Dynamical Measurement Method of Handle Reaction Vector for FES-Assisted Paraplegic Walking

To analyze the use of upper limb support during paraplegic walking assisted by functional electrical stimulation (FES), a new dynamical measurement for handle reaction vector (HRV) applied by patient to walker was proposed. To avoid the discomfort of direct monitoring, the dynamometer system was designed based on 12 string-gauge bridges instrumented on a standard walker frame. The detailed positions of these bridges were determined according to the deformation distributions of the walker frame under different directional components of HRV. To adapt the system to quantitative and reliable measurement, a redundant-optimized technique was developed in calibration. The measurement accuracy, nonlinearity, and crosstalk of the designed system were investigated, which were better than 1.01%, 2.91%, and 3.19% respectively. Clinical trials were done with 6 paraplegic subjects using the system and one case was given as the example of actual measurement. All experiment and clinical trial results show that this method is reliable and practicable.