Mechatronics is nowadays a dominating concept in design of various kinds of systems and technical devices. High speeds of data processing by control units of mechatronic systems, as well as high dynamics of their actuators allow the systems to be applied in wider fields. This refers to the medicine as well, especially while making attempts to replace lost human motor abilities by means of robots aiding the man. These devices can be divided into three groups: exoskeletons designed to strengthen the natural force of human muscles, orthotic robots that restore lost or weakened functions of human limbs, and prosthetic robots replacing an amputated limb. The first and the third group are known quite well, whereas the orthotic robots are at an initial phase of their development. The authors have worked on a device for aiding the motion of disabled people suffering from paresis of the lower limbs. The paper presents a concept and a structure of the system that has been created, comparing it with similar devices that have already existed. There are indicated some connections and areas where the subunits merge, as well as the rules of their working with the user.

No abstract

No abstract

The work presents modeling of interface phenomena in biological structures. Selected ways of numerical modeling of phenomena at the boundary of two materials by means of FEM methods are discussed. The work focuses on phenomena related to biological structures and their mutual interactions. Using an example of an implant-bone system, various techniques of modeling interface phenomena are compared and referred to experimental results. The study reveals the main features of the selected modeling techniques, e.g. complexity of creating the model, time-consumption of computation, reliability of the obtained results. The obtained results proved that the most advantageous method is the one that makes it possible to regard interactions as numerical values, without an excessive generation of the finite elements (the grid) at the materials boundary. The contact modeling technique based on the contact indicator showed the lowest value of standard deviation in relation to contact modeling techniques: with the use of elastic-damping elements, based on the so-called boundary slip line and based on the so-called bio-layer. The contact indicator should be understood as a numerical value describing the interaction of the boundary surfaces of two objects cooperating with each other. The value of the indicator was determined experimentally. The value have oscillated +/-0.0012mm. This is a very small value knowing that the standard deviation for the modeling technique of the contact employing damping-elastic elements gives a spread of +/-0,1442 mm. Keywords interface phenomena, artificial-material-biological-structure system, FEM of the contact/ interface modeling Contact phenomena modeling in biological structures on the example of the implant-bone Marcin Zaczyk et al.

No abstract