ELECTRODE DEVICE

Abstract: An electrode device for treatment of biological tissue comprising an electrode unit (1, 3, 3') and a supply unit (4) electrically insulated against the surrounds for sup ply of electricity from a voltage source to the said electrode unit (1, 3, 3'). The supply unit (4) is designed pliable and contains at least one duct for one or a plurality of electrical conductors (5-7) and for transport and guidance of aids (12-15, etc.) to and from the electrode unit (1, 3, 3').

Description: ELECTRODE DEVICE This invention relates to an electrode device intended to be temporarily inserted into the body of a living being and essentially locally to treat biological body tissue therein and subsequently, 5 upon completion of the treatment, to be removed, the said device incorporating an electrode unit introducable into the body tissue which it is intended to treat and a supply unit electrically insu¬ lated against other parts of the body for the supply of electricity from a voltage source to the said electrode unit. ° Various electrodes are already known, for example through the U.S. patents 4 103 690 and 3 348 548 and through the German patents 577 722, 651 428 and 1 143 937. Known electrode designs for the treatment of biological tissue are unsuitable for several reasons. -5 In order, for example, to treat a tumour with direct current, the electrode which is to be inserted in the tumour and which is arranged to electrically interact with a s ' econdary electrode which is located outside the tumour must be localized with great precision in the centre of the tumour. With prior art electrodes, it is very difficult 2- to achieve exact positioning and retention of the electrode in the tumour. One of the reasons for this is that the tissue and the tumour may move, for instance as a consequence of the respiratory motions of the patient. Moreover, the tumour, where the point of the electrode reaches to and is to be inserted into the tumour, may slide aside in 25 surrounding softer tissue. This means that repeated attempts frequently have to be made in order for an acceptable positioning of the tumour to be obtained. Severe problems in the treatment of tissues also arise as a con¬ sequence of gas formation, dehydration and/or material deposition on -' the surfaces of the electrode. One of the objects of the present invention is to provide an electrode device which permits certain and exact insertion and re¬ tention as well as removal of the active electrode unit in a bio¬ logical tissue without being moved out of position, for example in a - ~ tumour. A further object of the invention is to provide an electrode device with the aid of which gases generated at the surfaces of t electrode can be sucked out and liquid and/or medication can supplied to the tumour. These and other objects are obtained at the electrode devi specified in the descriptive preamEle according to the present i vention in that said device is given the features as are evident fr the characterizing clause of the accompanying Claim 1. Other essential features of the present invention are evident fr the accompanying claims. One embodiment of the invention is describ 10 below and with reference to the accompanying drawings, wherein Fig. shows a cut-away view of an example of an embodiment of the electro device according to the invention, Fig. 2 shows a first stage in t introduction of the electrode device in the direction towards tumour, Fig. 3 shows the introduction of an aid, for example *1 anchoring device, in the tumour, Fig. 4 shows the electrode devi inserted _ with the ' aid of the anchoring device an'd a stiffeni member, for example a cannula, and Fig. 5 shows the electrode devi with the anchoring device and cannula removed. According to Fig. the electrode device is in the treatment position in the tumour and 20 three-way cock is connected to the supply unit for extraction of g and/or introduction of liquid or medication. The embodiment of the electrode device shown in Fig. 1 compris an electrode unit, manufactured for example of platinum and having front section 1 with a pointed or narrowing cylindrical end 2 and o 25 or more rear cylindrical rings 3, 3'. These parts have a diameter approx. 1.9 mm. The electrode unit is shown here to consist of thr parts to illustrate that electrode units with different axial lengt for tissue areas of different sizes can be built up from standardized front section 1 and auxiliary rings 3, 3 1 since a lar 30 electrode surface is- required in order to enable sufficiently lar current intensities to pass through the tissu «e area to be treat within reasonable time. The front section 1 of the electrode unit, which obviously can used v/ithout auxiliary rings 3, 3', if for example a cancer tumo 35 which is to be treated is of such a size that the length of the pa 1 is sufficient, is attached by pressure to one end section of W1F supply unit 4 which in this case consists of a tube 4. This tube 4 is made pliable in order to be able to accompany movements in tissues and may be made for example of the plastic marketed under the trade mark Teflon. The rear rings 3 and 3' respectively are similarly attached by pressure to the tube 4. Attached to the inside of the cylindrical electrode section 1 are one or more electrical conductors 5, 6, 7, which are for example brazed or soldered. In the shown example, the conductors are three in number. The conductors 5-7 which in the same way as the electrode rings 1, 3, 3' are bright (blank) - j _0 and thus uninsulated in the shown embodiment, are clamped between the cylindrical inner surfaces of the parts 3, 3' and the cylindrical jacket surface of the tube 4. By this means, good electrical contact is afforded between the electrical conductors 5-7 and the rings 3, 3'. The three conductors 5-7 are inserted into the interior of the • j _5 tube 4 through a hole sited within the region for the ring 3', and are introduced via the interior of the tube 4 to, for example, one terminal 8, in the shown embodiment the positive terminal, of a direct voltage source 9. The second terminal of the latter is in this case connected to a second electrode 10 which is located at a 20 suitable distance from the tube in a conductive medium in the body. We have thus been able to show that the walls of the blood vessels function as insulators around a conductive medium - the blood plasma. Since a tumour is supplied by th.e surrounding blood vessels, a closed electrical circuit is obtained by this means, with the blood vessels 25 acting as mutually parallel electric conductors. Other conductive media in the body may nevertheless be used, for example tissue fluid, brain fluid, gall fluid, urine, gland secretion, etc. When an electrode which is inserted in a tumour acts as a positive electrode, a powerful emission of protones is obtained upon decom- 30 position of water, resulting in the tissue becoming highly acidic and in destruction of the tumour close to the electrode. Tumour cells possess negative surplus charges and are therefore retained by the positive electrode. At the same time, gas - for example chlorine gas and oxygen gas - is generated at the positive electrode and the gases deposit themselves on the surface of the electrode, thus impeding the process. Further biological effects in the electrical field have been CMPI ^ revealed and consist of electro-osmosis, electroforetic transport accumulation of white blood corpuscles around the anode and extend formation of blood clots in the capillaries around the anode, a factors contributing to the treatment. If medications such as cytostatics or antibiotics are desired in high local concentration within a treatment area, such medicatio can be attracted towards the electrical field of an electrode if t medication is imparted an electrical polarity which permits i electro-foretic attraction towards the electrode concerned. In th case, the medication can be administered in supply ducts, such blood paths, gland paths, etc. By means of the present invention, t medication can also be administered via the electrod duct. If t same polarity is given to the electrode as to the medication, this repelled in the tissue. If the opposite polarity is applied, t medication is rerained in the vicinity of the electrode. The tube 4 has an inner cylindrical duct which is largely equal as large as . the cylindrical duct 11 in the front section of t electrode unit 1. By giving a lug 23 for the end of the tube 4, slightly greater extent in the direction towards the centre than th corresponding to the wall thickness of the tube 4 in itself, additional lug is obtained against which a cylindrical body or ba (not shown) connected with a stiff but pliable thin wire can inserted in the tube 4 and act as a seal to close the opening in t end of the electrode unit 1 if necessary. A cannula with a diamet of approx. 1 mm may be introduced through the tube and through th duct 11. The said cannula is provided with, for example, an oblique ground off tip 13. The cannula 12 can be inserted into the positi shown in Fig. 1, i.e. to a position beyond the end 2 of the electro unit 1 and after insertion in the tissue together with the electro unit will form a guide device for the electrode unit 1, 3. While t cannula 12 is being inserted in a tumour, it is possibly rotat around its longitudinal axis. A wireshaped anchoring device 14, 1 which in the embodiment example has a screw-shaped end section which is terminated with a sharp point 15 is introducable into t cannula 12. The end of the anchoring device may instead be provid v.-ith other suitable means for improving the anchoring in a increasing the contact are against the tumour, for instance with hooks or barbs. As an alternative or a complement, the shell surface of the can¬ nula 12 and/or the electrode unit 1 may be screw-shaped to facilitate introduction into and increase the contact surface against the tumour. The anchoring device, designated by reference numeral 16 in Figs. 1 and 3, extends throughout the entire cannula 12 and some way beyond the end of the cannula facing away from the tip 13 and is provided with a knob 17 by means of which the screw-shaped end section 14 can be rotated. The electrical conductors 5-7 emanate through a connector 18, for example in the form of a screw socket. In this position of the cannula socket 19 - see Fig. 2 - the cannula 12 is entirely inserted in the tube 4 and in the electrode unit 1 and protrudes beyond the electrode unit 1. Fig. 2-5 illustrate various stages in application of the electrode unit' into a tumour 20 which is surrounded by body tissue 21. Fig. 2 shows how the electrode device has been passed through the body tissue 21 as far as the tumour 20 and the cannula 12 is here in its fully inserted position, whereupon the cannula socket 19 rests against the screw socket 18. When the tip of the cannula 12 has reached as far as the tumour 20, the anchoring device 16 will be in such a position that its screw-shaped end 14 lies entirely retracted in the cannula 12. In the next stage, the anchoring device 16 is anchored by means of its tip 14, which may, for example, be screw-shaped, in the tumour 20. For this purpose, the tube ' 4 and the cannula 12 are retained in the position shown in Fig. 2 and the knob 17 - see Fig. 3 - is turned in the entry direction of the screw-shaped tip 14 under light axial pressure. The tip 15 of the crew 14 first reaches the occasionally relatively hard tumour tissue and easily penetrates the surface of the rumour without essentially disturbing the 'position of the tumour 20. As the knob 17 continues to be turned, the screw 14 is drilled into the tumour 20, forming a reliable anchorage for the entire electrode device - see Fig. 3. When the screw has reached its intended position in the tumour 20 - something which in certain cases may require repeated attempts - which position may, for example, checked by X-ray fluoroscopy, the cannula socket 19 is passed inwar in the direction towards the tumour 20, whereby the cannula 12 a the electrode section 1 are moved in over the screw 14 and lea tumour cells in the threads of the latter - see Fig. 4. In th position, the anchoring device 16 serves as a guiding device for t cannula 12 and thus for the electrode unit, the cannula 12 also bei rotatable during the movement in order to facilitate insertion. T electrode unit 1, 3, 3' is moved into the tumour 20 together with t cannula 12 and the cannula 12 serves during this movement as support for the pliable supply unit 4 (the tube) and when t electrode unit 1, 3, 3 1 attached to the tube 4 reaches the intend position in the tumour 20, both the cannula 12 and the anchori device 16 are withdrawn from the front section 1 of the electrode a out of the tube with accompanying tumour material, which may used to advantage for cytological check. The anchoring device 16 - either threaded or unthreaded - may certain cases be used as a. temporary electrode for local destructi of tissue around the anchoring device 16. In this case, the device for example provided with a thin coating of electrical insulatio for example the plastic marketed under the trade mark Teflon, wi the exception of the portion which is intended to be inserted in the tumour. The anchoring device is then connected either to suitably sited electrode for direct current treatment or to a lar plate electrode applied to the surface of the body for application high frequency alternating current. When heat develops around th non-isolated part of the anchoring device in the tumour, local tiss destruction is accomplished which has a therapeutical effect an gives a lengthwise extending tissue cavity, into which, for example the cannula 12 and the electrode unit 1, 3, 3' can thus be mor easily inserted. At this juncture, a cock 22 can now be inserted, as shown in Fig 5, to the connector unit or the screw socket 18 in order to mak possible, for example, the introduction of fluids or medication t the tumour 20 through the free duct in the tube 4 via perforations o holes (not shown) in this tube under the electrode units 1, 3, 3' an CMFI in or between the walls of the electrodes 1, 3, 3' and/or for removal of gas or fluid from the tumour 20. For example, physiological sodium chloride solution may be introduced in order to increase the conductivity of the tumour 20 around the electrode unit. It is also possible for example to introduce cell poison. The cannula 12, which for example is made of stainless steel, should have a good fit against the electrode unit 1 and against the inside of the tube 4 but must slide easily in order to be insertable into and removable from the electrode unit 1 and the tube 4 without any greater effort. The anchoring device 16, which for example is made of stainless steel, has a good fit in the .cannula 12. The above described anchoring device 16 is made of rigid metal wire but it is also possible to use a flexible material, for instance spirally wound metal wire. Through the elaboration of the electrode device, a design is obtained which is soft, pliable and flexible and thus able to accom- • pany tissue movements, for instance muscle movements, respiratory movements, etc. and can be introduced, for example, into a curved gall passage without being broken. In the drawings, the electrical conductors 5-7 are shown to run inside the tube 4 but they may obviously instead be -embedded in the wall of the tube A . The invention is primarily intended for treatment of cancer tu¬ mours in the human body but is naturally also usable in animal bodies and may similarly be used to treat other disease conditions in tis¬ sues.

Claims: CLAIMS 1. An electrode device designed to be temporarily introduced in the body of a living being and essentially locally to treat biolog cal body tissue therein and to be subsequently removed upon co pletion of the treatment, the said device comprising an electro unit (1, 3, 3'), introducable into the body tissue which is intend to be treated and a supply unit (4) insulated electrically again other body parts for supply of electricity from a voltage source ( to the said electrode unit (1, 3, 3'), c h a r a c t e r i z e d in that the said insulated supply unit ( is elaborated pliably and contains at least one duct, the length which is so adapted that the duct emanates both in the said electro unit (1, 3, 3 1 ) and outside the body and which is so adapted in si that it incorporates not only a space which is electrically insulat against such parts of the body which are not intended to be. treat for one or a plurality of electrical conductors (5-7) for excitati of the electrode unit (1, 3, 3') but also a space limited again those parts of the body which are not intended to be treated but op or openable towards the body tissue which 'it is intended to treat f transport and/or guidance to and from the treatment point of aids f temporary stiffening of the pliable supply unit (4) , to facilita introduction and anchoring of the electrode unit (1, 3, 3 1 ) in t intended position in the body, sampling of body tissue, supplementa treatment of the body tissue and/or removal of residual products fr the treatment site. 2. An electrode device according to Claim 1, c h a r a c t e r i z e d in that the said spaces coincide, in th the supply unit (4) is elaborated as a tube and in that the sa electric conductors (5-7) run in the tube (4) . 3. An electrode device according to Claim 2, . c h a r a c t e r i z e d in that the said electrode unit (1, 3, ' 3 is provided in its end facing away from the said tube (4) with opening which is preferably located as an axial elongation of t mouth of the tube (4) in the electrode unit (1, 3, 3 1 ). 4. An electrode device according to Claim 3, c h a r a c t e r i z e d in that the electrode unit (1, 3, 3') in the said end is elaborated narrowingly (2), viewed in the direction of the electrode unit (1, 3, 3') away from the tube (4). 5. An electrode device according to Claim 3 or Claim 4, c h a r a c t e r i z e d in that the electrod ~ e unit (1, 3, 3') contains or surrounds a portion of one end of the tube (4) and in that the wall of the tube ' (4) within that portion of its one end which is contained or surrounded by the electrode unit (1, 3, 3 1 ) is provided with holes which are arranged to provide fluid and gas communication between the interior of the tube (4) and the outer surface of the tube (4) and of which at least one hole also serves to introduce the said electric conductors (5-7) to contact with the electrode unit (1, 3, 3'). 6. An electrode device according to Claim 5, c h a r a c t e r i z e d in that the hole in the wall of the tube (4) for the electric conductors (5-7) is located at such a distance' from one end of the tube (4) that a number of electrode units (l, 3, 3') can be attached to the tube (4) and electrically contact the said electrical conductors (5-7) and in that the said electrode units (1, 3. 3 « ) are so mutually adapted and/or provided with such holes or slots that fluid and gas communication is obtained between the outer surfaces of the said electrode units (1, 3, 3') and the outer surface of the tube (4) . 7. An electrode device according i Claim 6, c h a r a c t e r i z e d in that the aggregate length of the insu¬ lated supply unit (4) and the electrode unit (1, 3, 3 1 ) and the opening of the said closed space are so adapted in relation to the length and outside dimensions of a cannula (12) serving as a stif¬ fening body that the cannula (12} can be inserted into the said closed space and protrude beyond the portion of the electrode unit situated furthest away from the szL-i duct and .in that the said can¬ nula (12) in itself or a device (14, 16) movable in the said cannula (12) is elaborated as an anchoring device, which is arranged to be inserted into and anchored in relation to a biological tissue, into which at least the electrode unit '1, 3, 3') is to be inserted, and in that the electrode device is arranged to be movable relative to the cannula (12) and/or the said unit (14, 16). 8. An electrode device according to Claim 7, c h a r a c t e r i z e d in that the electrode unit (1, 3, 3'), t cannula (12) and/or the anchoring device (14) are elaborated wi barbs, screw ' shape or similar irregularities to increase the conta surface. 9. An electrode device according to any- of Claims 2-8, c h a r a c t e r i z e d in that the other end of the tube (4) furnished with a connector (18). 10. An electrode device according to any of Claims 2-9, c h a r a c t e r i z e d in that the electrode unit (1) is provid with an inner stop lug (23). 11. An electrode device according to Claim 10, c h a r a c t e r i z e d in that one end of the tube (4) is arrang to be stopped by the said stop lug (23) in the interior of t electrode unit (1) and in that the said stop lug (23) has an exte which in the direction towards the centre of the electrode unit ( exceeds the wa " ll thickness of the tube (4) in the same directio whereby apart from a stop for the tube (4) an additional stop is al obtained against- which, for example, a ball or cylinder equipped wi a wire can be made to rest to form a seal. OM

Inventors: NORDENSTROEM B, OLSSON M
Applicants: NORDENSTROEM B, OLSSON M, URSUS KONSULT AB
Application year: 1981
Main classification: A61N1
IPC codes: A61B10, A61B18, A61N1