Tool for a cold-plasma medical treatment device, and corresponding device

Abstract

The invention relates to a tool for a plasma medical treatment device, the tool comprising at least one instrument (11) which comprises a sheath (16) in which a channel (17) is provided, 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 a first end into the channel and to open at a second end to the outside of the sheath, the instrument further comprising at least one supply electrode (12) and a dielectric screen (13), the supply electrode being arranged inside the dielectric screen such that the distal end of the supply electrode is covered by the dielectric screen, a plasma that is generated by the treatment device during use propagating out of the instrument via the orifice. The invention further relates to a device comprising such a tool.

Description

[0001] TOOL FOR COLD PLASMA MEDICAL TREATMENT DEVICE AND CORRESPONDING DEVICE

[0002] The invention relates to a tool for a plasma medical treatment device.

[0003] Such a tool can be used just as well on a patient (human) as on an experimental model (animal).

[0004] 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 esophagus, stomach, pancreas, large intestine, small intestine, duodenum, bile duct...), laparoscopy, gynecology (including obstetrics), orthopedics...

[0005] 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.

[0006] Such a tool can be used to apply plasma directly to a given treatment area and / or indirectly via a liquid (solution, hydrogel, medical liquid, etc.) applied to the treatment area, the liquid being or having been previously treated with plasma.

[0007] The invention also relates to a device comprising such a tool. BACKGROUND OF THE INVENTION

[0008] Plasma is considered a state of matter, just like liquid, solid, and gas. This "fourth state" can be obtained by ionizing a gas subjected to an electric field or by heating it to a high temperature.

[0009] It has been observed that the action of 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 contains metallic walls; these walls can conduct electricity and thus electrocute both the patient (or experimental model) and the operator. In short, current prototypes do not allow for the safe generation of plasma in a catheter-type tool, itself inserted into an endoscope, for both the patient (or experimental model) and the operator.

[0012] SUBJECT OF THE INVENTION

[0013] One aim 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 provide 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 one end into the channel and at a second end outside the sheath, the instrument further comprising at least one supply electrode and a dielectric screen, the supply electrode being arranged inside the dielectric screen so that the distal end of the supply 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, plasma treatment can be applied laterally to the instrument and no longer longitudinally as with previous art devices: the distal end of the sheath remains solid, which provides more protection for a patient / experimental model / practitioner.

[0018] Optionally, the dielectric screen and the feed electrode are arranged in the channel.

[0019] 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.

[0020] Optionally, the distance separating the distal end of the internal dielectric screen from the distal end of the channel is between 1 millimeter and 40 centimeters.

[0021] Optionally at least one orifice extends radially into the sheath.

[0022] Optionally, the sheath includes a plurality of orifices through the thickness of the sheath so as to open at one end into the channel and at a second end outside the sheath.

[0023] Optionally, the orifices follow a circumferential direction of the sheath.

[0024] Optionally, the orifices form at least two series of orifices spaced axially apart from each other.

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

[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 the terminals closed.

[0032] BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The invention will be better understood in light of the following description with reference to the attached figures, among which:

[0034] [Fig. 1] Figure 1 is a schematic view of a device according to a particular embodiment of the invention;

[0035] [Fig. 2] Figure 2 is a perspective view of a medical tool of the device shown in Figure 1,

[0036] [Fig. 3] Figure 3 is a cross-sectional view, along an axial cutting plane, of the tool shown in Figure 2.

[0037] [Fig. 4] Figure 4 is a cross-sectional view, along a transverse cutting plane, of the sheath of the medical tool shown in Figure 2,

[0038] [Fig. 5] Figure 5 shows possible variations of the tool sheath illustrated in Figure 2,

[0039] [Fig. 6] Figure 6 is a cross-sectional view, along an axial cutting plane, of a variant of the tool shown in Figure 2.

[0040] DETAILED DESCRIPTION OF THE INVENTION

[0041] With reference to figure 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.

[0042] The endoscope 2 has 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 patient's body 100 and a distal end 2b of the endoscope intended to be positioned inside the patient's body 100 near an area to be treated. In this case, the endoscope 2 has several working conduits.

[0043] 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.

[0044] The endoscope 2 can be introduced into the patient via a natural or artificial cavity 101 of the patient.

[0045] As is known, endoscope 2 is flexible enough to deform in order to follow the natural path of cavity 101 if necessary. Endoscope 2 has a diameter of 12 millimeters for example.

[0046] 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...).

[0047] 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.

[0048] 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, the instrument 11 is also sufficiently flexible to deform and follow the movement of the associated endoscope 2.

[0049] Instrument 11 is a tubular instrument.

[0050] Instrument 11 also extends axially along a general direction X.

[0051] Instrument 11 extends more particularly here so that one or more of its axial ends protrude from endoscope 2. Tubular instrument 11 extends more particularly here so that both of its axial ends protrude from endoscope 2.

[0052] The distal end 11b of the instrument 11 extends out of the endoscope 2 (distal end side 2b of the endoscope 2) and the proximal end 11a of the instrument 11 extends out of the endoscope 2 (proximal end side 2a of the endoscope 2).

[0053] Device 1 also includes a plasma generation system which comprises 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. The electrical power supply source 4 has, for example, the following parameters:

[0054] use of a direct current, alternating current (square wave, sinusoidal wave, triangular wave, sawtooth wave...), pulsed voltage... and / or

[0055] using 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

[0056] using 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.

[0057] For example, the gas supply source 5 has the following parameters:

[0058] use of a carrier gas chosen from helium, argon, neon..., and / or

[0059] use of a carrier gas at a flow rate between 0 and 10 liters per minute (under standard temperature and pressure conditions 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

[0060] 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 (at standard temperature and pressure) and preferably between 0.01 and 1 liter per minute and preferably 0.05 liters per minute, and / or

[0061] use of a continuous, static, turbulent flow regime... 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.

[0062] 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.

[0063] With reference to figures 1 to 4, tool 10 will now be described.

[0064] The instrument 11 of said tool 10 comprises, from the inside out, at least the following layers:

[0065] a 12-volt power supply electrode,

[0066] an internal dielectric screen 13,

[0067] a sheath 16.

[0068] The power supply electrode 12 is a polarized electrode. The power supply electrode 12 is made of an electrically conductive material, for example a metal, for example copper-based or aluminum-based.

[0069] Preferably, the feed electrode 12 is a simple wire. The feed electrode 12 is thus very simple in structure.

[0070] The external diameter of the feed electrode 12 is, for example, between 0.01 and 10 millimeters, between 0.01 and 5 millimeters, between 0.05 and 0.35 millimeters, and between 0.1 and 0.3 millimeters. The feed electrode 12 is directly connected to the electrical power supply 4. Consequently, its electrical potential is not variable and depends only on the electrical characteristics of the power supply 4, which are known and precisely controlled. Therefore, the feed electrode 12 has a constant (and thus non-variable) potential.

[0071] Thus, the risk of the plasma transitioning to a thermal arc regime is advantageously limited. The instrument is therefore very safe to use.

[0072] 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 feed electrode 12, the coating then covering the distal end of the feed electrode 12 (the internal dielectric screen 13 then not having a definite shape until it is applied to the feed electrode 12).

[0073] In this way, the supply electrode 12 is entirely arranged inside the internal dielectric screen 13. In particular, the distal end of the supply electrode 12 is entirely 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...).

[0074] Thus, the power supply electrode 12 and the internal dielectric screen 13 are joined together.

[0075] 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.

[0076] Thus, the risk of the plasma transitioning to a thermal arc regime is advantageously limited.

[0077] 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 power supply source 4).

[0078] The internal dielectric screen 13 is of course made of a dielectric material.

[0079] The internal dielectric screen 13 is, for example, made of natural or synthetic rubber. The internal dielectric screen 13 is, for example, made of plastic (polyvinylidene fluoride, polytetrafluoroethylene, perfluoroalkoxy, etc.).

[0080] 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 feed electrode 12).

[0081] The sheath 16 forms a supporting structure for the instrument 11.

[0082] Sheath 16 is therefore not a counter electrode.

[0083] The sheath 16 is preferably made of an electrically insulating material.

[0084] The sheath 16 is, for example, made of natural or synthetic rubber. The sheath 16 is, for example, made of plastic (polyvinylidene fluoride, polytetrafluoroethylene, perfluoroalkoxy, polytetrafluoroethene, etc.). 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.

[0085] 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.

[0086] A channel 17 is formed within the sheath 16 so that it opens at the proximal end of the sheath 16 on one side and is closed at its distal end 17b. Thus, the channel 17 does not open outside the sheath 16 at its distal end 16b. Therefore, the distal wall of the channel 17 completely closes it at its distal end 17b.

[0087] 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.

[0088] The sheath 16 is thus closed at its distal end 16b.

[0089] 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.

[0090] At least when the instrument 11 extends straight along the general direction X, the channel 17 extends coaxially to this general direction X. The channel 17 presents, for example, the same cross-section over its entire length.

[0091] 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 within the patient's body 100 without rubbing against or damaging internal tissues.

[0092] 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.

[0093] Furthermore, the sheath 16 includes at least one orifice 18 passing through a thickness of the sheath 16 so as to open at one 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.

[0094] For example, orifice 18 has a maximum diameter between 100 and 1500 micrometers and for example between 200 and 1000 micrometers.

[0095] 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.

[0096] The orifice 18 is formed in the sheath 16 so as to open into the canal 17 at the distal end 17b of the canal 17, while being offset from the distal wall that completely closes the canal 17 at its distal end 17b. The orifice 18 therefore does not open at the level of said distal wall. There is thus an offset (along the general direction X) between said distal wall and the orifice 18.

[0097] 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).

[0098] The orifice 18 therefore extends in the immediate vicinity of the distal end 16b of the sheath 16 but does not extend into the interior of it.

[0099] 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.

[0100] Preferably, the sheath 16 includes several orifices 18 through the thickness of the sheath 16 so as to open at one end into the channel 17 and at a second end outside the sheath 16.

[0101] In this case, all the orifices 18 are identical to each other. Therefore, what was said above for one of the orifices 18 also applies to the other orifices 18.

[0102] Different configurations of 18 orifices are also possible.

[0103] According to a first variant illustrated in Figures 3 and 4, a first series of orifices 18 is provided in the sheath. 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.

[0104] The series of orifices 18 are axially offset from one another within 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.

[0105] 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.

[0106] Optionally, the different series are all identical to each other. The following description of the first series of 18 orifices is therefore also applicable here to the other series.

[0107] 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 individual 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, or, for example, between 300 and 500 micrometers, and is, for example, 400 micrometers.

[0108] For example the series has 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.

[0109] Preferably, the orifices 18 are provided in the sheath 16 so as to extend two by two in the continuation of one another.

[0110] 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.

[0111] Optionally at least one, and in this case all orifices 18, extend straight into the sheath 16.

[0112] Optionally at least one, and in this case all the orifices 18, have a cross-section which remains identical over the entire length of the orifice 18.

[0113] Optionally at least one, and in this case all 18 orifices, have a circular cross-section.

[0114] 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.

[0115] 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.

[0116] Since the assembly "supply electrode 12 and internal dielectric screen 13" is not fixed in this case to the sheath 16, the distance L4 can easily be modified during an intervention by the practitioner according to his needs.

[0117] 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:

[0118] - 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 Figure 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.

[0119] - 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 Figure 6). The distal end of the electrode 12 is then located upstream of the various orifices 18. Said section is then further from the distal end 16b of the sheath 16 than is the first series of orifices 18. Optionally, at least when the channel 17 extends straight ahead along the general direction X, the internal dielectric screen 13 (and therefore the electrode 12) also extends coaxially to said general direction X.

[0120] In the present case, at the distal end 11b of the instrument 11, the 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.

[0121] The instrument 11 includes at least one additional layer or element that acts as a counter-electrode as long as the instrument 11 remains inside the endoscope 2 (beyond this point, the patient themselves acts as the counter-electrode). For example, the distal end of the endoscope 2 has an electrically conductive portion, for example, made of metal. The counter-electrode, also made of an electrically conductive material, for example, metal, connects this electrically conductive portion to ground (for example, a ground external to the device 1, such as a mains power outlet). The counter-electrode can 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.It is therefore understood that although the counter electrode can be arranged around the sheath 16, it cannot be formed by the sheath 16 itself.

[0122] Instrument 11 thus comprises, from the inside out, the following successive layers:

[0123] - the power supply electrode 12, the internal dielectric screen 13,

[0124] sheath 16.

[0125] The different layers optionally extend coaxially with each other and in the X direction.

[0126] 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.

[0127] Optionally, tool 10 includes at least one guide cable 20 for tool 10.

[0128] Such a guide cable 20 facilitates the movement of the tool 10 in the patient's body 100, particularly when it is a matter of passing the tool 10 into cavities of very small diameters.

[0129] The guide cable 20 extends here mostly outside of the instrument 11. The guide cable 20 extends here mostly within the conduit 3, between the conduit 3 and the instrument 11.

[0130] 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.

[0131] 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.

[0132] The first end of the pipe 21 opens, for example, onto one side of the duct 16, like the orifices 18. For example, a section of the pipe ending at said first end extends radially into the duct 16.

[0133] 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).

[0134] Pipe 21, for example, has the same cross-section over its entire length.

[0135] 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.

[0136] This ensures very good guidance of instrument 11.

[0137] 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.

[0138] It is therefore possible to treat an area by bringing the distal end 11b of the instrument 11 close to said area.

[0139] Preferably, the area to be treated is exposed to 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.

[0140] Device 1, and in particular tool 10 as described above, allows for the targeted application of plasma to a patient. 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, Device 1, and in particular tool 10, as described above, has electrical insulation, making its use very safe for both the practitioner and the patient.Finally, tool 10 has little or no impact on the tissues surrounding the area to be treated.

[0141] 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 within this volume (with regard to the instrument 11), the plasma can also propagate out of the instrument 11 towards the area to be treated via the various orifices 18.

[0142] 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.

[0143] On the contrary, the plasma will propagate laterally with respect to the distal end 11b. In the specific example illustrated, the plasma propagates radially with respect to the distal end 11b. It is understood that tubular cavities of the patient can thus be easily treated with plasma thanks to the generation of plasma around the entire circumference of the instrument 11.

[0144] As mentioned above, different orifice configurations are possible.

[0145] With reference to Figure 5, the number of sets of orifices 18 may be less than three or greater than three. Example A thus proposes six sets of orifices 18.

[0146] 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 proposes eight orifices 18 for the same series.

[0147] At least one series of orifices 18 may have at least two orifices 18 different from each other.

[0148] 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 larger diameter as one approaches the most distal region 19 of the sheath 16, or conversely, with a decreasing diameter.

[0149] At least one orifice 18 may have a cross-section that is different over the length of the orifice 18: for example the cross-section may widen towards the outside of the sheath 16 or, on the contrary, narrow towards the outside of the sheath 16.

[0150] At least three sets of orifices 18 may not have the same axial spacing between two consecutive sets. At least three orifices 18 may not have the same circumferential spacing within the same set.

[0151] At least one orifice 18 may not extend straight in the sheath but may extend, for example, in a curved manner.

[0152] 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.

[0153] As indicated, the device may include other elements than what has been 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.

[0154] 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.

[0155] The counter electrode may differ from what has been specified. It may be arranged externally to the sheath and / or coaxially to the sheath, positioned around it, and / or externally to the internal dielectric shield and / or coaxially to the internal dielectric shield, positioned around it. The counter electrode may be a grounding electrode or a floating electrode.

[0156] The instrument may include other layers than those specified, such as an external dielectric screen. The external dielectric screen may be arranged externally to the sheath and / or coaxially to the sheath.

[0157] 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.

[0158] The device can be designed to operate in several modes. In the first mode, a gas will be injected into the instrument: the plasma generated within the instrument will then tend to propagate out of the instrument in the form of a plume (or "feather") 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 plume escapes and the area to be treated. It is understood that there will then be one plume per orifice. In the second mode, no gas will be injected into the instrument. The plasma will then be generated directly within the gas mixture naturally present in the instrument. In the third mode, a liquid and / or vapor solution (for example, a physiological medium, a pharmacological drug, etc.) will be injected into the instrument.The solution will thus be activated and / or treated by the plasma generated in the instrument throughout the progression of the liquid solution in the instrument before reaching the area to be treated.

[0159] At least one area of ​​the instrument (such as the distal end of the sheath) may include marking such as isotopic marking.

[0160] Although the thickness of the internal dielectric screen, as well as that of the sheath, is constant along its entire length, this thickness may vary along the length of the dielectric screen and / or the sheath. The thickness of the internal dielectric screen may therefore be greater at its distal end.

[0161] The orifices may optionally be covered (on one outer face of the sheath) with a layer of semi-permeable material, allowing plasma to escape from the instrument through the orifices while limiting fluid penetration into the instrument through the orifices. This layer of semi-permeable material could, for example, take the form of a membrane.

Claims

IONS CLAIMS 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, in which at least one orifice (18) extends radially in the sheath (16).

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

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

7. Tool according to claim 3 or claim 4, in which 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, in which 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 over 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 his instrument extends into the said conduit (3).

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