ELECTRODE APPLICATION TOOL

Description

[0001] The present invention relates to an electrode application instrument of minimally invasive design according to the preamble of claim 1. Background of the invention

[0002] For example, in cases of cardiac arrhythmia, pacemakers are often implanted in patients. These pacemakers are electrically connected to specific areas of the heart via electrical leads and electrodes mounted on their ends. It is crucial that the electrodes are correctly and securely installed / placed / anchored to the heart. For this purpose, the electrodes have screw- or corkscrew-like extensions / anchors that are screwed into the muscle tissue of the heart.

[0003] Two procedures have been established in the past for the implantation of such electrodes. Firstly, electrodes of this type can be inserted into the interior of the heart via a catheter via the carotid artery and fixed there. This has the advantage that the patient is only slightly injured during surgery (minimal surgical trauma) and therefore the risk of infection can be minimized as much as possible. However, this procedure has the disadvantage that positioning the electrodes is difficult and sometimes inaccurate. Secondly, electrodes of this type can be placed on the outside of the heart using a minimally invasive surgical instrument of the shaft type. For this purpose, for example, a minimally invasive patient access is created through which the instrument shaft of the surgical instrument can be inserted. State of the art

[0004] A shaft-type electrode application instrument is known from the prior art, for example, according to US Pat. No. 7,544,197B2. This instrument has a handle connected to the proximal end of an instrument shaft, at the distal end of which an effector is pivotably and rotatably mounted. The effector forms a jaw part / instrument head for receiving an electrode for its application to the outer wall of a heart. The jaw part is constructed in the shape of a tulip with three or four circumferentially spaced, spring-elastic tabs that form a type of receiving ring into which an electrode can be clamped. In addition, semicircular recesses or notches are formed between the tabs on the front side, through which the electrode strands can be guided when the electrode is clamped in the receiving ring.

[0005] It has been shown that a jaw designed in this way can hold and screw in the electrode securely, but cannot simply release the electrode once it has been attached to the heart muscle. Brief description of the invention

[0006] In view of this problem, it is an object of the present invention to provide an electrode application instrument with which the application of electrodes, in particular to the heart muscle, can be carried out in a simple and safe manner.

[0007] This object is achieved by a surgical instrument, in particular a minimally invasive electrode application instrument having the features of claim 1. Advantageous developments of the invention are the subject of the dependent claims.

[0008] More specifically, the present disclosure relates to a surgical electrode application instrument of minimally invasive design with an effector forming an instrument head mounted at the distal end of an instrument shaft so as to be rotatable and pivotable about its longitudinal axis, on which two opposing branches are mounted which can be moved towards one another in a scissor-like or pincer-like manner, of which at least one branch is designed with a front-side, partially circular notch for receiving an electrode strand and which are each shaped in a crescent-shaped cross-section at least in sections, wherein the mutually facing clamping sides in the crescent-shaped section of each branch each have a number, preferably a plurality, of grooves or undercuts spaced apart in the longitudinal direction of the branch and preferably running parallel in the transverse direction of the branch,wherein at least one or both branches are designed for their active actuation with articulation points for an actuating mechanism which has a number of actuating elements, one of which is coupled via a gear train to the branches at the corresponding articulation point, such that an actuating force can be applied via the one actuating element in both the opening and closing directions.

[0009] The core of the present invention therefore lies in the special design of the effector or jaw part with two opposing jaws that can be moved towards each other in a pincer-like manner, of which at least one jaw (preferably both) is designed with a front-side, partially circular notch (for receiving an electrode strand) and which are each bent or shaped in a sickle-shaped cross-section (when viewed in the proximal direction), whereby a groove shape extending in the longitudinal direction (proximally) is produced on the mutually facing inner sides of the jaws (at least in the region of an engagement section of the jaw). The mutually facing inner / clamping sides of each jaw also each have a number of axially spaced (inner circumferential) grooves or undercuts, which preferably have the same radii or groove depths and serve to (axially) receive an electrode (i.e.to accommodate the usually button- or plate-shaped electrode not from the side but from above).

[0010] At this point, it should be noted that even a single groove is sufficient for the correct holding of the electrode, namely in such a way that the corkscrew-like extension of a generally known electrode is aligned axially to the instrument head / jaw part, whereby a plurality of grooves is advantageous in that a higher torque can be transmitted to the electrode.

[0011] The jaws are pivotably mounted on an instrument head and coupled to a handle via an actuating device / gear train. The instrument head is pivotally mounted and rotatable (about its longitudinal axis) at a distal end of an instrument shaft. The handle is located at a proximal end of the instrument shaft, with the actuating device / gear train (at least partially) located within the instrument shaft. The handle has a number of actuating elements integrated into a handle, each of which separately rotates the instrument head about its longitudinal axis, angles / pivots it relative to the instrument shaft, and opens / closes the jaws.Such a basic concept of a surgical instrument of minimally invasive design, in particular the construction of the handle and the structure of the instrument head / jaw part, are known, for example, from the documents DE 103 24 844 A1, DE 103 30 604 A1, DE 10 2009 001 278 A1 and WO 2004 / 098 701 A.

[0012] The two branches of the jaw part are preferably identical to one another and more preferably have a branch neck that is axially offset in plan or bottom view (viewed toward the clamping side of the engagement section), which distally merges integrally into an axially centered engagement section / gripping section. The engagement section has the contour, curved in cross-section and crescent-shaped in cross-section, as described above, is preferably formed with a smooth surface on its radial outer side, and is provided on its radial inner side with the above-described axially spaced and circumferentially extending grooves.

[0013] The branch neck is preferably plate-shaped with a through-hole at the distal transition area between the branch neck and a gripping section and more preferably with an axially extending, but obliquely positioned to the longitudinal direction, elongated hole in the proximal end section of the branch neck. The plate-shaped branch neck is preferably rotated by approximately 90° to the gripping section such that the through-hole and the elongated hole are aligned in the transverse direction of the branch (along the inner circumferential grooves). In this way, the branches can be mounted in an instrument head in a scissor-like manner at the respective through-hole, wherein the respective elongated hole forms a type of sliding gate such that, for example, a cross pin guided longitudinally in the instrument head passes through the elongated hole and, during its longitudinal movement, the branch rotates about the hinge due to the inclination of the elongated hole.It should be noted that the translation of the sliding movement of the branch gear train can also be transformed into a pivoting movement of the branches by another mechanism (e.g. via connecting rods). Short description of the characters

[0014] The invention is explained in more detail below using a preferred embodiment with reference to the accompanying figures. Figure 1 shows a surgical electrode application instrument according to a preferred embodiment of the present invention, Figure 2 shows the instrument head of the surgical instrument according to Figure 1 , Figure 3 shows a longitudinal section of the instrument head according to Figure 2 , Figure 4 shows the side view of an instrument branch according to a preferred embodiment of the invention, as it is attached to the instrument head according to the Figure 3 is used, Figures 5a to 5dshow the engagement section of an instrument branch according to the present invention in cross section, in bottom view and in longitudinal section. Character description

[0015] The Figure 1 The surgical instrument 1 shown for applying electrodes (not shown further), for example, to a patient's heart, has a handle 2 in the form of a gripping piece that is mounted on the proximal end of an instrument shaft 4. At the distal end of the instrument shaft 4, an effector in the form of an instrument head 6 is mounted, which is rotatable about its longitudinal axis S and pivotable with respect to the longitudinal axis of the instrument shaft. In / on the instrument head 6, two branches 8a, 8b are mounted in a scissor-like or forceps-like manner (see in particular Fig. 2 ), such that they can be rotated and pivoted together with the instrument head 6 and can be opened and closed independently thereof.

[0016] A number of actuating elements (preferably three actuating elements) 10, 12, 14 are arranged on the handle / instrument handle 2. First, the instrument handle 2 has a type of joystick 10, which is pivotably or foldably mounted on a handle base 16 and is coupled to the instrument head 6 via a gear train guided in the instrument shaft 4 such that a pivoting movement of the joystick 10 with respect to the handle base 16 is transformed into a pivoting movement of the instrument head 6 with respect to the instrument shaft 4. Furthermore, a pivoting lever 12 is articulated to the joystick 10, the pivoting movement of which with respect to the joystick 10 is transmitted to the branches 8a, 8b via a separate gear train also guided in the instrument shaft 4 in order to open and close them like scissors or pincers.Finally, a rotary knob 14 is mounted on the free end of the control stick 10, the rotation of which acts on the instrument head 6 via a gear train also arranged separately in the instrument shaft 4 in order to rotate it about its longitudinal axis.

[0017] The construction of the handle 2, the respective separate gear trains and the instrument head 6 are known from the prior art according to the documents of the present applicant mentioned at the beginning, so that reference can be made to these documents at this point.

[0018] According to the present embodiment of the invention, the surgical instrument for applying electrodes differs from previously known surgical instruments of minimally invasive design essentially in the construction of the branches 8a, 8b used according to the invention.

[0019] Electrodes of known design for mounting, for example, on a patient's heart generally have a coin- or button-shaped (flat and round) electrode head, on the flat underside of which a corkscrew-like screw coil / anchor is arranged. This anchor can be connected, for example, to a pacemaker via an electrical wire (cable). Such an electrode must be screwed into the heart muscle for attachment. In order to hold it securely in the comparatively spongy heart muscle tissue, it is crucial that the screwing in process takes place as axially as possible along the screw coil, without any rocking or wobbling motion. This means that the electrode must be gripped and held in such a way that the screw coil extends essentially axially to the longitudinal axis of the instrument head 6.

[0020] To achieve this effect, the branches 8a, 8b provided in the instrument 1 according to the invention have a construction as is particularly known in the Figures 2 to 5 is shown.

[0021] First of all, it should be noted that the branches 8a, 8b mounted on the instrument head 6 in the manner of scissors or forceps are preferably of identical construction, so that only one of the two branches needs to be described below.

[0022] Each branch 8a, 8b accordingly has a proximal branch neck 80 and a distally integrally connected gripping section 82 (via an intermediate transition area). The gripping section 82 is formed by a plate which is crescent-shaped or groove-shaped in cross-section (seen in the longitudinal direction of the branch) (see Fig:5a ), which has a semi-circular notch 84 on its distal end face (see Fig. 5b) which is arranged substantially centrally with respect to the branch longitudinal axis B. A (radial) outer side of the gripping section 82 is preferably designed to have a smooth surface, whereas a (radial) inner side of the gripping section (hereinafter referred to as the clamping side) has a grooved profile.

[0023] In the preferred embodiment, the groove profile consists of a number of grooves 86 spaced apart in the direction of the branch axis, which extend in the transverse direction or in the circumferential direction of the gripping section 82 and thus essentially perpendicular to the branch longitudinal axis B over the entire gripping section 82. Furthermore, all grooves 86 preferably have the same radius or the same groove depth. The groove width also preferably remains the same, but can vary from distal to proximal.

[0024] The branch neck 80 has a plate-like or plate-like shape and is rotated by essentially 90° about the longitudinal axis of the branch relative to the gripping section 82. This means that while the gripping section 82 is oriented quasi-horizontally, for example, the plate-shaped branch neck 80 extends essentially vertically. At a distal transition region 88 between the branch neck 80 and the gripping section 82, a through-bore 90 is formed which, as a result of the 90° rotation, extends essentially along (tangentially) the grooves 86. At a proximal end section of the branch neck 82, an elongated hole 92 is also formed which extends along the longitudinal axis of the branch, but is additionally set at an (acute) angle (for example 15°-20°) to the longitudinal axis of the branch.

[0025] As particularly in the Fig. 4As shown, the longitudinal axis of the branches in the area of ​​the branch neck 80 and the longitudinal axis of the branch in the area of ​​the gripping section 82 run essentially parallel to each other, whereas the longitudinal axis B of the branch in the transition area 88 between the branch neck 80 and the gripping section 82 is inclined to this in the side view, resulting in an S-shaped branch profile in the side view. Consequently, the two branches 8a, 8b mounted on the instrument head 6 in the manner of scissors or pliers form a clamping gap between the opposite clamping sides when the two branches 8a, 8b are in a position in which the clamping sides are aligned parallel to each other. This position is, for example, in the Fig. 2 shown.

[0026] As finally from the Fig. 5b and 5dAs can be seen particularly clearly, the branch neck 80 and the gripping section 82 are arranged asymmetrically when viewed from below (i.e., looking at the clamping side of the gripping section 82). In other words, the branch neck 80 is offset parallel to the central or longitudinal axis (branch longitudinal axis B) of the gripping section 82, such that when two branches 8a, 8b lie adjacent to one another in the region of the branch necks 82, the two opposite clamping sides are essentially aligned or overlap. How it works

[0027] To apply an electrode, for example, to the outside of a patient's heart, the electrode is grasped at the edge with the scissor-like jaws 8a, 8b mounted on the instrument head, such that the electrode edge engages in the same grooves on the opposing jaws. This ensures that the electrode is aligned essentially perpendicular to the instrument head axis. Care must be taken to ensure that the electrode edge is received in the groove with a specific radius, so that the two jaws are aligned essentially parallel to each other when the electrode is held.

[0028] The gripping process is essentially carried out by actuating the lever 12, whereby a pin or stud 91 mounted axially displaceably in the instrument head 6 is displaced longitudinally via the associated gear train in the instrument shaft 4, which in turn engages in the elongated holes 92. Due to the inclined position of the elongated holes 92 with respect to the branch longitudinal axis B or the instrument head longitudinal axis S, the elongated holes 92 act as guide slots such that upon axial displacement of the pin / stud 91 along the elongated holes 92, the branches 8a, 8b are simultaneously rotated about a pivot pin 93 inserted into the through holes 90.

[0029] The electrode can now be screwed into the heart muscle by pivoting the instrument head 6 so that it is aligned essentially perpendicular to the outside of the heart. Then, the instrument head and the jaws 8a and 8b forming the jaws are rotated. Once the electrode is firmly screwed into the heart muscle, the jaws 8a and 8b can be opened, thus releasing the electrode.

Claims

1. A surgical electrode application instrument of the minimally invasive type, the instrument comprising an effector forming an instrument head (6) arranged at the distal end of an instrument shaft (4) and mounted so as to be rotatable about the longitudinal axis thereof and in a pivotable manner, on which effector two opposite branches (8a, 8b) are mounted, which can be moved towards each other in a scissors-like or forceps-like manner, of which at least one branch (8a) is formed with a part-circular notch (84) at an end face for receiving an electrode litz wire, and the cross-section of which is respectively sickle-shaped at least in portions, wherein the mutually facing clamping sides in the sickle-shaped portion of each branch (8a, 8b) each have a number, preferably a plurality, of grooves or undercuts (86) which are spaced apart in a longitudinal direction of the branch and are preferably parallel in a transverse direction of the branch, wherein at least one or both branches (8a, 8b), for active actuation thereof, are formed with articulation points for an actuating mechanism that has a number of actuating elements (12), one of which is coupled via a gear train to the branches (8a, 8b) at the respective articulation point, such that, via an actuating element (12), an actuating force can be applied both in an opening and in a closing direction, wherein the number of actuating elements (12) is mounted on the proximal end of the instrument shaft (4) and is coupled to the instrument head (6) via the gear train, which is arranged, at least partially, inside the instrument shaft (12).

2. The surgical electrode application instrument according to claim 1, characterized in that the actuating element (12) coupled to the branches (8a, 8b) is a manually operable pivot lever (12) which is hinged to an instrument handle (2) and which is provided and configured to manually apply the actuating force both in an opening as well as in an closing direction.

3. The surgical electrode application instrument according to claim 1 or 2, characterized in that the two branches (8a, 8b) are identical in construction to each other and each have a branch neck (80) which is axially offset in a plan view and merges distally into an engagement portion (82) arranged axially centrally in one piece.

4. The surgical electrode application instrument according to claim 3, characterized in that the engagement portion (82) has a sickle-shaped contour in cross-section, is formed with a smooth surface on its radial outside, and is provided on its radial inside with grooves (86) axially spaced apart and extending transversely in a circumferential direction.

5. The surgical electrode application instrument according to claim 3 or 4, characterized in that the branch neck (80) is shaped like a platelet with a through bore (90) on a distal transition portion (88) between the branch neck (80) and the engagement portion (82) and an axially extending elongated hole (92) in the proximal end portion of the branch neck (80), wherein the elongated hole (92) is set at an angle to a longitudinal axis (B) of a respective branch of the two branches (8a, 8b).

6. The surgical electrode application instrument according to claim 5, characterized in that the platelet-shaped branch neck (80) is rotated by approximately 90° about the longitudinal branch axis (B) with respect to the engagement portion (82) such that the through bore (90) and the elongated hole (92) are oriented substantially along the grooves (86) on the clamping side of the engagement portion (82).