Design, Development and Experimental Evaluation of a Transfer Assistive Device for Paraplegic Individuals Using Biomechanical Analysis

The present study aimed at designing a simple, yet safe transfer assistive device for lower-limb impaired individuals in the context of a developing country. A novel design methodology was adopted by combining the product design process with the concepts of biomechanics, anthropometry and human dynamics in a human–machine environment. The first phase of this paper elucidates design conceptualization using biomechanics in a human–machine environment. The second phase investigates experimental validation of the manufactured prototype concerning the user’s experience. Inertial parameters and design inputs were extracted from this setup that helped in the development of the 3D model. To evaluate the present device in terms of user’s comfort of use and level of physical strain, subjects including 19 healthy students serving as “patients” have participated in a laboratory-simulated setting. Data was collected based on user’s physiologic effort and rate of perceived exertion using heart rate monitoring device (Polar RS 400 heart taster) and Borg’s scale, respectively. The data was analyzed statistically and revealed that the regression equation for predicting the RPE from HR showed 31.3% of the variance in RPE was predictable from the level of HR. The ANOVA significance also indicates that the model is statistically significant with (p < 0.013). Similarly, the estimated strain level has computed in terms of %HRR, and the physical strain averaged over the subjects who performed the task (n = 19) was expressed in terms of (mean ± SD) %HRR were (16.21 ± 7.64%) which was a relatively smaller strain level as compared to the previous research report.