode 12).

[0072] The sheath 16 forms a supporting structure for the instrument 11.

[0073] The sheath 16 is preferably made of a dielectric material.

[0074] The sheath 16 is, for example, made of natural or artificial rubber. The sheath 16 is, for example, made of plastic (polyvinylidene fluoride, polytetrafluoroethylene, perfluoroalkoxy, polytetrafluoroethene, etc.).

[0075] The external diameter of the sheath 16 is for example between 0.5 and 50 millimeters, and for example between 1.2 and 4 millimeters and for example between 2.0 and 3.0 millimeters.

[0076] The total length of the sheath 16 is here between 0.05 millimeters and 5 meters, and preferably between 1 and 3 meters and preferably between 1.5 and 2.5 meters and is preferably 2 meters.

[0077] A channel 17 is provided in the sheath 16 so as to open at the proximal end of the sheath 16 on the one hand and to be closed at its distal end 17b. In this way, the channel 17 does not open outside the sheath 16 at the distal end 16b thereof.

[0078] When at least the distal end 11b of the instrument 11 extends straight, the distance L2 separating the distal end 17b of the channel 17 from the most distal area 19 of the distal end 16b of the sheath 16 furthest from the proximal end of the sheath 16 is for example between 1 micrometer and 200 millimeters, and is for example between 1 millimeter and 100 millimeters, and is for example between 10 millimeters and 50 millimeters and is for example 40 millimeters.

[0079] The sheath 16 is thus closed at its distal end 16b.

[0080] The sheath 16 is, for example, shaped into a tube which is hollow but closed at its distal end 16b. The distal end 16b of the sheath 16 is solid.

[0081] At least when the instrument 11 extends straight along the general direction X, channel 17 extends coaxially to this general direction X. Channel 17 presents for example, the same cross-section over its entire length.

[0082] Preferably, the distal end 16b of the sheath 16 is not flat. Rather, the distal end 16b of the sheath 16 is at least partially rounded and / or at least partially beveled. This allows the instrument 11 to slide and maneuver more easily into the patient's body 100 without rubbing against or damaging the internal tissues.

[0083] For example, the distal end 16b of the sheath 16 is shaped into a dome, and in particular into a half-dome. The distal end 16b of the sheath 16 is optionally shaped into a geodesic dome.

[0084] Furthermore, the sheath 16 includes at least one orifice 18 passing through a thickness of the sheath 16 so as to open at a first end into the channel 17 and at a second end outside the sheath 16. The second end thus opens outside the instrument 11 into the conduit 3.

[0085] The orifice 18 has, for example, a maximum diameter between 100 and 1500 micrometers and, for example, between 200 and 1000 micrometers.

[0086] The orifice 18 thus extends laterally in the sheath 16. Said orifice 18 extends, for example, radially in the sheath 16. Thus, when at least the distal end 16b of the sheath 16 extends straight along the general direction X, the orifice 18 extends orthogonally to the general direction X.

[0087] The orifice 18 is provided in the sheath 16 so as to open into the channel 17 at the level of the distal end 17b of the channel 17. Thus the orifice 18 does not extend into the distal end 16b of the sheath 16 and in particular does not extend longitudinally into the distal end 16b of the sheath 16 (does not extend parallel to the longitudinal axis X along which the distal end 16b of the sheath 16 extends).

[0088] The orifice 18 therefore extends in the immediate vicinity of the distal end 16b of the sheath 16 but does not extend inside it.

[0089] When at least the distal end 11b of the instrument 11 extends straight, the distance L3 separating the center of the orifice 18 from the distal end 17b of the channel 17 is for example between 1 nanometer and 1 meter, and is for example between 1 millimeter and 10 centimeters, and is for example between 5 millimeters and 20 millimeters and is for example between 5 millimeters and 10 millimeters and is for example 10 millimeters.

[0090] Preferably, the sheath 16 includes several orifices 18 through the thickness of the sheath 16 so as to open at a first end into the channel 17 and at a second end outside the sheath 16.

[0091] In the present case, all the orifices 18 are identical to each other. What has been said above for one of the orifices 18 is therefore also applicable to the other orifices 18.

[0092] Different configurations of orifices 18 are also conceivable.

[0093] According to a first variant illustrated in figures 3 and 4, a first series of orifices 18 is provided in the sheath.

[0094] Optionally, several series of orifices 18 are provided in the sheath 16. For example, between 1 and 20 series of orifices 18 are provided in the sheath 16 and for example between 2 and 10 series and for example between 3 and 6 series.

[0095] The series of orifices 18 are axially offset from one another in the sheath 16 (the axial direction being the longitudinal direction along which the sheath 16 extends when it is undeformed and therefore straight, i.e., here the general X direction). Optionally, the series of orifices are axially offset from one another by the same interval. This interval is, for example, between 50 micrometers and 50 millimeters, between 1 millimeter and 20 millimeters, or 10 millimeters.

[0096] The distance separating the distal end 17b of the channel 17 from the most distal area 19 of the distal end 16b of the sheath 16 is less than the distance separating the series of orifices (closest to the distal end 17b) from the most distal area 19 of the distal end 16b of the sheath 16.

[0097] Optionally, the different series are all identical to each other. The following description of the first series of orifices 18 is therefore also applicable here to the other series.

[0098] Preferably, at least when the channel 17 extends straight along the general direction X, the orifices 18 of the first series of orifices 18 all extend into the sheath 16 at the same distance (along the general direction X) from the distal end 16b of the sheath 16. The series of orifices 18 thus forms a ring around the sheath 16. Preferably, the different orifices 18 of the same series of orifices 18 are spaced from each other along the circumferential direction by the same interval. This interval is for example between 50 and 1000 micrometers and for example between 300 and 500 micrometers and is for example 400 micrometers.

[0099] For example the series comprises between 2 and 10 orifices and for example between 2 and 8 orifices and for example between 2 and 6 orifices and for example between 2 and 4 orifices.

[0100] Preferably, the orifices 18 are provided in the sheath 16 so as to extend two by two in the continuation of one another.

[0101] For example at least, and in the present case all the orifices 18, extend radially in the sheath 16. For example, all the orifices 18 are provided in the sheath 16 so as to extend radially two by two in opposite directions.

[0102] Optionally at least one, and in the present case all of the orifices 18, extend straight into the sheath 16.

[0103] Optionally at least one, and in the present case all the orifices 18, have a cross-section which remains identical over the entire length of the orifice 18.

[0104] Optionally at least one, and in the present case all of the orifices 18, have a circular cross-section.

[0105] Furthermore, the internal dielectric screen 13 (and therefore the electrode 12) is arranged in the channel 17 so as to extend into said channel 17.

[0106] When at least the distal end 11b of the instrument 11 extends straight, the distance L4 separating the distal end 13b of the internal dielectric screen 13 from the distal end 17b of the channel 17 is for example between 0 and 1 meter, and is for example between 1 millimeter and 40 centimeters, and is for example between 1 centimeter and 10 centimeters and is for example 5 centimeters.

[0107] Since the assembly "supply electrode 12 and internal dielectric screen 13" is not fixed in the present case to the sheath 16, the distance L4 can easily be modified during an intervention by the practitioner according to his needs.

[0108] Thus, depending on the positioning of the internal dielectric screen 13 (and therefore of the feed electrode 12 attached to the internal dielectric screen 13) with respect to the sheath 16, the internal dielectric screen 13 and the feed electrode 12: - can be arranged in the sheath so that at least one section of the feed electrode 12, surrounded by the dielectric screen 13, is opposite at least one of the various orifices 18. Optionally, said section can be arranged so as to be opposite all the various orifices 18 (as illustrated in [Fig. 3]). The distal end 13b of the internal dielectric screen 13 is then located downstream of the various orifices 18. Said section is then closer to the distal end 16b of the sheath 16 than is the first series of orifices 18. - can be arranged in the sheath so that no section of the feed electrode 12 surrounded by the internal dielectric screen 13 is opposite at least one of the various orifices 18 (as illustrated in [Fig. 6]). The distal end of the electrode 12 is then located upstream of the various orifices 18. This section is then further from the distal end 16b of the sheath 16 than is the first series of orifices 18.

[0109] Optionally, at least when the channel 17 extends straight along the general direction X, the internal dielectric screen 13 (and therefore the electrode 12) also extends coaxially to said general direction X.

[0110] In the present case, at the distal end 11b of the instrument 11, the power supply electrode 12 is arranged inside the internal dielectric screen 13, the distal end 13b of which is itself closed and itself arranged inside the sheath 16.

[0111] The instrument 11 comprises at least one additional layer or element acting as a counter-electrode as long as the instrument 11 remains inside the endoscope 2 (beyond this, the patient himself will act as the counter-electrode). For example, the distal end of the endoscope 2 comprises an electrically conductive portion, for example, made of metal. The counter-electrode, also made of an electrically conductive material, for example, metal, thus connects said electrically conductive portion to ground (for example, a ground external to the device 1, such as the ground of a mains socket). The counter-electrode may be formed by an electrically conductive wire, for example, a metallic wire. For example, the counter electrode is arranged around the sheath 16 of the instrument 11 (for example the counter electrode is twisted around the sheath 16) or extends through one of the channels (such as channel 3) of the endoscope 2.

[0112] Instrument 11 thus comprises, from the inside out, the following successive layers: - the feed electrode 12, - the internal dielectric screen 13, - the sheath 16.

[0113] The different layers optionally extend coaxially with each other and in the X direction.

[0114] Furthermore, the gas supply source 5 and the gas evacuation system 6 are also connected in the space delimited between the internal dielectric screen 13 and the sheath 16.

[0115] Optionally the tool 10 includes at least one guide cable 20 for the tool 10.

[0116] Such a guide cable 20 facilitates the movement of the tool 10 in the body 100 of the patient, in particular if it is a question of passing the tool 10 into cavities of very small diameters.

[0117] The guide cable 20 extends here mostly outside the instrument 11. The guide cable 20 extends here mostly in the conduit 3, between the conduit 3 and the instrument IL.

[0118] A channel 21 is provided here in the distal end 16b of the sheath 16. It is therefore understood that the channel 21 is provided so as not to open into one of the orifices 18 or into the channel 17.

[0119] The conduit 21 is here shaped to extend into the distal end 16b of the sheath 16 so as to open out at both ends of the sheath 16.

[0120] The first end of the pipe 21 opens, for example, onto a side of the duct 16, like the orifices 18. For example, a section of the pipe ending with said first end extends radially into the duct 16.

[0121] The second end of the pipe 21 opens here onto the front of the duct 16. For example, a section of the pipe 21 ending with said second end extends axially into the duct 16. Thus, when at least the end of the duct 16 extends straight along the general direction X, said section extends parallel (and preferably coaxially) to the general direction X. Preferably, the second end opens onto the most distal area 19 of the distal end 16b of the duct 16 (i.e. here the top of the dome).

[0122] Pipeline 21, for example, has the same cross-section over its entire length.

[0123] The guide cable 20 thus extends along the instrument 11 outside of it and then extends into said conduit 21 before exiting the instrument 11 from the front of it.

[0124] This ensures very good guidance of instrument 11.

[0125] In operation, an electrical voltage is applied to the supply electrode 12 which will cause, by potential difference between the supply electrode 12 and the counter electrode, the generation of a plasma inside the instrument 11 and / or outside the instrument 11 depending on the operating mode of the chosen device.

[0126] It is therefore possible to treat an area by bringing the distal end 11b of the instrument 11 close to said area.

[0127] Preferably, the area to be treated is exposed to the plasma for a time interval of between 0.01 seconds and 2 hours and preferably between 10 seconds and 30 minutes and preferably between 1 and 10 minutes.

[0128] Device 1 and in particular tool 10 as described allows targeted application of plasma to a patient.

[0129] The generated plasma is advantageously a "cold plasma," that is, a plasma out of thermodynamic equilibrium where the temperature of the electrons is much higher than that of the ions, which is itself higher than that of neutral species (atoms and molecules). The temperature of this cold plasma is compatible with the patient's body temperature. This plasma is generated at atmospheric pressure and therefore does not require any special enclosure (e.g., a vacuum chamber). The inventors were thus able to develop a prototype generating a plasma with a gas temperature below 40 degrees Celsius, thereby facilitating its direct application to the human body. Furthermore, the device 1, and in particular the tool 10, as described above, has electrical insulation, making its use very safe for both the practitioner and the patient. Finally, the tool 10 has little or no impact on the tissues surrounding the area to be treated.

[0130] In this first embodiment the generated plasma is said to be "volumetric" because it can extend into the volume separating the internal dielectric screen 13 from the sheath 16. Thus, the generated plasma is entirely contained in this volume (with regard to the instrument 11), the plasma being able to propagate out of the instrument 11 towards the area to be treated via the various orifices 18.

[0131] With reference to Figures 3 and 4, as the distal end of the sheath 16 is closed, the plasma does not propagate in the axial extension of the distal end 11b of the instrument 1.

[0132] On the contrary, the plasma will propagate laterally with respect to said distal end 11b. In the specific example illustrated, the plasma propagates radially with respect to said distal end 11b.

[0133] It is understood that tubular cavities of the patient can thus be easily treated with plasma thanks to the generation of plasma over the entire circumference of the instrument 11.

[0134] As mentioned above, different orifice configurations are possible.

[0135] With reference to [Fig. 5], the number of sets of orifices 18 may be less than three or may be greater than three. Example A thus proposes six sets of orifices 18.

[0136] At least one of the series of orifices 18 may have a number of orifices 18 less than four or greater than four. Example B thus provides eight orifices 18 for the same series.

[0137] At least one series of orifices 18 may have at least two orifices 18 different from each other.

[0138] At least two sets of orifices 18 may have at least one orifice 18 in the first set that differs from at least one orifice 18 in the second set, as illustrated in Example C. For example, the orifices 18 may be of the same shape but have different dimensions. For example, the sets may have orifices 18 with an increasingly large diameter as one approaches the most distal zone 19 of the sheath 16, or conversely, a decreasing diameter.

[0139] At least one orifice 18 may have a cross-section that differs along the length of the orifice 18: for example, the cross-section may widen towards the outside of the sheath 16 or, conversely, narrow towards the outside of the sheath 16.

[0140] At least three sets of orifices 18 may not have the same axial spacing between two consecutive sets.

[0141] At least three orifices 18 may not have the same circumferential spacing on the same series.

[0142] At least one orifice 18 may not extend straight in the sheath but may extend, for example, in a curved manner.

[0143] Of course the invention is not limited to the embodiment described and variations can be made to it without departing from the scope of the invention as defined by the claims.

[0144] As indicated, the device may include other elements than those indicated, such as one or more other tools inserted into the applicator (biopsy tool, camera-type observation tool, illumination tool, etc.) in addition to the described tool dedicated to the generation of plasma.

[0145] If a distal face is not planar, the distance taken between said face and another point shall be considered implicitly as being taken from the most distal point of said face to the other point.

[0146] The counter electrode may differ from what has been indicated. The counter electrode may be arranged externally to the sheath and / or arranged coaxially to the sheath by being arranged around it and / or arranged externally to the internal dielectric screen and / or arranged coaxially to the internal dielectric screen by being arranged around it. The counter electrode may be a grounding electrode or a floating electrode.

[0147] The instrument may include other layers than those indicated, such as an external dielectric screen. The external dielectric screen may be arranged externally to the sheath and / or coaxially to the sheath.

[0148] In all cases, if the sheath is surrounded externally or internally by one or more additional layers, the orifice(s) passing through the sheath will also pass through said layer so as to open at one end into the channel and at a second end outside the instrument.

[0149] The device may be designed to operate in several modes. In a first mode, a gas will be injected into the instrument: the plasma generated in the instrument will then tend to propagate out of the instrument in the form of a pen (or "feather" in English) whose dimensions can be adjusted by modifying, for example, the flow rate of the carrier gas and / or the distance between the orifice through which the pen exits and the area to be treated. It follows that there will then be one pen per orifice. In a second mode, no gas will be injected into the instrument. Plasma is then generated directly within the gas mixture already present in the instrument. In a third mode, a liquid and / or vapor solution (for example, a physiological medium, a pharmacological drug, etc.) is injected into the instrument. The solution is then activated and / or treated by the plasma generated within the instrument as it progresses through the instrument before reaching the treatment area.

[0150] At least one area of ​​the instrument (such as the distal end of the sheath) may include marking such as isotopic marking.

[0151] Although here the thickness of the internal dielectric screen, as well as that of the sheath, is constant along the entire length of the internal dielectric screen (respectively, the sheath), this thickness may vary along the length of the dielectric screen and / or the sheath. The thickness of the internal dielectric screen may thus be greater at the distal end of the internal dielectric screen.

[0152] The orifices may optionally be covered (on an external face of the sheath) with a layer of semi-permeable material allowing the plasma to escape from the instrument through the orifices, while limiting the penetration of fluid into the instrument through the orifices. The layer of semi-permeable material may thus, for example, take the form of a membrane.

Claims

Demands

1. Tool for a medical plasma treatment device, the tool comprising at least one instrument (11) which has a sheath (16) in which a channel (17) is formed, the channel being closed at its distal end and the sheath comprising at least one orifice (18) passing through a thickness of the sheath so as to open at one end into the channel and at a second end outside the sheath, the instrument further comprising at least one power electrode (12) and a dielectric screen (13), the power electrode being arranged inside the dielectric screen so that the distal end of the power electrode is covered by the dielectric screen, a plasma generated in operation by the treatment device propagating out of the instrument through the orifice.

2. Tool according to claim 1, wherein the dielectric screen (13) and the feed electrode (12) are arranged in the channel so that at least a section of the feed electrode surrounded by the dielectric screen is opposite the orifice.

3. Tool according to claim 1 or claim 2, wherein a distance (L4) separating the distal end (13b) of the internal dielectric screen (13) from the distal end (17b) of the channel (17) is between 1 millimeter and 40 centimeters.

4. Tool according to claim 1, wherein at least one orifice (18) extends radially into the sheath (16).

5. Tool according to claim 1 or claim 2, wherein the sheath (16) comprises a plurality of orifices (18) through the thickness of the sheath so as to open at a first end into the channel (17) and at a second end outside the sheath (16).

6. Tool according to claim 3, wherein the orifices (18) follow a circumferential direction of the sheath (16).

7. Tool according to claim 3 or claim 4, wherein the orifices (18) form at least two series of orifices spaced axially apart from each other.

8. Tool according to any one of the preceding claims, comprising a guide cable (20).

9. Tool according to claim 4, wherein a channel (21) is provided in the distal end (16b) of the sheath (16) without opening into the orifice (18) or into the channel (17), the guide cable (20) extending for part of its length in this channel.

10. Tool according to any one of the preceding claims, wherein the distal end (16b) of the sheath (16) is rounded and / or beveled.

11. Tool according to any one of the preceding claims, wherein the sheath (16) is made of or based on polytetrafluoroethene.

12. Tool according to claim 1, wherein the dielectric screen (13) and the feed electrode (12) are arranged in the channel such that no section of the feed electrode surrounded by the internal dielectric screen is opposite at least one of the different orifices.

13. Medical treatment device comprising an applicator in which at least one conduit (3) is provided, a tool according to any one of claims 1 to 12, being arranged so that at least its instrument extends into said conduit (3).

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