Surgical instrument with a locking mechanism

Abstract

A surgical instrument having two pivotable instrument branches, each of which is constructed with a distal clamping claw and a proximal handle element, wherein the second instrument branch has a tissue separation element for separating patient tissue held between the clamping claws, a drive mechanism for driving the tissue separation element and supporting a locking element so that it can move between a locked position and an open position, in which the locking element is engaged in the drive mechanism in a blocking manner in the locked position, and in the open position, the drive mechanism is not blocked by the locking element, wherein the locking element has a magnetic locking section and the first instrument branch has a magnetic operating section for operating the locking element in an area opposite the locking element, wherein the magnetic locking section and / or the magnetic operating section have a magnet so that when the instrument branches approach each other, the locking element is moved to the open position and the operation of the tissue separation element is released by magnetic attraction or repulsion between the magnetic locking section and the first magnetic operating section.

Description

Technical Field

[0001] The present disclosure relates to a surgical instrument for clamping and separating tissue (patient tissue), the surgical instrument having a first instrument branch and a second instrument branch that can be pivotally connected to or supported on the first instrument branch, which respectively form a distal clamping claw and a proximal handle element, wherein the second instrument branch has a tissue separation element for separating the patient tissue held between the clamping claws and a drive mechanism for driving the tissue separation element, and wherein a locking element is provided for locking or releasing the drive mechanism. Background Art

[0002] Surgical sealing and cutting instruments (sealing & cutting instruments) are used to grasp, seal, and separate or cut tissue during surgery. These instruments typically have a distal instrument tip, at which clamping jaws are provided for grasping and clamping the patient's tissue. In addition, such instruments have a separating or cutting element, which, for example, has a blade or separating edge that separates the patient's tissue. The handheld instrument also has a handle that the user can hold, and various operating elements are provided on the handle for controlling the movement of the clamping jaws and / or operating the separating or cutting element. To prevent unintentional manipulation of the separating or cutting element, the separating or cutting element is often lockable and unlockable.

[0003] For example, known corresponding electrosurgical forceps from EP 3 400 893 B1, described electrosurgical forceps has proximal handle branch, distal clamping claw and the blade that can move between retracted position and extended position.In a handle branch in the handle branch, provide blade locking portion, it prevents the distal movement of blade and can move to unlocked position from locked position to realize the distal movement of blade when approaching clamping claw.This blade locking portion has hook, and this hook can selectively be engaged with blade drive bar to lock this blade drive bar.The finger that is connected with hook protrudes towards the direction of other handle branch.When handle branch moves towards each other, other handle branches are pressed against on the finger, and described hook is loosened from described blade drive bar thus, thereby unlocks described blade drive bar.

[0004] A problem with the prior art is that an opening must be provided at the point where the finger extends from the instrument housing. Consequently, particles generated by mechanical friction in the instrument can fall through the opening into the patient's wound or surgical site and present there as unwanted foreign matter / impurities, thus endangering the patient. This presents a high risk of contamination. Furthermore, liquids (such as NaCl and blood) could unexpectedly penetrate the instrument and potentially obstruct or damage the mechanical / electronic components. To mitigate these problems, this point must be sealed or isolated, making the instrument more complex and expensive. Furthermore, the pin can break, especially when made of plastic. Furthermore, the locking mechanism is relatively complex, and its functionality can be impaired, particularly due to aging effects on plastic components. Another disadvantage is that the tool lock can be easily and without any auxiliary means by the user by manually pressing against the pin or hanging on it. This increases the risk of injury to the user and the risk of inadvertently cutting patient tissue. Furthermore, if the blade is preloaded before being unlocked, the blade may suddenly move forward rapidly when it is finally unlocked. This can likewise lead to undesired or uncontrolled cutting and is therefore a high safety risk. Summary of the Invention

[0005] The object of the present disclosure is to improve or eliminate the disadvantages of the prior art. In particular, a surgical instrument for clamping and separating patient tissue should also be provided, which surgical instrument can be used particularly robustly and safely.

[0006] The object on which the present disclosure is based is achieved by the surgical instrument according to the present invention. Advantageous embodiments are described in more detail below.

[0007] More specifically, the object underlying the present disclosure is achieved by a surgical instrument for clamping and separating patient tissue, comprising a first instrument branch and a second instrument branch pivotally articulated to the first instrument branch, each of which forms a distal clamping jaw and a proximal handle element. The second instrument branch comprises a tissue separation element for separating the patient tissue held between the clamping jaws and a drive mechanism for driving the tissue separation element. Furthermore, the second instrument branch supports a locking element so that it can be moved between a locked position, in which the locking element is blocked and engaged with the drive mechanism, and an open position, in which the drive mechanism is unblocked by the locking element. The locking element comprises a magnetic locking section. The first instrument branch comprises a magnetic actuation section in an area opposite the locking element for actuating the locking element. The magnetic locking section and / or the magnetic actuation section comprise magnets so that, when the instrument branches approach each other, magnetic attraction or repulsion between the magnetic locking section and the first magnetic actuation section causes the locking element to move into the open position and release actuation of the tissue separation element.

[0008] In other words, a general type of surgical instrument is provided, having a locking element for locking a separation and cutting element, which can enter into a blocking engagement with a drive mechanism. In the blocking engagement, that is, in the locked position, the drive mechanism is blocked and cannot or can only move slightly. Therefore, the tissue separation element cannot be manipulated to separate tissue. If the locking element is disengaged from the drive mechanism, that is, in the open position, the drive mechanism and thus the tissue separation element can be selectively manipulated by the user. The locking element is at least partially magnetic and can be manipulated by specifically approaching or moving away from the magnetic manipulation section. The locking element and / or the manipulation section have a magnet, in particular a permanent magnet. The locking element is movably supported, in particular transversely to the extension direction of the instrument branch.

[0009] Considered to be a magnet is a material section or component that is itself a magnet (generating a magnetic field), such as a neodymium magnet or can be magnetically attracted by an external magnetic field but does not necessarily have a magnet itself. This can be, for example, a ferromagnetic metal, such as steel or a permanent magnet. In the case of an embodiment based on attraction, it is advantageously possible (as described in more detail below) to achieve rapid switching of the locking element between the open position and the locked position. By appropriately designing the corresponding parameters (e.g., the position, shape, size, material of the magnetic element), in the case of an embodiment based on repulsion, it is advantageously possible (as described in more detail below) to achieve a low-impact gradual conversion of the locking element between the open position and the locked position. Alternatively, the design can also be selected so that a sudden conversion is achieved.

[0010] This has the particular advantage that the number of openings required in the instrument housing is minimized. This also reduces the risk of contamination. In addition, all components of the drive mechanism can be arranged in a protected manner within the instrument housing, minimizing the risk of damage. In other words, the blade lock can be completely enclosed or completely installed in the housing. Therefore, there are no components protruding from the housing and no seals, insulating parts, etc. are required. In addition, the instrument can be constructed more simply and more cost-effectively. In addition, undesirable unlocking of the drive mechanism is almost ruled out, as a separate magnet is required for this. The risk of injury caused by undesirable or uncontrolled manipulation of the tissue separation element is therefore minimized. This means that the blade lock cannot be manipulated or manipulated without auxiliary means.

[0011] It is particularly advantageous to attract the locking element in one direction by the operating element (or by the reset element). Because the magnetic attraction force is self-reinforcing, it can be achieved that the locking element is switched back from the locked position to the open position, that is, it can be changed to the locked position very quickly. This can, for example, avoid a semi-unlocked position of the locking element, thereby minimizing the risk of the tissue separation element suddenly performing a separation movement (for example, moving forward quickly) when the switch for operating the tissue separation element is just operated and the semi-unlocked locking element slides under such a preload. In other words, when the blade operation is preloaded, the locking element cannot be changed into the released position.

[0012] The tissue separation element can, for example, have a blade or edge that is pressed onto / moves onto the patient's tissue held by the clamping claws and separates the patient's tissue. For tissue separation, the tissue separation element can be supported in the second instrument branch in a distal direction. Alternatively or additionally, the tissue separation element can be pivotally supported on a clamping claw in the clamping claws. The drive mechanism can connect the tissue separation element to a manipulation switch, particularly in a (pure) mechanical manner, which can be manipulated by the user. The drive mechanism can, for example, have a rod and / or a gear transmission mechanism. The drive mechanism therefore has a moving component. The present disclosure utilizes this and provides a locking element so as to selectively block the movement of one or more moving components.

[0013] The two instrument branches can be pivotally connected to one another, particularly at a rotary joint between the clamping jaw and the handle element. In particular, the section of the instrument branch distal to the rotary joint is referred to as the clamping branch, and the section proximal to the joint is referred to as the handle element. The locking element and the magnetic actuation section are preferably provided on the handle element. Alternatively, it is also conceivable to arrange the handle element and the magnetic actuation section on the clamping jaw.

[0014] Preferably, the second instrument branch has a reset element that applies a reset force to the locking element. The reset force counteracts the attractive force or repulsive force between the magnetic locking section and the magnetic manipulation section, thereby applying a reset force to the locking element that acts in the direction of the locked position. Further preferably, the reset element comprises a spring or a magnetic element.

[0015] In other words, a reset element is provided that preloads the locking element into the locked position. As a result, when the force exerted by the actuating section on the locking element decreases, the locking pin can be reliably reset to the locked position. The position of the locking pin can thus be adjusted between the open position and the locked position in a controlled manner.

[0016] It is particularly advantageous if the magnetic actuation section, the magnetic locking section, and the reset element are designed and positioned relative to one another such that the locking element switches to the open position when a predetermined minimum pressure (predetermined surface pressure) is applied between the clamping jaws. In other words, the blade lock (locking element) can be designed so that it is not unlocked, i.e., the blade is released, until a defined pressure in the jaws (e.g., a minimum pressure of 0.1 N / mm^2 to 0.5 N / mm^2) is reached.

[0017] The locking element can be a magnet (i.e., a movable slide in which the (locking) magnet is located or the slide consists of the (locking) magnet), and the reset element and the actuating section can be designed without magnets (i.e., without a separate magnet). In this case, only one magnet is required, which is particularly cost-effective. The locking element can optionally form a protective cover or be coupled to a protective cover in a material-fitting, force-fitting, or form-fitting manner, which surrounds the magnet or magnetic section optionally accommodated therein (is injection-molded / thereby completely encapsulated). Alternatively, the locking element can be without magnets, and the actuating section and, if necessary, the reset element can have one magnet or multiple magnets. This is advantageous because the locking element can be moved back and forth between two positions and can be stopped in the corresponding end position, thereby potentially damaging the permanent magnet, which is usually made of fragile material.

[0018] Advantageously, the magnetic actuation section, the magnetic locking section, and the resetting element are designed and positioned relative to one another such that the locking element remains in the locked position in a first defined position of the instrument branches relative to one another and in the open position in a second defined position of the instrument branches relative to one another. In particular, the distal clamping jaws are open in the first position and in a predetermined clamping position in the second position.

[0019] In other words, the restoring element (particularly when the restoring element is a magnetic element) and / or the actuating section can be configured at a fixed position in the respective instrument branch. This has the advantage that the timing of the movement of the locking element between the open and locked positions can be precisely set using simple means. In other words, by adjusting the distances, positions, and / or dimensions of the magnetic sections or elements (i.e., the locking element and / or the actuating section and / or the restoring element) and / or the strength of one or more magnets inserted therein, a functionally effective balance can be achieved relative to one another. For example, this can ensure that the locking element is moved into the open position exactly when a defined surface pressure is applied between the clamping jaws or shortly before the clamping jaws come into contact, or that the locking element is moved into the open position exactly when the clamping jaws come into contact or at any other desired time. When designing and positioning the locking element, the actuating section, and, if necessary, the restoring element, it is advantageous to consider which other magnetic (e.g., metallic or magnetic) bodies or surfaces are installed in the instrument.

[0020] In this way, the manipulation of locking element can be directly coupled to when clamping claw is in the position that is suitable for separating tissue.In addition, can avoid the separation of tissue outside this position.

[0021] The device according to the present disclosure also has the advantage that the locking element changes abruptly into the open position and / or the locked position. As a result, the locking element can stop at the corresponding end position. This stop can be either cushioned, as described in more detail below, or used to provide feedback to the user regarding the switching of the locking element.

[0022] According to advantageous design, the motion of the locking element is limited by the buffer stop. In this case, a buffer section can be provided on the buffer stop and / or on the locking element on a side towards the buffer stop so as to cushion the collision of the locking element to the buffer stop.

[0023] In other words, the movement of the locking element is damped in at least one direction or at its end stop. This is particularly advantageous when the end stop and / or the locking element consist of a fragile material that could be damaged by a collision with the locking element. For example, the buffer section can comprise an elastomer and / or a spring and / or a buffer fluid. For example, the intermediate space between the locking element 15 and its guide in the area of its end stop / end position can be airtight or the outflowing air can be throttled so that the air in the intermediate space can respectively serve as a buffer section. Thus, in addition to the magnetic locking section, the locking element can also have a slider section coupled thereto (and, if necessary, buffered).

[0024] Alternatively or additionally, according to another advantageous embodiment, the movement of the locking element can be limited by a signal stop. In this case, a signal section can be provided on the signal stop and / or the locking element on the side facing the signal stop, which generates or reinforces tactile and / or acoustic feedback when the locking element strikes the signal stop, in order to signal to the user that the locked position and / or the open position has been reached.

[0025] In other words, (tactile) feedback or a noise (click) can be generated when the position / position of the slider movement / locking element is changed. The signal transmitter stop is a stop of the locking element at one of its end positions, in which an audible or tactile signal is generated when the stop occurs, for example, by two hard surfaces colliding with each other. For example, the signal transmitter stop section can be made of a fragile and / or bright or loud and / or oscillating and / or vibrating material. Thus, feedback or a signal can be generated or intensified when the locking element stops on the signal transmitter stop. The feedback / signal advantageously allows the user to know that the user has reached a specific position of the clamping jaws relative to each other, for example, there is a predetermined surface pressure between the clamping jaws, which surface pressure is necessary for tissue separation and, if necessary, tissue coagulation. In addition, the user can directly recognize that the user can now operate the tissue separation element. Therefore, this signal can be used as a safety feature.

[0026] Furthermore, the surgical instrument can have an instrument housing which preferably has a window in the region of the locking element. The region of the locking element behind the window can form a visible marking section which characterizes the locked state and / or the open state.

[0027] In other words, preferably, the section of the locking element that is located behind the window in the open position (i.e., thus visible from outside the instrument) has a first marking (e.g., red), and the other section of the locking element that is located behind the window in the locked position has a second marking (e.g., green). This marking can, for example, be identical to the marking of the poles of the locking element's magnet (i.e., the magnetic locking section). This has the advantage for the user that they can directly see which position the locking element is in at any given moment (even independently of feedback from the signal transmitter stop). This means that the various states of the blade lock can be visually communicated to the user. The marking section can have only the first and second markings, or it can each represent a gradual or smooth transition between the first and second markings, or between the open and locked positions.

[0028] It is also conceivable to use a window (visual observation window) to indicate when the user presses too hard, ie the pressure / surface pressure in the jaw part / between the clamping jaws is greater than 2 N / mm, for example.2 For example a specific orientation of the locking element (e.g. a movement beyond the open position) or a display / state of a further indicator member arranged behind a window in the housing can serve as an indicator of excessive pressure between the clamping jaws, which indicator member indicates pressure / exceeding a limit pressure.

[0029] Furthermore, the drive mechanism preferably includes a user-operated operating switch for operating the tissue separation element. Furthermore, the drive mechanism may include a preload element that preloads the tissue separation element into an unoperated position. Thus, the user can trigger the tissue separation element in only one direction (for tissue separation) and then automatically return it to its initial position. This makes the device particularly easy to use.

[0030] Advantageously, the drive mechanism comprises a driving rack or a driven rack and the locking element is movably supported transversely to the rack so that the locking element engages in the motion path of the rack in the locked position and is outside the motion path of the rack in the open position. This is particularly advantageous because it is a very simple, space-saving and cost-effective structure. The locking element can be particularly easily engaged in the motion path of the rack for engagement. For example, the (driving) input rack can be coupled to the operating switch, and the (driven) output rack can be coupled to the tissue separation element, and a gear can be coupled to these racks. As an alternative to the rack path, the locking element can also be engaged in the gear if necessary.

[0031] Preferably, the toothed rack and the locking element are constructed and arranged relative to one another so that, in the locked position, the locking element engages in a tooth of the toothed rack or in an undercut opposite the tooth. Further preferably, the locking element engages around the toothed rack in a U-shaped or O-shaped manner, at least in the locked position. In the latter case, the locking element can also taper in a wedge-shaped manner. In addition, the locking element can be arranged particularly flexibly, that is, along the entire toothed rack in the instrument. The entire structure is therefore particularly simple. In addition, in the case of a locking element that is at least partially constructed in a U-shaped or O-shaped manner, it is advantageous that implementation schemes based on (magnetic or elastic) repulsive forces between the locking element and the reset element or the operating section can be easily implemented. Alternatively, the locking element can engage behind the end of one of the toothed racks.

[0032] Furthermore, it is advantageous if the restoring element is a magnetic segment of the drive mechanism, such as a guide rail or plate, wherein one of the toothed racks is guided in the guide rail or plate. This allows the corresponding segment to fulfill a dual function, eliminating the need for a separate component as a restoring element. This further simplifies the design and reduces costs.

[0033] In other words, the object on which the present invention is based can be achieved, for example, as follows.

[0034] The surgical instrument comprises a first and a second handle (instrument branches) which are pivotally connected to one another, and a cutting knife as an example of a tissue separation element. To activate the cutting knife, the user places a finger on a knife trigger (i.e., an operating switch), which is configured as a slide, for example. As soon as the finger pulls the knife trigger, the knife trigger drives a rack, which drives a driven rack via a gear. The driven rack drives the blade. The mechanism is reset by a spring as an example of a preload element, which acts on the driven rack, for example, to pull it back into its initial position. The blade lock for locking the mechanism is implemented magnetically. For example, permanent neodymium magnets with different or identical holding forces are used here.

[0035] When the instrument is in the open state, the slider / locking element is pulled in the direction of the reset element by a magnet (in the locking element or reset element). In this position, the slider blocks the movement of the drive / input rack, making it impossible to manipulate the tissue separation element. When the two instrument branches are close, the locking element is increasingly strongly attracted to the magnetic manipulation section (which may have a magnet). The locking element thus moves in the direction of the manipulation section. When the locking element finally stops on the corresponding stop in the housing, the path for the drive mechanism / blade mechanism / transmission system is released to drive the tissue separation element. In other words, the tissue separation element can be manipulated.

[0036] When the instrument is opened or the instrument branches move away from each other, the attraction between the locking element and the actuating element becomes so weak from a certain point on that the attraction toward the restoring element becomes stronger. The locking section then moves again toward the restoring element and thus into the locked position (locked position). BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present disclosure will be described below according to preferred embodiments. However, these embodiments are merely illustrative and are not intended to limit the scope of protection of the present invention. In addition, when describing various embodiments, the same reference numerals are used for the same components to avoid repeated description of the components.

[0038] Figure 1 The instrument according to the first preferred embodiment of the present disclosure is shown from the outside and with the instrument housing disassembled.

[0039] Figure 2 A detailed view of the drive mechanism of the instrument of the first embodiment is shown.

[0040] Figure 3 and Figure 4 The locking mechanism of the first embodiment is shown in a locked position and an unlocked position.

[0041] Figure 5 and Figure 6Each illustrates a modification of the locking mechanism corresponding to the second and third embodiments of the present disclosure.

[0042] Figure 7 and Figure 8 A modified locking mechanism according to a fourth preferred embodiment is shown in a locked position and an unlocked position.

[0043] Figure 9 and Figure 10 The modified locking mechanism according to the fifth preferred embodiment is shown in the locked position and the unlocked position.

[0044] Among them: 1-instrument; 2-first instrument branch; 3-second instrument branch; 4-rotating joint / joint segment; 5-clamping claw / distal instrument tip; 7-driving mechanism; 8-operating switch; 9-driving / input rack; 10-gear; 11-driven / output rack; 12-tissue separation element / blade slider; 13-housing of the second instrument branch; 14-prestressing element / tension spring; 15-magnetic locking element; 16-magnetic resetting element; 17-magnetic operating element; 18-side recess; F-window / observation window. DETAILED DESCRIPTION

[0045] Figure 1 The instrument 1 according to the first preferred embodiment of the present disclosure is shown from the outside (above) and with the disassembled instrument housing (below). The instrument 1 has a first instrument branch 2 and a second instrument branch 3, which are connected to each other by an articulation at a joint section / rotational joint 4. Distal to the rotational joint 4, the instrument branches 2, 3 form a clamping claw 4 and a gripping section proximal thereto. A drive mechanism 7 is arranged in the gripping section of the second instrument branch, which can be operated by a user via an operating switch 8 and can be locked and unlocked, as described in more detail below. The housing can also have a window F, behind which a locking element 15, which will be described in detail below, is arranged, and the surface of the locking element can be constructed in the area of the window F with a marking section for characterizing the state / position of the locking element 15.

[0046] Figure 2A detailed view of the drive mechanism 7 of the instrument 1 of the first embodiment is shown. The two instrument branches 2, 3 are open, that is, pivoted away from each other around the rotary joint 4. The operating switch 8 is connected to the drive / input rack 9. The drive rack 9 drives the gear 10, which in turn drives the driven / output rack 11. The driven rack 11 is indirectly or directly connected to the tissue separation element 12 (here, a propellable blade slide). In this illustration, the tissue separation element 12 is not operated and locked, that is, it is arranged in the proximal position. The driven rack 11 or the tissue separation element 12 is connected to the instrument housing 13 of the second instrument branch 3 by a preload element 14 in the form of a helical tension spring, which preloads the tissue separation element 12 to an unoperated initial position.

[0047] In the current diagram and in Figure 3 The figure shows, enlarged, that the drive mechanism is blocked by a locking mechanism having a locking element 15, that is, the locking element 15 is in the locked position. The locking element 15 has a magnet oriented so that one pole faces the first instrument branch and the other pole faces away from the first instrument branch. The locking element 15 has a cover on its other pole that partially surrounds the magnet and engages behind the proximal end of the drive rack. The cover can serve as a buffer section to cushion the stop of the locking element 15 in the locked position. Alternatively, the cover can serve as a signal transmitter section, which generates a particularly loud noise when the locking element 15 stops in its corresponding end position (i.e., the signal transmitter stop). On the side opposite the other pole, another magnet is fastened to the instrument housing 13 of the second instrument half 3 as a reset element 16. The magnet of the reset element 16 has a pole that is attractively oriented toward the magnet of the locking element 15. The locking element 15 is held in the locked position by attraction between the magnet of the locking element 15 and the resetting element 16. A magnetic actuating element 17 is fastened in the grip section of the first instrument limb 2 in an area located opposite the locking element 15 and has a further magnet, one pole of which is oriented toward the locking element 15.

[0048] exist Figure 4 In the embodiment, the two instrument branches 2 and 3 are closed. Figure 2 and Figure 3 The position of the magnet in the instrument 1 is closer to the locking element 15. As a result, an attractive force exists between the operating element 17, the resetting element 16, and the locking element 15. As a result, the locking element 15 moves toward the operating element 17 and no longer engages proximally behind the drive rack 9. This means that the locking element 15 is in the open position. The drive rack 9 can therefore be moved in the proximal direction as shown here and actuate the tissue separation element 12.

[0049] Further embodiments are described below, which preferably correspond to the first embodiment, except for the differences explained below.

[0050] Figure 5 A modification of the locking mechanism according to the second embodiment of the present disclosure is shown. According to this modification, the locking element 15 does not have a cover. Figure 6 A further modification of the locking mechanism corresponding to the third embodiment of the present disclosure is shown, wherein the reset element 16 is formed by a metallic guide rail of the drive rack 9. Therefore, the reset element 16 does not have a magnet.

[0051] Figure 7 and Figure 8 The modified locking mechanism according to the fourth preferred embodiment is shown in the locked position or the open position. The drive rack 9 has a toothed side and a toothless side. An undercut 18 is formed on the toothless side and is designed to engage with the locking element 15 or its cover. The reset element 16 is designed as a (helical) spring. This spring is supported between the instrument housing 13 of the second instrument branch 3 and the locking element 15. If the first instrument half 2 is as shown Figure 8 When the locking element 15 and the actuating portion 17 are brought closer together, the magnetic attraction force between the locking element 15 and the actuating portion 17 exceeds the spring force of the restoring element 16 , so that the locking element 15 is pulled back into the open position.

[0052] Figure 9 and Figure 10 A modified locking mechanism according to a fifth preferred embodiment is shown in the locked position or in the open position. The locking element 15 is designed as a U-shaped or O-shaped clamp, which grips the drive rack 9. On the clamp side facing the first instrument branch 2, the locking element 15 has a magnet. On its clamp side opposite to the first instrument branch 2, the locking element has an engagement section, which is designed to engage in the teeth of the drive rack 9. The reset element 16 is designed as a (helical) spring, which presses against the locking element 15 on the clamp side opposite to the first instrument branch 2 in order to preload the locking element into the locked position, as shown in FIG. Figure 9 If the first instrument half 2 is as shown in Figure 10 When the locking element 15 and the actuating section 17 are brought closer together, the magnetic repulsive force between the locking element 15 and the actuating section 17 exceeds the spring force of the restoring element 16 , so that the locking element 15 is pulled / pushed back into the open position.

Claims

1. A surgical instrument (1) for clamping and separating patient tissue, comprising a first instrument branch (2) and a second instrument branch (3) pivotably connected to the first instrument branch (2), the first instrument branch and the second instrument branch forming a distal clamping jaw (5) and a proximal handle element, respectively, wherein: The second instrument branch (3) has a tissue separation element (12) for separating the patient tissue held between the clamping jaws (5), a drive mechanism (7) for driving the tissue separation element (12), and a locking element (15) supported in such a way that the locking element is movable between a locking position and an open position, in which the locking element engages in a blocking manner in the drive mechanism (7) and in which the drive mechanism (7) is not blocked by the locking element (15), characterized in that The locking element (15) has a magnetic locking section and the first instrument branch (2) has a magnetic manipulation section (17) for manipulating the locking element (15) in an area opposite the locking element (15), wherein the magnetic locking section and / or the magnetic manipulation section (17) have a magnet so that when the instrument branches (2, 3) approach each other, the locking element (15) is moved into the open position and the manipulation of the tissue separation element (12) is released by magnetic attraction or repulsion between the magnetic locking section and the magnetic manipulation section (17).

2. The surgical instrument (1) according to claim 1, wherein: The second instrument branch (3) has a reset element (16) which applies a reset force to the locking element (15), the reset force counteracting the attractive or repulsive force between the magnetic locking section and the magnetic manipulation section (17) so as to apply a reset force to the locking element (15) acting in the direction of the locking position.

3. The surgical instrument (1) according to claim 2, wherein: The magnetic manipulation section (17), the magnetic locking section and the resetting element (16) are designed and positioned relative to each other so that the locking element (15) remains in the locked position in a first position of the instrument branches (2, 3) relative to each other and remains in the open position in a second position of the instrument branches (2, 3) relative to each other.

4. The surgical instrument (1) according to claim 3, wherein: The distal clamping jaws (5) are open in the first position and are in a predetermined clamping position in the second position.

5. The surgical instrument (1) according to any one of claims 2 to 4, wherein: The resetting element (16) has a spring or a magnetic element.

6. The surgical instrument (1) according to claim 3, wherein: The magnetic actuation section (17), the magnetic locking section and the resetting element (16) are designed and positioned relative to one another such that the locking element (15) is transferred into the open position when a predetermined pressure is applied between the clamping jaws (5).

7. The surgical instrument (1) according to claim 1, wherein The movement of the locking element (15) is limited by a buffer stop and a buffer section is provided on the buffer stop and / or on the locking element (15) on the side facing the buffer stop in order to buffer the impact of the locking element (15) on the buffer stop.

8. The surgical instrument (1) according to claim 1, wherein The movement of the locking element (15) is limited by a signal transmitter stop and the signal transmitter stop and / or the locking element (15) is provided with a signal transmitter section on the side facing the signal transmitter stop, which generates or enhances tactile feedback and / or acoustic feedback when the locking element (15) hits the signal transmitter stop in order to signal to the user that the locked position and / or the open position has been reached.

9. The surgical instrument (1) according to claim 1, further comprising an instrument housing (13) having a window (F) in the region of the locking element (15), wherein The region of the locking element (15) located behind the window (F) forms a marking section which characterizes the locked state and / or the unlocked state.

10. The surgical instrument (1) according to claim 1, wherein The drive mechanism (7) has an operating switch (8) operable by a user for operating the tissue separation element (12) and a prestressing element (14) for prestressing the tissue separation element (12) into an unactuated position.

11. The surgical instrument (1) according to claim 1, wherein: The drive mechanism (7) has a toothed rack (9) and the locking element (15) is movable transversely to the toothed rack (9) so that in the locked position the locking element engages in the movement path of the toothed rack (9) and in the open position is outside the movement path of the toothed rack (9).

12. The surgical instrument (1) according to claim 11, wherein The toothed rack (9) and the locking element (15) are designed and arranged such that, in the locking position, the locking element (15) engages in a tooth of the toothed rack (9) or in an undercut (18) opposite the tooth.

13. The surgical instrument (1) according to any one of claims 11 and 12, wherein: The locking element (15) grips the toothed rack (9) in a U-shaped manner, at least in the locking position.

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