WO2007006574A1

WO2007006574A1 - Inserting instrument

Info

Publication number: WO2007006574A1
Application number: PCT/EP2006/006868
Authority: WO
Inventors: Hans Wilhelm Pau; Detlef Behrend; Wolfram Schmidt; Klaus-Peter Schmitz
Original assignee: Universität Rostock
Priority date: 2005-07-14
Filing date: 2006-07-13
Publication date: 2007-01-18
Also published as: DE102005032959A1

Abstract

The invention relates to an inserting instrument (1) for inserting a flexible elongated electrode arrangement (7) into a cavity in a human body. The inserting instrument (1) comprises an elongated body (2) with a distal (3) and a proximal end that has, at least only a portion of its length, a guide (6) in which an electrode arrangement (7) to be inserted can be displaced toward the distal end (3) of the elongated body (2). The inserting instrument also comprises a head (4), which is placed on the body (2) and which serves to release an electrode arrangement (7), which is to be inserted, from the inserting instrument (1), this head having an annular recess (10), which extends from the body (2) to an end of the head situated opposite the body, and in which the electrode arrangement (7) can be guided. The head (4) is designed and placed on the body (2) in such a manner that an electrode arrangement (7), which is displaced in the guide (6) of the body (2) toward the distal end (3) thereof, reaches, from the guide (6), the annular recess (10) of the head (4), is guided therein and can be displaced out of the end of the head (4) situated opposite the body (2).

Description

introducer

The present invention relates to an introducer for inserting a flexible electrode assembly into a cavity in a human body, and more particularly to an introducer for inserting a flexible stimulation electrode assembly into a human's cochlea.

In modern medicine, various therapeutic and diagnostic methods have been developed that rely on the implantation of pacing or sensing electrodes in a patient's body. For example, electrical stimulation electrodes in the form of very thin wires have been successfully implanted in the vicinity of the spinal cord of patients suffering from a severe chronic pain syndrome. To relieve the discomfort of such stimulation electrodes under the control of a neurostimulator electrical impulses are delivered to the nerves. Similarly, it is possible to ameliorate the movement disorders of patients with Parkinson's disease, in which case the stimulation electrodes are introduced into the brain of the patients. Pacemakers implant stimulation and sensing electrodes into the heart of a patient. The sensor electrodes of the pacemaker detect the electrical activity of the heart, and the stimulation electrodes deliver electrical pulses at appropriate times to activate the heart.

Other well-known examples are first attempts of artificial stimulation of nerve cells in the eye in the case of an inoperative retina and the established implantation of stimulation electrodes in the cochlea of deaf people. The latter method can help patients with deafness caused by the absence or destruction of hair cells in the cochlea. In the sound human ear These hair cells in the liquid into which the cochlea is filled, and put the liquid passing sound vibrations into electrical nerve impulses. These sound vibrations are generated by vibrations of the eardrum, which are transmitted via ossicles and the oval window of the inner ear to the liquid. Since the eardrum is vibrated by sound waves reaching it through the external auditory canal, the sound vibrations passing through the fluid are characteristic of the sound waves received by the ear. The same applies to the electrical nerve impulses generated by the movement of the hair cells, which are finally transmitted to the brain via the auditory nerve in order to produce a hearing impression. Since the hair cells therefore represent the transducer elements that convert the corresponding vibrations of the eardrum waves in the cochlea fluid into electrical nerve impulses, based on a malfunction of the hair cells deafness can not be overcome by conventional hearing aids that only amplify the through cause the ear to receive sound waves. Rather, the electrical nerve impulses to be transmitted to the brain must be artificially generated, which can be achieved by the above-mentioned stimulation electrodes, which form part of a so-called cochlear implant.

With cochlear implants, if the auditory nerve is intact, the hearing can often be at least partially restored in such a way that speech comprehension is possible. In practice, a cochlear implant includes a number of electrodes disposed at the ends of flexible electrical leads. The electrodes and the leads are regularly embedded in an elongated or strand-shaped flexible electrode carrier. This electrode assembly, which may be helically preformed in the shape of the cochlea, is introduced into the cochlea within the scope of an operation in such a way that the electrodes are arranged adjacent to the corresponding auditory nerves and can deliver electrical impulses directly to the auditory nerves. The electrical impulses are generated by a processor which communicates with the conduits and suitably processes sound waves collected by a microphone. The electrode arrangement must be introduced into the cochlea by a hole milled in the petrous bone and arranged there in a defined manner. In general, the electrodes must be introduced without damage, and the inevitable effects on the sensitive structures in the cochlea must be kept as small as possible.

Similar preconditions must be observed in all other procedures involving the implantation of electrodes. First, it must be ensured that the electrodes are placed precisely in the right place so that they can fulfill their task of stimulating certain nerve cells or detecting a specific electrical signal. On the other hand, the tissue and the nerve cells must not be damaged at the implantation site (in the case of the cochlea, for example, residual hair cells that still have residual hair cells that cause residual hearing). In general, there is the problem that it is extremely difficult to accurately insert very thin, flexible electrode carriers into anatomically preformed cavities without damaging or destroying, for example, soft tissue structures that are sensitive to inadvertent lateral movements. Thus, the usual insertion techniques, such as hands-free insertion or insertion with the help of locking tacks, are associated with sometimes considerable failure rates. In view of the regularly very small dimensions, ergonomic, jitter-free insertion in this way is virtually impossible. - A -

It is an object of the present invention to provide an easy-to-use and simply constructed insertion instrument for introducing a flexible electrode assembly, with a precise and low-damage insertion is possible and the disadvantages mentioned are eliminated.

This object is achieved by an insertion instrument having the features of claim 1. Advantageous embodiments of the insertion instrument are the subject of the associated subclaims.

According to the present invention, it is provided that an introducer for inserting a flexible electrode assembly and in particular a flexible elongate electrode assembly into a cavity in a human body has an elongated body having a distal and a proximal end. Here, the term "proximal" in the present application in the usual way refers to the end facing the operator, while the term "distal" refers in the usual way to the operator facing away from the patient and the end facing. An elongate electrode arrangement (or an elongate arrangement in general) is understood in the usual way to mean any electrode arrangement (or arrangement) that is strand-shaped and thus extends along a line-like path for a certain length, and has smaller dimensions transverse to this path as along this path. This path, or the course followed by the elongated Elektrodenanorndung may also be curved, so that an elongated electrode arrangement, for example, also be spirally or otherwise spatially preformed in order to achieve about a better adaptation to the shape of the cavity in question. The direction of the path or the course of the elongated electrode arrangement at a certain point is understood as meaning the direction of elongation or elongation of the elongated electrode arrangement. At a Accordingly, the non-rectilinear elongated electrode arrangement changes the longitudinal or extension direction along its length. The cavity into which the electrode assembly is inserted is optionally created in the course of the operation or by the insertion itself. For example, a cochlear implant electrode assembly may be inserted in a conventional manner into the fluid of the cochlea itself or, advantageously, into a space between the bony wall and the membranes surrounding the membranous cochlea. The body of the insertion instrument has at least along a part of its length a guide, which is designed such that in it an elongated electrode arrangement to be inserted along the longitudinal or Erstrek- kung direction of the elongated electrode assembly, ie, guided towards the distal end of the elongated body can be advanced. This guide thus extends in the longitudinal direction of the body to its distal end. The body may optionally be curved or spatially preformed in its longitudinal or extension direction in a suitable manner, in order to allow adaptation to the field of use and thus better handling by the physician.

Further, the insertion instrument has a head for delivering an electrode assembly to be inserted from the insertion instrument, ie, the electrode assembly exits the insertion instrument at the head. The head is disposed on the body and has an elongated trough-shaped recess (ie, a recess extending along a longitudinal direction that opens along its length transverse to the longitudinal direction) that extends in the longitudinal direction Extending or extending direction of the preferably also elongated head from the body of the insertion instrument to a body of the insertion opposite the distal end of the head extends. The groove-shaped recess is designed such that the electrode arrangement with a feed movement in the direction of Längsbzw. Extension direction of the electrode assembly can be performed in the channel-shaped depression. For this purpose, the channel-shaped depression can have any suitable cross-section. For example, in an electrode assembly of circular cross-section, the channel-shaped recess may have a section of circular cross-section. However, it may also be advantageous if the electrode arrangement has a non-circular cross-section and the cross-section of the groove-shaped depression is adapted to this cross-section in order to prevent twisting or twisting of the electrode arrangement in the insertion instrument. The head is formed in such a way and arranged on the body, that an electrode assembly, which is advanced in the guide of the body toward the distal end thereof, from the guide into the trough-shaped recess of the head pass, guided therein and from the Body opposite end of the head and its groove-shaped recess can be pushed out. In order to fix the electrode assembly longitudinally in the transverse direction in the groove-like depression, the insertion instrument can be easily tilted (about 1 to 10 °, preferably 5 to 10 °) in such a way that edge portions at the entrance and / or at the outlet of the channel-shaped depression press against the electrode assembly and this is so "jammed" is.

This introducer is very easy to use. It simultaneously serves as a guide rail during insertion and as a support for the electrode assembly. In this way it can be used for precise, targeted and secure positioning and insertion of the electrode assembly. For this purpose, first the elongate electrode arrangement is arranged in the guide in the elongated body and optionally, as described above, fixed by tilting or rotation of the insertion instrument with respect to the electrode arrangement. Subsequently, the electrode assembly in the guide is advanced toward the distal end of the guide and the body. If the electrode assembly advanced far enough, it enters with its front end in the trough-shaped depression of the head and during the further feed movement (also) in this out. Once the front end of the electrode assembly has reached the distal end of the head or trough-shaped depression, the insertion instrument is ready to actually insert the electrode assembly. For this purpose, the distal end of the head is positioned with the output-ready electrode assembly immediately in front of the insertion opening and then the electrode assembly targeted from the distal end of the head and its groove-shaped recess out through the insertion into the existing or possibly created by the introduction Cavity advanced. During insertion, the electrode assembly is securely guided by the trough-shaped depression in the head and optionally by the guide in the body of the introducer. After completion of the insertion process, the projecting from the insertion opening end of the electrode assembly, which may have, for example, plug contacts for electrical connection with other components of a cochlear implant, removed from the insertion instrument. This is possible by the formation of the guide in the head as a trough-shaped, ie open in the lateral or transverse direction recess in a simple manner by the head of the insertion instrument is laterally or transversely withdrawn from the projecting end or portion of the electrode assembly.

For cochlear implants, at least in the portion to be inserted into the cochlea, the electrode assembly usually has diameters of 1 mm or less, mostly 500 μm or less, and, for conventional circular cross-section electrode assemblies, typically about 300 μm on. Newer flat electrodes with an oval cross-section typically have a width of about 250 to 300 .mu.m and a thickness of about 200 .mu.m. Since it is advantageous if the guide in the elongate body and the groove-shaped recess of the head are adapted in their dimensions to the relevant electrode arrangement, it is preferred that in an insertion instrument for the electrode assembly of a cochlear implant, the guide in the elongated body and the guide provided by the trough-shaped depression of the head in the region in which they contact a guided electrode arrangement has a width of 1 mm or less (or a radius of curvature of 500 μm or less), preferably 500 μm or less (or a radius of curvature of 250 μm or less), and most preferably about 300 μm (or a radius of curvature of about 150 μm). The lower limit for these dimensions depends on the thinnest possible electrode arrangement. Typically, the width is at least 150 μm (or the radius of curvature at least 75 μm). In an advantageous embodiment, the depth of the channel-shaped recess of the head, ie the distance between its lateral opening and its lowest point, 600 to 800 microns. Further, in an insertion instrument for cochlea electrode arrangements, it is preferable that the head has a length of 1 mm to 5 mm, preferably about 1.5 mm to 4 mm, and most preferably about 2 mm along the extending direction of the groove-shaped recess.

The lateral opening of the channel-shaped depression of the head preferably has uniform dimensions along its entire length.

The body of the introducer can be advantageously formed with a handle portion that as many characteristics of the ear micro-instruments developed and established for several decades, such as needles or Check mark to facilitate the handling of the introducer by an operator. In this case, it is preferable if the body of the insertion instrument is made thinner in a section at its distal end than in the remaining part of the body. The thinnest possible training in this section has the advantage that the surgeon an unobstructed view of the work area is procured. In this embodiment, the head is preferably attached to the thin distal tip of the body. Further, it is preferred that the body be widened in a portion at its proximal end, ie wider than in the remainder of the body, to provide a secure hand grip and ergonomic manipulation of the proximal handpiece common in conventional ear instruments is.

In a preferred embodiment, the head is located at the distal end of the body.

The head may be formed integrally with the body. Preferably, it is designed as a separate, attached to the body element. It is particularly advantageous if the head is detachably attached to the body. Such an arrangement allows the targeted attachment of a head that is particularly suitable in its dimensions and in its configuration for a particular application or for a particular patient. A releasable connection can be made for example by brackets, screws, a plug connection or a snap connection. If no releasable attachment required, the attachment can be done for example by a solder, weld or adhesive bond.

In a further preferred embodiment, the body is at least in a portion which lies in front of the area in the direction from the proximal to the distal end of the body the head is arranged on the body, made flexible or plastically deformable. This has the advantage that different angles of the head can be adjusted with respect to the main part of the body, so that the insertion instrument is adaptable to different insertion conditions.

In a preferred embodiment, the trough-shaped depression of the head is curved along its longitudinal direction (ie, its extension direction), so that along its course or its length the direction changes and the normal of the cross-sectional areas at the two end of the trough-shaped depression at an angle are arranged to each other. In other words, the direction of entry of the elongated electrode arrangement defined by the guide of the channel-shaped depression is at the (proximal) end of the channel-shaped depression facing the body of the introducer instrument and the outlet direction of the elongate electrode arrangement defined by the channel-shaped recess guidance at the side facing away from the body of the insertion instrument (distal) end of the trough-shaped depression arranged at an angle to each other. In this way, an advanced by the leadership of the body electrode assembly can be deflected in the head in order to safely and precisely insert the electrode assembly at an optimal angle even with insufficient accessibility of the insertion onsöffnung. The angle is preferably 10 ° to 90 °, more preferably 10 ° to 60 ° and most preferably 10 ° to 30 °. The curvature can be designed so that the groove-shaped recess is curved in its longitudinal or extension direction along its entire length, that is, for example, is uniformly curved. Preferably, however, it is the largest in a longitudinal or extension direction of the channel-shaped recess middle section. Thus, it is particularly advantageous if the ends of the groove-shaped depression of the head are not curved, ie if the groove-shaped depression has sections at both ends. has, which are straight in the longitudinal or extension direction. In this way, the electrode order can enter the channel-shaped depression in a defined manner and exit from it.

If the trough-shaped depression of the head is curved in its longitudinal direction, it is furthermore advantageous if the curved gutter-shaped depression extends in a plane, i. extending in a plane, and when the along the length of the channel-shaped recess extending opening of the channel-shaped recess is transversely and preferably aligned perpendicular to this plane. By such an embodiment, in which the along the longitudinal extent of the channel-shaped recess extending opening of the channel-shaped recess is oriented transversely and preferably perpendicular to the plane in which the channel-shaped recess extends, can be achieved simultaneously that the head slightly after insertion by lateral or transverse stripping can be solved by the electrode assembly and that the electrode assembly is securely guided in the head.

In a further preferred embodiment, the groove-shaped depression of the head is narrowed at its edges running in the longitudinal direction or narrows in the direction of its lateral opening, so that an electrode arrangement guided in the groove-shaped depression transversely to the longitudinal or extension direction of the channel-shaped Well in the trough-shaped depression is held. This embodiment improves the lateral or transversal guidance of the electrode arrangement in the channel-shaped depression, which is provided without constriction solely by static friction on the walls of the channel-shaped depression. Such a narrowing can be achieved, for example, by forming the groove-shaped depression with a slightly more than semicircular cross-section or by, for example, in the case of a U-shaped cross-section. cut, provided at the edges inwardly directed projections. This can for example be done in a simple manner by the extending in the longitudinal direction of the channel-shaped recess edges are bent inwards. If these longitudinal edges of the channel-shaped depression are sharp and slightly curved inward, the fixation of the electrode arrangement can be further improved by the specific tilting or twisting of the insertion instrument described above. In general, any cross section is suitable which allows a guide of an electrode arrangement with a certain diameter in the annular recess and at the same time prevents the electrode arrangement from exiting laterally from the channel-shaped recess. If such a configuration is chosen, an electrode arrangement must be used in which the end projecting from the insertion opening after insertion has a smaller diameter than the inserted section in order to be able to pull the head laterally away from the electrode arrangement. For example, cochlea electrode arrangements in which the cross section in the section to be inserted usually increases from the distal towards the proximal end are formed in a regularly stepped manner, so that the cross section behind the section to be inserted decreases again.

In a preferred embodiment of the insertion instrument, the head has a U-shaped profile in cross-section. In other words, the head at each point in the direction of the longitudinal extension of the elongated channel-shaped depression perpendicular to this direction on a U-shaped profile. By this configuration, the head is particularly simple in design and manufacture. Thus, it is advantageously possible to form the head by a flat or plate-shaped element bent in a U-shape and then optionally provided with a suitable curvature in the direction of extension of the trough-shaped depression formed thereby. The guide in the body can be partially or completely formed as a tubular longitudinal bore in the body. This has the advantage of a particularly secure guidance and the longest possible protection of the introduced electrode assembly from damage and contamination. However, such a trained insertion instrument can be used only with such electrode assemblies, which are dimensioned in their length so that they have exited completely after completion of the insertion of the tubular closed part of the guide in the body, or if that after the introduction of the Insertion opening projecting end of the electrode assembly in the longitudinal direction can be pulled out of the tubular guide. By contrast, an insertion instrument designed in this way can not be used regularly, for example, if the electrode arrangement is already connected to another component of the cochlear implant, such as a coil or a power supply, at its end opposite the insertion end. In such cases, it is advantageous if the guide in the body is partially or completely formed as a groove-shaped depression in the outer surface of the body. As a result of this embodiment, the section of an electrode arrangement which is still in the guide in the body after insertion can be removed from the guide in a simple manner laterally or transversely. The lateral guide in the channel-shaped depression is provided by friction as in the head and can be improved as in the head by the trough-shaped depression narrows toward its lateral opening. In such a case it is preferred that the openings of the trough-shaped depressions of the head and of the body extending along the length of the groove-shaped depressions are aligned transversely and preferably perpendicular to one another. In this way it is advantageously prevented that the electrodes Order during the insertion unintentionally moved laterally out of the provided by the channel-shaped recesses guides.

In a further preferred embodiment, the insertion instrument has a feed device which is designed such that its actuation causes the advancement of an electrode arrangement arranged in the guide of the body in the direction of the distal end of the body. Even if a feed is possible in principle by manual feeding of the electrode arrangement at the proximal end, the feed can be made more precisely if a correspondingly adapted feed device is provided. Such advancing means may preferably comprise a wheel rotatably mounted on the body so as to engage and act upon an electrode assembly disposed in the guide in the body to effect its advancement. The feed is effected in this case, for example, by friction between the wheel and the electrode assembly. To facilitate the electrode assembly from the guide of the body, it may be advantageous if the wheel is removably disposed on the body, so that it can be detached from the body and then attached to this again. In a further advantageous embodiment, the wheel is slidably mounted on the body in such a way that it acts between a first position in the vicinity of the guide of the body in which the wheel engage and act on an electrode arrangement arranged in the guide in the body may be moved to effect its advancement and a second position remote from the guidance of the body. In this second position, the wheel does not engage with an electrode arrangement arranged in the guide of the body. With this configuration, the wheel can be selectively brought into an active position or feed position and into a passive position or non-feed position, wherein the wheel is preferably attached to at least in the active position or the feed position can be locked.

Another preferred advancing means comprises a slider slidably disposed on the body and engaging the guide in the elongate body to engage and act upon an electrode assembly disposed therein to effect its advancement. Such a slider may comprise an externally accessible actuator and an at least partially disposed in the guide in the body and displaceable along the guide member which engages the proximal end of the arranged in the guide electrode assembly and this upon actuation of the actuating element in the direction of the presses distal end of the body.

The invention will be explained in more detail below with reference to an embodiment with reference to the drawings.

FIG. 1 shows a perspective view of the distal end of an insertion instrument according to the invention.

FIG. 2 shows a side cross-sectional view of the distal end of the introducer instrument shown in FIG.

FIG. 3 shows a side cross-sectional view of a proximal portion of the body of the introducer instrument shown in FIG.

FIG. 4 shows a cross section along the line IV-IV from FIG. 3.

The insertion instrument 1 shown in FIG. 1 has an elongate body 2 (see also FIG. 3), at whose distal end 3 an elongated head 4 is fastened. The attachment of the head 4 on the body 2 is made in this example by a solder joint 5 (see Figure 2). The body 2 has along a part of its length a groove-shaped recess 6, which serves as a guide for an inserted electrode assembly 7. The electrode arrangement 7 has a multiplicity of electrical lines 8 connected to electrodes, which are embedded together with the electrodes in an elongate, flexible electrode carrier 9.

The head 4 has a U-shaped cross-sectional profile. In this way, in the head 4, an elongated groove-shaped recess 10 is formed, in which the electrode assembly 7 at a feed movement in the longitudinal direction of the head 4, i. in the longitudinal or extension direction of the groove-shaped recess 10, can be performed. As a result of this configuration, the electrode assembly 7 can be advanced in a guided manner along its longitudinal extent so that it emerges from the trough-shaped depression 10 and the head 4 at the distal end 12 of the head 4 and can be introduced into its destination. The head 4 can be easily manufactured by suitably bending and deforming a plate-shaped member.

The head 4 and thus also the channel-shaped depression 10 are curved along their longitudinal extent and accordingly along the feed direction of the electrode arrangement 7. The transverse or lateral (ie running along the length of the groove-shaped recess 10) opening 11 of the channel-shaped recess 10 has in a direction which is aligned perpendicular to the plane in which the curved gutter-shaped recess 10 and the curved head 4th runs. In this way, in the situation where the electrode assembly 7 is inserted so far that its rear end is disposed in the head 4, the head 4 can be easily removed from the electrode assembly 7 by turning the head 4 laterally (in FIG 1 to the right) is removed from the Elektrodenanorndung 7, wherein the electrode assembly 7 leaves the trough-shaped recess 10 through the lateral opening 11.

Figure 2 shows a side view of the portion of the insertion instrument 1 shown in Figure 1. It can be seen that the electrode assembly 7 enters from the trough-shaped recess 6 of the body 2 in the trough-shaped recess 10 of the head 4 and is guided in this until it the distal end

12 of the head 4 and the channel-shaped recess 10 exits the insertion instrument 1. The distal end 12 of the head 4 can be arranged in a suitable orientation in front of the insertion opening and then the electrode assembly 7 can be inserted precisely and safely into the insertion opening by advancing. The head 4 is curved in the advancing direction of the electrode assembly 7 (i.e., in the longitudinal direction of the groove-shaped recess 10). Here are the two end sections

13 of the head 4 in the feed direction of the electrode assembly 7 straight while a central portion 14 of the head 4 has a curvature. In this way, the two straight end portions 13 of the head 4 are arranged with their longitudinal axes at an angle 15 to each other, so that the electrode assembly 7 is deflected in the head 4. The angle 15, which is 30 ° in this example, can be chosen so that the introduction of the electrode assembly 7 can be accomplished precisely under suitable spatial conditions even with a suitable orientation.

Figure 1 shows a possible embodiment of extending in the longitudinal direction of the head 4 edges 16 of the U-profile. In order to prevent the electrode assembly 7 unintentionally leaving the trough-shaped depression 10 during the advancing movement, the edges 16 are bent inwards in order to achieve a constriction of the lateral opening 11 of the groove-shaped depression 10. Such an embodiment makes sense if the static friction between the walls of the channel-shaped recess 10 and the electrode assembly 7 does not ensure sufficient lateral guidance.

FIG. 3 shows the proximal end of the body 2 of an insertion instrument 1. In the example shown, the body 2 is straight. But it may also be advantageous if the body 2 has a curvature in the longitudinal direction. The body 2 has a grip portion 17, on which the insertion instrument 1 can be securely held and guided. An electrode assembly 7 to be introduced is introduced into the body 2 at an entry point 18 into the channel-shaped recess 6, which is used as a guide and described with reference to FIGS. 1 and 2. The channel-shaped recess 6 is formed in the surface of the body 2 and extends along the longitudinal direction of the body 2 up to the head 4. The channel-shaped recess 6 is shown in more detail in the cross-sectional image of Figure 4. From this it can be seen that the channel-shaped recess 6 has a rectangular shape in deviation from the example shown in Figures 1 and 2 in cross section.

In order to effect the advancement of the electrode arrangement 7 into the guides provided by the channel-shaped depressions 10 and 6 in the head 4 and the body 2, a feed device 20 is provided on the body 2. As shown in Figures 3 and 4, the feed device 20 to a wheel 21 which is rotatably supported between two formed on the body 2 lugs 22 on a pin 23 which defines the axis of rotation 24 of the wheel 21. As can be seen in particular in Figure 4, the wheel 21 is arranged in such a way that it engages with its outer surface at one of the electrode support 9 of an electrode assembly 7, which is located in the groove-shaped recess 6. As a result, by rotating the wheel 21 by means of friction between the outer surface of the wheel 21 and the electrode support 9, a force can be applied to the electrode assembly. 7, which causes their advancement in the direction of the distal end 3 of the body 2 or in the direction of the head 4 of the insertion instrument 1. During the advancing movement, the electrode arrangement 7 finally arrives, as in the example shown in FIGS. 1 and 2, in the channel-shaped depression 10 of the head 4 and can be guided safely and precisely guided through an insertion opening.

The lateral opening 19 of the trough-shaped recess 6 of the body 2 is aligned in the example shown in the direction of the plane defined by the curvature of the head 2, while the lateral opening 11 of the trough-shaped recess 10 of the head 4 is oriented perpendicular to this plane. By this arrangement, the lateral guidance of the electrode assembly is particularly well ensured at the same time easy removability from the guide.

After the introduction, the part of the electrode arrangement 7 protruding from the insertion opening can simply be removed from the insertion instrument 1 in the example shown in FIG. 3 by removing this part laterally from the channel-shaped depression 6. It may be advantageous if the wheel 21 is releasably secured to the lugs 22 to facilitate the removal of the electrode assembly 7 from the trough-shaped recess 6. For this purpose, a slot 25 is formed in each approach 22, which is inclined with respect to the body 2 and its groove-shaped recess 6 and in which the pin 23 of the wheel 21 is guided. In this way, by displacing the pin 23 in the slot 25, the wheel 21 can be moved to an operating position by moving it towards the channel-shaped recess 6 and bringing it into abutment with an electrode arrangement 7 arranged therein. In this operating position, the pin 23 can be locked by a locking device (not shown). On the other hand, the wheel 21 by shifting the Pin 23 are also removed from the groove-shaped recess 6 in the slot 25 to release an arranged therein electrode assembly 7. In this case, an opening 26 is provided at the end of the slot 25 remote from the annular recess 6, through which the pin 23 and the wheel 21 can be removed from the slot 25 and thus separated from the insertion instrument 1. Subsequently, the electrode assembly 7 can be removed in a simple manner from the channel-shaped recess 6.

Claims

claims

An insertion instrument for inserting a flexible electrode assembly (7) into a cavity in a human body, the insertion instrument (1) comprising: an elongate body (2) having a distal (3) and proximal end extending at least along a portion thereof Length has a guide (6) in which an electrode assembly (7) to be inserted can be advanced towards the distal end (3) of the elongated body (2) and a head (4) for delivery disposed on the body (2) an inserted electrode assembly (7) of the insertion instrument (1) having a groove-shaped recess (10) extending from the body (2) to an opposite end of the head (4) and in which the electrode assembly (7) out be formed, wherein the head (4) is formed in such a manner and on the body (2) is arranged, that an electrode assembly (7) in the guide (6) of the body (2) in the direction of dista The end (3) is advanced, from the guide (6) into the channel-shaped recess (10) of the head (4), guided in this and the body (2) opposite the end of the head (4) can be advanced out ,

2. introducer instrument according to claim 1, wherein the head (4) at the distal end (3) of the body (2) is arranged.

3. insertion instrument according to claim 1 or 2, wherein the head (4) is formed integrally with the body (2).

4. insertion instrument according to claim 1 or 2, wherein the head

(4) is formed by a separate element fixed to the body (2).

5. insertion instrument according to claim 4, wherein the head (4) releasably attached to the body (2).

6. An insertion instrument according to any one of the preceding claims, wherein the body (2) lies at least in a portion which is in the direction from the proximal to the distal end (3) of the body (2) in front of the region at which the head (4 ) is arranged on the body (2) is formed plastically deformable.

An insertion instrument according to any one of the preceding claims, wherein the trough-shaped recess (10) of the head (4) is curved along its longitudinal direction so as to change the direction along its length and the normal of the cross-sectional areas at the two ends of the trough-shaped depression (10). 10) are aligned at an angle (15) to each other.

8. insertion instrument according to claim 7, wherein the angle (15) is 10 ° to 60 °.

9. insertion instrument according to claim 7 or claim 8, wherein the curvature of the trough-shaped recess (10) of the head

(4) is greatest in its longitudinal direction in a central portion.

10. introducer according to any one of claims 7 to 9, wherein the trough-shaped recess (10) of the head (4) is not curved at their ends in their longitudinal direction.

11. An insertion instrument according to any one of claims 7 to 9, wherein the trough-shaped recess (10) of the head (4) is curved in its longitudinal direction along the entire length.

12. An insertion instrument according to one of claims 7 to 11, wherein the curved channel-shaped recess (10) of the head (4) extends in a plane and in which along the length of the channel-shaped recess (10) extending opening (11) of the channel-shaped Recess (10) is aligned transversely to the plane.

13. An insertion instrument according to claim 12, wherein the along the length of the channel-shaped recess (10) erstrek- kende opening (11) of the channel-shaped recess (10) is aligned perpendicular to the plane.

14. An insertion instrument according to any one of the preceding claims, wherein the trough-shaped recess (10) of the head (4) is narrowed at its longitudinal edges (16), so that in the trough-shaped recess (10) guided electrode assembly (7) transversely is held to the longitudinal direction of the channel-shaped depression (10) in the channel-shaped depression (10).

15. introducer according to any one of the preceding claims, wherein the head (4) has a U-shaped profile in cross section.

16. insertion instrument according to claim 15, wherein the head (4) has a U-shaped curved flat element.

17. insertion instrument according to one of the preceding claims, wherein the guide in the body (2) at least partially is formed as a tubular longitudinal bore in the body (2).

18. introducer according to any one of the preceding claims, wherein the guide (6) in the body (2) is at least partially formed as a groove-shaped recess (6) in the outer surface of the body (2).

19. An insertion instrument according to claim 18, wherein the along the length of the channel-shaped recesses (10, 6) extending openings (11, 19) of the channel-shaped recesses of the head (4) and the body (2) are aligned perpendicular to each other.

20. An insertion instrument according to any one of the preceding claims, further comprising a feed device (20) which is designed so that its operation advancing a in the guide (6) of the body (2) arranged electrode assembly (7) in the direction of the distal End (3) of the body (2) causes.

21. An insertion instrument according to claim 20, wherein the advancing means (20) comprises a wheel (21) rotatably arranged on the body (2) so as to be fixed to one in the guide (6) in the elongated body (2). 2) arranged electrode assembly (7) and can act on these to effect their feed.

22. An insertion instrument according to claim 21, wherein the wheel (21) is removably mounted on the body (2).

23. An insertion instrument according to claim 20, wherein the feed device (20) comprises a slider which is slidably mounted on the body (2) and in the guide

(6) engages in the elongate body (2) to engage an elongate body (2) This arranged electrode assembly (7) to attack and act on these to effect their feed.