A Developmental Rehabilitation Robotic System for a Rat With Complete Thoracic Spinal Cord Injury in Quadruped Posture

Spinal cord injury (SCI) leads to the impairment of impulse conduction and subsequently to an abnormality of limbs function. To regain locomotor performance in SCI cases, we establish a robust combinatorial regenerative and rehabilitative approach to enhance axonal regeneration in the Sprague-Dawley rat with complete thoracic SCI. This system consists of a body weight support system, five-bar linkage for driving the rat's ankles, and treadmill for training motor functions. This system is tested in a rat which is totally transected at T9 and T10 of the spinal cord. A nanofiber scaffold is implanted in a gap between T9 and T10 of the spinal cord in a spinalized rat for stimulating axonal regrowth. The position errors are quantified under five static load conditions (no load, 10, 30, 60, and 100 g) and dynamic load condition. Average root mean square (RMS) position errors in x - and y- axes of the manipulator are 2.1% and 5.3%, respectively. According to a preliminary test, this system can provide the constant force to support the body weight and can drive the rat's hindlimbs without inducing anxiety or irritation. From our experiment, average RMS position errors in x - and y- axes of the manipulator are 10% and 11.7%, respectively. The contribution of this research is the developmental rehabilitation robotic system for a rat with complete thoracic SCI in quadruped posture which can provide more natural walking posture. The scope of this letter is a developmental rehabilitation robotic system.