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Electrooculography (EOG) can be used to measure eye movements while the eyelids are open or closed and to assist in the diagnosis of certain eye diseases. However, challenges in biosignal acquisition and processing lead to limited accuracy, limited resolution (both temporal and spatial), as well as difficulties in reducing noise and detecting artifacts. Methods such as finite impulse response, wavelet transforms, and averaging filters have been used to denoise and enhance EOG measurements. However, these filters are not specifically designed to detect saccades, and so key features (e.g., saccade amplitude) can be over-filtered and distorted as a consequence of the filtering process. Here we present a model-based fusion technique to enhance saccade features within noisy and raw EOG signals. Specifically, we focus on Westheimer (WH) and linear reciprocal (LR) eye models with a Kalman filter. EOG signals were measured using OpenBCI’s Cyton Board (at 250 Hz), and these measurements were compared with a state-of-the-art EyeLink 1000 (EL; 250 Hz) eye tracker. On average, the LR model-based KF produced a 47% improvement of measurement accuracy over the bandpass filters. Thus, we conclude that our LR model-based KF outperforms standard bandpass filtering techniques in reducing noise, eliminating artifacts, and restoring missing features of saccade signatures present within EOG signals. [ABSTRACT FROM AUTHOR]

Background: In early case studies, use of a collagen barrier as a guided tissue regeneration (GTR) material has shown particular promise in procedures aimed at root coverage. The similarities between collagen membrane and subepithelial connective tissue graft (SCTG) have made collagen membrane an attractive and a possible alternative material for root coverage. The purpose of this randomized clinical trial was to compare these 2 techniques, SCTG versus a QTR-based procedure (QTRC), for root coverage/recession treatment. Methods: Sixteen patients with bilateral Miller's Class I or II (gingival recession ≥3.0 mm) recession defects were treated either with SCTG or GTRC using a newly designed collagen membrane. Clinical parameters monitored included recession depth (RD), clinical attachment level (CAL), probing depth (PD), width of keratinized gingiva (KG), attached gingiva (AG), and recession width (RW), each measured at the mid-buccal area to the nearest 0.5 mm. Measurements were taken at baseline and 6 months. A standard mucogingival surgical procedure was performed. Data were reported as means ± SD and were analyzed using the paired I test for univariate analysis and restricted/residual maximal likelihood (REML)-based mixed effect model for multivariate analysis. Results: No statistically significant differences were observed in RD, CAL, KG, and AQ between test and control groups at either time period. However, SCTG showed significantly more residual PD and more RW gain when compared to GTRC at 6 months. Both treatments resulted in a statistically significant (P <0.05) reduction of recession defects (2.5 mm and 2.8 mm), gain of CAL (2.6 mm and 2.3 mm), reduction of RW (1.9 mm and 2.7 mm), and increase of KG (0.7 mm and 1.1 mm) and AG (0.7 mm and 0.5 mm) for GTRC and SCTG, respectively, when comparing 6-month data to baseline. Mean root coverage of 73% (collagen membrane) and 84% (subepithelial connective tissue graft) was achieved. Conclusions: The 2 techniques are clinically comparable. Use of a modified collagen membrane to attain root coverage may alleviate the need for donor site procurement of connective tissue. [ABSTRACT FROM AUTHOR]

A variety of pharmaceutical agents has been proposed for use in periodontal therapy to inhibit loss of alveolar bone and to promote regeneration of tissues lost to disease. The purpose of this study was to determine the effects of such agents on periodontal cell-mediated gel contraction, an in vitro process considered representative of wound contraction and remodeling in vivo. Human gingival fibroblasts were cultured in a type I collagen lattice, and contraction was quantified by means of a computer-assisted video imaging system. Cell-gel combinations were prepared with cells both pre-exposed and non-exposed to agents; non-anchored cell-gels were then incubated with agents for various time periods. Agents tested included Demecolcine (an inhibitor of cytoskeletal contraction), growth factors (i.e., TGF-β1, PDGF, and IGF-1), and non-steroidal anti-inflammatory drugs (NSAIDs) (indomethacin, ibuprofen, naproxen, and flurbiprofen). While Demecolcine inhibited gel contraction, TGF-β1 (1-20 ng/mL), PDGF (100 ng/mL), IGF-1 (1000 ng/mL), and [PDGF + IGF], all of which have been reported to enhance wound healing in vivo, promoted lattice contraction in this system. In contrast, NSAIDs inhibited cell-gel contraction. Ethanol, used to solubilize two specific NSAIDs, also inhibited cell proliferation and gel contractile ability, even at very low concentrations. These findings indicate that periodontal cells respond differently to various agents in vitro and may be adversely affected by alcohol. Furthermore, the results of this study suggest that the cell-lattice contraction system holds potential as a method for screening agents for positive or negative effects on cell activity. [ABSTRACT FROM AUTHOR]