Abstract:
An upper body exoskeleton system or an orthotic device intended for patients with severe spinal cord injury (quadriplegia) which allows them with the ability to sit from a lying posture and vice versa on their own. This system composes of a chain of plate’s mechanism covering the back of patient/subject at different regions of the spine with 3 passive hinge joints between each plate junction (linkage between two plates). The axis of rotation for one joint is parallel to medio-lateral axis and two of the others have axis parallel to the antero-posterior axis. This provides each plate with a motion capability of 2 Degree of freedom (DOF) i.e. rotation along medio-lateral axis and restricted rotation at antero-posterior axis. Outfitting the system to give patient an ability to sit from a laying posture and conversely while providing spine with the flexibility (frontal plane) in the form of rotation along sagittal axis.
The actuation of the system is achieved through using two similar lead screw mechanisms positioned lateral to the abovementioned passive assembly. These lead screw mechanisms comprise of a rotating bar each with an axis parallel and lateral to the joint axis between hip section and L1(first lumber vertebra) that is actuated by the lead screw. Each bar is connected to the lateral ends of the top plate mechanically.
Hence, the passive assembly is within a rectangular frame consisting of active components (actuation mechanism) of the assembly located at the side of the frame, parallel to the torso. The top side of the fame is an angle iron (ALU) connecting the two actuator sides to fixate the frame while the lower side is made of aluminum plate which pivots the passive assembly at the bottom most plate of the passive assembly, through a hinge joint.
