EP0830174A1

EP0830174A1 - Compact instrument for iontophoresis, comprising a current regulator

Info

Publication number: EP0830174A1
Application number: EP96914386A
Authority: EP
Inventors: Giuseppe Bonfiglio; Carmelo Bianchetti
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-05-18
Filing date: 1996-05-15
Publication date: 1998-03-25
Also published as: WO1996036393A1; ITPA950015A0; IT1281159B1; CA2221320A1; ITPA950015A1; AU5777796A

Abstract

The instrument for iontophoresis has a compact shape and is intended for domestic use, it comprises a grip portion (1) made of an electrically conductive material, one or more batteries (14) and a current regulator (10) received inside the grip portion (1), and a replaceable part (17, 20) for the application of the ionic substance which can easily dissociate and penetrate inside the treated part of organism.

Description

Description Compact instrument for iontophoresis, comprising a current regulator-

Technical Field

The present invention relates to an instrument for dental iontophoresis and for the application of cosmetics on the skin by means of iontophoresis or for other treatments exploiting the principle of iontophoresis.

More particularly the invention relates to a compact instrument which is held by the user's hand, on its grip portion, during treatment, and comprising means for its electric power supply.

Background Art

According to known treatments involving iontophoresis, a person who must be subjected to this kind of treatment must go to a specialized surgery and cannot do this treatment by himself, without the help of physicians. Particularly, treatments for dental iontopheresis are practised by dentists by means of apparatus which are cumbersome and relatively complex. These apparatus comprise a constant current generator which is connected through electric wires to a grip portion made of electrically conductive materials and held by the user's hand, and they further comprise an anatomic spoon {whereon the medical substances are applied) ; to be introduced in the cavity of the mouth at the site of the dental arch.

The metallic grip portion, used as a reference electrode, is connected to the positive output of the electric current generator and through this portion, the whole body will take this polarity, in particular the cavity of the mouth.

The anatomic spoon which has a fluor gel applied thereon, is connected to the negative output of the generator.

When the spoon is put in contact with the dental arch, fluor contained in sodium fluoride separates from sodium and is attracted by the dental arch in the form of a negative ion, whereon it settles forming bonds with calcium and strengthening in this way the structure of the enamel of the teeth.

According to the state of the art, the apparatus for iontophoresis treatments, both for the application of cosmetics and for physiotherapy, comprises an electric current generator which is supplied by the electric network or by rechargeable batteries. These instruments, besides being cumbersome, require skilled persons for their operation. A pair of electrically conductive plates are connected to the generator through electric wires.

Each of said plates is introduced inside a pocket of spongy material which is damp and which carries the active principle. Said plates are laid on the body part to be treated and the generator connected thereto is switched on. The substances used have a dissociated structure and are therefore easily transformed into ions so that the current which flows between the two plates carries the ions of the substance through the skin.

Disclosure of Invention

An object of the present invention is to realize an instrument for iontophoresis, having a replaceable part, allowing a domestic application of cosmetics, fluor containing substances and other medicines on the respective body parts on which the iontophoresis treatment is performed. The instrument of the present invention can be held by the user's hand during treatment and is very handy and very simple to use.

Brief Description of Drawing The invention will now be described in detail with reference to two embodiments thereof which are given for illustrative and non-limitative purposes, wherein: Fig. 1 is a longitudinal cross sectional view of an instrument for iontophoresis, provided with a tooth- brush, according to the present invention;

Fig. 2 is an electric circuit arrangement of the constant current generator, contained inside the grip portion of the instrument of Fig. 1 ;

Fig. 3 is a lateral partially sectioned exploded view of the various constituents which form a replaceable part, which can be screwed on the grip portion of on instrument used for the iontophoresis of cosmetics;

Fig. 4 is a lateral view of the instrument of Fig. 3, in the assembled condition;

Fig. 5 is an electric circuit arrangement of the current generator contained inside the grip portion and which is alternative to the arrangement of Fig. 2;

Fig. 6 is a longitudinal sectional view of only the grip portion of the instrument of Fig. 1, wherein a cylindrical adapter has been screwed on the grip portion in place of the tooth-brush.

Best Mode of Carrying out the Invention

In the drawings, the same numeric references indicate identical or corresponding part.

Fig. 1 shows a first embodiment of the instrument for iontophoresis.

This instrument is used for dental treatment.

The cylindrical grip portion 1 made of an electrically conductive material is closed at both ends by plugs 2, 3 made of and electrically insulating material, both plugs being provided with an annular gasket, like an 0 ring 4,5, in order to insure a perfect seal againts the passage of liquids to the inside of the grip portion 1. The upper plug 2 carries internally a bush 6 made of an electrically conductive material, whereon the replaceable part 17 with the tooth-brush 7 may be inserted, by means of the internal conductive electrode 8. Said electrode 8 is connected to the conductive plate 9 which is located among the bristles of the tooth-brush 7. This plate provides the electric connection between the medical product laid on the bristles and the constant current generator 10 which is contained inside the grip portion and which is connected to the bush 6 through the connection 11. The constant current generator 10 is realized on a small printed circuit according to the electric circuit arrangement shown in Fig. 2 and is connected to one of the two poles of the electric supply battery 14, through the contact spring 12. The body of the battery 14 is electrically insulated from the grip portion 1, by means of the insulator 13. The electric contact between the other pole of the battery and the grip portion 1 is insured by the spring 16 and the screw 15 which fixes it on the lower plug 3, which may be removed in order to change the battery.

Fig. 2 shows the electric circuit arrangement of the constant current generator, comprising an n-channel FET FT, a resistance R, diodes D1,D2,D3,D4 and a battery 14. The connection indicated by 9 is the one leading to the plate 9 of the tooth-brush, the connection denoted by 1 is that which leads to the grip portion. By an analysis of this electric circuit arrangement it is possible to deduce that by suitably orienting the battery 14 inside the grip portion, it is possible to change the current direction, causing migration of substances containing active principles in the form of both positive and negative ions (as in the case of fluor, cited above). The instrument shown in figures 1 and 2 can be immediately used and does not require the intervention of skilled persons.

The instrument is conceived for domestic use and has the appearance of a common tooth-brush. However, it comprises all elements forming a complete device for conventional iontophoresis.

Moreover, according to the present invention, the current fed by the battery 14 is adjusted by the electronic micromodule or current regulator 10, so as to be perfectly constant indepentently from variation of external parameters, such as the contact resistance between the hand and the grip portion 1 , the conductivity of the product applied on the tooth-brush 17 and the charge level of the battery 14. In any condition whatever, the electronic module 1 adjusts the output voltage so as to balance said variations and to maintain the current withing pre- established limits. The electronic module is further provided with an effective protection against the wrong insertion of the battery 14 and an overload caused by a short circuit. The replaceable part 17 comprises the tooth brush 7 and is easily replaced by unscrewing it from its threaded seat 18. The electrode 8, the plate 9 located among the bristles of the tooth-brush 7, and the threaded end for the connection with the grip portion 1 , are preferably made of stainless steel. This fixing system of the tooth-brush by means of a threaded connection is preferred, as it insures a long mechanic life and a reliable electric connection. The described instrument does not require to be switched on or to be adjusted, and it is sealed against liquids. The instrument does not consume energy when it is not used and the life of the battery/batteries depends only on the number and duration of the single applications. An instrument for personal use, for intophoresis, will be described in the following, wherein the replaceable part 17 of Fig. 1 is substituted by the replaceable part 20 of Figs. 3 and 4, which serves for the application of cosmetics.

It must be noted that the instrument is not substantially modified, since the underlying principle remains the same, the grip portion 1 does not change or is modified within the limits hereinafter described, and the threaded seat 18 of the bush 6 is still present. The electronic module may in this case be realized according to the electric circuit arrangement of Fig. 5 which shows another kind of constant current generator. With reference to Figs. 3 and 4, the instrument for the application of cosmetics, lotions and pharmaceutical products on the skin or on the scalp, comprises the grip portion 1 having a bush 6 provided with a threaded seat 18 to be screwed on the threaded end 21 of an oblique connection element 22 included in the replaceable part 20. The oblique connection element 22 supports a clamping system for the small sponge or pad 23 which is soaked with the substance to be applied.

This clamping system has a bush 24 provided with a threaded seat 25, said bush being freely rotatable around the axis X-X inside the oblique connection element 22, a knob 26 integral with the bush 24, a conductive pad having a plate-like shape 27 and including a threaded connection 28, and finally an insulating pad 29 with a hole 30. The threaded connection 28 is introduced through the hole 30 and into the threaded seat 25 of the bush 24. By rotating the knob 26, the threaded seat 25 of the bush 24 is screwed on the threaded connection 28, so that the small sponge 23 enclosing the conductive pad 27 is clamped by the insulated counterpad 29.

It is possible, is this way, to easily replace the small sponge 23 when it is worn out, or to remove it for cleaning. Fig. 4 shows the instrument in the assembled condition. Fig. 5 shows that the electric circuit arrangement of the generator comprises two transistors TR1, TR2 , two resistances Rl , R2 , four diodes D1,D2,D3,D4, and one or more batteries 14. The battery 14 is connected to the grip portion 1 and to the generator 10 which is itself electrically connected to the replaceable part 20, more precisely to the conductive pad 27. As shown in Fig. 5, the "core" of the current regulator is interposed in a bridge comprising four diodes D1,D2,D3,D4 whose function is to allow the normal operation of the current regulator, for any polarity of the battery applied thereto, said diodes allowing ultimately to use the instrument with substances characterized by positive or negative ions, simply reversing the polarity of the battery inside the grip portion.

In fact, since the "core" of the current regulator is series connected to the polarization system comprising four diodes D1,D2,D3,D4, according to the ionized substance employed - whether positively or negatively ionized - it is in any case possible to obtain at the output a currrent which has the desired flow direction by simply reversing the polarity of the battery. This specific arrangement allowing polarity reversal provides an extremely versatile instrument from the view point of its possible different applications.

For illustrative purposes only and without thereby limiting the variety of all possible "cores" of current regulators (Fig. 2 shows the same polarization bridge with four diodes, employing a FET FT as active component) , a preferred embodiment of the present invention will be described in the following, wherein the current regulator is obtained by coupling together two transistors TR1 and TR2 , TR1 forming in this case the core of the regulator, which is polarized on its base by the resistance Rl; the current flowing out of its emitter, crosses the resistance R2 on which it produces a voltage drop. When this voltage drop becomes greater than the threshold value of the transistor TR2 , the latter becomes conductive thereby reducing the voltage on the base of the transistor TR1 , which brings the current at the output again to its nominal value, keeping it constant.

The value of the resistance R2 determines the maximum current which can be fed by the electric module and can be obtained from the ratio Vbe/I wherein Vbe is the voltage drop between the base and the emitter and I is the current required at the output.

In the embodiment of Figs. 3 and 4, the grip portion 1 has a structure similar to that of the electronic tooth¬ brush for dental iontophoresis shown in Fig. 1, however in Figs. 3 and 4 there are preferably provided two series connected batteries of 12V each, in order to obtain a supply voltage which is twice as great, that is 24V. This is due to the fact that since the skin is more dry than the mucous membrane of the mouth cavity, a greater voltage is necessary for ion penetration. Therefore, in this case the grip portion 1 will usually be longer.

The following table is an illustrative and non- limitative example of the electronic components which can be used: Rl = 1,2 Moh R2 = Vbe

I

TR1 = BC 547B or equivalent

TR2 = BC 547B or equivalent

Dl = IN 4148

D2 = IN 4148

D3 = IN 4148

D4 = IN 4148 wherein Vbe = base/emitter voltage drop of TR2

I = current required at the output. In Fig. 6 there is shown a cylindrical conductive element 39 which is provided with a threaded stem 40, to be screwed into the threaded seat 18 defined by the bush 6 of the instrument previously described with reference to Figs. 1, 3 and 4. Inside this cylindrical conductive element 39 there is obtained a hole 41. The cylindrical conductive element 39 will also be called adapter because it allows the insertion inside the hole 41 of a jack plug (not shown) of a conventional electrode used for instance by dentists.

A conventional electrode is for instance made up by a conductive plate in case of physiotherapic use or applications of cosmetics, or else by an anatomic spoon in case of dental applications. The jack plug of the electrode (not shown) instead of being connected to the apparatus, is inserted into the hole 41. In this case, notwithstanding the fact that conventional electrodes are used, it is however true that the practicalness in use of a compact and portable instrument like that described above, with respect to cumbersome apparatus, remains valid.

The adapter 39 shown in Fig. 6 will however allow also a professional use of the instrument of the present invention, by skilled physicians.

Claims

1. An instrument for iontophoresis, characterized in that it comprises an electrically conductive grip portion (1) , two electrically insulating plugs (2,3) at the ends of the grip portion (1), electric energy supply means including one or more batteries (14) received in the grip portion (1) or a connection system to the supply mains, in order to feed electrical energy to an electronic micromodule (10) consisting of a constant current generator which is also contained in the grip portion (1) ; wherein a pole of the battery (14) or of the voltage of mains is connected to the input of the micromodule (10) and the other pole is connected to the grip portion (1); means (6,11,18) for mechanical and electrical coupling being provided in order to connect electrically and mechanically the output of the electronic micromodule (10) with a replaceable part (17,20) used for the application of the cosmetic or of the medical product.

2. An instrument for iontophoresis according to claim 1, characterized in that said replaceable part (17) comprises a tooth-brush with a plate (9) located among the bristles and connected to an electrode (8) which is rod-like and extends inside the tooth-brush, terminating in a threaded portion which is inserted in a removable way inside a bush (6) provided with a threaded seat

(18), said bush (6) being formed on the insulating plug (2); said bush (6) being made of an electrically conductive material and being connected to the output of the micromodule (10) by means of a connection (11).

3. An instrument for iontophoresis according to claim 1, characterized in that said replaceable part (20) comprises an replaceable part (20) comprises an oblique connection element (22) facilitating the application of the cosmetic or of the medical product by means of a small sponge or pad (23), said oblique connection element (22) being provided with a clamping system (24,25,26,27,28,29) for the small sponge (23), and with a threaded end (21) which is screwed in a bush (6) provided with a threaded seat (18) inside the grip portion (1) ; a connection (11) of said bush (6) being electrically connected to the output of the micromodule (10).

4. An instrument for iontophoresis according to claim 1, characterized in that an insulator (13) is provided between the battery or batteries (14) and the grip portion (1) made of electrically conductive material.

5. An instrument for iontophoresis according to claim 1, characterized in that in order to provide a seal for the instrument, gaskets (4,5) are preferably incorporated in said plugs (4,5) made of an insulating material.

6. An instrument for iontophoresis according to claim 3, characterized in that the longitudinal axis (X-X) of the oblique connection element (22) preferably forms an angle of about 70° with the longitudinal symmetry axis of the grip portion (1).

7. An instrument for iontophoresis according to claims 3 and 6, characterized in that said clamping system (24,25,26,27,28,29) of the small sponge (23) comprises a knob (26) fixed to a bush (24), provided with an internal threaded seat (25) and freely rotatably mounted inside said oblique connection element (22), said bush being rotated by the knob (26) , a conductive pad (27) having a plate-like shape provided with a cylindrical threaded connection (28) which may be first introduced in a hole (30) of an insulating counterpad (29) and then screwed in the threaded seat (25) of said bush (24) of the oblique connection element (22); said small sponge (23) enclosing said conductive pad (27) and being clamped between the latter and the insulating counterpad (29); said bush (24) , said oblique connection element (22) and said threaded end (21) being made of electrically conductive material.

8. An instrument according to claim 1, characterized in that the micromodule (10) has means for protecting it from a wrong insertion of the battery (14) and from an overload due to a short circuit. - 16 -

9. An instrument according to claim 1, characterized in that the "core" of the current regulator is interposed between a bridge of four diodes (Dl ,D2,D3,D4) , having the function of allowing the normal operation of the current regulator for any polarity of the battery connected thereto, so that the instrument is arranged to adapt itself to a particular use according to the ionized substance employed, - whether positively or negatively -, this being obtained by simply reversing the polarity of the battery inside the grip portion, so that the output current will have the required flow direction.

10. An instrument according to claim 2, characterized in that in order to connect the grip portion (1) to a conventional electrode, there is provided a cylindrical adapter (39) having a hole (41) receiving the jack plug of the electrode, said adapter (39) , which is electrically conductive, being provided with a threaded stem (40) which may be screwed in said threaded seat (18) of said bush (6) .