Device and method for standardising the axial orientation and position of kinematics data with regard to a body joint of a patient

Abstract

The invention relates to a standard-kinematics evaluation system (1) for detecting, standardising and evaluating biomechanical kinematics data relating to a joint (G) of a patient (P), comprising: at least one detection device (2), which is adapted for detecting, by means of a sensor system (4), biomechanical kinematics of the joint (G) of the patient (P) and for providing said kinematics in a computer-readable manner; and a visual display device (6), in particular a surgical monitor, for visual output to a user; wherein the standard-kinematics evaluation system (1) also comprises: a control unit (8), which is adapted for: processing the provided detected kinematics of the patient and for determining therefrom at least one profile of kinematics parameters of the (observed) joint (G) with respect to a first joint element (G1) using a first joint coordinate system (20) and with respect to a second joint element (G2) using a second joint coordinate system (22), by means of a standardising unit (10), which is adapted and designed for determining, via a predefined target optimisation, a transformation for adapting an orientation and / or position of the first joint coordinate system (20) and / or the second joint coordinate system (22) in order to carry out a standardisation, and by means of an evaluation unit (12), which is adapted for carrying out, on the basis of the standardised kinematics parameters as movement data, an evaluation with regard to the joint (G) for at least one predefined evaluation parameter, and for outputting the evaluation via the display device (6). The invention also relates to a standardisation method and a computer-readable storage medium according to the additional independent claims.

Description

[0001] AE2046P-WO-0032 2022P00079 WO 1 / 35 Device and method for standardizing the axis alignment and position of kinematic data relating to a body joint of a patient Description Technical field The present disclosure relates to a standard kinematics evaluation system for detecting, standardizing and evaluating biomechanical kinematics data of a (selected) joint of a patient, comprising: at least one detection device adapted to detect (record) biomechanical kinematics of the patient's joint by means of sensors and to provide said data in a computer-readable format; and a visual display device, in particular an operating room monitor,for a visual output to a user. In addition, the present disclosure relates to a standardization method and a computer-readable storage medium according to the preambles of the independent claims. Background of the Disclosure: In a kinematic analysis of moving bodies or segments, the position, i.e., the orientation and position, but especially the orientation itself, of the underlying reference system of each participating segment has a significant influence on the size and characteristics / properties of the resulting (kinematic) curve, in particular waveforms, of three measured rotations corresponding to a specific joint connecting these segments.and possibly also measured translations in three spatial directions. This was previously attributed to crosstalk effects. Crosstalk results from incorrect alignment and, preferably, incorrect positioning of the axes of the coordinate system, so that a rotation in one plane is partially perceived as a rotation in other planes. AE2046P-WO-0032 2022P00079 WO 2 / 35 Methods for minimizing crosstalk effects generally attempt to achieve this by minimizing one or more selected objective functions for a specific activity, a measurement system, or a biomechanical model. Such a minimization is described, for example, in Baker et al. 1999 - A new approach to determine the hip rotation profile from clinical gait analysis data, Rivest 2005 - A correction for axis misalignment in the joint angle curves representing knee movement in gait analysis,Baudet et al. 2014 - Cross-Talk Correction Method for Knee Kinematics in Gait Analysis Using Principal Component Analysis (PCA): A New Proposal. These methods have a significant disadvantage in that, for at least one of the data sources to be compared, the orientation, and preferably the positioning, of the underlying reference frames relative to the segments they represent is unknown. The same applies to methods that attempt to compare the extent to which data from different sources (e.g., different biomechanical models, different laboratories, different marker sets, and the like) are affected by crosstalk effects. In these approaches, crosstalk has so far been quantified using at least one representative parameter (e.g., a measure of a determination between flexion / extension and abduction / adduction) and then the conclusion drawn.that a lower value of such a parameter could be interpreted as a sign of lower crosstalk effects (Kainz et al. 2016 - Joint kinematic calculation based on clinical direct kinematic versus inverse kinematic gait models). However, before performing such a comparison, all data sets must be made comparable and, to a certain extent, normalized. The reason for this is that any comparison of non-normalized data is invalid to a certain extent, as it is unclear whether the displayed kinematic differences actually reflect different movement patterns or are merely a result of different axis positions, especially orientation. AE2046P-WO-0032 2022P00079 WO 3 / 35 Much of the existing literature dealing with the use of methods to minimize crosstalk in rotational kinematic analysis attempts toto justify the appropriate choice of parameters to be optimized (or minimized) by referring to previous research on so-called "physiological" characteristics of movement. Such reasoning could be considered flawed, since any experiment that seeks to measure, say, the "physiological" range of rotation of a knee joint in the transverse and frontal planes during flexion (in order to know to which values ​​these rotations should be optimized in an algorithm to minimize crosstalk) necessarily requires the definition of a specific reference frame in a specific orientation. The precise definition of such a frame (especially its orientation) inevitably influences the magnitude of the measured rotations. Therefore, the acquired "physiological" profile, which is often cited as evidence for why a chosen objective function (or functions) is (are) valid,cannot, in reality, be meaningfully used as valid confirmation, as it itself is largely dependent on the frame definitions. When considering two or more datasets, differences in the orientation of the corresponding joint axes may arise, due, among other things, to the enforcement of different kinematic constraints, the consideration of different underlying assumptions, and different modality algorithms for axis definition (e.g., landmark-based vs. feature-based). As a result, the precise orientation of a joint reference frame relative to the connected rigid segments may vary from trial to trial. For example, considering two different trials that both use the same optical motion capture system for data acquisition, with the same subject performing the same activity,and where the axes are defined based on the manual identification of the positions of bony landmarks using a special pointer, it is quite conceivable, given the possibility that one of the required landmarks is identified in a slightly different position between these attempts (even if only by a few millimeters), that the sets of axes defined in each case are not perfectly aligned. Extending this scenario to the comparison of data from different studies, differences in alignment can arise to varying degrees from a number of these factors. Without the implementation of a protocol that harmonizes these differences in alignment, conclusions about the existence of significant differences between the groups are highly questionable. While there are methodsto minimize the effects of crosstalk, but these attempt to achieve this by minimizing one or more selected objective functions. As already mentioned, these methods have a significant disadvantage when researchers want to compare the quality of the resulting values ​​with another dataset for which either no crosstalk minimization or a different implementation of such minimization has been performed. The analysis of kinematic data from a patient's joint, particularly the knee, from different sources requires the use of standardized definitions and calculation conventions. While exact conversions exist for various underlying mathematical definitions, the normalization or standardization of the coordinate systems and their exact alignment is still challenging. For example, if manual assessments are used for an analysis, such as the so-called anterior drawer test,These are very subjective. Alternatively, there are methods that use devices to measure joint laxity that fix a reference joint segment and apply forces to another, connecting joint segment to induce and measure the resulting relative joint movement. However, neither of the two aforementioned approaches takes into account the effects of differences in the local positions and / or orientations of the segments, leading to inconsistent results and, disadvantageously, to an incorrect interpretation of the underlying joint movement and / or stability. AE2046P-WO-0032 2022P00079 WO 5 / 35 For example, research has already investigated the identification of patient phenotypes based on kinematic joint signals during activities of daily living (e.g., Zgolli et al., 2018, Kinematic data clustering for healthy knee gait characterization; Mezghani et al., 2021,Healthy Knee Kinematic Phenotypes Identification Based on a Clustering Data Analysis; Petersen 2021, Petersen et al. 2021, Patients with knee osteoarthritis can be divided into subgroups based on tibiofemoral joint kinematics of gait: an exploratory and dynamic radiostereometric study) each using complex methods to demonstrate the presence of statistically significant differences between patient clusters / groups. Unfortunately, further analyses have shown that these patient groups are also inconsistent when considering, for example, the possibility of differently oriented local frames of segments. A further disadvantage of these methods is that complex statistical analyses must be performed for three or six time series (three translations or three rotations, or both, i.e., both three translations and three rotations).to determine statistically significant differences (e.g., through statistical parameter assignment). Therefore, no reliable and uniform evaluation currently exists. Summary of the present disclosure The objects and aims of the present disclosure are therefore to avoid the disadvantages of the prior art and, in particular, to provide a standardization system or norming system and a standardization method or norming method for standardizing or norming biomechanical kinematics data. One sub-objective can be seen in drawing conclusions for a medical intervention, in particular regarding parameters of a medical implant and its relationship to the patient, based on the normed biomechanical kinematics data.In particular, an object of the invention is to provide a device and a method for standardizing or normalizing an axis alignment of biomechanical kinematics data, in particular rotational kinematics data and / or translational kinematics data, with respect to a body joint of a patient. The kinematics data thus comprise the translational kinematics data and / or the rotational kinematics data between two movable bodies or segments. The objects are achieved according to the invention with regard to a generic standardization system by the features of claim 1, with regard to a generic standardization method by the features of claim 11, and with regard to a computer-readable storage medium by the features of claim 14. A basic idea here is,to provide a normalization system and method for comparing kinematic patterns that does not require prior knowledge of the position / pose, i.e., the orientation and position, in particular the orientation / alignment, of the original underlying reference frames, but rather enables the alignment and / or positioning of the two frames for comparison by optimizing the value of a selected criterion. In other words, the present disclosure comprises a normalization or standardization method or specially adapted control units (similar to an algorithm) with which kinematic data from two or more sources (such as different experiments, different subjects, different motion capture technologies, different laboratories, and the like) are made comparable by processing the underlying kinematic data in such a way thatthat at least one selected parameter is optimized. By processing the at least two data sets (with a specific implementation of the optimization), a valid comparison of the resulting rotation data or translation data is enabled, since differences due to axis misalignments or axis mispositioning in the at least two data sets have been or can be corrected equally. In other words, the present disclosure proposes an optimization of the alignment and / or positioning, in particular the position, of coordinate systems for standardizing kinematics data. The proposed normalization system and normalization method are based on the fundamental understanding that methods for minimizing crosstalk require a decision as toHow the "correct" orientations and / or the "correct" positioning of the reference frame should be defined. These decisions, which can also be considered underlying assumptions, are reflected in the choice of the objective function(s) to be optimized (or minimized). Here, an approach is proposed that solves this problem by providing a method or customized control unit in which one or more specific (optimization) parameters or an objective function are selected and then each set of kinematic data is processed accordingly to obtain the rotations and / or translations resulting from performing the described optimization. Specifically, this processing involves the use of (mathematical) optimization algorithms to determine the orientations and / or positions of the segment reference frames.which optimize a previously defined objective function. These resulting angle curves (courses of normalized kinematic angles) and / or translation curves (courses of normalized kinematic translations) are then used for comparison and can be recorded for this purpose. The validity of the resulting comparison does not depend on the precise choice of the parameters to be optimized or the objective function(s). One may prefer a set of parameters or objective functions that, for example, produce waveforms that are easy to interpret clinically, but the comparison does not lose its validity if this is not the case. In particular, a device is proposed as a normalization system for standardizing an axis orientation of rotational kinematic data and / or an axis position of translational kinematic data, in particular an axis position / axis pose, with respect to a patient's body joint.comprising: a number of sensors for detecting and / or recording kinematic data sets, and a computer to which the sensors are or can be connected for data transmission purposes, wherein the computer is adapted and configured to standardize the orientation of the tibial and femoral coordinate systems from the rotational data resulting from the recorded kinematic data sets and / or the position of the tibial and femoral coordinate systems from the resulting translational data using a mathematical optimization method. In particular, a (standardization) method for standardizing an axis alignment and / or an axis position of kinematic data, in particular rotational kinematic data and / or translational kinematic data, with respect to a body joint of a patient using a device, preferably a standardization system according to the present disclosure,with the following method steps: Acquisition of kinematic data sets relating to a patient's body joint using a number of sensors; transmission to a computer; provision of rotation data and / or translation data resulting from the kinematic data sets; and standardization of the orientation and / or position of tibial and femoral coordinate systems for the provided rotation data using a mathematical optimization method. In other words, the present disclosure relates to a device and a method according to which the influence of the axis alignment on kinematic data (relating to a patient's joint, in particular a knee joint) and its effects can be determined / reduced, and an approach for normalization or standardization is provided. In still other words, the present disclosure relates to a standard kinematics evaluation system for acquisition,Standardization and evaluation of biomechanical kinematics data of a (selected) patient's joint, comprising: at least one detection device adapted to detect, by means of sensors, biomechanical kinematics of the patient's joint (in particular kinematic rotations and kinematic translations), record them, and provide them in a computer-readable format; and a visual display device, in particular an operating room monitor, for a visual output to a user. Furthermore, the standard kinematics evaluation system comprises a control unit specifically adapted to: process the provided detected kinematics of the patient and to derive therefrom at least one course of, in particular, three, kinematic angles (as rotation angle graphs) and / or of, in particular, three,to determine translations of the AE2046P-WO-0032 2022P00079 WO 9 / 35 (considered) joint relative to a first joint element with a first joint coordinate system and relative to a second joint element with a second joint coordinate system, via a normalization unit which is adapted and configured to determine a rotation vector or a rotation matrix for adjusting an orientation of the first joint coordinate system and / or a translation vector for adjusting a position of the first joint coordinate system via a predetermined target optimization, and to determine a rotation vector or a rotation matrix for adjusting an orientation of the second joint coordinate system and / or a translation vector for adjusting a position of the second joint coordinate system via a predetermined target optimization, in order to carry out a normalization,and an evaluation unit adapted to perform an evaluation of the joint for at least one predefined evaluation parameter based on the normalized kinematic angles and / or the normalized kinematic translations as movement data, and to output the evaluation via the display device. In particular, a method is provided for standardizing reference frame orientations and / or reference frame translations in biomechanical kinematic analysis using specific mathematical criteria. Very small changes in the orientation or positions of the underlying (reference) coordinate systems can cause large differences in the (characteristics of the) kinematic data. This effect can be considered, according to the disclosure, when identifying differences between gait patterns in order to excludethat any differences found are based on such alignment errors of the axes. Examples of standardization scenarios include the post-processing of gait laboratory data (for standardization purposes) and the pre-processing of known kinematic gait patterns for comparison (for harmonization purposes). AE2046P-WO-0032 2022P00079 WO 10 / 35 According to a further, second, and possibly independently claimable aspect of the present disclosure, a standard kinematics assessment system for acquiring, standardizing, and evaluating biomechanical kinematic data of a patient's joint and an associated method are provided, which assesses (characterizes) laxity and / or stability and / or function of a human body joint, in particular a knee, in a standardized (and thus standardized) manner, wherein this system or method is based on a mathematically predetermined target optimization,which optimizes and thus standardizes a reference frame according to the present disclosure with regard to position and / or orientation (reference frame alignment method). This allows consistent and comparable measurements to be achieved. In particular, this system and method, which can be used independently, comprises the acquisition of kinematic data over time or at multiple points in time, which are stored accordingly, and a comparison unit can be adapted to record changes over time. Particular attention is therefore paid to the detection of kinematic changes over time. The standard kinematics evaluation system according to the second aspect can, in particular, comprise optical and / or inertial sensors that are attached or can be attached to the (relevant) joint segments (i.e., joint segments adjacent to the joint to be examined).in particular, are releasably fixed or fixable, for example by means of a hook-and-loop fastener, an adhesive, or a tape, and are adapted to acquire spatial or inertial data suitable for characterizing the movements of the joint segments during a series of activity cycles, whether passively through movement of a joint by a medical professional or actively, such as walking or running. The acquired (raw) data from the sensors is forwarded to a control unit, which processes this data based on a biomechanical model to calculate the corresponding kinematic signals of the joints (in particular the joint segments associated with the joint). A reference frame alignment method based on the mathematical optimization of predetermined statistical parameters, in particular according to the present disclosure, can be used,to characterize these kinematic signals and to (re-)align / orient and / or (re-)position the respective local joint segment coordinate frames to fulfill a predetermined underlying objective function. This enables the consistent and reliable standardization of kinematic measurements for valid data comparison, particularly for analysis with respect to a point in time of interest, be it current, historical, or future. This reliable quantification of joint laxity and / or joint stability and / or joint function is particularly advantageous for determining a change, particularly deterioration, in a joint and thus an optimal or best time for surgical intervention or for evaluating the course of therapeutic treatment.in particular the progress of physiotherapy and / or rehabilitation after surgery. Thus, in particular, a technical application for quantifying joint laxity in human, animal, or mechanical joints is provided, which is preferably adapted to detect a change, in particular a deterioration and / or progression in a human and / or animal joint, such as a knee, hip, shoulder, head, neck, elbow, and the associated (tissue) soft tissue, in particular ligaments, muscles, cartilage, over time, and to evaluate it on the basis of this detection. In particular, a control unit can be adapted toto calculate a so-called optimization residual and output it to a medical professional. An evaluation of the optimization residual provides a direct objective measure of the agreement of the joint / axis estimate with a perfect joint / hinge. Any value deviating from zero provides a direct quantification of the laxity within the joint, which is used in the clinical examination, assessment, and monitoring of joint laxity / instability. According to yet a further, third, and possibly independently claimable aspect of the present disclosure, a phenotyping method is provided for distinguishing between kinematic phenotypes of a human joint based on motion data in order to guide the choice of treatment, for example, the type of implant.the implant position and / or the implant alignment (orientation) relative to the affected joint segments prior to surgery (e.g., in a total knee replacement). According to this phenotyping method, in a first step, the center of rotation of the first joint segment, in particular the femur, can be defined as the new origin of the frame (in particular after normalization according to the present disclosure as a second step) relative to an original (anatomical) first joint segment, in particular the femur. This new position of the first joint segment (e.g., the femur) enables the characterization of the joint kinematics (in particular of the knee joint) and individualized treatment recommendations, for example, by determining the specific implant design and / or position and / or orientation that best suits a specific phenotype / patient.thereby optimizing patient satisfaction and implant lifespan / durability. This third aspect serves to facilitate the consistent identification of subject phenotypes based on kinematic signals, in particular by simplifying the analysis of three or six complete time series (three translations or three rotations, or both three translations and rotations) over a motion-load cycle to obtain a simple evaluation of a 3x1 vector representing the relative first joint segment (specifically the femoral) frame center after standardizing the kinematic dataset with a so-called REFRAME. With this phenotyping method, using a suitable kinematics definition (translations of the femur expressed in a tibial frame as well as any rotation definition) and suitable optimization criteria,In particular, by minimizing the root mean square error (RMS) of all three translation components, a virtual femoral center of rotation can be determined. This virtual femoral center of rotation is directly related to the characteristic movements of common implant types, such as, in particular, a medially stabilized (MS) implantation type with a medial center of rotation, a laterally stabilized (LS) implantation type with a lateralized center of rotation, or a posteriorly stabilized (PS) implantation type with a more distal center of rotation. The phenotyping method can, in particular, comprise, as a further step, determining a virtual femoral center of rotation, and, based on the femoral center of rotation, selecting an implantation type, in particular determining the implantation type from the set of LS implantation types.MS implantation type and PS implantation type. In particular, in one step, a new joint coordinate system can be determined according to the present disclosure, and it can be determined to which of MS, LS, and PS this new joint coordinate system is closest. This closest KOS then indicates the implant type. For example, if the joint coordinate system is closest to the LS KOS, it can be determined that an LS implant type is suitable. Thus, according to the third aspect, a method and a system are provided that evaluate knee kinematics before surgery to determine the implant type that best fits the needs, gait, and movement profile of a specific patient.to improve the treatment outcome and the service life of the medical device. The disclosure according to the third aspect can, in particular, be part of a medical device for measuring joint kinematics in a clinical setting during preparation for a total knee replacement operation, in particular part of a standard kinematics assessment system according to the present disclosure. In particular, a (same) method can be used to determine an actual hip pivot point based on gait data with an anatomical reference in the pelvis. It is particularly important that the alignment of the axes is also specified.so that a consistent interpretation of the joint movement is possible without crosstalk between the axes. This enables the (correct) comparison of new movement data with historical movement data. In particular, the joint centers for the evaluation of a knee adduction moment can be determined in a single step. It should also be noted that this approach applies not only to joints and medical applications, but also to other application areas in which movement patterns from different sources or moving objects are (should be) clustered. In particular, this method can also significantly facilitate the comparison of movement patterns, as less effort is required for the correct arrangement of the coordinate frames. In particular, a rough (initial) placement is performed in one step, and in a subsequent step, the result is calculated using REFRAME.in particular according to the standard kinematics evaluation method according to the present disclosure. Advantageous embodiments are claimed in the subclaims and are explained in particular below. According to one embodiment, the at least one detection device can have at least one acceleration sensor and / or a gyro sensor, in particular an inertial measurement unit (IMU), as a sensor, and the detection device can be adapted to be attached, for example, to an extremity of the patient, in the region of the joint on the patient, in particular to the first joint element and / or the second joint element. According to a further preferred embodiment, the at least one detection device can have at least one optical recording unit as a sensor, in particular a 3D recording unit, preferably a stereo camera, which records the biomechanical kinematics of the patient's joint, preferably via optical markers.in particular via passive infrared markers that are attached to the patient in the region of the joint, preferably at least on the first joint element and / or the second joint element. Preferably, the predetermined target optimization can be a minimization of a variance, a standard deviation, a square error and / or a statistical error of the regression of one or more kinematic parameters, in particular one or more kinematic angles and / or one or more kinematic translations. Thus, in particular three kinematic angles, preferably two kinematic angles, can be determined, for which, AE2046P-WO-0032 2022P00079 WO 15 / 35 in particular over exactly one cycle of a joint movement, in particular a step cycle,a minimization of a variance or a quadratic error is determined as the objective function, and a change in the orientation of the first joint coordinate system and the second joint coordinate system is defined as the objective or result to be determined. The control unit therefore calculates a rotation / reorientation of the first local joint coordinate system around its origin and a rotation / reorientation of the second local joint coordinate system around its origin, in which one, two, or three of three kinematic angles are considered and, for example, an area of ​​the graph of the corresponding kinematic angle is minimized approximately around its zero line. In other words, the selected parameter can be a variance, a standard deviation, a quadratic error, or a statistical error of the regression of one or more kinematic angles. - Model that calculates the variance, the standard deviation,The mean square error, the root mean error, or the statistical error of the regression of one or more kinematic angles is used as criteria for minimizing crosstalk. In particular, the standard kinematics evaluation system can be adapted to capture a knee joint with a tibia coordinate system as the first joint coordinate system (tibial KOS) and a femur coordinate system (femoral KOS) as the second joint coordinate system and to determine (by means of a gait analysis) a course of the three kinematic angles of flexion, adduction, and internal rotation, and / or a course of the three kinematic translations, in particular for exactly one single step cycle, and the control unit can be adapted in particular toto output as an evaluation a determination of a gait type and / or a selection of a size of a knee endoprosthesis ( / knee implant) and / or an orientation of a knee endoprosthesis as evaluation parameters. Preferably, the predetermined target optimization can be defined as a minimization of a root-mean-square error (RMSE) (from the graph) of the kinematic angle of adduction and / or (from the graph) of the kinematic angle of internal rotation. Minimizing a root-mean-square error (RMSE) is a particularly suitable target optimization,because in this way, individual deflections are given less weight and any errors can be minimized. In particular, an RMSE (Root Mean Square Error) can be selected as a measure for the deviations of the varus / valgus and internal / external rotation curves. In particular, these can be reduced from 0.79 ± 0.30° to 0.29 ± 0.30° by rotating the coordinate systems by 3.32 ± 1.24° around the corresponding screw axis. Preferably, the predetermined target optimization can be defined as a minimization of a variance (of the graph) of the kinematic angle of adduction and / or (the graph) of the kinematic angle of internal rotation. When minimizing a variance, the graph of the corresponding kinematic angle can have an offset from the zero line, but the graph should be as smooth as possible, i.e. flat compared to the "new,offset zero line". According to one embodiment, the control unit can have a storage unit containing a database with an assignment of standardized kinematic angles and / or standardized kinematic translations to evaluation parameters, in particular an assignment of the standardized kinematic angles to a size and orientation of a knee endoprosthesis. In this way, depending on the selected evaluation parameter (to be selected from a column on the evaluation side), an optimal matching of standardized kinematic angles to the corresponding evaluation parameter can be found. According to a further embodiment, the control unit can be trained as an artificial intelligence system using a training data set with standardized kinematic angles and / or kinematic translations as input and an output for an endoprosthesis of the patient's joint, so that the control unit is adapted toWhen a patient's new biomechanical kinematics are detected, an assessment of an endoprosthesis, in particular a size and an orientation, is output using an artificial intelligence method via standardized kinematic angles and / or standardized kinematic translations. If, as a result of the present disclosure, standardized kinematic data in the form of standardized kinematic angles for patients in general are available, an assessment can be performed through this standardization using artificial intelligence or a trained system. This differs from the prior art, in which possible small errors lead to disproportionately large deviations and therefore make an assessment impossible. In particular, the control unit can be adapted to determine the kinematic angles based on the patient's detected biomechanical kinematics.Particularly when using an inertial measurement unit (IMU) as a sensor, to calculate three kinematic angles based on the accelerations and angular velocities. An IMU generally has an acceleration sensor for detecting acceleration in three directions, as well as a gyroscope for determining angular velocities. In particular, kinematic data sets for level walking on an (established) knee joint simulator (VIVO, AMTI, Watertown, MA) can be present or entered into the standard kinematics evaluation system and simultaneously compared with a number of sensors, preferably acceleration sensors and / or optical sensors, in particular at least one initial measurement unit.recorded. In particular, the sensors of the detection device can preferably be arranged in / on a knee cuff and can thus be temporarily attached and positioned on the knee, for example, in the manner of a bandage. The sensors are also preferably connected to the control unit (such as a specially adapted computer system) or coupled to it via data transmission technology. For the resulting kinematic angle / rotation data, the orientation of the tibial and femoral coordinate systems is then normalized or standardized using optimization (a mathematical optimization method). AE2046P-WO-0032 2022P00079 WO 18 / 35 The objects of the present disclosure are described with regard to a standard kinematics evaluation method for the acquisition, normalization, and evaluation of biomechanical kinematics data of a (selected) joint of a patient,In particular, in a standard kinematics assessment system according to the present disclosure, this object is achieved by comprising the steps of: detecting a patient's biomechanical kinematics by means of sensors of a detection device; determining, by a control unit on the basis of the provided kinematics of the patient, a course of kinematic angles and / or kinematic translations of the joint relative to a first joint element with a first joint coordinate system and a second joint element with a second joint coordinate system; determining, by a standardization unit of the control unit, via a predetermined target optimization, a rotation vector or a rotation matrix for adapting an orientation of the first joint coordinate system and / or a rotation vector or a rotation matrix for adapting an orientation of the second joint coordinate system and / or, via a predetermined target optimization,a translation vector for adjusting a position of the first joint coordinate system and / or a translation vector for adjusting a position of the second joint coordinate system; normalizing the course of the kinematic angles by adjusting the first and second joint coordinate systems using the correspondingly determined rotation vectors or rotation matrices and / or the course of the kinematic translations by adjusting the first and second joint coordinate systems using the correspondingly determined translation vectors; performing an evaluation of the joint with respect to a predefined evaluation parameter based on the normalized kinematic angles and / or normalized kinematic translations; and outputting the evaluation by a display device. In particular, the standard kinematics evaluation method or the control unit of the standard kinematics evaluation system can be adapted toto use a crosstalk minimization method as the target optimization. Preferably, the standard kinematics evaluation method or the control unit of the standard kinematics evaluation system can be adapted to perform an optimization of a reference frame orientation (reference coordinate system) in the knee kinematics. Preferably, the standard kinematics evaluation method or the control unit of the standard kinematics evaluation system can be adapted to provide a normalization (or standardization) of motion measurement systems. In particular, this includes systems based on optical markers and systems based on inertial measurement units (IMUs). In particular, the standard kinematics evaluation method can detect, normalize, and evaluate a patient's knee joint as a joint,wherein the predetermined target optimization is defined as a minimization of a root mean square error (RMSE) (from the graph) of the kinematic angle of adduction and / or (from the graph) of the kinematic angle of internal rotation. According to a further embodiment of the standard kinematics evaluation method, a patient's knee joint can be recorded, standardized, and evaluated as a joint, wherein the predetermined target optimization is defined as a minimization of a variance of the kinematic angle of adduction and / or the kinematic angle of internal rotation. With regard to a computer-readable storage medium, the objects are achieved in that it comprises instructions which, when executed by a computer, cause the computer toto carry out the method steps of the standard evaluation method according to one of the present claims. Brief description of the figures. The invention is explained in more detail below with reference to preferred embodiments with the aid of figures. They show: Fig. 1 shows a perspective view of a knee joint with a femoral coordinate system to illustrate an error in the prior art AE2046P-WO-0032 2022P00079 WO 20 / 35 with regard to analysis and evaluation, which can occur in the event of a deviation in orientation; Fig. 2 shows a schematic view of a standard kinematics evaluation system according to a first preferred embodiment of the present disclosure; Figs. 3 and 4 show a schematic view to explain the three kinematic angles of the patient's knee joint with corresponding standardization,Fig. 5 shows a sequence of a standard kinematics evaluation method according to a first preferred embodiment of the present disclosure; Fig. 6 shows a comparison of various sources as input to the standard kinematics evaluation system or a standard kinematics evaluation method; Figs. 6a to 6c show a schematic representation illustrating a standardization of a patient's kinematics data with a comparison to a kinematics simulation in which both the amplitude and the characteristics of curves a to d change fundamentally due to the reorientation of the joint coordinate system as reference systems. Fig. 7 shows an overview of various acquisitions of kinematics data from patients.which were normalized according to the standard kinematics evaluation system or the standard kinematics evaluation method of the present disclosure via reorientations of the joint coordinate system. Fig.8 is a flowchart of a standard kinematics evaluation method according to a preferred embodiment,and Fig. 9 shows a schematic representation of exemplary frame positions in a knee joint with typical centers of rotation for common implant types. AE2046P-WO-0032 2022P00079 WO 21 / 35 The figures are schematic in nature and are intended only to assist in understanding the invention. Identical elements are provided with the same reference numerals. The features of the various embodiments can be interchanged. Description of Preferred Embodiments An example of an illustration of an accompanying deviation due to a 3° rotation of the so-called flexion axis in a knee joint is shown in Fig. 1. In a femur with a distance of 10 cm between the medial and lateral epicondyles, a 5 mm (total) AP or PD error in the detection of the bone's landmarks leads to a rotation of the reference system, i.e., the femoral coordinate system (KOS).by 3° around the Z or Z-axis. The maximum width of the corridors in adduction and internal rotation for ±3° of the rotations Ry and Rz in the orientation of the tibial and femoral coordinate systems is already 14.5°. As described at the beginning of the present disclosure, crosstalk with corresponding crosstalk effects results from an incorrect alignment of the axes of the joint coordinate system, so that, for example, a rotation / turn in one plane is partially perceived as a rotation in other planes. A rotation of the femoral coordinate system around an axis therefore not only causes a change in a single kinematic angle, but also influences the other two kinematic angles. Fig. 2 shows a schematic view of a standard kinematics assessment system 1 according to a first preferred embodiment of the present disclosure. The standard kinematics assessment system 1 serves to detect,Standardization and (a comparative evaluation possible due to the standardization) of biomechanical kinematics data of a knee joint G of a patient (P), as explained below. The standard kinematics evaluation system 1 has at least one detection device 2 for detecting biomechanical kinematics of the knee joint G of the patient P, which detects this via an optical sensor system 4 and provides it to a control unit 8 in a computer-readable format. Furthermore, the standard kinematics evaluation system 1 has a display device, for example in the form of an operating room monitor, for displaying data relating to a surgical procedure to be performed on the patient P and for outputting the evaluation results. According to the present disclosure, the control unit 8 is specifically adapted toto process the recorded kinematics of the patient P provided by the recording device 2 and, based on the kinematic data, to determine a course of three kinematic angles 14, 16, 18, as rotation angle graphs, (and / or three kinematic translations) of the knee joint G relative to a first joint element G1 with a first joint coordinate system 20 and relative to a second joint element G2 with a second joint coordinate system 22. In other words, for exactly one step cycle of the patient, the three kinematic angles 14, 16, 18 (and / or three kinematic translations) of a model joint are extracted from the wealth of kinematic data. The standard kinematic evaluation system 1 is specifically adapted toto record a knee joint G with a tibia coordinate system (tibial KOS) as the first joint coordinate system 20 and a femur coordinate system (femoral KOS) as the second joint coordinate system 22, and to determine the course of the three kinematic angles 14, 16, 18, namely flexion 14, adduction 16, and internal rotation 18, during exactly one single step cycle. In order to be able to create the best possible comparison of kinematic analyses from different patients (as well as simulations) or to create the most standardized analysis and associated evaluation possible from different recordings (for example, staggered in time or using different recording methods, such as optical sensors versus attached sensors) of a single patient, the kinematic angle data must be standardized according to certain criteria in order to achieve a uniform,To this end, a standardization is carried out via a standardization unit 10, which is adapted and configured to determine a rotation vector 24 for adjusting an orientation of the first joint coordinate system 20, and a rotation vector 26 for adjusting an orientation of the second joint coordinate system, via a predetermined target optimization. The standard kinematics evaluation system 1 has an evaluation unit 12, which is adapted to, based on the standardized kinematic angles 14', 16',18' as movement data to perform an evaluation with respect to the joint G for at least one predefined evaluation parameter. In the present embodiment, a selection of a size of a knee endoprosthesis and an orientation of a knee endoprosthesis for the surgical procedure are output as evaluation parameters. The visual output of the evaluation is performed by the display device 6, in particular by displaying preoperative CT data of the patient P, in which the simulated knee endoprosthesis with the corresponding size and orientation is superimposed. The present standard kinematics evaluation system 1 enables robust and reliable evaluations to be performed,Because errors are minimized, the surgeon is even better supported in preparing for the surgical procedure and the implantation of the knee endoprosthesis, and patient safety is further increased. To record the patient's kinematics, the at least one detection device 2 has several inertial measurement units 28 (hereinafter referred to as IMUs) as sensors, which are attached to two (detachable) knee cuffs 36 on the patient P on the upper and lower legs. In addition to the IMUs, the standard kinematics evaluation system 1 has a further detection device 2, which has an optical recording unit 30 in the form of a stereo camera 32, which is directed obliquely from above toward a floor area.to externally record the biomechanical kinematics of the joint G of the patient P. For this purpose, infrared markers are arranged on the knee cuffs 36 in addition to the IMUs 28. AE2046P-WO-0032 2022P00079 WO 24 / 35 For illustrative purposes, Figs. 3 and 4 schematically illustrate a visualization of the three kinematic angles 14, 16, 18 and the joint coordinate systems 20, 22 of the standard kinematics evaluation system 1. The goal of the optimization in this embodiment is to minimize a root mean square error (RMSE) when varying the orientation of the joint coordinate systems 20, 22. Therefore, a first rotation vector 24 and a second rotation vector 26 should be found, for which a root mean square error (RMSE) of both the adduction kinematic angle 16 is minimized and a root mean square error (RMSE) of the internal rotation angle 18 is minimized. In this example, the first femoral rotation vector 24 (Rx, Ry, Rz) is (-0.055; 2.106; 2.44) and the second tibial rotation vector 26 (Rx, Ry, Rz) (0.051; 2.157; -0.295). The rotations occur gimbal-like, i.e., first the rotation around the X-axis, then the rotation around the Y-axis, and finally the rotation around the Z-axis (with the origin remaining the same). Fig. 5 shows a process for determining the orientation / alignment of the tibial and femoral coordinate systems (reference frames) by minimizing the RMSE of adduction and internal rotation for normalization. In particular, an adduction / internal rotation of zero can be assumed throughout the entire cycle. First, kinematic data from the patient are recorded, including kinematic data for a joint of interest. In the next step, three kinematic angles 14, 16, 18 are extracted from the wealth of kinematic data for a step cycle. These kinematic angles 14, 16,18 are still error-prone and a small deviation in the alignment of the tibial or femoral coordinate system 20, 22 has a major influence on the course of the kinematic angles. The next step is target optimization with regard to minimizing a root mean square error (RMSE) of the adduction angle and the internal rotation angle, i.e. of two of the three kinematic angles, calculating the rotation vectors, applying them to the coordinate systems, whereby the newly oriented coordinate systems now form the reference systems for the femur and the tibia, and thereby normalizing the kinematic angles 14', 16', 18' or their courses, which have changed accordingly due to the reorientation of the coordinate systems 20, 22. Fig.6 shows a standardization of the orientations of the reference system when measuring knee kinematics with a comparison data set of kinematics of another patient,In particular, from six patients. Through standardization, data from different data sets, different acquisition methods, and other data acquisition methods can now be compared with each other. Only through standardization can it be recognized, for example, that a mere alignment error is causing incomparable kinematic data, and the error can be corrected accordingly through standardization. With the standard kinematics evaluation system 1, reference frame orientations are standardized from measurements with different data sources in order to then make them comparable. Figures 6a to 6c show a schematic view of several recordings of the kinematic angles of flexion 14, adduction 16, and internal rotation 18 by two different acquisition devices, optical and IMU. It is immediately apparent that through standardization, the previously different kinematic angles 14, 16, and 18 are now aligned and represent standardized kinematic angles 14', 16', and 18'.which can now be used by the standard kinematics evaluation system 1 for evaluation. This is also logical, since the patient P has a single step cycle, which must nevertheless be replicated identically by various acquisition methods. Fig. 7 shows a schematic view of various series of acquired kinematics, with and without corresponding standardization by the standard kinematics evaluation system 1. Here, too, it can be seen that with adaptation, the curves overlap even better after standardization. Fig. 8 shows a flowchart of a standard kinematics evaluation method according to a preferred embodiment of the present disclosure. The standard kinematics evaluation method for acquisition, standardization, and evaluation AE2046P-WO-0032 2022P00079 WO 26 / 35 of biomechanical kinematic data of a knee joint G of a patient P,comprises the following steps. In a first step S1, the biomechanical kinematics of a patient P are recorded using sensors 4 of a recording device 2. In particular, this can be done using a stereo camera and optical markers or sensors attached to the patient. In a subsequent second step S2, a control unit 8 determines, based on the provided kinematics of the patient P, a course of three kinematic angles 14, 16, 18 of the knee joint G relative to a first joint element G1 (femur) with a first joint coordinate system 20 and a second joint element G2 (tibia) with a second joint coordinate system 22. This is followed by step S3: Determining, by a standardization unit 10 of the control unit 8, via a predetermined target optimization,a rotation vector 24 for adjusting the orientation of the first joint coordinate system 20 and a rotation vector 26 for adjusting the orientation of the second joint coordinate system 22; After the two rotation vectors 24, 26 have been found, step S4 of normalizing the course of the kinematic angles 14, 16, 18 by adjusting the first and second joint coordinate systems 20, 22 using the correspondingly determined rotation vectors 24, 26 takes place. Thus, the coordinate systems are rotated according to the rotation vectors and their orientations are adjusted accordingly (and / or the translation vectors are shifted and their positions are adjusted accordingly). The courses of the original kinematic angles 14, 16, 18 (and / or kinematic translations) are also adjusted and become normalized courses of the kinematic angles 14, 16, 18 (and / or kinematic translations).16' and 18' (and / or kinematic translations). In a final step S5, an evaluation of the knee joint is carried out with respect to a predefined evaluation parameter based on the AE2046P-WO-0032 2022P00079 WO 27 / 35 standardized kinematic angle. In particular, a classification of a gait is determined as an evaluation parameter and output in a final step S6 by a display device 4. Fig. 9 shows examples of different frame positions and thus also coordinate systems in a knee joint. This shows typical centers of rotation for common implant types, namely those of an MS implant type, an LS implant type, and a PS implant type. In particular, a standard kinematics evaluation method for acquiring, standardizing, and evaluating biomechanical kinematics data of a joint G of a patient P can be carried out in a standard kinematics evaluation system 1 according to the present disclosure.to determine a translation vector and thereby define a virtual position of the new joint coordinate system as a frame. After this, in a further step, the phenotyping method according to the third aspect of the present disclosure can be carried out. For example, if the new joint coordinate system that is closest to the MS coordinate system (KOS) is determined for the joint, it can be determined that an MS implant type is suitable. If, on the other hand, a new joint coordinate system that is closest to the LS KOS is determined, it can be determined that an LS implant type is suitable. Finally, if a new joint coordinate system that is closest to the PS KOS is determined, it can be determined that a PS implant type is suitable.

[0002] AE2046P-WO-0032 2022P00079 WO 28 / 35 List of reference symbols 1 Standard kinematics evaluation system 2 Detection device 4 Sensor system 6 Display device 8 Control unit 10 Standardization unit 12 Evaluation unit 14 Flexion kinematics angle 14' Standardized flexion kinematics angle 16 Adduction kinematics angle 16' Standardized adduction kinematics angle 18 Internerotation kinematics angle 18' Standardized internerotation kinematics angle 20 First joint coordinate system 22 Second joint coordinate system 24 First rotation vector 26 Second rotation vector 28 Inertial measuring unit (IMU) 30 Optical recording unit 32 Stereo camera 34 Storage unit 36 ​​Knee cuff G Joint G1 First joint element G2 second joint element P patient S1 Step Recording biomechanical kinematics by recording device S2 Step Determining a course of kinematic angles S3 Step Determining adaptation orientation AE2046P-WO-0032 2022P00079 WO 29 / 35 S4 Step Normalizing the course ofKinematic Angle S5 Step Evaluation Joint S6 Step Output Evaluation

Claims

AE2046P-WO-0032 2022P00079 WO 30 / 35 Claims 1. Standard kinematic evaluation system (1) for acquiring, standardizing, and evaluating biomechanical kinematic data of a joint (G) of a patient (P) comprising: at least one acquisition device (2) adapted to acquire biomechanical kinematics of the joint (G) of the patient (P) by means of sensors (4) and to provide them in a computer-readable format; and a visual display device (6), in particular an operating room monitor, for visual output to a user; characterized by a control unit (8) adapted to: process the acquired kinematics of the patient and generate from it at least one course of at least one, in particular three, kinematic angles (14, 16, 18) and / or of at least one, in particular three,to determine the kinematic translation of the joint (G) relative to a first joint element (G1) with a first joint coordinate system (20) and relative to a second joint element (G2) with a second joint coordinate system (22), via a normalization unit (10) adapted and configured for this purpose, to determine a rotation vector (24) or a rotation matrix for adapting an orientation of the first joint coordinate system (20) via a predetermined target optimization, and / or to determine a rotation vector (26) or a rotation matrix for adapting an orientation of the second joint coordinate system (22) in order to perform normalization, and / or to determine a translation vector for adapting a position of the first joint coordinate system (20) via a predetermined target optimization, and / or to determine a translation vector for adapting a position of the second joint coordinate system (22),to carry out a normalization, and via an evaluation unit (12) adapted for this purpose, based on the normalized kinematic angles (14', 16', 18') and / or the normalized kinematic translations as motion data, an evaluation with regard to the joint (G) for, AE2046P-WO-0032 2022P00079 WO 31 / 35 to perform at least one predefined evaluation parameter and to output the evaluation via the display device (6).

2. Standard kinematic evaluation system (1) according to claim 1, characterized in that the at least one detection device (2) has at least one accelerometer and / or one gyroscope, in particular an inertial measuring unit (28), as a sensor, and the detection device (2) is adapted to be attached in the region of the joint (G) on the patient (P), in particular on the first joint element (G1) and / or the second joint element (G2). 3.Standard kinematic evaluation system (1) according to claim 1 or 2, characterized in that the at least one detection device (2) comprises at least one optical recording unit (30) as a sensor, in particular a 3D recording unit, preferably a stereo camera (32), which detects a biomechanical kinematics of the joint (G) of the patient (P), preferably via optical markers, in particular via passive infrared markers, which are attached to the patient (P) in the region of the joint (G), preferably to the first joint element (G1) and / or the second joint element (G2).

4. Standard kinematic evaluation system (1) according to one of the preceding claims, characterized in that the predetermined target optimization is defined as a minimization of a variance, a standard deviation, a squared error and / or a statistical error of the regression of one or more kinematic angles (14, 16, 18). 5.Standard kinematic evaluation system (1) according to one of the preceding claims, characterized in that the standard kinematic evaluation system (1) is adapted to capture a knee joint (G) with a tibial coordinate system as the first joint coordinate system (20) and a femur coordinate system as the second joint coordinate system (22) and to determine a course of the three kinematic angles (14, 16, 18) of flexion, adduction and internal rotation, in particular during exactly one single step cycle. AE2046P-WO-0032 2022P00079 WO 32 / 35 Control unit (8) is particularly adapted to output, as an evaluation parameter, a determination of a gait type and / or a selection of a size of a knee endoprosthesis and / or an orientation of a knee endoprosthesis.

6. Standard kinematic evaluation system (1) according to claim 5, characterized in that the predetermined target optimization is defined as a minimization of a root mean square error (RMSE) of the kinematic angle (16) of adduction and / or the kinematic angle (18) of internal rotation.

7. Standard kinematic evaluation system (1) according to claim 5, characterized in that the predetermined target optimization is defined as a minimization of a variance of the kinematic angle (16) of adduction and / or the kinematic angle of internal rotation (18). 8.A standard kinematic evaluation system (1) according to one of the preceding claims, characterized in that the control unit (8) has a storage unit (34) with a database containing an assignment of standardized kinematic angles (14', 16', 18') to evaluation parameters, in particular an assignment of the standardized kinematic angles (14', 16', 18') to a size and orientation of a knee endoprosthesis. 9.Standard kinematic evaluation system (1) according to one of claims 1 to 7, characterized in that the control unit (8) is trained as an artificial intelligence system by means of a training data set with standardized kinematic angles (14', 16', 18') and / or standardized kinematic translations as input and output to an endoprosthesis of the joint (G) of the patient (P), so that the control unit (8) is adapted to output an evaluation of an endoprosthesis, in particular a size and an orientation, when a new biomechanical kinematic of a patient (P) is recorded via standardized kinematic angles (14', 16', 18') and / or standardized kinematic translations using a method of artificial intelligence. AE2046P-WO-0032 2022P00079 WO 33 / 35 10. Standard kinematic evaluation system (1) according to one of the preceding claims, characterized in that the control unit (8) is adapted to determine the kinematic angles (14, 16, 18) on the basis of the recorded biomechanical kinematics of the patient (P), in particular to calculate the three kinematic angles (14, 16, 18) and / or kinematic translations when using an inertial measuring unit (28) as a sensor on the basis of the accelerations and angular velocities.

11. Standard kinematics evaluation method for acquiring, standardizing and evaluating biomechanical kinematic data of a joint (G) of a patient (P), in particular in a standard kinematics evaluation system (1) according to one of the preceding claims, characterized by the steps: Acquiring (S1) a biomechanical kinematics of a joint (G) of a patient (P) by means of sensors (4) of an acquiring device (2);Determine (S2) by a control unit (8) based on the provided kinematics of the patient (P), a course of kinematic angles (14, 16, 18) and / or kinematic translations of the joint (G) relative to a first joint element (G1) with a first joint coordinate system (20) and a second joint element (G2) with a second joint coordinate system (22);Determine (S3) by a normalization unit (10) of the control unit (8) via a predetermined target optimization, a rotation vector (24) or a rotation matrix for an adjustment of an orientation of the first joint coordinate system (20) and / or a rotation vector (26) or a rotation matrix for an adjustment of an orientation of the second joint coordinate system (22), and / or via a predetermined target optimization to determine a translation vector for an adjustment of a position of the first joint coordinate system (20), and / or to determine a translation vector for an adjustment of a position of the second joint coordinate system (22);Normalizing (S4) the course of the kinematic angles (14,' 16', 18') by adjusting the first and second joint coordinate systems (20, 22) by the correspondingly determined rotation vectors (24, 26) or rotation matrices and / or the course of the kinematic translations by adjusting the first and second joint coordinate systems (20, 22) by the correspondingly determined translation vectors; AE2046P-WO-0032 2022P00079 WO 34 / 35 Performing (S5) an evaluation of the joint (G) with respect to a predefined evaluation parameter based on the normalized kinematic angles (14', 16', 18') and / or normalized kinematic translations; and outputting (S6) the evaluation by a display device (4).

12. Normalized kinematic evaluation method according to claim 11, characterized in that the normalized kinematic evaluation method detects, normalizes, and evaluates a patient's knee joint (P) as a joint (G), wherein, as a predetermined target optimization in the step Determining an Adjustment of the Orientation and / or Position (S3), a minimization of a Root Mean Square Error (RMSE) of the kinematic angle (16) of adduction and / or the kinematic angle (18) of internal rotation is defined. 13.A standard kinematics evaluation method according to claim 11, characterized in that the standard kinematics evaluation method captures, standardizes, and evaluates a patient's knee joint (P) as a joint (G), wherein, as a predetermined target optimization in step 1, determining an adjustment of the orientation (S3) and / or position, minimizing a variance of the kinematic angle (16) of adduction and / or the kinematic angle (18) of internal rotation is defined.

14. A computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to execute the process steps of the standard kinematics evaluation method according to any one of claims 11 to 13.

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