Fiber Optic Technology

We analyze whether the numerical-scale relation h 2 = e 0 t 0 (1) interpreted as an approximate proportionality between the square of Planck's constant and the product of a hypothetical fundamental energy quantum e 0 ("joulino") and a fundamental time quantum t 0 ("secondino"), can be ruled out by current experiments. Treated numerically rather than dimensionally, this relation links characteristic magnitudes of action, energy, and time in a discrete-graph picture of spacetime. We show that for e 0 ≲ 10-37-10-38 J and t 0 ≲ 10-29-10-30 s, no existing laboratory or astrophysical data contradict Eq. (1). Hence, the relation remains experimentally untested but not excluded.

The compact size, mechanical flexibility, and growing functionality of optical fiber and fiber optic devices are enabling several new modalities for imaging the mammalian nervous system in vivo. Fluorescence microendoscopy is a minimally invasive fiber modality that provides cellular resolution in deep brain areas. Diffuse optical tomography is a non-invasive modality that uses assemblies of fiber optic emitters and detectors on the cranium for volumetric imaging of brain activation. Optical coherence tomography is a sensitive interferometric imaging technique that can be implemented in a variety of fiber based formats and that might allow intrinsic optical detection of brain activity at a high resolution. Miniaturized fiber optic microscopy permits cellular level imaging in the brains of behaving animals. Together, these modalities will enable new uses of imaging in the intact nervous system for both research and clinical applications.

The objective of this study was to determine if flexible FOB could be performed safely without premedication other than topical anesthesia. A total of 281 procedures performed during a 12-month period at a VA medical center were reviewed. Ninety-one procedures performed without premedication were compared with 190 procedures performed with premedication. Complications occurred in 5 percent of patients in each group. Statistical analysis revealed no significant differences in age, spirometry, P(A-a)02 or Sa02 between both groups. Despite the proven safety of outpatient FOB without sedation, many bronchoscopists administer complicated premedication regimens and employ am-bulatory surgery beds or recovery rooms to monitor patients before and after procedures. These results support a simplified approach to routine FOB which would include no premedications and greater use of outpatient facilities resulting in decreased expenditures without compromising patient care, safety or comfort.

Study objectives: To determine whether routine scheduling of surveillance flexible fiberoptic bronchoscopy is warranted within 2 to 3 months after silicone stent insertion for central airway obstruction. Design: Retrospective cohort study. Setting: University medical center. Patients: All patients with silicone stents placed for benign or malignant tracheobronchial obstruction during a 3-year period. Methods: Incidence of stent-related complications, new respiratory symptoms, and need for therapeutic bronchoscopic intervention were noted in patients undergoing surveillance bronchoscopy (SFFB) and emergency bronchoscopy (EFFB), defined as flexible fiberoptic bronchoscopy prompted by onset of new symptoms before the date of scheduled SFFB. Results: One hundred one silicone stents were inserted in 88 patients (47 with cancer, 41 with benign disease). Eighteen patients died within 2 months and had no bronchoscopy. Seventy patients underwent either SFFB or EFFB. Stent-related complications were detected in 9 of 31 asymptomatic patients (29%) undergoing SFFB; all had received tumor-specific therapy after stent insertion (in 7 of 8 patients [88%] reporting new respiratory symptoms at the time of SFFB, and in 26 of 31 patients [84%] undergoing EFFB). Overall, stent-related complications were detected in nine asymptomatic patients (10% of total), of which only four patients (5% of total, but 13% of all asymptomatic patients) required therapeutic interventions. Conclusion: Routine SFFB within 2 to 3 months after stent insertion did not detect a high incidence of stent-related complications among patients without new respiratory symptoms.

Neuroendocrine carcinomas of the larynx include a range of rare tumors which have variable biologic behavior, affecting treatment and prognosis. Among these, typical carcinoid tumors are the least common type. Prognosis of typical carcinoid tumor is better than atypical carcinoid tumor and small cell carcinoma of the larynx. Conservation surgery is the preferred treatment modality. Transoral CO2 laser surgery can be a good alternative for appropriate cases because of the functional results and less morbidity. In this article, a 71-year-old female presented with complaints of feeling a mass during swallowing. Fiberoptic examination of the larynx revealed a mass located on the right aryepiglottic fold and biopsy revealed the tumor as a typical carcinoid tumor. We describe CO2 laser excision of a typical carcinoid tumor of the larynx in this case report.

Neuroendocrine carcinomas of the larynx include a range of rare tumors which have variable biologic behavior, affecting treatment and prognosis. Among these, typical carcinoid tumors are the least common type. Prognosis of typical carcinoid tumor is better than atypical carcinoid tumor and small cell carcinoma of the larynx. Conservation surgery is the preferred treatment modality. Transoral CO2 laser surgery can be a good alternative for appropriate cases because of the functional results and less morbidity. In this article, a 71-year-old female presented with complaints of feeling a mass during swallowing. Fiberoptic examination of the larynx revealed a mass located on the right aryepiglottic fold and biopsy revealed the tumor as a typical carcinoid tumor. We describe CO2 laser excision of a typical carcinoid tumor of the larynx in this case report.

Colloidal silica is an important biocompatible, inert and non-toxic material for imaging, therapy, and drug delivery biomedical applications. In this context, the evaluation of colloidal suspensions and their stabilities by a Fiber Optic Quasi-Elastic Light Scattering sensor is proposed. Two different silica nanoparticles were prepared and characterized by scanning electron microscopy and X-ray diffraction, being completely amorphous, with mean diameters of 125 and 159 nm and average specific weight of 1.94 g.cm -3 . The nanoparticles were dispersed in deionized water in different concentrations ranging from 0 to 2% (m/m), resulting in suspensions with mean kinematic viscosity of 0.009157 cm².s -1 . The sensor showed different sensitivities regarding concentrations and diameters, with an increase in the light intensity dispersion caused by the scattering. A decreasing tendency of the decay rate of the autocorrelation function of the light intensity signal was verified with the variation of pH, and this decay rate also showed an abrupt decrease with the enhancement of the ionic strength, detecting the limits of the colloidal stability. This work presents a simple and reliable methodology for the colloidal assessment in a low-cost and minimally invasive way, easily extendable for different chemical and biological systems.

Airway Assessment is one of the most crucial aspects of clinical medicine, forming the foundation of safe practice in anesthesia, emergency care, and critical care medicine. The decision to intervene arises when patients are unable to oxygenate, ventilate, or maintain airway patency, necessitating both noninvasive and invasive strategies. This article explores the central role of airway assessment in predicting and preventing complications, emphasizing both classical bedside methods and emerging technologies. Traditional tools such as the Mallampati classification, thyromental distance, sternomental distance, and neck mobility assessments remain indispensable but imperfect, requiring integration with clinical judgment. Recent advances-including ultrasonography, video laryngoscopy, awake flexible endoscopy, and the growing potential of artificial intelligence-offer promising refinements in pre-intubation risk stratification. Airway management equipment, ranging from basic facemask ventilation to advanced supraglottic devices and endotracheal tubes, must be selected based on patient condition, predicted difficulty, and situational urgency. The significance of interprofessional collaboration, communication, and ethical responsibility is underscored as central to improving outcomes. In conclusion, a holistic, systematic, and anticipatory approach to airway assessment-combining traditional methods, modern innovations, and effective teamwork-remains vital to enhancing patient safety across diverse clinical environments.

Resumen: El síndrome de Eagle consiste en una osificación del ligamento estilohioideo que en ocasiones se manifiesta por dolor en el cuello, disfagia o molestias inespecíficas en dicha región. En algunos casos se precisa el tratamiento quirúrgico de dicha lesión. Debido a su localización y a la osificación, cuando se realiza anestesia general con intubación traqueal pueden presentarse dificultades en el tratamiento de la vía aérea, especialmente en la intubación traqueal. Presentamos el caso de una paciente con síndrome de Eagle que iba a ser intervenida para resección de la osificación. Se discute la valoración y el tratamiento de la vía aérea. Palabras clave: síndrome de Eagle, intubación traqueal, anestesia general. Abstrac: Eagle syndrome consists in a ossification of the stylohioid ligament. Sometimes clinical symptoms due to this ossification develops, consisting in neck pain, dysphagia and other. In some instances surgical treatment is needed. In this cases, if

Los pacientes con malformaciones craneofaciales representan un reto y hacen necesario un plan de manejo avanzado de la via aerea. Generalmente estan acompanadas de sindromes que afectan diferentes aparatos y sistemas, entre ellos la via aerea, ocasionando variaciones anatomicas que modifi can su estructura de manera positiva, negativa o neutra. En este escenario clinico, la mayoria de las alteraciones se consideran via aerea dificil, defi nida como aquella situacion clinica en la cual un experto en via aerea experimenta difi cultad en la ventilacion con mascarilla facial, en la intubacion traqueal o en ambas(1). La via aerea esta compuesta de tejidos oseos y blandos; dentro de los cuales la cavidad oral, el espacio mandibular anterior, el maxilar, la articulacion temporomandibular y la columna vertebral presentan las alteraciones mas frecuentes(2). La clasifi cacion de las malformaciones craneofaciales segun la Asociacion Americana de Paladar Hendido las divide en: sinostosis, hendi...

Los pacientes con malformaciones craneofaciales representan un reto y hacen necesario un plan de manejo avanzado de la via aerea. Generalmente estan acompanadas de sindromes que afectan diferentes aparatos y sistemas, entre ellos la via aerea, ocasionando variaciones anatomicas que modifi can su estructura de manera positiva, negativa o neutra. En este escenario clinico, la mayoria de las alteraciones se consideran via aerea dificil, defi nida como aquella situacion clinica en la cual un experto en via aerea experimenta difi cultad en la ventilacion con mascarilla facial, en la intubacion traqueal o en ambas(1). La via aerea esta compuesta de tejidos oseos y blandos; dentro de los cuales la cavidad oral, el espacio mandibular anterior, el maxilar, la articulacion temporomandibular y la columna vertebral presentan las alteraciones mas frecuentes(2). La clasifi cacion de las malformaciones craneofaciales segun la Asociacion Americana de Paladar Hendido las divide en: sinostosis, hendi...

Few techniques are available to characterize in vivo the early cellular dynamics of long-term reconstitution of hematopoiesis after transplantation of hematopoietic stem cells (HSCs) after lethal irradiation. Using a fiber-optic imaging system, we track the early steps of in vivo recruitment and proliferation of Lin−Sca-1+c-Kit+CD34− (LSKCD34−) HSCs highly enriched in HSCs and transplanted into lethally irradiated mice. Recruitment of the transplanted LSKCD34− hematopoietic cells first occurs in the femoral head and is continuous during 24 hours. Quantification of the fluorescence emitted by the transplanted hematopoietic cells shows that proliferation of LSKCD34− hematopoietic cells in the femoral head was potent 3 days after transplantation. Using a development of this fiber-optic imaging system, we show that the transplanted LSKCD34− hematopoietic cells are associated with vascularized structures as early as 5 hours after transplantation. This early association is dependent on re...

Optical brain stimulation gained a lot of attention in neuroscience due to its superior cell-type specificity. In the design of illumination strategies, predicting the light propagation in a specific tissue is essential and requires knowledge of the optical properties of that tissue. We present the estimated absorption and reduced scattering in rodent brain tissue using non-destructive contact spatially resolved spectroscopy (cSRS). The obtained absorption and scattering in the cortex, hippocampus and striatum are similar, but lower than in the thalamus, leading to a less deep but broader light penetration profile in the thalamus. Next, the light distribution was investigated for different stimulation protocols relevant for fiber-optic based optogenetic experiments, using Monte Carlo simulation. A protocol specific analysis is proposed to evaluate the potential of thermally induced side effects.

Negative contralateral groin exploration for childhood hernias raises the question of whether contralateral groin exploration is necessary or not. To find out whether a contralateral processus vaginalis was patent, we performed laparoscopy with a flexible scope. After carbon dioxide insufflation, a flexible laparoscope was inserted through the opened hernia sac and the contralateral processus vaginalis orifice was examined. We considered a patent processus vaginalis as a potential hernia. The study involved 20 children: 16 boys and 4 girls. The symptomatic side was explored in a conventional manner and laparoscopy was performed through the opened hernia sac. A contralateral processus vaginalis was found in 6 children: 4 boys and 2 girls. These results were confirmed by exploring the opposite groin. We did not explore if the laparoscopic examination was within normal limits. There was one false-positive result in a female patient. Intraoperative non-puncture laparoscopy utilizing a f...

Managing a case of anticipated difficult airway successfully is like a dream come true for an anesthesiologist. We should have a good airway assessment to identify patients who may have difficult airways, at the same time knowing alternate approaches to airway management. We here intend to describe how we managed two cases of anticipated difficult airway in males both having posterior neck swelling with restricted neck movements. This report will exemplify the importance of workup for anticipated difficult airway including importance of considering predictors of difficult airway, preoperative awake direct laryngoscopy at the same time making availability of skilled anesthetist and difficult airway cart.

We report on a fiber-stabilized agile laser with ultra-low frequency noise. The frequency noise power spectral density is comparable to that of an ultra-stable cavity stabilized laser at Fourier frequencies higher than 30 Hz. When it is chirped at a constant rate of ~ 40 MHz/s, the max non-linearity frequency error is about 50 Hz peak-to-peak over more than 600 MHz tuning range. The Rayleigh backscattering is found to be a significant frequency noise source dependent on fiber length, chirping rate and the power imbalance of the interferometer arms. We analyze this effect both theoretically and experimentally and put forward techniques to reduce this noise contribution.

Since their introduction 30 years ago, Micro-Electrode Arrays (MEAs) have been exploited as devices providing distributed information about learning, memory and information processing in a cultured neuronal network, thus changing the field of view from the scale of the single cell (glass pipettes) to the scale of the complex network properties. MEAs represent a growing technology for the study of the functional activity of neuronal networks in a large-scale view providing the possibility (a) to gain information about the spatio-temporal dynamics of the neuronal network, (b) to allow recordings of electrical activity over periods of time not compatible with conventional electrodes and (c) to monitor network activity at several sites in parallel. More recently, according to the trend aimed at the reduction of animal tests, MEAs have been exploited as in vitro biosensors to monitor both acute and chronic effects of drugs and toxins on neuronal networks in physiological or pathophysiolo...

SummaryWe investigated the in vitro performance of the CeVOXTM system for continuous monitoring of central venous oxygen saturation by spectrophotometry (Pulsion Medical Systems, Munich, Germany). Oxygen inflow into the system was varied, and oxygen saturation values measured by CeVOX were documented. Blood samples were simultaneously taken to assess oxygen saturation by co‐oximetry, and values were compared by Bland–Altman analysis. Sixty‐six data pairs were obtained at CeVOX and co‐oximetry values of 16–99% and 5.5–100%, respectively. Overall, CeVOX values only slightly overestimated co‐oximetry values (mean bias + 2.4%), but limits of agreement (2 SD of bias) were wide (− 11.8 to + 16.6%). Saturation measured by CeVOX underestimated that measured by co‐oximetry at higher oxygen concentrations and overestimated it at lower oxygen concentrations. There was a nearly linear correlation of the mean bias, suggesting a systematic error. We conclude that the current version of the CeVOX ...

This paper describes a preliminary study of the thermoluminescence (TL) response of doped SiO2 optical fibres subjected to 241AmBe neutron irradiation. The TL materials, which comprise Al-and Ge-doped silica fibres, were exposed in close contact with the 241AmBe source to obtain fast neutron interactions through use of measurements obtained with and without a Cd filter (the filter being made to entirely enclose the fibres). The neutron irradiations were performed for exposure times of 1-, 2-, 3-, 5-and 7-days in a neutron tank filled with water. In this study, use was also made of the Monte Carlo N-particle (MCNPTM) code version 5 (V5) to simulate the neutron irradiations experiment. It was found that the commercially available Ge-doped and Al-doped optical fibres show a linear dose response subjected to fast neutrons from 241AmBe source up to seven days of irradiations. The simulation performed using MCNP5 also exhibits a similar pattern, albeit differing in sensitivity. The TL response of Ge-doped fibre is markedly greater than that of the Al-doped fibre, the total absorption cross section for Ge in both the fast and thermal neutrons region being some ten times greater than that of Al.

Impact detection in aeronautical structures allows predicting their future reliability and performance. An impact can produce microscopic fissures that could evolve into fractures or even the total collapse of the structure, so it is important to know the location and severity of each impact. For this purpose, optical fibers with Bragg gratings are used to analyze each impact and the vibrations generated by them. In this paper it is proven that optical fibers with Bragg gratings can be used to detect impacts, and also that a high-frequency interrogator is necessary to collect valuable information about the impacts. The use of two interrogators constitutes the main novelty of this paper.

A 15-years-old male was presented with hyperemic and painful right flank mass. His medical history was consisted of a treatment for pneumonia and hemoptysis in the other hospital five months ago. Diagnostic X-rays was showed consolidation in the posterobasal segment of right pulmonary lobe and abscess in the paravertebral muscle extending from L4-5 level. The patient was discharged after antibiotic treatment. At the second hospitalization, a grass inflorescence was discharged from the fistula. When the patient was reevaluated his history was consisted of the aspiration of a grass inflorescence eight months ago. To our knowledge, this patient represents the first case of penetration by a grass inflorescence migrated out of the lumbar region.

Editor-We read with interest the report by Mikuni and colleagues 1 as we had a similar experience with a 20-yr-old female patient who had undergone anterolateral spinal decompression at T4-6. Tracheal intubation with a doublelumen tube was unremarkable except for the failure of the first attempt. After operation, the patient had hoarseness of voice. On the first postoperative day, the patient went into respiratory failure and required mechanical ventilation. A fibreoptic bronchoscopy revealed gross hyperaemia of the glottis and arytenoids. A diagnosis of glottic oedema was made. The patient was managed with steroids and on the fifth postoperative day again extubated. A few hours later, the patient had to be reintubated due to respiratory failure. A CT scan of the neck was unremarkable. A repeat fibreoptic bronchoscopy revealed hyperaemia of glottis with swelling of the arytenoids. Bronchoscopy on the eighth postoperative day showed no hyperaemia in the glottic region, but the aytenoids were still swollen. A 708 scoping was done post-extubation, which showed sluggish movement of both vocal cords. A month later, the patient had some residual hoarseness. This prompted the diagnosis of post-intubation cricoarytenoid joint dysfunction probably after haemarthrosis of cricoarytenoid joint. Laryngeal oedema was a strong possibility but the delay in onset of respiratory distress and the persistence of hoarseness for nearly a month favoured the diagnosis of cricoarytenoid joint dysfunction.

The purpose of this study was to investigate the accuracy and interobserver reliability of examiners with different levels of clinical experience, when diagnosing radiographic proximal caries lesions. Bitewing radiographs were selected from a patient attending Operative Dentistry Clinic, Universidad de Chile. Radiographic examination was performed by three different groups: A: third year dentistry students, B: fourth year dentistry students, and C: dentist recently graduated. Thirty-two proximal surfaces were scored as: 0, sound; 1: enamel caries; and 2: dentinal caries. The data were analysed and accuracy and interexaminer reliability were calculated. Accuracy values for enamel caries were: A (0.54), B (0.55) and C (0.58), and dentinal caries were: A (0.55), B (0.61) and C (0.63). Interexaminer reliability denoted marginal agreement for all groups, A (0.249), B (0.213) and C (0.282) for enamel caries and A (0.058), B (0.102), and C (0.344) for dentinal caries. The results of this study indicate that the accuracy and interexaminer reliability of bitewing radiographic examination were influenced by the clinical experience when detecting radiographic proximal caries, however low values of accuracy and interexaminer reliability were noted, reinforcing the necessity of improving education and training in radiographic caries detection.

We report the first optical parametric generator (OPG) based on the new nonlinear material, orientationpatterned gallium phosphide (OP-GaP). Pumped by a Qswitched nanosecond Nd:YAG laser at 1064 nm with 25 kHz pulse repetition rate, the OPG can be tuned across 1721-1850 nm in the signal and 2504-2787 nm in the idler. Using a 40-mm-long crystal in single pass, we have generated a total average output power of up to ~18 mW, with ~5 mW of idler power at 2670 nm, for 2 W of input pump power. The OPG exhibits a passive stability in total output power better than 0.87% rms over 1 hour, at a crystal temperature of 120 ºC, compared to 0.14% rms for the input pump. The output signal pulses, recorded at 1769 nm, have duration of 5.9 ns for input pump pulses of 9 ns. Temperature-dependent loss measurements for the pump polarization along the [100] axis in the OP-GaP crystal have also been performed, for the first time, indicating a drop in transmission from 28.8% at 50ºC to 19.4% at 160ºC.

Spectroscopy in the wavelength range from 2 to 11 μm (900 to 5000 cm) implies a multitude of applications in fundamental physics, chemistry, as well as environmental and life sciences. The related vibrational transitions, which all infrared-active small molecules, the most common functional groups, as well as biomolecules like proteins, lipids, nucleic acids, and carbohydrates exhibit, reveal information about molecular structure and composition. However, light sources and detectors in the mid-infrared have been inferior to those in the visible or near-infrared, in terms of power, bandwidth, and sensitivity, severely limiting the performance of infrared experimental techniques. This article demonstrates the generation of femtosecond radiation with up to 5 W at 4.1 μm and 1.3 W at 8.5 μm, corresponding to an order-of-magnitude average power increase for ultrafast light sources operating at wavelengths longer than 5 μm. The presented concept is based on power-scalable near-infrared la...

We report on a femtosecond optical parametric oscillator (OPO) for the deep-infrared (deep-IR) based on the Kerr-lens-mode-locked Ti:sapphire laser as the pump source. By deploying a novel cascaded intracavity arrangement, comprising a femtosecond OPO based on the nonlinear crystal, CdSiP<sub>2</sub>, synchronously pumped internal to a MgO:PPLN femtosecond OPO, we have generated broadly tunable radiation across 5958-8117 nm using rapid static cavity delay tuning, with a maximum power of 64 μW at 6791 nm, limited by the absorption in mirror substrates as well as polarization-dependent intracavity losses. The deep-IR idler power exhibits excellent passive stability of better than 1.1% rms over 2 h, with a spectral bandwidth as large as ∼650  nm at ∼6800  nm. The demonstrated concept is generic and can be similarly deployed in other operating time scales and wavelength regions, also using different laser pump sources and nonlinear materials.

An effective corrosion monitoring technique is sought after by the engineers for assessing the steel bar corrosion at the early stage for the maintenance and repair works, especially in the corrosive environments, such as coastal and marine. In this work, tilted fiber Bragg grating (TFBG) with the optical sensor is employed in corrosion monitoring of a reinforced concrete structure. Taking advantage of the high sensitivity of TFBG cladding resonance wavelengths to the change in the surrounding medium, the sensor is mounted on the steel bar that is embedded in a concreted block during an accelerated corrosion process. The acquired transmission spectrum of the TFBG during the procedure is digitally processed using Fourier Transform to produce an index that is sensitive to the generated corrosion product surrounding the TFBG sensor. This eases the analysis of the sophisticated TFBG transmission spectra. The generated index can be used as an indicator (indicator J) for the corrosion pro...

Semiconductor nanowires (NWs)represent an ideal system for investigating low-dimensional physics and are expected to play an important role as both interconnects and functional device elements in nanoscale electronic and optoelectronic devices. Here we review a series of key advances defining a new paradigm of bottom-up assembling integrated nanosystems using semiconductor NW building blocks. We first introduce a general approach for the synthesis of a broad range of semiconductor NWs with precisely controlled chemical composition, physical dimension, and electronic, optical properties using a metal cluster-catalyzed vapor-liquid-solid growth mechanism. Subsequently, we describe rational strategies for the hierarchical assembly of NW building blocks into functional devices and complex architectures based on electric field or micro-fluidic flow. Next, we discuss a variety of new nanoscale electronic device concepts including crossed NW p-n diode and crossed NW field effect transistor...

We successfully integrate coherent one-way QKD at 1538 nm in a 7.7 km long hollow-core fiber link with 17 EDFA-boosted C-band data channels from 1540.56 to 1558.17 nm, aggregating a power of 11 dBm. QKD operation proves successful despite the wideband layout of classical channels.

Background The ProSeal Laryngeal Mask Airway (PLMA) (Laryngeal Mask Company, Henley-on-Thames, United Kingdom) is a new laryngeal mask with a modified cuff designed to improve its seal and a drain tube for gastric tube placement. Similarly, the Laryngeal Tube Suction (LTS) (VBM Medizintechnik Gmbh, Sulz a.N, Germany) is a new laryngeal tube that also has an additional channel for gastric tube placement. This study compared the placement and functions of these two devices. Methods One hundred fifty patients undergoing general anesthesia for elective surgery were randomly allocated to the PLMA (n = 75) or LTS (n = 75). Oxygenation and ventilation, ease of insertion, fiberoptic view, oropharyngeal leak pressure, ventilatory data, ease of gastric tube insertion, and postoperative airway morbidity were determined. Results After successful insertion of the devices in 96% of patients with the PLMA and in 94.4% with the LTS it was possible to maintain oxygenation, ventilation, and respirato...

We describe the Elisha Airway Device (EAD), a new reusable supraglottic ventilatory device. Its uniqueness consists of its ability to combine three functions in a single device: ventilation, blind and/or fiberopticaided intubation without interruption of ventilation, and gastric tube insertion. This study was performed in 70 ASA status I-II, Mallampati class I-II patients undergoing elective knee arthroscopy and receiving general anesthesia with mechanical ventilation. Anesthesia was induced with fentanyl and propofol and was maintained with isoflurane in N 2 O/oxygen. Neuromuscular blockade was achieved with vecuronium. Blind insertion of the device was successful in 96% of patients, with

A rhodamine organosilane derivative (Rh-UTES) has been obtained by one-pot synthesis. The chemical structure of Rh-UTES was confirmed by nuclear magnetic resonance (NMR) and infrared (FTIR) techniques. To obtain an inorganic-organic hybrid sensor, Rh-UTES was covalently immobilized on a porous silicon microcavity (PSiMc) via triethoxysilane groups. The attachment of the organic derivative into PSiMc was confirmed by FTIR, specular reflectance, and scanning electron microscopy (SEM). The optical performance of Rh-UTES receptor for Hg2+ detection was investigated by fluorescent spectroscopy and microscopy. Upon the addition of increasing amounts of Hg2+ ions, a remarkable enhancement in emission intensity was produced in both systems. In the solid phase, an increase of integrated fluorescent emission of 0.12- and 0.15-fold after Hg2+ receptor coordination was observed. The light harvesting capability of PSiMc devices allowed obtaining an enhanced fluorescent emission after Rh-UTES imm...

Background. Mammary ductoscopy (MD) allows direct visualisation of the mammary ducts using sub-millimetre fiberoptic microendoscopes inserted through the ductal opening onto the nipple surface. The sharp clear magnified images are viewed on a video monitor. Such scopes have working channels that allow irrigation and ductal lavage for cytological analysis. MD can be performed under local anaesthesia in the office setting. This article reviews the evolving role of MD in the diagnosis and treatment of intraductal breast disease. Methods. A literature search was carried out from Pubmed for indexed articles published over the last 30 years using the keywords 'mammary ductoscopy' and 'breast ductoscopy'. Results. The search yielded 27 indexed published articles and reports. Important major reports and studies were reviewed, screened and tracked for other relevant publications. The most important articles were analysed and discussed. The review also includes our published and unpublished original work in the field of MD. Conclusions. MD is a useful diagnostic adjunct in patients with pathological nipple discharge (PND). Furthermore, it can reduce the number and extent of duct excision operations for PND. However, its potential use in the early detection of breast cancer, guiding breast conserving surgery (BCS) for cancer, therapeutic ablation of intraductal disease, and guiding risk-reducing strategies among high risk women requires further research and evaluation. Future developments include the development of a biopsy kit, combining MD with molecular diagnostic markers and real-time optical biopsy system for the diagnosis of pre-malignant and early malignant disease and radiofrequency for curative ablation of intraductal lesions.

My indebt to my family members, who have ever done their best for me, makes me to present my gratitude to them. My special thanks and deepest heart felt appreciation goes to Ms. Dr. Sanaz Hariri Tabrizi for her immense knowledge, continuous support, patience, honest companionship and her gracious heart. It is not exaggerated if I say that she emerged in my life as a miracle. She actually revived me, my motivation and effort, and reminded me the sense of humanity. I could not have imagined having a better co-supervisor for my master studies. I would also like to thank Prof. Mustafa Halilsoy, Prof. Ozay Gurtug, my dear supervisor, and Prof. Habib Mazharimousavi for their assistance within this educational period. Moreover, I would like to thank Ms. Cilem Aydintan, dutiful and kind secretary, who helped me so much. Last but not the least, my thanks to Jalil Heydaripour, Ehsan Bahramzadeh, who while he was busy, he helped me out to remove my thesis-related problems,

P atients who require translaryngeal prolonged intu- bation are at risk for developing swallowing dysfunctions that may predispose aspiration and the subsequent development of nosocomial pneumonia. Nosocomial pneumonia is one of the major causes of infection in the ICU and is associated with an increase in patient morbidity and mortality and high costs of care. 2 In this setting, tracheostomy is one of the most common surgical procedures performed in this group of patients, 3 with an international prevalence of 10% to 20%. Currently, bedside percutaneous dilation tracheostomy (PDT) has become the method of Background: The aim of this study was to determine the incidence of swallowing dysfunction in nonneurologic critically ill patients who require percutaneous dilatational tracheostomy (PDT) for prolonged mechanical ventilation (MV) and to compare the duration of the cannulation period and length of stay in the critical care unit (CCU) in patients with and without swallowing dysfunction. Methods: A total of 40 consecutive patients without neurologic disorders who require PDT for prolonged MV were included. Previous to the tracheostomy decannulation process, an otolaryngologist performed a fi beroptic endoscopic evaluation of swallowing (FEES). We used analysis of variance for the analysis; the results are presented as mean values 6 SD. Results: Mean age was 62 6 15 years. Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores were 21 6 2 and 9 6 1, respectively. Time of MV previous to PDT was 20 6 11 days, total MV duration was 38 6 16 days, and CCU stay was 63 6 27 days. The incidence of swallowing dysfunction in this group of patients was 38% (15/40). No difference was found in the age or time period of MV previous to PDT between groups. The time period between FEES to tracheostomy decannulation process was 19 6 11 days in patients with swallowing dysfunction vs 2 6 4 days in those patients without dysfunction ( P , .001). Patients who developed swallowing dysfunction stayed longer in the CCU (69 6 23 vs 47 6 19 days, P , .01). Conclusions: Nearly 40% of nonneurologic critically ill patients requiring PDT for prolonged MV presented swallowing dysfunction and experienced a signifi cant delay in their tracheostomy decannulation process.

To advance neuroscience in vivo experiments, it is necessary to probe a high density of neurons in neural networks with single-cell resolution and be able to simultaneously use different techniques, such as electrophysiological recordings and optogenetic intervention, while minimizing brain tissue damage. We first fabricate electrical neural probes with a high density of electrodes and small tip profile (cross section of shank: 47-μm width × 16-μm thickness). Then, with similar substrate and fabrication techniques, we separately fabricate optical neural probes. We finally indicate a fabrication method that may allow integrating the two functionalities into the same device. High-density electrical probes have been fabricated with 64 pads. Interconnections to deliver the signal are 120-nm wide, and the pads are 5 × 25 μm. Separate optical probes with similar shank dimensions with silicon dioxide and silicon nitride ridge single-mode waveguides have also been fabricated. The waveguide core cross section is 250 nm × 160 nm. Light is focused above the waveguide plane in 2.35-μm diameter spots. The actual probes present two output focusing gratings on the shank.

The Fiber Sensor Demonstrator (FSD), for ESA's Proba-2 satellite is the first demonstration of a full fiber-optic sensor network in the space environment on a satellite. MPB Communications (MPBC) has developed the FSD as a lightweight (<1.3 kg) fiber-optic sensing system. It was launched on Proba-2 in November 2009 and is still completely functional, almost seven years after its launching. FSD contains also the first fiber laser in space, it is used to sweep the spectral range and read the intensity at each wavelength between 1520 and 1560 nm. The optoelectronic components and data acquisition board are about 500 g, and the rest (<800 g) is the mass of the protective monolithic aluminium enclosure that has to resist to the launching mechanical shock and vibrations. The advantages of the FSD approach include a central interrogation module that is positioned remotely from the sensors and used to control a variety of different fiber-optic sensors, based on Fiber Bragg Gratings (FBG). The FSD contains six parallel fiber lines multiplexed within the interrogation module. Sixteen speciallypackaged FBG temperature sensors are distributed on four fiber lines. They monitor the temperature at different locations in the propulsion system and the spacecraft bus over the range of -60 °C and +120°C. The fifth fiber line is dedicated to a High-Temperature (HT) sensor to measure the transient temperature response of the SSTL thruster to beyond 350°C. The last fiber line contains an innovative Pressure/Temperature (P/T) sensor that provides both temperature and pressure measurements of the SSTL Xe propellant tank. The fiber sensors are monitored periodically over the seven years of flight. Their measurements fit well with the standard sensors used by the satellite. The evolution of the FSD response in space shows the fibers and Interrogation module parameters are within 10 % variations, including the laser diodes power and the FBG sensors intensity. The total gamma radiation received by the FSD is about 7 krad, during the 7 years.

In this work, fabrication and demonstration of a strain sensitive long-period grating (LPG) sensor is discussed. Equally spaced inscription LPG has been fabricated in germanium doped silica (Ge-SiO 2 ) single-mode optical fibre. In the fabrication process amplitude mask approach was employed and KrF excimer laser with 248 nm wavelength has been used for inducing index modulation in the core of fibre. On a single mode fibre, uniform LPG of period 95 µm and 30 mm grating length has been inscribed and subsequently was used as a strain sensor to monitor the strain up to 7000 µ. Sensitivity of this sensor is found to be 0.931 nm/1000 µ whereas for standard fibre Bragg grating, it is 1.2 nm/1000 µ.

The tooth is a biological entity comprising of a hard enamel layer, encasing the softer (but still hard) dentine which conceals the much softer pulp chamber. Dental caries, commonly known as tooth decay, is the localized demineralization of enamel or dentine caused by the acidic by products of bacteria. Current methods of detection and diagnosis routinely used in the dental surgery are limited to the subjective act of visual inspection (with aide of a metal probe known as an explorer) and bitewing X-ray. Neither method provides quantitative information about the state of the disease in the tooth for accurate diagnosis and subsequent treatment planning. Such methods are also poor at detecting disease in the early (and most treatable) stages. There are, however, new technologies, generally optically based, making their way into the dental clinic, including Quantitative Light Fluorescence and the DiagnoDent tool. Both methods are able to improve the detection rates of dental caries, ho...

This study was designed to assess the feasibility and practicability of the employment of endoscopic methods for the diagnosis of dental caries and to compare the diagnostic performance, in posterior teeth, of visual endoscopic caries diagnosis (with and without the benefit of differential fluorescence) with that of conventional visual diagnosis, bite-wing radiography, and conventional transillumination. The two endoscopic methods were found to be clinically practicable, to be able to demonstrate the presence of small carious lesions, and to have both advantages and disadvantages compared to conventional methods. When all tooth sites were compared, the results indicated that the endoscopic methods may detect a greater number of carious lesions than do conventional visual, radiographic, or fiber-optic transilluminational methods of caries diagnosis. Further investigations involving histologic validation of diagnoses as well as larger numbers of patients and multiple examiners are ind...

A new approach for generating high-speed multispectral confocal images has been developed. The central concept is that spectra can be acquired for each pixel in a confocal spatial scan by using a fast spectrometer based on optical fiber delay lines. This approach merges fast spectroscopy with standard spatial scanning to create datacubes in real time. The spectrometer is based on a serial array of reflecting spectral elements, delay lines between these elements, and a single element detector. The spatial, spectral, and temporal resolution of the instrument is described and illustrated by multispectral images of laser-induced autofluorescence in biological tissues.

Fiber laser technology has been demonstrated as a versatile and reliable approach to laser source manufacturing with a wide range of applicability in various fields ranging from science to industry. The power/energy scaling of single-fiber laser systems has faced several fundamental limitations. To overcome them and to boost the power/energy level even further, combining the output powers of multiple lasers has become the primary approach. Among various combining techniques, the coherent beam combining of fiber amplification channels is the most promising approach, instrumenting ultra-high-power/energy lasers with near-diffraction-limited beam quality. This paper provides a comprehensive review of the progress of coherent beam combining for both continuous-wave and ultrafast fiber lasers. The concept of coherent beam combining from basic notions to specific details of methods, requirements, and challenges is discussed, along with reporting some practical architectures for both conti...

Soliton switching in nonlinear directional couplers implemented in photonic crystal fibers (PCF) examined here. A vector finite element method (FEM) has been developed to precisely calculate the dispersion along with coupling length of the guided modes. The PCF coupler geometry was carefully designed so that it can support soliton pulses. Soliton switching is demonstrated numerically at 1.55 μm for 100 femto-second (fs) pulses. Our theoretical results explain some of the key spectral features previously observed in the experiment.

Renal osteodystrophy (ROD) is a systemic bone metabolic disease caused by renal dysfunction and is a significant complication in patients with late-stage chronic kidney disease (CKD) or those undergoing hemodialysis. Patients with chronic kidney disease undergo long-term dialysis, which can lead to secondary hyperparathyroidism, hypocalcemia, hyperphosphatemia, and aluminium toxicity. This case presents a middle-aged woman who underwent long-term dialysis for uremia and developed hyperparathyroidism. She was scheduled to undergo parathyroidectomy under general anesthesia. During the pre-anesthesia assessment, deformities were found in the patient’s maxillofacial region. It was suspected that there would be difficulty with face mask ventilation and tracheal intubation. In this case, fibreoptic bronchoscopy-guided endotracheal intubation was successfully performed under mild sedation. An individualized anesthesia plan was developed, and successful airway management was achieved. Ultimately, the patient’s surgery went smoothly, with the tracheal tube being safely removed afterwards.

Louisiana researchers and universities are leading a concentrated, collaborative effort to advance statewide e-Research through a new cyberinfrastructure: computing systems, data storage systems, advanced instruments and data repositories, visualization environments and people, all linked together by software programs and high-performance networks. This effort has led to a set of interlinked projects that have started making a significant difference in the state, and has created an environment that encourages increased collaboration, leading to new e-Research. This paper describes the overall effort, the new projects and environment and the results to date.