Projects / Programmes
Development of the new cardiovascular surgical technique utilizing the intelligent PA materials
| Code |
Science |
Field |
Subfield |
| 2.04.00 |
Engineering sciences and technologies |
Materials science and technology |
|
| Code |
Science |
Field |
| T390 |
Technological sciences |
Polymer technology, biopolymers |
| T150 |
Technological sciences |
Material technology |
intelligent materials, multidimensional interactions, time dependent behaviour, influence of pressure, temperature and moisture, processing technology, cardiovascular surgery, endoscopic operation, shrinkage kinetics, shrinkage dynamics, thermal excitation
Researchers (9)
Organisations (1)
Abstract
In the field of endoscopic heart surgery, two world unique endoscopic valve operations with the first endoscopic aortic valve replacement were recently performed in Klinični center Ljubljana (research group of Prof. Geršak). Recently, the new generation of thermoplastic polymeric materials - the intelligent multimodal PA fibers - were developed. The materials were internationally patented in 156 countries (research group of Prof. Emri). The new generation intelligent fibers allow controlled changing of the intensity and time dependency of their shrinkage dynamics. Such intelligent fibers open new possibilities in many technical and medical applications.
One of the key problems in conventional, and especially in endoscopic surgery is the quality of sutures, which tighten the artificial valve or correct the properties of native valve for the lifetime. If the suture knot is not tightened enough or even if it becomes loose, the valve ring does not seal the space between the ring and the vessel wall tight enough. As a result the blood can leak in wrong direction, which leads to worse haemodynamic state and the need for reoperation. If the suture leaks, there is possibility of huge hemorrhage that leads to heart tamponade and possibly to the patient's death. This is a technical problem, arising from the fact that it is almost impossible to make a proper knot using highly elastic materials, which are currently used in surgery.
The unsolved technical problem deals with understanding of shrinkage kinetics of semi-thick polyamide fibers exposed to thermal (IR) excitation. Material structure formation during the solidification is possible only if the material is exposed to well-defined pressure, temperature and stress-strain boundary conditions. Properly selected boundary conditions will "guide" material structure formation towards the semi-equilibrium state in which material exhibits intelligent behavior. We know that the magnitude of fiber shrinkage depends on the amount of kinetic (thermal) energy introduced into the material. On the other hand, the shrinkage/extension kinetics depends on the rate of energy flux.
The new generation fibers allow controlled changing of fiber geometry depending on the magnitude and rate of energy input. The latter determines fiber's shrinkage- or extension-kinetics as required during the surgery. Two expert groups, one from medical side (group of Prof. Dr. Geršak) and one from the technical side (group of Prof. Dr. Emri), join their expertises to address this problem. The ultimate goal of this synergetic approach is to develop the new world first cardiovascular surgical technique utilizing the unique properties of the intelligent fibers. The new technique will be elaborated to the level of pre-clinical application, which is a common goal of the two proposed projects with a common title: ''Development of the new cardiovascular surgical technique utilizing the intelligent PA materials ''.
The technical part of the proposed research (this proposal) deals with problems, related to understanding of shrinkage dynamics induced by thermal excitation. The goal is to understand the multiscale interrelations between the macroscopic boundary conditions and the processes on the molecular level, which drive the material from one equilibrium state to the other. In this process fiber shrinks or extends depending on the amount of energy introduced into the material.
