DEVICE AND METHOD FOR PLASMA ACTIVATION OF A LIQUID

Abstract

A device for creation of a plasma-activated liquid with defined characteristics. The device includes a plasma application device having a plasma applicator. A liquid is brought into contact with a gas plasma in the plasma application device. A sensor device serves for analysis of the composition of the plasma-treated liquid at least in terms of a species created by the plasma treatment. Based on a concentration of one or more species detected by the sensor device, treatment parameters of the liquid in the plasma application device can be adjusted or modified. Thereby a plasma-treated liquid with defined characteristics for treatment of a patient is provided.

Claims

1. A device for supply of a medical instrument with a plasma-activated liquid, the device comprising: a plasma generator for supply of a plasma; a plasma application device in which a liquid can be brought into contact with the plasma and having an outlet in order to discharge liquid from the plasma application device and to supply it to the instrument; and a sensor device for detection of at least one chemical or physical parameter of the liquid during and/or after the plasma exposure in the plasma application device.

2. The device according to claim 1, wherein the plasma application device comprises a plasma applicator having a gas channel and at least one electrode being in contact with gas from the gas channel, as well as an electrode being in electrical contact with the liquid, both electrodes being connected to the plasma generator.

3. The device according to claim 1, wherein an outlet of the plasma application device is connected to a storage vessel that can be connected with the instrument.

4. The device according to claim 3, wherein the sensor device and/or a control device is connected to at least one control element in order to control the residence time of the liquid in the plasma application device.

5. The device according to claim 1, wherein the plasma generator can be controlled in terms of a supplied voltage, a supplied current, a supplied power, a supplied crest factor or a supplied wave form.

6. The device according to claim 5, wherein the sensor device and/or a control device is connected to the plasma generator in order to control it dependent on the detected parameter.

7. The device according to claim 2, wherein the gas channel is connected to a gas source that can be controlled in terms of the gas flow.

8. The device according to claim 7, wherein the sensor device and/or a control device is connected to the gas source in order to control its gas flow depending on the detected parameter.

9. The device according to claim 1, wherein the sensor device is configured to detect at least one of a temperature, a conductivity, an acidity (pH-value), a chemical composition and a concentration of particular chemical compounds.

10. The device according to claim 1, wherein the sensor device is configured to detect the concentration of plasma created substances in the plasma-activated liquid in the form of at least one of hydronium ions (H.sub.3O.sup.+), hydroxide ions (OH.sup.−), hydrogen peroxide (H.sub.2O.sub.2), nitrite ions (NO.sub.2.sup.−), nitrate ions (NO.sub.3.sup.−), of hydroxyl radicals (.OH).

11. The device according to claim 1, wherein the sensor device is configured to detect the concentration of plasma created substances in the plasma-activated liquid by spectroscopy.

12. The device according to claim 1, wherein the spectroscopy is absorption spectroscopy of electromagnetic radiation.

13. The device according to claim 1, wherein the sensor device is configured to detect the concentration of plasma created substances in the plasma-activated liquid in form of at least one of singlet oxygen (.sup.1O.sub.2), ozone (O.sub.3), oxygen (O.sub.2), superoxide radical ions (O.sub.2.sup.−), hydroperoxyl radicals (HOO.), peroxynitrite ions (ONOO.sup.−) and nitrogen oxides.

14. The device according to claim 1, wherein the sensor device is configured to detect the concentration of plasma created substances in the plasma-activated liquid by means of at least one of phosphorescence or electron spin resonance spectroscopy.

15. A method for providing a plasma-activated treatment liquid, the method comprising: providing a plasma by a plasma generator; bringing a liquid into contact with the plasma in a plasma application device and is supplied to an instrument; and detecting at least one chemical or physical parameter of the liquid during and/or after the plasma exposure in the plasma application device by means of a sensor device, wherein the operation of the plasma generator and/or the residence time of the plasma-treated liquid in a storage vessel is controlled for influencing of the parameter.

16. The method according to claim 15, further comprising: controlling at least one of a supplied voltage, supplied current, supplied power, supplied crest factor and supplied wave form of the plasma generator.

17. The method according to claim 16, further comprising: controlling the plasma generator dependent on the detected parameter.

18. The method according to claim 15, further comprising: controlling a gas flow from a gas source to a gas channel of the plasma application device depending on the detected parameter.

19. The method according to claim 15, further comprising: detecting with the sensor device at least one of a temperature, a conductivity, an acidity (pH-value), a chemical composition and a concentration of particular chemical compounds.

20. The method according to claim 15, further comprising: detecting with the sensor device a concentration of plasma created substances in the plasma-activated liquid in the form of at least one of hydronium ions (H.sub.3O.sup.+) hydroxide ions (OH.sup.−), hydrogen peroxide (H.sub.2O.sub.2), nitrite ions (NO.sub.2.sup.−), nitrate ions (NO.sub.3.sup.−) and hydroxyl radicals (.OH).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Further details of advantageous embodiments of the invention are subject of the specification or the drawings. The drawings show:

[0027] FIG. 1 shows a block diagram for illustration of structural and functional elements of an embodiment of the inventive device for supply of a medical element with a plasma-activated liquid, and

[0028] FIG. 2 shows a plasma application device for creation of plasma-activated liquids.

DETAILED DESCRIPTION

[0029] FIG. 1 illustrates a device 10 for supply of a medical instrument 11 with plasma-activated liquid with which at least one of different treatment methods can be carried out. Treatment methods are illustrated by function blocks in FIG. 1, wherein block 13 typifies sub-tissue injection with plasma-activated liquid. Block 14 typifies the alternating treatment of tissue with plasma, e.g. argon plasma, and/or with RF-current as well as plasma-activated liquid. Block 15 typifies the wetting or spraying of tissue with plasma-activated liquid.

[0030] An instrument 11 means any instrument with which at least one of the indicated methods illustrated in blocks 13-15 can be executed as well as other instruments for different applications of plasma-activated liquid on a patient or on biological tissue.

[0031] The device 10 comprises a treatment vessel 16 in which a liquid, e.g. sodium chloride solution, Ringer's solution, Ringer's lactate solution or another liquid that can be applied on a patient, is to be treated with plasma. The liquid originates from a reservoir vessel 17 that is connected with the treatment vessel 16 via a controllable pump 18. The pump 18 serves to pump liquid out of the reservoir vessel 17 into the treatment vessel 16 under control of the control device 19, as indicated by arrows 20, 21. In addition, the pump 18 can be configured at least as an option to pump liquid back from the treatment vessel 16 into the reservoir vessel 17, as indicated by arrows 22, 23. The feed direction and as required also the feed rate with which the pump 18 operates is set by the control device 19, as indicated by arrow 24.

[0032] The treatment vessel 16 can be a vessel in which the liquid F to be treated is provided as compact liquid body having a substantially horizontal surface, as illustrated in FIG. 2 in a sketchy manner. Also any other vessel can be used as treatment vessel 16 in which liquid can be brought into contact with a plasma. Such vessels are, e.g. pouring vessels in which a droplet curtain can be poured through a plasma or a liquid layer can be poured along a plasma, vessels having an atomizer that introduce the liquid as spray in a plasma, spinning devices that bring the liquid in form of a thin film in contact with the plasma or the like more. The treatment vessel 16 together with a plasma 30 created therein (FIG. 2) form a plasma application device 25.

[0033] For this FIG. 1 illustrates in function blocks 26-28 surrounded by dashes different mixing devices, at least one of which is at least preferably provided and that serve to distribute reactive species created in the treatment vessel homogeneously. A convector 26 can serve for this purpose that creates a convection flow by application of heat or cold on the liquid. As an alternative, a stirring device 27 can be provided that serves to bring the liquid F in the treatment vessel 16 in movement. A function block 28 illustrates a gas swirling device in order to bring the liquid in the treatment vessel in firm contact with the plasma 30. Each device symbolized by the function blocks 26, 27, 28 can be arranged individually or in combination with one or more of the indicated devices in or at the treatment vessel 16.

[0034] As apparent from FIG. 2, a plasma applicator 29 is assigned to the treatment vessel 16 that is configured for creation of a plasma 30. For example, the plasma applicator 29 can be an argon plasma applicator. It comprises a gas supply channel 31 via which an inert gas, e.g. nitrogen, a noble gas, e.g. argon or helium, or another gas provided for plasma creation, e.g. a reactive gas, e.g. an oxygen-containing gas, is supplied. The gas channel 31 is connected to a gas source 32. It can be configured in a controllable manner, as indicated in FIG. 1 and can be connected to the control device 19 in order to be controlled in terms of the point of time of the gas discharge and/or in terms of the amount of the gas flow.

[0035] The plasma applicator further comprises an electrode 33 configured in a non-insulated manner, i.e. an electrode 33 having an electrically conductive surface that is in contact with or surrounded by the gas flow of the gas supply channel 31.

[0036] The electrode is connected to a pole of a plasma generator 34, the other pole of which is, for example, connected with an electrode 35 surrounded by flow of liquid F. The plasma generator is preferably an RF-generator that is configured for supply of a radio frequency voltage and a radio frequency current. The generator is preferably controllable in terms of the amount of the supplied voltage and/or the supplied power and/or the current and/or in terms of the wave form, the modulation of the duty cycle, the crest factor or other parameters. For this the plasma generator 34 can be connected with the control device 19 and can be controlled by it, as illustrated in FIG. 1.

[0037] The device 10 further comprises a sensor device 36 that is configured and serves to carry out the analysis of the species formed in the treated liquid F. These species are substances that are formed by a plasma treatment of the liquid F in the broadest sense, also ions, radicals, fractions of molecules and the like. The sensor device 36 can be arranged outside of the treatment vessel 16, as schematically illustrated in FIG. 1 and can be supplied, for example, via a circulation 37 with liquid F from the treatment vessel 16.

[0038] A sensor device 36 for optical absorption spectroscopy is schematically illustrated in FIG. 2. For this the sensor device 36 comprises a light emitting device 38 and a light receiving device 39. The light emitting device 38 is, for example, configured to emit ultraviolet, visible and/or infrared light with a known spectral composition into the liquid F. The light receiving device 39 is preferably configured to detect the spectral composition of the ultraviolet, visible and/or infrared light that has passed through the liquid F. The control device 19 is configured to determine the presence and concentration of selected species from the difference between the spectrum of the light emitted by the light emitting device 38 and the light received by the light receiving device 39.

[0039] Instead of the sensor device 36 configured for optical absorption spectroscopy, also any other sensor device can be provided that is configured to detect the presence and/or concentration of one or more species in the liquid. Such sensor devices can be emission spectroscopy devices for ultraviolet, visible and/or infrared light. The sensor device can also be a phosphorescence detection device for ultraviolet, visible and/or infrared light, particularly for near infrared. The sensor device 36 can also be a device for pH-measurement, particularly a single rod measuring cell. The sensor device 36 can comprise one or multiple of the above-mentioned sensor devices.

[0040] The control device 19 can control the plasma generator 34 in order to control the concentration and/or composition of different species in the liquid F. For example, the control device 19 can control the current and/or voltage supplied by the plasma generator 34 in terms of power, amount, wave form, crest factor, frequency, modulation and the like in order to control the plasma and thereby the creation of species.

[0041] The treatment vessel 16 can be connected directly with the instrument 11 via a pump 40 in order to supply the instrument 11 with plasma-activated liquid. As an option, a storage vessel 41 can be provided between the pump 40 and the instrument 11 in which plasma-activated liquid can be stored over a predefined or selectable period of time.

[0042] The sensor device 36 can be connected with the storage vessel 41 in addition or as an alternative to the circulation 37. Similarly, the storage vessel 41 can be connected with an individual sensor device that is then in turn connected with the control device 19. By control of the pump 40 and/or a not further illustrated pump arranged between the storage vessel 41 and the instrument 11 the control device 19 can define a storage duration for the plasma-treated liquid F. Since the concentration of the species created in the plasma-treated liquid decreases with different rates after plasma treatment of a liquid F, the control device 19 can discharge plasma-treated liquid F by setting a defined storage duration as necessary under control of the sensor device 36 in which, for example, species with short lifetime have mostly disappeared, however, species with long lifetime are contained with higher concentration. On the other hand, if the treatment request comprises predominantly species with short lifetime, it can be determined by means of the sensor device 36 whether these have been created in sufficient concentration in order to supply them immediately to the instrument 11. For this purpose, it can be provided to supply liquid from the storage vessel 41 for post activation to the treatment vessel 16 as necessary. This is indicated in FIG. 1 by double arrows 42, 43.

[0043] The device 10 and the instrument 11 described so far operate as follows:

[0044] The reservoir vessel 17 is first filled with a liquid to be activated, e.g. sodium chloride solution, via a filler neck 44 (FIG. 1). The control device 19 now activates pump 18 and supplies liquid F in the treatment vessel 16, e.g. in that the treatment vessel 16 is filled with liquid F. In addition, the control device 19 activates the plasma generator 34 and as necessary the gas source 32, such that the plasma applicator 29 now creates a plasma 30 acting on the liquid F (FIG. 2). The sensor device 36 is operating continuously or in discrete intervals in order to detect the quality of the liquid F, i.e. its plasma activation. The quality of the plasma activation is thereby particularly defined by the concentration of selected species, as for example the content of hydronium ions, hydroxide ions, hydrogen peroxide, nitrite, nitrate, peroxynitrite, singlet oxygen, ozone, hydroperoxide, oxygen, superoxide radical ions, hydroxyl radicals and/or hydroperoxyl radicals. For detection of such species the sensor device 36 is configured as so-called pH-single rod measuring cell, as spectroscope for emitted light (IR, visible and/or UV), as absorption spectroscope (as illustrated in FIG. 2), as phosphorescence sensor, for example for radiation of the wave length of 1275 nm for measuring of singlet oxygen or as electron spin resonance spectroscope. The sensor device 36 can also comprise multiple of the indicated measuring devices.

[0045] Based on the concentration of the selected species determined by the sensor device, the control device 19 can set, extend or reduce the plasma treatment duration of the liquid, can regulate the parameters of the current or the voltage supplied by the plasma generator 34 and/or can influence the gas flow from the gas source 32. In addition or as an alternative, the control device 19 can set or limit the storage duration of the plasma-treated liquid in the storage vessel 41 and/or can control one or more of the devices 26-28.

[0046] The control device 19 can be configured to influence the quality of the liquid F in terms of one or more of the correlations indicated in the following: [0047] Influencing of the effect strength of the plasma, i.e. the electrical power transformed in the plasma or other parameters, depending on the desired pH-value. With a higher power, a lower pH-value is achieved. [0048] Defining the application duration of the plasma on the liquid, depending on the desired pH-value. With a higher application duration, a lower pH-value is achieved. [0049] Defining the effect strength of the plasma, i.e. the electrical power transformed in the plasma or other parameters, depending on the desired ratio of hydrogen to nitrate. [0050] Selection of the liquid to be treated, depending on the desired ratio of hydrogen to nitrate. The liquids provided for selection can be, for example, a NaCl-solution and phosphate buffered NaCl-solution.

[0051] The control device 19 can use the chemical and/or physical parameter(s) of the treated liquid F detected by the sensor device 36 in order to control the operation of the plasma application device 25 or the plasma generator 34 in order to achieve a desired quality of the liquid F, i.e. a desired composition of the obtained species. During control of the plasma generator at least one parameter of the current and/or the voltage supplied therefrom is influenced.

[0052] With embodiments of the invention a device 10 for creation of a plasma-activated liquid F with defined characteristics is provided. The device 10 comprises a plasma application device 25 provided with a plasma applicator 29, wherein a liquid F is brought into contact with a gas plasma 30 in the plasma application device 25. A sensor device 36 serves for analysis of the composition of the plasma-treated liquid F at least in terms of a species created by the plasma treatment. Based on a concentration of one or more species detected by the sensor device 36, treatment parameters of the liquid F in the plasma application device 25 can be adjusted or modified. Thereby a plasma-treated liquid F with defined characteristics for treatment of a patient is provided.