This paper’s objective was to explore the possibility of restoring movement to a patient with tetraplegia from a high-cervical spinal cord injury. In experiments done previously, the patient usually had a lower and less severe injury so there was less loss of function. This experiment aimed to stimulate both a reach and grasp movement using a combination of iBCIs and FES systems. Patients with these injuries need constant aid so this is aimed to make the patient become self-sufficient.
This experiment used a man with a severe spinal cord injury that occurred eight years before the testing. Its important to do these tests on humans because animals do not get these types of injuries and survive. The long period of time between injury and testing eliminates the possibility that the movement stimulated is a result of residual function in the muscles. The severity just shows how effective the systems are even with so much loss of function.
The paragraph is well
The paragraph is well structured and detailed the only thing I would add is a commaafter because in the second paragraph and a short sentence in the first paragraph explaining what iBCIs and FES systems are for readers who might not know what it is.
You could say "In previous experiments..." instead of "In experiments done previously..."
Your second sentence is a bit confusing maybe you can reword the structure of the sentence. Maybe be specific in what it means to be less loss of function.