Biomedical Engineering Reference
In-Depth Information
considerably (about 30% in average) compared to when HJC is estimated based on
dref
. Such amount of differences highlights the fact that the hip simulations can
give different results and conclusions when the HJC estimation method shifts to one
another, (especially from
dref
to
dconst
). The results also show that the difference
in penetration depth is subject dependent. In addition, the
dconst
and acetabulum
sphere present the highest variability with respect to the femoral head sphere and
double sphere methods. With regard to the different axes of rotation, the radial and
curvilinear penetration depths during adduction and external rotation show to be
less sensitive to the methods used for estimating HJC. On the other hand, flexion is
among the most sensitive types of rotation to the HJC estimation methods. As a brief
summary, the results indicate that hip medical investigations are not robust when the
HJC estimation method changes. In fact, researchers should be careful in choosing
the methods of HJC estimation, before providing any conclusion from their medical
research.
8.6 Summary and Conclusion
In this chapter a brief review of two different collisions detection methods, suitable
for evaluating rotating/sliding objects such as human joints, has been presented.
These methods can provide a basis for further studies of contact evaluation in human
joints. These studies can vary from medical investigation to medical applications.
Two different medical applications, inspired by these collision detection methods,
have been covered in this chapter. In one of these applications, maximum range of
motion of human joint could be calculated accurately and fast. In the other medical
application, penetration depths calculated in different directions could be used as an
indicator for diagnosing and also classifying different kinds of joint diseases (i.e.
FAI). In addition to these applications, again by exploiting the mentioned collision
detection strategy, sensitivity of the joint simulations to the estimated joint center of
rotation has been investigated. The experiments and validations were done in 3D hip
models. However, due to the generality of the explained collision detection methods
for joint evaluation, the investigations and the applications can be used or extended
for other human joints.
References
1. Martin, H. D. (2005). Clinical examination of the hip.
Operative Techniques in Orthopaedics
,
15
, 177-181.
2. Tannast, M., Kubiak-Langer, M., Langlotz, F., Puls, M., Murphy, S. B., & Siebenrock, K. A.
(2007). Noninvasive three-dimensional assessment of femoroacetabular impingement.
Jour-
nal of Orthopaedic Research
,
25
(1), 122-131.
3. Arbabi, E., Boulic, R., & Thalmann, D. (2007).
A fast method for finding range of motion in
the human joints
. Paper presented at the 29th Annual International Conference of the IEEE
