Device for performing high-frequency electrotherapy, and method for identifying a suitable carrier frequency

Abstract

The invention relates to a device (2) for performing high-frequency electrotherapy, and to a method for identifying a suitable carrier frequency. The device (2) according to the invention has two electrodes (22) or alternative skin-contact elements for coupling high-frequency signals into a body (100). The high-frequency signals are generated and transmitted using a transmitter and / or a modulator (18). A low-impedance signal generator (6, 16) is designed to generate a high-frequency carrier frequency, and a signal-generating device (4) is designed to generate a therapy frequency. The modulator (18) generates the high-frequency signal by means of an amplitude modulation of the high-frequency carrier frequency with the therapy frequency.

Description

[0001] Device for performing high-frequency electrotherapy and method for determining a suitable carrier frequency

[0002] >

[0003] Description

[0004] The invention relates to a device for carrying out high-frequency electrotherapy and a method for determining a suitable carrier frequency.

[0005] Devices for generating electrical, magnetic, and / or electromagnetic signals for treating the human body are known in practice, particularly in the form of electrostimulation devices. Such devices can usually be operated at various frequencies. The successful application of these devices often depends on determining and applying a suitable therapy frequency for each individual case. For this purpose, a specialist with appropriate experience is often consulted. Based on their experience and taking into account the circumstances of the individual case, they will determine and apply a suitable therapy frequency, or recommend it for use. Particular reference is made to devices known in practice, which are marketed in various versions under the brands "Timewaver" and "Healy."Reference is made to the products "Timewaver Frequency," "Timewaver Home," and "Healy" merely by way of example. The invention relates in particular to further developments in connection with these and comparable products. Therefore, express reference is hereby made to all technical features of the aforementioned products, in particular to those features that are implemented equally or in a similar manner in all aforementioned products. DE 10 2015 002 565 A1 discloses a system for controlling stimulation pulses during stimulation of a user, which system comprises at least one sensor, at least one data processing unit, and at least one pulse unit. Many different types of suitable sensors are mentioned, including near-infrared spectroscopy (NIRS) sensors.In this system, the data processing unit should be configured to compare a value measured by a sensor with a threshold value and to generate a control signal to the pulse unit when the measured value and the threshold value are in a predefined relationship to each other.

[0006] DE 297 09 094 U1 discloses a device for bioresonance therapy for the therapeutic delivery of electromagnetic therapy signals to a body, comprising an electrical circuit for receiving endogenous or substance-specific input signals by means of a receiving antenna or receiving electrode. A signal processing stage is also provided for processing the signals of an output circuit for supplying the output signals to a transmitting antenna or transmitting electrode. The signal processing stage comprises a delay circuit by means of which output signals can be delayed relative to the input signals.

[0007] DE 100 02 251 A1 discloses an interactive wellness device for holistic sensory stimulation of humans, the functions of which are controlled and modulated at least indirectly by measured body states of the person using it.

[0008] US 2006 / 0064139 A1 and DE 10 2015 002 565 A1 disclose devices for generating electrical, magnetic, and / or electromagnetic signals that can be used with different therapy frequencies to treat the human body. The invention is based on the object of providing a device for conducting high-frequency electrotherapy and a method for determining a suitable carrier frequency for introducing high-frequency signals into a body, which offer a new and easy-to-use possibility for conducting high-frequency electrotherapy, in particular for self-application at home without the implementation and / or supervision of a physician or other medically trained person, such as a naturopath or specialized therapist.

[0009] The object is achieved according to the invention with the features of the independent claims. Further practical embodiments are described in conjunction with the dependent claims.

[0010] A device according to the invention for performing high-frequency electrotherapy comprises two electrodes or alternative skin contact elements for coupling high-frequency signals into the body of a human or animal. Furthermore, the device comprises a transmitter for transmitting a high-frequency signal and / or a modulator for generating and transmitting a high-frequency signal to the electrodes or the alternative skin contact elements.

[0011] A transformer, within the meaning of the invention, is understood to be a structural unit designed in such a way that it can ensure a conductive separation from a power grid to a body. In other words, the design of the transformer ensures that mains current from the power grid cannot flow to earth through a body arranged on the device.

[0012] A modulator within the meaning of the invention is understood to be a component capable of modulating a signal. In particular, a modulator within the meaning of the invention is understood to be a component having at least two inputs and at least one output, wherein the modulator can amplitude modulate at least two input signals. The amplitude-modulated signal derived via the at least one output of the modulator is referred to below as a radio-frequency signal.

[0013] The two electrodes or alternative skin contact elements are provided for transmitting the high-frequency signal provided by the transmitter and / or the modulator. The high-frequency signal is coupled using the electrodes or alternative skin contact elements, in particular via the skin of the body. The device for performing high-frequency electrotherapy is designed for use on humans or animals. The skin contact elements are designed in particular as coil-like contact surfaces and / or as capacitive contact surfaces.

[0014] The device according to the invention further comprises a low-impedance signal generator for generating a high-frequency carrier frequency. This low-impedance signal generator has, in particular, a maximum internal resistance of 10 Ω. As a result, the internal resistance is significantly lower than the resistance that occurs between the two electrodes or the alternative skin contact elements arranged on a human or animal body when using the device according to the invention. This makes it possible to introduce a significant portion of the energy of the carrier frequency into the body.

[0015] A device according to the invention further comprises a signal generating device for generating a therapy frequency. A therapy frequency within the meaning of the invention is understood to mean both a single isolated frequency, but in particular also frequency mixtures. In this respect, noise, an audio signal, or a square wave are also to be understood as a therapy frequency within the meaning of the invention. A carrier frequency within the meaning of the invention is understood to be a single isolated frequency that is suitable for amplitude modulation with regard to the therapy frequency.

[0016] The carrier frequency and the therapy frequency are then applied to the inputs of the modulator, which performs amplitude modulation and provides the high-frequency signal.

[0017] The invention is based on the discovery that it is advantageous to use a high-frequency signal to conduct electrotherapy. By using a high-frequency signal, a uniform distribution of the signal can be achieved throughout the body of a human or animal. It has been recognized that therapeutic frequencies that do not originate from a high-frequency range can be transformed by amplitude modulation with a high-frequency carrier frequency in such a way that the resulting high-frequency signal propagates well throughout the body. In particular, it has been recognized that it is advantageous to conduct high-frequency electrotherapy using a device that can be positioned and operated in the immediate vicinity of the body (so-called wearables).The introduction of the high-frequency signal into the body via electrodes or alternative skin contact elements allows for efficient and widespread introduction of energy into the body without exceeding applicable guidelines for electromagnetic compatibility (EMC guidelines).

[0018] Furthermore, it has been found that the selection of a carrier frequency can depend on numerous properties that vary from body to body. Therefore, it can be advantageous to determine the carrier frequency individually for the body and the arrangement of the device on the body using a method for determining the carrier frequency. In this way, the effectiveness of a corresponding treatment can be optimized to the extent that the energy introduced into the body is distributed throughout the body as best as possible. In a practical embodiment of a device according to the invention, the signal generating device and the low-impedance signal generator are designed as mains-power-independent devices. In other words, the device can be carried on the body in particular and operated using portable energy storage devices.Treatment can then be carried out anywhere and independently of a suitable power infrastructure, for example while traveling, in nature or in areas with poor infrastructure.

[0019] Additionally or alternatively, in another practical embodiment of a device according to the invention, the signal generating device and the low-impedance signal generator can be functionally connected to a transformer with galvanic isolation. This can ensure that no mains current flows through the body to earth.

[0020] In a further practical embodiment of a device according to the invention, the device is designed such that the carrier frequency is at least twice as high as the therapy frequency.

[0021] Preferably, the carrier frequency is selected from a first frequency range between 0.5 MHz and 20 MHz or from a second frequency range between 100 and 200 MHz or from a third frequency range between 500 MHz and 1 GHz.

[0022] Additionally or alternatively, the therapy frequency is preferably selected from a frequency range between 0.1 MHz and 12.5 MHz.

[0023] In a further practical embodiment of a device according to the invention, the two electrodes or the alternative skin contact elements are spaced apart by a maximum of 20 cm. More preferably, the distance is a maximum of 15 cm, particularly preferably a maximum of 12 cm, a maximum of 10 cm, or a maximum of 5 cm. The distance can also be selected to be even smaller, for example, a maximum of 3 cm, a maximum of 2 cm, or a maximum of 1 cm. Depending on the respective distance selection, both electrodes or alternative skin contact elements can be arranged on a compact positioning unit, for example, on a bracelet, a leg band, a finger band, or a collar, while maintaining the respective maximum distance.

[0024] Additionally or alternatively, in a further practical embodiment of a device according to the invention, the two electrodes or the alternative skin contact elements for coupling high-frequency signals are part of at least one positioning unit, in particular a single positioning unit. By arranging the electrodes or the alternative skin contact elements on a positioning unit, their placement on the body can be facilitated.

[0025] In a further practical embodiment of the device according to the invention, the at least one positioning unit is designed in the manner of a band enclosing a body region. In this regard, particular reference is made to the possibilities of designing the positioning unit as a bracelet, a leg band, an abdominal belt, a limb band, a ring, or other band-like element. In this case, the positioning unit can be quickly and easily applied to the body. In particular, this arrangement facilitates the implementation and acceptance of high-frequency electrotherapy by a user, since the positioning unit can also be worn while moving and / or in various standing, sitting, and / or lying positions.Furthermore, in these cases, the positioning unit can be arranged discreetly and even concealed on a body, as it is small in size, arranged at non-visible body locations, and / or cannot be recognized as a component of an electrotherapy device due to its external appearance. In a further practical embodiment of the device according to the invention, a carrier frequency determination module is provided on the device. Such a carrier frequency determination module is particularly designed to perform at least one test measurement on a user in order to determine a carrier frequency particularly suitable for the user based on the result of the at least one test measurement.

[0026] Preferably, the carrier frequency detection module is designed as an integral component of the device. Alternatively, the carrier frequency detection module is manufactured as a separate element and functionally connected to the device.

[0027] In a further practical embodiment of the device according to the invention, the signal generating device and the low-impedance signal generator are each part of separate devices that are functionally connected to one another for use. In this way, for example, a device for generating electrical, magnetic, and / or electromagnetic signals for treating the human body, as known, for example, from WO 2018 / 228987 A1, can be used as the signal generating device. Through a functional connection with the low-impedance signal generator, high-frequency electrotherapy can be performed by combining the two devices.

[0028] In a further practical embodiment of the device according to the invention, the signal generating device and the low-impedance signal generator are designed to be directly or indirectly connected. The connection can be made, in particular, by plugging or other coupling. Preferably, the connection is tool-free. In a further preferred variant, the connection is established by means of a quick-release coupling. The invention also relates to a method for determining a suitable carrier frequency for introducing high-frequency signals into a body. For this purpose, a transmitting device and a measuring device are used, wherein the transmitting device corresponds to the device according to one of the embodiments described above. The method then comprises the following method steps:

[0029] In a first method step of the method according to the invention, a first radio frequency signal with a first frequency is generated by the transmitting device.

[0030] In a further step of the method according to the invention, the generated high-frequency signal is then coupled into the body. For this purpose, two electrodes or alternative skin contact elements are used, which are arranged at a first position on the surface of the body and are functionally connected to the transmitting device.

[0031] In a further step of the method according to the invention, the coupled high-frequency signal is then received at a second position on the surface of the body. The measuring device is used to receive the high-frequency signal.

[0032] In a further method step of the method according to the invention, a further high-frequency signal of a second frequency is generated by the transmitting device, wherein the second frequency is different from the first frequency.

[0033] In a further step of the method according to the invention, the generated further high-frequency signal is then coupled into the body. For this purpose, two electrodes or alternative skin

[0034] Contact elements are used which are arranged at a first position on the surface of the body and are functionally connected to the transmitting device.

[0035] In a further step of the method according to the invention, the coupled additional high-frequency signal is then received at a second position on the surface of the body. The measuring device is used to receive the high-frequency signal.

[0036] In practice, the process steps, comprising generating a high-frequency signal with different frequencies, coupling this high-frequency signal into the body and receiving the high-frequency signal, can be repeated as often as desired.

[0037] In particular, frequencies can be selected for generating the high-frequency signals, which are derived from the previous signals using a predetermined step size. In this way, for example, different frequencies can be selected from a given frequency range. High-frequency signals with these frequencies are generated and coupled into the body one after the other. This achieves an iterative "sampling" of the given frequency range.

[0038] It should be noted that the step size can also be variable. In this case, the distance between the frequencies at which high-frequency signals are generated is unequal. For example, the step size can be selected so that a given frequency range can be iteratively "sampled" within a given time, given the time for a measurement process. Or, with the help of a mathematical model, a rough scan can first be carried out with a larger step size, followed by another scan with a smaller step size in a smaller selected frequency range. It is also possible to keep the number of optimization processes variable - for example, within a specific time window - and to reduce the optimization by continuously reducing the step size with each sampling process, taking advantage of a given time window.

[0039] In a further step of the method according to the invention, the received high-frequency signals are evaluated using a processor unit. This can be either a processor unit of the measuring device or a processor unit of a transmitting device. During this evaluation, the frequency of the high-frequency signal at which the quotient of the power received by the measuring device to the power emitted by the transmitting device is greatest is determined as the carrier frequency. In other words, the frequency of the high-frequency signal that exhibits the lowest losses when passing through the body is selected as the carrier frequency.

[0040] The method according to the invention has the advantage that a carrier frequency can be determined individually, in particular adapted to the respective physical properties of a body to be treated and the arrangement of the electrodes and / or the alternative skin contact elements, so that a good propagation of the carrier frequency in the body can take place.

[0041] In one embodiment of the method according to the invention, either the transmitting device and / or the measuring device has at least one transformer with galvanic isolation.

[0042] The transmitting device and / or the measuring device can therefore be designed as either mains-powered or mains-powered devices. In the latter case, suitable galvanic isolation ensures that the mains current is not connected to earth via the body. In a mains-powered device, galvanic isolation is achieved through the use of a battery / accumulator. In this case, the design of a separate element, such as a transformer, to achieve galvanic isolation is unnecessary.

[0043] In one embodiment of the method according to the invention, the high-frequency signals introduced into the body are selected from a predeterminable frequency range. For example, the predeterminable frequency range can be the aforementioned frequency range of the therapy frequencies. This makes it possible for the high-frequency signal, since it is selected from the frequency range of the therapy frequency, to be used as a therapy frequency itself. Thus, by using this high-frequency signal for amplitude modulation with a therapy frequency, two therapies can be performed simultaneously.

[0044] Further practical embodiments and advantages of the invention are described below in conjunction with the drawings. They show:

[0045] Fig. 1 is a schematic representation of a circuit diagram of a device according to the invention,

[0046] Fig. 2 is a schematic representation of the operation of the device according to the invention shown in Fig. 1 during use,

[0047] Fig. 3 is a schematic representation of a circuit diagram of a device according to the invention with a transformer,

[0048] Fig. 4 is a schematic representation of the functioning of the device according to the invention with transformer shown in Fig. 3 during use, Fig. 5 is a schematic representation of a circuit diagram of a method according to the invention and

[0049] Fig. 6 is a schematic representation of a circuit diagram of a method according to the invention with transformers.

[0050] Fig. 1 shows a schematic representation of a circuit diagram of a device 2 according to the invention. The device 2 shown has a signal generator 6 for generating a carrier frequency, which is embodied here as a high-frequency signal generator 16. Furthermore, the device 2 has a signal generating device 4 comprising a low-frequency signal generator 14. The signal generating device 4 is designed to provide a therapy frequency. This therapy frequency is fed through an amplifier 10 and a plug connection 20 to a modulator 18. The modulator 18 is also connected to the output of the high-frequency signal generator 16 and designed to perform amplitude modulation of the carrier frequency and the therapy frequency. The resulting high-frequency signal is fed through the low-impedance amplifier 12 to two electrodes 22 and guided through these into a body 100, here into the upper body of a human body 100.

[0051] In addition or alternatively to electrodes 22, skin contact elements (not shown) can be used to introduce the high-frequency signal into the body 100. Reference is made to the corresponding explanations given above, which also apply to this embodiment.

[0052] Regarding the therapy frequency and the carrier frequency, reference is also made to the above statements, which also apply to this exemplary embodiment. The device 2 is preferably formed in its geometric dimensions by a relatively small housing, so that it can be worn comfortably on a person's body 100—and, if desired, also concealed. Dimensions of less than 20 cm x 20 cm x 1 cm are preferred, and more preferably less than 10 cm x 10 cm x 0.5 cm.

[0053] The device 2 shown in Fig. 1 has portable energy storage devices 30, 32 for providing electrical energy for the aforementioned elements 4, 6, 10, 12, 14, 16, 18, 20, 22 (here: electronic components), which in the practical embodiment shown here are designed as accumulators and / or batteries.

[0054] It is pointed out that all elements 4, 6, 10, 12, 14, 16, 18, 20, 22 (here: electronic components) can also be supplied with energy by only a single energy storage device 30, 32.

[0055] Fig. 2 shows a schematic representation of the operation of the device 2 according to the invention shown in Fig. 1 during use. In the embodiment shown, the device 2 is arranged on the forearm 101 of a body 100. The high-frequency signal is introduced into the body 100 via electrodes 22 and spreads from there over the entire body or at least over a large part of the body (see Fig. 1).

[0056] Fig. 3 shows a schematic representation of a circuit diagram of a device according to the invention with a transformer 42. In contrast to the embodiment shown in Fig. 1, in Fig. 2, the elements 4, 6, 10, 12, 14, 16, 18, 20, 22, 42 (here: the electronic components) are supplied with electrical energy via a connection 40 to the power grid. The body 100 is then separated from the circuit of the device 2 by a transformer 42 to protect against charges that could otherwise flow from the power grid through the body 100 into the ground. It is pointed out that only some of the elements 4, 6, 10, 12, 14, 16, 18, 20, 22, 42 shown (here: electronic components) can be supplied with energy from the power grid, while others are supplied with energy by energy storage devices 30, 32.

[0057] Fig. 4 shows a schematic representation of the operation of the device 2 according to the invention shown in Fig. 3 with transformer 42 during use. The body 100 is separated from the electrical circuit of the device 2 by the transformer 42, so that no charges can flow from the connection 40 to the power grid via the body 100 to earth.

[0058] Fig. 5 shows a schematic representation of a circuit diagram of a method according to the invention for determining a suitable carrier frequency for introducing high-frequency signals into a body 100.

[0059] For this purpose, a transmitting device 2 and a measuring device 50 are used, wherein the transmitting device, as explained above, introduces an amplitude-modulated radio-frequency signal into a body 100 via electrodes 22. The amplitude-modulated radio-frequency signal is generated by a modulator 18, which is connected at its inputs to a high-frequency signal generator 16 and a low-frequency signal generator 14. The resulting amplitude-modulated radio-frequency signal can be influenced in its intensity by a low-impedance amplifier 12.

[0060] The transmitting device also has an antenna 24, via which a processor unit 26 can communicate with the measuring device 50. The measuring device 50 is also arranged on the body 100, but at a different position than the transmitting device 2. The radio-frequency signal emitted by the transmitting device 2 is guided into the measuring device 50 via electrodes 52, which are arranged on the skin of the body 100. The intensity of the radio-frequency signal can be influenced using an amplifier 56 such that a processor unit 56 can effectively process the resulting signal. The processor unit 56 is connected to an antenna 58, via which communication with the transmitting device 2 takes place. As described above, the carrier frequency is determined such that the transmitting device introduces various radio-frequency signals of known intensity into the body 100.These high-frequency signals are received by the measuring device 50, and the intensity reaching the measuring device 50 can be determined. In this way, for different frequencies of the high-frequency signal, the attenuation caused by the body 100 at this frequency can be determined for the selected arrangement of the electrodes 22, 52. The frequency with the lowest measured attenuation is then determined as the carrier frequency. In the embodiment shown, the transmitting device 2 and the measuring device 50 are powered by portable energy storage devices, such as accumulators and / or batteries. Additionally or alternatively, a power supply can also be provided via a power grid, as shown in Fig. 6.

[0061] Fig. 6 shows a schematic representation of a circuit diagram of a method according to the invention for determining a suitable carrier frequency for introducing high-frequency signals into a body 100 using transformers. For this purpose, a transmitting device 2 and a measuring device 50 are connected to the power grid. By using two transformers 42 here, the electrical circuit of the transmitting device 2 and the measuring device 50 is separated from the body 100, so that no charges can flow to earth via the body 100. This is marked in Fig. 6 by the current flow Se, which is 0. Regarding the method, reference is made to the above explanations, which also apply analogously here.

[0062] The features of the invention disclosed in the present description, the drawings, and the claims may be essential, both individually and in any combination, for the realization of the invention in its various embodiments. The invention may be varied within the scope of the claims and taking into account the knowledge of the person skilled in the art.

[0063] All features mentioned in relation to the device, including the optional features, can also be understood as features of the method and can thus be used to describe the method.

[0064] List of reference symbols

[0065] 2 high-frequency electrotherapy device

[0066] 4 Signal generating device

[0067] 6 Signal generator

[0068] 10 amplifiers

[0069] 12 low-impedance amplifiers

[0070] 14 Low frequency signal generator

[0071] 16 High-frequency signal generator

[0072] 18 Modulator

[0073] 20 plugs

[0074] 22 electrodes

[0075] 24 antenna

[0076] 26 Processor unit

[0077] 30 energy storage units

[0078] 32 energy storage units

[0079] 40 Connection to the power grid

[0080] 42 transformers

[0081] 50 measuring device

[0082] 52 electrodes

[0083] 54 amplifiers

[0084] 56 Processor unit

[0085] 58 Antenna

[0086] 100 bodies

[0087] 101 Forearm

Claims

Patent claims 1. Device (2) for carrying out high-frequency electrotherapy with a) two electrodes (22) or alternative skin contact elements for coupling high-frequency signals into a body (100) of a human or an animal, b) a transmitter (42) for transmitting a high-frequency signal and / or a modulator (18) for generating and transmitting a high-frequency signal to the electrodes (22) or to the alternative skin contact elements, c) wherein a low-impedance signal generator (6, 16) is designed to generate a high-frequency carrier frequency and a signal generating device (4) is designed to generate a therapy frequency, and d) wherein the modulator (18) generates the high-frequency signal in such a way that it results from an amplitude modulation of the high-frequency carrier frequency with the therapy frequency.

2. Device according to claim 1, characterized in that the signal generating device (4) and the low-impedance signal generator (6, 16) have at least one of the following features: The signal generating device (4) and the low-impedance signal generator (6, 16) are designed as mains-independent devices; the signal generating device (4) and the low-impedance signal generator (6, 16) are functionally connected to a transformer (42) with galvanic isolation.

3. Device according to claim 1 or 2, characterized in that the carrier frequency is at least twice as high as the highest therapy frequency.

4. Device according to one of the preceding claims, characterized in that the therapy frequency is selected from a frequency range between 0.1 MHz and 12.5 MHz.

5. Device according to one of the preceding claims, characterized in that the two electrodes (22) or the alternative skin contact elements are spaced apart by a maximum of 20 cm.

6. Device according to one of the preceding claims, characterized in that the two electrodes (22) or the alternative skin contact elements for coupling in high-frequency signals are part of at least one positioning unit.

7. Device according to the preceding claim, characterized in that the at least one positioning unit is designed in the manner of a band enclosing a body region.

8. Device according to one of the preceding claims, characterized in that a carrier frequency determination module (50) is provided which is designed to carry out at least one test measurement on a user in order to determine a carrier frequency particularly suitable for the user based on the result of the at least one test measurement.

9. Device according to one of the preceding claims, characterized in that the signal generating device (4) and the low-impedance signal generator (6, 16) are each part of separate devices which are functionally linked to each other for the application.

10. Device according to one of the preceding claims, characterized in that the signal generating device (4) and the low-impedance signal generator (6, 16) are designed to be directly or indirectly connectable.

11. A method for determining a suitable carrier frequency for introducing high-frequency signals into a body (100) with a transmitting device (2) according to one of claims 1 to 10 and a measuring device (50), the method comprising at least the following method steps: (i) generating a radio frequency signal of a first frequency using the transmitting device (2); (ii) coupling the generated radio frequency signal into the body (100) using two electrodes (22) or alternative skin contact elements at a first position on the surface of the body (100); (iii) receiving the coupled radio frequency signal at a second position on the surface of the body (100) using the measuring device (50); (iv) generating at least one further radio frequency signal of at least a second frequency using the transmitting device (2); (v) coupling the generated at least one further radio frequency signal into the body (100) using two electrodes (22) or alternative skin contact elements at a first position on the surface of the body (100); (vi) receiving the coupled-in at least one further radio-frequency signal at a second position on the surface of the body (100) using the measuring device (50); and (vii) evaluating the received high-frequency signals using a processor unit (56) of the measuring device (50) or using a processor unit (26) of the transmitting device (2), wherein the carrier frequency is determined to be the frequency of the high-frequency signal at which the quotient of the power received by the measuring device (50) to the power generated by the transmitting device (2) is greatest.

12. Method according to the preceding claim, wherein either the transmitting device (2) and / or the measuring device (50) has at least one transformer (42) with galvanic isolation.

13. Method according to one of the two preceding claims, wherein after carrying out the method steps (i) to (vi) of claim 11, the method steps (iv) to (vi) of claim 11 are carried out several times with different radio frequency signals of different frequencies.

14. Method according to one of the preceding claims 11 to 13, wherein all high-frequency signals introduced into a body (100) are selected from a predeterminable frequency range.

Images