Main point

The goal is a three-dimensional model of a human hand which is made up of

• kinematics, i.e. how can the bones move?
• visualisation, including skin
• dynamics, i.e. how do either (i) joint torques or (ii) tendon forces accelerate the finger segments and produce forces at contact points?
• physics engine for interaction of the hand with objects.

The computations are three-dimensional, the output is two-dimensional (on a computer screen).

Tasks

Many of these points are already solved – there exist kinematic hand models, there exist hand visualisations, the dynamics formulas have been solved, there are physics engines around. It is necessary to find out what is out there already, and if it can be obtained, and to find out what is still missing, to implement the missing points and to integrate everything so that it is useful for phantom limb pain treatment. 

These topics are probably too much for one single student project. Therefore, it is possible to pick a part of it. During the application process or in the first phase of the student project it will be decided which particular aspect of the problem will be tackled.

Phantom limb pain (PLP)

Hand amputees (people who have lost one or both of their hands) have commonly some feeling or consciousness of their lost hand, e.g. the posture of the hand. This is called the “phantom limb”. Often, they feel pain in the non-existing hand. For some unilateral amputees (people who have lost one hand), there is a way to alleviate the pain: they imagine moving both hands synchronously, while the remaining hand moves. A mirror is placed between the forearms, so that it looks as if both hands were moving. This improves the condition in some patients. Research has shown that PLP correlates with cortical reorganisation, i.e. how the motor cortex of the brain attributes nerve signals to certain body regions. For example, some amputees, when touched on their face, have the feeling that their phantom limb is touched. The mirror therapy is thought to reverese cortical reorganisation, i.e. to reconnect the nerve signals to the correct body regions. 

Much of the research in this area is due to Vilayanur Ramachandran. Also see: 

 http://en.wikipedia.org/wiki/Phantom_limb
 http://en.wikipedia.org/wiki/Phantom_pains

Related work at DLR

Dr. Claudio Castellini at DLR works in establishing a therapy related to the mirror therapy: The intended hand movement of an amputee is extracted from ultrasound measurements on the stump and shown as a computer graphics visualisation. This has the advantage that also bilateral amputees can use the method and that the hands can be moved independently. The method has been shown to work on healthy subjects and is in the process of being tested on amputees. There already exists a computer graphics hand visualisation at DLR, realised in Blender. What is still missing is more natural kinematics with oblique joint axes, a model adaptable to different hand sizes and kinematics, a dynamics model and a physics engine for interaction with objects.

Georg Stillfried at DLR works in kinematic models of the human hand, based on MRI and optical measurements. He will be the main supervisor of the student work, with Dr. Castellini as co-supervisor.

Prerequisites

• Studies in scientific or engineering subject
• experience in computer programming
• ability to work and solve problems on your own
• open communication attitude