WO1996041599A1

WO1996041599A1 - Process for controlling the knee brake of a knee prosthesis and thigh prosthesis

Info

Publication number: WO1996041599A1
Application number: PCT/DE1996/001041
Authority: WO
Inventors: Georges Van Der Perre; Louis Peeraer; Jos Vander Sloten; Bruno Aeyels
Original assignee: Otto Bock Orthopädische Industrie Besitz- Und Verwaltungskommanditgesellschaft
Priority date: 1995-06-13
Filing date: 1996-06-06
Publication date: 1996-12-27
Also published as: DE19521464A1; DE19521464C2

Abstract

A process is disclosed for controlling the knee brake (11) of a knee joint (4) that joins a stump bed (1) to a prosthesis lower part (2) provided with a foot prosthesis (3). The computer-controlled braking moment is continuously variable between 'free' and 'blocked' depending on the walking movements of the prosthesis user. The walking movements are characterised by EMG values measured in the stump bed (1), by pressure values measured in the foot area, by the momentary knee angle and by the momentary angular speed between thigh prosthesis and lower leg prosthesis in the form of electric signals (hereafter 'measurement data '). Also disclosed is a thigh prosthesis. In order to better adapt the knee brake control to various natural walking types, the following steps are disclosed: (a) the momentary walking type among a plurality of predetermined walking types for each prosthesis user is determined by evaluating at least some of the measurement data; (b) the control programme associated with the detected walking type is selected; (c) for each control program, the period of a step defined as a time span between two successive contacts between heel and ground is subdivided into several phases whose respective end is determined by means of predetermined measurement data for each phase; (d) defined, possibly variable braking values for the knee brake are determined for each phase.

Description

Method for controlling the knee brake of a prosthetic knee joint and thigh prosthesis

The invention relates to a method for controlling the knee brake of a knee joint connecting a stump bed with a lower prosthesis part with a connected prosthetic foot, the computer-controlled braking torque being continuously variable between "free" and "blocked" depending on the walking movement of the prosthesis wearer, and the walking movement EMG values measured in the stump bed, pressure values measured in the foot area, are characterized by the respective knee angle and the respective angular velocity measured between the upper and lower leg of the prosthesis in the form of electrical signals (hereinafter “measurement data”).

The invention further relates to a thigh prosthesis with a stump bed which is designed for connection to a thigh stump of the prosthesis wearer; a lower leg of the prosthesis to which a prosthetic foot is connected; a knee joint, which connects an upper knee joint connection for the stump bed via a knee axis with a lower knee joint connection for the lower leg of the prosthesis; a computer-controlled brake which applies a braking torque which can be changed continuously between "free" and "blocked" on a brake shaft; a knee joint transmission for transmitting the braking torque from the brake shaft to the knee axis; - A control unit, which acts on the brake as a function of the walking movement of the prosthesis wearer via a control algorithm;

EMG sensors, which are arranged in the stump bed for contact with certain thigh muscles and emit signals to the control unit;

Foot pressure sensors, which are arranged in the tread of the prosthetic foot and transmit signals to the control unit. give; a coding device which measures the respective knee angle and the respective angular velocity between the upper and lower leg of the prosthesis and emits it to the control unit in the form of electrical signals.

EP 0 549 855 A2 discloses a knee brake control in which a hydraulic damper controls the angular velocity in the knee joint. A microprocessor determines the usual gear pattern from a load measurement and a knee angle measurement and acts on a motor at various gear transition points, which in turn adjusts a valve device provided in the hydraulic damper. This embodiment enables the prosthesis wearer to use the prosthesis in different gaits including climbing stairs and sitting down.

DE 39 09 672 C2 discloses a swing phase-regulated thigh prosthesis with an upper shaft, which is articulated to a lower shaft via a knee joint shaft and is acted upon by a pressure cylinder. The pressure cylinder is controlled via a valve, the degree of opening of which is set by a regulating device as a function of several walking speeds selected during walking tests. An operating mode selector device is provided for selecting different degrees of opening for several different walking speeds in a teaching program input mode and for a playback mode. Also provided are a detection device which determines the degrees of opening, a device which stores the degrees of opening of the operating mode selector, a phase determination device which detects swing and stance phases, a walking speed determination device which determines the actual walking speed on the basis of the respective time periods the swing and stance phases ascertained by the phase determination device and one

Control device with the walking speed actually determined by the walking speed determination device compares the corresponding stored opening degrees of the operating mode selector and adjusts the opening degree of the valve. Only the oscillation phase is thus controlled. A knee angle sensor and stretch limit switch are used as sensors. The duration of the stance phase is used as a parameter for controlling the damping coefficient in the oscillation phase.

French patent application 89 194 844 also discloses a pneumatic knee actuation device. Either foot contact sensors or load measurements in combination with a stretch limit switch are used as sensors. The controller triggers an automatic knee lock during the stance phase and adjusts the damping coefficient of the gait cycle duration during the oscillation phase.

The object of the invention is to develop a knee brake control which is better adapted to the various natural gaits and a thigh prosthesis which is more suitable for this purpose.

Based on the method described in the introduction, this object is achieved according to the invention by the following features:

a) determining the respective gait from a number of predetermined gaits previously determined for this prosthesis wearer by evaluating at least some of the measurement data transmitted in each case;

b) selection of the control program assigned to this determined gait;

c) for each control program, a step period defined as a time period between two successive heel / floor contacts is divided into several phases, the end point of which is determined by measurement data transmitted for this phase; d) each phase is assigned certain braking values which may change during this phase and which are applied to the knee brake.

It is advantageous if the knee brake is applied at a constant frequency.

Furthermore, it can be expedient if additional measurement data are determined from the moments acting on the knee and on the hip.

Different gaits can be defined or defined beforehand (e.g. walking on a level surface; climbing stairs; descending stairs; walking on a rising or sloping surface; movements when stationary, etc.).

According to the invention, one proceeds from a step period which is defined as the time interval between two heel / floor contacts. This step period is plotted on a time axis and then subdivided into a specific number of step phases, a transition, that is to say a change from one phase to the other, being provided between two phases. Each phase thus represents a time segment of a step period, with a controlled knee movement taking place during the phase. Each phase transition is based on measurement data.

With the method according to the invention, there is basically the possibility of changing from one gait to another gait at any time, each gait being assigned a special control program. However, it can be stipulated that a change from the control program of the gait currently being used to the control program of another gait is only carried out at a previously selected special phase of the step period of the gait currently used or of the new gait.

According to the invention, the exercise carried out is determined Gait by comparing the transmitted actual measurement data with the reference measurement data specified for each gait. It is useful if the reference measurement data are determined from the EMG data measured for each individual gait.

According to the invention, it is advantageous if a curve representing the muscle activity is created for each of the specified gaits for each scanned hip joint muscle over a step period. In practice, this curve can e.g. B. created by thirty measurements. When comparing the

However, actual measurement data with the reference values cannot easily be determined with which of the thirty measurement values of a muscle activity curve mentioned, for example, the actual value just determined has to be compared. An assignment must therefore be made within the step period. However, this step period is different for different gaits and can vary even within the same gait. However, since the actual measurement data are transmitted in real time, that is to say over a specific time course, but the reference data are available for a predetermined time course and thus usually in percentages related to the step period, a comparison of the real time with percentages is not is possible, the actual step period must be adapted in its "time length" to the reference step period. This is done as follows:

After a curve representing the muscle activity has been created for each of the given gaits for each scanned hip joint muscle over a step period, the EMG measurement data defining this curve are then reduced by equidistant linear interpolation to a specific number of EMG reference values, which then define the EMG reference curve. The first and the last EMG reference value then correspond to the EMG measurement data for heel / ground contact. In order to compare a certain number of actual EMG measurement data with matching reference EMG measurement data, the respective point in time within the step period is determined, namely by pre-calculating the Time of the end point of the respective phase. The EMG reference values of the EMG reference curve that come closest to them in the course time are then selected for the actual measurement data. It has proven to be useful not to use all EMG data of the complete step period, but only EMG data from a certain section of the step period, depending on the gait.

The determination of the gait time is looking for an answer to the question!

Where are we in the stride period ?. It has proven to be useful to define certain fixed gait points within a step period. For example in the following order:

1. heel / ground contact: rising edge of the heel pressure, determined by means of a threshold value;

Start of stance bending phase: rising flank of the knee angle, determined by means of a threshold value;

Flat foot: metatarsal head I - pressure becomes greater than the heel pressure;

Maximum at metatarsal head I: metatarsal head I -

Pressure becomes maximum;

Diffraction swing phase: rising flank of the knee angle, determined by means of a threshold value; maximum flexion swing phase: knee angle becomes maximum;

Extension swing phase: falling flank of the knee angle, determined by means of a threshold value;

8. Full extension: knee angle becomes minimal or negative (hyperextension). These fixed gait points are distributed over a step period and subdivide the step period into the phases explained above.

The "on-line" gait time base determines the gait time of the current point in time before the current step period has ended. And this is done according to the invention by calculating in advance the time of the arrival of a future event with a known gear time.

The main advantage of the method according to the invention can be seen in the fact that when the gait is changed, the control of the knee brake is also changed, in each case by adapting a stored reference pattern.

The object on which the invention is based is achieved on the basis of the thigh prosthesis described at the outset by the following features:

a) at least two foot pressure sensors are arranged in downwardly open recesses in the sole of the foot, namely in the heel area and in the head area of an OS metatarsal;

b) the brake is a magnetic powder brake, which is controlled via pulsed control signals of a pulse width modulation circuit (PWM circuit), the pulse width determining the current flowing through the brake and thus the braking torque;

c) an adjustment and calibration system to adapt the

Brake applying control algorithm to the gear of the prosthesis wearer.

According to the invention, at least two EMG sensors are preferably used. In addition, sensors for measuring the knee moment and / or the hip moment can be provided. The knee brake is preferably operated at a constant frequency, e.g. B. 100 Hz. Basically, all measurement data can be completely processed at any time; in practice, however, only selected measurement data are used for the individual calculations. In any case, all measurement data are saved by a computer over a certain period of time (e.g. over 2.5 seconds), ie not immediately destroyed.

According to the invention, three alternatives are proposed for the knee joint transmission.

According to the invention, it is fundamentally possible to use the above-mentioned EMG electrodes to identify the gait, the gait phase within a step period and the transitions between gait and phases, even if only for checking the pressure values measured in the foot area and / or the knee angle Measurements.

According to the invention, a control method is preferred in which the EMG values measured in the stump in conjunction with the pressure values measured in the foot area and the respective knee angles are fed as information into the microprocessor in order to identify the gait and phases and the transitions between them. In each of the gait phases, the combination of the pressure values measured in the foot area with the measured knee angle is used as control parameters for the feedback control algorithm. A closed knee impact device comprises a gear and a magnetic powder brake, which enable direct, continuous control of the knee braking torque both in the stance phase and in the swing phase. The combination of these three feature complexes leads to a two-layer control system: the first layer includes the identification of the gait and phase as well as the selection of the gait-specific control algorithm, while the second layer is defined by the direct control of the knee braking torque using the appropriate algorithm . As a result, the prosthesis automatically adapts to the gait and phase of the prosthesis wearer. A major advantage of the thigh prosthesis designed in accordance with the invention is the fact that an adaptation to the respective prosthesis wearer must take place exclusively in the software, but not in the hardware. This considerably simplifies adaptation.

Further features of the invention are the subject of the subclaims and are explained in connection with further advantages of the invention using several exemplary embodiments.

The drawing shows some exemplary embodiments of the invention which serve as examples. Show it:

Figure 1 - a schematic representation of a thigh prosthesis;

Figure 2 - on an enlarged scale the stump bed according to Figure 1 in front view;

Figure 3 - a cross section along the line III-III in Figure 2;

Figure 4 - a prosthetic foot in side view;

Figure 5 - on an enlarged scale, a foot pressure sensor in a vertical longitudinal section;

Figure 6 - the foot pressure sensor according to Figure 5 in Unteran¬ view;

FIG. 7 - a side view of a knee joint in a first embodiment;

Figure 8 - the knee joint according to Figure 7 in a lateral front view; Figure 9 - a vertical section in the front plane through the knee joint according to Figure 7;

Figure 10 - a vertical section in the sagittal plane through the joint according to Figure 7;

Figure 11 - in plan view a horizontal section through the knee joint according to Figure 8;

Figure 12 - a second embodiment of a knee joint in a representation according to Figure 9;

Figure 13 - the knee joint according to Figure 12 in a presen- tation according to Figure 10;

FIG. 14 - the knee joint according to FIG. 12 in a representation according to FIG. 11;

Figure 15 - a third embodiment in a diagram for a knee joint;

Figure 16 - the knee joint according to Figure 15 in longitudinal section;

Figure 17 - a schematic representation for the definition of the knee angle;

Figure 18 - a schematic representation of a thigh prosthesis, the lower leg of the prosthesis is equipped with pairs of strain gauges;

FIG. 19 - a diagram in which the foot pressure and knee angle are plotted over a step period and a phase diagram illustrating these curves;

Figure 20 - a somewhat modified phase diagram in a representation according to Figure 19; Figure 21 - electronic hardware in a block diagram;

Figure 22 - a block diagram for a digital control unit and

Figure 23 - in a block diagram a control unit with two controllers.

The thigh prosthesis shown in Figure 1 essentially consists of a stump bed 1, which is designed for connection to a thigh stump of the prosthesis wearer, a lower leg prosthesis 2, to which a prosthetic foot 3 is connected, and a knee joint 4, which has an upper one via a knee axis 5 Knee joint connection 6 for the stump bed 1 connects in an articulated manner to a lower knee joint connection 7 for the lower leg of the prosthesis 2. EMG sensors 8 are indicated in the stump bed 1 and foot pressure sensors 9 are indicated in the underside of the prosthetic foot 3. A knee angle sensor 10 and a brake 11 are shown schematically on the knee joint 4. To control this brake 11 are also used a schematically shown microcomputer 12 and batteries 13 which the prosthesis wearer can wear on a belt, but which can also be integrated directly into the lower leg 2 of the prosthesis. In an alternative solution, the knee brake 11 can be controlled by an external computer.

FIGS. 2 and 3 show that three EMG sensors 8 are provided, each of which is assigned to a muscle acting on the hip joint, namely the muscles rectus femoris, adductor longus and hamstrings. The EMG sensors 8 are resiliently fixed in the inner wall of the stump bed 1 in order to ensure permanent, reliable contact with the assigned muscle. The electrical connections of the EMG sensors 8 are laid on the outside of the stump bed 1. The distance of the EMG sensors 8 from the edge la of the stump bed 1 is approximately 10 cm. Figure 1 shows that four foot pressure sensors 9 are provided, of which Figure 4 shows only two. The first foot pressure sensor lies in the heel area, the second in the area of an OS metatarsal area, the third in the head area of an OS metatarsal area and the fourth in the toe area. Each foot pressure sensor 9 is supported against a metal insert 14 which is inserted into a recess 15 which is filled around the foot pressure sensor 9 with the material of the prosthetic foot tread.

A knee joint transmission is provided to amplify the braking force acting on the knee joint. FIGS. 7 to 11 show a first embodiment for a knee joint transmission 16. The knee axis 5 sits together with a first transmission gear 17 firmly on the upper knee joint connection 6, while the lower knee joint connection 7 is designed as a transmission housing 18 which supports the knee axis 5 forms and includes the actual transmission, the brake 11 and a coding device which measures the respective knee angle and also the respective angular velocity between the upper and lower leg of the prosthesis via the knee angle sensor 10 and outputs it in the form of electrical signals to a control unit 19 (see Figure 21).

The brake 11, which is not shown in detail in the drawing, is a magnetic powder brake which is controlled via pulsed control signals of a pulse width modularization circuit (PWM circuit), the pulse width the current flowing through the brake and thus the braking torque certainly. The first knee joint gear 16 is a two-stage reduction gear with a knee axis 5, intermediate shaft 20 and brake shaft 21 arranged parallel to one another, which are rotatably mounted in the gear housing 18 and are each equipped with a gear 17, 22, 23, the Intermediate shaft 20 also carries an intermediate gear 24 meshing with the gear 23 of the brake shaft 21.

FIGS. 7 and 8 show a stop 25 for the stretched position of the lower leg of the prosthesis 2. FIG. 8 also shows a spring-elastic advancer 26, while in FIG. 9 one on the brake shaft 21 seated knee angle coding disk 27 is indicated, to which the above-mentioned coding device 28 indicated in FIG. 11 is assigned.

FIGS. 12 to 14 show a second embodiment for a knee joint transmission 29. Here, the knee axis 5 is at the same time designed as a brake shaft and rotatably mounted in both the upper and lower knee joint connections 6, 7. On this knee axis 5, which forms the brake shaft, a gearwheel 30 is seated in a rotationally fixed manner, which meshes with a gearwheel 31 of an intermediate shaft 32 which engages via a second gearwheel 33 with a gearwheel 34 fixedly connected to the upper knee joint connection 6.

Otherwise, the components that correspond to the first knee joint transmission 16 have been provided with the same reference numerals.

FIGS. 15 and 16 show a third embodiment for a knee joint transmission 35. This has a lever 36, which is firmly connected at one end to the upper knee joint connection 6 and which, with its free end, is guided on a spindle 37 and represents the rotary nut 38 representing its rotary drive supports. The latter is displaceable against the action of a spring 39 on the spindle 37, which forms the brake shaft and is rotatably supported with its lower end on the lower knee joint connection 7.

FIG. 17 shows a relative pivoting between the stump bed 1 and the lower leg of the prosthesis 2 and the resulting knee angle α.

FIG. 18 shows in a schematic representation that the lower leg of the prosthesis 2 is equipped with two pairs of strain gauges 40, wherein - seen in the sagittal plane - one pair of strain gauges 40 in each case one strain gauge at the front and the other at the rear on the lower leg of the prosthesis 2 are arranged. It is a sensor for measuring the knee moment. The same strain gauge pairs 40 or two additional strain gauge pairs also serve as a sensor for measuring the hip joint. The lower arrow A symbolizes the ground reaction force; The bending moment is plotted on axis B. Points B1 and B2 indicate the bending moments determined by the two pairs of strain gauges 40. By linear extrapolation of these two measuring points B1, B2, the value for the knee moment B _κ is obtained in the "height" of the knee axis 5 and the value for the hip moment B _H in the case of further linear extrapolation up to the "height" of the hip joint 41. With this type of measurement of the hip moment, the knee joint 4 must be blocked in the extended position of the lower leg 2 of the prosthesis.

In the diagram shown in FIG. 19, the respectively measured foot pressure in percent or the respectively measured knee angle in angular degrees are plotted on the vertical axis, while the horizontal axis indicates the time span of a complete step period. Of the four foot pressure sensors 9 shown in FIG. 1, only one pressure curve D1 for the heel pressure sensor and one pressure curve D2 for a pressure sensor in the head region of the OS metatarsal I are shown. The curve K _α is also entered for the respective knee angle.

The step period shown in the diagram is the time period between two successive heel / floor contacts of the prosthetic foot 3. This step period is divided according to the invention into several phases (eight phases in the example shown), the respective end point of which is determined by measurement data specified for this phase. Each phase is assigned certain braking values, which may change during this phase and which are applied to the knee brake 11.

In the lower illustration in FIG. 19, the three phases 1 to 3 to the right of the dashed line show the maintenance phase, phases 4 to 8 to the left of the dashed line the swing phase. In this case, for example, the possibilities are provided for transitioning directly from phase 1 to phase 4 and / or from phase 4 to phase 6.

FIG. 20 shows a somewhat simplified example of walking on flat ground for the phase diagram shown in FIG. 19. Here, too, the phases symbolized by a circle each mean a short period of a step period, with a controlled knee movement taking place during each phase. The arrows between the phases indicate the respective phase transition. These are predetermined threshold values or fixed points which define the end point of a phase and are each determined by measurement data transmitted by sensors.

FIG. 21 shows an example of the electronic hardware provided for controlling the knee brake 11. This includes the control unit 19 already mentioned above, which has interfaces for the three EMG sensors 8, for two foot pressure sensors 9 and for the coding device 28. The power supply for the control unit 19 is designated 42. The control unit 19 is connected to an external computer 43 and has a control line 44 for controlling the brake 11.

According to FIG. 22, the control unit 19 has a microcontroller structure, which comprises a microcontroller 45, at least one RAM and a serial interface for bidirectional data exchange with the external computer 43. The microcontroller 45 comprises an internal 2 kB EEPROM for storing the operating and control software as well as the fixed data and is connected to an external 8 kB RAM for recording the volatile data during operation.

FIG. 23 shows an alternative embodiment with two controllers. Here the control unit 19 has a microcontroller In a master-slave configuration, the master controller 46 is connected to the coding device 28 and the foot pressure sensors 9 and the slave controller 47 connected to the master controller 46 in direct data exchange with the EMG sensors 8. Both controllers 46, 47 each have their own peripheral circuit, RAM and a serial connection to the external computer 43.

Gr / is / af / bk

Claims

Patent claims:

1. Method for controlling the knee brake (11) of a

Stump bed (1) with a lower part of the prosthesis

(2) with the connected prosthetic foot (3) connecting the knee joint (4), the computer-controlled braking torque being continuously variable between “free” and “blocked” depending on the walking movement of the prosthetic wearer, and the walking movement through the stump bed (1) measured EMG values, pressure values measured in the foot area, are characterized by the respective knee angle and the respective angular velocity measured between the upper and lower legs of the prosthesis in the form of electrical signals (hereinafter "measured data"), characterized by the following features:

b) selection of the control program assigned to this determined gait;

c) for each control program, a step period defined as a time period between two successive heel/ground contacts is divided into several phases, the respective end point of which is determined by measurement data transmitted for this phase;

d) each phase will be certain, during this

If necessary, changing braking values are assigned to the phase, with which the knee brake is applied.

Method according to claim 1, characterized in that the application of the knee brake to a constant Frequency occurs.

3. The method according to claim 1 or 2, characterized in that additional measurement data is determined from the moments acting on the knee and the hip.

4. The method according to claim 3, characterized in that the predetermined gaits are defined with the help of the different measurement data resulting from the measurement of the moments acting on the knee and hip.

5. Method according to one of the preceding claims, characterized in that the determination of the respective gait is carried out by comparing the transmitted actual measurement data with the reference measurement data specified for each gait.

6. The method according to claim 5, characterized in that the reference measurement data is determined from the EMG data measured for each individual gait.

7. The method according to claim 6, characterized in that for each of the predetermined gaits, a curve representing the muscle activity is created for each hip joint muscle sampled over a step period, and then the EMG measurement data defining this curve are set to a certain number by equidistant linear interpolation EMG reference values are reduced, which then define the EMG reference curve, and that in order to compare a certain number of actual EMG measurement data with matching reference EMG measurement data, the respective point in time within the step period is determined by pre-calculating the time of the end point of the respective phase , whereby the EMG reference values of the EMG reference curve that come closest to them in terms of time are then searched for from the actual measurement data.

8. The method according to one of the preceding claims, characterized in that a change from the control program of the gait currently being used to the control program of a different gait is only carried out in a previously selected special phase of the step period of the gait currently being used or of the new gait becomes.

9. Method according to one of the preceding claims, characterized in that all measurement data are saved at short notice.

10. Femoral prosthesis, with

- a stump bed (1), which is designed to be connected to a thigh stump of the prosthesis wearer;

- a prosthetic lower leg (2) to which a prosthetic foot (3) is connected;

- A knee joint (4), which connects an upper knee joint connection (6) for the stump bed (1) to a lower knee joint connection via a knee axis (5).

(7) for the prosthetic lower leg (2);

- a computer-controlled brake (11), which applies a braking torque that can be continuously varied between “free” and “blocked” to a brake shaft (21; 5; 37);

- a knee joint gear (16; 29; 35) for transmitting the braking torque from the brake shaft (21; 5; 37) to the knee axis (5);

- a control unit (19), which applies the brake (11) via a control algorithm depending on the walking movement of the prosthesis wearer;

- EMG sensors (8), which are arranged in the stump bed (1) to rest on certain thigh muscles and send signals to the control unit (19); - Foot pressure sensors (9), which are arranged in the running surface of the prosthetic foot (3) and emit signals to the control unit (19); - a coding device (28) which measures the respective knee angle and the respective angular velocity between the upper and lower legs of the prosthesis (2) and sends them to the control unit (19) in the form of electrical signals; in particular for carrying out the method according to one of the preceding claims, characterized by the following features:

a) at least two foot pressure sensors (9) are arranged in downwardly open recesses (15) in the sole of the foot, namely in the heel area and in the head area of a metatarsal bone;

b) the brake (11) is a magnetic powder brake which is controlled via pulsed control signals from a pulse width modulation circuit (PWM circuit), the pulse width determining the current flowing through the brake and thus the braking torque;

c) an adjustment and calibration system for adapting the control algorithm acting on the brake (11) to the gait of the prosthesis wearer.

11. Thigh prosthesis according to claim 10, characterized by a third foot pressure sensor (9) in the area of

OS metatarsal and a fourth foot pressure sensor (9) in the toe area.

12. Thigh prosthesis according to claim 10 or 11, characterized in that in the inner wall of the stump bed

(1) at least two EMG sensors (8) are fixed, the electrical connections of which are laid on the outside of the stump bed (1).

13. Thigh prosthesis according to claim 12, characterized in that the two EMG sensors (8) are assigned to the rectus femoris and hamstrings muscles.

14. Thigh prosthesis according to claim 12 or 13, characterized by a third EMG sensor (8) assigned to the adductor longus.

15. Thigh prosthesis according to claim 12, 13 or 14, characterized in that the EMG sensors are fixed in a resilient manner.

16. Thigh prosthesis according to one of claims 10 to 15, characterized in that the distance between the EMG sensors

(8) is approximately 10 cm from the edge (la) of the stump bed (1). (Figure 2)

17. Thigh prosthesis according to one of claims 10 to 16, characterized in that each foot pressure sensor (9) is supported against a metal insert (14) which is inserted into a recess (15) which surrounds the foot pressure sensor (9). is filled with the material of the prosthetic foot tread. (Figures 5 and 6)

18. Thigh prosthesis according to one of claims 10 to 17, characterized in that each foot pressure sensor (9) emits the size of the pressure exerted by the sensor contact surface on the floor in the form of electrical signals.

19. Thigh prosthesis according to one of claims 10 to 18, characterized by a sensor for measuring the knee moment.

20. Thigh prosthesis according to claim 15, characterized in that the knee moment sensor consists of at least two pairs of strain gauges (40), which are arranged in the sagittal plane at the front and rear of the prosthetic lower leg (2). (Fig. 18)

21. Thigh prosthesis according to one of claims 10 to 20, characterized by a sensor for measuring the hip movement mentes.

22. Thigh prosthesis according to claim 21, characterized in that the hip moment sensor consists of at least two pairs of strain gauges (40), which are arranged in the sagittal plane at the front and back of the prosthetic lower leg (2), and that for measurement the knee joint (4) is blocked. (Fig. 18)

23. Thigh prosthesis according to one of claims 10 to 22, characterized in that the knee axis (5) and a first gear wheel (17) sit firmly on the upper knee joint connection (6), while the lower knee joint connection (7) acts as a gear housing (18). is designed, which forms the bearing for the knee axis (5) and includes gear, brake (11) and coding device (28).

24. Thigh prosthesis according to claim 23, characterized by a two-stage reduction gear (16) with a knee axis (5) arranged parallel to one another, an intermediate shaft (20) and a brake shaft (21), which are rotatably mounted in the gear housing (18) and each with a Gear (17) are equipped, with the intermediate shaft (20) also carrying an intermediate gear (24) which meshes with the gear (23) of the brake shaft (21). (Figures 7 - 11)

25. Thigh prosthesis according to claim 23, characterized in that the knee axis (5) is also designed as a brake shaft and is rotatably mounted in both the upper and lower knee joint connection (6, 7) and carries a gear (30) in a rotationally fixed manner, which meshes with a gear (31) of an intermediate shaft (32), which is in engagement via a second gear (33) with a gear (34) which is firmly connected to the upper knee joint connection (6). (Figure 6)

26. Thigh prosthesis according to one of claims 10 to 25, characterized in that the knee joint drive (35) has a lever (36) which is firmly connected at one end to the upper knee joint connection (6), the free end of which is guided on a spindle (37) and represents its rotary drive Rotary nut (38) is supported, which can be moved on the spindle (37), which forms the brake shaft and is rotatably mounted with its lower end on the lower knee joint connection (7). (Figures 15 and 16)

27. Thigh prosthesis according to one of claims 10 to 26, characterized in that the coding device (28) comprises an optical encoder and a coding disk (27) seated on a gear shaft (21; 32; 37). (Figures 11 and 14)

28. Thigh prosthesis according to one of claims 10 to 27, characterized in that the electronic hardware is composed of the digital control unit (19), its cabling with an energy source (42), the EMG and foot pressure sensors (8, 9), the coding device (28) and the brake (11), and from an external computer (43), which forms the setting and calibration system, for temporary data exchange, adaptation and calibration of the control unit (19). (Figure 21)

29. Thigh prosthesis according to one of claims 10 to 28, characterized in that the digital control unit (19) is arranged in a housing on the prosthetic lower leg (2).

30. Thigh prosthesis according to claim 28 or 29, characterized in that the external computer (43) has its own interfaces for the sensors and actuators, with which it can be connected directly via parallel cables. Gr/is/af/bk