DE10038015A1 - blade - Google Patents

Abstract

The invention relates to a blade with a blade body and at least one electrical function element in or on the blade body, characterised in that the blade body consists at least partly of diamond and comprises electrically conducting diamond regions as electrical function element.

Description

The present invention relates to a clin ge with a blade body and at least one elec trical functional element in or on the blade body by. Such blades are used, for example, in the Medicine, especially microsurgery, endo scopia, minimally invasive surgery as well as all common to surgery, such as in Au genetic operations as lancets or for skin incisions used as cutting blades.

The use of coagulation to stop bleeding gene, for example in surgical use, is egg a common method. Traditionally, the Koa gulation to stop bleeding from open wounds with the help of pliers, tweezers, wire or a blade with which the bleeding vessel in the case of pliers, for example, compressed and then a high frequency current through the tip of the pliers  to be led. The high frequency current can also over a blade is introduced into the surrounding tissue the. The electrical resistance of the tissue causes then gently convert the electrical energy into thermal energy and thus the heating and koa gulation of the tissue.

Alternatively, a blade can be used which is heated directly and so the thermal lei generated in the blade and over the blade in the tissue is inserted.

However, all of these coagulation methods are common sam that the dosage of thermal output per is blematic because protein denaturation (coagula tion) essentially from the temperature reached in the tissue and thus from the performance implemented there depends. However, tissue can vary widely have thermal and electrical properties that to a large extent the temperature distribution and thus the Coagulation range and degree of coagulation influenced sen. Above all, inhomogeneities occur due to the temperature-related blood flow change during the Ap plication on.

Further coagulation techniques from the prior art nik are electrical or high-frequency coagulation with a high frequency current of 100 kHz to 2 MHz and power up to 400 W. In addition, the micro wave coagulation, electro-hydro-thermization, photocoagulation, for example by means of a Nd: YAG, excimer or argon lasers as well as the induc tion thermocoagulation or ultrasound coa gulation with sound waves in the range between 4 and 9 MHz used.  

US 5,792,137 shows a verse with a cutting edge Hene coagulation forceps that can be heated for coagulation is. This pliers consists essentially of one Silicon substrate that do so on its surface is that it has a high resistance. Silici are located within the silicon substrate umelektroden as electrical functional elements between where a current can flow so that the sub strat is heated. Because this pliers in depth the substrate is heated, can not be sufficient and rapid heat supply to the surface of the pliers cutting edge can be effected; for example, lo kale hot spots.

Furthermore, due to the different expansion coefficients of the conductive silicon electrodes and the non-conductive Si silicon dioxide or silicon nitride regions (SiO ₂ , Si ₃ N ₄ ), these tongs result in tension and damage within the cutting edge during heating up or cooling down.

In contrast, the publications US 4,485,810 and 4,069,336 another way of heating one Blade. There is a blade in both publications fenbart, for example made of silicon or silicon carbide exists and electrical on its surface Heat conductor carries as electrical functional elements. This surface is finished with an art electrically insulated fabric cover. Those blades who only used for skin incisions, not ever but for eye surgery purposes. The electrical Heating conductors are made of metal, for example copper fer. This ensures that there is sufficient heat input the blade ensures. However, art has fabric cover a low thermal conductivity, which there is poor heat transfer from the inside of the blade  on the surface of the blade. Still is the structure of this blade is very complex, since it is different ne materials must be connected. The problem of tension also arises or damage due to different expansion nation coefficients of the materials used.

Another disadvantage is that all of the blades the state of the art only with difficulty or not at all Loss of function of the blade are to be cleaned and there can only be used as a disposable scalpel.

The object of the present invention is therefore a Blade with an electrical functional element for To make available the principles outlined len removes restrictions.

This task is done by a blade after the Oberbe handle of claim 1 in conjunction with his kenn drawing features solved. Advantageous training The blade of the invention can be found in the dependent claims.

According to the invention, the blade has a blade body on that at least partially advantageously its surface made of diamond, monocrystalline or polycrystalline, exists and as an electrical function on-element electrically conductive doped areas, also made of diamond. In this configuration a metal-free blade surface is possible. A diamond blade body has the advantage that diamond is chemically completely inert and therefore bio is medically compatible so that it can be used without hesitation medical purposes, for example in surgery, can be used. It is also advantageous that the blade of the invention with conventional  Processes of microtechnology and microelectronics can be put.

The blade of the invention takes place, for example, as Lancet for eye surgery or as a cutting blade in the microsurgical field application. in the special is due to the chemical resistance by Diamant a safe and easy cleaning of the Blade possible. There are only incrustations on top flat as a matrix on the diamond without chemical And can form bonds with the underground can be removed easily and completely at any time. This Blade is therefore reusable. The fiction moderate blades are resistant to chemicals fully biocompatible.

In addition to the inert properties of diamond on the upper surface of the blade enables the termination of the Surface diamond layer setting the physi calic and / or chemical properties of the upper area such as hydrophobicity / hydro philicity of the surface. By suitable terminology Surface adherence can continue of tissue can be reduced or avoided.

With monolithic integration of the functional elements there is a detachment in the insulating diamond layer of the functional elements from the blade impossible. because this results in increased security for the customer pancake.

The surface of the blade according to the invention can be white be electrically passivated by the blades body on its surface a nominally undoped Has diamond layer, so that the functional elements as well as burying the leads in the blade body  are. In this case, no metals appear on the Surface of the blade exposed, as all are electrically conductive trending elements made of diamond or buried in diamond are. In this case, no current can come from the blade pass into the tissue, so that secured none electrical coagulation, but only one thermal coagulation of the tissue takes place, the Insulation layer made of diamond due to its very high hen thermal conductivity has no influence on the intrin sische heating behavior of such a blade has.

Such electrical insulation allows one blade set in hydrothermization, d. H. For the transfer of heat from the blade by means of Liquid on the tissue.

Diamond has some for the blade according to the invention other very advantageous properties, esp especially when advantageously the electrical radio tion element is a heating element, so that the blade is heated. So diamond has an extraordinary high thermal conductivity in contrast to other Iso lators, which is even higher than that of copper and Silver. For example, with single-crystal Diamond has a thermal conductivity of 22 W / (cm × K) and thermal conductivity for polycrystalline diamond of 10-20 W / (cm × K). These values lie up to 22 or 5 times higher than the values of silver and copper. Because of this extremely high Thermal conductivity is for example in use a heatable blade according to the invention with a Heating conductor as an electrical functional element a very good heat balance between individual points the blade body ensures that no tempera gradient and therefore no hot spots occur  and also supplying heat to the blade surface even with very high heating outputs and a low one Heating time (up to <1 s / 100 ° C) is ensured. The Heating phase, for example the heating time and the The course of heating of the blade can be at the blade according to the invention by the waveform of the Heating elements supplied heating current regulated who the. Because of the high thermal conductivity and The tempera follows the low heat capacity of the blade the blade quickly and with little delay Signal curve of the heating current.

It is also advantageous that the thermal expansion coefficient of diamond with α _Di = 0.8 - 1.0 × 10 ^-6 1 / K is quite low. In particular, conductive, for example boron-doped, and insulating diamond layers have similar thermal expansion coefficients, so that no stresses or damage occur when the temperature of the blade changes.

Silicon, as used in the prior art for the clinical body, in contrast, has an expansion coefficient of 2.56 × 10 ^-6 1 / K for conductive silicon layers and for insulating silicon layers of 0.4 × 10 in the case of silicon dioxide ^-6 1 / K or in the case of silicon nitride 0.8 × 10 ^-6 1 / K. When using silicon technology therefore occur with temperature changes in the blade tension so that damage in a corre sponding blade as in the prior art are to be expected.

Another advantage of the blade according to the invention is that diamond is known as the hardest material. The blades according to the invention therefore retain  prolonged use. In particular tre due to the high stability of the cutting edge less damage, e.g. B. on spark. Also the elastic modulus of diamond is the highest al ler known materials. Despite these properties is relatively elastic with a high diamond Breaking stress of 10.5 GPa with single crystal and 4.8 GPa for polycrystalline diamond.

The electrical functional element becomes very high doped diamond, it has no tem temperature dependence of its resistance. It proper then net itself to the production of resistance Heating elements, leads, electrodes, for example se electrical, chemical or physiological elec troden, or also for mono- or bipolar coagulation onselektroden.

With medium doping, heating element / tempe temperature sensor combinations.

Weak doping is suitable for temperature sensors ren.

With different amounts of doping or different Chen doping materials in different areas can also use Hall sensors for magnetic field measurement, e.g. B. for location using nuclear magnetic resonance imaging (NNR) or X-ray computed tomography (CT), chemo-sensi tive components (ion-sensitive field effect trans disturb (FET), pH-dependent resistors), piezo resistive sensors (pressure, force, acceleration), Radiation sensors (UV, X-ray, gamma radiation) or Flow sensors are manufactured.  

The electrical functional element can be used as a conductor track be carried out, in the case of heating conductors Heating conductor with optimized, d. H. as large as possible Cross section are made so the electrical Resistance of the heating conductor is low. The Versor supply voltage can then be kept relatively low that, for example, are sufficient in the case of the invention Blade supply voltages in the range between 8 and 13 V to air on the blades for the Koa gulation required to heat approx. 100 ° C.

The temperature of the blade according to the invention is constant in air and varies on the surface of the Blade depending on depth of penetration and tissue spatially only a few degrees when the blade with the Point pierced into tissue and ge in the tissue leads. In the case of an invented temperature heatable blade according to the invention is particularly efficient be readjusted.

A made on the blade surface or also buried temperature sensor can be made of doped slide mant exist with temperature-dependent resistance. This temperature dependence of the resistance can be used for temperature measurement.

To keep the temperature of the surface of the blade wide The power supply can be kept constant are regulated by the measured values of the temperature sensor sors used to control the power supply the. It can be due to the large thermal Material performance is a high performance provided that these are used to maintain the tempe rature of the surface of the blade is required. There Diamond has a high coefficient of thermal conductivity and only a small heat storage capacity, the  Regulation when using diamond for the blades body with minimal delays the. This rapid response leads to the fact that the temperature of the blade can be regulated more quickly can and in particular rapid heating of the clin ge is possible without overheating, if necessary pulse operation is also possible. So a defi temperature at the respective coagulation point le secured.

P ^- - doped diamond is particularly suitable as a temperature sensor. P ⁺ -doped diamond is suitable as heating elements, for example with a specific resistance greater than approximately 6.2 mΩ cm. The doping can be done with boron and / or lithium, in the case of n-doping also with nitrogen, phosphorus and / or sulfur.

Both the temperature sensor and the heating element are used as leads and / or metallizations Contact elements with electrical voltage of one Power supply supplied. The power supply can for example externally via cable or through in Handle of the blade integrated batteries are made. The The power supply is controlled, for example wise via a control circuit that is in the grip of the Blade or be arranged in the blade itself can.

The handle of the blade should come off the blade be thermally insulated to prevent heat loss from the Avoid or minimize the blade in the handle. Edel is a suitable material for the handle steel or plastic, when using a Stainless steel handle a separate thermal insulation tion must be provided while this is in use  suitable plastics are unnecessary.

In the following some examples according to the invention blades are described.

Show it:

FIG. 1 is a heatable blade with monolithically in tegriertem temperature sensor;

Fig. 2 is a cross section of the heatable blade of Fig. 1 along the line A-A ';

. Fig. 3 is a cross section of the heatable blade of Figure 1 along the lines B-B '; such as

Fig. 4 shows a further heatable blade.

Fig. 1 shows a heatable blade 1 , with a blade body 8 made of diamond, which has a curved cutting edge 6 . On the surface of the clinical body 6 there are heating conductors 2 made of highly doped diamond regions, for example doped with boron. These heating conductors are connected to metallizations 5 at one end of the blade body 8 , via which an electrical voltage can be applied to the heating conductors 2 . The heating conductors 2 save an area on the blade surface in which a temperature sensor 3 with supply lines 4 is arranged. The supply lines 4 are also connected to metallizations 5 in order to apply an electrical voltage to them. The temperature sensor 3 consists of p ^- - doped diamond. The respective dopings can be introduced into the blade body 8 in a conventional manner during the manufacturing process. It is also possible to let the blade body 8 grow, for example by CVD method, on a substrate and to incorporate the doping into the diamond of the blade body during the growth process.

FIG. 2 shows a section through a blade according to FIG. 1, the same reference numerals as in FIG. 1 denoting corresponding elements. It can be seen that the blade body 8 has an insulating slide layer 11 which is arranged on a silicon substrate 10 . On the side of the diamond layer 11 facing away from the silicon substrate 10 there is a further diamond layer 12 of the blade body 8 as a p ⁺ -doped heating conductor 2 . This diamond layer 12 also forms the cutting edge 6 .

Along the cross section it can be seen that an area of the diamond layer 12 is recessed approximately in the center of the blade, in which the temperature sensor 3 is arranged. The temperature sensor 3 consists of doped diamond, and the temperature dependence of the resistance value can be adjusted via the level of the dopant concentration. The tempera ture sensor 3 can already be generated during or immediately after the production of the diamond layers 11 and 12 on the substrate 10 by doping the growing diamond, and an etching process can also be provided to the temperature sensor 3 from the p ⁺ -doped heating conductors 2 to separate.

Fig. 3 shows a further section through the blade of FIG. 1 along the line B-B '. Again, similar elements are identified by the same reference numerals, so that their description is partially omitted. It can be seen that in the middle loading area of the blade only the leads 4 for the temperature sensor are now available. On the slide layer 12 of the p ⁺ -doped heating conductors 2 , a metallization 5 is provided in the area of the section BB 'on both sides of the feed lines 4 , which is in electrical contact with the p ⁺ -doped heating conductors 2 .

Via these metallizations 5 , a voltage can now be applied to the p ⁺ -doped areas of the heating conductor 2 in order to heat the blade.

As a further variant of a heatable blade according to the invention, which is not shown in detail here, however, the blade according to FIGS. 1 to 3 can be designed such that no silicon substrate 10 is present. However, all other elements of the blade are as they emerge from FIGS. 1 to 3.

Fig. 4 shows a further example of a heatable blade, here again with the same reference characters similar elements are referred to and therefore their description is at least partially omitted.

The blade from FIG. 4 is a lancet with cutting edges 6 , 6 'which form a tip. The surface 7 , which is formed between the cutting edges 6 , 6 'and the dashed line in FIG. 4, forms beveled cutting surfaces.

In the lancet shown in FIG. 4, too, a temperature sensor 3 with supply lines 4 is provided, which can be supplied with voltage via metallizations 5 '. The heating conductors are not shown in FIG. 4, but are arranged in strips in the same way as in FIG. 1. These heating conductors are contacted via the metallizations 5 , which means that they can be supplied with voltage. The remaining areas can be used for contacting further functional elements.

Claims (28)

1. Blade with a blade body and at least one electrical functional element in or on the blade body, characterized in that
the blade body consists at least partially of diamond and
has electrically conductive diamond regions as the electrical functional element. 2. Blade according to the preceding claim, characterized characterized in that the functional element is a Wi derstands heating element, a supply line, a electrical, chemical and / or physiological Electrode, a monopolar or bipolar Koagu lation electrode, a heating element Temperature sensor combination, a Temperatursen sor, a Hall sensor for magnetic field measurement chemo-sensitive component, such as an ion-sensitive tive field effect transistor or a pH value dependent resistance, a piezoresistive sen sor, such as a pressure sensor, force sensor or loading acceleration sensor, a radiation sensor, like for UV, X-ray or γ radiation, or a Is flow sensor.   3. Blade according to claim 1, characterized in that the areas of electrical functionalities mentes with bar, phosphorus, nitrogen, sulfur and / or lithium are doped. 4. Blade according to claim 2 or 3, characterized records that the areas of electrical Functional element for a resistance Heating element, a supply line, an electrical, chemical and / or physiological electrode, ei ne monopolar or bipolar coagulation electro de heavily endowed, for a heating element Temperature sensor combination medium strong do tiert, weak for a temperature sensor or for a Hall sensor to the magnetic field measurement, a chemo-sensitive component, such as an ion sensitive field effect transistor or a pH-dependent resistor, a piezo resistive sensor, like a pressure sensor, Force sensor or acceleration sensor, on Radiation sensor, such as for UV, X-ray or γ- Radiation, or a flow sensor in some areas are endowed with different strengths. 5. Blade according to one of the preceding claims, characterized in that the electrical func tion element is a heating element having a Do animal concentration greater than 1 × 10 ¹⁸ cm ^-3 . 6. Blade according to the preceding claim, characterized in that the heating element has a dopant concentration of 5 × 10 ²⁰ cm ^-3 . 7. Blade according to one of the preceding claims, characterized in that the electrical Functional element in the form of conductor tracks has. 8. Blade according to one of the preceding claims, characterized in that the electrical Functional element at least partially on the Surface of the blade body and / or in the Blade body buried runs. 9. Blade according to one of the preceding claims, characterized in that on the blade body per with the electrical functional element least an electrically connected contact element as another electrical functional element is arranged. 10. Blade according to the preceding claim, characterized characterized in that the contact elements are metal contain. 11. Blade according to one of the preceding claims, characterized in that on the surface  of the blade body and / or in the blade body bury at least one temperature sensor as electrical functional element is arranged. 12. Blade according to the preceding claim, characterized characterized in that the temperature sensor Width of approx. 0.03 mm and a length of approx. Has 0.06 mm. 13. Blade according to one of the two previous types sayings, characterized in that the tempe rature sensor consists of doped diamond. 14. Blade according to one of the three previous types sayings, characterized in that with the Temperature sensor electrical leads as further electrical functional elements connected are. 15. Blade according to the preceding claim, characterized characterized that the electrical leads consist of doped diamond. 16. Blade according to one of the two previous types sayings, characterized in that the elec trical feed lines with boron, phosphorus, stick substance, sulfur and / or lithium are doped. 17. Blade according to one of the two preceding claims, characterized in that the feed lines have a dopant concentration between 1 × 10 ¹⁸ cm ^-3 and 1 × 10 ²² cm ^-3 . 18. Blade according to one of the three preceding claims, characterized in that the feed lines have a dopant concentration of 5 × 10 ²⁰ cm ³ . 19. Blade according to one of claims 14 to 18, there characterized in that the feed lines Have the shape of conductor tracks. 20. Blade according to one of claims 12 to 17, there characterized by that on that of the blades pointed side facing away from the leads electrically connected contact elements as wide re arranged electrical functional elements are. 21. Blade according to the preceding claim, characterized characterized in that the contact elements of the zu Pipes contain metal. 22. Blade according to one of the preceding claims, characterized in that the surface of the Blade in the area of the electrical functional element mentes a possibly with the exception of the Kon clock elements closed, nominally undoped  Has diamond layer. 23. Blade according to one of the preceding claims, characterized in that the entire surface surface of the blade, with the possible exception of Contact elements a closed, nominally un has doped diamond layer. 24. Blade according to one of the preceding claims, characterized in that they have a tax circuit for controlling the electrical Functional element applied voltage and / or of the applied to the electrical functional element has current. 25. Blade according to the preceding claim, characterized characterized that the control is dependent of signals from other functional elements follows. 26. Blade according to the preceding claim, characterized characterized in that the control circuit is a in tegrated circuit. 27. Blade according to one of the two previous types sayings, characterized in that the tax circuit an integrated circuit on slide mant basis is.   28. Blade according to one of the preceding claims, characterized in that it is a tension has supply.