WO2004084749A1

WO2004084749A1 - Device for determining the position of a target region in the brain

Info

Publication number: WO2004084749A1
Application number: PCT/EP2003/003156
Authority: WO
Inventors: Helmut Bader; Stefan Fischer; Robert Nitzschmann; Marcus Götz
Original assignee: Mrc Systems Gmbh
Priority date: 2003-03-26
Filing date: 2003-03-26
Publication date: 2004-10-07

Abstract

The invention relates to a device for determining the position of a target region (1, 1') in the brain (2) and for finding this target region again. The device comprises an insertion device (5), which can be placed on the head (3) of a patient and which guides an electrode (6) into the area (7) of the target region (1, 1') according to specified space coordinates (x, y, z) and to a specified direction of insertion (Fx Fy). The electrode is guided in order to carry out an exact determination of the position of the target region by detecting neuronal processes of the target region (1, 1'), and to render the position data available and reproducible for a therapeutic intervention. A position detection device (8) serves to determine the insertion depth (a, a', a'') of the electrode (6) during the detection of a neuronal process. The aim of the invention is to preserve healthy tissue to the greatest possible extent. To this end, the electrode (6) is designed with a working direction (9) for detecting neuronal processes that can be laterally adjusted with regard to the electrode (6) while pointing in all directions (360°). In addition, the position detection device (8) also has an angle detection device (10) via which the angle (α) of the working direction (9) can be determined during the detection of a neuronal process.

Description

Device for determining the position of a target area to be treated in the brain

description

The invention relates to a device for determining the position of a target area to be treated in the brain with an insertion device which can be arranged on the head of a patient and which, according to predetermined spatial coordinates and a predetermined insertion direction, leads an electrode into the previously determined area of the target area in order to determine the exact position thereof To carry out detection of neuronal processes in the target area and to make the position data available and reproducible for a therapeutic intervention, the insertion depth of the electrode being able to be determined by detecting a neuronal process by means of a position detection device.

In the field of neurosurgery, especially functional neurosurgery, it is often necessary to carry out interventions in precisely defined target areas of the brain that cannot be determined with such accuracy using imaging methods such as X-rays. It is therefore necessary, based on a preliminary determination of the engagement area, e.g. B. by imaging to make a more precise determination of the target area of the intervention.

Such interventions are used, for example, to eliminate dysregulated centers in Parkinson's and similar diseases. The interventions can consist of neurons being influenced, for example by high-frequency signals. If, for example, a dysregulated center can be switched off in this way, it is possible to free a patient from the symptoms caused by it and to significantly improve his quality of life again. Another possibility to achieve this goal is thermocoagulation, which permanently switches off such an area, but the disadvantage of an inexact limitation of the treatment area Has. For this reason, attempts are being made to generate targeted coagulation, for example by electrodes, or to stimulate it in order to avoid permanent damage. Another option is to remove or switch off such an area using laser beams. Of course there are a number of other treatment options, such as the introduction of an active ingredient or radioactive implants.

If neurons are temporarily affected, and much more if the neurons to be treated are switched off permanently, exact localization of the neurons to be treated is necessary, since any incorrect localization would mean damage and, if neurons were switched off, permanent damage would also result.

A device of the type mentioned is known from DE 199 38 549 AI. This document teaches how to navigate the target area by inserting an electrode by means of a controllable propulsion until the area of the target area is reached, which can be registered in that the neural signals are detected. Based on this data, the treatment is then carried out using a therapy electrode. Even if the preliminary determination of the area in which the target area to be treated is located is very precise, the latter can only be detected precisely if the predetermined direction of introduction precisely hits the target area lying within this area. If the probe is guided past the target area, but the signals are detected by appropriate amplification, then either only the location of a partial area of the previously determined area in which the target area is located is located, or the probe must be re-embarked after a correction of the introduction path , In the former case, more neurons than those in the immediate target area are subjected to treatment, since only an area extending around the electrode can be localized, even if the target area lies on one side of the electrode. In the second case, additional neurons are also damaged by the further insertion of the probe.

From US 6, 129, 685 it is also known to flexibly design an electrode and to provide it with a magnetic tip. This makes it possible to use the electrode first insert it into the brain area to be treated using a tube, and then use a magnetic field to move the electrode freely in all directions at the end of the tube in search of the target area. For this, however, a force must be exerted on the magnetic tip when the electrode is guided freely, which enables the electrode to penetrate brain parts. This generation of force by means of the magnetic field requires a certain size of the tip of the electrode, which in turn means that a correspondingly large side effect occurs because the tip clears a wide path due to its size and thereby unnecessarily damages neurons. In addition, the electrode cannot be directed in the direction of the target area, since this direction cannot be determined beforehand. The acquisition of the position data by means of magnetic resonance imaging is also complex and is questionable with regard to the accuracy in the event that the target area may have to be found again. A target area can only be determined precisely if the probe encounters it on its advance path, since the probe cannot detect which side of the probe the target area is with the magnetic tip. In the case of a target area lying to the side of the probe, detection and thus also treatment can also be carried out only in the manner already mentioned above in a larger area with the disadvantages mentioned.

The invention is therefore based on the object of creating the conditions for making an intervention possible with the greatest possible protection of healthy tissue.

The object is achieved according to the invention in that the electrode is designed in such a way that it has an effective direction for detecting neuronal processes, which can be set in all directions to the side of the electrode and that the position detection device also has an angle detection device through which the Angle of the direction of action when detecting a neural process can be determined.

The invention makes it possible to detect the position of the target area much more precisely, since it is not only the depth of insertion in which the target area is located that is but also the direction in which a target area is located to the side of the electrode can be gently determined. It is no longer necessary for the entire area of a certain insertion depth, which extends concentrically around a measuring point, to be subjected to a treatment of the type mentioned above to such an extent that the target area is definitely included. Rather, it is possible to measure on all sides at every insertion depth in order to determine exactly which side the target area is on. The data is then acquired when the detector responds, and subsequent intervention can be based on this data. A significant further advantage is that no new introduction is required if the target area is a little off the insertion path, since its lateral position can also be determined and is available as a measure of the angle for the subsequent treatment. Of course, the device according to the invention can also be used to register when the probe is in the middle of the target area, since the neural processes of the target area can then be determined when the direction of action is rotated all around. If this is ascertained, the invention makes it possible to reduce the treatment area in a corresponding manner, so that in this case too the intervention can be restricted to the target area.

In contrast to the above-mentioned US Pat. No. 6,129,685, it is not necessary to carry out lateral “test bores” on all sides in the search for the target area with a thick electrode with a magnetic tip. The direction in which the target area is seen from the electrode lies, can be determined in all configurations with the help of the lateral direction of action without additional lateral penetration, so that the impaired area is limited to the introduction path, the target area as a result of the necessary treatment and at most the path from the introduction path laterally to the target area, but the latter only when The direction in which the target area lies is determined, and only if it turns out that the angle of the direction of action has not been recorded exactly, can a further lateral penetration be provided in the case of an embodiment with a pole carrier which can be extended in the direction of action (will be described further below) for target area detection. However, this is a e usually one-off correction, which is justified to achieve an even higher precision. This is not comparable with the “test bores” of US Pat. No. 6, 129, 685 required on all sides. The angle of the direction of action is thus detected without any tissue destruction, in particular without penetration of tissue by means of a probe in this direction. This is further illustrated in the drawing In addition, the invention makes it possible to make the electrode to be introduced very slim and thus to be able to travel a very narrow and therefore gentle introduction path.

For equally gentle treatment, it is expedient if the device for performing the medical intervention is introduced with the same direction of insertion in the same depth of insertion, in order not to cause additional damage by a further insertion path. This device should also be very slim.

Appropriate insertion devices are known, for example from the F.L. Fischer brochure "Riechert's Stereotaxic System" (5/87). However, other stereotaxy systems can also be used, such as that proposed by DE 100 32 203.

The device according to the invention is expediently additionally equipped with a device for carrying out the medical intervention, which also has a lateral effect, since only this combination allows the intervention to be carried out in a gentle manner. Such a device is known from US Pat. No. 5,785,704 for the purpose of tumor treatment, but it can also be used for the purpose of this invention, the prerequisite for this being the device according to the invention for detecting the position of the target area. However, the invention also proposes further treatment devices with side effects.

Appropriate developments of the invention optimize the effect according to the invention and pursue the purpose of achieving even greater protection of healthy tissue and determination of the target area in an even more precise manner. Two design options relate to the detection of a neural process. The device can thus be designed in such a way that the position of the target area can be determined by the electrode receiving the brain waves of the neural process of the target area and feeding it to a detector which is designed such that it detects it. Then the registration of the brain waves indicates that the insertion depth and the direction of action point to the target area. An alternative embodiment provides that the device is designed in such a way that the electrode applies parts of the previously determined area to excite the neural process of the target area with current signals, whereby the location of the target area can be determined by triggering the neural process of the target area. In this case, the current is applied to the brain cells and, depending on which brain area has been stimulated, a corresponding reaction of the patient can be observed. This observation can be carried out by an operator who signals to the device that the target area has just been excited by the current signal, which means that the device registers this position as the determined position. Of course, it is also possible that the device itself picks up the corresponding nerve impulses and thereby detects the triggering of the neuronal process.

The device can be designed for manual guiding and manual finding of the target area. For example, manual drives with gear ratios can be used for precise insertion and rotation within the smallest areas. A further embodiment of the device provides that it has a controller which is designed such that the position of the target area in the previously determined area can be determined by changing the detection area of the electrode by at least changing the insertion depth and the angle of the direction of action. These changes can include different search strategies, the electrode can be rotated step by step and at different insertion depths and 360 °, or it is possible for the poles of the electrode to perform a helical movement in order to move the entire space through a multiplicity of measuring points in this way to capture. Of course, there are also other strategies for detecting the electrode surrounding space possible. For this purpose, the device is expediently equipped with at least one drive for effecting the changes in the detection area, the control effecting the changes and detecting the entire area around the electrode by means of the detection areas, by scanning this area, so to speak, until the detection area hits the target area.

The angle of the direction of action to the direction of introduction can be fixed, it can be 90 ° or another angle can be provided. One embodiment provides that the device is designed such that the angle β of the effective direction to the direction of introduction is adjustable. It is then expedient if this angle β can be detected by the position detection device and used to determine the position of the target area to be treated. This can be used, for example, for the exact position of the target area to be determined by the respective approached insertion depth by means of the angle β when gradually approaching certain insertion depths.

An expedient development of the invention provides that the device is designed in such a way that the distance of the target area from the axis of the introduction path and thus also of the electrode from the position detection device can be detected and used to determine the position of the target area to be treated. This has the advantage of a much more precise determination of the target area, even if it is away from the introduction path. This distance must, of course, be within the detectable range. Such an exact detection also makes it possible to carry out a medical intervention just as precisely. Another advantage is that target areas can also be detected if there is no straight entry path to them, since there are brain or nerve areas that must not be penetrated on a insertion path.

At least the insertion depth and the

Angle of the direction of action detected. The latter angle specifies the angle of 360 ° from which the direction of action is directed away from the electrode, that is to say as a rule the degree of rotation of an electrode whose detection area is directed sideways outwards is. The 0 ° or 360 ° position is defined by definition. Furthermore, the position detection device can also detect the distance of the target area from the axis of the introduction path, as provided for in the aforementioned exemplary embodiment. In the event that the angle of the effective direction to the direction of insertion is not fixed, for example is not oriented perpendicular to the axis of the insertion path, but is variable, this angle should also be detectable by the position detection device in order to be able to indicate the exact position of the target area.

The position detection device can be designed in different ways, for example it can have a mechanism with pointers and scales for detecting at least one distance and / or at least one angle. Another possibility is that the position detection device has electronics for detecting at least one distance and / or at least one angle. This is preferable when computer acquisition and control is provided. Electronic detection can also be designed in various ways, for example the position detection device can have at least one potentiometer for detecting at least one distance and / or at least one angle, or it is possible for at least one light barrier system to detect at least one distance and / or at least one angle is provided. The light barrier system can, for example, be designed in such a way that it has at least one plate with openings which is connected to the electrode in such a way that it follows its positioning movements. One or more diodes and one or more photocells can then be arranged opposite one another at the openings, which emit and receive the signals to be processed by the electronics. For the detection of a distance it is then a slidable plate and for the detection of the angle of the direction of action a round disk, so that the angle of the rotational position can be detected.

The electrode must have at least one side-facing pole, and it is possible that the opposite pole can or can be applied to the patient's skin possible that the opposite pole is also arranged on the electrode and is directed in the same direction as the aforementioned pole.

Different insertion depths can be created not only by moving the electrode along the insertion path, but also by arranging several poles one below the other in the same direction and by applying the current signal from pairs of poles to the insertion depth, from which the effective direction to Target area leads, is determined. Here too, the direction of action can lead from the axis of the introduction path perpendicular to the target area or at a different, optionally adjustable angle. Different angles of the direction of action to the direction of insertion are also possible, so that each pair of poles can be used to examine an area assigned to it and thus a larger area can be continuously detected by the electrode. The advantage of an electrode with a large number of poles is that it can cover the entire area to be detected with one rotation.

If the position of the target area is determined by triggering a neural process and the distance of the target area from the axis of the introduction path is to be determined, it is possible that the position detection device is designed such that it also measures the distance of the target region from the axis of the introduction path Determines the amount of current required to generate a neural state of the target area. Of course, such circumstances as the current conductivity of the tissue and the sensitivity of the neurons in the target area must be taken into account.

With regard to the angle of the direction of action to the direction of insertion, there are various possibilities depending on the manner in which a neuronal process is detected: If the brain waves are detected, the position detection device can be designed such that the angle of the direction of action to the direction of insertion is based on the different strengths of the signals that arrive at the two poles can be determined. If, for example, they are of equal strength, this angle of the direction of action is 90 °, if you take the base point of the perpendicular between the two electrodes as a reference point. If the signals at an electrode are stronger, the target area is closer to the electrode at which the stronger signals are received, in accordance with this signal difference. If the neural processes are detected by the fact that they are triggered by the application of current signals, it can be provided that the poles can be subjected to signals of different strengths and the position detection device is designed in such a way that it assigns angles of the direction of action to the direction of introduction to this difference in the signals, the Angle of the most triggered neuronal process can be determined as true. Signals of different strengths are thus played through until such a series of experiments can be used to identify which signal strengths the most triggered neuronal process can be assigned, in order to then determine the aforementioned angle from them.

A distance of the target area from the axis of the introduction path can also be determined by the electrode covering this distance. For this purpose, it is proposed that the electrode have a displaceable, flexible pole carrier with an insulating jacket, which carries at least one pole at its tip and is guided around a curve in a guide tube in such a way that the tip can emerge laterally from the guide tube. The position detection device is then expediently designed in such a way that it determines the distance of the target area from the axis of the insertion path on the basis of the extent of the tip's emergence from the guide tube. In this case, the sensitivity is set in such a way that brain waves are only measured at the tip of the electrode, i.e. directly at the poles, or the current is so weak that only an electrode in the target area can trigger neuronal processes. In this way, not only the direction of the target area from the axis of the entry path can be determined, but also an exact distance of a target area from this axis, which makes it possible to determine the position considerably more accurately, even if the entry path to the target area is a certain distance away. In order not to injure tissue unnecessarily, however, the device is designed in such a way that first the insertion path and the direction of action with the pole carrier retracted and only then the distance of the target area with extended Renem pole carrier can be determined. Then, in order to determine the insertion depth and the direction of action, a higher sensitivity in the detection of brain waves must be set in order to be able to detect the brain wave of the neural process of the target area at a certain distance. In the other method, a stronger current must be applied to trigger the neuronal process of the target area located at a certain distance. Only then is the electrode moved out of the guide tube in order to carry out a fine determination of the target area by determining the distance from the axis of the insertion path. For this purpose, the device is designed in such a way that the tip can be retracted and only emerges from the guide tube to determine the distance. If the target area is not hit exactly, a correction can be made by extending it again in a slightly different direction of action.

In order that an intervention with the greatest possible protection of healthy tissue is possible, it is expedient if the insertion device and the position detection device are designed in such a way that a treatment device for performing the medical intervention can also be attached to the insertion device and that the position detection device also serves for the positioning of this treatment device. Then the treatment device is expediently introduced on the same introduction path. This can also be ensured in that the device has an insertion tube, through which the electrode and after determining the position of the target area, the treatment device can be brought into its working position without intermediate removal of the insertion tube. Such an insertion tube can also be identical to the above-mentioned guide tube for the pole carrier in order to guide a second pole carrier for treatment to the target region after the position of the target region has been determined.

In order to make the aim of the invention possible, namely an intervention with the greatest possible protection of healthy tissue, the device should additionally be equipped with a treatment device for performing the medical intervention, which has a lateral direction of action for the treatment of the target area. It can are, for example, the laser beam device already mentioned above with a laser beam emerging from the side. A treatment device can be carried out separately or by means of the insertion tube, or it is possible for the electrode and the treatment device to be integrated into one component. The electrode for determining the target area can also be designed such that it can be used as a treatment device. Such a treatment device can be a treatment electrode with two poles, which are directed sideways in one direction with regard to their action and thereby develop their action in a manner determined according to the depth of insertion and the angle of the direction of action. Such a treatment electrode can of course also be designed and inserted separately. However, a treatment device can also be designed as a treatment electrode with a pole, the effect of which is directed sideways in one direction. Monopolar coagulation can thus be carried out. Such a treatment electrode can be identical to an already described electrode for detecting the target area, which also has only one pole. The difference between target area detection and treatment then lies in the fact that the treatment requires a corresponding current application.

As already mentioned, the treatment electrode can also be designed in such a way that it can develop an effect in a target area that is at a distance from the insertion path. As an example of such a treatment device, it is possible that the treatment electrode is designed as a displaceable, flexible pole carrier with an insulating jacket, which has at least one pole in the region of its tip and is guided around a curve in a guide tube in such a way that the tip emerges laterally from the Guide tube can come out. This treatment electrode therefore corresponds to the electrode already designed above for determining the position of the target area. Of course, it is also possible that the latter electrode is designed to detect the neural process of the target area in such a way that it can also be used for medical treatment by appropriate current signal application or current application to the target area. For example, this current application can then be designed such that a dysregulated center is not excited, but is influenced or switched off.

The above-mentioned embodiments of the invention are only exemplary embodiments, other possibilities are also conceivable in which the position of a target area can be determined by distances and angles without any unnecessary tissue damage, which then serve to position a treatment device or which serve the location of the treatment to record exactly for further medical measures.

The invention is explained below with reference to the drawing. Show it

1 shows the principle of the invention on the basis of a first exemplary embodiment,

Fig. 2 shows another embodiment with an improved

Target area detection and an explanation of the difference to the state of the art,

3 shows all necessary and possible positioning,

4 and 4a an exemplary embodiment of a feeding device with control and drives,

5 and 5a an embodiment of an electrode with two poles and a detection example,

6 shows another detection example of an electrode with two poles,

7 shows an electrode with a plurality of poles,

8 shows an electrode with a displaceable pole carrier, 9 shows a treatment electrode with a displaceable pole carrier,

10 shows a mechanical position detection device,

11 shows a light barrier system for path detection and

Fig. 12 is a light barrier system for angle detection.

Fig. 1 shows the principle of the invention based on a first embodiment. In order to determine the position of the type mentioned at the outset, an electrode 6 on the patient's head 3 is brought into a defined position and is introduced into the brain 2 in an insertion direction φ _x , φ _y through the skull cap 36, this insertion path 12 being determined by a preliminary examination at which the area 7 (see FIG. 2) of the target area 1, 1 'was determined. The exact location of this target area 1, 1 'is to be found by means of the electrode.

The above-mentioned prior art provided for determining a penetration depth a in which a partial area T (see FIG. 2) of the previously determined area 7 with the target area 1, 1 'is located on the insertion path 12. The penetration depth a is measured from a defined point, for example the penetration point 4 into the head 3. Since the previous determination of the area 7 of the target area 1, 1 'always has inaccuracies and the electrode 6 often passes the target area 1, 1', this determination of position was often very imprecise. It could sometimes only be done by increasing the sensitivity of the detection of the target area 1, 1 'by the electrode in order to also locate a target area 1, 1', which is located next to the insertion path 12. However, this had the consequence that the entire partial area T then had to be subjected to the treatment, since it could not be determined on which side of the introduction path 12 the target area 1, 1 'is located. Therefore, the invention provides that the electrode 6 for the detection of the target area 1, 1 'has a lateral direction of action 9, the angle of which can be included in the position determination in addition to the abovementioned determination of the depth of penetration a. A direction of action 9 for detecting a neuronal process can mean the measurement of the brain waves of the neuronal process that arrive at the electrode 6 starting from the target area 1, 1 '. For this purpose, the electrode 6 rotates with the poles 19 and 20 until the signals are received. It is also possible for the electrode to emit current signals in different directions of action 9, which trigger a neuronal process and thereby enable the determination of the target area 1, 1 'by detecting the angle α when the neuronal process of the target area 1, 1' is triggered. The insertion depth a and the angle α of the direction of action can thus be detected at the moment the neural process of the target area is triggered, the latter can be registered by observation or by measuring nerve impulses.

However, in order to detect the position of the target area 1, 1 ', the direction of action 9 of the electrode 6 must be adjustable in all directions of a circle of 360 °. This all-round movement of the direction of action 9 takes place at different insertion depths a, a ', a "until the detection area 32 of the electrode 6 meets the target area 1, 1', which is noticeable by triggering the neuronal process or by measuring the brain waves The angle is determined by determining the position of the target area 1, 1 'starting from an axis 11. The 0 or 360 ° position is defined by definition within the circle and the angle is measured from there.

There are various possibilities for achieving an effective direction 9 of the electrode 6. One is that the electrode 6 has a pole 19 and an opposite pole 20, which are directed laterally in one direction in order to send out current signals in this direction or to detect brain waves coming from this direction. In this detection process, after the electrode 35 has been introduced 35, a rotation 34 must take place at different insertion depths a and an application 35 after the detection of the target area 1, 1 '. Different search strategies are possible, for example, the electrode 6 can also be guided with rotation 34 in the direction of the arrow 35, in order to thereby scan the brain areas in which the target area 1, 1 'can be located by means of a helical movement.

FIG. 2 shows a further exemplary embodiment with an improved target area detection and an explanation of the difference from the prior art. First, the area 7 of the target area 1, 1 'is drawn in on the basis of this representation, as was previously determined by an imaging method. According to the prior art, this area 7 was limited to a partial area 7 ', which included the target area 1, 1' but was still large enough to surround the electrode 6 in a rotationally symmetrical manner. This area T was then also treated, with the result that, for example, neurons were switched off which are not at all in the target area 1 'to be treated, for example dysregulated. This causes damage, which is particularly large if there is a risk organ 33 within the treated area 7 '. In the latter case, treatment was often even impossible because there was a fear of a loss of vital functions. For this reason, the electrode 6 according to the invention determines the lateral position of the target area 1, 1 'in the manner shown above.

However, this determination of the position of the target area 1, 1 'by the angle α is often not precise enough if the target area 1' is at a distance b from the axis 11 of the introduction path 12 in its exact delimitation 1 '. If in this case only the angle α and the insertion depth a were determined, then a target area 1 would have to be treated which, starting from the insertion path 12, comprises an area in which the precisely defined target area 1 'lies. The larger target area 1 would thus be determined and this would also have to be treated, although neurons that do not belong to the dysregulated neurons would also be treated here, albeit to a much lesser extent. This also produces side effects which can be avoided by only detecting and treating the narrowly limited target area 1 '. This is possible because the distance b of the target area 1 'from the axis 11 is determined. The possibilities of determining such a distance b will also be discussed on the basis of the other representations.

The effective direction 9 can have an angle β of 90 ° to the axis 11 or it is also possible to provide an effective direction 9 with a different angle β. It is also possible to make this angle β of the effective direction 9 variable with respect to the axis 12 extending in the direction of introduction φ _x , φ _y and also to detect the setting of this angle β. Execution options for this are also described.

Fig. 3 shows a representation of all necessary and possible positions, first a point in space must be defined as the starting point for the introduction of the electrode 6, for example the insertion point 4 according to the coordinates x, y and z. Proceeding from this, the introduction path 12, the axis 11 of which is drawn in here, must also be defined, by starting from point 4, the introduction direction is determined according to the coordinates φ _x and φ _y . Only then can the electrode 6 be introduced, the approximate depth of the area 7 of the target area 1, 1 'also being prerecorded in order not to have to scan an excessively large area by means of different directions of action 9. This scanning takes place around the electrode 6, that is to say in a circle of 360 °. If the angle β of the direction of action 9 to the axis 11 is 90 °, this scanning takes place on circular disks of different insertion depths a, a ', a ",..., To protect tissue, it is preferable to start at a shallower depth and then to greater depths If this angle ß deviates from 90 °, this scanning takes place in a corresponding cylinder jacket plane, scanning an area of the brain 2 until the location of the target area 1 is found and by the insertion depth a and the angle In order to be able to find a precisely delimited target area 1 'which lies at a certain distance b from the introduction path 12, the distance b of the target area 1' from the axis 11 of the introduction path 12 must also be determined.

4 and 4a show an embodiment of an insertion device 5 with a controller 26 and drives 27, which the setting of the insertion path 12 and finally serve to find the above positions. The insertion device 5 expediently serves not only to hold the electrode 6, but also to hold and position a treatment device 28, so that it is also possible to position it exactly in relation to the target area 1 or 1 ′ and to carry out the treatment there. Of course, the design of this insertion device 5 is only exemplary, as mentioned at the beginning, other insertion devices can also be provided.

The insertion device 5 shown has a head ring 37 which is fixed on the head 3 of the patient. Such determinations can be made by adjusting screws on the skullcap 36 or in some other way. On this head ring 37 a pivot bracket 38 is fastened in a pivotable manner, which is semicircular and on which a holder 39 is mounted such that it is displaceable on the circular ring of the pivot bracket 38. The latter is illustrated in Fig. 4a. In this way it is possible to move to any insertion point 4 on the head 3 by means of the displacement of the holder 39 on the swivel bracket 38 and by the swivel of the bracket 38 to the head ring 37. The holder 39 serves for receiving the electrode 6 or for receiving a drive 26 and a positioning device 45 and a position detection device 8. This can be used to set the insertion direction φ _x and φ _y , the insertion and removal 36 of the electrode 6 and its rotation 34 carry out and at the same time hold on to all of the above-mentioned positions. It is thus possible to set and record the insertion depth a, a ', a ", the angle and possibly also the angle β and the distance b of the target area 1' from the axis 11, and to find them again for treatment by means of a treatment device 28 drives 27 are also provided for pivoting the swivel bracket 38 and for adjusting the holder 39 on the swivel bracket 38. The adjustments of the swivel bracket 38 and the holder 39 are indicated by arrows 46.

A controller 26 designed as a computer is preferably provided, which is equipped with all drives 27, with the position detection device 8 and the positioning device. tion device 45 is connected and which performs all of the aforementioned setting options, performs the search for the target area 1, 1 'by the electrode 6 using a defined strategy and determines the position of the target area 1, 1' in such a way that it is carried out by a treatment device 28 medical intervention can be found again.

5 and 5a show an exemplary embodiment of an electrode 6 with two poles 19 and 20 and a detection example for the distance b of the target area 1 'from the axis 11.

FIG. 5 shows the electrode 6 with the poles 19 and 20 arranged one above the other, which serve to detect a laterally located target area 1, 1 'due to their lateral alignment.

5a shows how the distance b of a target area 1 'from the axis 11 of the insertion path 12 and thus also the electrode 6 can also be measured by means of such poles 19 and 20. This is possible, for example, in that a current signal is applied in different directions of action 9 and the position of the target area 1 'is determined in that a certain current strength of the signals is required to trigger the neural process of the target area 1'. The required current strength is a measure of the path b and thus of the distance b that the current has to travel to reach the target area 1 '. Of course, when converting the required current strength into the distance b, the current conductivity of the tissue and the sensitivity of the neurons to be stimulated must be taken into account, and experience values can be used as a basis

FIG. 5a also shows an insertion tube 29 which serves to first lead the electrode 6 and then a treatment device 28 for performing the medical intervention without stressing the adjacent tissue parts again. 6 shows a further exemplary embodiment of an electrode 6 with two poles 19 and 20. In this exemplary embodiment, the signal strength at the poles 19 and 20 is used to determine the angle β which the effective direction 9 has to the axis 11. In this embodiment, the direction of action 9 is the direction from which - viewed from the electrode 6 - the brain waves 40, 40 'arise, that is, the neurons of the target area 1, 1' produce them. The starting point of the direction of action 9 must be precisely defined. The point of axis 11 is chosen as the starting point, which lies exactly in the middle between the poles 19 and 20. If the target area 1, 1 'is exactly in the middle between the poles 19 and 20, this is the target area 1, 1', which is drawn with a closed line, the brain waves 40 which are from this target area 1, 1 ' start, received equally strong by poles 19 and 20, since the distances are the same. If the target area 1, 1 'is not in the middle between the two poles 19 and 20, as is the case with the dashed target area 1, 1', the brain waves 40 'have to travel uneven paths and are therefore at the poles 19 and received 20 different strengths. In the present case, the signals at the opposite pole 20 are stronger than at the pole 19, and the angle β of the effective direction 9 can be calculated from this difference in signal strength.

In the other method of detecting the neural process, the angle β of the direction of action 9 to the direction of introduction φ _x and φ _{y can be} detected. In this case, poles 19 and 20 emit current signals of different strengths in order to detect the strength at which these signals trigger a neuronal process in the target area 1, 1 '. For example, in the target area 1, 1 ', which is drawn with the closed line, the strongest neuronal process is triggered when both signals are of the same strength. A correspondingly strong neural process in the target area

1, 1 ', which is drawn in broken lines, the signals of the poles 19, 20 must be so different that they arrive equally strong in this target area 1, 1'. It also applies to the representation of Fig. 6, if you look at the arrows of the

Lines showing brain waves 40, 40 'converse and thereby these lines symbolize the signals emitted by the poles 19, 20. 7 shows an electrode 6 with a multiplicity of poles 19, 20. This electrode 6 can be inserted and removed in the direction of arrow 35, it not being necessary to find the insertion depth a, a 'or a "the electrode 6. Rather, it is possible to select two of these poles 19, 20 in each case in order to determine, in the manner already described, the insertion depth a, a ', a ", ... the target area 1, 1' is.

8 shows an electrode 6 with a displaceable pole carrier 21. This pole carrier 21 is flexible, has a sheathing 22 and feed lines 42 to the poles 19, 20, and a tip 23. It is mounted in a guide tube 24 which has a longitudinal bore, has a curve 25 and then a transverse bore. The latter extends at an angle β, which determines the direction of action 9 to the axis 11. The angle β can be 90 ° or another angle. By means of a displaceability 41 of the pole carrier 21 it can be achieved that its tip 23 closes with the outer wall of the electrode 6 or it can be displaced in such a way that a dimension b from the axis 11 to the poles 19, 20 is achieved. The dimension b corresponds to the distance b of the target area 1 'from the axis 11 when the neuronal process is optimally received or optimally triggered, depending on which of the two detection options listed is selected.

The detection of the neural process is preferably carried out by the tip 23 being first in the electrode 6 and a displacement in the direction of the arrow 35 and a rotation in the direction of the arrow 34 until the detector connected to the electrode 6 responds, that is to say that neural processes are stimulated or brain waves associated with them are received. In order to enable reception from a target area 1 'which is distant from the introduction path 12, the signals must have a certain strength or the signal reception must be amplified accordingly. If the insertion depth a and the angle α of the position of the target area 1, 1 'are determined in this way, the displacement b of the pole carrier 21 can also be used to determine the dimension b, which is the distance of the target area 1' from the axis 11 of the electrode 6 indicates. Preferably be a large number of measuring points are recorded during this displacement 41, preferably starting at the electrode 6 for protection.

This configuration enables a very exact detection of the position of a target area 1 ', penetration of tissues through the pole carrier 21 is only necessary where dimension b has to be detected. A trial run through the pole carrier 21 is not necessary to determine the insertion depth a and the angle α. Extending again can only serve as an exception to correct a not exactly determined insertion depth a or an angle that is not exactly recorded. The pole carrier 21 can also be made very thin, so that the extension represents only a minor impairment.

Alternatively, the pole carrier 21 can also be equipped with a pole 19, which is arranged, for example, at the tip 23.

FIG. 9 shows a treatment device 28 designed as a treatment electrode 30, which is constructed according to the same principle as the aforementioned electrode 6 and which can also be identical to the latter, the functions differing only in that the treatment requires a current to be applied through which the success of the treatment is achieved. Identical reference numerals or the aforementioned reference numerals, which are identified here with a line, correspond to the components already mentioned above. In contrast to the pole carrier 21, the pole carrier 21 'has poles 31 and 31' for carrying out a treatment. These are poles 31 and 31 ', which send out current signals which serve to influence neurons in target area 1', be it that the neurons are excited thereby or that these are functionally switched off by the application of current or the heat generated thereby, in order to malfunction to eliminate.

The advantage of this treatment electrode 30 is that in a precisely defined target area 1 ', which is distant from the axis 11 of the insertion path 12 by the dimension b, the

Intervention can be carried out without neurons that the target area 1 ' neighboring are affected to a relevant extent. Here, too, the pole carrier 21 'can be made very thin in order to minimize any impairment due to the extension of the pole carrier 21'.

The treatment electrode 30 can alternatively be equipped in such a way that the pole carrier 21 'has only one pole 31, which is located, for example, at the tip 23'. Such a single-pole treatment electrode 30 then serves to produce a targeted monopolar coagulation at a distance b from the axis 11.

10 shows a mechanical position detection device 8. The arrangement is as shown in FIGS. 4 and 4a, with the mechanical position detection device 8 taking the place of electronics. This consists of a scale 14 with a pointer 13 which indicates the insertion depth a currently achieved due to the displacement of the electrode 6.

Furthermore, this mechanical position detection device 8 consists of an angle detection device 10 which has a circular scale 15 for the angle detection by means of a pointer 13. The pointer 13 or the scale 15 is coupled to the electrode 6 and the other part is fixed so that the rotation 34 can be read. Of course, one of the abovementioned acquisitions can also be carried out mechanically and the other electronically, or it is possible to provide both acquisition systems at the same time, so that an immediate visualization on the insertion device 5 is possible and at the same time the control 26 can be acted upon with electronic signals.

11 shows a light barrier system 16 for path detection, in which a plate 17 with openings 18 takes the place of the scale 14, the plate 17 being displaceable in the direction of the double arrow 35 with the electrode 6. A light-emitting diode 43 and a photocell 44 are arranged so that the position of the plate 17 can be determined from the light receptions. For example, electronics can count the light signals and thereby assign the position of the plate 17. Of course, that could also Light-emitting diode 43 and the photocell 44 can be moved and the plate 17 is fixed. Both the insertion depth a and the distance b can be detected by this or the path detection shown above. In the latter, the amount of displacement of the pole carrier 21 or 21 'to the guide tube 24 or 24' must be determined.

12 shows a light barrier system 16 for angle detection 10. Here, a round plate 17 'with openings 18 is provided and also a light-emitting diode 43 and a photo cell 44, which are not shown, however. The principle is the same, the angle α of the direction of action 9 being detectable.

Of course, the illustrations only show exemplary implementation options. It would be conceivable, for example, that the electrode 6 with the displaceable pole carrier 21 of FIG. 8 also serves as a treatment electrode, as is shown in FIG. 9, thereby maintaining the position for the medical intervention, or of course also being detected to log the treatment and to know the target area 1 'with regard to its location for further medical treatment.

There are also a wide variety of options for designing insertion devices 5; for example, fixation by means of an articulated arm can also be provided. The formation of the electrode 6 is also possible in another way, for example a pole carrier 21 could also have poles 19, 20 directed to the side in order to detect the position of a target area 1 ′ even more precisely. In a corresponding manner, this could also be provided for a treatment electrode 30. Further variations and combinations of different features are conceivable. Device for determining the position of a target area to be treated in the brain

LIST OF REFERENCE NUMBERS

1, 1 'target area

1 'exact localized target area

2 brain

3 head

4 penetration point

5 insertion device

6 electrode

7 area of the target area (pre-determined)

T part of the target area through the device

Technology determined

8 position detection device

9 Arrow: direction of action

10 angle detection device

11 axis

12 feed path

13 hands

14 Scale for path detection

15 Scale for angle detection

16 light barrier system

17, 17 'plate

17 for recording the insertion depth

17 'for the detection of the angle α of the direction of action perforations

pole

Flexible pole carrier movable against the opposite pole

jacket

top

guide tube

Curve ', 22', 23 '', 25 'formed the above components for a treatment electrode 30

control

drive

Treatment device for performing a medical procedure

Einbringröhre

Treatment electrode, 31 'poles of the treatment electrode

Coverage area

risk organ

Double arrow: rotation of the electrode

Double arrow: insertion and removal of the electrode

skullcap

head ring

swivel bracket

Bracket, 40 'brain waves at ß = 90 ° 40 'at ß> 90 °

41 Slidability of the pole carrier

42 feed lines to the poles

43 light emitting diode

44 photocell

45 positioning device

46 arrows: adjustment of the swivel bracket 38 and the bracket 39

φ _x , φ _y insertion direction a, a ', a "insertion depth a', a" insertion depth in a device that enables directions of action from different depths α angle of the direction of action ß angle of the direction of action to the direction of insertion b distance of the target area 1 'from the axis 11 of the insertion path 12

(where b is measured at an angle ß = or ≠ 90 ° to the axis)

Claims

Device for determining the position of a target area to be treated in the brain

1. Device for determining the position of a target area to be treated (1, 1 ') in the brain (2) with an insertion device (5) which can be arranged on the head (3) of a patient, according to predetermined spatial coordinates (x, y, z) and a predetermined insertion direction (φ _x , φ _y ) leads an electrode (6) into the previously determined area (7) of the target area (1, 1 ') in order to make an exact determination of the position thereof by detecting neuronal processes in the target area (1, 1') and to make the position data available for a therapeutic intervention and reproducible, the insertion depth (a, a ', a ") of the electrode (6) being detectable by means of a position detection device (8) when detecting a neuronal process, characterized in that the electrode ( 6) is designed such that it has a direction of action (9) for detecting neuronal processes, which can be set to the side of the electrode (6) pointing in all directions (360 °), and that the position detection Solution device (8) also has an angle detection device (10), by means of which the angle (α) of the effective direction (9) can be determined when a neuronal process is detected.

2. Device according to claim 1, characterized in that it is designed such that the position of the target area (1, 1 ') can be determined in that the electrode (6) the brain waves of the neuronal process of the target area (1, 1') receives and supplies a detector which is designed such that it detects them.

BESTATIGUNGSKOPIE

3. Apparatus according to claim 1, characterized in that it is designed such that the electrode (6) parts of the area (7) for excitation of the neural process of the target area (1, 1 ') with current signals, whereby the location of the target area (1, 1 ') can be determined by triggering the neural process of the target area (1, 1').

4. Apparatus according to claim 2 or 3, characterized in that it is designed for a manual introduction and a manual location of the target area (1, 1 ').

5. The device according to claim 4, characterized in that manual drives with translations of the exact introduction (35) and rotation (34) of the electrode (6) serve within the smallest areas.

6. Apparatus according to claim 2 or 3, characterized in that it has a controller (26) which is designed such that the position of the target area (1, 1 ') in the area (7) by changes in the detection area (32) Electrode (6) can be determined by changing at least the insertion depth (a, a ', a ") and the angle (α) of the direction of action (9).

7. The device according to claim 6, characterized in that it has at least one drive (27) for effecting the changes in the detection area (32).

8. Device according to one of claims 1 to 7, characterized in that the angle (β) of the effective direction (9) to the direction of introduction (φ _x , φ _y ) is fixed.

9. The device according to claim 8, characterized in that the angle (ß) is 90 °.

10. Device according to one of claims 1 to 7, characterized in that it is designed such that the angle (β) of the effective direction (9) to the direction of introduction (φ _x , φ _y ) is adjustable.

11. The device according to claim 10, characterized in that the angle (ß) of the position detection device (8, 10) can be detected and used to determine the position of the target area to be treated (1, 1 ').

12. The device according to one of claims 1 to 11, characterized in that it is designed such that the distance (b) of the target area (1 ') from the axis (11) of the introduction path (12) from the position detection device (8, 10) is detectable and can be used to determine the location of the target area to be treated (1 ').

13. Device according to one of claims 1 to 12, characterized in that the position detection device (8, 10) has a mechanism with pointers (13) and scales (14, 15) for detecting at least one distance (a, a ', a ", b) and / or at least one angle (α, β).

14. Device according to one of claims 1 to 13, characterized in that the position detection device (8, 10) an electronics for detecting at least one distance (a, a ', a ", b) and / or at least one angle (, ß) having.

15. The apparatus according to claim 14, characterized in that the position detection device (8, 10) has at least one potentiometer for detecting at least one distance (a, a ', a ", b) and / or at least one angle (α, ß).

16. The apparatus according to claim 14 or 15, characterized in that the position detection device (8, 10) at least one light barrier system (16) for detecting at least one distance (a, a ', a ", b) and / or at least one angle (, ß).

17. The apparatus according to claim 16, characterized in that the light barrier system (16) has at least one plate (17) with openings (18) which is connected to the electrode (6) in such a way that the adjusting movements (a, a ', a ",, ß, b) participates.

18. The device according to one or more of claims 1 to 17, characterized in that the electrode (6) has a side-facing pole (19).

19. The apparatus according to claim 18, characterized in that the opposite pole (20) on the skin of the patient (4) can be applied.

20. The apparatus according to claim 19, characterized in that the opposite pole (20) on the electrode (6) is arranged in the same direction as the pole (17) directed.

21. Device according to one of claims 1 to 17, characterized in that a plurality of poles (17, 20) are arranged one below the other in the same direction and by means of the current application of pairs of poles (17, 20) the insertion depth (a, a ', a "), from which the effective direction (9) leads to the target area (1, 1 ') can be determined.

22. The apparatus of claim 3 and 12 with claim 20 or 21, characterized in that the position detection device (8) is designed such that it the distance (b) of the target area (1 ') from the axis (11) of the introduction path (12th ) determined with the aid of the current intensity which is required for generating the neural state of the target area (1 ').

23. The device according to claim 2 and one of claims 20 or 21, characterized in that the position detection device (8) is designed such that the angle (β) of the effective direction (9) to the direction of introduction (φ _x, φ _y ) from the different The strength of the signals arriving at the two poles (17, 20) can be determined.

24. The device according to claim 3 and one of claims 20 to 22, characterized in that the poles (17, 20) can be acted upon with signals of different strengths and the position detection device (8) is designed such that it angle this difference of the signals (ß ) assigns the direction of action (9) to the direction of insertion (φ _x, φ _y ), the angle (β) of the most triggered neuronal process being able to be determined as applicable.

25. The device according to one or more of claims 1 to 17, characterized in that the electrode (6) has a displaceable flexible pole carrier (21) with an insulating sheath (22) which in the region of its tip (23) at least one pole ( 19, 20) and is guided in a guide tube (24) around a curve (25) in such a way that the tip (23) can emerge from the side of the guide tube (24).

26. The apparatus according to claim 25, characterized in that the position detection device (8) is designed such that it the distance (b) of the target area (1) from the axis (11) of the insertion path (12) due to the degree of emergence of the tip (23) determined from the guide tube (24).

27. The apparatus of claim 25 or 26, characterized in that a plurality of guide tubes (24) are formed with such different curves (25) that thereby different angles (β) of the direction of action (9) to the direction of introduction (φ _> φ _y ) are available ,

28. Device according to one of claims 1 to 27, characterized in that it is designed such that first the introduction path (a) and the angle (α) of the direction of action (9) and then the distance (b) of the target area (1 ' ) can be determined by the axis (11).

29. The device according to claim 28, characterized in that the tip (23) only emerges from the guide tube (24) to determine the distance (b).

30. The device according to one or more of claims 1 to 29, characterized in that the insertion device (5) and the position detection device (8, 10) are designed such that a treatment device (28) for performing the medical intervention can be attached to this and that the position detection device (8, 10) also serves to position this treatment device (28).

31. The device according to claim 30, characterized in that the treatment device (28) is introduced on the same introduction path (12).

32. Device according to one of claims 1 to 31, characterized in that it has an insertion tube (29) through which the electrode (6) and after determining the position of the target area (1, 1 '), the treatment device (28) without intermediate Removal of the insertion tube (29) can be moved into their working positions.

33. Device according to one of claims 30, 31 or 32, characterized in that it is additionally equipped with a treatment device (28) for performing the medical intervention, which has a lateral direction of action (9) for treating the target area (1, 1 ' ) having.

34. Apparatus according to claim 33, characterized in that the treatment device (28) is a laser beam device with a laterally emerging laser beam.

35. Apparatus according to claim 33 or 34, characterized in that the electrode (6) and the treatment device (28) are integrated in one component.

36. Apparatus according to claim 33, characterized in that the electrode (6) for determining the target area (1, 1 ') is such that it can also be used as a treatment device (28).

37. Apparatus according to claim 33, 35 or 36, characterized in that the treatment device (28) is a treatment electrode (30) with two poles (31, 31 ') which are directed sideways in one direction with regard to their action.

38. Apparatus according to claim 31 to 33, 35 or 36, characterized in that the treatment device (28) is a treatment electrode (3) with a pole (31), the effect of which is directed sideways in one direction.

39. Apparatus according to claim 33 or 35 to 38, characterized in that the treatment device (28) is designed such that it can be used to develop an effect in a target area (1 ') which is at a distance (b) from the introduction path ( 12) lies.

40. Apparatus according to claim 39, characterized in that the treatment electrode (30) is designed as a displaceable, flexible pole carrier (21 ') with an insulating jacket (22') which has at least one pole (31,) in the region of its tip (23 '). 31 ') and is guided in a guide tube (24') around a curve (25 ') such that the tip (23') can emerge laterally from the guide tube (24 ').

41. Device according to one of claims 36 to 40, characterized in that the electrode (6) is designed to detect the neuronal process in such a way that it can also be used for medical treatment by corresponding current application to the target area (1, 1 ') ,