Real-time interfacial load monitoring and tracking between the composite prosthetic socket and residual limb for below-knee amputees

摘要

Real time-in-service interfacial load measurement and load tracking between prosthetic socket and the residual limb is of paramount importance. Noroozi et al proposed an inverse method approach using ANN to predict the magnitude and location of the interfacial load between prosthetic socket and the residual limb from the structural response of the socket to the normal internal load due to contact between the stump and the socket. Here the socket mechanical properties act as the transfer function between the forces acting normal to the internal surface of the socket forces and the resultant strains generated on the external surface of the socket. Using this method, it is possible to use the external strains to predict the internal load that caused the strain. With this method, there will be no need for the socket or tissue properties or the exact socket thickness. Using this technique, one can simply transform everyone's socket into their own dedicated transducer suitable for measuring, tracking and monitoring the resultant interfacial load on the internal surfaces of the socket for that user. Currently, all socket interfacial load measurement systems require tactile sensors which require the prior knowledge of the location of the contact points. This makes it impossible for the tactile sensor to predict the magnitude and location of high-pressure points. Alternative tools are tactile sensor placed in liners or drilled and mounted through the socket wall, or total surface bearing ones that are subjective and not suitable for everyday use. For that reason, they require the knowledge of the contact point or areas of high load intensities. The proposed new system requires none of the above constraints and due to its unique design, it is immune to the changes in the overall boundary conditions, making it an invaluable clinical system.