End-effector type quad-arm robot system

Abstract

End-effector type quad-arm robot system for unilateral upper limb movement rehabilitation, comprising: a pedestal (1) with moving devices; a wheelchair docking platform (2) that can be folded down from the pedestal (1); a desk (3) connected to the wheelchair docking platform (2) in a detachable manner; a first robot arm (4a) mounted on the pedestal (1), and to which an elbow orthosis (5a) is connected for moving the elbow and shoulder girdle; a second robot arm (4b) mounted on the pedestal (1) or the first robot arm (4a), and to which a hand orthosis (5b) is connected for moving the hand and wrist; characterised in that it further comprises: a third robot arm (4c) mounted on the second robot arm (4b), and to which a thumb orthosis (5c) is connected for moving the thumb; a fourth robot arm (4d) mounted on the second robot arm (4b), and to which a finger orthosis (5d) is connected for moving the index finger, middle finger, ring finger and little finger.

Description

[0001] End-effector type quad-arm robot system

[0002] Field of the invention

[0003] The present invention relates to an end-effector type quadarm robot system, in particular for unilateral upper limb rehabilitation .

[0004] State of the art

[0005] For three decades, rehabilitation robots have been assisting physiotherapists with the physically demanding, highly repetitive tasks of movement therapy in neurorehabilitation. There are several types of rehabilitation robots, depending on which part of the body needs to be moved, whether we are in the acute, subacute or chronic phase of rehabilitation, and whether the robot is end-effector or exoskeleton-based. In connection with the present invention, we review the state of the art in end-effector type robot systems for unilateral upper limb movement rehabilitation.

[0006] The patent document WO2015048688A1 describes an end-effector type unilateral upper limb rehabilitation robot system that uses a robot arm with multiple degrees of freedom to move the upper limb . In the preferred embodiment, the robot arm is connected to the patient ' s forearm. The robot system comprises the following: a pedestal and an end-effector type robot arm. Of the anatomical joints of the upper limbs, the system moves the shoulder and the elbow.

[0007] The patent document CN107595547A describes an end-effector type unilateral upper limb rehabilitation robot system thatuses two robot arms with multiple degrees of freedom to move the upper limb . The robot arms are supported by a pedestal . The robot arms are connected to the treated body parts in the figure showing the preferred embodiment : the forearm and upper arm. Of the anatomical joints of the upper limbs, the system moves the shoulder and the elbow.

[0008] The patent document W02020098109A1 describes an end-effector type unilateral upper limb rehabilitation robot system that uses two robot arms with multiple degrees of freedom to move the upper limb . The pedestal supporting the robot arms is movable and convertible; therefore, the installation position of the robot arms is adjustable . The robot arms are connected to the treated body parts in the figure showing the preferred embodiment : the hand and upper arm. A game synchronised with the movement of the upper limb, displayed on a screen, is used for interaction with the patient . Of the anatomical joints of the upper limbs, the system moves the shoulder and the elbow.

[0009] The patent document WO2022257073A1 describes an end-effector type unilateral upper limb rehabilitation robot system that uses two robot arms with multiple degrees of freedom to move the upper limb . The robots are loosely connected to the treated body parts in the figure showing the preferred embodiment : the hand and upper arm, which the inventors consider useful in avoiding overdetermination. A master communication unit is used to interact with the patient . Of the anatomical joints of the upper limbs, the system moves the shoulder and the elbow.

[0010] Regardless of the number of built-in robot arms, the common disadvantage of end-effector type unilateral upper limb rehabilitation robot systems, according to the current stateof the art, is that they do not move all the anatomical joints of the upper limb simultaneously; thus, they cannot control the entire movement of the treated upper limb with all its degrees of freedom.

[0011] The present invention aims to eliminate the disadvantages of known solutions by creating a unilateral upper limb endeffector type robot system that can move the upper limb in all degrees of freedom.

[0012] The present invention is based on the recognition that by synchronously moving the anatomical joints of the shoulder girdle, elbow, forearm, wrist and fingers, full movement of the upper limb with all degrees of freedom can be achieved during rehabilitation treatment . The invention enables patient-robot interaction with real obj ects and in a physical environment, in addition to computer-based solutions .

[0013] In light of the above, the present invention relates to an end-effector type quad-arm robot system, which comprises : pedestal with moving devices;

[0014] a wheelchair docking platform that can be folded down from the pedestal ;

[0015] a desk connected to the wheelchair docking platform in a detachable manner;

[0016] a first robot arm mounted on the pedestal, and to which an elbow orthosis is connected for moving the elbow and shoulder girdle ;

[0017] a second robot arm mounted on the pedestal or on the first robot arm, and to which a hand orthosis is connected for moving the hand and wrist; characterised in that it further comprises :a third robot arm mounted on the second robot arm, and to which a thumb orthosis is connected for moving the thumb;

[0018] a fourth robot arm mounted on the second robot arm, and to which a finger orthosis is connected for moving the index finger, middle finger, ring finger and little finger .

[0019] The preferred example embodiments of the end-effector type quad-arm robot system are defined in the sub-claims .

[0020] The invention will be described in detail below based on the accompanying figures, which show an advantageous embodiment of the end-effector type quad-arm robot system according to the invention .

[0021] In the figures

[0022] Figure 1 shows a perspective view of an advantageous embodiment of the quad-arm robot system according to the invention;

[0023] Figure 2 shows the possible movement of the hand moved by the quad-arm robot system according to the invention;

[0024] Figure 3 shows the connection of the orthoses of the quad-arm robot system according to the invention and the location of the first plane in which the third robot arm 4c moves during movement, and the second plane in which the fourth robot arm 4d moves during movement;

[0025] Figure 4 shows the drinking from glass movement exercise performed with the quad-arm robot system according to the invention;

[0026] Figure 5 shows the combing movement exercise performed with the quad-arm robot system according to the invention;

[0027] Figure 6 shows the movement exercise of placing a book on a shelf performed with the quad-arm robot system according to the invention;Figures 7a and 7b show the movement exercise of placing a basket onto the lap performed with the quad-arm robot system according to the invention;

[0028] Figure 8 shows the movement exercise of moving a bottle performed with the quad-arm robot system according to the invention;

[0029] Figure 9 shows the movement exercise of picking up the telephone and lifting it to the ear performed with the quadarm robot system according to the invention;

[0030] Figure 10 shows a movement exercise of pressing the door handle and opening and closing the door performed with the quad-arm robot system according to the invention;

[0031] Figure 11 shows the finger orthosis according to the invention.

[0032] Figure 1 shows a quad-arm robot system comprising a pedestal 1, a wheelchair docking platform 2, a desk 3, a first robot arm 4a, a second robot arm 4b, a third robot arm 4c and a fourth robot arm 4d, and orthoses connected to each robot arm.

[0033] The role of the pedestal 1 is to support the robot system, including the first robot arm 4a and the second robot arm 4b, which are connected to the pedestal 1 . In addition, the wheelchair docking platform 2 is also connected to the pedestal 1. The pedestal 1 is designed as a rigid frame box that contains the control and electronic components of the robot arms . Moreover, it has lockable moving devices that ensure easy movement of pedestal 1 and its immobility when placed in the right place . Such moving devices include, for example, heavy-duty levelling caster wheels for easy movement .The wheelchair docking platform 2 is an element that can be folded down from the pedestal 1 to hold the wheelchair and the patient sitting in the wheelchair in place . The wheelchair docking platform 2 is a flat surface that can be folded up and down. It includes bumpers to position the wheelchair wheels . Depending on which upper limb is affected, a right-side or left-side wheelchair docking platform 2 can be used to connect the robot arms .

[0034] Desk 3 is a desk with a flat support surface that contains a computer display. The role of desk 3 is to provide a control surface for the therapist and to show the exercises to be performed, indicating the location of the obj ects to be placed during each exercise for the patient . Desk 3 is connected to the wheelchair docking platform 2 in a detachable manner when the wheelchair docking platform 2 is in the folded-down position. The wheelchair docking platform 2 is positioned so that a patient seated in a wheelchair can comfortably access the desk 3. Desk 3 is also connected to the pedestal 1 in a rotatable manner, for example by means of a multi-joint mechanism, so that its position can be adjusted, allowing the same desk 3 to be adjusted to both the right-side and leftside wheelchair docking platform 2. Of course, we do not rule out the possibility that desk 3 is not adjustable, but is set in only one direction, can be removed from the system and can be connected to either of the two wheelchair docking platforms 2, once to the right-side wheelchair docking platform and once to the left-side wheelchair docking platform.

[0035] The first robot arm 4a is a robot arm connected to the pedestal 1, and to which an elbow orthosis 5a is connected. The first robot arm 4a is designed to move the elbow and, through it,the shoulder girdle, and therefore has at least six degrees of freedom. Depending on its design, the elbow orthosis 5a can be connected to the patient ' s elbow, the forearm near the elbow and / or the upper arm near the elbow.

[0036] The second robot arm 4b, similar to the first robot arm 4a, is connected to the pedestal 1. The second robot arm 4b is connected to the dorsal side of the patient ' s hand via a hand orthosis 5b, to move the patient ' s hand and, through it, the wrist . The second robot arm 4b has at least six degrees of freedom. Figure 2 shows a possible path of the hand of the upper limb moved by the second robot arm 4b .

[0037] The third and fourth robot arms 4c, 4d are connected to the second robot arm 4b . A thumb orthosis 5c is connected to the third robot arm 4c, through which it can be attached to the patient ' s thumb to move the patient ' s thumb . The thumb orthosis 5c is preferably attached to the nail, ensuring comfortable wear and providing sufficient space for the distal phalanx of the thumb to move . However, we do not rule out solutions in which the thumb orthosis 5c is connected to a part of the thumb other than the nail . The third robot arm 4c has at least five degrees of freedom.

[0038] The fourth robot arm 4d is connected to a finger orthosis 5d, which can be attached to the patient ' s index-, middle-, ring-, and little fingers, allowing the fourth robot arm 4d to move these fingers . In a possible embodiment of the fourth robot arm 4d shown in Figure 11, the finger orthosis 5d is connected to the middle finger and to the index and ring fingers by a flexible element, such as a polymer plate 51. Due to the different anatomical dimensions of the little finger, it ispreferably connected to the ring finger by a flexible strip so that it can follow the movement of the ring finger in a natural manner . The fourth robot arm 4d has at least three degrees of freedom. A possible embodiment of the invention is shown in Figure 3, where the third robot arm 4c moves in the first plane 6 and the fourth robot arm 4d moves in the second plane 7 during movement .

[0039] The various orthoses are available in right- and left-sided versions and can be manufactured to the individual dimensions of the patient . The orthoses, for example, can be 3D-printed from measurements taken from the given body part . A major advantage of this production method is that it does not require Velcro fasteners, which pose risks to patients .

[0040] Knowledge of robot arms is part of the mandatory knowledge of a person skilled in the art; unless otherwise specified, the robot arms are of conventional design.

[0041] The end-effector type quad-arm robot system according to the invention naturally also has other parts that are obvious to the person skilled in the art . These include, for example, the computer control system located in pedestal 1, robot controllers, an isolation transformer, safety systems, displacement sensors, and force / torque sensors in the robot arms . The quad-arm robot system also includes a data communication device and control devices, which are obvious to the person skilled in the art, so we will not describe them in detail .

[0042] The quad-arm robot system performs free passive movement exercises within the anatomical joint range of motion of thetreated left or right upper limb, as well as executing active functional movement exercises, including obj ect grasping and manipulation. The end-effector type quad-arm robot system can be used effectively in the neurorehabilitation of patients in the acute, subacute and chronic stages of stroke and other neuromotor impairments .

[0043] In the context of the present invention, an end-effector type robot system is understood to be a robot system that has at least three degrees of freedom, containing manipulators with serial, parallel or hybrid kinematics and a degree of autonomy, the manipulators further including elementary kinematic pairs, e . g. a revolute pair, a prismatic pair, a screw pair, a cylindrical pair moving in a hole or a spherical pair . Endeffector type robot systems do not conform to the shape, kinematic structure or size of the moved limb; they are typically located at a distance from it . Furthermore, endeffector type robot systems have one or more structures for mechanical connection to the moved body part, point-like or on a surface that is negligible in size compared to the body part .

[0044] We maintain the coordination between the four robot arms using master-slave and admittance controllers, thus achieving natural movement of the upper limb on one side of the patient in the five anatomical joints of the shoulder girdle, one in the elbow, one in the forearm, two in the wrist, four in the thumb, and twelve in the index, middle, ring and little fingers .

[0045] We use the quad-arm robot system in physiotherapy to help patients, who have suffered a stroke or other neuromotor damage, relearn movement . The patient is placed in awheelchair, which is then pushed onto the wheelchair docking platform 2 until the front wheels collide with the bumpers . The wheelchair is fixed on the wheelchair docking platform 2 by using its brake . Then, desk 3 is pushed onto the wheelchair docking platform 2 and attached to it . This ensures the patient can be placed in the same position during subsequent treatments, facilitating the execution of exercises tailored to the individual .

[0046] Next, we connect the first robot arm 4a to the patient ' s elbow via the elbow orthosis 5a, preferably on the dorsal side (as shown in Figure 3) , the second robot arm 4b is connected to the patient ' s hand via the hand orthosis 5b, preferably on the dorsal side (as shown in Figure 3) , the third robot arm 4c is connected to the dorsal part of the distal phalanx of the patient ' s thumb, preferably to the nail, via the thumb orthosis 5c (as shown in Figure 3) , the fourth robot arm 4d is connected to the index, middle and ring fingers via the finger orthosis 5d (as shown in Figure 3) , preferably to the dorsal part of the middle phalanx of the middle finger, and is also connected to the index and ring fingers using a polymer plate 51. The little finger is indirectly connected to the finger orthosis 5d via a rubber band connected to the ring finger . Of course, we do not rule out the use of other orthosis designs and connections .

[0047] The angle enclosed by the third robot arm 4c and the fourth robot arm 4d was determined by having a 5th percentile female and a 95th percentile male volunteer perform obj ect-grasping experiments . In the experiment, the volunteer' s hand and the base of the fourth robot arm 4d were fixed to a stand. The third robot arm 4c was connected to a robot with six degreesof freedom, which could move it arbitrarily within a range of 49 degrees and 42 degrees around each coordinate axis of the thumb orthosis ' s 5d coordinate system. The motion angle range was determined by paying attention to avoid collisions between the hand, three obj ects that differed significantly in shape or size (a glass, a hairbrush, and a book) , the desk, and the robot system. Across 252 experiments, volunteers rated the movement ergonomics of opening and closing the thumb, the reliability and comfort of obj ect grasping, and the avoidance of collisions on a 5-point Likert scale . After processing the results, we determined that the ideal configuration occurs when the first plane 6 of the third robot arm 4c forms a 137-degree angle with the second plane 7 of the fourth robot arm 4d, as shown in Figure 11.

[0048] If a quad-arm robot system set up for the left side needs to be connected to the right upper limb, it can be conveniently repositioned. Figure 1 shows that the quad-arm robot system configured for a patient with left hemiplegia . This can be seen in the robot arms being on the left side of the wheelchair, i . e . they are set up for a person with paralysis on the left side . It belongs to the knowledge of a person skilled in robotics that with the use of tool changers the third robot arm 4c can be easily exchanged between the right-and left-side positions when connected to the second robot arm 4b .

[0049] If the third robot arm 4c, which has more degrees of freedom than the fourth robot arm 4d can perform the movement tasks of the fourth robot arm 4d, and the second robot arm 4b has the necessary movement capability characterised by the increased rotation range of the kinematic pairs, then it is advantageousto use a second copy of the third robot arm 4c instead of the fourth robot arm 4d. In this case, there is no need to switch between the left and right tool changers of the third robot arm 4c, instead, the two third robot arms 4c can preferably be permanently mounted on the second robot arm 4b . By motorised rotation of the second robot arm 4b 137 degrees as described above, it can achieve a role reversal between the third robot arms 4c . The third robot arm 4c, that moved the thumb of one hand before the 137-degree rotation, then moves the index, middle, ring and little fingers of the other hand after the rotation, and vice versa . A person skilled in robotics shall use their knowledge to design the connector of the thumb orthosis 5c and the connector of the finger orthosis 5d so that they can be connected to any of the third robot arms 4c, playing any role .

[0050] After connecting the quad-arm robot system to the patient, the patient can learn the movement exercises by executing them with the quad-arm robot system using the display integrated into the desk 3. Such movement exercises include, for example, seven functional movements carefully selected from the daily activities of eating, personal hygiene, communication, transportation and shopping, which are preferably practised with real obj ects : a) drinking from a glass (Figure 4 ) , b) combing hair with a hairbrush (Figure 5) , c) placing a book on a shelf (Figure 6) , d) placing a bag / basket onto the lap (Figures 7a and 7b) , e) moving a bottle (Figure 8 ) , f ) picking up the telephone and lifting it to the ear (Figure 9) , g) pressing the door handle and opening / closing the door (Figure

Claims

Claims1. End-effector type quad-arm robot system for unilateral upper limb movement rehabilitation, comprising:a pedestal ( 1 ) with moving devices;a wheelchair docking platform (2 ) that can be folded down from the pedestal ( 1 ) ;a desk (3) connected to the wheelchair docking platform (2 ) in a detachable manner;a first robot arm (4a) mounted on the pedestal ( 1 ) , and to which an elbow orthosis (5a) is connected for moving the elbow and shoulder girdle;a second robot arm (4b) mounted on the pedestal ( 1 ) or the first robot arm (4a) , and to which a hand orthosis (5b) is connected for moving the hand and wrist; characterised in that it further comprises : a third robot arm (4c) mounted on the second robot arm (4b) , and to which a thumb orthosis (5c) is connected for moving the thumb;a fourth robot arm (4d) mounted on the second robot arm (4b) , and to which a finger orthosis (5d) is connected for moving the index finger, middle finger, ring finger and little finger .

2. Quad-arm robot system according to claim 1, characterised in that the first robot arm (4a) mounted on the pedestal ( 1 ) has at least six degrees of freedom.

3. Quad-arm robot system according to any of the preceding claims, characterised in that the second robot arm (4b) mounted on the pedestal ( 1 ) has at least six degrees of freedom.

4. Quad-arm robot system according to any of the preceding claims, characterised in that the third robot arm (4c)has at least five degrees of freedom.

5. Quad-arm robot system according to any of the preceding claims, characterised in that the fourth robot arm (4d) has at least three degrees of freedom.

6. Quad-arm robot system according to any of the preceding claims, characterised in that the desk (3) is connected to the pedestal ( 1 ) by a multi-joint mechanism.

7. Quad-arm robot system according to any of the preceding claims, characterised in that the desktop of the desk (3) comprises a computer display.

8. Quad-arm robot system according to any of the preceding claims, characterised in that the third robot arm ( 4c) is connected to the second robot arm (4b) in a detachable manner with a right-side or left-side position.

9. Quad-arm robot system according to any of claims 1 to 7, characterised in that the fourth robot arm (4d) has at least five degrees of freedom and is connected to the second robot arm (4b) .

10. End-effector type quad-arm robot system according to claim 1, characterised in that the first plane ( 6) of the third robot arm (4c) and the second plane (7 ) of the fourth robot arm (4d) form an angle of 137 ° ±5° .

11. Method by using the end-effector type quad-arm robot system according to any of the preceding claims, comprising the following steps :a) placing a patient in a wheelchair on the wheelchair docking platform (2 ) and fixing its position relative to the desk ( 3 ) ;b) the elbow orthosis (5a) connected to the first robot arm (4a) is attached to the patient ' s elbow or the area above / below the elbow;c) the hand orthosis (5b) connected to the second robotarm (4b) is attached to the dorsal part of the patient ' s hand;d) the thumb orthosis (5c) connected to the third robot arm (4c) is attached to the dorsal part of the distal phalanx of the patient' s thumb .e) the finger orthosis (5d) connected to the fourth robot arm (4d) is attached to the dorsal part of the middle phalanx of the patient ' s middle finger, which is also attached to the index finger and ring finger, and the little finger is connected to the ring finger with a rubber band;f ) free movement exercises are performed with the patient using the robot arms .

12. Method according to claim 11, wherein in step f ) at least some of the movement exercises involving grasping, moving and placing the following real obj ects are performed :drinking from a glass, combing hair with a hairbrush, placing a book on a shelf, placing a bag / basket onto the lap, moving a bottle, picking up the telephone and lifting it to the ear, pressing the door handle and opening / closing the door .

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