MIRA University of Twente
Department of Biomechanical Engineering


Design of a control method and testing of the knee simulator







Knee Tester


Prof. dr. ir. N. Verdonschot

ir. E.E.G.Hekman

dr. ir. A.H.A. Stienen



Starting date:



At first sight the human knee seems to be a fairly simple hinge joint. However, a closer look reveals that the joint is a complex system of three bony parts. cartilage and ligaments, lubricated in a mechanism which is still not completely understood, and actuated by a number of muscles.

At the orthopaedic lab of the University Medical Centre Nijmegen (UMCN) the function of the healthy knee, as well as the function and performance of implants are studied both in silico and in vitro. These studies, apart from giving scientific insight, are aimed at the development of new or improved surgical procedures and implants.

To support this research, a new knee tester has been designed (Figure 1). Partners are the UMCN, UT and BAAT (a company which develops medical technology). The new tester must enable the researcher to impose functional movements under loading on cadaveric knees. Construction of the hardware will be carried out by a student from SAXION, under supervision of BAAT. The control of the tester remains to be developed, implemented, and tested in practice.

Description: A description...

Figure 1: design drawing of the new knee tester


Your assignment will be to develop a control system for the actuators. Data taken from known literature and simulation (Anybody) are to be used to perform functional movements on a knee specimen.


Steps that are to be taken include:

- review relevant literature, get input from the other partners e.g. the other student working on this project

- translate the desired loading profile into force or displacement profiles for the actuators.

- determine the desired control method

- implement the method in Matlab

- test the total system in a pilot experiment

- give recommendations on further development and improvements of the tester

Further information

Prof. dr. ir. N. Verdonschot HR W208 / UMCN

ir. E.E.G.Hekman HR W214

dr. ir. A.H.A. Stienen HR W214