During the realization of the reconstructive microsurgery of the peripheral nerves, including the brachial plexus, by knowing that the structure of the sensitive, muscle and neurovegetative components is constantly modifying from 1mm to the other, the exact identification of the fascicles on the surface of the nerve trunk sections has a vital importance for obtaining a better functional result. The project has a high degree of novelty because it’s aim is to realize a micro- electro- mechanical system with applications in biomedicine (BioMEMS) for: the investigation of nervous fascicles during peripheral nerve reconstruction by microsurgery; the determination of the peripheral nerve’s injury type; diagnostic of the anomalies and physicopathological aspects; processing of the etiopathogenic data.
The proposed intelligent microsystem for the immobilization of the peripheral nerves inside microchannels, investigation of the interactions in supramolecular systems in order to reveal some new interactions and solve the mechanisms through which these interactions can trigger the behaviour of peripheral nerve fascicles (on the molecular level) is a combination between a microfluidic system and a microelectronic one – bionic. With the help of the microsystem realized during this project we will be able to conduct studies closer to the truth about the peripheral nerve and it’s capacity of regeneration and reconstruction. Also, we will be able to study what is happening to the section heads of the nerve and the segment added to rebuid the nerve’s continuity and we will be able to study the physiological function and it’s physiopathology. Thus, we will be able to predict the future of recontructive microsurgery for any of these components.
In this project we want to develop a technique able to identify the exact position of each type of nervous fiber at the nerve’s head. In order to determine the fiber nerve types we will use the variation of the rest potential, the variation of the activity potential, the variation of the velocity of the nervous impulse and also the electrical capacity of the membrane, the transmembrane currents and the ion channel currents. The rest potential can be directly measured with the help of microelectrodes, or indirectly by using ionised fluorescent substances (for example the tiocianate). The piercing of the membrane with a microelectrode doesn’t create a considerable injury to the membrane, and the short-circuit between the citoplasma and the extracelular fluid doesn’t take place, because of the membrane which sticks to the electrode tip (due to the surface tension). There are two types of action potentials: local action potentials and all-or-nothing action potentials (AP-an). These potentials can be measured by microelectrodes experiments. The local action potentials can be obtained by applying low intensity depolarizing stimuli. The local potentials can be characterized by amplitude proportional to the intensity of the stimulus and by a decremental propagation. The all-or-nothing action potentials are triggered when the intensity of the stimulus reaches a critical value. In order to measure the transmembrane currents and the ion channel currents we will use the “voltage-clamp” and, respectively, “patch-clamp” methods