Stable six degrees of freedom haptic feedback for flexible ligand-protein docking

This paper presents a new method for haptic feedback in molecular docking simulations as applied to the design of new drugs. These simulations, typically used by the pharmaceutical industry, for example Sanofi-Aventis, are based on the description of atomic energies to estimate the interactions between a ligand and a protein. The main drawback is that forces and torques cannot be calculated using a simple derivation. Moreover, when considering flexible ligand-protein docking, it is essential to take into account the delay in the molecular simulator's response, as it may lead to an unstable bilateral control scheme. The proposed method allows for stable haptic feedback using wave variables. For the operator to feel the molecular interactions, this method builds a local energy model based on the interatomic interactions and on the haptic device's displacement. The interaction wrench can be obtained using an analytic derivation of the energy model. Consequently, the teleoperation system is software independent, and can be extended to any bio-application, provided that it is energy based. Additionally, it ensures stable six degrees of freedom manipulation, therefore allowing comprehensive and stable haptic feedback. (C) 2009 Elsevier Ltd. All rights reserved.