Bionic prosthesis that perceives the environment

Abstract

The present invention relates to a bionic prosthesis (1) for a lower or upper limb, comprising a prosthetic distal segment, i.e., a prosthetic foot (11) or a prosthetic hand, adapted to come into contact with a surface (2) or with an object to be grasped; a prosthetic middle segment, i.e., a prosthetic tibia (12) or a prosthetic forearm; at least one motorized articulation device (13), one of which is mechanically connected on one side to the prosthetic distal segment and on the other side to the prosthetic middle segment; at least one depth camera (15) adapted to generate a three-dimensional point cloud; a control unit (14) configured to process the three-dimensional point cloud and control said at least one motorized articulation device (13) so as to adapt the positioning of the prosthetic distal segment relative to the surface (2) or the object to be grasped. Abstract figure: Figure 1

Description

Title of the invention: Bionic prosthesis perceiving the environment Technical field

[0001] The present invention relates to the field of bionic prostheses intended for persons with amputations of a limb. In particular, the present invention provides a bionic prosthesis for a lower or upper limb that perceives the environment and a method for controlling said bionic prosthesis. STATE OF THE ART

[0002] As is known, a prosthesis makes it possible to replace a limb from both a functional and aesthetic point of view. In the context of a person with a lower limb amputation, it is desirable to have a prosthesis that makes walking as natural as possible and allows the user to maintain their balance, particularly when going up and down stairs, or when walking backwards. Similarly, in the context of a person with an upper limb amputation, it is desirable to facilitate the gripping of objects, taking into account in particular the shape and nature of the object to be grasped. For example, the optimal clamping force and position of the prosthesis differ for gripping a glass and for gripping a piece of fruit.

[0003] In particular, a bionic prosthesis is distinguished in that it implements a robotic process which, based on commands corresponding to the intentions of the amputee, initiates movement of the prosthesis. Different categories of bionic prostheses are documented in the state of the art, the most widespread being myoelectric prostheses, hydraulic prostheses, neuroelectric prostheses, and electronic prostheses.

[0004] As is known, myoelectric prostheses rely on muscle activation. Sensors, particularly positioned at the stump, detect muscle contractions and send electrical signals to control the prosthesis. The use of this prosthesis by the amputee requires a great deal of rehabilitation work in order to learn to control muscle contractions appropriately. Thus, the use of a myoelectric prosthesis requires perfect control by the amputee to be able to initiate movements with adequate precision and force. In addition, the possible movements are generally limited.

[0005] According to another known example, electronic prostheses have pre-programmed actions that the amputee can activate, in particular via a mobile application.

[0006] Therefore, according to the two previous examples, the movement results from the will and deliberate actions of the amputee. In addition to the difficulty in making precise control of the movements performed possible, another disadvantage lies in the mental burden that mastering this type of prosthesis implies for the user.

[0007] There is therefore a need for bionic prostheses allowing more natural movement, in particular without requiring heavy learning or a significant mental load for the user.

[0008] Furthermore, bionic prostheses may comprise resistance measuring means in order to adapt the movement control. Thus, bionic prostheses according to the state of the art are mainly reactive, in other words they have limited awareness of the external environment. The set of possible movements is limited accordingly.

[0009] Therefore, there is a need for a bionic prosthesis having improved autonomy and precision, in particular a bionic prosthesis that perceives the environment autonomously. PRESENTATION OF THE INVENTION

[0010] More specifically, according to one aspect of the invention, the invention relates to a bionic prosthesis for a lower or upper limb, comprising:

[0011] - a prosthetic distal segment of the lower or upper limb, in other words a prosthetic foot or, respectively, a prosthetic hand, at a free end of the bionic prosthesis, adapted to come into contact with a terrain or, respectively, with an object to be grasped;

[0012] - a prosthetic middle segment, in other words a prosthetic tibia or, respec tively, a prosthetic forearm;

[0013] - at least one motorized articulation device, a first of said at least one motorized articulation device being mechanically connected on the one hand to the prosthetic distal segment and on the other hand to the prosthetic middle segment;

[0014] - a control unit configured to control said at least one device motorized articulation from control signals corresponding to an intention of movement;

[0015] - at least one depth camera adapted to generate a three-dimensional point cloud dimensional of the environment of the bionic prosthesis, including the terrain or, respectively, the object to be grasped,

[0016] Then, the control unit is configured to process the three-dimensional point cloud in order to detect the terrain or, respectively, the object to be grasped, and to control said at least one motorized articulation device so as to adapt the positioning of the prosthetic distal segment relative to the terrain or, respectively, relative to the object to be grasped. The use of depth cameras offers the considerable advantage of improving the perception of the external environment and consequently improving the movement of the bionic prosthesis by supplementing the unconscious sensory perceptions of the amputee. The present invention also allows the implementation of motorized articulation devices having a higher number of degrees of freedom, making the movement of the bionic prosthesis more natural.

[0017] Advantageously, the bionic prosthesis according to the invention comprises a system of myoelectric sensors configured to generate the control signals corresponding to an intention of movement.

[0018] According to a first embodiment of the invention, the bionic prosthesis forms a bionic lower limb prosthesis, comprising a prosthetic foot at a free end of the bionic prosthesis, adapted to come into contact with a terrain, a prosthetic tibia, at least one motorized articulation device, a control unit configured to control said at least one motorized articulation device from control signals corresponding to a movement intention, and at least one depth camera adapted to generate a three-dimensional point cloud of the environment of the prosthetic foot including the terrain. A first of said at least one motorized articulation device is mechanically connected on the one hand to the prosthetic foot and on the other hand to the prosthetic tibia.In addition, the control unit is configured to process the three-dimensional point cloud in order to detect the terrain and to control said at least one motorized articulation device so as to adapt the positioning of the prosthetic foot relative to the terrain.

[0019] Advantageously, said at least one depth camera consists of two depth cameras configured so as to respectively cover a front field and a rear field of the environment of the prosthetic foot.

[0020] Advantageously, the prosthetic foot having a directional vector of the foot oriented substantially in a longitudinal direction of the prosthetic foot, the bionic lower limb prosthesis comprises a set of accelerometers capable of measuring the directional vector of the foot.

[0021] According to an example of the invention, the bionic lower limb prosthesis according to the first embodiment of the invention comprises a prosthetic femur, said at least one motorized articulation device then comprising a second motorized articulation device being mechanically connected on the one hand to the prosthetic tibia and on the other hand to the prosthetic femur.

[0022] According to another aspect of the invention, the invention relates to a control method of the bionic prosthesis of lower or upper limb according to the invention, the method, following an instruction corresponding to an intention of movement and comprising:

[0023] - the measurement of the current state of the bionic prosthesis including in particular the measurement of directional vectors of the prosthetic distal segment, of the prosthetic middle segment, and where applicable of the prosthetic proximal segment;

[0024] - the acquisition by said at least one depth camera of a point cloud sorted dimensional of the bionic prosthesis environment;

[0025] - processing of the three-dimensional point cloud by the control unit;

[0026] - the calculation by the control unit of the movements to be implemented by said at less than one motorized articulation device;

[0027] - the setting in motion of the bionic prosthesis.

[0028] Advantageously, the method for controlling a bionic lower limb prosthesis according to the first embodiment of the invention, following an instruction corresponding to an intention of movement, comprises:

[0029] - measuring the current state of the bionic prosthesis comprising measuring a directional vector of the foot oriented substantially in a longitudinal direction of the prosthetic foot;

[0030] - the acquisition by said at least one depth camera of the three-dimensional point cloud mental of the environment of the bionic prosthesis;

[0031] - processing of the three-dimensional point cloud by the control unit comprising extracting a set of points from the three-dimensional point cloud corresponding to the terrain and calculating the normal to a surface defined by said set of points, designated normal to the terrain;

[0032] - the calculation by the control unit of the movements to be implemented by said at at least one motorized articulation device such that the directional vector of the foot is substantially perpendicular to the normal to the terrain;

[0033] - the setting in motion of the bionic prosthesis.

[0034] Advantageously, the method according to the invention comprises a step of reconstructing the three-dimensional point cloud comprising the assembly of a plurality of three-dimensional point clouds corresponding to a succession of generation of three-dimensional point clouds by said at least one depth camera, the reconstruction step being carried out prior to the calculation of the normal to the terrain.

[0035] Advantageously, the measurement of the directional vector of the foot is carried out by a set of accelerometers. PRESENTATION OF FIGURES

[0036] The invention will be better understood upon reading the following description, given solely by way of example, and referring to the accompanying drawings given as non-limiting examples, in which identical references are given to similar objects and in which:

[0037] [Fig.l]: [Fig.l] is a schematic representation of a view of the bionic lower limb prosthesis according to one aspect of a first embodiment of the invention;

[0038] [Fig.2]: [Fig.2] is a schematic representation of the control method of the bionic lower limb prosthesis according to another aspect of the first embodiment of the invention;

[0039] [Fig.3]: [Fig.3] is a schematic representation of the control method of the bionic upper limb prosthesis according to one aspect of a second embodiment of the invention.

[0040] It should be noted that the figures set out the invention in detail to enable the invention to be implemented, said figures of course being able to serve to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0041] According to one aspect of the invention, the invention relates to a bionic prosthesis and will be described below in the context of a myoelectric bionic prosthesis for a person with a lower or upper limb amputation. The invention is not limited to this scope of application, it can also be adapted to any bionic prosthesis of the lower or upper limb.

[0042] The bionic prosthesis according to the invention comprises a prosthetic distal segment of the lower or upper limb, in other words a prosthetic foot or, respectively, a prosthetic hand, at a free end of the bionic prosthesis, and adapted to come into contact with a terrain or, respectively, with an object to be grasped; a prosthetic middle segment, in other words a prosthetic tibia or, respectively, a prosthetic forearm; at least one motorized articulation device, a control unit, and at least one depth camera.

[0043] A first of said at least one motorized articulation device is mechanically connected on the one hand to the prosthetic distal segment and on the other hand to the prosthetic middle segment. The first motorized articulation device corresponds in particular to the ankle joint for a bionic lower limb prosthesis and to the wrist joint for a bionic upper limb prosthesis.

[0044] The control unit is configured to control said at least one motorized articulation device from control signals corresponding to a movement intention. Preferably, the control unit implements the ROS operating system ("Robotic Operation System") or ROS 2.

[0045] In order to connect the bionic prosthesis according to the invention to the amputee, the bionic prosthesis may advantageously comprise a fitting member adapted to relate to a residual end of an amputated limb. Alternatively, it is also possible to connect the bionic prosthesis to the amputee by an implant system, in particular an OPRA implant system, put in place by an osseointegration method.

[0046] In the context of a myoelectric bionic prosthesis, the bionic prosthesis notably comprises a myoelectric sensor system configured to generate the control signals corresponding to a movement intention. The control signals may notably be a simple order, such as an order to walk for a lower limb prosthesis, or to grasp an object for an upper limb prosthesis. The myoelectric sensor system may also allow more advanced control of the prosthesis, notably by being able to capture a speed and a duration of execution associated with the movement intention, so as to allow a more precise movement, of the order of a few degrees, and at low speed. In this context, the movement intention corresponds to muscular contractions of the amputee detected by the myoelectric sensor system. The myoelectric sensor system may be integrated into the fitting member if necessary.

[0047] Said at least one depth camera is adapted to generate a three-dimensional point cloud of the environment of the bionic prosthesis, comprising the terrain, or, respectively, the object to be grasped. Then, the control unit is configured to process the three-dimensional point cloud in order to detect the terrain or, respectively, the object to be grasped, and to control said at least one motorized articulation device so as to adapt the positioning of the prosthetic distal segment relative to the terrain or, respectively, relative to the object to be grasped.

[0048] Thus, the use of depth cameras advantageously makes it possible to improve the perception of the external environment and consequently to improve the movement of the bionic prosthesis by supplementing the unconscious sensory perceptions of the amputee. The present invention therefore has the considerable advantage of allowing the implementation of motorized articulation devices having a higher number of degrees of freedom, making the movement of the bionic prosthesis more natural.

[0049] In particular, a depth camera, also referred to as a time-of-flight camera or TOF (“Time of Flight”) camera, comprises two infrared depth sensors for capturing distances and shapes in a three-dimensional space.

[0050] In addition, said at least one depth camera is preferably activated only when the bionic prosthesis is in motion and otherwise is at rest. This operation advantageously reduces the power consumption of the bionic prosthesis.

[0051] Furthermore, the bionic prosthesis may comprise, where appropriate, a prosthetic proximal segment. The prosthetic proximal segment corresponds in particular to a prosthetic femur, or respectively, to a prosthetic arm for an amputation of the lower limb, or for an amputation of the upper limb. In addition, said at least one motorized articulation device then preferably comprises a second motorized articulation device corresponding to the knee joint for an amputation of the lower limb, and to the elbow joint for an amputation of the upper limb.

[0052] The bionic prosthesis preferably comprises a set of accelerometers capable of measuring a current state of the bionic prosthesis.

[0053] With reference to Figures 2 and 3, according to another aspect of the invention, the invention relates to a method for controlling the bionic prosthesis of a lower or upper limb, as described previously, the method comprising, following an instruction 3 corresponding to an intention of movement:

[0054] - the measurement El of the current state 17 of the bionic prosthesis including in particular the measurement of directional vectors of the distal prosthetic segment, of the middle prosthetic segment, and where appropriate of the proximal prosthetic segment, in particular by the set of accelerometers;

[0055] - the acquisition E2 by said at least one depth camera of a point cloud three-dimensional 16 of the bionic prosthesis environment;

[0056] - the processing of the three-dimensional point cloud 16 by the control unit;

[0057] - the calculation E5 by the control unit of the movements to be implemented by said at least one motorized articulation device;

[0058] - the setting in motion E6 of the bionic prosthesis.

[0059] Furthermore, a possible acquisition frequency of said at least one depth camera is 5Hz. The choice of the acquisition frequency results in particular from a compromise between obtaining a sufficient number of data to have a sufficient representation of the environment, while limiting the number of data to be processed in order to reduce the processing time and consequently save the battery of the control unit.

[0060] The calculation by the control unit of the movements to be carried out by said at least one motorized articulation device may in particular consist of an optimization of the movements according to the different degrees of freedom of said at least one motorized articulation device.

[0061] The bionic prosthesis forming a bionic lower limb prosthesis, according to a first embodiment of the invention, is described in more detail below.

[0062] With reference to [Fig. 1], the bionic lower limb prosthesis 1 according to the first embodiment of the invention comprises a prosthetic foot 11 at a free end of the bionic prosthesis 1 and adapted to come into contact with a terrain 2; a prosthetic tibia 12; at least one motorized articulation device 13, a first of said at least one motorized articulation device 13 being mechanically connected on the one hand to the prosthetic foot 11 and on the other hand to the prosthetic tibia 12; a control unit 14 configured to control said at least one motorized articulation device 13 from control signals corresponding to a movement intention;at least one depth camera 15 adapted to generate a three-dimensional point cloud of the environment of the prosthetic foot 11, comprising the terrain 2, the control unit 14 being configured to process the three-dimensional point cloud in order to detect the terrain 2 and to control said at least one motorized articulation device 13 so as to adapt the positioning of the prosthetic foot 11 relative to the terrain 2.;

[0063] In particular, the terrain is defined as a surface on which the amputee uses support to move. The surface may in particular be flat, such as a floor or a step, or it may be inclined. In addition, the surface may also be uneven and include obstacles or roughness (holes, stones, etc.) which it is advantageous to identify.

[0064] In addition, said at least one depth camera may be adapted to view the other leg of the amputee in addition to the terrain.

[0065] Furthermore, said at least one depth camera 15 may consist of two depth cameras configured so as to respectively cover a front field and a rear field of the environment of the prosthetic foot 11 as shown in [Fig.l]. Such a camera configuration makes it possible to perceive the environment in the context of forward walking and backward walking. Thus, the two depth cameras may be positioned for example respectively at the front and at the rear of the bionic prosthesis, or on either side of the lower limb bionic prosthesis.

[0066] In addition, said at least one depth camera preferably has a fixed origin relative to the lower limb bionic prosthesis.

[0067] In a first example, the bionic lower limb prosthesis according to the invention is adapted for a case of tibial amputation, i.e. below the knee. Then, only the first motorized articulation device, corresponding to the ankle, is controlled by the control unit. Then, the first motorized articulation device can advantageously have three degrees of freedom represented by two-way arrows in [Fig.l]. The control unit controls therefore three degrees of freedom in total.

[0068] In a second example, the bionic lower limb prosthesis according to the invention is suitable for a case of trans-femoral amputation, i.e. above the knee. The bionic lower limb prosthesis then advantageously comprises a prosthetic femur. In addition, for a bionic lower limb prosthesis, said at least one motorized articulation device comprises in particular the second motorized articulation device being mechanically connected on the one hand to the prosthetic tibia and on the other hand to the prosthetic femur. In other words, the second motorized articulation device corresponds to the knee joint.

[0069] In this second example, the three degrees of freedom of the first motorized articulation device are added to the degrees of freedom of the second motorized articulation device. The present invention advantageously makes it possible to adapt with greater precision the height to which the bionic lower limb prosthesis, and in particular the second motorized articulation device corresponding to the knee, must be lifted, to avoid gripping the ground, in particular for uneven ground.

[0070] Furthermore, the prosthetic foot 11 has in particular a directional vector of the foot 111 oriented substantially in a longitudinal direction of the prosthetic foot 11 as illustrated in [Fig.l]. The bionic lower limb prosthesis 1 may then comprise a set of accelerometers capable of measuring the directional vector of the foot 111, the set of accelerometers preferably comprising two accelerometers. The directional vector of the foot 111 may in particular be defined with respect to a reference system defined by three axes corresponding to a reference position of the prosthetic foot 11.

[0071] With reference to [Fig.2], the method of controlling the bionic lower limb prosthesis, following an instruction 3 corresponding to a movement intention, comprises:

[0072] - the measurement El of the current state 17 of the bionic lower limb prosthesis including the measurement of the directional vector of the foot, in particular by the set of accelerometers;

[0073] - the acquisition E2 by said at least one depth camera of the point cloud three-dimensional 16;

[0074] - the processing of the three-dimensional point cloud 16 by the control unit comprising the extraction E32 of a set of points from the three-dimensional point cloud 16 corresponding to the terrain and the calculation of the normal E34 to a surface defined by said set of points, designated normal to the terrain;

[0075] - the calculation E5 by the control unit 14 of the movements to be implemented by said at least one motorized articulation device such that the directional vector of the foot is substantially perpendicular to the normal to the terrain;

[0076] - the setting in motion E6 of the bionic prosthesis.

[0077] Furthermore, said at least one depth camera is preferably activated only when walking and is otherwise at rest.

[0078] In particular, the extraction of a set of points from the three-dimensional point cloud corresponding to the terrain may consist of the execution of an algorithm for detecting flat surfaces and followed by the selection of the flat surface having a greater number of points. Thus, the invention makes it possible to advantageously detect flat and inclined surfaces.

[0079] Furthermore, the method for controlling the bionic lower limb prosthesis may comprise identifying the nature of the terrain E33, as illustrated in [Fig.2], for example a stair step. The identification of the nature of the terrain may in particular be carried out by means of learning algorithms. In the context of a stair step, the first motorized articulation device, corresponding to the ankle, must tilt forward to avoid falling while being flat in order to guarantee stable support. Thus, the forward tilt is a constraint to be taken into account when calculating by the control unit the movements to be performed by said at least one motorized articulation device.

[0080] In addition, as illustrated in [Fig.2], the method according to the invention may comprise a step of reconstruction E31 of the three-dimensional point cloud 16 comprising the assembly of a plurality of three-dimensional point clouds 16 corresponding to a succession of acquisitions of three-dimensional point clouds by said at least one depth camera, the reconstruction step being carried out in particular prior to the calculation of the normal to the terrain E34. Thus, the reconstruction step E31 may be carried out prior to or following the extraction E32 and the identification of the terrain E33. The reconstruction step advantageously makes it possible to reconstruct the areas obstructed by the prosthetic foot in order to obtain an improved perception of the terrain. Thus, any uncertainties linked to the calculation of the normal to the terrain are reduced.

[0081] The reconstruction step may preferably comprise the execution of a SLAM (“Simultaneous Localization And Mapping”) algorithm.

[0082] The calculation by the control unit of the movements to be performed by said at least one motorized articulation device may in particular consist of an optimization of the movements according to the different degrees of freedom of said at least one motorized articulation device. The objective is to ensure a positioning of the prosthetic foot substantially parallel to the ground for improved grip while minimizing the required movements so as to reduce fatigue and consumption of the motors of said at least one motorized articulation device.

[0083] The bionic prosthesis forming a bionic upper limb prosthesis, according to a second embodiment of the invention, is described in more detail below.

[0084] The bionic upper limb prosthesis according to the second embodiment of the invention comprises a prosthetic hand at a free end of the bionic prosthesis and adapted to come into contact with an object to be grasped; a prosthetic forearm; at least one motorized articulation device, a first of said at least one motorized articulation device being mechanically connected on the one hand to the prosthetic hand and on the other hand to the prosthetic forearm; a control unit configured to control said at least one motorized articulation device from control signals corresponding to a movement intention;at least one depth camera adapted to generate a three-dimensional point cloud of the environment of the prosthetic hand, comprising the object to be grasped, the control unit being configured to process the three-dimensional point cloud in order to detect the object to be grasped and to control said at least one motorized articulation device so as to adapt the positioning of the prosthetic hand relative to the object to be grasped.;

[0085] Furthermore, said at least one depth camera may, preferably, be integrated between the elements corresponding to the thumb and index finger of the prosthetic hand, in the palm of the prosthetic hand, or on the face opposite the palm of the prosthetic hand. In addition, it is also possible to use several depth cameras, each covering a field of the environment.

[0086] In a third example, the bionic upper limb prosthesis according to the invention is adapted for a case of amputation of the forearm, i.e. below the elbow. The first motorized articulation device, corresponding to the wrist joint, is controlled by the control unit. Then, the first motorized articulation device can advantageously have three degrees of freedom. In addition, other additional articulation devices, corresponding in particular to the finger joints, can be added to the first motorized articulation device.

[0087] In a fourth example, the bionic upper limb prosthesis according to the invention is suitable for a case of amputation of the arm, i.e. above the elbow. The bionic upper limb prosthesis then advantageously comprises a prosthetic arm. In addition, for a bionic upper limb prosthesis, said at least one motorized articulation device comprises in particular the second motorized articulation device being mechanically connected on the one hand to the prosthetic forearm and on the other hand to the prosthetic arm. In other words, the second motorized articulation device corresponds to the elbow joint. In this second example, the three degrees of freedom of the first motorized articulation device are added to the degrees of freedom of the second motorized articulation device.

[0088] The present invention advantageously makes it possible to adapt the position of the prosthetic hand more precisely to the object to be grasped, thus making it possible to improve precision when grasping an object and to make the grasping more natural for the user of the prosthesis.

[0089] With reference to [Fig.3], the method of controlling the bionic upper limb prosthesis, following an instruction 3 corresponding to a movement intention, comprises:

[0090] - the measurement El of the current state 17 of the bionic upper limb prosthesis comprising the measurement of a directional vector of the hand, in particular by the set of accelerometers;

[0091] - the acquisition E2 by said at least one depth camera of the point cloud three-dimensional 16;

[0092] - the processing of the three-dimensional point cloud 16 by the control unit comprising the extraction E42 of a set of points from the three-dimensional point cloud 16 corresponding to the object to be grasped and the identification of the object to be grasped E43, in particular the nature and shape of the object to be grasped;

[0093] - the calculation E5 by the control unit of the movements to be implemented by said at least one motorized articulation device so as to ensure the gripping of the object by the prosthetic hand;

[0094] - the setting in motion E6 of the bionic prosthesis.

[0095] In particular, the extraction of a set of points from the three-dimensional point cloud corresponding to the object to be grasped and the identification of the object to be grasped can be carried out by means of learning algorithms.

[0096] Furthermore, as illustrated in [Fig. 3], the method according to the invention may comprise a step E41 of reconstructing the three-dimensional point cloud 16 comprising the assembly of a plurality of three-dimensional point clouds 16 corresponding to a succession of acquisitions of three-dimensional point clouds by said at least one depth camera. The reconstruction step may preferably comprise the execution of a SLAM (“Simultaneous Localization And Mapping”) algorithm. The reconstruction step advantageously makes it possible to reconstruct the obstructed areas in order to obtain an improved perception of the object to be captured, and possibly to make it possible to limit the number of depth cameras used.

[0097] In summary, the present invention provides a bionic prosthesis capable of perceiving the environment by the use of depth cameras and a method for controlling said bionic prosthesis. Thus, the invention has the substantial gain of reducing the mental and physical cost of using a bionic prosthesis. For example, the person with a lower limb amputation no longer has to worry about whether the bionic prosthesis is raised high enough to avoid tripping on the stairs or on uneven ground. Similarly, the person with an upper limb amputation no longer has to worry about the position and force exerted by the prosthetic hand to grasp an object. Consequently, the present invention allows for more natural, intuitive, and stable movement. In addition, the use of the prosthesis is simplified.

[0098] In addition, the present invention makes it possible to have improved control of the different degrees of freedom of the motorized articulation devices, and to allow the control of bionic prostheses having a greater number of degrees of freedom. For example, according to the state of the art, conventional lower limb bionic prostheses generally only comprise one degree of freedom at the first motorized articulation device corresponding to the ankle joint. Thanks to the invention, it is possible to use a first motorized articulation device having, for example, three degrees of freedom. Similarly, conventional upper limb bionic prostheses generally only comprise one degree of freedom at the first motorized articulation device corresponding to the wrist joint in the form of an infinite rotation.The number of degrees of freedom can also be increased in the latter case. Thus, the invention offers a wider range of movement, allowing, in the context of a bionic lower limb prosthesis, to maintain balance when going up and down stairs or when walking backwards, and in the context of a bionic upper limb prosthesis, to grasp delicate objects such as fruit or a stemmed glass.

Claims

Claims

1. Bionic prosthesis (1) for a lower or upper limb, comprising: • a prosthetic distal segment of the lower or upper limb, in other words a prosthetic foot (11) or, respectively, a prosthetic hand, at a free end of the bionic prosthesis (1), adapted to come into contact with a terrain (2) or, respectively, with an object to be grasped; • a prosthetic middle segment, in other words a prosthetic tibia (12) or, respectively, a prosthetic forearm; • at least one motorized articulation device (13), a first of said at least one motorized articulation device (13) being mechanically connected on the one hand to the prosthetic distal segment and on the other hand to the prosthetic middle segment; • a control unit (14) configured to control said at least one motorized articulation device (13) from control signals (3) corresponding to a movement intention; characterized in that the bionic prosthesis (1) comprises at least one depth camera (15) adapted to generate a three-dimensional point cloud (16) of the environment of the bionic prosthesis (1), comprising the terrain (2) or, respectively, the object to be grasped, the control unit (14) being configured to process the three-dimensional point cloud (16) in order to detect the terrain (2) or, respectively, the object to be grasped, and to control said at least one motorized articulation device (13) so as to adapt the positioning of the prosthetic distal segment relative to the terrain (2) or, respectively, relative to the object to be grasped, the control unit (14) being configured to perform a reconstruction of the three-dimensional point cloud (16) comprising the assembly of a plurality of three-dimensional point clouds (16) corresponding to a succession of acquisition of three-dimensional point clouds (16) by said at least one depth camera (15).

2. Bionic prosthesis (1) according to claim 1, forming a bionic prosthesis (1) of a lower limb, comprising: • a prosthetic foot (11) at a free end of the prosthesis bionic (1), adapted to come into contact with a terrain (2); • a prosthetic tibia (12); • at least one motorized articulation device (13), a first of said at least one motorized articulation device (13) being mechanically connected on the one hand to the prosthetic foot (11) and on the other hand to the prosthetic tibia (12); • a control unit (14) configured to control said at least one motorized articulation device (13) from control signals (3) corresponding to a movement intention;characterized in that the bionic prosthesis (1) comprises at least one depth camera (15) adapted to generate a three-dimensional point cloud (16) of the environment of the prosthetic foot (11), comprising the terrain (2), the control unit (14) being configured to process the three-dimensional point cloud (16) in order to detect the terrain (2) and to control said at least one motorized articulation device (13) so as to adapt the positioning of the prosthetic foot (11) relative to the terrain (2).;

3. Bionic prosthesis (1) according to the preceding claim, characterized in that said at least one depth camera (15) consists of two depth cameras configured so as to cover respectively a front field and a rear field of the environment of the prosthetic foot (11).

4. Bionic prosthesis (1) according to any one of the preceding claims, characterized in that it comprises a myoelectric sensor system configured to generate the control signals (3) corresponding to a movement intention.

5. Bionic prosthesis (1) according to any one of the preceding claims combined with claim 2, the prosthetic foot (11) having a directional vector of the foot (111) oriented substantially in a longitudinal direction of the prosthetic foot (11), characterized in that it comprises a set of accelerometers capable of measuring the directional vector of the foot (111).

6. Bionic prosthesis (1) according to any one of the preceding claims combined with claim 2, characterized in that it comprises a prosthetic femur, said at least one device motorized articulation device (13) comprising a second motorized articulation device being mechanically connected on the one hand to the prosthetic tibia (12) and on the other hand to the prosthetic femur.

7. Method for controlling a bionic prosthesis (1) of a lower or upper limb comprising a prosthetic distal segment of the lower or upper limb, in other words a prosthetic foot (11) or, respectively, a prosthetic hand, configured to come into contact with a terrain (2) or, respectively, with an object to be grasped; a prosthetic middle segment, in other words a prosthetic tibia (12) or, respectively, a prosthetic forearm; optionally a prosthetic proximal segment, in other words a prosthetic femur or, respectively, a prosthetic arm; at least one motorized articulation device (13); a control unit (14) configured to control the motorized articulation device (13);at least one depth camera (15) adapted to generate a three-dimensional point cloud (16) of the environment of the bionic prosthesis (1) comprising the terrain (2) or, respectively, the object to be grasped, the method, following an instruction (3) corresponding to a movement intention, comprising:; • the measurement (El) of the current state (17) of the bionic prosthesis (1), comprising the measurement of directional vectors of the distal prosthetic segment, of the middle prosthetic segment, and where appropriate of the proximal prosthetic segment by a set of accelerometers; • the acquisition (E2) by said at least one depth camera (15) of a three-dimensional point cloud (16) of the environment of the bionic prosthesis (1); • a step of reconstruction (E31, E41) of the three-dimensional point cloud (16) comprising the assembly of a plurality of three-dimensional point clouds (16) corresponding to a succession of acquisition of three-dimensional point clouds (16) by said at least one depth camera (15); • processing of the three-dimensional point cloud (16) by the control unit (14); • the calculation (E5) by the control unit (14) of the movements to be implemented by said at least one motorized articulation device (13); • the setting in motion (E6) of the bionic prosthesis (1).

8. Method for controlling a bionic prosthesis (1) according to the preceding claim, suitable for a lower limb bionic prosthesis comprising a prosthetic foot (11) configured to come into contact with a terrain (2), a prosthetic tibia (12), at least one motorized articulation device (13), a control unit (14) configured to control the motorized articulation device (13), at least one depth camera (15) suitable for generating a three-dimensional point cloud (16) of the environment of the bionic prosthesis (1) comprising the terrain (2), the method, following an instruction (3) corresponding to a movement intention, comprising: • the measurement (El) of the current state (17) of the bionic prosthesis (1), comprising the measurement of a directional vector of the foot (111) oriented substantially in a longitudinal direction of the prosthetic foot (11) by a set of accelerometers; • the acquisition (E2) by said at least one depth camera (15) of the three-dimensional point cloud (16) of the environment of the bionic prosthesis (1); • the processing of the three-dimensional point cloud (16) by the control unit (14) comprising the extraction (E32) of a set of points from the three-dimensional point cloud (16) corresponding to the terrain (2), the step of reconstruction (E31) of the three-dimensional point cloud (16), and the calculation of the normal (E34) to a surface defined by said set of points, designated normal to the terrain; • the calculation (E5) by the control unit (14) of the movements to be implemented by said at least one motorized articulation device (13) so that the directional vector of the foot (111) is substantially perpendicular to the normal to the terrain; • the setting in motion (E6) of the bionic prosthesis (1).

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