This device was made to statically and dynamically measure the distribution of stress applied to the knee joint during standing up motion using an accurate shape model of human knee joint.
The bone model was made with a 3D Printer based on 3D data obtained from CT images and MRI images of human femur, tibia and meniscus. The femur motion data was created based on human standing up motion data measured by motion capture camera. In addition, the time series force data of the longitudinal direction of the femur and its perpendicular direction were obtained using a musculoskeletal simulator (SIMM).
By immobilizing the tibia and moving the femur with the robot arm and applying force to the femur from two directions using the air cylinder, the stress on the knee joint during standing up motion is reproduced. The force applied by the air cylinder is detected by the force sensor, and feedback controlled. The pressure distribution in the knee joint and its change over time are measured by installing thin film pressure sensor in the knee joint.

Joint Stress Measuring device Using Human Accurate Shape Knee Joint Model
2013
Size: 700×700×600
Collection: Asama and Yamashita Lab, Department of Precision Engineering, School of Engineering, The University of Tokyo
The stress applied to the knee joint during the standing up motion is reproduced by moving the femur with the robot arm and applying force with the air cylinder in the longitudinal direction of the femur and its perpendicular direction.