Cutting element made of an electromechanical material

Abstract

The invention relates to a cutting element (1) comprising a blade section (2) having a cutting portion (22) for cutting material and a holding section (3) for holding the cutting element (1), wherein at least the blade section (2) comprises a material with electromechanical properties and, in particular, piezoelectric or magnetostrictive properties, and electrodes (4) or at least one coil for exciting mechanical vibrations in the blade section are arranged on the electromechanical material of the blade section. The invention also relates to a cutting device (100) with such a cutting element (1). Furthermore, the invention relates to a method for operating a aforementioned cutting element (1) or a aforementioned cutting device (100).

Description

[0001] The invention relates to a cutting element made of an electromechanical material according to claim 1 as well as to a cutting device with such a cutting element according to claim 13 and to a method for operating such a cutting element according to claim 15.

[0002] In cutting devices, improvements in the cutting ability of the blade of the cutting element used are regularly sought, particularly with a view to increasing the efficiency and precision of the cutting process. One possibility for increasing the efficiency of the cutting process is to excite the blade of the cutting element to mechanical vibrations, particularly ultrasonic vibrations.

[0003] One possibility to cause the blade of the cutting element of a cutting device known from the prior art to vibrate is to arrange it at the tip of an ultrasonic transducer, preferably a Langevin transducer.

[0004] An alternative method involves arranging the metallic blade of a cutting element between two piezoelectric elements and applying electrical signals to the piezoelectric elements, as disclosed, for example, in US Pat. No. 1,135,959 B2. The mechanical vibrations thus induced in the piezoelectric elements are transmitted to the metallic blade due to their contact with the blade, causing the blade and its cutting edge to oscillate or vibrate. The oscillations or vibrations at the cutting edge of the blade increase its cutting ability or cutting efficiency.

[0005] A disadvantage of the method known from US Pat. No. 11,350,959 B2 for generating vibrations in the blade is the fact that losses occur during the transmission of the mechanical vibrations generated in the piezoelectric elements to the blade, so that only a portion of the vibration energy is transferred to the metallic blade. The transmission of vibration energy is most successful when the vibrations induced in the piezoelectric elements by appropriate electrical voltages have a frequency that is equal to or close to the blade's resonant frequency. However, to ensure this, complex control electronics are required.

[0006] There is also another general disadvantage of metallic blades: when they come into contact with organic tissue, they can cause oxidation, meaning that the healing process after surgery takes longer.

[0007] The object of the present invention is to provide a cutting element whose blade or blade section can be particularly effectively excited to oscillations and in which chemical interactions between the blade and the material to be cut, in particular organic, i.e., human or animal, tissue, are reduced or completely eliminated. Furthermore, the object of the invention is to provide a method for operating such a cutting element.

[0008] The first-mentioned object is achieved by a cutting element according to device claim 1, wherein the subclaims directly or indirectly referring thereto contain at least expedient developments. The second-mentioned object is achieved by a method according to claim 15.

[0009] Essential for the cutting element according to the invention is the provision of a blade section, wherein the blade section comprises and preferably consists of a material with electromechanical properties, and means for exciting mechanical vibrations in the blade section in the form of electrodes or at least one coil are arranged or applied to the electromechanical material of the blade section. In this case, a cutting section is designed in one piece or integrally with the blade section, wherein the cutting section is intended for contact with the material to be cut, in particular organic matter, and is designed accordingly. The cutting section is accordingly formed or machined out of the blade section, for example by a grinding process, to produce a sharp cutting edge suitable for cutting.

[0010] Because the blade section has and preferably consists of a material with electromechanical and in particular piezoelectric or magnetostrictive properties, on which either electrodes or at least one coil are arranged, the blade section or the cutting section formed integrally therewith can be directly and immediately excited to oscillate, without the need for mechanical transmission of oscillations generated elsewhere or at another location to the blade section.

[0011] It is conceivable that the blade section is attached to the holding section or that these two sections of the cutting element are assembled or joined together. A material-to-material connection, such as by means of adhesive bonding, is conceivable here, but other joining principles or methods are also possible. For example, it is conceivable that the blade section is positively connected to the holding section. Combinations of joining principles or methods are also conceivable. The holding section preferably comprises a different material or a different material composition than the blade section, whereby it is also conceivable that the materials of the blade section and the holding section are identical.

[0012] An electrical voltage can be applied to the blade section via electrical leads that are connected to or in electrical contact with at least one of the electrodes or with the at least one coil, wherein the electrical voltage is such that a defined oscillation form that promotes a cutting process can be generated in the blade section.

[0013] In a preferred embodiment, the blade section and the holding section of the cutting element are designed as one piece or integral with one another, wherein the blade section and the holding section comprise and preferably consist of the same or substantially the same material with electromechanical properties. Accordingly, the cutting element comprises a blade section formed integrally with the holding section formed from an electromechanical material and formed from the same or substantially the same electromechanical material. 'One piece' or 'integral' in this context means that in the cutting element according to the invention, the blade section and the holding section were not originally separate or as individual parts and then assembled, for example by a joining process, but rather the blade section and holding section are manufactured or machined from one piece.The term 'essentially identical electromechanical material' refers in particular to embodiments in which the electromechanical material has slight deviations in composition, for example due to the introduction of dopants that affect the internal or microscopic structure of the material.

[0014] The cutting element according to the invention can be realized with any other feature provided according to the invention of a combination of features described herein in such a way that the electrodes are arranged such that they cover both the holding section and the blade section at least in sections and are electrically connected to one another. In this case, it can be advantageous for the electrodes or the respective sections of the electrodes to have a shape that is geometrically similar to the holding section or the blade section. Preferably, the electrodes or electrode sections that cover the blade section and the holding section are designed in one piece or integrally with one another. However, it is also conceivable for the electrodes that cover the holding section and the blade section to be present as separately formed electrodes that are connected via electrically conductive connections, e.g.in the form of web sections, but also in the form of cables or similar, are in electrical contact with each other.

[0015] The cutting element according to the invention can be implemented with any other feature provided according to the invention of a combination of features described herein in such a way that the electrodes cover the blade section or the holding section by at least 50% and preferably by at least 75%. At these degrees of coverage, sufficient mechanical deformation can be achieved in the respective covered sections of the cutting element comprising an electromechanical material.

[0016] The cutting element according to the invention can be realized with any other feature provided according to the invention of a combination of features described herein, such that the electrodes comprise platinum, gold, or silver and are preferably made of these materials. These electrically conductive materials have the advantage of being chemically inert, so that, for example, no oxidation reactions occur upon contact with human tissue.

[0017] The cutting element according to the invention can be realized with any other feature provided according to the invention of a combination of features described herein in such a way that the electromechanical material comprises or consists of a monocrystalline material, preferably lithium niobate. Alternatively, the electromechanical material comprises a ceramic material, preferably aluminum nitride. The material groups or materials listed above are particularly suitable for the cutting element according to the invention because, in addition to the required electromechanical properties, they also have the mechanical properties necessary for forming a blade or cutting section. Furthermore, they are harmless, for example, when in contact with human tissue.

[0018] The cutting element according to the invention can be realized with any other feature provided according to the invention of a combination of features described herein in such a way that the electromechanical material has magnetostrictive properties and, in a particularly advantageous manner, comprises or consists of Galfenol, and the at least one coil for exciting mechanical vibrations in the blade section surrounds at least a portion of the blade section or the holding section, wherein the portion surrounded or encompassed by the at least one coil having magnetostrictive properties forms the corresponding coil core. In this case, it can be particularly advantageous for the portion of the blade section or the holding section surrounded or encompassed by the at least one coil, which forms the coil core, to be web-shaped.

[0019] The cutting element according to the invention can be implemented with any other feature provided according to the invention of a combination of features described herein in such a way that the blade section or the holding section has a permanent magnet arranged between the part of the blade section or the holding section surrounded by the at least one coil and the remaining part of the blade section or the holding section. The permanent magnet closing the corresponding magnetic circuit is capable of amplifying the magnetic field generated by the at least one coil.

[0020] The invention further relates to a cutting device with a cutting element as described above, wherein grip elements are arranged on the holding section of the cutting element, at least one of which has a contacting area that is in electrically conductive contact with at least one of the electrodes or with the at least one coil of the cutting element. It may be advantageous for at least one of the grip elements to have an integrated voltage source in the form of a battery, accumulator, or supercapacitor, and electronics for generating alternating voltages from the direct voltage of the battery or accumulator. The grip elements of the cutting device allow, in particular, more comfortable handling of the cutting element contained therein, and they also enable simple and expedient contacting of the electrodes.

[0021] The invention also relates to a method for operating a cutting element as described above or a cutting device as described above, in which the electrodes or the at least one coil are subjected to an electrical voltage which is suitable for causing bending vibrations or longitudinal vibrations in the blade section.

[0022] Whenever the word 'or' is used herein, it is to be understood as a non-exclusive disjunction or an inclusive 'or', unless explicitly stated otherwise. Thus, for example, the phrase 'characteristic A or B' covers characteristic A or characteristic B, or a combination of characteristic A and characteristic B.

[0023] The term "electromechanical" as used herein refers to the property of a material in which a deformation of the material can be induced by the application of an electric or magnetic field, such as a change in the length of a cylinder made of an electromechanical material. In particular, this includes materials with piezoelectric, electrostrictive, or magnetostrictive properties.

[0024] Advantages and benefits of the invention will become clearer from the following description of preferred embodiments with reference to the figures. They show: Fig. 1: Schematic representation of a cutting element according to the invention in perspective view Fig. 2: Exploded view of a cutting device according to the invention with a cutting element according to Fig. 1 Fig. 3: Schematic representation of a blade section of a cutting element according to the invention in perspective view

[0025] Fig. Figure 1 schematically shows a perspective view of a cutting element 1 according to the invention. The cutting element 1 comprises a blade portion 2 made of a piezoelectric material with piezoelectric properties, with a cutting portion 22 formed integrally or in one piece therewith. The cutting portion 22 is formed by tapering the blade portion 2.

[0026] Formed in one piece or integrally with the blade section 2 is a holding section 3, which is made of the same electromechanical material as the blade section 2. The holding section essentially has the shape of a rectangular plate of constant thickness, while the blade section 2 has the typical shape for a scalpel. Of course, other and different shapes are conceivable for both the blade section 2 and the holding section 3.

[0027] On the two largest and opposite surfaces of the cutting element 1, which are each formed by the blade section 2 together with the holding section 3, a respective one-piece electrode 4 is arranged, wherein in Fig. 1 only one of them can be seen. The corresponding surfaces of the cutting element 1 define arrangement surfaces 24, 34, i.e. those areas or surfaces on which the electrodes 4 are arranged. Due to the illustration, in Fig. 1 only the upper arrangement surfaces 24, 34 can be seen, while the identically designed and oppositely arranged arrangement surfaces Fig. 1 cannot be removed.

[0028] The Fig. 1 electrode not visible is identical to the one in Fig. 1 and are also arranged identically to this, so that the two electrodes 4 completely cover one another. The electrodes 4 or their respective sections are geometrically similar in shape to the blade section 2 and to the holding section 3 or their arrangement surfaces 24, 34, wherein the electrodes 4 or their corresponding sections are somewhat smaller in area, so that a gap exists between them and the boundary of the respective arrangement surface 24, 34. In other words: the electrodes 4 or their sections do not reach up to the boundary of the respective arrangement surface 24, 34 and thus do not completely cover it. However, complete coverage of the arrangement surfaces 24, 34 with the electrodes 4 or their sections is also conceivable.

[0029] The cutting element 1 would be in the Fig. 1, since the current- or voltage-carrying electrodes 4 are not insulated, particularly in the area of ​​the holding section 3. This could be remedied, for example, by providing an insulating coating at least in the area of ​​the holding section 3, so that it could be held in the hand by a surgeon, for example, without being exposed to the direct risk of electric shock during operation of the cutting element 1.

[0030] However, the one in Fig. 2 shows an exploded view of a cutting device 100 according to the invention, which comprises a cutting element 1 according to Fig. 1. The cutting device 100 has two only schematically illustrated and identically designed handle elements 102, 104 made of an electrically non-conductive material, each of which has a contact area 106 on one of its two largest surfaces, wherein Fig. 2 only the contact area 106 of the lower handle element 104 is visible. Fig. 2 upper handle element 102 has such an identically designed contacting area 106, which faces the electrode 4 or its section in the area of ​​the holding section 3 and therefore in Fig. 2. However, it is conceivable that only one of the grip elements 102, 104 has a contacting area 106 and thus electrically contacts one of the electrodes 4.

[0031] The contacting area 106 comprises an electrically conductive material which is provided for contact with the electrodes 4 or their section in the area of ​​the holding section 3, so that, for example, via the grip elements 102, 104 arranged and in Fig. 2 electrical supply lines (not shown), which are in electrically conductive connection on the one hand to an electrical voltage source and on the other hand to the contacting regions 106, an electrical voltage can be applied to the electrodes 4 via the contact between the contacting regions 106 and the latter, so that an electromechanical material lying between the oppositely arranged electrodes 4 undergoes deformations, in particular periodic deformations. It is also conceivable here for a battery or accumulator to be arranged in the handle elements 102, 104, which, by means of suitable electronics likewise provided in the handle elements, can deliver electrical voltage signals for exciting, in particular, periodic deformations in the electromechanical material arranged between the electrodes 4.In this case, the applied electrical voltages are advantageously designed and suitable for causing bending vibrations in the blade section 2.

[0032] Fig. Figure 3 schematically shows a perspective view of a blade section 2 of a cutting element according to the invention, made of an electromechanical material with magnetostrictive properties. The blade section 2 has, in the part adjacent to the tip, two substantially web-shaped sections 26 and 27, wherein the web-shaped section 27 simultaneously forms the cutting section 22, while a part of the web-shaped section 26, which is spaced from the tip of the blade section 2 and runs substantially parallel to the section 27, is surrounded or enclosed by a coil 5. The coil 5 is in electrical contact with a suitable current or voltage source (in Fig. 3 not shown), whereby periodically changing magnetic fields can be generated, which lead to periodic deformations and thus vibrations of the blade section 2.

[0033] A permanent magnet 28 is arranged between the end sections of the web-shaped sections 26 and 27 and in contact therewith, which closes the magnetic circuit in the blade section 2 and which ensures an amplification of the magnetic field generated by the coil.

[0034] It is conceivable to provide more than one coil 5 in order to excite the electromechanical or magnetostrictive material of the blade section 2 to periodic deformations or vibrations. Furthermore, it is conceivable to provide one or more coils 5 in the area of ​​the blade section 2 adjoining (and in Fig.3 not shown), wherein the holding section then also comprises an electromechanical material with magnetostrictive properties. Advantageously, in the above case, the blade section and the holding section are formed in one piece or integrally with one another. List of reference symbols 1 cutting element 2 blade section 3 holding section 4 Electrode 5 coil 22 Cutting section (of blade section 2) 24 Arrangement surface (of the blade section 2) 26, 27 Bar-shaped sections (of blade section 2) 28 permanent magnet 34 Arrangement surface (of the holding section 3) 100 cutting device 102, 104 Handle elements (of the cutting device 100) 106 Contact area (of the handle elements 102, 104) QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 11 350 959 B2 [0004, 0005]

Claims

[1] Cutting element (1) with a blade section (2) having a cutting section (22) for cutting material and with a holding section (3) for holding the cutting element (1), wherein at least the blade section (2) comprises a material with electromechanical properties and means (4, 5) for exciting mechanical vibrations are arranged on the electromechanical material. [2] Cutting element (1) according to claim 1, characterized by that the holding section (3) comprises the same material as the blade section (2) and the blade section and the holding section are formed integrally with one another. [3] Cutting element (1) according to claim 1 or 2, characterized bythat the electromechanical material has piezoelectric or electrostrictive properties and the means for exciting mechanical vibrations in the blade section (2) comprise electrodes (4) which are arranged such that they cover both the holding section (3) and the blade section (2) at least in sections. [4] Cutting element (1) according to claim 3, characterized by that the respective sections of the electrodes (4) have a geometrically similar shape to the holding section (3) or the blade section (2). [5] Cutting element (1) according to one of the preceding claims, characterized by that the electrodes (4) cover the blade section (2) or the holding section (3) by at least 50% and preferably by at least 75%. [6] Cutting element (1) according to one of the preceding claims, characterized by that the electrodes (4) comprise platinum or gold or silver. [7] Cutting element (1) according to one of the preceding claims, characterized by that the electromechanical material comprises a single-crystal material, preferably lithium niobate. [8] Cutting element (1) according to one of the preceding claims 1 to 6, characterized by that the electromechanical material comprises a ceramic material, preferably aluminum nitride. [9] Cutting element (1) according to claim 1 or 2, characterized by that the electromechanical material has magnetostrictive properties and the means for exciting mechanical vibrations in the blade section (2) comprise at least one coil (5) which surrounds at least part of the blade section (2) or the holding section (3). [10] Cutting element according to claim 9, characterized by that the part of the blade section (2) or the holding section (3) surrounded by the at least one coil (5) is web-shaped. [11] Cutting element according to claim 10, characterized by that the blade section (2) or the holding section (3) has a permanent magnet (28) which is arranged between the part of the blade section (2) or the holding section (3) surrounded by the at least one coil (5) and the remaining part of the blade section (2) or the holding section (3). [12] Cutting element according to one of the preceding claims 9 to 11, characterized by that the electromechanical material includes Galfenol. [13] Cutting device (10) with a cutting element (1) according to one of the preceding claims, characterized by that the cutting device (10) comprises grip elements (32, 34) which are arranged on the holding section (3) of the cutting element (1), wherein at least one of the grip elements (102, 104) has a contacting area (106) which is in electrically conductive contact with at least one of the electrodes (4) or with the at least one coil (5). [14] Cutting device (1) according to claim 13, characterized by that at least one of the handle elements (102, 104) has a voltage source integrated therein in the form of a battery or an accumulator or a supercapacitor as well as electronics for generating alternating voltages. [15] Method for operating a cutting element (1) according to one of claims 1 to 12 or for operating a cutting device (100) according to claim 13 or 14, characterized by that the electrodes (4) or the at least one coil (5) is or are subjected to an electrical voltage which is suitable for causing bending vibrations or longitudinal vibrations in the blade section (2).

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