DE2944730A1 - SURGICAL INSTRUMENT - Google Patents

Description

ALEXANDER R. HERZFELD β ™ ankfur-a.m bo LAWYER ^ ZEPPCUNAUEE 71 fiQ / / T'S f | BBDEMLAWaERICHTFRANKFURTAMMMN O TELEPHONE 0β11 / 77ΜΙ8 ζ, ν? * ♦ * + '^ V

Applicant: Corning Glass Works
Corning, NY, USA

Surgical instrument

The invention relates to a surgical instrument, in particular a surgical cutting instrument that is used for simultaneous Cauterization and hemostasis of organic tissues is suitable.

Bleeding caused by surgical or other interventions or wounds can be stopped by applying heat energy, by cauterization. For this purpose, are known with electric resistance elements equipped cutters or knives, which the tissue a temperature of 200 - 500 ⁰ C suspend. In the process, the parts of the scalpel that do not come into contact with the tissue are greatly overheated, which can endanger both the patient and the surgeon using the scalpel. The measures proposed so far for eliminating this source of danger in turn lead to serious disadvantages. Heating elements divided into segments require complex, separate temperature and

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.systems. Heating elements with a strongly negative tenvoeraturl oof fizi erten of the electrical V / iderntan.dy need very high tones for operation. Oxygen discharge passing through the patient's body is dangerous, difficult to regulate, and can not cause malicious v / s or scars.

The invention asked a surgical instrument to the task that by applying to tissue parts with physiological, electrical guiding importance, with or without a cut, a cautery - '. ierun °; and hemostatization without undue effort :. ;;, require or produce dangerous side effects.

This object is achieved by the surgical instrument of the invention solved in that a support body, cutting blade or the like has a cutting edge and close to the same one over has at least two electrical connection means connected to the electrical power source, which via at least two isolated parallel conduction paths or conductors through the moist, conductive tissue as it is heated directly.

The device can cut and cauterize at the same time, so it allows a faster surgical procedure Cut. When an electrical potential is applied, no current flows between the electrodes as long as the electrode gap is open has not yet been bridged by contact with physiological fluid of moist tissue. In particular, when applied lower voltage no electrical breakdown, e.g.

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by building an electric arc. So no heat is generated anymore. This only happens after contact with moist tissue, and only at this point, not at other points on the cutting blade or scalpel. If you pause with the cutting movement: ¹ :, the tissue becomes increasingly drier due to cauterization, and the heat generation automatically decreases. Cautery and herostasis are also possible without incision, as long as the tissue is moist, ie wetted with a physiological, electrically conductive fluid.

The electrodes consist e.g. of a layer of platinum, Palladium or other, physiologically compatible metals or alloys. Direct current operation is possible, but alternating current is given preference. In this case, the arrangement, particularly in the higher frequency range, has the effect of more loss Rectifier as soon as a conductive substance, e.g. physiological liquid with salt content in the electrode gap or electrode boundary area occurs. The heating can then be regulated by frequency modulation.

The substrate, cutting blade or scalpel carrying the electrodes is preferably made of glass, glass ceramic or fine-grained glass ceramic Structure.

The principle of the invention can be developed in various ways. Thus, the conductive or non-conductive substrate near the cutting edge can be alternating, interlocking

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Rails made of ladders and insulators, which met by conduction or discharge through the moist tissue generating heat. It can also be elongated ßlektrodenelemente with interlocking Leitfintern can be provided on one or both sides. It is also possible to have a training with a metal cutting edge connects to one electrode on both sides of the Sclineid sheet, or one electrode on each side of the sheet can reach over the cutting edge like a finger to the other side, and possibly with guide fingers of the other Side be interlaced in the shape of a finger or a fan.

The handle is electrically isolated from the cutting blade, preferably light weight and removable and usable for cutting blades or scalpels of various types and shapes.

The invention will be explained in more detail on the basis of the drawings. Show here:

FIG. 1a) shows an embodiment of the invention in a schematic side view;

Figure 1b) the device of Figure 1a) in section along the section line 1b-1b, and schematically the mode of operation on Example of a surgical incision with hemostasis;

Figures 2) and 5) embodiments of the device according to the invention with finger- or fan-shaped interlocking guide fingers;

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294 V / 30

FIG. 4) shows a partial section along section line 4-4 Figure 3;

FIG. 5 shows a further embodiment of the invention as a partial view a cutting device with several conductive layers on both sides of the cutting edge;

Figures 6 and 7 show a further embodiment of the invention with alternating conductive and insulating layers.

To explain the basic principle of the invention, shows FIG. 1 a) a surgical cutting blade or scalpel 10 with a cutting edge 11 as a substrate made of insulating material. On the cutting blade 10 there are conductive electrical input means 12, referred to here as electrodes E and E *. You can made of overlays or coatings made of metal foil with interlocking, separate guide fingers c1 and c2 exist. The input means, e.g. the electrodes, are provided via contacts 18 and pages 13 connected to a high frequency power source. Although the invention is explained in connection with a cutting process as an example, is a section for achieving hemostasis with the aid of the invention Device not required. Since the physiological fluid present in the tissue conducts electricity, this can normally moist tissue is electrically cauterized according to the invention without having to make a cut, that is, by simply placing the sheet 10 on the moist tissue. When drying out the liquid continues the process at a lower level. Only one is needed due to the presence of an electrolytic one By means of conductive tissue, usually in the form of the

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nfiysiolofrischen liquid. The invention is given as an example only but described for the full process including an incision and simultaneous cauterization.

In FIG. 1b), the cutting edge 11 is used to cut into the tissue 14 at the point 15. As a result, a surface layer with conductive physiological fluid is exposed on the opposite incision surfaces 15a-15b. For the sake of clarity, the distance between the sheet 16 and the surfaces 15a 15b is shown exaggerated, in reality they are in close contact. The electrical energy is conducted via the input means 12 to the cutting edge 11, and the physiological fluid closes one or more ^{current paths 17 connecting the electrode E to the electrode E 1.} The same applies to any input means attached to the left side of the sheet; attachment to both sides of the sheet is preferred 1

Alternating current is preferred because direct current undesirably polarizes the electrodes E-E 'and thereby stimulates the muscles can. High-frequency current of 100-10 kilohertz is still preferred, because the input voltage can be low, e.g. 30 - 50 volts, i.e. considerably below the breakdown or arc threshold.

The heat generated along the pathways 17 cauterizes the incision 15, but also dries the body fluids. This makes the routes disappear 17. The process is therefore self-limiting,

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If the incision is lengthened or deepened, new body fluid is exposed and current flows through it damp places or routes. A complex process regulation is thus dispensable, the process is regulated by itself and severe temperature fluctuations and the risk of excessive and dangerous tissue heating or overheating parts of the blade are avoided.

In the embodiment of Figures 2 and 3, the substrate in the form of a surgical scalpel with removable handle, the cutting blade 10 near the cutting edge 11 contains the input means, KB electrodes E, E ¹ , as a conductive rail along the cutting edge, with interlocking guide fingers. In contrast to FIG. 1, the electrode E1 is located as a precipitate on and on the scan edge, while the electrode E ¹ is attached at a distance from the cutting edge 11. Your guide fingers c2 engage in the spaces between guide fingers c1 of the electrode E and form conductive paths leading from the electrode E to the electrode E '. Electrical connections 13 connect the input means via contacts 18-18 ', and the cable connection 19, 20-20' with a high-frequency source 8. If an incision is made, the salty body fluid passes to the interface, but dries up as soon as the point is cauterized so that the process regulates itself. Energy is therefore only released in that part of the input means that is in contact with the moist tissue (see FIG. 1b) and the tissue temperature near these parts of the input means 12 remains almost constant.

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In the embodiments of the invention according to FIGS. 1a-2, the heat-generating input means 12 are located near the cutting edge 11 on one side of the cutting blade 10, and the guide fin / rer c1, for example. c2 range from one to the other electrode E h?, w. E ¹ . This finger-shaped interlocking arrangement generates on the substrate surface 10 conductive paths 1? for the current through the distances 23. In FIG. 1 a, the input element is arranged at a distance from the cutting edge 11, while in the embodiment according to FIG.

In FIGS. 3 and 4, the electrode E 'is attached with the guide fingers c2 on one side (the right side) of the substrate, and the guide fingers extend over the cutting edge to the other side. The same applies to the electrode E on the other side, so that the guide fingers d, c2 form a finger-like interlocking arrangement. The guide paths 17 running along the side of the cutting edge bridge the isolated spaces 23 when the cutting blade is in contact with moist tissue 14 (see FIG. 1b). All of the routes 17 of the input means are connected in parallel ^{between the electrodes E, E 1.}

Contacts 18-18, lines 13 and cable connections 20-20 ' can consist of a material such as platinum, gold, tungsten or the like, which makes good contact with the input means 12 forms and not at the elevated operating temperatures

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oxidized too easily. The input element 12 can be made of tin oxide or a precious metal such as platinum, gold or tungsten.

In all of the aforementioned configurations, the cable connections 20-20 'are connected to a suitable high-frequency voltage generator 8, see Pig. 2, which supplies the energy required by all parts of the input means 12 and ^{keeps the voltage between the electrodes EE 1} essentially constant when various parts become conductive. When this constant voltage is applied, the moist areas consume more current and emit more energy than the drier areas, and thereby generate the high temperature required for cauterization and hemostasis in the tissue in contact with the cutting edge 11. The operating temperature at the cutting edge 11 can be adjusted by changing the output power and frequency of the generator 8. A regulated direct current motor can be used as an auxiliary source for the heater 30. In tests with power sources and high frequency generators for carrying out the invention, it has been found that, in order to achieve a uniform operating temperature along the entire length of the cutting edge, the input element should have a substantially uniform resistance per unit area which is lower than the resistance of the tissue exposed to the input element.

As electrode material, precious metals, semi-precious metals, are more rustproof Steel, etc., depending on the conditions of use.

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A particular advantage of a close electrode spacing and the low voltage is the avoidance of an arc, as is customary in the known high-frequency electrosurgical devices. Both possible low voltages used here prevent the build-up of an electric arc and electric current only flows between the electrodes when there is a contact connection through moist tissue containing physiological fluid 16. After cauterization, the tissue at the cut surfaces 15 becomes dry and the conductive connection of the electrodes EE 'ceases to exist. This avoids fire damage to the tissue, the electrical energy is regulated automatically, and the voltage and energy consumption are constantly regulated at different cutting speeds at the tissue locations to be cut.

In the preferred embodiment of FIG. 1, each cutting blade has a similar cross-sectional profile. It can consist of hard glass, glass ceramic or ceramics that are so solid, fine-grained and homogeneous that a good cutting edge is obtained. The thickness of the cutting blade 10 increases after the cutting edge to about 0.15 now. Before forming the cutting edge, two strips of appropriately shaped metal foil or metal layers bb ^{1 are} applied to one or both sides. The cutting edge can then be removed by removing part of the material of the heating element 12, and the electrodes EE 'come as close as possible to lie on the cutting edge.

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As an example, a glass (Corning No. 1723) is pressed against a molybdenum foil by vacuum pressing above the softening temperature pressed, or glass ceramics or ceramics with adapted thermal expansion coefficients are pressed with foils or metallized. For very thin rietal films (less than 1 mm) or foils made of drawable metals such as aluminum, silver, platinum, Gold, etc., the thermal expansion correspondence is less critical.

In the embodiment of Figure 1, 0.1 mm thick molybdenum is covered the tapered part 26 of the substrate 10 near the cutting edge 11, which at the same time provides a certain reinforcement of the part results. Metal films thinner than 1 mn are best made of tin oxide, Platinum, gold, or the same, the special good adhere to substrate 10 and have good electrochemical resistance.

The mode of operation is self-regulating when the voltage is kept below the threshold value for the formation of an arc. For the exemplary embodiment in FIG. 1, this means approximately 50-20 volts, ^{depending on the distance between the electrodes EE 1.} If the distance between the electrodes is smaller, the voltages must be kept lower. The energy spread is different depending on the cutting speed and the contact area at the interface 15 and is mostly in the range of 5-50 watts. The high-frequency energy used largely avoids nerve stimulation and electrical polarization of the interface 15 with undesirable side effects. Sin usable frequency range is

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between 10 kilohertz and 10 megahertz. With such a wide frequency range, a variable frequency power source can be used to match the impedance of the supply circuit with the consumer circuit (10, 12 and electrical connections). As a rule, the supply is set in such a way that, for a given blade shape, the necessary energy is supplied at the lowest possible voltage .

The device of the invention is not limited to use in surgical procedures. For example , the device can be used to cut electrically conductive materials or material which is made conductive by applying electrically conductive liquids. The treated material can then be cut and sealed or welded at the same time.

In the further embodiment of FIG. 6 , the input elements 12 consist of multilayered conductive layers b1, b2, b1 ·, b2 ·, for example made of tin oxide or similar material, alternating with insulator layers. These are supplied with electrical energy on both sides of the cutting blade 10 by the high-frequency source 8. However, the high-frequency current can only bridge the insulating distances 7 if a conductive medium, for example body fluid, is present. In this case, for example when the cutting edge is in contact with moist tissue, an electrical current flows along the conductive paths 17, 17 ^f , 17 ^{ir between the conductive films b1 and b2, as well as b1 'and b2 f} . The route can

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between the individual layers on one side of the cutting blade or across the cutting edge 11, depending on the relative polarity of the layers b1, b2, b1 ·, b2 ^f . The tissue 14 conducts, for example, as a result of the body fluid 16 bound in the cells, the fluid on intact tissue, or on surfaces of freshly cut or cut tissue. If, for example, an incision 15 is cauterized, the liquid dries near the incision or the contact point with the cutting blade 10, and the electric current becomes weaker in a self-limiting or self-regulating manner. Electrical energy is therefore only released at that part of the input element 12 that is in contact with the moist tissue 14. The tissue temperature near this part of the input element 12 can thus be kept at a sufficiently high temperature which brings about the cauterization and hemostasis.

In the further embodiments of FIGS. 7 and 8, the substrate, for example the cutting blade 10, consists of conductive material b. The insulating layers a1, a1 ', a2, a2' are arranged alternately with the conductive layers b1, b ·, b2, b2 'and form the electrodes E, E ¹ . The cutting blade can form the common electrical line for the conductive layers.

In Figure 8, the cutting blade consists, for example, of a uniform, insulating ceramic body a with alternating conductive and insulating layers fired together or one after the other and the corresponding counterparts on both sides of the cutting blade.

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The electrode spacing is small and precisely set and close to the cutting edge. The e.g. 10 - 100 / µm thick layers are then not affected by wear of the cutting edge.

The dielectric layers consist, for example, of polymeric membranes, lacquer layers, glazes, mica etc. The electrodes consist of stainless steel or other noble or base metals, depending on the intended use. In the embodiment of Figure 8, the conductive and dielectric layers, as well as the cable connections ^{20-20 1} , the lines 13, and the contacts 18-18 'can be burned together, which allows a better adjustment of the flat shape of the cutting edge 11 and the heating surfaces of the Cutting blade 10 allowed.

The distance between the electrodes EE 'and the cutting edge 11 depends on the electrode distance d, i.e. the distance between two electrodes over the cutting edge 11. For the input element 12 running parallel to the cutting edge 11, the distance d is twice the distance -x from the cutting edge to each of electrodes E and E '.

The electrodes E-E 'can e.g. at a distance d of 1.5 mm (■ * = 0.75 mm) arranged and with 100 kilohertz high frequency current are supplied by 100 volts or less without creating an arc bridging the gap. A low voltage is preferred for example 20 - 80 volts.

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Claims (9)

£ 944730 Claims { 1, y Surgical instrument which is operated by an electrical power source and which cauterizes electrically conductive tissue in the presence of physiological fluid and at the same time hemostatizes it, characterized in that a support body, cutting blade or the like (10) has a cutting edge (11) and close to it a has input means (12) connected to the electrical power source via at least two electrical connection means, which directly heats the moist, conductive tissue via at least two isolated parallel conductors or conductors. 2. Surgical instrument according to claim 1, characterized in that the input means (12) has at least two electrodes (E, E ¹ ) with mutually engaging parallel guide fingers (d, c2) extending transversely to the cutting edge and the routing is aligned laterally along the cutting edge are. 3. Surgical instrument according to claim 2, characterized in that that the electrodes are arranged on opposite sides of the cutting blade and separate, the cutting edge traversing and with their free ends arranged at a distance from electrodes on the opposite side of the electrode elements exhibit. 030022/0609 29U73Q 4. Surgical instrument according to claim 3, characterized in that that at least one of the electrodes is near the cutting edge (11) lies. 5. Surgical instrument according to one of claims 1-4, characterized in that the electrodes are connected to an alternating current source an amplitude and frequency generating arc-free conductors for the given electrode spacing are connected, 6. Surgical instrument according to claim 5, characterized by an electrode spacing, which for a given amplitude allows a current to flow only when the input means (12) come into contact with a conductive substance. 7. Surgical instrument according to claim 6, characterized in that that the electrode spacing is 1-0.1 mm and the electrical power supplied has an electrode voltage of 20-80 volts resulting height of 5-50 watts. 8. Surgical instrument according to one of claims 1-7, characterized in that the input means consists of several separate ones Elements. 9. Surgical instrument according to one of claims 1-8, characterized characterized in that the input means consist of alternating conductive and dielectric layers. 030022/0609