Now, a virtual hand that goes underneath the skin

London, Aug 15 : Surgeons would soon be able to reconstruct damaged hands more effectively, all thanks to computer animated models of hand that not only gives the image of life-like movements of the limbs, but also provides a closer look of how the muscles and tendons function while moving.

These new stunningly realistic animations of the human hand are detailed enough to shed light on the mystery of how the tendons and muscles of the human hand interact when we move.

With advances in motion capture technology, that records the way people move, it is easy to making characters that move realistically.

But now, Shinjiro Sueda, Andrew Kaufman and Dinesh Pai at the University of British Columbia in Vancouver, Canada have developed hand animations that go below the skin surface to show how tendons and muscles co-ordinate while moving.

The developers used anatomical data from medical images to model the 17 bones and 54 tendons and muscles of the hand and forearm.

The new software can synchronize the contraction and relaxation of muscles, and also details the way forces are transmitted by tendons for producing any desired hand gesture.

"Motion capture is data driven - you just capture the data and play it back. Our approach is a simulation in which the starting point is the physics of muscle and tendon movement," New Scientist quoted Sueda, as saying.

The researchers also covered their virtual muscles and tendons in a layer of skin and saw that its shape depends on the anatomy beneath it.

"The parameters to control the deformation of the skin aren't biomechanical - it's just cosmetic," said Sueda.

However, due to the accurate placement of the essentially controlled muscles and tendons, the resultant hand animation is highly realistic.

Sueda said that the model would certainly prove to be a boon to surgeons, saying: "The network of muscles and tendons in the hand is very complicated," he adds. Even now people don't know how it actually works in detail."

This advance would also add a little realism to the complicated procedure of surgery, in case of any damage to the limbs.

In case a tendon is damaged, the muscle it's attached to no longer functions properly. While the surgeons try to restore movement by taking a nearby tendon and re-routing it along the path of the damaged one, but it is difficult to predict the results.

"Using our technique, you can show what effect rerouting a tendon would have on the hand before you actually do the surgery," said Sueda.

In fact, the new technology has also been built as a plug-in for existing graphics software to allow animators to quickly and easily add more realism to their hand animations.

The new hand animation models will be presented at the SIGGRAPH computer graphics conference in Los Angeles.

ANI