DE102007009016A1 - Marker for determining position of target tissue of human brain during e.g. surgery, has capsule which is biologically degradable after medical intrusion, and containing substance detected by detection system - Google Patents

Abstract

The marker (10) has a detecting system (14) for detecting a target tissue (12) during medical intrusion. A capsule (16) which is biologically degradable after the intrusion is provided in the marker. The capsule contains a substance (18) detected by the detection system, where the substance is provided in the form of particles (20), nano-particles or biocompatible aggregate. Gold, iodine or barium contained in the capsule is detected by x-ray. The capsule is loaded with iron and/or gadolinium, which are detected by a magnetic resonance unit. An independent claim is also included for a method for determining position of a target tissue.

Description

The The present invention relates to a mark for position determination of a target tissue and a method for determining the location of a target tissue during a medical procedure. Furthermore, a Location system specified, especially for a surgical Navigation system application finds.

A generic mark is from the WO-A 97/045064 known. This marking is optically detectable during a medical procedure by means of a camera system and in this case serves to calibrate the camera system. The calibration is used to calibrate image data of a vision-guided surgical system. This image data contains information regarding the position of the marker to the operation area.

A location system having the features of the preamble of claim 13 is known from US 5,389,101 known. This location system determines the position of an instrument during a medical procedure with a data processor which has position data of a marking arranged on a patient and relates to the position of the instrument which can be determined by the positioning system.

Either the marker as well as the locating system are used in medical Interventions such as operations or examinations are used to accomplish this used instruments with image-based navigation systems regarding their situation.

there is of a fixed arrangement of a to be examined or to be processed target tissue, otherwise recalibration necessary is. A body part comprising the target tissue is to be fixed until the end of the procedure. This is at a constantly moving organ such as a heart or a lung only possible with great effort. Also, the target tissue may be through the intervention itself from its initial position remove. For example, this can be done by mechanical force occur, which is a stretching, compression and / or deformation of the target tissue caused. Furthermore, changes in the target tissue conceivable during the procedure, as when removing by Disease altered material or adding of implants. Of particular disadvantage is that a location of the Instruments is no longer sufficient to determine its exact location. In particular, its relative position to the target tissue is not detectable.

Of the The invention is therefore based on the object of specifying a marking, the with technically simple means a continuous position determination of the target tissue.

These Task is the marking of the invention achieved in that the mark formed by a capsule which is biodegradable after the procedure and at least contains a detectable by the locating system substance.

From A particular advantage here is that the capsule very close to the Target tissue can be brought and for a variety of Locating systems is customizable. The location system can be the capsule continuously during the procedure and detect their movement especially in real time. Also, a distance is the Marking no longer necessary, which in addition to a cost savings especially the risk of infection greatly reduced.

To the one, the mark can be designed passive. The location system detects the mark, for example by means of radiation, wherein the detectable substance that weakens radiation, scatters or absorbed. On the other hand, the label can be actively formulated be. The detectable by the locating system substance has this certain physical or chemical properties of Sensors of the positioning system can be detected. These Property of the substance could be more radioactive, more magnetic or optical type.

Around the marker for different target tissues and locating systems To make it usable, it is intended that the locating system detectable substance in the form of particles, nanoparticles or a biocompatible complex. Thus, the substance can be quantitative be varied. By means of the complex can also their whereabouts in the target tissue from hours over days to weeks set become. Are, for example, screening of a Planned longer, may be on a re-marking be waived.

A sees particularly advantageous embodiment of the marker that gold, iodine, barium or a combination thereof in the Capsule is contained, which from the locating system using X-rays is detectable. Such substances have for example one high X-ray contrast and can be very good be located. In addition, a low dose of radiation from the location system be used.

According to a further embodiment of the marking, the capsule is loaded with iron and / or gadolinium, which can be detected by the locating system by means of magnetic resonance. This is in particular A very precise three-dimensional tracking of the movement of the target tissue is possible.

Also the marking can be carried out by means of sonographic scanning devices be followed. For this purpose, it is particularly advantageous if microbubbles, in particular from carbon dioxide, contained in the capsule, which from the locating system can be localized by means of ultrasound. This allows during the procedure also different tissues of the target tissue be presented, so that in addition to a precise position determination also a distinction of the tissue is possible.

The accurate positioning of the mark can also be used be in addition to translational movements and a change of Orientation, for example, to detect a rotation of the target tissue. The marker according to the invention can be advantageous be developed such that the capsule a magnetic moment that can be detected by the locating system by means of a magnetometer is. In particular, by a plurality of markings and a Variety of magnetometers can be a multi-dimensional record the movement and orientation of the target tissue.

Favorable Way the marker is designed so that the capsule a has approximately circular cross-section. The mark has thereby particularly flow-optimized profile, for example, over a blood vessel with a catheter, a needle or the like, to be arranged close to the target tissue.

For this furthermore, the marking can advantageously be formed so on, that the capsule with a holding element for fixing to a vessel wall is provided. Here, in addition to the capsule and the retaining element be dissociated from the bloodstream or transported away.

A particularly advantageous embodiment of the invention Marking provides that the capsule is absorbed by the body, degraded or excreted. In addition to the detectable substance can the capsule or its capsule shell after the procedure biodegraded. Materials for this can for example, biodegradable polyesters, such as polyglycolide, polyactide, its copolymers or copolymers with units of trimethylene carbonate, Polycaprolactam, poly (para-dioxanone) and starch-based polymers be.

It Another object of the present invention is a method for determining the position of a target tissue, which is technically simple means a continuous position tracking of the target tissue provides.

These The object is achieved according to the invention that a marker of the aforementioned type close to the target tissue is arranged, whose target coordinates are determined by the sensor and transmitted from the sensor to the data processor, the difference coordinates from the sensor coordinates and the target coordinates calculates which position of the target tissue relative to the sensor correspond.

These Solution is characterized in particular by the fact that the capsule can be arranged close to the target tissue and in particular its Position during the procedure with high repetition rate very is exactly determinable. The sensor provides a reference point is the starting point for calculating distances between the sensor and the markings is. The mark represents the Position of the target tissue. In other words, the show Difference coordinates from the sensor the position of the target tissue at. Even moving tissue can thus very accurately from the sensor starting with the direction and distance from the difference co-ordinates are derivable.

To a particularly advantageous embodiment of the invention Procedure, it is provided that the capsule by means of a needle or a catheter over a vessel or by means of a firing device or a puncture needle percutaneously is introduced into the target tissue. Thus, by a minimally invasive Intervention that can occur during the procedure, the Marking be placed targeted close to the target tissue. Especially can for the purpose of accurate tracking of changes in position also several spaced-apart markings be set.

The The inventive method can also be advantageous be developed such that the sensor on an instrument is arranged. Is the instrument used to examine a the mark provided organ used which over a vein, an artery or another vessel for Organ is to be led, can be by means of Sensors to determine the distance to the target tissue. This can be special then be advantageous when it comes to accurate positioning of the Instruments arrives during medical intervention. This is for example in the case of vascular dilatation.

It Another object of the present invention is a location system specify the type mentioned, the position of an instrument determined in relation to the mobile target tissue, whereby the Positioning system detected position of the instrument to the position change of the target tissue is corrected.

These The object is achieved according to the invention that the position data of the marking of the above Kind of locating system are repeatedly detectable, with which the data processor calculated a relative position to the mark, wherein the determined Position of the instrument serves as origin coordinates. Thus, will the basis for calculating the relative position of an instrument repeatedly corrected during an intervention by the position of the marking currently detected by the positioning system for calculation can be used.

After all the marker of the invention is the above mentioned type with a navigation system for medical Interventions used that a inventive Location system includes.

Further Features and advantages of the invention will become apparent from the following Description of several embodiments and from the Drawings, to which reference is made below. Show it:

1 a schematic representation of a first embodiment of a marker according to the invention;

2 a cross-sectional view of a second embodiment of a marker;

3 another embodiment of a marker;

4 a schematic representation of another marker according to the present invention;

5 an embodiment of a location system for determining the position of a marker according to the invention;

6 a diagram of a method according to the invention;

7 a partial diagram of a second embodiment of a method according to this invention; and

8th a further partial diagram of a third embodiment of a method according to the invention.

Provided not otherwise stated below, the following description applies always for all figures and the same reference numbers always refer to the same technical characteristics.

In 1 is a mark 10 shown in the position of use for determining the position of a target tissue 12 serves. This target tissue 12 is a section of a human brain being examined during a medical procedure. The brain virtually floats in a brain shell and moves in particular under mechanical stress during the procedure. The mark 10 is by means of a location system 14 detectable. Thus, a change in position of the target tissue 12 be tracked because the mark 10 close to the target tissue 12 is arranged and the movement of the target tissue 12 follows. The mark 10 is in the form of a capsule 16 trained, which is biodegradable after the procedure. This eliminates the need for another procedure for removing the mark 10 , To the mark 10 by means of the location system 14 to capture, contains the capsule 16 at least one detectable substance 18 , The substance 18 lies in the form of particles 20 in front of the location system 14 is very accurate to locate by means of magnetic resonance. The capsule 16 is here with particles 20 laden, containing iron and / or gadolinium. Such substances 18 are known as magnetic resonance contrast agents and significantly differentiate from the surrounding tissue in magnetic resonance images, so that reliable detection of the label 10 is possible.

At the in 2 shown second embodiment of a marker 10 is the capsule 16 within the target tissue 12 arranged. The capsule 16 contains at least one detectable substance 18 , The substance 18 lies in the form of a biocompatible complex 22 before, containing a gold, iodine and / or barium-containing compound. The location system 14 in this case comprises a two-level X-ray system, which by means of X-rays 24 the position of the mark 10 and thus the target tissue 12 detected. The substance 18 provides a high X-ray contrast, so that a very accurate location by means of X-ray fluoroscopy with low exposure to radiation for patients and medical personnel is possible.

In 3 lies the detectable substance 18 in the form of nanoparticles 21 in front. These nanoparticles 21 have a permanent magnetic moment 29 on and are so in the capsule 16 arranged that its individual moments outside the mark 10 of magnetometers 30 are detectable. Become several magnetometers 30 arranged with appropriate geometry to each other, as it is realized, for example, in a system of Fa. STL Koblenz, the positioning system 14 next to the position of the marker 10 at the target tissue 12 also detect their rotation. This is of great advantage when manipulating target tissues 12 , which are located close to a joint such as a knee and during the medical procedure allows a functional check.

The capsule 16 the mark 10 has a roughly circular cross-section 32 , The circular cross section 32 is here at standardized inner diameter of a cannula, a catheter 35 or the like adapted to pass through a small channel in the target tissue 12 to be applied.

Such an embodiment of the marking according to the invention 10 is in 4 shown below. The capsule 16 is by means of a catheter 35 over a blood vessel 36 introduced, close to the target tissue 12 runs. The capsule 16 is with a retaining element 40 for fixation on a vessel wall 37 Mistake. The holding element 40 is a resilient, outwardly projecting part of the capsule shell, the manner of a hook in the vessel wall 37 can be introduced. Due to the substantially circular cross-section 32 the capsule 16 a low flow resistance and a marginal vasoconstriction are guaranteed. The mark 10 does not have to be removed afterwards. The capsule 16 and the locating system 14 detectable substance 18 be from the body 45 biodegraded. The substance 18 is with a carrier, such as a biodegradable polymer, to the capsule 16 pressed. The carrier dissolves in the blood and is fed to the metabolism. The substance 18 can be excreted, for example, depending on the chemical composition.

Alternatively, the mark 10 , as in 4 shown right, percutaneously by means of a needle 34 close to the target tissue 12 into the body. The needle 34 can also be part of a shooting device 38 be to the mark 10 with predeterminable depth close to the target tissue 12 use. A stitch channel generated in this case can then be used to position an instrument 42 be used as in 5 shown. Another injury to the target tissue 12 can thus be avoided during a medical intervention.

The mark 10 has microbubbles 26 low density, the one from the location system 14 detectable substance 18 contains. These microbubbles 26 are by means of ultrasound 28 easy to locate, especially if carbon dioxide is present. In addition to a safe distinction of the mark 10 from the target tissue 12 is also a differentiation of the tissue types possible. Thus, tumor tissue from healthy tissue of a lung can be ultrasound 28 its exact location by means of the mark 10 from the location system 14 is determined.

5 shows a location system 14 for determining the position of an instrument 42 during a medical procedure according to the invention. The location system 14 has a data processor 46 on, the position data 48 one on a patient 44 arranged marking 10 has saved and with one from the location system 14 determinable position 41 of the instrument 42 relates.

To a movement of the target tissue 12 , which by a translation direction 56 to track, detects the location system 14 repeats the position data 48 a marker 10 of the type mentioned above. The data processor 46 become the position data 48 made available. This is done by means of ultrasound 28 a substance 18 inside the capsule 16 detected. From this the data processor calculates 46 a relative position 52 , where the determined position 41 of the instrument 42 as origin coordinates 54 serves. The relative position here also includes information about the distance 58 the mark 10 in terms of the sensor 43 ,

As continues in 5 As can be seen, becomes a mark 10 of the aforementioned type with a navigation system 50 used for medical interventions, the locating system according to the invention 14 includes. During the intervention supplies the location system 14 the relative coordinates of the target tissue 12 depending on the position 41 of the instrument 42 , The from the location system 14 determined relative coordinates capture the relative movement of the target tissue 12 ,

In 6 is a flowchart of a method according to the invention 100 for determining the position of a target tissue 12 presented during a medical procedure. In the process step 102 becomes a sensor 43 from a location system 14 captured to a starting point for the position of the target tissue 12 set. Its sensor coordinates 47 be in a further process step 104 determined and as indicated by a connecting line to a data processor 46 forwards. In an independent process step 106 becomes a marker 10 according to one of the preceding claims close to the target tissue 12 arranged. This is a movement of the target tissue 12 exactly traceable. From the sensor 43 be by means of a fourth process step 108 target coordinates 49 of the target tissue 12 detected and from the sensor 43 to the data processor 46 transmitted as shown by another connecting line. In a final process step 110 be from the data processor 46 differential coordinates 51 from the sensor coordinates 47 and the destination coordinates 49 calculates which of the position of the target tissue 12 relative to the sensor 43 correspond. During the medical procedure, a process cycle is repeated from the process steps 102 . 104 . 108 and 110 , The calculated difference coordinates 51 Provide information about distance and direction to the target tissue 12 , being from the location system 14 determined position of the sensor 43 forms the starting point.

Two alternative embodiments of the method 100 are with respect to arranging a mark 10 close to the target tissue 12 in 7 shown. In this independent process step 106 will be like in 3 shown the capsule 16 after a process step 112 by means of a needle 34 or a catheter 35 over a vessel 36 into the target tissue 12 brought in. On the other hand, the capsule 16 after an alternative process step 114 by means of a Schussvor direction 38 or a puncture needle 39 percutaneously in the target tissue 12 be applied. It is clear to the person skilled in the art that for better positioning of the target tissue 12 Of course, several markings 10 can be used, for example, to define an area quasi. Naturally, both process steps can be used 112 and 114 to be used.

In 8th is another subsection of a procedure 100 shown in more detail. In an additional process step 116 becomes the sensor 43 on an instrument 42 arranged. By means of the data processor 46 determined difference coordinates 51 It is possible, starting from the instrument 42 which is to be used during the medical procedure, the movement of the target tissue 12 specify. Thus, the instrument 42 precisely in the moving target tissue 12 be guided.

The The present invention relates to a mark for position determination a target tissue during a medical procedure, which is biodegradable and thus not removed after the procedure must become. Furthermore, the invention teaches a method for tracking a movement of the target tissue during a medical Intervention. By means of a locating system according to the invention is the position of a target mobile tissue with respect to a Sensor detectable, especially with a navigation system for medical interventions can be used.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• WO 97/045064 A [0002]
• - US 5389101 [0003]

Claims (14)

Marking ( 10 ) for determining the position of a target tissue ( 12 ), which during a medical intervention by means of a location system ( 14 ) is detectable, characterized in that the marking ( 10 ) of a capsule ( 16 ) which is biodegradable after the procedure and at least one of the locating system ( 14 ) detectable substance ( 18 ) contains. Marking ( 10 ) according to claim 1, characterized in that the locating system ( 14 ) detectable substance ( 18 ) in the form of particles ( 20 ), Nanoparticles ( 21 ) or a biocompatible complex ( 22 ) is present. Marking ( 10 ) according to claim 1 or 2, characterized in that gold, iodine, barium or a combination thereof in the capsule ( 16 ) contained by the location system ( 14 ) by means of X-radiation ( 24 ) is detectable. Marking ( 10 ) according to one of claims 1 to 3, characterized in that the capsule ( 16 ) is loaded with iron and / or gadolinium which is removed from the locating system ( 14 ) can be detected by means of magnetic resonance. Marking ( 10 ) according to one of claims 1 to 4, characterized in that microbubbles ( 26 ), in particular of carbon dioxide, in the capsule ( 16 ) contained by the location system ( 14 ) by means of ultrasound ( 28 ) are localizable. Marking ( 10 ) according to one of claims 1 to 5, characterized in that the capsule ( 16 ) a magnetic moment ( 29 ) detected by the location system ( 14 ) by means of a magnetometer ( 30 ) is detectable. Marking ( 10 ) according to one of claims 1 to 6, characterized in that the capsule ( 16 ) has an approximately circular cross-section ( 32 ) having. Marking ( 10 ) according to one of claims 1 to 7, characterized in that the capsule ( 16 ) with a holding element ( 40 ) for fixation on a vessel wall ( 37 ) is provided. Marking ( 10 ) according to one of claims 1 to 8, characterized in that the capsule ( 16 ) from the body ( 45 ) is absorbed, degraded or excreted. Procedure ( 100 ) for determining the position of a target tissue ( 12 ) during a medical procedure, wherein - ( 102 ) a sensor ( 43 ) of a location system ( 14 ), - ( 104 ) its sensor coordinates ( 47 ) and sent to a data processor ( 46 ), characterized in that - ( 106 ) a mark ( 10 ) according to one of the preceding claims close to the target tissue ( 12 ), - ( 108 ) whose destination coordinates ( 49 ) from the sensor ( 43 ) and from the sensor ( 43 ) to the data processor ( 46 ), - ( 110 ) of the difference coordinates ( 51 ) from the sensor coordinates ( 47 ) and the target coordinates ( 49 ) which determines the position of the target tissue ( 12 ) relative to the sensor ( 43 ) correspond. Procedure ( 100 ) according to claim 10, characterized in that the capsule ( 16 ) - ( 112 ) by means of a needle ( 34 ) or a catheter ( 35 ) via a vessel ( 36 ) or - ( 114 ) by means of a firing device ( 38 ) or a puncture needle ( 39 ) percutaneously - ( 106 ) into the target tissue ( 12 ) is introduced. Procedure ( 100 ) according to claim 10 or 11, characterized in that ( 116 ) the sensor ( 43 ) on an instrument ( 42 ) is arranged. Location system ( 14 ) for determining the position of an instrument ( 42 ) during a medical procedure, with a data processor ( 46 ), the position data ( 48 ) one on a patient ( 44 ) arranged mark ( 10 ) and with the locating system ( 14 ) determinable position of the instrument ( 42 ), characterized in that the position data ( 48 ) of the mark ( 10 ) according to one of claims 1 to 9 from the locating system ( 14 ) are repeatedly detectable, with which the data processor ( 46 ) a relative position ( 52 ) to the mark ( 10 ), the determined position of the instrument ( 42 ) as origin coordinates ( 54 ) serves. Use of a marker ( 10 ) according to one of claims 1 to 9 with a navigation system ( 50 ) for medical interventions according to claim 13.