Trackers for surgical navigation systems

Abstract

A tracker (100) for a surgical navigation system is provided. The tracker (100) includes one or more markers (12) for determining the position of the tracker (100) and an attachment element (14) configured to releasably attach the tracker (100) to a surgical tool. The attachment element (14) includes an opening for receiving the surgical tool, wherein the opening defines a longitudinal axis (20). The one or more markers (12) are coupled to the attachment element (14) to be symmetrically arranged relative to the longitudinal axis (20).

Description

Technical Field

[0001] The present disclosure generally relates to a tracker for use in a surgical navigation system (or referred to as a surgical navigation system). In particular, a tracker is proposed that is configured to be releasably attached to a surgical tool (or referred to as a surgical tool). Background Art

[0002] During surgery, surgeons often use surgical tools that must be inserted into the patient's body. Once inside the patient, the surgeon cannot see the end of the tool. To help the surgeon navigate the tool in such situations, a surgical navigation system can be used that tracks the tool and provides visual or auditory guidance to the surgeon.

[0003] One way to track a tool is to attach a tracker to the tool. A camera in the operating room detects the tracker and generates data that is used to calculate the position of the tracker and, therefore, the tool. Typically, the patient is also tracked, which enables the position of the tool relative to the patient to be calculated.

[0004] Surgical navigation can be performed using passive or active trackers (or referred to as passive or active trackers). Passive trackers include markers that reflect light. The reflected light can be detected by a camera. Active trackers generate light that can be detected by a camera (e.g., through a light emitting diode).

[0005] Furthermore, known navigation tools may be tracked by using integrated markers or by attaching external tracking devices.

[0006] The advantages of integrated markers are light weight, good balance and small footprint. However, since surgical tools with trackers are provided as an integrated tracking system, when the tracking technology changes, the surgeon must adapt to the new system as a whole and usually cannot continue to use the surgical tools he is accustomed to.

[0007] In contrast, on the one hand, external tracking devices have the advantage that they can be used flexibly in combination with different types of surgical tools, so that when changing tracking technology, the surgeon does not have to switch to a new surgical tool that he is not familiar with. On the other hand, for the surgeon, the operation of an otherwise familiar surgical tool will be adversely affected when an external tracking device is attached to it, because the surgical tool with an attached external tracking device is much heavier and loses balance than a surgical tool without an attached external tracking device. Summary of the invention

[0008] What is needed is a tracker that addresses one or more of the above-mentioned problems.

[0009] According to one aspect, a tracker for a surgical navigation system (also referred to as a surgical navigation system) is provided. The tracker includes one or more markers for determining the position of the tracker and an attachment element configured to releasably attach the tracker to a surgical tool. The attachment element includes an opening configured to receive the surgical tool, wherein the opening defines a longitudinal axis. One or more markers are coupled to the attachment element to be symmetrically arranged relative to the longitudinal axis.

[0010] One or more markers may be or may include one or more passive markers (or referred to as passive markers). Thus, they may be reflective for a predetermined spectrum of light (e.g., infrared light). Based on the reflected light, the navigation system may determine the position of the tracker.

[0011] The one or more markers may be or may include one or more active markers (or referred to as active markers). Thus, an active marker is configured to emit a predetermined spectrum of light, such as infrared light. For example, an active tracker may include a light emitting diode. Based on the emitted light, the position of the tracker may be determined. Active markers and passive markers may be combined in the one or more markers.

[0012] By providing an attachment element, the tracker can be releasably attached to a surgical tool. Therefore, the tracker proposed in this article is an external tracker that can be associated with any surgical tool intended to be tracked. The shape and size of the opening of the attachment element can be adapted to the shape and size of the surgical tool intended to be used with the tracker. Therefore, the size of the opening is suitable for receiving the surgical tool. The opening of the attachment element defines a longitudinal axis, which can extend in the longitudinal direction of the attachment element. The opening can extend through the entire attachment element, thereby becoming a through hole.

[0013] In some variations, the longitudinal axis may also define a direction along which a surgical tool may be slid into an opening of an attachment element to be attached to the tracker. In other variations, the tracker may be attached to a surgical tool by moving the tracker in a direction different from that defined by the longitudinal axis.

[0014] One or more markers may be coupled directly to the attachment element. Alternatively, they may be coupled to the attachment element via other coupling elements.

[0015] The one or more markings are arranged symmetrically with respect to the longitudinal axis of the attachment element, thereby providing a well-balanced arrangement.The one or more markings may thus be arranged axisymmetrically with respect to the longitudinal axis.

[0016] The tracker disclosed herein can be used in conjunction with a biopsy needle. The tracker disclosed herein can also be used in conjunction with other surgical tools, for example, to track the insertion depth of a semi-rigid straight object (e.g., shunts) into a body cavity. The tracker can also be used in conjunction with a surgical drill to track the insertion depth of the drill. In general, the tracker can track the insertion depth and trajectory of any rigid straight instrument.

[0017] The attachment element may comprise a sleeve defining an opening for receiving a surgical tool.Thus, the attachment element may comprise a hollow elongate body at least partially surrounded by a wall.

[0018] In a variation, the one or more marks may be arranged on the attachment element on or along the longitudinal axis defined by the opening. In this variation, each of the one or more marks is arranged directly on the attachment element. One or more marks are arranged so that they extend along the longitudinal axis. Two or more marks may be arranged with a distance between each mark. At least one of the one or more marks may be arranged at a longitudinal end of the attachment element.

[0019] In this variation, the one or more markers may be configured and arranged to be rotationally symmetrical with respect to the longitudinal axis. For example, the markers may each form a ball or a disk, and they may be arranged on the attachment element so that the attachment element passes through the center of each ball or disk.

[0020] In another variation, the one or more markers include two or more markers that can be arranged at a distance from the attachment element. In this variation, the marker can be coupled to the attachment element via a coupling element such as a mounting post or wing. The two or more markers can be arranged symmetrically with respect to the longitudinal axis, for example, axisymmetrically with respect to the longitudinal axis.

[0021] In another variant, the two or more markers may be arranged on a mounting post. The mounting post may be coupled to the attachment element to be oriented substantially perpendicular to the longitudinal axis of the attachment element. In this regard, the marker is coupled to the attachment element via the mounting post. The marker may be releasably mounted to the mounting post so as to be sterilized separately or to be disposable separately. The marker may also be fixedly connected to the mounting post.

[0022] The mounting post and the attachment element can be constructed as a one-piece component (e.g., using injection molding). The mounting post and the attachment element can further be made of the same material or materials. For example, the mounting post and the attachment element can be made of metal or metallic materials, such as steel or stainless steel. The mounting post and the attachment element can also be made of plastic material (e.g., as an injection molded component). The one-piece construction allows for comfortable operation of the tracker and enables cost-effective production.

[0023] The attachment element may be configured to be attached to a surgical tool via a clip mechanism. The attachment element may have an open side, and the surgical tool may be inserted into the opening of the attachment element via the open side by moving the surgical tool in a direction perpendicular to the longitudinal axis. If the attachment element is configured as a sleeve, the sleeve may be formed with an open side, and the surgical tool may be received via the open side. The material of the attachment element may be flexible enough so that the attachment element can be clamped on the surgical tool. For example, the attachment element may be made of a plastic material, such as polyether ether ketone (PEEK). Due to the clip mechanism, no additional fixing member is required to fix the tracker to the surgical tool.

[0024] The tracker may further include a fixing member for fixing the tracker in position relative to the surgical tool. For example, after the tracker with the attachment element is slid onto the surgical tool, the tracker may be fixed in position by the fixing member.

[0025] The fixing member may include a screw element. The screw element may act on the attachment mechanism to clamp the attachment mechanism to the surgical tool. The screw element may act directly on the surgical tool to fix the tracker relative to the surgical tool. The fixing member may include a plastic material, such as PEEK. The fixing member may be an element separate from the attachment mechanism, or may be included by the attachment mechanism. For example, the fixing member may be mounted on the attachment element, thereby forming a separate element.

[0026] The tracker may include a stop element configured to cooperate with a guide (e.g., a guide tube) to limit the insertion depth of the surgical tool. In particular, during surgery, a guide is typically used to guide the movement of the surgical tool in the patient's body, i.e., the surgical tool with the tracker is inserted into the guide member. The stop element is configured to cooperate with the guide so as to stop the movement of the surgical tool in the guide when a predetermined position is reached. The predetermined position is defined by a target value for at least one of the relative position and orientation between the stop element / tracker and the target surgical area in the patient's body. For example, when the end of the surgical tool has reached the target surgical area, a target value for at least one of the relative position and orientation is given.

[0027] The stop element may be mounted to the attachment element at a longitudinal end of the attachment element. Thus, the stop element of the surgical tool may be integrated into the tracker. The stop element may be releasably or fixedly mounted to the attachment element. The stop element may also include a screw element or any other fixing means for releasably fixing the stop element to the attachment element.

[0028] Alternatively, the attachment element may form a stop element configured to cooperate with the catheter to limit the insertion depth of the surgical tool. Thus, the attachment element not only has the function of attaching the tracker to the surgical tool, but also has the function of limiting the insertion depth of the surgical tool.

[0029] In both options, i.e. when the attachment element forms the stop element or when the stop element is constructed as a separate element, the stop element can also form the fixing member. In this way, no separate fixing member is required, but the stop element comprises a fixing device for fixing the attachment element in position to the surgical tool. The fixing device can be the same fixing device as the fixing device that fixes the stop element to the attachment element, or it can be a separate fixing device.

[0030] Furthermore, in both options, i.e. when the attachment element forms a stop element or when the stop element is constructed as a separate element, the stop element is combined with a tracker, thereby enabling a double checking of the position of the stop element. Specifically, before using a surgical tool comprising a tracker, the position of the stop element can be determined or confirmed. For example, the stop element can be positioned on the surgical tool so that the distance between the end of the surgical tool and the proximal stop surface of the stop element substantially corresponds to the target insertion depth of the surgical tool, in particular to the insertion depth of the surgical tool in the guide, where the insertion is to be stopped for surgery. The stop element, i.e. the positioning of the proximal stop surface of the stop element relative to the end of the surgical tool, can be determined with the aid of a ruler. During surgery, the position and / or orientation of the tracker (relative to both the camera and the patient's body) can be determined by the one or more markings.

[0031] Since the stop element of the present disclosure is integrated into the tracker, the relative position between the proximal stop surface of the stop element and the one or more marks can be calibrated or determined before surgery. Therefore, based on the position and / or orientation of the tracker, the position and / or orientation of the stop element (i.e., its stop surface) can also be determined, also relative to both the camera and the patient's body. Therefore, for example, it can be checked based on these data whether the relative position and / or orientation of the stop element relative to the target surgical area in the patient's body corresponds to the target value for the relative position and / or orientation between the stop element / tracker and the target surgical area in the patient's body. When the end of the surgical tool has reached the target surgical area, a target value for the relative position and / or orientation is given. The target value can be planned before surgery.

[0032] In the event of an unexpected bending of a surgical tool such as a biopsy needle, the proximal stop surface of the stop element may come into contact with the guide tube before the expected insertion depth is reached. That the expected insertion depth has not been reached can be verified by means of position and orientation data calculated based on the light received from the tracker. Based on these data, the surgeon can then decide whether he or she is to stop the insertion of the surgical tool, which corresponds to a "warning" from the stop element, or whether he or she is to continue the insertion. In this way, since the stop element is integrated into the tracker and the distance between the stop element and one or more markings is known, in addition to a preoperative procedure of verifying the position of the stop element, the position of the stop element can also be checked or tracked during surgery.

[0033] The marker may include one or more passive markers. One or more of the one or more markers may have a generally spherical shape. One or more of the plurality of markers may generally have a disc shape. One or more active markers may also be used.

[0034] The one or more marks may be exactly two marks, but the one or more marks may also be more than two marks, such as three marks, four marks or five marks.

[0035] One or more or all of the one or more markers may be detachable from the attachment element.For this reason, complementary interfaces may be provided at each detachable marker and attachment element.

[0036] According to a second aspect, a surgical system is provided. The surgical system comprises a tracker as described herein and a surgical tool releasably coupled to the tracker such that a plurality of markers are symmetrically arranged with respect to a longitudinal axis of an attachment element.

[0037] The surgical system may have a longitudinal axis that coincides with the longitudinal axis of the attachment element. The longitudinal axis may be the longitudinal axis of a surgical rod, a needle, or any other longitudinally extending member of the surgical tool. Thus, a plurality of markings may be arranged symmetrically with respect to the longitudinal axis of the surgical tool, thereby providing a well-balanced surgical tool.

[0038] The surgical tool may have a longitudinal member for receiving the tracker. For example, the surgical tool may be a biopsy needle. A biopsy needle is a known surgical tool and is used to obtain a tissue sample through a biopsy window at the end of the biopsy needle.

[0039] According to a third aspect, a surgical system is provided, in which the tracker includes a stop element, and the surgical system includes a precision arm with a guide, which is used to receive a surgical tool so that it can be linearly moved in one direction and in a direction opposite to the one direction. The precision arm is configured to be movable three-dimensionally, in particular to move the guide three-dimensionally. The guide includes an abutment surface that cooperates with a proximal stop surface of the stop element to limit the linear movement of the surgical tool in one direction within the guide. The guide may include a guide tube or a plurality of coaxial holes into which the surgical tool can be slidably inserted. The guide may have a surface for cooperating with the stop element to limit the insertion depth within the guide tube.

[0040] According to a fourth aspect, a surgical navigation system (also referred to as a surgical navigation system) is provided, which includes a tracker or surgical tool system as described herein, and an optical sensor capable of detecting light reflected or emitted by multiple markers and capable of generating a sensor signal indicative of the detected light.

[0041] The optical sensor may include at least one camera. The optical sensor may include a monocular camera and / or a stereo camera. The optical sensor may be configured to have an increased sensitivity to the spectrum reflected or emitted by the multiple markers. The spectrum may be an infrared (IR) spectrum or a visible spectrum, or other spectrum. Higher sensitivity may be achieved by an optical filter or a circuit that filters the sensor signal data according to the relevant wavelength of the sensor signal data.

[0042] The surgical navigation system may further include a navigation controller capable of receiving the sensor signal and registering and / or tracking the tracker based on the received sensor signal.

[0043] According to a fifth aspect, a method for operating a surgical navigation system is provided. The surgical navigation system includes an optical sensor and a tracker, wherein the tracker has one or more markers for determining the position of the tracker, an attachment element configured to releasably attach the tracker to a surgical tool, and a stop element configured to cooperate with a guide to limit the insertion depth of the surgical tool. The attachment element includes an opening for receiving the surgical tool, wherein the opening defines a longitudinal axis. The one or more markers are coupled to the attachment element to be symmetrically arranged relative to the longitudinal axis. The method includes the following steps: determining the relative position between the proximal stop surface of the stop element and at least one of the one or more markers; detecting light reflected or emitted by the one or more markers by an optical sensor; calculating at least one of the position and orientation of the tracker in the coordinate system of the surgical navigation system based on the detected light; calculating at least one of the position and orientation of the proximal stop surface of the stop element in the coordinate system of the surgical navigation system based on the determined relative position and at least one of the calculated position and orientation of the tracker.

[0044] The relative position between the proximal stop surface of the stop element and at least one of the one or more markings may be defined by a distance between the proximal stop surface and the at least one marking and how the proximal stop surface is oriented relative to the at least one marking.

[0045] Calculating the position and / or orientation of the tracker in the coordinate system of the surgical navigation system may include calculating the position and / or orientation of the tracker relative to the optical sensor. Subsequent steps regarding the proximal stop surface may then include calculating the position and / or orientation of the proximal stop surface of the stop element relative to the optical sensor.

[0046] Typically, the patient's body is also tracked by an optical sensor so that the position and / or orientation of the patient's body relative to the optical sensor can be calculated. Thus, the position and / or orientation of the proximal stop surface of the stop element relative to the patient's body can be determined based on the calculated position and / or orientation of the proximal stop surface relative to the optical sensor and the position and / or orientation of the patient's body relative to the optical sensor.

[0047] Determining the position and / or orientation of the proximal stop surface relative to the patient's body may include determining the position and / or orientation of the proximal stop surface of the stop element relative to the target surgical area in the patient's body. Then, it can be checked whether the position and / or orientation of the proximal stop surface of the stop element relative to the target surgical area in the patient's body corresponds to the target relative position and / or target relative orientation of the proximal stop surface of the stop element relative to the target surgical area. In particular, the target relative position and / or target relative orientation of the proximal stop surface relative to the target surgical area is the position and / or orientation of the proximal stop surface relative to the target surgical area when the distal end of the surgical tool has reached the target surgical area when the surgical tool is inserted into the patient's body.

[0048] In a variation of the fifth aspect, the tracker can be part of a surgical tool system comprising the tracker and a surgical tool, the surgical tool being configured to be releasably coupled to the tracker such that one or more markers are arranged symmetrically relative to a longitudinal axis of the attachment element. The method can include the steps of coupling the tracker to the surgical tool, and securing the tracker to the surgical tool such that a position and / or orientation of a proximal stop surface of the stop element relative to a tip of the surgical tool corresponds to a target relative position and / or a target relative orientation.

[0049] In one variation, the position of the stop element can be double-checked. For example, if it is determined that the position and / or orientation of the proximal stop surface of the stop element relative to the target surgical area in the patient's body corresponds to the target relative position and / or target relative orientation of the proximal stop surface of the stop element relative to the target surgical area, the stop element should abut against the abutment surface of the guide. Or, vice versa, if the stop element abuts against the abutment surface of the guide, thereby limiting further insertion of the surgical tool, the determined position and / or orientation of the proximal stop surface of the stop element relative to the target surgical area in the patient's body should correspond to the target position and / or target orientation of the proximal stop surface of the stop element relative to the target surgical area. If this is not the case, there may be an error or defect. For example, a surgical tool such as a biopsy needle may be accidentally bent, or the tracker may not be correctly positioned to the surgical tool. In this case, the surgical navigation system can output a warning. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Other details, advantages and aspects of the present disclosure will become apparent from the following embodiments in conjunction with the accompanying drawings, in which:

[0051] Figure 1 A first embodiment of a tracker is shown.

[0052] Figure 2 A second embodiment of a tracker is shown, which includes a stop element.

[0053] Figure 3 Shows Figure 2 A modification of the second embodiment, in which the stop element also has the function of fixing the component.

[0054] Figure 4 Shown include Figure 2 Implementation of a tracker surgical tool system.

[0055] Figure 5 Another embodiment of a surgical tool system is shown that includes a tracker having indicia disposed on a mounting post.

[0056] Figure 6 Shows Figure 4 A modified embodiment of a surgical tool system.

[0057] Figure 7 A third embodiment of a tracker is shown in cross-section.

[0058] Figure 8 Shown in top view Figure 7 Tracker.

[0059] Fig. 9 An embodiment of a surgical guidance system is shown.

[0060] Fig.10 Shown include Figure 2 Tracker-based surgical navigation systems, and

[0061] Fig.11 A flow chart of a method of operating a surgical navigation system is shown. DETAILED DESCRIPTION

[0062] Figure 1 A first embodiment of a tracker for a surgical navigation system is shown. The tracker 10 includes one or more markers 12 and an attachment element 14 on which the one or more markers 12 are mounted. Figure 1 In the embodiment, two marks 12 are provided, and each of the marks 12 has a spherical shape. In an alternative embodiment, one of the two marks 12 can be omitted.

[0063] The marker 12 is mounted to the attachment element 14 on opposing longitudinal ends 16 , 18 of the attachment element 14 . Figure 1 The attachment element 14 defines a longitudinal opening (not shown here) through the interior of the attachment element 14. The opening extends longitudinally along the longitudinal axis 20. The opening is configured to receive a surgical tool such as a biopsy needle. Figure 1In the example of the embodiment of the present invention, the attachment element 14 has a round outer cross section. The attachment element 14 may also have a square or rectangular outer cross section. The marker 12 has a longitudinal opening extending through the marker for mounting the marker to the attachment element, and the longitudinal opening has a corresponding round or rectangular cross section. In the case of a rectangular cross section, the marker 12 is non-rotatably mounted on the attachment element 14.

[0064] exist Figure 1 In the embodiment of the present invention, the marker 12 is shown as a passive marker, which is configured to reflect light, in particular, light of a predetermined spectrum such as IR light. However, Figure 1 The tracker 10 and all tracker embodiments disclosed herein may also be equipped with an active tracker, which is configured to emit light, in particular light of a predetermined spectrum, such as IR light.

[0065] The opening extending through the attachment element 14 for receiving a surgical tool has a cross-section that is adapted to the outer shape of the surgical tool intended to be used in conjunction with the tracker 10. For example, in the case of a biopsy needle, the opening has a circular cross-section. In each case, the cross-sectional dimensions of the opening are such that a surgical tool intended to be used in conjunction with the tracker can be inserted into the opening of the attachment element. The opening is configured as a through hole so that it extends over the entire axial length of the attachment element 14. Thus, the tracker 10 is formed as a sleeve that can be slidably moved along the surgical tool when received by the surgical tool.

[0066] from Figure 1 It can also be seen that the tracker 10 also includes a fixing member 22 for fixing the tracker in position relative to the surgical tool. In the present embodiment, the fixing member 22 is mounted on the attachment element 14. In particular, the fixing member 22 is also configured as a sleeve 24, which can optionally slide along the longitudinal axis 20 of the attachment element 14. The fixing member 22 includes a screw 26, which is rotatably received by the sleeve 24 of the fixing member 26. By tightening the screw 26, the attachment element 14 can be clamped to the surgical tool. In this case, the attachment element 14 should be made of a deformable material. The attachment element 14 can also be fixed to the surgical tool by the screw 26 of the fixing member 26 acting directly on the surgical tool. In this case, the attachment element 14 can have a hole for the screw (not shown), and the attachment element 14 can also be formed of a rigid material. It will be understood that the fixing member 26 can be configured differently, for example, in order to be manually activated and deactivated (no screwdriver is required). To this end, the fixing member 26 can be provided with a lever.

[0067] like Figure 1As further shown, the markings 12 are arranged along the longitudinal axis 20 of the attachment element 14. In particular, each of the one or more markings 12 is symmetrically arranged relative to the longitudinal axis 20 of the attachment element 14. More specifically, each marking 12 is arranged rotationally symmetrically relative to the longitudinal axis 20.

[0068] Figure 2 Shows Figure 1 A second embodiment of the tracker 10 is provided. Figure 2 The tracker 100 of FIG. 1 is provided with a stopper element 28 attached to the attachment element 14, which corresponds to Figure 1 tracker 10. The stop element 28 is used to limit the insertion depth of the surgical tool equipped with the tracker 100. Specifically, the stop element 28 is configured to cooperate with a guide, such as a precision arm, such as a guide tube or a guide hole for receiving the surgical tool to which the tracker 100 is attached. The stop element 28 is configured to cooperate with the guide to limit the insertion depth of the surgical tool. The stop element 28 is attached to the longitudinal end 18 of the attachment element 14. Thereby, the mark 12 of one of the two marks 12 is no longer arranged at the longitudinal end 18 of the auxiliary element 14, but is moved in the longitudinal direction of the fixing element 14 toward the center of the fixing element 14. Similar to the fixing member 26, the stop element 28 is constructed as a sleeve 30, which can be received by the attachment element 14 and includes a screw 32 for fixing the stop element 28 to the attachment element 14.

[0069] The stop element 28 can also be fixed to the attachment element 14 by other means than the screw 32, for example by a Luer-Lock connection. The stop element 28 can also be configured to be fixedly connected to the attachment element 14, for example by gluing. The stop element 28 can also be formed integrally with the attachment element 14. In these cases, a fixing element such as a screw 32 is not required.

[0070] The fixing member 22, or at least the sleeve 24 of the fixing member 22, and / or the stop element 28 can be made of a plastic material. For example, the plastic material can be PEEK, which is characterized by being resistant to many chemicals, being biocompatible and being able to be sterilized repeatedly. The plastic material can also be polyphenylenesulfone (PPSO2). A typical material of the attachment element 14 is a metal material, such as steel or stainless steel.

[0071] Figure 3 Shows Figure 2 The tracker 110 corresponds to a modified version of the tracker 100 of Figure 2Tracker 100 of the embodiment of the present invention, except that fixing member 22 is no longer provided. As an alternative, attachment element 14 may be fixed to a surgical tool such as a biopsy needle by means of screw 32 of stop element 28 or by any other fixing means such as a Luer lock connection.

[0072] Figure 4 A surgical tool system 200 is shown having a surgical tool (here a biopsy needle 34), such as Figure 2 The tracker 100 is shown already attached to the surgical tool. The biopsy needle 34 also includes a handle 40 at its longitudinal end 36 opposite the tip 38 of the needle 34 that allows the surgeon to manipulate the biopsy needle 34. Figure 4 As can be seen in the figure, the tracker 100 is slid onto the biopsy needle and the tracker 100 is clamped or fixed to the biopsy needle 34 by the screw 26 of the fixing member 22. The tracker 100 is attached to the biopsy needle 34 in position. In addition, a stop element 28 is provided on the longitudinal end 18 of the tracker 100 near the end 38 of the biopsy needle 34. The outer cross-sectional dimensions of the stop element 28 are large enough to limit the insertion depth of the biopsy needle 34 in the guide tube or other guide. The guide tube can be attached to a precision arm that has a fixed position relative to the patient to be treated. In this way, the axial position of the stop element 28 relative to the guide together with the three-dimensional position and orientation of the guide relative to the patient determines the depth to which the needle 34 is (allowed to) be inserted into the patient's body.

[0073] Figure 4 The Tracker 100 can also be used Figure 1 The tracker 10 of is replaced. In this case, a separate stop element should be provided on the surgical tool.

[0074] Tracker 10 or 100 may also be mounted to the surgical tool on the opposite side of handle 40. Thus, tracker 10 or 100100 may not be mounted on the handle 40. Figure 4 The left side of the handle is mounted on the Figure 4 , for example on the axial extension (not shown here) of the handle 40. In this case, it is not necessary to provide the stop element 28 at the tracker 100, and a separate stop element known in the prior art can be attached to a surgical tool such as a biopsy needle.

[0075] Figure 5 A surgical tool system 210 (or otherwise referred to as a surgical tool system) having another embodiment of a tracker 300 is shown. Figure 5 The tracker 300 is again shown attached to the biopsy needle 34, but the tracker 300 may also be used in conjunction with other surgical tools having a generally longitudinal extension in accordance with the present disclosure. Figure 4 Biopsy needle 34, Figure 5The biopsy needle 34 includes a tip 38 (having a biopsy window 42) at one longitudinal end thereof and an operating handle 40 at the other longitudinal end thereof.

[0076] Similar to Figures 1 to 4 Tracker, Figure 5 The tracker 300 is slid onto the biopsy needle 34. Specifically, the tracker 300 includes an attachment element 44 having an opening for receiving a surgical tool (here, the biopsy needle 34), wherein the opening defines a longitudinal axis 20. The longitudinal axis 20 of the attachment element 44, which is configured as a sleeve, coincides with the longitudinal axis 46 of the biopsy needle 34. Laterally to the attachment element 44 and the biopsy needle 34 and at a certain distance from the attachment element 44 and the biopsy needle 34, a plurality of markers 12 are arranged. Figure 5 In an embodiment, at least two marks 12 are provided. Here, two marks 12 are provided. In addition, Figure 5 In an embodiment of the present invention, the marker 12 is configured as a ball. The marker 12 is attached to a mounting post 48, wherein the mounting post 48 is in turn attached to the attachment element 44. In particular, the mounting post 48 is arranged substantially perpendicular to the longitudinal axis 20 of the attachment element 44. The two markers 12 are equally designed and arranged at the same distance from the attachment element 44. Therefore, the plurality of markers 12 are arranged symmetrically with respect to the longitudinal axis 20 of the attachment element and the longitudinal axis 46 of the biopsy needle 34.

[0077] exist Figure 5 In the embodiment of the present invention, the attachment element 44 also has the function of the above-mentioned stop element to limit the insertion depth of the surgical tool. Figure 2 and Figure 3 Instead of a separate stop element as shown, the attachment element 44 forms the stop element in one piece. Figures 2 to 4 The stop element is similar in manner, Figure 5 The stop element (which is also an attachment element) includes a screw 50 for fixing the tracker 300 to the surgical tool 34. Therefore, no separate fixing member is required.

[0078] Figure 6 Shows that there is Figure 5 300 is a modified version of the surgical tool system 220 shown in FIG. Figure 6 Tracker 400 with Figure 5 The tracker 300 of FIG. 5 differs in that the marker 57 is disc-shaped and is not coupled to the attachment element by a mounting post, but rather via a wing 58. Figure 5 In a similar manner to the spherical marker 12, Figure 6The disc-shaped marking 57 is arranged symmetrically with respect to the longitudinal axis 20 of the attachment element 44 and is located on a wing 57 extending from the attachment element 44 in a direction away from the attachment element 44 (i.e. extending in a direction substantially perpendicular to the longitudinal axis 20). In this way, the disc-shaped marking 47 is also provided to the attachment element 44 laterally, rather than laterally as in Figures 1 to 4 axially as marked.

[0079] The attachment element 44 and the mounting post 12 or wing 58 may be made of metal, such as steel or stainless steel. Figure 5 and Figure 6 In the embodiment, the trackers 300, 400 may also be arranged on the opposite side of the handle 50, that is, on the handle 50 Figure 5 and Figure 6 on the right side of the screen.

[0080] Figure 7 Shows Figure 5 300 is a plan view of another modified version 500 of the tracker 300 shown in FIG. According to this modified version 500, the attachment element 60 is also configured as a sleeve, but the sleeve is open on its side 62. The sleeve has an opening 64 extending along the longitudinal axis 20 of the attachment element 60 (see FIG. 20 ). Figure 8 ). The cross-section of opening 64 is adapted to the cross-section of a surgical tool intended for use with tracker 500, and the size of opening 64 is such that the surgical tool may be received therein.

[0081] The attachment element 60 with the side opening forms a clamp mechanism. In particular, a surgical tool such as a biopsy needle is not inserted into the opening 64 of the attachment element 60 so as to slide along the longitudinal axis 20 of the attachment element 60, but the tracker 500, more specifically the tracker 500 attachment element 60, is clamped on a surgical tool such as a biopsy needle by receiving the surgical tool via the open side 62. In particular, the attachment element 60 is clamped on the surgical tool by moving the attachment element 60 in a direction perpendicular to the longitudinal axis 20 to receive the surgical tool via the open side. In order to be clampable on the surgical tool, the attachment element 60 should be at least partially made of an elastic material, for example made of a plastic material such as PEEK or PPSO2.

[0082] The attachment element 60 of the tracker 500 has a protrusion 66 which extends in a lateral direction (by Figure 7 The tracker 500 also includes a mounting post 68 connected to the protrusion 66 of the attachment element 60 and configured to receive a marker (not shown here). Figure 7 and 8In the embodiment of the present invention, two protrusions 66 and two mounting posts 68 for two markings are provided. The mounting posts 68 are designed to be symmetrical relative to the longitudinal axis 20, which is defined by the opening extending in the longitudinal direction of the attachment element 60. In addition, as can be seen from Figure 6 As can be seen in the cross-sectional view of , the mounting post 68 is arranged to be centered relative to the middle (center) of the opening 64.

[0083] The marker can be connected to the mounting post 68 by any known attachment mechanism. Such attachment mechanisms may include, for example, threads, snap connections, and quick connections. The mounting post 68 and the attachment element may be made of the same material. For example, they may both be made of PEEK. The marker may have a Figures 1 to 5 The spherical shape shown or any other shape. As an alternative to being connected to the attachment element 60, the mounting post 68 and the attachment element 60 can be constructed as a one-piece component, for example as an injection molded component.

[0084] exist Figure 7 and Figure 8 In a variant, the attachment element 60 may also have the function of a stop element to limit the insertion depth of the surgical tool, in particular in a guide tube or in a hole of a guide of a precision arm.

[0085] In all embodiments, the marker 12, 58 can be releasably mounted to the attachment element 14 and / or the mounting post 48, 68 (if provided), and thereby can be disposed of separately from the attachment element 14 and / or the mounting post 48, 68, and / or can be sterilized separately from the attachment element 14 and / or the mounting post 48, 68. Alternatively, the marker 12 is non-releasably mounted to the attachment element 14 and / or the mounting post 48, 68.

[0086] Fig. 9 4 shows an embodiment of a surgical guidance system 80. The surgical guidance system 80 includes a tracker 400. Figure 6 The surgical tool system 220 of the present invention may also include any other surgical tool system disclosed herein. The surgical guide system 80 also includes a precision arm 82 that can be moved and fixed in three dimensions relative to the patient. To this end, the precision arm 82 includes a plurality of arms 84 that are connected in series to each other via joints 86. The precision arm 82 also includes a guide 88 that is coupled to adjacent arms 84 via joints 86. The guide 88 includes two holes 90 that define the insertion direction of the surgical tool system 220. The two holes 90 form the actual guide structure. In other embodiments, a guide tube may be used instead of the hole 90.

[0087] As in Fig. 9As can be seen in FIG. 1 , the proximal stop surface 45 of the stop element 44 (see Figure 6 ), that is, a surface 45 of the stop element 44 that faces the guide 88 and is proximal to the distal end 38 of the surgical tool 34 cooperates with an abutment surface 92 of the guide 88 to limit movement of the surgical tool 34 in the insertion direction within the hole 90. Or in other words, the placement of the stop element 44 relative to the distal end 38 of the surgical tool 34 determines the insertion depth of the surgical tool 34, that is, how far the surgical tool 34 can be inserted into the hole 90 of the precision arm 82 (and, therefore, into the patient's body) before stopping.

[0088] As in Fig. 9 As can be seen in FIG. 1 , the position and / or orientation of the precision arm 82 can be tracked by one or more markings 94 of the precision arm 82. In particular, Fig. 9 In an embodiment of the present invention, the guide 88 is equipped with one or more markers 94, more specifically, three markers 94. With the help of these markers 94, the three-dimensional position and / or orientation of the precision arm 82 relative to the patient's body (which is also tracked) can be determined, and the precision arm 82 can be positioned and / or oriented so that a target surgical area within the patient's body (e.g., the patient's skull) can be treated with the surgical tool 34 of the surgical guidance system 80. Or, in other words, the three-dimensional orientation and / or position of the precision arm 82 relative to the patient's body can be achieved by tracking the precision arm 82 with the markers 94, thereby defining the motion trajectory of the surgical tool 34. The position of the stop element 44 then defines (in one dimension) how far the surgical tool 34 can move along the trajectory.

[0089] Fig.10 A surgical navigation system 70 is shown, which includes a tracker and an optical sensor 72. Fig.10 In the figure, it is shown that Figure 2 The surgical navigation system 70 is configured to be used with the tracker 100 of the present invention. However, the surgical navigation system 70 may be used in conjunction with any tracker implementation described herein.

[0090] The optical sensor 72 includes a camera, such as a stereo camera. The optical sensor 72 is configured to detect a spectrum of light reflected (in the case of passive markers) or emitted (in the case of active markers) by a plurality of markers. The optical sensor can, for example, be configured to detect light in the IR spectrum. In this case, the surgical navigation system 70 is less affected by ambient light. The optical sensor is configured to generate sensor data indicating the detected light.

[0091] The surgical navigation system 70 includes a tracker 100 for associating with a surgical tool. Alternatively, the surgical navigation system 70 may include the surgical tool systems 200, 210, 220 as described above.

[0092] The surgical navigation system 70 also includes a navigation controller 74, which is configured to receive the sensor data and register or track the tracker 100 based on the received sensor data. The navigation controller 74 can be part of the optical sensor 72 or a separate device. Alternatively, the navigation controller 74 can be a separate device that is not part of the surgical navigation system 70, such as a computer that manages patient data, but it can be additionally used to calculate the sensor data of the optical sensor 72.

[0093] The surgical navigation system 70 may further include an output device 76 or be connected to the output device 76. The output device 76 includes at least one of a display, a speaker, a projector (beamer), and a tactile feedback device. The output device 76 is configured to output information and / or instructions resulting from the tracking of the tracker 100. The output information may include at least one of: a visual display of the tracked tracker 100 or an associated surgical tool, a visual display of the tracker 100 or an associated surgical tool relative to the registered patient data, and an audio signal indicating the position of the tracker 100 (e.g., relative to a virtual boundary of a reference patient). The instructions may include at least one of: a visual display of a target shape, target position, and target orientation of the tracker 100, and a voice output to guide the surgeon.

[0094] Fig.11 A flow chart illustrating an embodiment of a method of operating a surgical navigation system. The surgical navigation system may be Fig.10 The surgical navigation system 70 has any one of the trackers 100, 110, 300, 400, 500 disclosed herein, the tracker including an integrated stop element. The surgical navigation system may also include Fig. 9 Precision arm 82.

[0095] In step S100, a relative position between a proximal stop surface of the stop element and at least one of the one or more markers of the tracker 100, 110, 300, 400, 500 is determined. In step S200, light reflected or emitted by the one or more markers is detected by an optical sensor. In step S300, at least one of a position and an orientation of the tracker in a coordinate system of the surgical navigation system is calculated based on the detected light. Then, in step S400, at least one of a position and an orientation of the proximal stop surface of the stop element in a coordinate system of the surgical navigation system is calculated based on the determined relative position and the calculated position and / or orientation of the tracker.

[0096] The relative position may be defined by the distance between the proximal stop surface and the at least one marker and how the proximal stop surface is oriented relative to the at least one marker. Since the stop element is part of the tracker 100, 110, 300, 400, 500, the relative position between the stop surface and the marker may be a known or predefined variable, or may be simply determined in step S100 by common means such as a ruler.

[0097] In step S300, calculating the position and / or orientation of the tracker in the coordinate system of the surgical navigation system may include calculating the position and / or orientation of the tracker relative to the optical sensor. The calculation may be performed in one dimension (the further dimension may be based on Fig. 9 Step S400 may then comprise calculating the position and / or orientation of the proximal stop surface of the stop element relative to the optical sensor.

[0098] Typically, the patient's body is also tracked by the optical sensor so that the position and / or orientation of the patient's body relative to the optical sensor can be calculated. Therefore, based on the data calculated in step S400 and the position and / or orientation of the patient's body relative to the optical sensor, the position and / or orientation of the proximal stop surface of the stop element relative to the patient's body can be determined in three dimensions.

[0099] In not in Fig.11 In another method step shown in , the position and / or orientation of the proximal stop surface of the stop element relative to the target surgical area in the patient can be determined. Then, in a subsequent method step, it can be checked whether the position and / or orientation of the proximal stop surface of the stop element relative to the target surgical area in the patient corresponds to a pre-planned target relative position and / or target relative orientation of the proximal stop surface of the stop element relative to the target surgical area. In particular, the target relative position and / or target relative orientation of the proximal stop surface relative to the target surgical area is the position and / or orientation of the proximal stop surface relative to the target surgical area when the tip of the surgical tool has reached the target surgical area when the surgical tool is inserted into the patient.

[0100] In one embodiment of the method proposed herein, the position of the stop element is confirmed before the above-mentioned method step S100. Specifically, the tracker is coupled to the surgical tool, and the tracker can be fixed to the surgical tool so that the relative position and / or relative orientation between the proximal stop surface of the stop element and the end of the surgical tool corresponds to a pre-planned target value of the relative position and / or relative orientation. The target position and / or target orientation of the proximal stop surface relative to the target surgical area is the position and / or orientation of the proximal stop surface relative to the target surgical area when the end of the surgical tool has reached the target surgical area when the surgical tool is inserted into the patient's body. Fig. 9 In the surgical guide system of the present invention, the target position and / or target orientation of the proximal stop surface relative to the target surgical area is defined by the relative position and / or relative orientation between the abutment surface of the guide and the target surgical area in the patient's body.

[0101] Therefore, by the disclosed method, the position of the stop element can be double-checked. For example, if it is determined in the step that the position and / or orientation of the proximal stop surface of the stop element relative to the target surgical area in the patient's body corresponds to the target relative position and / or target relative orientation of the proximal stop surface of the stop element relative to the target surgical area, the proximal stop surface of the stop element should abut against the adjacent surface of the guide. Or, vice versa, if the stop element abuts against the adjacent surface of the guide to limit the further insertion of the surgical tool, the position and / or orientation of the proximal stop surface of the stop element determined relative to the target surgical area in the patient's body should correspond to the target position and / or target orientation of the proximal stop surface of the stop element relative to the target surgical area. If this is not the case, there may be an error or defect. For example, a surgical tool such as a biopsy needle may be accidentally bent, or the tracker may not be correctly positioned on the surgical tool. A warning can then be output to the surgeon 80. Based on this particular situation, the surgeon can then decide whether he or she wants to stop the insertion of the surgical tool or whether he or she wants to continue the insertion.

[0102] As is apparent from the exemplary embodiments above, the present invention provides an external tracker that is designed to be symmetrical with respect to the longitudinal axis of the attachment element and, when it is connected to a surgical tool like a biopsy needle, optionally also symmetrical with respect to the longitudinal axis of the surgical tool that coincides with the longitudinal axis of the attachment element. In addition, compared to known solutions of external trackers, the tracker according to the present disclosure has a small footprint and is light in weight. Therefore, the surgical tool, also with the tracker attached, is well balanced and only slightly increased in weight, and can therefore be operated by the surgeon in a familiar manner.

[0103] Furthermore, since the present tracker is an external tracker that can be attached to the surgical tool, rather than an integrated solution, the surgeon can use the surgical tools he is accustomed to without having to switch to a new, unfamiliar system.

[0104] As mentioned above Figures 2 to 9 As described, a stopper for defining the depth at which a surgical tool is allowed to enter can be combined with a tracker. In an exemplary biopsy workflow, the target, entry point, and trajectory of the biopsy can be defined (i.e., pre-planned). The depth of the target is calculated and can be used to manually adjust the stopper before surgery to perfectly align the biopsy window in the needle with the target. Since the position of the end of the needle needs to be verified anyway, using the stopper in combination with the tracker can double-check the placement of the stopper.

[0105] Figures 5 to 8 Embodiments provide a tracker with an attachment element configured as a clip mechanism and / or a mounting post for mounting a marker, wherein the attachment element and the mounting post may be made of the same material and may also be configured as an integral component, Figures 5 to 8 The embodiment provides a solution that is easy to manufacture and is therefore relatively cheap. In addition, since it is sterilizable, it can be reused.

Claims

1. A tracker for a surgical navigation system, the tracker comprising a plurality of markers for determining the position of the tracker; and an attachment element configured to be releasably attached to a surgical tool, wherein, The attachment element includes an opening for receiving a surgical tool, the opening defining a longitudinal axis, the longitudinal axis defined by the opening coinciding with a tool longitudinal axis of the surgical tool when the attachment element is releasably attached to the surgical tool; and in The plurality of markings are coupled to the attachment element so as to be axially symmetrically arranged relative to the longitudinal axis of the attachment element, wherein for each of the plurality of markings, the respective marking is arranged on a common plane with at least one other marking of the plurality of markings, wherein the longitudinal axis of the attachment element is located within the common plane.

2. The tracker according to claim 1, wherein The attachment element includes a sleeve defining the opening for receiving the surgical tool.

3. The tracker according to claim 1, wherein The plurality of markings are arranged on the attachment element along a longitudinal axis defined by the opening.

4. The tracker according to claim 1, wherein The plurality of markings are arranged at a distance from the attachment element.

5. The tracker according to claim 4, wherein The at least two markings are disposed on a mounting post or wing coupled to the attachment element to be oriented substantially perpendicular to the longitudinal axis of the attachment element.

6. The tracker according to claim 1, wherein The attachment element is configured to be attachable to a surgical tool via a clip mechanism.

7. The tracker according to claim 1, wherein The tracker includes a fixing member for fixing the tracker in position relative to the surgical tool.

8. The tracker according to claim 7, wherein The fixing member is mounted to the attachment element.

9. The tracker of claim 1, wherein The tracker includes a stop element configured to cooperate with the guide of the precision arm to limit the insertion depth of the surgical tool in the guide in one direction when the attachment element is releasably attached to the surgical tool and the surgical tool is received in the guide so as to be able to move linearly in one direction and in a direction opposite to the one direction.

10. The tracker according to claim 9, wherein The stop element is releasably mounted to the attachment element at a longitudinal end of the attachment element, or the attachment element forms the stop element.

11. The tracker according to claim 9, wherein The stop element forms a fixing means for fixing the tracker in position relative to the surgical tool.

12. The tracker of claim 1, wherein The plurality of markers is exactly two markers.

13. The tracker of claim 1, wherein One or more of the plurality of markers may be detachable from the attachment element.

14. The tracker according to claim 3, wherein: The plurality of markings are configured and arranged to be rotationally symmetrical with respect to the longitudinal axis.

15. The tracker according to claim 5, wherein: One or more of the plurality of markers may be removable from the mounting post or wing.

16. The tracker according to claim 6, wherein: The attachment element has open sides for inserting a surgical tool in a direction perpendicular to the longitudinal axis.

17. A surgical system comprising A tracker, the tracker comprising: a plurality of markers and attachment elements for determining the position of the tracker, and Surgical tools, wherein the attachment element is configured to be releasably attached to the surgical tool, wherein the attachment element includes an opening for receiving a surgical tool, the opening defining a longitudinal axis; and wherein the surgical tool has a tool longitudinal axis, and when the attachment element is releasably attached to the surgical tool, the longitudinal axis of the surgical tool coincides with the longitudinal axis of the attachment element, wherein the plurality of marks are coupled to the attachment element so as to be axially symmetrically arranged relative to the tool longitudinal axis when the surgical tool is received in the opening, wherein for each of the plurality of marks, the respective mark is arranged on a common plane with at least one other mark of the plurality of marks, wherein when the attachment element is releasably attached to the surgical tool, the tool longitudinal axis is located in the common plane.

18. The surgical system of claim 17, wherein The tracker includes a stop element; Further comprising a precision arm having a guide for receiving the surgical tool so that the surgical tool can be linearly moved in one direction and in a direction opposite to the one direction, wherein, The precision arm is configured to be moved three-dimensionally; And wherein the guide includes an abutment surface that cooperates with a proximal stop surface of the stop element to limit linear movement of the surgical tool within the guide in the one direction.

19. The surgical system according to claim 17, comprising An optical sensor is capable of detecting light reflected or emitted by the plurality of markers and of generating a sensor signal representative of the detected light.

20. The surgical system of claim 19, further comprising A navigation controller is capable of receiving the sensor signal and registering and / or tracking the tracker based on the received sensor signal.

21. A method of operating a surgical navigation system, the surgical navigation system comprising: An optical sensor and a surgical tool system, the surgical tool system comprising a tracker and a surgical tool, the surgical tool being configured to be releasably coupled to the tracker, the tracker comprising one or more markers for determining the position of the tracker, an attachment element configured to be releasably attached to the surgical tool, and a stop element mounted to a longitudinal end of the attachment element, the stop element being configured to cooperate with a guide of a precision arm to limit the insertion depth of the surgical tool in the guide when the surgical tool is received in the guide so as to be able to move linearly in one direction and in a direction opposite to the one direction, wherein the attachment element comprises an opening for receiving the surgical tool, the opening defining a longitudinal axis, the longitudinal axis defined by the opening coinciding with a tool longitudinal axis of the surgical tool when the attachment element is releasably attached to the surgical tool, wherein the one or more markers are coupled to the attachment element to be symmetrically arranged relative to the surgical longitudinal axis when the attachment element is releasably attached to the surgical tool, Wherein, the method comprises the following steps: coupling the tracker to the surgical tool; and securing the tracker to the surgical tool such that at least one of a position and an orientation of a proximal stop surface of a stop element relative to a tip of the surgical tool corresponds to at least one of a target relative position and a target relative orientation; determining a relative position between a proximal stop surface of the stop element and at least one of the one or more markings; detecting, by the optical sensor, light reflected or emitted by the one or more markers; calculating at least one of a position and an orientation of the tracker in a coordinate system of the surgical navigation system based on the detected light; and At least one of a position and an orientation of a proximal stop surface of the stop element in a coordinate system of the surgical navigation system is calculated based on the calculated at least one of a position and an orientation of the tracker and the determined relative position.

22. A tracker for a surgical navigation system, the tracker comprising: one or more markers for determining the position of the tracker; as well as An attachment element configured to be releasably attached to a surgical tool, wherein the attachment element includes an opening for receiving the surgical tool, the opening defining a longitudinal axis, the longitudinal axis defined by the opening coinciding with a tool longitudinal axis of the surgical tool when the attachment element is releasably attached to the surgical tool, and wherein the one or more markers are coupled to the attachment element to be symmetrically arranged relative to the tool longitudinal axis of the attachment element when the attachment element is releasably attached to the surgical tool, and The tracker further includes a stop element mounted to a longitudinal end of the attachment element and having a proximal stop surface, the stop element being configured to abut against an abutment surface of a guide of the precision arm to limit an insertion depth of the surgical tool in the guide in the one direction when the attachment element is releasably attached to the surgical tool and the surgical tool is received in the guide so as to be linearly movable in one direction and in a direction opposite to the one direction, Wherein the stop element is configured to be arranged in a predefined, fixed position relative to the one or more markings, wherein the predefined, fixed position is determined by a target value for a relative position between the one or more markings and a target surgical area.

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