Design and evaluation of a hybrid passive–active knee prosthesis on energy consumption

Abstract

Abstract. The existing lower limb prostheses with passive knees have disadvantages, causing an asymmetric gait and higher metabolic cost during level walking which is in contrast with a normal gait. However, most existing active knee prostheses need a significant amount of energy. In this paper, a novel hybrid passive–active knee prosthesis (HPAK) that allows passive and active operating modes is proposed, which contains an active motor unit and a novel hydraulic damper with an electrically controlled valve that adjusts the damping torque dynamically during each gait cycle. An energy consumption model was built to evaluate the energy consumption when walking on level ground in three different simulation conditions to, respectively, simulate the complete HPAK, an ordinary active prosthesis (AKP) and an ordinary passive prosthesis (PKP). The results show that, in a cycle, the HPAK consumes only 16.19 J, which is 3.6 times lower than the AKP (58.95 J), and the PKP consumes only 1.24 J due to the novel spring–hydraulic damper structure designed and presented in this paper. These results indicate that the proposed novel hybrid passive–active knee prosthesis can have a positive effect on reducing energy consumption and improving the approximation of healthy gait characteristics when walking on level ground, contrasting with active or passive knee prostheses.

Advances in active knee brace technology: A review of gait analysis, actuation, and control applications

“…The hybrid type is a combination of both active and passive. The details of power consumption of one gait cycle for normal walking are given in Table 4 [ 77 ]. Design and evaluation of a hybrid passive-active knee prosthesis on energy consumption.…”

Prosthetic Knee Mechanism Using a Double Locking System as a Safety Measure

“…Escalona and Torrealba (2015), a linear hydraulic actuator with modular response has been designed to actuate and control the prosthetic device, which acts as a variable lock during the patient's gait cycle. Similarly, the research by Wang et al (2020) developed a passive-active hybrid knee with two energy-saving modes of operation, which has an active mode that works with a resistance actuator or a variable lock. Murthy-Arelekatti and Winter (2018), a mechanism is presented that has an automatic initial stance phase lock for stability and a differential friction damping system for stance and roll control.…”