Bipolar mapping and suction instrument

Abstract

The invention relates to a suction instrument for surgical purposes, in particular to a bipolar mapping suction instrument for surgical purposes, and to a system for suction of body fluids and tissue and for monitoring of nerve tissue. The suction instrument comprises a cannula unit comprising an electrically conductive outer cannula, an electrically conductive inner cannula and an insulation. The electrically conductive inner cannula is electrically connected to a first pole of a bipolar electrical connection of a second interface. The electrically conductive inner cannula is arranged concentrically within the outer cannula, which is optionally insulated from the outside. The electrically conductive inner cannula is mechanically connected to a handpiece and / or a first interface. The electrically conductive outer cannula is electrically connected to a second pole of the bipolar electrical connection of the second interface. The insulation is arranged concentrically between the outer cannula and the inner cannula. The insulation is designed to completely electrically insulate the outer cannula and the inner cannula with respect to each other.

Description

TECHNICAL FIELD

[0001] The present invention relates to a suction instrument for surgical purposes, in particular a bipolar mapping suction instrument for surgical purposes, and to a system for suctioning body fluids and tissue and for monitoring neural tissue. BACKGROUND

[0002] Surgical treatment of the human body, for example tumor resection, involves a high risk of accidental nerve damage, which depends on the surgical site in particular. It is particularly important during operations in the vicinity of important functional centers and nerves not to damage the neural tissue in order to prevent motor, sensory and autonomic disorders in the patient, as well as psychological disorders.

[0003] Intraoperative nerve monitoring is an established method for monitoring neural tissue and can be used, for example, during tumor resection, for example in the brain. Interventions in the case of tumors directly adjacent to neural tissue, such as nerves or neural pathways, are particularly dangerous. In order to preserve this neural tissue as much as possible during surgical intervention and in order to identify the pathways of this neural tissue, intraoperative nerve monitoring is used in clinical practice. Here, the tissue to be examined is stimulated and it is checked whether a stimulation response is detected. To this end, the surgeon or another member of the surgical staff places a stimulation probe or stimulation electrode on the tissue and stimulates it, for example electrically, during the operation. At the same time, an evoked potential, for example an electromyogram (EMG), is obtained from the patient, usually via a conductive electrode, for example a needle electrode or a surface electrode, and the response signal is presented to the surgeon on a nerve monitor for interpretation. It can thus be determined whether healthy tissue is involved. In order to identify neural pathways, the surgeon scans the surgical area with the stimulation probe. Furthermore, based on the stimulation strength used, it is possible to estimate the distance to the motor conduction pathway. The distinction between healthy and tumor tissue allows more efficient tumor resection.

[0004] Furthermore, during surgery, the surgical site must be as free as possible of (body) fluids, regardless of the location of the tumor, in order not to hinder the surgeon's view. In order for the surgeon or the operator to be able to observe the surgical site unhindered, the surgical site should be as free as possible of body fluids, such as blood or other body fluids. This enables the surgeon to identify tissue that needs to be preserved at an early stage.

[0005] For example, in tumor resection, depending on the tumor and the surgical site, the operation is carried out in a minimally invasive manner through a small skin incision or through a natural body orifice. Furthermore, for larger tumors, an "open" operation with a larger skin incision can be necessary. The choice of the appropriate surgical technique depends on the site and extent of the tumor, although the goal of all methods is to remove the tumor as extensively as possible without affecting the neural tissue and its function.

[0006] Based on this, the object is therefore to aspirate tumor tissue and body fluids, while at the same time continuously localizing nerve tissue and monitoring its function during surgery, for example tumor resection, in order to avoid nerve damage with possible consequences for the patient. It is desirable to have an instrument that continuously stimulates the tissue and provides the surgeon with feedback as to whether the tissue is tissue that needs to be removed. At the same time, nerve tissue and its flow should be recognized and preserved. (Body) fluids should be able to be aspirated at any time, so that the user can observe the dry surgical site without restriction.

[0007] In order to achieve both objectives, a special suction device is used, which can both aspirate body fluids, such as blood or irrigation medium, and electrically stimulate the tissue. In a monopolar suction device, only one stimulation pole is located on the suction device itself. At least one additional counter electrode or auxiliary electrode, for example a needle electrode or a surface electrode, is attached as a second pole. The placement of needle electrodes usually carries the risk of bleeding, which is why a more patient-friendly method is needed. Furthermore, with this method, the distance between the two stimulation poles is so great that only a high-sensitivity, but not selective, measurement is possible.

[0008] This is a situation that needs to be improved. SUMMARY

[0009] In view of this, the object of the present invention is to combine intraoperative nerve monitoring with tissue resection or removal of body fluids from the surgical site and also to eliminate or at least alleviate the disadvantages of the prior art.

[0010] According to the invention, this object is achieved by a suction instrument for surgical purposes, in particular a bipolar mapping suction instrument for surgical purposes, comprising a handpiece, a first interface configured to establish at least one fluid connection with an external suction device and / or an external irrigation device, and a second interface configured to establish a bipolar electrical connection with an external stimulation device, and

[0011] a cannula unit extending in an axial direction from the handpiece and mechanically connected to the handpiece at a proximal end of the cannula unit, the cannula unit comprising

[0012] an electrically conductive inner cannula electrically connected to a first pole of the bipolar electrical connection of the second interface,

[0013] an electrically conductive outer cannula electrically connected to a second pole of the bipolar electrical connection of the second interface, wherein the electrically conductive inner cannula is arranged concentrically in the outer cannula and fluidically connected to the first interface, and

[0014] - an insulation, which is arranged concentrically between the outer cannula and the inner cannula and which is configured to fully electrically insulate the outer cannula and the inner cannula with respect to each other.

[0015] Alternatively, the object is also solved by a system for aspirating body fluids and tissue and for monitoring neural tissue having the features of the further independent patent claim. Further embodiments are the subject of the respective dependent patent claims.

[0016] The aspiration device and system according to the present application are suitable for monopolar or bipolar stimulation of any kind of tissue to distinguish between tumor tissue and healthy tissue and to locate surrounding neural tissue and its pathways, as well as for parallel or sequential aspiration of tissue and body fluids, such as blood. Thus, neural damage can be avoided during a surgical procedure.

[0017] According to a first aspect of the present application, an aspiration instrument for surgical purposes, in particular a bipolar mapping aspiration instrument, comprises a handpiece, a first interface, a second interface and a cannula unit. The first interface is configured to establish at least one fluid connection with an external aspiration device and additionally or alternatively with an irrigation device. The second interface is configured to establish a bipolar electrical connection with an external stimulation device. The cannula unit extends from the handpiece in an axial direction and is mechanically connected to the handpiece at a proximal end of the cannula unit. The cannula unit comprises an electrically conductive outer cannula, an electrically conductive inner cannula and an insulation. The electrically conductive inner cannula is electrically connected to a first pole of the bipolar electrical connection of the second interface. The electrically conductive inner cannula is arranged concentrically within the outer cannula. The electrically conductive inner cannula is fluidly connected to the first interface. The electrically conductive outer cannula is electrically connected to a second pole of the bipolar electrical connection of the second interface. The insulation is arranged concentrically between the outer cannula and the inner cannula. The insulation is configured to fully electrically insulate the outer cannula and the inner cannula with respect to each other.

[0018] According to a second aspect of the present invention, a system for aspirating body fluids and tissue and additionally or alternatively irrigating a surgical site and monitoring neural tissue comprises an aspiration instrument according to the first aspect of the present invention, an aspiration device and additionally or alternatively an irrigation device, at least one, preferably two, electrically conductive electrodes, and an intraoperative neuromonitoring (IOM) system. The at least one, preferably two, electrically conductive electrodes can be attached to a patient in the vicinity of neural tissue to be monitored. The IOM system comprises a stimulation device and a monitoring device. The monitoring device is communicatively connected to the stimulation device. The aspiration device and additionally or alternatively the irrigation device are fluidically connected to the aspiration device via a first interface by a fluid line, in particular a semi-rigid tube. The stimulation device of the IOM system is electrically connected to the aspiration device in a monopolar way or alternatively in a bipolar way via a second interface by a monopolar connection or alternatively a bipolar connection, in particular a monopolar cable or alternatively a bipolar cable. The stimulation device is configured to electrically stimulate tissue via at least one of the two cannulas (monopolar stimulation) and additionally or alternatively via the two cannulas (bipolar stimulation). The monitoring device is electrically connected to the at least one electrically conductive electrode, preferably at least two electrically conductive electrodes, and is configured to monitor a stimulation response recorded by the electrically conductive electrodes, e.g. needle electrodes or surface electrodes, and additionally or alternatively to output this stimulation response acoustically and additionally or alternatively visually to a user.

[0019] In the context of the present invention, the term fluid transfer is understood to mean that a liquid or gaseous fluid can be tightly conveyed along a fluid transfer conduit or through a fluid transfer interface. In this context, the term tightly is understood to mean that no leakage occurs which would interfere with the operation of the aspiration device.

[0020] In the context of the present invention, the term electric is understood to mean that both electric current and information can be transmitted via an electrical connection or via an electrical interface. In this context, an electrical line or electrical connection or electrical interface can have several electrical lines or several electrical connections or several electrical contacts, e.g. plugs or sockets, through which not only information can be transmitted serially, but also information can be transmitted in parallel.

[0021] In the following, the terms "proximal" and "distal" are used in the following way: The definition is related to the user. "Distal" means the end which is further away from the user (end towards the aspiration device). Correspondingly, "proximal" means the end which is closer to the user (in this case, the handpiece which the user holds).

[0022] In this context, the surgical purpose is understood to mean all purposes which can be achieved using the aspiration device in the context of a surgical procedure, e.g. minimally invasive tumor resection.

[0023] A user, for example a surgeon, uses the handpiece to manipulate the suction device. The user can hold and guide the suction device by the handpiece. The handpiece can preferably be made of a plastic material. Furthermore, the handpiece can particularly preferably be an ergonomic shape so that the handpiece sits in the user's hand when the user guides the suction device.

[0024] The handpiece is mechanically connected to the cannula unit. The handpiece and the cannula unit are preferably firmly connected to each other so that a rotation or translation relative to each other is not possible. The handpiece and the cannula unit can be mechanically connected to each other by a positive locking and additionally or alternatively by a frictional locking and additionally or alternatively by a material locking. In particular, the outer cannula of the cannula unit and additionally or alternatively the inner cannula of the cannula unit can be mechanically connected to the handpiece for this purpose in order to provide a mechanical connection between the cannula unit and the handpiece.

[0025] The first interface serves to connect an external suction device and additionally or alternatively an external irrigation device to the suction instrument. For this purpose, the first interface can be of a standardized design. The first interface can be configured in the form of one or several sockets, for example, with a semi-rigid tube having one fluid line, or a semi-rigid tube having two fluid lines integrated therein, or two separate semi-rigid tubes can be connected to the socket. By means of the first interface, a fluid transfer connection is established between the inner cannula, more precisely the inner lumen of the inner cannula, and the suction device and additionally or alternatively the irrigation device.

[0026] The first interface can be arranged on the handpiece or alternatively on the cannula unit. If the first interface is arranged on the cannula unit, the first interface is directly fluidically connected to the inner cannula of the cannula unit or its lumen. If the first interface is arranged on the handpiece, for example at the proximal end of the handpiece or behind the gripping surface of the handpiece, the first interface is mechanically connected, for example by a connector, to the handpiece. Alternatively, the handpiece and the first interface can be of one-piece or unitary design. Furthermore, the first interface is fluidically connected to the inner cannula by one or more fluid channels in the handpiece. For this purpose, for example, the interior of the handpiece can be hollow and a fluid transfer connection is established between the first interface arranged on the handpiece in this example and the inner cannula or its lumen through this hollow space. The fluid channels of the handpiece, for example the cavities of the interior, are fluidically and tightly connected to the inner cannula.

[0027] Thus, a negative pressure or vacuum can be provided through the first interface from a connected suction device, which can be used to aspirate body fluids, such as blood and tissue, such as tumor tissue, from a site, a surgical site. Additionally or alternatively, a flushing medium, such as an isotonic saline solution, can be provided through the first interface from a connected flushing device at a predetermined pressure, so that the site can be flushed. If the suction device and the flushing device are connected together through the first interface in a fluid-conveying manner to the suction device, the tissue can be wetted and cleaned by the flushing medium from the flushing device and adhesions can be unbound, and the flushing medium as well as blood and tissue can be sucked away by the negative pressure of the suction device.

[0028] The second interface is used to connect an external stimulation device. To this end, the interface can be standardized, for example in accordance with DIN 42802 (touchproof plug / socket). The second interface can be configured in the form of one or more plugs or one or more sockets. The plug can have several terminals and the socket can have several receptacles for the terminals. A corresponding cable can be connected to the second interface. Alternatively, the second interface itself can comprise at least one, in particular two or more, such cables. Through the second interface, an electrical connection is established between the inner cannula and the stimulation device, and additionally or alternatively between the outer cannula and the stimulation device.

[0029] The second interface can be arranged on the handpiece, or alternatively on the cannula unit. When the second interface is arranged on the cannula unit, a first pole of a bipolar electrical connection of the second interface is directly electrically connected to the inner cannula of the cannula unit, and a second pole of the bipolar electrical connection of the second interface is electrically connected to the outer cannula of the cannula unit. When the second interface is arranged on the handpiece, for example at a distal end of the handpiece or in front of a gripping surface of the handpiece, a first pole of a bipolar electrical connection of the second interface is electrically connected to the inner cannula through a first electrical lead in the handpiece or on the handpiece, and a second pole of the bipolar electrical connection of the second interface is electrically connected to the outer cannula through a second electrical lead in the handpiece or on the handpiece. For example, the first electrical lead and the second electrical lead in the handpiece or on the handpiece can be a combined electrical lead.

[0030] Thus, through the second interface, a current with a voltage can be provided at one of the two poles by a connected stimulation device, so that a current with a voltage is provided at the inner cannula (first pole) or at the outer cannula (second pole), or, alternatively, a current with a voltage is provided between the two poles, and thus between the inner cannula and the outer cannula, through which a tissue, in particular a neural tissue, can be electrically stimulated.

[0031] The stimulation response of the stimulated (nerve) tissue can then be recorded by electrically conductive electrodes (e.g. needle electrodes or surface electrodes) attached to the patient in the vicinity of the nerve tissue to be monitored and electrically transmitted to an electrically connected monitoring device for further analysis.

[0032] The outer cannula is configured to be electrically conductive so that it can be used as an electrode for stimulating the (nerve) tissue or, alternatively, for recording or detecting the stimulation response of the stimulated tissue. The outer cannula can be electrically insulated from the environment (e.g. an electrically insulating plastic / polymer coating, paint or ceramic). However, this is not absolutely necessary in the case of bipolar stimulation, since in this case the electrical current only flows between the two stimulation contacts, i.e. from the inner cannula to the outer cannula or from the outer cannula to the inner cannula. If monopolar stimulation is carried out via the inner cannula and a separate counter electrode (e.g. needle electrode or surface electrode) that has been attached to the patient at the appropriate site, the outer cannula can be insulated from the outside. On the other hand, in the case of monopolar stimulation via the outer cannula and the counter electrode, the outer cannula must be insulated from the outside in order to deliver the electrical current so that the tissue is stimulated only by the tip of the cannula unit and not at the shaft or outer surface of the outer cannula.

[0033] The inner cannula is also configured to be electrically conductive so that it can be used as an electrode for stimulating the tissue or, alternatively, for recording or detecting the stimulation response of the stimulated tissue. The inner cannula is arranged concentrically within the outer cannula and extends from the proximal end of the outer cannula to the tip (distal end) of the outer cannula. A lumen is extended within the inner cannula which is able to convey body fluids, tissue or gas. The inner cannula can extend from the proximal end of the outer cannula so as to extend into the interior of the handpiece.

[0034] The interior of the handpiece can be empty (hollow) or can be divided into, for example, two cavities extending parallel to one another to the point of origin of the inner cannula, for example by means of a partition wall extending axially in the handpiece. The cavities represent separate fluid lines for body fluids or for negative pressure and irrigation media. One cavity can be fluidically connected to the suction device via the first interface and, optionally, via a corresponding fluid line in the handpiece. The other cavity can be fluidically connected to the irrigation device via the first interface and, optionally, via a corresponding fluid line in the handpiece.

[0035] An insulating piece is arranged between the outer cannula and the inner cannula. The insulating piece can be formed as a one-piece tube extending concentrically along the two cannulas and electrically insulating the inner tube surface of the outer cannula from the outer tube surface of the inner cannula to prevent an electrical short circuit. The insulating piece can also be formed as one or more spacers (e.g. rings) which prevent contact between the inner tube surface of the outer cannula and the outer tube surface of the inner cannula, thereby preventing an electrical short circuit. The electrical insulation of the two cannulas makes it possible for them to be used as stimulation electrodes for stimulating the (nerve) tissue.

[0036] In addition to the suction instrument described above, the system comprises a suction device and additionally or alternatively a flushing device, at least one, preferably two, electrically conductive electrodes, and an IOM system, each of the suction device and the flushing device being fluidically connected to the suction instrument by fluid lines (semi-rigid tubes) connected to the first interface.

[0037] The IOM system comprises a stimulation device connected to the second interface in monopolar or alternatively bipolar fashion by a monopolar connection (cable) or alternatively a bipolar connection (cable) and thus in monopolar or alternatively bipolar fashion to the outer and inner cannula of the cannula unit of the suction device, respectively. In addition, the IOM system comprises a monitoring device communicatively connected to the stimulation device, for example by a wiring or bus system.

[0038] For bipolar stimulation, the stimulation device can electrically stimulate tissue through both cannulae. For monopolar stimulation, the stimulation device can electrically stimulate tissue through one of the two cannulae, but due to the more concentrated excitation and insulation, it is preferred to electrically stimulate tissue through the inner cannula. In addition, a counter electrode (needle electrode or surface electrode) is placed on the patient to enable monopolar stimulation. The stimulation response of the stimulated tissue can be recorded or derived by the at least one, preferably two, electrically conductive electrodes in the system. The recorded stimulation response of the monopolar or alternatively bipolar stimulated tissue (nerve tissue) can be recorded by the monitoring device as a detection signal, additionally or alternatively, and amplified and filtered. Subsequently, the monitoring device provides the optionally amplified or filtered stimulation response or detection signal. The user (e.g. surgeon) monitors the stimulation response or detection signal (e.g. estimated distance to nerve tissue, etc.) with the signal displayed, for example visually or acoustically, on a monitor, for example. Alternatively or additionally, the monitoring device outputs the stimulation response or detection signal to the user visually (e.g. by a display or monitor on which the progress of the stimulation response or detection signal is displayed graphically) or acoustically (e.g. by a signal tone whose volume increases with decreasing distance to the nerve tissue). In both stimulation variants, the stimulation response recorded by the electrically conductive electrodes can be recorded as an evoked potential and thus recorded by the monitoring device as an electrically conductive signal, additionally or alternatively amplified and / or filtered. Subsequently, the monitoring device provides the optionally filtered or amplified stimulation response or derived signal visually, for example on a monitor or tablet, for analysis and monitoring. Alternatively or additionally, the monitoring device outputs the tissue stimulation and / or EMG signal acoustically to the user by a loudspeaker (e.g. by a beep).

[0039] Accordingly, the present invention provides an aspiration instrument and a system comprising the same, which aspirates tissue by two nested cannulas. The aspiration device can aspirate tumor tissue as well as body fluids, so that the user, e.g. a surgeon, can achieve an unobstructed view of the surgical site. By an alternative or additional irrigation function, the site can also be irrigated to prevent drying and to unstick or dry surgical residues. This enables a reliable differentiation of tumor tissue and healthy tissue and enables the localization of nerves in the tissue, so that a patient-friendly resection is achieved. The aspiration instrument or bipolar mapping aspiration instrument and system according to the present invention can be used, for example, for a tumor resection sparing the patient. The combination of the surgical aspiration device and the bipolar stimulation probe implemented by the aspiration device enables the aspiration of tumor tissue and body fluids on-site during a tumor resection, for example on the peripheral and central nervous system, and at the same time a continuous, dynamic identification (mapping) of the nerve tissue, for example of the motor pathways (pyramidal pathways) of the central nervous system. A main advantage of the present invention is that it no longer requires a cumbersome switching between a stimulation probe or stimulation electrode and an aspiration instrument or irrigation instrument, or the simultaneous use of both instruments on-site. In particular, the bipolar stimulation, i.e. the stimulation of tissue by two cannulas, has the advantage that it no longer requires the attachment of a second electrode as a counter electrode (needle electrode or surface electrode) for stimulating the patient. The current flows between the two predetermined electrode contacts (inner cannula and outer cannula) in a more controllable manner and does not spread into the surrounding tissue, so that a very concentrated stimulation of the tissue and a detailed examination are possible.

[0040] Accordingly, the tissue can be stimulated bipolarly or monopolarly as required, and the best type of stimulation can be applied during a surgical procedure.

[0041] According to a further embodiment of the present invention, the aspiration instrument further comprises an illumination device. The illumination device comprises a light outlet, a light guide, and additionally or alternatively a light source. The light outlet is arranged on the handpiece or, alternatively, on the cannula unit and is configured to allow light to be emitted from the light guide or, alternatively, from the light source in the direction of the surgical site. The light guide is configured to guide light emitted from the light source or, alternatively, from an external light source to the light outlet.

[0042] The light outlet is arranged in a region of the tip of the cannula unit or at the distal end of the handpiece. The light outlet can comprise a lens for focusing or diffusing the emitted light. The light outlet can directly emit light from the light source, such as directly from a light source arranged at the distal end of the handpiece. Alternatively, the light outlet can emit light that has been guided through the light guide from the light source or an external light source to the light outlet.

[0043] For example, the light guide can be an optical fiber or an optical fiber bundle along which light from the (external) light source can be guided. For example, the light guide can extend from the proximal end of the cannula unit to its distal end and guide light from a light source arranged at the exemplary distal end of the handpiece to the distal end of the cannula unit. The light guide can extend along the outer tube surface of the outer cannula. Alternatively, the light guide can extend along the inner tube surface of the outer cannula, wherein the light guide can be embedded in the insulation and optionally can extend along the outer tube surface of the inner cannula. Also alternatively, the light guide can extend along the outer tube surface of the inner cannula, wherein the light guide can be embedded in the insulation. Or alternatively, the light guide can extend along the inner tube surface of the inner cannula. Alternatively, the light guide can extend from the external light source through the handpiece and / or the cannula unit to the light outlet, thereby guiding externally generated light to the light outlet.

[0044] The light guide is optically connected with the light source or an external light source. For example, the light source is either enclosed by the suction instrument and integrated into the handpiece or the light source is an external light source. The external light source can be a stand-alone external device or can be enclosed by an external device, e.g. a stimulation device or an IOM system. The light source enclosed by the suction instrument can be powered, e.g. through the second interface. The light source or the external light source can preferably be an LED. The LED can be electrically connected to a power source, wherein the power source is e.g. comprised in the stimulation device or the IOM system and powers the LED. The LED can be directly integrated on or in the handpiece, preferably at the distal end of the handpiece. Alternatively, the LED can be directly arranged on the cannula unit.

[0045] With light directly emitted from the light source at the light outlet or light emitted from the light guide at the light outlet, the surgical site can be better illuminated to enable a better observation of the surgical structures and tissue arranged at the site by the user or surgeon and a better differentiation of them.

[0046] According to another aspect of the present application, the suction instrument further comprises a tracking element. The tracking element is configured to be detected by an external navigation device. The tracking element is fixedly or releasably mechanically connected to the handpiece or the cannula unit.

[0047] The tracking element can be an active element (e.g. a light emitting diode, an electromagnetic element) or can be a passive tracking element (e.g. an optical marker). The tracking element comprises at least one, preferably three (active or passive) markers, which are arranged in a predetermined geometric shape relative to each other (e.g. three tracking balls are arranged on the tracking element in a predetermined non-equilateral triangle). The markers can be detected in space by a navigation device (e.g. a stereo camera, two electromagnetic sensors, etc.). From the position and pose (position and orientation) of the markers, the navigation system can indicate the relative position and pose of the suction instrument relative to the patient and the registered image data of the patient.

[0048] The tracking element can be detachably mechanically connected to the handpiece or directly to the cannula unit, for example by screwing in or by a snap-in mechanism, or alternatively firmly or rigidly mechanically connected, for example to the proximal end of the handpiece or to the cannula unit.

[0049] By means of the tracking element, the user or surgeon can be shown the position and pose of the suction instrument relative to the patient and in the registered image data of the patient, whereby the user or surgeon can identify the position and pose of the tip of the suction instrument at the site, i.e. in the patient, even if this site cannot be observed from the outside.

[0050] According to a further embodiment of the present application, the outer cannula and optionally the inner cannula and additionally or alternatively the insulation are biocompatible or bioinert. In particular, the outer cannula and additionally or alternatively the inner cannula are made of stainless steel and additionally or alternatively the insulation is made of plastic, in particular of polyamide.

[0051] The biocompatible design ensures that small amounts of substances (e.g. ions) radiated by the outer cannula or the inner cannula or the insulation do not induce negative reactions (e.g. allergies, changes in pH value, poisoning, etc.) in the site or the patient. The bioinert design ensures that no substances are released from the outer cannula or the inner cannula or the insulation into the site.

[0052] According to a further embodiment of the present application, the outer diameter of the cannula unit ranges from 1 mm [millimeter] to 15 mm.

[0053] Depending on the type of surgical procedure and the location of the surgical site on the patient, different diameters of the cannula unit or the outer cannula can be useful.

[0054] The wall thickness of the outer cannula and additionally or alternatively of the inner cannula can be 1% [percent] to 10% of the outer diameter of the cannula unit. In this regard, the outer cannula and the inner cannula can have the same wall thickness or each cannula can have a different wall thickness.

[0055] The wall thickness allows the area of the outer cannula and the inner cannula that is in contact with the tissue to be adjusted to the optimal electrical properties for stimulating the tissue and recording or detecting the stimulation response.

[0056] According to a further embodiment of the present application, the length of the cannula unit is 10 cm [centimeter] to 40 cm.

[0057] Depending on the type of surgical procedure and the location of the surgical site on the patient, different lengths of the cannula unit, i.e. of the outer cannula and the inner cannula, can be useful.

[0058] According to a further embodiment of the application, the cannula unit is straight or has an angle in the proximal region of 10° to 60°, preferably 30°.

[0059] Depending on the type of surgery and the location of the surgical site on the patient, the cannula unit or both cannula units can not only be straight, but also curved at the proximal end of the handpiece at an angle, preferably at an angle of 30°, so that the user's view of the structures and tissues in the surgical site is not influenced by his own hand.

[0060] According to a further embodiment of the application, the handpiece comprises a suction control orifice fluidically connected to the inner cannula.

[0061] The suction control orifice is fluidically connected to the lumen of the inner cannula by means of a corresponding fluid line in the handpiece. For example, the suction control orifice can be fluidically connected to a cavity in the handpiece, which connects the first interface to the inner cannula or its lumen. Furthermore, the suction control orifice can be tightly closed by the user's finger, preferably the thumb. Alternatively, the suction control opening can also be closed with a (finger-actuated) slider or flap. Preferably, the suction control opening is arranged on the upper side of the handpiece.

[0062] If the suction control opening is free and uncovered, the negative pressure or vacuum at the tip (distal end) of the cannula unit is reduced, which reduces the suction force. The more the suction control opening is closed (with the finger), the greater the suction force at the tip of the cannula unit becomes again. Thus, the suction control opening serves to control the suction strength. During the suction process, the user can close the suction control opening (with the thumb) and accordingly increase the suction at the tip of the cannula unit. For example, if undesired tissue (e.g. nerve tissue) is sucked by the tip of the cannula unit during surgery, the suction at the tip can be reduced by opening the suction control opening (lifting the thumb) and the tissue at the tip will loosen.

[0063] According to a further embodiment, the cannula unit is fixedly or releasably mechanically connected to the handpiece at the proximal end of the cannula unit.

[0064] For example, the cannula unit can be screwed into or fixed in or on the handpiece, for example by a spring lock or a snap lock or a luer lock, and thus can be detachably mechanically connected to the handpiece. Alternatively, the cannula unit can be firmly mechanically connected to the handpiece, for example by adhesion or by casting into the handpiece. If fluid lines and additionally or alternatively electrical lines are provided in the handpiece for connecting the first and second cannula to the first and second interface, respectively, corresponding seals or contacts are provided on the handpiece to ensure fluid transfer or electrical connection from the outer and inner cannula to the first and second interface, respectively.

[0065] This has the advantage that, in particular if the first interface and the second interface are arranged directly on the cannula unit, the handpiece can be constructed in a particularly simple manner (without electrical lines or fluid channels). Furthermore, existing standard handpieces can be retrofitted with a cannula unit according to the application. Furthermore, the handpiece and the cannula unit can be separated from one another after a surgical procedure, then cleaned separately, and, for example, the cannula unit can be sterilized, while the handpiece is only disinfected.

[0066] The suction apparatus and its individual parts can be configured for single or multiple use. Thus, the materials used for the manufacture can also be used for possible reprocessing, for example with ethylene oxide.

[0067] According to a further embodiment of the application, the suction apparatus further comprises a first controllable valve and a second controllable valve. The inner cannula is fluidically connected to the outer suction apparatus via the first controllable valve and the first fluid port of the first interface. Additionally or alternatively, the inner cannula is fluidically connected to the outer irrigation device via the second controllable valve and the second fluid port of the first interface.

[0068] The controllable valves are configured as controllable check valves or flow control valves. Both controllable valves can be locked / unlocked in idle and released / opened upon actuation or, conversely, released / opened in idle and locked / unlocked upon actuation. The controllable valves can be mechanically driven (e.g. by a knob, a switch, a lever, a tap, etc.) and additionally or alternatively electrically driven (by a circuit with appropriate wiring) and additionally or alternatively magnetically driven (integrated or externally switchable electromagnet), i.e. movable from an open position to a closed position and from a closed position to an open position.

[0069] By means of the first controllable valve and the second controllable valve, the suction device or the irrigation device can be selectively opened or closed, so that the surgical site can be suctioned or irrigated as required.

[0070] According to a further embodiment of the application, the handpiece further comprises a first operating element. The first operating element is configured to switch between a suction function of the outer suction apparatus and an irrigation function of the outer irrigation device.

[0071] The first operating element is thereby configured to selectively switch between the suction function and the irrigation function, so that tissue or body fluids can be suctioned as required or the surgical site can be irrigated. By actuating the first operating element, the suction apparatus can be used to suction body fluids, tissue or gas or to irrigate the surgical site.

[0072] To this end, the suction apparatus can comprise, for example, a first controllable valve and a second controllable valve. In this aspect, the first operating element is configured to open the first controllable valve and simultaneously close the second controllable valve, and to close the first controllable valve and simultaneously open the second controllable valve. Optionally, the first operating element can additionally be configured to close both controllable valves.

[0073] Alternatively, both valves or a single valve can be integrated at the fluid transfer connection of the first interface with the suction device and / or the irrigation device. Also alternatively, the external suction device and the external irrigation device can also be controlled, i.e. switched on and off, by the first operating element. To this end, the first operating element is communicatively connected with the external suction device and / or the external irrigation device, for example via the first interface or the second interface. In these exemplary embodiments, the controllable valves in the handpiece or on the handpiece can be dispensed with.

[0074] For example, the first operating element can be configured as a switch on the handpiece or, alternatively, as a switch on the cannula unit, which controls the first controllable valve and the second controllable valve, for example mechanically, or the external suction device and the external irrigation device communicatively.

[0075] For example, the user can operate the first operating element (switch) with a finger. Preferably, the first operating element is arranged on a side surface of the handpiece and can be operated with the thumb or index finger.

[0076] The first operating element can be moved into a first position (e.g. the switch is always flipped up / right) and a second position (e.g. the switch is always flipped down / left). In the first position, the first operating element can open the suction function and close the washing function to allow the suction of body fluids while preventing simultaneous washing of the surgical site. This can be done, for example, by the first operating element opening the external suction device and closing the external irrigation device. Alternatively, the first operating element can simultaneously open the first controllable valve and close the second controllable valve. In the second position, the first operating element can close the suction function and open the irrigation function to allow irrigation by the irrigation fluid while preventing simultaneous suction of the surgical site. This can be done, for example, by the first operating element closing the external suction device and opening the external irrigation device. Alternatively, the first operating element can simultaneously close the first controllable valve and open the second controllable valve. Thus, only one function can be performed at a time by operating the switch: suction or irrigation.

[0077] Optionally, the first operating element can additionally be moved into a third position (e.g. the switch is switched to an intermediate or neutral position). In the third position, the first operating element can close the external suction device and the external irrigation device, or alternatively, close the first controllable valve and simultaneously close the second controllable valve. Neither suction nor irrigation is possible so that only pure monopolar or bipolar stimulation can be performed by the suction apparatus.

[0078] By means of the first operating element, the suction device and the irrigation device can be opened and closed, so that the surgical site can be suctioned or irrigated, or neither suctioned nor irrigated, in particular easily and quickly.

[0079] According to a further embodiment of the application, the second interface comprises two connection pins for establishing a monopolar or bipolar connection. Alternatively, the second interface comprises a bipolar cable for making a monopolar or bipolar electrical connection.

[0080] The two connection pins are uninsulated, electrically conductive protrusions, which can have a substantially cylindrical shape. Preferably, the two connection pins are touch-proof connectors, which are particularly preferably configured to comply with DIN 42802. One of the two connection pins is provided for a first pole of a bipolar electrical connection, and the other of the two connection pins is provided for a second pole of a bipolar electrical connection. Alternatively, by connecting a monopolar cable to only one of the two connection pins, preferably to the first pole connected to the inner cannula of the cannula unit, a monopolar connection and thus a monopolar stimulation is possible.

[0081] The two connection pins can be arranged on the handpiece, preferably on the lower side of the handpiece and particularly preferably on the distal end of the lower side of the handpiece, and can be electrically connected to the inner cannula and the outer cannula, for example by means of a lead solder joint or a fusion weld. Alternatively, the two connection pins can be arranged directly on the cannula, preferably on the lower side of the cannula unit and particularly preferably on the proximal end of the lower side of the cannula unit, and are directly electrically connected to the inner cannula and the outer cannula. A cable can be connected to each of the two connection pins for bipolar stimulation, or, alternatively, if monopolar stimulation is required, only one cable can be connected to the connection pin for electrical connection to the stimulation device.

[0082] The advantage here is that the suction instrument can be disconnected from the respective connection cable, if required, for example for cleaning and sterilization.

[0083] Instead of the two connection terminals a bipolar cable can be provided. The bipolar cable can have two plugs at its end, or two terminals in a common plug, or two sockets or two jacks in a common socket, which are preferably touch-proof and particularly preferably configured to comply with DIN 42802. The bipolar cable is either directly connected to the handpiece, preferably to the lower side of the handpiece, particularly preferably to the distal end of the lower side of the handpiece, and electrically connected to the outer sleeve and the inner sleeve, for example by suitable electrical connections, for example by solder joints or welding seams. Alternatively, the bipolar cable is directly connected to the sleeve unit, preferably to the lower side of the sleeve unit, and particularly preferably to the proximal end of the lower side of the sleeve unit, and directly electrically connected to the outer sleeve and the inner sleeve. The stimulation device can be connected to the bipolar cable. If the bipolar cable consists of the second interface, only one of the two sockets or connectors of the bipolar cable can be plugged into the stimulation device to allow monopolar stimulation.

[0084] The advantage is that the cable does not have to be connected to the suction instrument before use, which saves time.

[0085] The two connection terminals or the bipolar cable allow the suction instrument to be electrically connected to the stimulation device in monopolar or bipolar fashion particularly easily and quickly.

[0086] According to a further embodiment of the application, the suction instrument further comprises a second operating element. The second interface is further configured to establish a communication connection of the second operating element with the external stimulation device. The second operating element is configured to switch between monopolar operation and bipolar operation.

[0087] The second operating element can be a switch or the like. The second operating element is movable into two or alternatively three positions (for example, the switch is flipped completely upwards / rightwards, the switch is flipped completely downwards / leftwards, and the switch is flipped to an intermediate or neutral position). In a first position, the second operating element can communicate (for example, a rising edge or the like) to the stimulation device via the second interface that a bipolar operation is to be performed, in which the tissue is stimulated by a current flow between the two sleeves. In a second position, the second operating element can communicate (for example, a falling edge or the like) to the stimulation device via the second interface that a monopolar operation is to be performed, in which the tissue is stimulated by one of the two sleeves. In monopolar stimulation, an external counter electrode is attached in the vicinity of the (nerve) tissue to be stimulated on the patient, and a current or voltage is applied between the respective sleeve and the external counter electrode. The stimulation response of the tissue stimulated by the bipolar or monopolar stimulation is recorded or derived by additional conductive electrodes attached on the patient. In a third position of the second operating element, the stimulation device does not stimulate (neither monopolar nor bipolar), so that only the tissue and body fluids can be suctioned and the surgical site can be irrigated.

[0088] The second operating element can be used to switch between bipolar and monopolar operation as required, so that the user can quickly and easily select the optimum mode. Furthermore, the tissue stimulation can be quickly and completely switched off.

[0089] According to a further aspect of the application, the system further comprises an impedance measurement device, which is communicatively connected to the monitoring unit and configured to perform impedance measurements, or alternatively, the IOM system is configured to perform impedance measurements. Impedance measurements involve measuring the complex resistance of the tissue surrounding the tip of the cannula unit at various frequencies. The system, in particular the monitoring unit, is configured to determine the type of tissue based on the measured impedance and output it to the user.

[0090] Impedance spectroscopy can be performed by the cannula unit of the suction instrument. During a surgical procedure, the electrical impedance of the tissue surrounding the tip of the cannula unit at different frequencies can be measured to determine the type of tissue. This involves, for example, the differentiation of bone, nerve tissue and / or skin, and preferably the differentiation of tumor tissue and healthy tissue (for example in the brain). Thus, the impedance of the tissue is measured, for example, within an annular volume at the uninsulated tip of the cannula unit, wherein the distribution of the electrical current is dependent on the tissue properties. An alternating current with different predetermined frequencies is introduced into the tissue. Depending on the respective frequency, different types of tissue each have a different impedance. The impedance at different predetermined frequencies is characteristic of different types of tissue.

[0091] In impedance spectroscopy, an alternating current signal, for example a predetermined alternating current or voltage, for example but not exclusively in the form of a square wave signal or a sinusoidal signal, is applied to the tissue at the tip of the cannula unit by one of the cannulas. The impedance meter or the IOM system then measures the voltage or current at the other cannula accordingly and calculates the impedance of the tissue by means of a corresponding signal processing chain and / or software.

[0092] The possibility of impedance spectroscopy by the suction instrument also eliminates the need to change instruments, as the signal transfer is also carried out by the system that delivers monopolar stimulation and / or bipolar stimulation. In the bipolar setting, the current or voltage path is advantageously concentrated in the region between the two stimulation poles, whereby the impedance measurement is largely influenced only by the local tissue, while in the monopolar setting the current or voltage path is guided through tissue that is irrelevant to the examination and to a counter electrode (for example a needle electrode or a surface electrode) attached to the patient's body, so that the measurement of the impedance can be influenced.

[0093] The above embodiments and further embodiments can be combined with each other, if useful, as desired. Other possible embodiments, further embodiments and implementation forms of the application also include combinations of features of the application which are not explicitly mentioned before or after the embodiments. In particular, the person skilled in the art will add individual aspects as improvements or supplements to the respective basic embodiment of the application from this. BRIEF DESCRIPTION OF DRAWINGS

[0094] The application is explained in more detail below with reference to the embodiments shown in the schematic drawings, in which

[0095] Figure 1 a schematic view of a suction instrument according to the first aspect of the application is shown,

[0096] Figure 2 a schematic view of a further embodiment of a suction instrument according to the first aspect of the application is shown, Figure 1

[0097] Figure 3 a schematic view of a further embodiment of a suction instrument according to the first aspect of the application is shown,

[0098] Figure 4 a schematic view of a further embodiment of a suction instrument according to the first aspect of the application is shown,

[0099] Figure 5 a schematic view of a further embodiment of a suction instrument according to the first aspect of the application is shown, and

[0100] Figure 6 a schematic view of a system according to the second aspect of the application is shown.

[0101] The accompanying drawings are intended to provide a further understanding of the exemplary embodiments of the application. The embodiments illustrate principles and concepts of the application and are not intended to limit the scope of the application. Numerous advantages and other embodiments are mentioned and will be apparent to the skilled person. The elements of the drawings are not necessarily shown to scale.

[0102] In the drawings, identical elements, features and components have the same function and act in the same way, unless stated otherwise, and each element, feature and component is given the same reference sign. DETAILED DESCRIPTION

[0103] In Figure 1 , a suction instrument 1 according to the first aspect of the application is shown schematically, in this case a bipolar mapping suction instrument. The suction instrument 1 comprises a handpiece 2, a first interface 3, a second interface 4 and a cannula unit 5.

[0104] ​The handpiece 2 is ergonomically shaped and made of plastic (e.g. polyether ether ketone, PEEK, PC / ABS). The surgeon can hold the handpiece 2 in his hand and guide the suction instrument 1 via it during a surgical procedure.

[0105] The first interface 3 is formed as a fluid transfer coupling for a semi-rigid tube (not shown) at a proximal end of the handpiece 2. Both a suction device (not shown) and a flushing device (not shown) can be fluidically connected to the first interface 3 by the semi-rigid tube.

[0106] The second interface 4 is formed as two connector terminals on a distal end of a bottom surface of the handpiece 2 to which a bipolar cable (not shown) can be connected, the second interface 4 comprising a bipolar connection. A stimulation device (not shown) can be electrically connected to the second interface 4 by the bipolar cable and thus can be connected in a bipolar fashion. Alternatively, a unipolar cable can be connected to one of the two connection terminals.

[0107] A proximal end of the cannula unit 5 is firmly mechanically connected to the handpiece 2. The cannula unit 5 extends towards a tip or distal end of the cannula unit 5. Thus, the cannula unit 5 has an angle of 30° downwards in a proximal region of the cannula unit 5.

[0108] The specific structure of the cannula unit 5 is schematically shown in Figure 2 The cannula unit 5 comprises an outer cannula 5.1, an inner cannula 5.2 and an insulation 5.3.

[0109] The outer cannula 5.1 is made of stainless steel and detachably firmly mechanically connected (e.g. screwed, snap-connected, etc.) to the handpiece 2. The outer cannula extends from the handpiece 2 to the tip of the cannula unit 5. Furthermore, the outer cannula 5.1 is mechanically connected to the handpiece 2 and electrically connected to one pole of the bipolar connection of the second interface 4, thereby electrically connected to the stimulation device via electrical contacts (e.g. at a brazing or welding seam) in the handpiece 2. Thus, the outer cannula 5.1, in particular at the tip of the cannula unit 5, can serve as an electrode for monopolar or bipolar stimulation of tissue by the stimulation device.

[0110] The inner cannula 5.2 is made of stainless steel and extends concentrically to the outer cannula 5.1, wherein the inner cannula 5.2 extends from the tip of the cannula unit 5 beyond the proximal end of the outer cannula 5.1 and into the handpiece 2. The inner cannula 5.2 is mechanically connected to the handpiece 2 and electrically connected to the corresponding other pole of the bipolar connection of the second interface 4 and thus electrically connected to the stimulation device via electrical contacts (e.g. at a brazing or welding seam) in the handpiece 2. Thus, the inner cannula 5.2 can serve as an electrode for monopolar or bipolar stimulation of tissue by the stimulation device.

[0111] The insulation 5.3 is formed as a polyamide tube and insulates the outer sleeve 5.1 from the inner sleeve 5.2 extending concentrically therein over its entire length, thus preventing an electrical short circuit between the two sleeves 5.1, 5.2 and enabling a bipolar stimulation of the tissue by the control device.

[0112] The inner sleeve 5.2 has a lumen 5.4 extending from the tip of the sleeve unit 5 to the distal end of the inner sleeve 5.2. The lumen 5.4 of the inner sleeve 5.2 is mechanically connected within the handpiece 2, thus fluidically connected to the first interface 3 and thus to the suction device and the irrigation device. The interior of the handpiece 2 can be formed in two parts, such that a first cavity (not shown) is separated from a second cavity (not shown) by a partition (not shown) up to the beginning of the inner sleeve 5.2. For example, the suction device can be fluidically connected to the first cavity, while the irrigation device can be fluidically connected to the second cavity. Thus, by means of the suction apparatus, a negative pressure or vacuum can be applied to the lumen 5.4 of the inner sleeve 5.2, such that a suction effect is generated at the tip of the sleeve unit 5, with which bodily fluids such as blood and tissue can be sucked out of the surgical site. Similarly, the irrigation device can thus deliver an irrigation medium such as an isotonic saline solution to the tip of the sleeve unit 5 and can irrigate or moisten the surgical site with it. The irrigation medium from the irrigation device can then be sucked out of the surgical site at the tip of the sleeve unit 5 by means of the suction apparatus.

[0113] In Figure 3 , a further embodiment of the suction apparatus 1 according to the first aspect of the application is schematically shown. Figure 3 The suction apparatus 1 of Figure 1 corresponds largely to the suction apparatus 1 of . Therefore, only the differences are explained in the following.

[0114] Instead of two connection terminals, the second interface 4 is here configured as a bipolar cable 4.1. The bipolar cable 4.1 has two sockets 4.2 or, alternatively, two plugs at its free end, which can be directly connected to the IOM system, more precisely to the stimulation device. The bipolar cable 4.1 is firmly integrated into the handpiece 2 and is electrically connected to the outer sleeve 5.1 and the inner sleeve 5.2, respectively, by two electrical contacts 4.3, for example, soldered or welded contacts.

[0115] In Figure 4 , a further embodiment of the suction apparatus 1 according to the first aspect of the application is schematically shown. Figure 4 The suction apparatus 1 of Figure 1 corresponds largely to the suction apparatus 1 of Figure 3 and . Therefore, only the differences are explained in the following.

[0116] The first interface 3 and the second interface 4 are here arranged directly on the sleeve unit 5 instead of on the handpiece 2 or are formed / integral with the sleeve unit. The second interface 4 can be implemented by two connection terminals as shown or, alternatively, by a bipolar cable 4.1 as described for the embodiments in Figure 3 . According to the embodiment examples from Figure 1 and Figure 3 , in each case, only one of the two interfaces 3, 4 can also be arranged directly on the sleeve unit 5 and the other of the two interfaces 3, 4 can be arranged on the handpiece 2.

[0117] In Figure 5 , a further embodiment of the suction instrument 1 according to the first aspect of the application is shown schematically. Figure 5 The suction instrument 1 of Figure 1 , Figure 3 and Figure 4 corresponds largely to the suction instrument 1 of . Thus, only the differences are explained below.

[0118] The suction instrument 1 here also comprises an LED 6, a tracking element 7, a suction control opening 8, a first operating element 9.1 and a second operating element 9.2.

[0119] The LED 6 is integrated in the handpiece 2. The LED 6 can be switched on and off directly on the handpiece 2 or by means of a stimulation device. The LED 6 can alternatively be connected to a light guide (not shown) which extends along the outer tube surface of the outer sleeve 5.1, where it can illuminate the surgical site. The light guide transports the light emitted from a light source or from the LED and illuminates the surgical site.

[0120] The tracking element 7 is here arranged at the proximal end of the handpiece 2. Alternatively, the tracking element 7 can also be arranged at the proximal end of the sleeve unit 5. Exemplarily, the tracking element 7 here has three markers in the form of reflective spheres which are arranged in a predetermined non-equilateral triangle relative to one another. The position and the pose of the tracking element 7 can be determined by an external navigation device 40 with a stereo camera by means of triangulation. Thereby, the position and the pose of the suction instrument 1, in particular of the tip of the sleeve unit 5, can be displayed in the registered or registered image data of the patient.

[0121] The suction control opening 8 is arranged on the upper side of the handpiece 2 and is fluidically connected to the lumen 5.4 of the inner sleeve 5.2 by means of a fluid channel in the handpiece 2. The suction opening 8 can be closed with the thumb, which allows the suction effect at the tip of the sleeve unit 5 to be controlled.

[0122] The first operating element 9.1 is configured as a switch and is arranged on the handpiece 2 or, alternatively, on a suction apparatus or irrigation device (not shown) or, alternatively, on a fluid transfer cable or, alternatively, on the cannula unit 5. By means of the first operating element 9.1, a first controllable valve (not shown) and a second controllable valve (not shown) can be opened and closed in opposite directions, which can be arranged in the handpiece 2, preferably directly at the first interface 3. The first controllable valve can fluidically connect the lumen 5.4 of the inner cannula 5.2 to the first interface 3 and above it to the suction apparatus. The second controllable valve can fluidically connect the lumen 5.4 of the inner cannula 5.2 to the first interface 3 and above it to the irrigation device. If the first controllable valve is opened by the first operating element 9.1 in a first position and at the same time the second controllable valve is closed, a negative pressure can be applied to the tip of the cannula unit 5 by the suction apparatus and body fluids and tissue can be sucked from the surgical site. If the first controllable valve is closed by the first operating element 9.1 in a second position and at the same time the second controllable valve is opened, an irrigation medium can be delivered to the tip of the cannula unit 5 by the irrigation device and the surgical site can be irrigated or moistened. Alternatively, the operating element 9.1 can also be moved into a third position in which both controllable valves are closed.

[0123] The second operating element 9.2 is configured as a switch and is arranged on the handpiece 2. The second operating element 9.2 is used to switch between monopolar operation and bipolar operation. For this purpose, the second operating element 9.2 is communicatively connected to the stimulation device by means of the second interface 4. In a first position of the second operating element 9.2, the control device is caused to operate in bipolar mode and to stimulate tissue by means of both cannulas 5.2 and 5.1, the stimulation response of the stimulated tissue being detected by means of corresponding conductive electrodes (not shown) on the patient. In a second position of the second operating element 9.2, the stimulation device is caused to operate in monopolar mode and to electrically stimulate tissue by means of, for example, the inner cannula 5.2, further requiring an additional counter electrode to be attached to the patient (not shown). The stimulation response of the stimulated tissue can then be detected by means of at least one, preferably two, conductive electrodes (not shown) on the patient. In a third position of the second operating element 9.2, no stimulation is carried out and only a separate irrigation or suction process is performed.

[0124] Figure 6 A system 100 for suctioning body fluids and tissue and monitoring nerve tissue according to the second aspect of the application is schematically illustrated. The system 100 comprises one of the suction apparatuses 1 according to the first aspect of the application, and a suction device 10, an irrigation device 20, an IOM system 30, and at least one, preferably two, additional conductive electrodes 50 (only one conductive electrode is shown for the sake of clarity). Figures 1 to 5 The system 100 further comprises a control device 40, which is communicatively connected to the suction device 10, the irrigation device 20, the IOM system 30, and the at least one, preferably two, additional conductive electrodes 50.

[0125] The IOM system 30 can be a control device comprising a data processing device (e.g. a computer, a laptop, etc.). The IOM system 30 comprises a stimulation device 31 and a monitoring device 32 in communication connection with the stimulation device 31. The stimulation device 31 and the monitoring device 32 can be integrated in the IOM system 30 as separate hardware modules or implemented in the IOM system 30 as software modules.

[0126] The suction apparatus 1 is fluidly connected at the first interface 3 to the suction device 10 and the irrigation device 20 by a semi-rigid tube, which exemplarily comprises two separate fluid lines. Further, at the second interface 4, the suction apparatus 1 is electrically connected to the IOM system 30 or directly to the stimulation device 31 by a bipolar cable.

[0127] If a bipolar operation is selected (e.g. by a second operating element, not shown here), the stimulation device 31 can electrically stimulate the tissue in contact with the tip of the cannula unit 5 by both cannula 5.1 and 5.2. The stimulation response of the stimulated tissue is detected by one, preferably two additional conductive electrodes 50 (here implemented as needle electrodes) attached to the patient and transferred as a conductive signal to the monitoring device 32. The derived signal can be amplified by an amplifier (analog or digital, not shown) and / or filtered by a filter device (not shown). A user (e.g. a surgeon), and alternatively or additionally the monitoring device 32, monitors the rejection signal and compares it to a predetermined threshold value. The monitoring device 32 can output the detection signal, and if the limit value is exceeded, a warning signal is outputted visually by a screen (not shown) and / or acoustically by a loudspeaker (not shown).

[0128] The conductive electrodes 50 (here needle electrodes, or alternatively surface electrodes) are electrically connected to the IOM system 30, or directly to the monitoring device 32 by a cable.

[0129] Assuming the stimulation device 31 is set to a monopolar operation, the tissue in the surgical site is stimulated, e.g. by the inner cannula 5.2 and an additional counter electrode (not shown) attached to the patient and electrically connected to the stimulation device 31 or the IOM system 30, and the stimulation response of the stimulated tissue is detected by the conductive electrodes 50. The detected stimulation response is transferred as a rejection signal to the monitoring device 32. The rejection signal can be amplified by an amplifier (analog or digital, not shown), and additionally or alternatively filtered by a filter device (not shown). A user (e.g. a surgeon), and alternatively or additionally the monitoring unit 32, monitors the rejection signal and compares it to a predetermined threshold value. The monitoring unit 32 can output the rejection signal, and if the limit value is exceeded, a warning signal is outputted visually by a display (not shown) and / or acoustically by a loudspeaker (not shown).

[0130] Prior to performing, for example, an intracerebral tumor resection, the suction instrument 1 is connected via a bipolar cable to the IOM system 30 or directly to the stimulation device 31. The conduction takes place via additionally inserted conductive electrodes 50 in (needle electrodes) muscles or on (surface electrodes) muscles. Preferably, different muscles of the upper extremities or the head are selected, which are provided with several conductive electrodes 50. During the intracerebral tumor resection, the tip of the cannula unit 5 is placed at the surgical site to be resected and the tissue at the tip of the cannula unit 5 between the inner cannula 5.2 and the outer cannula 5.1 is electrically stimulated by adding a current to the inner cannula 5.2. A check is made to see if the stimulation triggers a MEP (motor evoked potential) at the site. If no MEP is evoked on the motor cortex, it is tumor tissue that can be resected, while a successful MEP lead indicates that it is functionally relevant tissue and the stimulation and resection should be continued at another surgical site. Monopolar stimulation is performed via one of the two stimulation poles on the cannula unit 5, preferably the inner cannula 5.2, and an additional counter electrode inserted on the patient. The conductive electrodes 50 are placed according to the bipolar stimulation. In the present case, monopolar stimulation can also be used as a distance radar. Depending on the stimulation intensity, the arrangement distance of the motor pathway can be estimated. Here, the empirical rule of 1 mA per 1 mm applies. This means that a successful MEP stimulation at 5 mA indicates that the pyramidal tract is approximately 5 millimeters away. The tip of the cannula unit 5 can be in the tissue in the check and stimulate it continuously (continuous subcortical mapping) at any time during the critical phases of the operation. Body fluids and tumor tissue are suctioned through the lumen 5.4 of the inner cannula 5.2 without damaging the nerve tracts in the vicinity of the patient. Serious consequences such as injuries and paralysis are largely avoided.

[0131] The following examples serve to illustrate the present application without limiting its scope.

[0132] The subject is a resection of a vestibular schwannoma, also called acoustic neuroma (AKN). A vestibular schwannoma is a tumor that originates from the vestibular cochlear nerve sheath and is directly adjacent to this nerve. The vestibular cochlear nerve is a cranial nerve responsible for hearing and balance functions. Typical complaints of patients with a vestibular schwannoma are dizziness, hearing loss and tinnitus. A pronounced vestibular schwannoma also affects the function of the facial nerve. The removal of the AKN is carried out using intraoperative neuromonitoring in neurosurgical operations. It is important here to monitor the auditory function by means of the acoustic evoked potential and the facial nerve function by means of electromyography (EMG). In this case, electrical stimulation is also used. In the case of a broad-based tumor, it can be advisable to monitor other cranial nerves (e.g. trigeminal and caudal cranial nerves) by means of EMG.

[0133] In this case, the suction instrument 1 or bipolar mapping suction instrument is used to directly stimulate the facial nerve or other cranial nerves. Here both bipolar stimulation and monopolar stimulation can be used, which means that the conductive electrode 50 is placed in the vicinity of the surgical site. The two connection terminals of the second interface 4 of the suction instrument 1 are connected to the stimulation device 31 of the IOM system 30 via a bipolar cable with touchproof sockets. The handpiece 2 of the suction instrument 1 is fluidically connected to the suction device 10 at the first interface 3 via a semi-rigid tube. In this case, the conductive electrode 50 is placed in the target muscle of the cranial nerve. In the case of the facial nerve, for example, this is primarily the mimic muscles of the face.

[0134] After access has been gained through a skin incision and a posterior craniotomy, the overall function of the facial nerve can be estimated by monopolar stimulation, which is activated by the second operating element 9.2 (switch) on the handpiece 2 or one of the sockets of the bipolar cable being disconnected, and the distance to the nerve is approximately determined by stimulation threshold determination.

[0135] During stimulation, the monitor of the IOM system 30 displays the stimulation response in real time for interpretation and acoustically indicates the stimulation response via a loudspeaker. At the same time, suction of body fluids or tissue can be performed using the same instrument. During further surgical procedures, when this is performed in the immediate vicinity of the cranial nerves, the system switches to bipolar function (via the second operating element 9.2 (switch) on the handpiece 2 or the second socket of the bipolar cable is connected to the second interface 4). Individual cranial nerves can now be very selectively identified by bipolar stimulation. Continuous mapping enables the surgeon to accurately know where the cranial nerves and the tumor are located, thus better targetedly preserving the nerves. Once a stimulation response is triggered, it is healthy and functional nerve tissue. On the other hand, if no stimulation response is triggered, it is tumor tissue to be resected. The fact that the suction instrument and the stimulation probe are combined in the suction instrument 1 or bipolar mapping suction instrument allows the nerves to be closely monitored and their function to be controlled, since there is no need to change instruments. Additionally or alternatively, impedance spectroscopy can be used to distinguish between tumor tissue and healthy tissue by measuring the impedance of the tissue around the tip of the cannula 5.

[0136] In order to prevent the surgical site from drying out or surgical residues from drying, the suction instrument 1 can also be used to irrigate the surgical site. The irrigation body fluids and tissue residues can then be suctioned with the suction instrument 1. The suction process or the suction strength can be controlled with the suction control opening 8 on the handpiece 2.

[0137] Light is emitted through LEDs or light guides from the handpiece 2 or alternatively from the tip of the cannula unit 5. This provides additional illumination for the surgical area. Optionally, a tracking element 7 can additionally be inserted onto the handpiece 2. The camera of the navigation system 40 can then determine the current position and pose of the suction instrument 1 and track it. This offers significant advantages, in particular in neurosurgery and spinal surgery, such as increased precision and orientation during minimally invasive surgery.

[0138] The main advantage of the suction instrument 1 or bipolar mapping suction instrument is therefore that there is no longer a need to change instruments in a cumbersome manner. The suction instrument 1 combines a suction instrument with two stimulation contacts. The goal of completely resecting a tumor without damaging nearby nerve bundles is supported and simplified by the suction instrument 1. Furthermore, the operating time is shortened by avoiding the need to change instruments. Bipolar stimulation also enables focused and selective stimulation and identification of nerve pathways, and the switching function between bipolar and monopolar operation enables the two methods to be combined in one instrument.

[0139] Although the application has been fully described above with reference to the preferred embodiments, the application is not limited thereto, but can be modified in various ways.

[0140] List of reference signs

[0141] 1 suction instrument

[0142] 2 handpiece

[0143] 3 first interface

[0144] 4 second interface

[0145] 4.1 bipolar cable

[0146] 4.2 socket

[0147] 4.3 electrical contact

[0148] 5 cannula unit

[0149] 5.1 outer cannula

[0150] 5.2 inner cannula

[0151] 5.3 insulation

[0152] 6 LED

[0153] 7 tracking element

[0154] 8 suction control opening

[0155] 9.1 first operating element

[0156] 9.2 second operating element

[0157] 10 suction device

[0158] 20 irrigation device

[0159] 30 IOM system

[0160] 31 stimulation device

[0161] 32 monitoring device

[0162] 40 navigation device

[0163] 50 deflection electrode

Claims

1. A suction instrument (1) for surgical purposes, the suction instrument (1) comprising: - a handpiece (2); - a first interface (3) configured to establish at least one fluid connection with an external suction device (10) and / or an external irrigation device (20); and - a second interface (4) configured to establish a bipolar electrical connection with an external stimulation device (31); and - a cannula unit (5) extending in an axial direction from the handpiece (2) and being mechanically connected to the handpiece (2) at a proximal end portion of the cannula unit (5), the cannula unit (5) comprising: - an electrically conductive inner cannula (5.2) electrically connected to a first pole of the bipolar electrical connection of the second interface (4); - an electrically conductive outer cannula (5.1) electrically connected to a second pole of the bipolar electrical connection of the second interface (4), wherein the electrically conductive inner cannula (5.2) is arranged concentrically in the outer cannula (5.1) and is fluidically connected to the first interface (3); and - an insulating piece (5.3) arranged concentrically between the outer cannula (5.1) and the inner cannula (5.2) and configured to fully electrically insulate the outer cannula (5.1) and the inner cannula (5.2) relative to each other.

2. The suction instrument (1) according to claim 1, further comprising: - an illumination device comprising a light outlet, a light source (6) and / or a light guide, wherein the light outlet is arranged on the handpiece (2) or, alternatively, on the cannula unit (5) and is configured to allow light to be emitted from the light guide or, alternatively, from the light source (6) in the direction of a surgical site, wherein the light guide is configured to guide light emitted from the light source (6) or, alternatively, from an external light source to the light outlet.

3. The suction instrument (1) according to any one of the preceding claims, further comprising a tracking element (7) configured to be detected by an external navigation device (40), the tracking element (7) being fixedly or detachably mechanically connected to the handpiece (2) or the cannula unit (5).

4. The suction apparatus (1) according to any one of the preceding claims, wherein The outer cannula (5.1) and the inner cannula (5.2) and / or the insulating piece (5.3) are made biocompatible or bioinert.

5. The suction apparatus (1) according to any one of the preceding claims, wherein The outer diameter of the cannula unit (5) is 1 mm to 15 mm.

6. The suction apparatus (1) according to any one of the preceding claims, wherein The length of the cannula unit (5) is 10 cm to 40 cm.

7. The suction apparatus (1) according to any one of the preceding claims, wherein The cannula unit (5) is straight or, alternatively, has a bend in the proximal region with an angle of 10° to 60°.

8. The suction apparatus (1) according to any one of the preceding claims, wherein The handpiece (2) comprises a suction control opening (8) fluidically connected to the inner cannula (5.2).

9. The suction apparatus (1) according to any one of the preceding claims, wherein The cannula unit (5) is fixedly or detachably mechanically connected to the handpiece (2) at a proximal end portion of the cannula unit (5).

10. The suction apparatus (1) according to any one of the preceding claims, further comprising: - a first controllable valve, wherein the inner cannula (5.2) is fluidically connected to the external suction device (10) by the first controllable valve and the first fluid connection of the first interface (3), and / or - a second controllable valve, wherein the inner cannula (5.2) is fluidically connected to the external irrigation device (20) by the second controllable valve and the second fluid connection of the first interface (3).

11. The suction apparatus (1) according to claim 10, wherein The handpiece (2) further comprises a first operating element (9.1) configured to switch between a suction function of the external suction device (10) and an irrigation function of the external irrigation device (20).

12. The suction apparatus (1) according to any one of the preceding claims, wherein The second interface (4) comprises two connection terminals for establishing a monopolar connection or a bipolar connection, or wherein the second interface (4) comprises a bipolar cable for establishing the monopolar or bipolar electrical connection.

13. The suction apparatus (1) according to any one of the preceding claims, wherein, The handpiece (2) further comprises a second operating element (9.2), wherein the second interface (4) is further configured to establish a communication connection of the second operating element with the external stimulation device (31), and wherein the second operating element (9.2) is configured to switch between a monopolar operation and a bipolar operation.

14. A system (100) for suctioning bodily fluids and tissue and / or for irrigating a surgical site and for monitoring neural tissue, comprising: - a suction apparatus (1) according to any one of the preceding claims; - a suction device (10) and / or an irrigation device (20); - at least one electrically conductive electrode (50) attachable to a patient in the vicinity of neural tissue to be monitored; and - an IOM system (30) comprising a stimulation device (31) and a monitoring device (32) communicatively connected to the stimulation device (31), wherein the suction device (10) and / or the irrigation device (20) are fluidically connected to the suction apparatus (1) via the first interface (3) by fluid lines (11, 12), wherein the stimulation device (31) of the IOM system (30) is electrically connected to the suction apparatus (1) in a monopolar or bipolar manner via the second interface (4) by a monopolar or bipolar connection (33), wherein the stimulation device (31) is configured to electrically stimulate tissue by at least one of the two cannulas (5.1, 5.2) and / or by both cannulas (5.1, 5.2), and wherein the monitoring device (32) is electrically connected to the at least two electrically conductive electrodes (50) and is configured to monitor and / or to output an auditory and / or visual stimulation response recorded by the at least two electrically conductive electrodes (50) to a user.

15. The system (100) of claim 14, wherein, The system (100) further comprises an impedance measurement device, which is communicatively connected to the monitoring device (32) and configured to perform impedance measurements, or alternatively, the IOM system (30) is configured to perform the impedance measurements, wherein the complex resistance of the tissue surrounding the tip of the cannula unit (5) is measured at different frequencies for impedance measurements, and wherein the system is configured to determine the type of tissue based on the measured impedance and output it to the user.

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