Measuring method and apparatus for determining the length conditions, the position and/or the radius of movement of the lower extremities of a bed-bound patient

Abstract

A measuring method determines the length conditions, the position and/or the radius of movement of the lower extremities of a bed-bound patient. A knee module of a rehabilitation mechanism is connected to a point of application of a leg of the patient. A measuring device records and determines a trajectory solely of the point of application during a movement of the leg by the knee module. A model generation device creates a kinematic model from the data. This allows a determination of the length conditions, the position and/or the radius of movement during an initializing movement without having to undertake any surgical intervention. This does away with the need for complex sensor technology and provides a kinematic model of the radius of movement of the patient, the parameters of which kinematic model are used for establishing new therapeutic procedures within the patient's physical therapy.

Claims

1. A measuring method for determining length conditions, position and/or a radius of movement of lower extremities of a bedridden patient, which comprises the steps of: operatively connecting at least one knee module of a rehabilitation mechanism to an application point of a leg of the patient; using a measuring device for recording and/or determining a trajectory solely of the application point during a movement of the leg with the at least one knee module of the rehabilitation mechanism; creating, via a model-generating means, from data thus obtained, a kinematic model of the length conditions, the position and/or the radius of movement of at least parts of the lower extremities of the patient; comparing coordinate pairs or coordinate triplets with a model function in a form of a coordinate equation, and in a context of a curve-fitting, a position of a rotation point and/or a length between the application point and the rotation point, and an angle between two points on the trajectory and the rotation point being determined; using the coordinate equation $\frac{{\left(Y_n-M_Y\left(Y_H\right)\right)}^2}{L_0^2}+\frac{{\left(Z_n-M_Z\left(Z_H\right)\right)}^2}{{\left(L_0\pm \Delta L\right)}^2}=1$ for an ellipse as the model function, where L.sub.0±ΔL represents a possible displacement of the position of the rotation point during the movement; using as a parameter for a center point of the ellipse, a function according to the position of the rotation point; and using as a semi-major axis of the ellipse, the length between the application point and the rotation point.

2. The measuring method according to claim 1, wherein the application point is a knee joint of the patient.

3. The measuring method according to claim 1, which further comprises securing the application point of the leg to the knee module by means of a knee orthosis.

4. The measuring method according to claim 1, wherein the measuring device, proceeding from a starting position, records a manually guided and/or automated movement of the leg in a form of coordinate pairs or time-dependently in a form of coordinate triplets.

5. The measuring method according to claim 1, wherein the measuring device determines the trajectory of the application point in a form of the coordinate pairs or time-dependently in a form of the coordinate triplets, with an aid of at least two sensors from angle positions of eccentrics that are driven by an electric motor.

6. The measuring method according to claim 1, wherein the rotation point is a hip joint of the patient.

7. The measuring method according to claim 1, which further comprises: providing a control module for controlling planned rehabilitation movements of at least joints, muscles and tendons of legs of the bedridden patient by means of the at least one knee module, wherein the control module: determines, from patient-specific data generated from the kinematic model, trajectories for rehabilitation movements of the leg of the patient with respect to the application point; and on a basis of the trajectories, controls the at least one knee module.

8. The measuring method according to claim 1, which further comprises controlling the rehabilitation mechanism and/or the at least one knee module, during a manually guided and/or automated movement of the leg, with an aid of a control module in such a way that an effect of forces along an axis, defined by the application point and a rotation point, through the rehabilitation mechanism and/or the at least one knee module on the leg of the bedridden patient is avoided.

9. The measuring method according to claim 7, wherein the control module, on a basis of the trajectories calculated for the application point, controls the at least one knee module and/or the rehabilitation mechanism in such a way that the application point is moved along new, modified trajectories with an aid of the at least one knee module.

10. The measuring method according to claim 7, which further comprises: after each automated movement of the leg, calculating new values, from each new time-dependently recorded trajectory of application points, for the length between the application point and the rotation point, the position of the rotation point, and the angle between the two points on the trajectory and the rotation point; and comparing the new values with corresponding values of previously measured trajectories.

11. The measuring method according to claim 7, wherein on a basis of a comparison of values for: the length between the application point and the rotation point; the position of the rotation point; and the angle between the two points on the trajectory and the rotation point; in each case of two successively measured trajectories, an updated model with improved values for the length between the application point and the rotation point, the position of the rotation point, and the angle between the two points on the trajectory and the rotation point is generated by means of an optimization algorithm.

12. The measuring method according to claim 7, wherein values of an updated model serve as a basis for a further automated movement of the leg.

13. The measuring method according to claim 1, wherein the application point is a hip joint, a knee joint, a lower leg and/or an upper leg of the patient.

14. An apparatus for carrying out a measuring method for determining length conditions, a position and/or a radius of movement of lower extremities of a bedridden patient, the apparatus comprising: a rehabilitation mechanism having at least one knee module operatively connected to an application point of a leg of the patient and with at least two eccentrics and at least one electric motor for driving said at least two eccentrics on said at least one knee module; a measuring device for recording and/or determining a trajectory solely of the application point during a movement of the leg; and a model-generating means for creating, from data thus obtained, a kinematic model of the length conditions, the position and/or the radius of movement of at least parts of lower extremities of the patient, the apparatus with said model-generating means programmed to: compare coordinate pairs or coordinate triplets with a model function in a form of a coordinate equation, and in a context of a curve-fitting, a position of a rotation point and/or a length between the application point and the rotation point, and an angle between two points on the trajectory and the rotation point being determined; use the coordinate equation $\frac{{\left(Y_n-M_Y\left(Y_H\right)\right)}^2}{L_0^2}+\frac{{\left(Z_n-M_Z\left(Z_H\right)\right)}^2}{{\left(L_0\pm \Delta L\right)}^2}=1$ for an ellipse as the model function, where L.sub.0±ΔL represents a possible displacement of the position of the rotation point during the movement; use as a parameter for a center point of the ellipse, a function according to the position of the rotation point; and use as a semi-major axis of the ellipse, the length between the application point and the rotation point.

15. The apparatus according to claim 14, wherein said measuring device has at least two sensors for determining an angle position of a shaft of said electric motor and/or of said eccentrics.

16. The apparatus according to claim 14, further comprising a control module for controlling planned rehabilitation movements of at least joints, muscles and tendons of legs of the bedridden patient by means of said at least one knee module, wherein said control module is configured to determine, from patient-specific data generated from the kinematic model, trajectories for rehabilitation movements of the leg of the patient with respect to the application point, and, on a basis of the trajectories, to control said at least one knee module.

17. The apparatus according to claim 14, wherein said at least one knee module has: at least one knee orthosis for receiving a knee joint of the bedridden patient; a connection element connected to said at least one knee orthosis; an extension arm on which said connection element is secured; and a mechanical device driven by means of said control module, wherein said mechanical device introduces a defined force into said at least one knee orthosis, via said extension arm and said connection element, in such a way that the joints, the muscles and the tendons of the leg perform planned rehabilitation movements via the application point.

18. The apparatus according to claim 17, wherein said rehabilitation mechanism contains: at least one angle sensor which monitors an angle adopted by said connection element to said at least one knee orthosis and/or to said extension arm; and/or a force sensor which monitors the force introduced into said at least one knee orthosis via said extension arm and said connection element.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) Additional details and further advantages of the invention are described below on the basis of preferred illustrative embodiments, to which the invention is not limited however, and in conjunction with the attached schematic drawing, in which:

(2) FIG. 1 shows a first flowchart of a measuring method for determining the length conditions, the position and/or the radius of movement of the lower extremities of a bedridden patient, such as hip joint, knee joint and/or upper leg;

(3) FIG. 2a shows a torso and a leg of a bedridden patient in a possible movement of the leg during kinesitherapy;

(4) FIG. 2b shows a knee joint trajectory resulting from the movement in FIG. 2a, on the basis of three coordinate pairs within a basic coordinate system, and a possible model function prior to curve fitting;

(5) FIG. 2c shows the trajectory of the knee joint from FIG. 2b with an adapted model function, here in the form of a circle, and also the parameters, generated from the adaptation, for the length of an upper leg and for the position of the hip joint;

(6) FIG. 3 shows the adaptation of the model function of an ellipse to the coordinate pairs of a trajectory of the knee joint;

(7) FIG. 4 shows a perspective view of a left-hand extension arm of a knee module of a rehabilitation mechanism of an apparatus for carrying out the method according to the invention;

(8) FIG. 5 shows an example of the extension arm from FIG. 4 in an enlarged side view;

(9) FIG. 6 shows a perspective view of a bedridden patient secured in a conventional bed according to the prior art, in particular an intensive care bed, with the applied knee module and foot module of a rehabilitation mechanism, before the bed is moved to a vertical position;

(10) FIGS. 7a to c show a trajectory, generated by the rehabilitation mechanism via the knee orthosis, for flexion or extension of the leg of a patient;

(11) FIG. 8 shows a trajectory of an application point on an upper leg of a patient with an adapted model function and the force exerted on the leg of the patient via the application point when the leg is elevated by a rehabilitation mechanism and/or a knee module, and also the effect of forces on the leg of the bedridden patient along an axis defined by application point and rotation point;

(12) FIG. 9 shows angles determined, in the context of curve fitting, between two points on the trajectory and the rotation point, here specifically an angle θ.sub.max with maximum elevation of the application point and an angle θ.sub.min with minimal elevation of the application point; and

(13) FIGS. 10a and b show a second flowchart (divided between the two figures) of a preferred measuring method according to the invention for determining the length conditions, the position and/or the radius of movement of the lower extremities of a bedridden patient, such as hip joint, knee joint and/or upper leg, with the possibility of automatic error correction and rapid adaptation to external interference.

DESCRIPTION OF THE INVENTION

(14) In the following description of preferred embodiments of the present invention, identical reference signs designate identical or comparable components.

(15) FIG. 1 shows a flowchart of a measuring method for determining the length conditions, the position and/or the radius of movement of the lower extremities of a bedridden patient 90, such as hip joint 98, knee joint 93 and/or upper leg 96.

(16) First, at least one knee module 50 of a rehabilitation mechanism 30 is operatively connected to a knee joint 93 of the patient 90. For this purpose, the leg 92, in particular the knee joint 93, the upper leg 96 and/or a lower leg 97, can be secured to the knee module 50 by means of a knee orthosis 51 for example (cf. also FIG. 4 and FIG. 6).

(17) In a second method step, by means of a measuring device 68, a trajectory T of the knee joint 93 can then be recorded and/or determined during a movement of the leg 92, in particular during an initialization movement performed by a therapist, with the knee module 50 of the rehabilitation mechanism 30. During this initialization movement, it may be advantageous if the rehabilitation mechanism 30 and/or the knee module 50 are controlled with the aid of the control module 60, during the manually guided movement of the leg 92, in such a way that the effect of forces N exerted on the leg 92 of the bedridden patient 90 by the rehabilitation mechanism 30 and/or the knee module 50 is avoided.

(18) FIGS. 10a and 10b show a second flowchart (divided between the two figures) of a preferred measuring method according to the invention for determining the length conditions, the position and/or the radius of movement of the lower extremities of a bedridden patient 90, such as hip joint 98, knee joint 93 and/or upper leg 96 with the possibility of automatic error correction and rapid adaptation to external interference. The initialization of a model is effected in a way comparable to that shown in the first flowchart of FIG. 1, wherein the measuring device 68, this time proceeding from a starting position P.sub.0, records a manually guided and/or automated movement of the leg 92, in particular as trajectory T.sub.n; T.sub.n+1 of a an application point AP in the form of coordinate triplets Y.sub.1/Z.sub.1/t.sub.1, Y.sub.2/Z.sub.2/t.sub.2, . . . , Y.sub.n/Z.sub.n/t.sub.n, in a time-dependent manner. As the application point AP via which at least one knee module 50 of a rehabilitation mechanism 30 is operatively connected to a leg 92 of the patient 90, it is possible to choose preferably the knee joint 93, the upper leg 96 or lower leg 97, or indeed any point of the leg 92.

(19) The measuring device 68 can determine the trajectory T.sub.n; T.sub.n+1 of the application point AP, in particular of the knee joint 93, in turn in the form of coordinate triplets Y.sub.1/Z.sub.1/t.sub.1, Y.sub.2/Z.sub.2/t.sub.2, . . . , Y.sub.n/Z.sub.n/t.sub.n with the aid of at least two sensors 681; 682 from the angle positions of eccentrics 63; 64 that are driven by an electric motor.

(20) The time-dependent recording of the trajectory T.sub.n; T.sub.n+1 of an application point AP in the form of coordinate triplets Y.sub.1/Z.sub.1/t.sub.1, Y.sub.2/Z.sub.2/t.sub.2, . . . , Y.sub.n/Z.sub.n/t.sub.n affords in the first place the advantage that, by assigning a measurement time t.sub.1, t.sub.2, . . . , t.sub.n to the measured coordinate pairs Y.sub.1/Z.sub.1, . . . , Y.sub.n/Z.sub.n, it is advantageously possible to distinguish between a lifting movement and lowering movement of the leg 92. In the second place, the sequence of the measurement values that can be determined in this way can advantageously be taken into account during the optimization by means of an optimization algorithm and can thus improve the optimization results. This is based on the understanding that measurement values lying close to each other in time ought also to be adjacent on a measured trajectory T.sub.n; T.sub.n+1 and therefore ought also to have similar physical properties.

(21) Following the initialization, it is now possible that, after each automated movement of the leg 92, new values for the length L.sub.0 between application point AP and rotation point DP, the position Y.sub.H(t)/Z.sub.H(t) of the rotation point DP and the angle θ_DP between two points on the trajectory T.sub.n+1 and the rotation point DP can be calculated from each new, time-dependently recorded trajectory T.sub.n+1 and compared with the corresponding values of previously measured trajectories T.sub.n. The position Y.sub.H(t)/Z.sub.H(t) of the rotation point DP, wherein the rotation point DP can be for example the hip joint 98 of the patient 90, can be an approximately fixed position Y.sub.H(t)/Z.sub.H(t) with Y.sub.H(t.sub.1)=Y.sub.H(t.sub.2)= . . . =Y.sub.H(t.sub.n) and Z.sub.H(t.sub.1)=Z.sub.H(t.sub.2)= . . . =Z.sub.H(tn) in space, i.e. a real rotation “point”, or, as can often be the case particularly in older patients 90 on account of wear of the acetabulum, it can be a “variable” time-dependent position Y.sub.H(t)/Z.sub.H(t) of the rotation point DP, in particular of the hip joint 98 of the patient 90, which position changes during a movement.

(22) Based on the comparison of the values for the length Lo between application point AP and rotation point DP, the position YH(t)/ZH(t) of the rotation point DP and the angle between two points on the trajectory T.sub.n; T.sub.n+1 and the rotation point DP of in each case two successively measured trajectories T.sub.n, T.sub.n+1, it is then possible, by means of an optimization algorithm, in particular a least-squares algorithm, to generate an updated model with improved values for the length L.sub.O between application point AP and rotation point D, the position YH(t)/ZH(t) of the rotation point DP and an angle θ_DP between two points on the trajectory T.sub.n; T.sub.n+1 and the rotation point DP, the values of which updated model can advantageously serve as a basis for a further automated movement of the leg 92.

(23) The measuring method according to the invention thus means that an apparatus 1 according to the invention for carrying out such a measuring method can advantageously undergo “machine learning” of a therapy movement during the automated movement sequence (“cycle”). This possibility of “machine learning” advantageously makes it possible to offer the patient 90, with the aid of a rehabilitation mechanism 30, an individualized form of kinesitherapy which, by virtue of the error correction possibility provided, is robust against external interference whether caused by changes to the rehabilitation mechanism 30 itself or by changes of the patient 90 during use.

(24) FIGS. 2a to 2c illustrate this recording and/or determination process.

(25) FIG. 2a shows a torso and a leg 92 of a bedridden patient 90 in a possible movement of the leg 92 during kinesitherapy.

(26) FIG. 2b shows, resulting from this movement, a trajectory T of the knee joint 93 on the basis of three coordinate pairs Y.sub.n/Z.sub.n within a basic coordinate system, and also a possible model function F prior to curve fitting. Proceeding from a starting position P.sub.0, and during a manually guided movement of the leg 92, the trajectory T of the knee joint 93 can be recorded, preferably by a measuring device 68, in particular in the form of coordinate pairs Y.sub.1/Z.sub.1, Y.sub.2/Z.sub.2, . . . , Y.sub.n/Z.sub.n. The determination of the coordinate pairs Y.sub.1/Z.sub.1, Y.sub.2/Z.sub.2, . . . , Y.sub.n/Z.sub.n can advantageously be effected with the aid of at least two sensors 681; 682 from the angle positions of eccentrics 63; 64 that are driven by electric motor (cf. FIGS. 4, 5, 7a to c).

(27) The trajectory T is advantageously determined by comparing the identified coordinate pairs Y.sub.1/Z.sub.1; Y.sub.2/Z.sub.2; . . . / . . . ; Y.sub.n/Z.sub.n with a model function in the form of a coordinate equation.

(28) As model function F, it is possible for example to use a coordinate equation (Y.sub.n−Y.sub.H).sup.2+(Z.sub.n−Z.sub.H).sup.2=L.sub.O.sup.2 for a circle with the position Y.sub.H/Z.sub.H of the hip joint 98 as the center point of the circle and with the length L.sub.O of the upper leg 96 of the bedridden patient 90 as the radius of the circle.

(29) FIG. 2c shows the trajectory T of the knee joint 93 from FIG. 2b with an adapted model function F in the form of the coordinate equation of a circle, and also the parameters, generated from the adaptation, for the length L.sub.O of an upper leg 96 and for the position Y.sub.H/Z.sub.H of the hip joint 98.

(30) As an alternative to this, it is also possible to use as model function F the coordinate equation

(31) $\frac{{\left(Y_n-M_Y\left(Y_H\right)\right)}^2}{L_0^2}+\frac{{\left(Z_n-M_Z\left(Z_H\right)\right)}^2}{{\left(L_0\pm \Delta L\right)}^2}=1$
for an ellipse, wherein the parameter for the center point of the ellipse can now be a function M.sub.Y(Y.sub.H)/M.sub.Z(Z.sub.H) in accordance with the position Y.sub.H/Z.sub.H of the hip joint 98, and the parameter for the semi-major axis of the ellipse can be the length L.sub.O of the upper leg 96 of the bedridden patient 90. The term L.sub.0±ΔL describes a possible shift of the position Y.sub.H/Z.sub.H of the hip joint 98 during the movement.

(32) FIG. 3 shows an example of such an adaptation of the model function F of an ellipse to the coordinate pairs Y.sub.n/Z.sub.n of a trajectory T of the knee joint 93, wherein the function M.sub.Y(Y.sub.H)/M.sub.Z(Z.sub.H) resulting from the shift of the position Y.sub.H/Z.sub.H of the hip joint 98 can likewise be represented, as can be seen, as an elliptical function, but with a semi-major axis perpendicular to the semi-major axis of the model ellipse.

(33) Finally, from the data thus obtained, it is possible, with the aid of a model-generating means 69, to create a kinematic model of the length conditions, the position and/or the radius of movement of at least parts of the lower extremities of the patient 90.

(34) With the aid of a control module 60 for controlling planned rehabilitation movements of at least the joints, muscles and tendons of the legs 92 of the bedridden patient 90 by means of the knee module 50, it is then possible, in a further method step, preferably using the patient-specific data generated from the kinematic model, to determine trajectories T, in particular new, modified trajectories T, for the rehabilitation movements of the knee joint 93 and, on the basis of these trajectories T, to control the knee module 50 preferably in accordance with user inputs. On the basis of the calculated trajectories T for the knee joint 93, the control module 60 can control the knee module 50 and/or the rehabilitation mechanism 30 in such a way that the knee joint 93 of the bedridden patient 90 is moved, with the aid of the knee module 50 and optionally the knee orthosis 51, along these in particular new and modified trajectories T.

(35) FIG. 8 correspondingly shows a trajectory T.sub.n; T.sub.n+1 of an application point AP on an upper leg 96 of a patient 90 with an adapted model function F, and the force N1 exerted on the leg 92 of the patient 90 via the application point AP during elevation of the leg 92 by a rehabilitation mechanism 30 and/or a knee module 50, and also the effect of forces N2 on the leg 92 of the bedridden patient 90 along the axis application point AP-rotation point DP.

(36) FIG. 9 shows by way of example two angles θ_DP, determined in the context of a curve fitting, between in each case two points on the trajectory T.sub.n; T.sub.n+1 and the rotation point DP, here specifically an angle θ.sub.max with maximum elevation of the application point AP and an angle θ.sub.min with minimum elevation of the application point AP.

(37) The difference of the angles θ.sub.min and θ.sub.max advantageously provides information on the mobility of the patient 90 and therefore on the progress made by the therapy.

(38) FIGS. 4 to 7c show, by way of example, various views of an embodiment of an apparatus for carrying out the measuring method according to the invention. As regards the mechanical functioning of the rehabilitation mechanism 30 and of the knee module 50 as such, reference is made to the entirety of WO 2017/063639 A1 from the applicant.

(39) FIGS. 4 and 5 (corresponding to FIGS. 3 and 12 of WO 2017/063639 A1) show, by way of example, a left extension arm 53 of a knee module 50 of a rehabilitation mechanism 30 of an apparatus for carrying out the measuring method according to the invention, in a perspective view (FIG. 4) and in an enlarged side view (FIG. 5).

(40) FIG. 6 (corresponding to FIG. 4 of WO 2017/063639 A1) shows a perspective side view of a bedridden patient 90 secured in a conventional bed according to the prior art, in particular an intensive care bed, with the fitted knee module 50 and foot module 40 of a rehabilitation mechanism 30 prior to the bed being moved to a vertical position.

(41) The apparatus according to the invention for carrying out the measuring method comprises at least one rehabilitation mechanism 30 with at least one knee module 50 which can be operatively connected to the knee joint 93 of a patient 90 and comprises at least one electric motor 62 or, as shown in FIG. 4, at least two electric motors 62 for driving at least two eccentrics 63; 64.

(42) The apparatus according to the invention additionally comprises a measuring device 68 for recording and/or determining a trajectory T of the knee joint 93 during the movement of the leg 92, wherein the measuring device 68 can preferably comprise at least two sensors 681; 682 for determining the angle position of the shaft of the one or more electric motors 62 and/or of the eccentrics 63; 63.

(43) In addition, the apparatus 1 according to the invention comprises a model-generating means 69 for creating a kinematic model of the length conditions, the position and/or the radius of movement of at least parts of the lower extremities of the patient 90 from the data obtained by the measuring device 68 recording and/or determining a trajectory T of the knee joint 93 during the movement of the leg 92.

(44) FIG. 6 additionally shows a control module 60 for controlling planned rehabilitation movements of at least the joints, muscles and tendons of the legs 92 of the bedridden patient 90 by means of the knee module 50, which control module 60 can preferably be configured to determine, from the patient-specific data generated from the kinematic model, trajectories T, in particular new, modified trajectories T, for the rehabilitation movements of the knee joint 93 and, on the basis of these trajectories T, to control the knee module 50 preferably in accordance with user inputs.

(45) The knee module 50 preferably comprises at least one knee orthosis 51 receiving the knee joint 93 of the bedridden patient 90, a connection element 52 connected to the knee orthosis 51, an extension arm 53 on which the connection element 52 is secured, and a mechanical device 61 which can be controlled by means of a control module 60 and which introduces a defined force N into the knee orthosis 51, via the extension arm 53 and the connection element 52, in such a way that the joints, muscles and tendons of the leg 92 perform planned rehabilitation movements via the knee joint 93 of the bedridden patient 90.

(46) FIGS. 7a to 7c illustrate a trajectory T, generated by the rehabilitation mechanism 30 via the knee orthosis 51, for flexion and extension of the leg 92 of a patient 90. By way of the connection element 52, the knee orthosis 51 can be either rigidly connected to the extension arm 53, or, as can be seen here, it can be articulated movably on the extension arm 53. In the latter case, i.e. in the case of the movable articulation and the associated greater number of degrees of freedom, a further measuring device 68, in particular in the form of an angle sensor 55, can preferably be provided for exact recording and/or determination of the trajectory T of the knee joint 93.

(47) Finally, FIG. 5 shows an example of a rehabilitation mechanism 30 with an angle sensor 55 which monitors the angle adopted by a connection element 52 to the knee orthosis 51 and/or to the extension arm 53. Alternatively or in addition to this, a force sensor 56 can also be provided which monitors the force N introduced into the knee orthosis 51 via the extension arm 53 and the connection element 52.

(48) The present invention relates to a measuring method for determining the length conditions, the position and/or the radius of movement of the lower extremities of a bedridden patient 90, and an apparatus 1 for carrying out such a method, in which at least one knee module 50 of a rehabilitation mechanism 30 is operatively connected to a knee joint 93 of the patient 90, a measuring device 68 is used to record and/or determine trajectory T of the knee joint 93 during a movement of the leg 92 with the knee module 50 of the rehabilitation mechanism 30, and, from the data thus obtained, a kinematic model is created by a model-generating means 69. This advantageously permits the determination of the length conditions, the position and/or the radius of movement without surgical intervention during at least one initializing movement. Without the need for expensive sensor technology, the invention advantageously makes available a kinematic model of the radius of movement of the patient 90, the parameters of which model can serve as a basis for establishing new therapeutic procedures within the kinesitherapy, and also as a starting model for automated therapeutic methods and examination methods.

LIST OF REFERENCE SIGNS

(49) 10 bed, in particular a care bed, sickbed, hospital bed or intensive care bed 11 bed frame 12 longitudinal sides 13 transverse sides 14 longitudinal barrier 15 transverse barrier 16 castors 20 mattress 21 mattress frame 30 rehabilitation mechanism 32 support plate, for rehabilitation mechanism 30, fastenable to the bed frame 11 or mattress frame 21 40 foot module 41 securing means 42 tread surface 43 fixing straps 50 knee module 51 knee orthosis 52 connection element 53 extension arm 531 distal portion of the extension arm 53 532 proximal portion of the extension arm 53 533 middle portion of the extension arm 53 54 receiving points 55 angle sensor 56 force sensor 57 butterfly nut 60 control module 61 mechanical device 62 electric motor 63 first eccentric 631 eccentric shaft of the first eccentric 63 632 eccentric disk of the first eccentric 63 633 control pin of the first eccentric 63 64 second eccentric 641 eccentric shaft of the second eccentric 64 642 eccentric disk of the second eccentric 64 643 control pin of the second eccentric 64 65 radial bearing 66 sliding bearing 67 slide block 68 measuring device 681 sensor of the first eccentric 63 682 sensor of the second eccentric 64 69 model-generating means 70 adjustment mechanism 80 stabilizing mechanism 90 patient 91 chest—heart/lungs 92 leg 93 knee joint 94 foot 95 sole 96 upper leg 97 lower leg 98 hip joint F model function N1 force exerted on the leg 92 of the patient 90 via the application point AP N2 force along the axis: application point AP-rotation point DP T.sub.n; T.sub.n+1 trajectories L.sub.O length of the upper leg 96 Y.sub.n Y coordinates of the trajectory T of the knee joint 93 Z.sub.n Z coordinates of the trajectory T of the knee joint 93 t.sub.1, t.sub.2, . . . , t.sub.n measurement time Y.sub.H/Z.sub.H position of the hip joint 98 of the bedridden patient 90 AP application point DP rotation point θ_DP angle between two points on the trajectory (T.sub.n; T.sub.n+1) and the rotation point (DP)