摘要 |
Torsional loads can impart painful and potentially injurious shear stresses upon residual limb soft tissues in lower limb amputees. To protect the soft tissues, a controllable transverse rotation adapter (TRA) has been developed that permits rotation of the prosthetic socket relative to the prosthetic foot, relieving some of the rotational loads experienced by the residual limb, and controlling either the stiffness resisting the transverse rotational torque, or the torque. This TRA uses series elastic actuator (SEA) technology and includes a prime mover, a speed reduction device, and a torsion spring mounted in series. By measuring a displacement of the spring (e.g., using a strain gauge), motor current, and the motor shaft position, the load torque and position can be used to calculate actual stiffness or applied torque. The motor position is then adjusted relative to the load, to control the effective stiffness or torque. |