CN1878517A - Instrumented prosthetic foot - Google Patents

Abstract

The present application discloses an instrument prosthetic foot (20) for use with an actuated leg prothesis (14) controlled by a controller, the instrumented prosthetic foot (20) comprising a connector to connect the instrumented prosthetic foot (20) to the leg prothesis (14), an ankle structure connected to the connector, a ground engaging member connected to the ankle, at least one sensor (22a, 22b, 24a, 24b, 26) for detecting changes in weight distribution along the foot, and an interface for transmitting signals from the sensor to the controller.

Description

Instrumented prosthetic foot

Background technology

As knowing, sometimes be not easy to realize the automatization of complex mechanical system for Control Engineering teacher.Although this system, the conventional electric artificial limb is a bankruptcy of reputation because control problem is arranged.These traditional artificial limbs are equipped with basic controller, the artificial linear joint of described basic controller, and less than any reaction from the amputee, and only can produce basic exercise.This basic controller is not considered the dynamic condition of working environment, no matter artificial limb needs to produce the fact of suitable control in application in practice.Their common shortages must be used for the strategy with the predictability of the response of its artificial limb, and lack the control parameter that allows for the artificial limb dynamic trait and regulate.Because it is complicated process that the human limb moves, comprise simultaneously random, reflection and incident at random, traditional artificial limb does not have simultaneously and human body and the mutual ability of external environment condition, thereby has minimum suitable function.

Therefore, the application's purpose is elimination or alleviates some or all top defective.

Summary of the invention

According to the present invention, a kind of instrumented prosthetic foot of using in the mode of the excitation leg prosthesis by controller control is provided, this instrumented prosthetic foot comprises the adapter of connection instrumented prosthetic foot to leg prosthesis, be connected to the ankle structure of adapter, be connected to the ground engagement parts of ankle, the pick off that at least one distributes and change along the foot sense weight, and be used to send the interface of the signal of autobiography sensor to controller.

Description of drawings

By with reference to the accompanying drawings example only embodiments of the invention are described, wherein:

Fig. 1 shows the lower body with artificial limb, has instrumented prosthetic foot and the healthy leg that has on opposite side on a side;

Fig. 2 shows the block chart of the control system of the artificial limb that is used to have excitation mechanism;

Fig. 3 is the perspective view of going up slightly from the front of instrumented prosthetic foot;

Fig. 4 is the decomposition diagram of the instrumented prosthetic foot of Fig. 3;

Fig. 5 is the perspective view of going up slightly from the front of the alternative embodiment of the instrumented prosthetic foot of Fig. 3;

Fig. 6 is the decomposition diagram of the instrumented prosthetic foot of Fig. 5;

Fig. 7 is the perspective view of going up slightly from the front of another alternative embodiment of the instrumented prosthetic foot of Fig. 3;

Fig. 8 is the decomposition diagram of the instrumented prosthetic foot of Fig. 7;

Fig. 9 is the sketch map that is in application to the pressure of foot;

The perspective view that Figure 10 goes up slightly from the front of the further another alternative embodiment of the instrumented prosthetic foot of Fig. 3;

Figure 11 is the decomposition diagram of the instrumented prosthetic foot of Figure 10;

The perspective view that Figure 12 goes up slightly from the front of the further alternative embodiment of the instrumented prosthetic foot of Fig. 3;

Figure 13 is the decomposition diagram of the instrumented prosthetic foot of Figure 12;

The perspective view that Figure 14 goes up slightly from the front of the further another alternative embodiment of the instrumented prosthetic foot of Fig. 3;

Figure 15 is the decomposition diagram of the instrumented prosthetic foot of Figure 14.

The specific embodiment

Accompanying drawing shows to have the pick off that is used to use (22A, instrumented prosthetic foot 22E) (20) in conjunction with possible additional sensor (24A, 24B, 26), is used for the control system (100) that control has the artificial limb (14) of excitation mechanism (16).Be appreciated that the present invention is not limited to described embodiment,, and do not break away from the scope of accessory claim because can implement various changes and modification in this.

Therefore with reference to Fig. 1, individual (10) have pair of leg (26) and (28).One (26) is in the knee amputation.Artificial limb (14) is connected to lower limb (26), and comprises excitation mechanism (16), and it can be passive or active.Instrumented prosthetic foot (20) is connected to artificial limb (14), and comprise pick off (22A, 22B).(24A 24B) be positioned on the healthy foot, and additional pick off (26) is positioned on individuality (10) and/or the artificial limb (14) additional pick off.Passive excitation mechanism (16) can be restricted to the electric mechanical parts that only absorb mechanical energy usually, thereby revise the dynamic characteristic of the mechanical joint of artificial limb, active excitation mechanism can be restricted to the electromechanical parts of absorption and gadgetize energy usually simultaneously, thereby the dynamic trait of the mechanical joint of artificial limb is set.

Be that the name of January 22 calendar year 2001 application is called the U.S. patent application No.09/767 of " ELECTRONICALLYCONTROLLED PROSTHETIC KNEE ", described the example of passive excitation mechanism in 367.The example of active excitation mechanism is called the U.S. patent application No.10/463 of " ACTUATEDPROSTHESIS FOR ABOVE-KNEE AMPUTEE " in the name of application on June 17th, 2003 people such as StephaneBedard, the example of active excitation mechanism has been described in 495, in this with its content all with reference to combination.

As schematically showing among Fig. 2, by comprising the basic control system (100) of pick off (22A, 22B, 24A, 24B, 26), it is connected to controller (40) by interface (30), control artificial limb (14).Controller (40) provides the excitation mechanism (16) of signal to the artificial limb (14), such as shown in Figure 1.The purposes of control system (100) provides the signal that needs for control excitation mechanism (16).In order to do like this, utilize pick off (22A, 22B, 24A, 24B, 26), control system (100) is connected with amputee (10), to guarantee the suitable coordination between the motion of amputee (10) and artificial limb (14).Pick off (22A, 22B, 24A, 24B, 26) captured in real time is about the information of the dynamic characteristic of amputee's motion, and provides this information via interface (30) for controller (40).In the situation of passive excitation mechanism, controller (40) utilizes this information then, to determine to be applied to the impedance in joint, perhaps in the situation of active excitation mechanism, determine needed angular force that must be applied in joint trajectories and joint or moment of torsion, thereby the motion of coordination is provided.

Pick off (22A, 22B, 24A, 24B, 26) can comprise myoelectric sensor, neural sensor, motion sensor, dynamic pickup, strain gauge or plantar pressure sensor.Myoelectric sensor is to be used to measure the outside of skeletal muscle or the electrode of inner myoelectrical activity.Neural sensor is used to measure the summation of one or more action potentials of nervus peripheralis.Motion sensor is used to measure the position of Movable joint, than the mobility speed or the acceleration of lower end.Dynamic pickup is used to measure the angular force of Movable joint place or than the counteracting force of lower end.Strain gauge is used to measure the adaptability to changes at specific underfoot area place.Plantar pressure sensor is used to measure the vertical plantar pressure of specific underfoot area.Certainly, also can use the pick off of other type of the various information that the dynamics that moves about the people is provided.For the application that provides, the use of pick off (22A, 22B, 24A, 24B, 26) is not limited to the pick off of specified type, can use polytype pick off of combination in every way.

As shown in Figure 1, (22A 22B) can comprise the localized plantar pressure sensors that is positioned at the last interval location place of pseudopod (20) to pick off, to measure the vertical plantar pressure of specific underfoot area.Similarly, can provide at the interval location place in the custom made footwear inner bottom vola pick off that is positioned on healthy foot one side (24A, 24B), preferably the footwear inner bottom with standard orthopaedy is a form, and it is modified, to embed two pick off (24A, 24B), be used for the measurement of two localized plantar pressure.Pick off (22A, 22B, 24A, be exercisable 24B), shift that these pick offs combine with other pick off (26) to measure along the weight of foot along with individual movement, such as motion sensor, with the angular velocity of measurement than the body segment of lower end, and motion sensor, to measure the kneed angle of artificial limb (14).

Each pick off (24A 24B) can comprise the interface (30) that is connected directly to control system (100) or utilize the intermediate system (not shown) for 22A, 22B, wireless transmitter for example, and thin force-sensing resistor device (FSR) the polymer unit that connects indirectly.Certainly, also can use the communication link technologies of other type, such as optics.The FSR unit has the electrical impedance that reduces of pressure that response vertically is applied to the increase on its surface.The signal of telecommunication that becomes when each unit is exported, for this reason, intensity is the total vertical plantar pressure on its surf zone in proportion to.In moving process, can limit plantar pressure sensor (22A, 22B, 24A, size 24B) and position according to the stability and the richness (intensity) of the localized plantar pressure signal that provides by a certain underfoot area.For example, in being the experiment in two zones of vola portion, heel and toe zone find that wherein the maximum variation of plantar pressure (PPMV) can be considered to provide the signal of temperature and abundant information.

In addition, controller (40) can be used to from four localized plantar pressure sensors (22A, 22B, 24A, data signal 24B), and the information of collecting from the data signal of other pick off (26), such as motion sensor, thereby with the mobile state that resolves into limited quantity of individual (10), and produce suitable control signal, to control excitation mechanism (16) according to moving.Certainly, controller (40) is not limited to and uses the aforementioned data signal.

The U.S. patent application No.10/600 that is called " CONTROLSYSTEM AND METHOD FOR CONTROLLING AN ACTUATEDFROSTHESIS " at Stephane Bedard in the name of application on June 20th, 2003, described in 725 to utilize and comprised the controller (40) of plantar pressure sensor and motion sensor and the example of control system (100), thus in this with its content whole with reference to combination.

For realize with can repeat and reliably mode obtain data, (22A 22B) is bonded to the structure of foot (20) with pick off.The embodiment of instrumented prosthetic foot (20) is shown with details in Fig. 3 and 4.Instrumented prosthetic foot (20) comprises pedal plate (53), forms tensile main body, adapter at one end (51), and toe plate (55A) and heel slab (55B), it is from pedal plate (53) cantilevered.Provide this device by for example Vari-flex  pseudopod from Ossur.Be provided with in the position of the downside longitudinal separation of pedal plate (53) and heel slab (55) respectively pressure transducer (22A, 22B).By rigid plate (52A, 52B) and elastic insert (54A, 54B) covering sensor (22A, 22B).(22A, 22B), thereby response puts on load on the instrumented prosthetic foot (20) in the location that corresponds respectively to toe zone and heel zone to pressure sensors.

(22A, (52A 52B), although not necessary, helps optimization pick off (22A, whole lip-deep pressure branch 22B) and suppress any shear, and can being made by the polyurethane of 85A hardness to rigid plate 22B) to covering sensor.Certainly, also can use the material of other type.

Liner (54A, 54B) surround rigid plate (52A, 52B) and pick off (22A, 22B), formation ground engagement parts, thereby the contact between optimization instrumented prosthetic foot (20) and the ground.(54A 54B) can be made by the polyurethane of 40A hardness liner.Certainly, also can use the material of other type.

Therefore in operation, when foot (20) when crossing ground, measure the pressure that is applied to heel slab (55B) by pick off (22B), and corresponding signal is sent to controller (40).Also measure and be applied to the pressure of toe plate (55A), and measure the relative load between two positions by pick off (22A).When foot (20) when crossing ground continuously, the pressure that is applied to the toe zone increases, and reduces in heel place, so that a pair of signal to be provided, can determine the distribution of lower limb from described signal, and the suitable control that is supplied to activator (16).

Alternative embodiment in instrumented prosthetic foot shown in Fig. 5 and 6 (20).Instrumented prosthetic foot (20) comprises adapter (61), pedal plate (63), and toe plate (64A) and heel slab (64B) are such as providing by for example Vari-flex  pseudopod from Ossur.Pressure transducer (22A, 22B) be positioned at pedal plate (63) and rigid plate (62A, 62B) between.(22A, 22B), thereby response puts on load on the instrumented prosthetic foot (20) in the location that corresponds respectively to toe zone and heel zone to pressure sensors.More specifically, pressure transducer (22A) is clipped between a pair of rigid plate (62A), and this is positioned at again between heel slab (64B) and the pedal plate (63) rigid plate.Pressure transducer (22B) is clipped between a pair of rigid plate (62B), and this is positioned at again between pedal plate (63) and the adapter (61) rigid plate.

As for previous embodiment, covering sensor (22A, rigid plate (62A 22B), 62B), although not necessarily, help optimization pick off (22A, whole lip-deep pressure branch 22B) and suppress any shear, and can make by the polyurethane of 85A hardness.Certainly, also can use the material of other type.

Another alternative embodiment in instrumented prosthetic foot shown in Fig. 7 and 8 (20).Instrumented prosthetic foot (20) comprises adapter (71), top pedal plate (75), and foam cushion core (73) and bottom foot plate (74) are such as providing by for example LP Talux  pseudopod from Ossur.Pressure transducer (22A, 22B) be clipped in paired rigid plate (72A, 72B) between.(22A, 22B), thereby response puts on load on the instrumented prosthetic foot (20) in the location that corresponds respectively to toe zone and heel zone to pressure sensors.More specifically, pressure transducer (22A) is clipped between a pair of rigid plate (72A), and this is arranged in gap (76A) again to rigid plate, and this gap is positioned between pedal plate (74) and the foam cushion core (73).Pressure transducer (22B) is clipped between a pair of rigid plate (72B), and this is arranged in gap (76B) again to rigid plate, and this gap is in the foam cushion core (73).

Again, as for previous embodiment, covering sensor (22A, rigid plate (72A 22B), 72B), although unessential, help optimization pick off (22A, whole lip-deep pressure branch 22B) and suppress any shear, and can make by the polyurethane of 85A hardness.Certainly, also can use the material of other type.

Among the embodiment formerly, (22A, 22B) pressure (power) of acquisition toe and heel location is respectively F_toe and F_heel by direct pressure sensors in those location.More specifically, with reference to Fig. 9, following acquisition F_toe and F_heel:

F_toe=F_toe_meas equation 1

F_heel=F_heel_meas equation 2

In other possible embodiment of instrumented prosthetic foot (20), pick off (22A, 22B) be not limited to and directly be positioned toe and heel location, the axial compressive force at the equivalent torque by measuring the ankle place and the adapter place of instrumented prosthetic foot (20) can obtain equivalent information.Equation below utilizing, according to the moment of torsion that the ankle place is measured, M_ankle_meas and the pressure of measuring at the adapter place, F_conn_neas can limit F_toe and F_heel:

$F\_\mathrm{toe}=\frac{M\_\mathrm{ankle}\_\mathrm{meas}+(F\_\mathrm{conn}\_\mathrm{meas}\·I\_\mathrm{heel})}{(I\_\mathrm{heel}+I\_\mathrm{toe})}$ Equation 3

$F\_\mathrm{heel}=\frac{-M\_\mathrm{ankle}\_\mathrm{meas}+(F\_\mathrm{conn}\_\mathrm{meas}\·I\_\mathrm{heel})}{(I\_\mathrm{heel}+I\_\mathrm{toe})}$ Equation 4

Wherein, 1_heel is the distance between the center in the center of adapter and heel zone;

1_toe is the center of adapter and the distance between the toe regional center.

And then (22A, the previous discussion of position 22B) is in the further alternative embodiment of instrumented prosthetic foot shown in Figure 10 and 11 (20) about pick off.Instrumented prosthetic foot (20) comprises adapter (81), pedal plate (83), and toe plate (84A) and heel slab (84B), such as providing by for example Vari-Flex  pseudopod from Ossur, and load unit (22A, 22B).Under adapter (91), locate load unit (22A, 22B), towards the toe zone of foot offset load unit (22A) a little, and towards the heel zone offset load unit (22B) a little.Owing to directly do not locate load unit (22A at toe and heel location, 22B), can use equation 3 and equation 4, for example by controller (40), by the equivalent torque at qualification ankle place and the axial compressive force at adapter place, calculate the pressure of equal value of toe and heel location with following:

F_conn_meas=F_22B+F_22A equation 5

M_ankle_meas=F_22bI_22A equation 6

Wherein,

F_22B is the pressure of measuring at pick off 22B place;

F_22A is the pressure of measuring at pick off 22A place;

1_22B is the distance between the center of the center of adapter (81) and pick off 22B;

1_22A is the distance between the center of the center of adapter (81) and pick off 22A.

In the previous embodiment of instrumented prosthetic foot (20), by direct pressure sensors (22A in those location, 22B) or by in other zone pressure sensors or load unit (22A, 22B) the pressure (power) of acquisition toe and heel location, be respectively F_toe and F_heel, and obtain equivalent information by the equivalent torque at calculating ankle place and the axial compressive force at adapter place.Also can use the pick off of other type, with the equivalent torque at acquisition ankle place and the axial compressive force at adapter place.Further embodiment by instrumented prosthetic foot (20) describes this example, and it is shown in Figure 12 and Figure 13.Instrumented prosthetic foot (20) comprises adapter (91), is assemblied on the rotation ankle (93).At rotation ankle (93) and be positioned at locate between the rocker plate (95) on the pedal plate (94) buffer (92A, 92B).Rotation ankle (93) is connected to rocker plate (95) by rotating dog (96).By for example providing this device from Elation  pseudopod.Load unit (22A) and optical encoder (22B) are bonded to foot (20), to provide along the measurement of the pressure distribution of foot (20).Between adapter (91) and rotation ankle (93), locate load unit (22A).Optical encoder (22B) comprises reader (221) and disk (223).Go up location reader (221) at rotation ankle (93), simultaneously at rocker plate (95) positioning disk (223) and around rotating dog (96).Again, can use equation 3 and equation 4,,, calculate the pressure of equal value of toe and heel location with the following axial compressive force of locating by the equivalent torque and the adapter (91) at qualification ankle place for example by controller (40):

F_conn_meas=F_22A equation 7

M_ankle_meas=R_anke_measR_const equation 8

Wherein

F_22A is the pressure of measuring at pick off 22A place;

R_ankle_meas is the rotation ankle (93) measured by optical encoder (22B) wheel measuring about rotating dog (96);

R_const be with in order to compression (this constant is based on the changes in material of using for 92A, the constant that impedance 92B) is relevant with buffer.

Another alternative embodiment in instrumented prosthetic foot shown in Figure 14 and Figure 15 (20).Instrumented prosthetic foot (20) comprises adapter (101), is assemblied on the rotation ankle (103).At rotation ankle (103) and be positioned at locate between the rocker plate (105) on the pedal plate (104) buffer (102A, 102B).Rotation ankle (103) is connected to rocker plate (105) by rotating dog (106).By for example providing this device from Elation  pseudopod.Pressure transducer (22A, 22B) and load unit (22C) be bonded to foot (20), to provide along the measurement of the pressure distribution of foot (20).Pressure sensors (22A) between rocker plate (85) and buffer (82A), pressure sensors (22B) between rocker plate (85) and buffer (82B) simultaneously.Between adapter (91) and rotation ankle (93), locate load unit (22C).

In this embodiment, equation 6 is used to calculate the equivalent torque at ankle place, the axial compressive force that the Equation for Calculating adapter (101) below utilizing is simultaneously located:

F_conn_meas=F_22C equation 9

Need load unit (22C) to calculate the axial compressive force that adapter (101) is located, because when having moment of torsion at the ankle place, when just the user of artificial limb stood still, axial force all was applied on the rotating dog (96).

In whole described embodiment, (22A 22B) can be connected directly to the interface (30) of control system (100) or utilize the intermediate system (not shown) to connect indirectly, for example wireless transmitter to pick off.Certainly, can use the communication link of other type, such as optics.

Also can use the non-activity or the movable pseudopod of other type, as long as the pseudopod of selecting provides the approximately uniform dynamic response of mentioning as top here.However, pseudopod provides optimum performance.This instrumented prosthetic foot (20) can further have the metal or the composite structure of exposure, and the decoration that maybe can have the outward appearance that provides people's ankle and foot covers.

Be appreciated that the present invention is not confined to its use the control system described in the frame for movement described in Fig. 1 or Fig. 2 (100).It can be used to have the leg prosthesis more than a joint.For example, locate outside the knee joint, it can be used for having ankle joint, the artificial limb of metatarsophalangeal joints or hip joint.In addition, replace traditional socket, also can use the skeleton integrating device, guarantee the mechanical part of artificial limb and the direct connection between amputee's skeleton.Also can use other artificial limb.

Claims (18)

1. instrumented prosthetic foot that is used for by the excitation leg prosthesis of controller control, this instrumented prosthetic foot comprises:

Stretching main body with top and bottom;

Be used to connect the adapter of instrumented prosthetic foot to leg prosthesis, this adapter is connected to the top of stretching main body;

Be connected to the ground engagement parts of the bottom of stretching main body;

Be used to detect at least one pick off that changes along the distribution of weight of foot; And

Be used to send the interface of the signal of autobiography sensor to controller.

2. according to the instrumented prosthetic foot of claim 1, wherein:

The ground engagement parts comprise a pair of basic foot position, and the first area is corresponding to the heel zone of people's foot, and second area is corresponding to the toe zone of people's foot.

3. according to the instrumented prosthetic foot of claim 2, wherein:

At least two pick offs are provided, and the basic foot of each of pick off and ground engagement parts position interrelates.

4. according to the instrumented prosthetic foot of claim 3, wherein:

Pick off comprises strain sensor, to measure the strain that applies in the corresponding basic foot position of ground engagement parts.

5. according to the instrumented prosthetic foot of claim 3, wherein:

Pick off comprises pressure transducer, to measure at the corresponding basic foot position of ground engagement parts applied pressure.

6. according to the instrumented prosthetic foot of claim 3, wherein:

Pick off comprises load unit, to measure at the corresponding basic foot position of ground engagement parts applied pressure.

7. according to the instrumented prosthetic foot of claim 3, wherein:

Alignment sensor under the ground engagement parts.

8. according to the instrumented prosthetic foot of claim 3, wherein:

Alignment sensor between ground engagement parts and stretching main body.

9. according to the instrumented prosthetic foot of claim 3, wherein:

Alignment sensor between stretching main body and adapter.

10. according to the instrumented prosthetic foot of claim 5, wherein:

Pressure transducer is the force-sensing resistor device.

11. the instrumented prosthetic foot according to claim 5 further comprises:

Be arranged at the rigid plate at least one side of pick off.

12. the instrumented prosthetic foot according to claim 11 further comprises:

Cover the elastic insert of rigid plate and pick off.

13. the instrumented prosthetic foot according to claim 1 further comprises:

The stretching main body that is rotatably connected is to the ankle structure of adapter.

14. according to the instrumented prosthetic foot of claim 13, wherein:

At least two pick offs are provided, and this pick off comprises localized two load units between adapter and ankle structure.

15. according to the instrumented prosthetic foot of claim 13, wherein:

At least two pick offs are provided, and this pick off comprises optical encoder and load unit, locatees optical encoder near the ankle structure the rotating shaft with stretching main body, and locate load unit between ankle structure and adapter.

16. according to the instrumented prosthetic foot of claim 1, wherein:

The signal that is used to send the autobiography sensor to the interface of controller is a wired connection.

17. according to the instrumented prosthetic foot of claim 1, wherein:

The signal that is used to send the autobiography sensor to the interface of controller is wireless connections.

18. the instrumented prosthetic foot according to claim 1 further comprises:

The device of instrumented prosthetic foot to leg prosthesis is used to removably connect.

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