Medical instrument

Abstract

An instrument for medical or surgical treatment of a human or animal patient according to the invention comprises at least one tool adapted to affect the patient, which is located in the field of view of an optical element. The optical element is arranged in a channel in which a fluid flow can be maintained or can be induced in the distal direction. The light passage window of the optical element is offset in the proximal direction relative to the distal opening of the channel. A closure device is arranged between the light passage window and the opening of the channel, which, as long as it is in the closed position, blocks the passage of substances, in particular of liquid droplets and particles, from the opening to the light passage window. If the closure device is open, it leaves the fluid path and the light path between the light passage window and the opening unblocked. Preferably, the closure device is pneumatically controlled by means of a liquid or gaseous fluid flowing in the channel. By this measure, contamination of the light passage window during operation of the instrument can be reliably avoided or at least reduced to a small extent.

Description

Technical Field

[0001] This invention relates to a medical device for medical or surgical treatment of human or animal patients. In particular, this invention relates to a device comprising a light guide configured to conduct light from the site of action of the device, or additionally or alternatively to direct light to the site of action of the device. Background Technology

[0002] A device comprising a surgical instrument and a cannula is known from EP 2 113 190 A1, the instrument being movable through a working channel of the device. The device includes a light guide by means of which light can be received or emitted at the distal end of the instrument. The cannula has one or more protective elements at its distal end that block the working channel and thus prevent fluid from entering it. When the protective elements are moved distally, the device can remove the protective elements to obtain unrestricted observation of the target area of ​​the instrument.

[0003] EP 3 195 824 A1 discloses an apparatus having a channel in which an optical fiber is longitudinally movably arranged. The optical fiber includes a light-emitting surface at its distal end from which a laser beam can exit. A wiper element 21 is disposed at the distal end of the channel; when the optical fiber is retracted, the wiper element 21 closes the channel and prevents small fluid droplets from entering the channel and depositing on the light-exiting surface of the optical fiber. During forward movement of the optical fiber, the wiper element wipes the light-exiting surface, thus cleaning it.

[0004] Another prior art is formed by EP 1 773 223 B1, which shows an apparatus for argon plasma solidification, wherein the gas guide channel of the apparatus is provided with a closed member.

[0005] There are applications in which another optical element of the light guide device or instrument should or must be immovably supported so that it cannot be moved out of the contaminated area. Summary of the Invention

[0006] Thus, the objective upon which this invention is based is to provide a possibility for keeping the optical components of the device as clean as possible during its use.

[0007] This objective is achieved by means of the apparatus according to claim 1:

[0008] The device according to the invention includes a device body in which at least one channel is formed, the channel comprising a distal end and a proximal end. Alternatively, such a channel may also be formed "on" the device, as it is formed in a separate element connected to the device body, for example by means of one or more clamps (e.g., spring clamps). The following description applies to both embodiments.

[0009] The channel may extend specifically from the distal end of the instrument to its proximal end, where a connecting device may be configured to connect the proximal end of the instrument, along with the channel, to a fluid source. The fluid source may be specifically configured to supply a gaseous fluid, such as air, a pure gas, such as nitrogen, argon, carbon dioxide, or another desired gas, or a mixture of one or more gases. Thus, the fluid source may be further configured to supply the gaseous fluid at a predetermined pressure to regulate the predetermined pressure and / or airflow in the channel. The instrument body may include multiple channels for receiving or discharging fluid at the distal end of the instrument. In particular, the instrument may include one or more gas supply channels and / or one or more suction channels.

[0010] The at least one channel includes a fluid discharge opening at its distal end. This fluid discharge opening is also a light path opening in the device according to the invention, through which light can enter and / or exit. Preferably, the light path opening faces the site of action of the device, where, for example, an electrode can be arranged to be held on the device. Furthermore, multiple electrodes can be provided. One or more such electrodes can be arranged immovably or movably on the device. Additionally, the at least one electrode can be connected to a power source, such as a radio frequency voltage source, to influence biological tissue by means of current. In particular, the power source is configured to provide voltages and currents so high that they are sufficient to generate sparks on the electrodes. For example, the electrode is a cutting electrode, the voltage is a cutting voltage, and the current flowing from the electrode to the tissue is a cutting current. The generated spark emits light, which illuminates the channel via the light path opening.

[0011] Furthermore, the optical element, including the optical path window, is arranged within the channel at a certain distance from the far end of the channel. The optical path window and the optical element are immovably arranged together within the channel. For example, the optical element is immovably connected to the main body of the instrument. Additionally, the optical path window of the optical element is located proximally away from the optical path opening, which is achieved by a gas exhaust opening.

[0012] A closing device is arranged between the light path window and the light path opening. This closing device includes a closing member movable between an open position and a closed position. In its closed position, the closing member is configured to block the channel, preventing particles and, in particular, droplets from passing through, and thus protecting the light path window of the optical element from contamination. In the open position, the closing member is also configured to release the channel for gas passage and for light passage. In particular, even though the optical element should be movably arranged within the channel, the closing member is not controlled by means of the movement of the optical element. There is no operational connection between the optical element and the closing device, and especially its closing member. Preferably, the optical element and the closing member do not contact each other.

[0013] More preferably, the optical element is arranged at a distance from the channel from which the light leaves the opening, remaining constant.

[0014] Optical elements may specifically include, or be implemented by, light guiding devices. For example, an optical element may be a single optical fiber or a bundle of optical fibers, wherein one or more optical fibers each include an optical path window at their respective distal ends.

[0015] For analytical and / or therapeutic purposes, the light path window can be used to radiate light onto the tissue to be treated. The light path window can also be used to receive light generated during tissue treatment, such as the light from a spark burning between an electrode and the tissue, and to supply the light to a light analysis device. Light analysis can be used, for example, to identify the tissue being treated. Other parameters (such as spark stability and similar parameters) can also be determined. For optical evaluation of the light, such as for tissue analysis, optical emission spectroscopy (OES), optical coherence tomography (OCT), Raman spectroscopy, photoacoustic analysis, or other optical methods can be used.

[0016] In different embodiments, the closure member may have one end immovably supported on the instrument, from which the remainder extends away. The supported end can be immovably or movably connected to the instrument, for example, pivotally connected. The remainder of the closure member is thus movably supported on the instrument and can therefore move back and forth between an open position and a closed position. The closure member can be rigid or elastic, stiff or loose.

[0017] Embodiments operating with only a single closing member are possible. Alternatively, embodiments exist with multiple closing members, which are, for example, dispersed apart from each other in the open position and adjacent to each other in the closed position. One or more closing members can be implemented from flexible sheets. They can be elastically pre-stretched to define a conical or pyramidal shape, whereby the contact line is the surface line of the cone or the edge of the pyramid. In the open position, the sheets can be dispersed apart from each other. For this purpose, it is advantageous if the sheets are composed of a flexible material. Additionally or alternatively, the closing members can be made of a stretchable material. For example, the closing member can then have the shape of a cone or pyramid with a small opening at its apex. To open, the material is stretched accordingly, such that the opening at the cone or pyramid is enlarged. In all these embodiments, the base of the pyramid or cone can correspond to the cross-section of the channel.

[0018] Preferably, the closing member is arranged such that it blocks the passage in a resting position, thereby allowing it to transition to an open position by means of pressure and / or the flow of fluid (especially gas) present within the passage. In this sense, the closing member can be configured to be pneumatically actuated. The passage can be a purge gas passage, whereby the pressure of the purge gas or other gas supplied by a fluid source is sufficient to open the closing member.

[0019] Preferably, the light path window includes a cone extending through the fluid discharge opening and thus through the light path opening. The closing member of the closing device is preferably configured such that it blocks the cone in the closed position, but does not block the cone in the open position.

[0020] As described above, the closing device can be controlled by means of fluid guided through the channel, particularly its pressure or flow rate. The fluid acts directly on the closing member, which is thus self-controlled. However, an externally controlled closing device connected to a mechanical actuator can also be provided. For example, the mechanical actuator can be an electromagnetic actuator, a pneumatic actuator, or a manual actuator. For instance, the closing member can be mechanically connected to the actuating base of the instrument to move back and forth in a controlled manner between an open position and a closed position. Electromechanical or pneumatic actuators can also be provided for the movement of the closing member between the open and closed positions.

[0021] The common feature of all embodiments is that the channel between the light path opening and the light path window is released in a controlled and piloted manner by means of airflow or by other actuating elements or actuating media to control the closing device. Unobstructed access (i.e., opening of the closing device) can be particularly limited to the stage where light passage is indeed required. Furthermore, the device can be configured to open and close the closing device synchronously with the supply of fluid (e.g., purifying gas) to the device's action site. Additionally, the device and / or its supply equipment can be configured to begin gas supply through the channel before RF electrode activation and terminate gas supply only after RF electrode activation has ended. However, it can be ensured that the channel between the light path window and the light path opening is merely unobstructed, and that contamination of the light path window is largely avoided if there is also airflow guided to the distal direction from the light path window. In the absence of airflow, the closing device closes the passage from the light path opening to the light path window, thus avoiding contamination of the light path window. When the closing device is open, contamination is avoided by means of airflow that carries away all contaminating particles or droplets from the light path opening.

[0022] The closing device may include a closing member that is elastically pre-stretched toward its closed position, which may be moved to an open position by means of an actuator or the airflow itself. Alternatively, a suction device may be configured to actuate the closing device. For this purpose, the device may include a suction channel opening near the distal end of the device. An actuator connected to the suction channel is then configured to open and close the closing device depending on the presence of negative pressure in the suction channel. The suction channel may be connected to a suction device configured to be activated synchronously with a generator supplying electrodes. Alternatively, the suction device may be configured to be activated before the generator is activated and deactivated only after the generator is deactivated. Generally, it is also possible to ensure that a) the closing device opens only when current is supplied to the electrodes, or b) the closing device opens only when a purge flow is established in the purge channel in a distal direction, or c) the closing device opens only when a proximal flow is established in the suction channel. Attached Figure Description

[0023] Further advantageous details of the invention will emerge from the claims, the description, and the accompanying drawings, which are shown below:

[0024] Figure 1 It is an overview diagram of the supply equipment with the instruments connected to it.

[0025] Figure 2 It is based on Figure 1 A schematic cross-sectional view of the distal end of the instrument.

[0026] Figure 3a and 3bThis is a schematic diagram of a part of the device, showing the closing mechanism in both closed and open states.

[0027] Figures 4a to 9b This is a further embodiment of the instrument and its closing device, which are respectively in the open and closed positions. Detailed Implementation

[0028] Figure 1 An apparatus 10 according to the invention is shown, which is connected to a supply device 11. The device 11 is connected to the apparatus 10 via a corresponding line 12 and is configured to supply at least one operating medium to the apparatus 10. For this purpose, the device 11 may include one or more fluid sources 13, one or more electric generators 14 and / or one or more suction devices 15, which are respectively connected to the line 12 or the apparatus 10 via one or more connectors 16. Figure 1 The invention is shown as a handheld instrument for use in open surgery. However, the invention extends to instruments with other configurations, such as instruments or probes for use in laparoscopy, which can be inserted into the patient through the working channel of an endoscope, a cannula, or other access route.

[0029] The device 10 includes a distal end 17 and a proximal end 18, wherein the proximal end 18 may be implemented by a connector 16 or a segment of its line 12.

[0030] The distal end 17 of the device 10 is in Figure 2 The device 10 is shown separately. It includes a distal segment of the device body 19 through which at least one channel 20 extends. The channel 20 is particularly a fluid guiding channel, such as a gas guiding channel, which preferably extends from the distal end 17 through the device 10 and the entire tubing 12 to the proximal end 18 or connector 16, and connects thereto to the gas source 13. Alternatively, the device 10 may include additional channels, such as a suction channel 21, which also extends from the distal end 17 of the device 10 to its proximal end 18 or connector 16, and connects thereto to the suction device 15. Alternatively, other channels and / or additional channels may be provided to deliver liquids and / or gases to or from the distal end 17 of the device 10, and to allow them to enter or leave there.

[0031] The device 10 may include a tool for influencing biological tissue. Such a tool may be an electrode 22, for example, held in or on the distal end 17 of the device 10 and terminated there, or extending from or terminating shortly before the gas passage opening. The electrode 22 is connected to the generator 14 via a wire 24 extending through line 12 to the proximal end 18 or connector 16. However, multiple electrodes or other tools, such as water jet tools, laser tools, etc., may also be provided.

[0032] Channel 20 includes a distal opening that serves as both a gas exhaust opening and a light path opening 25. Within channel 20, an optical element 26, preferably in the form of an optical fiber, is preferably immovably arranged, and this optical element includes a light path window 27 at its distal end. The light path window 27 may be formed by a surface of the optical element 26, i.e., by a surface of an optical fiber. The light path window 27 and the optical element 26 therewith are preferably arranged axially immovably within channel 20. Preferably, the light path window 27 is arranged with a distance relative to the light path opening 25 in the proximal direction.

[0033] A closing device 28 is disposed between the light path window 27 and the light path opening 25. The closing device 28 is configured to ensure, in a controlled manner, that the passage from the light path opening 25 to the light path window 27 is not obstructed or that the passage from the light path opening 25 to the light path window 27 is obstructed. Preferably, the closing device 28 is controlled by airflow within the channel 20, or by other media, but never by any movement of the optical element 26, which is preferably arranged immovably as described above.

[0034] The first embodiment of the closing device 28 is from Figure 3a and 3b As is evident. The closing device 28 is achieved by a generally conical closing member 29 made of a tensile elastic material, which includes an expandable opening at its tip 30. The tip 30 faces the light path opening 25. The opening at the tip 30 is very narrow, or completely closed under closed conditions. The tensile elasticity of the material of the closing member 29 is so high that the opening 30 can be stretched so wide by means of the pressure present inside the channel 20 that the desired airflow can exit from the light path opening 25, and thus the light path from the light path opening 25 to the light path window 27 is not obstructed. If airflow is present, the closing member 29 is in the open position.

[0035] exist Figure 4a and 4b The modified embodiment is shown below, and the above description applies to this embodiment except for the following features:

[0036] The closing device 28 includes a plurality of closing members 29a, 29b, 29c, which are flexible and form a cone when they abut against each other with their edges. At its tip 30, the sheet-like closing members 29a, 29b, 29c, etc., are connected to each other, and thus close the passage from the light path opening 25 to the light path window 27. However, if the channel 20 is supplied with gas, the closing members 29a, 29b, 29c, etc., will open as... Figure 4b The dispersion is shown. Therefore, the passage for gas and light is not blocked by the closing device 28, and the closing members 29a, 29b, etc. are in the open position.

[0037] The closure member 29 includes a section that is immovably held on the device 10. This section is realized in the closure member 29 by a circular segment that defines the foot of the cone realized by the closure member 29. This segment is immovably connected to the wall of the channel 20. The remainder of the conical closure member 29 can deform in an elastic or flexible manner and can move within this range.

[0038] Figure 5a and 5b Another modified embodiment of the closing device 28 is shown, wherein the closing member 29 is made of a foldable, flexible, and relaxed material, such as a foil hose segment. It collapses in the absence of a gas supply to channel 20 and acts as an irregularly shaped body to block channel 20. In the case of airflow, as... Figure 5b As shown, the closing member 29 unfolds, thus ensuring that the passage for light and gas between the light path window 27 and the light path opening 25 is not obstructed. Furthermore, the above description applies accordingly.

[0039] exist Figures 3a to 5b In the embodiments described above, a channel with a circular cross-section has been used as the basis for illustration. However, similarly, in these embodiments, the channel 20 may have other cross-sections, such as polygonal cross-sections, including triangles, rectangles, hexagons, or polygons with curved edges. Only through Figure 6a and 6b The example illustrates a configuration of a channel 20 with a rectangular cross-section and a closure device 28. Here, the closure device 28 includes a closure member configured as a flap, the circumference of which is equal to the cross-section of the channel 20. The flap-shaped closure member 29 is connected to the wall of the instrument or channel 20 via an edge 31. Thus, the edge 31 can be rigidly anchored, and the closure member 29 can be configured to be flexible. Alternatively, the edge 31 can be implemented in a hinge-like manner. According to... Figure 6a In the blocking position, the closing member 29 blocks the channel 20, and thus the path between the light path window 27 and the light exit opening 25. The closing member 29 can be elastically pre-stretched toward this position. This elastic pre-tension can be provided by the inherent elasticity of the closing member 29 or by a separate spring element. A stop can be provided to the closing member 29, against which the closing member 29 abuts in the blocking position (not shown). This is particularly advantageous in embodiments where the closing member 29 is held at the edge 31 by means of a hinge. Figure 6b The diagram shows the open position of the closing device 28, wherein the closing member 29 moves from its rest position to the open position by means of gas flowing through the channel 20 in the distal direction.

[0040] Figure 7a and7b Another embodiment of the fluid-actuated closure device 28 is shown. In this case, a sac-like hollow closure member 29 is part of the closure device 28, wherein the closure member 29 is also arranged between the light path window 27 and the light path opening 25. The sac-like closure member 29 is fluidly connected to a Venturi opening 32 arranged in the gas path, through which the static pressure of the gas flow becomes effective. Figure 7b As shown, if the static pressure decreases due to the velocity of the airflow, it causes the collapse of the bladder-like closure member 29, so that the closure member 29 does not obstruct the gas path.

[0041] In a preferred embodiment, the bladder-like closure member 29 or an actuator for actuating the closure member 29 is connected to the suction channel 21. Thus, the negative pressure of the suction can be used to actuate the closure device 28. For this purpose, a transverse hole can be provided at the level of element 28 to element 21. Figure 2 This results in a robust system. In particular, it allows for larger pressure differentials and thus greater actuation force.

[0042] In such an embodiment, preferably, the suction device 15 and the purified gas source 13 are synchronized with the RF generator 14. This reduces the acoustic pressure load, which would otherwise be too high during continuous operation.

[0043] The common feature of all the above embodiments is that the closing member 29 of the closing device 28 is pneumatically controlled due to the influence of gas or its flow within the channel 20. However, the closing device 28 can also be controlled externally, such as... Figure 8a and 8b The first, simple example is shown below. The device 10 includes an actuation device 33, which is only schematically shown and can be implemented, for example, by means of an actuation button on the device 10. Thus, the actuation device 33 can be provided to activate or deactivate the device 10, and consequently activate or deactivate the connected generator 14. The actuation device 33 can also be additionally or alternatively configured to trigger other activation or switching processes, such as for triggering spectral analysis of light originating from electrode sparks. Simultaneously, the actuation device can move the closing member 29 via a suitable transmission mechanism, schematically shown here only by means of a double-arm lever 34, such that the closing member 29 is moved according to… Figure 8a In the closed position, the path between the light path window 27 and the light path opening 25 is blocked, and according to Figure 8b The actuation position ensures that the pathway is not blocked.

[0044] from Figure 9a and 9bAs is evident, the actuation of the closing device 28 can also be implemented by means of other actuators, such as a magnetic actuator 35, which allows the closing member 29 to be positioned within the channel 20 according to... Figure 9a The closed position and channel 20 outside, such as Figure 9b The opening position is shown.

[0045] According to the present invention Figure 1 The operation of instrument 10 is as follows:

[0046] For application on a patient, the instrument 10 is moved toward the surgical site and activated by actuation of a suitable switch (e.g., actuation device 33). Alternatively, other switching devices may be used for activation, such as a foot switch or other operating device. The device 11 thereby receives the corresponding switching pulse and activates the corresponding addressed or present device, such as gas source 13, electric generator 14, and / or suction device 15. If the instrument 10 is an electrosurgical instrument, typically, gas source 13 is activated before generator 14 is activated. As long as gas source 13 is not activated, i.e., channel 20 is not supplied with gas, the closure device 28 is closed. Once a sufficiently high pressure and / or airflow is established within channel 20, if used according to Figures 3a to 7b In one of the embodiments, the closing device 28 is at least open.

[0047] After the generator 14 is activated, the light originating from the electrode 22 is received by the optical element 26. The electrode 22 is preferably located in the field of view of the optical element 26, which is located in the cone of view originating from the light path window 27 and extending through the light path opening 25. The spark light originating from the electrode can be detected and can be further transmitted from the optical element 26 to an analytical device, such as a spectral analysis device, which may be part of the instrument 10 or may be configured and arranged separately.

[0048] The airflow propelled through channel 20 and discharged from the light path opening 25 effectively prevents the deposition of particles, droplets, or other contaminants on the light path window 27. However, once the airflow stops, for example because the airflow is interrupted, the closing device 28 closes. Even if contamination continues due to turbulence, such as due to the activation of the suction device 15, which draws liquid or other substances from the operating area via the suction channel 21, the light path window 27 remains sealed and protected from contamination. This also applies if operation continues with electrode 22 without a gas supply through channel 20, and particles are released in this manner.

[0049] Figures 8a to 9b The embodiment of the device 10 shown operates in a similar manner. According to... Figure 8a and 8bIn this embodiment, if the actuation device 33 is activated, the closing device 28 is always unobstructed. Activation of the actuation device 33 can be performed independently of the activation of device 11 and generator 14. For example, low-pressure gas can be supplied to channel 20. If the closing device 28 is closed, it can simultaneously block airflow and light from passing through. The closing device 28 also blocks contaminants from passing through. Once the closing device 28 is opened by means of the actuation device 33, the light path is opened. Simultaneously, airflow is released, preventing contaminants from entering. If airflow is also possible, a bypass parallel to the closing device 28 can be provided if the closing device 28 is closed; this bypass is opaque to light.

[0050] According to Figure 9a and 9b In this embodiment, the closing device 28 is actuated by means of a magnetic actuator 35 or another suitable electric actuator. Applying current to the actuator 35 can be done simultaneously with or independently of applying current to the electrode 22. The latter, for example, if light from the electrode 22 should only be received occasionally. The device 11 connected to the instrument 10 is then configured such that the spectrometer and actuator 35 are simultaneously activated to receive light from the treatment site, for example, for spectral analysis of the light. Thus, the light path window 27 is permanently protected from contamination. Under activated conditions, the airflow through the channel 20 is prevented from contamination. In the deactivated state, the closing device 28 closes and shuts off the light path window 27. This principle applies to all embodiments.

[0051] This invention is not limited to electrosurgical instruments. It can also be used with laser surgical instruments or cryosurgery instruments. In the case of laser surgery, the optical element 26 can be configured to emit a laser beam through the light path opening 25 toward the tissue exiting the light path window 27. When activated, airflow within the channel 20 keeps the light path window 27 free from contamination. When deactivated, the closing device 28 closes, for example, according to… Figures 8a to 9b The principle.

[0052] Instrument 10 may also be a water-jet surgical instrument or other instruments. In addition to or as a replacement for electrode 22, a water channel may be provided to treat the corresponding tissue at the surgical site, preferably within the field of view of optical element 26. Otherwise, the above description applies accordingly.

[0053] The instrument according to the invention for medical or surgical treatment of human or animal patients includes at least one tool adapted to affect the patient, such as an electrode 22, located within the field of view of an optical element 26. The optical element 26 is arranged within a channel 20, in which fluid flow can be maintained or induced in a distal direction. The light path window 27 of the optical element 26 is offset proximally relative to the distal opening 25 of the channel 20. A closure device 28 is arranged between the light path window 27 and the opening 25 of the channel 20, which, when in the closed position, blocks the passage of material, particularly droplets and particles, from the opening 25 to the light path window 27. If the closure device 28 is open, it allows unobstructed fluid and optical paths between the light path window 27 and the opening 25. Preferably, the closure device 28 is pneumatically controlled by means of a liquid or gaseous fluid flowing within the channel 20. This measure reliably prevents, or at least reduces, contamination of the light path window 27 during operation of the instrument 10.

[0054] List of reference numerals in the attached diagram:

[0055] 10 Instruments

[0056] 11 Equipment

[0057] Line 12

[0058] 13 Gas Source

[0059] 14 Electric generator

[0060] 15. Suction device

[0061] 16 connectors

[0062] 17. Distal end of device 10

[0063] 18. Proximal end of device 10

[0064] 19. Main body of the instrument

[0065] 20 channels

[0066] 21 Suction Channels

[0067] 22 electrodes

[0068] 23 Gas passage opening

[0069] 24 Wires

[0070] 25. The distal opening of channel 20, the optical path opening.

[0071] 26 Optical Components / Fiber Optics

[0072] 27 Optical Path Window

[0073] 28 Closing device

[0074] 29 Closed components

[0075] 30 The tip of the closing member 29

[0076] 31 Figure 6a , 6b The edge of the closed member 29 in

[0077] 32 Venturi opening

[0078] 33 Actuation device

[0079] 34 rods

[0080] 35. Actuator.

Claims

1. An instrument (10) for performing medical or surgical treatment on human or animal patients. The device has a body (19) in which at least one channel (20) is formed, the channel comprising a distal end (17) and a proximal end (18). in, The channel (20) is connected to a fluid source (13) at its proximal end (18) and includes an opening (25) at its distal end. It has an optical element (26), which includes at least one optical path window (27) that is immovably arranged inside the channel (20). It has a closing device (28) arranged within the channel (20) between the optical path window (27) and the distal end (17) of the fluid channel (20), and includes at least one closing member (29) movable between an open position and a closed position. The characteristic feature is that the closing member (29) is arranged such that it can be actuated by fluid flowing through the fluid channel (20).

2. The device according to claim 1, characterized in that, The closing member (29) includes an end that is nonmovably supported on the device (10).

3. The device according to claim 1, characterized in that, The closing device (28) includes a plurality of closing members (29a, 29b), each of which is pivotally supported at one end on the instrument (10).

4. The device according to claim 1, characterized in that, The closing device (28) includes a plurality of flexible sheets.

5. The device according to claim 1, characterized in that, The closing member (29) is an element made of a stretchable material.

6. The device according to claim 1, characterized in that, The channel (20) can be connected to a gas source (13) as a fluid source.

7. The device according to claim 1, characterized in that, The device (10) includes at least one additional channel (20) for supplying or discharging fluid.

8. The device according to claim 1, characterized in that, The visual cone is defined by a light path window (27) extending through the opening (25).

9. The device according to claim 1, characterized in that, The device (10) includes electrodes (22).

10. The device according to claim 9, characterized in that, The electrode (22) is arranged inside or in front of the opening (25).

11. The device according to claim 9, characterized in that, The electrode (22) is at least partially disposed within the cone of vision.

12. The device according to claim 1, characterized in that, The closing device (28) is connected to the mechanical actuation device (33).

13. The device according to claim 1, characterized in that, The closing device (28) is connected to the electromagnetic actuator (35).

14. The device according to any one of the preceding claims, characterized in that, The closing device (28) is connected to the pneumatic venturi actuator (32).

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