A Complete Robotic Knee As a Tool for a Better Understanding of Joint Dynamics
Lead Research Organisation:
Imperial College London
Department Name: Mechanical Engineering
Abstract
It is proposed that current understanding of knee mechanics could be greatly improved by using advanced robotic tools to simulate the mechanics of the joint. The project aim is to build a complete anthropologically accurate robotic model of the knee complete with actuators to simulate muscles and sensor arrays to measure joint position and forces. The model will be used to explore a number of areas, however, a particular focus will be put on the ligaments within the joint in order to explore their role in improving both the control of the system and forces required to produce a particular response. The system will also have applications in the preclinical testing of implant designs for knee arthroplasty as a more accurate and rapid method than existing preclinical practises.
Organisations
People |
ORCID iD |
| Ravi Vaidyanathan (Primary Supervisor) | |
| Felix Russell (Student) |
Publications
Russell F
(2018)
A Kinematic Model for the Design of a Bicondylar Mechanical Knee
Russell F
(2017)
Challenges in using compliant ligaments for position estimation within robotic joints.
in IEEE ... International Conference on Rehabilitation Robotics : [proceedings]
Russell F
(2020)
The Impact of ACL Laxity on a Bicondylar Robotic Knee and Implications in Human Joint Biomechanics
in IEEE Transactions on Biomedical Engineering
Russell F
(2018)
A biomimicking design for mechanical knee joints.
in Bioinspiration & biomimetics
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509486/1 | 01/10/2016 | 31/03/2022 | |||
| 1790878 | Studentship | EP/N509486/1 | 03/10/2016 | 02/04/2020 | Felix Russell |
| Description | This award facilitated the development of a new method for investigating human knee and leg biomechanics. This method uses a robotic joint which has features that directly replicate the critical structures of the human knee. This includes: springs in place of ligaments; joint surfaces copied from human bones; a knee cap (patella); and two actuators to replicate the quadriceps and hamstrings muscle groups connected to the joint with cord to mimic tendons. This novel method was validated by comparing results to data from studies on living humans (in vivo) and on cadaver limbs (in vitro). This method significantly improves repeatability and control of test conditions compared with in vitro and in vivo studies, facilitating new discoveries. Specifically, it facilitated studies that show that the complete removal of one of the ACL (one of the ligaments) has no effect of the required muscle forces despite dramatically changing the relative motion of the joint surfaces. This is because the patella, remaining ligaments and joint surface shapes interact to mitigate against the expected changes in required muscle force. The removal or tearing of the ACL is a common joint injury among athletes and those undergoing knee surgery. It's hoped that this deeper understanding of the effect of ACL removal will facilitate improved outcomes for patients. Additional studies both on the robot and in computer simulation have shown that the design of the joint may have applications for prosthetic legs for amputees. These studies, conducted as part of new collaborations with Tokyo Institute of Technology, show that the adjustable lengths of the ligament and control using two pairs of actuators both facilitate precise control of joint stiffness. This knee stiffness is known to be critical in the stability of prosthetic legs. This is coupled with the natural stability in standing of the joint design which, just like the human knee, locks out when fully extended, facilitating low energy standing without the risk of the joint buckling. This work, the work on the robotic method and the discoveries about human knee have all been published in Q1/Q2 journals and at international conferences. Investigations into using the ligament lengths to estimate joint angle showed that this estimation method is unlikely to be suitable in the field. This is due to significant effect on the ligament length from external forces. |
| Exploitation Route | The award provided a good foundation to show that the humanoid joint could have significant advantages for stability, symmetry and cost when incorporated into a prosthetic joint for amputees. The awardees believe this research direction shows particular promise if taken forward. |
| Sectors | Healthcare,Pharmaceuticals and Medical Biotechnology |