EP4408274A1

EP4408274A1 - Medical system and method

Info

Publication number: EP4408274A1
Application number: EP22797297.3A
Authority: EP
Inventors: Michael Utz; Allan Maas
Original assignee: Aesculap AG
Current assignee: Aesculap AG
Priority date: 2021-09-27
Filing date: 2022-09-23
Publication date: 2024-08-07
Also published as: WO2023046926A1; DE102021124873A1; JP2024533743A

Abstract

The invention relates to a medical system for determining the kinematics of a patient's bones connected to one another at a joint, comprising: a capturing unit for creating at least one image of a bone arrangement comprising at least the bones in a defined orientation of the bones relative to one another, preferably in a defined viewing direction towards the bones; a data-processing unit, which is designed and programmed to provide at least one output data set relating to the bones on the basis of the at least one image; a memory unit in which at least one pattern data set which can be assigned to the respective bone is stored, the data-processing unit being designed and programmed to adapt a respective pattern data set mathematically to the at least one output data set and to provide a patient-specific static model data set relating to the bones; a sensor unit having respective sensor elements which can be arranged in a defined spatial relationship to the respective bone on the patient's body part comprising the bones, the data-processing unit being designed and programmed to provide a dynamic model data set relating to the bones on the basis of the static model data set and on the basis of information from the sensor elements as a result of a preferably defined movement of the bones relative to one another, said dynamic model data set comprising information about the relative position and/or the relative mobility of the bones relative to one another. The invention also relates to a method.

Description

Medical technology system and method

The present invention relates to a medical-technical system and a method for determining the kinematics of a patient's bones that are connected to one another at a joint, in particular with regard to better patient care.

The present invention proves to be advantageous, for example, for conveying the kinematics of leg bones, in particular the femur and the tibia, relative to one another, which are connected to one another via the knee joint. The present invention can also be used, for example, to determine the kinematics of the femur relative to the pelvic bone. Further exemplary applications can be found in the area of the elbow joint, the shoulder joint and/or the spine.

To determine the leg kinematics, for example of the knee joint and/or the hip joint, complex systems are used in gait laboratories today, which have, for example, infrared cameras, reflective marker elements, force measurement plates on the floor and fluoroscopes in order to determine clinically usable kinematic data for individual patients. Despite reliable results, the system is not suitable for use in daily clinical practice due to the considerable amount of equipment involved.

The object of the present invention is to provide a medical-technical system and a medical-technical method of the type mentioned at the outset, with which the kinematics of the bones can be determined in a structurally simple manner and preferably individually for the patient.

This object is achieved by a medical-technical system according to the invention for determining the kinematics of a patient's bones connected to one another at a joint, comprising a recording unit for creating at least one recording of a bone arrangement comprising at least the bones in a defined alignment of the bones to one another, preferably in a defined viewing direction of the bones, a data processing unit that is designed and programmed based on the at least one recording provide at least one initial data set of the bones, a memory unit in which at least one sample data set that can be assigned to the respective bone is stored, the data processing unit being designed and programmed to mathematically adapt a respective sample data set to the at least one initial data set, and a patient-specific static model data set of the bones provide a sensor unit w ith particular sensor elements that can be arranged in a defined spatial relationship to the respective bone on a part of the patient's body that includes the bones, the data processing processing unit is designed and programmed to provide a dynamic model data set of the bones based on the static model data set and based on information from the sensor elements as a result of a preferably defined movement of the bones relative to one another, which provides information about the relative position and/or the relative mobility of the Includes bones to each other.

In particular, a medical-technical (kinematics detection) system for determining the kinematics of a patient's bones connected to one another at a joint (or at least a first and second bone of a patient's joint) is proposed and provided, with: a recording unit for Creation of at least one (patient-specific, real) image of a bone arrangement comprising at least the bones (of the joint), in particular in a defined alignment of the bones to one another, preferably in a defined viewing direction of the bones, preferably an X-ray device for creating an X-ray image of the bones of the joint , - A data processing unit (control unit) which is adapted/designed to provide at least one digital output data set (with parameters) of the actually recorded bones based on the at least one recording, in particular with geometric parameters for the at least first and second bones of the joint and/or density information from at least one bone of the joint, particularly preferably with geometric parameters of a length of the respective first and second bone and/or a varus-valgus angle between a femur and a tibia, a storage unit in which at least one (Parametric bone model) pattern data set is stored/stored for the at least one first bone and the second bone of the joint, which can be assigned in particular to the respective bone, with the data processing unit being designed to generate a parametric bone model from the stored pattern data set with regard to z in order to adapt at least one parameter to the at least (one parameter) of the initial data set, in particular to the dimension of the (real) bone of the recording, and thus to provide a patient-specific three-dimensional model data set of the first and second bone, a sensor unit with a respective defined spatial Licher Sensor elements that can be arranged in relation to the respective bone, in particular on a body part of the patient comprising the bones, with the data processing unit being adapted for this, taking the patient-specific three-dimensional model data set as a basis and based on information from the sensor elements, preferably as a result of a defined movement of the bones relative to one another patient-specific dynamic kinematics model data set of the bones, which includes at least one information about the relative position and/or the relative mobility of the bones (of the joint) to one another. This dynamic (kinematic) model data set, in particular a dynamic bone model of the joint, can preferably be output via a visual display device such as an operating room monitor, preferably with annotations, in order to evaluate the kinematics and thus, for example, to facilitate medical intervention. This information can also be used to simplify calibration of the sensor elements and to increase the precision of these sensor elements. By integrating patient-specific data, a dynamic model of the joint can be recorded and simulated even better, for example in order to carry out an assessment, for example for joint loads, in order to use this to draw conclusions about implant loads and to avoid overloading of the implant and a long service life and to ensure patient satisfaction.

The present invention incorporates the consideration that, in particular for determining the kinematics of the bones connected via the joint, a movement of the bones relative to one another is required. Via the sensor unit, in which at least one sensor element can be fixed to the body part comprising a bone, preferably defined movements can be carried out, for example under the guidance of a doctor. Information from the sensor elements can be calculated by the data processing unit to form a patient-specific dynamic model data set, in order in particular to determine the relative mobility of the bones and/or their relative position to one another. In order to determine the static, patient-specific model data set, at least one recording of the bones and/or a bone arrangement comprising the bones can be created in a structurally simple manner. In this way, a patient-specific static model data set can be provided in a structurally simple manner by mathematically adapting at least one predetermined sample data set that can be assigned to a respective bone.

The patient-specific dynamic model data set can, for example, be used as a basis for subsequent treatment of the patient and can be used, for example, to simplify the selection of a suitable implant.

The relative position in the dynamic model data record can, for example, include at least one of the following: an angle at which the bones are oriented to one another in a static position, e.g. axes defined by the bone being oriented at the angle; the location of a joint center of the joint between the bones; the location of a joint center of a joint through which one of the bones is connected to another bone.

The relative mobility of the dynamic model data set can preferably include at least one of the following: at least one angular extent, within which the bones can be moved relative to one another at the joint; at least one angular extent under which a bone can be moved via a joint on another bone.

In a preferred embodiment, the recording unit is an X-ray unit, for example, and the at least one output data record preferably includes a two-dimensional representation of the bones. In this way, the initial data record can be created in a structurally simple manner. When examining a leg, for example, an X-ray image can be created in a frontal view and/or in a side view (from the side) and then analyzed by the data processing unit.

It is conceivable for a CT unit to be used as the recording unit, with the at least one initial data set including a three-dimensional representation of the bones. Compared to the CT unit, however, the X-ray unit with two-dimensional representation of the bones has proven to be advantageous due to the reduced radiation exposure.

Advantageously, the data processing unit is designed and programmed to calculate characteristic landmarks and/or a joint center of the joint in the at least one output data set. A relevant piece of information can preferably be stored in the at least one output data record. Already on the basis of at least one From the output data set, valuable usable information can be obtained for the subsequent dynamic model data set.

For the same purpose, it is favorable if the system has a display unit for displaying a graphic representation of the at least one initial data set, in particular the representation of the bone, and an input unit for a user, and if characteristic landmarks and/or a joint center of the joint are entered by the user can be predetermined and/or changed by the input unit, for example correctable. Conveniently, relevant information can be stored in at least one output data set.

The above advantageous embodiments can provide, for example, when using the knee joint that its joint center and/or anatomical landmarks such as epicondyles on the femur, the trochanter on the femur and/or the hip center on the femur are already determined.

Based on the above estimates and/or measurements, estimates and/or measurements can advantageously already be carried out on at least one initial data set. In an application for the knee joint, a varus-valgus angle between the femur and tibia can preferably be determined and/or the length of these two bones. However, in the case of radiographs, these estimates and/or measurements may be limited to only two dimensions.

The at least one output data set can include a scale, in particular for the above-mentioned estimates and/or measurements, with the data processing unit being designed and programmed to determine axes defined by the bones and/or an angle between the bones and preferably in the m to store at least one initial data set. Here, the angle is defined, for example, by the axes. It is advantageous if a plurality of sample data sets are stored in the memory unit and can be assigned to a respective bone and if the data processing unit is designed and programmed to determine the most suitable sample data set from the plurality of sample data sets using a statistical shape model and to send it to the adjust bones. In relation to a respective bone, preferably several and in particular a large number of pattern data sets can be stored. It is favorable here if the most suitable sample data set can be selected and mathematically adapted. A corresponding algorithm that is executed by the data processing unit can, for example, take into account at least one of the following non-exhaustive characteristics of the patient: age, size, gender, medical history, ethnicity, sociocultural background...

It is advantageous if the sample data set includes a three-dimensional representation of the bone and if the data processing unit is designed and programmed to provide a three-dimensional static model data set and a three-dimensional dynamic model data set based thereon. In this way, a three-dimensional, patient-specific model data set can be generated, which in particular includes spatial information about the bones and the position of the bones relative to one another.

In the case of the exemplary application of the knee joint with femur and tibia, mechanical and/or anatomical axes, an epicondyle axis, the center of the knee and, taking the pelvic bone into account, the center of the hip, for example, can be determined.

When used with the knee joint, for example, the spatial position of the femur, tibia and possibly the pelvis in relation to one another can preferably be determined in an upright, standing position. For example, it is possible to determine the varus-valgus angle when standing and thus the alignment of bony structures in the frontal plane, but also their alignment and position in relation to one another in a sagittal plane. It is advantageous if the sample data record includes information about characteristic landmarks of the bone and the data processing unit is designed and programmed to contain information in the static model data record about axes defined by the bones, dimensions of the bones, in particular their lengths, characteristic landmarks, joint centers between the bones and/or an angle between the bones.

It is favorable if the sensor elements include a fastening device or if such a fastening device is assigned to them and is included in the system, via which fastening device the sensor elements can be attached non-invasively to the body parts comprising the bones. Each sensor element can be assigned its own fastening device. The non-invasive attachment option minimizes patient trauma during the procedure. It is favorable, for example, to achieve compression of the soft tissue above the bone in such a way that the sensor element is as stationary as possible in relation to the bone in order to define a valid reference.

When used on the femur, the sensor element is attached to the thigh, for example in the area of the epicondyles. In the case of the tibia, for example, the sensor element can be attached close to the knee or far down close to the ankle, preferably on the front edge of the tibia.

The sensor elements preferably include an acceleration sensor, with the data processing unit being designed and programmed to determine a range of motion of a bone based on a signal from the acceleration sensor, taking time into account. The amount and preferably the direction of the distance covered by the acceleration sensor can be determined from the acceleration values of the acceleration sensor. The data processing unit can use this information to determine a movement of the bones and in particular of the bones relative to one another. In particular, an I MU sensor (I MU, I nertial Measurement Unit) is used as a sensor element, for example.

In particular, a first I MU sensor can be rigidly arranged relative to a first bone of the joint and a second I MU sensor can be rigidly arranged relative to a second bone of the same joint, for example a first I MU sensor on the tibia and a second I MU sensor on the remote ur.

In particular, the data processing unit can be adapted to adapt the statistical bone model to the landmarks and dimensions set in the recording. This creates a three-dimensional patient-specific bone model in which, for example, axes, such as mechanical and/or anatomical axes, in particular epicondyle axes and/or a knee center and/or a hip center and/or a pelvic inclination can be determined and used for an evaluation.

The sensor elements can be coupled wirelessly to the data processing unit, for example, to achieve a structurally simple embodiment.

It is favorable if the system includes an indication unit, in particular an optical display unit, on which indications for the execution of characteristic movements by the patient can be output. For example, the patient can perform the characteristic movements that are given to him on the notification unit under the guidance of a user such as a doctor or independently.

When executing the movements, the data processing unit preferably uses the information provided by the sensor unit to determine the relative position and/or the relative mobility of the bones a. The movements are particularly indicative of a condition of the bone and the joint, specifically the kinematics of the bones over the joint. For example, a stored program can be executed in the data processing unit, which, in particular via a workflow, successively provides information on the execution of different types of movements. With each movement, information provided by the sensor elements can be evaluated by the data processing unit.

The moves can be mandatory or optional.

The user and/or the patient can, for example, be guided through the information via a workflow. Provision can be made for the data processing unit to be switched to a state in which it is ready to receive the data from the sensor elements when an actuating element is actuated.

It is advantageous if the data processing unit is designed and programmed to determine and store its spatial relationship of the sensor elements to the bones in the dynamic model data set on the basis of information from the sensor elements. The position of the sensor elements on the body parts comprising the physical bones can be virtually transferred to the dynamic model data set, so to speak. In this way, movements of the sensor elements can be mapped directly in the dynamic model data set.

It is preferably possible to implement a three-dimensional movement image of the bones in the dynamic model data set using the information from the sensor elements. To a certain extent, the bones in the dynamic model dataset can be moved just like the physical bones, with the model dataset also being supplemented with information such as axial position, length of bones, joint centers, range of motion, angles, etc. It is advantageous if the data processing unit is designed and programmed to determine axes of the bones and a point of intersection of the axes on the basis of information from the sensor elements and to relate them to the static model data set in such a way that the axes contained therein are the bones are brought into congruence with the axes determined using the information from the sensor elements. In this way, the sensor elements can be calibrated to a certain extent in the model data set. The axes determined via the sensor elements intersect, as a result of which a joint center can be determined. The respective axes can be superimposed on the axes contained in the static model data set. In the case of a three-dimensional static model data record, preferably provided with a scale, the length of the bones (defined via the axes) can be used for calibrating the sensor elements, for example.

Based on this, for example, a position of the axes of the bones, an intersection point of the axes and a length of the bones are stored in the dynamic model data set.

In the case of a leg, for example, the knee joint, the length of the femur and the tibia can be determined. Using information from the pelvic bone, for example, the position of the center of the hip joint and, in the case of ankle bones, the center of the ankle can be inferred.

A virtual model of the bones is preferably obtained, to which the virtual equivalents of the sensor elements are, as it were, attached. To a certain extent, a digital image ("twin") of the sensor elements on the bones, for example the leg bones, is created.

As previously mentioned, the bones may be the patient's femur and tibia. At least one of the following items of information is preferably stored in the dynamic model data set: mechanical and/or anatomical femoral axis and/or tibial axis; position of the knee joint center;

position of the center of the hip joint;

position of the center of the ankle;

varus-valgus position of the femur and tibia;

information on range of motion in flexion and/or extension; information on internal and/or external rotation of the femur and tibia;

Information on the translation of the tibia to the femur;

Stride length information. By additionally considering the time, for example, a movement image of the patient can be created, with the speed and the distance covered being determined.

Information about characteristic landmarks, for example of epicondyles and/or trochanters.

For example, in another application, one bone is the femur and the other bone is the pelvis. The sensor elements are arranged, for example, on the greater trochanter of the femur and on the sacroiliac joint or the anterior superior spine of the pelvic bone. In this way, for example, the tilting of the pelvis can be tracked and recorded in different situations and during different movements.

It can be provided that the data processing unit is designed and programmed to compare the dynamic model data set with an experimentally obtained measurement data set, for example based on a gait analysis in a gait laboratory, to determine any deviations and to provide the user with relevant information on a notification unit to provide.

The information obtained using the inventive system can thus be checked for plausibility using a model data set. A user can be informed via the notes, for example, about the degree of agreement and/or any discrepancies. For example, it is possible to teach the system to improve consistency. As mentioned at the outset, the present invention also relates to a method.

A medical-technical method according to the invention, which achieves the object mentioned at the outset, for determining the kinematics of bones of a patient that are connected to one another at a joint, comprises:

Creation of at least one recording of a bone arrangement comprising at least the bones in a defined alignment of the bones to one another, preferably in a defined viewing direction of the bones;

providing, on the basis of the at least one recording, at least one initial data set of the bones by means of a data processing unit;

Adapting, arithmetically by means of the data processing unit, a sample data record stored in a memory unit and assignable to the respective bone, and providing a patient-specific static model data record;

Providing a dynamic model data set of the bones, which includes information about the relative position and/or the relative mobility of the bones to one another, based on the static model data set and based on information from sensor elements as a result of a preferably defined movement of the bones relative to one another.

The advantages that have already been mentioned in connection with the explanation of the system according to the invention can also be achieved when the method is implemented. In this regard, reference is made to the above statements.

Advantageous exemplary embodiments of the method according to the invention result from advantageous embodiments of the device according to the invention. The objects of the present invention are achieved with regard to a computer-readable storage medium in that it comprises instructions which, when executed by a computer, cause it to carry out the steps of the method according to the present invention.

The objects are achieved with regard to a computer program in that it comprises instructions which, when executed by a computer, cause it to carry out the steps of the method according to the present invention.

The following description of a preferred embodiment of the invention is used in conjunction with the drawing to explain the invention in more detail. A preferred exemplary embodiment of the method according to the invention can be carried out with the preferred embodiment of the system according to the invention. Show it:

FIG. 1: a schematic representation of a medical-technical system according to the invention in a preferred embodiment for carrying out a preferred embodiment of the method according to the invention;

FIG. 2 shows a schematic representation of an image of bones, in this case the femur and tibia in a bone arrangement, also comprising the pelvic bone and the foot bones;

FIG. 3: schematic representations of the femur and the tibia in the initial data set from the front (left) and from the side (from lateral, right);

FIG. 4: schematic representations of bones in pattern data records which are stored in a memory unit of the system;

FIG. 5: a representation of a bone arrangement in a static model data set from the front and exemplary markings for determining a varus-valgus angle; FIG. 6: an illustration corresponding to FIG. 5 from the side for determining a flexion angle;

FIG. 7: the bones in the static model data set and sensor elements of a sensor unit of the system in a schematic representation; and

characters

8 to 15: pictograms as instructions for performing movements by the patient, it being possible for the pictograms to be displayed on a display unit of the system.

FIG. 1 shows a schematic representation of an advantageous embodiment of a medical-technical system according to the invention, denoted overall by reference numeral 10 . The system 10 can be used to carry out a method according to the invention in a preferred embodiment.

The system 10 comprises a data processing unit 12, a recording unit 14, a storage unit 16, a sensor unit 18 and an indication unit 20. The data processing unit 12 is coupled to the units 14, 16, 18 and 20 for transmitting information and/or signals. It is conceivable that two or more of the units 12, 14, 16, 18 and 20 are spatially and/or functionally integrated into one another.

The system 10 allows the kinematics of a patient's 22 bones to be examined. This serves in particular to determine patient-specific information for later care, for example for the implantation of an implant, in particular for the selection of an implant and/or the implantation technique.

As has already been described above and will be explained below, the bones are recorded via the recording unit 14 and a relevant output data set is created based on a sample data set static model data set and based on this with the aid of the sensor unit 18 creates a dynamic model data set. The model data sets are just as patient-specific as the original data set.

In the present case, the femur 28 and the tibia 30 serve as bones 24, which are connected to one another in an articulated manner at a joint 26, with the joint 26 being the knee joint. However, as already explained above, the invention is not restricted to this. In particular, the relative position of the femur 28 and tibia 30 and their relative mobility can be determined by means of the system 10 .

The imaging unit 14 is an x-ray unit 46 in the present case. In the present case, the receptacles 36 each include a scale 48.

FIG. 2 shows a recording 36, the bone arrangement 34 also showing the pelvic bone 38 and the foot bone 40 in addition to the femur 28 and the tibia 30. FIG. Both legs are shown, i. H. the recording 36 includes two fem ura 28, two tibiae 30 and two foot bones 40. In addition, the hip joints 42 and the ankle joints 44 are shown in the recording 36. The joints 26, 42 and 44 each include a joint center 27, 43 and 45, respectively.

FIG. 2 shows an example of a frontal recording 36 of the bone arrangement 34. In addition, at least one recording 36 is preferably made from the side (lateral).

The data processing unit 12 is designed and programmed to create a patient-specific output data set 50 based on the recordings 36 . The output data set 50 includes, in particular, at least one two-dimensional representation of the bones 24, in the present example also of the other bones Bone arrangement 34. In the present case, the notification unit 20 is designed in particular as a display unit 52 which includes a controllable image display 54 . Graphic representations of the bones 24 can be displayed to a user 56, in particular a doctor, on the display unit 52.

Characteristic landmarks and/or a joint center, in particular the joint center 27, can be specified by the user 56 on the basis of the representation on an input unit 58 and relevant information can be stored in the output data record 50.

Provision can also preferably be made for the data processing unit 12 itself to determine information, for example about the landmarks and/or the joint center 27 , without any action on the part of the user 56 , and to store the relevant information in the output data record 50 .

Based on the scale 48, for example, axes of the bones 24 can be determined and/or an angle between the bones 24 can be determined and stored in the initial data record 50. This can be, for example, the mechanical femoral axis 60 and the mechanical tibial axis 62, as FIG. 3 shows schematically. This enables the data processing unit 12 to already determine a varus-valgus angle based on the axes 60, 62 (not shown in FIG. 3).

The representations of the bones 24 in the initial data set 50 are two-dimensional. To create a three-dimensional patient model, the data processing unit 12 draws on model data sets 64 that are stored in the memory unit 16 . Figure 4 shows an example of a plurality of sample data records 64 for the femur 28 and the tibia 30.

The sample data sets 64 differ, for example, in terms of size and/or shape, with additional criteria being able to be used to differentiate between the sample data sets, for example sex, age, anamnesis, socio-cultural background, ethnicity... The pattern data sets 64 each include a three-dimensional representation of the bones 24.

The data processing unit 12 is designed and programmed to mathematically adapt the most suitable pattern data set 64 to the femur 28 . Correspondingly, the tibia 30 is mathematically adapted to the most suitable pattern data record 64 . It goes without saying that the femur 28 and tibia 30 in the initial data set 50 are meant here.

The data processing unit 12 creates a static model data set 66 on the basis of the data sets 50 and 64. The model data set 66 is patient-specific and includes in particular a three-dimensional representation of the bones 24.

In the model data set 66, for example, different axes and joint centers as well as characteristic landmarks can be determined and derived.

From the adaptation of the model datasets 64 to the initial dataset 50, an estimation of the spatial position of the femur 28, tibia 30 and possibly pelvic bones 38 and/or foot bones 40 relative to one another can be estimated while standing.

FIGS. 5 and 6 show this as an example on the basis of a front view (FIG. 5) or a side view (FIG. 6). In this case, however, the representations are based on the three-dimensional representation of the bones 24 in the static model data set 66.

For example, FIG. 5 shows the mechanical femoral axis 60 and the mechanical tibial axis 62, from which a varus-valgus angle 70 can be determined. Figure 2 also shows the anatomical femoral axis 68.

Figure 6 shows an example of a flexion angle 72 between the mechanical femoral axis 60 and the mechanical tibial axis 62 when standing. The joint center 27 can also be determined in the static model data set 66 . In addition, there is the possibility of using the scale 48 to determine the respective length of the femur 28 and tibia 30 .

This gives, for example, the possibility of also determining the joint center 43 of the hip joint 42 and/or the joint center 45 of the ankle joint 44 .

It may be possible, for example on the basis of the flexion angle 72, to already determine a possible stretching deficit in the three-dimensional model in the static model data record 66. If necessary, a measurement with a protractor (e.g. goniometer) can also be used to check the calculated value.

FIGS. 5 and 6 each only show the bones 24 of one leg of the patient 22. It goes without saying that the model data record 66 can have three-dimensional representations for both legs and the corresponding information about geometries and/or characteristic landmarks. The bones 24 of the left leg in this case are not shown in FIGS. 5 and 6 for the sake of clarity.

The data processing unit 12 can use information from the sensor unit 18 to determine a dynamic model data set 74 by calculation from the static model data set 66 . The dynamic model data record 74 includes, in particular, a three-dimensional representation of the bones 24. In addition, at least one of the following items of information is stored in the dynamic model data record 74: mechanical and/or anatomical femur axis 60, 68 and/or tibia axis 62;

position of the knee joint center 27;

position of hip joint center 43;

position of the ankle center 45;

Varus-valgus position of femur 28 and tibia 30; information on range of motion in flexion and/or extension;

information on internal and/or external rotation of femur 28 and tibia 30;

Information on the translation of the tibia 30 to the femur 28;

stride length information;

I nformation about characteristic landmarks, for example from

epicondyles and/or trochanters.

In this way, it is possible to use the system 10 to obtain information about the relative position and the relative mobility of the bones 24--here in particular the femur 28 and tibia 30. A three-dimensional kinetic model is present, which also preferably also includes information about the pelvic bone 38 and/or the foot bone 40 and the joint centers 43 or 45 .

Based on this, for example, patient 22 can be treated individually on the basis of patient-specific dynamic model data set 74 .

In the present case, the sensor unit 18 comprises two sensor elements 76. These are, for example, IMUs (inertial measurement units) each with at least one acceleration sensor 78.

A respective sensor element 76 comprises a fastening device 80. The sensor element 76 can advantageously be fixed non-invasively to a body part comprising the bone 24 via the respective fastening device 80. For example, a sensor element 76 is fixed non-invasively on the thigh (not shown in the drawing) and a sensor element 76 non-invasively on the lower leg (not shown in the drawing).

In this case, a determination is preferably made such that a valid reference of the sensor elements 76 to the respective bone 24 can be achieved by preventing a soft tissue movement as far as possible. To this end For example, the fastening device 80 can be designed as a belt or bandage, which causes a compression of the soft tissue and thereby fastens the sensor element 76 to the bone 24 essentially free of movement.

Information from the sensor elements 76 is recorded by the data processing unit 12 and the dynamic model data set 74 is calculated based on this from the static model data set 66 .

In this case, there is in particular the possibility of calibrating the sensor elements 76 to a certain extent on the basis of the model data set 66 . For example, as a result of the movement of the sensor elements 76, axes (e.g. the axes 60 and 62) and their point of intersection and an angle between these axes can be determined, with the spatial relationship to the corresponding axes and angles in the static model data set 66 being used to generate the dynamic Model data set 74 is made by the data processing unit 12 men. For example, the axes 60, 62 determined via the sensor elements 76 can be made to coincide with the corresponding axes 60, 62 in the model data record 66. In this way, the calibration of the sensor elements 76 in the measuring system of the sensor unit 18 can take place on the basis of the respective length of the bones 42 .

Conversely, a spatial relationship between the sensor elements 76 and the bones 24 can be determined and stored in the dynamic model data record 74 . In a sense, virtual equivalents of the sensor elements 76 are stored in the model data set 74 .

With regard to data acquisition that is as complete and reliable as possible, it can be advantageous if instructions are given to the user 56 and/or the patient 22 via the data processing unit 12, for example on the display unit 52 the data processing unit 12, for example, via a program m a workflow can be executed, which successively outputs a plurality of notices. The movements themselves can be mandatory or optional. A selection may be made by the user 56 and/or the patient 22, for example.

FIGS. 8 to 15 show pictograms 82 by way of example, which are used to clarify which movement is to be carried out. The pictograms 82 can be displayed on the display unit 52 in particular.

The icon 82 according to FIG. 8 suggests a movement in which the patient 22 walks in a straight line for a few meters, for example.

The icon m 82 according to FIG. 9 suggests, for example, climbing a predetermined number of steps and then going down again.

For example, the icon 82 of FIG. 10 suggests that the patient 22 sit down and get up again.

The pictogram m 82 according to FIG. 11 suggests, for example, that the patient 22 perform a predetermined number of knee bends, in particular to accommodate flexion and/or extension.

For example, the pictogram m 82 according to FIG. 12 suggests bringing the knee from maximum extension to flexion.

The pictogram m 82 according to FIG. 13 suggests, for example, lateral and medial loading of the knee in order to determine the patient's maximum varus and valgus.

The pictogram m 82 according to FIG. 14 suggests, for example, that the tibia be pulled forward or pushed backward as much as possible.

For example, icon 82 of Figure 15 suggests rotating the tibia internally and externally to the maximum possible angle. Reference list:

10 systems

12 data processing unit

14 recording unit

16 storage unit

18 sensor unit

20 notice unit

22 patient

24 bones

26 knee joint

27 joint center

28 femur

30 tibia

34 bone arrangement

36 recording

38 pelvic bones

40 foot bones

42 hip joint

43 joint center

44 hock

45 joint center

46 x-ray unit

48 scale

50 output record

51, 52 display unit

54 image display

56 users

58 input unit

60 mechanical femoral axis

62 mechanical tibial axis

64 sample record

66 static model data set anatomical femoral axis varus-valgus angle flexion angle dynamic model dataset sensor element acceleration sensor attachment device pictogram

Claims

25

Medical technology system for determining the kinematics of bones (24) connected to one another at a joint (26) of a patient (22), comprising a recording unit (14) for creating at least one recording (36) of at least the bones (24) comprising bone arrangement (34) in a defined alignment of the bones (24) to each other, preferably in a defined viewing direction of the bones (24), a data processing unit (12), which is designed and programmed, based on the at least one recording (36) at least to provide an initial data set (50) of the bones, a memory unit (16) in which at least one pattern data set (64) that can be assigned to the respective bone (24) is stored, the data processing unit (12) being designed and programmed to store a respective pattern data set (64 ) to be mathematically adapted to the at least one initial data set (50) and a patient-specific static model datasa tz (66) of the bones (24), a sensor unit (18) with respective sensor elements (76) that can be arranged in a defined spatial relationship to the respective bone (24) on a body part of the patient (22) that encompasses the bones (24), wherein the data processing unit (12) is designed and programmed, based on the static model data set (66) and based on information from the sensor elements (76) as a result of a preferably defined movement of the bones (24) relative to one another, a dynamic model data set (74) of knot Chen (24) to provide an I nformation on the relative position and / or the relative mobility of the bones (24) to each other. Medical technology system according to claim 1, characterized in that the relative position to at least one of the following includes: an angle (70, 72) at which the bones (24) are aligned to one another in a static position; the position of a joint center (27) of the joint (26) between the bones (24); the position of a joint center (27) of a joint (26) via which one of the bones (24) is connected to another bone (24). Medical-technical system according to Claim 1 or 2, characterized in that the relative mobility comprises at least one of the following: at least one angular range, by which the bones (24) can be moved relative to one another at the joint (26); m at least one angular extent under which a bone (24) can be moved via a joint (26) on a further bone (24). Medical technology system according to one of the preceding claims, characterized in that the recording unit (14) is an X-ray unit (46) and the at least one output data set (50) comprises a two-dimensional representation of the bones (24), preferably in a frontal view or in one view from lateral. Medical technology system according to one of the preceding claims, characterized in that the data processing unit (12) is designed and programmed to store characteristic landmarks and/or a joint center (27) of the at least one output data set (50). Joint (26) to be determined by calculation and preferably to store a relevant I nformation in at least one output data set (50). Medical technology system according to one of the preceding claims, characterized in that the system (10) has a display unit (52) for displaying a graphical representation of the at least one output data set (50) and an input unit (58) for a user (56), and that characteristic landmarks and/or a joint center (27) of the joint (26) can be specified and/or changed by the user (56) on the input unit (58), and that relevant information can be stored in at least one output data record (50). Medical technology system according to one of the preceding claims, characterized in that the at least one output data set (50) comprises a scale (48) and that the data processing unit (12) is designed and programmed to define axes (60) of the bones (24), 62, 68) and/or to determine an angle (70, 72) between the bones (24) and preferably to store at least one initial data set (50). Medical technology system according to one of the preceding claims, characterized in that a plurality of sample data sets (64) are stored in the memory unit (16) and can be assigned to a respective bone (24) and that the data processing unit (12) is designed and programmed from the plurality of the pattern data sets (64) using a statistical shape model to determine the most suitable pattern data set (64) and to adapt it to the bone (24). Medical technology system according to one of the preceding claims, characterized in that the sample data set (64) comprises a three-dimensional representation of the bone (24) and that the data 28

Processing unit (12) is designed and programmed to provide a three-dimensional static model data set (66) and based thereon a three-dimensional dynamic model data set (74). 0. Medical technology system according to one of the preceding claims, characterized in that the sample data record (64) includes information about characteristic landmarks of the bone (24) and the data processing unit (12) is designed and programmed, in the static model data record (66) I Information about axes (60, 62, 68) defined by the bones (24), dimensions of the bones (24), in particular their lengths, characteristic landmarks, joint centers (27, 43, 45) between the bones (24) and/or a store angles (70, 72) between the bones (24). 1 . Medical technology system according to one of the preceding claims, characterized in that the sensor elements (76) comprise a fastening device (80) or such is assigned to them, via which the sensor elements (76) can be attached non-invasively to the body parts comprising the bones (24). 2. Medical technology system according to one of the preceding claims, characterized in that the sensor elements (76) include an acceleration sensor (78) and that the data processing unit (12) is designed and programmed to calculate a range of motion of a bone (24) based on a signal from the Acceleration sensor (78) to be determined taking into account the time men. 3. Medical technology system according to one of the preceding claims, characterized in that the system (10) comprises an indication unit (20) on which indications for the execution of characteristic movements by the patient (22) can be output, the data processing unit (12) upon execution of the movements by the sensor unit 29

(18) includes the information provided in the determination of the relative position and/or the relative mobility of the bones (24). Medical technology system according to one of the preceding claims, characterized in that the data processing unit (12) is designed and programmed, on the basis of information from the sensor elements (76), to determine a spatial relationship between the sensor elements (76) and the bones in the dynamic model data set ( 74) to determine and save. Medical technology system according to one of the preceding claims, characterized in that the data processing unit (12) is designed and programmed on the basis of information from the sensor elements (76), axes (60, 62, 68) of the bones (24) and an intersection to determine the axes (60, 62, 68) and to relate it to the static model data set (66) in such a way that the axes (60, 62, 68) of the bones (24) contained therein are compared with the information based on the information the axes (60, 62, 68) determined by the sensor elements (76) are brought into congruence. Medical technology system according to claim 15, characterized in that based on this in the dynamic model data set (74) a position of the axes (60, 62, 68) of the bones (24), an intersection of the axes (60, 62, 68) and a length the bone (24) is stored. Medical technology system according to one of the preceding claims, characterized in that the bones (24) are the femur (28) and the tibia (30) of the patient (22) and that in the dynamic model data set (74) at least one of the following I Information is stored: mechanical and/or anatomical femoral axis (62, 68) and/or tibial axis (62);

position of the center of the knee joint (27); 30

position of the center of the hip joint (43);

position of the center of the ankle (45);

Varus-valgus position of the femur (28) and tibia (30); information on range of motion in flexion and/or extension;

Information on internal and/or external rotation of the femur (28) and tibia (30);

I nformation on the translation of the tibia (30) to the femur (28); stride length information;

Information about characteristic landmarks, for example of epicondyles and/or trochanters. Medical technology system according to one of the preceding claims, characterized in that the data processing unit (12) is designed and programmed to compare the dynamic model data set (74) with a measurement data set obtained experimentally, for example on the basis of a gait analysis in a gait laboratory, any to determine matches and/or discrepancies and to provide the user (56) with relevant information on a notification unit (20). Medical technology method for determining the kinematics of bones (24) connected to one another at a joint (26) of a patient (22), comprising:

Creating at least one recording (36) of a bone arrangement (34) comprising at least the bones (24) in a defined alignment of the bones (24) to one another, preferably in a defined viewing direction of the bones (24);

Providing, on the basis of the at least one recording (36), at least one initial data set (50) of the bones (24), by means of a data processing unit (12); 31

Adapting, arithmetically by means of the data processing unit (12), a sample data record (64) stored in a memory unit (16) and assignable to the respective bone (24), and providing a patient-specific static model data record (66);

Providing a dynamic model data set (74) of the bones (24), which includes information about the relative position and/or the relative mobility of the bones (24) to one another, based on the static model data set (66) and based on information from sensor elements (76) as a result of a preferably defined movement of the bones (24) relative to one another. A computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to perform the method steps of claim 19. A computer program comprising instructions which, when the program is executed by a computer, cause it to carry out the method steps according to claim 19.