Medical robot system and control method

Abstract

The invention relates to a medical robot system (2), comprising a medical instrument (4), a movable robot arm (10), a guide device (14), a control unit (30) and a navigation system (34), wherein a stop geometry (8) of the instrument (4) is immovable relative to an instrument tip (6) of the instrument (4) and the control unit (30) is configured to position the robot arm (10) such that the stop geometry (8) of the instrument (4) lies against the counter stop geometry (16) of the guide device (14), when the instrument tip (4) reaches a predetermined insertion depth (E) along a pre-planned trajectory (T). The invention also relates to a control method for the medical robot system (2).

Description

[0001] Medical robot system and control methods

[0002] Description

[0003] Technical field

[0004] The present disclosure relates to a medical robotic system. The robotic system is used in particular for surgical, preferably cranial, procedures on a patient. Furthermore, the present disclosure relates to a control method for a medical robotic system, in particular the medical robotic system itself.

[0005] Background of the Revelation

[0006] A fundamental requirement for robot-assisted medical or surgical procedures is the precise guidance of a medical instrument. The medical instrument is attached to the distal end / end effector of a (cantilevered) robotic arm of the robotic system. Instruments guided in this way are used, for example, in frameless stereotactic surgery. The precise attachment and alignment of the instrument is achieved via a guide device, in particular a guide sleeve, which defines at least one axial direction / longitudinal axis alignment or orientation.

[0007] Such a robotic system is known, for example, from US 2020 / 0246025 A1, wherein the robotic system comprises a robotic arm, an instrument holder attached to it, and an instrument having a (distal) working end, a shaft, and a (proximal) stop element. The shaft of the instrument is mounted on the instrument holder and is longitudinally movable between the working end and the stop element relative to the instrument holder. Furthermore, a robotic system is known from WO 2023 / 148722 A1, wherein the robotic system comprises a robotic arm with a guide sleeve and depth stop.

[0008] Furthermore, a system for neuronavigation registration and guidance of robotic trajectories is known from EP 3 827 760 A1.

[0009] The use of such a guide device is carried out in particular as follows: The robot arm is aligned along a planned trajectory, defined by an entry point and an end point, and moved to a defined height, based on the planned trajectory, above a surgical area, in particular the surface of the patient's skull. The robot arm maintains its height or position and is not moved again initially, so that a fixed distance exists between the robot arm and the surgical area, in particular the patient's skull. The guide device is then inserted into an opening of a coupling system of the robot arm along the same planned trajectory.

[0010] To prevent the instrument from penetrating too far or too deeply into the surgical area, particularly the patient's skull, and endangering the patient's health—for example, by damaging the cortical surface—it is essential to stop instrument manipulation, especially drilling, in a timely manner. Often, this relies on the surgeon's expertise, who, when operating a manually guided instrument, feels, for example, the resistance, when the patient's skull has been penetrated or perforated, and then stops the instrument from penetrating further. However, this is very imprecise and poses a high risk to the patient.

[0011] Furthermore, to limit the insertion depth, particularly the drilling depth, of the instrument, it is possible to set the insertion depth using a manual stop attached to the instrument itself. For this, the surgeon determines the required position for the stop, either manually or with software assistance, and measures this position or the required length directly on the instrument using a ruler, then sets the stop at the measured position. There are also instruments with an integrated stop, but its position must still be manually adjusted. However, these insertion depth limits are cumbersome and also imprecise.

[0012] Summary of the present disclosure

[0013] The purpose of this disclosure is therefore to avoid or at least reduce the disadvantages of the prior art. In particular, a medical robot system and a control method for a medical robot system are to be provided which ensure, in a particularly simple, precise and safe manner, that the instrument is not moved too deeply or too far.

[0014] The problem described in this disclosure is solved by a medical robot system with the features of claim 1 and by a control method with the features of the dependent claim. Advantageous embodiments are the subject of the dependent claims.

[0015] The present disclosure relates to a medical, in particular surgical, robotic system. The robotic system is used, in particular, for a surgical procedure, preferably cranial surgery, on a patient, preferably on the patient's skull, for example, to open the patient's skull or to pierce a skull bone. Such a procedure often needs to be performed at the beginning of a minimally invasive cranial surgery. The robotic system may preferably have a fixed / rigid mount or head support that is connected or connectable to the patient or the patient's head. The mount or head support may, in particular, be fixed or attachable to an environment, for example, an operating table.

[0016] The robotic system includes a medical, in particular surgical, instrument. The instrument may preferably be a drill or drilling instrument. The instrument is specifically designed for opening the patient's skull or drilling through the skull bone. The instrument has an instrument tip and a stop geometry positioned axially fixed to the instrument tip. In particular, the instrument tip may be located at a distal end of the instrument, and the stop geometry may be located at a proximal end or end region of the instrument. The stop geometry may, in particular, have a larger outer diameter than the instrument tip or form a (distal) stop surface.

[0017] The robot system comprises a movable robot arm or robotic holding arm and a guide device attached to the robot arm (in particular to its end effector). The guide device is designed to guide the instrument. The guide device is, in particular, a (circumferentially closed) guide sleeve. The guide device may, in particular, have a (slightly) larger inner diameter than the instrument tip. This means that the instrument tip can be inserted (axially) into or guided through the guide device (from the proximal side). The guide device has a counter-stop geometry (in particular, designed to be complementary to the stop geometry of the instrument). The counter-stop geometry is designed to limit the insertion depth of the instrument.The counter-stop geometry can in particular form a (proximal) stop surface against which the (distal) stop surface of the instrument can axially rest to limit the insertion depth.

[0018] The robotic system includes a control unit. This control unit is configured to register / capture the patient based on preoperative and / or intraoperative, particularly radiological (three-dimensional), image data and the patient's current pose, i.e., position and orientation. This means that the control unit is configured to capture the patient's current position and orientation, or the patient's anatomy—in the case of neurosurgery, specifically the patient's head or face—within a global coordinate system and / or to link or assign this current position and orientation to the patient's preoperative and / or intraoperative image data. The robotic system may include a recording unit, particularly a camera.The recording unit may be configured, in particular, to capture the patient's current pose, specifically to create a real-time image of the patient, especially of the patient's skull / head or face. The recording unit may also be configured, in particular, to create a real-time three-dimensional image of the patient, specifically a live image feed. The recording unit may, in particular, be a stereo camera.

[0019] The robotic system may include a tracking unit, in particular a tracked pointer. The tracking unit may be configured to capture the patient's current pose, specifically to be guided to certain points or anatomical landmarks of the patient in order to determine the respective position of these points in space (and thus the patient's current pose).

[0020] The robotic system includes a navigation system. The navigation system is configured to track the robotic arm and / or navigate relative to the (registered) patient. This means that a relative position between the robotic arm and the patient, or the patient's current pose, is known, with the current pose being linked to the patient's image data. The navigation system can, in particular, be an infrared navigation system. The navigation system preferably includes a patient reference tracker rigidly attached to the mount or head mount.

[0021] According to a key aspect of the present disclosure, the stop geometry is immovable in the axial / longitudinal direction, i.e., translationally, relative to the instrument tip. This means that the stop geometry is not manually and / or (only) temporarily connected to the instrument tip or the instrument itself, but rather has a predetermined (known) position or a known geometric relationship to the instrument tip with respect to the axial direction. In other words, the stop geometry is not translationally adjustable relative to the instrument tip. According to the key aspect of the present disclosure, the control unit is configured to position the robot arm such that the stop geometry of the instrument rests against the counter-stop geometry when the instrument tip is moved along a pre-planned trajectory to a predetermined insertion depth or reaches a predetermined insertion depth.The predetermined insertion depth corresponds, in particular, to the skull thickness (measured from a skull surface to the inner / lower end of the skull bone) along the pre-planned trajectory. This means that the robot arm is aligned so that, firstly, an axis of the guide device or the instrument (guided within it) corresponds to an axis of the pre-planned trajectory, or the instrument (with its longitudinal axis) is aligned along the pre-planned trajectory, and secondly, it is positioned relative to the patient or patient's head such that the desired insertion depth is achieved (exactly) when the (specific) instrument is fully inserted into the guide device (limited only by the stop geometry or the counter-stop geometry, and not by an additional adjustable stop). The predetermined insertion depth can, in particular, be 1 to 2 cm.

[0022] In other words, the robot arm, and thus also the guide device, is moved to such a (variable) distance that the (always in the same and known position) stop geometry of the (specific) instrument is positioned precisely far enough from the patient or the counter-stop geometry of the guide device that the instrument tip reaches the predetermined insertion depth (simultaneously) when the stop geometry contacts the counter-stop geometry. The distance between the robot arm and the patient can be, in particular, 1 to 3 cm. This means that, unlike the prior art, the position of the stop geometry relative to the instrument tip is not adjusted or changed, but rather, with a fixed and known geometric relationship between the stop geometry and the instrument tip, the position, in particular the distance, of the robot arm to the patient is adjusted.is changed.

[0023] In other words, positioning the robot arm to limit the insertion depth of the instrument is only possible if the navigation system can determine the corresponding poses of the patient and the robot arm relative to the (planned) trajectory, the robot system can position the robot arm precisely in space, and the dimensions or relative positioning of the instrument tip and the stop geometry are known or tightly tolerated.

[0024] This has the advantage of avoiding inaccuracies that arise in prior art, particularly when setting the correct distance between the stop geometry and the instrument tip. Because only one position of the robot arm needs to be changed, and this positioning can be performed with high precision, accuracy can be significantly improved. Furthermore, adjusting the robot arm position is considerably faster and less time-consuming than adjusting the stop geometry position.

[0025] According to a preferred embodiment, the counter-stop geometry can be fixed axially to the robot arm. This means that the counter-stop geometry is not adjustable translationally (relative to the robot arm). In particular, the guide device is axially fixed (and not axially adjustable) on the robot arm. This ensures precise positioning between the counter-stop geometry and the robot arm.

[0026] According to a preferred embodiment, the guide device can be designed as a rigid sleeve. This means that the guide device itself is immovable. Furthermore, this design ensures a particularly simple construction.

[0027] According to a preferred embodiment, the guide sleeve can have a flange. In particular, the flange can rest against the robot arm at its distal end face and form the counter-stop geometry at its proximal end face. This enables precise positioning. According to a preferred embodiment, the instrument can have a rigid first section / component, which includes the instrument tip, and a rigid second section / component (separate from the first section), which includes the stop geometry. This means that the instrument has a multi-part structure. The first section can rest axially against or be axially supported by the second section. In particular, the first section and the second section can be calibrated relative to each other. This ensures precise positioning at a predetermined axial distance in a multi-part structure.

[0028] According to an alternative embodiment, the instrument can be rigid / one-piece. This means that the instrument tip and the stop geometry are rigid / one-piece. This makes it easy to ensure that the instrument tip and the stop geometry are arranged at a predetermined axial distance from each other.

[0029] According to a preferred embodiment, the position of the counter-stop geometry relative to the robot arm can be calibrated. This means that the geometric relationship between the robot arm and the guide device is precisely known and reliably reproducible.

[0030] According to a preferred embodiment, the position of the stop geometry relative to the instrument tip can be calibrated. This means that the geometric relationship between the stop geometry and the instrument tip is precisely known and reliably reproducible.

[0031] According to a preferred embodiment, the navigation system can be configured for planning the pre-planned / planned trajectory, in particular for manually planning the pre-planned trajectory. The trajectory can, in particular, extend along a straight line. The trajectory can, in particular, be defined by an entry point and a destination point. The planning of the trajectory can, in particular, be performed preoperatively. The entry point can, in particular, be located on the skin. BN3158P-WQ-0004

[0032] 9 / 26 or on the skull surface. The target point can correspond to an anatomical target in particular.

[0033] According to a preferred embodiment, the control unit can be configured to automatically determine the predetermined insertion depth based on the pre-planned trajectory and the image data. In particular, due to the normalization of the color / grayscale of the image data, a bone structure, especially the thickness of the patient's skull or the required insertion depth of the instrument, can be automatically determined. This has the advantage that the position of the robot arm can be set automatically and therefore particularly quickly. The insertion depth can be determined, in particular, preoperatively.

[0034] According to a preferred embodiment, the control unit can be configured to display a (two-dimensional) cross-section from the patient's image data, containing one axis of the pre-planned trajectory, and the predetermined insertion depth can be manually set within this cross-section. This has the advantage that displaying the corresponding cross-section simplifies trajectory planning and may allow for more accurate results. In particular, it enables precise determination of the skull bone thickness along the trajectory. The insertion depth can be determined, in particular, preoperatively.

[0035] According to a preferred embodiment, the instrument tip can be rotatably driven. That is, the instrument has a rotating tip. According to the preferred embodiment, the instrument tip can be freely rotatable relative to the stop geometry. That is, the stop geometry is rotationally independent of the instrument tip. In other words, the stop geometry does not rotate with the instrument tip. This has the advantage that friction is avoided when the stop geometry contacts the (stationary) counter-stop geometry.

[0036] According to a preferred embodiment, the instrument tip can be fixed. This means that the instrument tip is not rotatable. In the case of a fixed instrument tip, the stop geometry can be freely rotatable relative to the stop geometry or rotationally fixed to the instrument tip.

[0037] According to a preferred embodiment, the instrument can have an instrument sleeve arranged axially between the instrument tip and the stop geometry, within which the instrument tip is received. The instrument sleeve is preferably designed such that (exclusively) the instrument sleeve, and especially not the instrument tip, comes into (radial) contact with the guide device.

[0038] According to a preferred embodiment, the instrument tip (in the case of a rotatable instrument tip) can be freely rotatable within the instrument sleeve. This means that the instrument sleeve is rotationally independent of the instrument tip. In other words, the instrument sleeve does not rotate with the instrument tip. This ensures that the components coming into contact with the guide do not rotate and that no motion is transmitted. According to a preferred embodiment, the instrument tip can extend within the instrument sleeve to be connected to a drive arranged proximally (to the stop geometry).

[0039] According to a preferred embodiment, the instrument can be manually guided or guided. Particularly with such manually guided instruments, it is necessary to ensure reliable limitation of the insertion depth.

[0040] According to a preferred embodiment, the instrument can be a high-speed drill. The high-speed drill is specifically designed to achieve a cutting speed of more than 20,000 rpm, preferably more than 30,000 rpm, and particularly more than 45,000 rpm or 60,000 rpm. Compared to a low-speed drill, the high-speed drill can prevent the instrument from slipping (so-called "skiving") or pushing the patient away. Accordingly, in combination with the high-speed drill, guidance along the pre-planned trajectory can be ensured more easily or even in the first place. Alternatively, the instrument can be a low-speed drill. The instrument can, in particular, have a drilling diameter of 3 to 4 mm.The instrument can have a length of 8 to 12 cm, for example 9 to 10 cm, from the tip of the instrument to the striking geometry.

[0041] According to an alternative preferred embodiment, the instrument can be an electrode. This ensures correct positioning even when using an electrode.

[0042] According to a preferred embodiment, the robot system can have an input unit with which the insertion depth can be adjusted incrementally or, preferably, continuously up to the predetermined insertion depth. Preferably, the control unit can be configured to display the (currently selected) insertion depth. This allows for easy visual verification of the setting. The input unit can, for example, be a rotary or sliding control knob or a touchpad. For instance, the control unit can be configured to display a cutting plane that can be moved along the pre-planned trajectory by user input, in particular by moving the rotary or sliding control knob or by touch input (finger scrolling). The cutting plane is preferably perpendicular to the pre-planned trajectory. This allows the predetermined insertion depth to be set particularly intuitively.

[0043] According to a preferred embodiment, the control unit can be configured to readjust the position of the robot arm, in particular to move it closer to the patient, if the instrument's stop geometry is in contact with the counter-stop geometry and the instrument tip has not yet reached the predetermined insertion depth or a corrected insertion depth (greater than the predetermined insertion depth). This means that, particularly if the predetermined insertion depth is insufficient to completely penetrate the patient's skull, the insertion depth limit can be easily adjusted without, for example, having to manually reposition a stop. At the same time, a reliable insertion depth limit is ensured even with the readjusted position of the robot arm.

[0044] According to a preferred embodiment, the robotic system may include a CT scanner and / or an MRI scanner for generating the patient's image data.

[0045] According to a preferred embodiment, the recording unit can be a component of the navigation system. In particular, the recording unit can serve as a navigation camera. The recording unit can also be a surgical microscope. The recording unit can be attached to the robot arm (especially to its end effector). The robot system can, in particular, have a robot cart, preferably with a monitor. The recording unit can be attached to the robot cart or to the monitor.

[0046] According to a preferred embodiment, the target point of the planned trajectory can be a pathology (e.g., a tumor). According to a preferred embodiment, the guided instrument can be a rigid surgical instrument (e.g., a biopsy needle).

[0047] According to a preferred embodiment, the robotic system can operate in a simulated environment or a digital twin. This allows the surgical procedure to be practiced.

[0048] The present disclosure also relates to a (computer-implemented) control method for a medical robot system, preferably the described medical robot system, comprising the following steps:

[0049] - Planning a trajectory based on preoperative and / or intraoperative image data of a patient,

[0050] - Determining the insertion depth of an instrument tip along the pre-planned trajectory, in particular such that the instrument tip penetrates a skull bone of the patient upon reaching the predetermined insertion depth, - Moving a robot arm into a position in which the instrument can be guided along the pre-planned trajectory by a guide device attached to the robot arm to such an extent that a stop geometry of the instrument rests against a counter-stop geometry of the guide device (in particular, one that is immobile axially to the robot arm) upon reaching the predetermined insertion depth of the instrument tip.

[0051] This means that the robot arm is positioned so that the instrument (with its axis corresponding to the pre-planned trajectory) can be guided within the guide device in the direction of the patient, or can be (fully) inserted / plugged into the guide device, and in the (fully) inserted position, i.e. when the stop geometry hits the counter-stop geometry, the instrument tip reaches the predetermined insertion depth.

[0052] According to a preferred embodiment, the patient's image data can be generated before planning the trajectory, in particular using a CT scanner and / or MRI scanner.

[0053] According to a preferred embodiment, a current image of the patient can be acquired, particularly using the recording unit, before the trajectory is planned. Alternatively, a current pose of the patient can be determined, for example, using a tracked pointer.

[0054] According to a preferred embodiment, the patient can be registered using the image data and the current image capture or the patient's current pose before the trajectory is planned. This means that the image data and the current pose can be linked before the trajectory is planned.

[0055] After the robot arm has been moved, a surgical procedure can be performed on the patient, and in particular, the instrument can be inserted into the patient's skull to the predetermined depth. During the surgical procedure, neither the robot arm nor the patient is moved.

[0056] In summary, this disclosure relates to an optimized robot-assisted instrument guidance system for skull opening. Skull opening is the first step in many minimally invasive cranial surgical procedures, such as biopsies. Performing such a skull opening can pose risks, such as damage to the cortical surface, which in turn can lead to severe bleeding. With knowledge of the surgical instrument used to open the skull and preoperative planning of the drilling depth along a trajectory, a robotic guidance system can be positioned in a way that ensures optimal and safe guidance of the drill. Using a high-speed drill as the drilling instrument can further improve the resulting drilling accuracy.

[0057] In particular, an (infrared) navigation system, a robotic holding arm tracked by the navigation system, navigation and planning software that displays preoperative scans and enables trajectory planning, a calibrated guide device for instruments mounted on the robotic holding arm, a tracking Z-tracking reference rigidly attached to a patient head rest, and a high-speed drill for more accurate drilling compared to a low-speed drill can be used.

[0058] In the first step, a user / surgeon plans a trajectory with an entry point and an end point based on a CT or MRI scan. The entry point is located on the skin or skull surface, and the end point corresponds to the anatomical target of the procedure. In the second step, the user / surgeon plans the required drilling depth based on the trajectory, starting from the entry point and using the image data. A cross-section of the image volume is displayed along the axis of the planned trajectory, allowing the surgeon to clearly see the skull thickness along the trajectory. The lower end of the skull marks the required drilling depth and can be determined by the surgeon.In a third step, the system, knowing the location of the (high-speed) drill used to open the skull, positions a robotic guide mechanism in line with the planned trajectory at a distance from the patient. This allows the specific drill to be fully inserted into the guide mechanism to achieve the desired drilling depth (without an additional stop). The main advantages of this approach are improved drilling safety for the patient at the cost of minimal additional planning time: Trajectory planning is usually already performed, and specifying the drilling depth takes only seconds. This keeps the workflow streamlined and fast while significantly reducing the risks associated with drilling the skull (e.g., damage to the dura mater / brain). The risk of slippage is also considerably reduced by using a high-speed drill.Conventional low-speed drills produced only inadequate results without further stabilization measures at the head or head clamp.

[0059] Brief description of the characters

[0060] Figures 1 to 3 show different embodiments of the medical robot system or a part of the medical robot system according to the present disclosure.

[0061] Fig. 4 shows an exemplary embodiment of an instrument of the medical robot system.

[0062] Fig. 5 shows an exemplary embodiment of a guide device and part of a robot arm of the medical robot system.

[0063] Fig. 6 shows a schematic representation of a control method according to the present disclosure.

[0064] Figures 7 to 9 show individual steps of the control method according to the present disclosure. Description of preferred embodiments.

[0065] Figures 1 to 3 show a medical, in particular surgical, robotic system 2 or a part of the robotic system 2 according to the present disclosure. The robotic system 2 is used in particular for cranial surgery on a patient P, preferably on a patient's skull / head. In particular, the robotic system 2 serves to open the patient's skull or to (completely) pierce a skull bone K of the patient P.

[0066] The robot system 2 preferably comprises a head support (not shown in detail) that is rigidly connected or connectable to the patient's head. The head support can, in particular, be rigidly attached or attachable to an environment, for example, an operating table 0.

[0067] The robot system 2 comprises a medical, in particular surgical, instrument 4. The instrument 4 is preferably a drill. The instrument 4 is particularly a high-speed drill. The instrument 4 can particularly have a drilling diameter of 3 to 4 mm. The instrument 4 is particularly designed for drilling through the skull bone K. Alternatively, the instrument 4 can be an electrode. The instrument 4 can particularly be manually guided or guided.

[0068] The instrument 4 has an instrument tip 6 and a stop geometry 8 positioned axially fixed to the instrument tip 6. The stop geometry 8 is, in particular, immovable relative to the instrument tip 6 in the axial / longitudinal direction of the instrument. Specifically, the instrument tip 6 can be located at a distal end of the instrument 4, and the stop geometry 8 can be arranged at a proximal end or end region of the instrument 4. Preferably, the position of the stop geometry 8 relative to the instrument tip 6 can be calibrated. For example, the diameter of the stop geometry 8 can increase distally. The stop geometry 8 can, in particular, have a larger outer diameter than the instrument tip 6 or form a (distal) stop surface. The instrument 4 can, in particular, have a length of 5 to 15 cm, for example, 8 to 12 cm, from the instrument tip 6 to the stop geometry 8.An exemplary embodiment of instrument 4 is shown in Fig. 4.

[0069] Preferably, the instrument tip 6 can be rotatably driven. That is, the instrument 4 has a rotating tip. In particular, the instrument tip 4 can be freely rotatable relative to the stop geometry 8. That is, the stop geometry 8 is rotationally independent of the instrument tip 6. In other words, the stop geometry 8 does not rotate with the instrument tip 6.

[0070] Furthermore, the instrument 4 can have an instrument sleeve 9 arranged axially between the instrument tip 6 and the stop geometry 8. The instrument tip 6 can be received within the instrument sleeve 9 (in order to be connected to a drive arranged proximally to the stop geometry 8).

[0071] Preferably, the instrument tip 6 (in the case of a rotatable instrument tip 6) can be freely rotatable within the instrument sleeve 9. This means that the instrument sleeve 9 is rotationally independent of the instrument tip 6. In other words, the instrument sleeve 9 does not rotate with the instrument tip 6.

[0072] The robot system 2 has a movable robot arm 10 and a guide device 14 attached to the robot arm 10 (in particular to its end effector 12).

[0073] The guide device 14 is configured to guide the instrument 4. In particular, the guide device 14 is designed as a guide sleeve. The guide device 14 has a counter-stop geometry 16. The counter-stop geometry 16 is designed to be complementary to the stop geometry 8 of the instrument 4. The counter-stop geometry 16 is configured to limit the insertion depth of the instrument 4. The counter-stop geometry 16 can, in particular, form a (proximal) stop surface against which the (distal) stop surface of the instrument 4 can axially abut to limit the insertion depth. Preferably, the position of the counter-stop geometry 16 relative to the robot arm 10 can be calibrated.

[0074] The guide device 14 can, in particular, have a larger inner diameter than the instrument tip 6. This means that the instrument tip 6 can be inserted (axially) into or passed through the guide device 14 (proximally).

[0075] The instrument sleeve 9 is preferably designed such that (exclusively) the instrument sleeve 9, and especially not the instrument tip 6, comes into (radial) contact with the guide device 14. This means that no rotating parts of the instrument come into contact with the guide device 14, in order to prevent the transmission of movement.

[0076] An exemplary embodiment of the end effector 12 and the guide device 14 is shown in Fig. 5. The end effector 12 has a fork-shaped, medical-grade mounting adapter 18 and a quick-release coupling 20 permanently attached to it. The guide device 14 can be inserted into, received, and coupled into the quick-release coupling 20. For this purpose, the guide device 14 has a corresponding coupling geometry 22. The mounting adapter 18 can be detachable and, for example, attached by means of a three-point support of a three-part coupling structure. The mounting position of the mounting adapter 18 on the end segment 12 can be varied between at least two positions by means of an adjusting device 24 designed as a screw mechanism.

[0077] The robot system 2 can include a recording unit 26. The recording unit 26 is configured to create a real-time image of the patient P, in particular of the patient's head. The recording unit 26 is specifically configured to create a real-time three-dimensional image of the patient P, in particular a live image feed. The recording unit 26 can, in particular, be a stereo camera. The recording unit 26 can be arranged externally (see Fig. 2) and / or on or below a monitor 28 (see Fig. 3) and / or be configured as a surgical microscope (not shown), preferably arranged on the end effector 12.

[0078] The robot system 2 has a control unit 30. The control unit 30 is configured to register / capture the patient P based on preoperative and / or intraoperative, in particular radiological (three-dimensional) CT image data of the patient P and a current pose of the patient P. The current pose can be determined by capturing the patient P in real time or by guiding a tracked pointer to specific points or landmarks of the patient P.

[0079] The robot system 2 can include a CT scanner 32 (see Fig. 3). The CT scanner 32 can be configured to generate the (preoperative) CT image data of patient P.

[0080] The robot system 2 includes a navigation system 34. The navigation system 34 is configured to track the robot arm 10 and / or to navigate relative to the (registered) patient P. The navigation system 34 can, in particular, be an infrared navigation system. The navigation system 34 can preferably include a patient reference tracker (not shown) that is rigidly connected to the head mount.

[0081] Preferably, the navigation system 34 can be configured for planning a pre-planned trajectory T, in particular for manually planning the pre-planned trajectory T. The trajectory T can, in particular, extend along a straight line. The trajectory T can, in particular, be defined by an entry point and a destination point.

[0082] The control unit 30 is configured to position the robot arm 10 such that the stop geometry 8 of the instrument 4 rests against the counter-stop geometry 16 when the instrument tip 6 is moved along the pre-planned trajectory T to a predetermined insertion depth E. BN3158P-WQ-0004

[0083] 20 / 26

[0084] Preferably, the control unit 30 can be configured to automatically determine the predetermined insertion depth E based on the pre-planned trajectory T and the CT image data. Alternatively or additionally, the control unit 30 can be configured to display a (two-dimensional) cross-section containing the pre-planned trajectory T from the CT image data. The predetermined insertion depth E can be manually set in this cross-section. The predetermined insertion depth E can, in particular, be 1 to 2 cm.

[0085] Preferably, the control unit 30 can be configured to readjust the position of the robot arm 10, in particular to move it closer to the patient, when the stop geometry 8 of the instrument 4 is in contact with the counter-stop geometry 16 and the instrument tip 6 has not yet reached the predetermined insertion depth E or the patient's skull bone P has not yet been completely pierced.

[0086] Fig. 6 shows a schematic representation of a control method for a medical robot system, preferably the described medical robot system 2. Figs. 7 to 9 show individual steps of the control method.

[0087] In the first preparatory step VS1 of the control procedure, CT image data of patient P, in particular of the patient's skull, is generated (see Fig. 7). This generation is carried out primarily using the CT scanner 32 and / or MRI scanner. Furthermore, in the first preparatory step VS1, a current image of patient P, in particular of the patient's skull, is generated. This generation is carried out primarily using the acquisition unit 26.

[0088] In a second preparatory step (VS2) of the control procedure, the patient P, in particular the patient's skull, is registered using the CT image data and the current scan. This means that the CT image data and the current scan are linked together.

[0089] In the first step S1 of the control procedure, a (preoperative)

[0090] Planning the trajectory T using CT image data (see Fig. 8). This planning is primarily done manually by the surgeon S. The trajectory is defined as a straight line through an entry point on the skull surface and a target tissue. The target tissue is, in particular, the tissue that will be operated on in a subsequent (e.g., minimally invasive) surgical procedure after opening the patient's skull.

[0091] In a second step S2 of the control procedure, an insertion depth E of the instrument 4 or the instrument tip 6 of the instrument 4 is determined along the pre-planned trajectory T (see Fig. 9). Specifically, the insertion depth E is determined such that the instrument tip 6 (completely) penetrates or opens the skull bone K upon reaching the predetermined insertion depth E. This means that the predetermined insertion depth is defined by an inner / lower end of the skull bone K or a skull thickness along the pre-planned trajectory T.

[0092] In a third step S3 of the control procedure, the robot arm 10 is moved into a position in which the instrument 4 can be guided (i.e. spaced apart) by the guide device 14 attached to the robot arm along the pre-planned trajectory T (i.e. aligned on a common axis) to such an extent that the stop geometry 8 of the instrument 4 abuts a counter-stop geometry 16 of the guide device 14 upon reaching the predetermined insertion depth E of the instrument tip 6.

[0093] After moving the robot arm 10, a surgical procedure (which is not part of the control procedure) can be performed on patient P, and in particular, the instrument 4 can be inserted into the patient's skull to the predetermined insertion depth E. During the surgical procedure, neither the robot arm 10 nor patient P is moved. Reference list

[0094] 2 medical robotic systems

[0095] 4 Instrument

[0096] 6 Instrument tip

[0097] 8 Stop geometry

[0098] 9 Instrument sleeve

[0099] 10 robot arms

[0100] 12 End effector

[0101] 14 Guide device

[0102] 16 Counter-stop geometry

[0103] 18 mounting adapters

[0104] 20 quick couplings

[0105] 22 Clutch geometry

[0106] 24 Adjustment devices

[0107] 26 recording units

[0108] 28" Monitor

[0109] 30 control unit

[0110] 32 CT scanner

[0111] 34 Navigation system

[0112] Patient

[0113] K skull bones

[0114] S Operator

[0115] 0 Operating table

[0116] T pre-planned trajectory

[0117] E predetermined insertion depth

[0118] CT image data

[0119] S1 first step

[0120] S2 second step

[0121] S3 third step

[0122] VS1 first step

[0123] VS2 second regulation

Claims

Claims 1. Medical robot system (2), comprising a medical instrument (4) having an instrument tip (6) and a stop geometry (8) positioned axially fixed to the instrument tip (6), a movable robot arm (10), a guide device (14) attached to the robot arm (6) and configured to guide the instrument (4) with a counter-stop geometry (16) for limiting the insertion depth of the instrument (4), wherein the instrument tip (6) is preferably axially passable through the guide device (14), a control unit (30) configured to register the patient (P) using image data (CT) of the patient (P) and a current pose of the patient (P), and a navigation system (34) configured to track the robot arm (10) and / or navigate relative to the patient (P), characterized in thatthat the stop geometry (8) is axially immovable relative to the instrument tip (6) and the control unit (30) is configured to position the robot arm (10) such that the stop geometry (8) of the instrument (4) rests against the counter-stop geometry (16) of the guide device (14) when the instrument tip (4) reaches a predetermined insertion depth (E) along a pre-planned trajectory (T).

2. Robot system (2) according to claim 1 , characterized in that the counter-stop geometry (16) is immovable in the axial direction relative to the robot arm (6).

3. Robot system (2) according to claim 1 or 2, characterized in that a position of the counter-stop geometry (16) is calibrated relative to the robot arm (10) and a position of the stop geometry (8) is calibrated relative to the instrument tip (6). BN3158P-WQ-0004 24 / 26 4. Robot system (1 ) according to one of claims 1 to 3, characterized in that the navigation system (34) is set up for planning the pre-planned trajectory (T).

5. Robot system (2) according to one of claims 1 to 4, characterized in that the control unit (30) is configured to automatically determine the predetermined insertion depth (E) based on the pre-planned trajectory (T) and the image data (CT).

6. Robot system (2) according to one of claims 1 to 5, characterized in that the control unit (30) is configured to display a cross-section containing the pre-planned trajectory (T) from the image data (CT) of the patient (P), and the predetermined insertion depth (E) can be manually set in the cross-section.

7. Robot system (2) according to one of claims 1 to 6, characterized in that the instrument tip (6) is rotatably driven, wherein the instrument tip (6) is freely rotatable relative to the stop geometry (8), or that the instrument tip (6) is stationary.

8. Robot system (2) according to one of claims 1 to 7, characterized in that the instrument (4) has an instrument sleeve (9) arranged axially between the instrument tip (6) and the stop geometry (8), within which the instrument tip (6) is freely rotatable.

9. Robot system (2) according to one of claims 1 to 8, characterized in that the instrument (4) is a high-speed drill.

10. Robot system (2) according to one of claims 1 to 9, characterized in that the control unit (30) is configured to readjust a position of the robot arm (10) when the stop geometry (8) of the instrument (4) is in contact with the counter-stop geometry (16) and the instrument tip (6) has not yet reached the predetermined insertion depth (E).

11. Control method for a medical robot system (2), preferably according to one of claims 1 to 10, comprising the following steps: - Planning a trajectory (T) based on image data (CT) of a patient (P), - Determining an insertion depth (E) of an instrument tip (6) of an instrument (4) along the pre-planned trajectory (T), in particular such that the instrument tip (6) penetrates a skull bone (K) of the patient (P) upon reaching the predetermined insertion depth (E), - Moving the robot arm (10) into a position in which the instrument (4) can be guided along the pre-planned trajectory (T) by a guide device (14) attached to the robot arm (10) to such an extent that a stop geometry (8) of the instrument (4) abuts a counter-stop geometry (16) of the guide device (14) upon reaching the predetermined insertion depth (E) of the instrument tip (4).

Images