EP2535032B1

EP2535032B1 - Suitable apparatus for the rehabilitation therapy of patients with brain damage

Info

Publication number: EP2535032B1
Application number: EP20110382194
Authority: EP
Inventors: Manuel Menchon Bofill; Elena Sanchez Duran; José María Sabater Navarro; Nicolás Garcia Aracil; Carlos Perez Vidal; José María Azorin Poveda; Eduardo Fernandez Jover
Original assignee: Alboaires SA
Current assignee: Alboaires SA
Priority date: 2011-06-13
Filing date: 2011-06-13
Publication date: 2015-04-22
Anticipated expiration: 2031-06-13
Also published as: EP2535032A1

Description

Object of the Invention

The present invention relates to a device or apparatus for aiding in the rehabilitation treatment of patients with brain damage.

Background of the Invention

Patients with brain damage whose consciousness or intellectual response capacity is affected also have physical disabilities because the brain is the organ responsible for coordinating the movements of the different limbs of the human body.
In most cases, these physical disabilities do not correspond with damage in the affected limb but rather it is the brain that is damaged and is not capable of suitably coordinating movement.
The brain is capable of sending signals to the muscles to perform a particular movement and in turn to learn increasingly more complex movements through the manner in which the senses perceive the movement that has actually occurred. This feedback phenomenon is a complex mechanism. The brain emits a command to the muscle through the motor pathways and peripheral nerves to perform a certain movement. There are many muscles involved in this movement and in most cases such movements must be done by following a certain sequence and each of them is done by applying a different intensity. The brain is capable of assessing corrections in the way of giving commands and thus making the movement with which the body responds similar to the target movement in the brain. These corrections are evaluated through the perception that the brain receives as to how the movement has actually been produced.
When the brain suffers some type of damage, some of the intermediate steps mentioned above may fail. In these cases, it is necessary to apply therapies based on repetitive exercises which typically require a great deal of time of each patient. If for example the patient only perceives a small percentage of the sensations produced by his own movement, then learning is less but the therapeutic task takes advantage of the few resources that the damaged brain has to enhance them.
Therapeutic exercises are exercises in which the patient performs a movement requiring a certain degree of coordination and which require the help of another.
Robots and devices responsible for helping in this therapeutic task are known, such as that described in Spanish patent with publication number ES2338623 where the patient remains stretched out on a hospital-type bed and two independent robot arms act on the patient in order to help him perform the repetitive exercises.
A first robot arm moves down from the ceiling and reaches the patient's hand through several mechanical connections. The patent describes the use of several redundant degrees of freedom so that one and the same final position of the robot arm holding the arm of the patient can be reached by means of different intermediate positions of the first robot arm. The redundancy, i.e., being able to adopt different intermediate positions of the mechanical connections for one and the same end position, allows the therapist to help the patient and move the first robot arm so that it does not get in the way of him working with the patient and to do this such that he continues to hold the hand of the patient in the suitable position and orientation.
It is important for the robot to have a force that can be easily overcome by the patient. The movement the robot follows is thereby a movement which serves as a guide and can be easily altered by the patient if he forces a different trajectory. The reason for this feature is evident. A patient with brain damage may have an inhibited perception of movement or feeling in one of his limbs. A forced movement could hurt the patient and he would not realize or even say that he is being hurt.
In order to achieve this, the aforementioned patent describes the use of artificial muscles offering this type of behavior.
The movement of the arm of the patient cannot be guided just by means of a single support point on the hand or wrist of the patient but a second and also guided support point which is fixed at the elbow or in a region close to the elbow is necessary.
The aforementioned patent with publication number ES2338623 incorporates an arm arranged on a side of the hospital-type bed that the patient is laying on. This second arm must have a movement coordinated with that of the first robot arm.
The most effective type of movement for therapy to work on the coordination of the hand and the arm of the patient consists of a trajectory of the arm starting from a position virtually extended along the length of his body and located on the same side. The movement of the hand or wrist of the patient corresponds to a trajectory ending at or approaching the opposite shoulder. This movement must be performed with extended elbow and also with a trajectory which approaches the one followed by the hand. This second trajectory of the elbow must be guided by a second robot arm.
Even though the elbow does not reach the opposite shoulder, the movement of the elbow requires a considerable shift from its side of the hospital-type bed towards the opposite side.
The second robot arm described in the aforementioned patent with publication number ES2338623 has several drawbacks. The first drawback is that the second robot arm is linked to the hospital-type bed. The hospital-type bed is part of the device intended for therapy. For example, this device is not suitable for a person who must remain in a wheelchair. Though it is not obligatory for this patient to remain in the chair, he will always have to get up and get on the hospital-type bed to receive therapy as he cannot receive therapy in the wheelchair itself.
A second drawback of this second arm is that it has a cartesian configuration where one of the shifts is longitudinal along the length of the hospital-type bed. This movement is achieved because the hospital-type bed has a guide on one side allowing the arm to be shifted in this direction. This Cartesian movement is insufficient and in practice the results show that the described configuration does not allow reaching the entire range required by the possible movements of the elbow. This same configuration also prevents applying therapy to the two arms. To switch therapy to the other arm it is necessary to remove the anchor and install it on the other side of the hospital-type bed taking into account that the second robot arm does not have to be symmetrical to thus maintain an operating mode on the patient that is symmetrical. The other solution proposed in patent ES2338623 is to incorporate two arms, one on each side of the hospital-type bed "The closest prior art US 2008161733 discloses an apparatus suitable for one side rehabilitation. The apparatus comprises two arms which can act simultaneously on the patient. However, the movement achieved by the apparatus is a Cartesian movement and it is insufficient to reach all the movement of the elbow".
An object of this invention is to provide a single apparatus that overcomes all the aforementioned drawbacks. The present invention particularly allows applying therapy both to patients laying on a hospital-type bed and to patients in a wheelchair. The present invention further allows acting both on the right arm of the patient and on the left arm with one and the same second arm without having to duplicate devices or having to uninstall or reinstall a second arm.

Description of the Invention

The present invention as claimed comprises a suitable apparatus for the rehabilitation therapy of patients with brain damage comprising:

a base on which there is a first arm intended for holding and guiding the distal end of the arm of the patient,
a second arm on the same base for holding and guiding the elbow of the arm of the patient,
the base has an area intended for situating the patient.

With this basic configuration a base from which the two arms acting simultaneously on the patient emerge is provided, according to one embodiment one arm is lifted above the patient and serves to hold and guide the distal end of the arm of the patient; and the second arm simultaneously and in coordination with the first holds and guides the arm of the patient, mainly in the area close to the elbow.
The working area intended for situating the patient can be occupied by a hospital-type bed which is close to the base. This hospital-type bed does not have to be part of the apparatus and it is where the patient is situated, for example, laying down. In this case the head will be oriented towards the base.
Another possibility is for the patient to be in a wheelchair. In this case the back of the wheelchair is close to the base and the apparatus according to the invention acts on the patient by passing the first arm (of the apparatus) above the patient and the second arm (of the apparatus) on either side.
The invention is characterized in that this second arm has a rotating support such that the end of this rotating support can be arranged on either side of the area intended for situating the patient to allow access by means of the second arm to either side of the patient.
This special configuration of the second arm allows being able to access the patient on either side with a single arm and more easily guiding the arm of the patient. Additionally, it also allows the patient to be situated on a hospital-type bed or on a chair because the hospital-type bed does not have to be part of the base and therefore of the apparatus.
Those objects defined in dependent claims 2 to 13 as well as those resulting from the different dependencies are also considered to be incorporated in this description by reference.

Description of the Drawings

These and other features and advantages of the invention will be more clearly understood from the following detailed description of a preferred embodiment given only by way of illustrative and non-limiting example with reference to the attached drawings.

Figure 1 shows a general perspective view of an embodiment of the invention. This view shows the apparatus with the two arms on the base, a hospital-type bed with a patient receiving therapy and a monitor connected to a computer for aiding in therapy by means of virtual reality programs.
Figure 2 shows a partial detail of the first arm according to the previous embodiment.
Figure 3 shows a partial detail of the second arm together with the details of the actuators and their kinematic connections. The right side of the figure shows a perspective view of the arm and the way of fixing on the lower part of the base; and with two enlarged details the figure shows both the area of the ball joint and the area of the fixing intended for being attached to the elbow of the patient.
Figure 4 shows a schematic detail depicting the apparatus according to an embodiment in plan view and acting on a working area in which there is a patient receiving therapy.

Detailed Description of the Invention

Figure 1 shows an embodiment of the invention acting on a patient (P) according to what is shown in the diagram of Figure 4.
The patient (P) is being subjected to therapy consisting of the repetitive practice of an arm movement in which the trajectory of two relevant points is highlighted:

the distal end (P₁) of the arm of the patient (P) following a trajectory identified as M₁ and following an arc shifting from the side of the arm to the opposite shoulder; and,
the elbow (P₂) following a trajectory identified as M₂ and following an arc shifting with the tendency to follow the trajectory of the distal end (P₁) of the arm of the patient (P) as is also shown in Figure 4.

Both trajectories (M₁, M₂) must be coordinated either by a therapist or by making use of an apparatus such as the one of the invention by means of two mechanical arms collaborating in the movement. It is said that they "collaborate" because they exert a gentle force making the arm of the patient tend to follow the correct trajectory but it does not impose the trajectory in a forced manner and without any deviation so as to prevent damage to any joint, tendon or muscle of the patient (P).
In this embodiment the hospital-type bed is a support for the patient (P) that does not belong to the base (1.1) of the apparatus (1) on which the two main arms, the first arm (1.2) and the second arm (1.3), are fixed. The hospital-type bed can thereby be removed to bring in another patient who receives therapy, for example, in a wheelchair.
The first arm (1.2) is intended for guiding the arm of the patient (P) by the distal end (P₁). The distal end (P₁) can be the hand because the patient grips a support (S), or the wrist because the patient is incapable of holding an object and the first arm (1.2) is linked through some type of grip, for example a Velcro strap.
The second arm (1.3) is intended for guiding the elbow (P₂) in a manner coordinated with the distal end (P₁).
The diagram of Figure 4 shows two end positions of the rotating support (1.3.1) of the second arm (1.3) according to the embodiment. According to the embodiment, this rotating support (1.3.1) is an L-shaped tubular body emerging from the lower part of the base (1.1) raising up vertically and then extending horizontally. Due to the rotation according to a vertical shaft, this second horizontal section is located on either side of the patient. The two end positions have been identified as X₁ and X₂.
According to the particular configuration of both arms (1.2, 1.3), the elements making up said arms are described below.

The first arm (1.2)

The first arm (1.2) is made up of several sections kinematically connected from the base (1.1) to a support (S) intended for fixing the distal end (P₁) of the patient (P). The kinematics of this first arm (1.2) is characterized by the degrees of freedom in each connection and those chosen for this embodiment can be seen in greater detail in Figure 2.
The first section is a first rigid section (1.2.1) which is lifted above the area intended for situating the patient (P). Any point for working the distal end (P₁) of the arm of the patient (P) can be covered on this lifted position without interfering with the therapist's job and without hitting the patient (P).
A second projecting section (1.2.2) emerges from this first rigid section (1.2.1). According to this embodiment, this second projecting section (1.2.2) moves in a horizontal plane because it is linked to the rigid section (1.2.1) through a first vertical shaft (1.2.1.1). Figure 2 shows an actuator (A₃) which, like the remaining actuators (A₁, A₂, A₄, A₅), acts like an artificial muscle.
A second vertical section (1.2.3) emerges from the end of this first projecting section (1.2.2). This vertical section (1.2.3) is also linked with the projecting section (1.2.2) through a rotating articulation with a second rotation shaft (1.2.2.1) arranged vertically. The second vertical section (1.2.3) thereby switches the orientation of its lower end.
In this embodiment, between the lower end of the second vertical section (1.2.3) and the support (S) for the distal end (P₁) of the patient (P) there is an intermediate connection formed by a articulated parallelogram (1.2.4).
The articulated parallelogram (1.2.4) comprises 4 bars parallel to one another in sets of two. A first vertical bar is the lower portion of the second vertical section (1.2.3). In this lower portion there are two rotating attachment points from which two oblique parallel bars emerge. In the graphic depiction of Figure 2, since the second vertical section (1.2.3) is rotated, the two oblique bars are oriented towards the base, hence the upper part of the oblique bars is covering part of the projecting section (1.2.2).
These two oblique bars are attached through a third vertical section (1.2.5) which ends in the lower portion in the support (S) for the distal end (P₁) of the arm of the patient (P).
The attachment between the support (S) and the third vertical section (1.2.5) is by means of a rotating attachment allowing any orientation of the support (S).
As a result of the kinematics of the articulated parallelogram (1.2.4), this third vertical section (1.2.5) can be located at any height. A horizontal shaft (oblique according to the perspective in the drawing) emerging from the actuator (A₅) located in this articulation is shown in the lower part of the second vertical section (1.2.3). As Figure 2 is oriented, to the right of the actuator (A₅), the side opposite to where the articulated parallelogram (1.2.4) is located, there is a counterweight (1.2.4.1) integral with one of the oblique bars of the articulated parallelogram (1.2.4) which allows compensating for the weight of said parallelogram (1.2.4).
With this configuration, the first sections of the first arm (1.2) allow scanning the different points of the working plane, shown according to a plan projection in schematic Figure 4, where the trajectory to be described by the distal end (P₁) of the patient (P) extends. The last sections of the first arm (1.2) allow reaching any height on the same working plane, thereby generating the working range required for the correct application of the therapy.

The second arm (1.3)

A second arm (1.3) located on a rotating support (1.3.1) allowing this second arm (1.3) to reach the elbow (P₂) of the patient (P) either from his right or from his left side has been described in the description of the invention.
Figure 3 shows in detail the parts making up the second arm (1.3) according to one embodiment; nevertheless, Figure 4 shows several geometric aspects of relevance.
In the diagram of Figure 4, the patient (P) is laying on a hospital-type bed with the support (1.1) on his head. If instead of being in a hospital-type bed the patient were in a wheelchair then the support (1.1) of the apparatus (1) would be behind the patient (P).
In both cases, the movement would be very similar and could be aided by the two arms (1.2, 1.3) of the apparatus (1).
At the end of the rotating support (1.3.1) there is a ball joint (1.3.2) from which an axially extendable section (1.3.3) emerges. As described above, the diagram of Figure 4 particularly shows the trajectory (M₂) of the elbow and it is guided by the second arm (1.3).
The position of the shaft X₁ is the position in which the horizontal section of the rotating support (1.3.1) of the second arm (1.3) extends. This position is slightly oblique and allows locating the ball joint (1.3.2) at a point of the end of the rotating support (1.3.1) close to the places where the instant centers of rotation of the trajectory M₂ are located.
To pass the rotating support (1.3.1) of the second arm (1.3) from one side of the area where the patient (P) is located to the other side, for example from position X₁ to position X₂, the attachment of the rotating support (1.3.1) has a quick fixing which unlocks or locks the angular position of said rotating support (1.3.1) at will.
The ball joint (1.3.2) allows the rotation in the form of an arc imposed by trajectory (M₂) of the elbow (P₂) where this arc is projected in space in plan view in the diagram of Figure 4; and also a rotation to allow the end of the extendable section (1.3.3) to reach any height required by the elbow (P₂).
These two rotations (E₁, E₂) are shown in greater detail in Figure 3.
At the end of the rotating arm (1.3.1) there is a support with a vertical actuator (A₂) allowing the orientation according to a first vertical shaft (E₁) of a vertical rotating support (1.3.2.1). In this embodiment the vertical rotating support (1.3.2.1) has in its upper part two U-shaped arms at the upper ends of which there is rotatably anchored a support of the extendable section (1.3.2.2). The rotatable attachment between the vertical rotating support (1.3.2.1) and the support of the extendable section (1.3.2.2) is according to a vertical shaft (E₂).
This second rotational movement would be free were it not for the presence of another horizontal actuator (A₁). This other horizontal actuator (A₁) is also (like the aforementioned vertical actuator A₂) attached to the rotating support (1.3.1).
There is a rotating structure (G) in the shaft of the horizontal actuator (A₁) connected by means of a pivoting attachment (U) and it acts on the support (1.3.2.2) of the axially extendable section (1.3.3) at a point located above the vertical shaft (E₂) to allow lifting and lowering the axially extendable section (1.3.3). The rotation of the horizontal actuator (A₁) causes the rotation of the rotating structure (G). The rotation of the rotating structure (G) means that those points far from its rotation shaft experience a shift in a circular trajectory, particularly the pivoting attachment point (U). This point is arranged above both the shaft (E₃) of the horizontal actuator (A₁) and above the horizontal rotation shaft (E₂) of the support (1.3.2.2) of the extendable section (1.3.3). It must be noted that both shafts (E₂, E₃) are horizontal but different, hence the pivoting attachment (U) is a ball joint-type attachment to allow any relative orientation between the support (1.3.2.2) of the extendable section (1.3.3) and the rotating structure (G).
The shift of the point where the pivoting attachment (U) is located through the rotation of the horizontal actuator (A₁) means that the extendable arm (1.3.3) is lifted or lowered. Going back to the diagram of Figure 4, it shows a plan view of both direction X₁ in which the rotating support (1.3.3) extends and the perpendicular direction in plan view, drawing where the ball joint (1.3.2) from which the axially extendable section (1.3.3) emerges is located and identified with the symbol meaning "perpendicular".
Given that the horizontal shafts (E₂, E₃) of the horizontal actuator (A₁) and of the support (1.3.2.2) of the extendable section (1.3.3) are different, the lift force exerted by the horizontal actuator (A₁) will have a greater modulus value when the extendable arm (1.3.3) is extended in the direction perpendicular to the rotating support (1.3.1). If the extendable arm (1.3.3) is not located in a direction perpendicular to the rotating support (1.3.1), then the lift force will be less the farther away said direction is with respect to said perpendicular.
For that reason, direction X₁ is not perpendicular to the longitudinal shaft of the hospital-type bed but it has a certain angle which approaches the natural trajectory of the elbow (P₂).
The rotating structure (G) is shown in this embodiment as an arm (G.3) reaching a counterweight (G.1). The extension of the elements of the rotating structures is adjustable, as shown in the figure by means of a guide (G.2) and a setscrew (G.1.1). It should also be pointed out that the counterweight (G.1) acts in the preferred direction of action of the horizontal actuator (A₁) because it is located in the rotating structure (G) and exerts force in the same way as the horizontal actuator (A₁) does.
Finally, the extendable section (1.3.3) of the second arm (1.3) allows describing the curved trajectory (M₂) of the elbow (P₂) because the arc does not have to have all the instant centers of rotation where the ball joint (1.3.2) is located.
The detail of Figure 3 shows fixing means (1.3.4) for fixing the end of the axially extendable section (1.3.3) to the elbow (P₂).
Figure 1 shows a display (2) which can be oriented so that the patient (P) can see it. This display (2) can present images representing objects generated by means of virtual reality techniques and controlled by a processing unit. The processing unit collects the signals from different sensors arranged in the articulations of the apparatus (1) and is capable of knowing at all times the position and orientation of the distal ends of the first arm (1.2) and second arm (1.3).
The feedback generated in the brain of the patient (P) by the image of a graphically displayed object moved by his arm enhances the brain's learning and therefore the therapy to be applied.
Given that the apparatus (1) has sensors determining the position of each of the intermediate sections of the first arm (1.2) and of the second arm (1.3), one embodiment incorporates a movement learning program comprising the movement to be applied to the patient repetitively which is defined (learned by the apparatus (1)) with a training phase in which the arms (1.2, 1.3) of the apparatus (1) are moved manually following the trajectory to be repeated.

Claims

A suitable apparatus (1) for aiding in upper limb in one side the rehabilitation therapy of patients with brain damage comprising:
- a base (1.1) on which there is a first arm (1.2) intended for holding and guiding the distal end (P₁) of the arm of the patient (P),

- a second arm (1.3) on the same base (1.1) for holding and guiding the arm (P₂) of the patient (P),

- the base (1.1) has an area intended for situating the patient (P) wherein, this second arm (1.3) has a rotating support (1.3.1) such that the end of this rotating support (1.3.1) can be arranged on either side of the area intended for situating the patient (P) to allow access by means of the second arm (1.3) to either side of the patient (P), characterized

in that the second arm (1.3) has a ball joint (1.3.2) combining two independent angular rotations (E1, E2) and an axially extendable section (1.3.3) extends from this ball joint (1.3.2) until reaching fixing means (1.3.4) for being fixed to the elbow of the patient (P).
The apparatus according to claim 1, characterized in that a first rotation shaft of the two independent angular rotations (E1, E2) having the ball joint (1.3.2) is vertical (E₁) and the second rotation shaft is horizontal (E₂).
The apparatus according to claim 2, characterized in that the ball joint comprises two parts:
- a vertical rotating support (1.3.2.1) according to the vertical shaft (E1);

- a support (1.3.2.2) of the axially extendable section (1.3.3) where this support (1.3.2.2) is rotatably fixed on the vertical rotating support (1.3.2.1) according to the horizontal shaft (E₂).
The apparatus according to claim 3, characterized in that the ball joint (1.3.2) comprises:
- a vertical actuator (A₂) fixed on the rotating support (1.3.1) of the second arm (1.3) and acts on the vertical rotating support (1.3.2.1) of the ball joint (1.3.2),

- a horizontal actuator (A₁) fixed on the rotating support (1.3.1) of the second arm (1.3) and acting on the support (1.3.2.2) of the axially extendable section (1.3.3) at a point located above the horizontal shaft (E₂) by means of a rotating structures (G) connected by means of a pivoting attachment (U) to allow lifting and lowering the axially extendable section (1.3.3).
The apparatus according to claim 4, characterized in that the rotating structure (G) has a counterweight (G.1).
The apparatus according to claim 1, characterized in that the rotating support (1.3.1) is L-shaped with a first vertical section and a second horizontal section where the end of this horizontal section is intended for being located on either side of the patient (P).
The apparatus according to claim 1, characterized in that the first arm (1.2) comprises a first rigid section (1.2.1) which is lifted above the area intended for situating the patient (P) from which a projecting section (1.2.2) emerges and a second vertical section (1.2.3) in turn emerges from this projecting section (1.2.2), all of them being rotatably linked to one another according to vertical rotation shafts, and the last vertical section (1.2.3) reaching a support (S) through an intermediate connection for holding the distal end of the patient (P) where this final support (S) has the capacity for vertical shifting through the intermediate connection.
The apparatus according to claim 7, characterized in that the intermediate connection comprises a articulated parallelogram (1.2.4) with bars parallel to one another in sets of two, with two of them being vertical, at least a portion of the second vertical section (1.2.3) being one of these vertical bars.
The apparatus according to claim 1, characterized in that one or move movements of the articulations of the arms are actuated by means of preferably pneumatic artificial muscles.
The apparatus according to claim 1, characterized in that the articulations have position sensors.
The apparatus according to claim 10, characterized in that it comprises a processing unit suitable for learning a movement for its subsequent repeated execution.
The apparatus according to claims 10 and 11, characterized in that it comprises graphic display means controlled by the processing control unit such that they provide a virtual reality system coordinated with the movements detected by the position sensors for feeding back the learning processes of the rehabilitation treatment.