Portable device for upper limb rehabilitation
The invention refers to a portable device ( 100 ) for upper limb ( 2, 3 ) rehabilitation which is movable over a surface, usually a flat horizontal surface, and which comprises means for detecting an intention to move from the user ( 1 ), thereby providing assistance/resistance to perform the right movement just when needed, especially when the goal movement is non-deterministic. Additionally, the portable device ( 100 ) of the invention comprises a support structure for the forearm of a user (which can be similar to an armrest) which is pivotable, preferably in a direction of the rotational joint of elbow (it pivots vertically around a horizontal axis), thereby allowing free ergonomic elbow and shoulder flexion/extension, but restricting shoulder rotation, which is determined by the orientation of the device in order to avoid injuries. The invention further refers to a method for rehabilitating an upper limb ( 2, 3 ) of a user ( 1 ), and to a rehabilitation system for an upper limb ( 2, 3 ) of a user ( 1 ), comprising such portable device ( 100 ).
1. A portable device for rehabilitating an upper limb of a user, the portable device comprising:
a support movable over a surface
means for moving the support over the surface;
a first support structure for supporting a forearm of the user;
monitoring means for monitoring the movement of the support;
a second support structure wherein the first support structure is coupled to the second support structure by means of a first joint having one rotational degree of freedom, the second support structure being coupled to the support by means of a second joint having three rotational degrees of freedom;
a force sensing means for sensing a force exercised by an arm of the user on the support;
angle sensor means for measuring an angle of inclination of the first support structure with respect to the second support structure; and
processing means for detecting movement intention of the user based on the force measured by the force sensing means and on the angle of the first support structure.
2. The portable device of claim 1 wherein the one rotational degree of freedom of the first joint is pitch.
3. The portable device of claim 1 wherein the first support structure comprises first fastening means for fastening at least the forearm of a user.
4. The portable device of claim 3 wherein the first support structure further comprises second fastening means for fastening a wrist or a hand of the user, the first and second fastening means being located at separate points on the first support structure which define a first direction.
5. The portable device of claim 4 wherein the force sensing means comprises at least two load cells, wherein the at least two load cells are placed on the second support structure parallel to the first direction.
6. The portable device of claim 4 wherein the force sensing means comprises at least two load cells, wherein the at least two load cells are placed on the support symmetrically from a plane parallel to the first direction and which contains the first and second fastening means.
7. The portable device of claim 1 wherein the force sensing means are located between the second support structure and the support.
8. The portable device of claim 1 wherein the force sensing means comprises at least two load cells.
9. The portable device of claim 1 wherein the angle sensor means comprise a potentiometer mounted on the first joint.
10. The portable device of claim 1 wherein the processing means for detecting a movement intention of the user are configured to determine an intention of the user to move in a first direction and in one sense or the opposite within that first direction based on a value of the angle of the first support structure and its sign, respectively, as provided by the angle sensor means.
11. The portable device of claim 10 wherein the processing means for detecting a movement intention of the user are configured to determine an intention of the user to move in a first direction based on the angle of the first support structure and on the force measured by the force sensing means when the angle of the first support structure is above a pre-established value.
12. The portable device of claim 10 wherein the processing means are configured to produce an intention vector which defines a direction of the user's movement intention based on the intention of the user to move in the first direction and on the intention of the user to move in a second direction and on the position and orientation of the portable device on the surface provided by the monitoring means.
13. The portable device of claim 1 wherein the processing means for detecting a movement intention of the user are configured to determine an intention of the user to move in a second direction based on the force measured by the force sensing means.
14. A method for rehabilitating an upper limb of a user, the method comprising:
attaching at least a portion the upper limb of the user to the portable device defined in claim 1 ;
monitoring the movement of the support;
measuring a force exercised by the upper limb of the user on the support;
measuring an angle of inclination of the first support structure with respect to the second support structure; and
detecting a movement intention of the user based on the force measured by the force sensing means and on the angle of the first support structure.
15. A rehabilitation system for an upper limb of a user, comprising:
the portable device of claim 1 ;
a remote control and visualization unit; and
a training and assessment unit, which is configured to provide a training session; wherein the training and assessment unit is configured to determine a target position and orientation of the upper limb of the user based on an intention vector provided by the processing means and a set of possible target positions of the training session.