Surgical instrument having a locking mechanism
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-03-28
- Publication Date
- 2026-03-26
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
[Technical field]
[0001] The present disclosure relates to a surgical instrument for clamping and separating tissue (patient tissue) comprising a first instrument branch and a second instrument branch pivotally hinged to or supported on the first instrument branch, each forming a distal clamp jaw element and a proximal grasping element, the second instrument branch comprising a tissue separating element for separating patient tissue held between the clamp jaws and a drive mechanism for driving the tissue separating element, wherein a locking element is provided for locking or releasing the drive mechanism. [Background technology]
[0002] Surgical sealing and cutting instruments are used to grasp, seal, separate or cut patient tissue during surgery. Typically, these instruments have a distal instrument tip with clamping jaws for grasping and clamping patient tissue. Additionally, such instruments have a separating or cutting element with a blade or separating edge, e.g., for cutting through the patient tissue. Handheld instruments also have a handle that can be grasped by a user, which is provided with various actuating elements for actuating the movement of the clamping jaws and / or for actuating the separating or cutting element. To prevent inadvertent actuation of the separating or cutting element, the actuating elements are typically capable of being locked and unlocked.
[0003] For example, from EP 3 400 893 B1, a corresponding electrosurgical forceps is known having a proximal handle, a distal clamping jaw, and a blade movable between a retracted position and an extended position. A blade lock is provided on one of the handle branches, which prevents distal displacement of the blade and is movable from a locked position to an unlocked position when the jaws are brought closer together to allow distal displacement of the blade. The blade lock has a hook which can be selectively engaged and locked to the blade drive linkage. A finger connected to the hook projects in the direction of the other handle branch. When the handle branches are moved towards each other, the other handle branch presses the finger, releasing the hook from the blade drive linkage and releasing the lock.
[0004] A problem with the prior art is that an opening must be provided at the point where the finger protrudes from the instrument housing. As a result, particles resulting from the mechanical friction of the instrument can fall through the opening into the patient's wound or surgical site and be present there as unwanted foreign material / objects, endangering the patient. This means that there is a high risk of contamination. Furthermore, liquids (NaCl, blood, etc.) can inadvertently penetrate the instrument and interfere with or damage the mechanical / electronics. To mitigate these problems, the point must be sealed or protected, making the device more complex and expensive. Furthermore, the pins can break, especially if made of plastic. Furthermore, the locking mechanism is relatively complex. Its function can be impaired by aging, especially of the plastic parts. Furthermore, the blade locking mechanism has the disadvantage that the user can easily circumvent it without tools by pushing or hooking the pin with his hand. This increases the risk of injury to the user and the risk of unintentionally cutting the patient's tissue. If the blade actuation is preloaded before it is unlocked, the blade may suddenly break forward when it is finally unlocked, again potentially causing an unintended or uncontrolled cut and therefore representing a major safety risk. Summary of the Invention [Means for solving the problem]
[0005] The objective underlying the present disclosure is to improve or eliminate the drawbacks of the prior art, in particular to provide a surgical instrument for clamping and separating patient tissue that is particularly robust and safe to use.
[0006] The problem on which the present disclosure is based is solved by a surgical instrument comprising the features of claim 1. Advantageous embodiments are the subject matter of the subclaims and are explained in more detail hereinafter.
[0007] More specifically, the problem underlying the present disclosure is solved by a surgical instrument for clamping and separating patient tissue, the surgical instrument comprising a first instrument branch and a second instrument branch pivotally hinged to the first instrument branch, the instrument branches forming a distal clamping jaw and a proximal grasping element, respectively. The second instrument branch comprises a tissue separating element for separating the patient tissue held between the clamping jaws, and a drive mechanism for driving the tissue separating element. Additionally, the second instrument branch supports a locking element movably between a locked position in which the locking element engages the drive mechanism in a blocking manner, and an open position in which the drive mechanism is unblocked by the locking element. The locking element comprises a magnetic locking portion. The first instrument branch comprises a magnetic actuation portion in an area opposite the locking element for actuating the locking element. The magnetic lock and / or magnetic actuation portion includes a magnet for moving the locking element to an open position and disengaging the tissue separation element by magnetic attraction or repulsion between the magnetic lock and the first magnetic actuation portion when the instrument branches approach each other.
[0008] In other words, a general surgical instrument is provided that includes a locking element for locking the separating cutting element, which can be brought into blocking engagement with the drive mechanism. In the blocking engagement, i.e. locked position, the drive mechanism is blocked and cannot or can only move slightly. Thus, the tissue separating element cannot be actuated to separate tissue. When the locking element is not engaged with the drive mechanism, i.e. in the open position, the drive mechanism and thus the tissue separating element can be optionally actuated by the user. The locking element is at least partially magnetic and can be actuated by targeted approach or removal of a magnetic actuation part. The locking element and / or the actuation part have a magnet, in particular a permanent magnet. The locking element is supported movably, in particular transversely to the extension direction of the instrument branch.
[0009] A material section or member may be considered magnetic, either one that is itself a magnet (generating a magnetic field), such as a neodymium magnet, or one that can be magnetically attracted by an external magnetic field, but does not necessarily have a magnet itself. For example, ferromagnetic metals such as steel, or permanent magnets. In the case of an arrangement based on attraction, it is advantageous to have the locking element snap between the locked and released positions quickly (as described in more detail below). In the case of an arrangement based on repulsion, a low-shock, gradual change of the locking element between the locked and released positions can be advantageously achieved (as described in more detail below) if the corresponding parameters (e.g. position, shape, size, material of the magnetic element) are appropriately laid out. Alternatively, the layout can be selected to obtain a jerky change.
[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. Furthermore, all parts of the drive mechanism can be arranged in a protected way inside the instrument housing, which minimizes the risk of damage. In other words, the blade locking mechanism is fully encapsulated or completely integrated into the housing. This means that no parts protrude from the housing and no sealing, protection, etc. are required. Furthermore, the instrument becomes simpler and more cost-effective. Furthermore, unintentional unlocking of the drive mechanism is virtually impossible, since a separate magnet is required for unlocking. This minimizes the risk of injury due to unintentional or uncontrolled activation of the tissue separation element. This means that the blade locking mechanism cannot be operated or destroyed without the instrument.
[0011] It is particularly advantageous if the locking element is attracted in one direction by the actuation element (or by the reset element). Since the magnetic attraction is self-reinforcing, it is thereby achieved that the locking element snaps from the locked position to the open position, i.e. changes to the locked position very quickly. In this way, it is possible to avoid the locking element coming into a half-unlocked position, so that the risk of a situation in which, for example, when the switch for actuating the tissue separation element is actuated, the tissue separation element suddenly performs a separating action (for example snaps forward) and the half-unlocked locking element slips under such a preload is minimized. In other words, the locking element cannot change to the unlocked position if it is prestressed for the actuation of the blade.
[0012] The tissue separating element may have, for example, a blade or edge that is pressed / driven against the patient tissue held by the clamp jaws and separates the tissue. For tissue separation, the tissue separating element may be attached to the second instrument branch so as to be movable in the distal direction. Alternatively or additionally, the tissue separating element may be pivotally attached to one of the clamp jaws. The drive mechanism may, in particular in a (purely) mechanical manner, connect the tissue separating element to an activation switch, which may be activated by the user. The drive mechanism may have, for example, a link mechanism and / or a gear drive. Thus, the drive mechanism has moving parts. The present disclosure takes advantage of this and provides a locking element in such a way that the locking element optionally prevents one or more movements of the moving parts.
[0013] The two instrument branches can be pivotally hinged to one another, in particular at the pivotal connection between the clamp jaws and the gripping element. In particular, the instrument branch distal to the pivotal connection is called the clamping branch and the instrument branch proximal to the junction is called the gripping element. The locking element and the magnetic actuation element are preferably provided on the gripping element. Alternatively, it is also conceivable to arrange the gripping element and the magnetic actuation element on the clamp jaws.
[0014] Preferably, the second instrument branch comprises a reset element for applying a reset force to the locking element counteracting the attractive or repulsive force between the magnetic locking portion and the magnetic actuation portion to apply a restoring force to the locking element acting towards the locked position.More preferably, the reset element comprises a spring or a magnetic element.
[0015] In other words, a reset element is provided which prestresses the locking element into the locked position, thereby ensuring that the lock returns to the locked position when the force exerted by the actuator on the locking element is reduced, and thus the position of the lock between the open and locked positions can be set in a controlled manner.
[0016] In particular, the magnetic actuation portion, the magnetic locking portion and the reset element are advantageously arranged and positioned relative to one another such that the locking element changes to the open position when a predetermined minimum pressure (predetermined surface pressure) is applied between the clamp jaws. In other words, the blade lock (locking element) can be configured to only release the lock, i.e., release the blade, from a set pressure (e.g., a minimum pressure of 0.1 N / mm^2 to 0.5 N / mm^2) on the jaws.
[0017] The locking element can be magnetic (i.e. a movable slider on which a (locking) magnet is arranged or which consists of a (locking) magnet) and the reset element and the actuating part can be magnet-free (i.e. without magnets of their own). In this case, only one magnet is required, which is particularly cost-effective. The locking element can optionally form a protective cover around the magnet or magnet part which can be housed therein (overmolded / fully encapsulated) or be coupled thereto in a material-fit, force-fit or form-fit manner. Alternatively, the locking element can have no magnet and the actuating element and possibly the reset element can have one or more magnets. This is advantageous since the locking element can shuttle between two positions and stop at the respective end positions, which can damage permanent magnets which generally have a fragile material.
[0018] Advantageously, the magnetic actuation portion, the magnetic locking portion and the reset element are designed and arranged relative to one another such that the locking element is held in a locked position in a first defined position of the instrument branches relative to one another and in an 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 predefined clamping position in the second position.
[0019] In other words, the reset element, especially if this is a magnetic element, and / or the actuating part can be formed at a fixed position on the respective instrument branch. The advantage of this is that it is easy to set exactly when the locking element moves between the open and locked positions. In other words, a functional balance can be achieved by adjusting the individual distances and / or positions and / or dimensions of the magnetic parts or elements (i.e. the locking element and / or the actuating part and / or the reset element) and / or the strength of the magnet(s) used therein relative to one another. This can be achieved, for example, by the locking element changing to the open position exactly when a defined surface pressure is applied between the clamping jaws, or just before the clamping jaws come into contact with one another, or when the clamping jaws come into contact with one another, or at any other time. When designing and positioning the locking element, the actuating part and possibly the reset element, it is preferable to take into account what other magnetic (e.g. metal or magnetic) bodies or surfaces are installed on the instrument.
[0020] In this way, actuation of the locking element can be directly linked to the fact that the clamp jaws are in a suitable position to separate tissue, and further, separation of tissue outside of this position can be avoided.
[0021] The device according to the present disclosure further has the advantage that the change of the locking element to the open position and / or to the locked position is immediate, which allows the locking element to stop at a corresponding end position, which can be damped or used to provide feedback to the user about the movement of the locking element, as described in more detail below.
[0022] According to an advantageous embodiment, the movement of the locking element is limited by a damper stop, whereby a damper part can be provided on the damper stop and / or on the side of the locking element facing the damper stop in order to damp the impact of the locking element on the damper stop.
[0023] In other words, the movement of the locking element is damped at least in one direction or at its end stop points. This is particularly advantageous if the end stop points and / or the locking element have a brittle material that can be damaged by the locking element hitting it. The damper part may for example have an elastomer and / or a spring and / or a fluid damper. For example, the intermediate space between the locking element 15 and its guide in the region of its end stop points / end positions can be airtight or throttle the outflowing air so that the air in this intermediate space can act as a damper part, respectively. In addition to the magnetic locking part, the locking element may therefore have a (possibly damped) slider part coupled to it.
[0024] Alternatively or additionally, according to a further advantageous embodiment, the movement of the locking element can be limited by a signal transmitter stop, which and / or the locking element on the side facing the signal transmitter stop can in this case be provided with a signal transmitter part, which generates or amplifies a tactile and / or audible feedback when the locking element hits the signal transmitter stop in order to inform the user that the locked and / or released position has been reached.
[0025] In other words, a (tactile) feedback or sound (click) can be generated when the slider moves / the locking element changes position. The signal transmitter stop is one at which the locking element stops in one of its end positions, and an audible or tactile signal is generated when the locking element stops, e.g. when two hard surfaces come together. For example, the signal transmitter stop may have a high and / or clear or loud sound emitting material and / or a vibrating material. This generates or amplifies a feedback or signal when the locking element hits the signal transmitter stop. This feedback / signal advantageously indicates to the user that the clamping jaws have reached a certain position relative to each other, e.g. that there is a certain surface compression between the clamping jaws required for tissue separation and possibly tissue coagulation. Furthermore, the user is immediately aware that he may now activate the tissue separation element. In this way, this signal can be used as a safety feature.
[0026] The surgical instrument may also include an instrument housing, preferably having a window in the region of the locking element, the region of the locking element rearward of the window may form a visible marker portion identifying a locked and / or open state.
[0027] In other words, preferably, the part of the locking element that is located behind the window in the open state (i.e., therefore visible on the outer surface of the instrument) has a first marking (e.g., red color) and a further part of the locking element that is located behind the window in the locked state has a second marking (e.g., green color). The marking can, for example, be equal to the marking of the pole of the magnet (i.e., the magnetic locking part) of the locking element. This has the advantage for the user that the position of the locking element is always immediately known (independently of the feedback of the signal transmitter stop). This means that the respective state of the blade lock can be visually communicated to the user. The marker part can have only the first and second markings or can show a gradual or smooth transition between the first and second markings or between the open and locked positions.
[0028] It is further envisaged that a window (optical viewing window) may be used to indicate if the user is pressing too hard, i.e. if the pressure / surface compression within / between the clamping jaws is greater than, for example, 2N / mm2. For example, a particular position of the locking element (e.g. displacement beyond open position) indicating that the pressure / pressure limit has been exceeded, or an indication / state of a separate indicator member located behind the window on the housing, may serve as an indication that the pressure between the clamping jaws is excessive.
[0029] It is also preferred if the drive mechanism comprises an activation switch operable by the user to activate the tissue separating element. Furthermore, the drive mechanism may comprise a prestressing element for prestressing the tissue separating element into a non-activated position, whereby the user can only activate / move the tissue separating element in one direction (to separate tissue), after which the tissue separating element automatically returns to its initial position. This makes the device particularly easy to use.
[0030] Advantageously, the drive mechanism comprises a drive rack or a toothed rack, the locking element being mounted so as to be movable laterally relative to the toothed rack, such that in the locked position it engages in the path of movement of the toothed rack and in the released position it is outside the path of movement of the toothed rack. This is particularly advantageous as it is a very simple, space-saving and cost-effective construction. The locking element can be particularly easily engaged in the path of movement of the toothed rack. For example, the (driving) input toothed rack can be coupled to the actuation switch and the (driven) output rack can be coupled to the tissue separation element, with a gear wheel coupling these racks. As an alternative to a toothed rack path, the locking element may also be engaged in a gear wheel if required.
[0031] Preferably, the toothed rack and the locking element are shaped and arranged relative to each other such that in the locked position the locking element engages in the teeth of the toothed rack or in an undercut facing the teeth. More preferably, the locking element engages in a U- or O-shape around the toothed rack, at least in the locked position. In the latter case, the locking element can also be wedge-shaped. Furthermore, the locking element can be arranged in a particularly elastic manner, i.e. along the entire toothed rack of the instrument. The overall construction is therefore particularly simple. Furthermore, in the case of at least partially U- or O-shaped locking elements, it is advantageous that a design based on (magnetic or elastic) repulsion forces between the locking element and the reset element and the actuating part, respectively, is easy to implement. Alternatively, the locking element may be engaged behind one end of the toothed rack.
[0032] It is furthermore advantageous if the reset element is a magnetic part of the drive mechanism, such as a guide rail or plate along which one of the toothed racks is guided, so that the corresponding part can perform a dual function and no separate part as reset element is required, which further simplifies the construction and makes it more cost-effective.
[0033] In other words, the problem underlying the present invention can be solved, for example, as follows.
[0034] The surgical instrument has a first and a second shaft (instrument branch) pivotally connected to each other and a cutting blade as an example of a tissue separation element. To activate the cutting blade, the user places his finger on a cutting trigger (i.e. an activation switch) in the form of, for example, a slider. As soon as the cutting trigger is pulled forward, the toothed rack is driven, which drives the driven toothed rack via a gear. The driven toothed rack pushes the blade with it. This drive mechanism is reset via a spring as an example of a prestressing element, which acts, for example, on the driven toothed rack to pull it back to its initial position. To magnetically lock this mechanism, a blade lock is used. For example, permanent neodymium magnets with different or equal holding power are used.
[0035] When the instrument is in the open state, the slider / locking element is pulled towards the reset element by the magnet (in the locking element or in the resetting element). In this position, the slider blocks the movement of the drive / input toothed rack, and therefore does not actuate the tissue separation element. As the two instrument branches approach each other, the locking element is increasingly attracted towards the magnetic actuation part (which may have a magnet). This causes the locking element to move towards the actuation part. When the locking element finally hits a corresponding stop in the housing, a path is freed for the drive mechanism / blade mechanism / drive train to drive the tissue separation element. Thus, the tissue separation element can be actuated.
[0036] As the instrument opens or the instrument branches move away from each other, at some point the attractive force between the locking element and the actuation element weakens and the attractive force against the reset element increases, causing the locking element to move back towards the reset element and into the locked position.
[0037] In the following, the present disclosure will be described by preferred embodiments. However, these are merely illustrative in nature and are not intended to limit the scope of protection of the present invention. Furthermore, in the description of various embodiments, the same reference numerals are used for the same components to avoid redundant description. [Brief description of the drawings]
[0038] [Figure 1] FIG. 1 shows an instrument according to a first preferred embodiment of the present disclosure from the outside with the instrument housing disassembled; [Diagram 2] FIG. 2 is a detailed view of the drive mechanism of the instrument according to the first embodiment. [Diagram 3] FIG. 4 is a diagram showing the locking mechanism of the first embodiment in a locked position. [Figure 4] FIG. 2 is a diagram showing the locking mechanism of the first embodiment in an open position. [Diagram 5] 13A and 13B are diagrams illustrating a modified example of a locking mechanism according to the second embodiment of the present disclosure. [Figure 6] 13A and 13B are diagrams illustrating a modified example of a locking mechanism according to the third embodiment of the present disclosure. [Figure 7] FIG. 13 shows an alternative locking mechanism according to the fourth preferred embodiment, in the locked position; [Figure 8] FIG. 13 shows an alternative locking mechanism in accordance with the fourth preferred embodiment, in the open position; [Figure 9] FIG. 13 shows an alternative locking mechanism according to the fifth preferred embodiment, in the locked position; [Figure 10] FIG. 13 shows an alternative locking mechanism according to the fifth preferred embodiment, in the open position; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] FIG. 1 shows an instrument 1 according to a first preferred embodiment of the present disclosure from the outside (top) and with the instrument housing disassembled (bottom). The instrument 1 comprises a first instrument branch 2 and a second instrument branch 3, which are hinged to one another at a hinge / pivot connection 4. Distal to the pivot connection 4, the instrument branches 2, 3 form a clamp jaw 5, proximal to which forms a handle. In the handle of the second instrument branch a drive mechanism 7 is arranged, which can be actuated by a user via an actuation switch 8 and which allows locking and unlocking, as will be described in more detail below. Furthermore, the housing may have a window F, behind which a locking element 15, which will be described in more detail below, is arranged, the surface of which may form a marker in the region of the window F to indicate the state / position of the locking element 15.
[0040] FIG. 2 is a detailed view of the drive mechanism 7 of the instrument 1 of the first embodiment. The two instrument branches 2, 3 are opened, i.e. pivoted, away from each other about the pivot connection 4. An activation switch 8 is connected to a drive / input toothed rack 9. The input toothed rack 9 drives a gear 10, which in turn drives an output rack 11. The output rack 11 is directly or indirectly connected to a tissue separating element 12, in this case an advancing blade slider. In this embodiment, the tissue separating element 12 is not activated and is locked, i.e. is located in a proximal position. The output rack 11 or the tissue separating element 12 is connected to the instrument housing 13 of the second instrument branch 3 via a prestressing element 14 in the form of a helical tension spring, which biases the tissue separating element 12 to a non-activated starting position.
[0041] In this enlarged view of FIG. 3, the drive mechanism is blocked by a locking mechanism with a locking element 15, i.e. the locking element 15 is in the locked position. The locking element 15 comprises a magnet arranged with one pole facing towards the first instrument branch and the other pole facing away from it. At its other pole, the locking element 15 has a cap which partially surrounds the magnet and engages behind the proximal end of the drive rack. The cap can function as a damper part for damping the stop of the locking element 15 in the locked position. Alternatively, the cap can function as a signal transmitter part, which for example functions to emit a particularly loud sound when the locking element 15 stops in its corresponding end position (i.e. a signal transmitter stop). On the side opposite to the other pole, a further magnet is mounted in 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 oriented to attract in the direction of the magnet of the locking element 15. The locking element 15 is held in the locked position by the force of attraction between the magnet of the locking element 15 and the reset element 16. In the area of the handle part of the first instrument branch 2 facing the locking element 15, a magnetic actuation element 17 is attached, which also comprises a further magnet, one pole of which is arranged towards the locking element 15.
[0042] In Figure 4, the two instrument branches 2, 3 are closed. The actuation element 17 is closer to the magnet of the locking element 15 than in the position in the instrument 1 shown in Figures 2 and 3. As a result, an attractive force is created between the actuation element 17 and the reset element 16 and locking element 15. As a result, the locking element 15 has moved towards the actuation element 17 and is no longer proximally engaged behind the drive rack 9, i.e., the locking element 15 is in the open position. Thus, the drive rack 9 can be moved proximally to actuate the tissue separation element 12, as shown here.
[0043] Further embodiments are described below which preferably correspond to the first embodiment, except for the differences which are described below.
[0044] Fig. 5 shows a variant of the locking mechanism according to the second embodiment of the present disclosure. According to this variant, the locking element 15 does not have a cap. Fig. 6 shows a further variant of the locking mechanism according to the third embodiment of the present disclosure. In this embodiment, the reset element 16 is formed by the metal guide rail of the drive rack 9. Thus, the reset element 16 does not have a magnet.
[0045] Figures 7 and 8 show the variant locking mechanism according to the fourth preferred embodiment in the locked and open positions, respectively. The drive rack 9 has a toothed and a toothless side. In the toothless side, an undercut 18 is formed and designed to engage with the locking element 15 or its cap. The reset element 16 is formed as a (helical) spring. This spring supports itself between the locking element 15 and the instrument housing 13 of the second instrument branch 3. As shown in Figure 8, when the first instrument half 2 approaches, the magnetic attraction force between the locking element 15 and the actuation part 17 overcomes the spring force of the reset element 16 and the locking element 15 is pulled back to the open position.
[0046] Figures 9 and 10 show the variant locking mechanism according to the fifth preferred embodiment in the locked and open positions, respectively. The locking element 15 is designed as a U- or O-shaped gripper that grips around the drive rack 9. On the gripper side facing the first instrument branch 2, the locking element 15 has a magnet. On the gripper side facing the first instrument branch 2, the locking element has an engagement part, which is formed to engage with a tooth of the drive rack 9. The reset element 16 is designed as a (helical) spring, which presses against the locking element 15 on the gripper side facing the first instrument branch 2 in order to prestress the locking element 15 into the locked position, as shown in Figure 9. When the first instrument half 2 approaches, the magnetic repulsion between the locking element 15 and the actuation part 17 overcomes the spring force of the reset element 16 and the locking element 15 is pulled back / pushed back into the open position, as shown in Figure 10. [Explanation of symbols]
[0047] 1. Equipment 2 First instrument branch 3 Second instrument branch 4 Pivot joint / joint 5 Clamp jaw / distal instrument end 7 Driving mechanism 8 Operation switch 9 Drive / Input Rack 10 Gears 11 Driven / output rack 12 Tissue Separation Element / Blade Slider 13 Second instrument branch housing 14 Prestressing elements / tension springs 15 Magnetic Locking Elements 16 Magnetic Reset Element 17 Magnetic Actuating Elements 18 Undercut F window / viewport
Claims
1. A surgical instrument for clamping and separating patient tissue, The first device branch and, The device comprises a second device branch that is rotatably articulated and connected to the first device branch, Each of the first and second instrument branches forms a distal clamp jaw and a proximal gripping element, The second branch of the device is, The device comprises a tissue separation element for separating patient tissue held between the clamp jaws, and a drive mechanism for driving the tissue separation element, The locking element is supported so as to be movable between a locked position in which the locking element engages with the drive mechanism in a blocking manner, and an open position in which the drive mechanism is released from being blocked by the locking element. The locking element includes a magnetic locking portion. The first device branch portion is provided with a magnetic actuation part for activating the locking element in the region facing the locking element. A surgical instrument comprising a magnet for moving the locking element to the open position and releasing the operation of the tissue separation element by magnetic attraction or repulsion between the magnetic locking part and the magnetic operating part when the first instrument branch and the second instrument branch approach each other.
2. The surgical instrument according to claim 1, wherein the second instrument branch includes a reset element that applies a reset force to the locking element that acts in the direction of the locked position, thereby canceling out the attractive or repulsive force between the magnetic locking part and the magnetic operating part.
3. The surgical instrument according to claim 2, wherein the magnetic actuation part, the magnetic locking part, and the resetting element are configured and arranged relative to each other such that the locking element is held in the locked position at a first relative position of the first instrument branch and the second instrument branch, and is held in the open position at a second relative position of the first instrument branch and the second instrument branch.
4. The surgical instrument according to claim 3, wherein the distal clamp jaw is open in the first position and in a predetermined clamping position in the second position.
5. The surgical instrument according to claim 2, wherein the reset element comprises a spring or a magnetic element.
6. The surgical instrument according to claim 3, wherein the magnetic actuation part, the magnetic locking part, and the resetting element are configured and arranged relative to each other such that the locking element moves to the open position when a predetermined pressure is applied between the clamp jaws.
7. The movement of the aforementioned locking element is restricted by the damper stop. The surgical instrument according to claim 1, wherein a damper portion is provided on the damper stop and / or on the side of the locking element facing the damper stop in order to reduce the impact of the locking element on the damper stop.
8. The movement of the locking element is restricted by the signal transmitter stop. The signal transmitter stop and / or the locking element comprises a signal transmitter section on the side facing the signal transmitter stop. The surgical instrument according to claim 1, wherein the signal transmitter unit generates or amplifies tactile feedback and / or audible feedback to inform the user that the locking position and / or the open position has been reached when the locking element strikes the signal transmitter stop.
9. The device housing further comprises a window in the region of the locking element, The surgical instrument according to claim 1, wherein the region of the locking element located behind the window forms a marker portion that characterizes the locked state and / or the open state.
10. The surgical instrument according to claim 1, wherein the drive mechanism comprises an operating switch that can be operated by a user to activate the tissue separation element, and a prestressing element that applies prestress to the tissue separation element to a non-operating position.
11. The aforementioned drive mechanism includes a toothed rack, The surgical instrument according to claim 1, wherein the locking element is movable laterally relative to the toothed rack such that it engages with the movement path of the toothed rack in the locked position and is located outside the movement path of the toothed rack in the open position.
12. The surgical instrument according to claim 11, wherein the toothed rack and the locking element are configured and positioned so that, in the locked position, the locking element engages with the teeth of the toothed rack or an undercut opposite to the teeth.
13. The surgical instrument according to claim 11, wherein the locking element engages in a U-shape around the toothed rack, at least in the locked position.