Design Reliable Bus Structure Distributed Fiber Bragg Grating Sensor Network Using Gated Recurrent Unit Network.

The focus of this paper was designing and demonstrating bus structure FBG sensor networks using intensity wavelength division multiplexing (IWDM) techniques and a gated recurrent unit (GRU) algorithm to increase the capability of multiplexing and the ability to detect Bragg wavelengths with greater accuracy. Several Fiber Bragg grating (FBG) sensors are coupled with power ratios of 90:10 and 80:10, respectively in the suggested experimental setup. We used the latest IWDM multiplexing technique for the proposed scheme, as the IWDM system increases the number of sensors and allows us to alleviate the limited operational region drawback of conventional wavelength division multiplexing (WDM). However, IWDM has a crosstalk problem that causes high-sensor signal measurement errors. Thus, we proposed the GRU model to overcome this crosstalk or overlapping problem by converting the spectral detection problem into a regression problem and considered the sequence of spectral features as input. By feeding this sequential spectrum dataset into the GRU model, we trained the GRU system until we achieved optimal efficiency. Consequently, the well-trained GRU model quickly and accurately identifies the Bragg wavelength of each FBG from the overlapping spectra. The Bragg wavelength detection performance of our proposed GRU model is tested or validated using different numbers of FBG sensors, such as 3-FBG, 5-FBG, 7-FBG, and 10-FBG, separately. As a result, the experiment result proves that the well-trained GRU model accurately identifies each FBG Bragg wavelength, and even the number of FBG sensors increase, as well as the spectra of FBGs, which are partially or fully overlapped. Therefore, to boost the detection efficiency, reliability, and to increase the multiplexing capabilities of FBG sensor networks, the proposed sensor system is better than the other previously proposed methods.

Can pillar suturing promote efficacy of adenotonsillectomy for pediatric OSAS? A prospective randomized controlled trial.

OBJECTIVES/HYPOTHESIS: Pediatric obstructive sleep apnea syndrome (OSAS) is a common disorder with serious clinical implications if left untreated. The recommended initial treatment for pediatric patients with obstructive sleep apnea syndrome (OSAS) is adenotonsillectomy. However, recent reports have shown variable surgical results with adenotonsillectomy in the treatment of pediatric OSAS. STUDY DESIGN: Prospective, controlled study. METHODS: From April 2007 to August 2010, 24 participants were assigned alternatively to either adenotonsillectomy with pillar suturing (intervention group) or adenotonsillectomy alone (control group). RESULT: The average improvement in apnea hypopnea index (AHI) was 42.6% in the control group and 79.9% in the intervention group (P=0.037). The success rate was 50% in the control group and 91.6% in the intervention group (P=0.034). Six patients (50%) in the intervention group achieved complete resolution of pediatric OSAS, as defined by an AHI <1/hour, compared to 2 patients (16.7%) in the control group (P=0.097). CONCLUSION: Adenotonsillectomy with pillar suturing showed significant improvement in treating pediatric patients with OSAS compared to adenotonsillectomy alone. The procedure is simple and safe. LEVEL OF EVIDENCE: 4.

Biofilm formations in nasopharyngeal tissues of patients with nasopharyngeal osteoradionecrosis.

OBJECTIVE: Determine the presence of nasopharynx biofilms in patients with nasopharyngeal cancer (NPC) and osteoradionecrosis (ORN) and patients with NPC but no ORN. STUDY DESIGN: Cross-sectional study. SETTING: Tertiary referral medical center. SUBJECTS AND METHODS: We enrolled 27 patients with NPC from our outpatient clinic during January 2010 to June 2012. These patients were diagnosed with NPC between 1980 and 2012, and all had received radiotherapy. Of these 27 patients, 15 presented with ORN, and 12 did not. The nasopharynx biopsied specimens were processed and analyzed within 2 hours of collection with the FilmTracer LIVE_DEAD Biofilm Viability Kit (Molecular Probes, Invitrogen, Carlsbad, California). A blinded investigator determined the formation of biofilms by fluorescence microscopy. Bacterial cultures were collected. RESULTS: Eleven of 15 (73%) ORN patients had biofilm formations in nasopharynx biopsy specimens. Five of these samples (45%) yielded positive cultures, and 4 of these cultures indicated the presence of methicillin-resistant Staphylococcus aureus (MRSA). Only 1 of 12 NPC patients without ORN had nasopharynx biofilm formation, and all culture results were negative. CONCLUSION: Biofilm formations were common in nasopharynx samples of NPC patients with ORN but rare in samples of NPC patients without ORN. The presence of biofilms, especially MRSA, may have a role in the disease progression of ORN or may contribute to the chronicity and resistance to antibiotic treatment.

Peripheral neuropathology of the upper airway in obstructive sleep apnea syndrome.

Obstructive sleep apnea syndrome (OSAS) is a common sleep disorder that leads to significant morbidity and mortality without adequate treatment. Though much emphasis on the pathogenesis of OSAS has been placed on a narrow upper airway space and associated muscular factors, possible neuropathy of the upper airway has not been fully elucidated. Increasing peer reviewed evidence suggests involvement of neurologic lesions of the upper airway in OSAS patients. In this article, we review the etiology and pathophysiology of OSAS, the evidence and possible mechanisms leading to upper airway neuropathy, and the relationship between upper airway neuropathy and OSAS. Further studies should focus on the long term effects of the upper airway neuropathy as related to the duration and severity of snoring and or apnea, and also on the potential methods of prevention and management of the neuropathy in sleep disordered breathing.