Abstract: Objective To investigate the geometric modeling method for trans-femoral prosthetic socket. Methods The socket reference shapes (i.e. shape templates) were constructed based on the statistic analysis and integrated into the CASD program. The initial socket shape was obtained by transformation from the corresponding reference shape based on the data from the patient's stump and the final socket shape was determined by a kind of three-dimensional interaction method under the OpenGL environment. The fabrication experiment is conducted on the specialized numerical control machine. Results The interactive modification method was easy to use. The machined socket mold is consistent with the designed model in the shape and the precision. Conclusion This method can meet the clinical requirements in the main, but need to optimize the surface shaping characters and rules during the interactive modification stage.

Key words: computer assisted socket design, geometric modeling, prosthetic socket