WO1994008656A1

WO1994008656A1 - Method and device for the treament of human muscles and/or tissue

Info

Publication number: WO1994008656A1
Application number: PCT/NL1993/000209
Authority: WO
Inventors: Benjamin Van Zanten
Original assignee: B. Van Zanten B.V.
Priority date: 1992-10-20
Filing date: 1993-10-20
Publication date: 1994-04-28
Also published as: NL9201819A; EP0662854A1

Abstract

Device for the treatment of muscles and/or human tissue. It comprises an electrode and generator. In the device, the electrode according to the invention is brought to a comparatively small distance from the body by means of a comparatively thin insulating layer (0.1-2 mm thick) and placed against the body with an appreciable pressure. A voltage is then generated which has a frequency between 75 and 375 kHz. Preferably, the electrode is of smooth construction. Such an electrode which has a comparatively thin insulating layer and is used in the frequency range described above can also be used internally. For this purpose it is preferably spherical and possibly inflatable.

Description

METHODANDDEVICE FORTHETREAMENTOFHUMAN MUSCLESAND/ORTISSUE

The present invention relates to a device for the treatment of human muscles and/or tissue, comprising an electrode and a generator, the electrode being designed to be pressed against the body parts to be treated and the generator being designed to supply an alternating current to the electrode. Such a device is disclosed in European Patent

029532. In the latter, a plate-like electrode is described which is enveloped by an insulating material, which insulating material is to be placed against the human body. Situated between the plate-like electrode and the insulating material is a series of glass tubes. As a result, there is an appreciable distance between the plate-like electrode and the skin contact area. As a result of the comparatively large thickness of such an electrode, it is necessary to employ high frequencies. In addition, a higher electric voltage is necessary to introduce sufficient power into the human body to obtain the desired heat emission. Such a treatment of human muscles or tissue is, for example, of importance in diathermy. In the latter, the heat is introduced not only into the surface of the tissue but also at more deeply situated points. This heating at a depth has a beneficial effect on muscles and other tissue. In such treatment, there is, however, the problem that the human shapes are not regular and the tissue structure has varying electrical properties. The plates serving as the high-frequency electrode are therefore kept at some distance from the tissue because the electrical field is disturbed by the irregularly shaped body part. As a result of increasing the distance of the plates from the body, the electrical field becomes more homogeneous and, as described above, an increasingly greater high-frequency power is necessary. If, however, the voltages increase too much, there is the risk of arcing or point discharge. The frequencies used in the prior art have constantly increased further in order to provide sufficient depth action. In the case of the distances now used between electrode and skin, very high voltages would be necessary to obtain sufficient depth action at low frequency, with all the safety consequences thereof.

The object of the present invention is to avoid the disadvantages described above and to provide a device which has an improved action.

This object is achieved in a device described above in that the electrode comprises an electrically insulating continuous layer to be brought direct into contact with the body and having a thickness of between 0.1 and 2 mm and an area of less than 20 cm², and, directly adjacent thereto, an electrode made of electrically conducting material and connected to the generator, and in that the generator is designed to operate at a frequency of between 75 and 375 kHz.

The invention is based on the insight that a comparatively low frequency can be employed as a result of using a very thin insulation. The high voltage, which is so dangerous, used in the prior art is no longer necessary. In addition, use is made of the effect that human tissue compressed by the electrode has a lower electrical resistance. As a result, energy can be emitted more easily at that position. As a result of exerting pressure on the electrode, the disadvantageous effect that the blood vessels generally dilate when heat is introduced is counteracted. After all, this dilation of blood vessels is evidenced by a greater flow as a result of which some of the heat introduced is immediately removed again. The compression compensates for said dilation, and the cooling and screening action of the blood vessels is thereby counteracted. As a result, an improved action can be obtained without further measures. The electrode according to the invention has a comparatively small area, as a result of which a comparatively large pressure per unit area can be applied. Because passage of current is aided in this compressed area, in particular, by the lowering of the electrical resistance, there is no risk that electrical short-circuiting occurs laterally in the surrounding tissue. It has been found that particularly good results are obtained with the comparatively low frequency of between 75 and 375 kHz. According to an advantageous embodiment of the invention, the insulating layer at the side to be placed against the body is of smooth construction. The capacitance with respect to the tissue to be treated is preferably not less that 2.5 pF. The maximum voltage used is preferably 1500 volts. Although the device described above is particularly safe, according to a further embodiment, a provision can be made in the electrode to prevent overheating.

The electrode does not necessarily have to be placed against external body parts. It can also be placed inside the body and in such a case it is, in particular, of spherical construction. In order to generate sufficient pressure, said electrode may then be of inflatable construction. In such a case, the electrode also serves to eliminate malignant tissues. It has been found that certain malignant cells are more sensitive to heat than the surrounding healthy tissue. Keeping said cells at a somewhat increased temperature for a short time results in them dying off. In this connection, it has been observed that such dead cells can be removed by the normal system of the body (white blood corpuscles). The invention also relates to a method of using the electrode described above. From the above it has already become clear that it is important to place the electrode against the human tissue and/or muscles with appreciable force.

The invention will be explained below in greater detail with reference to exemplary embodiments shown in the drawings. In the drawings:

Figure 1 diagrammatically shows a cross section of a first embodiment of an assembly comprising pressure electrode and high-frequency generator according to the invention; Figure 2 diagrammatically shows a cross section of a second embodiment of the electrode-generator assembly more particularly intended for internal use, and

Figure 3 diagrammatically shows a third embodiment. The electrode-generator assembly is indicated in its entirety by 1 in Figure 1. The generator is indicated by 2 and the electrode by 3. Both are accommodated in a housing ^«**., which is provided with a flat bottom designed to be placed on base 5. The generator 2 is designed to operate at a voltage of not more than 1500 volts and a frequency situated between 75 and 375 kHz. The generator is connected to a mains supply 7 which is shown in diagrammatic form. One output 6 of the generator is linked to an earth connection. The other output 8 of the generator is connected to the conducting plate 9 of electrode 3> The latter may be a comparatively thin metal foil, such as copper or aluminium foil. Applied over said plate is an insulating layer which has a thickness of 0.5 mm and an area of 10 cm². Said insulating layer is indicated by 10. It is composed of a material which is, on the one hand, strong enough to offer resistance to the mechanical loads during use but, on the other hand, has an adequate insulating value. An example is an epoxy printed circuit board layer. Input 11 of the generator 2 is connected to a temperature- sensitive element 12. If for any reason the temperature at the electrode 3 becomes too high, said temperature can be adjusted by the control system in the generator 2, with the result that no dangerous situations arise. The pressure electrode employed here is used by placing it on the base. The body part to be treated is then placed on the insulating layer 10 and the device is switched on. If necessary, additional pressure can be generated, but the weight of the body parts concerned will usually be sufficient to provide the pressure necessary for the effect according to the invention to be achieved.

It is also possible to construct the electronics not in the housing of the electrode but as a separate flexible part. In such a case, there is a separation between generator and electrode and it is necessary to provide an electrical connection in-between, as will be described below.

Figure 2 shows a further embodiment of the device according to the invention. In this case, the electrical generator is indicated by 13. Said generator 13 is designed to operate with same characteristics as generator 2. The latter is, on the one hand, earthed at 6. In the embodiment shown in Figure 2, the other output of the generator is connected to hollow conductor 16, which is accommodated in a catheter tube 17. The catheter tube is provided with an inflatable balloon 18 at the front. Said inflatable balloon comprises a layer 19 of insulating material having a thickness of approximately 1 mm. Provided therein is a foil 20 made of electrically conducting material and connected to conductor 16. In Figure 2, the position during the introduction into, for example, tissue to be treated is shown.

If the balloon catheter formed in this way is positioned as required, air is pumped through conductor 16 by means which are not shown in greater detail, as a result of which balloon 18 is inflated to the position shown diagrammatically in Figure 2a. As a result, appreciable pressure is applied to the tissue surrounding the balloon. Generator 13 is then switched on and the relevant treatment is performed. Figure 3 shows an embodiment for the treatment of fingers or toes 15. It is indicated in its entirety by 14 and is provided with a common conductor to be connected to a generator according to the invention, earth being provided in the manner described above. It is also possible to operate in a bipolar manner, i.e. the voltage from the generator is applied across the clamp halves and no separate earthing conductor is present.

Although the invention has been described above with reference to a few exemplary embodiments, it must be understood that numerous modifications can be made thereto without departing from the scope of the present application as described in the appended claims. For example, it is possible to construct the electrode according to the invention in many other ways and to integrate or not integrate the associated generator. The electrode can be constructed, for example, as an inflatable tube and can be pressed against the body when used externally by all the means known in the prior art.

Claims

1. Device for the treatment of human muscles and/or tissue, comprising an electrode and a generator, the electrode being designed to be pressed against the body parts to be treated and the generator being designed to supply alternating current to the electrode, characterized in that the electrode comprises an electrically insulating continuous layer to be brought direct into contact with the body and having a thickness of between 0.1 and 2 mm and an area of less than 20 cm², and, directly adjacent thereto, an electrode made of electrically conducting material and connected to the generator, and in that the generator is designed to operate at a frequency of between 75 and 375 kHz.

2. Device according to Claim 1, in which the insulating layer on the side to be placed against the body is of smooth construction.

3. Device according to one of the preceding claims, in which the capacitance of the electrode with respect to the tissue to be treated is not less than 2.5 pF. . Device according to one of the preceding claims, in which the generator is designed for a maximum generator voltage of 1500 volts.

5. Device according to one of the preceding claims, in which the electrode comprises a curved post.

6. Device according to one of the preceding claims, in which temperature-measuring means are provided in the electrode.

7. Device according to one of the preceding claims, in which the electrode is flexible. 8. Device according to one of the preceding claims, in which the electrode is of spherical construction and is provided with connecting means.

9. Device according to Claim 8, in which the electrode comprises an inflatable balloon. 10. Method for the treatment of human muscles and/or tissue, comprising bringing an electrode according to one of Claims 1-7 into contact with the body, pressing the electrode and the human body against one another, and applying a voltage having a frequency of between 75 and 375 kHz. 11. Method according to Claim 10, in which pressing the electrode and the body against one another comprises placing the electrode on a support (such as a table) and placing the body (part) to be treated on the electrode. 12. Method for the treatment of human muscles and/or tissue, comprising introducing an electrode according to Claim 8 or 9 into the body and providing contact pressure between the electrode and the body part-to be treated.

13. Method according to Claim 12, in which the contact pressure is achieved by inflating the electrode.