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  • Author: V. Uzunov x
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V. Uzunov

Abstract

Some industrial processes have nonlinearities and large delays. This causes instabilities and many difficulties for the system tuning. This paper presents tuning of a fuzzy PD controller for a nonlinear object with a large delay and an integrator in its structure. The simulation and respective results shows that the presented options assist for much better and easier system setup.

Open access

V. Svechtarov, S. Nencheva-Svechtarova and Ts. Uzunov

Summary

The objective of this study is to analyze the distribution of the most common diagnoses observed in patients with chronic temporomandibular disorders, based on the new diagnostic criteria (DC/TMD) adopted in 2014. The previous Research Diagnostic Criteria (RDC/TMD) adopted in 1992, consisted of three main groups of eight diagnostic subgroups and is currently transformed into two main groups and twelve subgroups, respectively. All subgroups correspond to the nomenclature of the ICD-10. The new clinical diagnostic indices are also modified. The analysis showed a prevalence of Pain-Related TMD compared with that of intra-articular disorders in ratio 57.89% to 42.10%. In Pain-Related TMD arthralgia was represented in 55% of cases; local myalgia - in 12%, myofascial pain - in 18%, myofascial pain with referral - in 14%, headache attributed to TMD - in 1%. In Intra-articular TMD disc displacement with reduction was found in 23% of the cases, disc displacement with reduction with intermittent locking - in 3%, disc displacement without reduction with limited opening - in 25%, disc displacement without reduction and without limited opening - in 8%. Degenerative diseases were found in 14.28%, and hypermobility and subluxations - in 26.98%. These analyzes differ and can only partly be compared with previous analyzes based on RDC system. The changes in the diagnostic criteria require new clinical studies in order to refine the picture of temporomandibular pathology in accordance with the modern views on the matter.

Open access

Savina Nencheva-Sveshtarova, V. Sveshtarov, Ts. Uzunov and K. Prodanova

Summary

The objective of this study was to test the clinical effectiveness of the combined gallium-aluminum-arsenide laser (GaAlAs; 785 nm) and superluminiscent diods (SLD; 633 nm) phototherapy (MedX 1100 device) for the treatment of 62 patients with 7 of the most common pain-related temporomandibular disorders with highest sensitivity and specificity according to diagnostic criteria DC/TMD. Using paired samples t-test a positive effect in the pain relief for all tested conditions was demonstrated. The most manifested and statistically significant reduction of pain was found in arthralgia attributed to osteoarthritis and systemic (rheumatoid) arthritis (p = 0.0000001), and disc displacement without reduction with limited opening (p = 0.0000002). Similar levels of pain reduction were found in arthralgia attributed to subluxation, myofascial pain with referral, local myalgia (p values vary between 0.000001 and 0.000284); the lowest values were recorded for myofascial pain (p = 0.001789) and hypermobility-related myalgia (p = 0.018443). The combined laser and SLD phototherapy can be defined as very effective treatment option particularly in pain reduction of internal derangement disorders as well as in some myogenic-related pain conditions affected by TMJ dysfunction.

Open access

S. Nencheva-Svechtarova, V. Svechtarov, A. Gisbrecht and Tz. Uzunov

Summary

The objective of this study was to test the clinical effectiveness of the gallium-aluminum-arsenide laser (GaAlAs; 785 nm) and superluminiscent diodes (633 nm) phototherapy (MedX 1100 device) for the treatment of patients with temporomandibular disorders and myofascial pain syndrome. The results demonstrated a positive effect in pain relief. A significant reduction (p < 0.05) in the level of pain was observed for the temporomandibular joint and for the masseter muscles using paired samples t-test and Wilcoxon signed rank test. The experimental study on pork muscle samples showed that a) the main part of laser radiation is absorbed by the tissue in thin layer of 3-4 mm, b) in the spectral region 650-950 nm the intensity of light penetration is about 0.2-0.25 percent of the initial light intensity.