DEVICE FOR SUPPORTING A TREATMENT USING PULSED ELECTRIC FIELDS IN ORDER TO HEAL WOUNDS AND/OR FOR THE INACTIVATION OF MICROORGANISMS, AND METHOD FOR THE INACTIVATION OF MICROORGANISMS

Abstract

The invention relates to a device (10) for supporting a treatment using pulsed electric fields in order to heal wounds and/or for the inactivation of microorganisms. The device comprises an electric energy storage device (16), a pulse generator (17) for providing electric excitation pulses, a transformer (26) for providing high-frequency electric pulses (200) on an output side (28), a first connection of the input side (27) of the transformer (26) being connected to the pulse generator (17), and a treatment instrument (100) which comprises a closed body (102) made of an electrically insulating material and an electrode (110) arranged in the interior of the body (102). A gas or a gas mixture is received in the interior of the body (102), and the treatment instrument (100) is designed to discharge gas in the event of an electric excitation. A first end (103) of the treatment instrument (100) is designed to couple to a first connection of the output side (28) of the transformer (26). Furthermore, a second end (104) of the treatment instrument (100) is designed to contact surfaces and/or biological tissue, and a second connection of the output side (28) of the transformer (26) is connected to a second connection of the input side (27) of the transformer (26) and a housing shielding (13). The housing shielding (13) is electrically insulated from the outer environment by a housing of the device and is thus designed as an ungrounded mass, and the transformer (26) and the pulse generator (17) are designed such that the high-frequency electric pulses (200) have a frequency ranging from 10 kHz to 100 kHz and a pulse repetition rate ranging from 100 kHz to 400 kHz. The invention additionally relates to a method for the inactivation of microorganisms, wherein such a device (10) is provided, and the treatment instrument (100) of the device (10) is excited with high-frequency electric pulses.

Claims

1. An apparatus (10) for assisting a treatment with pulsed electrical fields for the healing of wounds and/or for the inactivation of microorganisms, comprising an electrical energy storage unit (16), a pulse generator (17) for providing electrical excitation pulses, a transformer (26) for providing radiofrequency electrical pulses (200) on an output side (28), a first terminal of an input side (27) of the transformer (26) being connected to the pulse generator (17), and a treatment instrument (100) that comprises a closed body (102) made of an electrically insulating material and an electrode (110) arranged in the interior of the body (102), a gas or gas mixture being received in the interior of the body (102) and the treatment instrument (100) being configured for a gas discharge in response to electrical excitation, a first end (103) of the treatment instrument (100) being configured for coupling to a first terminal of the output side (28) of the transformer (26), characterized in that a second end (104) of the treatment instrument (100) is configured for the contacting of surfaces and/or biological tissue, and in that a second terminal of the output side (28) of the transformer (26) is connected to a second terminal of an input side (27) of the transformer (26) and to a housing shield (13), the housing shield (13) being electrically insulated from the surroundings by a housing of the apparatus and therefore being configured as a floating ground, and the transformer (26) and the pulse generator (17) being configured in such a way that the radiofrequency electrical pulses (200) have a frequency in the range of from 10 kHz to 100 kHz and a pulse repetition rate in the range of from 100 Hz to 400 Hz, the treatment instrument being configured to conduct the generated radiofrequency electrical pulses, or the electric fields thereof, to an object to be treated or to an organic or biological material to be treated.

2. The apparatus (10) as claimed in claim 1, characterized in that the apparatus (10) furthermore comprises a safety device (20), which is configured to measure a voltage and/or a frequency of the radiofrequency electrical pulses (200) on the output side (28) of the transformer (26) and to interrupt an energy supply to the transformer (26) if a voltage and/or a frequency of the radiofrequency electrical pulses (200) exceeds and/or falls below predetermined limit values, and/or which is configured to detect an electrical connection of the apparatus (10) to a power supply system and, if such a connection exists, to interrupt an energy supply to the transformer (26).

3. The apparatus as claimed in claim 1, characterized in that the transformer (26) is formed as a pulse-driven transformer and is excited with excitation pulses (210) in order to provide the radiofrequency electrical pulses (200), a repetition rate of the excitation pulses (210) corresponding to the pulse repetition rate of the radiofrequency electrical pulses.

4. The apparatus as claimed in claim 3, characterized in that an excitation of the pulse-driven transformer is adjusted by shifting the placement of a primary coil in relation to a secondary coil.

5. The apparatus as claimed in claim 2, characterized in that the transformer (26) is formed as a pulse-driven transformer and is excited with excitation pulses (210) in order to provide the radiofrequency electrical pulses (200), a repetition rate of the excitation pulses (210) corresponding to the pulse repetition rate of the radiofrequency electrical pulses, and a measurement of the voltage and/or frequency of the radiofrequency electrical pulse is carried out during an excitation pause of the pulse-driven transformer by means of a measurement of the voltage induced on the primary side of the pulse-driven transformer.

6. The apparatus (10) as claimed in claim 1, characterized in that the treatment instrument (100) has a current feed-through for the electrode (110) at the first end (103), and the current feed-through comprises an end cap (112) made of a plastic.

7. The apparatus (10) as claimed in claim 6, characterized in that the plastic of the end cap (112) is reinforced with fibers.

8. The apparatus (10) as claimed in claim 1, characterized in that the body (102) of the treatment instrument (100) is filled with a noble gas (124) or a noble gas mixture having a pressure in the range of from 0.001 mbar to 7 mbar.

9. The apparatus (10) as claimed in claim 1, characterized in that there is a connecting region (106) with a first diameter DS next to the first end (103) of the treatment instrument (100) and there is a bulb region (108) with a second diameter DK next to the second end (103) of the treatment instrument (100), the second diameter DK being greater than the first diameter DS and the bulb region (108) occupying at least one third of the total length of the body (102).

10. The apparatus (10) as claimed in claim 9, characterized in that the treatment instrument (100) has a current feed-through for the electrode (110) at the first end (103), the current feed-through comprises an end cap (112) made of a plastic, and the end cap (112) has a sleeve region (114) that at least partially encloses the connecting region (106) of the treatment instrument (100), and in that the treatment instrument (100) is held on the sleeve region (114) by means of a clamping device (32).

11. The apparatus (10) as claimed in claim 1, characterized in that the treatment instrument (100) is configured for autoclaving with steam at a temperature in the range of from 110° C. to 140° C.

12. A method for the inactivation of microorganisms, wherein an apparatus (10) as claimed in claim 1 is provided and the treatment instrument (100) of the apparatus (10) is excited with radiofrequency electrical pulses, characterized in that the treatment instrument (100) is applied onto a surface of an object in which microorganisms are intended to be inactivated, so that the body (102) of the treatment instrument (100) touches the surface, and the treatment instrument (100) is guided over the surface of the object, the housing shield (13) being electrically isolated from the object so that no electrically conductive connection is established between the object and the second terminals (27b, 28b) of the transformer (26).

13. The method as claimed in claim 12, characterized in that the object is selected from medical instruments and organic material.

14. The method as claimed in claim 13, wherein the organic material is skin or a tissue sample.

15. The method as claimed in claim 12, characterized in that microorganisms in the interior of the object are also inactivated.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0135] Embodiments of the invention will be explained in more detail with the aid of the drawings and the following description.

[0136] FIG. 1a shows a schematic representation of the apparatus for assisting the healing of wounds and/or for the inactivation of microorganisms as a sectional view from above,

[0137] FIG. 1b shows a schematic sectional view of a transformer,

[0138] FIG. 2 shows a simplified schematic circuit diagram of the apparatus,

[0139] FIG. 3 shows a schematic representation of a treatment instrument of the apparatus,

[0140] FIG. 4 shows a detail view of the treatment instrument,

[0141] FIG. 5 shows a qualitative representation of a radiofrequency electrical pulse, and

[0142] FIG. 6 shows a qualitative representation of an electrical excitation pulse for the excitation of the transformer.

EMBODIMENTS OF THE INVENTION

[0143] In the following description of the embodiments of the invention, elements which are the same or similar are denoted by the same references, repeated description of these elements being omitted in certain cases. The figures represent the subject-matter of the invention only schematically.

[0144] FIG. 1a shows an apparatus 10 for assisting the healing of wounds and/or for the inactivation of microorganisms. The apparatus 10 comprises a housing 12 that accommodates all the components of the apparatus 10 except for a part of a treatment instrument 100. At the location where the treatment instrument 100 protrudes from the housing 12, an instrument guide 14 is provided. The housing 12 with the instrument guide 14 is made of an electrically insulating material, for example a plastic. In the example shown in FIG. 1a, the housing 12 of the apparatus 10 is provided with a handle section 12a on which the apparatus 10 can be held ergonomically in the hand during a treatment.

[0145] The apparatus 10 comprises an electrical energy storage unit 16, which supplies a controller 18 with electrical energy. The electrical energy storage unit 16 is preferably configured as a lithium ion battery. In order to charge the electrical energy storage unit 16, a charging terminal 22 that is accessible through an opening in the housing 12 is provided.

[0146] The controller 18 is connected to the input side 27 of a transformer 26. During operation of the apparatus 10, by using a pulse generator 17, the controller 18 generates electrical excitation pulses that are delivered to the input side 27 of the transformer 26. The transformer 26 then generates a high voltage in the form of radiofrequency electrical pulses, which are emitted on an output side 28 of the transformer 26. The high voltage is used in order to excite the treatment instrument 100, which is electrically coupled to the transformer 26. A housing shield 13, which in the example represented is configured in the form of an electrically conductive foil on the inner side of the housing 12, is arranged for electrical shielding of the components accommodated in the housing 12. Alternatively, the housing shield 13 may for example also be configured as an electrically conductive coating of the inner side of the housing 12.

[0147] The schematic representation of the transformer 26 shows that a primary coil 270 is inserted between two parts of a secondary coil 280. A first terminal 27a of the input side of the transformer 26, that is to say of the primary coil 270, is in this case connected directly to the controller 18 and therefore to the pulse generator 17. A second terminal 27b of the primary coil 270 is connected via a safety device 20 to the controller 18 and is connected via the controller 18 to the housing shield 13. A first terminal 28a of the output side of the transformer 26, that is to say of the secondary coil 280, is connected to the treatment instrument 100. A second terminal 28b of the secondary coil 280 is connected to the controller 18, and via the latter to the housing shield 13. The second terminals 27b and 28b are in this case respectively connected indirectly via the controller 18 to the housing shield 13, and therefore have the same electrical potential. The electrical ground formed by the housing shield 13 is not grounded, but is electrically isolated by the housing 12.

[0148] The treatment instrument 100 comprises a body 102 made of an electrically insulating material. The body 102 is in this case configured elongately, and has a connecting region 106 and a bulb region 108. The material of the body 102 is, for example, a glass. There is a first end 103 of the treatment instrument 100 next to the connecting region 106 and a second end 104 of the treatment instrument 100 next to the bulb region 108. The bulb region 108 protrudes entirely from the housing 12 of the apparatus 10, while the connecting region 106 is at least partially enclosed by the housing 12. The interior of the body 102 is filled with a noble gas 124, which has a reduced pressure in comparison with the ambient pressure.

[0149] Next to the first end 103, the treatment instrument 100 has an end cap 112, which is made of a plastic. The end cap 112 has a sleeve region 114 that encloses a part of the connecting region 106 next to the first end 103. An electrical contact surface 116, which is electrically connected through the end cap 112 and the body 102 to an electrode 110, is furthermore arranged at the first end 103.

[0150] The treatment instrument 100 is received replaceably in the apparatus 10. For this purpose, a clamping apparatus 32 is provided, which receives the treatment instrument 100 at the sleeve region 114 of the end cap 112. In this position, the electrical contact surface 116 of the treatment instrument 100 is contacted with an electrical spring contact 30, which is connected to the output side 28 of the transformer 26. The treatment instrument 100 is therefore electrically coupled to the transformer 26 when the treatment instrument 100 is received in the clamping apparatus 32 of the apparatus 10.

[0151] In order to turn the apparatus 10 on and/or off and in order to make it possible to change operating parameters, control elements 24 that are connected to the controller 18 are provided. The control elements 24 are, for example, configured as buttons. After the apparatus 10 is turned on, the controller 18 starts to generate low-voltage electrical excitation pulses, which are delivered to the transformer 26 as a control signal on the input side 27 of the latter. The electrical excitation pulses are transformed by the transformer into high-voltage radiofrequency electrical pulses and used as an excitation signal for the excitation of the treatment instrument 100. In this case, the noble gas 124 received in the interior of the body 102 of the treatment instrument 100 is excited into a gas discharge. Furthermore, high alternating electric fields are created.

[0152] The function of the apparatus 10 is preferably monitored. For this purpose, the apparatus 10 in the embodiment represented in FIG. 1a comprises a safety device 20, which in this embodiment is configured as an additional component. As an alternative thereto, the safety device 20 may also be configured as part of the controller 18. The safety device 20 is configured and adapted to monitor the high voltage on the output side 28 of the transformer 26, that is to say the radiofrequency electrical pulses, in respect of predetermined limit values for electrical parameters not being fallen below or exceeded. The electrical parameters comprise for example the electrical current, the voltage, a pulse repetition rate, a pulse width and a pulse frequency. In the embodiment represented in FIG. 1a, the measurement is carried out on the input side 27 of the transformer 26, use being made of the fact that, after the decay of the electrical excitation pulse, the radiofrequency electrical pulses generate a signal on the input side 27 of the transformer 26, which can be measured. For a measurement of these electrical parameters, in the example represented the second terminal 27b of the input side 27 of the transformer 26 is connected via the safety device 20 to the controller 18. If the limit values are exceeded or fallen below, the energy supply to the transformer 26 is interrupted by the controller 16. As an alternative or in addition, it is possible to monitor the electrical parameters on the output side of the transformer 26. In this case, for example, the first terminal 28a of the output side 28 has an additional connection to the safety device 20.

[0153] FIG. 1b shows a schematic sectional view of the transformer 26 configured as a resonant transformer. The view is in two parts, the upper half showing a plan view and the lower half showing a sectional view of the transformer 26. The transformer 26 has a core 262, which in the example represented in FIG. 1b has seven coil compartments 264.

[0154] In the example represented, the secondary coil 280 of the transformer 26 is divided into six coil segments 282, one of the coil segments 282 respectively being arranged in one of the coil compartments 264. The individual coil segments 282 are arranged at a distance from one another by the coil compartments 264. Electrically, the individual coil segments 282 are connected in series, two coil segments 282 arranged next to one another respectively being electrically connected to one another by a connection 284. Because of the distance respectively between two of the coil segments 282, an electrical capacitance is in each case formed, which influences the natural frequency or resonant frequency of the oscillating system on the output side 28, cf. FIG. 1a, of the transformer 26. Correspondingly, this resonant frequency may be adjusted by changing the distances.

[0155] In the example represented, the primary coil 270 is configured as a single segment, which is likewise arranged in one of the coil compartments 264. In this case, the primary coil 270 is located between two coil segments 282 of the secondary coil 280.

[0156] FIG. 2 shows a simplified schematic circuit diagram of the apparatus 10. In this case, in particular, the way in which the safety device 20 is connected to the transformer 26 in order to measure electrical parameters is represented. The transformer 26 is configured as a pulse-driven transformer and has a primary coil 270 and a secondary coil 280. A first terminal 27a of the input side 27, or of the primary coil 270, is connected to the pulse generator 17. A second terminal 27b of the input side 27, or of the primary coil 270, is connected to the housing shield 13. A first terminal 28a of the output side 28, or of the secondary coil 280, is connected to the treatment instrument 100 and a second terminal 28b of the output side 28, or of the secondary coil 280, is likewise connected to the housing shield 13.

[0157] In the simplified representation of FIG. 2, the pulse generator 17 comprises a DC voltage source 17a, which is connected via the switch 17b to the transformer 26 for the duration of an electrical excitation pulse.

[0158] In the embodiment of FIG. 2, the schematically represented safety device 20 is configured to determine electrical parameters of the radiofrequency electrical pulses by means of a measurement of the voltage induced in the primary coil by these radiofrequency electrical pulses. For this purpose, the safety device 20 is connected to the first and second terminals 27a, 27b of the primary coil 270.

[0159] The safety device 20 checks the electrical parameters of the radiofrequency electrical pulses by means of the measurement of a voltage at a capacitor 206, which is charged by a current induced in the primary coil 270. For this purpose the capacitor 207 is connected, via a diode 204 and an impedance converter 203 and a voltage divider formed by a first resistor 201 and a second resistor 202, to the first terminal 27a of the primary coil 270. By means of a controllable switch 205, which is for example configured as a MOSFET, the output of the impedance converter 203 can be short-circuited to the housing shield 13, and therefore to the second terminal 27b of the primary coil 270, during the electrical excitation pulse so that the electrical excitation pulse cannot charge the capacitor 206. Only after the end of the excitation of the transformer 26 is the controllable switch 205 turned off so that the positive half-waves of the oscillation existing in the transformer 26 respectively charge the capacitor 206. The voltage applied to the capacitor 206 may then be measured by voltage measuring means 207. The controller 18 may then control the pulse generator 17 as a function of the result of the voltage measurement, and for example turn the pulse generator 17 off if predetermined limit values are exceeded or fallen below.

[0160] In the representation of FIG. 2, the pulse generator 17, the safety device 20 and the controller 18 are represented as separate components. Provision may, however, be made to configure several or all of these components as a common unit, as is indicated in FIG. 1a.

[0161] The treatment instrument 100 of the apparatus 10 is schematically represented in FIG. 3.

[0162] The treatment instrument 100 comprises a body 102, which is made of an electrically insulating material, for example glass.

[0163] Next to the first end 103 of the treatment instrument 100, there is the connecting region 106, which has a first diameter D.sub.S, and next to the second end 104 of the treatment instrument 100 there is the bulb region 108, which has a second diameter D.sub.K. The second diameter D.sub.K is in this case greater than the first diameter D.sub.S. The connecting region 106 has a first length L.sub.S, and the bulb region 108 has a second length L.sub.K. The first length L.sub.S of the connecting region 106 occupies about 45% of the total length of the body 102 in the embodiment represented.

[0164] Preferably, the volume of the bulb region 108 occupies at least two thirds of the total volume of the body 102 of the treatment instrument 100.

[0165] As may be seen from the representation of FIG. 3, the bulb region 108 and the connecting region 106 do not merge abruptly into one another. The body 102 has a continuous transition between the connecting region 106 and the bulb region 108.

[0166] In the embodiment represented, the second end 104 of the body 102 of the treatment instrument 100 is configured to be substantially planar, so that a circular surface closes the bulb region 108. This surface merges via a continuous transition into the cylindrical bulb region 108. For contact with an object to be treated, or with organic material to be treated, both the substantially planar surface and the curved wall of the bulb region 108 may be used.

[0167] The end cap 112 encloses the body 102 of the treatment instrument 100 at the first end 103, an electrical contact surface 116, cf. FIGS. 1 and 3, remaining free at the first end 103. The end cap 112 comprises a sleeve region 114, which extends over at least a part of the connecting region 106 starting from the first end. The sleeve region 114 has a length L.sub.H and a diameter D.sub.H.

[0168] FIG. 4 shows a detail view of the treatment instrument 100, which shows the part next to the first end 103 in a sectional view. It may be seen that the end cap 112 encloses the body 102 of the treatment instrument 100 at the first end 103, an electrical contact surface 116 contacting the electrode 110 in the interior of the body 112 through the end cap 112. Between the electrical contact surface 116 and an electrical feed-through 120 through the body 102, in the embodiment shown in FIG. 3 there is a rivet 118 made of an electrically insulating material, which surrounds an electrical connection between the electrical feed-through 120 and the electrical contact surface 116.

[0169] It may furthermore be seen in FIG. 4 that the end cap 112 covers an evacuation opening 126 of the body 102. Through the evacuation opening 126, during the production of the body 102, air was initially evacuated and a noble gas 124, for example neon, was subsequently introduced into the interior of the body 102. The evacuation opening 126 was then closed.

[0170] The end cap 112 furthermore comprises the sleeve region 114, which extends over at least a part of the connecting region 106 starting from the first end 103. The sleeve region 114 has a length L.sub.H and a diameter D.sub.H. In order to fasten the end cap 112 on the body 102, in the embodiment represented in FIG. 3 an epoxy adhesive 122 is used, which is arranged between the body 102 and the sleeve region 114 of the end cap 112.

[0171] FIG. 5 shows the qualitative profile of a radiofrequency electrical pulse 200 on the output side 27 of the transformer 26. The radiofrequency electrical pulse 200 is created after an excitation pulse 210, which is represented in FIG. 6 and is generated by the pulse generator 17 of the controller 18, has been applied to the transformer 26. The excitation pulse 210 excites the transformer 26 configured as a resonant transformer, cf. FIG. 1a, into oscillation, so that a high-voltage radiofrequency signal that is used as a radiofrequency electrical pulse 200 for the electrical excitation of the treatment instrument 100 is generated.

[0172] In FIGS. 5 and 6, the voltage is plotted on the Y axis and the time is plotted on the X axis. The excitation pulse 210 shown in FIG. 6 is, for example, obtained by a DC voltage being turned on and off again by means of a semiconductor switch, for example a MOSFET. FIGS. 5 and 6 respectively show a single pulse.

[0173] The radiofrequency electrical pulse 200 represented in FIG. 5 has an envelope 202 that follows an exponential decay in the example shown. A pulse width, or pulse duration, of the radiofrequency electrical pulse 200 may be defined here as the time until the decay of the envelope 202 has fallen to a value of A/e, where A is the maximum amplitude and e is Euler's number.

[0174] The invention is not restricted to the exemplary embodiments described here and the aspects highlighted therein. Rather, many variants that lie within the capacity of the person skilled in the art are possible within the scope specified by the claims.

LIST OF REFERENCES

[0175] 10 apparatus

[0176] 12 housing

[0177] 12a handle section

[0178] 13 housing shield

[0179] 14 instrument guide

[0180] 16 electrical energy storage unit

[0181] 17 pulse generator

[0182] 17a voltage source

[0183] 17b switch

[0184] 18 controller

[0185] 20 safety device

[0186] 201 first resistor

[0187] 202 second resistor

[0188] 203 impedance converter

[0189] 204 diode

[0190] 205 switch

[0191] 206 capacitor

[0192] 207 voltage measuring means

[0193] 22 charging terminal

[0194] 24 control element

[0195] 26 transformer

[0196] 262 core

[0197] 264 coil compartment

[0198] 27 input side

[0199] 27a first input side terminal

[0200] 27b second input side terminal

[0201] 270 primary coil

[0202] 28 output side

[0203] 28a first output side terminal

[0204] 28b second output side terminal

[0205] 280 secondary coil

[0206] 282 coil segment

[0207] 284 connection

[0208] 30 electrical spring contact

[0209] 32 clamping device

[0210] 100 treatment instrument

[0211] 102 body

[0212] 103 first side

[0213] 104 second side

[0214] 106 connecting region

[0215] 108 bulb region

[0216] 110 electrode

[0217] 112 end cap

[0218] 114 sleeve region

[0219] 116 electrical contact surface

[0220] 118 rivet

[0221] 120 electrical feed-through

[0222] 122 epoxy adhesive

[0223] 124 noble gas

[0224] 126 evacuation opening

[0225] 200 radiofrequency electrical pulse

[0226] 202 envelope

[0227] 210 excitation pulse

[0228] D diameter (S=connecting region, H=sleeve region, K=bulb region)

[0229] L length (S=connecting region, H=sleeve region, K=bulb region)