Time-lapse imagery allows us to witness, first-hand, how plants grow and heal, sway in cyclical motions, and even “dance” in reaction to various environmental factors.

The analysis of mechanical behaviour of spinal column is until now still a challenge, in spite of the great amount of research which has been conducted over the last years. It is a particularly complex structure considering number of components, their shapes and mechanical characteristics. The objectives of the presented investigations are to understand the mechanisms of the mechanical behaviour of the spine structure and the role of its components, as well as the factors of its dysfunctions as scoliosis discopathy, spondylolisthesis. Also some mechanical effects of surgical interventions by total disc replacement is considered. To account for the 3D character of the spine system including vertebrae, discs, ligaments, muscles etc. the finite element method (FEM) formulation was used throughout the paper. Some specific features of the structure are included in the models as non-conservative loads and muscular tension control performed by the nervous system. The finite element method together with CAD programs and experimental validation was used in investigations of a new type of artificial disc for lumbar spine. The stress analyses were performed for the prostheses being in clinical use and for some original new designs. The conclusions concern most important determinants of the mechanical behaviour of the system and the quality of the intervertebral disc prosthesis.

Using a highly sensitive and precise apparatus, series of spatial movements of human cervical segments (C3/C4) were measured. They followed cyclic varied pure torques for axial rotation, lateral flexion, and flexion-extension in the presence of axially directed preloads as running parameter, whose force lines were shifted over the segments. By successive resections of the uncovertebral and zygapophysial joints as well as ligamental structures, the reach of these guiding structures for segmental kinematics and stiffness could be evaluated. For the first time, the biomechanical significance of the uncovertebral joints could be substantiated. In axial rotation and in lateral bending, the instantaneous helical axis (IHA) was found to be not stationary. Its position depended on the size of the rotational angle. The ensemble of the skew IHA formed a ruled surface with a waist. Torque and unit vector of the IHA were found to be parallel only for flexion-extension. In this case, all four joints were in guiding function, whereas in axial rotation and lateral flexion the joints alternated with each other. IHA included with torque T_z(t) for axial rotation ≈+30deg, and with torque T_x(t) ≈−30deg: These motions were coupled. Resection of all ligaments did hardly influence the kinematical structure.

Dual quaternions and dual quaternion interpolation are powerful mathematical tools for the spatial analysis of rigid body motions. In this paper, after a review of some basic results and formulas, it will be presented an attempt to use these tools for the the kinematic modeling of human joints. In particular, the kinematic parameters extracted from experimentally acquired data are compared with those theoretically computed from dual quaternions rigid body motion interpolation.

The goal of the project is to investigate the influence of elastic mechanisms on technical, bipedal locomotion. In particular, the paper presents the parameter identification for a biologically inspired two-legged robot model. The simulation model consists of a rigid body model equipped with rubber straps. The arrangement of the rubber straps is based on the arrangement of certain muscle groups in a human being. The parameters of the elastic elements are identified applying numerical optimisation. Thus two optimisation algorithms are investigated and compared with respect to robustness and computing time. Moreover, different objective functions are defined and discussed. The behaviour of the resulting configuration of the system is explored in terms of biomechanics.

Whatever the type of surgery related to inner organs, traditional or robotic, the contact with them during surgery is a key moment for pursuing the intervention. Contacts by means of surgery instruments namely scalpels, staples, clamps, graspers, etc. are decisive moments. False, and erroneous touching and manoeuvring of organs operated on can cause irreversible damage as regard morphological aspects (outer impact) and physiological aspects (inner impact). The topic is a great challenge in the effort to measure and characterize damages. In general, electrical instruments for surgery employ the following technologies: ultrasound, radiofrequency (monopolar, and bipolar), and laser. They all result in thermal damages difficult to evaluate. The article proposes a method for a pre-screening of organ features during robotic surgery sessions by pointing out mechanical and thermal stresses. A dedicated modelling has been developed based on experimental activities during surgery session. The idea is to model tissue behaviour from real images to help surgeons to be aware of handling during surgery. This is the first step for generalization by considering the type of organ. The measurement acquisitions have been performed by means of an advanced external camera located over the surgery quadrant. The modelling and testing have been carried out on kidneys. The modelling, carried out through Comsol Multiphysics, is based on the bioheat approach. A further comparative technique has been implemented. It is based on computer vision for robotics. The findings of human tissue behavior exhibit reliable results.