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Sample records for early fiberoptic bronchoscopy

  1. Bronchoscopy

    MedlinePlus

    Fiberoptic bronchoscopy; Lung cancer - bronchoscopy; Pneumonia - bronchoscopy; Chronic lung disease - bronchoscopy ... from sarcoidosis or rheumatoid arthritis may be found. Lung cancer , or cancer in the area between the lungs. ...

  2. [Emergency fiberoptic bronchoscopy for diagnostics and treatment of lung atelectasis].

    PubMed

    Mironov, A V; Pinchuk, T P; Selina, I E; Kosolapov, D A

    2013-01-01

    The article deals with results of fiberoptic bronchoscopy using during treating of patients suffering atelectasis. According to the research atelectasis is likely to advance in the first three days after serious patients have been admitted to the intensive therapy unit or after operative treatment. Left-sided atelectasis is half as widespread again the right-sided one. The research highlights the effectiveness of atelectasis X-ray diagnosis. Fiberoptic bronchoscopy in almost all the cases allowed diagnosing the degree of tracheobronchial tree obstruction and its causes. Single suction fiberoptic bronchoscopy leads to normalization and encouraged positive dynamics in 76% of all the cases (57 patients). Repeated endoscopic sanation in the first two days was necessary for 25 patients (25.3%) with unresolved or reoccurring atelectasis. The effectiveness of second research was to 84%. It's important to add that mostly patients with serious chest injury were subjected to unresolved or reoccurring atelectasis. And mainly in these cases blood was seen through the tracheobronchial tree lumen.

  3. Early fiberoptic bronchoscopy during non-invasive ventilation in patients with decompensated chronic obstructive pulmonary disease due to community-acquired-pneumonia

    PubMed Central

    2010-01-01

    Introduction Inefficient clearance of copious respiratory secretion is a cause of non-invasive positive pressure ventilation (NPPV) failure, especially in chronic respiratory patients with community-acquired-pneumonia (CAP) and impaired consciousness. We postulated that in such a clinical scenario, when intubation and conventional mechanical ventilation (CMV) are strongly recommended, the suction of secretions with fiberoptic bronchoscopy (FBO) may increase the chance of NPPV success. The objective of this pilot study was, firstly, to verify the safety and effectiveness of early FBO during NPPV and, secondly, to compare the hospital outcomes of this strategy versus a CMV-based strategy in patients with decompensated chronic obstructive pulmonary disease (COPD) due to CAP who are not appropriate candidates for NPPV because of inefficient mucous clearance and hypercapnic encephalopathy (HE). Methods This is a 12-month prospective matched case-control study performed in one respiratory semi-intensive care unit (RSICU) with expertise in NPPV and in one intensive care unit (ICU). Fifteen acutely decompensated COPD patients with copious secretion retention and HE due to CAP undergoing NPPV in RSICU, and 15 controls (matched for arterial blood gases, acute physiology and chronic health evaluation score III, Kelly-Matthay scale, pneumonia extension and severity) receiving CMV in the ICU were studied. Results Two hours of NPPV significantly improved arterial blood gases, Kelly and cough efficiency scores without FBO-related complications. NPPV avoided intubation in 12/15 patients (80%). Improvement in arterial blood gases was similar in the two groups, except for a greater PaO2/fraction of inspired oxygen ratio with CMV. The rates of overall and septic complications, and of tracheostomy were lower in the NPPV group (20%, 20%, and 0%) versus the CMV group (80%, 60%, and 40%; P < 0.05). Hospital mortality, duration of hospitalisation and duration of ventilation were similar

  4. Early fiberoptic bronchoscopy during non-invasive ventilation in patients with decompensated chronic obstructive pulmonary disease due to community-acquired-pneumonia.

    PubMed

    Scala, Raffaele; Naldi, Mario; Maccari, Uberto

    2010-01-01

    Inefficient clearance of copious respiratory secretion is a cause of non-invasive positive pressure ventilation (NPPV) failure, especially in chronic respiratory patients with community-acquired-pneumonia (CAP) and impaired consciousness. We postulated that in such a clinical scenario, when intubation and conventional mechanical ventilation (CMV) are strongly recommended, the suction of secretions with fiberoptic bronchoscopy (FBO) may increase the chance of NPPV success. The objective of this pilot study was, firstly, to verify the safety and effectiveness of early FBO during NPPV and, secondly, to compare the hospital outcomes of this strategy versus a CMV-based strategy in patients with decompensated chronic obstructive pulmonary disease (COPD) due to CAP who are not appropriate candidates for NPPV because of inefficient mucous clearance and hypercapnic encephalopathy (HE). This is a 12-month prospective matched case-control study performed in one respiratory semi-intensive care unit (RSICU) with expertise in NPPV and in one intensive care unit (ICU). Fifteen acutely decompensated COPD patients with copious secretion retention and HE due to CAP undergoing NPPV in RSICU, and 15 controls (matched for arterial blood gases, acute physiology and chronic health evaluation score III, Kelly-Matthay scale, pneumonia extension and severity) receiving CMV in the ICU were studied. Two hours of NPPV significantly improved arterial blood gases, Kelly and cough efficiency scores without FBO-related complications. NPPV avoided intubation in 12/15 patients (80%). Improvement in arterial blood gases was similar in the two groups, except for a greater PaO2/fraction of inspired oxygen ratio with CMV. The rates of overall and septic complications, and of tracheostomy were lower in the NPPV group (20%, 20%, and 0%) versus the CMV group (80%, 60%, and 40%; P < 0.05). Hospital mortality, duration of hospitalisation and duration of ventilation were similar in the two groups. In patients

  5. [Flexible Fiberoptic Bronchoscopy in children with persistent atelectasis: a case series report].

    PubMed

    Talamoni, Hernán Lucio; Pisapia, Néstor Daniel; Buendía, Jefferson Antonio

    2015-04-01

    Most patients with pulmonary atelectasis have complete resolution with medical therapy. In patients with persistent atelectasis, endoscopic treatment has proven to be an effective therapy. To describe our experience using flexible fiberoptic bronchoscopy in children with persistent atelectasis. This is a case series report of children treated with flexible bronchoscopy between January 2005 and December 2013, at the Pediatric Pulmonology Section of the Hospital Italiano de Buenos Aires. From a total of 106 bronchoscopies performed, 32 of the patients had a diagnosis of persistent atelectasis. Mean age, 5 years. Laryngeal mask airway was the most common route for flexible bronchoscopy. In 28/32 patients, the procedure was therapeutically useful (complete or partial re-expansion). The procedure was well tolerated and presented only mild complications. Flexible bronchoscopy proved to be a safe and effective tool for the treatment of children with persistent atelectasis.

  6. Optimizing cerebral perfusion pressure during fiberoptic bronchoscopy in severe head injury: effect of hyperventilation.

    PubMed

    Previgliano, I J; Ripoll, P I; Chiappero, G; Galíndez, F; Germani, L; González, D H; Ferrari, N; Hlavnicka, A; Purvis, C

    2002-01-01

    The aim of this study was to evaluate if Hyperventilation (HV) could avoid the Intracranial Pressure (ICP) peak that occurs during Fiberoptic Bronchoscopy (FB) in severely head injured patients. A Cerebral Perfusion Pressure (CPP) > 75 mmHg was maintained in 34 patients, with a subgroup randomized to receive controlled HV during FB. Measurements were done before the procedure, during maximum ICP values and 30 minutes after FB. The HV group had minor ICP values after FB, without differences in CPP and ICP peak values.

  7. Admission Chest CT Complements Fiberoptic Bronchoscopy in Prediction of Adverse Outcomes in Thermally Injured Patients

    DTIC Science & Technology

    2012-08-01

    other CT scoring systems exist for conditions including cystic fibrosis and ARDS, these are not in widespread clinical use and have not been... diagnosis of inhalation injury.10,11 However, degree and depth of damage to main airway mucosa cannot at present be accurately distinguished by eye...injury can result in progressive pulmonary dysfunction, infection, and death. Although bronchoscopy is the standard for diagnosis , it only assesses

  8. [Value of liquid-based cytology of brushing specimens obtained via fiberoptic bronchoscopy for the diagnosis of lung cancer].

    PubMed

    Zhao, Huan; Guo, Huiqin; Zhang, Chuanxin; Zhao, Linlin; Cao, Jian; Pan, Qinjing

    2015-06-01

    To investigate the value of the liquid-based cytology (LBC) of brushing specimens obtained via fiberoptic bronchoscopy for clinical diagnosis of lung cancer. We retrospectively analyzed the LBC cases in our hospital from January 2011 to May 2012, and evaluate its role in the diagnosis of lung cancer. The clinical data of a total of 4 380 cases were reviewed and 3 763 of them had histopathological or clinical follow-up results (including 3 306 lung cancer cases and 457 benign lesion cases). The sensitivity, specificity, and accuracy of LBC diagnosis for lung cancer were 72.4% (2 392/3 306), 99.3% (454/457) and 75.6% (2 846/3 763), respectively. Of the 1 992 lung cancer cases diagnosed by brushing LBC, 528 cases (26.5%) were failed to take forceps biopsy and 113 cases (5.7%) showed negative forceps biopsy results. The accurate rate of subtyping of LBC for non-small cell carcinoma and small cell carcinoma was 99.0% (1 487/1 502) (P < 0.001). Take the resection histopathology as gold standard, the accurate rates of subtyping squamous cell carcinoma, adenocarcinoma and small cell carcinoma by LBC were 95.6% (351/367), 95.6% (351/367) and 100% (367/367), respectively, (P < 0.001). The accurate rates of subtyping of squamous cell carcinoma, adenocarcinoma and small cell carcinoma by forceps biopsy were 97.0% (293/302), 97.4% (294/302) and 99.7% (301/302), respectively, (Kappa = 0.895, P < 0.001). There was no significant difference in subtyping respectively between forceps biopsy and brushing LBC (P > 0.05). Fiberoptic bronchoscopic brushing liquid-based cytology can significantly improve the detection rate of lung cancer, and have a high specificity and accurate rate of subtyping. It is an effective tool for the diagnosis and subtyping of lung cancer.

  9. [Effect of fiberoptic bronchoscopy (FOB) with bronchoalveolar lavage (BAL) on gas exgange in patients after cardiac surgery].

    PubMed

    Benova, A; Dimitrov, N; Stoilova, M; Evstatiev, I; Tsarianski, G; Chirkov, A

    2005-01-01

    Fiberoptic bronchoscopy (FOB) has become a commonplace procedure in ICUs in patients after operation. We studied the outcomes of 35 FOBs performed in 26 patients (18 male and 8 female) during their stay in the ICU of "St. Ekaterina" University Hospital in Sofia after cardiac surgery with Cardiopulmonary Bypass. 33 (95%) of our patients were receiving mechanical ventilation at the time of the FOB. Bronchoalveolar lavage (BAL) was added to all procedures. 21 (60%) patients demonstrated an improvement after FOB. We defined improvement as either an increase of PaO2 with 10 or more mmHg in 6 hours after the procedure or better aeration on the follow-up chest radiograph (CXR). In 19 (54%) FOBs a great amount of secretions, plugging up bronchial lumens was seen. 14 (73%) of these patients were improved after the FOB. From the rest 16 patients, in whom such increased amount of secretions was not seen on FOB, only 7 (43%) demonstrated an improvement after the FOB. 16 procedures were performed on indications of atelectasis. 9 (56%) of them showed an improvement after the FOB. When atelectasis was not present on the CXR, an improvement was found in 12 (63%) cases. 1. FOB is most effective in removing retained secretions. 2. Although not so effective in resolving atelectasis that is not caused by central plugging, FOB should not be neglected because of the additional benefit of BAL for clearing more distal airways.

  10. Can fiberoptic bronchoscopy be applied to critically ill patients treated with noninvasive ventilation for acute respiratory distress syndrome? Prospective observational study.

    PubMed

    Korkmaz Ekren, Pervin; Basarik Aydogan, Burcu; Gurgun, Alev; Tasbakan, Mehmet Sezai; Bacakoglu, Feza; Nava, Stefano

    2016-05-31

    Noninvasive ventilation (NIV) is a cornerstone for the treatment of acute respiratory failure of various etiologies. Using NIV is discussed in mild-to-moderate acute respiratory distress syndrome (ARDS) patients (PaO2/FiO2 > 150). These patients often have comorbidities that increase the risk for bronchoscopy related complications. The primary outcome of this prospective observational study was to evaluate the feasibility, safety and contribution in diagnosis and/or modification of the ongoing treatment of fiberoptic bronchoscopy (FOB) in patients with ARDS treated with NIV. ARDS patients treated with NIV and who require FOB as the diagnostic or therapeutic procedure were included the study. Intensive care ventilators or other dedicated NIV ventilators were used. NIV was applied via simple oro-nasal mask or full-face mask. Pressure support or inspiratory positive airway pressure (IPAP), external positive end expiratory pressure (PEEP) or expiratory positive airway pressure (EPAP) levels were titrated to achieve an expiratory tidal volume of 8 to 10 ml/kg according to ideal body weight, SpO2 > 90 % and respiratory rate below 25/min. Twenty eight subjects (mean age 63.3 ± 15.9 years, 15 men, 13 women, PaO2/FiO2 rate 145 ± 50.1 at admission) were included the study. Overall the procedure was well tolerated with only 5 (17.9 %) patients showing minor complications. There was no impairment in arterial blood gas and cardiopulmonary parameters after FOB. PaO2/FiO2 rate increased from 132.2 ± 49.8 to 172.9 ± 63.2 (p = 0.001). No patient was intubated within 2 h after the bronchoscopy. 10.7, 32.1 and 39.3 % of the patients required invasive mechanical ventilation after 8 h, 24 h and 48 h, respectively. Bronchoscopy provided diagnosis in 27 (96.4 %) patients. Appropriate treatment was decided according to the results of the bronchoscopic sampling in 20 (71.4 %) patients. FOB under NIV could be considered as a feasible tool for

  11. [Effect of bronchoalveolar lavage with fiberoptic bronchoscopy combined with vibration sputum drainage on mechanically ventilated patients with severe pneumonia: a prospective randomized controlled trial in 286 patients].

    PubMed

    Shi, Zeya; Qin, Yuelan; Zhu, Yimin; Pan, Xiaoji; Zhou, Xu; Tan, Yuting; Liu, Yanhui

    2017-01-01

    To investigate the curative effect of bronchoalveolar lavage with fiberoptic bronchoscopy combined with vibration sputum drainage in the treatment of severe pneumonia patients undergoing mechanical ventilation (MV). A prospective randomized controlled trial was conducted. 286 severe pneumonia patients undergoing MV admitted to intensive care unit (ICU) of Hunan People's Hospital from January 2014 to July 2016 were enrolled, and they were divided into control group and observation group according to random number table, with 143 patients in each group. Patients in both groups received sensitive antibiotics for anti-infection, etiological treatment, and calefacient and humidifying treatment. The patients in the control group received bronchoalveolar lavage with fiberoptic bronchoscopy, and those in the observation group received bronchoalveolar lavage combined with vibration sputum drainage. The parameters of respiratory function and inflammation before and after treatment, curative effect, and prognosis were compared between the two groups. (1) There were no significant differences in respiratory function parameters between the two groups before treatment, 2 hours after treatment, the parameters were improved in both groups. Moreover, oxygenation index (PaO 2 /FiO 2 ) in observation group was significantly higher than that of control group [mmHg (1 mmHg = 0.133 kPa): 379.1±20.2 vs. 351.8±24.7], and arterial partial pressure of carbon dioxide (PaCO 2 ) and airway resistance (Raw) were significantly lower than those of the control group [PaCO 2 (mmHg): 36.5±5.8 vs. 45.3±6.9, Raw (cmH 2 O, 1 cmH 2 O = 0.098 kPa): 12.9±0.6 vs. 13.1±0.8, all P < 0.01]. (2) There were no significant differences in inflammation parameters between the two groups before treatment, 24 hours after intervention, which were significantly decreased in both groups. Moreover, white blood cell count (WBC), procalcitonin (PCT) and C-reactive protein (CRP) in the observation group were

  12. [Decrease in paO2 following intratracheal application of a local anesthetic and a 0.9% sodium chloride solution. A prospective study on the use of fiberoptic bronchoscopy in ventilated patients during local anesthesia].

    PubMed

    Konrad, F; Deller, A; Diatzko, J; Schmitz, J E; Kilian, J

    1989-04-01

    Flexible fiberoptic bronchoscopy of intubated patients can be performed in general or local anesthesia (LA). Up to now, no results have been published on the effects of LA for bronchoscopy in ventilated patients. We studied the hemodynamic changes caused by bronchoscopy under LA in mechanically ventilated patients and the effect of LA on the endoscopic decline in arterial pO2. Differences between the widely used agents lidocaine and oxybuprocaine hydrochloride were also studied. We found a decline in paO2 after the administration of LA and further investigated the influence of bronchial lavage on paO2. METHOD. A total of 70 ventilator patients, excluding patients with atelectasis, massive mucous-plug retention, and those under muscle relaxants, were examined in a surgical intensive care unit. In 40 long-term ventilator patients bronchoscopy was performed with either oxybuprocaine hydrochloride 1% (Novesin) (group 1; n = 20) or Lidocaine 1% (Xylocaine) (group 2; n = 20) (2-3 ml LA in repeated doses into the trachea and main bronchi; total amount 10 ml). We looked for hemodynamic changes and effects of LA on the bronchoscopic decline in paO2. In 15 long-term ventilator patients (group 3), LA was applied without bronchoscopy to investigate the duration of the LA-caused decline in paO2. In 15 intubated patients (group 4), the influence of intratracheal administration of 10 ml normal saline was examined. Patient data are shown in Table 2. Measurements were performed in groups 1 and 2 before and after LA, immediately after bronchoscopy and 15, 30, and 60 min after bronchoscopy and in groups 3 and 4 before and 5, 15, 30, and 60 min after LA. RESULTS. There was no effect on cardiocirculatory function during bronchoscopy in LA, but we found a decrease in paO2 after administration of LA in all patients (median in group 1 from 100 to 78 mmHg in group 2 from 104 to 86 mmHg). The subsequent bronchoscopy caused only a small, nonsignificant further decline in paO2. The

  13. Flexible Bronchoscopy.

    PubMed

    Miller, Russell J; Casal, Roberto F; Lazarus, Donald R; Ost, David E; Eapen, George A

    2018-03-01

    Flexible bronchoscopy has changed the course of pulmonary medicine. As technology advances, the role of the flexible bronchoscope for both diagnostic and therapeutic indications is continually expanding. This article reviews the historical development of the flexible bronchoscopy, fundamental uses of the flexible bronchoscope as a tool to examine the central airways and obtain diagnostic tissue, and the indications, complications, and contraindications to flexible bronchoscopy. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Enhancing the Sensitivity of Fluorescence Bronchoscopy for Early Lung Cancer Detection Using a Fluorescent Deoxyglucose Analog

    DTIC Science & Technology

    2013-11-01

    overexpression of glucose transporters ( Gluts ) and the increased activity of mitochondria- bound hexokinases in tumors (5, 6). Since 1976, 2-(fluorine-18...glucose transport through the cell membrane via Gluts has been reported as an important factor in the increase of FDG uptake in malignant tumors (5). In...capabilities of bronchoscopy without substantially increasing cost. Although there has been no work evaluating the use of 2-NBDG for lung cancer

  15. Laser bronchoscopy.

    PubMed

    Duhamel, D R; Harrell, J H

    2001-11-01

    Because the lung cancer epidemic shows no signs of abating, little doubt exists that the need for interventional bronchoscopists will persist for many years to come. The Nd:YAG laser and the rigid bronchoscope remain crucial weapons in the fight against lung cancer. With more than 4000 published interventions pertaining to it, this combination is ideal for treating central airways obstruction. The safety and efficacy of laser bronchoscopy has been well established, and the reported incidence of complications is impressively low. If complications were to arise, a skilled bronchoscopist can manage them easily by using the beneficial attributes of the rigid bronchoscope. Many complications can be avoided by implementing the established safety procedures and techniques. A solid understanding of laser physics and tissue interactions is a necessity to anyone performing laser surgery. The team approach, relying on communication among the bronchoscopist, anesthesiologist, laser technician, and nurses, leads to a safer and more successful procedure. It is important to remember, however, that this is typically a palliative procedure, and therefore the focus should be on alleviating symptoms and improving quality of life. Unfortunately, because not every patient is a candidate for laser bronchoscopy, there are specific characteristics of endobronchial lesions that make them more or less amenable to resection. Each year a promising new technology is being developed, such as argon plasma coagulation, cryotherapy, and endobronchial electrosurgery. Although it is unclear what role these technologies will have, prospective controlled studies must be done to help clarify this question. The future may lay in combining these various technologies along with Nd:YAG laser bronchoscopy to maximize the therapeutic, palliative, and possibly even curative effect. As the experience of the medical community with Nd:YAG laser bronchoscopy continues to grow and as more health-care professionals

  16. Inexpensive anatomical trainer for bronchoscopy.

    PubMed

    Di Domenico, Stefano; Simonassi, Claudio; Chessa, Leonardo

    2007-08-01

    Flexible fiberoptic bronchoscopy is an indispensable tool for optimal management of intensive care unit patients. However, the acquisition of sufficient training in bronchoscopy is not straightforward during residency, because of technical and ethical problems. Moreover, the use of commercial simulators is limited by their high cost. In order to overcome these limitations, we realized a low-cost anatomical simulator to acquire and maintain the basic skill to perform bronchoscopy in ventilated patients. We used 1.5 mm diameter iron wire to construct the bronchial tree scaffold; glazier-putty was applied to create the anatomical model. The model was covered by several layers of newspaper strips previously immersed in water and vinilic glue. When the model completely dried up, it was detached from the scaffold by cutting it into six pieces, it was reassembled, painted and fitted with an endotracheal tube. We used very cheap material and the final cost was euro16. The trainer resulted in real-scale and anatomically accurate, with appropriate correspondence on endoscopic view between model and patients. All bronchial segments can be explored and easily identified by endoscopic and external vision. This cheap simulator is a valuable tool for practicing, particularly in a hospital with limited resources for medical training.

  17. [Application of flexible bronchoscopy in diagnosis and treatment of 104 children with pulmonary atelectasis].

    PubMed

    Zhang, Dai-jia; Zhao, De-yu; Liang, Hui; Tian, Man; Han, Qing

    2010-10-01

    To evaluate the value of flexible fiberoptic bronchoscopy in diagnosis and treatment of pulmonary atelectasis in children. Totally 104 patients with pulmonary atelectasis, who were admitted to this department, received flexible fiberoptic bronchoscopy from January 2006 to May 2010, were enrolled in a retrospective analysis. The analysis on causes of pulmonary atelectasis showed that 76 cases (73%) of the 104 patients had sputum obstructions, which was the main cause of atelectasis. Thirteen cases (13%) had bronchopulmonary dysplasia, 9 cases among these were infants. Twelve cases (12%) had foreign body aspiration, 8 cases among these were under the age of 3-year. After flexible fiberoptic bronchoscopy, 100 cases got expansion of pulmonary atelectasis. Sixty-five of the sputum obstruction cases got atelectasis reexpansion after one time of flexible fiberoptic bronchoscopy. Eight of the sputum obstruction cases got atelectasis reexpansion after two times of flexible fiberoptic bronchoscopy. Two of the sputum obstruction cases got atelectasis reexpansion after three times of flexible fiberoptic bronchoscopy. The rate of atelectasis reexpansion after one time of alveolus lavement was higher in the cases whose courses of disease were under 3 weeks, than in the cases whose courses of disease were beyond 3 weeks. Etiology of pulmonary atelectasis varied at different age. The morbidity of bronchopulmonary dysplasia was high in infants. Foreign body aspiration was the common cause of pulmonary atelectasis in children from 1 to 3-year of age. Sputum obstruction was the main cause of pulmonary atelectasis in over 3-year-old children. Most cases got atelectasis reexpansion after alveolar lavage. The patients who had shorter course of disease might have higher rate of atelectasis reexpansion after alveolar lavage once. Flexible fiberoptic bronchoscopy plays an important role in diagnosis and treatment of pulmonary atelectasis.

  18. Advances in Diagnostic Bronchoscopy

    PubMed Central

    Haas, Andrew R.; Vachani, Anil; Sterman, Daniel H.

    2010-01-01

    Diagnostic bronchoscopy has undergone two major paradigm shifts in the last 40 years. First, the advent of flexible bronchoscopy gave chest physicians improved access to the tracheobronchial tree with a rapid learning curve and greater patient comfort compared with rigid bronchoscopy. The second paradigm shift has evolved over the last 5 years with the proliferation of new technologies that have significantly enhanced the diagnostic capabilities of flexible bronchoscopy compared with traditional methods. At the forefront of these new technologies is endobronchial ultrasound. In its various forms, endobronchial ultrasound has improved diagnostic yield for pulmonary masses, nodules, intrathoracic adenopathy, and disease extent, thereby reducing the need for more invasive surgical interventions. Various navigational bronchoscopy systems have become available to increase flexible bronchoscope access to small peripheral pulmonary lesions. Furthermore, various modalities of airway assessment, including optical microscopic imaging technologies, may play significant roles in the diagnosis of a variety of pulmonary diseases in the future. Finally, the combination of new diagnostic bronchoscopy technologies and novel approaches in molecular analysis and biomarker assessment hold promise for enhanced diagnosis and personalized management of many pulmonary disorders. In this review, we provide a contemporary review of diagnostic bronchoscopy developments over the past decade. PMID:20378726

  19. Anaesthesia for bronchoscopy

    PubMed Central

    Chadha, Meenu; Kulshrestha, Mayank; Biyani, Alok

    2015-01-01

    Bronchoscopy as an investigation or therapeutic procedure demands anaesthesiologist to act accordingly. The present review will take the reader from rigid to fibreoptic flexible bronchoscopy. These procedures are now done as day care procedures in the operation theatre or in critical care units. Advantages and limitations of both rigid and flexible bronchoscopy are analysed. Recently, conscious sedation has come up as the commonly used anaesthetic technique for simple bronchoscopic procedures. However, general anaesthesia still remains a standard technique for more complex procedures. New advances in the field of anaesthesiology such as use of short acting opioids, use of newer drugs such as dexmedetomidine, supraglottic airways and mechanical jet ventilators have facilitated and eased the conduct of the procedure. PMID:26556915

  20. Electromagnetic Navigation Diagnostic Bronchoscopy

    PubMed Central

    Gildea, Thomas R.; Mazzone, Peter J.; Karnak, Demet; Meziane, Moulay; Mehta, Atul C.

    2006-01-01

    Rationale: Electromagnetic navigation bronchoscopy using superDimension/Bronchus System is a novel method to increase diagnostic yield of peripheral and mediastinal lung lesions. Objectives: A prospective, open label, single-center, pilot study was conducted to determine the ability of electromagnetic navigation bronchoscopy to sample peripheral lung lesions and mediastinal lymph nodes with standard bronchoscopic instruments and demonstrate safety. Methods: Electromagnetic navigation bronchoscopy was performed using the superDimension/Bronchus system consisting of electromagnetic board, position sensor encapsulated in the tip of a steerable probe, extended working channel, and real-time reconstruction of previously acquired multiplanar computed tomography images. The final distance of the steerable probe to lesion, expected error based on the actual and virtual markers, and procedure yield was gathered. Measurements: 60 subjects were enrolled between December 2004 and September 2005. Mean navigation times were 7 ± 6 min and 2 ± 2 min for peripheral lesions and lymph nodes, respectively. The steerable probe tip was navigated to the target lung area in all cases. The mean peripheral lesions and lymph nodes size was 22.8 ± 12.6 mm and 28.1 ± 12.8 mm. Yield was determined by results obtained during the bronchoscopy per patient. Results: The yield/procedure was 74% and 100% for peripheral lesions and lymph nodes, respectively. A diagnosis was obtained in 80.3% of bronchoscopic procedures. A definitive diagnosis of lung malignancy was made in 74.4% of subjects. Pneumothorax occurred in two subjects. Conclusion: Electromagnetic navigation bronchoscopy is a safe method for sampling peripheral and mediastinal lesions with high diagnostic yield independent of lesion size and location. PMID:16873767

  1. Adult Bronchoscopy Training

    PubMed Central

    Wahidi, Momen M.; Read, Charles A.; Buckley, John D.; Addrizzo-Harris, Doreen J.; Shah, Pallav L.; Herth, Felix J. F.; de Hoyos Parra, Alberto; Ornelas, Joseph; Yarmus, Lonny; Silvestri, Gerard A.

    2015-01-01

    BACKGROUND: The determination of competency of trainees in programs performing bronchoscopy is quite variable. Some programs provide didactic lectures with hands-on supervision, other programs incorporate advanced simulation centers, whereas others have a checklist approach. Although no single method has been proven best, the variability alone suggests that outcomes are variable. Program directors and certifying bodies need guidance to create standards for training programs. Little well-developed literature on the topic exists. METHODS: To provide credible and trustworthy guidance, rigorous methodology has been applied to create this bronchoscopy consensus training statement. All panelists were vetted and approved by the CHEST Guidelines Oversight Committee. Each topic group drafted questions in a PICO (population, intervention, comparator, outcome) format. MEDLINE data through PubMed and the Cochrane Library were systematically searched. Manual searches also supplemented the searches. All gathered references were screened for consideration based on inclusion criteria, and all statements were designated as an Ungraded Consensus-Based Statement. RESULTS: We suggest that professional societies move from a volume-based certification system to skill acquisition and knowledge-based competency assessment for trainees. Bronchoscopy training programs should incorporate multiple tools, including simulation. We suggest that ongoing quality and process improvement systems be introduced and that certifying agencies move from a volume-based certification system to skill acquisition and knowledge-based competency assessment for trainees. We also suggest that assessment of skill maintenance and improvement in practice be evaluated regularly with ongoing quality and process improvement systems after initial skill acquisition. CONCLUSIONS: The current methods used for bronchoscopy competency in training programs are variable. We suggest that professional societies and certifying

  2. [Fiber optic bronchoscopy in extraction of tracheo-bronchial foreign bodies in adults].

    PubMed

    Donado Uña, J R; de Miguel Poch, E; Casado López, M E; Alfaro Abreu, J J

    1998-02-01

    The aim of this study was to determine the clinical, radiologic and endoscopic characteristics of adults with tracheobronchial foreign bodies (FB), and to review the role of fiberoptic bronchoscopy in extracting them. We reviewed the case histories and bronchoscopic reports for all patients over 14 years of age with FB treated between 1976 and 1995. Fifty-nine FB were removed from 56 patients; 68% were male and 48% were over 60 years of age. The most common clinical presentations were symptoms of respiratory infection and acute choking. In only in 28% could a risk factor for aspiration be identified. The X-ray was non specific and in 37% of cases the chest film was normal. In 66% FB aspiration was an unexpected endoscopic finding. The FB was removed from the right lung in 81.3%. FB were food items in 71% of cases. Fiberoptic bronchoscopy was useful for removal in 95% of cases, with few and unimportant complications. Two cases were resolved with rigid bronchoscopy and only one patient required surgery. FB aspiration is common and diagnosis is difficult in the adult. Fiberoptic bronchoscopy resolved most aspirations in adults with no important complications. The rigid bronchoscope should be reserved for very specific cases.

  3. Electromagnetic Navigational Bronchoscopy

    PubMed Central

    Port, Jeffrey; Harrison, Sebron

    2013-01-01

    Despite advances in technology and treatment options, lung cancer remains a deadly disease. National screening programs are being instituted in an attempt to discover lung cancer in high-risk individuals at an earlier stage. Such screening programs invariably discover small peripheral nodules that previously would not have been clinically apparent; the management of such lesions can be challenging. Current diagnostic options such as percutaneous biopsy are effective; however, they are hindered by their risk of morbidity such as pneumothorax. Electromagnetic bronchoscopy (ENB) is an emerging technology that allows the practitioner the ability to both sample and treat small peripheral pulmonary lesions. In experienced centers, ENB provides high rates of diagnostic yield for small lesions and a complication rate significantly lower than that of more conventional diagnostic modalities. Although there are current barriers to its widespread utilization (cost, specialized imaging, technical training), these obstacles will handled similarly to any other emerging technology and will likely not be long-term impediments to its use. PMID:24436528

  4. Virtual reality bronchoscopy simulation: a revolution in procedural training.

    PubMed

    Colt, H G; Crawford, S W; Galbraith, O

    2001-10-01

    In the airline industry, training is costly and operator error must be avoided. Therefore, virtual reality (VR) is routinely used to learn manual and technical skills through simulation before pilots assume flight responsibilities. In the field of medicine, manual and technical skills must also be acquired to competently perform invasive procedures such as flexible fiberoptic bronchoscopy (FFB). Until recently, training in FFB and other endoscopic procedures has occurred on the job in real patients. We hypothesized that novice trainees using a VR skill center could rapidly acquire basic skills, and that results would compare favorably with those of senior trainees trained in the conventional manner. We prospectively studied five novice bronchoscopists entering a pulmonary and critical care medicine training program. They were taught to perform inspection flexible bronchoscopy using a VR bronchoscopy skill center; dexterity, speed, and accuracy were tested using the skill center and an inanimate airway model before and after 4 h of group instruction and 4 h of individual unsupervised practice. Results were compared to those of a control group of four skilled physicians who had performed at least 200 bronchoscopies during 2 years of training. Student's t tests were used to compare mean scores of study and control groups for the inanimate model and VR bronchoscopy simulator. Before-training and after-training test scores were compared using paired t tests. For comparisons between after-training novice and skilled physician scores, unpaired two-sample t tests were used. Novices significantly improved their dexterity and accuracy in both models. They missed fewer segments after training than before training, and had fewer contacts with the bronchial wall. There was no statistically significant improvement in speed or total time spent not visualizing airway anatomy. After training, novice performance equaled or surpassed that of the skilled physicians. Novices performed

  5. Bronchoscopy Simulation: A Brief Review

    ERIC Educational Resources Information Center

    Davoudi, Mohsen; Colt, Henri G.

    2009-01-01

    More than 500,000 flexible bronchoscopies are performed annually by chest physicians in the United States (Ernst et al., Chest 123:1693-1717, 2003). Indications include diagnosis of lung cancer and airway tumors, benign strictures, pulmonary infections, and treatment of central airway obstruction, emphysema, and intraepithelial lesions such as…

  6. Simulation-Based Bronchoscopy Training

    PubMed Central

    Kennedy, Cassie C.; Maldonado, Fabien

    2013-01-01

    Background: Simulation-based bronchoscopy training is increasingly used, but effectiveness remains uncertain. We sought to perform a comprehensive synthesis of published work on simulation-based bronchoscopy training. Methods: We searched MEDLINE, EMBASE, CINAHL, PsycINFO, ERIC, Web of Science, and Scopus for eligible articles through May 11, 2011. We included all original studies involving health professionals that evaluated, in comparison with no intervention or an alternative instructional approach, simulation-based training for flexible or rigid bronchoscopy. Study selection and data abstraction were performed independently and in duplicate. We pooled results using random effects meta-analysis. Results: From an initial pool of 10,903 articles, we identified 17 studies evaluating simulation-based bronchoscopy training. In comparison with no intervention, simulation training was associated with large benefits on skills and behaviors (pooled effect size, 1.21 [95% CI, 0.82-1.60]; n = 8 studies) and moderate benefits on time (0.62 [95% CI, 0.12-1.13]; n = 7). In comparison with clinical instruction, behaviors with real patients showed nonsignificant effects favoring simulation for time (0.61 [95% CI, −1.47 to 2.69]) and process (0.33 [95% CI, −1.46 to 2.11]) outcomes (n = 2 studies each), although variation in training time might account for these differences. Four studies compared alternate simulation-based training approaches. Inductive analysis to inform instructional design suggested that longer or more structured training is more effective, authentic clinical context adds value, and animal models and plastic part-task models may be superior to more costly virtual-reality simulators. Conclusions: Simulation-based bronchoscopy training is effective in comparison with no intervention. Comparative effectiveness studies are few. PMID:23370487

  7. Simulation in bronchoscopy: current and future perspectives.

    PubMed

    Nilsson, Philip Mørkeberg; Naur, Therese Maria Henriette; Clementsen, Paul Frost; Konge, Lars

    2017-01-01

    To provide an overview of current literature that informs how to approach simulation practice of bronchoscopy and discuss how findings from other simulation research can help inform the use of simulation in bronchoscopy training. We conducted a literature search on simulation training of bronchoscopy and divided relevant studies in three categories: 1) structuring simulation training in bronchoscopy, 2) assessment of competence in bronchoscopy training, and 3) development of cheap alternatives for bronchoscopy simulation. Bronchoscopy simulation is effective, and the training should be structured as distributed practice with mastery learning criteria (ie, training until a certain level of competence is achieved). Dyad practice (training in pairs) is possible and may increase utility of available simulators. Trainee performance should be assessed with assessment tools with established validity. Three-dimensional printing is a promising new technology opening possibilities for developing cheap simulators with innovative features.

  8. Hybrid rendering of the chest and virtual bronchoscopy [corrected].

    PubMed

    Seemann, M D; Seemann, O; Luboldt, W; Gebicke, K; Prime, G; Claussen, C D

    2000-10-30

    Thin-section spiral computed tomography was used to acquire the volume data sets of the thorax. The tracheobronchial system and pathological changes of the chest were visualized using a color-coded surface rendering method. The structures of interest were then superimposed on a volume rendering of the other thoracic structures, thus producing a hybrid rendering. The hybrid rendering technique exploit the advantages of both rendering methods and enable virtual bronchoscopic examinations using different representation models. Virtual bronchoscopic examinations with a transparent color-coded shaded-surface model enables the simultaneous visualization of both the airways and the adjacent structures behind of the tracheobronchial wall and therefore, offers a practical alternative to fiberoptic bronchoscopy. Hybrid rendering and virtual endoscopy obviate the need for time consuming detailed analysis and presentation of axial source images.

  9. Electromagnetic navigation diagnostic bronchoscopy for small peripheral lung lesions.

    PubMed

    Makris, D; Scherpereel, A; Leroy, S; Bouchindhomme, B; Faivre, J-B; Remy, J; Ramon, P; Marquette, C-H

    2007-06-01

    The present study prospectively evaluated the diagnostic yield and safety of electromagnetic navigation-guided bronchoscopy biopsy, for small peripheral lung lesions in patients where standard techniques were nondiagnostic. The study was conducted in a tertiary medical centre on 40 consecutive patients considered unsuitable for straightforward surgery or computed tomography (CT)-guided transthoracic needle aspiration biopsy, due to comorbidities. The lung lesion diameter was mean+/-sem 23.5+/-1.5 mm and the depth from the visceral-costal pleura was 14.9+/-2 mm. Navigation was facilitated by an electromagnetic tracking system which could detect a position sensor incorporated into a flexible catheter advanced through a bronchoscope. Information obtained during bronchoscopy was superimposed on previously acquired CT data. Divergence between CT data and data obtained during bronchoscopy was calculated by the system's software as a measure of navigational accuracy. All but one of the target lesions was reached and the overall diagnostic yield was 62.5% (25-40). Diagnostic yield was significantly affected by CT-to-body divergence; yield was 77.2% when estimated divergence was bronchoscopy has the potential to improve the diagnostic yield of transbronchial biopsies without additional fluoroscopic guidance, and may be useful in the early diagnosis of lung cancer, particularly in nonoperable patients.

  10. Detection of airway ischaemic damage after lung transplantation by using autofluorescence imaging bronchoscopy.

    PubMed

    Iga, Norichika; Oto, Takahiro; Okada, Masanori; Harada, Masaaki; Nishikawa, Hitoshi; Miyoshi, Kentaroh; Otani, Shinji; Sugimoto, Seiichiro; Yamane, Masaomi; Toyooka, Shinichi; Miyoshi, Shinichiro

    2014-03-01

    Airway complications related to ischaemia are a major cause of morbidity after lung transplantation. Early detection of airway ischaemia and optimal management of the anastomotic site could reduce the risk of airway complications. Autofluorescence imaging (AFI) bronchoscopy has been increasingly recognized as an effective technique for detecting abnormal mucosal thickening. The aim of this study was to investigate whether AFI bronchoscopy can facilitate the detection of airway ischaemic damage in lung transplant patients. Twenty Landrace pigs were used to create a tracheal autotransplantation model. A four-ring length of trachea was excised and implanted orthotopically. The tracheal autograft was observed on postoperative days 0, 2, 4 and 7 with AFI bronchoscopy. The extent and origin of graft autofluorescence were examined using histology and measured according to fluorescence intensity. The lesions on the tracheal autografts appeared as bright green fluorescence on AFI bronchoscopy. On confocal fluorescence microscopy, high-intensity green fluorescence was observed in the elastin fibre layer of the submucosa. The fluorescence intensity of elastin was significantly higher in the graft showing fluorescence than the graft that did not show fluorescence and that at the control site. Bright green fluorescence was seen in an elastin fibre layer in the submucosa, which was likely a result of epithelial sloughing. There is a close relationship between the bright green fluorescence pattern observed using AFI bronchoscopy and airway ischaemic damage. We conclude that AFI bronchoscopy may detect airway ischaemic damage after lung transplantation.

  11. A randomized multi-institutional crossover comparison of the GlideScope® Cobalt Video laryngoscope to the flexible fiberoptic bronchoscope in a Pierre Robin manikin.

    PubMed

    Fiadjoe, John E; Hirschfeld, Matthew; Wu, Stephan; Markley, James; Gurnaney, Harshad; Jawad, Abbas F; Stricker, Paul; Kilbaugh, Todd; Ross, Patrick; Kovatsis, Pete

    2015-08-01

    The GlideScope Cobalt Video laryngoscope is being used more often in children with challenging laryngoscopy. There are, however, no pediatric trials comparing it to flexible fiberoptic bronchoscopy, the current accepted gold standard. This preliminary manikin study compares the first-attempt intubation success of the GlideScope Cobalt video laryngoscope to the flexible fiberoptic bronchoscope when performed by attending pediatric anesthesiologists at two major pediatric centers. This prospective randomized, crossover study evaluated 120 attempts (60 with each study device) to intubate the AirSim Pierre Robin manikin (PRM) with fiberoptic bronchoscopy and video laryngoscopy (VL). Attending pediatric anesthesiologists from two quaternary pediatric centers were eligible to participate. Each attending anesthesiologist randomly performed a single tracheal intubation attempt with one of the study devices followed by the alternate method. The primary outcome was the first-attempt success rate of tracheal intubation. Blinding was not feasible. We hypothesized that first-attempt success would be higher with fiberoptic bronchoscopy. Thirty anesthesiologists from each center were randomized to use one of the study devices followed by the alternate method. We analyzed all participants' data. There was no overall difference in first-attempt success between VL and fiberoptic bronchoscopy (88.3% vs 85% respectively, P = 0.59). There were significant institutional differences in first-attempt success using VL (76.7% vs 100%). There was no difference in first-attempt success of tracheal intubation using VL vs fiberoptic bronchoscopy when performed by attending anesthesiologists at two large pediatric centers. However, institutional differences exist in success rates with VL across the two centers. Results from single-center device evaluations should be verified by multi-center evaluations. A significant proportion of attending anesthesiologists lack experience with advanced

  12. Algorithm for Video Summarization of Bronchoscopy Procedures

    PubMed Central

    2011-01-01

    Background The duration of bronchoscopy examinations varies considerably depending on the diagnostic and therapeutic procedures used. It can last more than 20 minutes if a complex diagnostic work-up is included. With wide access to videobronchoscopy, the whole procedure can be recorded as a video sequence. Common practice relies on an active attitude of the bronchoscopist who initiates the recording process and usually chooses to archive only selected views and sequences. However, it may be important to record the full bronchoscopy procedure as documentation when liability issues are at stake. Furthermore, an automatic recording of the whole procedure enables the bronchoscopist to focus solely on the performed procedures. Video recordings registered during bronchoscopies include a considerable number of frames of poor quality due to blurry or unfocused images. It seems that such frames are unavoidable due to the relatively tight endobronchial space, rapid movements of the respiratory tract due to breathing or coughing, and secretions which occur commonly in the bronchi, especially in patients suffering from pulmonary disorders. Methods The use of recorded bronchoscopy video sequences for diagnostic, reference and educational purposes could be considerably extended with efficient, flexible summarization algorithms. Thus, the authors developed a prototype system to create shortcuts (called summaries or abstracts) of bronchoscopy video recordings. Such a system, based on models described in previously published papers, employs image analysis methods to exclude frames or sequences of limited diagnostic or education value. Results The algorithm for the selection or exclusion of specific frames or shots from video sequences recorded during bronchoscopy procedures is based on several criteria, including automatic detection of "non-informative", frames showing the branching of the airways and frames including pathological lesions. Conclusions The paper focuses on the

  13. [Hybrid 3-D rendering of the thorax and surface-based virtual bronchoscopy in surgical and interventional therapy control].

    PubMed

    Seemann, M D; Gebicke, K; Luboldt, W; Albes, J M; Vollmar, J; Schäfer, J F; Beinert, T; Englmeier, K H; Bitzer, M; Claussen, C D

    2001-07-01

    The aim of this study was to demonstrate the possibilities of a hybrid rendering method, the combination of a color-coded surface and volume rendering method, with the feasibility of performing surface-based virtual endoscopy with different representation models in the operative and interventional therapy control of the chest. In 6 consecutive patients with partial lung resection (n = 2) and lung transplantation (n = 4) a thin-section spiral computed tomography of the chest was performed. The tracheobronchial system and the introduced metallic stents were visualized using a color-coded surface rendering method. The remaining thoracic structures were visualized using a volume rendering method. For virtual bronchoscopy, the tracheobronchial system was visualized using a triangle surface model, a shaded-surface model and a transparent shaded-surface model. The hybrid 3D visualization uses the advantages of both the color-coded surface and volume rendering methods and facilitates a clear representation of the tracheobronchial system and the complex topographical relationship of morphological and pathological changes without loss of diagnostic information. Performing virtual bronchoscopy with the transparent shaded-surface model facilitates a reasonable to optimal, simultaneous visualization and assessment of the surface structure of the tracheobronchial system and the surrounding mediastinal structures and lesions. Hybrid rendering relieve the morphological assessment of anatomical and pathological changes without the need for time-consuming detailed analysis and presentation of source images. Performing virtual bronchoscopy with a transparent shaded-surface model offers a promising alternative to flexible fiberoptic bronchoscopy.

  14. A survey of flexible bronchoscopy practices in India: The Indian bronchoscopy survey (2017)

    PubMed Central

    Madan, Karan; Mohan, Anant; Agarwal, Ritesh; Hadda, Vijay; Khilnani, Gopi C; Guleria, Randeep

    2018-01-01

    Background: There is a lack of contemporaneous data on the practices of flexible bronchoscopy in India. Aim: The aim of the study was to study the prevalent practices of flexible bronchoscopy across India. Methods: The “Indian Bronchoscopy Survey” was a 98-question, online survey structured into the following sections: general information, patient preparation and monitoring, sedation and topical anesthesia, procedural/technical aspects, and bronchoscope disinfection/staff protection. Results: Responses from 669 bronchoscopists (mean age: 40.2 years, 91.8% adult pulmonologists) were available for analysis. Approximately, 70,000 flexible bronchoscopy examinations had been performed over the preceding year. A majority (59%) of bronchoscopists were performing bronchoscopy without sedation. A large number (45%) of bronchoscopists had learned the procedure outside of their fellowship training. About 55% used anticholinergic premedication either as a routine or occasionally. Nebulized lignocaine was being used by 72%, while 24% utilized transtracheal administration of lignocaine. The most commonly (75%) used concentration of lignocaine was 2%. Midazolam with or without fentanyl was the preferred agent for intravenous sedation. The use of video bronchoscope was common (80.8%). The most common (94%) route for performing bronchoscopy was nasal. Conventional transbronchial needle aspiration (TBNA) was being performed by 74%, while 92% and 78% performed endobronchial and transbronchial lung biopsy, respectively. Therapeutic airway interventions (stents, electrocautery, cryotherapy, and others) were being performed by 30%, while endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) and rigid bronchoscopy were performed by 27% and 19.5%, respectively. Conclusion: There is a wide national variation in the practices of performing flexible bronchoscopy. However, there has been a considerable improvement in bronchoscopy practices compared to previous

  15. A survey of flexible bronchoscopy practices in India: The Indian bronchoscopy survey (2017).

    PubMed

    Madan, Karan; Mohan, Anant; Agarwal, Ritesh; Hadda, Vijay; Khilnani, Gopi C; Guleria, Randeep

    2018-01-01

    There is a lack of contemporaneous data on the practices of flexible bronchoscopy in India. The aim of the study was to study the prevalent practices of flexible bronchoscopy across India. The "Indian Bronchoscopy Survey" was a 98-question, online survey structured into the following sections: general information, patient preparation and monitoring, sedation and topical anesthesia, procedural/technical aspects, and bronchoscope disinfection/staff protection. Responses from 669 bronchoscopists (mean age: 40.2 years, 91.8% adult pulmonologists) were available for analysis. Approximately, 70,000 flexible bronchoscopy examinations had been performed over the preceding year. A majority (59%) of bronchoscopists were performing bronchoscopy without sedation. A large number (45%) of bronchoscopists had learned the procedure outside of their fellowship training. About 55% used anticholinergic premedication either as a routine or occasionally. Nebulized lignocaine was being used by 72%, while 24% utilized transtracheal administration of lignocaine. The most commonly (75%) used concentration of lignocaine was 2%. Midazolam with or without fentanyl was the preferred agent for intravenous sedation. The use of video bronchoscope was common (80.8%). The most common (94%) route for performing bronchoscopy was nasal. Conventional transbronchial needle aspiration (TBNA) was being performed by 74%, while 92% and 78% performed endobronchial and transbronchial lung biopsy, respectively. Therapeutic airway interventions (stents, electrocautery, cryotherapy, and others) were being performed by 30%, while endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) and rigid bronchoscopy were performed by 27% and 19.5%, respectively. There is a wide national variation in the practices of performing flexible bronchoscopy. However, there has been a considerable improvement in bronchoscopy practices compared to previous national surveys.

  16. Buying Fiber-Optic Networks.

    ERIC Educational Resources Information Center

    Fickes, Michael

    2003-01-01

    Describes consortia formed by college and university administrators to buy, manage, and maintain their own fiber-optic networks with the goals of cutting costs of leasing fiber-optic cable and planning for the future. Growth capacity is the real advantage of owning fiber-optic systems. (SLD)

  17. Investigative bronchoprovocation and bronchoscopy in airway diseases.

    PubMed

    Busse, William W; Wanner, Adam; Adams, Kenneth; Reynolds, Herbert Y; Castro, Mario; Chowdhury, Badrul; Kraft, Monica; Levine, Robert J; Peters, Stephen P; Sullivan, Eugene J

    2005-10-01

    Basic and clinical research strategies used for many lung diseases have depended on volunteer subjects undergoing bronchoscopy to establish access to the airways to collect biological specimens and tissue, perhaps with added bronchoprovocation in asthma syndromes. These procedures have yielded a wealth of important scientific information. Since the last critical review more than a decade ago, some of the techniques and applications have changed, and untoward events have occurred, raising safety concerns and increasing institutional review scrutiny. To reappraise these investigational methods in the context of current knowledge, the National Heart, Lung, and Blood Institute and the National Institute of Allergy and Infectious Diseases of the National Institutes of Health convened a working group to review these procedures used for airway disease research, emphasizing asthma and chronic obstructive pulmonary disease. The group reaffirmed the scientific importance of investigative bronchoscopy and bronchoprovocation, even as less invasive technologies evolve. The group also considered the safety of bronchoscopy and bronchoprovocation with methacholine and antigen to be acceptable for volunteer subjects and patients, but stressed the need to monitor this closely and to emphasize proper training of participating medical research personnel. Issues were raised about vulnerable volunteers, especially children who need surrogates for informed consent. This review of investigative bronchoscopy and bronchoprovocation could serve as the basis for future guidelines for the use of these procedures in the United States.

  18. The Evolutional History of Electromagnetic Navigation Bronchoscopy: State of the Art.

    PubMed

    Mehta, Atul C; Hood, Kristin L; Schwarz, Yehuda; Solomon, Stephen B

    2018-04-30

    Electromagnetic navigation bronchoscopy (ENB) has come a long way from the early roots of electromagnetic theory. Current ENB devices have the potential to change the way lung cancer is detected and treated. This paper provides an overview of the history, current state, and future of ENB. Copyright © 2018. Published by Elsevier Inc.

  19. [Bronchoscopy in ventilated patients: full narcosis or local anesthesia?].

    PubMed

    Konrad, F; Wiedeck, H; Winter, H; Kilian, J

    1990-04-01

    In a prospective, randomised trial bronchoscopy was performed either in local anaesthesia (LA) or general anaesthesia, each on 15 ventilated patients. LA was carried out with oxybuprocain-hydrochloride 1% in repeated doses injected into the trachea and main bronchi, general anaesthesia with midazolam, piritramide and vecuronium bromide. Measurements were performed before, 3 minutes after induction of anaesthesia, immediately after bronchoscopy and 15 and 60 minutes after bronchoscopy. There was no effect on cardiocirculatory function during bronchoscopy in both groups, but we found a decrease in paO2 from 97 to 80 mmHg (median) after application of LA. Subsequent bronchoscopy did not significantly influence paO2. The present study shows that in ventilation patients undergoing fibreoptic bronchoscopy, the application of LA will usually result in a decline of arterial oxygen tension. This procedure should therefore only be performed if general anaesthesia is undesirable, as e.g. in patients being weaned from ventilation.

  20. Transmission of Infection by Flexible Gastrointestinal Endoscopy and Bronchoscopy

    PubMed Central

    Peters, Frans T. M.; van der Mei, Henny C.; Degener, John E.

    2013-01-01

    SUMMARY Flexible endoscopy is a widely used diagnostic and therapeutic procedure. Contaminated endoscopes are the medical devices frequently associated with outbreaks of health care-associated infections. Accurate reprocessing of flexible endoscopes involves cleaning and high-level disinfection followed by rinsing and drying before storage. Most contemporary flexible endoscopes cannot be heat sterilized and are designed with multiple channels, which are difficult to clean and disinfect. The ability of bacteria to form biofilms on the inner channel surfaces can contribute to failure of the decontamination process. Implementation of microbiological surveillance of endoscope reprocessing is appropriate to detect early colonization and biofilm formation in the endoscope and to prevent contamination and infection in patients after endoscopic procedures. This review presents an overview of the infections and cross-contaminations related to flexible gastrointestinal endoscopy and bronchoscopy and illustrates the impact of biofilm on endoscope reprocessing and postendoscopic infection. PMID:23554415

  1. THE ACUTE PHASE RESPONSE INDUCED BY BRONCHOSCOPY WITH LAVAGE

    EPA Science Inventory

    Bronchoscopy has been used to evaluate the inflammatory responses in vitro and in vivo. The procedure may affect acute inflammation in the lower respiratory tract. We reviewed consecutive bronchoscopies done in normal healthy non-smokers between April, 1998 and April, 2004. The...

  2. Transbronchial needle aspiration cytology (TBNA) in endobronchial lesions: a valuable technique during bronchoscopy in diagnosing lung cancer and it will decrease repeat bronchoscopy.

    PubMed

    Shital, Patil; Rujuta, Ayachit; Sanjay, Mundkar

    2014-05-01

    Lung cancer is the leading cause of cancer deaths around the world. Globally, lung cancer is the largest contributor to new cancer diagnosis and to death from cancer. Various conventional diagnostic techniques (CDTs) such as endobronchial forcep biopsy (FB), bronchial washing (BW) and bronchial brushing (BB), and transbronchial needle aspiration cytology (TBNA) are employed during fiber-optic bronchoscopy. This is a prospective study conducted between June 2012 and September 2013 at Bronchoscopy unit of MIMSR Medical College Latur, India, to find the role of TBNA in exophytic endobronchial lesions in confirming the diagnosis of lung cancer and to find additive yield over other techniques such as BB, BW and FB, and included 150 patients on the basis of clinical and radiological features of malignancy. In exophytic endobronchial lesions, predominant endoscopic findings were cauliflower, polypoidal-like or nodular or multinodular endobronchial growth. TBNA, FB, BB and BW were performed in all the cases during FOB. Histopathological and cytological examinations of specimens were performed at Pathology department. The statistical analysis was done using chi-square test. Total 150 patients, between age group 24-80 years, mean age was 57.93 years, male population constitutes 86.17 % of total. 76.14 % cases were smoker of them 61.87 % cases having history of >40 pack years. Commoner symptoms were cough (91.33 %), hemoptysis (54.00 %) and chest pain (46.66 %), and mass lesion (40.66 %), hilar opacity (31.33 %) and collapse segmental/lobar (29.33 %) were commoner radiological abnormalities. Yield of TBNA, CDT and TBNA plus CDT in exophytic lesions is 60.66, 79.33 and 84.66 %, respectively, in diagnosis of lung malignancies (P < 0.001). Sensitivity of forcep biopsy and TBNA in diagnosing lung malignancy was 88.18 and 71.65 %, respectively (P < 0.01). FOB-related hypoxemia documented in two cases and minor bleeding in six cases. Other complications such as significant bleeding

  3. Effects of bronchoscopy on lung function in asthmatics.

    PubMed

    Bellinger, Christina; Bleecker, Eugene R; Peters, Stephen; Pascual, Rodolfo; Krings, Jeffrey; Smith, Regina; Hastie, Annette T; Moore, Wendy C

    2017-10-01

    To better understand the changes in pulmonary physiology related to asthma severity following bronchoscopy, we performed scheduled pre- and post-procedure spirometry on subjects undergoing bronchoscopy in our research program. Control subjects and asthma subjects were recruited for bronchoscopy. On the day of bronchoscopy, subjects underwent spirometry pre-bronchoscopy and then up to three sets within 2 hour following the completion of bronchoscopy. A subset of patients had a second bronchoscopy after 2 weeks of treatment with oral prednisolone (40mg daily). A total of 92 subjects had at least one bronchoscopy (12 control subjects, 56 nonsevere asthma (NSA), 24 severe asthma (SA)). The SA and NSA groups had similar decreases in forced expiratory volume in 1 second (FEV1) (-20±13% vs.-19±16%, p = 0.92) and forced vital capacity (FVC) (-20±12% vs.-20±14%, p = 0.80), but no change in FEV1/FVC ratio. The control and NSA group had more rapid recovery of both FEV1 and FVC by 2 hour compared to the SA group (p = 0.01). In the subset of 36 subjects (22 NSA, 14 SA) who underwent a second bronchoscopy following the administration of oral prednisolone for 14 days, steroids resulted in more rapid recovery of lung function (p < 0.04). Following bronchoscopy the lung function of NSA subjects recovered more quickly than SA subjects. Treatment with oral corticosteroids was associated with a quicker recovery of FEV1 which suggests an inflammatory mechanism for these changes in lung compliance.

  4. Airway stent complications: the role of follow-up bronchoscopy as a surveillance method

    PubMed Central

    Labaki, Wassim; Yu, Diana H.; Salwen, Benjamin; Gilbert, Christopher; Schneider, Andrea L. C.; Ortiz, Ricardo; Feller-Kopman, David; Arias, Sixto; Yarmus, Lonny

    2017-01-01

    Background Airway stenting has become an integral part of the therapeutic endoscopic management of obstructive benign and malignant central airway diseases. Despite increased use of airway stents and frequent stent-associated complications, no clear guidelines for surveillance and maintenance exist. This study aim is to elucidate predictive factors associated with development of stent complications, as well as an optimal surveillance period for follow-up bronchoscopy for early detection and possible prevention of stent-associated complications. Methods Retrospective cohort study of all patients who underwent airway stent placements at our institution from April 2010 to December 2013 for benign and malignant airway diseases. Metallic, silicone (straight, Y stent, T-tube) and hybrid stents were included in the study. Stent complications were analyzed at the time of follow-up bronchoscopy performed four to six weeks after initial stent placement or earlier if patients became symptomatic. Results The study included 134 patients of which 147 stents were placed. Follow-up bronchoscopy was performed in 94 patients. Symptomatic status at the time of follow-up bronchoscopy was not associated with stent complications [odds ratio (OR) =1.88; 95% CI: 0.79–4.45; P=0.15]. Patient age, sex, indication for stent placement, and stent location, were not associated with development of complications (all P>0.05). Compared to all other stents, hybrid stents were more likely to migrate (OR =6.60; 95% CI: 2.16–20.2; P=0.001) or obstruct by secretions (OR =2.53; 95% CI: 1.10–5.84; P=0.03). There were no complications associated with surveillance bronchoscopy. Conclusions Surveillance bronchoscopy within 4 to 6 weeks of stent placement may be useful for early detection of complications and their subsequent management, regardless of symptomatic status and indication for stent placement. Prospective multicenter studies are needed to compare optimal surveillance methods and the impact

  5. Induced sputum and bronchoscopy in the diagnosis of pulmonary tuberculosis

    PubMed Central

    McWilliams, T; Wells, A; Harrison, A; Lindstrom, S; Cameron, R; Foskin, E

    2002-01-01

    Background: Previous studies suggest that bronchoscopy and a single induced sputum sample are equally effective for diagnosing pulmonary tuberculosis. Methods: In a prospective study of subjects with possibly active pulmonary tuberculosis, the diagnostic yield of three induced sputum tests was compared with that of bronchoscopy. Subjects either produced no sputum or (acid fast) smear negative sputum. Bronchoscopy was only performed if at least two induced sputum samples were smear negative. Results: Of 129 subjects who completed all tests, 27 (21%) had smear negative and culture positive specimens, 14 (52%) on bronchoscopy and 26 (96%) on induced sputum (p<0.005). One patient was culture positive on bronchoscopy alone compared with 13 on induced sputum alone; 13 were culture positive on both tests. Induced sputum positivity was strikingly more prevalent when chest radiographic appearances showed any features of active tuberculosis (20/63, 32%) than when appearances suggested inactivity (1/44, 2%; p<0.005). Induced sputum costs were about one third those of bronchoscopy, and the ratio of costs of the two tests per case of tuberculosis diagnosed could be as much as 1:6. Conclusions: In subjects investigated for possibly active or inactive tuberculosis who produce no sputum or have smear negative sputum, the most cost effective strategy is to perform three induced sputum tests without bronchoscopy. Induced sputum testing carries a high risk of nosocomial tuberculosis unless performed in respiratory isolation conditions. The cost benefits shown could be lost if risk management measures are not observed. PMID:12454293

  6. Moderate Sedation Changes for Bronchoscopy in 2017.

    PubMed

    Nelson, Michael E

    2017-10-01

    The reimbursement for procedures using moderate (conscious) sedation has changed significantly as of January 1, 2017. Due to the increasing use of anesthesia services to provide moderate sedation during endoscopy, the Centers for Medicare & Medicaid Services made the decision to remove work relative value units from many of the services requiring moderate sedation, including the bronchoscopy codes. If a bronchoscopist provides moderate sedation to a patient without using anesthesia services or another qualified provider, that work (and revenue) can be reclaimed by using the relevant codes. An understanding of the recent changes in coding and billing is essential for appropriate reimbursement. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  7. Fiberoptic bronchoscopic treatment of blood aspiration and use of sugammadex in a patient with epistaxis

    PubMed Central

    Ryu, Taeha; Kim, Dong Hyuck; Byun, Sung Hye

    2018-01-01

    Abstract Rationale: In patients with oropharyngeal and nasopharyngeal bleeding, blood aspiration can make airway management difficult and lead to severe pulmonary complications. Patient concerns: A 44-year-old male patient with recurrent epistaxis underwent surgery for hemostasis. The patient aspirated blood through the endotracheal tube when he hiccupped during the surgery. Diagnosis: The patient was diagnosed with blood aspiration after intraoperative fiberoptic bronchoscopy revealed a blood clot and viscous mucus in the airways, but no sign of active bleeding. Interventions: Tracheobronchial suctioning and irrigation with normal saline was performed through the bronchoscope to remove the aspirated blood clot. Prior to emergence from anesthesia, sugammadex was administered to induce complete neuromuscular recovery and enable the patient to cough up any blood remaining in the airways. Outcomes: The patient was successfully extubated and fully recovered with no complications. Lessons: Blood aspiration due to oropharyngeal or nasopharyngeal bleeding can be diagnosed and treated by tracheobronchial suctioning via fiberoptic bronchoscopy. In addition, sugammadex can enable patients to recover spontaneous breathing, facilitate extubation, and enable patients to cough up any blood remaining in the airways. PMID:29642212

  8. The role of bronchoscopy in the diagnosis of airway disease

    PubMed Central

    Dixon, Jennifer; Tieu, Brandon H.

    2016-01-01

    Endoscopy of the airway is a valuable tool for the evaluation and management of airway disease. It can be used to evaluate many different bronchopulmonary diseases including airway foreign bodies, tumors, infectious and inflammatory conditions, airway stenosis, and bronchopulmonary hemorrhage. Traditionally, options for evaluation were limited to flexible and rigid bronchoscopy. Recently, more sophisticated technology has led to the development of endobronchial ultrasound (EBUS) and electromagnetic navigational bronchoscopy (ENB). These technological advances, combined with increasing provider experience have resulted in a higher diagnostic yield with endoscopic biopsies. This review will focus on the role of bronchoscopy, including EBUS, ENB, and rigid bronchoscopy in the diagnosis of bronchopulmonary diseases. In addition, it will cover the anesthetic considerations, equipment, diagnostic yield, and potential complications. PMID:28149583

  9. Fiberoptics for propulsion control system

    NASA Technical Reports Server (NTRS)

    Baumbick, R. J.

    1984-01-01

    In aircraft systems with digital controls, fiberoptics has advantages over wire systems because of its inherent immunity to electromagnetic noise (EMI) and electromagnetic pulses (EMP). It also offers a weight benefit when metallic conductors are replaced by optical fibers. To take full advantage of the benefits of optical waveguides, passive optical sensors are also being developed to eliminate the need for electrical power to the sensor. Fiberoptics may also be used for controlling actuators on engine and airframe. In this application, the optical fibers, connectors, etc. will be subjected to high temperature and vibrations. This paper discussed the use of fiberoptics in aircraft propulsion systems together with the optical sensors and optically controlled actuators being developed to take full advantage of the benefits which fiberoptics offers. The requirements for sensors and actuators in advanced propulsion systems are identified. The benefits of using fiberoptics in place of conventional wire systems are discussed as well as the environmental conditions under which the optical components must operate.

  10. Bronchoscopy Simulation Training as a Tool in Medical School Education.

    PubMed

    Gopal, Mallika; Skobodzinski, Alexus A; Sterbling, Helene M; Rao, Sowmya R; LaChapelle, Christopher; Suzuki, Kei; Litle, Virginia R

    2018-07-01

    Procedural simulation training is rare at the medical school level and little is known about its usefulness in improving anatomic understanding and procedural confidence in students. Our aim is to assess the impact of bronchoscopy simulation training on bronchial anatomy knowledge and technical skills in medical students. Medical students were recruited by email, consented, and asked to fill out a survey regarding their baseline experience. Two thoracic surgeons measured their knowledge of bronchoscopy on a virtual reality bronchoscopy simulator using the Bronchoscopy Skills and Tasks Assessment Tool (BSTAT), a validated 65-point checklist (46 for anatomy, 19 for simulation). Students performed four self-directed training sessions of 15 minutes per week. A posttraining survey and BSTAT were completed afterward. Differences between pretraining and posttraining scores were analyzed with paired Student's t tests and random intercept linear regression models accounting for baseline BSTAT score, total training time, and training year. The study was completed by 47 medical students with a mean training time of 81.5 ± 26.8 minutes. Mean total BSTAT score increased significantly from 12.3 ± 5.9 to 48.0 ± 12.9 (p < 0.0001); mean scores for bronchial anatomy increased from 0.1 ± 0.9 to 31.1 ± 12.3 (p < 0.0001); and bronchoscopy navigational skills increased from 12.1 ± 5.7 to 17.4 ± 2.5 (p < 0.0001). Total training time and frequency of training did not have a significant impact on level of improvement. Self-driven bronchoscopy simulation training in medical students led to improvements in bronchial anatomy knowledge and bronchoscopy skills. Further investigation is under way to determine the impact of bronchoscopy simulation training on future specialty interest and long-term skills retention. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  11. Intravenous Dexmedetomidine Provides Superior Patient Comfort and Tolerance Compared to Intravenous Midazolam in Patients Undergoing Flexible Bronchoscopy

    PubMed Central

    Goneppanavar, Umesh; Periyadka Janardhana, Bhavya; Krishna Achar, Shreepathi

    2015-01-01

    Dexmedetomidine, an α 2 agonist, has demonstrated its effectiveness as a sedative during awake intubation, but its utility in fiberoptic bronchoscopy (FOB) is not clear. We evaluated the effects of midazolam and dexmedetomidine on patient's response to FOB. The patients received either midazolam, 0.02 mg/kg (group M, n = 27), or dexmedetomidine, 1 µg/kg (group D, n = 27). A composite score of five different parameters and a numerical rating scale (NRS) for pain intensity and distress were used to assess patient response during FOB. Patients rated the quality of sedation and level of discomfort 24 h after the procedure. Ease of bronchoscopy, rescue medication requirement, and haemodynamic variables were noted. Ideal or acceptable composite score was observed in 15 and 26 patients, respectively, in group M (14.48 ± 3.65) and group D (9.41 ± 3.13), p < 0.001. NRS showed that 11 patients in group M had severe pain and discomfort as compared to one patient with severe pain and two with severe discomfort in group D during the procedure, p < 0.001. Rescue midazolam requirement was significantly higher in group M (p = 0.023). We conclude that during FOB, under topical airway anaesthesia, IV dexmedetomidine (1 µg/kg) provides superior patient comfort and tolerance as compared to IV midazolam (0.02 mg/kg). PMID:26543645

  12. A fiberoptic reflection oximeter.

    PubMed

    Landsman, M L; Knop, N; Kwant, G; Mook, G A; Zijlstra, W G

    1978-03-20

    A catheter tip oximeter is described consisting of a cardiac catheter containing optical fibers, and incandescent light source, a light detection unit and a processing unit. Half of the optical fibers guide the light to the blood at the tip of the catheter, the other half the backscattered (reflected) light to the detection unit. The detection unit contains a dichroic mirror, transmitting most of the light with lambda less than 800 nm and reflecting most of the light with lambda greater than 900 nm, thus splitting the light into two beams. These pass through interference filters with nominal wavelengths of 640 and 920 nm respectively, and are focused on silicium barrier layer photocells. The photocell signals are amplified and fed into a divider giving the ratio of measuring (R640) and compensating (R920) photocell output. The relationship between log R640/R920 and oxygen saturation is represented by a slightly curved line. The relation may be linearized by subtracting a constant voltage from the divided output before taking the logarithm. The slope of the calibration line is dependent on the total haemoglobin concentration. Nonetheless an average calibration line can be used between 70 and 100% oxygen saturation. For 78 measurements of pig blood samples in this range (haemoglobin concentration between 96 and 161 g.1(-1)), the standard deviation of the difference between the fiberoptic oximeter and a Radiometer OSM1 oxygen saturation meter was 1.9% saturation, for 152 samples over the entire saturation range the standard deviation of the difference was 3.1% saturation. The influence of the flow velocity of blood on the light reflection depends on wavelength as well as on oxygen saturation. Therefore, complete compensation for the flow effect is not possible by simple means.

  13. Bronchoscopic lung biopsy using noninvasive ventilatory support: case series and review of literature of NIV-assisted bronchoscopy.

    PubMed

    Agarwal, Ritesh; Khan, Ajmal; Aggarwal, Ashutosh N; Gupta, Dheeraj

    2012-11-01

    Fiberoptic bronchoscopy and lung biopsy are important diagnostic tools in patients with diffuse pulmonary infiltrates. However, these patients often have hypoxemic respiratory failure that makes this procedure hazardous. Noninvasive ventilation (NIV) has been shown to improve oxygenation in hypoxemic patients. To report the efficacy and safety of an innovative technique of NIV-assisted bronchoscopic lung biopsy in a small case-series of hypoxemic subjects with diffuse parenchymal infiltrates; also to systematically review the literature on NIV-assisted bronchoscopy. Subjects with bilateral diffuse parenchymal infiltrates and P(aO(2))/F(IO(2)) < 200 mm Hg underwent bronchoscopic lung biopsy under NIV support. NIV was initiated 10 min before the procedure and continued for 30 min after the procedure. The primary outcomes were performance of successful procedure and episodes of decline in S(pO(2)) < 90%. Secondary end points were the change in the respiratory and hemodynamic parameters during the procedure and occurrence of complications such as pneumothorax, hemorrhage, and endotracheal intubation. Six subjects, with a mean ± SD age of 44.5 ± 11.6 years, were included in the study. The median (interquartile range [IQR]) P(aO(2))/F(IO(2)) prior to lung biopsy was 164.5 mm Hg (146.3-176.3 mm Hg), and the median (IQR) inspiratory and expiratory positive airway pressures were 14 cm H(2)O (12-15 cm H(2)O) and 5 cm H(2)O. Fiberoptic bronchoscopy was well tolerated and all subjects maintained S(pO(2)) > 92% during the procedure. One subject required endotracheal intubation due to hemoptysis. A definite diagnosis was obtained in 5 of the 6 subjects. A repeat procedure was performed in one subject, which again yielded no diagnosis. No other periprocedural complications were encountered. NIV-assisted bronchoscopic lung biopsy is a novel method for obtaining diagnosis in hypoxemic patients with diffuse lung infiltrates. However, this approach should be reserved for centers

  14. Can a bronchoscopist reliably assess a patient's experience of bronchoscopy?

    PubMed Central

    Hadzri, HM; Azarisman, SMS; Fauzi, ARM; Roslan, H; Roslina, AM; Adina, ATN; Fauzi, MA

    2010-01-01

    Objectives Bronchoscopy is an essential investigative tool in many respiratory complaints. The procedure can be unpleasant for both bronchoscopists and patients. To the best of our knowledge, there are only a few studies that correlate the bronchoscopist's satisfaction with that of the patient's during bronchoscopy. The aim of our study is to assess whether or not a bronchoscopist could reliably assess a patient's satisfaction during bronchoscopy. Design Cross-sectional, observational study with convenience sampling. Setting Patients attending flexible fibreoptic bronchoscopy appointments at the bronchoscopy suite, Respiratory Unit, Universiti Kebangsaan Malaysia Medical Centre (UKMMC), Cheras, Kuala Lumpur, Malaysia between March and September 2006. Participants Sixty patients undergoing bronchoscopy over a 6-month period completed a questionnaire after the procedure. All patients received standard pre-medication with intravenous midazolam. Main outcome measures Bronchoscopists and patients rated the level of satisfaction of the procedure using a 10 cm visual analogue scale (VAS). Lower scores indicated better satisfaction or less discomfort. Patients and bronchoscopists also rated coughing, choking and vomiting perception using the same 10 cm VAS. Reliability analysis (intra-class correlation coefficient [ICC]) was used to analyse the correlation between patients' and bronchoscopists' VAS scores. Results All 60 patients answered the questionnaire. The median overall satisfaction scored by bronchoscopists was 2.2 (2.0) with a non-significant (p = 0.880) trend to a better median overall satisfaction of 1.9 (2.3) scored by patients. The VAS scores for cough sensation were 1.9 (2.7) and 1.5 (5.0), respectively. There was positive correlation between bronchoscopists' and patients' VAS scores for coughing sensation (p = 0.047, ICC = 0.233). No significant correlation for overall satisfaction, vomiting sensation and choking sensation was found. Conclusion Positive

  15. Establishing pass/fail criteria for bronchoscopy performance.

    PubMed

    Konge, Lars; Clementsen, Paul; Larsen, Klaus Richter; Arendrup, Henrik; Buchwald, Christian; Ringsted, Charlotte

    2012-01-01

    Several tools have been created to assess competence in bronchoscopy. However, educational guidelines still use an arbitrary number of performed procedures to decide when basic competency is acquired. The purpose of this study was to define pass/fail scores for two bronchoscopy assessment tools, and investigate how these scores relate to physicians' experience regarding the number of bronchoscopy procedures performed. We studied two assessment tools and used two standard setting methods to create cut scores: the contrasting-groups method and the extended Angoff method. In the first we compared bronchoscopy performance scores of 14 novices with the scores of 14 experienced consultants to find the score that best discriminated between the two groups. In the second we asked an expert group of 7 experienced bronchoscopists to judge how a borderline trainee would perform on each item of the test. Using the contrasting-groups method we found a standard that would fail all novices and pass all consultants. A clear pass related to prior experience of 75 procedures. The consequences of using the extended Angoff method were also acceptable: all trainees who had performed less than 50 bronchoscopies failed the test and all consultants passed. A clear pass related to 80 procedures. Our proposed pass/fail scores for these two methods seem appropriate in terms of consequences. Prior experience with the performance of 75 and 80 bronchoscopies, respectively, seemed to ensure basic competency. In the future objective assessment tools could become an important aid in the certification of physicians performing bronchoscopies. Copyright © 2011 S. Karger AG, Basel.

  16. Image-based global registration system for bronchoscopy guidance

    NASA Astrophysics Data System (ADS)

    Khare, Rahul; Higgins, William E.

    2011-03-01

    Previous studies have shown that bronchoscopy guidance systems improve accuracy and reduce skill variation among physicians during bronchoscopy. In the past, we presented an image-based bronchoscopy guidance system that has been extensively validated in live bronchoscopic procedures. However, this system cannot actively recover from adverse events, such as patient coughing or dynamic airway collapses. After such events, the bronchoscope position is recovered only by moving back to a previously seen and easily identifiable bifurcation such as the main carina. Furthermore, the system requires an attending technician to closely follow the physician's movement of the bronchoscope to avoid misguidance. Also, when the physician is forced to advance the bronchoscope across multiple bifurcations, the system is not able to detect faulty maneuvers. We propose two system-level solutions. The first solution is a system-level guidance strategy that incorporates a global-registration algorithm to provide the physician with updated navigational and guidance information during bronchoscopy. The system can handle general navigation to a region of interest (ROI), as well as adverse events, and it requires minimal commands so that it can be directly controlled by the physician. The second solution visualizes the global picture of all the bifurcations and their relative orientations in advance and suggests the maneuvers needed by the bronchoscope to approach the ROI. Guided bronchoscopy results using human airway-tree phantoms demonstrate the potential of the two solutions.

  17. Navigation bronchoscopy for diagnosis and small nodule location

    PubMed Central

    Muñoz-Largacha, Juan A.; Litle, Virginia R.

    2017-01-01

    Lung cancer continues to be the most common cause of cancer death. Screening programs for high risk patients with the use of low-dose computed tomography (CT) has led to the identification of small lung lesions that were difficult to identify using previous imaging modalities. Electromagnetic navigational bronchoscopy (ENB) is a novel technique that has shown to be of great utility during the evaluation of small, peripheral lesions, that would otherwise be challenging to evaluate with conventional bronchoscopy. The diagnostic yield of navigational bronchoscopy however is highly variable, with reports ranging from 59% to 94%. This variability suggests that well-defined selection criteria and standardized protocols for the use of ENB are lacking. Despite this variability, we believe that this technique is a useful tool evaluating small peripheral lung lesions when patients are properly selected. PMID:28446971

  18. Frequent Oxygen Desaturation During Sleep on the Day of Bronchoscopy Evaluated by Continuous Pulse Oximeter Monitoring.

    PubMed

    Chojin, Yasuo; Ishimoto, Hiroshi; Noguchi, Shingo; Kawanami, Toshinori; Kato, Tatsuji; Mukae, Hiroshi; Yatera, Kazuhiro

    To perform a bronchoscopy safely, it is very important to make a risk assessment before and after the procedure. There have been no reports of hypoxemia during sleep on the day after a bronchoscopic examination; therefore, we evaluated the oxygen saturation status during sleep on the days before and after bronchoscopy. Thirty patients that underwent bronchoscopy were studied. Continuous pulse oximetry monitoring was performed on the day before bronchoscopy and the day when the bronchoscopy was performed. The average oxygen saturation levels and the oxygen desaturation index (ODI) were evaluated. There was a significant increase (P < 0.05) in the ODI-3% during sleep on the day of the bronchoscopy compared to the day before the bronchoscopy. Clinicians should pay careful attention to hypoxia not only during bronchoscopy, but also during sleep on the night following the procedure.

  19. Oxygen supplementation is required in healthy volunteers during bronchoscopy with lavage

    EPA Science Inventory

    Hypoxemia can complicate bronchoscopy. Common causes of hypoxemia during bronchoscopy include preexisting lung disease, upper airway obstruction, pneumothorax and bleeding secondary to either transbronchial lung biopsy or another interventional bronchoscopic procedure, hypoventil...

  20. Management of Foreign Body Removal in Children by Flexible Bronchoscopy.

    PubMed

    Tenenbaum, Tobias; Kähler, Georg; Janke, Christoph; Schroten, Horst; Demirakca, Süha

    2017-01-01

    Rigid bronchoscopy remains the gold standard in many countries to remove airway foreign bodies (FBs). We aimed to analyze the feasibility of airway FB removal in children, primarily by flexible bronchoscopy through a laryngeal mask. Between 2008 and 2013, 62 children with suspected airway FB who underwent flexible bronchoscopy were analyzed in a retrospective chart review at a tertiary university hospital with respect to clinical presentation and medical management. In 28/62 children (45.2%) an airway FB could be found and in all patients removed by flexible bronchoscopy. Additional 19/34 children (55.8%), in which no FB was found, showed macroscopic evidence of prior FB aspiration. The most frequently removed airway FBs were nuts (13/28; 46.4%) followed by other organic airway FBs (9/28; 32.2%) and nonorganic airway FBs (6/28; 21.4%). All FBs were uneventfully removed with a grasping forceps (16/28; 57.1%), basket forceps (9/28; 32.2%), suction (2/28; 7.1%), or polypectomy snare (1/28; 3.6%). Children with proven airway FB were significantly younger than children without an airway FB (24 vs. 27 mo). Adjuvant antibiotic therapy was given in 15/28 (53.6%) children with proven airway FB and 13/34 (38.2%) without, steroids in 24/28 (85.7%) and 21/34 (61.8%), respectively. In 6/28 (9.7%) children epinephrine intrabronchial was used to mobilize the airway FB during bronchoscopy. In an optimized clinical setting, flexible bronchoscopy can be regarded as a feasible procedure to remove airway FB through a laryngeal mask. Short-term and long-term outcome is favorable.

  1. Rate of new findings in diagnostic office bronchoscopy.

    PubMed

    Soldatova, Liuba; DeSilva, Brad W; Matrka, Laura A

    2017-06-01

    Awake Flexible Tracheobronchoscopy (FTB) is an alternative to rigid bronchoscopy or sedated flexible bronchoscopy and allows an awake examination of the tracheobronchial tree. We hypothesized that the ability to perform office bronchoscopy as the need arises during a clinic visit would lead to a high rate of previously undiagnosed and clinically relevant findings. This study reports the rate and nature of such findings for this procedure at our institution. Retrospective chart review. The records of 127 adult patients evaluated at the voice and swallowing disorders clinic between June of 2012 and January of 2015 were reviewed. New findings were defined as new pathology visualized during FTB exam that was not previously diagnosed by means of other diagnostic modalities. A total of 233 scope procedures (84 transnasal bronchoscopies and 149 tracheoscopies) were reviewed, 232 of which were completed and one of which was incomplete due to severe subglottic stenosis. New, clinically relevant findings were seen in 57% of transnasal bronchoscopies (48 of 84) and 21% of tracheoscopies (32 of 149). All of these findings provided additional information directing workup or resulted in a change in patient management. Office-based evaluation of the tracheobronchial tree yields a high rate of new findings. In our study, office bronchoscopy had a 57% rate of new findings and was performed without complications. The utility of tracheoscopy was also apparent in its ability to quickly and safely examine the trachea, with a 21% rate of new findings. 4. Laryngoscope, 127:1376-1380, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  2. Role of virtual bronchoscopy in children with a vegetable foreign body in the tracheobronchial tree.

    PubMed

    Behera, G; Tripathy, N; Maru, Y K; Mundra, R K; Gupta, Y; Lodha, M

    2014-12-01

    Multidetector computed tomography virtual bronchoscopy is a non-invasive diagnostic tool which provides a three-dimensional view of the tracheobronchial airway. This study aimed to evaluate the usefulness of virtual bronchoscopy in cases of vegetable foreign body aspiration in children. The medical records of patients with a history of foreign body aspiration from August 2006 to August 2010 were reviewed. Data were collected regarding their clinical presentation and chest X-ray, virtual bronchoscopy and rigid bronchoscopy findings. Cases of metallic and other non-vegetable foreign bodies were excluded from the analysis. Patients with multidetector computed tomography virtual bronchoscopy showing features of vegetable foreign body were included in the analysis. For each patient, virtual bronchoscopy findings were reviewed and compared with those of rigid bronchoscopy. A total of 60 patients; all children ranging from 1 month to 8 years of age, were included. The mean age at presentation was 2.01 years. Rigid bronchoscopy confirmed the results of multidetector computed tomography virtual bronchoscopy (i.e. presence of foreign body, site of lodgement, and size and shape) in 59 patients. In the remaining case, a vegetable foreign body identified by virtual bronchoscopy was revealed by rigid bronchoscopy to be a thick mucus plug. Thus, the positive predictive value of virtual bronchoscopy was 98.3 per cent. Multidetector computed tomography virtual bronchoscopy is a sensitive and specific diagnostic tool for identifying radiolucent vegetable foreign bodies in the tracheobronchial tree. It can also provide a useful pre-operative road map for rigid bronchoscopy. Patients suspected of having an airway foreign body or chronic unexplained respiratory symptoms should undergo multidetector computed tomography virtual bronchoscopy to rule out a vegetable foreign body in the tracheobronchial tree and avoid general anaesthesia and invasive rigid bronchoscopy.

  3. Fiber-optic fluorescence imaging

    PubMed Central

    Flusberg, Benjamin A; Cocker, Eric D; Piyawattanametha, Wibool; Jung, Juergen C; Cheung, Eunice L M; Schnitzer, Mark J

    2010-01-01

    Optical fibers guide light between separate locations and enable new types of fluorescence imaging. Fiber-optic fluorescence imaging systems include portable handheld microscopes, flexible endoscopes well suited for imaging within hollow tissue cavities and microendoscopes that allow minimally invasive high-resolution imaging deep within tissue. A challenge in the creation of such devices is the design and integration of miniaturized optical and mechanical components. Until recently, fiber-based fluorescence imaging was mainly limited to epifluorescence and scanning confocal modalities. Two new classes of photonic crystal fiber facilitate ultrashort pulse delivery for fiber-optic two-photon fluorescence imaging. An upcoming generation of fluorescence imaging devices will be based on microfabricated device components. PMID:16299479

  4. Fiberoptic bronchoscopic treatment of blood aspiration and use of sugammadex in a patient with epistaxis: A case report.

    PubMed

    Ryu, Taeha; Kim, Dong Hyuck; Byun, Sung Hye

    2018-04-01

    In patients with oropharyngeal and nasopharyngeal bleeding, blood aspiration can make airway management difficult and lead to severe pulmonary complications. A 44-year-old male patient with recurrent epistaxis underwent surgery for hemostasis. The patient aspirated blood through the endotracheal tube when he hiccupped during the surgery. The patient was diagnosed with blood aspiration after intraoperative fiberoptic bronchoscopy revealed a blood clot and viscous mucus in the airways, but no sign of active bleeding. Tracheobronchial suctioning and irrigation with normal saline was performed through the bronchoscope to remove the aspirated blood clot. Prior to emergence from anesthesia, sugammadex was administered to induce complete neuromuscular recovery and enable the patient to cough up any blood remaining in the airways. The patient was successfully extubated and fully recovered with no complications. Blood aspiration due to oropharyngeal or nasopharyngeal bleeding can be diagnosed and treated by tracheobronchial suctioning via fiberoptic bronchoscopy. In addition, sugammadex can enable patients to recover spontaneous breathing, facilitate extubation, and enable patients to cough up any blood remaining in the airways.

  5. Complications Following Therapeutic Bronchoscopy for Malignant Central Airway Obstruction

    PubMed Central

    Ernst, Armin; Grosu, Horiana B.; Lei, Xiudong; Diaz-Mendoza, Javier; Slade, Mark; Gildea, Thomas R.; Machuzak, Michael; Jimenez, Carlos A.; Toth, Jennifer; Kovitz, Kevin L.; Ray, Cynthia; Greenhill, Sara; Casal, Roberto F.; Almeida, Francisco A.; Wahidi, Momen; Eapen, George A.; Yarmus, Lonny B.; Morice, Rodolfo C.; Benzaquen, Sadia; Tremblay, Alain; Simoff, Michael; Kovitz, Kevin L.; Greenhill, Sara; Gildea, Thomas R.; Machuzak, Michael; Almeida, Francisco A.; Cicenia, Joseph; Wahidi, Momen; Mahmood, Kamran; MacEachern, Paul; Tremblay, Alain; Simoff, Michael; Diaz-Mendoza, Javier; Ray, Cynthia; Feller-Kopman, David; Yarmus, Lonny B.; Estrada-Y-Martin, Rosa; Casal, Roberto F.; Toth, Jennifer; Karunakara, Raj; Slade, Mark; Ernst, Armin; Rafeq, Samaan; Ost, David E.; Eapen, George A.; Jimenez, Carlos A.; Morice, Rodolfo C.; Benzaquen, Sadia; Puchalski, Jonathan

    2015-01-01

    BACKGROUND: There are significant variations in how therapeutic bronchoscopy for malignant airway obstruction is performed. Relatively few studies have compared how these approaches affect the incidence of complications. METHODS: We used the American College of Chest Physicians (CHEST) Quality Improvement Registry, Evaluation, and Education (AQuIRE) program registry to conduct a multicenter study of patients undergoing therapeutic bronchoscopy for malignant central airway obstruction. The primary outcome was the incidence of complications. Secondary outcomes were incidence of bleeding, hypoxemia, respiratory failure, adverse events, escalation in level of care, and 30-day mortality. RESULTS: Fifteen centers performed 1,115 procedures on 947 patients. There were significant differences among centers in the type of anesthesia (moderate vs deep or general anesthesia, P < .001), use of rigid bronchoscopy (P < .001), type of ventilation (jet vs volume cycled, P < .001), and frequency of stent use (P < .001). The overall complication rate was 3.9%, but significant variation was found among centers (range, 0.9%-11.7%; P = .002). Risk factors for complications were urgent and emergent procedures, American Society of Anesthesiologists (ASA) score > 3, redo therapeutic bronchoscopy, and moderate sedation. The 30-day mortality was 14.8%; mortality varied among centers (range, 7.7%-20.2%, P = .02). Risk factors for 30-day mortality included Zubrod score > 1, ASA score > 3, intrinsic or mixed obstruction, and stent placement. CONCLUSIONS: Use of moderate sedation and stents varies significantly among centers. These factors are associated with increased complications and 30-day mortality, respectively. PMID:25741903

  6. [Bronchoscopy in Germany. Cross-sectional inquiry with 681 institutions].

    PubMed

    Markus, A; Häussinger, K; Kohlhäufl, M; Hauck, R W

    2000-11-01

    Bronchoscopy represents an integral part of the diagnostic tools in pulmonary medicine. Recently, it has also gained considerable attention for its therapeutic properties. To elucidate equipment, indications and procedural techniques of bronchoscopy units, a retrospective survey of 1232 hospitals and practices is conducted. 687 questionnaires are received back (response rate 56%). 681 of which are statistically evaluated. Two thirds of the physicians in charge are internists, one third are pulmonary care specialists. A total of 200,596 endoscopic procedures is included. The majority of procedures is done with an average of 3 bronchoscopists and in over 57% (388) of cases with an average number of 100 or less procedures per year. The five main indications are tumor, hemoptysis, infection or pneumonia, drainage of secretions and suspected interstitial disease. Overall complication rate amounts to 2.7% with an incidence of 4.6% minor and 0.7% major complications and a bronchoscopy-related mortality of 0.02%. The patterns seen in premedication, intra- and post-procedural monitoring, disinfection practices as well as documentation are quite heterogeneous. It is suggested to establish revised and updated standards for bronchoscopy, which should take the data collected into particular account. Those standards should provide the basis for a high level bronchological care throughout Germany.

  7. Operative rigid bronchoscopy: indications, basic techniques and results.

    PubMed

    Petrella, Francesco; Borri, Alessandro; Casiraghi, Monica; Cavaliere, Sergio; Donghi, Stefano; Galetta, Domenico; Gasparri, Roberto; Guarize, Juliana; Pardolesi, Alessandro; Solli, Piergiorgio; Tessitore, Adele; Venturino, Marco; Veronesi, Giulia; Spaggiari, Lorenzo

    2014-05-27

    Palliative airway treatments are essential to improve quality and length of life in lung cancer patients with central airway obstruction. Rigid bronchoscopy has proved to be an excellent tool to provide airway access and control in this cohort of patients. The main indication for rigid bronchoscopy in adult bronchology remains central airway obstruction due to neoplastic or non-neoplastic disease. We routinely use negative pressure ventilation (NPV) under general anaesthesia to prevent intraoperative apnoea and respiratory acidosis. This procedure allows opioid sparing, a shorter recovery time and avoids manually assisted ventilation, thereby reducing the amount of oxygen needed, while maintaining optimal surgical conditions. The major indication for NPV rigid bronchoscopy at our institution has been airway obstruction by neoplastic tracheobronchial tissue, mainly treated by laser-assisted mechanical dissection. When strictly necessary, we use silicone stents for neoplastic or cicatricial strictures, reserving metal stents to cover tracheo-oesophageal fistulae. NPV rigid bronchoscopy is an excellent tool for the endoscopic treatment of locally advanced tumours of the lung, especially when patients have exhausted the conventional therapeutic resources. Laser-assisted mechanical resection and stent placement are the most effective procedures for preserving quality of life in patients with advanced stage cancer. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-thoracic Surgery. All rights reserved.

  8. Computer-based route-definition system for peripheral bronchoscopy.

    PubMed

    Graham, Michael W; Gibbs, Jason D; Higgins, William E

    2012-04-01

    Multi-detector computed tomography (MDCT) scanners produce high-resolution images of the chest. Given a patient's MDCT scan, a physician can use an image-guided intervention system to first plan and later perform bronchoscopy to diagnostic sites situated deep in the lung periphery. An accurate definition of complete routes through the airway tree leading to the diagnostic sites, however, is vital for avoiding navigation errors during image-guided bronchoscopy. We present a system for the robust definition of complete airway routes suitable for image-guided bronchoscopy. The system incorporates both automatic and semiautomatic MDCT analysis methods for this purpose. Using an intuitive graphical user interface, the user invokes automatic analysis on a patient's MDCT scan to produce a series of preliminary routes. Next, the user visually inspects each route and quickly corrects the observed route defects using the built-in semiautomatic methods. Application of the system to a human study for the planning and guidance of peripheral bronchoscopy demonstrates the efficacy of the system.

  9. Technician-free system for image-guided bronchoscopy

    NASA Astrophysics Data System (ADS)

    Khare, Rahul; Bascom, Rebecca; Higgins, William E.

    2013-03-01

    Previous studies have shown that guidance systems improve accuracy and reduce skill variation among physicians during bronchoscopy. However, most of these systems suffer from one or more of the following limitations: 1) an attending technician must carefully keep the system position synchronized with the bronchoscope position during the procedure; 2) extra bronchoscope tracking hardware may be required; 3) guidance cannot take place in real time; 4) the guidance system is unable to detect and correct faulty bronchoscope maneuvers; and 5) a resynchronization procedure must be followed after adverse events such as patient cough or dynamic airway collapse. Here, we propose an image-based system for technician-free bronchoscopy guidance that relies on two features. First, our system precomputes a guidance plan that suggests natural bronchoscope maneuvers at every bifurcation leading toward a region of interest (ROI). Second, our system enables bronchoscope position verification that relies on a global-registration algorithm to establish the global bronchoscope position and, thus, provide the physician with updated navigational information during bronchoscopy. The system can handle general navigation to an ROI, as well as adverse events, and is directly controlled by the physician by a foot pedal. Guided bronchoscopy results using airway-tree phantoms and human cases demonstrate the efficacy of the system.

  10. Fiducial marker placement using endobronchial ultrasound and navigational bronchoscopy for stereotactic radiosurgery: an alternative strategy.

    PubMed

    Harley, Daniel P; Krimsky, William S; Sarkar, Saiyad; Highfield, David; Aygun, Cengis; Gurses, Burak

    2010-02-01

    Stereotactic radiosurgery is being increasingly used to treat patients with early-stage non-small cell lung cancers (NSCLC) who are not candidates for surgical resection. Stereotactic radiosurgery usually needs fiducial markers (FMs) for the tracking process. FMs have generally been placed using percutaneous computed axial tomography scan guidance. We report the results of FM placement using endobronchial ultrasound (EBUS) in 43 patients. A multidisciplinary tumor board evaluates NSCLC patients before they are offered stereotactic radiosurgery. In patients selected for stereotactic radiosurgery, FMs were inserted into peripheral, central, and mediastinal tumors using EBUS and, in selected patients, navigational bronchoscopy. Patients underwent repeat computed axial tomography chest scans 2 weeks later to ensure stability of the FMs before beginning stereotactic radiosurgery. Included were 43 consecutive patients (21 men, 22 women; mean age, 74.4 years). Forty-two (98%) had NSC carcinomas (5 recurrences); 1 had a carcinoid tumor. Twenty-two tumors were located in the left lung, 19 in the right lung, 1 at the carina, and 1 pretracheal. Two to 5 FMs were placed in and around all tumor masses using EBUS and, for peripheral lesions, EBUS combined with navigational bronchoscopy. Thirty patients had no displacement of FMs. In the 13 who had displaced 1 or more FMs, the ability to use the remaining FMs for stereotactic radiosurgery was unimpaired. EBUS and navigational bronchoscopy are safe and effective methods to position FMs for preparing patients with both central and peripheral lung cancers for stereotactic radiosurgery. 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  11. Tracheobronchial Foreign Bodies in Children: The Role of Emergency Rigid Bronchoscopy

    PubMed Central

    Baram, Aram; Sherzad, Hewa; Saeed, Sara; Kakamad, Fahmi H.; Hamawandi, Adnan M. H.

    2017-01-01

    Foreign body aspiration (FBA) is a common and lethal accident in the pediatric age group. It requires early recognition and treatment by rigid bronchoscopy to avoid fatal outcomes. Objective. The aim of this study was to study the pattern of FBA in the tracheobronchial tree as well as the success rate of rigid bronchoscopy in children admitted to a single center and to analyze the relationship of the type of foreign body (FB) with patients’ age, presentation, and complications. Methods. A retrospective cross-sectional study of FBA was conducted in children in the Sulaimani/Kurdistan region, Iraq, admitted to the emergency teaching hospital of the University of Sulaimani from January 2014 to March 2016. Result. Data of 83 patients between 6 months and 15 years old were studied. The most affected was the 1- to 5-year-old group. There was a slight female predominance (male to female ratio 0.93:1). The most common FB was sunflower seed (49.4%). History of choking was present in 92.8% of patients; 55.4% had normal air entry, and 37.3% had no added sound on chest auscultation. Normal chest X-ray (CXR) was found in 40% of patients. The most common site was the right bronchial tree (39.8%). Two patients needed mechanical ventilation; both of them died. There was a significant relationship between the type of FB (P = .013, .000, respectively). Conclusion. Medical history is the most important factor for reaching the diagnosis; bronchoscopy is mandatory if choking was witnessed, even if examination and CXR are normal. Organic material causes more local reaction than nonorganic material. PMID:29226187

  12. A comparison of virtual bronchoscopy versus flexible bronchoscopy in the diagnosis of tracheobronchomalacia in children.

    PubMed

    Su, Siew Choo; Masters, Ian Brent; Buntain, Helen; Frawley, Kieran; Sarikwal, Anubhav; Watson, Debbie; Ware, Frances; Wuth, Jan; Chang, Anne Bernadette

    2017-04-01

    Flexible bronchoscopy (FB) is the current gold standard for diagnosing tracheobronchomalacia. However, it is not always feasible and virtual bronchoscopy (VB), acquired from chest multi-detector CT (MDCT) scan is an alternative diagnostic tool. We determined the sensitivity, specificity, and positive and negative predictive values of VB compared to FB in diagnosing tracheobronchomalacia. Children aged <18-years scheduled for FB and MDCT were recruited. FB and MDCT were undertaken within 30-min to 7-days of each other. Tracheobronchomalacia (mild, moderate, severe, very severe) diagnosed on FB were independently scored by two pediatric pulmonologists; VB was independently scored by two pairs (each pair = pediatric pulmonologist and radiologist), in a blinded manner. In 53 children (median age = 2.5 years, range 0.8-14.3) evaluated for airway abnormalities, tracheomalacia was detected in 37 (70%) children at FB. Of these, VB detected tracheomalacia in 20 children, with a sensitivity of 54.1% (95%CI 37.1-70.2), specificity = 87.5% (95%CI 60.4-97.8), and positive predictive value = 90.9% (95%CI 69.4-98.4). The agreement between pediatric pulmonologists for diagnosing tracheomalacia by FB was excellent, weighted κ = 0.8 (95%CI 0.64-0.97); but only fair between the pairs of pediatric pulmonologists/radiologists for VB, weighted κ = 0.47 (95%CI 0.23-0.71). There were 42 cases of bronchomalacia detected on FB. VB had a sensitivity = 45.2% (95%CI 30.2-61.2), specificity = 95.5% (95%CI 94.2-96.5), and positive predictive value = 23.2 (95%CI 14.9-34.0) compared to FB in detecting bronchomalacia. VB cannot replace FB as the gold standard for detecting tracheobronchomalacia in children. However, VB could be considered as an alternative diagnostic modality in children with symptoms suggestive of tracheobronchomalacia where FB is unavailable. Pediatr Pulmonol. 2017;52:480-486. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  13. Electromagnetic Navigation Bronchoscopy for Identifying Lung Nodules for Thoracoscopic Resection.

    PubMed

    Marino, Katy A; Sullivan, Jennifer L; Weksler, Benny

    2016-08-01

    Pulmonary nodules smaller than 1 cm can be difficult to identify during minimally invasive resection, necessitating conversion to thoracotomy. We hypothesized that localizing nodules with electromagnetic navigation bronchoscopy and marking them with methylene blue would allow minimally invasive resection and reduce conversion to thoracotomy. We retrospectively identified all patients who underwent electromagnetic navigation bronchoscopy followed by minimally invasive resection of a pulmonary nodule from 2011 to 2014. Lung nodules smaller than 10 mm and nodules smaller than 20 mm that were also located more than 10 mm from the pleural surface were localized and marked with methylene blue. Immediately after marking, all patients underwent resection. Seventy patients underwent electromagnetic navigation bronchoscopy marking followed by minimally invasive resection. The majority of patients (68/70, 97%) had one nodule localized; 2 patients (2/70, 3%) had two nodules localized. The median nodule size was 8 mm (range, 4-17 mm; interquartile range, 5 mm). The median distance from the pleural surface was 6 mm (range, 1-19 mm; interquartile range, 6 mm). There were no conversions to thoracotomy. Nodule marking was successful in 70 of 72 attempts (97.2%); two nodules were identified by palpation. The nodules were most commonly metastases from other sites (31/70, 44.3%). There were no adverse events related to electromagnetic navigation bronchoscopy-guided marking or wedge resection, and minimal adverse events after resections that were more extensive. Localizing and marking small pulmonary nodules using electromagnetic navigation bronchoscopy is safe and effective for nodule identification before minimally invasive resection. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  14. Spectrum-Modulating Fiber-Optic Sensors

    NASA Technical Reports Server (NTRS)

    Beheim, Glenn; Fritsch, Klaus

    1989-01-01

    Family of spectrum-modulating fiber-optic sensors undergoing development for use in aircraft-engine control systems. Fiber-optic sensors offer advantages of small size, high bandwidth, immunity to electromagnetic interference, and light weight. Furthermore, they reduce number of locations on aircraft to which electrical power has to be supplied.

  15. Fiber-optic liquid level sensor

    DOEpatents

    Weiss, Jonathan D.

    1991-01-01

    A fiber-optic liquid level sensor measures the height of a column of liquid through the hydrostatic pressure it produces. The sensor employs a fiber-optic displacement sensor to detect the pressure-induced displacement of the center of a corrugated diaphragm.

  16. Pseudo-Outbreak of Actinomyces graevenitzii Associated with Bronchoscopy

    PubMed Central

    Peaper, David R.; Havill, Nancy L.; Aniskiewicz, Michael; Callan, Deborah; Pop, Olivia; Towle, Dana

    2014-01-01

    Outbreaks and pseudo-outbreaks of infection related to bronchoscopy typically involve Gram-negative bacteria, Mycobacterium species or Legionella species. We report an unusual bronchoscopy-related pseudo-outbreak due to Actinomyces graevenitzii. Extensive epidemiological and microbiological investigation failed to identify a common source. Strain typing revealed that the cluster was comprised of heterogeneous strains of A. graevenitzii. A change in laboratory procedures for Actinomyces cultures was coincident with the emergence of the pseudo-outbreak, and we determined that A. graevenitzii isolates more readily adopted a white, dry, molar tooth appearance on anaerobic colistin nalidixic acid (CNA) agar which likely facilitated its detection and identification in bronchoscopic specimens. This unusual pseudo-outbreak was related to frequent requests of bronchoscopists for Actinomyces cultures combined with a change in microbiology laboratory practices. PMID:25355767

  17. Pseudo-outbreak of Actinomyces graevenitzii associated with bronchoscopy.

    PubMed

    Peaper, David R; Havill, Nancy L; Aniskiewicz, Michael; Callan, Deborah; Pop, Olivia; Towle, Dana; Boyce, John M

    2015-01-01

    Outbreaks and pseudo-outbreaks of infection related to bronchoscopy typically involve Gram-negative bacteria, Mycobacterium species or Legionella species. We report an unusual bronchoscopy-related pseudo-outbreak due to Actinomyces graevenitzii. Extensive epidemiological and microbiological investigation failed to identify a common source. Strain typing revealed that the cluster was comprised of heterogeneous strains of A. graevenitzii. A change in laboratory procedures for Actinomyces cultures was coincident with the emergence of the pseudo-outbreak, and we determined that A. graevenitzii isolates more readily adopted a white, dry, molar tooth appearance on anaerobic colistin nalidixic acid (CNA) agar which likely facilitated its detection and identification in bronchoscopic specimens. This unusual pseudo-outbreak was related to frequent requests of bronchoscopists for Actinomyces cultures combined with a change in microbiology laboratory practices. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  18. Electromagnetic navigational bronchoscopy and robotic-assisted thoracic surgery.

    PubMed

    Christie, Sara

    2014-06-01

    With the use of electromagnetic navigational bronchoscopy and robotics, lung lesions can be diagnosed and resected during one surgical procedure. Global positioning system technology allows surgeons to identify and mark a thoracic tumor, and then robotics technology allows them to perform minimally invasive resection and cancer staging procedures. Nurses on the perioperative robotics team must consider the logistics of providing safe and competent care when performing combined procedures during one surgical encounter. Instrumentation, OR organization and room setup, and patient positioning are important factors to consider to complete the procedure systematically and efficiently. This revolutionary concept of combining navigational bronchoscopy with robotics requires a team of dedicated nurses to facilitate the sequence of events essential for providing optimal patient outcomes in highly advanced surgical procedures. Copyright © 2014 AORN, Inc. Published by Elsevier Inc. All rights reserved.

  19. Bronchoscopy findings in children with recurrent and chronic stridor.

    PubMed

    Najada, Abdelhamid S; Dahabreh, Muna M

    2011-01-01

    To describe the bronchoscopic findings and treatment decision of children with chronic or recurrent stridor referred to the pediatric respiratory clinic at Queen Rania Hospital for Children. All children who underwent flexible bronchoscopy at the pediatric bronchoscopy unit for chronic stridor from January 2009 to January 2010 were included. Stridor was divided into 3 groups: inspiratory, expiratory, or biphasic. All patients from 2 weeks of age till 14 years were included. Files of these patients were retrospectively reviewed. A specially formulated data sheet including clinical history and physical findings, type of stridor, bronchoscopic findings, and management decision was used. Radiologic investigation results were included when relevant. Flexible bronchoscopy was performed under sedation and topical anesthesia. A total of 64 children [35 (54.7%) male and 29 (45.3%) female] were included. Twenty-four patients had inspiratory stridor. There were 33 patients with biphasic stridor (subglottic stenosis in 9, paradoxical vocal cord movement in 6, vascular ring in 5, subglottic hemangioma in 3, vocal cord paralyses in 4, foreign body in 2, laryngeal web in 2, and absent vocal cord and tracheal bronchus in 1 each). Seven children had expiratory stridor. Of patients with laryngomalacia, 50% had associated tracheomalacia and 70% of those with laryngomalacia and all patients with tracheomalacia had associated gastroesophageal reflux. Two patients with paradoxical vocal cord movement were found to have Arnold-Chiari malformation. All patients with vascular rings underwent surgery. Flexible bronchoscopy should be performed in all patients with chronic or recurrent stridor to assess the airway and guide further investigations and management.

  20. [Premedication in fiber optic bronchoscopy from the patient's and the physician's viewpoint--a randomized study for the comparison of midazolam and hydrocodone].

    PubMed

    Mendes de Leon, C; Bezel, R; Karrer, W; Brändli, O

    1986-09-13

    To evaluate side effects and patients' assessment of fiberoptic bronchoscopy under local anesthesia, 122 consecutive patients answered questions from an outside interviewer (an experienced psychiatrist) and not from the endoscopists themselves. The effect of premedication with midazolam (5 mg i.m.) and hydrocodonum (15 mg i.m.) was compared in a randomized study. In a multiple choice questionnaire 68% of all patients indicated considerable fear in the days before bronchoscopy. They were more afraid of the possible diagnosis of cancer (23%) than of dyspnea or asphyxiation (14%). Coughing is considered the worst side effect of bronchoscopy by 25% of patients (36% of the endoscopists) followed by dyspnea during insertion of the scope (21%) and discomfort during local anesthesia. Although the patients premedicated with midazolam are more sedated (p = 0.025 by physicians' assessment vs. p = 0.11 in patients' view), they cough more (p = 0.001 vs. p = 0.22) and usually tolerate the examination less well (p = 0.009 vs. p = 0.08) than patients premedicated with hydrocodonum. 42% of patients premedicated with midazolam had anterograde amnesia. Although they did not remember all the unpleasant side effects, only 77% said they would repeat the procedure with the same premedication, compared with 90% of patients premedicated with hydrocodonum (p = 0.08). Before and two hours after premedication the reaction times had not changed (optical sign, Wiener reaction device) and were identical in the two patient groups. At that time 37% of the patients premedicated with midazolam and 27% of those premedicated with hydrocodonum were still sleepy and could not be regarded as fit for any form of travel.

  1. Fiber-optic sensor applications in civil and geotechnical engineering

    NASA Astrophysics Data System (ADS)

    Habel, Wolfgang R.; Krebber, Katerina

    2011-09-01

    Different types of fiber-optic sensors based on glass or polymeric fibers are used to evaluate material behavior or to monitor the integrity and long-term stability of load-bearing structure components. Fiber-optic sensors have been established as a new and innovative measurement technology in very different fields, such as material science, civil engineering, light-weight structures, geotechnical areas as well as chemical and high-voltage substations. Very often, mechanical quantities such as deformation, strain or vibration are requested. However, measurement of chemical quantities in materials and structure components, such as pH value in steel reinforced concrete members also provides information about the integrity of concrete structures. A special fiber-optic chemical sensor for monitoring the alkaline state (pH value) of the cementitious matrix in steel-reinforced concrete structures with the purpose of early detection of corrosion-initiating factors is described. The paper presents the use of several fiber-optic sensor technologies in engineering. One example concerns the use of highly resolving concrete-embeddable fiber Fabry-Perot acoustic emission (AE) sensors for the assessment of the bearing behaviour of large concrete piles in existing foundations or during and after its installation. Another example concerns fiber Bragg grating (FBG) sensors attached to anchor steels (micro piles) to measure the strain distribution in loaded soil anchors. Polymer optical fibers (POF) can be — because of their high elasticity and high ultimate strain — well integrated into textiles to monitor their deformation behaviour. Such "intelligent" textiles are capable of monitoring displacement of soil or slopes, critical mechanical deformation in geotechnical structures (dikes, dams, and embankments) as well as in masonry structures during and after earthquakes.

  2. Multimodal system for the planning and guidance of bronchoscopy

    NASA Astrophysics Data System (ADS)

    Higgins, William E.; Cheirsilp, Ronnarit; Zang, Xiaonan; Byrnes, Patrick

    2015-03-01

    Many technical innovations in multimodal radiologic imaging and bronchoscopy have emerged recently in the effort against lung cancer. Modern X-ray computed-tomography (CT) scanners provide three-dimensional (3D) high-resolution chest images, positron emission tomography (PET) scanners give complementary molecular imaging data, and new integrated PET/CT scanners combine the strengths of both modalities. State-of-the-art bronchoscopes permit minimally invasive tissue sampling, with vivid endobronchial video enabling navigation deep into the airway-tree periphery, while complementary endobronchial ultrasound (EBUS) reveals local views of anatomical structures outside the airways. In addition, image-guided intervention (IGI) systems have proven their utility for CT-based planning and guidance of bronchoscopy. Unfortunately, no IGI system exists that integrates all sources effectively through the complete lung-cancer staging work flow. This paper presents a prototype of a computer-based multimodal IGI system that strives to fill this need. The system combines a wide range of automatic and semi-automatic image-processing tools for multimodal data fusion and procedure planning. It also provides a flexible graphical user interface for follow-on guidance of bronchoscopy/EBUS. Human-study results demonstrate the system's potential.

  3. Fiberoptic sensors for rocket engine applications

    NASA Technical Reports Server (NTRS)

    Ballard, R. O.

    1992-01-01

    A research effort was completed to summarize and evaluate the current level of technology in fiberoptic sensors for possible applications in integrated control and health monitoring (ICHM) systems in liquid propellant engines. The environment within a rocket engine is particuarly severe with very high temperatures and pressures present combined with extremely rapid fluid and gas flows, and high-velocity and high-intensity acoustc waves. Application of fiberoptic technology to rocket engine health monitoring is a logical evolutionary step in ICHM development and presents a significant challenge. In this extremely harsh environment, the additional flexibility of fiberoptic techniques to augment conventional sensor technologies offer abundant future potential.

  4. Is bronchoscopy an obsolete tool in cystic fibrosis? The role of bronchoscopy in cystic fibrosis and its clinical use

    PubMed Central

    2017-01-01

    Cystic fibrosis (CF) is a progressive life threatening multisystem genetic disease which affects the CF transmembrane conductance regulator channel. Respiratory causes remain the most common mortality in CF. With the onset of newborn screening, initiating treatments both for prophylaxis and disease management, optimizing nutritional support, and developing therapies targeting CF transmembrane conductance regulator protein, this has significantly changed the face of managing this devastating disease. Bronchoscopy and related procedures such as bronchoalveolar lavage (BAL), transbronchial biopsies, and protected brush sampling have been looked at in the management of CF as patients with CF continue to live longer with the help of newer therapies, the microbiome in the lung becomes less diverse along with increased occurrences for noninfectious causes of airway diseases. Though bronchoscopy has been used in conjunction with other modalities such as computed tomography and sputum induction providing a better understanding of the progression of the disease, it still remains valuable in the diagnosis and management of CF. PMID:29214071

  5. Integrated Fiber-Optic Coupler.

    DTIC Science & Technology

    1987-04-01

    p. 563, 1984. 1 .T.H. W. n h= n , G.M. Metze, B.- Y . Tuu ,J.C.C. Far., "A a s double-heterostructure diode lasers fabricated on a monolithic GaAs/Si...INII RAitI) R HR ( OLIlIR HR t( N ,% NOS( I D108 I R IOst\\1 tN( LASS~l1 D R 87 mm mhhh z V. 0 0- z C ,, Technical Document 1086 April 1987 Integrated...Cmeed".~) n Interated Fiber-Optic Coupler 12 PERSONAL AU1HOS) P.L Pruaal, E.R. Foesuim 139 TYPE OF RE[POR 3b, IME COVERED4 DATE OF REPORT (’r. 4#e ow S

  6. Fiberoptic probe and system for spectral measurements

    DOEpatents

    Dai, S.; Young, J.P.

    1998-10-13

    A fused fiberoptic probe, a system, method and embodiments thereof for conducting spectral measurements are disclosed. The fused fiberoptic probe comprises a probe tip having a specific geometrical configuration, an exciting optical fiber and at least one collection optical fiber fused within a housing, preferably silica. The specific geometrical configurations in which the probe tip can be shaped include a slanted probe tip with an angle greater than 0{degree}, an inverted cone-shaped probe tip, and a lens head. 12 figs.

  7. Fiberoptic probe and system for spectral measurements

    DOEpatents

    Dai, Sheng; Young, Jack P.

    1998-01-01

    A fused fiberoptic probe, a system, method and embodiments thereof for conducting spectral measurements are disclosed. The fused fiberoptic probe comprises a probe tip having a specific geometrical configuration, an exciting optical fiber and at least one collection optical fiber fused within a housing, preferrably silica. The specific geometrical configurations in which the probe tip can be shaped include a slanted probe tip with an angle greater than 0.degree., an inverted cone-shaped probe tip, and a lens head.

  8. Sealed fiber-optic bundle feedthrough

    DOEpatents

    Tanner, Carol E.

    2002-01-01

    A sealed fiber-optic bundle feedthrough by which a multitude of fiber-optic elements may be passed through an opening or port in a wall or structure separating two environments at different pressures or temperatures while maintaining the desired pressure or temperature in each environment. The feedthrough comprises a rigid sleeve of suitable material, a bundle of individual optical fibers, and a resin-based sealing material that bonds the individual optical fibers to each other and to the rigid sleeve.

  9. [Virtual bronchoscopy: the correlation between endoscopic simulation and bronchoscopic findings].

    PubMed

    Salvolini, L; Gasparini, S; Baldelli, S; Bichi Secchi, E; Amici, F

    1997-11-01

    We carried out a preliminary clinical validation of 3D spiral CT virtual endoscopic reconstructions of the tracheobronchial tree, by comparing virtual bronchoscopic images with actual endoscopic findings. Twenty-two patients with tracheobronchial disease suspected at preliminary clinical, cytopathological and plain chest film findings were submitted to spiral CT of the chest and bronchoscopy. CT was repeated after endobronchial therapy in 2 cases. Virtual endoscopic shaded-surface-display views of the tracheobronchial tree were reconstructed from reformatted CT data with an Advantage Navigator software. Virtual bronchoscopic images were preliminarily evaluated with a semi-quantitative quality score (excellent/good/fair/poor). The depiction of consecutive airway branches was then considered. Virtual bronchoscopies were finally submitted to double-blind comparison with actual endoscopies. Virtual image quality was considered excellent in 8 cases, good in 14 and fair in 2. Virtual exploration was stopped at the lobar bronchi in one case only; the origin of segmental bronchi was depicted in 23 cases and that of some subsegmental branches in 2 cases. Agreement between actual and virtual bronchoscopic findings was good in all cases but 3 where it was nevertheless considered satisfactory. The yield of clinically useful information differed in 8/24 cases: virtual reconstructions provided more information than bronchoscopy in 5 cases and vice versa in 3. Virtual reconstructions are limited in that the procedure is long and difficult and needing a strictly standardized threshold value not to alter virtual findings. Moreover, the reconstructed surface lacks transparency, there is the partial volume effect and the branches < or = 4 pixels phi and/or meandering ones are difficult to explore. Our preliminary data are encouraging. Segmental bronchi were depicted in nearly all cases, except for the branches involved by disease. Obstructing lesions could be bypassed in some cases

  10. Autofluorescence bronchoscopy with white light bronchoscopy compared with white light bronchoscopy alone for the detection of precancerous lesions: a European randomised controlled multicentre trial

    PubMed Central

    Haussinger, K; Becker, H; Stanzel, F; Kreuzer, A; Schmidt, B; Strausz, J; Cavaliere, S; Herth, F; Kohlhaufl, M; Muller, K; Huber, R; Pichlmeier, U; Bolliger, C.

    2005-01-01

    Background: The potential of autofluorescence bronchoscopy (AFB) to detect precancerous lesions in the central airways and its role in lung cancer screening is uncertain. A study was undertaken to evaluate the prevalence of moderate/severe dysplasia (dysplasia II–III) and carcinoma in situ (CIS) using a newly developed AFB system in comparison with conventional white light bronchoscopy (WLB) alone. Methods: In a prospective randomised multicentre trial, smokers ⩾40 years of age (⩾20 pack-years) were stratified into four different risk groups and investigated with either WLB+AFB (arm A) or WLB alone (arm B). Results: 1173 patients (916 men) of mean age 58.7 years were included. Overall (arms A and B), preinvasive lesions (dysplasia II–III and CIS) were detected in 3.9% of the patients. The prevalence of patients with preinvasive lesions in the WLB arm was 2.7% compared with 5.1% in the WLB+AFB arm (p = 0.037). For patients with dysplasia II–III, WLB+AFB increased the detection rate by a factor of 2.1 (p = 0.03), while for CIS the factor was only 1.24 (p = 0.75). The biopsy based sensitivity of WLB alone and WLB+AFB for detecting dysplasia II–III and CIS was 57.9% compared with 82.3% (1.42-fold increase). The corresponding specificity was 62.1% compared with 58.4% (0.94-fold decrease). Conclusions: This first randomised study of AFB showed that the combination of WLB+AFB was significantly superior to WLB alone in detecting preneoplastic lesions. Our findings do not support the general use of AFB as a screening tool for lung cancer, but suggest that it may be of use in certain groups. The precise indications await further study. PMID:15923251

  11. Autofluorescence bronchoscopy with white light bronchoscopy compared with white light bronchoscopy alone for the detection of precancerous lesions: a European randomised controlled multicentre trial.

    PubMed

    Häussinger, K; Becker, H; Stanzel, F; Kreuzer, A; Schmidt, B; Strausz, J; Cavaliere, S; Herth, F; Kohlhäufl, M; Müller, K-M; Huber, R-M; Pichlmeier, U; Bolliger, Ch T

    2005-06-01

    The potential of autofluorescence bronchoscopy (AFB) to detect precancerous lesions in the central airways and its role in lung cancer screening is uncertain. A study was undertaken to evaluate the prevalence of moderate/severe dysplasia (dysplasia II-III) and carcinoma in situ (CIS) using a newly developed AFB system in comparison with conventional white light bronchoscopy (WLB) alone. In a prospective randomised multicentre trial, smokers > or = 40 years of age (> or = 20 pack-years) were stratified into four different risk groups and investigated with either WLB+AFB (arm A) or WLB alone (arm B). 1173 patients (916 men) of mean age 58.7 years were included. Overall (arms A and B), preinvasive lesions (dysplasia II-III and CIS) were detected in 3.9% of the patients. The prevalence of patients with preinvasive lesions in the WLB arm was 2.7% compared with 5.1% in the WLB+AFB arm (p = 0.037). For patients with dysplasia II-III, WLB+AFB increased the detection rate by a factor of 2.1 (p = 0.03), while for CIS the factor was only 1.24 (p = 0.75). The biopsy based sensitivity of WLB alone and WLB+AFB for detecting dysplasia II-III and CIS was 57.9% compared with 82.3% (1.42-fold increase). The corresponding specificity was 62.1% compared with 58.4% (0.94-fold decrease). This first randomised study of AFB showed that the combination of WLB+AFB was significantly superior to WLB alone in detecting preneoplastic lesions. Our findings do not support the general use of AFB as a screening tool for lung cancer, but suggest that it may be of use in certain groups. The precise indications await further study.

  12. [Development of a virtual model of fibro-bronchoscopy].

    PubMed

    Solar, Mauricio; Ducoing, Eugenio

    2011-09-01

    A virtual model of fibro-bronchoscopy is reported. The virtual model represents in 3D the trachea and the bronchi creating a virtual world of the bronchial tree. The bronchoscope is modeled to look over the bronchial tree imitating the displacement and rotation of the real bronchoscope. The parameters of the virtual model were gradually adjusted according to expert opinion and allowed the training of specialists with a virtual bronchoscope of great realism. The virtual bronchial tree provides clues of reality regarding the movement of the bronchoscope, creating the illusion that the virtual instrument is behaving as the real one with all the benefits in costs that this means.

  13. Role of electromagnetic navigational bronchoscopy in pulmonary nodule management

    PubMed Central

    Dahagam, Chanukya; Breen, David P.; Sarkar, Saiyad

    2016-01-01

    The incidence of pulmonary nodules and lung cancer is rising. Some of this increase in incidence is due to improved pick up by newer imaging modalities. However, the goal is to diagnose these lesion, many of which are located in the periphery, by safe and relatively non-invasive methods. This has led to the emergence of numerous techniques such as electromagnetic navigational bronchoscopy (ENB). Current evidence supports a role for these techniques in the diagnostic pathway. However, numerous factor influence the diagnostic accuracy. Thus despite significant advances, more research needs to be undertaken to further improve the currently available diagnostic technologies. PMID:27606080

  14. Subinterlobular Pleural Location Is a Risk Factor for Pneumothorax After Bronchoscopy.

    PubMed

    Chino, Haruka; Iikura, Motoyasu; Saito, Nayuta; Sato, Nahoko; Suzuki, Manabu; Ishii, Satoru; Morino, Eriko; Naka, Go; Takasaki, Jin; Izumi, Shinyu; Hojo, Masayuki; Takeda, Yuichiro; Sugiyama, Haruhito

    2016-12-01

    Pneumothorax is one of the most important complications after bronchoscopy. This study was conducted to determine the risk factors for post-bronchoscopy pneumothorax. We retrospectively reviewed the medical records of 23 consecutive subjects who were diagnosed with iatrogenic pneumothorax after bronchoscopy between August 2010 and February 2014. Forty-six control subjects who did not develop pneumothorax after bronchoscopy were randomly selected. The factors affecting the occurrence of pneumothorax were determined by univariate and multivariate analyses. Among 991 patients who underwent bronchoscopy during the study period, 23 (2.3%) developed pneumothorax after bronchoscopy. Among these 23 subjects, 13 (57%) required chest tube drainage. Compared with the control group (46 randomly selected from 968 subjects who did not develop pneumothorax), the group that developed pneumothorax had a preponderance of women and had more target lesions located in the subpleural area (odds ratio [OR] 7.8, 95% CI 0.9-64), especially those that were close to the interlobular pleura (OR 5.1, 95% CI 1.6-16.1) and the left lung (OR 3.2, 95% CI 1.1-9.5). Multivariate analysis revealed that a subinterlobular pleural location of a lesion was a risk factor for pneumothorax (OR 4.8, 95% CI 1.1-20.4). Pneumothorax occurred significantly more frequently when bronchoscopy was performed for subinterlobular pleural lesions. Close attention and care should be taken during bronchoscopy, especially when target lesions are abutting the interlobular pleura. Copyright © 2016 by Daedalus Enterprises.

  15. Fiber-Optic Ammonia Sensors

    NASA Technical Reports Server (NTRS)

    Carter, Michael T.

    2003-01-01

    Reversible, colorimetric fiber-optic sensors are undergoing development for use in measuring concentrations of ammonia in air at levels relevant to human health [0 to 50 parts per million (ppm)]. A sensor of this type includes an optical fiber that has been modified by replacing a portion of its cladding with a polymer coat that contains a dye that reacts reversibly with ammonia and changes color when it does so. The change in color is measured as a change in the amount of light transmitted from one end of the fiber to the other. Responses are reversible and proportional to the concentration of ammonia over the range from 9 to 175 ppm and in some cases the range of reversibility extends up to 270 ppm. The characteristic time for the response of a sensor to rise from 10 to 90 percent of full scale is about 25 seconds. These sensors are fully operational in pure carbon dioxide and are not adversely affected by humidity. This work was done by Michael T. Carter

  16. Fiberoptic characteristics for extreme operating environments

    NASA Technical Reports Server (NTRS)

    Delcher, R. C.

    1992-01-01

    Fiberoptics could offer several major benefits for cryogenic liquid-fueled rocket engines, including lightning immunity, weight reduction, and the possibility of implementing a number of new measurements for engine condition monitoring. The technical feasibility of using fiberoptics in the severe environments posed by cryogenic liquid-fueled rocket engines was determined. The issues of importance and subsequent requirements for this use of fiberoptics were compiled. These included temperature ranges, moisture embrittlement succeptability, and the ability to withstand extreme shock and vibration levels. Different types of optical fibers were evaluated and several types of optical fibers' ability to withstand use in cryogenic liquid-fueled rocket engines was demonstrated through environmental testing of samples. This testing included: cold-bend testing, moisture embrittlement testing, temperature cycling, temperature extremes testing, vibration testing, and shock testing. Three of five fiber samples withstood the tests to a level proving feasibility, and two of these remained intact in all six of the tests. A fiberoptic bundle was also tested, and completed testing without breakage. Preliminary cabling and harnessing for fiber protection was also demonstrated. According to cable manufacturers, the successful -300 F cold bend, vibration, and shock tests are the first instance of any major fiberoptic cable testing below roughly -55 F. This program has demonstrated the basic technical feasibility of implementing optical fibers on cryogenic liquid-fueled rocket engines, and a development plan is included highlighting requirements and issues for such an implementation.

  17. Absence of bacterial colonization of the airways after therapeutic rigid bronchoscopy without stenting.

    PubMed

    Noppen, M; Piérard, D; Meysman, M; Herreweghe, R V; Vincken, W

    2000-12-01

    Following airway stenting, bacterial colonization of the airways with potentially pathogenic micro-organisms occurs within 4 weeks after treatment in the majority of patients. The objective of this study was to prospectively investigate whether nonstenting therapeutic rigid bronchoscopy (using laser, cryotherapy, mechanical dilatation or debridement) is followed by airway colonization or infection. Protected specimen brush sampling of the central airways and quantitative culture were performed immediately prior to, and 4 weeks after nonstenting therapeutic rigid bronchoscopy in 20 consecutive patients with central airway lesions. Prior to therapeutic bronchoscopy, airway colonization/infection was present in nine of 20 (45%) patients. In these nine patients, 10 different potential pathogens were identified: Streptococcus pneumoniae (four cases), Pseudomonas aeruginosa (three), Haemophilus influenzae (two), and Serratia marcescens (one). Eight of these nine patients had a history of postobstructive infections, of which three were currently being treated with antibiotics. Four weeks following therapeutic bronchoscopy, airway colonization/infection was present in five of 20 (25%) patients, each of whom had airway colonization/infection prior to bronchoscopy. In three of these five patients, the same organisms were found 4 weeks after bronchoscopy as at baseline bronchoscopy. In two of five patients new organisms were identified: one case of Streptococcus viridans and one case of Haemophilus parainfluenzae, both considered to be nonpathogens. In four of nine patients with airway colonization/infection prior to bronchoscopy, the airways were clear of micro-organisms after the procedure. The authors conclude that: 1) nonstenting therapeutic rigid bronchoscopy is not complicated by airway colonization or infection by new potential pathogens; and 2) therapeutic rigid bronchoscopy led to clearing of airway colonization/infection in almost half of the patients studied.

  18. 21 CFR 876.4530 - Gastroenterology-urology fiberoptic retractor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gastroenterology-urology fiberoptic retractor. 876... SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4530 Gastroenterology-urology fiberoptic retractor. (a) Identification. A gastroenterology-urology fiberoptic retractor...

  19. 21 CFR 876.4020 - Fiberoptic light ureteral catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fiberoptic light ureteral catheter. 876.4020... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4020 Fiberoptic light ureteral catheter. (a) Identification. A fiberoptic light ureteral catheter is a device that consists of a...

  20. 21 CFR 876.4020 - Fiberoptic light ureteral catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Fiberoptic light ureteral catheter. 876.4020... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4020 Fiberoptic light ureteral catheter. (a) Identification. A fiberoptic light ureteral catheter is a device that consists of a...

  1. 21 CFR 876.4020 - Fiberoptic light ureteral catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Fiberoptic light ureteral catheter. 876.4020... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4020 Fiberoptic light ureteral catheter. (a) Identification. A fiberoptic light ureteral catheter is a device that consists of a...

  2. 21 CFR 876.4020 - Fiberoptic light ureteral catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Fiberoptic light ureteral catheter. 876.4020... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4020 Fiberoptic light ureteral catheter. (a) Identification. A fiberoptic light ureteral catheter is a device that consists of a...

  3. CATV Fiberoptic Cable Markets In The U.S.

    NASA Astrophysics Data System (ADS)

    Kessler, John N.

    1984-03-01

    "Bandwidth on a metropolitan CATV cable plant is a resource that may be compared today with the crude oil beneath the Arabian desert at the turn of the century. It will provide a radically new two-way communications medium for homes and businesses, and it will change not only the way we communicate but possibly even the way we live." This prediction was made last year by William Zachman, vice president of research for International Data Corp. If Zachman is right, and our research tends to indicate he is, then fiberoptics will become the transmission medium that will facilitate two-way broadband communication. However, many of the multiple system CATV operators in the U.S. as well as many of the manufacturers of fiberoptic waveguide and cable believe that interactive video systems are not really very important. They are wrong. Broadband fiberoptic systems have just begun to impact the U.S. communications market. And within 5 years, tremendous changes will occur not only with regard to growth, but with regard to the supplier industry structure. Interactive, switched, video systems in the U.S. go back to the early 1960s, and the experiments at Bell Laboratories with what was then called Picturephone. This was com-pressed video transmission via telephone lines from one subscriber to another. Field trials were conducted in several U.S. cities for a period of years. But the commercial response to Picturephone at that time was so lacking that AT&T discontinued the trials and the work. But that is changing. Part of the reason for the change is due to the changing communication needs of the U.S. and of the world: the increase in the amount of information used by large numbers of people, the concurrent rise in the use of computers, the digitization of communications media, the rise in the level of experience with electronic communications, and perhaps most importantly the convergence of audio, data, image and video communications. There are technological reasons for the slow

  4. Fiber-optic technology for transport aircraft

    NASA Astrophysics Data System (ADS)

    1993-07-01

    A development status evaluation is presented for fiber-optic devices that are advantageously applicable to commercial aircraft. Current developmental efforts at a major U.S. military and commercial aircraft manufacturer encompass installation techniques and data distribution practices, as well as the definition and refinement of an optical propulsion management interface system, environmental sensing systems, and component-qualification criteria. Data distribution is the most near-term implementable of fiber-optic technologies aboard commercial aircraft in the form of onboard local-area networks for intercomputer connections and passenger entertainment.

  5. Effect of Heliox on Respiratory Outcomes during Rigid Bronchoscopy in Term Lambs.

    PubMed

    Sowder, Justin C; Dahl, Mar Janna; Zuspan, Kaitlin R; Albertine, Kurt H; Null, Donald M; Barneck, Mitchell D; Grimmer, J Fredrik

    2018-03-01

    Objective To (1) compare physiologic changes during rigid bronchoscopy during spontaneous and mechanical ventilation and (2) evaluate the efficacy of a helium-oxygen (heliox) gas mixture as compared with room air during rigid bronchoscopy. Study Design Crossover animal study evaluating physiologic parameters during rigid bronchoscopy. Outcomes were compared with predicted computational fluid analysis. Setting Simulated ventilation via computational fluid dynamics analysis and term lambs undergoing rigid bronchoscopy. Methods Respiratory and physiologic outcomes were analyzed in a lamb model simulating bronchoscopy during foreign body aspiration to compare heliox with room air. The main outcome measures were blood oxygen saturation, heart rate, blood pressure, partial pressure of oxygen, and partial pressure of carbon dioxide. Computational fluid dynamics analysis was performed with SOLIDWORKS within a rigid pediatric bronchoscope during simulated ventilation comparing heliox with room air. Results For room air, lambs desaturated within 3 minutes during mechanical ventilation versus normal oxygen saturation during spontaneous ventilation ( P = .01). No improvement in respiratory outcomes was seen between heliox and room air during mechanical ventilation. Computational fluid dynamics analysis demonstrates increased turbulence within size 3.5 bronchoscopes when comparing heliox and room air. Meaningful comparisons could not be made due to the intolerance of the lambs to heliox in vivo. Conclusion During mechanical ventilation on room air, lambs desaturate more quickly during rigid bronchoscopy on settings that should be adequate. Heliox does not improve ventilation during rigid bronchoscopy.

  6. The effect of respiratory motion on pulmonary nodule location during electromagnetic navigation bronchoscopy.

    PubMed

    Chen, Alexander; Pastis, Nicholas; Furukawa, Brian; Silvestri, Gerard A

    2015-05-01

    Electromagnetic navigation has improved the diagnostic yield of peripheral bronchoscopy for pulmonary nodules. For these procedures, a thin-slice chest CT scan is performed prior to bronchoscopy at full inspiration and is used to create virtual airway reconstructions that are used as a map during bronchoscopy. Movement of the lung occurs with respiratory variation during bronchoscopy, and the location of pulmonary nodules during procedures may differ significantly from their location on the initial planning full-inspiratory chest CT scan. This study was performed to quantify pulmonary nodule movement from full inspiration to end-exhalation during tidal volume breathing in patients undergoing electromagnetic navigation procedures. A retrospective review of electromagnetic navigation procedures was performed for which two preprocedure CT scans were performed prior to bronchoscopy. One CT scan was performed at full inspiration, and a second CT scan was performed at end-exhalation during tidal volume breathing. Pulmonary lesions were identified on both CT scans, and distances between positions were recorded. Eighty-five pulmonary lesions were identified in 46 patients. Average motion of all pulmonary lesions was 17.6 mm. Pulmonary lesions located in the lower lobes moved significantly more than upper lobe nodules. Size and distance from the pleura did not significantly impact movement. Significant movement of pulmonary lesions occurs between full inspiration and end-exhalation during tidal volume breathing. This movement from full inspiration on planning chest CT scan to tidal volume breathing during bronchoscopy may significantly affect the diagnostic yield of electromagnetic navigation bronchoscopy procedures.

  7. Electromagnetic Navigational Bronchoscopy Reduces the Time Required for Localization and Resection of Lung Nodules.

    PubMed

    Bolton, William David; Cochran, Thomas; Ben-Or, Sharon; Stephenson, James E; Ellis, William; Hale, Allyson L; Binks, Andrew P

    The aims of the study were to evaluate electromagnetic navigational bronchoscopy (ENB) and computed tomography-guided placement as localization techniques for minimally invasive resection of small pulmonary nodules and determine whether electromagnetic navigational bronchoscopy is a safer and more effective method than computed tomography-guided localization. We performed a retrospective review of our thoracic surgery database to identify patients who underwent minimally invasive resection for a pulmonary mass and used either electromagnetic navigational bronchoscopy or computed tomography-guided localization techniques between July 2011 and May 2015. Three hundred eighty-three patients had a minimally invasive resection during our study period, 117 of whom underwent electromagnetic navigational bronchoscopy or computed tomography localization (electromagnetic navigational bronchoscopy = 81; computed tomography = 36). There was no significant difference between computed tomography and electromagnetic navigational bronchoscopy patient groups with regard to age, sex, race, pathology, nodule size, or location. Both computed tomography and electromagnetic navigational bronchoscopy were 100% successful at localizing the mass, and there was no difference in the type of definitive surgical resection (wedge, segmentectomy, or lobectomy) (P = 0.320). Postoperative complications occurred in 36% of all patients, but there were no complications related to the localization procedures. In terms of localization time and surgical time, there was no difference between groups. However, the down/wait time between localization and resection was significant (computed tomography = 189 minutes; electromagnetic navigational bronchoscopy = 27 minutes); this explains why the difference in total time (sum of localization, down, and surgery) was significant (P < 0.001). We found electromagnetic navigational bronchoscopy to be as safe and effective as computed tomography-guided wire placement

  8. Predictors of pain control in patients undergoing flexible bronchoscopy.

    PubMed

    Lechtzin, N; Rubin, H R; Jenckes, M; White, P; Zhou, L M; Thompson, D A; Diette, G B

    2000-08-01

    The purpose of this study was to assess the extent to which patients undergoing flexible bronchoscopy (FOB) experience pain and to identify patient factors and process of care factors that are associated with pain. We conducted a prospective cohort study on 481 patients undergoing FOB. Overall control of pain during FOB was the primary outcome. The mean age of the patients was 48 yr, 50% were male, and 32% required supplemental oxygen prior to FOB. Pain control was excellent in 36% of patients, but 10% considered it to be fair or poor. Patient factors associated with excellent pain control were excellent health (versus poor health, OR = 6.25 [95% CI, 2.28-16.67]), more education (college education versus high school education, OR = 1.72 [95% CI, 1.05-2.86]), and not having asthma (OR = 2.86 [95% CI, 1.09-7.14]). Process of care factors associated with excellent pain control were not being bothered by scope insertion (versus bothered, OR = 3.65 [95% CI, 1.99-6.98]), no memory of FOB (versus some memory, OR = 2.33 [95% CI, 1.24-4.44]), and higher ratings of information about the procedure (per 1-point increase on a 12-point scale, OR = 1.57 [95% CI, 1.41-1.78]). This is the first large-scale, prospective study to evaluate patient and process of care factors that influence pain control during FOB. It demonstrated that there are patient characteristics and process of care factors that need to be considered when evaluating pain during bronchoscopy. Improved preparation of patients with lower education, inferior health status, and asthma may lead to decreased pain during FOB. Bronchoscopists may be able to reduce pain during FOB by identifying methods to decrease pain on scope insertion, by improving the information provided to patients, and by achieving greater levels of amnesia during FOB.

  9. Overview of Fiber-Optical Sensors

    NASA Technical Reports Server (NTRS)

    Depaula, Ramon P.; Moore, Emery L.

    1987-01-01

    Design, development, and sensitivity of sensors using fiber optics reviewed. State-of-the-art and probable future developments of sensors using fiber optics described in report including references to work in field. Serves to update previously published surveys. Systems incorporating fiber-optic sensors used in medical diagnosis, navigation, robotics, sonar, power industry, and industrial controls.

  10. In Situ Fiber-Optic Reflectance Monitor

    NASA Technical Reports Server (NTRS)

    Linton, Roger C.; Gray, Perry A.

    1996-01-01

    In situ fiber-optic reflectance monitor serves as simple means of monitoring changes in reflectance of specimen exposed to simulated outerspace or other environments in vacuum chamber. Eliminates need to remove specimen from vacuum chamber, eliminating optical changes and bleaching such removal causes in coatings.

  11. Early Localization of Bronchogenic Carcinoma

    PubMed Central

    Macaulay, C.; Leriche, J. C.; Ikeda, N.; Palcic, B.

    1994-01-01

    The performance of a fluorescence imaging device was compared with conventional white-light bronchoscopy in 100 patients with lung cancer, 46 patients with resected stage I non-small cell lung cancer, 10 patients with head and neck cancer, and 67 volunteers who had smoked at least 1 pack of cigarettes per day for 25 years or more. Using differences in tissue autofluorescence between premalignant, malignant, and normal tissues, fluorescence bronchoscopy was found to detect significantly more areas with moderate/severe dysplasia or carcinoma in situ than conventional white-light bronchoscopy with a similar specificity. Multiple foci of dysplasia or cancer were found in 13–24% of these individuals. Fluorescence bronchoscopy may be an important adjunct to conventional bronchoscopic examination to improve our ability to detect and localize premalignant and early lung cancer lesions. PMID:18493345

  12. Mobile fiber-optic sensor for detection of oral and cervical cancer in the developing world.

    PubMed

    Yu, Bing; Nagarajan, Vivek Krishna; Ferris, Daron G

    2015-01-01

    Oral and cervical cancers are a growing global health problem that disproportionately impacts women and men living in the developing world. The high death rate in developing countries is largely due to the fact that these countries do not have the appropriate medical infrastructure and resources to support the organized screening and diagnostic programs that are available in the developed world. Diffuse reflectance spectroscopy (DRS) with a fiber-optic probe can noninvasively quantify the optical properties of epithelial tissues and has shown the potential as a cost-effective, easy-to-use, and sensitive tool for diagnosis of early precancerous changes in the cervix and oral cavity. However, current fiber-optic DRS systems have not been designed to be robust and reliable for use in developing countries. They are subject to various sources of systematic or random errors, arising from the uncontrolled probe-tissue interface and lack of real-time calibration, use bulky and expensive optical components, and require extensive training. This chapter describes a portable DRS device that is specifically designed for detection of oral and cervical cancers in resource-poor settings. The device uses an innovative smart fiber-optic probe to eliminate operator bias, state-of-the-art photonics components to reduce size and power consumption, and automated software to reduce the need of operator training. The size and cost of the smart fiber-optic DRS system may be further reduced by incorporating a smartphone based spectrometer.

  13. Comparison of Distributed Acoustic Sensing (DAS) from Fiber-Optic Cable to Three Component Geophones in an Underground Mine

    NASA Astrophysics Data System (ADS)

    Speece, M. A.; Nesladek, N. J.; Kammerer, C.; Maclaughlin, M.; Wang, H. F.; Lord, N. E.

    2017-12-01

    We conducted experiments in the Underground Education Mining Center on the Montana Tech campus, Butte, Montana, to make a direct comparison between Digital Acoustic Sensing (DAS) and three-component geophones in a mining setting. The sources used for this project where a vertical sledgehammer, oriented shear sledgehammer, and blasting caps set off in both unstemmed and stemmed drillholes. Three-component Geospace 20DM geophones were compared with three different types of fiber-optic cable: (1) Brugg strain, (2) Brugg temperature, and (3) Optical Cable Corporation strain. We attached geophones to the underground mine walls and on the ground surface above the mine. We attached fiber-optic cables to the mine walls and placed fiber-optic cable in boreholes drilled through an underground pillar. In addition, we placed fiber-optic cables in a shallow trench at the surface of the mine. We converted the DAS recordings from strain rate to strain prior to comparison with the geophone data. The setup of the DAS system for this project led to a previously unknown triggering problem that compromised the early samples of the DAS traces often including the first-break times on the DAS records. Geophones clearly recorded the explosives; however, the large amount of energy and its close distance from the fiber-optic cables seemed to compromise the entire fiber loop. The underground hammer sources produced a rough match between the DAS records and the geophone records. However, the sources on the surface of the mine, specifically the sources oriented inline with the fiber-optic cables, produced a close match between the fiber-optic traces and the geophone traces. All three types of fiber-optic cable that were in the mine produced similar results, and one type did not clearly outperform the others. Instead, the coupling of the cable to rock appears to be the most important factor determining DAS data quality. Moreover, we observed the importance of coupling in the boreholes, where

  14. Detection and Mapping of the September 2017 Mexico Earthquakes Using DAS Fiber-Optic Infrastructure Arrays

    NASA Astrophysics Data System (ADS)

    Karrenbach, M. H.; Cole, S.; Williams, J. J.; Biondi, B. C.; McMurtry, T.; Martin, E. R.; Yuan, S.

    2017-12-01

    Fiber-optic distributed acoustic sensing (DAS) uses conventional telecom fibers for a wide variety of monitoring purposes. Fiber-optic arrays can be located along pipelines for leak detection; along borders and perimeters to detect and locate intruders, or along railways and roadways to monitor traffic and identify and manage incidents. DAS can also be used to monitor oil and gas reservoirs and to detect earthquakes. Because thousands of such arrays are deployed worldwide and acquiring data continuously, they can be a valuable source of data for earthquake detection and location, and could potentially provide important information to earthquake early-warning systems. In this presentation, we show that DAS arrays in Mexico and the United States detected the M8.1 and M7.2 Mexico earthquakes in September 2017. At Stanford University, we have deployed a 2.4 km fiber-optic DAS array in a figure-eight pattern, with 600 channels spaced 4 meters apart. Data have been recorded continuously since September 2016. Over 800 earthquakes from across California have been detected and catalogued. Distant teleseismic events have also been recorded, including the two Mexican earthquakes. In Mexico, fiber-optic arrays attached to pipelines also detected these two events. Because of the length of these arrays and their proximity to the event locations, we can not only detect the earthquakes but also make location estimates, potentially in near real time. In this presentation, we review the data recorded for these two events recorded at Stanford and in Mexico. We compare the waveforms recorded by the DAS arrays to those recorded by traditional earthquake sensor networks. Using the wide coverage provided by the pipeline arrays, we estimate the event locations. Such fiber-optic DAS networks can potentially play a role in earthquake early-warning systems, allowing actions to be taken to minimize the impact of an earthquake on critical infrastructure components. While many such fiber-optic

  15. Rigid bronchoscopy and silicone stents in the management of central airway obstruction

    PubMed Central

    Yarmus, Lonny

    2015-01-01

    The field of interventional pulmonology has grown significantly over the past several decades now including the diagnosis and therapeutic treatment of complex airway disease. Rigid bronchoscopy is an invaluable tool in the diagnosis and management of several malignant and non-malignant causes of central airway obstruction (CAO) and has become integral after the inception of airway stenting. The management of CAO can be a complicated endeavor with significant risks making the understanding of basic rigid bronchoscopy techniques, ablative technologies, anesthetic care and stenting of utmost importance in the care of these complex patients. This review article will focus on the history of rigid bronchoscopy, the technical aspects of performing a rigid bronchoscopy as well as the use of silicone stents their indications, complications and placement techniques. PMID:26807283

  16. Value of flexible bronchoscopy in the pre-operative work-up of solitary pulmonary nodules.

    PubMed

    Schwarz, Carsten; Schönfeld, Nicolas; Bittner, Roland C; Mairinger, Thomas; Rüssmann, Holger; Bauer, Torsten T; Kaiser, Dirk; Loddenkemper, Robert

    2013-01-01

    The diagnostic value of flexible bronchoscopy in the pre-operative work-up of solitary pulmonary nodules (SPN) is still under debate among pneumologists, radiologists and thoracic surgeons. In a prospective observational manner, flexible bronchoscopy was routinely performed in 225 patients with SPN of unknown origin. Of the 225 patients, 80.5% had lung cancer, 7.6% had metastasis of an extrapulmonary primary tumour and 12% had benign aetiology. Unsuspected endobronchial involvement was found in 4.4% of all 225 patients (or in 5.5% of patients with lung cancer). In addition, flexible bronchoscopy clarified the underlying aetiology in 41% of the cases. The bronchoscopic biopsy results from the SPN were positive in 84 (46.5%) patients with lung cancer. Surgery was cancelled due to the results of flexible bronchoscopy in four cases (involvement of the right main bronchus (impaired pulmonary function did not allow pneumonectomy) n=1, small cell lung cancer n=1, bacterial pneumonia n=2), and the surgical strategy had to be modified to bilobectomy in one patient. Flexible bronchoscopy changed the planned surgical approach in five cases substantially. These results suggest that routine flexible bronchoscopy should be included in the regular pre-operative work-up of patients with SPN.

  17. A fiber-optic current sensor for aerospace applications

    NASA Technical Reports Server (NTRS)

    Patterson, Richard L.; Rose, A. H.; Tang, D.; Day, G. W.

    1990-01-01

    A robust, accurate, broad-band, alternating current sensor using fiber optics is being developed for space applications at power frequencies as high as 20 kHz. It can also be used in low and high voltage 60 Hz terrestrial power systems and in 400 Hz aircraft systems. It is intrinsically electromagnetic interference (EMI) immune and has the added benefit of excellent isolation. The sensor uses the Faraday effect in optical fiber and standard polarimetric measurements to sense electrical current. The primary component of the sensor is a specially treated coil of single-mode optical fiber, through which the current carrying conductor passes. Improved precision is accomplished by temperature compensation by means of signals from a novel fiber-optic temperature sensor embedded in the sensing head. The technology contained in the sensor is examined and the results of precision tests conducted at various temperatures within the wide operating range are given. The results of early EMI tests are also given.

  18. A fiber-optic current sensor for aerospace applications

    NASA Technical Reports Server (NTRS)

    Patterson, Richard L.; Rose, A. H.; Tang, D.; Day, G. W.

    1990-01-01

    A robust, accurate, broadband, alternating current sensor using fiber optics is being developed for space applications at power frequencies as high as 20 kHz. It can also be used in low and high voltage 60-Hz terrestrial power systems and in 400-Hz aircraft systems. It is intrinsically electromagnetic interference (EMI) immune and has the added benefit of excellent isolation. The sensor uses the Faraday effect in optical fiber and standard polarimetric measurements to sense electrical current. The primary component of the sensor is a specially treated coil of single-mode optical fiber, through which the current carrying conductor passes. Improved precision is accomplished by temperature compensation by means of signals from a novel fiber-optic temperature sensor embedded in the sensing head. The technology used in the sensor is examined and the results of precision tests conducted at various temperatures within the wide operating range are given. The results of early EMI tests are also given.

  19. A fiber-optic current sensor for aerospace applications

    NASA Technical Reports Server (NTRS)

    Patterson, Richard L.; Rose, A. H.; Tang, D.; Day, G. W.

    1990-01-01

    A robust, accurate, broadband, alternating current sensor using fiber optics is being developed for space applications at power frequencies as high as 20 kHz. It can also be used in low- and high-voltage 60-Hz terrestrial power systems and in 400-Hz aircraft systems. It is intrinsically EMI (electromagnetic interference) immune and has the added benefit of excellent isolation. The sensor uses the Faraday effect in optical fiber and standard polarimetric measurements to sense electrical current. The primary component of the sensor is a specially treated coil of single-mode optical fiber, through which the current carrying conductor passes. Improved precision is accomplished by temperature compensation by means of signals from a fiber-optic temperature sensor embedded in the sensing head. The authors report on the technology contained in the sensor and also relate the results of precision tests conducted at various temperatures within the wide operating range. The results of early EMI tests are shown.

  20. Fiber-optic push-pull sensor systems

    NASA Technical Reports Server (NTRS)

    Gardner, David L.; Brown, David A.; Garrett, Steven L.

    1991-01-01

    Fiber-optic push-pull sensors are those which exploit the intrinsically differential nature of an interferometer with concommitant benefits in common-mode rejection of undesired effects. Several fiber-optic accelerometer and hydrophone designs are described. Additionally, the recent development at the Naval Postgraduate School of a passive low-cost interferometric signal demodulator permits the development of economical fiber-optic sensor systems.

  1. [Diagnostic and curative bronchoscopy for purulent-destructive pulmonary diseases].

    PubMed

    Pinchuk, T P; Yasnogorodsky, O O; Guryanova, Yu V; Taldykin, M V; Kachikin, A S; Catane, Yu A

    To assess an efficacy of diagnostic and curative bronchoscopy in patients with purulent-destructive pulmonary diseases. Diagnosis and treatment of 34 patients with purulent-destructive pulmonary diseases including small-focal destruction (14) and lung abscesses (19) were analyzed. 33 patients underwent diagnostic fibrobronchoscopy (FBS) with brush and transbronchial biopsy. Curative endoscopy included bronchial tree sanation, peribronchial administration of antibiotics (5) and transbronchial drainage of abscess (14). Atrophic bronchitis and cicatricial deformity of the 2-3rd segmental bronchi were revealed in 81.8% and 15.2% respectively. Transbronchial biopsy confirmed malignant neoplasms (15.2%) and pulmonary tuberculosis (6.1%). Peribronchial administration of amikacin in patients with small-focal pulmonary destruction and transbronchial drainage of abscesses accelerated pulmonary tissue repair and complete recovery. Transbronchial biopsy in patients with destructive pulmonary diseases verifies pathological process and excludes malignant and specific pulmonary damage. Complex use of endoscopic methods is associated with positive clinical result in all patients with pulmonary destruction.

  2. A novel platform for electromagnetic navigated ultrasound bronchoscopy (EBUS).

    PubMed

    Sorger, Hanne; Hofstad, Erlend Fagertun; Amundsen, Tore; Langø, Thomas; Leira, Håkon Olav

    2016-08-01

    Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) of mediastinal lymph nodes is essential for lung cancer staging and distinction between curative and palliative treatment. Precise sampling is crucial. Navigation and multimodal imaging may improve the efficiency of EBUS-TBNA. We demonstrate a novel EBUS-TBNA navigation system in a dedicated airway phantom. Using a convex probe EBUS bronchoscope (CP-EBUS) with an integrated sensor for electromagnetic (EM) position tracking, we performed navigated CP-EBUS in a phantom. Preoperative computed tomography (CT) and real-time ultrasound (US) images were integrated into a navigation platform for EM navigated bronchoscopy. The coordinates of targets in CT and US volumes were registered in the navigation system, and the position deviation was calculated. The system visualized all tumor models and displayed their fused CT and US images in correct positions in the navigation system. Navigating the EBUS bronchoscope was fast and easy. Mean error observed between US and CT positions for 11 target lesions (37 measurements) was [Formula: see text] mm, maximum error was 5.9 mm. The feasibility of our novel navigated CP-EBUS system was successfully demonstrated. An EBUS navigation system is needed to meet future requirements of precise mediastinal lymph node mapping, and provides new opportunities for procedure documentation in EBUS-TBNA.

  3. Electromagnetic Navigation Bronchoscopy-directed Pleural Tattoo to Aid Surgical Resection of Peripheral Pulmonary Lesions.

    PubMed

    Tay, Jun H; Wallbridge, Peter D; Larobina, Marco; Russell, Prudence A; Irving, Louis B; Steinfort, Daniel P

    2016-07-01

    Limited (wedge) resection of pulmonary lesions is frequently performed as a diagnostic/therapeutic procedure. Some lesions may be difficult to locate thoracoscopically with conversion to open thoracotomy or incomplete resection being potential limitations to this approach. Multiple methods have been described to aid video-assisted thoracoscopic surgical (VATS) wedge resection of pulmonary nodules, including hookwire localization, percutaneous tattoo, or intraoperative ultrasound. We report on our experience using electromagnetic navigation bronchoscopic dye marking of small subpleural lesions to aid VATS wedge resection. A retrospective cohort study of consecutive patients undergoing VATS wedge resection of peripheral lesions. Preoperative bronchoscopy with electromagnetic navigation was utilized to guide a 25 G needle to within/adjacent to the target lesion with injection of 1 mL of methylene blue or indigo carmine under fluoroscopic vision. Six patients underwent bronchoscopic marking of peripheral pulmonary lesions, navigation deemed successful in all patients, with no procedural complications. Surgery was performed within 24 hours of bronchoscopic marking. Pleural staining by dye was visible thoracoscopically in all 6 lesions either adjacent to or overlying the lesion. All lesions were fully excised with wedge resection. Pathologic examination confirmed accuracy of dye staining. Electromagnetic navigation bronchoscopic dye marking of peripheral lesions is feasible, without complications commonly associated with percutaneous marking procedures. Further experience is required but early findings suggest that this method may have utility in aiding minimally invasive resection of small subpleural lesions.

  4. Interactive CT-Video Registration for the Continuous Guidance of Bronchoscopy

    PubMed Central

    Merritt, Scott A.; Khare, Rahul; Bascom, Rebecca

    2014-01-01

    Bronchoscopy is a major step in lung cancer staging. To perform bronchoscopy, the physician uses a procedure plan, derived from a patient’s 3D computed-tomography (CT) chest scan, to navigate the bronchoscope through the lung airways. Unfortunately, physicians vary greatly in their ability to perform bronchoscopy. As a result, image-guided bronchoscopy systems, drawing upon the concept of CT-based virtual bronchoscopy (VB), have been proposed. These systems attempt to register the bronchoscope’s live position within the chest to a CT-based virtual chest space. Recent methods, which register the bronchoscopic video to CT-based endoluminal airway renderings, show promise but do not enable continuous real-time guidance. We present a CT-video registration method inspired by computer-vision innovations in the fields of image alignment and image-based rendering. In particular, motivated by the Lucas–Kanade algorithm, we propose an inverse-compositional framework built around a gradient-based optimization procedure. We next propose an implementation of the framework suitable for image-guided bronchoscopy. Laboratory tests, involving both single frames and continuous video sequences, demonstrate the robustness and accuracy of the method. Benchmark timing tests indicate that the method can run continuously at 300 frames/s, well beyond the real-time bronchoscopic video rate of 30 frames/s. This compares extremely favorably to the ≥1 s/frame speeds of other methods and indicates the method’s potential for real-time continuous registration. A human phantom study confirms the method’s efficacy for real-time guidance in a controlled setting, and, hence, points the way toward the first interactive CT-video registration approach for image-guided bronchoscopy. Along this line, we demonstrate the method’s efficacy in a complete guidance system by presenting a clinical study involving lung cancer patients. PMID:23508260

  5. An audit of bronchoscopy practice in the United Kingdom: a survey of adherence to national guidelines

    PubMed Central

    Honeybourne, D.; Neumann, C. S.

    1997-01-01

    BACKGROUND: Both patient and staff safety are of major importance during the procedure of fibreoptic bronchoscopy. Patient safety depends partly on adequate disinfection of instruments and accessories used as well as careful monitoring during the procedure. Adequate facilities, manpower and training are also essential. Staff safety depends partly on adequate procedures to minimise any risks of sensitisation to agents such as glutaraldehyde. An audit was carried out of bronchoscopy procedures in hospitals in the UK and the findings were compared with published guidelines on good practice and clinical consensus. METHODS: A postal questionnaire was sent to 218 bronchoscopy units in the UK. Findings were then compared with published evidence of good practice in the areas of disinfection, including the use of glutaraldehyde, patient monitoring, manpower, facilities, and training. RESULTS: A 73% response rate was obtained. Recommended minimum disinfection times before and after routine bronchoscopies were not achieved by 35% of units. No disinfection was carried out in 34% of units before emergency bronchoscopies and in 19% of units after suspected cases of tuberculosis. Adequate rinsing of the bronchoscope with sterile or filtered water was not carried out by 43% of units. Contrary to recommendations, 31% of departments were still using glutaraldehyde in the patient examination room and inadequate room ventilation was common. Protective clothing was often not worn by staff during bronchoscopy. Inadequate intravenous access and use of supplementary oxygen were found in many units. Practice standards were higher in departments where dedicated bronchoscopy/endoscopy units of the hospital were used, and also where staff had been on external training courses. CONCLUSIONS: This audit has shown that many units do not adhere to guidelines on disinfection procedures and patient monitoring. Unnecessary potential risks due to staff exposure to glutaraldehyde were apparent

  6. Fiducial marker placement via conventional or electromagnetic navigation bronchoscopy (ENB): an interdisciplinary approach to the curative management of lung cancer.

    PubMed

    Hagmeyer, Lars; Priegnitz, Christina; Kocher, Martin; Schilcher, Burkhart; Budach, Wilfried; Treml, Marcel; Stieglitz, Sven; Randerath, Winfried

    2016-05-01

    Conventional and electromagnetic navigation bronchoscopy (ENB) is generally used as a diagnostic tool in suspicious pulmonary nodules. The use of this technique for the placement of fiducial markers in patients with inoperable but early-stage lung cancer could present an innovative approach enabling risk-reduced therapy. We present seven clinical cases where conventional bronchoscopy and ENB were used as part of an experimental interdisciplinary approach to clinical management and therapy planning. In each case, we analyzed the clinical indication, endoscopic procedures and post-interventional outcome. In six patients (three females, three males) with peripheral non-small cell lung cancer (NSCLC), stage cT1cN0cM0, surgery and conventional stereotactic radiation therapy was not possible because of end-stage chronic obstructive pulmonary disease. ENB was used for fiducial marker placement prior to cyberknife radiotherapy. No procedure-related complications were observed. Complete remission could be achieved in four cases, partial remission in two cases and no relevant complications induced by radiotherapy were observed. In one male patient, an endoluminal relapse in the right lower lobe was diagnosed following a right upper lobe resection for a NSCLC. The tumor could not be clearly identified by computerized tomography, so that the bronchoscopic placement of a fiducial marker in the tumor was performed in order to allow stereotactic radiochemotherapy, by which complete remission could be achieved. Fiducial marker placement may be an interesting bronchoscopic technique in the interdisciplinary therapeutic approach to inoperable early-stage lung cancer. In the described cases, therapy planning was successful and no procedure-related complications were observed. © 2014 John Wiley & Sons Ltd.

  7. Evaluation of a low-cost, 3D-printed model for bronchoscopy training.

    PubMed

    Parotto, Matteo; Jiansen, Joshua Qua; AboTaiban, Ahmed; Ioukhova, Svetlana; Agzamov, Alisher; Cooper, Richard; O'Leary, Gerald; Meineri, Massimiliano

    2017-01-01

    Flexible bronchoscopy is a fundamental procedure in anaesthesia and critical care medicine. Although learning this procedure is a complex task, the use of simulation-based training provides significant advantages, such as enhanced patient safety. Access to bronchoscopy simulators may be limited in low-resource settings. We have developed a low-cost 3D-printed bronchoscopy training model. A parametric airway model was obtained from an online medical model repository and fabricated using a low-cost 3D printer. The participating physicians had no prior bronchoscopy experience. Participants received a 30-minute lecture on flexible bronchoscopy and were administered a 15-item pre-test questionnaire on bronchoscopy. Afterwards, participants were instructed to perform a series of predetermined bronchoscopy tasks on the 3D printed simulator on 4 consecutive occasions. The time needed to perform the tasks and the quality of task performance (identification of bronchial anatomy, technique, dexterity, lack of trauma) were recorded. Upon completion of the simulator tests, participants were administered the 15-item questionnaire (post-test) once again. Participant satisfaction data on the perceived usefulness and accuracy of the 3D model were collected. A statistical analysis was performed using the t-test. Data are reported as mean values (± standard deviation). The time needed to complete all tasks was 152.9 ± 71.5 sec on the 1st attempt vs. 98.7 ± 40.3 sec on the 4th attempt (P = 0.03). Likewise, the quality of performance score improved from 8.3 ± 6.7 to 18.2 ± 2.5 (P < 0.0001). The average number of correct answers in the questionnaire was 6.8 ± 1.9 pre-test and 13.3 ± 3.1 post-test (P < 0.0001). Participants reported a high level of satisfaction with the perceived usefulness and accuracy of the model. We developed a 3D-printed model for bronchoscopy training. This model improved trainee performance and may represent a valid, low-cost bronchoscopy training tool.

  8. Scarring Airway Stenosis in Chinese Adults: Characteristics and Interventional Bronchoscopy Treatment

    PubMed Central

    Wang, Ting; Zhang, Jie; Qiu, Xiao-Jian; Wang, Juan; Pei, Ying-Hua; Wang, Yu-Ling

    2018-01-01

    Background: Scarring airway stenosis is commonly seen in China as compared to other developed countries, due to the high prevalence of tuberculosis. Nowadays, interventional bronchoscopy treatment has been widely used to treat this disease in China. This study demonstrated the characteristics of scarring airway stenosis in Chinese adults and retrospectively evaluated the efficacy of interventional bronchoscopy treatment of this disease. Methods: Patients with scarring airway stenosis from 18 tertiary hospitals were enrolled between January 2013 and June 2016. The causes, site, and length of scarring airway stenosis were analyzed, and the efficacy of the interventional bronchoscopy treatment was evaluated. Results: The final study cohort consisted of 392 patients. Endotracheobronchial tuberculosis (EBTB) was the most common cause of scarring airway stenosis (305/392, 77.8%) in Chinese adults with a high rate of incidence in young women. The left main bronchus was most susceptible to EBTB, and most posttuberculosis airway scarring stenosis length was 1.1–2.0 cm. The average clinical success rate of interventional bronchoscopy treatment for scarring airway stenosis in Chinese patients is 60.5%. The stent was inserted in 8.7% scarring airway stenosis in China. Conclusions: Scarring airway stenosis exhibits specific characteristics in Chinese patients. Interventional bronchoscopy is a useful and safe treatment method for the disease. PMID:29363641

  9. Novel Fiber-Optic Ring Acoustic Emission Sensor.

    PubMed

    Wei, Peng; Han, Xiaole; Xia, Dong; Liu, Taolin; Lang, Hao

    2018-01-13

    Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber-optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber-optic ring sensor acoustic emission system is built based on this method. Finally, fiber-optic ring acoustic emission experiments are performed. The novel fiber-optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber-optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber-optic ring acoustic emission sensor. In the future, this novel fiber-optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments.

  10. Status of fiberoptics technology for propulsion control systems

    NASA Technical Reports Server (NTRS)

    Baumbick, R. J.

    1982-01-01

    Optical sensors and optically controlled actuators for use in airbreathing engine control systems are discussed. The environmental conditions in which the aircraft will operate require the fiberoptic cables and optical connectors to perform reliably at temperatures over the -55 C to 260 C range. The status of fiberoptics technology for operation in this environment is reviewed.

  11. 21 CFR 870.1230 - Fiberoptic oximeter catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fiberoptic oximeter catheter. 870.1230 Section 870.1230 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1230 Fiberoptic oximeter...

  12. Novel Fiber-Optic Ring Acoustic Emission Sensor

    PubMed Central

    Han, Xiaole; Xia, Dong; Liu, Taolin; Lang, Hao

    2018-01-01

    Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber-optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber-optic ring sensor acoustic emission system is built based on this method. Finally, fiber-optic ring acoustic emission experiments are performed. The novel fiber-optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber-optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber-optic ring acoustic emission sensor. In the future, this novel fiber-optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments. PMID:29342858

  13. 21 CFR 870.1230 - Fiberoptic oximeter catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Fiberoptic oximeter catheter. 870.1230 Section 870.1230 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1230 Fiberoptic oximeter...

  14. Fiberoptic metal detector capable of profile detection.

    PubMed

    Hua, Wei-Shu; Hooks, Joshua R; Erwin, Nicholas A; Wu, Wen-Jong; Wang, Wei-Chih

    2011-03-31

    The purpose of this paper is to develop a novel ferromagnetic polymeric metal detector system by using a fiber-optic Mach-Zehnder interferometer with a newly developed ferromagnetic polymer as the magnetostrictive sensing device. This ferromagnetic polymeric metal detector system is simple to fabricate, small in size, and resistant to RF interference (which is common in typical electromagnetic type metal detectors). Metal detection is made possible by disrupting the magnetic flux density present on the magnetostrictive sensor. This paper discusses the magnetic properties of the ferromagnetic polymers. In addition, the preliminary results of successful sensing of different geometrical metal shapes will be discussed.

  15. A Coherent Fused Silica Fiberoptic Array.

    DTIC Science & Technology

    1986-07-01

    7 AD-R I? 09 3 COHERENT FUSED SILIC FIBEROPTIC ARR AY(U) O ALILED / ELECTRa-OPTICS CORP STURBRIDGE MR J E ROURKE ET AL. JUL 86 ORL-CR-557 DAAIKiS...7. AUTHOR(a) 6. CONTRACT OR GRANT NUMUER(a) J. Edward Rourke * Dean J. Geraci Mark L. DeLong DAAA15-85- C -Olll 9. PERFORMING ORGANIZATION NAME AND...3r.4 c Le o COL 0) * EE >0 a) LL 141 opposite end. A variation of light intensity vs. angular position was approximately Gaussian. The NA is

  16. Microbend fiber-optic chemical sensor

    DOEpatents

    Weiss, Jonathan D.

    2002-01-01

    A microbend fiber-optic chemical sensor for detecting chemicals in a sample, and a method for its use, is disclosed. The sensor comprises at least one optical fiber having a microbend section (a section of small undulations in its axis), for transmitting and receiving light. In transmission, light guided through the microbend section scatters out of the fiber core and interacts, either directly or indirectly, with the chemical in the sample, inducing fluorescence radiation. Fluorescence radiation is scattered back into the microbend section and returned to an optical detector for determining characteristics of the fluorescence radiation quantifying the presence of a specific chemical.

  17. Subglottic granuloma after aortic replacement: resection via flexible bronchoscopy after an emergency tracheostomy

    PubMed Central

    Nose, Naohiro; So, Tetsuya; Sekimura, Atsushi; Miyata, Takeaki; Yoshimatsu, Takashi

    2014-01-01

    A subglottic granuloma is one of the late-phase complications that can occur after intubation. It can cause a life-threatening airway obstruction; therefore, a rapid diagnosis and appropriate treatment plan is necessary. A 62-year-old male had undergone an emergency total arch replacement for acute aortic dissection. Postoperative ventilation support had been performed until the 15th postoperative day (POD). He was discharged from the hospital on POD 30. On POD 50, he was brought to our hospital by an ambulance with severe dyspnea. A large subglottic granuloma occupying the trachea was identified by flexible bronchoscopy. After an emergency tracheostomy, resection of the granuloma with argon plasma coagulation via flexible bronchoscopy was performed safely. Physicians should suspect a post-intubation subglottic granuloma when patients who have undergone intubation report feeling throat discomfort. Resection via flexible bronchoscopy after tracheostomy is a safe and feasible procedure that may shorten the duration of therapy and hospital stay. PMID:25180216

  18. High-risk respiratory patients' experiences of bronchoscopy with conscious sedation and analgesia: A qualitative study.

    PubMed

    Saxon, Catherine; Fulbrook, Paul; Fong, Kwun M; Ski, Chantal F

    2017-10-20

    To understand the experiences of high-risk respiratory patients undergoing bronchoscopy with conscious sedation. Due to possible complications, high-risk respiratory patients are usually given smaller, cautious doses of sedation and analgesia for bronchoscopy. Described as "conscious sedation," this facilitates depression of the patient's consciousness without causing respiratory compromise. Previously, studies have investigated patient experience using quantitative methods. This is the first study that has explored the patient experience during bronchoscopy from a qualitative perspective. Qualitative, phenomenological approach as described by Van Manen. The setting was an endoscopy unit within an Australian tertiary hospital. Unstructured interviews were conducted with 13 patients with chronic obstructive pulmonary disease who underwent day-case bronchoscopy. All participants received conscious sedation. They were interviewed twice, within a week, postprocedure. Interviews were transcribed verbatim and analysed using Van Manen's interpretive approach. Participants had varying experiences. Five themes emerged from the analysis: Frustration and fear; Comfort and safety; Choking and coughing; Being aware; and Consequences. Whilst not all participants experienced procedural awareness or remembered it, for those who did it was a significant event. Overall, experiences were found to be negative; however, participants accepted and tolerated them, perceiving them as necessary to obtain a diagnostic result. The findings demonstrate that often patients are aware during the procedure and their experience may be uncomfortable and distressing. These findings have implications for patient preparation pre- and post-bronchoscopy in terms of what they might expect, and to discuss what has happened after the procedure. Some practices of the bronchoscopy team during the procedure may need modification. For example, in anticipation of the possibility that the patient may be aware

  19. Assessment of central airway obstruction using impulse oscillometry before and after interventional bronchoscopy.

    PubMed

    Handa, Hiroshi; Huang, Jyongsu; Murgu, Septimiu D; Mineshita, Masamichi; Kurimoto, Noriaki; Colt, Henri G; Miyazawa, Teruomi

    2014-02-01

    Spirometry is used to physiologically assess patients with central airway obstruction (CAO) before and after interventional bronchoscopy, but is not always feasible in these patients, does not localize the anatomic site of obstruction, and may not correlate with the patient's functional impairment. Impulse oscillometry may overcome these limitations. We assessed the correlations between impulse oscillometry measurements, symptoms, and type of airway narrowing, before and after interventional bronchoscopy, and whether impulse oscillometry parameters can discriminate between fixed and dynamic CAO. Twenty consecutive patients with CAO underwent spirometry, impulse oscillometry, computed tomography, dyspnea assessment, and bronchoscopy, before and after interventional bronchoscopy. The collapsibility index (the percent difference in airway lumen diameter during expiration versus during inspiration) was calculated using morphometric bronchoscopic images during quiet breathing. Variable CAO was defined as a collapsibility index of > 50%. Fixed CAO was defined as a collapsibility index of < 50%. The degree of obstruction was analyzed with computed tomography measurements. After interventional bronchoscopy, all impulse oscillometry measurements significantly improved, especially resistance at 5 Hz, which decreased from 0.67 ± 0.29kPa/L/s to 0.38 ± 0.17kPa/L/s (P < .001), and reactance at 20 Hz, which increased from -0.09 ± 0.11 to 0.03 ± 0.08 (P < .001). Changes in dyspnea score correlated with resistance at 5 Hz, the difference between the resistance at 5 Hz and the resistance at 20 Hz, and the reactance at 5 Hz, but not with spirometry measurements. The type of obstruction also correlated with dyspnea score, and showed distinct impulse oscillometry measurements. Impulse oscillometry measurements correlate with symptom improvements after interventional bronchoscopy. Impulse oscillometry might be useful to discriminate variable from fixed central airway obstruction

  20. Surveillance bronchoscopy in children during the first year after lung transplantation: Is it worth it?

    PubMed

    Benden, C; Harpur-Sinclair, O; Ranasinghe, A S; Hartley, J C; Elliott, M J; Aurora, P

    2007-01-01

    Since January 2002, routine surveillance bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial biopsy has been performed in all paediatric recipients of lung and heart-lung transplants at the Great Ormond Street Hospital for Children, London, UK, using a newly revised treatment protocol. To report the prevalence of rejection and bacterial, viral or fungal pathogens in asymptomatic children and compare this with the prevalence in children with symptoms. The study population included all paediatric patients undergoing single lung transplantation (SLTx), double lung transplantation (DLTx) or heart-lung transplantation between January 2002 and December 2005. Surveillance bronchoscopies were performed at 1 week, and 1, 3, 6 and 12 months after transplant. Bronchoscopies were classified according to whether subjects had symptoms, defined as the presence of cough, sputum production, dyspnoea, malaise, decrease in lung function or chest radiograph changes. Results of biopsies and BAL were collected, and procedural complications recorded. 23 lung-transplant operations were performed, 12 DLTx, 10 heart-lung transplants and 1 SLTx (15 female patients). The median (range) age of patients was 14.0 (4.9-17.3) years. 17 patients had cystic fibrosis. 95 surveillance bronchoscopies were performed. Rejection (> or =A2) was diagnosed in 4% of biopsies of asymptomatic recipients, and in 12% of biopsies of recipients with symptoms. Potential pathogens were detected in 29% of asymptomatic patients and in 69% of patients with symptoms. The overall diagnostic yield was 35% for asymptomatic children, and 85% for children with symptoms (p < 0.001). The complication rate for bronchoscopies was 3.2%. Many children have silent rejection or subclinical infection in the first year after lung transplantation. Routine surveillance bronchoscopy allows detection and targeted treatment of these complications.

  1. Fiber-optic security monitoring sensor

    NASA Astrophysics Data System (ADS)

    Englund, Marja; Ipatti, Ari; Karioja, Pentti

    1997-09-01

    In security monitoring, fiber-optic sensors are advantageous because strong and rugged optical fibers are thin, light, flexible and immune to electromagnetic interference. Optical fibers packaged into cables, such as, building and underground cables, can be used to detect even slightest disturbances, movements, vibrations, pressure changes and impacts along their entire length. When running an optical cable around a structure, and when using speckle pattern recognition technique for alarm monitoring, the distributed monitoring of the structure is possible. The sensing cable can be strung along fences, buried underground, embedded into concrete, mounted on walls, floors and ceilings, or wrapped around the specific components. In this paper, a fiber-optic security monitoring sensor based on speckle pattern monitoring is described. The description of the measuring method and the results of the experimental fiber installations are given. The applicability of embedded and surface mounted fibers to monitor the pressure and impact induced vibrations of fences and concrete structures as well as the loosening of critical parts in a power plant machinery were demonstrated in field and laboratory conditions. The experiences related to the applications and optical cable types are also discussed.

  2. Fiber-optic couplers as displacement sensors

    NASA Astrophysics Data System (ADS)

    Baruch, Martin C.; Gerdt, David W.; Adkins, Charles M.

    2003-04-01

    We introduce the novel concept of using a fiber-optic coupler as a versatile displacement sensor. Comparatively long fiber-optic couplers, with a coupling region of approximately 10 mm, are manufactured using standard communication SM fiber and placed in a looped-back configuration. The result is a displacement sensor, which is robust and highly sensitive over a wide dynamic range. This displacement sensor resolves 1-2 μm over distances of 1-1.5 mm and is characterized by the essential absence of a 'spring constant' plaguing other strain gauge-type sensors. Consequently, it is possible to couple to extremely weak vibrations, such as the skin displacement affected by arterial heart beat pulsations. Used as a wrist-worn heartbeat monitor, the fidelity of the arterial pulse signal has been shown to be so high that it is possible to not only determine heartbeat and breathing rates, but to implement a new single-point blood pressure measurement scheme which does not squeeze the arm. In an application as a floor vibration sensor for the non-intrusive monitoring of independently living elderly, the sensor has been shown to resolve the distinct vibration spectra of different persons and different events.

  3. Automated anatomical labeling of bronchial branches using multiple classifiers and its application to bronchoscopy guidance based on fusion of virtual and real bronchoscopy

    NASA Astrophysics Data System (ADS)

    Ota, Shunsuke; Deguchi, Daisuke; Kitasaka, Takayuki; Mori, Kensaku; Suenaga, Yasuhito; Hasegawa, Yoshinori; Imaizumi, Kazuyoshi; Takabatake, Hirotsugu; Mori, Masaki; Natori, Hiroshi

    2008-03-01

    This paper presents a method for automated anatomical labeling of bronchial branches (ALBB) extracted from 3D CT datasets. The proposed method constructs classifiers that output anatomical names of bronchial branches by employing the machine-learning approach. We also present its application to a bronchoscopy guidance system. Since the bronchus has a complex tree structure, bronchoscopists easily tend to get disoriented and lose the way to a target location. A bronchoscopy guidance system is strongly expected to be developed to assist bronchoscopists. In such guidance system, automated presentation of anatomical names is quite useful information for bronchoscopy. Although several methods for automated ALBB were reported, most of them constructed models taking only variations of branching patterns into account and did not consider those of running directions. Since the running directions of bronchial branches differ greatly in individuals, they could not perform ALBB accurately when running directions of bronchial branches were different from those of models. Our method tries to solve such problems by utilizing the machine-learning approach. Actual procedure consists of three steps: (a) extraction of bronchial tree structures from 3D CT datasets, (b) construction of classifiers using the multi-class AdaBoost technique, and (c) automated classification of bronchial branches by using the constructed classifiers. We applied the proposed method to 51 cases of 3D CT datasets. The constructed classifiers were evaluated by leave-one-out scheme. The experimental results showed that the proposed method could assign correct anatomical names to bronchial branches of 89.1% up to segmental lobe branches. Also, we confirmed that it was quite useful to assist the bronchoscopy by presenting anatomical names of bronchial branches on real bronchoscopic views.

  4. Interventional bronchoscopy for treatment of tracheal obstruction secondary to benign or malignant thyroid disease.

    PubMed

    Noppen, Marc; Poppe, Kris; D'Haese, Jan; Meysman, Marc; Velkeniers, Brigitte; Vincken, Walter

    2004-02-01

    Surgery is the treatment of choice for symptomatic tracheal obstruction due to benign or malignant thyroid disease. In case of inoperability, or when surgery is refused, few therapeutic alternatives are available. Interventional bronchoscopic procedures have only been reported anecdotally. The objective of this study is to evaluate the results of interventional bronchoscopic procedures in the treatment of severe tracheal obstruction due to thyroid disease. Retrospective cohort analysis. University hospital, tertiary referral center. Thirty consecutive patients referred for bronchoscopic treatment of benign (n = 17) or malignant (n = 13) thyroid-related upper airway obstruction due to tracheomalacia, extrinsic compression, and/or tracheal ingrowth. Indications for bronchoscopic treatment were medical or surgical inoperability, prevention or treatment of tracheomalacia, and refusal of surgery. There were no procedure-related complications. Rigid bronchoscopy with dilatation, stenting and/or Nd-YAG laser treatment, and clinical follow-up. Subjective improvement, pulmonary function tests, early and late complications, and survival. In the benign group, immediate (100% relief of dyspnea) and long-term (88% relief of dyspnea) results were excellent after airway stenting (21 stents used in 17 patients). There was one unrelated death 1 week after stenting in a 98-year-old patient. There were 6% and 30% short-term and long-term complications, respectively, that could be managed endoscopically. In the malignant group, Nd-YAG laser treatment (n = 3) and stenting (n = 13) yielded immediate and long-term success in 92% of patients. There were 15% short-term and 8% long-term complications. Median survival time was 540 days. Interventional bronchoscopic procedures including Nd-YAG laser treatment and stenting are valuable alternatives to surgery in inoperable thyroid-induced tracheal obstruction, or when surgery is refused.

  5. Flexible bronchoscopy during non-invasive positive pressure mechanical ventilation: are two better than one?

    PubMed

    Scala, Raffaele

    2016-09-01

    Flexible bronchoscopy (FBO) and non-invasive positive pressure ventilation (NIPPV) are largely applied in respiratory and general intensive care units. FBO plays a crucial role for the diagnosis of lung infiltrates of unknown origin and for the treatment of airways obstruction due to bronchial mucous plugging and hemoptysis in critical patients. NIPPV is the first-choice ventilatory strategy for acute respiratory failure (ARF) of different causes as it could be used as prevention or as alternative to the conventional mechanical ventilation (CMV) via endotracheal intubation (ETI). Some clinical scenarios represent contraindications for these techniques such as severe ARF in spontaneous breathing patients for FBO and accumulated tracheo-bronchial secretions in patients with depressed cough for NIPPV. In these contexts, the decision of performing ETI should carefully consider the risk of CMV-correlated complications. An increasing amount of published data suggested the use of FBO during NIPPV in ARF in order to avoid/reduce the need of ETI. Despite a strong rationale for the combined use of the two techniques, there is not still enough evidence for a large-scale application of this strategy in all different clinical scenarios. The majority of the available data are in favor of the "help" given by NIPPV to diagnostic FBO in high-risk spontaneously breathing patients with severe hypoxemia. Preliminary findings report the successful "help" given by early FBO to NIPPV in patients with hypoxemic-hypercapnic ARF who are likely to fail because of hypersecretion. Synergy of FBO and NIPPV application is emerging also to perform ETI in challenging situations, such as predicted difficult laringoscopy and NPPV failure in severely hypoxemic patients. This combined approach should be performed only in centers showing a wide experience with both NIPPV and FBO, where close monitoring and ETI facilities are promptly available.

  6. Development of a nonlinear fiber-optic spectrometer for human lung tissue exploration

    PubMed Central

    Peyrot, Donald A.; Lefort, Claire; Steffenhagen, Marie; Mansuryan, Tigran; Ducourthial, Guillaume; Abi-Haidar, Darine; Sandeau, Nicolas; Vever-Bizet, Christine; Kruglik, Sergei G.; Thiberville, Luc; Louradour, Frédéric; Bourg-Heckly, Geneviève

    2012-01-01

    Several major lung pathologies are characterized by early modifications of the extracellular matrix (ECM) fibrillar collagen and elastin network. We report here the development of a nonlinear fiber-optic spectrometer, compatible with an endoscopic use, primarily intended for the recording of second-harmonic generation (SHG) signal of collagen and two-photon excited fluorescence (2PEF) of both collagen and elastin. Fiber dispersion is accurately compensated by the use of a specific grism-pair stretcher, allowing laser pulse temporal width around 70 fs and excitation wavelength tunability from 790 to 900 nm. This spectrometer was used to investigate the excitation wavelength dependence (from 800 to 870 nm) of SHG and 2PEF spectra originating from ex vivo human lung tissue samples. The results were compared with spectral responses of collagen gel and elastin powder reference samples and also with data obtained using standard nonlinear microspectroscopy. The excitation-wavelength-tunable nonlinear fiber-optic spectrometer presented in this study allows performing nonlinear spectroscopy of human lung tissue ECM through the elastin 2PEF and the collagen SHG signals. This work opens the way to tunable excitation nonlinear endomicroscopy based on both distal scanning of a single optical fiber and proximal scanning of a fiber-optic bundle. PMID:22567579

  7. Fiber-Optic Chemical Sensors and Fiber-Optic Bio-Sensors

    PubMed Central

    Pospíšilová, Marie; Kuncová, Gabriela; Trögl, Josef

    2015-01-01

    This review summarizes principles and current stage of development of fiber-optic chemical sensors (FOCS) and biosensors (FOBS). Fiber optic sensor (FOS) systems use the ability of optical fibers (OF) to guide the light in the spectral range from ultraviolet (UV) (180 nm) up to middle infrared (IR) (10 µm) and modulation of guided light by the parameters of the surrounding environment of the OF core. The introduction of OF in the sensor systems has brought advantages such as measurement in flammable and explosive environments, immunity to electrical noises, miniaturization, geometrical flexibility, measurement of small sample volumes, remote sensing in inaccessible sites or harsh environments and multi-sensing. The review comprises briefly the theory of OF elaborated for sensors, techniques of fabrications and analytical results reached with fiber-optic chemical and biological sensors. PMID:26437407

  8. Fiber-Optic Chemical Sensors and Fiber-Optic Bio-Sensors.

    PubMed

    Pospíšilová, Marie; Kuncová, Gabriela; Trögl, Josef

    2015-09-30

    This review summarizes principles and current stage of development of fiber-optic chemical sensors (FOCS) and biosensors (FOBS). Fiber optic sensor (FOS) systems use the ability of optical fibers (OF) to guide the light in the spectral range from ultraviolet (UV) (180 nm) up to middle infrared (IR) (10 μm) and modulation of guided light by the parameters of the surrounding environment of the OF core. The introduction of OF in the sensor systems has brought advantages such as measurement in flammable and explosive environments, immunity to electrical noises, miniaturization, geometrical flexibility, measurement of small sample volumes, remote sensing in inaccessible sites or harsh environments and multi-sensing. The review comprises briefly the theory of OF elaborated for sensors, techniques of fabrications and analytical results reached with fiber-optic chemical and biological sensors.

  9. Development of a polymer based fiberoptic magnetostrictive metal detector system.

    PubMed

    Hua, Wei Shu; Hooks, Joshua Rosenberg; Wu, Wen Jong; Wang, Wei Chih

    2010-10-01

    This paper presents a new metal detector using a fiberoptic magnetostriction sensor. The metal sensor uses a fiber-optic Mach-Zehnder interferometer with a newly developed ferromagnetic polymer as the magnetostrictive sensing material. This polymeric magnetostrictive fiberoptic metal sensor is simple to fabricate, small in size, and resistant to RF interference (which is common in typical electromagnetic type metal detectors). Metal detection is based on disruption of the magnetic flux density across the magnetostriction sensor. In this paper, characteristics of the material being sensed and magnetic properties of the ferromagnetic polymers will be discussed.

  10. Modulated-splitting-ratio fiber-optic temperature sensor

    NASA Technical Reports Server (NTRS)

    Beheim, Glenn; Anthan, Donald J.; Rys, John R.; Fritsch, Klaus; Ruppe, Walter A.

    1988-01-01

    A fiber-optic temperature sensor is described, which uses a small silicon beamsplitter whose splitting ratio varies as a function of temperature. A four-beam technique is used to measure the sensor's temperature-indicating splitting ratio. This referencing method provides a measurement that is largely independent of the transmission properties of the sensor's optical fiber link. A significant advantage of this sensor, relative to other fiber-optic sensors, is its high stability, which permits the fiber-optic components to be readily substituted, thereby simplifying the sensor's installation and maintenance.

  11. Distributed practice. The more the merrier? A randomised bronchoscopy simulation study

    PubMed Central

    Bjerrum, Anne Sofie; Eika, Berit; Charles, Peder; Hilberg, Ole

    2016-01-01

    Introduction The distribution of practice affects the acquisition of skills. Distributed practice has shown to be more effective for skills acquisition than massed training. However, it remains unknown as to which is the most effective distributed practice schedule for learning bronchoscopy skills through simulation training. This study compares two distributed practice schedules: One-day distributed practice and weekly distributed practice. Method Twenty physicians in training were randomly assigned to one-day distributed or weekly distributed bronchoscopy simulation practice. Performance was assessed with a pre-test, a post-test after each practice session, and a 4-week retention test using previously validated simulator measures. Data were analysed with repeated measures ANOVA. Results No interaction was found between group and test (F(4,72) <1.68, p>0.16), except for the measure ‘percent-segments-entered’, and no main effect of group was found for any of the measures (F(1,72)< 0.87, p>0.36), which indicates that there was no difference between the learning curves of the one-day distributed practice schedule and the weekly distributed practice schedule. Discussion We found no difference in effectiveness of bronchoscopy skills acquisition between the one-day distributed practice and the weekly distributed practice. This finding suggests that the choice of bronchoscopy training practice may be guided by what best suits the clinical practice. PMID:27172423

  12. Distributed practice. The more the merrier? A randomised bronchoscopy simulation study.

    PubMed

    Bjerrum, Anne Sofie; Eika, Berit; Charles, Peder; Hilberg, Ole

    2016-01-01

    Introduction The distribution of practice affects the acquisition of skills. Distributed practice has shown to be more effective for skills acquisition than massed training. However, it remains unknown as to which is the most effective distributed practice schedule for learning bronchoscopy skills through simulation training. This study compares two distributed practice schedules: One-day distributed practice and weekly distributed practice. Method Twenty physicians in training were randomly assigned to one-day distributed or weekly distributed bronchoscopy simulation practice. Performance was assessed with a pre-test, a post-test after each practice session, and a 4-week retention test using previously validated simulator measures. Data were analysed with repeated measures ANOVA. Results No interaction was found between group and test (F(4,72) <1.68, p>0.16), except for the measure 'percent-segments-entered', and no main effect of group was found for any of the measures (F(1,72)< 0.87, p>0.36), which indicates that there was no difference between the learning curves of the one-day distributed practice schedule and the weekly distributed practice schedule. Discussion We found no difference in effectiveness of bronchoscopy skills acquisition between the one-day distributed practice and the weekly distributed practice. This finding suggests that the choice of bronchoscopy training practice may be guided by what best suits the clinical practice.

  13. Distributed practice. The more the merrier? A randomised bronchoscopy simulation study.

    PubMed

    Bjerrum, Anne Sofie; Eika, Berit; Charles, Peder; Hilberg, Ole

    2016-01-01

    The distribution of practice affects the acquisition of skills. Distributed practice has shown to be more effective for skills acquisition than massed training. However, it remains unknown as to which is the most effective distributed practice schedule for learning bronchoscopy skills through simulation training. This study compares two distributed practice schedules: One-day distributed practice and weekly distributed practice. Twenty physicians in training were randomly assigned to one-day distributed or weekly distributed bronchoscopy simulation practice. Performance was assessed with a pre-test, a post-test after each practice session, and a 4-week retention test using previously validated simulator measures. Data were analysed with repeated measures ANOVA. No interaction was found between group and test (F(4,72) <1.68, p>0.16), except for the measure 'percent-segments-entered', and no main effect of group was found for any of the measures (F(1,72)< 0.87, p>0.36), which indicates that there was no difference between the learning curves of the one-day distributed practice schedule and the weekly distributed practice schedule. We found no difference in effectiveness of bronchoscopy skills acquisition between the one-day distributed practice and the weekly distributed practice. This finding suggests that the choice of bronchoscopy training practice may be guided by what best suits the clinical practice.

  14. Bronchoscopy for the diagnosis of pulmonary tuberculosis in patients with negative sputum smear microscopy results.

    PubMed

    Jacomelli, Márcia; Silva, Priscila Regina Alves Araújo; Rodrigues, Ascedio Jose; Demarzo, Sergio Eduardo; Seicento, Márcia; Figueiredo, Viviane Rossi

    2012-01-01

    To evaluate the diagnostic accuracy of bronchoscopy in patients with clinical or radiological suspicion of tuberculosis who were unable to produce sputum or with negative sputum smear microscopy results. A prospective cross-sectional study involving 286 patients under clinical or radiological suspicion of having pulmonary tuberculosis and submitted to bronchoscopy-BAL and transbronchial biopsy (TBB). The BAL specimens were submitted to direct testing and culture for AFB and fungi, whereas the TBB specimens were submitted to histopathological examination. Of the 286 patients studied, 225 (79%) were diagnosed on the basis of bronchoscopic findings, as follows: pulmonary tuberculosis, in 127 (44%); nonspecific chronic inflammation, in 51 (18%); pneumocystis, fungal infections, or nocardiosis, in 20 (7%); bronchiolitis obliterans organizing pneumonia, alveolites, or pneumoconiosis, in 14 (5%); lung or metastatic neoplasms, in 7 (2%); and nontuberculous mycobacterium infections, in 6 (2%). For the diagnosis of tuberculosis, BAL showed a sensitivity and a specificity of 60% and 100%, respectively. Adding the TBB findings significantly increased this sensitivity (to 84%), as did adding the post-bronchoscopy sputum smear microscopy results (total sensitivity, 94%). Minor post-procedure complications occurred in 5.6% of the cases. Bronchoscopy is a reliable method for the diagnosis of pulmonary tuberculosis, with low complication rates. The combination of TBB and BAL increases the sensitivity of the method and facilitates the differential diagnosis with other diseases.

  15. [Virtual bronchoscopy in the child using multi-slice CT: initial clinical experiences].

    PubMed

    Kirchner, J; Laufer, U; Jendreck, M; Kickuth, R; Schilling, E M; Liermann, D

    2000-01-01

    Virtual bronchoscopy of the pediatric patient has been reported to be more difficult because of artifacts due to breathing or motion. We demonstrate the benefit of the accelerated examination based on multislice spiral CT (MSCT) in the pediatric patient which has not been reported so far. MSCT (tube voltage 120 kV, tube current 110 mA, 4 x 1 mm Slice thickness, 500 ms rotation time, Pitch 6) was performed on a CT scanner of the latest generation (Volume Zoom, Siemens Corp. Forchheim, Germany). In totally we examined 11 patients (median age 48 months, range 2-122 months) suspected of having tracheoesophageal fistula (n = 2), tracheobronchial narrowing (n = 8) due to intrinsic or extrinsic factors or injury of the bronchial system (n = 1). In all patients we obtained sufficient data for 3D reconstruction avoiding general anesthesia. 6/11 examinations were described to be without pathological finding. A definite diagnosis was obtained in 10 patients. Virtual bronchoscopy could avoid other invasive diagnostic examination in 8/11 patients (73%). Helical CT provides 3D-reconstruction and virtual bronchoscopy in the newborn as well as the infant. It avoids additional diagnostic bronchoscopy in a high percentage of all cases.

  16. [Clinical analysis of interventional bronchoscopy for the treatment of malignant obstructive atelectasis].

    PubMed

    Wang, Hongwu; Li, Dongmei; Zhang, Nan; Zou, Hang; Zhou, Yunzhi; Li, Jing; Liang, Sujuan

    2011-08-01

    Obstructive atelectasis is frequently accompanied by pulmonary infection and hypoxia. The key to treating this condition is by directly reopening the obstructive airway. The aim of the present study is to explore the safety and efficacy of interventional bronchoscopy for the treatment of malignant obstructive atelectasis. A total of 120 cases with pathology-proved malignant obstructive atelectasis were retrospectively analyzed for the treatment of argon plasma coagulation and cryosurgery under bronchoscopy. Patients' age is between 5 and 90 years old. A total of 120 cases had 187 atelectasis originating from 98 lesions with primary airway tumors and 89 with metastases. The most common location of atelectasis was in the upper lobe in the primary group and in the single lung in the metastasis group. Although there was no significant difference in tumor debulging between the two groups, the reopening rate of atelectasis was lower in the primary group than that in the metastasis group. The Karnofsky physical score significantly increased, and shortbreath scale decreased after interventional bronchoscopy. Among the patients, 3/4 had hypoxemia and 3.4% had severe bleeding, which caused the death of 1 patient during a procedure. The mean survival time was 6 months, and the survival rate of 1 year was 27.1%. Bronchoscopy can rapidly and effectively debulge the airway tumor and reopen the atelectasis.

  17. Computer-based System for the Virtual-Endoscopic Guidance of Bronchoscopy.

    PubMed

    Helferty, J P; Sherbondy, A J; Kiraly, A P; Higgins, W E

    2007-11-01

    The standard procedure for diagnosing lung cancer involves two stages: three-dimensional (3D) computed-tomography (CT) image assessment, followed by interventional bronchoscopy. In general, the physician has no link between the 3D CT image assessment results and the follow-on bronchoscopy. Thus, the physician essentially performs bronchoscopic biopsy of suspect cancer sites blindly. We have devised a computer-based system that greatly augments the physician's vision during bronchoscopy. The system uses techniques from computer graphics and computer vision to enable detailed 3D CT procedure planning and follow-on image-guided bronchoscopy. The procedure plan is directly linked to the bronchoscope procedure, through a live registration and fusion of the 3D CT data and bronchoscopic video. During a procedure, the system provides many visual tools, fused CT-video data, and quantitative distance measures; this gives the physician considerable visual feedback on how to maneuver the bronchoscope and where to insert the biopsy needle. Central to the system is a CT-video registration technique, based on normalized mutual information. Several sets of results verify the efficacy of the registration technique. In addition, we present a series of test results for the complete system for phantoms, animals, and human lung-cancer patients. The results indicate that not only is the variation in skill level between different physicians greatly reduced by the system over the standard procedure, but that biopsy effectiveness increases.

  18. High-Strength Fiber-Optic Waveguide

    DTIC Science & Technology

    1978-11-01

    kAD may not be an adequate characterization of the fiber. 40 0 I- U) LU L CL U Z -m wZ CL) LU o CL C LL Z 04 - --j L- 1 Lu CLC 4LL . -4 - LUi ua. 0 c ...reveal1 thaIt .large Irt ion of the IOW strength rup- ttre re oi tli , charater. 74 7094-6 (ai) Vv p i c I I lil in ilt 1111-s izkc d o p -I i Ig I Z1...t. HIGH-STRENGTH FIBER-OPTIC WAVEGUIDE )G.D. Robertson Hughes Research Laboratories D T C 3011 Malibu Canyon Road Malibu, CA 90265 November 1978 H

  19. Simulation-based bronchoscopy training: systematic review and meta-analysis.

    PubMed

    Kennedy, Cassie C; Maldonado, Fabien; Cook, David A

    2013-07-01

    Simulation-based bronchoscopy training is increasingly used, but effectiveness remains uncertain. We sought to perform a comprehensive synthesis of published work on simulation-based bronchoscopy training. We searched MEDLINE, EMBASE, CINAHL, PsycINFO, ERIC, Web of Science, and Scopus for eligible articles through May 11, 2011. We included all original studies involving health professionals that evaluated, in comparison with no intervention or an alternative instructional approach, simulation-based training for flexible or rigid bronchoscopy. Study selection and data abstraction were performed independently and in duplicate. We pooled results using random effects meta-analysis. From an initial pool of 10,903 articles, we identified 17 studies evaluating simulation-based bronchoscopy training. In comparison with no intervention, simulation training was associated with large benefits on skills and behaviors (pooled effect size, 1.21 [95% CI, 0.82-1.60]; n=8 studies) and moderate benefits on time (0.62 [95% CI, 0.12-1.13]; n=7). In comparison with clinical instruction, behaviors with real patients showed nonsignificant effects favoring simulation for time (0.61 [95% CI, -1.47 to 2.69]) and process (0.33 [95% CI, -1.46 to 2.11]) outcomes (n=2 studies each), although variation in training time might account for these differences. Four studies compared alternate simulation-based training approaches. Inductive analysis to inform instructional design suggested that longer or more structured training is more effective, authentic clinical context adds value, and animal models and plastic part-task models may be superior to more costly virtual-reality simulators. Simulation-based bronchoscopy training is effective in comparison with no intervention. Comparative effectiveness studies are few.

  20. Bronchoscopy, Imaging, and Concurrent Diseases in Dogs with Bronchiectasis: (2003-2014).

    PubMed

    Johnson, L R; Johnson, E G; Vernau, W; Kass, P H; Byrne, B A

    2016-01-01

    Bronchiectasis is a permanent and debilitating sequel to chronic or severe airway injury, however, diseases associated with this condition are poorly defined. To evaluate results of diagnostic tests used to document bronchiectasis and to characterize underlying or concurrent disease processes. Eighty-six dogs that had bronchoscopy performed and a diagnosis of bronchiectasis. Retrospective case series. Radiographs, computed tomography, and bronchoscopic findings were evaluated for features of bronchiectasis. Clinical diagnoses of pneumonia (aspiration, interstitial, foreign body, other), eosinophilic bronchopneumopathy (EBP), and inflammatory airway disease (IAD) were made based on results of history, physical examination, and diagnostic testing, including bronchoalveolar lavage fluid analysis and microbiology. Bronchiectasis was diagnosed in 14% of dogs (86/621) that had bronchoscopy performed. Dogs ranged in age from 0.5 to 14 years with duration of signs from 3 days to 10 years. Bronchiectasis was documented during bronchoscopy in 79/86 dogs (92%), thoracic radiology in 50/83 dogs (60%), and CT in 34/34 dogs (100%). Concurrent airway collapse was detected during bronchoscopy in 50/86 dogs (58%), and focal or multifocal mucus plugging of segmental or subsegmental bronchi was found in 41/86 dogs (48%). Final diagnoses included pneumonia (45/86 dogs, 52%), EBP (10/86 dogs, 12%) and IAD (31/86 dogs, 36%). Bacteria were isolated in 24/86 cases (28%), with Streptococcus spp, Pasteurella spp, enteric organisms, and Stenotrophomonas isolated most frequently. Bronchiectasis can be anticipated in dogs with infectious or inflammatory respiratory disease. Advanced imaging and bronchoscopy are useful in making the diagnosis and identifying concurrent respiratory disease. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  1. Bronchoscopy in the investigation of outpatients with hemoptysis at a lung cancer clinic.

    PubMed

    Arooj, Parniya; Bredin, Emily; Henry, Michael T; Khan, Kashif A; Plant, Barry J; Murphy, Desmond M; Kennedy, Marcus P

    2018-06-01

    In the investigation of lung cancer, current practice in many healthcare systems would support bronchoscopy regardless of CT findings in patients with hemoptysis. We sought to identify the cause, the diagnostic yield of CT and bronchoscopy and the requirement for bronchoscopy in at risk patients with hemoptysis with a normal CT scan through our rapid access lung cancer clinic (RALC). Initially, a chart review was performed on all patients with hemoptysis (2011-2012) and thereafter a prospective analysis was performed (2013-2016). Our analysis represents the largest study to date in outpatients with hemoptysis. In our retrospective study, 155 patients reported hemoptysis. Causes were lower respiratory tract infections (RTIs) (47%) and lung cancer (16%). Our prospective study included 182 patients. The causes of hemoptysis were RTIs (50%) and lung cancer (18%). There were no false negative CT-scans for lung cancer. 47/57 present with lung cancer underwent bronchoscopy and 43/47 were positive for lung cancer (92%). Patients with hemoptysis and lung cancer have a higher stage of malignancy with a predominance of squamous cell lung carcinoma. Smoking status, the duration of hemoptysis or description of hemoptysis were not predictive of lung cancer however lung cancer was not identified in patients age <50. One sixth of patients presenting with hemoptysis to our lung cancer clinic had lung cancer. No patient identified with cancer related haemoptysis had a CT negative for lung cancer and a combination of bronchoscopy plus endobronchial ultrasound trans-bronchial needle aspiration (EBUS-TBNA) in those patients with a CT suspicious of lung cancer is 92% sensitive for lung cancer causing hemoptysis. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Fiber-optic dosimeters for radiation therapy

    NASA Astrophysics Data System (ADS)

    Li, Enbang; Archer, James

    2017-10-01

    According to the figures provided by the World Health Organization, cancer is a leading cause of death worldwide, accounting for 8.8 million deaths in 2015. Radiation therapy, which uses x-rays to destroy or injure cancer cells, has become one of the most important modalities to treat the primary cancer or advanced cancer. The newly developed microbeam radiation therapy (MRT), which uses highly collimated, quasi-parallel arrays of x-ray microbeams (typically 50 μm wide and separated by 400 μm) produced by synchrotron sources, represents a new paradigm in radiotherapy and has shown great promise in pre-clinical studies on different animal models. Measurements of the absorbed dose distribution of microbeams are vitally important for clinical acceptance of MRT and for developing quality assurance systems for MRT, hence are a challenging and important task for radiation dosimetry. On the other hand, during the traditional LINAC based radiotherapy and breast cancer brachytherapy, skin dose measurements and treatment planning also require a high spatial resolution, tissue equivalent, on-line dosimeter that is both economical and highly reliable. Such a dosimeter currently does not exist and remains a challenge in the development of radiation dosimetry. High resolution, water equivalent, optical and passive x-ray dosimeters have been developed and constructed by using plastic scintillators and optical fibers. The dosimeters have peak edge-on spatial resolutions ranging from 50 to 500 microns in one dimension, with a 10 micron resolution dosimeter under development. The developed fiber-optic dosimeters have been test with both LINAC and synchrotron x-ray beams. This work demonstrates that water-equivalent and high spatial resolution radiation detection can be achieved with scintillators and optical fiber systems. Among other advantages, the developed fiber-optic probes are also passive, energy independent, and radiation hard.

  3. Fiber-Optic Strain Sensors With Linear Characteristics

    NASA Technical Reports Server (NTRS)

    Egalon, Claudio O.; Rogowski, Robert S.

    1993-01-01

    Fiber-optic modal domain strain sensors having linear characteristics over wide range of strains proposed. Conceived in effort to improve older fiber-optic strain sensors. Linearity obtained by appropriate choice of design parameters. Pattern of light and dark areas at output end of optical fiber produced by interference between electromagnetic modes in which laser beam propagates in fiber. Photodetector monitors intensity at one point in pattern.

  4. The role of fiberoptics in remote temperature measurement

    NASA Technical Reports Server (NTRS)

    Vanzetti, Riccardo

    1988-01-01

    The use of optical fibers in conjunction with infrared detectors and signal processing electronics represents the latest advance in the field of non-contact temperature measurement and control. The operating principles and design of fiber-optic radiometric systems are discussed and the advantages and disadvantages of using optical fibers are addressed. Signal processing requirements and various infrared detector types are also described. Several areas in which infrared fiber-optic instrumentation is used for temperature monitoring and control are discussed.

  5. Long microwave delay fiber-optic link for radar testing

    NASA Astrophysics Data System (ADS)

    Newberg, I. L.; Gee, C. M.; Thurmond, G. D.; Yen, H. W.

    1990-05-01

    A long fiberoptic delay line is used as a radar repeater to improve radar testing capabilities. The first known generation of 152 microsec delayed ideal target at X-band (10 GHz) frequencies having the phase stability and signal-to-noise ratio (SNR) needed for testing modern high-resolution Doppler radars is demonstrated with a 31.6-km experimental externally modulated fiberoptic link with a distributed-feedback (DFB) laser. The test application, link configuration, and link testing are discussed.

  6. Alternative Controller for a Fiber-Optic Switch

    NASA Technical Reports Server (NTRS)

    Peters, Robert

    2007-01-01

    A simplified diagram of a relatively inexpensive controller for a DiCon VX (or equivalent) fiber-optic switch -- an electromechanically actuated switch for optically connecting one or two input optical fibers to any of a number of output optical fibers is shown. DiCon VX fiber-optic switches are used primarily in research and development in the telecommunication industry. This controller can control any such switch having up to 32 output channels.

  7. Assessing carotid atherosclerosis by fiber-optic multispectral photoacoustic tomography

    NASA Astrophysics Data System (ADS)

    Hui, Jie; Li, Rui; Wang, Pu; Phillips, Evan; Bruning, Rebecca; Liao, Chien-Sheng; Sturek, Michael; Goergen, Craig J.; Cheng, Ji-Xin

    2015-03-01

    Atherosclerotic plaque at the carotid bifurcation is the underlying cause of the majority of ischemic strokes. Noninvasive imaging and quantification of the compositional changes preceding gross anatomic changes within the arterial wall is essential for diagnosis of disease. Current imaging modalities such as duplex ultrasound, computed tomography, positron emission tomography are limited by the lack of compositional contrast and the detection of flow-limiting lesions. Although high-resolution magnetic resonance imaging has been developed to characterize atherosclerotic plaque composition, its accessibility for wide clinical use is limited. Here, we demonstrate a fiber-based multispectral photoacoustic tomography system for excitation of lipids and external acoustic detection of the generated ultrasound. Using sequential ultrasound imaging of ex vivo preparations we achieved ~2 cm imaging depth and chemical selectivity for assessment of human arterial plaques. A multivariate curve resolution alternating least squares analysis method was applied to resolve the major chemical components, including intravascular lipid, intramuscular fat, and blood. These results show the promise of detecting carotid plaque in vivo through esophageal fiber-optic excitation of lipids and external acoustic detection of the generated ultrasound. This imaging system has great potential for serving as a point-ofcare device for early diagnosis of carotid artery disease in the clinic.

  8. Fiberoptic nasopharyngolaryngoscopy for airway monitoring after obstructive sleep apnea surgery.

    PubMed

    Li, K K; Riley, R W; Powell, N B; Zonato, A

    2000-12-01

    This study evaluated the upper airway characteristics in the early postoperative period after reconstructive surgery for obstructive sleep apnea (OSA). During a 24-month period, the upper airway of patients who underwent uvulopalatopharyngoplasty (UPPP) with genioglossus advancement (GA) or hyoid myotomy (HM) or maxillomandibular advancement (MMA) were evaluated with fiberoptic nasopharyngolaryngoscopy (NPG) preoperatively and 24 to 72 hours postoperatively. NPG was performed on 271 patients. One hundred seventy-three patients had UPPP with GA or HM, and the remainder had MMA. All of the patients who underwent UPPP with GA or HM were found to have varying degrees of soft tissue edema involving the soft palate and the tongue base. The patients who underwent tonsillectomies and UPPP with GA or HM had greater soft palate/pharyngeal wall edema. In contrast, patients who underwent MMA had minimal edema involving the soft palate and the base of tongue, but diffuse lateral pharyngeal wall edema throughout the upper airway was identified. Eighteen of the MMA patients had ecchymosis and edema involving the pyriform sinus and aryepiglottic fold; 4 of these patients also had a hypopharyngeal hematoma involving the pyriform sinus, aryepiglottic fold, arytenoid, and false vocal cord, which partially obstructed the airway. These 4 patients were closely monitored for 1 to 2 additional days, and all were discharged without problems. None of the patients in the study had postoperative airway obstruction. NPG may be useful in postoperative airway monitoring and assist in discharge planning after upper airway reconstruction in the OSA patients.

  9. Robust Mapping of Incoherent Fiber-Optic Bundles

    NASA Technical Reports Server (NTRS)

    Roberts, Harry E.; Deason, Brent E.; DePlachett, Charles P.; Pilgrim, Robert A.; Sanford, Harold S.

    2007-01-01

    A method and apparatus for mapping between the positions of fibers at opposite ends of incoherent fiber-optic bundles have been invented to enable the use of such bundles to transmit images in visible or infrared light. The method is robust in the sense that it provides useful mapping even for a bundle that contains thousands of narrow, irregularly packed fibers, some of which may be defective. In a coherent fiber-optic bundle, the input and output ends of each fiber lie at identical positions in the input and output planes; therefore, the bundle can be used to transmit images without further modification. Unfortunately, the fabrication of coherent fiber-optic bundles is too labor-intensive and expensive for many applications. An incoherent fiber-optic bundle can be fabricated more easily and at lower cost, but it produces a scrambled image because the position of the end of each fiber in the input plane is generally different from the end of the same fiber in the output plane. However, the image transmitted by an incoherent fiber-optic bundle can be unscrambled (or, from a different perspective, decoded) by digital processing of the output image if the mapping between the input and output fiber-end positions is known. Thus, the present invention enables the use of relatively inexpensive fiber-optic bundles to transmit images.

  10. Bending of an Aspirated Pin During Rigid Bronchoscopy: Safeguards and Pitfalls.

    PubMed

    Elsayed, Abdelrahman A A; Mansour, Albaraa A; Amin, Ahmed A A; Ahmed, Mohsen S M

    2018-04-13

    Pin aspiration is a common problem in Muslim countries, where many women wear veils (hijab). This condition is usually treated using either a rigid or a flexible bronchoscope, and yet occasionally requires surgical approach. Pin bending may be necessary to extract impacted pins during the therapeutic rigid bronchoscopy. Medical records of patients who had pins extracted with a bending technique during the period from January 2012 to December 2016 in 1 institution were analyzed. Information on intraoperative and postoperative complications was collected. Between 2012 and 2016, 315 rigid bronchoscopies were performed for pin extraction; in 38 cases, bending of the pin was required for the extraction because they were in a position that did not allow simple extraction. The procedure was successful in cases and there were no major complications. The extraction of visible, distally located or impacted pins can be safely performed by experienced bronchoscopists using the bending technique. Some safeguards and pitfalls must be noted to ensure maximum safety.

  11. [Granular Cell Tumor of the Lung - a Visual Diagnosis on Bronchoscopy?

    PubMed

    Keymel, S; Büter, S; Krüger, S

    2018-05-22

    A 38 years old patient presented with a progressive reduction of his general condition and weight loss. Chest imaging revealed consolidations and cavities suggesting a mycobacterial infection. For further diagnosis, a bronchoscopy was performed. In fact, a nontuberculous mycobacterial infection was found. As an incidental finding, we saw a white polypoid tumor in the middle lobe bronchus. The histology of this tumor revealed a granular cell tumor (GCT). The GCT is a rare tumor entity which occurs at different anatomical locations. In the lungs, the GCT may become symptomatic as it can cause bronchial obstruction. In chest imaging, it can manifest as infiltration, atelectasis or nodule. Likewise, GCT can be found as an incidental finding in bronchoscopy. First choice treatment is surgical resection of the tumor. © Georg Thieme Verlag KG Stuttgart · New York.

  12. A fiber-optic fluorescence microscope using a consumer-grade digital camera for in vivo cellular imaging.

    PubMed

    Shin, Dongsuk; Pierce, Mark C; Gillenwater, Ann M; Williams, Michelle D; Richards-Kortum, Rebecca R

    2010-06-23

    Early detection is an essential component of cancer management. Unfortunately, visual examination can often be unreliable, and many settings lack the financial capital and infrastructure to operate PET, CT, and MRI systems. Moreover, the infrastructure and expense associated with surgical biopsy and microscopy are a challenge to establishing cancer screening/early detection programs in low-resource settings. Improvements in performance and declining costs have led to the availability of optoelectronic components, which can be used to develop low-cost diagnostic imaging devices for use at the point-of-care. Here, we demonstrate a fiber-optic fluorescence microscope using a consumer-grade camera for in vivo cellular imaging. The fiber-optic fluorescence microscope includes an LED light, an objective lens, a fiber-optic bundle, and a consumer-grade digital camera. The system was used to image an oral cancer cell line labeled with 0.01% proflavine. A human tissue specimen was imaged following surgical resection, enabling dysplastic and cancerous regions to be evaluated. The oral mucosa of a healthy human subject was imaged in vivo, following topical application of 0.01% proflavine. The fiber-optic microscope resolved individual nuclei in all specimens and tissues imaged. This capability allowed qualitative and quantitative differences between normal and precancerous or cancerous tissues to be identified. The optical efficiency of the system permitted imaging of the human oral mucosa in real time. Our results indicate this device as a useful tool to assist in the identification of early neoplastic changes in epithelial tissues. This portable, inexpensive unit may be particularly appropriate for use at the point-of-care in low-resource settings.

  13. Lung lobar collapse as the first manifestation of pulmonary epithelioid haemangioendothelioma diagnosed with fibreoptic bronchoscopy.

    PubMed

    Abdalla, Ahmed; Seedahmed, Elfateh; Bachuwa, Ghassan; Congdon, Douglas

    2016-10-24

    Pulmonary epithelioid haemangioendothelioma (PEH) is a rare tumour of endothelial origin that usually occurs in the lung and liver. It usually presents as bilateral multiple nodular lesions. We report a middle-aged woman with a unique presentation of PEH with lung lobar collapse. The diagnosis was made with fibreoptic bronchoscopy rather than video-assisted thoracoscopy. Clinicians and pathologists should be aware of rare conditions that can present as lung lobar collapse. 2016 BMJ Publishing Group Ltd.

  14. Plasmonic fiber-optic vector magnetometer

    NASA Astrophysics Data System (ADS)

    Zhang, Zhaochuan; Guo, Tuan; Zhang, Xuejun; Xu, Jian; Xie, Wenping; Nie, Ming; Wu, Qiang; Guan, Bai-Ou; Albert, Jacques

    2016-03-01

    A compact fiber-optic vector magnetometer based on directional scattering between polarized plasmon waves and ferro-magnetic nanoparticles is demonstrated. The sensor configuration reported in this work uses a short section of tilted fiber Bragg grating (TFBG) coated with a nanometer scale gold film and packaged with a magnetic fluid (Fe3O4) inside a capillary. The transmission spectrum of the sensor provides a fine comb of narrowband resonances that overlap with a broader absorption of the surface plasmon resonance (SPR). The wavelength of the SPR attenuation in transmission shows high sensitivity to slight perturbations by magnetic fields, due to the strong directional scattering between the SPR attenuated cladding modes and the magnetic fluid near the fiber surface. Both the orientation (2 nm/deg) and the intensity (1.8 nm/mT) of magnetic fields can be determined unambiguously from the TFBG spectrum. Temperature cross sensitivity can be referenced out by monitoring the wavelength of the core mode resonance simultaneously.

  15. Fiber-optically sensorized composite wing

    NASA Astrophysics Data System (ADS)

    Costa, Joannes M.; Black, Richard J.; Moslehi, Behzad; Oblea, Levy; Patel, Rona; Sotoudeh, Vahid; Abouzeida, Essam; Quinones, Vladimir; Gowayed, Yasser; Soobramaney, Paul; Flowers, George

    2014-04-01

    Electromagnetic interference (EMI) immune and light-weight, fiber-optic sensor based Structural Health Monitoring (SHM) will find increasing application in aerospace structures ranging from aircraft wings to jet engine vanes. Intelligent Fiber Optic Systems Corporation (IFOS) has been developing multi-functional fiber Bragg grating (FBG) sensor systems including parallel processing FBG interrogators combined with advanced signal processing for SHM, structural state sensing and load monitoring applications. This paper reports work with Auburn University on embedding and testing FBG sensor arrays in a quarter scale model of a T38 composite wing. The wing was designed and manufactured using fabric reinforced polymer matrix composites. FBG sensors were embedded under the top layer of the composite. Their positions were chosen based on strain maps determined by finite element analysis. Static and dynamic testing confirmed expected response from the FBGs. The demonstrated technology has the potential to be further developed into an autonomous onboard system to perform load monitoring, SHM and Non-Destructive Evaluation (NDE) of composite aerospace structures (wings and rotorcraft blades). This platform technology could also be applied to flight testing of morphing and aero-elastic control surfaces.

  16. Fiber-optic interferometric sensors for measurements of pressure fluctuations: Experimental evaluation

    NASA Technical Reports Server (NTRS)

    Cho, Y. C.; Soderman, P. T.

    1993-01-01

    This paper addresses an anechoic chamber evaluation of a fiber-optic interferometric sensor (fiber-optic microphone), which is being developed at NASA Ames Research Center for measurements of pressure fluctuations in wind tunnels.

  17. Web-based versus traditional lecture: are they equally effective as a flexible bronchoscopy teaching method?

    PubMed

    Mata, Caio Augusto Sterse; Ota, Luiz Hirotoshi; Suzuki, Iunis; Telles, Adriana; Miotto, Andre; Leão, Luiz Eduardo Vilaça

    2012-01-01

    This study compares the traditional live lecture to a web-based approach in the teaching of bronchoscopy and evaluates the positive and negative aspects of both methods. We developed a web-based bronchoscopy curriculum, which integrates texts, images and animations. It was applied to first-year interns, who were later administered a multiple-choice test. Another group of eight first-year interns received the traditional teaching method and the same test. The two groups were compared using the Student's t-test. The mean scores (± SD) of students who used the website were 14.63 ± 1.41 (range 13-17). The test scores of the other group had the same range, with a mean score of 14.75 ± 1. The Student's t-test showed no difference between the test results. The common positive point noted was the presence of multimedia content. The web group cited as positive the ability to review the pages, and the other one the role of the teacher. Web-based bronchoscopy education showed results similar to the traditional live lecture in effectiveness.

  18. Dual-Fiberoptic Microcantilever Proximity Sensor

    SciT

    Goedeke, S.M.

    2001-08-08

    Microcantilevers are key components of many Micro-Electro-Mechanical Systems (MEMS) and Micro-Optical-Electro-Mechanical Systems (MOEMS) because slight changes to them physically or chemically lead to changes in mechanical characteristics. An inexpensive dual-fiberoptic microcantilever proximity sensor and model to predict its performance are reported here. Motion of a magnetic-material-coated cantilever is the basis of a system under development for measuring magnetic fields. The dual fiber proximity sensor will be used to monitor the motion of the cantilever. The specific goal is to sense induction fields produced by a current carrying conductor. The proximity sensor consists of two fibers side by side with claddingsmore » in contact. The fiber core diameter, 50 microns, and cladding thickness, 10 microns, are as small as routinely available commercially with the exception of single mode fiber. Light is launched into one fiber from a light-emitting diode (LED). It emerges from that fiber and reflects from the cantilever into the adjacent receiving fiber connected to a detector. The sensing end is cast molded with a diameter of 3-mm over the last 20-mm, yielding a low profile sensor. This reflective triangulation approach is probably the oldest and simplest fiber proximity sensing approach, yet the novelty here is in demonstrating high sensitivity at low expense from a triangular microstructure with amorphous magnetic coatings of iron, cobalt, permalloy, etc. The signal intensity versus distance curve yields an approximate gaussian shape. For a typical configuration, the signal grows from 10% to 90% of maximum in traversing from 6 to 50 microns from a coated cantilever. With signal levels exceeding a volt, nanometer resolution should be readily achievable for periodic signals.« less

  19. Post-bronchoscopy pneumonia in patients suffering from lung cancer: Development and validation of a risk prediction score.

    PubMed

    Takiguchi, Hiroto; Hayama, Naoki; Oguma, Tsuyoshi; Harada, Kazuki; Sato, Masako; Horio, Yukihiro; Tanaka, Jun; Tomomatsu, Hiromi; Tomomatsu, Katsuyoshi; Takihara, Takahisa; Niimi, Kyoko; Nakagawa, Tomoki; Masuda, Ryota; Aoki, Takuya; Urano, Tetsuya; Iwazaki, Masayuki; Asano, Koichiro

    2017-05-01

    The incidence, risk factors, and consequences of pneumonia after flexible bronchoscopy in patients with lung cancer have not been studied in detail. We retrospectively analyzed the data from 237 patients with lung cancer who underwent diagnostic bronchoscopy between April 2012 and July 2013 (derivation sample) and 241 patients diagnosed between August 2013 and July 2014 (validation sample) in a tertiary referral hospital in Japan. A score predictive of post-bronchoscopy pneumonia was developed in the derivation sample and tested in the validation sample. Pneumonia developed after bronchoscopy in 6.3% and 4.1% of patients in the derivation and validation samples, respectively. Patients who developed post-bronchoscopy pneumonia needed to change or cancel their planned cancer therapy more frequently than those without pneumonia (56% vs. 6%, p<0.001). Age ≥70 years, current smoking, and central location of the tumor were independent predictors of pneumonia, which we added to develop our predictive score. The incidence of pneumonia associated with scores=0, 1, and ≥2 was 0, 3.7, and 13.4% respectively in the derivation sample (p=0.003), and 0, 2.9, and 9.7% respectively in the validation sample (p=0.016). The incidence of post-bronchoscopy pneumonia in patients with lung cancer was not rare and associated with adverse effects on the clinical course. A simple 3-point predictive score identified patients with lung cancer at high risk of post-bronchoscopy pneumonia prior to the procedure. Copyright © 2017 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.

  20. Association Between Hospital Case Volume and the Use of Bronchoscopy and Esophagoscopy During Head and Neck Cancer Diagnostic Evaluation

    PubMed Central

    Sun, Gordon H.; Aliu, Oluseyi; Moloci, Nicholas M.; Mondschein, Joshua K.; Burke, James F.; Hayward, Rodney A.

    2013-01-01

    Background There are no clinical guidelines on best practices for the use of bronchoscopy and esophagoscopy in diagnosing head and neck cancer. This retrospective cohort study examined variation in the use of bronchoscopy and esophagoscopy across hospitals in Michigan. Patients and Methods We identified 17,828 head and neck cancer patients in the 2006–2010 Michigan State Ambulatory Surgery Databases. We used hierarchical, mixed-effect logistic regression to examine whether a hospital’s risk-adjusted rate of concurrent bronchoscopy or esophagoscopy was associated with its case volume (<100, 100–999, or ≥1000 cases/hospital) for those undergoing diagnostic laryngoscopy. Results Of 9,218 patients undergoing diagnostic laryngoscopy, 1,191 (12.9%) received concurrent bronchoscopy and 1,675 (18.2%) underwent concurrent esophagoscopy. The median hospital rate of bronchoscopy was 2.7% (range 0–61.1%), and low-volume (OR 27.1 [95% CI 1.9, 390.7]) and medium-volume (OR 28.1 [95% CI 2.0, 399.0]) hospitals were more likely to perform concurrent bronchoscopy compared to high-volume hospitals. The median hospital rate of esophagoscopy was 5.1% (range 0–47.1%), and low-volume (OR 9.8 [95% CI 1.5, 63.7]) and medium-volume (OR 8.5 [95% CI 1.3, 55.0]) hospitals were significantly more likely to perform concurrent esophagoscopy relative to high-volume hospitals. Conclusions Head and neck cancer patients undergoing diagnostic laryngoscopy are much more likely to undergo concurrent bronchoscopy and esophagoscopy at low- and medium-volume hospitals than at high-volume hospitals. Whether this represents over-use of concurrent procedures or appropriate care that leads to earlier diagnosis and better outcomes merits further investigation. PMID:24114146

  1. Contact diode laser: high power application through fiberoptic cutting tips.

    PubMed

    Wafapoor, H; Peyman, G A; Moritera, T

    1994-01-01

    Diode laser energy has been applied through a fiberoptic probe using a power setting of 2.5 watts (W) in the continuous mode. In this study we employed high-power diode laser energy (4 to 12 W, continuous wave) to incise ocular tissue through a fiberoptic probe using 100 microns and 300 microns tips. The retina was photocoagulated with a 300 microns orb tip. No bleeding occurred at the incision sites. Histologic evaluation revealed coagulation into the healthy tissue ranging from 10 to 50 microns.

  2. Fiber-Optic Terahertz Data-Communication Networks

    NASA Technical Reports Server (NTRS)

    Chua, Peter L.; Lambert, James L.; Morookian, John M.; Bergman, Larry A.

    1994-01-01

    Network protocols implemented in optical domain. Fiber-optic data-communication networks utilize fully available bandwidth of single-mode optical fibers. Two key features of method: use of subpicosecond laser pulses as carrier signals and spectral phase modulation of pulses for optical implementation of code-division multiple access as multiplexing network protocol. Local-area network designed according to concept offers full crossbar functionality, security of data in transit through network, and capacity about 100 times that of typical fiber-optic local-area network in current use.

  3. The efficacy of dexmedetomidine-remifentanil versus dexmedetomidine-propofol in children undergoing flexible bronchoscopy

    PubMed Central

    Zhang, Hongquan; Fang, Baojun; Zhou, Wenjing

    2017-01-01

    Abstract Flexible bronchoscopy has been more and more used for diagnosis and management diseases of respiratory system in pediatrics. Previous studies have reported that remifentanil (RF) and propofol are safe and effective for flexible bronchoscopy in adults, however, there have no trials evaluate the efficacy of DEX-RF versus dexmedetomidine-propofol in children undergoing flexible bronchoscopy. We divided 123 children undergoing flexible bronchoscopy with DEX-RF or dexmedetomidine-propofol into 2 groups: Group DR (n = 63, DEX infusion at 1.0 μg kg−1 for 10 minutes, then adjusted to 0.5–0.7 μg kg−1 h−1; RF infusion at 1.0 μg kg−1 for 5 minutes, then adjusted to 0.05–0.2 μg kg−1 min−1), Group DP (n = 60, DEX infusion at 1.0 μg kg−1 for 10 minutes, then adjusted to 0.5–0.7 μg kg−1 h−1; propofol infusion at 10 μg kg−1 for 5 minutes, then adjusted to 0.05–0.1 μg kg−1 min−1). Ramsay sedation scale of the 2 groups was maintained at 3. Anesthesia onset time; total number of intraoperative patient movements; hemodynamics; total cumulative dose of DEX; amount of and time to first-dose rescue midazolam and lidocaine; postoperative recovery time; adverse events; and bronchoscopist satisfaction score were recorded. Anesthesia onset time was significantly shorter in DP (8.22 ± 2.48 vs 12.25 ± 6.43 minutes, respectively, for DP, DR, P = 0.015). The perioperative hemodynamic profile was more stable in DR than DP group. More children moved during flexible bronchoscopy in DP group (P = 0.009). Total dose of rescue midazolam and lidocaine was significantly higher in DR than in DP (P < 0.001). Similarly, the time to first dose of rescue midazolam and lidocaine was significantly longer in DP than in DR (P < 0.001). Total cumulative dose of DEX was more in DR than DP group (P < 0.001). The time to recovery for discharge from the postanesthesia care unit

  4. Fiber-optic temperature probe system for inner body

    NASA Astrophysics Data System (ADS)

    Liu, Bo; Deng, Xing-Zhong; Cao, Wei; Cheng, Xianping; Xie, Tuqiang; Zhong, Zugen

    1991-08-01

    The authors have designed a fiber-optic temperature probe system that can quickly insert its probe into bodies to measure temperature. Its thermometer unit has the function of program- controlled zeroing. The single-chip microcomputer is used to control the whole system and process data. The sample system has been tested in a coal furnace.

  5. Silicon-Etalon Fiber-Optic Temperature Sensor

    NASA Technical Reports Server (NTRS)

    Beheim, Glenn; Fritsch, Klaus; Flatico, Joseph M.; Azar, Massood Tabib

    1993-01-01

    Developmental temperature sensor consists of silicon Fabry-Perot etalon attached to end of optical fiber. Features immunity to electrical interference, small size, light weight, safety, and chemical inertness. Output encoded in ration of intensities at two different wavelengths, rather than in overall intensity, with result that temperature readings not degraded much by changes in transmittance of fiber-optic link.

  6. Fiber-Optical Sensors: Basics and Applications in Multiphase Reactors

    PubMed Central

    Li, Xiangyang; Yang, Chao; Yang, Shifang; Li, Guozheng

    2012-01-01

    This work presents a brief introduction on the basics of fiber-optical sensors and an overview focused on the applications to measurements in multiphase reactors. The most commonly principle utilized is laser back scattering, which is also the foundation for almost all current probes used in multiphase reactors. The fiber-optical probe techniques in two-phase reactors are more developed than those in three-phase reactors. There are many studies on the measurement of gas holdup using fiber-optical probes in three-phase fluidized beds, but negative interference of particles on probe function was less studied. The interactions between solids and probe tips were less studied because glass beads etc. were always used as the solid phase. The vision probes may be the most promising for simultaneous measurements of gas dispersion and solids suspension in three-phase reactors. Thus, the following techniques of the fiber-optical probes in multiphase reactors should be developed further: (1) online measuring techniques under nearly industrial operating conditions; (2) corresponding signal data processing techniques; (3) joint application with other measuring techniques.

  7. Distributed Fiber-Optic Sensors for Vibration Detection

    PubMed Central

    Liu, Xin; Jin, Baoquan; Bai, Qing; Wang, Yu; Wang, Dong; Wang, Yuncai

    2016-01-01

    Distributed fiber-optic vibration sensors receive extensive investigation and play a significant role in the sensor panorama. Optical parameters such as light intensity, phase, polarization state, or light frequency will change when external vibration is applied on the sensing fiber. In this paper, various technologies of distributed fiber-optic vibration sensing are reviewed, from interferometric sensing technology, such as Sagnac, Mach–Zehnder, and Michelson, to backscattering-based sensing technology, such as phase-sensitive optical time domain reflectometer, polarization-optical time domain reflectometer, optical frequency domain reflectometer, as well as some combinations of interferometric and backscattering-based techniques. Their operation principles are presented and recent research efforts are also included. Finally, the applications of distributed fiber-optic vibration sensors are summarized, which mainly include structural health monitoring and perimeter security, etc. Overall, distributed fiber-optic vibration sensors possess the advantages of large-scale monitoring, good concealment, excellent flexibility, and immunity to electromagnetic interference, and thus show considerable potential for a variety of practical applications. PMID:27472334

  8. Distributed Fiber-Optic Sensors for Vibration Detection.

    PubMed

    Liu, Xin; Jin, Baoquan; Bai, Qing; Wang, Yu; Wang, Dong; Wang, Yuncai

    2016-07-26

    Distributed fiber-optic vibration sensors receive extensive investigation and play a significant role in the sensor panorama. Optical parameters such as light intensity, phase, polarization state, or light frequency will change when external vibration is applied on the sensing fiber. In this paper, various technologies of distributed fiber-optic vibration sensing are reviewed, from interferometric sensing technology, such as Sagnac, Mach-Zehnder, and Michelson, to backscattering-based sensing technology, such as phase-sensitive optical time domain reflectometer, polarization-optical time domain reflectometer, optical frequency domain reflectometer, as well as some combinations of interferometric and backscattering-based techniques. Their operation principles are presented and recent research efforts are also included. Finally, the applications of distributed fiber-optic vibration sensors are summarized, which mainly include structural health monitoring and perimeter security, etc. Overall, distributed fiber-optic vibration sensors possess the advantages of large-scale monitoring, good concealment, excellent flexibility, and immunity to electromagnetic interference, and thus show considerable potential for a variety of practical applications.

  9. Contact diode laser application through a fiberoptic cutting tip.

    PubMed

    Peyman, G A; Cruz, S A; Ruiz-Lapuente, C

    1991-01-01

    We applied diode laser energy through a fiberoptic probe to cut ocular structures. The diameter of the probe's tip was 100 microns. The amount of energy used for cutting the lid, the cornea, or for perforation of the glove was 2.5 watts in the continuous mode. The incised border demonstrated coagulation into the healthy tissue ranging from 10 to 50 microns.

  10. Kansas Communication and Instruction System through Fiber-Optic Transmission.

    ERIC Educational Resources Information Center

    Kansas State Dept. of Education, Topeka.

    Schools and communities will restructure as they move into the next decade. The success of this restructuring will be dependent upon access to and sharing of quality teaching and information through an expanded communication system. One of the major two-way interactive technologies is the fiber-optic cable: a delivery system that will provide…

  11. A Method of Assembling Compact Coherent Fiber-Optic Bundles

    NASA Technical Reports Server (NTRS)

    Martin, Stefan; Liu, Duncan; Levine, Bruce Martin; Shao, Michael; Wallace, James

    2007-01-01

    A method of assembling coherent fiber-optic bundles in which all the fibers are packed together as closely as possible is undergoing development. The method is based, straightforwardly, on the established concept of hexagonal close packing; hence, the development efforts are focused on fixtures and techniques for practical implementation of hexagonal close packing of parallel optical fibers.

  12. Interventional bronchoscopy in malignant central airway obstruction by extra-pulmonary malignancy.

    PubMed

    Shin, Beomsu; Chang, Boksoon; Kim, Hojoong; Jeong, Byeong-Ho

    2018-03-13

    Interventional bronchoscopy is considered an effective treatment option for malignant central airway obstruction (MCAO). However, there are few reports of interventional bronchoscopy in patients with MCAOs due to extra-pulmonary malignancy. Therefore, the objective of this study was to investigate treatment outcomes and prognostic factors for bronchoscopic intervention in patients with MCAO due to extra-pulmonary malignancy. We retrospectively analyzed consecutive 98 patients with MCAO due to extra-pulmonary malignancy who underwent interventional bronchoscopy between 2004 and 2014 at Samsung Medical Center (Seoul, Korea). The most common primary site of malignancy was esophageal cancer (37.9%), followed by thyroid cancer (16.3%) and head & neck cancer (10.2%). Bronchoscopic interventions were usually performed using a combination of mechanical debulking (84.7%), stent insertion (70.4%), and laser cauterization (37.8%). Of 98 patients, 76 (77.6%) patients had MCAO due to progression of malignancy, and 42 (42.9%) patients had exhausted all other anti-cancer treatment at the time of bronchoscopic intervention. Technical success was achieved in 89.9% of patients, and acute complications and procedure-related deaths occurred in 20.4% and 3.1% of patients, respectively. Reduced survival was associated with MCAO due to cancer other than thyroid cancer or lymphoma, mixed lesions, and not receiving adjuvant treatment after bronchoscopic intervention. Bronchoscopic intervention could be a safe and effective procedure for MCAO due to end-stage extra-pulmonary malignancies. In addition, we identified possible prognostic factors for poor survival after intervention, which could guide clinicians select candidates that will benefit from bronchoscopic intervention.

  13. Three-dimensional virtual bronchoscopy using a tablet computer to guide real-time transbronchial needle aspiration.

    PubMed

    Fiorelli, Alfonso; Raucci, Antonio; Cascone, Roberto; Reginelli, Alfonso; Di Natale, Davide; Santoriello, Carlo; Capuozzo, Antonio; Grassi, Roberto; Serra, Nicola; Polverino, Mario; Santini, Mario

    2017-04-01

    We proposed a new virtual bronchoscopy tool to improve the accuracy of traditional transbronchial needle aspiration for mediastinal staging. Chest-computed tomographic images (1 mm thickness) were reconstructed with Osirix software to produce a virtual bronchoscopic simulation. The target adenopathy was identified by measuring its distance from the carina on multiplanar reconstruction images. The static images were uploaded in iMovie Software, which produced a virtual bronchoscopic movie from the images; the movie was then transferred to a tablet computer to provide real-time guidance during a biopsy. To test the validity of our tool, we divided all consecutive patients undergoing transbronchial needle aspiration retrospectively in two groups based on whether the biopsy was guided by virtual bronchoscopy (virtual bronchoscopy group) or not (traditional group). The intergroup diagnostic yields were statistically compared. Our analysis included 53 patients in the traditional and 53 in the virtual bronchoscopy group. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy for the traditional group were 66.6%, 100%, 100%, 10.53% and 67.92%, respectively, and for the virtual bronchoscopy group were 84.31%, 100%, 100%, 20% and 84.91%, respectively. The sensitivity ( P  = 0.011) and diagnostic accuracy ( P  = 0.011) of sampling the paratracheal station were better for the virtual bronchoscopy group than for the traditional group; no significant differences were found for the subcarinal lymph node. Our tool is simple, economic and available in all centres. It guided in real time the needle insertion, thereby improving the accuracy of traditional transbronchial needle aspiration, especially when target lesions are located in a difficult site like the paratracheal station. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  14. Evaluation of Ignition and Burn Risk Associated with Contemporary Fiberoptic and Distal Sensor Endoscopic Technology.

    PubMed

    Spradling, Kyle; Uribe, Brittany; Okhunov, Zhamshid; Hofmann, Martin; Del Junco, Michael; Hwang, Christina; Gruber, Caden; Youssef, Ramy F; Landman, Jaime

    2015-09-01

    To evaluate the ignition and burn risk associated with contemporary fiberoptic and distal sensor endoscopic technologies. We used new and used SCB Xenon 300 light sources to illuminate a 4.8 mm fiberoptic cable, 10 mm laparoscope, 5 mm laparoscope, rigid cystoscope, semirigid ureteroscope, flexible cystoscope, flexible fiberoptic ureteroscope, distal sensor cystoscope, and a distal sensor ureteroscope (Karl Storz, Inc., Tuttlingen, Germany). We measured peak temperatures at the distal end of each device. We then evaluated each device on a flat and folded surgical drape to establish ignition risk. Finally, we evaluated the effects of all devices on human cadaver skin covered by surgical drape. Peak temperatures recorded for each device ranged from 26.9°C (flexible fiberoptic ureteroscope) to 194.5°C (fiberoptic cable). Drape ignition was noted when the fiberoptic cable was placed against a fold of drape. Contact with the fiberoptic cable, 10 mm laparoscope, 5 mm laparoscope, and distal sensor cystoscope resulted in cadaver skin damage. Cadaver skin damage occurred despite little or no visible change to the surgical drape. Rigid and flexible fiberoptic cystoscopes and flexible fiberoptic ureteroscopes had no effect on surgical drapes or cadaver skin. Fiberoptic light cables and some endoscopic devices have the potential to cause thermal injury and drape ignition. Thermal injury may occur without visible damage to drapes. Surgeons should remain vigilant regarding the risks associated with these devices and take necessary safety precautions to prevent patient injury.

  15. An update on the role of advanced diagnostic bronchoscopy in the evaluation and staging of lung cancer

    PubMed Central

    Belanger, Adam R.; Akulian, Jason A.

    2017-01-01

    Lung cancer remains a common and deadly disease. Many modalities are available to the bronchoscopist to evaluate and stage lung cancer. We review the role of bronchoscopy in the staging of the mediastinum with convex endobronchial ultrasound (EBUS) and discuss emerging role of esophageal ultrasonography as a complementary modality. In addition, we discuss advances in scope technology and elastography. We review the bronchoscopic methods available for the diagnosis of peripheral lung nodules including radial EBUS and navigational bronchoscopy (NB) with a consideration of the basic methodologies and diagnostic accuracies. We conclude with a discussion of the comparison of the various methodologies. PMID:28470104

  16. Demographic and Clinical Findings in Children Undergoing Bronchoscopy for Foreign Body Aspiration.

    PubMed

    Safari, Mojgan; Manesh, Mohammad Reza Hashemi

    2016-01-01

    Foreign body aspiration (FBA) is a significant cause of airway distress, mortality, and morbidity in children. Diagnosis of FBA can be challenging and is sometimes delayed for weeks or even months. If not diagnosed and treated promptly, FBA can result in serious consequences. For this retrospective study, we investigated the medical records of 89 children who underwent bronchoscopy for suspected FBA and recorded relevant demographic, clinical, and treatment data. Of the 89 patients identified for this study, 51 had a definitive diagnosis of FBA. Among these patients, choking, chronic cough and wheezing, cyanosis, and dyspnea were the most frequent symptoms of FBA. The foreign bodies were located in the left bronchus (45.1%), the right bronchus (35.3%), the trachea (15.7%), and in both the right and left bronchi (3.9%). Seeds were the most prevalent foreign body, found in 39.2% of the patients. Lack of complete medical history in patients with suspected FBA is one of the main causes of delayed FBA diagnosis. Bronchoscopy is considered the definitive diagnostic method for FBA and should be conducted in all patients with suspected FBA because of the low risk of complications and reduced probability that FBA diagnosis and treatment will be delayed.

  17. Demographic and Clinical Findings in Children Undergoing Bronchoscopy for Foreign Body Aspiration

    PubMed Central

    Safari, Mojgan; Manesh, Mohammad Reza Hashemi

    2016-01-01

    Background: Foreign body aspiration (FBA) is a significant cause of airway distress, mortality, and morbidity in children. Diagnosis of FBA can be challenging and is sometimes delayed for weeks or even months. If not diagnosed and treated promptly, FBA can result in serious consequences. Methods: For this retrospective study, we investigated the medical records of 89 children who underwent bronchoscopy for suspected FBA and recorded relevant demographic, clinical, and treatment data. Results: Of the 89 patients identified for this study, 51 had a definitive diagnosis of FBA. Among these patients, choking, chronic cough and wheezing, cyanosis, and dyspnea were the most frequent symptoms of FBA. The foreign bodies were located in the left bronchus (45.1%), the right bronchus (35.3%), the trachea (15.7%), and in both the right and left bronchi (3.9%). Seeds were the most prevalent foreign body, found in 39.2% of the patients. Conclusion: Lack of complete medical history in patients with suspected FBA is one of the main causes of delayed FBA diagnosis. Bronchoscopy is considered the definitive diagnostic method for FBA and should be conducted in all patients with suspected FBA because of the low risk of complications and reduced probability that FBA diagnosis and treatment will be delayed. PMID:27303219

  18. Cost minimization analysis for combinations of sampling techniques in bronchoscopy of endobronchial lesions.

    PubMed

    Roth, Kjetil; Hardie, Jon Andrew; Andreassen, Alf Henrik; Leh, Friedemann; Eagan, Tomas Mikal Lind

    2009-06-01

    The choice of sampling techniques in bronchoscopy with sampling from a visible lesion will depend on the expected diagnostic yields and the costs of the sampling techniques. The aim of this study was to determine the most economical combination of sampling techniques when approaching endobronchial visible lesions. A cost minimization analysis was performed. All bronchoscopies from 2003 and 2004 at Haukeland university hospital, Bergen, Norway, were reviewed retrospectively for diagnostic yields. 162 patients with endobronchial disease were included. Potential sampling techniques used were biopsy, brushing, endobronchial needle aspiration (EBNA) and washings. Costs were estimated based on registration of equipment costs and personnel costs. Sensitivity analyses were performed to determine threshold values. The combination of biopsy, brushing and EBNA was the most economical strategy with an average cost of Euro 893 (95% CI: 657, 1336). The cost of brushing had to be below Euro 83 and it had to increase the diagnostic yield more than 2.2%, for biopsy and brushing to be more economical than biopsy alone. The combination of biopsy, brushing and EBNA was more economical than biopsy and brushing when the cost of EBNA was below Euro 205 and the increase in diagnostic yield was above 5.2%. In the current study setting, biopsy, brushing and EBNA was the most economical combination of sampling techniques for endobronchial visible lesions.

  19. Cytological analysis of bronchoalveolar lavage fluid acquired by bronchoscopy in healthy ferrets: A pilot study

    PubMed Central

    Bercier, Marjorie; Langlois, Isabelle; Dunn, Marilyn; Hélie, Pierre; Burns, Patrick; Gara-Boivin, Carolyn

    2016-01-01

    The objective of this study was to investigate the normal cytological evaluation of bronchoalveolar lavage (BAL) fluid in healthy adult ferrets (N = 12). These ferrets underwent bronchoscopy and BAL using sterile saline [1.5 mL/kg body weight (BW)]. Percentage of fluid recovered, total leukocyte count, differential leukocyte count, and cell count of the epithelial lining fluid (ELF) were determined. The mean percentage of lavage volume recovered from the right lung and left lung were 67.8 ± 14.9% and 69.7 ± 20.0%, respectively. Gender (P = 0.12) and weight (P = 0.17) did not significantly affect the mean percentage of recovered volume. The mean percentage of recovered volume (P = 0.47) and the mean leukocyte count (P = 0.17) from the right and left lung were not significantly different. Macrophages were the main leukocyte component of the lavages, followed by neutrophils, lymphocytes, and eosinophils. The mean proportion of ELF in BAL fluid was 9.3 ± 3.7% v/v. Bronchoscopy is clinically useful for collecting good quality BAL samples for cytological analysis in ferrets. The leucocyte differential was established, which may help veterinarians to make better clinical decisions when treating respiratory disease. Further studies are required with a larger group in order to establish the healthy reference intervals for BAL values in ferrets. PMID:26733735

  20. Cytological analysis of bronchoalveolar lavage fluid acquired by bronchoscopy in healthy ferrets: A pilot study.

    PubMed

    Bercier, Marjorie; Langlois, Isabelle; Dunn, Marilyn; Hélie, Pierre; Burns, Patrick; Gara-Boivin, Carolyn

    2016-01-01

    The objective of this study was to investigate the normal cytological evaluation of bronchoalveolar lavage (BAL) fluid in healthy adult ferrets (N = 12). These ferrets underwent bronchoscopy and BAL using sterile saline [1.5 mL/kg body weight (BW)]. Percentage of fluid recovered, total leukocyte count, differential leukocyte count, and cell count of the epithelial lining fluid (ELF) were determined. The mean percentage of lavage volume recovered from the right lung and left lung were 67.8 ± 14.9% and 69.7 ± 20.0%, respectively. Gender (P = 0.12) and weight (P = 0.17) did not significantly affect the mean percentage of recovered volume. The mean percentage of recovered volume (P = 0.47) and the mean leukocyte count (P = 0.17) from the right and left lung were not significantly different. Macrophages were the main leukocyte component of the lavages, followed by neutrophils, lymphocytes, and eosinophils. The mean proportion of ELF in BAL fluid was 9.3 ± 3.7% v/v. Bronchoscopy is clinically useful for collecting good quality BAL samples for cytological analysis in ferrets. The leucocyte differential was established, which may help veterinarians to make better clinical decisions when treating respiratory disease. Further studies are required with a larger group in order to establish the healthy reference intervals for BAL values in ferrets.

  1. Patient-specific bronchoscopy visualization through BRDF estimation and disocclusion correction.

    PubMed

    Chung, Adrian J; Deligianni, Fani; Shah, Pallav; Wells, Athol; Yang, Guang-Zhong

    2006-04-01

    This paper presents an image-based method for virtual bronchoscope with photo-realistic rendering. The technique is based on recovering bidirectional reflectance distribution function (BRDF) parameters in an environment where the choice of viewing positions, directions, and illumination conditions are restricted. Video images of bronchoscopy examinations are combined with patient-specific three-dimensional (3-D) computed tomography data through two-dimensional (2-D)/3-D registration and shading model parameters are then recovered by exploiting the restricted lighting configurations imposed by the bronchoscope. With the proposed technique, the recovered BRDF is used to predict the expected shading intensity, allowing a texture map independent of lighting conditions to be extracted from each video frame. To correct for disocclusion artefacts, statistical texture synthesis was used to recreate the missing areas. New views not present in the original bronchoscopy video are rendered by evaluating the BRDF with different viewing and illumination parameters. This allows free navigation of the acquired 3-D model with enhanced photo-realism. To assess the practical value of the proposed technique, a detailed visual scoring that involves both real and rendered bronchoscope images is conducted.

  2. Fiber-Optic Array Scanning Technology (FAST) for Detection and Molecular Characterization of Circulating Tumor Cells.

    PubMed

    Ao, Zheng; Liu, Xiaohe

    2017-01-01

    Circulating tumor cell (CTC) as an important component in "liquid biopsy" holds crucial clinical relevance in cancer prognosis, treatment efficiency evaluation, prediction and potentially early detection. Here, we present a Fiber-optic Array Scanning Technology (FAST) that enables antigen-agnostic, size-agnostic detection of CTC. By immunofluorescence staining detection of a combination of a panel of markers, FAST technology can be applied to detect rare CTC in non-small cell lung cancer (NSCLC) setting with high sensitivity and specificity. In combination with Automated Digital Microscopy (ADM) platform, companion markers on CTC such as Vimentin and Programmed death-ligand 1 (PD-L1) can also be analyzed to further characterize these CTCs. FAST data output is also compatible with downstream single cell picking platforms. Single cell can be isolated post ADM confirmation and used for "actionable" genetic mutations analysis.

  3. Fiber-optic evanescent-field sensor for attitude measurement

    NASA Astrophysics Data System (ADS)

    Liu, Yun; Chen, Shimeng; Liu, Zigeng; Guang, Jianye; Peng, Wei

    2017-11-01

    We proposed a new approach to attitude measurement by an evanescent field-based optical fiber sensing device and demonstrated a liquid pendulum. The device consisted of three fiber-optic evanescent-filed sensors which were fabricated by tapered single mode fibers and immersed in liquid. Three fiber Bragg gratings were used to measure the changes in evanescent field. And their reflection peaks were monitored in real time as measurement signals. Because every set of reflection responses corresponded to a unique attitude, the attitude of the device could be measured by the three fiber-optic evanescent-filed sensors. After theoretical analysis, computerized simulation and experimental verification, regular responses were obtained using this device for attitude measurement. The measurement ranges of dihedral angle and direction angle were 0°-50° and 0°-360°. The device is based on cost-effective power-referenced scheme. It can be used in electromagnetic or nuclear radiation environment.

  4. Scanning properties of a resonant fiber-optic piezoelectric scanner

    NASA Astrophysics Data System (ADS)

    Li, Zhi; Yang, Zhe; Fu, Ling

    2011-12-01

    We develop a resonant fiber-optic scanner using four piezoelectric elements arranged as a square tube, which is efficient to manufacture and drive. Using coupled-field model based on finite element method, scanning properties of the scanner, including vibration mode, resonant frequency, and scanning range, are numerically studied. We also physically measure the effects of geometry sizes and drive signals on the scanning properties, thus providing a foundation for general purpose designs. A scanner adopted in a prototype of imaging system, with a diameter of ˜2 mm and driven by a voltage of 10 V (peak to peak), demonstrates the scanning performance by obtaining an image of resolution target bars. The proposed fiber-optic scanner can be applied to micro-endoscopy that requires two-dimensional scanning of fibers.

  5. Polarization anisotropy in fiber-optic second harmonic generation microscopy.

    PubMed

    Fu, Ling; Gu, Min

    2008-03-31

    We report the investigation and implementation of a compact second harmonic generation microscope that uses a single-mode fiber coupler and a double-clad photonic crystal fiber. Second harmonic polarization anisotropy through the fiber-optic microscope systems is quantitatively measured with KTP microcrystals, fish scale and rat tail tendon. It is demonstrated that the polarized second harmonic signals can be excited and collected through the single-mode fiber coupler to analyze the molecular orientations of structural proteins. It has been discovered that a double-clad photonic crystal fiber can preserve the linear polarization in the core, although a depolarization effect is observed in the inner cladding region. The feasibility of polarization anisotropy measurements in fiber-optic second harmonic generation microscopy will benefit the in vivo study of collagen-related diseases with a compact imaging probe.

  6. The safety and efficacy of dexmedetomidine-remifentanil in children undergoing flexible bronchoscopy

    PubMed Central

    Li, Xia; Wang, Xue; Jin, Shuguang; Zhang, Dongsheng; Li, Yanuo

    2017-01-01

    Abstract Flexible bronchoscopy is more and more used for diagnosis and management of various pulmonary diseases in pediatrics. As poor coordination of children, the procedure is usually performed under general anesthesia with spontaneous or controlled ventilation to increase children and bronchoscopists’ safety and comfort. Previous studies have reported that dexmedetomidine (DEX) could be safely and effectively used for flexible bronchoscopy in both adulate and children. However, there is no trial to evaluate the dose-finding of safety and efficacy of dexmedetomidine-remifentanil (DEX-RF) in children undergoing flexible bronchoscopy. The objective of this study is to evaluate the dose-finding of safety and efficacy of DEX-RF in children undergoing flexible bronchoscopy. One hundred thirty-five children undergoing flexible bronchoscopy with DEX-RF were divided into 3 groups: Group DR1 (n = 47, DEX infusion at 0.5 μg·kg–1 for 10 minutes, then adjusted to 0.5–0.7 μg kg–1 h–1; RF infusion at 0.5 μg kg–1 for 2 minutes, then adjusted to 0.05–0.2 μg kg–1 min–1), Group DR2 (n = 43, DEX infusion at 1 μg kg–1 for 10 minutes, then adjusted to 0.5–0.7 μg kg–1 h–1; RF infusion at 1 μg kg–1 for 2 minutes, then adjusted to 0.05–0.2 μg kg–1 min–1), Group DR3 (n = 45, DEX infusion at 1.5 μg kg–1 for 10 minutes, then adjusted to 0.5–0.7 μg kg–1 h–1; RF infusion at 1 μg kg–1 for 2 minutes, then adjusted to 0.05–0.2 μg kg–1 min–1). Ramsay sedation scale of the 3 groups was maintained 3. Anesthesia onset time, total number of intraoperative children movements, hemodynamics (heart rate, arterial pressure, pulse oxygen saturation (SpO2), respiratory rate), total cumulative dose of dexmedetomidine and remifentanil, the amount of midazolam and lidocaine, time to first dose of rescue midazolam and lidocaine, postoperative recovery time, adverse events, bronchoscopist satisfaction

  7. Raman fiber-optical method for colon cancer detection: Cross-validation and outlier identification approach

    NASA Astrophysics Data System (ADS)

    Petersen, D.; Naveed, P.; Ragheb, A.; Niedieker, D.; El-Mashtoly, S. F.; Brechmann, T.; Kötting, C.; Schmiegel, W. H.; Freier, E.; Pox, C.; Gerwert, K.

    2017-06-01

    Endoscopy plays a major role in early recognition of cancer which is not externally accessible and therewith in increasing the survival rate. Raman spectroscopic fiber-optical approaches can help to decrease the impact on the patient, increase objectivity in tissue characterization, reduce expenses and provide a significant time advantage in endoscopy. In gastroenterology an early recognition of malign and precursor lesions is relevant. Instantaneous and precise differentiation between adenomas as precursor lesions for cancer and hyperplastic polyps on the one hand and between high and low-risk alterations on the other hand is important. Raman fiber-optical measurements of colon biopsy samples taken during colonoscopy were carried out during a clinical study, and samples of adenocarcinoma (22), tubular adenomas (141), hyperplastic polyps (79) and normal tissue (101) from 151 patients were analyzed. This allows us to focus on the bioinformatic analysis and to set stage for Raman endoscopic measurements. Since spectral differences between normal and cancerous biopsy samples are small, special care has to be taken in data analysis. Using a leave-one-patient-out cross-validation scheme, three different outlier identification methods were investigated to decrease the influence of systematic errors, like a residual risk in misplacement of the sample and spectral dilution of marker bands (esp. cancerous tissue) and therewith optimize the experimental design. Furthermore other validations methods like leave-one-sample-out and leave-one-spectrum-out cross-validation schemes were compared with leave-one-patient-out cross-validation. High-risk lesions were differentiated from low-risk lesions with a sensitivity of 79%, specificity of 74% and an accuracy of 77%, cancer and normal tissue with a sensitivity of 79%, specificity of 83% and an accuracy of 81%. Additionally applied outlier identification enabled us to improve the recognition of neoplastic biopsy samples.

  8. Application of Fiber-Optical Techniques in the Access Transmission and Backbone Transport of Mobile Networks

    NASA Astrophysics Data System (ADS)

    Hilt, Attila; Pozsonyi, László

    2012-09-01

    Fixed access networks widely employ fiber-optical techniques due to the extremely wide bandwidth offered to subscribers. In the last decade, there has also been an enormous increase of user data visible in mobile systems. The importance of fiber-optical techniques within the fixed transmission/transport networks of mobile systems is therefore inevitably increasing. This article summarizes a few reasons and gives examples why and how fiber-optic techniques are employed efficiently in second-generation networks.

  9. Fiber-Optic Ultrasound Sensors for Smart Structures Applications

    DTIC Science & Technology

    2000-01-25

    Introduction 1 1.1 Objectives 1 1.2 Relevance to Air Force 1 1.3 Fiber Optics Ultrasound Sensors 2 2. Research Accomplishments 2 2.1 Fabry - Perot ...fiber-optic ultrasound receivers: - Fabry - Perot (FOFP) sensors, - Sagnac Ultrasound Sensor (SUS), and - Bragg-Grating Ultrasound (BGU) sensors. We...ultrasound receivers with excellent normal-incidence response can be configured as local ( Fabry - Perot ) or non-local (Sagnac) sensors. The Sagnac

  10. Fiber-Optic Pressure Sensor With Dynamic Demodulation Developed

    NASA Technical Reports Server (NTRS)

    Lekki, John D.

    2002-01-01

    Researchers at the NASA Glenn Research Center developed in-house a method to detect pressure fluctuations using a fiber-optic sensor and dynamic signal processing. This work was in support of the Intelligent Systems Controls and Operations project under NASA's Information Technology Base Research Program. We constructed an optical pressure sensor by attaching a fiber-optic Bragg grating to a flexible membrane and then adhering the membrane to one end of a small cylinder. The other end of the cylinder was left open and exposed to pressure variations from a pulsed air jet. These pressure variations flexed the membrane, inducing a strain in the fiber-optic grating. This strain was read out optically with a dynamic spectrometer to record changes in the wavelength of light reflected from the grating. The dynamic spectrometer was built in-house to detect very small wavelength shifts induced by the pressure fluctuations. The spectrometer is an unbalanced interferometer specifically designed for maximum sensitivity to wavelength shifts. An optimum pathlength difference, which was determined empirically, resulted in a 14-percent sensitivity improvement over theoretically predicted path-length differences. This difference is suspected to be from uncertainty about the spectral power difference of the signal reflected from the Bragg grating. The figure shows the output of the dynamic spectrometer as the sensor was exposed to a nominally 2-kPa peak-to-peak square-wave pressure fluctuation. Good tracking, sensitivity, and signal-to-noise ratios are evident even though the sensor was constructed as a proof-of-concept and was not optimized in any way. Therefore the fiber-optic Bragg grating, which is normally considered a good candidate as a strain or temperature sensor, also has been shown to be a good candidate for a dynamic pressure sensor.

  11. The effect of general anesthesia versus intravenous sedation on diagnostic yield and success in electromagnetic navigation bronchoscopy.

    PubMed

    Bowling, Mark R; Kohan, Matthew W; Walker, Paul; Efird, Jimmy; Ben Or, Sharon

    2015-01-01

    Navigational bronchoscopy is utilized to guide biopsies of peripheral lung nodules and place fiducial markers for treatment of limited stage lung cancer with stereotactic body radiotherapy. The type of sedation used for this procedure remains controversial. We performed a retrospective chart review to evaluate the differences of diagnostic yield and overall success of the procedure based on anesthesia type. Electromagnetic navigational bronchoscopy was performed using the superDimension software system. Once the targeted lesion was within reach, multiple tissue samples were obtained. Statistical analysis was used to correlate the yield with the type of sedation among other factors. A successful procedure was defined if a diagnosis was made or a fiducial marker was adequately placed. Navigational bronchoscopy was performed on a total of 120 targeted lesions. The overall complication rate of the procedure was 4.1%. The diagnostic yield and success of the procedure was 74% and 87%, respectively. Duration of the procedure was the only significant difference between the general anesthesia and IV sedation groups (mean, 58 vs. 43 min, P=0.0005). A larger tumor size was associated with a higher diagnostic yield (P=0.032). All other variables in terms of effect on diagnostic yield and an unsuccessful procedure did not meet statistical significance. Navigational bronchoscopy is a safe and effective pulmonary diagnostic tool with relatively low complication rate. The diagnostic yield and overall success of the procedure does not seem to be affected by the type of sedation used.

  12. Evaluation of virtual reality bronchoscopy as a learning and assessment tool.

    PubMed

    Moorthy, K; Smith, S; Brown, T; Bann, S; Darzi, A

    2003-01-01

    Conventional training in bronchoscopy involves a trainee performing on a real patient under supervision. This method of training is not only expensive, but there is also potential for increased patient discomfort. Simulators permit the acquisition of necessary technical skills required for the procedure. Virtual reality (VR) has been an integral part of training in aviation, and the application of this technology in medical training needs to be evaluated. This study was conducted to evaluate the efficacy of a VR bronchoscopy simulator as a learning and assessment tool. The bronchoscopic simulator (HT Medical Systems, Maryland, USA) is a VR computer programme. The simulator has the ability to assess competence by a set of parameters, which formed the data for the study. Nine novices without previous bronchoscopic experience formed the study group (group 1). Nine experienced bronchoscopists having performed between 200 and 1000 bronchoscopies formed the other group (group 2). We assessed the efficacy of the system as a learning tool by studying whether there was a significant difference between the first and subsequent sessions of the subjects from group 1 and by comparing the performance of the two groups. Statistical analysis was done using the Mann-Whitney U test and the Wilcoxon signed ranks test. There was a significant difference in performance between the first attempt of group 1 and the performance of the experts in terms of percentage of segments visualised and number of wall collisions and the economy of performance. Among the subjects from group 1, there was a significant improvement in percentage of segments visualised by the third attempt (p = 0.04), in the economy of performance by the sixth attempt (0.008) and in the number of wall collisions by the sixth attempt (0.024). When each attempt of the novices was compared with the performance of group 2, the significance in the difference of the percentage of segments studied (p = 0.09) and the economy of

  13. Fiber-Optic Micrometeoroid/Orbital Debris Impact Detector System

    NASA Technical Reports Server (NTRS)

    Christiansen, Eric L.; Tennyson, R. C.; Morison, W. D.

    2012-01-01

    A document describes a reliable, lightweight micrometeoroid/orbital debris (MMOD) detection system that can be located at strategic positions of "high consequence" to provide real-time warning of a penetration, its location, and the extent of the damage to a spacecraft. The concept is to employ fiber-optic sensors to detect impact damage and penetration of spacecraft structures. The fibers are non-electrical, employ light waves, and are immune to electromagnetic interference. The fiber-optic sensor array can be made as a stand-alone product, being bonded to a flexible membrane material or a structure that is employed as a MMOD shield material. The optical sensors can also be woven into hybrid MMOD shielding fabrics. The glass fibers of the fiber-optic sensor provide a dual purpose in contributing to the breakup of MMOD projectiles. The grid arrays can be made in a modular configuration to provide coverage over any area desired. Each module can be connected to a central scanner instrument and be interrogated in a continuous or periodic mode.

  14. Transbronchial Catheter Drainage via Fiberoptic Bronchoscope in Intractable Lung Abscess

    PubMed Central

    Jeong, Man Pyo; Kim, Woo Sung; Han, Sung Koo; Shim, Young Soo; Kim, Keun Youl; Han, Yong Chol

    1989-01-01

    The use of the fiberoptic bronchoscope as a drainage procedure for lung abscess has become more and more widespread. We have recently adopted the technique of inserting a simple polyethylene catheter through the flexible fiberoptic bronchoscope into the abscess cavity of 11 patients with lung absess. All cases had not responded to aggressive postural drainage and adequate antibiotic therapy for at least a week. The results were as follows: Among 11 patients, the therapeutic response was dramatic in 6 patients.In the successful group, the abscess sizes were greater than 8cm in diameter and the air-fluid levels were higher than two-thirds of the cavity.Additional diagnoses, other than bacterial lung abscess, could be made in 2 cases when otherwise the diagnosis would have remained in doubt. The authors suggest that catheter drainage via fiberoptic bronchoscpope is an effective treatment modality in the large lung abscess with a high air-fluid level which is intractable to other medical approaches, and it is also a safe procedure. PMID:2487405

  15. [Diagnostic values of bronchoscopy and multi-slice spiral CT for congenital dysplasia of the respiratory system in infants: a comparative study].

    PubMed

    Wang, Xing-Lu; Huang, Ying; Li, Qu-Bei; Dai, Ji-Hong

    2013-09-01

    To investigate and compare the diagnostic values of bronchoscopy and multi-slice spiral computed tomography (CT) for congenital dysplasia of the respiratory system in infants. Analysis was performed on the clinical data, bronchoscopic findings and multi-slice spiral CT findings of 319 infants (≤1 years old) who underwent bronchoscopy and/or multi-slice spiral CT and were diagnosed with congenital dysplasia of the respiratory system. A total of 476 cases of congenital dysplasia of the respiratory system were found in the 319 infants, including primary dysplasia of the respiratory system (392 cases) and compressive dysplasia of the respiratory system (84 cases). Of the 392 cases of primary dysplasia of the respiratory system, 225 (57.4%) were diagnosed by bronchoscopy versus 167 (42.6%) by multi-slice spiral CT. There were significant differences in etiological diagnosis between bronchoscopy and multi-slice spiral CT in infants with congenital dysplasia of the respiratory system (P<0.05). All 76 cases of primary dysplasia of the respiratory system caused by tracheobronchomalacia were diagnosed by bronchoscopy and all 17 cases of primary dysplasia of the respiratory system caused by lung tissue dysplasia were diagnosed by multi-slice spiral CT. Of the 84 cases of compressive dysplasia of the respiratory system, 74 cases were diagnosed by multi-slice spiral CT and only 10 cases were diagnosed by bronchoscopy. Compared with multi-slice spiral CT, bronchoscopy can detect primary dysplasia of the respiratory system more directly. Bronchoscopy is valuable in the confirmed diagnosis of tracheobronchomalacia. Multi-slice spiral CT has a higher diagnostic value for lung tissue dysplasia than bronchoscopy.

  16. Ultrathin bronchoscopy for solitary pulmonary lesions in a region endemic for tuberculosis: a randomised pilot trial.

    PubMed

    Franzen, Daniel; Diacon, Andreas H; Freitag, Lutz; Schubert, Pawel T; Wright, Colleen A; Schuurmans, Macé M

    2016-04-27

    The evaluation of solitary pulmonary lesions (SPL) requires a balance between procedure-related morbidity and diagnostic yield, particularly in areas where tuberculosis (TB) is endemic. Data on ultrathin bronchoscopy (UB) for this purpose is limited. To evaluate feasibility and safety of UB compared to SB for diagnosis of SPL in a TB endemic region. In this prospective randomised trial we compared diagnostic yield and adverse events of UB with standard-size bronchoscopy (SB), both combined with fluoroscopy, in a cohort of patients with SPL located beyond the visible range of SB. We included 40 patients (mean age 55.2 years, 45 % male) with malignant SPL (n = 16; 40 %), tuberculous SPL (n = 11; 27.5 %) and other benign SPL (n = 13; 32.5 %). Mean procedure time in UB and SB was 30.6 and 26.0 min, respectively (p = 0.15). By trend, adverse events were recorded more often with UB than with SB (30.0 vs. 5.0 %, p = 0.091), including extensive coughing (n = 2), blocked working channel (n = 2), and arterial hypertension requiring therapeutic intervention (n = 1), all with UB. The overall diagnostic yield of UB compared to SB was 55.0 % vs. 80.0 %, respectively (p = 0.18). Sensitivity for the diagnosis of malignancy of UB and SB was 50.0 % and 62.5 %, respectively (p = 0.95). UB is not superior to SB for the evaluation of SPL in a region endemic with tuberculosis, when combined with fluoroscopic guidance only. ClinicalTrials.gov (Identifier: NCT02490059 ).

  17. NONLINEAR AND FIBER OPTICS: Propagation of femtosecond solitons in a fiber-optic loop

    NASA Astrophysics Data System (ADS)

    Zakhidov, É. A.; Mirtadzhiev, F. M.; Khaĭdarov, D. V.; Kuznetsov, A. V.; Okhotnikov, A. G.

    1991-03-01

    An investigation was made of the propagation of fundamental femtosecond soliton pulses in a fiber-optic loop, which is an element with promising applications in logic operations. It is shown that such a loop can filter off the nonsoliton component effectively. The conditions for high-contrast self-switching of fundamental solitons in a fiber-optic loop are identified.

  18. Fiber-Optic Network Architectures for Onboard Avionics Applications Investigated

    NASA Technical Reports Server (NTRS)

    Nguyen, Hung D.; Ngo, Duc H.

    2003-01-01

    This project is part of a study within the Advanced Air Transportation Technologies program undertaken at the NASA Glenn Research Center. The main focus of the program is the improvement of air transportation, with particular emphasis on air transportation safety. Current and future advances in digital data communications between an aircraft and the outside world will require high-bandwidth onboard communication networks. Radiofrequency (RF) systems, with their interconnection network based on coaxial cables and waveguides, increase the complexity of communication systems onboard modern civil and military aircraft with respect to weight, power consumption, and safety. In addition, safety and reliability concerns from electromagnetic interference between the RF components embedded in these communication systems exist. A simple, reliable, and lightweight network that is free from the effects of electromagnetic interference and capable of supporting the broadband communications needs of future onboard digital avionics systems cannot be easily implemented using existing coaxial cable-based systems. Fiber-optical communication systems can meet all these challenges of modern avionics applications in an efficient, cost-effective manner. The objective of this project is to present a number of optical network architectures for onboard RF signal distribution. Because of the emergence of a number of digital avionics devices requiring high-bandwidth connectivity, fiber-optic RF networks onboard modern aircraft will play a vital role in ensuring a low-noise, highly reliable RF communication system. Two approaches are being used for network architectures for aircraft onboard fiber-optic distribution systems: a hybrid RF-optical network and an all-optical wavelength division multiplexing (WDM) network.

  19. Distributed fiber-optic temperature sensing for hydrologic systems

    NASA Astrophysics Data System (ADS)

    Selker, John S.; ThéVenaz, Luc; Huwald, Hendrik; Mallet, Alfred; Luxemburg, Wim; van de Giesen, Nick; Stejskal, Martin; Zeman, Josef; Westhoff, Martijn; Parlange, Marc B.

    2006-12-01

    Instruments for distributed fiber-optic measurement of temperature are now available with temperature resolution of 0.01°C and spatial resolution of 1 m with temporal resolution of fractions of a minute along standard fiber-optic cables used for communication with lengths of up to 30,000 m. We discuss the spectrum of fiber-optic tools that may be employed to make these measurements, illuminating the potential and limitations of these methods in hydrologic science. There are trade-offs between precision in temperature, temporal resolution, and spatial resolution, following the square root of the number of measurements made; thus brief, short measurements are less precise than measurements taken over longer spans in time and space. Five illustrative applications demonstrate configurations where the distributed temperature sensing (DTS) approach could be used: (1) lake bottom temperatures using existing communication cables, (2) temperature profile with depth in a 1400 m deep decommissioned mine shaft, (3) air-snow interface temperature profile above a snow-covered glacier, (4) air-water interfacial temperature in a lake, and (5) temperature distribution along a first-order stream. In examples 3 and 4 it is shown that by winding the fiber around a cylinder, vertical spatial resolution of millimeters can be achieved. These tools may be of exceptional utility in observing a broad range of hydrologic processes, including evaporation, infiltration, limnology, and the local and overall energy budget spanning scales from 0.003 to 30,000 m. This range of scales corresponds well with many of the areas of greatest opportunity for discovery in hydrologic science.

  20. Fiberoptics technology and its application to propulsion control systems

    NASA Technical Reports Server (NTRS)

    Baumbick, R. J.

    1983-01-01

    Current work on optical sensors and optically controlled actuators for use in air-breathing engine control systems is reviewed with particular reference to the design and operation of several new fiber-optic devices. These include a tachometer, a rotary position encoder, a Fabry-Perot interferometer and a rare-earth sensor for measuring engine gas temperatures, a high-temperature photoswitch designed for the range -55 to 260 C, and optical cables and connectors. The advantages of optics over conventional wire systems used for sensing and actuator control are briefly discussed.

  1. Fiber-Optic Distribution Of Pulsed Power To Multiple Sensors

    NASA Technical Reports Server (NTRS)

    Kirkham, Harold

    1996-01-01

    Optoelectronic systems designed according to time-sharing scheme distribute optical power to multiple integrated-circuit-based sensors in fiber-optic networks. Networks combine flexibility of electronic sensing circuits with advantage of electrical isolation afforded by use of optical fibers instead of electrical conductors to transmit both signals and power. Fiber optics resist corrosion and immune to electromagnetic interference. Sensor networks of this type useful in variety of applications; for example, in monitoring strains in aircraft, buildings, and bridges, and in monitoring and controlling shapes of flexible structures.

  2. High-density fiber-optic DNA random microsphere array.

    PubMed

    Ferguson, J A; Steemers, F J; Walt, D R

    2000-11-15

    A high-density fiber-optic DNA microarray sensor was developed to monitor multiple DNA sequences in parallel. Microarrays were prepared by randomly distributing DNA probe-functionalized 3.1-microm-diameter microspheres in an array of wells etched in a 500-microm-diameter optical imaging fiber. Registration of the microspheres was performed using an optical encoding scheme and a custom-built imaging system. Hybridization was visualized using fluorescent-labeled DNA targets with a detection limit of 10 fM. Hybridization times of seconds are required for nanomolar target concentrations, and analysis is performed in minutes.

  3. High-accuracy fiber-optic shape sensing

    NASA Astrophysics Data System (ADS)

    Duncan, Roger G.; Froggatt, Mark E.; Kreger, Stephen T.; Seeley, Ryan J.; Gifford, Dawn K.; Sang, Alexander K.; Wolfe, Matthew S.

    2007-04-01

    We describe the results of a study of the performance characteristics of a monolithic fiber-optic shape sensor array. Distributed strain measurements in a multi-core optical fiber interrogated with the optical frequency domain reflectometry technique are used to deduce the shape of the optical fiber; referencing to a coordinate system yields position information. Two sensing techniques are discussed herein: the first employing fiber Bragg gratings and the second employing the intrinsic Rayleigh backscatter of the optical fiber. We have measured shape and position under a variety of circumstances and report the accuracy and precision of these measurements. A discussion of error sources is included.

  4. Development of plasma bolometers using fiber-optic temperature sensors

    SciT

    Reinke, M. L., E-mail: reinkeml@ornl.gov; Han, M.; Liu, G.

    Measurements of radiated power in magnetically confined plasmas are important for exhaust studies in present experiments and expected to be a critical diagnostic for future fusion reactors. Resistive bolometer sensors have long been utilized in tokamaks and helical devices but suffer from electromagnetic interference (EMI). Results are shown from initial testing of a new bolometer concept based on fiber-optic temperature sensor technology. A small, 80 μm diameter, 200 μm long silicon pillar attached to the end of a single mode fiber-optic cable acts as a Fabry–Pérot cavity when broadband light, λ{sub o} ∼ 1550 nm, is transmitted along the fiber.more » Changes in temperature alter the optical path length of the cavity primarily through the thermo-optic effect, resulting in a shift of fringes reflected from the pillar detected using an I-MON 512 OEM spectrometer. While initially designed for use in liquids, this sensor has ideal properties for use as a plasma bolometer: a time constant, in air, of ∼150 ms, strong absorption in the spectral range of plasma emission, immunity to local EMI, and the ability to measure changes in temperature remotely. Its compact design offers unique opportunities for integration into the vacuum environment in places unsuitable for a resistive bolometer. Using a variable focus 5 mW, 405 nm, modulating laser, the signal to noise ratio versus power density of various bolometer technologies are directly compared, estimating the noise equivalent power density (NEPD). Present tests show the fiber-optic bolometer to have NEPD of 5-10 W/m{sup 2} when compared to those of the resistive bolometer which can achieve <0.5 W/m{sup 2} in the laboratory, but this can degrade to 1-2 W/m{sup 2} or worse when installed on a tokamak. Concepts are discussed to improve the signal to noise ratio of this new fiber-optic bolometer by reducing the pillar height and adding thin metallic coatings, along with improving the spectral resolution of the

  5. Fiber-Optic Gratings for Lidar Measurements of Water Vapor

    NASA Technical Reports Server (NTRS)

    Vann, Leila B.; DeYoung, Russell J.

    2006-01-01

    Narrow-band filters in the form of phase-shifted Fabry-Perot Bragg gratings incorporated into optical fibers are being developed for differential-absorption lidar (DIAL) instruments used to measure concentrations of atmospheric water vapor. The basic idea is to measure the relative amounts of pulsed laser light scattered from the atmosphere at two nearly equal wavelengths, one of which coincides with an absorption spectral peak of water molecules and the other corresponding to no water vapor absorption. As part of the DIAL measurement process, the scattered light is made to pass through a filter on the way to a photodetector. Omitting other details of DIAL for the sake of brevity, what is required of the filter is to provide a stop band that: Surrounds the water-vapor spectral absorption peaks at a wavelength of 946 nm, Has a spectral width of at least a couple of nanometers, Contains a pass band preferably no wider than necessary to accommodate the 946.0003-nm-wavelength water vapor absorption peak [which has 8.47 pm full width at half maximum (FWHM)], and Contains another pass band at the slightly shorter wavelength of 945.9 nm, where there is scattering of light from aerosol particles but no absorption by water molecules. Whereas filters used heretofore in DIAL have had bandwidths of =300 pm, recent progress in the art of fiber-optic Bragg-grating filters has made it feasible to reduce bandwidths to less than or equal to 20 pm and thereby to reduce background noise. Another benefit of substituting fiber-optic Bragg-grating filters for those now in use would be significant reductions in the weights of DIAL instruments. Yet another advantage of fiber-optic Bragg-grating filters is that their transmission spectra can be shifted to longer wavelengths by heating or stretching: hence, it is envisioned that future DIAL instruments would contain devices for fine adjustment of transmission wavelengths through stretching or heating of fiber-optic Bragg-grating filters

  6. Modulated Fourier Transform Raman Fiber-Optic Spectroscopy

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J. (Inventor); Cooper, John B. (Inventor); Wise, Kent L. (Inventor)

    2000-01-01

    A modification to a commercial Fourier Transform (FT) Raman spectrometer is presented for the elimination of thermal backgrounds in the FT Raman spectra. The modification involves the use of a mechanical optical chopper to modulate the continuous wave laser, remote collection of the signal via fiber optics, and connection of a dual-phase digital-signal-processor (DSP) lock-in amplifier between the detector and the spectrometer's collection electronics to demodulate and filter the optical signals. The resulting Modulated Fourier Transform Raman Fiber-Optic Spectrometer is capable of completely eliminating thermal backgrounds at temperatures exceeding 300 C.

  7. Development of plasma bolometers using fiber-optic temperature sensors

    NASA Astrophysics Data System (ADS)

    Reinke, M. L.; Han, M.; Liu, G.; van Eden, G. G.; Evenblij, R.; Haverdings, M.; Stratton, B. C.

    2016-11-01

    Measurements of radiated power in magnetically confined plasmas are important for exhaust studies in present experiments and expected to be a critical diagnostic for future fusion reactors. Resistive bolometer sensors have long been utilized in tokamaks and helical devices but suffer from electromagnetic interference (EMI). Results are shown from initial testing of a new bolometer concept based on fiber-optic temperature sensor technology. A small, 80 μm diameter, 200 μm long silicon pillar attached to the end of a single mode fiber-optic cable acts as a Fabry-Pérot cavity when broadband light, λo ˜ 1550 nm, is transmitted along the fiber. Changes in temperature alter the optical path length of the cavity primarily through the thermo-optic effect, resulting in a shift of fringes reflected from the pillar detected using an I-MON 512 OEM spectrometer. While initially designed for use in liquids, this sensor has ideal properties for use as a plasma bolometer: a time constant, in air, of ˜150 ms, strong absorption in the spectral range of plasma emission, immunity to local EMI, and the ability to measure changes in temperature remotely. Its compact design offers unique opportunities for integration into the vacuum environment in places unsuitable for a resistive bolometer. Using a variable focus 5 mW, 405 nm, modulating laser, the signal to noise ratio versus power density of various bolometer technologies are directly compared, estimating the noise equivalent power density (NEPD). Present tests show the fiber-optic bolometer to have NEPD of 5-10 W/m2 when compared to those of the resistive bolometer which can achieve <0.5 W/m2 in the laboratory, but this can degrade to 1-2 W/m2 or worse when installed on a tokamak. Concepts are discussed to improve the signal to noise ratio of this new fiber-optic bolometer by reducing the pillar height and adding thin metallic coatings, along with improving the spectral resolution of the interrogator.

  8. Fiber-optic sensors for aerospace electrical measurements: An update

    NASA Technical Reports Server (NTRS)

    Patterson, Richard L.; Rose, A. H.; Tang, D.; Day, G. W.

    1991-01-01

    Fiber-optic sensors are being developed for electrical current, voltage, and power measurements in aerospace applications. These sensors are presently designed to cover ac frequencies from 60 Hz to 20 kHz. The current sensor, based on the Faraday effect in optical fiber, is in advanced development after some initial testing. Concentration is on packaging methods and ways to maintain consistent sensitivity with changes in temperature. The voltage sensor, utilizing the Pockels effect in a crystal, has excelled in temperature tests. This paper reports on the development of these sensors, the results of evaluation, improvements now in progress, and the future direction of the work.

  9. Fiber-optic two-photon optogenetic stimulation.

    PubMed

    Dhakal, K; Gu, L; Black, B; Mohanty, S K

    2013-06-01

    Optogenetic stimulation of genetically targeted cells is proving to be a powerful tool in the study of cellular systems, both in vitro and in vivo. However, most opsins are activated in the visible spectrum, where significant absorption and scattering of stimulating light occurs, leading to low penetration depth and less precise stimulation. Since we first (to the best of our knowledge) demonstrated two-photon optogenetic stimulation (TPOS), it has gained considerable interest in the probing of cellular circuitry by precise spatial modulation. However, all existing methods use microscope objectives and complex scanning beam geometries. Here, we report a nonscanning method based on multimode fiber to accomplish fiber-optic TPOS of cells.

  10. Fiber-optic beam control systems using microelectromechanical systems

    NASA Astrophysics Data System (ADS)

    Sumriddetchkajorn, Sarun

    This dissertation, for the first time, proposes, studies, and experimentally demonstrated novel fiber-optic beam control systems based on the use of microelectromechanical system (MEMS) technology in which the miniaturized versions of mechanical systems can be obtained. Beam control modules include optical add/drop filters, optical switches, variable photonic delay lines (VPDLs), and variable optical attenuators (VOAs). The optical add/drop filter functions as a multiwavelength optical switch that offers the ability to drop and add a certain number of desired wavelengths at an intermediate location where access to all the propagating optical channels is not required between transmission terminals. The VOA can also be used in networks where stocking and tracking of fixed attenuators is difficult. Other specific applications of the VOA are optical gain equalization and polarization dependent loss and gain compensation required in high data-rate wavelength division multiplexed (WDM) lightwave systems. A VPDL can be used to adjust timing amongst multiwavelength optical signals in order to reduce timing jitter and burst traffic in photonic packet switching and parallel signal processing systems. In this dissertation, a small tilt micromirror device is proposed for the implementation of all fiber-optic beam control modules. In particular, the macro-pixel approach where several micromirrors are used to manipulate the desired optical beam is introduced to realize high speed and fault tolerant beam control modules. To eliminate the need of careful optical alignment, an all fiber-connectorized multiwavelength optical switch structure is presented and experimentally demonstrated by using a fiber-loop mirror concept with polarization control. In addition, liquid crystal (LC) devices are studied and are used to implement a compact retro- reflective 2 x 2 fiber-optic switch. Compared to MEMS- based mirror technology, the LC technology is more sensitive to temperature, thereby

  11. Evaluation of a flexible bronchoscope prototype designed for bronchoscopy during mechanical ventilation: a proof-of-concept study.

    PubMed

    Nay, M-A; Auvet, A; Mankikian, J; Herve, V; Dequin, P-F; Guillon, A

    2017-06-01

    Bronchoscopy during mechanical ventilation of patients' lungs significantly affects ventilation because of partial obstruction of the tracheal tube, and may thus be omitted in the most severely ill patients. It has not previously been possible to reduce the external diameter of the bronchoscope without reducing the diameter of the suction channel, thus reducing the suctioning capacity of the device. We believed that a better-designed bronchoscope could improve the safety of bronchoscopy in patients whose lungs were ventilated. We designed a flexible bronchoscope prototype with a drumstick-shaped head consisting of a long, thin proximal portion; a short and large distal portion for camera docking; and a large suction channel throughout the length of the device. The aims of our study were to test the impact of our prototype on mechanical ventilation when inserted into the tracheal tube, and to assess suctioning capacity. We first tested the efficiency of the suction channel, and demonstrated that the suction flow of the prototype was similar to that of conventional adult bronchoscopes. We next evaluated the consequences of bronchoscopy when using the prototype on minute ventilation and intrathoracic pressures during mechanical ventilation: firstly, in vitro using a breathing simulator; and secondly, in vivo using a porcine model of pulmonary ventilation. The insertion of adult bronchoscopes into the tracheal tube immediately impaired the protective ventilation strategy employed, whereas the prototype preserved it. For the first time, we have developed an innovative flexible bronchoscope designed for bronchoscopy during invasive mechanical ventilation, that both preserved the protective ventilation strategy, and enabled efficient suction flow. © 2017 The Association of Anaesthetists of Great Britain and Ireland.

  12. Comparison of midazolam with fentanyl-midazolam combination during flexible bronchoscopy: A randomized, double-blind, placebo-controlled study

    PubMed Central

    Prabhudev, Amithash Marulaiah; Chogtu, Bharti; Magazine, Rahul

    2017-01-01

    BACKGROUND: Sedation during flexible bronchoscopy is desirable, but the drugs and the dosage protocols that are used vary. OBJECTIVE: To study and compare the effects of midazolam with fentanyl-midazolam combination during flexible bronchoscopy. MATERIALS AND METHODS: The study was conducted on 144 patients, from October 2013 to July 2015. They answered Hospital Anxiety and Depression Scale-Anxiety subscale and a prebronchoscopy questionnaire to assess their expectation toward flexible bronchoscopy. The patients were randomized into three groups: placebo, midazolam, and fentanyl-midazolam. Vitals signs including heart rate, respiratory rate, blood pressure, and oxygen saturation (SpO2) were recorded. Furthermore, Ramsay Sedation Scale was assessed during the procedure. Primary outcome measure was the composite score of patient-reported tolerance and satisfaction (assessed after the procedure). Secondary outcome measures were composite score of physician-reported feasibility of the procedure, hemodynamic changes during bronchoscopy, and side effects. RESULTS: Patient-reported tolerance and satisfaction composite scores (median, interquartile range) for placebo, midazolam, and fentanyl-midazolam groups were 54 (52, 57), 59 (57, 61.5), 62 (58.5, 66), respectively; P < 0.001. Physician-reported feasibility composite scores (median, interquartile range) for the respective groups were 24.5 (20.5, 28), 25 (21, 27), 26 (25, 29); P = 0.004. There was no significant difference between the groups so far as mean heart rate (P = 0.305), mean systolic blood pressure (P = 0.532), mean diastolic blood pressure (P = 0.516), mean respiratory rate (P = 0.131), and mean SpO2 (P = 0.968) were concerned. CONCLUSION: Conscious sedation with fentanyl and midazolam combination can result in better patient and operator satisfaction when compared with midazolam alone. PMID:29326491

  13. Fiber-optic projected-fringe digital interferometry

    NASA Technical Reports Server (NTRS)

    Mercer, Carolyn R.; Beheim, Glenn

    1990-01-01

    A phase-stepped projected-fringe interferometer was developed which uses a closed-loop fiber-optic phase-control system to make very accurate surface profile measurements. The closed-loop phase-control system greatly reduces phase-stepping error, which is frequently the dominant source of error in digital interferometers. Two beams emitted from a fiber-optic coupler are combined to form an interference fringe pattern on a diffusely reflecting object. Reflections off of the fibers' output faces are used to create a phase-indicating signal for the closed-loop optical phase controller. The controller steps the phase difference between the two beams by pi/2 radians in order to determine the object's surface profile using a solid-state camera and a computer. The system combines the ease of alignment and automated data reduction of phase-stepping projected-fringe interferometry with the greatly improved phase-stepping accuracy of our closed-loop phase-controller. The system is demonstrated by measuring the profile of a plate containing several convex surfaces whose heights range from 15 to 25 micron high.

  14. Computational imaging through a fiber-optic bundle

    NASA Astrophysics Data System (ADS)

    Lodhi, Muhammad A.; Dumas, John Paul; Pierce, Mark C.; Bajwa, Waheed U.

    2017-05-01

    Compressive sensing (CS) has proven to be a viable method for reconstructing high-resolution signals using low-resolution measurements. Integrating CS principles into an optical system allows for higher-resolution imaging using lower-resolution sensor arrays. In contrast to prior works on CS-based imaging, our focus in this paper is on imaging through fiber-optic bundles, in which manufacturing constraints limit individual fiber spacing to around 2 μm. This limitation essentially renders fiber-optic bundles as low-resolution sensors with relatively few resolvable points per unit area. These fiber bundles are often used in minimally invasive medical instruments for viewing tissue at macro and microscopic levels. While the compact nature and flexibility of fiber bundles allow for excellent tissue access in-vivo, imaging through fiber bundles does not provide the fine details of tissue features that is demanded in some medical situations. Our hypothesis is that adapting existing CS principles to fiber bundle-based optical systems will overcome the resolution limitation inherent in fiber-bundle imaging. In a previous paper we examined the practical challenges involved in implementing a highly parallel version of the single-pixel camera while focusing on synthetic objects. This paper extends the same architecture for fiber-bundle imaging under incoherent illumination and addresses some practical issues associated with imaging physical objects. Additionally, we model the optical non-idealities in the system to get lower modelling errors.

  15. Anatomy and bronchoscopy of the porcine lung. A model for translational respiratory medicine.

    PubMed

    Judge, Eoin P; Hughes, J M Lynne; Egan, Jim J; Maguire, Michael; Molloy, Emer L; O'Dea, Shirley

    2014-09-01

    The porcine model has contributed significantly to biomedical research over many decades. The similar size and anatomy of pig and human organs make this model particularly beneficial for translational research in areas such as medical device development, therapeutics and xenotransplantation. In recent years, a major limitation with the porcine model was overcome with the successful generation of gene-targeted pigs and the publication of the pig genome. As a result, the role of this model is likely to become even more important. For the respiratory medicine field, the similarities between pig and human lungs give the porcine model particular potential for advancing translational medicine. An increasing number of lung conditions are being studied and modeled in the pig. Genetically modified porcine models of cystic fibrosis have been generated that, unlike mouse models, develop lung disease similar to human cystic fibrosis. However, the scientific literature relating specifically to porcine lung anatomy and airway histology is limited and is largely restricted to veterinary literature and textbooks. Furthermore, methods for in vivo lung procedures in the pig are rarely described. The aims of this review are to collate the disparate literature on porcine lung anatomy, histology, and microbiology; to provide a comparison with the human lung; and to describe appropriate bronchoscopy procedures for the pig lungs to aid clinical researchers working in the area of translational respiratory medicine using the porcine model.

  16. The bovine lung in biomedical research: visually guided bronchoscopy, intrabronchial inoculation and in vivo sampling techniques.

    PubMed

    Prohl, Annette; Ostermann, Carola; Lohr, Markus; Reinhold, Petra

    2014-07-03

    There is an ongoing search for alternative animal models in research of respiratory medicine. Depending on the goal of the research, large animals as models of pulmonary disease often resemble the situation of the human lung much better than mice do. Working with large animals also offers the opportunity to sample the same animal repeatedly over a certain course of time, which allows long-term studies without sacrificing the animals. The aim was to establish in vivo sampling methods for the use in a bovine model of a respiratory Chlamydia psittaci infection. Sampling should be performed at various time points in each animal during the study, and the samples should be suitable to study the host response, as well as the pathogen under experimental conditions. Bronchoscopy is a valuable diagnostic tool in human and veterinary medicine. It is a safe and minimally invasive procedure. This article describes the intrabronchial inoculation of calves as well as sampling methods for the lower respiratory tract. Videoendoscopic, intrabronchial inoculation leads to very consistent clinical and pathological findings in all inoculated animals and is, therefore, well-suited for use in models of infectious lung disease. The sampling methods described are bronchoalveolar lavage, bronchial brushing and transbronchial lung biopsy. All of these are valuable diagnostic tools in human medicine and could be adapted for experimental purposes to calves aged 6-8 weeks. The samples obtained were suitable for both pathogen detection and characterization of the severity of lung inflammation in the host.

  17. Design and characterization of a novel multimodal fiber-optic probe and spectroscopy system for skin cancer applications

    PubMed Central

    Sharma, Manu; Marple, Eric; Reichenberg, Jason; Tunnell, James W.

    2014-01-01

    The design and characterization of an instrument combining Raman, fluorescence, and reflectance spectroscopic modalities is presented. Instrument development has targeted skin cancer applications as a novel fiber-optic probe has been specially designed to interrogate cutaneous lesions. The instrument is modular and both its software and hardware components are described in depth. Characterization of the fiber-optic probe is also presented, which details the probe's ability to measure diagnostically important parameters such as intrinsic fluorescence and absorption and reduced scattering coefficients along with critical performance metrics such as high Raman signal-to-noise ratios at clinically practical exposure times. Validation results using liquid phantoms show that the probe and system can extract absorption and scattering coefficients with less than 10% error. As the goal is to use the instrument for the clinical early detection of skin cancer, preliminary clinical data are also presented, which indicates our system's ability to measure physiological quantities such as relative collagen and nicotinamide adenine dinucleotide concentration, oxygen saturation, blood volume fraction, and mean vessel diameter. PMID:25173240

  18. Multi-function diamond film fiberoptic probe and measuring system employing same

    DOEpatents

    Young, Jack P.

    1998-01-01

    A fused fiberoptic probe having a protective cover, a fiberoptic probe system, and embodiments thereof for conducting electromagnetic spectral measurements are disclosed. The fused fiberoptic probe comprises a probe tip having a specific geometrical configuration, an exciting optical fiber and at least one collection optical fiber fused within a housing, preferrably silica, with a protective cover disposed over at least a portion of the probe tip. The specific geometrical configurations in which the probe tip can be shaped include a slanted probe tip with an angle greater than 0.degree., an inverted cone-shaped probe tip, and a lens head.

  19. Design of high-capacity fiber-optic transport systems

    NASA Astrophysics Data System (ADS)

    Liao, Zhi Ming

    2001-08-01

    We study the design of fiber-optic transport systems and the behavior of fiber amplifiers/lasers with the aim of achieving higher capacities with larger amplifier spacing. Solitons are natural candidates for transmitting short pulses for high-capacity fiber-optic networks because of its innate ability to use two of fiber's main defects, fiber dispersion and fiber nonlinearity to balance each other. In order for solitons to retain its dynamic nature, amplifiers must be placed periodically to restore powers to compensate for fiber loss. Variational analysis is used to study the long-term stability of a periodical- amplifier system. A new regime of operation is identified which allows the use of a much longer amplifier spacing. If optical fibers are the blood vessels of an optical communication system, then the optical amplifier based on erbium-doped fiber is the heart. Optical communication systems can avoid the use of costly electrical regenerators to maintain system performance by being able to optically amplify the weakened signals. The length of amplifier spacing is largely determined by the gain excursion experienced by the solitons. We propose, model, and demonstrate a distributed erbium-doped fiber amplifier which can drastically reduce the amount of gain excursion experienced by the solitons, therefore allowing a much longer amplifier spacing and superior stability. Dispersion management techniques have become extremely valuable tools in the design of fiber-optic communication systems. We have studied in depth the advantage of different arnplification schemes (lumped and distributed) for various dispersion compensation techniques. We measure the system performance through the Q factor to evaluate the added advantage of effective noise figure and smaller gain excursion. An erbium-doped fiber laser has been constructed and characterized in an effort to develop a test bed to study transmission systems. The presence of mode-partition noise in an erbium

  20. Fiber-optic epoxy composite cure sensor. II. Performance characteristics

    NASA Astrophysics Data System (ADS)

    Lam, Kai-Yuen; Afromowitz, Martin A.

    1995-09-01

    The performance of a fiber-optic epoxy composite cure sensor, as previously proposed, depends on the optical properties and the reaction kinetics of the epoxy. The reaction kinetics of a typical epoxy system are presented. It is a third-order autocatalytic reaction with a peak observed in each isothermal reaction-rate curve. A model is derived to describe the performance characteristics of the epoxy cure sensor. If a composite coupon is cured at an isothermal temperature, the sensor signal can be used to predict the time when the gel point occurs and to monitor the cure process. The sensor is also shown to perform well in nonstoichiometric epoxy matrices. In addition the sensor can detect the end of the cure without calibration.

  1. Fiberoptics technology and its application to propulsion control systems

    NASA Technical Reports Server (NTRS)

    Baumbick, R. J.

    1983-01-01

    Electro-optical systems have many advantages over conventional electrical systems. Among these are optics' insensitivity to electro-magnetic interference, good electrical isolation and the ability to make measurements in highly explosive areas without risk. These advantages promise to help improve the reliability of future aircraft engine control systems which will be entirely electronic digital. To improve the reliability of these systems, especially against lightning strikes, passive, optical, sensors and fiberoptic transmission lines are being considered for use in future engine systems. Also under consideration are actuators which receive their command signals over fiber optic cables. This paper reviews concepts used for optical instrumentation and actuation systems and discusses work being done by NASA Lewis Research Center in this area.

  2. Hollow fiber-optic Raman probes for small experimental animals

    NASA Astrophysics Data System (ADS)

    Katagiri, Takashi; Hattori, Yusuke; Suzuki, Toshiaki; Matsuura, Yuji; Sato, Hidetoshi

    2007-02-01

    Two types of hollow fiber-optic probes are developed to measure the in vivo Raman spectra of small animals. One is the minimized probe which is end-sealed with the micro-ball lens. The measured spectra reflect the information of the sample's sub-surface. This probe is used for the measurement of the esophagus and the stomach via an endoscope. The other probe is a confocal Raman probe which consists of a single fiber and a lens system. It is integrated into the handheld microscope. A simple and small multimodal probe is realized because the hollow optical fiber requires no optical filters. The performance of each probe is examined and the effectiveness of these probes for in vivo Raman spectroscopy is shown by animal tests.

  3. High-temperature fiber-optic lever microphone

    NASA Technical Reports Server (NTRS)

    Zuckerwar, Allan J.; Cuomo, Frank W.; Nguyen, Trung D.; Rizzi, Stephen A.; Clevenson, Sherman A.

    1995-01-01

    The design and construction of a fiber-optic lever microphone, capable of operating continuously at temperatures up to 538 C (1000 F) are described. The design is based on the theoretical sensitivities of each of the microphone system components, namely, a cartridge containing a stretched membrane, an optical fiber probe, and an optoelectronic amplifier. Laboratory calibrations include the pistonphone sensitivity and harmonic distortion at ambient temperature, and frequency response, background noise, and optical power transmission at both ambient and elevated temperatures. A field test in the Thermal Acoustic Fatigue Apparatus at Langley Research Center, in which the microphone was subjected to overall sound-pressure levels in the range of 130-160 dB and at temperatures from ambient to 538 C, revealed good agreement with a standard probe microphone.

  4. Quantitative fiber-optic Raman spectroscopy for tissue Raman measurements

    NASA Astrophysics Data System (ADS)

    Duraipandian, Shiyamala; Bergholt, Mads; Zheng, Wei; Huang, Zhiwei

    2014-03-01

    Molecular profiling of tissue using near-infrared (NIR) Raman spectroscopy has shown great promise for in vivo detection and prognostication of cancer. The Raman spectra measured from the tissue generally contain fundamental information about the absolute biomolecular concentrations in tissue and its changes associated with disease transformation. However, producing analogues tissue Raman spectra present a great technical challenge. In this preliminary study, we propose a method to ensure the reproducible tissue Raman measurements and validated with the in vivo Raman spectra (n=150) of inner lip acquired using different laser powers (i.e., 30 and 60 mW). A rapid Raman spectroscopy system coupled with a ball-lens fiber-optic Raman probe was utilized for tissue Raman measurements. The investigational results showed that the variations between the spectra measured with different laser powers are almost negligible, facilitating the quantitative analysis of tissue Raman measurements in vivo.

  5. Transoral tracheal intubation of rodents using a fiberoptic laryngoscope.

    PubMed

    Costa, D L; Lehmann, J R; Harold, W M; Drew, R T

    1986-06-01

    A fiberoptic laryngoscope which allows direct visualization of the deep pharynx and epiglottis has been developed for transoral tracheal intubation of small laboratory mammals. The device has been employed in the intubation and instillation of a variety of substances into the lungs of rats, and with minor modification, has had similar application in mice, hamsters, and guinea pigs. The simplicity and ease of handling of the laryngoscope permits one person to intubate large numbers of enflurane anesthetized animals either on an open counter top or in a glove-box, as may be required for administration of carcinogenic materials. Instillation of 7Be-labeled carbon particles into the lungs of mice, hamsters, rats, and guinea pigs resulted in reasonably consistent interlobal distribution of particles for each test animal species with minimal tracheal deposition. However, actual lung tissue doses of carbon exhibited some species dependence.

  6. Design and fabrication of engineering model fiber-optics detector

    NASA Technical Reports Server (NTRS)

    Mcsweeney, A.

    1972-01-01

    The design and fabrication of an annular ring detector consisting of optical fibers terminated with photodetectors is described. The maximum width of each concentric ring has to be small enough to permit the resolution of a Ronchi ruling transform with a dot spacing of 150 microns. A minimum of 100 concentric rings covering a circular area of 2.54 cm diameter also is necessary. A fiber-optic array consisting of approximately 89,000 fibers of 76 microns diameter was fabricated to meet the above requirements. The fibers within a circular area of 2.5 cm diameter were sorted into 168 adjacent rings concentric with the center fiber. The response characteristics of several photodetectors were measured, and the data used to compare their linearity of response and dynamic range. Also, coupling loss measurements were made for three different methods of terminating the optical fibers with a photodetector.

  7. Fiber-optic sensors for aerospace electrical measurements - An update

    NASA Technical Reports Server (NTRS)

    Patterson, Richard L.; Rose, A. H.; Tang, D.; Day, G. W.

    1991-01-01

    The authors report the progress made on the development of aerospace current and voltage sensors which use fiber-optic and optical sensing heads. These sensors are presently designed to cover ac frequencies from 60 Hz to 20 kHz. The current sensor, based on the Faraday effect in optical fiber, is in advanced development after some initial testing. The emphasis is on packaging methods and ways to maintain consistent sensitivity with changes in temperature. The voltage sensor, utilizing the Pockels effect in a crystal, has excelled in temperature tests. The authors report on the development of these sensors. The authors also relate the technology used in the sensors, the results of evaluation, improvements being made, and the future direction of the work.

  8. Design of a fiber-optic multiphoton microscopy handheld probe

    PubMed Central

    Zhao, Yuan; Sheng, Mingyu; Huang, Lin; Tang, Shuo

    2016-01-01

    We have developed a fiber-optic multiphoton microscopy (MPM) system with handheld probe using femtosecond fiber laser. Here we present the detailed optical design and analysis of the handheld probe. The optical systems using Lightpath 352140 and 352150 as objective lens were analyzed. A custom objective module that includes Lightpath 355392 and two customized corrective lenses was designed. Their performances were compared by wavefront error, field curvature, astigmatism, F-θ error, and tolerance in Zemax simulation. Tolerance analysis predicted the focal spot size to be 1.13, 1.19 and 0.83 µm, respectively. Lightpath 352140 and 352150 were implemented in experiment and the measured lateral resolution was 1.22 and 1.3 µm, respectively, which matched with the prediction. MPM imaging by the handheld probe were conducted on leaf, fish scale and rat tail tendon. The MPM resolution can potentially be improved by the custom objective module. PMID:27699109

  9. Design of a fiber-optic multiphoton microscopy handheld probe.

    PubMed

    Zhao, Yuan; Sheng, Mingyu; Huang, Lin; Tang, Shuo

    2016-09-01

    We have developed a fiber-optic multiphoton microscopy (MPM) system with handheld probe using femtosecond fiber laser. Here we present the detailed optical design and analysis of the handheld probe. The optical systems using Lightpath 352140 and 352150 as objective lens were analyzed. A custom objective module that includes Lightpath 355392 and two customized corrective lenses was designed. Their performances were compared by wavefront error, field curvature, astigmatism, F-θ error, and tolerance in Zemax simulation. Tolerance analysis predicted the focal spot size to be 1.13, 1.19 and 0.83 µm, respectively. Lightpath 352140 and 352150 were implemented in experiment and the measured lateral resolution was 1.22 and 1.3 µm, respectively, which matched with the prediction. MPM imaging by the handheld probe were conducted on leaf, fish scale and rat tail tendon. The MPM resolution can potentially be improved by the custom objective module.

  10. Maximum-performance fiber-optic irradiation with nonimaging designs.

    PubMed

    Fang, Y; Feuermann, D; Gordon, J M

    1997-10-01

    A range of practical nonimaging designs for optical fiber applications is presented. Rays emerging from a fiber over a restricted angular range (small numerical aperture) are needed to illuminate a small near-field detector at maximum radiative efficiency. These designs range from pure reflector (all-mirror), to pure dielectric (refractive and based on total internal reflection) to lens-mirror combinations. Sample designs are shown for a specific infrared fiber-optic irradiation problem of practical interest. Optical performance is checked with computer three-dimensional ray tracing. Compared with conventional imaging solutions, nonimaging units offer considerable practical advantages in compactness and ease of alignment as well as noticeably superior radiative efficiency.

  11. Miniaturized fiber-optic Michelson-type interferometric sensors

    NASA Technical Reports Server (NTRS)

    Murphy, Kent A.; Miller, William V., III; Tran, Tuan A.; Vengsarkar, Ashish M.; Claus, Richard O.

    1991-01-01

    A novel, miniaturized Michelson-type fiber-optic interferometric sensor that is relatively insensitive to temperature drifts is presented. A fused-biconical tapered coupler is cleaved immediately after the coupled length and polished down to the region of the fused cladding, but short of the interaction region. The end of one core is selectively coated with a reflective surface and is used as the reference arm; the other core serves as the sensing arm. The detection of surface acoustic waves, microdisplacements, and magnetic fields is reported. The sensor is shown to be highly stable in comparison to a classic homodyne, uncompensated Michelson interferometer, and signal-to-noise ratios of 65 dB have been obtained.

  12. Fiber-optical switch controlled by a single atom.

    PubMed

    O'Shea, Danny; Junge, Christian; Volz, Jürgen; Rauschenbeutel, Arno

    2013-11-08

    We demonstrate highly efficient switching of optical signals between two optical fibers controlled by a single atom. The key element of our experiment is a whispering-gallery-mode bottle microresonator, which is coupled to a single atom and interfaced by two tapered fiber couplers. This system reaches the strong coupling regime of cavity quantum electrodynamics, leading to a vacuum Rabi splitting in the excitation spectrum. We systematically investigate the switching efficiency of our system, i.e., the probability that the fiber-optical switch redirects the light into the desired output. We obtain a large redirection efficiency reaching a raw fidelity of more than 60% without postselection. Moreover, by measuring the second-order correlation functions of the output fields, we show that our switch exhibits a photon-number-dependent routing capability.

  13. Development Of Antibody-Based Fiber-Optic Sensors

    NASA Astrophysics Data System (ADS)

    Tromberg, Bruce J.; Sepaniak, Michael J.; Vo-Dinh, Tuan

    1988-06-01

    The speed and specificity characteristic of immunochemical complex formation has encouraged the development of numerous antibody-based analytical techniques. The scope and versatility of these established methods can be enhanced by combining the principles of conventional immunoassay with laser-based fiber-optic fluorimetry. This merger of spectroscopy and immunochemistry provides the framework for the construction of highly sensitive and selective fiber-optic devices (fluoroimmuno-sensors) capable of in-situ detection of drugs, toxins, and naturally occurring biochemicals. Fluoroimmuno-sensors (FIS) employ an immobilized reagent phase at the sampling terminus of a single quartz optical fiber. Laser excitation of antibody-bound analyte produces a fluorescence signal which is either directly proportional (as in the case of natural fluorophor and "antibody sandwich" assays) or inversely proportional (as in the case of competitive-binding assays) to analyte concentration. Factors which influence analysis time, precision, linearity, and detection limits include the nature (solid or liquid) and amount of the reagent phase, the method of analyte delivery (passive diffusion, convection, etc.), and whether equilibrium or non-equilibrium assays are performed. Data will be presented for optical fibers whose sensing termini utilize: (1) covalently-bound solid antibody reagent phases, and (2) membrane-entrapped liquid antibody reagents. Assays for large-molecular weight proteins (antigens) and small-molecular weight, carcinogenic, polynuclear aromatics (haptens) will be considered. In this manner, the influence of a system's chemical characteristics and measurement requirements on sensor design, and the consequence of various sensor designs on analytical performance will be illustrated.

  14. Safety of interventional rigid bronchoscopy using intravenous anesthesia and spontaneous assisted ventilation. A prospective study.

    PubMed

    Perrin, G; Colt, H G; Martin, C; Mak, M A; Dumon, J F; Gouin, F

    1992-11-01

    To investigate the safety of total intravenous anesthesia and spontaneous assisted ventilation during interventional rigid bronchoscopy (IRB). Prospective, noncomparative study. A university hospital thoracic endoscopy and laser center. Eighty-three patients underwent a total of 124 procedures (including Nd:Yag laser therapy, stent insertions, transbronchial biopsies/bronchoalveolar lavages (TBB/BALs) in transplant patients and others). Results of preanesthesia consultation, endoscopic and anesthesia intervention, perioperative complications, and time spent in recovery room were recorded prospectively. Respiratory complications occurred in 22 procedures (18 percent) and included severe intraoperative or postoperative oxyhemoglobin desaturations (19 cases), bronchospasms/laryngospasms (two cases), and one recurrent pneumothorax. These complications were mostly related to the endobronchial surgical procedure. Respiratory complications occurred more frequently in patients with American Society of Anesthesiologists (ASA) 3 and 4 status (p < 0.005) and in patients with a karnofsky Performance Scale (KPS) below 70 (p < 0.05). No cardiac complications were noted, although 13 patients had significant underlying heart disease. Propofol was used in 121 procedures. Etomidate was used 15 times for induction and three times for both induction and maintenance in patients with ASA status 4 or low blood pressure before induction. Total intravenous anesthesia and spontaneous assisted ventilation is a well-suited technique for IRB. Severe hypoxemia, however, may occur in approximately 15 percent of patients. This complication is usually related to the procedure itself and is easy to reverse. Propofol is well tolerated in the majority of patients but it must be used with care in patients with poor functional or cardiovascular status.

  15. A multimodal image guiding system for Navigated Ultrasound Bronchoscopy (EBUS): A human feasibility study

    PubMed Central

    Hofstad, Erlend Fagertun; Amundsen, Tore; Langø, Thomas; Bakeng, Janne Beate Lervik; Leira, Håkon Olav

    2017-01-01

    Background Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is the endoscopic method of choice for confirming lung cancer metastasis to mediastinal lymph nodes. Precision is crucial for correct staging and clinical decision-making. Navigation and multimodal imaging can potentially improve EBUS-TBNA efficiency. Aims To demonstrate the feasibility of a multimodal image guiding system using electromagnetic navigation for ultrasound bronchoschopy in humans. Methods Four patients referred for lung cancer diagnosis and staging with EBUS-TBNA were enrolled in the study. Target lymph nodes were predefined from the preoperative computed tomography (CT) images. A prototype convex probe ultrasound bronchoscope with an attached sensor for position tracking was used for EBUS-TBNA. Electromagnetic tracking of the ultrasound bronchoscope and ultrasound images allowed fusion of preoperative CT and intraoperative ultrasound in the navigation software. Navigated EBUS-TBNA was used to guide target lymph node localization and sampling. Navigation system accuracy was calculated, measured by the deviation between lymph node position in ultrasound and CT in three planes. Procedure time, diagnostic yield and adverse events were recorded. Results Preoperative CT and real-time ultrasound images were successfully fused and displayed in the navigation software during the procedures. Overall navigation accuracy (11 measurements) was 10.0 ± 3.8 mm, maximum 17.6 mm, minimum 4.5 mm. An adequate sample was obtained in 6/6 (100%) of targeted lymph nodes. No adverse events were registered. Conclusions Electromagnetic navigated EBUS-TBNA was feasible, safe and easy in this human pilot study. The clinical usefulness was clearly demonstrated. Fusion of real-time ultrasound, preoperative CT and electromagnetic navigational bronchoscopy provided a controlled guiding to level of target, intraoperative overview and procedure documentation. PMID:28182758

  16. Integrated bronchoscopic video tracking and 3D CT registration for virtual bronchoscopy

    NASA Astrophysics Data System (ADS)

    Higgins, William E.; Helferty, James P.; Padfield, Dirk R.

    2003-05-01

    Lung cancer assessment involves an initial evaluation of 3D CT image data followed by interventional bronchoscopy. The physician, with only a mental image inferred from the 3D CT data, must guide the bronchoscope through the bronchial tree to sites of interest. Unfortunately, this procedure depends heavily on the physician's ability to mentally reconstruct the 3D position of the bronchoscope within the airways. In order to assist physicians in performing biopsies of interest, we have developed a method that integrates live bronchoscopic video tracking and 3D CT registration. The proposed method is integrated into a system we have been devising for virtual-bronchoscopic analysis and guidance for lung-cancer assessment. Previously, the system relied on a method that only used registration of the live bronchoscopic video to corresponding virtual endoluminal views derived from the 3D CT data. This procedure only performs the registration at manually selected sites; it does not draw upon the motion information inherent in the bronchoscopic video. Further, the registration procedure is slow. The proposed method has the following advantages: (1) it tracks the 3D motion of the bronchoscope using the bronchoscopic video; (2) it uses the tracked 3D trajectory of the bronchoscope to assist in locating sites in the 3D CT "virtual world" to perform the registration. In addition, the method incorporates techniques to: (1) detect and exclude corrupted video frames (to help make the video tracking more robust); (2) accelerate the computation of the many 3D virtual endoluminal renderings (thus, speeding up the registration process). We have tested the integrated tracking-registration method on a human airway-tree phantom and on real human data.

  17. Advanced training of specialists in area of fiber-optic communication lines maintenance

    NASA Astrophysics Data System (ADS)

    Andreev, Vladimir A.; Voronkov, Andrey A.; Bukashkin, Sergey A.; Buzova, Maria A.

    2017-04-01

    The paper considers the concept of fiber-optic communication lines (FOCL) maintenance. Performance criterion of FOCL technical maintenance was proposed. For the first time the algorithm for evaluation of the FOCL maintenance efficiency at telecommunication specialists training was applied.

  18. Three-dimensional image formation in fiber-optical second-harmonic-generation microscopy.

    PubMed

    Gu, Min; Fu, Ling

    2006-02-06

    Three-dimensional (3-D) image formation in fiber-optical second-harmonic-generation microscopy is revealed to be purely coherent and therefore can be described by a 3-D coherent transfer function (CTF) that exhibits the same spatial frequency passband as that of fiber-optical reflection-mode non-fluorescence microscopy. When the numerical aperture of the fiber is much larger than the angle of convergence of the illumination on the fiber aperture, the performance of fiber-optical second-harmonic-generation microscopy behaves as confocal second-harmonic-generation microscopy. The dependence of axial resolution on fiber coupling parameters shows an improvement of approximately 7%, compared with that in fiber-optical two-photon fluorescence microscopy.

  19. Role of bronchoscopy in evaluation of cases with sputum smear negative pulmonary tuberculosis, interstitial lung disease and lung malignancy: A retrospective study of 712 cases.

    PubMed

    Kumar, Raj; Gupta, Nitesh

    2015-01-01

    The introduction of flexible bronchoscope has revolutionized the field of pulmonary medicine and is a standard instrument used for diagnostic purpose. A retrospective analysis of the clinico-radiological profile, indication, biopsy procedure and complications, for patients undergoing bronchoscopy at one of the respiratory unit at a tertiary care center in India. Retrospective analysis of 712 bronchoscopies was done in regard to demographic profile, clinical and radiological presentation and diagnostic indication. The results were analyzed on basis of bronchoscopy inspection and histopathological specimen obtained from transbronchial (TBLB), endobronchial biopsy (EBLB) and cytology specimen by transbronchial needle aspiration (TBNA). Furthermore, diagnostic yield of each biopsy procedure and their combination was evaluated. Of 712 patients undergoing bronchoscopy, the pathological diagnosis was achieved in 384 (53.93%). Of 384 diagnosed cases, the clinic-radio-pathological diagnosis of pulmonary tuberculosis in 88 (22.19%), interstitial lung disease (ILDs) in 226 (58.85%), and lung cancer in 70 (18.22%) cases. Of 116 sputum smear negative tuberculosis patients, 88 (75.86%) were diagnosed to be pulmonary tuberculosis; the contribution of BAL being 71.59%. Of 226 ILDs, sarcoidosis was most common 148/226 (65.48%). Among 70 lung cancer diagnosed cases, squamous cell carcinoma was most common (54.28%). The results from current study reemphasizes on the diagnostic utility as well as safety of the bronchoscopy procedure. Copyright © 2015 Tuberculosis Association of India. Published by Elsevier B.V. All rights reserved.

  20. Characteristics of Extrinsic Fabry-Perot Interferometric (EFPI) Fiber-Optic Strain Gages

    NASA Technical Reports Server (NTRS)

    Hare, David A.; Moore, Thomas C., Sr.

    2000-01-01

    The focus of this paper is a comparison of the strain-measuring characteristics of one type of commercially available fiber-optic strain sensor with the performance of conventional resistance strain gages. Fabry-Perot type fiber-optic strain sensors were selected for this testing program. Comparative testing is emphasized and includes load testing at room temperature with apparent strain characterization cryogenically and at elevated temperatures. The absolute accuracy of either of these types of strain gages is not addressed.

  1. Development of a novel polymeric fiber-optic magnetostrictive metal detector.

    PubMed

    Hua, Wei-Shu; Hooks, Joshua Rosenberg; Wu, Wen-Jong; Wang, Wei-Chih

    2010-01-01

    The purpose this paper is the development a novel polymeric fiber-optic magnetostrictive metal detector, using a fiber-optic Mach-Zehnder interferometer and polymeric magnetostrictive material. Metal detection is based on the strain-induced optical path length change steming from the ferromagnetic material introduced in the magnetic field. Varied optical phase shifts resulted largely from different metal objects. In this paper, the preliminary results on the different metal material detection will be discussed.

  2. Design of a fiber-optic transmitter for microwave analog transmission with high phase stability

    NASA Technical Reports Server (NTRS)

    Logan, R. T., Jr.; Lutes, G. F.; Primas, L. E.; Maleki, L.

    1990-01-01

    The principal considerations in the design of fiber-optic transmitters for highly phase-stable radio frequency and microwave analog transmission are discussed. Criteria for a fiber-optic transmitter design with improved amplitude and phase-noise performance are developed through consideration of factors affecting the phase noise, including low-frequency laser-bias supply noise, the magnitude and proximity of external reflections into the laser, and temperature excursions of the laser-transmitter package.

  3. An evaluation of in-office flexible fiber-optic biopsies for laryngopharyngeal lesions.

    PubMed

    Lee, Francisco; Smith, Kristine A; Chandarana, Shamir; Matthews, T Wayne; Bosch, J Douglas; Nakoneshny, Steven C; Dort, Joseph C

    2018-05-09

    Operative endoscopy and flexible fiber-optic in-office tissue biopsy are common techniques to assess suspicious laryngopharyngeal lesions. The primary outcome was the delay to the initiation of treatment. Secondary outcomes were delay to biopsy, histopathological diagnosis, and assessment at a multidisciplinary oncology clinic. A retrospective analysis was performed to assess the relative delays between these approaches to biopsy of laryngopharyngeal lesions. There were 114 patients in the study cohort; 44 in-office and 70 operative endoscopic biopsies). The mean delay from consultation to biopsy was 17.4 days for the operative endoscopy group and 1.3 days for the in-office group. The mean delay from initial otolaryngology consultation to initiation of treatment was 51.7 days and 44.6 days for the operative endoscopy and in-office groups, respectively. In-office biopsy reduced the time from initial consultation to biopsy. The temporal gains via in-office biopsy did not translate into faster access to treatment. This outcome highlights the opportunity to improve access to treatment for patients with early diagnosis.

  4. Music does not alter anxiety in patients with suspected lung cancer undergoing bronchoscopy: a randomised controlled trial.

    PubMed

    Jeppesen, Elisabeth; Pedersen, Carsten M; Larsen, Klaus R; Rehl, Anne; Bartholdy, Karen; Walsted, Emil S; Backer, Vibeke

    2016-01-01

    The use of music to relieve anxiety has been examined in various studies, but the results are inconclusive. From April to October 2015, 160 patients undergoing examination of pulmonary nodules were randomly assigned to MusiCure or no music. MusiCure was administered through earplugs to ensure blinding of the staff and was played from admission to the operating theatre to the end of the bronchoscopy. Spielberger's State-Trait Anxiety Inventory (STAI) was administered on admission, immediately before bronchoscopy, and on discharge. Secondary outcomes were p -cortisol, physiological variables, dosage of sedatives, movements measured by Actigraph, bronchoscopy duration, number of re-examinations, and overall perception of the sounds in the operating theatre measured by Visual analogue scale. The STAI scores were similar on admission, but after a 10-min wait in the operating theatre, scores varied significantly between patients with and without music, with lower scores in the music group [median (interquartile range, IQR) 35 (18) vs. 43 (25); p= 0.03]. Post hoc multiple regression revealed treatment group as insignificant when adjusting for sex and baseline anxiety. However, there was a significantly more positive perception of the sounds in the operating theatre in the music group (median (IQR) 8.2 (1.8) vs. 5.4 (6.8); p <0.0001) and fewer re-examinations in the music group (19.2% vs. 7.7%, p< 0.032). Ten minutes with MusiCure does not alter anxiety when adjusting for baseline anxiety and sex. The current study indicates that this field of research has many confounders.

  5. 1% Versus 2% Lignocaine for Airway Anesthesia in Flexible Bronchoscopy Without Lignocaine Nebulization (LIFE): A Randomized Controlled Trial.

    PubMed

    Madan, Karan; Biswal, Shiba K; Mittal, Saurabh; Hadda, Vijay; Mohan, Anant; Khilnani, Gopi C; Pandey, Ravindra M; Guleria, Randeep

    2018-04-01

    The ideal concentration of lignocaine for topical anesthesia in bronchoscopy remains investigational. In this randomized, double blind study, we compared 1% versus 2% lignocaine for topical anesthesia. Consecutive patients undergoing bronchoscopy were randomized to receive either 1% or 2% lignocaine solution by spray-as-you-go technique. All received 10% lignocaine spray to the oropharynx along with nasal 2% lignocaine gel. Nebulized lignocaine was not administered. Primary outcomes were operator-rated overall procedural satisfaction, visual analogue scale (VAS)-rated and operator-rated cough, VAS. Secondary objectives were total lignocaine dose administered, patient-rated pain on faces pain scale, cumulative dose of lignocaine and procedural complications. A total of 500 patients (250 in each group) were randomized. Baseline characteristics were comparable. Operator-rated overall procedural satisfaction, VAS (72.05±20.16 and 72.20±21.96 in 1% and 2% group respectively; P=0.93) and operator-rated cough, VAS [1% group: 19.1 (12.6-34.6) and 2% group: 20.6 (12.5-36.9); P>0.05] were similar between the 2 groups. Cumulative dose of lignocaine used in 2% lignocaine group was greater (220.89±12.96 mg in 1% and 319.55±19.32 mg in 2% group; P<0.001). Patients receiving sedation were comparable between the 2 groups. (10% in 1% lignocaine group and 6% in 2% lignocaine group; P=0.13). Minor complications occurred in 2 patients in each group. One percent lignocaine in flexible bronchoscopy is as efficacious as 2% lignocaine when administered using the spray as you go technique without concurrent lignocaine nebulization, at a significantly lower total dose of lignocaine administered.

  6. Percutaneous fiber-optic sensor for the detection of chemotherapy-induced apoptosis in vivo

    NASA Astrophysics Data System (ADS)

    O'Kelly, James; Liao, Kuo-Chih; Clifton, William; Lu, Daning; Koeffler, Phillip; Loeb, Gerald

    2010-02-01

    Early imaging of tumor response to chemotherapy has the potential for significant clinical benefits. We are developing a family of fiber-optic sensors called SencilsTM (sensory cilia), which are disposable, minimally invasive, and can provide in vivo monitoring of various analytes for several weeks. The objective of this study was to develop and test our sensor to image the labeling of phosphatidylserine by apoptotic cells in response to chemotherapeutic drugs. FM1-43 was a better fluorescent marker for detecting phosphatidylserine expression than Annexin V-FITC; both the proportion of labeled cells (Annexin V, 15%; FM1-43, 58%) and the relative fluorescent increase (Annexin V-FITC, 1.5-fold; FM1-43, 4.5-fold) was greater when FM1-43 was used to detect apoptosis. Initial testing of the optical sensing technology using Taxol-treated MCF-7 cells demonstrated that injection of FM1-43 resulted in a rapid, transient increase in fluorescence that was greater in apoptotic cells compared to control cells (apoptotic cells, 4-fold increase; control cells, 2-fold increase). Using an established animal model, mice were injected with cyclophosphamide and hepatic apoptosis was assessed by imaging of PS expression. Both the amplitude of fluorescence increase and the time taken for the amplitude to decay to half of its peak were increased in livers from animals treated with cyclophosphamide. Our optical sensing technology can be used to detect the early apoptotic response of cells to chemotherapeutic drugs both in vitro and in vivo. This novel technology represents a unique option for the imaging of tumor responses in vivo, and provides an inexpensive, specific system for the detection of early-stage apoptosis.

  7. Comparing Patient Satisfaction and Intubating Conditions Using Succinylcholine or Low-Dose Rocuronium for Rigid Bronchoscopy: A Randomized Study.

    PubMed

    Ghezel-Ahmadi, Verena; Ghezel-Ahmadi, David; Mangen, Jacques; Bolukbas, Servet; Welker, Andreas; Kuerschner, Veit Christian; Fischer, Andreas; Schirren, Joachim; Beck, Grietje

    2015-09-01

    Despite its serious side effects, succinylcholine is commonly used for neuromuscular relaxation in short procedures, such as rigid bronchoscopy and tracheobronchial interventions. The application of low-dose rocuronium reversed by low-dose sugammadex might be a modern alternative. The aim of this study was to compare patient satisfaction, incidence of postoperative myalgia (POM) as well as intubating conditions of these two muscle relaxants for rigid bronchoscopy. A single-center, prospective-randomized, blinded study of 95 patients, scheduled for rigid bronchoscopy and tracheobronchial intervention was conducted. The patients were anesthetized with propofol, remifentanil and either low-dose succinylcholine (S) (0.5 mg/kg) or low-dose rocuronium (0.25 mg/kg) with sugammadex (RS) (0.5 mg/kg). All patients were evaluated on the first and second postinterventional day for their satisfaction with the treatment (rigid bronchoscopy) using a Numeric Analog Rating Scale (NAS 0-10) and the presence and severity of POM (NAS 1-4). Intubating conditions were assessed as excellent, good, or poor on the basis of position of vocal cords and reaction to insertion of the rigid bronchoscope. Patients in the S group were less satisfied with the treatment than patients in RS group (72.7 vs. 93.7%, p = 0.007). The incidence of POM on the first day after intervention was significantly higher in the S group then in the RS group (56.9% vs. 4.3%, p < 0.001). Although the intubation was faster (p < 0.001) and the intubating conditions significantly superior (p < 0.003) with succinylcholine, acceptable conditions were also achieved with low-dose rocuronium in 75% of patients. The anesthetic drug costs were significantly higher in the RS group then in the S group (p < 0.001). The results suggest that low-dose rocuronium provided better patient satisfaction and less POM. But with the use of low-dose succinylcholine, the intubating conditions are more comfortable, and it is

  8. Fiber-Optic Sensor Would Monitor Growth of Polymer Film

    NASA Technical Reports Server (NTRS)

    Beamesderfer, Michael

    2005-01-01

    A proposed optoelectronic sensor system would measure the increase in thickness of a film of parylene (a thermoplastic polymer made from para-xylene) during growth of the film in a vapor deposition process. By enabling real-time monitoring of film thickness, the system would make it possible to identify process conditions favorable for growth and to tailor the final thickness of the film with greater precision than is now possible. The heart of the sensor would be a pair of fiber-optic Fabry-Perot interferometers, depicted schematically in the figure. (In principle, a single such interferometer would suffice. The proposal calls for the use of two interferometers for protective redundancy and increased accuracy.) Each interferometer would include a light source, a fiber-optic coupler, and photodetectors in a control box outside the deposition chamber. A single-mode optical fiber for each interferometer would run from inside the control box to a fused-silica faceplate in a sensor head. The sensory tips of the optical fibers would be polished flush with the free surface of the faceplate. In preparation for use, the sensor head would be mounted with a hermetic seal in a feed-through port in the deposition chamber, such that free face of the faceplate and the sensory tips of the optical fibers would be exposed to the deposition environment. During operation, light would travel along each optical fiber from the control box to the sensor head. A small portion of the light would be reflected toward the control box from the end face of each fiber. Once growth of the parylene film started, a small portion of the light would also be reflected toward the control box from the outer surface of the film. In the control box, the two reflected portions of the light beam would interfere in one of the photodetectors. The difference between the phases of the interfering reflected portions of the light beam would vary in proportion to the increasing thickness of the film and the known

  9. [Electrocautery and bronchoscopy as a first step for the management of central airway obstruction and associated hemoptysis].

    PubMed

    Jalilie, Alfredo; Carvajal, Juan Carlos; Aparicio, Rodrigo; Meneses, Manuel

    2016-11-01

    Central airway obstruction caused by malignant or benign lesions, associated in some cases with hemoptysis, is a condition with high morbidity and mortality. The use of electrocautery by flexible bronchoscopy is an initial treatment option with immediate improvement of obstruction symptoms. It is as effective as Nd: YAG laser. To describe the usefulness of electrocautery in the management of central obstruction of the airway and hemoptysis. A retrospective, descriptive study of patients referred for management of central airway obstruction or associated hemoptysis. Diagnoses, symptoms (dyspnea, cough, and hemoptysis) and radiology before and after the procedures were analyzed. Eighteen patients aged 59 ± 12 years (66% males) were evaluated, registering 25 endoscopic procedures. Three conditions were found: partial or complete airway obstruction, hemoptysis and post lung transplant bronchial stenosis. Seventy two percent presented with dyspnea, 61% with cough and 33% with hemoptysis. Sixty six percent of patients had airway obstruction caused by malignant metastatic lesions. After electrocautery, 17 patients (94.4%) improved their symptoms and achieved complete airway clearing. Three patients had significant bronchial stenosis after lung transplant achieving subsequent clearing after electrocautery. Electrocautery during flexible bronchoscopy is an effective and safe procedure for the management of central airway obstruction and associated hemoptysis.

  10. [How practical guidelines can be applied in poor countries? Example of the introduction of a bronchoscopy unit in Cambodia].

    PubMed

    Couraud, S; Chan, S; Avrillon, V; Horn, K; Try, S; Gérinière, L; Perrot, É; Guichon, C; Souquet, P-J; Ny, C

    2013-10-01

    According to UN, Cambodia is one of the poorest countries in the World. Respiratory diseases are current public health priorities. In this context, a new bronchoscopy unit (BSU) was created in the respiratory medicine department of Preah Kossamak hospital (PKH) thanks to a tight cooperation between a French and a Cambodian team. Aim of this study was to describe conditions of introduction of this equipment. Two guidelines for practice are available. They are respectively edited by the French and British societies of pulmonology. These guidelines were reviewed and compared to the conditions in which BS was introduced in PKH. Each item from guidelines was combined to a categorical value: "applied", "adapted" or "not applied". In 2009, 54 bronchoscopies were performed in PKH, mainly for suspicion of infectious or tumour disease. In total, 52% and 46% of the French and British guideline items respectively were followed in this Cambodian unit. Patient safety items are those highly followed. By contrast "staff safety" items were those weakly applied. Implementation of EBS in developing countries seems feasible in good conditions of quality and safety for patients. However, some recommendations cannot be applied due to local conditions. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  11. [A comparison of various supraglottic airway devices for fiberoptical guided tracheal intubation].

    PubMed

    Metterlein, Thomas; Dintenfelder, Anna; Plank, Christoph; Graf, Bernhard; Roth, Gabriel

    Fiberoptical assisted intubation via placed supraglottic airway devices has been described as safe and easy procedure to manage difficult airways. However visualization of the glottis aperture is essential for fiberoptical assisted intubation. Various different supraglottic airway devices are commercially available and might offer different conditions for fiberoptical assisted intubation. The aim of this study was to compare the best obtainable view of the glottic aperture using different supraglottic airway devices. With approval of the local ethics committee 52 adult patients undergoing elective anesthesia were randomly assigned to a supraglottic airway device (Laryngeal Tube, Laryngeal Mask Airway I-Gel, Laryngeal Mask Airway Unique, Laryngeal Mask Airway Supreme, Laryngeal Mask Airway Aura-once). After standardized induction of anaesthesia the supraglottic airway device was placed according to the manufacturers recommendations. After successful ventilation the position of the supraglottic airway device in regard to the glottic opening was examined with a flexible fiberscope. A fully or partially visible glottic aperture was considered as suitable for fiberoptical assisted intubation. Suitability for fiberoptical assisted intubation was compared between the groups (H-test, U-test; p<0.05). Demographic data was not different between the groups. Placement of the supraglottic airway device and adequate ventilation was successful in all attempts. Glottic view suitable for fiberoptical assisted intubation differed between the devices ranging from 40% for the laringeal tube (LT), 66% for the laryngeal mask airway Supreme, 70% for the Laryngeal Mask Airway I-Gel and 90% for both the Laryngeal Mask Airway Unique and the Laryngeal Mask Airway Aura-once. None of the used supraglottic airway devices offered a full or partial glottic view in all cases. However the Laryngeal Mask Airway Unique and the Laryngeal Mask Airway Aura-once seem to be more suitable for fiberoptical

  12. A comparison of various supraglottic airway devices for fiberoptical guided tracheal intubation.

    PubMed

    Metterlein, Thomas; Dintenfelder, Anna; Plank, Christoph; Graf, Bernhard; Roth, Gabriel

    Fiberoptical assisted intubation via placed supraglottic airway devices has been described as safe and easy procedure to manage difficult airways. However visualization of the glottis aperture is essential for fiberoptical assisted intubation. Various different supraglottic airway devices are commercially available and might offer different conditions for fiberoptical assisted intubation. The aim of this study was to compare the best obtainable view of the glottic aperture using different supraglottic airway devices. With approval of the local ethics committee 52 adult patients undergoing elective anesthesia were randomly assigned to a supraglottic airway device (Laryngeal Tube, Laryngeal Mask Airway I-Gel, Laryngeal Mask Airway Unique, Laryngeal Mask Airway Supreme, Laryngeal Mask Airway Aura-once). After standardized induction of anesthesia the supraglottic airway device was placed according to the manufacturers recommendations. After successful ventilation the position of the supraglottic airway device in regard to the glottic opening was examined with a flexible fiberscope. A fully or partially visible glottic aperture was considered as suitable for fiberoptical assisted intubation. Suitability for fiberoptical assisted intubation was compared between the groups (H-test, U-test; p<0.05). Demographic data was not different between the groups. Placement of the supraglottic airway device and adequate ventilation was successful in all attempts. Glottic view suitable for fiberoptical assisted intubation differed between the devices ranging from 40% for the laringeal tube (LT), 66% for the laryngeal mask airway Supreme, 70% for the Laryngeal Mask Airway I-Gel and 90% for both the Laryngeal Mask Airway Unique and the Laryngeal Mask Airway Aura-once. None of the used supraglottic airway devices offered a full or partial glottic view in all cases. However the Laryngeal Mask Airway Unique and the Laryngeal Mask Airway Aura-once seem to be more suitable for fiberoptical

  13. Lightning Current Measurement with Fiber-Optic Sensor

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Ely, Jay J.; Szatkowski, George N.; Mata, Carlos T.; Mata, Angel G.; Snyder, Gary P.

    2014-01-01

    A fiber-optic current sensor is successfully developed with many potential applications for electric current measurement. Originally developed for in-flight lightning measurement, the sensor utilizes Faraday Effect in an optical fiber. The Faraday Effect causes linear light polarization in a fiber to rotate when the fiber is exposed to a magnetic field. The polarization change is detected using a reflective polarimetric scheme. Forming fiber loops and applying Ampere's law, measuring the total light rotation results in the determination of the total current enclosed. The sensor is conformable to complex structure geometry. It is also non-conductive and immune to electromagnetic interference, saturation or hysteresis. Installation is non-intrusive, and the sensor can be safely routed through flammable areas. Two similar sensor systems are described in this paper. The first system operates at 1310nm laser wavelength and is capable of measuring approximately 300 A - 300 kA, a 60 dB range. Laboratory validation results of aircraft lighting direct and in-direct effect current amplitudes are reported for this sensor. The second system operates at 1550nm wavelength and can measure about 400 A - 400 kA. Triggered-lightning measurement data are presented for this system. Good results are achieved in all cases.

  14. Fiber-Optic Surface Temperature Sensor Based on Modal Interference.

    PubMed

    Musin, Frédéric; Mégret, Patrice; Wuilpart, Marc

    2016-07-28

    Spatially-integrated surface temperature sensing is highly useful when it comes to controlling processes, detecting hazardous conditions or monitoring the health and safety of equipment and people. Fiber-optic sensing based on modal interference has shown great sensitivity to temperature variation, by means of cost-effective image-processing of few-mode interference patterns. New developments in the field of sensor configuration, as described in this paper, include an innovative cooling and heating phase discrimination functionality and more precise measurements, based entirely on the image processing of interference patterns. The proposed technique was applied to the measurement of the integrated surface temperature of a hollow cylinder and compared with a conventional measurement system, consisting of an infrared camera and precision temperature probe. As a result, the optical technique is in line with the reference system. Compared with conventional surface temperature probes, the optical technique has the following advantages: low heat capacity temperature measurement errors, easier spatial deployment, and replacement of multiple angle infrared camera shooting and the continuous monitoring of surfaces that are not visually accessible.

  15. Fiber-optic bending sensor for cochlear implantation

    NASA Astrophysics Data System (ADS)

    Li, Enbang; Yao, Jianquan

    2006-09-01

    Cochlear implantation has been proved as a great success in treating profound sensorineural deafness in both children and adults. Cochlear electrode array implantation is a complex and delicate surgical process. Surgically induced damage to the inner wall of the scala tympani could happen if the insertion angle of the electrode is incorrect and an excessive insertion force is applied to the electrode. This damage could lead to severe degeneration of the remaining neural elements. It is therefore of vital importance to monitor the shape and position of the electrode during the implantation surgery. In this paper, we report a fiber-optic bending sensor which can be integrated with the electrode and used to guide the implantation process. The sensor consists of a piece of optical fiber. The end of the fiber is coated with aluminum layer to form a mirror. Bending the fiber with the electrode introduces loss to the light transmitting in the fiber. By detecting the power of the reflected light, we can detennine the bending happened to the fiber, and consequently measure the curved shape of the electrode. Experimental results show that the proposed fiber sensor is a promising technique to make in-situ monitoring of the shape and position of the electrode during the implantation process.

  16. Controlling formation and suppression of fiber-optical rogue waves.

    PubMed

    Brée, Carsten; Steinmeyer, Günter; Babushkin, Ihar; Morgner, Uwe; Demircan, Ayhan

    2016-08-01

    Fiber-optical rogue waves appear as rare but extreme events during optical supercontinuum generation in photonic crystal fibers. This process is typically initiated by the decay of a high-order fundamental soliton into fundamental solitons. Collisions between these solitons as well as with dispersive radiation affect the soliton trajectory in frequency and time upon further propagation. Launching an additional dispersive wave at carefully chosen delay and wavelength enables statistical manipulation of the soliton trajectory in such a way that the probability of rogue wave formation is either enhanced or reduced. To enable efficient control, parameters of the dispersive wave have to be chosen to allow trapping of dispersive radiation in the nonlinear index depression created by the soliton. Under certain conditions, direct manipulation of soliton properties is possible by the dispersive wave. In other more complex scenarios, control is possible via increasing or decreasing the number of intersoliton collisions. The control mechanism reaches a remarkable efficiency, enabling control of relatively large soliton energies. This scenario appears promising for highly dynamic all-optical control of supercontinua.

  17. Portable fiber-optic taper coupled optical microscopy platform

    NASA Astrophysics Data System (ADS)

    Wang, Weiming; Yu, Yan; Huang, Hui; Ou, Jinping

    2017-04-01

    The optical fiber taper coupled with CMOS has advantages of high sensitivity, compact structure and low distortion in the imaging platform. So it is widely used in low light, high speed and X-ray imaging systems. In the meanwhile, the peculiarity of the coupled structure can meet the needs of the demand in microscopy imaging. Toward this end, we developed a microscopic imaging platform based on the coupling of cellphone camera module and fiber optic taper for the measurement of the human blood samples and ascaris lumbricoides. The platform, weighing 70 grams, is based on the existing camera module of the smartphone and a fiber-optic array which providing a magnification factor of 6x.The top facet of the taper, on which samples are placed, serves as an irregular sampling grid for contact imaging. The magnified images of the sample, located on the bottom facet of the fiber, are then projected onto the CMOS sensor. This paper introduces the portable medical imaging system based on the optical fiber coupling with CMOS, and theoretically analyzes the feasibility of the system. The image data and process results either can be stored on the memory or transmitted to the remote medical institutions for the telemedicine. We validate the performance of this cell-phone based microscopy platform using human blood samples and test target, achieving comparable results to a standard bench-top microscope.

  18. Duplexed sandwich immunoassays on a fiber-optic microarray.

    PubMed

    Rissin, David M; Walt, David R

    2006-03-30

    In this paper, we describe a duplexed imaging optical fiber array-based immunoassay for immunoglobulin A (IgA) and lactoferrin. To fabricate the individually addressable array, microspheres were functionalized with highly specific monoclonal antibodies. The microspheres were loaded in microwells etched into the distal face of an imaging optical fiber bundle. Two microsphere-based sandwich immunoassays were developed to simultaneously detect IgA and lactoferrin, two innate immune system proteins found in human saliva. Individual microspheres could be interrogated for the simultaneous measurement of both proteins. The working concentration range for IgA detection was between 700 pM and 100 nM, while the working concentration range for lactoferrin was between 385 pM and 10 nM. The cross-reactivity between detection antibodies and their non-specific targets was relatively low in comparison to the signal generated by the specific binding with their targets. These results suggest that the degree of multiplexing on this fiber-optic array platform can be increased beyond a duplex.

  19. A Fiber-Optic Aircraft Lightning Current Measurement Sensor

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Ely, Jay J.; Szatkowski, George N.

    2013-01-01

    A fiber-optic current sensor based on the Faraday Effect is developed for aircraft installations. It can measure total lightning current amplitudes and waveforms, including continuing current. Additional benefits include being small, lightweight, non-conducting, safe from electromagnetic interference, and free of hysteresis and saturation. The Faraday Effect causes light polarization to rotate in presence of magnetic field in the direction of light propagation. Measuring the total induced light polarization change yields the total current enclosed. The system operates at 1310nm laser wavelength and can measure approximately 300 A - 300 kA, a 60 dB range. A reflective polarimetric scheme is used, where the light polarization change is measured after a round-trip propagation through the fiber. A two-detector setup measures the two orthogonal polarizations for noise subtraction and improved dynamic range. The current response curve is non-linear and requires a simple spline-fit correction. Effects of high current were achieved in laboratory using combinations of multiple fiber and wire loops. Good result comparisons against reference sensors were achieved up to 300 kA. Accurate measurements on a simulated aircraft fuselage and an internal structure illustrate capabilities that maybe difficult with traditional sensors. Also tested at a commercial lightning test facility from 20 kA to 200 kA, accuracy within 3-10% was achieved even with non-optimum setups.

  20. Novel adaptive fiber-optics collimator for coherent beam combination.

    PubMed

    Zhi, Dong; Ma, Pengfei; Ma, Yanxing; Wang, Xiaolin; Zhou, Pu; Si, Lei

    2014-12-15

    In this manuscript, we experimentally validate a novel design of adaptive fiber-optics collimator (AFOC), which utilizes two levers to enlarge the movable range of the fiber end cap. The enlargement of the range makes the new AFOC possible to compensate the end-cap/tilt aberration in fiber laser beam combining system. The new AFOC based on flexible hinges and levers was fabricated and the performance of the new AFOC was tested carefully, including its control range, frequency response and control accuracy. Coherent beam combination (CBC) of two 5-W fiber amplifiers array with simultaneously end-cap/tilt control and phase-locking control was implemented successfully with the novel AFOC. Experimental results show that the average normalized power in the bucket (PIB) value increases from 0.311 to 0.934 with active phasing and tilt aberration compensation simultaneously, and with both controls on, the fringe contrast improves to more than 82% from 0% for the case with both control off. This work presents a promising structure for tilt aberration control in high power CBC system.

  1. Fiber-Optic Network Observations of Earthquake Wavefields

    NASA Astrophysics Data System (ADS)

    Lindsey, Nathaniel J.; Martin, Eileen R.; Dreger, Douglas S.; Freifeld, Barry; Cole, Stephen; James, Stephanie R.; Biondi, Biondo L.; Ajo-Franklin, Jonathan B.

    2017-12-01

    Our understanding of subsurface processes suffers from a profound observation bias: seismometers are sparse and clustered on continents. A new seismic recording approach, distributed acoustic sensing (DAS), transforms telecommunication fiber-optic cables into sensor arrays enabling meter-scale recording over tens of kilometers of linear fiber length. We analyze cataloged earthquake observations from three DAS arrays with different horizontal geometries to demonstrate some possibilities using this technology. In Fairbanks, Alaska, we find that stacking ground motion records along 20 m of fiber yield a waveform that shows a high degree of correlation in amplitude and phase with a colocated inertial seismometer record at 0.8-1.6 Hz. Using an L-shaped DAS array in Northern California, we record the nearly vertically incident arrival of an earthquake from The Geysers Geothermal Field and estimate its backazimuth and slowness via beamforming for different phases of the seismic wavefield. Lastly, we install a fiber in existing telecommunications conduits below Stanford University and show that little cable-to-soil coupling is required for teleseismic P and S phase arrival detection.

  2. Fiber-Optic Strain Gauge With High Resolution And Update Rate

    NASA Technical Reports Server (NTRS)

    Figueroa, Fernando; Mahajan, Ajay; Sayeh, Mohammad; Regez, Bradley

    2007-01-01

    An improved fiber-optic strain gauge is capable of measuring strains in the approximate range of 0 to 50 microstrains with a resolution of 0.1 microstrain. (To some extent, the resolution of the strain gauge can be tailored and may be extensible to 0.01 microstrain.) The total cost of the hardware components of this strain gauge is less than $100 at 2006 prices. In comparison with prior strain gauges capable of measurement of such low strains, this strain gauge is more accurate, more economical, and more robust, and it operates at a higher update rate. Strain gauges like this one are useful mainly for measuring small strains (including those associated with vibrations) in such structures as rocket test stands, buildings, oilrigs, bridges, and dams. The technology was inspired by the need to measure very small strains on structures supporting liquid oxygen tanks, as a way to measure accurately mass of liquid oxygen during rocket engine testing. This improved fiber-optic strain gauge was developed to overcome some of the deficiencies of both traditional foil strain gauges and prior fiber-optic strain gauges. Traditional foil strain gages do not have adequate signal-to-noise ratios at such small strains. Fiber-optic strain gauges have been shown to be potentially useful for measuring such small strains, but heretofore, the use of fiberoptic strain gauges has been inhibited, variously, by complexity, cost, or low update rate.

  3. Calibration and Deployment of a Fiber-Optic Sensing System for Monitoring Debris Flows

    PubMed Central

    Huang, Ching-Jer; Chu, Chung-Ray; Tien, Tsung-Mo; Yin, Hsiao-Yuen; Chen, Ping-Sen

    2012-01-01

    This work presents a novel fiber-optic sensing system, capable of monitoring debris flows or other natural hazards that produce ground vibrations. The proposed sensing system comprises a demodulator (BraggSCOPE, FS5500), which includes a broadband light source and a data logger, a four-port coupler and four Fiber Bragg Grating (FBG) accelerometers. Based on field tests, the performance of the proposed fiber-optic sensing system is compared with that of a conventional sensing system that includes a geophone or a microphone. Following confirmation of the reliability of the proposed sensing system, the fiber-optic sensing systems are deployed along the Ai-Yu-Zi and Chu-Shui Creeks in Nautou County of central Taiwan for monitoring debris flows. Sensitivity test of the deployed fiber-optic sensing system along the creek banks is also performed. Analysis results of the seismic data recorded by the systems reveal in detail the frequency characteristics of the artificially generated ground vibrations. Results of this study demonstrate that the proposed fiber-optic sensing system is highly promising for use in monitoring natural disasters that generate ground vibrations. PMID:22778616

  4. Theoretical and experimental analysis of analyte transport in a fiber-optic, protein C immuno-biosensor.

    PubMed

    Tang, Liang; Kwon, Hyun J; Kang, Kyung A

    2004-12-30

    Protein C (PC) is an important anticoagulant in human blood plasma, and early diagnosis of PC deficiency is critical for preventing dangerous thromboembolic complications. A fiber-optic PC immuno-biosensor has been under development in our research group for real-time PC-deficiency diagnosis. The sensor has demonstrated a good sensitivity and specificity for quantifying PC in buffered solutions. However, for plasma samples, with a limited sample reaction time, the sensor produced only 30% of the signal intensity of PC in buffer. The high plasma viscosity (1.9 cP) was speculated as the major reason for signal intensity reduction. In this investigation, the sensing performance of the fiber-optic PC biosensor is systematically characterized in terms of physical and chemical properties of the sample media. Theoretical and experimental analyses indicate that the reduced diffusion rate of PC molecules in viscous samples caused the sensing system to be more mass-transfer-limited. Convective flow of sample/reagent solutions during immunoreactions can increase the rate of the analyte mass transport from the bulk solution to the sensor surface, with reaction kinetics changing from mass-transfer-limited to reaction-limited as flow velocity increases. It was shown that PC sensor performance was significantly improved for plasma samples with convection. The effect of the flow velocity and incubation times for samples and reagents on the sensor performance was also systematically analyzed to optimize the assay protocol for PC sensing. Currently, a 6-cm-long immuno-biosensor is capable of quantifying PC in plasma (1 mL) in the heterozygous PC deficiency range (0.5 to 2.5 microg/mL) within 5 minutes, at an average signal-to-noise ratio of 50. 2004 Wiley Periodicals, Inc.

  5. High-speed fiber-optic links for distribution of satellite traffic

    NASA Technical Reports Server (NTRS)

    Daryoush, Afshin S.; Saedi, Reza; Ackerman, Edward; Kunath, Richard; Shalkhauser, Kurt

    1990-01-01

    Low-loss fiberoptic links are designed for distribution of data and the frequency reference in large-aperture phased-array antennas based on the transmit/receive-level data mixing architecture. In particular, design aspects of a fiberoptic link satisfying the distribution requirements of satellite data traffic are presented. The design is addressed in terms of reactively matched optical transmitter and receiver modules. Analog and digital characterization of a 50-m fiberoptic link realized using these modules indicates the applicability of this architecture as the only viable alternative for distribution of data signals inside a satellite at present. It is demonstrated that the design of a reactive matching modules enhances the link performance. A dynamic range of 88 dB/MHz was measured for analog data over a 500-1000-MHz bandwidth.

  6. Architecture for fiber-optic sensors and actuators in aircraft propulsion systems

    NASA Technical Reports Server (NTRS)

    Glomb, W. L., Jr.

    1990-01-01

    This paper describes a design for fiber-optic sensing and control in advanced aircraft Electronic Engine Control (EEC). The recommended architecture is an on-engine EEC which contains electro-optic interface circuits for fiber-optic sensors. Size and weight are reduced by multiplexing arrays of functionally similar sensors on a pairs of optical fibers to common electro-optical interfaces. The architecture contains interfaces to seven sensor groups. Nine distinct fiber-optic sensor types were found to provide the sensing functions. Analysis revealed no strong discriminator (except reliability of laser diodes and remote electronics) on which to base a selection of preferred common interface type. A hardware test program is recommended to assess the relative maturity of the technologies and to determine real performance in the engine environment.

  7. Fiber-optical sensor with intensity compensation model in college teaching of physics experiment

    NASA Astrophysics Data System (ADS)

    Su, Liping; Zhang, Yang; Li, Kun; Zhang, Yu

    2017-08-01

    Optical fiber sensor technology is one of the main contents of modern information technology, which has a very important position in modern science and technology. Fiber optic sensor experiment can improve students' enthusiasm and broaden their horizons in college physics experiment. In this paper the main structure and working principle of fiberoptical sensor with intensity compensation model are introduced. And thus fiber-optical sensor with intensity compensation model is applied to measure micro displacement of Young's modulus measurement experiment and metal linear expansion coefficient measurement experiment in the college physics experiment. Results indicate that the measurement accuracy of micro displacement is higher than that of the traditional methods using fiber-optical sensor with intensity compensation model. Meanwhile this measurement method makes the students understand on the optical fiber, sensor and nature of micro displacement measurement method and makes each experiment strengthen relationship and compatibility, which provides a new idea for the reform of experimental teaching.

  8. Distributed fiber-optic laser-ultrasound generation based on ghost-mode of tilted fiber Bragg gratings.

    PubMed

    Tian, Jiajun; Zhang, Qi; Han, Ming

    2013-03-11

    Active ultrasonic testing is widely used for medical diagnosis, material characterization and structural health monitoring. Ultrasonic transducer is a key component in active ultrasonic testing. Due to their many advantages such as small size, light weight, and immunity to electromagnetic interference, fiber-optic ultrasonic transducers are particularly attractive for permanent, embedded applications in active ultrasonic testing for structural health monitoring. However, current fiber-optic transducers only allow effective ultrasound generation at a single location of the fiber end. Here we demonstrate a fiber-optic device that can effectively generate ultrasound at multiple, selected locations along a fiber in a controllable manner based on a smart light tapping scheme that only taps out the light of a particular wavelength for laser-ultrasound generation and allow light of longer wavelengths pass by without loss. Such a scheme may also find applications in remote fiber-optic device tuning and quasi-distributed biochemical fiber-optic sensing.

  9. Thermal injury secondary to laparoscopic fiber-optic cables.

    PubMed

    Hindle, A Katharine; Brody, Fred; Hopkins, Vernon; Rosales, Greg; Gonzalez, Florencia; Schwartz, Arnold

    2009-08-01

    Laparoscopy requires a reliable light source to provide adequate visualization. However, thermal energy is produced as a by-product from the optical cable. This study attempts to quantify the degree of possible thermal damage secondary to the fiber-optic light source. Using a digital thermometer, temperature measurements were recorded at the tip of optical cables from five different light sources (Karl Storz, Inc., Tuttlingen, Germany). Temperature measurements were recorded with new and old bulbs. The tip of the cable was applied to surgical drapes and the time to charring was recorded. Subsequently, the tip of the optical cable was applied to a porcine model and tissue samples were obtained after varying amounts of time (5, 15, 30, 60, and 90 s). Sections of the damaged tissue were prepared for microscopic evaluation. Parameters for thermal injury included extent of epidermal, dermal, and subcutaneous fat damage and necrosis. The lateral extent and depth of injury were measured. The maximum temperature at the tip of the optical cable varied between 119.5 degrees C and 268.6 degrees C. When surgical drapes were exposed to the tip of the light source, the time to char was 3-6 s. The degree and volume of injury increased with longer exposure times, and significant injury was recorded with the optical cable 3 mm from the skin. This study demonstrates that the temperature at the tip of the optical light cord can induce extensive damage. The by-product of light, heat, can produce immediate superficial tissue necrosis that can extend into the subcutaneous fat even when the optical tip is not in direct contact with the skin. In addition, our study shows the variation in temperature that exists between light sources and bulb status. Overall, surgeons must realize and respect the potential complications associated with optical technology.

  10. Multipurpose fiber-optic sensor with sloped tip

    NASA Astrophysics Data System (ADS)

    Melnik, Ivan S.; Krivokhizha, A. M.; Ptashnik, O. V.

    1991-08-01

    Fiber-optic sensors C FOS) are wi. del y used for rioncontact measurements due to their simplicity, small size, insensitivity to I nfl uence of el ectromagneti C fiel ds , hi gh metrol ogi cal characteristics, etc. The operation principle of FOS with intensity modul ati on techni que I s based on the photodetector regi strati on of 1ight , reflected from the control 1 ed surface E I ) . The i ntensi ty of detected 1 1 ght depends on th FOS' s di stance from the control 1 ed surface, its form and inclination to sensor's axis, FOS shift speed, etc. So they can be consider multipurpose. We are devel opi ng FOS wi th i ntensi ty modul ati on techni que wi th traight tips as well as with sloped tips. In FOS with sloped tips the light ring spot is appearing on the controlled surface due to the effect of symmetry. We use thi s phenomena to empl oy refl ected 1 i ght more efficiently and to increase the FOS characteristics. Tak i ng I nto account the fact that pr obl ems of cal cul aWl on of fibers with sloped tip were not analyzed in details earlier-, in particular, only the case of light distribution of parallel beams runni ng was consi dered E 2) we wi I 1 conduct a consi stent cal cul ati on of bounds of i rradi ance fi ci d , created by a fi ber wi th sl oped tip, esti mate I i ght di stri buti on I n a 1 1 ght spot , and determi. ne characteristics of the FOS with sloped tip.

  11. Attenuation characteristics of fiberoptic plates for digital mammography and other X-ray imaging applications.

    PubMed

    Vedantham, S; Karellas, A; Suryanarayanan, S

    2003-01-01

    Spatially coherent fiberoptic plates are important components of some charge-coupled device (CCD)-based x-ray imaging systems. These plates efficiently transmit scintillations from the phosphor, and also filter out x-rays not absorbed by the phosphor, thus protecting the CCD from direct x-ray interaction. The thickness of the fiberoptic plate and the CCD package present a significant challenge in the design of a digital x-ray cassette capable of insertion into the existing film-screen cassette holders of digital mammography systems. This study was performed with an aim to optimize fiberoptic plate thickness. Attenuation measurements were performed on nine fiberoptic plates varying in material composition that exhibit desirable optical characteristics such as good coupling efficiency. Mammographic spectra from a clinical mammographic system and an Americium-241 (Am-241) source (59.54 KeV) were used. The spectra were recorded with a high-resolution cadmium zinc telluride (CZT)-based spectrometer and corrected for dead time and pile-up. The linear attenuation coefficients varied by a factor of 3 in the set of tested fiberoptic plates at both mammographic energies and 59.54 keV. Our results suggest that a 3-mm thick high-absorption plate might provide adequate for shielding at mammographic energies. A thickness of 2-mm is feasible for mammographic applications with further optimization of the fiberoptic plate composition by incorporating non-scintillating, high-atomic number material. This would allow more space for cooling components of the cassette and for a more compact device, which is critical for clinical implementation of the technology.

  12. Rigid ventilation bronchoscopy under general anesthesia for treatment of pediatric pulmonary atelectasis caused by pneumonia: A review of 33 cases.

    PubMed

    Wu, Kuo-Hwa; Lin, Chih-Fu; Huang, Chun-Jen; Chen, Chien-Chuan

    2006-01-01

    Pediatric pulmonary atelectasis caused by pneumonia is a common disease. If the mucus plugs or secretions occlude the bronchial trees and cannot be cleaned by coughing, suctioning, or vigorous respiratory and physical therapy, is rigid ventilation bronchoscopy (V-B) effective and safe as a therapeutic procedure in such patients? We collected 33 cases of pediatric pulmonary atelectasis that were treated by rigid V-B under general anesthesia for removal of the mucus plugs or foreign bodies. During the rigid V-B with lung lavage performed by experienced bronchoscopists, the oxygen saturation was maintained in good condition. No disastrous complications were noted. Sixty-four percent (21/33) of those with pediatric pulmonary atelectasis had significant improvement in either oxygen saturation or chest radiography within 72 hours. We conclude that when the traditional treatment in pediatric pulmonary atelectasis was ineffective, rigid V-B might be an adequate and safe procedure to remove the mucus plugs and restore pulmonary function.

  13. Physical layer security in fiber-optic MIMO-SDM systems: An overview

    NASA Astrophysics Data System (ADS)

    Guan, Kyle; Cho, Junho; Winzer, Peter J.

    2018-02-01

    Fiber-optic transmission systems provide large capacities over enormous distances but are vulnerable to simple eavesdropping attacks at the physical layer. We classify key-based and keyless encryption and physical layer security techniques and discuss them in the context of optical multiple-input-multiple-output space-division multiplexed (MIMO-SDM) fiber-optic communication systems. We show that MIMO-SDM not only increases system capacity, but also ensures the confidentiality of information transmission. Based on recent numerical and experimental results, we review how the unique channel characteristics of MIMO-SDM can be exploited to provide various levels of physical layer security.

  14. Digital phase demodulation for low-coherence interferometry-based fiber-optic sensors

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Strum, R.; Stiles, D.; Long, C.; Rakhman, A.; Blokland, W.; Winder, D.; Riemer, B.; Wendel, M.

    2018-03-01

    We describe a digital phase demodulation scheme for low-coherence interferometry-based fiber-optic sensors by employing a simple generation of phase-shifted signals at the interrogation interferometer. The scheme allows a real-time calibration process and offers capability of measuring large variations (up to the coherence of the light source) at the bandwidth that is only limited by the data acquisition system. The proposed phase demodulation method is analytically derived and its validity and performance are experimentally verified using fiber-optic Fabry-Perot sensors for measurement of strains and vibrations.

  15. Modeling of Thermal Phase Noise in a Solid Core Photonic Crystal Fiber-Optic Gyroscope

    PubMed Central

    Song, Ningfang; Ma, Kun; Jin, Jing; Teng, Fei; Cai, Wei

    2017-01-01

    A theoretical model of the thermal phase noise in a square-wave modulated solid core photonic crystal fiber-optic gyroscope has been established, and then verified by measurements. The results demonstrate a good agreement between theory and experiment. The contribution of the thermal phase noise to the random walk coefficient of the gyroscope is derived. A fiber coil with 2.8 km length is used in the experimental solid core photonic crystal fiber-optic gyroscope, showing a random walk coefficient of 9.25 × 10−5 deg/h. PMID:29072605

  16. Modeling of Thermal Phase Noise in a Solid Core Photonic Crystal Fiber-Optic Gyroscope.

    PubMed

    Song, Ningfang; Ma, Kun; Jin, Jing; Teng, Fei; Cai, Wei

    2017-10-26

    A theoretical model of the thermal phase noise in a square-wave modulated solid core photonic crystal fiber-optic gyroscope has been established, and then verified by measurements. The results demonstrate a good agreement between theory and experiment. The contribution of the thermal phase noise to the random walk coefficient of the gyroscope is derived. A fiber coil with 2.8 km length is used in the experimental solid core photonic crystal fiber-optic gyroscope, showing a random walk coefficient of 9.25 × 10 -5 deg/√h.

  17. Fiber-optic temperature sensor using a spectrum-modulating semiconductor etalon

    NASA Technical Reports Server (NTRS)

    Beheim, Glenn; Anthan, Donald J.; Beheim, Glenn; Anthan, Donald J.

    1987-01-01

    Described is a fiber-optic temperature sensor that uses a spectrum modulating SiC etalon. The spectral output of this type of sensor may be analyzed to obtain a temperature measurement which is largely independent of the transmission properties of the sensor's fiber-optic link. A highly precise laboratory spectrometer is described in detail, and this instrument is used to study the properties of this type of sensor. Also described are a number of different spectrum analyzers that are more suitable for use in a practical thermometer.

  18. Development of a Meso-Scale Fiberoptic Rotation Sensor for a Torsion Actuator.

    PubMed

    Sheng, Jun; Desai, Jaydev P

    2018-01-01

    This paper presents the development of a meso-scale fiberoptic rotation sensor for a shape memory alloy (SMA) torsion actuator for neurosurgical applications. Within the sensor, a rotary head with a reflecting surface is capable of modulating the light intensity collected by optical fibers when the rotary head is coupled to the torsion actuator. The mechanism of light intensity modulation is modeled, followed by experimental model verification. Meanwhile, working performances for different rotary head designs, optical fibers, and fabrication materials are compared. After the calibration of the fiberoptic rotation sensor, the sensor is capable of precisely measuring rotary motion and controlling the SMA torsion actuator with feedback control.

  19. FIBER AND INTEGRATED OPTICS: Compact fiber-optic compressor of ultrashort pulses

    NASA Astrophysics Data System (ADS)

    Nikitin, S. P.; Onishchukov, G. I.; Fomichev, A. A.

    1992-02-01

    A theoretical design of a universal compact fiber-optic compressor based on a monochromator with a spherical mirror in the plane of its exit slit was considered. Ultrashort pulses emitted by an actively mode-locked YAG:Nd3+ laser, whose spectrum was broadened in a fiber-optic waveguide, were compressed experimentally to 2.7 ns. A universal compact compressor was developed: it produced 4-ns pulses with an average radiation power of about 1 W. The dimensions of this compressor were several times smaller than those of a traditional scheme using a diffraction grating to compress pulses having an initial duration of about 100 ns.

  20. Digital phase demodulation for low-coherence interferometry-based fiber-optic sensors

    SciT

    Liu, Y.; Strum, R.; Stiles, D.

    In this paper, we describe a digital phase demodulation scheme for low-coherence interferometry-based fiber-optic sensors by employing a simple generation of phase-shifted signals at the interrogation interferometer. The scheme allows a real-time calibration process and offers capability of measuring large variations (up to the coherence of the light source) at the bandwidth that is only limited by the data acquisition system. Finally, the proposed phase demodulation method is analytically derived and its validity and performance are experimentally verified using fiber-optic Fabry–Perot sensors for measurement of strains and vibrations.

  1. Digital phase demodulation for low-coherence interferometry-based fiber-optic sensors

    DOE PAGES

    Liu, Y.; Strum, R.; Stiles, D.; ...

    2017-11-20

    In this paper, we describe a digital phase demodulation scheme for low-coherence interferometry-based fiber-optic sensors by employing a simple generation of phase-shifted signals at the interrogation interferometer. The scheme allows a real-time calibration process and offers capability of measuring large variations (up to the coherence of the light source) at the bandwidth that is only limited by the data acquisition system. Finally, the proposed phase demodulation method is analytically derived and its validity and performance are experimentally verified using fiber-optic Fabry–Perot sensors for measurement of strains and vibrations.

  2. Pleural Dye Marking Using Radial Endobronchial Ultrasound and Virtual Bronchoscopy before Sublobar Pulmonary Resection for Small Peripheral Nodules.

    PubMed

    Lachkar, Samy; Baste, Jean-Marc; Thiberville, Luc; Peillon, Christophe; Rinieri, Philippe; Piton, Nicolas; Guisier, Florian; Salaun, Mathieu

    2018-01-01

    Minimally invasive surgery of pulmonary nodules allows suboptimal palpation of the lung compared to open thoracotomy. The objective of this study was to assess endoscopic pleural dye marking using radial endobronchial ultrasound (r-EBUS) and virtual bronchoscopy to localize small peripheral lung nodules immediately before minimally invasive resection. The endoscopic procedure was performed without fluoroscopy, under general anesthesia in the operating room immediately before minimally invasive surgery. Then, 1 mL of methylene blue (0.5%) was instilled into the guide sheath, wedged in the subpleural space. Wedge resection or segmentectomy were guided by visualization of the dye on the pleural surface. Contribution of dye marking to the surgical procedure was rated by the surgeon. Twenty-five nodules, including 6 ground glass opacities, were resected in 22 patients by video-assisted thoracoscopic wedge resection (n = 11) or robotic-assisted thoracoscopic surgery (10 segmentectomies and 1 wedge resection). The median greatest diameter of nodules was 8 mm. No conversion to open thoracotomy was needed. The endoscopic procedure added an average 10 min to surgical resection. The dye was visible on the pleural surface in 24 cases. Histological diagnosis and free margin resection were obtained in all cases. Median skin-to-skin operating time was 90 min for robotic segmentectomy and 40 min for video-assisted wedge resection. The same operative precision was considered impossible by the surgeon without dye marking in 21 cases. Dye marking using r-EBUS and virtual bronchoscopy can be easily and safely performed to localize small pulmonary nodules immediately before minimally invasive resection. © 2018 S. Karger AG, Basel.

  3. Fiber-Optic Continuous Liquid Sensor for Cryogenic Propellant Gauging

    NASA Technical Reports Server (NTRS)

    Xu. Wei

    2010-01-01

    An innovative fiber-optic sensor has been developed for low-thrust-level settled mass gauging with measurement uncertainty <0.5 percent over cryogenic propellant tank fill levels from 2 to 98 percent. The proposed sensor uses a single optical fiber to measure liquid level and liquid distribution of cryogenic propellants. Every point of the sensing fiber is a point sensor that not only distinguishes liquid and vapor, but also measures temperature. This sensor is able to determine the physical location of each point sensor with 1-mm spatial resolution. Acting as a continuous array of numerous liquid/vapor point sensors, the truly distributed optical sensing fiber can be installed in a propellant tank in the same manner as silicon diode point sensor stripes using only a single feedthrough to connect to an optical signal interrogation unit outside the tank. Either water or liquid nitrogen levels can be measured within 1-mm spatial resolution up to a distance of 70 meters from the optical interrogation unit. This liquid-level sensing technique was also compared to the pressure gauge measurement technique in water and liquid nitrogen contained in a vertical copper pipe with a reasonable degree of accuracy. It has been demonstrated that the sensor can measure liquid levels in multiple containers containing water or liquid nitrogen with one signal interrogation unit. The liquid levels measured by the multiple fiber sensors were consistent with those virtually measured by a ruler. The sensing performance of various optical fibers has been measured, and has demonstrated that they can survive after immersion at cryogenic temperatures. The fiber strength in liquid nitrogen has also been measured. Multiple water level tests were also conducted under various actual and theoretical vibration conditions, and demonstrated that the signal-to-noise ratio under these vibration conditions, insofar as it affects measurement accuracy, is manageable and robust enough for a wide variety of

  4. Highly Sensitive Temperature Sensors Based on Fiber-Optic PWM and Capacitance Variation Using Thermochromic Sensing Membrane.

    PubMed

    Khan, Md Rajibur Rahaman; Kang, Shin-Won

    2016-07-09

    In this paper, we propose a temperature/thermal sensor that contains a Rhodamine-B sensing membrane. We applied two different sensing methods, namely, fiber-optic pulse width modulation (PWM) and an interdigitated capacitor (IDC)-based temperature sensor to measure the temperature from 5 °C to 100 °C. To the best of our knowledge, the fiber-optic PWM-based temperature sensor is reported for the first time in this study. The proposed fiber-optic PWM temperature sensor has good sensing ability; its sensitivity is ~3.733 mV/°C. The designed temperature-sensing system offers stable sensing responses over a wide dynamic range, good reproducibility properties with a relative standard deviation (RSD) of ~0.021, and the capacity for a linear sensing response with a correlation coefficient of R² ≈ 0.992 over a wide sensing range. In our study, we also developed an IDC temperature sensor that is based on the capacitance variation principle as the IDC sensing element is heated. We compared the performance of the proposed temperature-sensing systems with different fiber-optic temperature sensors (which are based on the fiber-optic wavelength shift method, the long grating fiber-optic Sagnac loop, and probe type fiber-optics) in terms of sensitivity, dynamic range, and linearity. We observed that the proposed sensing systems have better sensing performance than the above-mentioned sensing system.

  5. Embedded fiber-optic sensing for accurate internal monitoring of cell state in advanced battery management systems part 1: Cell embedding method and performance

    NASA Astrophysics Data System (ADS)

    Raghavan, Ajay; Kiesel, Peter; Sommer, Lars Wilko; Schwartz, Julian; Lochbaum, Alexander; Hegyi, Alex; Schuh, Andreas; Arakaki, Kyle; Saha, Bhaskar; Ganguli, Anurag; Kim, Kyung Ho; Kim, ChaeAh; Hah, Hoe Jin; Kim, SeokKoo; Hwang, Gyu-Ok; Chung, Geun-Chang; Choi, Bokkyu; Alamgir, Mohamed

    2017-02-01

    A key challenge hindering the mass adoption of Lithium-ion and other next-gen chemistries in advanced battery applications such as hybrid/electric vehicles (xEVs) has been management of their functional performance for more effective battery utilization and control over their life. Contemporary battery management systems (BMS) reliant on monitoring external parameters such as voltage and current to ensure safe battery operation with the required performance usually result in overdesign and inefficient use of capacity. More informative embedded sensors are desirable for internal cell state monitoring, which could provide accurate state-of-charge (SOC) and state-of-health (SOH) estimates and early failure indicators. Here we present a promising new embedded sensing option developed by our team for cell monitoring, fiber-optic sensors. High-performance large-format pouch cells with embedded fiber-optic sensors were fabricated. The first of this two-part paper focuses on the embedding method details and performance of these cells. The seal integrity, capacity retention, cycle life, compatibility with existing module designs, and mass-volume cost estimates indicate their suitability for xEV and other advanced battery applications. The second part of the paper focuses on the internal strain and temperature signals obtained from these sensors under various conditions and their utility for high-accuracy cell state estimation algorithms.

  6. Design, assembly, and optical bench testing of a high-numerical-aperture miniature injection-molded objective for fiber-optic confocal reflectance microscopy.

    PubMed

    Chidley, Matthew D; Carlson, Kristen D; Richards-Kortum, Rebecca R; Descour, Michael R

    2006-04-10

    The design, analysis, assembly methods, and optical-bench test results for a miniature injection-molded plastic objective lens used in a fiber-optic confocal reflectance microscope are presented. The five-lens plastic objective was tested as a stand-alone optical system before its integration into a confocal microscope for in vivo imaging of cells and tissue. Changing the spacing and rotation of the individual optical elements can compensate for fabrication inaccuracies and improve performance. The system performance of the miniature objective lens is measured by use of an industry-accepted slanted-edge modulation transfer function (MTF) metric. An estimated Strehl ratio of 0.61 and a MTF value of 0.66 at the fiber-optic bundle Nyquist frequency have been obtained. The optical bench testing system is configured to permit interactive optical alignment during testing to optimize performance. These results are part of an effort to demonstrate the manufacturability of low-cost, high-performance biomedical optics for high-resolution in vivo imaging. Disposable endoscopic microscope objectives could help in vivo confocal microscopy technology mature to permit wide-scale clinical screening and detection of early cancers and precancerous lesions.

  7. Bronchoscopy versus an endotracheal tube mounted camera for the peri-interventional visualization of percutaneous dilatational tracheostomy - a prospective, randomized trial (VivaPDT).

    PubMed

    Grensemann, Jörn; Eichler, Lars; Kähler, Sophie; Jarczak, Dominik; Simon, Marcel; Pinnschmidt, Hans O; Kluge, Stefan

    2017-12-29

    Percutaneous dilatational tracheostomy (PDT) in critically ill patients often involves bronchoscopic optical guidance. However, this procedure is not without disadvantages. Therefore, we aimed to study a recently introduced endotracheal tube-mounted camera (VivaSight TM -SL tube [VST]; ETView, Misgav, Israel) for guiding PDT. This was a randomized controlled trial involving 46 critically ill patients who received PDT using optical guidance with a VST or with bronchoscopy. The primary outcome measure was visualization of the tracheal structures (i.e., identification and monitoring of the thyroid, cricoid, and tracheal cartilage and the posterior wall) rated on 4-point Likert scales. Secondary measures were the quality of ventilation (before puncture and during the tracheostomy procedure rated on 4-point Likert scales) and blood gases sampled at standardized time points. The mean ratings for visualization (lower values better; values given for per-protocol analysis) were 5.4 (95% CI 4.5-6.3) for the VST group and 4.0 (95% CI 4.0-4.0) for the bronchoscopy group (p < 0.001). Mean ventilation ratings were 2.5 (95% CI 2.1-2.9) for VST and 5.0 (95% CI 4.4-5.7) for bronchoscopy (p < 0.001). Arterial carbon dioxide increased to 5.9 (95% CI 5.4-6.5) kPa in the VST group vs. 8.3 (95% CI 7.2-9.5) kPa in the bronchoscopy group (p < 0.001), and pH decreased to 7.40 (95% CI 7.36-7.43) in the VST group vs. 7.26 (95% CI 7.22-7.30) in the bronchoscopy group (p < 0.001), at the end of the intervention. Visualization of PDT with the VST is not noninferior to guidance by bronchoscopy. Ventilation is superior with less hypercarbia with the VST. Because visualization is not a prerequisite for PDT, patients requiring stable ventilation with normocarbia may benefit from PDT with the VST. ClinicalTrials.gov, NCT02861001 . Registered on 13 June 2016.

  8. The diagnostic value of narrow-band imaging for early and invasive lung cancer: a meta-analysis.

    PubMed

    Zhu, Juanjuan; Li, Wei; Zhou, Jihong; Chen, Yuqing; Zhao, Chenling; Zhang, Ting; Peng, Wenjia; Wang, Xiaojing

    2017-07-01

    This study aimed to compare the ability of narrow-band imaging to detect early and invasive lung cancer with that of conventional pathological analysis and white-light bronchoscopy. We searched the PubMed, EMBASE, Sinomed, and China National Knowledge Infrastructure databases for relevant studies. Meta-disc software was used to perform data analysis, meta-regression analysis, sensitivity analysis, and heterogeneity testing, and STATA software was used to determine if publication bias was present, as well as to calculate the relative risks for the sensitivity and specificity of narrow-band imaging vs those of white-light bronchoscopy for the detection of early and invasive lung cancer. A random-effects model was used to assess the diagnostic efficacy of the above modalities in cases in which a high degree of between-study heterogeneity was noted with respect to their diagnostic efficacies. The database search identified six studies including 578 patients. The pooled sensitivity and specificity of narrow-band imaging were 86% (95% confidence interval: 83-88%) and 81% (95% confidence interval: 77-84%), respectively, and the pooled sensitivity and specificity of white-light bronchoscopy were 70% (95% confidence interval: 66-74%) and 66% (95% confidence interval: 62-70%), respectively. The pooled relative risks for the sensitivity and specificity of narrow-band imaging vs the sensitivity and specificity of white-light bronchoscopy for the detection of early and invasive lung cancer were 1.33 (95% confidence interval: 1.07-1.67) and 1.09 (95% confidence interval: 0.84-1.42), respectively, and sensitivity analysis showed that narrow-band imaging exhibited good diagnostic efficacy with respect to detecting early and invasive lung cancer and that the results of the study were stable. Narrow-band imaging was superior to white light bronchoscopy with respect to detecting early and invasive lung cancer; however, the specificities of the two modalities did not differ

  9. FIBER-OPTIC BIOSENSOR FOR DIRECT DETERMINATION OF ORGANOPHOSPHATE NERVE AGENTS. (R823663)

    EPA Science Inventory

    A fiber-optic enzyme biosensor for the direct measurement of organophosphate nerve
    agents was developed. The basic element of this biosensor is organophosphorus hydrolase
    immobilized on a nylon membrane and attached to the common end of a bifurcated optical fiber
    bundle....

  10. Microwave analog fiber-optic link for use in the deep space network

    NASA Technical Reports Server (NTRS)

    Logan, R. T., Jr.; Lutes, G. F.; Maleki, L.

    1990-01-01

    A novel fiber-optic system with dynamic range of up to 150 dB-Hz for transmission of microwave analog signals is described. The design, analysis, and laboratory evaluations of this system are reported, and potential applications in the NASA/JPL Deep Space Network are discussed.

  11. Temperature and pressure fiber-optic sensors applied to minimally invasive diagnostics and therapies

    NASA Astrophysics Data System (ADS)

    Hamel, Caroline; Pinet, Éric

    2006-02-01

    We present how fiber-optic temperature or pressure sensors could be applied to minimally invasive diagnostics and therapies. For instance a miniature pressure sensor based on micro-optical mechanical systems (MOMS) could solve most of the problems associated with fluidic pressure transduction presently used for triggering purposes. These include intra-aortic balloon pumping (IABP) therapy and other applications requiring detection of fast and/or subtle fluid pressure variations such as for intracranial pressure monitoring or for urology diagnostics. As well, miniature temperature sensors permit minimally invasive direct temperature measurement in diagnostics or therapies requiring energy transfer to living tissues. The extremely small size of fiber-optic sensors that we have developed allows quick and precise in situ measurements exactly where the physical parameters need to be known. Furthermore, their intrinsic immunity to electromagnetic interference (EMI) allows for the safe use of EMI-generating therapeutic or diagnostic equipments without compromising the signal quality. With the trend of ambulatory health care and the increasing EMI noise found in modern hospitals, the use of multi-parameter fiber-optic sensors will improve constant patient monitoring without any concern about the effects of EMI disturbances. The advantages of miniature fiberoptic sensors will offer clinicians new monitoring tools that open the way for improved diagnostic accuracy and new therapeutic technologies.

  12. Integrated Fiber-Optic Light Probe: Measurement of Static Deflections in Rotating Turbomachinery

    NASA Technical Reports Server (NTRS)

    Kurkov, Anatole P.

    1998-01-01

    At the NASA Lewis Research Center, in cooperation with Integrated Fiber Optic Systems, Inc., an integrated fiber-optic light probe system was designed, fabricated, and tested for monitoring blade tip deflections, vibrations, and to some extent, changes in the blade tip clearances of a turbomachinery fan or a compressor rotor. The system comprises a set of integrated fiber-optic light probes that are positioned to detect the passing blade tip at the leading and trailing edges. In this configuration, measurements of both nonsynchronous blade vibrations and steady-state blade deflections can be made from the timing information provided by each light probe-consisting of an integrated fiber-optic transmitting channel and numerical aperture receiving fibers, all mounted in the same cylindrical housing. With integrated fiber-optic technology, a spatial resolution of 50 mm is possible while the outer diameter is kept below 2.5 mm. To evaluate these probes, we took measurements in a single-stage compressor facility and an advanced fan rig in Lewis' 9- by 15-Foot Low-Speed Wind Tunnel.

  13. "Fiberoptic variable message signs" : Swift Interchange - Delta Park Interchange Section, Pacific Highway (Interstate 5) : final report.

    DOT National Transportation Integrated Search

    1995-02-01

    The SYLVIA fiberoptic variable message signs (VMS) were installed on the Pacific Highway (I-5) as a part of the "Swift Interchange - Delta Park Interchange" project at milepost 298.47 and at milepost 305.66 in January 1991. Initially, during project ...

  14. Prevalence of Visible and Occult Blood on the Surfaces of Fiberoptic Bronchoscopes

    DTIC Science & Technology

    2000-10-01

    Mycobacterium chelonae and Rhodotorula rubra) in the 2 suction channels of fiberoptic endoscopes. (Cox, deBorja, & Bach, 1997; Hagan, Koltz, Bartholomew...Hagen, M.E., Klotz, S.A., Bartholomew, W., Potter, L., & Nelson, M. (1996). A pseudoepidemic of rhodotorula rubra: A marker for microbial

  15. Complex approach to the investigation of short fiber-optic comunication lines

    NASA Astrophysics Data System (ADS)

    Sukhoivanov, I. A.; Kontar', A. A.; Kublik, A. V.; Makarevich, V. S.

    The paper proposes a method of complex measurements based on the consideration of the parameters of all the elements used in a specific multimode fiber-optic communication line. It is shown that the error in measuring losses in waveguides up to 20 m long can reach a value of 60 percent.

  16. [Difficult fiberoptic tracheal intubation in 1 month-old infant with Treacher Collins Syndrome].

    PubMed

    Fuentes, Ricardo; De la Cuadra, Juan Carlos; Lacassie, Hector; González, Alejandro

    Neonates and small infants with craniofacial malformation may be very difficult or impossible to mask ventilate or intubate. We would like to report the fiberoptic intubation of a small infant with Treacher Collins Syndrome using the technique described by Ellis et al. An one month-old infant with Treacher Collins Syndrome was scheduled for mandibular surgery under general endotracheal anesthesia. Direct laryngoscopy for oral intubation failed to reveal the glottis. Fiberoptic intubation using nasal approach and using oral approach through a 1.5 size laryngeal mask airway were performed; however, both approach failed because the fiberscope loaded with a one 3.5mm ID uncuffed tube was stuck inside the nasal cavity or inside the laryngeal mask airway respectively. Therefore, the laryngeal mask airway was keep in place and the fiberoptic intubation technique described by Ellis et al. was planned: the tracheal tube with the 15mm adapter removed was loaded proximally over the fiberscope; the fiberscope was advanced under video-screen visualization into the trachea; the laryngeal mask airway was removed, leaving the fiberscope in place; the tracheal tube was passed completely through the laryngeal mask airway and advanced down over the fiberscope into the trachea; the fiberscope was removed and the 15mm adapter was reattached to the tracheal tube. The fiberoptic intubation method through a laryngeal mask airway described by Ellis et al. can be successfully used in small infants with Treacher Collins Syndrome. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  17. 21 CFR 874.4350 - Ear, nose, and throat fiberoptic light source and carrier.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ear, nose, and throat fiberoptic light source and carrier. 874.4350 Section 874.4350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... of plastic fibers and that is intended to provide illumination at the tip of an ear, nose, or throat...

  18. Simple fiber-optic confocal microscopy with nanoscale depth resolution beyond the diffraction barrier.

    PubMed

    Ilev, Ilko; Waynant, Ronald; Gannot, Israel; Gandjbakhche, Amir

    2007-09-01

    A novel fiber-optic confocal approach for ultrahigh depth-resolution (fiber-optic confocal microscope approach that is compatible with a differential confocal microscope technique. To improve the dynamic range of the resolving laser power and to achieve a high resolution in the nanometric range, we have designed a simple apertureless reflection confocal microscope with a highly sensitive single-mode-fiber confocal output. The fiber-optic design is an effective alternative to conventional pinhole-based confocal systems and offers a number of advantages in terms of spatial resolution, flexibility, miniaturization, and scanning potential. Furthermore, the design is compatible with the differential confocal pinhole microscope based on the use of the sharp diffraction-free slope of the axial confocal response curve rather than the area around the maximum of that curve. Combining the advantages of ultrahigh-resolution fiber-optic confocal microscopy, we can work beyond the diffraction barrier in the subwavelength (below 200 nm) nanometric range exploiting confocal nanobioimaging of single cell and intracellular analytes.

  19. Design of a fiber-optic interrogator module for telecommunication satellites

    NASA Astrophysics Data System (ADS)

    Putzer, Philipp; Koch, Alexander W.; Plattner, Markus; Hurni, Andreas; Manhart, Markus

    2017-11-01

    In this paper we present the results of the radiation tests performed on the optical components of the fiber-optic interrogator module as a part of the Hybrid Sensor Bus (HSB) system. The HSB-system is developed in the frame of an ESAARTES program and will be verified as flight demonstrator onboard the German Heinrich Hertz satellite in 2016. The HSB system is based on a modular concept which includes sensor interrogation modules based on I2C electrical and fiber Bragg grating (FBG) fiber-optical sensor elements. Onboard fiber-optic sensing allows the implementation of novel control and monitoring methods. For read-out of multiple FBG sensors, a design based on a tunable laser diode as well as a design based on a spectrometer is considered. The expected and tested total ionizing dose (TID) applicable to the HSB system is in the range between 100 krad and 300 krad inside the satellite in the geostationary orbit over a life time of 15 years. We present radiation test results carried out on critical optical components to be used in the fiber-optic interrogation module. These components are a modulated grating Y-branch (MGY) tunable laser diode acting as light source for the tuning laser approach, the line detector of a spectrometer, photodetectors and the FBG sensors acting as sensor elements. A detailed literature inquiry of radiation effects on optical fibers and FBG sensors, is also included in the paper. The fiber-optic interrogator module implemented in the HSB system is based on the most suitable technology, which sustains the harsh environment in the geostationary orbit.

  20. On-Board Fiber-Optic Network Architectures for Radar and Avionics Signal Distribution

    NASA Technical Reports Server (NTRS)

    Alam, Mohammad F.; Atiquzzaman, Mohammed; Duncan, Bradley B.; Nguyen, Hung; Kunath, Richard

    2000-01-01

    Continued progress in both civil and military avionics applications is overstressing the capabilities of existing radio-frequency (RF) communication networks based on coaxial cables on board modem aircrafts. Future avionics systems will require high-bandwidth on- board communication links that are lightweight, immune to electromagnetic interference, and highly reliable. Fiber optic communication technology can meet all these challenges in a cost-effective manner. Recently, digital fiber-optic communication systems, where a fiber-optic network acts like a local area network (LAN) for digital data communications, have become a topic of extensive research and development. Although a fiber-optic system can be designed to transport radio-frequency (RF) signals, the digital fiber-optic systems under development today are not capable of transporting microwave and millimeter-wave RF signals used in radar and avionics systems on board an aircraft. Recent advances in fiber optic technology, especially wavelength division multiplexing (WDM), has opened a number of possibilities for designing on-board fiber optic networks, including all-optical networks for radar and avionics RF signal distribution. In this paper, we investigate a number of different novel approaches for fiber-optic transmission of on-board VHF and UHF RF signals using commercial off-the-shelf (COTS) components. The relative merits and demerits of each architecture are discussed, and the suitability of each architecture for particular applications is pointed out. All-optical approaches show better performance than other traditional approaches in terms of signal-to-noise ratio, power consumption, and weight requirements.

  1. SU-E-T-159: Characteristics of Fiber-Optic Radiation Sensor for Proton Therapeutic Beam

    SciT

    Son, J; Kim, M; Hwang, U

    Purpose: A fiber-optic radiation sensor using Cerenkov radiation has been widely studied for use as a dosimeter for proton therapeutic beam. Although the fiber-optic radiation sensor has already been investigated for proton therapeutic, it has been examined relatively little work for clinical therapeutic proton beams. In this study, we evaluated characteristics of a fiber-optic radiation sensor for clinical therapeutic proton beams. We experimentally evaluated dose-rate dependence, dose response and energy dependence for the proton beam. Methods: A fiber-optic radiation sensor was placed in a water phantom. Beams with energies of low, middle and high were used in the passively-scattered protonmore » therapeutic beam at the National Cancer Center in Korea. The sensor consists of two plastic optical fibers (POF). A reference POF and 2 cm longer POF were used to utilize the subtraction method for having sensitive volume. Each POF is optically coupled to the Multi-Anode Photo Multiplier Tube (MAPMT) and the MAPMT signals are processed using National Instruments Data Acquisition System (NI-DAQ). We were investigated dosimetric properties including dose-rate dependence, dose response and energy dependence. Results: We have successfully evaluated characteristics of a fiber optic radiation sensor using Cerenkov radiation. The fiber-optic radiation sensor showed the dose response linearity and low energy dependence. In addition, as the dose-rate was increased, Cerenkov radiation increased linearly. Conclusion: We evaluated the basic characteristics of the fiber optic radiation sensor, the dosimetry tool, to raise the quality of proton therapy. Based on the research, we developed a real time dosimetry system of the optic fiber to confirm the real time beam position and energy for therapeutic proton pencil beam.« less

  2. Decision Support for the Capacity Management of Bronchoscopy Devices: Optimizing the Cost-Efficient Mix of Reusable and Single-Use Devices Through Mathematical Modeling.

    PubMed

    Edenharter, Günther M; Gartner, Daniel; Pförringer, Dominik

    2017-06-01

    Increasing costs of material resources challenge hospitals to stay profitable. Particularly in anesthesia departments and intensive care units, bronchoscopes are used for various indications. Inefficient management of single- and multiple-use systems can influence the hospitals' material costs substantially. Using mathematical modeling, we developed a strategic decision support tool to determine the optimum mix of disposable and reusable bronchoscopy devices in the setting of an intensive care unit. A mathematical model with the objective to minimize costs in relation to demand constraints for bronchoscopy devices was formulated. The stochastic model decides whether single-use, multi-use, or a strategically chosen mix of both device types should be used. A decision support tool was developed in which parameters for uncertain demand such as mean, standard deviation, and a reliability parameter can be inserted. Furthermore, reprocessing costs per procedure, procurement, and maintenance costs for devices can be parameterized. Our experiments show for which demand pattern and reliability measure, it is efficient to only use reusable or disposable devices and under which circumstances the combination of both device types is beneficial. To determine the optimum mix of single-use and reusable bronchoscopy devices effectively and efficiently, managers can enter their hospital-specific parameters such as demand and prices into the decision support tool.The software can be downloaded at: https://github.com/drdanielgartner/bronchomix/.

  3. The Effect of Dextromethorphan Premedication on Cough and Patient Tolerance During Flexible Bronchoscopy: A Randomized, Double-blind, Placebo-controlled Trial.

    PubMed

    Amini, Shahideh; Peiman, Soheil; Khatuni, Mahdi; Ghalamkari, Marziyeh; Rahimi, Besharat

    2017-10-01

    Patients undergoing bronchoscopy can experience problems such as anxiety and cough, requiring various doses of sedatives and analgesics. The purposes of this study were to investigate the effect of premedication with dextromethorphan on patients' cough and anxiety, and the use of analgesics/sedatives during flexible bronchoscopy (FB). A randomized, double-blind, placebo-controlled, prospective study was performed to assess the effect of dextromethorphan premedication on patients who underwent diagnostic bronchoscopy. Seventy patients included in this study were randomly allocated into 2 groups: group A consisted of 35 patients who received dextromethorphan before FB; and group B consisted of 35 patients who received a placebo. A questionnaire was given to the patients and bronchoscopist about perception of cough, anxiety, and discomfort. The amount of sedative medication and lidocaine use during the procedure and the procedure time were recorded. The group that was premedicated with dextromethorphan had lower complaint scores, significantly less coughing, significantly less stress assessed by the patient and the physician evaluation, shorter total procedure time, and fewer midazolam requirements during FB (P-value <0.05). Considering its safety profile, dextromethorphan premedication is an effective approach to facilitate the performance of FB for the physician, and could improve patient comfort.

  4. Lung abscess following bronchoscopy due to multidrug-resistant Capnocytophaga sputigena adjacent to lung cancer with high PD-L1 expression.

    PubMed

    Migiyama, Yohei; Anai, Moriyasu; Kashiwabara, Kosuke; Tomita, Yusuke; Saeki, Sho; Nakamura, Kazuyoshi; Okamoto, Shinichiro; Ichiyasu, Hidenori; Fujii, Kazuhiko; Kohrogi, Hirotsugu

    2018-04-24

    Lung abscess following flexible bronchoscopy is a rare and sometimes fatal iatrogenic complication. Here, we report the first case of a lung abscess caused by multidrug-resistant Capnocytophaga sputigena following bronchoscopy. A 67-year-old man underwent bronchoscopy to evaluate a lung mass. Seven days after transbronchial lung biopsy, he presented with an abscess formation in a lung mass. Empirical antibiotic therapy, including with garenoxacin, ampicillin/sulbactam, clindamycin and cefepime, was ineffective. Percutaneous needle aspiration of lung abscess yielded C. sputigena resistant to multiple antibiotics but remained susceptible to carbapenem. He was successfully treated by the combination therapy with surgery and with approximately 6 weeks of intravenous carbapenem. Finally he was diagnosed with a lung abscess with adenocarcinoma expressing high levels of programmed cell death ligand 1. The emergence of multidrug-resistant Capnocytophaga species is a serious concern for effective antimicrobial therapy. Clinicians should consider multidrug-resistant C. sputigena as a causative pathogen of lung abscess when it is refractory to antimicrobial treatment. Copyright © 2018 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  5. Multi-Stress Monitoring System with Fiber-Optic Mandrels and Fiber Bragg Grating Sensors in a Sagnac Loop

    PubMed Central

    Kim, Hyunjin; Sampath, Umesh; Song, Minho

    2015-01-01

    Fiber Bragg grating sensors are placed in a fiber-optic Sagnac loop to combine the grating temperature sensors and the fiber-optic mandrel acoustic emission sensors in single optical circuit. A wavelength-scanning fiber-optic laser is used as a common light source for both sensors. A fiber-optic attenuator is placed at a specific position in the Sagnac loop in order to separate buried Bragg wavelengths from the Sagnac interferometer output. The Bragg wavelength shifts are measured with scanning band-pass filter demodulation and the mandrel output is analyzed by applying a fast Fourier transform to the interference signal. This hybrid-scheme could greatly reduce the size and the complexity of optical circuitry and signal processing unit, making it suitable for low cost multi-stress monitoring of large scale power systems. PMID:26230700

  6. Investigation into longitudinal placement of fiber-optic cable in Interstate right-of-way in Louisiana : technical assistance report.

    DOT National Transportation Integrated Search

    1995-11-01

    Fiber-optic cable is recognized as one of the most efficient and reliable mediums of telecommunication available today. The last decade has witnessed an enormous growth in this form of telecommunication. However, one of its major disadvantages is tha...

  7. Defining a Ventilation Strategy for Flexible Bronchoscopy on Mechanically Ventilated Patients in the Medical Intensive Care Unit.

    PubMed

    Greenstein, Yonatan Y; Shakespeare, Eric; Doelken, Peter; Mayo, Paul H

    2017-07-01

    Flexible bronchoscopy (FB) in intubated patients on mechanical ventilation increases airway resistance. During FB, two ventilatory strategies are possible: maintaining tidal volume (VT) while maintaining baseline CO2 or allowing reduction of VT. The former strategy carries risk of hyperinflation due to expiratory flow limitation with FB. The aim of the authors was too study end expiratory lung volume (EELV) during FB of intubated subjects while limiting VT. We studied 16 subjects who were intubated on mechanical ventilation and required FB. Changes in EELV were measured by respiratory inductance plethysmography. Ventilator mechanics, EELV, and arterial blood gases, were measured. FB insertions decreased EELV in 64% of cases (-325±371 mL) and increased it in 32% of cases (65±59 mL). Suctioning decreased EELV in 76% of cases (-120±104 mL) and increased it in 16% of cases (29±33 mL). Respiratory mechanics were unchanged. Pre-FB and post-FB, PaO2 decreased by 61±96 mm Hg and PaCO2 increased by 15±7 mm Hg. There was no clinically significant increase in EELV in any subject during FB. Decreases in EELV coincided with FB-suctioning maneuvers. Peak pressure limiting ventilation protected the subject against hyperinflation with a consequent, well-tolerated reduction in VT, and hypercapnea. Suctioning should be limited, especially in patients vulnerable to derecruitment effect.

  8. Speech-language pathologist-led fiberoptic endoscopic evaluation of swallowing: functional outcomes for patients after stroke.

    PubMed

    Bax, Louise; McFarlane, Mary; Green, Emma; Miles, Anna

    2014-03-01

    Dysphagia is a common complication after stroke and is associated with the development of pneumonia. Early detection of dysphagia and specifically aspiration is, therefore, critical in the prevention of pneumonia. Fiberoptic endoscopic evaluation of swallowing (FEES) is a safe bedside instrumental tool for detecting dysphagia and aspiration and, therefore, has the potential to inform dysphagia management. This study investigated the clinical utility of a speech-language pathologist-led FEES service on functional outcomes for patients after acute stroke. A retrospective file audit was carried out on 220 patients before FEES was introduced and on 220 patients after the implementation of a speech-language pathologist-led FEES service. The primary outcome measure was incidence of pneumonia, and secondary outcome measures included mortality, diet on discharge, discharge destination, duration nil-by-mouth, incidence of nonoral feeding, and length of stay. There was a significant increase in instrumental assessment use in the group that had access to FEES (P < .001). There was a significant reduction of pneumonia rates in the group that had access to FEES (P = .037). Patients were also significantly more likely to leave hospital on standard diets (P = .004) but had longer periods of nonoral feeding (P = .013) and increased length of hospitalization (P < .001). When used selectively, FEES services have potential for improving functional outcomes for patients after stroke. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  9. Combined pulsed dye laser and fiberoptic Nd-YAG laser for the treatment of hypertrophic port wine stain.

    PubMed

    Radmanesh, Mohammed; Radmanesh, Ramin

    2017-10-01

    The hypertrophic Port Wine Stain (PWS) is only partially and superficially treated with the Pulsed dye laser (PDL) because of its limited depth of penetration. We used combined PDL and fiberoptic 1444-nm Nd-YAG laser to treat a case with hypertrophic PWS. After tumescent anesthesia, few holes were made by a 16-gauge needle on different sides of the lesion. The fiberoptic tip of 1444-nm Nd-YAG laser was inserted within the holes and was pushed forward while triggering. In a fan pattern and by a back and forth movement, the subcutaneous and deep dermal areas were coagulated. The skin and outer mucosal surfaces were then treated by PDL. The fiberoptic system used was Accusculpt 1444-nm Nd-YAG laser (Lutronic lasers, South Korea), and the PDL used was 585 nm Nlite system (Chromogenex UK). The parameters used for PDL were fluence = 9 Joules/cm 2 and the spot size was 5 mm. The parameters used for fiberoptic 1444-nm Nd-YAG laser were: Pulse rate = 30 Hz, pulse energy = 300 mJ, power = 6 W, and the total energy = 4000 J for the whole face and mucosa. Little sign of regression and moderate purpura were detected immediately after combined fiberoptic Nd-YAG and PDL therapy. The lesion gradually regressed within 4 months with satisfactory color and volume change. Combined fiberoptic Nd-YAG laser and PDL can be used for the treatment of deeper and superficial layers of hypertrophic PWS.

  10. Label-Free Detection of Cancer Biomarkers Using an In-Line Taper Fiber-Optic Interferometer and a Fiber Bragg Grating

    PubMed Central

    Sun, Dandan; Wang, Guanjun

    2017-01-01

    A compact and label-free optical fiber sensor based on a taper interferometer cascaded with a fiber Bragg grating (FBG) is proposed and experimentally demonstrated for detection of a breast cancer biomarker (HER2). The tapered fiber-optic interferometer is extremely sensitive to the ambient refractive index (RI). In addition, being insensitive to the RI variation, the FBG can be applied as a temperature thermometer due to its independent response to the temperature. Surface functionalization to the sensor is carried out to achieve specific targeting of the unlabeled biomarkers. The result shows that the proposed sensor presents a low limit-of-detection (LOD) of 2 ng/mL, enabling its potentials of application in early diagnosis on the breast cancer. PMID:29113127

  11. CT Bronchus Sign and the Diagnostic Yield of Guided Bronchoscopy for Peripheral Pulmonary Lesions: A Systematic Review and Meta-Analysis.

    PubMed

    Ali, Muhammad S; Sethi, Jaskaran; Taneja, Amit; Musani, Ali; Maldonado, Fabien

    2018-06-07

    Indeterminate peripheral pulmonary lesions often require tissue diagnosis. If non-surgical biopsy techniques are considered, deciding between bronchoscopic transbronchial vs. CT guided transthoracic biopsy can be difficult. The former has a low diagnostic yield with a low complication risk, while the latter has a better diagnostic yield but a higher complication rate. Investigators have looked at various lesion characteristics that can predict the diagnostic yield of guided bronchoscopic biopsies. While consensus exists that larger size and proximity to the hilum increase the diagnostic yield, there is ongoing debate about the association between CT bronchus sign (air-filled bronchus in close proximity of the lesion as seen on CT) and the diagnostic yield of guided bronchoscopic modalities. To perform a meta-analysis and systematic review, determining the association between CT bronchus sign and the diagnostic yield of guided bronchoscopy for peripheral pulmonary lesions. MEDLINE, Embase, Scopus and Google Scholar were searched in January 2018 for guided bronchoscopy studies that had assessed the impact of CT bronchus sign on the diagnostic yield. The quality of included studies was assessed using Quality Assessment, Data Abstraction and Synthesis-2 tool. Meta-analysis was performed using MedCalc (version 18). Odds ratios were used to compare yield of lesions with and without bronchus sign. Random effects model was used when significant heterogeneity was observed (I2>40%). For 2199 lesions with CT bronchus sign, the overall weighted diagnostic yield was 74.1% (95% CI: 68.3-79.5%). For 971 lesions without CT bronchus sign, the overall weighted diagnostic yield was 49.6% (95% CI: 39.6-59.5%). The odds ratio for successfully diagnosing a lesion with CT bronchus was 3.4 (95% CI: 2.4-5.0). Possible sources of heterogeneity in the meta-analysis included differences in study designs, guidance modalities and cancer prevalence. The odds ratio for successfully diagnosing a

  12. A compact fiber-optic probe-based singlet oxygen luminescence detection system.

    PubMed

    Gemmell, Nathan R; McCarthy, Aongus; Kim, Michele M; Veilleux, Israel; Zhu, Timothy C; Buller, Gerald S; Wilson, Brian C; Hadfield, Robert H

    2017-02-01

    This paper presents a novel compact fiberoptic based singlet oxygen near-infrared luminescence probe coupled to an InGaAs/InP single photon avalanche diode (SPAD) detector. Patterned time gating of the single-photon detector is used to limit unwanted dark counts and eliminate the strong photosensitizer luminescence background. Singlet oxygen luminescence detection at 1270 nm is confirmed through spectral filtering and lifetime fitting for Rose Bengal in water, and Photofrin in methanol as model photosensitizers. The overall performance, measured by the signal-to-noise ratio, improves by a factor of 50 over a previous system that used a fiberoptic-coupled superconducting nanowire single-photon detector. The effect of adding light scattering to the photosensitizer is also examined as a first step towards applications in tissue in vivo. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Dynamics analysis of microsphere in a dual-beam fiber-optic trap with transverse offset.

    PubMed

    Chen, Xinlin; Xiao, Guangzong; Luo, Hui; Xiong, Wei; Yang, Kaiyong

    2016-04-04

    A comprehensive dynamics analysis of microsphere has been presented in a dual-beam fiber-optic trap with transverse offset. As the offset distance between two counterpropagating beams increases, the motion type of the microsphere starts with capture, then spiral motion, then orbital rotation, and ends with escape. We analyze the transformation process and mechanism of the four motion types based on ray optics approximation. Dynamic simulations show that the existence of critical offset distances at which different motion types transform. The result is an important step toward explaining physical phenomena in a dual-beam fiber-optic trap with transverse offset, and is generally applicable to achieving controllable motions of microspheres in integrated systems, such as microfluidic systems and lab-on-a-chip systems.

  14. Fiberoptic nasopharyngoscopy for evaluating a potentially difficult airway in a patient with elevated intracranial pressure.

    PubMed

    Kurnutala, Lakshmi N; Sandhu, Gurneet; Bergese, Sergio D

    2016-11-01

    A 62-year-old man with a left temporal lobe tumor was scheduled for a semiurgent craniotomy for tumor excision. Previously, the patient had a laryngeal carcinoma that was resected and treated with chemotherapy and radiotherapy and a history of laryngeal biopsy with awake fiberoptic intubation. Because a difficult airway was anticipated, awake fiberoptic nasopharyngoscopy of the airway was performed under topical anesthesia in the operating room. This revealed a narrow glottic opening with no supraglottic pathology or friable tissue. Based on these airway observations, we proceeded safely with intravenous induction and secured the airway in a controlled fashion, thereby minimizing the risk of increased intracranial pressure and catastrophic complications. Nasopharyngoscopy can be used safely to evaluate the upper airway to stratify airway management in patients with a history of head and neck cancer presenting for neurosurgical procedures in the setting of elevated intracranial pressure. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Determination of bacterial activity by use of an evanescent-wave fiber-optic sensor

    NASA Astrophysics Data System (ADS)

    John, M. Shelly; Kishen, Anil; Sing, Lim Chu; Asundi, Anand

    2002-12-01

    A novel technique based on fiber-optic evanescent-wave spectroscopy is proposed for the detection of bacterial activity in human saliva. The sensor determines the specific concentration of Streptococcus mutans in saliva, which is a major causative factor in dental caries. In this design, one prepares the fiber-optic bacterial sensor by replacing a portion of the cladding region of a multimode fiber with a dye-encapsulated xerogel, using the solgel technique. The exponential decay of the evanescent wave at the core-cladding interface of a multimode fiber is utilized for the determination of bacterial activity in saliva. The acidogenic profile of Streptococcus mutans is estimated by use of evanescent-wave absorption spectra at various levels of bacterial activity.

  16. Research Progress on F-P Interference—Based Fiber-Optic Sensors

    PubMed Central

    Huang, Yi Wen; Tao, Jin; Huang, Xu Guang

    2016-01-01

    We review our works on Fabry-Perot (F-P) interferometric fiber-optic sensors with various applications. We give a general model of F-P interferometric optical fiber sensors including diffraction loss caused by the beam divergence and the Gouy phase shift. Based on different structures of an F-P cavity formed on the end of a single-mode fiber, the F-P interferometric optical sensor has been extended to measurements of the refractive index (RI) of liquids and solids, temperature as well as small displacement. The RI of liquids and solids can be obtained by monitoring the fringe contrast related to Fresnel reflections, while the ambient temperature and small displacement can be obtained by monitoring the wavelength shift of the interference fringes. The F-P interferometric fiber-optic sensors can be used for many scientific and technological applications. PMID:27598173

  17. A hybrid demodulation method of fiber-optic Fabry-Perot pressure sensor

    NASA Astrophysics Data System (ADS)

    Yu, Le; Lang, Jianjun; Pan, Yong; Wu, Di; Zhang, Min

    2013-12-01

    The fiber-optic Fabry-Perot pressure sensors have been widely applied to measure pressure in oilfield. For multi-well it will take a long time (dozens of seconds) to demodulate downhole pressure values of all wells by using only one demodulation system and it will cost a lot when every well is equipped with one system, which heavily limits the sensor applied in oilfield. In present paper, a new hybrid demodulation method, combining the windowed nonequispaced discrete Fourier Transform (nDFT) method with segment search minimum mean square error estimation (MMSE) method, was developed, by which the demodulation time can be reduced to 200ms, i.e., measuring 10 channels/wells was less than 2s. Besides, experimental results showed the demodulation cavity length of the fiber-optic Fabry-Perot sensor has a maximum error of 0.5 nm and consequently pressure measurement accuracy can reach 0.4% F.S.

  18. Fiber-optic sensor demonstrator (FSD) for the monitoring of spacecraft subsystems on ESA's PROBA-2

    NASA Astrophysics Data System (ADS)

    Kruzelecky, Roman V.; Zou, Jing; Mohammed, Najeeb; Haddad, Emile; Jamroz, Wes; Ricci, Francesco; Lamorie, Joshua; Edwards, Eric; McKenzie, Iain; Vuilleumier, Pierrik

    2017-11-01

    MPB Communications (MPBC) is developing solutions to the monitoring requirements of spacecraft based on its fiber-laser and Fiber Bragg Grating expertise. This is cumulating in the Fiber Sensor Demonstrator for ESA's Proba-2 that is scheduled for launch in 2007. The advantages of the MPBC approach include a central interrogation system that can be used to control a variety of different fiber-optic sensors including temperature, pressure, actuator status, and propellant leakage. This paper reviews the design and ground qualification of the FSD system in preparation for integration with Proba-2. The FSD will provide monitoring for various Proba-2 subsystems, including a hybrid propulsion system. Some of the challenges associated with using fiber-optics in space are discussed.

  19. Alpha-fetoprotein detection by using a localized surface plasmon coupled fluorescence fiber-optic biosensor

    NASA Astrophysics Data System (ADS)

    Chang, Ying-Feng; Chen, Ran-Chou; Li, Ying-Chang; Yu, Chih-Jen; Hsieh, Bao-Yu; Chou, Chien

    2007-11-01

    Alpha-fetoprotein (AFP) detection by using a localized surface plasmon coupled fluorescence (LSPCF) fiber-optic biosensor is setup and experimentally demonstrated. It is based on gold nanoparticle (GNP) and coupled with localized surface plasmon wave on the surface of GNP. In this experiment, the fluorophores are labeled on anti-AFP which are bound to protein A conjugated GNP. Thus, LSPCF is excited with high efficiency in the near field of localized surface plasmon wave. Therefore, not only the sensitivity of LSPCF biosensor is enhanced but also the specific selectivity of AFP is improved. Experimentally, the ability of real time measurement in the range of AFP concentration from 0.1ng/ml to 100ng/ml was detected. To compare with conventional methods such as enzyme-linked immunosorbent assay (ELISA) or radioimmunoassay (RIA), the LSPCF fiber-optic biosensor performs higher or comparable detection sensitivity, respectively.

  20. Microminiaturized minimally invasive intravascular micro-mechanical systems powered and controlled via fiber-optic cable

    DOEpatents

    Fitch, Joseph P.; Hagans, Karla; Clough, Robert; Matthews, Dennis L.; Lee, Abraham P.; Krulevitch, Peter A.; Benett, William J.; Da Silva, Luiz; Celliers, Peter M.

    1998-01-01

    A micro-mechanical system for medical procedures is constructed in the basic form of a catheter having a distal end for insertion into and manipulation within a body and a near end providing for a user to control the manipulation of the distal end within the body. A fiberoptic cable is disposed within the catheter and having a distal end proximate to the distal end of the catheter and a near end for external coupling of laser light energy. A microgripper is attached to the distal end of the catheter and providing for the gripping or releasing of an object within the body. A laser-light-to-mechanical-power converter is connected to receive laser light from the distal end of the fiberoptic cable and connected to mechanically actuate the microgripper.

  1. Multipoint fiber-optic laser-ultrasonic actuator based on fiber core-opened tapers.

    PubMed

    Tian, Jiajun; Dong, Xiaolong; Gao, Shimin; Yao, Yong

    2017-11-27

    In this study, a novel fiber-optic, multipoint, laser-ultrasonic actuator based on fiber core-opened tapers (COTs) is proposed and demonstrated. The COTs were fabricated by splicing single-mode fibers using a standard fiber splicer. A COT can effectively couple part of a core mode into cladding modes, and the coupling ratio can be controlled by adjusting the taper length. Such characteristics are used to obtain a multipoint, laser-ultrasonic actuator with balanced signal strength by reasonably controlling the taper lengths of the COTs. As a prototype, we constructed an actuator that generated ultrasound at four points with a balanced ultrasonic strength by connecting four COTs with coupling ratios of 24.5%, 33.01%, 49.51%, and 87.8% in a fiber link. This simple-to-fabricate, multipoint, laser-ultrasonic actuator with balanced ultrasound signal strength has potential applications in fiber-optic ultrasound testing technology.

  2. Microminiaturized minimally invasive intravascular micro-mechanical systems powered and controlled via fiber-optic cable

    DOEpatents

    Fitch, J.P.; Hagans, K.; Clough, R.; Matthews, D.L.; Lee, A.P.; Krulevitch, P.A.; Benett, W.J.; Silva, L. Da; Celliers, P.M.

    1998-03-03

    A micro-mechanical system for medical procedures is constructed in the basic form of a catheter having a distal end for insertion into and manipulation within a body and a near end providing for a user to control the manipulation of the distal end within the body. A fiber-optic cable is disposed within the catheter and having a distal end proximate to the distal end of the catheter and a near end for external coupling of laser light energy. A microgripper is attached to the distal end of the catheter and providing for the gripping or releasing of an object within the body. A laser-light-to-mechanical-power converter is connected to receive laser light from the distal end of the fiber-optic cable and connected to mechanically actuate the microgripper. 22 figs.

  3. Evaluation of fiberoptic dermofluorometry as a means of clinically assessing tissue perfusion.

    PubMed

    Leopold, P W; Chang, B B; Shah, D M; Corson, J D; Shandall, A A; Young, H L; Leather, R P; Karmody, A M

    1987-01-01

    Fiberoptic dermofluorometry (FDF) transcutaneously measures fluorescence, following an intravenous injection of sodium fluorescein (NaFl), which is transmitted along a fiberoptic bundle to a photomultiplier tube and converted into dermofluorescence units (DFU). In five normal subjects studied, the plasma concentration of NaFl peaked at 5-15 minutes before decaying with first order kinetics and corresponding dermofluorescence (DF) rose to a peak between 10-20 minutes before decaying. Peak DF in the head and neck was significantly higher (P less than .001) compared to other skin sites which were similar. Application to patients (n = 16) undergoing successful lower limb revascularization showed a significant (P less than 0.01) improvement in perfusion at the foot level only. The reproducibility of FDF was poor when studied on the control limbs. We conclude that FDF does not, at present, constitute a valid measure of skin perfusion.

  4. Composite material embedded fiber-optic Fabry-Perot strain rosette

    NASA Astrophysics Data System (ADS)

    Valis, Thomas; Hogg, Dayle; Measures, Raymond M.

    1990-12-01

    A fiber-optic strain rosette is embedded in Kevlar/epoxy. The individual arms of the rosette are fiber Fabry-Perot interferometers operated in reflection-mode with gauge (i.e., cavity) lengths of approximately 5 mm. Procedures for manufacturing the cavities, and bending the fibers, to form a strain rosette are described. Experimental results showing 2D interlaminar strain-tensor measurement are presented. The sensor is also tested as a surface adhered device.

  5. New Methods for Rotation Sensing by Using a Two-Coupler Fiber-Optic Ring Resonator

    NASA Astrophysics Data System (ADS)

    Seraji, Faramarz E.

    1993-04-01

    This paper presents a theoretical analysis of new methods for rotation sensing by using a two-coupler type fiber-optic ring resonator. It is shown that in the proposed methods a resonance spike can be generated whose amplitude gives a direct measure of the rotation rates. The approaches are simple and have a major advantage of not using a closed-loop to control the operating points for resonance.

  6. Apparatus and Method for Elimination of Polarization-Induced Fading in Fiber-optic Sensor System

    NASA Technical Reports Server (NTRS)

    Chan, Hon Man (Inventor); Parker, Jr., Allen R. (Inventor)

    2015-01-01

    The invention is an apparatus and method of eliminating polarization-induced fading in interferometric fiber-optic sensor system having a wavelength-swept laser optical signal. The interferometric return signal from the sensor arms are combined and provided to a multi-optical path detector assembly and ultimately to a data acquisition and processing unit by way of a switch that is time synchronized with the laser scan sweep cycle.

  7. Time-division multiplexing of polarization-insensitive fiber-optic Michelson interferometric sensors

    NASA Astrophysics Data System (ADS)

    Huang, S. C.; Lin, W. W.; Chen, M. H.

    1995-06-01

    A system of time-division multiplexing of polarization-insensitive fiber-optic Michelson interferometric sensors that uses Faraday rotator mirror elements is demonstrated. This system is constructed with conventional low-birefringence single-mode fiber and is able to solve the polarization-fading problem by a combination of Faraday rotator mirrors with unbalanced Michelson interferometers. The system is lead-fiber insensitive and has potentials for practical field applications.

  8. Proven high-reliability assembly methods applied to avionics fiber-optics high-speed transceivers

    NASA Astrophysics Data System (ADS)

    Lauzon, Jocelyn; Leduc, Lorrain; Bessette, Daniel; Bélanger, Nicolas; Larose, Robert; Dion, Bruno

    2012-06-01

    Harsh environment avionics applications require operating temperature ranges that can extend to, and exceed -50 to 115°C. For obvious maintenance, management and cost arguments, product lifetimes as long as 20 years are also sought. This leads to mandatory long-term hermeticity that cannot be obtained with epoxy or silicone sealing; but only with glass seal or metal solder or brazing. A hermetic design can indirectly result in the required RF shielding of the component. For fiber-optics products, these specifications need to be compatible with the smallest possible size, weight and power consumption. The products also need to offer the best possible high-speed performances added to the known EMI immunity in the transmission lines. Fiber-optics transceivers with data rates per fiber channel up to 10Gbps are now starting to be offered on the market for avionics applications. Some of them are being developed by companies involved in the "normal environment" telecommunications market that are trying to ruggedize their products packaging in order to diversify their customer base. Another approach, for which we will present detailed results, is to go back to the drawing boards and design a new product that is adapted to proven MIL-PRF-38534 high-reliability packaging assembly methods. These methods will lead to the introduction of additional requirements at the components level; such as long-term high-temperature resistance for the fiber-optic cables. We will compare both approaches and demonstrate the latter, associated with the redesign, is the preferable one. The performance of the fiber-optic transceiver we have developed, in terms of qualification tests such as temperature cycling, constant acceleration, hermeticity, residual gaz analysis, operation under random vibration and mechanical shocks and accelerated lifetime tests will be presented. The tests are still under way, but so far, we have observed no performance degradation of such a product after more than

  9. Fiberoptic microneedles: novel optical diffusers for interstitial delivery of therapeutic light.

    PubMed

    Kosoglu, Mehmet A; Hood, Robert L; Rossmeisl, John H; Grant, David C; Xu, Yong; Robertson, John L; Rylander, Marissa Nichole; Rylander, Christopher G

    2011-11-01

    Photothermal therapies have limited efficacy and application due to the poor penetration depth of light inside tissue. In earlier work, we described the development of novel fiberoptic microneedles to provide a means to mechanically penetrate dermal tissue and deliver light directly into a localized target area.This paper presents an alternate fiberoptic microneedle design with the capability of delivering more diffuse, but therapeutically useful photothermal energy. Laser lipolysis is envisioned as a future clinical application for this design. A novel fiberoptic microneedle was developed using hydrofluoric acid etching of optical fiber to permit diffuse optical delivery. Microneedles etched for 10, 30, and 50 minutes, and an optical fiber control were compared with three techniques. First, red light delivery from the microneedles was evaluated by imaging the reflectance of the light from a white paper.Second, spatial temperature distribution of the paper in response to near-IR light (1,064 nm, 1 W CW) was recorded using infrared thermography. Third, ex vivo adipose tissue response during 1,064 nm, (5 W CW)irradiation was recorded with bright field microscopy. Acid etching exposed a 3 mm length of the fiber core, allowing circumferential delivery of light along this length. Increasing etching time decreased microneedle diameter, resulting in increased uniformity of red and 1,064 nm light delivery along the microneedle axis. For equivalent total energy delivery, thinner microneedles reduced carbonization in the adipose tissue experiments. We developed novel microscale optical diffusers that provided a more homogeneous light distribution from their surfaces, and compared performance to a flat-cleaved fiber, a device currently utilized in clinical practice. These fiberoptic microneedles can potentially enhance clinical laser procedures by providing direct delivery of diffuse light to target chromophores, while minimizing undesirable photothermal damage in adjacent

  10. Analysis of Photonic Phase-Shifting Technique Employing Amplitude-Controlled Fiber-Optic Delay Lines

    DTIC Science & Technology

    2012-01-13

    Controlled Fiber-Optic Delay Lines January 13, 2012 Approved for public release; distribution is unlimited. Meredith N. draa ViNceNt J. Urick keith J...Draa, Vincent J. Urick , and Keith J. Williams Naval Research Laboratory, Code 5652 4555 Overlook Avenue, SW Washington, DC 20375-5320 NRL/MR/5650--12...9376 Approved for public release; distribution is unlimited. Unclassified Unclassified Unclassified UU 29 Vincent J. Urick (202) 767-9352 Fiber optics

  11. Design and Performance of Ka-Band Fiber-Optic Delay Lines

    DTIC Science & Technology

    2012-12-28

    Approved for public release; distribution is unlimited. Vincent J. Urick Joseph M. singley christopher e. sUnderMan John F. diehl keith J...PAGES 17. LIMITATION OF ABSTRACT Design and Performance of Ka-Band Fiber-Optic Delay Lines Vincent J. Urick , Joseph M. Singley, Christopher E...Approved for public release; distribution is unlimited. Unclassified Unlimited Unclassified Unlimited Unclassified Unlimited 64 Vincent J. Urick (202

  12. Murray secretion scale and fiberoptic endoscopic evaluation of swallowing in predicting aspiration in dysphagic patients.

    PubMed

    Kuo, Chia-Wei; Allen, Clint Tanner; Huang, Chu-Chun; Lee, Chia-Jung

    2017-06-01

    The objective of this retrospective review is to evaluate the ability of the Murray secretion scale to predict aspiration as determined by fiberoptic endoscopic evaluation of swallowing. Patients with dysphagia undergoing a fiberoptic endoscopic evaluation of swallowing study between January 2013 and November 2015 from a single, tertiary care institution were retrospectively reviewed. The Murray secretion scale and penetration aspiration scale on fiberoptic endoscopic evaluation of swallowing examination were determined. Spearman's correlation analysis, sensitivity, specificity, predictive values, and relative risk evaluating the relationship between the Murray secretion scale and aspiration on fiberoptic endoscopic evaluation of swallowing were calculated. Subgroups of head and neck cancer patients, penetration group, and aspiration group were also analyzed. The mean age of the cases (N = 212) was 62.4 years. Eighty percent were male. There was a strong correlation between Murray secretion scale grade and penetration aspiration scale score (r = 0.785, p < 0.001). The sensitivity and specificity of a Murray secretion scale grade 2 or higher in predicting aspiration were 74 and 90%, respectively. Individuals with a Murray secretion scale grade of 2 or higher were 13.6 times more likely to aspirate than patients with a lower Murray secretion scale grade. All subgroups showed similar trend. Determination of a Murray secretion scale grade, determined by flexible nasopharyngoscopy, may predict patients at high risk for aspiration. In clinical scenarios where more complete assessments of aspiration risk are immediately impossible or impractical, the Murray secretion scale grade may add valuable information to assist in clinical decision-making in patients with dysphagia.

  13. Fiber-Optic Sensing System: Overview, Development and Deployment in Flight at NASA

    NASA Technical Reports Server (NTRS)

    Chan, Hon Man; Parker, Allen R.; Piazza, Anthony; Richards, W. Lance

    2015-01-01

    An overview of the research and technological development of the fiber-optic sensing system (FOSS) at the National Aeronautics and Space Administration Armstrong Flight Research Center (NASA AFRC) is presented. Theory behind fiber Bragg grating (FBG) sensors, as well as interrogation technique based on optical frequency domain reflectometry (OFDR) is discussed. Assessment and validation of FOSS as an accurate measurement tool for structural health monitoring is realized in the laboratory environment as well as large-scale flight deployment.

  14. Fiberoptic endoscopic-assisted diverticulotomy: a novel technique for the management of Zenker's diverticulum.

    PubMed

    Altman, Jason I; Genden, Eric M; Moche, Jason

    2005-05-01

    Endoscopic diverticulotomy is rapidly becoming the procedure of choice for treatment of Zenker's diverticulum. The endoscopic approach has resulted in significant decreases in patient morbidity, time to resumption of oral intake, and overall cost as compared with open treatment. However, a small but significant patient population is unable to accommodate the rigid laryngoscope and therefore requires open treatment. We present a novel technique, flexible fiberoptic endoscopic-assisted diverticulotomy, for the management of patients who are unable to undergo rigid endoscopy.

  15. Rad-Tolerant, Thermally Stable, High-Speed Fiber-Optic Network for Harsh Environments

    NASA Technical Reports Server (NTRS)

    Leftwich, Matt; Hull, Tony; Leary, Michael; Leftwich, Marcus

    2013-01-01

    Future NASA destinations will be challenging to get to, have extreme environmental conditions, and may present difficulty in retrieving a spacecraft or its data. Space Photonics is developing a radiation-tolerant (rad-tolerant), high-speed, multi-channel fiber-optic transceiver, associated reconfigurable intelligent node communications architecture, and supporting hardware for intravehicular and ground-based optical networking applications. Data rates approaching 3.2 Gbps per channel will be achieved.

  16. Fire/burn risk with electrosurgical devices and endoscopy fiberoptic cables.

    PubMed

    Smith, Lee P; Roy, Soham

    2008-01-01

    The purpose of the study was to systematically explore the fire and burn risk associated with fiberoptic cables and electrosurgical devices. A 300-W light source was connected to a standard gray fiberoptic light cable. The end of the cable was either rested atop or buried within a cotton towel or polypropylene drape in the presence or absence of 100% oxygen for up to 10 minutes. A monopolar electrosurgical device set at 1 W, 10 W, or 30 W was tested on a cotton towel or polypropylene drape for a period of 30 seconds. All trials were repeated. Resting the light cable on top of the cotton towel or polypropylene drape with or without oxygen produced no result. Burying the end of the cable within the drape produced a hole in the drape within 15 seconds both with and without oxygen. Burying the end of the cable within the cotton towel produced a yellow discoloration after 2 minutes both with and without oxygen. The monopolar electrosurgical device set at 30 W burned immediately through the polypropylene drape, producing a skin burn. All other trials with monopolar electrocautery produced no result. No flame or fire was produced in any trial. Fiberoptic cables and electrosurgical generators represent a serious burn risk for surgical patients, with operating room drapes and towels affording only limited protection. Otolaryngologists should be keenly aware of the risks that these devices represent because our specialty uses them frequently.

  17. Partially reduced graphene oxide based FRET on fiber-optic interferometer for biochemical detection

    NASA Astrophysics Data System (ADS)

    Yao, B. C.; Wu, Y.; Yu, C. B.; He, J. R.; Rao, Y. J.; Gong, Y.; Fu, F.; Chen, Y. F.; Li, Y. R.

    2016-03-01

    Fluorescent resonance energy transfer (FRET) with naturally exceptional selectivity is a powerful technique and widely used in chemical and biomedical analysis. However, it is still challenging for conventional FRET to perform as a high sensitivity compact sensor. Here we propose a novel ‘FRET on Fiber’ concept, in which a partially reduced graphene oxide (prGO) film is deposited on a fiber-optic modal interferometer, acting as both the fluorescent quencher for the FRET and the sensitive cladding for optical phase measurement due to refractive index changes in biochemical detection. The target analytes induced fluorescence recovery with good selectivity and optical phase shift with high sensitivity are measured simultaneously. The functionalized prGO film coated on the fiber-optic interferometer shows high sensitivities for the detections of metal ion, dopamine and single-stranded DNA (ssDNA), with detection limits of 1.2 nM, 1.3 μM and 1 pM, respectively. Such a prGO based ‘FRET on fiber’ configuration, bridging the FRET and the fiber-optic sensing technology, may serve as a platform for the realization of series of integrated ‘FRET on Fiber’ sensors for on-line environmental, chemical, and biomedical detection, with excellent compactness, high sensitivity, good selectivity and fast response

  18. Fiber-optic manipulation of urinary stone phantoms using holmium:YAG and thulium fiber lasers

    NASA Astrophysics Data System (ADS)

    Blackmon, Richard L.; Case, Jason R.; Trammell, Susan R.; Irby, Pierce B.; Fried, Nathaniel M.

    2013-02-01

    Fiber-optic attraction of urinary stones during laser lithotripsy may be exploited to manipulate stone fragments inside the urinary tract without mechanical grasping tools, saving the urologist time and space in the ureteroscope working channel. We compare thulium fiber laser (TFL) high pulse rate/low pulse energy operation to conventional holmium:YAG low pulse rate/high pulse energy operation for fiber-optic suctioning of plaster-of-paris (PoP) stone phantoms. A TFL (wavelength of 1908 nm, pulse energy of 35 mJ, pulse duration of 500 μs, and pulse rate of 10 to 350 Hz) and a holmium laser (wavelength of 2120 nm, pulse energy of 35 to 360 mJ, pulse duration of 300 μs, and pulse rate of 20 Hz) were tested using 270-μm-core optical fibers. A peak drag speed of ˜2.5 mm/s was measured for both TFL (35 mJ and 150 to 250 Hz) and holmium laser (210 mJ and 20 Hz). Particle image velocimetry and thermal imaging were used to track water flow for all parameters. Fiber-optic suctioning of urinary stone phantoms is feasible. TFL operation at high pulse rates/low pulse energies is preferable to holmium operation at low pulse rates/high pulse energies for rapid and smooth stone pulling. With further development, this novel technique may be useful for manipulating stone fragments in the urinary tract.

  19. Cerebral arterial oxygen saturation measurements using a fiber-optic pulse oximeter.

    PubMed

    Phillips, J P; Langford, R M; Chang, S H; Maney, K; Kyriacou, P A; Jones, D P

    2010-10-01

    A pilot investigation was undertaken to assess the performance of a novel fiber-optic cerebral pulse oximetry system. A fiber-optic probe designed to pass through the lumen of a cranial bolt of the type used to make intracranial pressure measurements was used to obtain optical reflectance signals directly from brain tissue. Short-duration measurements were made in six patients undergoing neurosurgery. These were followed by a longer duration measurement in a patient recovering from an intracerebral hematoma. Estimations of cerebral arterial oxygen saturation derived from a frequency domain-based algorithm are compared with simultaneous pulse oximetry (SpO2) and hemoximeter (SaO2) blood samples. The short-duration measurements showed that reliable photoplethysmographic signals could be obtained from the brain tissue. In the long-duration study, the mean (±SD) difference between cerebral oxygen saturation (ScaO2) and finger SpO2 (in saturation units) was -7.47(±3.4)%. The mean (±SD) difference between ScaO2 and blood SaO2 was -7.37(±2.8)%. This pilot study demonstrated that arterial oxygen saturation may be estimated from brain tissue via a fiber-optic pulse oximeter used in conjunction with a cranial bolt. Further studies are needed to confirm the clinical utility of the technique.

  20. Locating illicit connections in storm water sewers using fiber-optic distributed temperature sensing.

    PubMed

    Hoes, O A C; Schilperoort, R P S; Luxemburg, W M J; Clemens, F H L R; van de Giesen, N C

    2009-12-01

    A newly developed technique using distributed temperature sensing (DTS) has been developed to find illicit household sewage connections to storm water systems in the Netherlands. DTS allows for the accurate measurement of temperature along a fiber-optic cable, with high spatial (2m) and temporal (30s) resolution. We inserted a fiber-optic cable of 1300m in two storm water drains. At certain locations, significant temperature differences with an intermittent character were measured, indicating inflow of water that was not storm water. In all cases, we found that foul water from households or companies entered the storm water system through an illicit sewage connection. The method of using temperature differences for illicit connection detection in storm water networks is discussed. The technique of using fiber-optic cables for distributed temperature sensing is explained in detail. The DTS method is a reliable, inexpensive and practically feasible method to detect illicit connections to storm water systems, which does not require access to private property.

  1. Modeling and testing of fast response, fiber-optic temperature sensors

    NASA Astrophysics Data System (ADS)

    Tonks, Michael James

    The objective of this work was to design, analyze and test a fast response fiber-optic temperature probe and sensor. The sensor is intended for measuring rapid temperature changes such as produced by a blast wave formed by a detonation. This work was performed in coordination with Luna Innovations Incorporated, and the design is based on extensions of an existing fiber-optic temperature sensor developed by Luna. The sensor consists of a glass fiber with an optical wafer attached to the tip. A basic description of the principles behind the fiber-optic temperature sensor and an accompanying demodulation system is provided. For experimental validation tests, shock tubes were used to simulate the blast wave experienced at a distance of 3.0 m from the detonation of 22.7 kg of TNT. The flow conditions were predicted using idealized shock tube theory. The temperature sensors were tested in three configurations, flush at the end of the shock tube, extended on a probe 2.54 cm into the flow and extended on a probe 12.7 cm into the flow. The total temperature was expected to change from 300 K to 1130 K for the flush wall experiments and from 300 K to 960 K for the probe experiments. During the initial 0.1 milliseconds of the data the temperature only changed 8 K when the sensors were flush in the end of the shock tube. The sensor temperature changed 36 K during the same time when mounted on a probe in the flow. Schlieren pictures were taken of the flow in the shock tube to further understand the shock tube environment. Contrary to ideal shock tube theory, it was discovered that the flow did not remain stagnant in the end of the shock tube after the shock reflects from the end of the shock tube. Instead, the effects of turbulence were recorded with the fiber-optic sensors, and this turbulence was also captured in the schlieren photographs. A fast-response thermocouple was used to collect data for comparison with the fiber-optic sensor, and the fiber-optic sensor was proven to

  2. Partially reduced graphene oxide based FRET on fiber-optic interferometer for biochemical detection

    PubMed Central

    Yao, B. C.; Wu, Y.; Yu, C. B.; He, J. R.; Rao, Y. J.; Gong, Y.; Fu, F.; Chen, Y. F.; Li, Y. R.

    2016-01-01

    Fluorescent resonance energy transfer (FRET) with naturally exceptional selectivity is a powerful technique and widely used in chemical and biomedical analysis. However, it is still challenging for conventional FRET to perform as a high sensitivity compact sensor. Here we propose a novel ‘FRET on Fiber’ concept, in which a partially reduced graphene oxide (prGO) film is deposited on a fiber-optic modal interferometer, acting as both the fluorescent quencher for the FRET and the sensitive cladding for optical phase measurement due to refractive index changes in biochemical detection. The target analytes induced fluorescence recovery with good selectivity and optical phase shift with high sensitivity are measured simultaneously. The functionalized prGO film coated on the fiber-optic interferometer shows high sensitivities for the detections of metal ion, dopamine and single-stranded DNA (ssDNA), with detection limits of 1.2 nM, 1.3 μM and 1 pM, respectively. Such a prGO based ‘FRET on fiber’ configuration, bridging the FRET and the fiber-optic sensing technology, may serve as a platform for the realization of series of integrated ‘FRET on Fiber’ sensors for on-line environmental, chemical, and biomedical detection, with excellent compactness, high sensitivity, good selectivity and fast response PMID:27010752

  3. Multiplexed fluorescent microarray for human salivary protein analysis using polymer microspheres and fiber-optic bundles.

    PubMed

    Nie, Shuai; Benito-Peña, Elena; Zhang, Huaibin; Wu, Yue; Walt, David R

    2013-10-10

    Herein, we describe a protocol for simultaneously measuring six proteins in saliva using a fiber-optic microsphere-based antibody array. The immuno-array technology employed combines the advantages of microsphere-based suspension array fabrication with the use of fluorescence microscopy. As described in the video protocol, commercially available 4.5 μm polymer microspheres were encoded into seven different types, differentiated by the concentration of two fluorescent dyes physically trapped inside the microspheres. The encoded microspheres containing surface carboxyl groups were modified with monoclonal capture antibodies through EDC/NHS coupling chemistry. To assemble the protein microarray, the different types of encoded and functionalized microspheres were mixed and randomly deposited in 4.5 μm microwells, which were chemically etched at the proximal end of a fiber-optic bundle. The fiber-optic bundle was used as both a carrier and for imaging the microspheres. Once assembled, the microarray was used to capture proteins in the saliva supernatant collected from the clinic. The detection was based on a sandwich immunoassay using a mixture of biotinylated detection antibodies for different analytes with a streptavidin-conjugated fluorescent probe, R-phycoerythrin. The microarray was imaged by fluorescence microscopy in three different channels, two for microsphere registration and one for the assay signal. The fluorescence micrographs were then decoded and analyzed using a homemade algorithm in MATLAB.

  4. Effect of Fiberoptic Collimation Technique on 808 nm Wavelength Laser Stimulation of Cochlear Neurons.

    PubMed

    Wang, Jingxuan; Lu, Jianren; Tian, Lan

    2016-06-01

    The purpose of this study was to evaluate the effects of fiberoptic collimation technique on auditory neural stimulation in the cochlea with 808 nm wavelength lasers. Recently, the pulsed near-infrared lasers in the 800-1000 nm wavelength range have been investigated as an emerging technique to trigger auditory neural response in the cochlea. A laser beam divergence in the optical stimulation pathway exists, which may affect stimulation efficiency and spatial selectivity. The fiberoptic collimation technique was proposed for cochlear neuron stimulation, and the C-lens element was designed as the collimation structure. The spiral ganglion cells in deafened guinea pigs' cochlea were irradiated with collimated and uncollimated near-infrared lasers. Optically evoked auditory brainstem response (OABR) under the two laser output modes were recorded. Laser with the collimation technique evoked an average 58% higher OABR amplitude than the uncollimated laser output. In addition, the collimated laser setup consumed on average 35.2% of laser energy compared with the uncollimated laser when evoking the same OABR amplitude. The fiberoptic collimation technique improved stimulation efficiency and reduced stimulating energy consumption in near-infrared neural stimulation in cochlea. The positive effects of laser collimation technique could benefit further research in optically based cochlear implants.

  5. Linearization of Positional Response Curve of a Fiber-optic Displacement Sensor

    NASA Astrophysics Data System (ADS)

    Babaev, O. G.; Matyunin, S. A.; Paranin, V. D.

    2018-01-01

    Currently, the creation of optical measuring instruments and sensors for measuring linear displacement is one of the most relevant problems in the area of instrumentation. Fiber-optic contactless sensors based on the magneto-optical effect are of special interest. They are essentially contactless, non-electrical and have a closed optical channel not subject to contamination. The main problem of this type of sensors is the non-linearity of their positional response curve due to the hyperbolic nature of the magnetic field intensity variation induced by moving the magnetic source mounted on the controlled object relative to the sensing element. This paper discusses an algorithmic method of linearizing the positional response curve of fiber-optic displacement sensors in any selected range of the displacements to be measured. The method is divided into two stages: 1 - definition of the calibration function, 2 - measurement and linearization of the positional response curve (including its temperature stabilization). The algorithm under consideration significantly reduces the number of points of the calibration function, which is essential for the calibration of temperature dependence, due to the use of the points that randomly deviate from the grid points with uniform spacing. Subsequent interpolation of the deviating points and piecewise linear-plane approximation of the calibration function reduces the microcontroller storage capacity for storing the calibration function and the time required to process the measurement results. The paper also presents experimental results of testing real samples of fiber-optic displacement sensors.

  6. Fiber-optic manipulation of urinary stone phantoms using holmium:YAG and thulium fiber lasers.

    PubMed

    Blackmon, Richard L; Case, Jason R; Trammell, Susan R; Irby, Pierce B; Fried, Nathaniel M

    2013-02-01

    Fiber-optic attraction of urinary stones during laser lithotripsy may be exploited to manipulate stone fragments inside the urinary tract without mechanical grasping tools, saving the urologist time and space in the ureteroscope working channel. We compare thulium fiber laser (TFL) high pulse rate/low pulse energy operation to conventional holmium:YAG low pulse rate/high pulse energy operation for fiber-optic suctioning of plaster-of-paris (PoP) stone phantoms. A TFL (wavelength of 1908 nm, pulse energy of 35 mJ, pulse duration of 500 μs, and pulse rate of 10 to 350 Hz) and a holmium laser (wavelength of 2120 nm, pulse energy of 35 to 360 mJ, pulse duration of 300 μs, and pulse rate of 20 Hz) were tested using 270-μm-core optical fibers. A peak drag speed of ~2.5 mm/s was measured for both TFL (35 mJ and 150 to 250 Hz) and holmium laser (210 mJ and 20 Hz). Particle image velocimetry and thermal imaging were used to track water flow for all parameters. Fiber-optic suctioning of urinary stone phantoms is feasible. TFL operation at high pulse rates/low pulse energies is preferable to holmium operation at low pulse rates/high pulse energies for rapid and smooth stone pulling. With further development, this novel technique may be useful for manipulating stone fragments in the urinary tract.

  7. Development and Testing of a Post-Installable Deepwater Monitoring System Using Fiber-Optic Sensors

    NASA Technical Reports Server (NTRS)

    Seaman, Calvin H.; Brower, David V.; Le, Suy Q.; Tang, Henry H.

    2015-01-01

    This paper addresses the design and development of a fiber-optic monitoring system that can be deployed on existing deepwater risers and flowlines; and provides a summary of test article fabrication and the subsequent laboratory testing performed at the National Aeronautics and Space Administration-Johnson Space Center (NASA-JSC). A major challenge of a post-installed instrumentation system is to ensure adequate coupling between the instruments and the riser or flowline of interest. This work investigates the sensor coupling for pipelines that are suspended in a water column (from topside platform to seabed) using a fiber-optic sensor clamp and subsea bonding adhesive. The study involved the design, fabrication, and test of several prototype clamps that contained fiber-optic sensors. A mold was produced by NASA using 3-D printing methods that allowed the casting of polyurethane clamp test articles to accommodate 4-inch and 8-inch diameter pipes. The prototype clamps were installed with a subsea adhesive in a "wet" environment and then tested in the NASA Structures Test Laboratory (STL). The tension, compression, and bending test data showed that the prototype sensor clamps achieved good structural coupling, and could provide high quality strain measurement for active monitoring.

  8. The fiber-optic high-speed data bus for a new generation of military aircraft

    NASA Astrophysics Data System (ADS)

    Uhlhorn, Roger W.

    1991-02-01

    The avionic suite for the next generation of military aircraft is being designed with component and module commonality in mind in order to control recurring costs and capitalize on economy of scale. The backbone of the suite fashioned out of these modular building blocks is the fiber-optic bit-serial time-division multiplexed high-speed data bus (HSDB), operating at 50 Mb/s, which provides command and control communications among most of the aircraft subsystems and can be used to provide communications for a fly-by-light flight-control system or for the block transfer of data between mass memories and data processors. The fiber-optic HSDB is examined from the top down, beginning with an overview of the evolution of avionic architectures. A review is given of the standardization activity associated with development of the network, the protocols chosen to implement the desired communication functions, configuration options, and the fiber-optic components used in the bus interfaces or other active nodes of the network. It is believed that the utility of the bus extends beyond aircraft to spacecraft, ships, and land vehicles.

  9. Fiberoptic intubation in 327 neurosurgical patients with lesions of the cervical spine.

    PubMed

    Fuchs, G; Schwarz, G; Baumgartner, A; Kaltenböck, F; Voit-Augustin, H; Planinz, W

    1999-01-01

    In patients with lesions of the cervical spine, direct laryngoscopy for endotracheal intubation entails the risk of injuring the spinal cord. In an attempt to avoid this complication, the authors used flexible fiberoptic nasal intubation in a series of 327 patients with cervical lesions undergoing elective neurosurgical procedures. The nasal route was preferred for laryngeal intubation because it is easier than the oral route and a restraining collar or halo device does not impair the intubating maneuver. Bronchoscopic intubation was possible in all patients. In 12 patients (3.6%), anatomic abnormalities prevented transnasal insertion of the endotracheal tube, and transoral fiberoptic intubation was necessary. Endotracheal intubation was graded as slightly difficult in 85 patients (26%). The minimal peripheral oxygen saturation during intubation exceeded 90% in 289 patients (88%). In the other 38 patients, the mean O2 saturation was 84.2+/-4.3% (range, 72-89%). Intubation was well tolerated by all patients and none had recall of the procedure. Cervical stabilizers did not have to be removed for intubation in any patient. None of the patients had postoperative neurologic deficits attributable to the intubation procedure. The authors consider fiberoptic transnasal intubation to be a useful alternative to direct laryngoscopic tracheal intubation in patients undergoing elective surgical procedures on the cervical spine to avoid potential injury to the cervical spinal cord.

  10. Evaluation of hollow fiberoptic tips for the conduction of Er:YAG laser.

    PubMed

    Alves, Paulo Roberto Vieira; Aranha, Norberto; Alfredo, Edson; Marchesan, Melissa Andréia; Brugnera Junior, Aldo; Sousa-Neto, Manoel D

    2005-08-01

    The use of Er:YAG laser operating in the 3 microm range with adjustable power and pulses has become popular for dental and medical practice due to its high photoablative capacity, surgical precision and antimicrobial action. The existing fiberoptic tips irradiate lasers parallel to the long axes of the tooth limiting its efficiency in the root canal. We evaluated hollow fiberoptic tips obtained from silicate glass as a means of Er:YAG laser conduction in dental procedures. The fiber tips were molded from capillary tubes with different profiles so that their ends would have cylindric, conical or spherical shapes. The performance of the three fibers as a means of propagation of Er:YAG (lambda = 2.94 microm) laser radiation was compared to that of a solid sapphire fiber at 10 Hz and 200 mJ and of 20 Hz and 500 mJ. The profiles of frontal and lateral burning were visualized on thermal paper. Analysis of these profiles demonstrated that the sapphire tip and the hollow fiber of cylindric section did not differ significantly in the profiles of frontal burning, and no lateral burning was detected. The fibers of the conical and spherical sections, although presenting attenuation in the frontal output power, showed a larger burning area in the frontal profile, in addition to producing lateral burning. The results indicate that commercial hollow fiberoptics have advantages such as easy manufacture of the different tip shapes, great adaptability, low cost, and a low loss of transmission.

  11. Effects of different anaesthetics on cytokine levels in children with community-acquired pneumonia undergoing flexible fibreoptic bronchoscopy.

    PubMed

    Chen, Lin; Cheng, Jing; Wang, Yan-Lin

    2016-06-01

    To determine the effects of propofol and sevoflurane on cytokine levels in children with community-acquired pneumonia undergoing flexible fibreoptic bronchoscopy (FFB). Children with community-acquired pneumonia were randomly assigned to receive 3-5 mg/kg propofol i.v. or 8% inhaled sevoflurane. Haemodynamic variables, stress hormone responses and serum cytokines were compared between the two groups. Out of 50 children aged 2-12 years (propofol, n = 25; sevoflurane, n = 25), there were no significant between-group differences in haemodynamic variables and stress hormones. Interleukin (IL)-6 and IL-10 decreased significantly following FFB in both groups. IL-6 levels were significantly lower in the sevoflurane group than propofol group at 4 h and 1 d following FFB (61.3 ± 11.9 versus 82.6 ± 19.7 pg/ml; 52.8 ± 9.7 versus 75.4 ± 13.6 pg/ml, respectively). IL-10 levels in the sevoflurane group were significantly lower than in the propofol group at 1 d following FFB. In children with community-acquired pneumonia, use of sevoflurane was associated with lower circulating IL-6 and IL-10 levels compared with propofol, following FFB. Pneumonia severity is reflected by higher blood cytokine levels, thus, sevoflurane may be more beneficial to recovery from community-acquired pneumonia than propofol, however further studies are required to test this hypothesis. © The Author(s) 2016.

  12. Blinded evaluation of interrater reliability of an operative competency assessment tool for direct laryngoscopy and rigid bronchoscopy.

    PubMed

    Ishman, Stacey L; Benke, James R; Johnson, Kaalan Erik; Zur, Karen B; Jacobs, Ian N; Thorne, Marc C; Brown, David J; Lin, Sandra Y; Bhatti, Nasir; Deutsch, Ellen S

    2012-10-01

    OBJECTIVES To confirm interrater reliability using blinded evaluation of a skills-assessment instrument to assess the surgical performance of resident and fellow trainees performing pediatric direct laryngoscopy and rigid bronchoscopy in simulated models. DESIGN Prospective, paired, blinded observational validation study. SUBJECTS Paired observers from multiple institutions simultaneously evaluated residents and fellows who were performing surgery in an animal laboratory or using high-fidelity manikins. The evaluators had no previous affiliation with the residents and fellows and did not know their year of training. INTERVENTIONS One- and 2-page versions of an objective structured assessment of technical skills (OSATS) assessment instrument composed of global and a task-specific surgical items were used to evaluate surgical performance. RESULTS Fifty-two evaluations were completed by 17 attending evaluators. The instrument agreement for the 2-page assessment was 71.4% when measured as a binary variable (ie, competent vs not competent) (κ = 0.38; P = .08). Evaluation as a continuous variable revealed a 42.9% percentage agreement (κ = 0.18; P = .14). The intraclass correlation was 0.53, considered substantial/good interrater reliability (69% reliable). For the 1-page instrument, agreement was 77.4% when measured as a binary variable (κ = 0.53, P = .0015). Agreement when evaluated as a continuous measure was 71.0% (κ = 0.54, P < .001). The intraclass correlation was 0.73, considered high interrater reliability (85% reliable). CONCLUSIONS The OSATS assessment instrument is an effective tool for evaluating surgical performance among trainees with acceptable interrater reliability in a simulator setting. Reliability was good for both the 1- and 2-page OSATS checklists, and both serve as excellent tools to provide immediate formative feedback on operational competency.

  13. Trans-bronchoscopy with implantation of 125I radioactive seeds in patients with pulmonary atelectasis induced by lung cancer.

    PubMed

    Lu, Mingjian; Pu, Deli; Zhang, Weidong; Liao, Jiangrong; Zhang, Tao; Yang, Guang; Liu, Zhenyin; Singh, Sristi; Gao, Fei; Zhang, Fujun

    2015-07-01

    To evaluate the role of low-dose-rate interstitial brachytherapy using trans-bronchoscope 125 I radioactive seeds implantation in patients with pulmonary atelectasis induced by lung cancer, in terms of feasibility, safety, quality of life (QOL), and survival time. Between April 2008 and June 2011, 15 patients from two medical institutions that had obstructive pulmonary atelectasis caused by inoperable lung cancer were assigned to receive 125 I implantation endoluminal brachytherapy by bronchoscopy. Subsequent to the implantation of 125 I seeds, the outcomes were measured in terms of procedure success rate, reopening of atelectasis, complications associated with the procedure, Karnofsky performance status (KPS) scores and survival time. The surgical procedure was successfully performed in all 15 patients. No procedure-associated mortality occurred and the complications were mild and considered acceptable. Irritable cough and temporary increase of hemoptysis occurred in 11 (73.3%) and 10 (66.7%) patients respectively, and were the most common complications. The pulmonary atelectasis reopening rate subsequent to the procedure was 86.7, 76.9, 80.0, 75.0 and 50.0% at 2, 6, 12, 18 and 24 months, respectively. The KPS score significantly improved following the implantation of 125 I seeds and the duration of improvement ranged between 3 and 27 months. The median and mean survival times were 15.6 and 16 months, respectively. Actuarial survival rates at 6, 12 and 24 months after the procedure were 86.7, 66.7 and 13.3%, respectively. In patients with advanced lung cancer and those presenting with obstructive pulmonary atelectasis, treatment with intraluminal implantation of 125 I seeds is a safe and effective therapy option with easy accessibility.

  14. Trans-bronchoscopy with implantation of 125I radioactive seeds in patients with pulmonary atelectasis induced by lung cancer

    PubMed Central

    LU, MINGJIAN; PU, DELI; ZHANG, WEIDONG; LIAO, JIANGRONG; ZHANG, TAO; YANG, GUANG; LIU, ZHENYIN; SINGH, SRISTI; GAO, FEI; ZHANG, FUJUN

    2015-01-01

    To evaluate the role of low-dose-rate interstitial brachytherapy using trans-bronchoscope 125I radioactive seeds implantation in patients with pulmonary atelectasis induced by lung cancer, in terms of feasibility, safety, quality of life (QOL), and survival time. Between April 2008 and June 2011, 15 patients from two medical institutions that had obstructive pulmonary atelectasis caused by inoperable lung cancer were assigned to receive 125I implantation endoluminal brachytherapy by bronchoscopy. Subsequent to the implantation of 125I seeds, the outcomes were measured in terms of procedure success rate, reopening of atelectasis, complications associated with the procedure, Karnofsky performance status (KPS) scores and survival time. The surgical procedure was successfully performed in all 15 patients. No procedure-associated mortality occurred and the complications were mild and considered acceptable. Irritable cough and temporary increase of hemoptysis occurred in 11 (73.3%) and 10 (66.7%) patients respectively, and were the most common complications. The pulmonary atelectasis reopening rate subsequent to the procedure was 86.7, 76.9, 80.0, 75.0 and 50.0% at 2, 6, 12, 18 and 24 months, respectively. The KPS score significantly improved following the implantation of 125I seeds and the duration of improvement ranged between 3 and 27 months. The median and mean survival times were 15.6 and 16 months, respectively. Actuarial survival rates at 6, 12 and 24 months after the procedure were 86.7, 66.7 and 13.3%, respectively. In patients with advanced lung cancer and those presenting with obstructive pulmonary atelectasis, treatment with intraluminal implantation of 125I seeds is a safe and effective therapy option with easy accessibility. PMID:26171002

  15. Bronchoscopy with endobronchial ultrasound guided transbronchial needle aspiration vs. transthoracic needle aspiration in lung cancer diagnosis and staging.

    PubMed

    Munoz, Mark L; Lechtzin, Noah; Li, Qing Kay; Wang, KoPen; Yarmus, Lonny B; Lee, Hans J; Feller-Kopman, David J

    2017-07-01

    In evaluating patients with suspected lung cancer, it is important to not only obtain a tissue diagnosis, but also to obtain enough tissue for both histologic and molecular analysis in order to appropriately stage the patient with a safe and efficient strategy. The diagnostic approach may often be dependent on local resources and practice patterns rather than current guidelines. We Describe lung cancer staging at two large academic medical centers to identify the impact different procedural approaches have on patient outcomes. We conducted a retrospective cohort study of all patients undergoing a lung cancer diagnostic evaluation at two multidisciplinary centers during a 1-year period. Identifying complication rates and the need for multiple biopsies as our primary outcomes, we developed a multivariate regression model to determine features associated with complications and need for multiple biopsies. Of 830 patients, 285 patients were diagnosed with lung cancers during the study period. Those staged at the institution without an endobronchial ultrasound (EBUS) program were more likely to require multiple biopsies (OR 3.62, 95% CI: 1.71-7.67, P=0.001) and suffer complications associated with the diagnostic procedure (OR 10.2, 95% CI: 3.08-33.58, P<0.001). Initial staging with transthoracic needle aspiration (TTNA) and conventional bronchoscopy were associated with greater need for subsequent biopsies (OR 8.05 and 14.00, 95% CI: 3.43-18.87 and 5.17-37.86, respectively) and higher complication rates (OR 37.75 and 7.20, 95% CI: 10.33-137.96 and 1.36-37.98, respectively). Lung cancer evaluation at centers with a dedicated EBUS program results in fewer biopsies and complications than at multidisciplinary counterparts without an EBUS program.

  16. Electromagnetic navigational bronchoscopy with dye marking for identification of small peripheral lung nodules during minimally invasive surgical resection

    PubMed Central

    Muñoz-Largacha, Juan A.; Ebright, Michael I.; Litle, Virginia R.

    2017-01-01

    Background Identification of small peripheral lung nodules during minimally invasive resection can be challenging. Electromagnetic navigational bronchoscopy (ENB) with injection of dye to identify nodules can be performed by the surgeon immediately prior to resection. We evaluated the effectiveness of ENB with dye marking to aid minimally invasive resection. Methods Patients with peripheral pulmonary nodules underwent ENB before planned thoracoscopic or robotic-assisted thoracoscopic resection. Methylene blue was injected directly into the lesion for pleural-based lesions or peripherally for lesions deep to the pleural surface. Surgical resection was then immediately performed. Technical success was defined as identification of the dye marking within/close to the lesion with pathological confirmation after minimally invasive surgical resection. Results Seventeen patients (19 nodules) underwent ENB with dye marking followed by minimally invasive resection. Median lesion size was 9 mm (4–32 mm) and the median distance from the pleura was 9.5 mm (1–40 mm). Overall success rate was 79% (15/19). In two cases the dye was not visualized and in the remaining two there was extravasation of dye into the pleural space. There were trends favoring technical success for nodules that were larger or closer to the pleural surface. Five patients required adhesiolysis to visualize the target lesion and all were successful. There were no significant adverse events and a definitive diagnosis was ultimately accomplished in all patients. Conclusions ENB with dye marking is useful for guiding minimally invasive resection of small peripheral lung nodules. ENB can be undertaken immediately before performing resection in the operating room. This improves workflow and avoids the need for a separate localization procedure. PMID:28449489

  17. Cough suppression during flexible bronchoscopy using combined sedation with midazolam and hydrocodone: a randomised, double blind, placebo controlled trial

    PubMed Central

    Stolz, D; Chhajed, P; Leuppi, J; Brutsche, M; Pflimlin, E; Tamm, M

    2004-01-01

    Background: Current British Thoracic Society guidelines do not recommend routinely the combined use of a benzodiazepine and opiate during flexible bronchoscopy (FB). A randomised, placebo controlled, double blind study was undertaken to determine whether hydrocodone in combination with midazolan improves cough suppression during FB without increasing the risk of desaturation. Methods: 120 patients were randomised to receive midazolam and 5 mg IV hydrocodone or midazolam and placebo with topical anaesthesia. Pulse oximetry was recorded continuously during FB. Bronchoscopists and nurses charted their perception of cough and the patients rated their discomfort during the procedure on a 10 cm visual analogue scale (VAS). Results: There was no significant difference between the two groups with regard to the indication for FB, duration of procedure (21 (11) min v 22 (10) min, p = 0.570), doses of supplemental lignocaine (171 (60) mg v 173 (66) mg, p = 0.766) and midazolam (4.5 (2.3) mg v 4.9 (2.7) mg, p = 0.309), lowest oxygen saturation (94.8 (2.7) v 94.9 (2.7), p = 0.433), and desaturations ⩽90%. Perception of cough by both the bronchoscopist and the nurse was significantly lower in the hydrocodone group (3 (0–10) and 3 (0–10)) than in the placebo group (6 (0–10) and 6 (0–10)), respectively (p = 0.001). According to the VAS scale, patients' tolerance was also significantly better with hydrocodone than with placebo (2 (0–8) v 3 (0–9), p = 0.043). Conclusion: The combination of midazolam and hydrocodone markedly reduces cough during FB without causing significant desaturation, especially when invasive diagnostic procedures are performed. PMID:15333854

  18. Electromagnetic navigation bronchoscopy to access lung lesions in 1,000 subjects: first results of the prospective, multicenter NAVIGATE study.

    PubMed

    Khandhar, Sandeep J; Bowling, Mark R; Flandes, Javier; Gildea, Thomas R; Hood, Kristin L; Krimsky, William S; Minnich, Douglas J; Murgu, Septimiu D; Pritchett, Michael; Toloza, Eric M; Wahidi, Momen M; Wolvers, Jennifer J; Folch, Erik E

    2017-04-11

    Electromagnetic navigation bronchoscopy (ENB) is an image-guided, minimally invasive approach that uses a flexible catheter to access pulmonary lesions. NAVIGATE is a prospective, multicenter study of the superDimension™ navigation system. A prespecified 1-month interim analysis of the first 1,000 primary cohort subjects enrolled at 29 sites in the United States and Europe is described. Enrollment and 24-month follow-up are ongoing. ENB index procedures were conducted for lung lesion biopsy (n = 964), fiducial marker placement (n = 210), pleural dye marking (n = 17), and/or lymph node biopsy (n = 334; primarily endobronchial ultrasound-guided). Lesions were in the peripheral/middle lung thirds in 92.7%, 49.7% were <20 mm, and 48.4% had a bronchus sign. Radial EBUS was used in 54.3% (543/1,000 subjects) and general anesthesia in 79.7% (797/1,000). Among the 964 subjects (1,129 lesions) undergoing lung lesion biopsy, navigation was completed and tissue was obtained in 94.4% (910/964). Based on final pathology results, ENB-aided samples were read as malignant in 417/910 (45.8%) subjects and non-malignant in 372/910 (40.9%) subjects. An additional 121/910 (13.3%) were read as inconclusive. One-month follow-up in this interim analysis is not sufficient to calculate the true negative rate or diagnostic yield. Tissue adequacy for genetic testing was 80.0% (56 of 70 lesions sent for testing). The ENB-related pneumothorax rate was 4.9% (49/1,000) overall and 3.2% (32/1,000) CTCAE Grade ≥2 (primary endpoint). The ENB-related Grade ≥2 bronchopulmonary hemorrhage and Grade ≥4 respiratory failure rates were 1.0 and 0.6%, respectively. One-month results of the first 1,000 subjects enrolled demonstrate low adverse event rates in a generalizable population across diverse practice settings. Continued enrollment and follow-up are required to calculate the true negative rate and delineate the patient, lesion, and procedural factors contributing to diagnostic

  19. Study of distributed fiber-optic laser-ultrasound generation based on ghost-mode of tilted fiber Bragg gratings

    NASA Astrophysics Data System (ADS)

    Tian, Jiajun; Zhang, Qi; Han, Ming

    2013-05-01

    Fiber-optic ultrasonic transducers are an important component of an active ultrasonic testing system for structural health monitoring. Fiber-optic transducers have several advantages such as small size, light weight, and immunity to electromagnetic interference that make them much more attractive than the current available piezoelectric transducers, especially as embedded and permanent transducers in active ultrasonic testing for structural health monitoring. In this paper, a distributed fiber-optic laser-ultrasound generation based on the ghost-mode of tilted fiber Bragg gratings is studied. The influences of the laser power and laser pulse duration on the laser-ultrasound generation are investigated. The results of this paper are helpful to understand the working principle of this laser-ultrasound method and improve the ultrasonic generation efficiency.

  20. Dexmedetomidine for an awake fiber-optic intubation of a parturient with Klippel-Feil syndrome, Type I Arnold Chiari malformation and status post released tethered spinal cord presenting for repeat cesarean section

    PubMed Central

    Shah, Tanmay H.; Badve, Manasi S.; Olajide, Kowe O.; Skorupan, Havyn M.; Waters, Jonathan H.; Vallejo, Manuel C.

    2011-01-01

    Patients with Klippel-Feil Syndrome (KFS) have congenital fusion of their cervical vertebrae due to a failure in the normal segmentation of the cervical vertebrae during the early weeks of gestation and also have myriad of other associated anomalies. Because of limited neck mobility, airway management in these patients can be a challenge for the anesthesiologist. We describe a unique case in which a dexmedetomidine infusion was used as sedation for an awake fiber-optic intubation in a parturient with Klippel-Feil Syndrome, who presented for elective cesarean delivery. A 36-year-old female, G2P1A0 with KFS (fusion of cervical vertebrae) who had prior cesarean section for breech presentation with difficult airway management was scheduled for repeat cesarean delivery. After obtaining an informed consent, patient was taken in the operating room and non-invasive monitors were applied. Dexmedetomidine infusion was started and after adequate sedation, an awake fiber-optic intubation was performed. General anesthetic was administered after intubation and dexmedetomidine infusion was continued on maintenance dose until extubation. Klippel-Feil Syndrome (KFS) is a rare congenital disorder for which the true incidence is unknown, which makes it even rare to see a parturient with this disease. Patients with KFS usually have other congenital abnormalities as well, sometimes including the whole thoraco-lumbar spine (Type III) precluding the use of neuraxial anesthesia for these patients. Obstetric patients with KFS can present unique challenges in administering anesthesia and analgesia, primarily as it relates to the airway and dexmedetomidine infusion has shown promising result to manage the airway through awake fiberoptic intubation without any adverse effects on mother and fetus. PMID:24765318

  1. Sensitivity and Specificity of Cardiac Tissue Discrimination Using Fiber-Optics Confocal Microscopy.

    PubMed

    Huang, Chao; Sachse, Frank B; Hitchcock, Robert W; Kaza, Aditya K

    2016-01-01

    Disturbances of the cardiac conduction system constitute a major risk after surgical repair of complex cases of congenital heart disease. Intraoperative identification of the conduction system may reduce the incidence of these disturbances. We previously developed an approach to identify cardiac tissue types using fiber-optics confocal microscopy and extracellular fluorophores. Here, we applied this approach to investigate sensitivity and specificity of human and automated classification in discriminating images of atrial working myocardium and specialized tissue of the conduction system. Two-dimensional image sequences from atrial working myocardium and nodal tissue of isolated perfused rodent hearts were acquired using a fiber-optics confocal microscope (Leica FCM1000). We compared two methods for local application of extracellular fluorophores: topical via pipette and with a dye carrier. Eight blinded examiners evaluated 162 randomly selected images of atrial working myocardium (n = 81) and nodal tissue (n = 81). In addition, we evaluated the images using automated classification. Blinded examiners achieved a sensitivity and specificity of 99.2 ± 0.3% and 98.0 ± 0.7%, respectively, with the dye carrier method of dye application. Sensitivity and specificity was similar for dye application via a pipette (99.2 ± 0.3% and 94.0 ± 2.4%, respectively). Sensitivity and specificity for automated methods of tissue discrimination were similarly high. Human and automated classification achieved high sensitivity and specificity in discriminating atrial working myocardium and nodal tissue. We suggest that our findings facilitate clinical translation of fiber-optics confocal microscopy as an intraoperative imaging modality to reduce the incidence of conduction disturbances during surgical correction of congenital heart disease.

  2. The role of fiberoptic nasopharyngoscopy in the management of the acute airway in angioneurotic edema.

    PubMed

    Bentsianov, B L; Parhiscar, A; Azer, M; Har-El, G

    2000-12-01

    Angioneurotic edema of the upper aerodigestive tract (AEUAT) often challenges the otolaryngologist with the decision of surgical intervention versus observation. To develop a logical approach to the evaluation and management of the airway in patients with AEUAT, emphasizing fiberoptic examination (FOE) findings. A computer-based retrospective review of all patients diagnosed with AEUAT was performed. The charts were reviewed for demographics, etiology, medical history, presentation, physical examination, imaging studies, intervention, and outcome. Findings on FOE as well as other covariants were statistically compared. Seventy patients with AEUAT were identified. The etiologies consisted of 24 cases of angiotensin converting enzyme inhibitor use (33%), 10 allergic reactions (17%), 1 hereditary (1.5%), and 35 idiopathic cases (48%). Fourteen patients underwent airway intervention, including 6 tracheotomies and 8 intubations. Of the 14 patients, 5 underwent emergent intervention before fiberoptic examination, 4 had laryngeal edema only, and 5 had both laryngeal and base of tongue edema. No patients with both laryngeal and base of tongue edema were observed. The remaining 52 patients were observed in a monitored setting and required no subsequent intervention. FOE is an invaluable tool in the assessment of the compromised airway in patients with angioneurotic edema Laryngeal edema alone is an ominous physical finding. When laryngeal and pharyngeal edema are present together, the physician should consider immediate intervention. Our findings indicate that symptoms, including stridor, hoarseness, and dysphagia, do correlate with disease severity; however, they must be confirmed with fiberoptic visualization. Although sound clinical judgment should always be exercised, we present our results in the management of the acute airway in angioneurotic edema.

  3. Use of fiberoptic endoscopic evaluation of swallowing (FEES) in the management of psychogenic dysphagia in children.

    PubMed

    Thottam, Prasad John; Silva, Rodrigo C; McLevy, Jennifer D; Simons, Jeffrey P; Mehta, Deepak K

    2015-02-01

    To describe the use of fiberoptic endoscopic evaluation of swallowing (FEES) as an adjunct in the management of children presenting with psychogenic dysphagia, defined as food avoidance and excessive fear of eating without identifiable anatomic or functional swallowing abnormalities. Case series of patients presenting to the otolaryngology clinic of a tertiary pediatric teaching hospital between 2007 and 2008 that were evaluated and managed with the utilization of FEES. The outcomes measured were age, gender, duration of symptoms, findings of FEES, additional work-up and resolution of symptoms at follow-up. Five patients (4 males, 1 female) with ages ranging from 5 to 13 years old (mean=8.6). The median duration of symptoms before presentation was 3 weeks. Four families described refusal of solids starting after choking episode and variable estimated weight loss (mean 2.8kg). One child presented with vague complaints of intermittent odynophagia and food refusal. Fiberoptic endoscopic evaluation of swallowing was performed on all patients. No abnormalities of the oropharyngeal swallow were appreciated. Additional management included different combinations of modified barium swallow study, esophagastroduodenoscopy (EGD), upper GI series, antibiotics, and psychotherapy. Mean follow-up with clinic visit was 4.2 months. Three of the five children reported complete resolution of symptoms after FEES at follow-up visit. Fiberoptic endoscopic evaluation of swallowing can be a useful management tool in children with psychogenic dysphagia as it provides direct visualization of the oropharyngeal swallowing mechanism. This can be used to provide visual reassure and biofeedback to patients and parents. Additional workup should be decided on an individual basis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. In Vivo Fiber-Optic Raman Mapping Of Metastases In Mouse Brains

    NASA Astrophysics Data System (ADS)

    Stelling, A.; Kirsch, M.; Steiner, G.; Krafft, C.; Schackert, G.; Salzer, R.

    2010-08-01

    Vibrational spectroscopy, in particular Raman spectroscopy, has potential applications in the field of in vivo diagnostics. Raman and FT-IR spectroscopy analyze the complete biochemical information at any given pixel within the visual field. Here we demonstrate the feasibility of performing Raman spectroscopic measurements on living mice brains using a fiber-optic probe with a nominal spatial resolution of 60 μm. The objectives of this study were to 1) evaluate preclinical models, namely murine brain slices containing experimental tumors, 2) optimize the preparation of pristine brain tissue to obtain reference information, to 3) optimize the conditions for introducing a fiber-optic probe to acquire Raman maps in vivo, and 4) to transfer results obtained from human brain tumors to an animal model. Disseminated brain metastases of malignant melanomas were induced by injecting tumor cells into the carotid artery of mice. The procedure mimicked hematogenous tumor spread in one brain hemisphere while the other hemisphere remained tumor free. Three series of sections were prepared consecutively from whole mouse brains: pristine, 2-mm thick sections for Raman mapping and dried, thin sections for FT-IR imaging, hematoxylin and eosin-stained thin sections for histopathological assessment. Raman maps were collected serially using a spectrometer coupled to a fiber-optic probe. FT-IR images were recorded using a spectrometer with a multi-channel detector. The FT-IR images and the Raman maps were evaluated by multivariate data analysis. The results obtained from the thin section studies were employed to guide measurements of murine brains in vivo. Raman maps with an acquisition time of over an hour could be performed on the living animals. No damage to the tissue was observed.

  5. Fiber-optic sensing in cryogenic environments. [for rocket propellant tank monitoring

    NASA Technical Reports Server (NTRS)

    Sharma, M.; Brooks, R. E.

    1980-01-01

    Passive optical sensors using fiber-optic signal transmission to a remote monitoring station are explored as an alternative to electrical sensors used to monitor the status of explosive propellants. The designs of passive optical sensors measuring liquid level, pressure, and temperature in cryogenic propellant tanks are discussed. Test results for an experimental system incorporating these sensors and operating in liquid nitrogen demonstrate the feasibility of passive sensor techniques and indicate that they can serve as non-hazardous replacements for more conventional measuring equipment in explosive environments.

  6. High resolution (<1nm) interferometric fiber-optic sensor of vibrations in high-power transformers.

    PubMed

    Garcia-Souto, Jose A; Lamela-Rivera, Horacio

    2006-10-16

    A novel fiber-optic interferometric sensor is presented for vibrations measurements and analysis. In this approach, it is shown applied to the vibrations of electrical structures within power transformers. A main feature of the sensor is that an unambiguous optical phase measurement is performed using the direct detection of the interferometer output, without external modulation, for a more compact and stable implementation. High resolution of the interferometric measurement is obtained with this technique (<1 nm). The optical-fiber transducer is also specifically designed for magnifying the localized vibrations in order to modulate deeply the interferometric signal. Other advantages of the implementation for measurements within transformers are also highlighted.

  7. Theory of fiber-optic, evanescent-wave spectroscopy and sensors

    NASA Astrophysics Data System (ADS)

    Messica, A.; Greenstein, A.; Katzir, A.

    1996-05-01

    A general theory for fiber-optic, evanescent-wave spectroscopy and sensors is presented for straight, uncladded, step-index, multimode fibers. A three-dimensional model is formulated within the framework of geometric optics. The model includes various launching conditions, input and output end-face Fresnel transmission losses, multiple Fresnel reflections, bulk absorption, and evanescent-wave absorption. An evanescent-wave sensor response is analyzed as a function of externally controlled parameters such as coupling angle, f number, fiber length, and diameter. Conclusions are drawn for several experimental apparatuses.

  8. Fiber-Optic Magnetic-Field-Strength Measurement System for Lightning Detection

    NASA Technical Reports Server (NTRS)

    Gurecki, Jay; Scully, Robert; Davis, Allen; Kirkendall, Clay; Bucholtz, Frank

    2011-01-01

    A fiber-optic sensor system is designed to measure magnetic fields associated with a lightning stroke. Field vector magnitudes are detected and processed for multiple locations. Since physical limitations prevent the sensor elements from being located in close proximity to highly conductive materials such as aluminum, the copper wire sensor elements (3) are located inside a 4-cubic-in. (.66-cubic-cm) plastic housing sensor head and connected to a fiber-optic conversion module by shielded cabling, which is limited to the shortest length feasible. The signal path between the conversion module and the avionics unit which processes the signals are fiber optic, providing enhanced immunity from electromagnetic radiation incident in the vicinity of the measurements. The sensors are passive, lightweight, and much smaller than commercial B-dot sensors in the configuration which measures a three-dimensional magnetic field. The system is expandable, and provides a standard-format output signal for downstream processing. Inside of the sensor head, three small search coils, each having a few turns on a circular form, are mounted orthogonally inside the non-metallic housing. The fiber-optic conversion module comprises three interferometers, one for each search coil. Each interferometer has a high bandwidth optical phase modulator that impresses the signal received from its search coil onto its output. The output of each interferometer travels by fiber optic cable to the avionics unit, and the search coil signal is recovered by an optical phase demodulator. The output of each demodulator is fed to an analog-to-digital converter, whose sampling rate is determined by the maximum expected rate of rise and peak signal magnitude. The output of the digital processor is a faithful reproduction of the coil response to the incident magnetic field. This information is provided in a standard output format on a 50-ohm port that can be connected to any number of data collection and processing

  9. PMD compensation in fiber-optic communication systems with direct detection using LDPC-coded OFDM.

    PubMed

    Djordjevic, Ivan B

    2007-04-02

    The possibility of polarization-mode dispersion (PMD) compensation in fiber-optic communication systems with direct detection using a simple channel estimation technique and low-density parity-check (LDPC)-coded orthogonal frequency division multiplexing (OFDM) is demonstrated. It is shown that even for differential group delay (DGD) of 4/BW (BW is the OFDM signal bandwidth), the degradation due to the first-order PMD can be completely compensated for. Two classes of LDPC codes designed based on two different combinatorial objects (difference systems and product of combinatorial designs) suitable for use in PMD compensation are introduced.

  10. Fiber-optic extrinsic Fabry-Perot interferometer sensors with three-wavelength digital phase demodulation.

    PubMed

    Schmidt, M; Fürstenau, N

    1999-05-01

    A three-wavelength-based passive quadrature digital phase-demodulation scheme has been developed for readout of fiber-optic extrinsic Fabry-Perot interferometer vibration, acoustic, and strain sensors. This scheme uses a superluminescent diode light source with interference filters in front of the photodiodes and real-time arctan calculation. Quasi-static strain and dynamic vibration sensing with up to an 80-kHz sampling rate is demonstrated. Periodic nonlinearities owing to dephasing with increasing fringe number are corrected for with a suitable algorithm, resulting in significant improvement of the linearity of the sensor characteristics.

  11. Advanced Fiber-optic Monitoring System for Space-flight Applications

    NASA Technical Reports Server (NTRS)

    Hull, M. S.; VanTassell, R. L.; Pennington, C. D.; Roman, M.

    2005-01-01

    Researchers at Luna Innovations Inc. and the National Aeronautic and Space Administration s Marshall Space Flight Center (NASA MSFC) have developed an integrated fiber-optic sensor system for real-time monitoring of chemical contaminants and whole-cell bacterial pathogens in water. The system integrates interferometric and evanescent-wave optical fiber-based sensing methodologies with atomic force microscopy (AFM) and long-period grating (LPG) technology to provide versatile measurement capability for both micro- and nano-scale analytes. Sensors can be multiplexed in an array format and embedded in a totally self-contained laboratory card for use with an automated microfluidics platform.

  12. High-temperature fiber-optic Fabry-Perot interferometric sensors.

    PubMed

    Ding, Wenhui; Jiang, Yi; Gao, Ran; Liu, Yuewu

    2015-05-01

    A photonic crystal fiber (PCF) based high-temperature fiber-optic sensor is proposed and experimentally demonstrated. The sensor head is a Fabry-Perot cavity manufactured with a short section of endless single-mode photonic crystal fiber (ESM PCF). The interferometric spectrum of the Fabry-Perot interferometer is collected by a charge coupled device linear array based micro spectrometer. A high-resolution demodulation algorithm is used to interrogate the peak wavelengths. Experimental results show that the temperature range of 1200 °C and the temperature resolution of 1 °C are achieved.

  13. High-temperature fiber-optic Fabry-Perot interferometric sensors

    NASA Astrophysics Data System (ADS)

    Ding, Wenhui; Jiang, Yi; Gao, Ran; Liu, Yuewu

    2015-05-01

    A photonic crystal fiber (PCF) based high-temperature fiber-optic sensor is proposed and experimentally demonstrated. The sensor head is a Fabry-Perot cavity manufactured with a short section of endless single-mode photonic crystal fiber (ESM PCF). The interferometric spectrum of the Fabry-Perot interferometer is collected by a charge coupled device linear array based micro spectrometer. A high-resolution demodulation algorithm is used to interrogate the peak wavelengths. Experimental results show that the temperature range of 1200 °C and the temperature resolution of 1 °C are achieved.

  14. Screening unlabeled DNA targets with randomly ordered fiber-optic gene arrays.

    PubMed

    Steemers, F J; Ferguson, J A; Walt, D R

    2000-01-01

    We have developed a randomly ordered fiber-optic gene array for rapid, parallel detection of unlabeled DNA targets with surface immobilized molecular beacons (MB) that undergo a conformational change accompanied by a fluorescence change in the presence of a complementary DNA target. Microarrays are prepared by randomly distributing MB-functionalized 3-microm diameter microspheres in an array of wells etched in a 500-microm diameter optical imaging fiber. Using several MBs, each designed to recognize a different target, we demonstrate the selective detection of genomic cystic fibrosis related targets. Positional registration and fluorescence response monitoring of the microspheres was performed using an optical encoding scheme and an imaging fluorescence microscope system.

  15. Multivariate reference technique for quantitative analysis of fiber-optic tissue Raman spectroscopy.

    PubMed

    Bergholt, Mads Sylvest; Duraipandian, Shiyamala; Zheng, Wei; Huang, Zhiwei

    2013-12-03

    We report a novel method making use of multivariate reference signals of fused silica and sapphire Raman signals generated from a ball-lens fiber-optic Raman probe for quantitative analysis of in vivo tissue Raman measurements in real time. Partial least-squares (PLS) regression modeling is applied to extract the characteristic internal reference Raman signals (e.g., shoulder of the prominent fused silica boson peak (~130 cm(-1)); distinct sapphire ball-lens peaks (380, 417, 646, and 751 cm(-1))) from the ball-lens fiber-optic Raman probe for quantitative analysis of fiber-optic Raman spectroscopy. To evaluate the analytical value of this novel multivariate reference technique, a rapid Raman spectroscopy system coupled with a ball-lens fiber-optic Raman probe is used for in vivo oral tissue Raman measurements (n = 25 subjects) under 785 nm laser excitation powers ranging from 5 to 65 mW. An accurate linear relationship (R(2) = 0.981) with a root-mean-square error of cross validation (RMSECV) of 2.5 mW can be obtained for predicting the laser excitation power changes based on a leave-one-subject-out cross-validation, which is superior to the normal univariate reference method (RMSE = 6.2 mW). A root-mean-square error of prediction (RMSEP) of 2.4 mW (R(2) = 0.985) can also be achieved for laser power prediction in real time when we applied the multivariate method independently on the five new subjects (n = 166 spectra). We further apply the multivariate reference technique for quantitative analysis of gelatin tissue phantoms that gives rise to an RMSEP of ~2.0% (R(2) = 0.998) independent of laser excitation power variations. This work demonstrates that multivariate reference technique can be advantageously used to monitor and correct the variations of laser excitation power and fiber coupling efficiency in situ for standardizing the tissue Raman intensity to realize quantitative analysis of tissue Raman measurements in vivo, which is particularly appealing in

  16. Evaluation of an improved fiberoptics luminescence skin monitor with background correction.

    PubMed

    Vo-Dinh, T

    1987-06-01

    In this work, an improved version of a fiberoptics luminescence monitor, the prototype luminoscope II, is evaluated for in situ quantitative measurements. The instrument was developed to detect traces of luminescing organic contaminants on skin. An electronic background-nulling system was designed and incorporated into the instrument to compensate for various skin background emissions. A dose-response curve for a coal liquid spotted on mouse skin was established. The results illustrated the usefulness of the instrument for in vivo detection of organic materials on laboratory mouse skin.

  17. High Resolution Sub-MM Fiberoptic Endoscope Final Report CRADA No. TSB-1447-97

    SciT

    Stone, Gary F.; Smith, John

    2018-01-22

    At the time of the CRADA, LLNL needed to develop a sub-mm outer diameter fiberoptic endoscope with 25pm or better resolution at 3-lOmm working distance to support the Enhanced Surveillance Program (ESP) and the Core Surveillance Program for DOE. The commercially available systems did not meet the image resolution requirements and development work was needed to reach three goals. We also needed to perform preliminary investigations into the production of such an endoscope with a steerable-articulated distal end. The goal of such an endoscope was to allow for a 45 degree inspection cone including the lens field of view.

  18. High-Sensitivity Fiber-Optic Ultrasound Sensors for Medical Imaging Applications

    PubMed Central

    Wen, H.; Wiesler, D.G.; Tveten, A.; Danver, B.; Dandridge, A.

    2010-01-01

    This paper presents several designs of high-sensitivity, compact fiber-optic ultrasound sensors that may be used for medical imaging applications. These sensors translate ultrasonic pulses into strains in single-mode optical fibers, which are measured with fiber-based laser interferometers at high precision. The sensors are simpler and less expensive to make than piezoelectric sensors, and are not susceptible to electromagnetic interference. It is possible to make focal sensors with these designs, and several schemes are discussed. Because of the minimum bending radius of optical fibers, the designs are suitable for single element sensors rather than for arrays. PMID:9691368

  19. Grating-assisted polarization optical time-domain reflectometry for distributed fiber-optic sensing.

    PubMed

    Han, Ming; Wang, Yunjing; Wang, Anbo

    2007-07-15

    We report a novel type of polarization optical time-domain reflectometry (POTDR) for fully distributed fiber-optic sensing, in which the reflected optical signal is from a series of fiber Bragg gratings that are uniformly distributed along the fiber. Compared with a conventional POTDR that uses the Rayleigh backscattering, this grating-assisted POTDR can have a much better signal-to-noise ratio and consequently a better measurement resolution and a larger measurement range of the fiber birefringence. Experimental results have shown that the measurement resolution of the grating-assisted POTDR is almost an order of magnitude better than that of a conventional POTDR.

  20. A fiber-optic ice detection system for large-scale wind turbine blades

    NASA Astrophysics Data System (ADS)

    Kim, Dae-gil; Sampath, Umesh; Kim, Hyunjin; Song, Minho

    2017-09-01

    Icing causes substantial problems in the integrity of large-scale wind turbines. In this work, a fiber-optic sensor system for detection of icing with an arrayed waveguide grating is presented. The sensor system detects Fresnel reflections from the ends of the fibers. The transition in Fresnel reflection due to icing gives peculiar intensity variations, which categorizes the ice, the water, and the air medium on the wind turbine blades. From the experimental results, with the proposed sensor system, the formation of icing conditions and thickness of ice were identified successfully in real time.

  1. Fly-By-Light/Power-By-Wire Fault-Tolerant Fiber-Optic Backplane

    NASA Technical Reports Server (NTRS)

    Malekpour, Mahyar R.

    2002-01-01

    The design and development of a fault-tolerant fiber-optic backplane to demonstrate feasibility of such architecture is presented. The simulation results of test cases on the backplane in the advent of induced faults are presented, and the fault recovery capability of the architecture is demonstrated. The architecture was designed, developed, and implemented using the Very High Speed Integrated Circuits (VHSIC) Hardware Description Language (VHDL). The architecture was synthesized and implemented in hardware using Field Programmable Gate Arrays (FPGA) on multiple prototype boards.

  2. Fiber-optic photoelastic pressure sensor with fiber-loss compensation

    NASA Technical Reports Server (NTRS)

    Beheim, G.; Anthan, D. J.

    1987-01-01

    A new fiber-optic pressure sensor is described that has high immunity to the effects of fiber-loss variations. This device uses the photoelastic effect to modulate the proportion of the light from each of two input fibers that is coupled into each of two output fibers. This four-fiber link permits two detectors to be used to measure the sensor's responses to the light from each of two independently controlled sources. These four detector outputs are processed to yield a loss-compensated signal that is a stable and sensitive pressure indicator.

  3. Infrared fiber-optic fire sensors - Concepts and designs for Space Station applications

    NASA Technical Reports Server (NTRS)

    Tapphorn, Ralph M.; Porter, Alan R.

    1990-01-01

    Various design configurations used for testing IR fiber-optic (IFO) fire-sensor concepts are presented. Responsibility measurements conducted to select the best concept are reviewed. The results indicate that IFO fire-sensor systems based on distributed fiber sensors are feasible for future aerospace applications. For Space Station Freedom, these systems offer alternative fire detectors for monitoring areas within equipment or stage compartments where the ventilation may be inadequate for proper operation of smoke detectors. They also allow a large number of areas to be monitored by a single central detector unit, which reduces the associated cost and weight.

  4. Upconversion fiber-optic confocal microscopy under near-infrared pumping.

    PubMed

    Kim, Do-Hyun; Kang, Jin U; Ilev, Ilko K

    2008-03-01

    We present a simple upconversion fiber-optic confocal microscope design using a near-infrared laser for pumping of a rare-earth-doped glass powder. The nonlinear optical frequency conversion process is highly efficient with more than 2% upconversion fluorescence efficiency at a near-infrared pumping wavelength of 1.55 microm. The upconversion confocal design allows the use of conventional Si detectors and 1.55 microm near-infrared pump light. The lateral and axial resolutions of the system were equal to or better than 1.10 and 13.11 microm, respectively.

  5. Fiber-optic confocal reflectance microscope with miniature objective for in vivo imaging of human tissues.

    PubMed

    Sung, Kung-Bin; Liang, Chen; Descour, Michael; Collier, Tom; Follen, Michele; Richards-Kortum, Rebecca

    2002-10-01

    We have built a fiber-optic confocal reflectance microscope capable of imaging human tissues in near real time. Miniaturization of the objective lens and the mechanical components for positioning and axially scanning the objective enables the device to be used in inner organs of the human body. The lateral resolution is 2 micrometers and axial resolution is 10 micrometers. Confocal images of fixed tissue biopsies and the human lip in vivo have been obtained at 15 frames/s without any fluorescent stains. Both cell morphology and tissue architecture can be appreciated from images obtained with this microscope.

  6. Fiber-optical switch using cam-micromotor driven by scratch drive actuators

    NASA Astrophysics Data System (ADS)

    Kanamori, Y.; Aoki, Y.; Sasaki, M.; Hosoya, H.; Wada, A.; Hane, K.

    2005-01-01

    We fabricated a 1 × 1 fiber-optic switch using a cam-micromotor driven by scratch drive actuators (SDAs). Using the cam-micromotor, mechanical translation and precise positioning of an optical fiber were performed. An optical fiber of diameter 50 µm was bent and pushed out with a cam-mechanism driven by the SDAs fabricated by surface micromachining. The maximum rotation speed of the cam-micromotor was 7.5 rpm at a driving frequency of 1.5 kHz. The transient time of the switch to attenuate coupling efficiency less than -40 dB was around 10 ms.

  7. Wavelength tunable and broadband variable fiber-optic attenuators using liquid crystals

    NASA Astrophysics Data System (ADS)

    Khan, Sajjad A.; Riza, Nabeel A.

    2005-05-01

    Fiber-Optic Variable Optical Attenuators (VOAs) are demonstrated using Liquid Crystals (LC) for broadband as well as wavelength tunable applications. Attenuation is achieved by using a beam spoiling approach implemented via electrically reconfigurable non-pixelated no moving parts Nematic LC deflectors. The VOAs feature in-line architecture and polarization insensitive design without the use of bulky polarization splitting and combining optics. The proof-of-concept VOAs in the 1550 nm band demonstrate >30 dB attenuation ranges, low polarization dependent losses and low power consumption. Applications for these VOAs include agile wavelength tunable secure data communications networks and RF sensor systems.

  8. Fiber-Optic Sensors for Measurements of Torsion, Twist and Rotation: A Review.

    PubMed

    Budinski, Vedran; Donlagic, Denis

    2017-02-23

    Optical measurement of mechanical parameters is gaining significant commercial interest in different industry sectors. Torsion, twist and rotation are among the very frequently measured mechanical parameters. Recently, twist/torsion/rotation sensors have become a topic of intense fiber-optic sensor research. Various sensing concepts have been reported. Many of those have different properties and performances, and many of them still need to be proven in out-of-the laboratory use. This paper provides an overview of basic approaches and a review of current state-of-the-art in fiber optic sensors for measurements of torsion, twist and/or rotation.Invited Paper.

  9. Fiber-optic coupling based on nonimaging expanded-beam optics.

    PubMed

    Moslehi, B; Ng, J; Kasimoff, I; Jannson, T

    1989-12-01

    We have fabricated and experimentally tested low-cost and mass-producible multimode fiber-optic couplers and connectors based on nonimaging beam-expanding optics and Liouville's theorem. Analysis indicates that a pair coupling loss of -0.25 dB can be achieved. Experimentally, we measured insertion losses as low as -0.38 dB. The beam expanders can be mass produced owing to the use of plastic injection-molding fabrication techniques and packaged in standard connector housings. This design is compatible with the fiber geometry and can yield highly stable coupling owing to its high tolerance for misalignments.

  10. Fiber-Optic Sensors for Measurements of Torsion, Twist and Rotation: A Review †

    PubMed Central

    Budinski, Vedran; Donlagic, Denis

    2017-01-01

    Optical measurement of mechanical parameters is gaining significant commercial interest in different industry sectors. Torsion, twist and rotation are among the very frequently measured mechanical parameters. Recently, twist/torsion/rotation sensors have become a topic of intense fiber-optic sensor research. Various sensing concepts have been reported. Many of those have different properties and performances, and many of them still need to be proven in out-of-the laboratory use. This paper provides an overview of basic approaches and a review of current state-of-the-art in fiber optic sensors for measurements of torsion, twist and/or rotation. PMID:28241510

  11. Fiber-Optic Sensor for Aircraft Lightning Current Measurement

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Ely, Jay J.; Szatkowski, George G.; Mata, Carlos T.; Mata, Angel G.; Snyder, Gary P.

    2012-01-01

    An electric current sensor based on Faraday rotation effect in optical fiber was developed for measuring aircraft lightning current. Compared to traditional sensors, the design has many advantages including the ability to measure total current and to conform to structure geometries. The sensor is also small, light weight, non-conducting, safe from interference, and free of hysteresis and saturation. Potential applications include characterization of lightning current waveforms, parameters and paths, and providing environmental data for aircraft certifications. In an optical fiber as the sensing medium, light polarization rotates when exposed to a magnetic field in the direction of light propagation. By forming closed fiber loops around a conductor and applying Ampere s law, measuring the total light rotation yields the enclosed current. A reflective polarimetric scheme is used, where polarization change is measured after the polarized light travels round-trip through the sensing fiber. The sensor system was evaluated measuring rocket-triggered lightning over the 2011 summer. Early results compared very well against a reference current shunt resistor, demonstrating the sensor s accuracy and feasibility in a lightning environment. While later comparisons show gradually increasing amplitude deviations for an undetermined cause, the overall waveforms still compared very well.

  12. Fiber-Optic Current Sensor Validation with Triggered Lightning Measurements

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Ely, Jay J.; Szatkowski, George N.; Mata, Carlos T.; Mata, Angel G.; Snyder, Gary P.

    2013-01-01

    A fiber optic current sensor based on the Faraday Effect is developed that is highly suitable for aircraft installation and can measure total current enclosed in a fiber loop down to DC. Other attributes include being small, light-weight, non-conducting, safe from electromagnetic interference, and free of hysteresis and saturation. The Faraday Effect causes light polarization to rotate when exposed to a magnetic field in the direction of light propagation. Measuring the induced light polarization rotation in fiber loops yields the total current enclosed. Two sensor systems were constructed and installed at Camp Blanding, Florida, measuring rocket-triggered lightning. The systems were similar in design but with different laser wavelengths, sensitivities and ranges. Results are compared to a shunt resistor as reference. The 850nm wavelength system tested in summer 2011 showed good result comparison early. However, later results showed gradual amplitude increase with time, attributed to corroded connections affecting the 50-ohm output termination. The 1550nm system also yielded good results in the summer 2012. The successful measurements demonstrate the fiber optic sensor's accuracies in capturing real lightning currents, and represent an important step toward future aircraft installation.

  13. Fiberoptic endoscopic evaluation of swallowing in intensive care unit patients

    PubMed Central

    Hafner, Gert; Neuhuber, Andreas; Hirtenfelder, Sylvia; Schmedler, Brigitte

    2007-01-01

    Aspiration in critically ill patients frequently causes severe co-morbidity. We evaluated a diagnostic protocol using routine FEES in critically ill patients at risk to develop aspiration following extubation. We instructed intensive care unit physicians on specific risk factors for and clinical signs of aspiration following extubation in critically ill patients and offered bedside FEES for such patients. Over a 45-month period, we were called to perform 913 endoscopic examinations in 553 patients. Silent aspiration or aspiration with acute symptoms (cough or gag reflex as the bolus passed into the trachea) was detected in 69.3% of all patients. Prolonged non-oral feeding via a naso-gastric tube was initiated in 49.7% of all patients. In 13.2% of patients, a percutaneous endoscopic gastrostomy was initiated as a result of FEES findings, and in 6.3% an additional tracheotomy to prevent aspiration had to be initiated. In 59 out of 258 patients (22.9%), tracheotomies were closed, and 30.7% of all 553 patients could be managed with the immediate onset of an oral diet and compensatory treatment procedures. Additional radiological examinations were not required. FEES in critically ill patients allows for a rapid evaluation of deglutition and for the immediate initiation of symptom-related rehabilitation or for an early resumption of oral feeding. PMID:17968575

  14. Fiber-Optic Sensor for Aircraft Lightning Current Measurement

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Ely, Jay J.; Szatkowski, George G.; Mata, Carlos T.; Mata,Angel G.; Snyder, Gary P.

    2012-01-01

    An electric current sensor based on Faraday rotation effect in optical fiber was developed for measuring aircraft lightning current. Compared to traditional sensors, the design has many advantages including the ability to measure total current and to conform to structure geometries. The sensor is also small, light weight, non-conducting, safe from interference, and free of hysteresis and saturation. Potential applications include characterization of lightning current waveforms, parameters and paths, and providing environmental data for aircraft certifications. In an optical fiber as the sensing medium, light polarization rotates when exposed to a magnetic field in the direction of light propagation. By forming closed fiber loops around a conductor and applying Ampere s law, measuring the total light rotation yields the enclosed current. A reflective polarimetric scheme is used, where polarization change is measured after the polarized light travels round-trip through the sensing fiber. The sensor system was evaluated measuring rocket-triggered lightning over the 2011 summer. Early results compared very well against a reference current shunt resistor, demonstrating the sensor's accuracy and feasibility in a lightning environment. While later comparisons show gradually increasing amplitude deviations for an undetermined cause, the overall waveforms still compared very well.

  15. Accuracy and reproducibility of the measurement of actively circulating blood volume with an integrated fiberoptic monitoring system.

    PubMed

    Kisch, H; Leucht, S; Lichtwarck-Aschoff, M; Pfeiffer, U J

    1995-05-01

    Bedside monitoring of circulating blood volume has become possible with the introduction of an integrated fiberoptic monitoring system that calculates blood volume from the changes in blood concentration of indocyanine green dye 4 mins after injection. The aim of this investigation was to compare the blood volume estimate of the integrated fiberoptic monitoring system (group 1) with the standard methods of blood volume measurement using Evans blue (group 2), and indocyanine green measured photometrically (group 3). Prospective laboratory study. Animal laboratory of a University's institute for experimental surgery. Eleven anesthetized, paralyzed, and mechanically ventilated piglets. A central venous catheter was used for the injection of the indicator dyes (Evans blue and indocyanine green). A fiberoptic thermistor catheter was advanced into the thoracic aorta. The fiberoptic catheter detects indocyanine green by reflection densitometry for the estimation of blood volume of the integrated fiberoptic monitoring system. Samples for the determination of Evans blue and indocyanine green concentrations were drawn from an arterial catheter in the femoral artery over a period of 17 mins after injection. Measurements were performed during normovolemia, hypovolemia (blood withdrawal of < or = 30 mL/kg), and hypervolemia (retransfusion of the withdrawn blood plus an infusion of 10% hydroxyethyl starch [45 mL/kg]). Linear regression, correlation, and bias were calculated for the comparison of the blood volume estimates by the fiberoptic monitoring system (group 1) vs. the total blood volume estimates using Evans blue (group 2) and indocyanine green (group 3): group 1 = 0.82.group 2-26 mL; r2 = 82.71%; r = .91; n = 40; group 1-group 2 +/- 1 SD = -435 +/- 368 mL; group 1 = 0.79.group 3 + 50 mL; r2 = 74.81%; r = .87; n = 28; group 1-group 3 +/- 1 SD = -506 +/- 374 mL. The results demonstrate that the blood volume estimate of the fiberoptic monitoring system (group 1) correlates

  16. Aspiration in children and adolescents with neurogenic dysphagia: comparison of clinical judgment and fiberoptic endoscopic evaluation of swallowing.

    PubMed

    Beer, Sabrina; Hartlieb, Till; Müller, Arnd; Granel, Michael; Staudt, Martin

    2014-12-01

    A total of 30 children and adolescents with dysphagia due to various chronic neurological disorders were assessed for their risk of aspiration. This assessment was performed clinically by experienced speech and swallowing therapists, and verified thereafter by fiberoptic endoscopy. We found the clinical judgment to be correct in only 70% (for aspiration of saliva), 55% (of puree), and 67% (of thin liquids). We conclude that, because of this unacceptably high error rate of clinical assessment, a fiberoptic evaluation of swallowing is a necessary diagnostic step both for the planning of therapy and for the development of feeding strategies in children and adolescents with neurogenic dysphagia. Georg Thieme Verlag KG Stuttgart · New York.

  17. Spatial Frequency Multiplexing of Fiber-Optic Interferometric Refractive Index Sensors Based on Graded-Index Multimode Fibers

    PubMed Central

    Liu, Li; Gong, Yuan; Wu, Yu; Zhao, Tian; Wu, Hui-Juan; Rao, Yun-Jiang

    2012-01-01

    Fiber-optic interferometric sensors based on graded-index multimode fibers have very high refractive-index sensitivity, as we previously demonstrated. In this paper, spatial-frequency multiplexing of this type of fiber-optic refractive index sensors is investigated. It is estimated that multiplexing of more than 10 such sensors is possible. In the multiplexing scheme, one of the sensors is used to investigate the refractive index and temperature responses. The fast Fourier transform (FFT) of the combined reflective spectra is analyzed. The intensity of the FFT spectra is linearly related with the refractive index and is not sensitive to the temperature.

  18. What is Bronchoscopy?

    MedlinePlus

    ... Learn more about getting to NIH Get Email Alerts Receive automatic alerts about NHLBI related news and ... Connect With Us Contact Us Directly Get Email Alerts Receive automatic alerts about NHLBI related news and ...

  19. Taking a look at the calibration of a CCD detector with a fiber-optic taper

    PubMed Central

    Alkire, R. W.; Rotella, F. J.; Duke, N. E. C.; Otwinowski, Zbyszek; Borek, Dominika

    2016-01-01

    At the Structural Biology Center beamline 19BM, located at the Advanced Photon Source, the operational characteristics of the equipment are routinely checked to ensure they are in proper working order. After performing a partial flat-field calibration for the ADSC Quantum 210r CCD detector, it was confirmed that the detector operates within specifications. However, as a secondary check it was decided to scan a single reflection across one-half of a detector module to validate the accuracy of the calibration. The intensities from this single reflection varied by more than 30% from the module center to the corner of the module. Redistribution of light within bent fibers of the fiber-optic taper was identified to be a source of this variation. The degree to which the diffraction intensities are corrected to account for characteristics of the fiber-optic tapers depends primarily upon the experimental strategy of data collection, approximations made by the data processing software during scaling, and crystal symmetry. PMID:27047303

  20. Application and the key technology on high power fiber-optic laser in laser weapon

    NASA Astrophysics Data System (ADS)

    Qu, Zhou; Li, Qiushi; Meng, Haihong; Sui, Xin; Zhang, Hongtao; Zhai, Xuhua

    2014-12-01

    The soft-killing laser weapon plays an important role in photoelectric defense technology. It can be used for photoelectric detection, search, blinding of photoelectric sensor and other devices on fire control and guidance devices, therefore it draws more and more attentions by many scholars. High power fiber-optic laser has many virtues such as small volume, simple structure, nimble handling, high efficiency, qualified light beam, easy thermal management, leading to blinding. Consequently, it may be used as the key device of soft-killing laser weapon. The present study introduced the development of high power fiber-optic laser and its main features. Meanwhile the key technology of large mode area (LMA) optical fiber design, the beam combination technology, double-clad fiber technology and pumping optical coupling technology was stated. The present study is aimed to design high doping LMA fiber, ensure single mode output by increasing core diameter and decrease NA. By means of reducing the spontaneous emission particle absorbed by fiber core and Increasing the power density in the optical fiber, the threshold power of nonlinear effect can increase, and the power of single fiber will be improved. Meantime, high power will be obtained by the beam combination technology. Application prospect of high power fiber laser in photoelectric defense technology was also set forth. Lastly, the present study explored the advantages of high power fiber laser in photoelectric defense technology.

  1. Fiber-optic evanescent-wave spectroscopy for fast multicomponent analysis of human blood

    NASA Astrophysics Data System (ADS)

    Simhi, Ronit; Gotshal, Yaron; Bunimovich, David; Katzir, Abraham; Sela, Ben-Ami

    1996-07-01

    A spectral analysis of human blood serum was undertaken by fiber-optic evanescent-wave spectroscopy (FEWS) by the use of a Fourier-transform infrared spectrometer. A special cell for the FEWS measurements was designed and built that incorporates an IR-transmitting silver halide fiber and a means for introducing the blood-serum sample. Further improvements in analysis were obtained by the adoption of multivariate calibration techniques that are already used in clinical chemistry. The partial least-squares algorithm was used to calculate the concentrations of cholesterol, total protein, urea, and uric acid in human blood serum. The estimated prediction errors obtained (in percent from the average value) were 6% for total protein, 15% for cholesterol, 30% for urea, and 30% for uric acid. These results were compared with another independent prediction method that used a neural-network model. This model yielded estimated prediction errors of 8.8% for total protein, 25% for cholesterol, and 21% for uric acid. spectroscopy, fiber-optic evanescent-wave spectroscopy, Fourier-transform infrared spectrometer, blood, multivariate calibration, neural networks.

  2. Fiberoptic Applications in Sensors and Telemetry for the Electric Power Industry

    NASA Astrophysics Data System (ADS)

    Werneck, M. M.; Silva, A. V.; Souza, N. C. C.; Miguel, M. A. L.; Beres, C.; Yugue, E. S.; Carvalho, C. C.; Maciel, F. L.; Silva-Neto, J.; Guimarães, C. R. F.; Allil, R. C. S. B.; Baliosian, J. A. G.

    2008-10-01

    This presentation features the origin and the work of the Photonics and Instrumentation Laboratory (LIF) in instrumentation, fiberoptic sensors and POF technology. LIF started its work in 1986, twenty and two years ago, with only one lecturer and a few students. The first project was the development of the first Brazilian plotter with the purpose, at the time, to substitute expensive imported technology. LIF has today 25 people between students, technicians, scientists, engineers and teachers. We present here several successful projects of fiberoptic sensors using both silica and POF fibers, most of them applied on the field mainly for the electric power industry. Described are: a oil leakage sensor in petroleum hoses, PMMA evanescent sensors, temperature by the ruby fluorescence phenomenon, a current sensor calibrator for 500 kV current transformers, a leakage sensor to measure 500 kV insulators in extra-high voltage transmission line, etc. Many of the sensors presented here have been tested in the field, patented and transferred to the industry. We have also technical collaboration with several industries in Brazil, one of them a spin-off from LIF. Our objective is to become a reference centre in POF technology in Latin America and for this we are intended to keep producing "out of the shelves" POF technology and innovative industry solutions for many areas.

  3. A Fiber-Optic Coupled Telescope for Water Vapor DIAL Receivers

    NASA Technical Reports Server (NTRS)

    DeYoung, Russell J.; Lonn, Frederick

    1998-01-01

    A fiber-optic coupled telescope of low complexity was constructed and tested. The major loss mechanisms of the optical system have been characterized. Light collected by the receiver mirror is focused onto an optical fiber, and the output of the fiber is filtered by an interference filter and then focused onto an APD detector. This system was used in lidar field measurements with a 532-nm Nd:YAG laser beam. The results were encouraging. A numerical model used for calculation of the expected return signal agreed with the lidar return signal obtained. The assembled system was easy to align and operate and weighed about 8 kg for a 30 cm (12") mirror system. This weight is low enough to allow mounting of the fiber-optic telescope receiver system in a UAV. Furthermore, the good agreement between the numerical lidar model and the performance of the actual receiver system, suggests that this model may be used for estimation of the performance of this and other lidar systems in the future. Such telescopes are relatively easy to construct and align. The fiber optic cable allows easy placement of the optical detector in any position. These telescope systems should find widespread use in aircraft and space home DIAL water vapor receiver systems.

  4. Investigation of Carbon-Polymer Structures with Embedded Fiber-Optic Bragg Gratings

    NASA Technical Reports Server (NTRS)

    Grant, Joseph; Kaul, R.; Taylor, S.; Myers, G.; Sharma, A.

    2003-01-01

    Several Bragg-grating sensors fabricated within the same optical fiber are buried within multiple-ply carbon-epoxy planar and cylindrical structures. Effect of different orientation of fiber-sensors with respect to carbon fibers in the composite structure is investigated. This is done for both fabric and uni-tape material samples. Response of planar structures to axial and transverse strain up to 1 millistrain is investigated with distributed Bragg-grating sensors. Material properties like Young's Modulus and Poisson ratio is measured. A comparison is made between response measured by sensors in different ply-layers and those bonded on the surface. The results from buried fiber- sensors do not completely agree with surface bonded conventional strain gauges. A plausible explanation is given for observed differences. The planar structures are subjected to impacts with energies up to 10 ft-lb. Effect of this impact on the material stiffness is also investigated with buried fiber-optic Bragg sensors. The strain response of such optical sensors is also measured for cylindrical carbon-epoxy composite structures. The sensors are buried within the walls of the cylinder as well as surface bonded in both the axial as well as hoop directions. The response of these fiber-optic sensors is investigated by pressurizing the cylinder up to its burst pressure of around 1500 psi. This is done at both room temperature as well as cryogenic temperatures. The recorded response is compared with that from a conventional strain gauge.

  5. Embedded infrared fiber-optic sensor for thermometry in a high temperature/pressure environment

    NASA Astrophysics Data System (ADS)

    Yoo, Wook Jae; Jang, Kyoung Won; Moon, Jinsoo; Han, Ki-Tek; Jeon, Dayeong; Lee, Bongsoo; Park, Byung Gi

    2012-11-01

    In this study, we developed an embedded infrared fiber-optic temperature sensor for thermometry in high temperature/pressure and water-chemistry environments by using two identical silver-halide optical fibers. The performance of the fabricated temperature sensor was assessed in an autoclave filled with an aqueous coolant solution containing boric acid and lithium hydroxide. We carried out real-time monitoring of the infrared radiation emitted from the signal and reference probes for various temperatures over a temperature range from 95 to 225 °C. In order to decide the temperature of the synthetic coolant solution, we measured the difference between the infrared radiation emitted from the two temperature-sensing probes. Thermometry with the proposed sensor is immune to any changes in the physical conditions and the emissivity of the heat source. From the experimental results, the embedded infrared fiber-optic temperature sensor can withstand, and normally operate in a high temperature/pressure test loop system corresponding to the coolant system used for nuclear power plant simulation. We expect that the proposed sensor can be developed to accurately monitor temperatures in harsh environments.

  6. Pressure sensor based on the fiber-optic extrinsic Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Yu, Qingxu; Zhou, Xinlei

    2011-03-01

    Pressure sensors based on fiber-optic extrinsic Fabry-Perot interferometer (EFPI) have been extensively applied in various industrial and biomedical fields. In this paper, some key improvements of EFPI-based pressure sensors such as the controlled thermal bonding technique, diaphragm-based EFPI sensors, and white light interference technology have been reviewed. Recent progress on signal demodulation method and applications of EFPI-based pressure sensors has been introduced. Signal demodulation algorithms based on the cross correlation and mean square error (MSE) estimation have been proposed for retrieving the cavity length of EFPI. Absolute measurement with a resolution of 0.08 nm over large dynamic range has been carried out. For downhole monitoring, an EFPI and a fiber Bragg grating (FBG) cascade multiplexing fiber-optic sensor system has been developed, which can operate in temperature 300 °C with a good long-term stability and extremely low temperature cross-sensitivity. Diaphragm-based EFPI pressure sensors have been successfully used for low pressure and acoustic wave detection. Experimental results show that a sensitivity of 31 mV/Pa in the frequency range of 100 Hz to 12.7 kHz for aeroacoustic wave detection has been obtained.

  7. Fiber-optic microarray for simultaneous detection of multiple harmful algal bloom species.

    PubMed

    Ahn, Soohyoun; Kulis, David M; Erdner, Deana L; Anderson, Donald M; Walt, David R

    2006-09-01

    Harmful algal blooms (HABs) are a serious threat to coastal resources, causing a variety of impacts on public health, regional economies, and ecosystems. Plankton analysis is a valuable component of many HAB monitoring and research programs, but the diversity of plankton poses a problem in discriminating toxic from nontoxic species using conventional detection methods. Here we describe a sensitive and specific sandwich hybridization assay that combines fiber-optic microarrays with oligonucleotide probes to detect and enumerate the HAB species Alexandrium fundyense, Alexandrium ostenfeldii, and Pseudo-nitzschia australis. Microarrays were prepared by loading oligonucleotide probe-coupled microspheres (diameter, 3 mum) onto the distal ends of chemically etched imaging fiber bundles. Hybridization of target rRNA from HAB cells to immobilized probes on the microspheres was visualized using Cy3-labeled secondary probes in a sandwich-type assay format. We applied these microarrays to the detection and enumeration of HAB cells in both cultured and field samples. Our study demonstrated a detection limit of approximately 5 cells for all three target organisms within 45 min, without a separate amplification step, in both sample types. We also developed a multiplexed microarray to detect the three HAB species simultaneously, which successfully detected the target organisms, alone and in combination, without cross-reactivity. Our study suggests that fiber-optic microarrays can be used for rapid and sensitive detection and potential enumeration of HAB species in the environment.

  8. Ultrafast Fabry-Perot fiber-optic pressure sensors for multimedia blast event measurements.

    PubMed

    Zou, Xiaotian; Wu, Nan; Tian, Ye; Zhang, Yang; Fitek, John; Maffeo, Michael; Niezrecki, Christopher; Chen, Julie; Wang, Xingwei

    2013-02-20

    A shock wave (SW) is characterized as a large pressure fluctuation that typically lasts only a few milliseconds. On the battlefield, SWs pose a serious threat to soldiers who are exposed to explosions, which may lead to blast-induced traumatic brain injuries. SWs can also be used beneficially and have been applied to a variety of medical treatments due to their unique interaction with tissues and cells. Consequently, it is important to have sensors that can quantify SW dynamics in order to better understand the physical interaction between body tissue and the incident acoustic wave. In this paper, the ultrafast fiber-optic sensor based on the Fabry-Perot interferometric principle was designed and four such sensors were fabricated to quantify a blast event within different media, simultaneously. The compact design of the fiber-optic sensor allows for a high degree of spatial resolution when capturing the wavefront of the traveling SW. Several blast event experiments were conducted within different media (e.g., air, rubber membrane, and water) to evaluate the sensor's performance. This research revealed valuable knowledge for further study of SW behavior and SW-related applications.

  9. Fiber-optic annular detector array for large depth of field photoacoustic macroscopy.

    PubMed

    Bauer-Marschallinger, Johannes; Höllinger, Astrid; Jakoby, Bernhard; Burgholzer, Peter; Berer, Thomas

    2017-03-01

    We report on a novel imaging system for large depth of field photoacoustic scanning macroscopy. Instead of commonly used piezoelectric transducers, fiber-optic based ultrasound detection is applied. The optical fibers are shaped into rings and mainly receive ultrasonic signals stemming from the ring symmetry axes. Four concentric fiber-optic rings with varying diameters are used in order to increase the image quality. Imaging artifacts, originating from the off-axis sensitivity of the rings, are reduced by coherence weighting. We discuss the working principle of the system and present experimental results on tissue mimicking phantoms. The lateral resolution is estimated to be below 200 μm at a depth of 1.5 cm and below 230 μm at a depth of 4.5 cm. The minimum detectable pressure is in the order of 3 Pa. The introduced method has the potential to provide larger imaging depths than acoustic resolution photoacoustic microscopy and an imaging resolution similar to that of photoacoustic computed tomography.

  10. Wide-field lensless fluorescent microscopy using a tapered fiber-optic faceplate on a chip.

    PubMed

    Coskun, Ahmet F; Sencan, Ikbal; Su, Ting-Wei; Ozcan, Aydogan

    2011-09-07

    We demonstrate lensless fluorescent microscopy over a large field-of-view of ~60 mm(2) with a spatial resolution of <4 µm. In this on-chip fluorescent imaging modality, the samples are placed on a fiber-optic faceplate that is tapered such that the density of the fiber-optic waveguides on the top facet is >5 fold larger than the bottom one. Placed on this tapered faceplate, the fluorescent samples are pumped from the side through a glass hemisphere interface. After excitation of the samples, the pump light is rejected through total internal reflection that occurs at the bottom facet of the sample substrate. The fluorescent emission from the sample is then collected by the smaller end of the tapered faceplate and is delivered to an opto-electronic sensor-array to be digitally sampled. Using a compressive sampling algorithm, we decode these raw lensfree images to validate the resolution (<4 µm) of this on-chip fluorescent imaging platform using microparticles as well as labeled Giardia muris cysts. This wide-field lensfree fluorescent microscopy platform, being compact and high-throughput, might provide a valuable tool especially for cytometry, rare cell analysis (involving large area microfluidic systems) as well as for microarray imaging applications.

  11. High Precision Temperature Insensitive Strain Sensor Based on Fiber-Optic Delay

    PubMed Central

    Yang, Ning; Su, Jun; Fan, Zhiqiang; Qiu, Qi

    2017-01-01

    A fiber-optic delay based strain sensor with high precision and temperature insensitivity was reported, which works on detecting the delay induced by strain instead of spectrum. In order to analyze the working principle of this sensor, the elastic property of fiber-optic delay was theoretically researched and the elastic coefficient was measured as 3.78 ps/km·με. In this sensor, an extra reference path was introduced to simplify the measurement of delay and resist the cross-effect of environmental temperature. Utilizing an optical fiber stretcher driven by piezoelectric ceramics, the performance of this strain sensor was tested. The experimental results demonstrate that temperature fluctuations contribute little to the strain error and that the calculated strain sensitivity is as high as 4.75 με in the range of 350 με. As a result, this strain sensor is proved to be feasible and practical, which is appropriate for strain measurement in a simple and economical way. Furthermore, on basis of this sensor, the quasi-distributed measurement could be also easily realized by wavelength division multiplexing and wavelength addressing for long-distance structure health and security monitoring. PMID:28468323

  12. Taking a look at the calibration of a CCD detector with a fiber-optic taper

    DOE PAGES

    Alkire, R. W.; Rotella, F. J.; Duke, Norma E. C.; ...

    2016-02-16

    At the Structural Biology Center beamline 19BM, located at the Advanced Photon Source, the operational characteristics of the equipment are routinely checked to ensure they are in proper working order. After performing a partial flat-field calibration for the ADSC Quantum 210r CCD detector, it was confirmed that the detector operates within specifications. However, as a secondary check it was decided to scan a single reflection across one-half of a detector module to validate the accuracy of the calibration. The intensities from this single reflection varied by more than 30% from the module center to the corner of the module. Redistributionmore » of light within bent fibers of the fiber-optic taper was identified to be a source of this variation. As a result, the degree to which the diffraction intensities are corrected to account for characteristics of the fiber-optic tapers depends primarily upon the experimental strategy of data collection, approximations made by the data processing software during scaling, and crystal symmetry.« less

  13. Fiber-optic control and thermometry of single-cell thermosensation logic.

    PubMed

    Fedotov, I V; Safronov, N A; Ermakova, Yu G; Matlashov, M E; Sidorov-Biryukov, D A; Fedotov, A B; Belousov, V V; Zheltikov, A M

    2015-11-13

    Thermal activation of transient receptor potential (TRP) cation channels is one of the most striking examples of temperature-controlled processes in cell biology. As the evidence indicating the fundamental role of such processes in thermosensation builds at a fast pace, adequately accurate tools that would allow heat receptor logic behind thermosensation to be examined on a single-cell level are in great demand. Here, we demonstrate a specifically designed fiber-optic probe that enables thermal activation with simultaneous online thermometry of individual cells expressing genetically encoded TRP channels. This probe integrates a fiber-optic tract for the delivery of laser light with a two-wire microwave transmission line. A diamond microcrystal fixed on the fiber tip is heated by laser radiation transmitted through the fiber, providing a local heating of a cell culture, enabling a well-controlled TRP-assisted thermal activation of cells. Online local temperature measurements are performed by using the temperature-dependent frequency shift of optically detected magnetic resonance, induced by coupling the microwave field, delivered by the microwave transmission line, to nitrogen--vacancy centers in the diamond microcrystal. Activation of TRP channels is verified by using genetically encoded fluorescence indicators, visualizing an increase in the calcium flow through activated TRP channels.

  14. Fiber-optic system for checking the acoustical parameters of gas-turbine engine flow-through passages

    NASA Astrophysics Data System (ADS)

    Vinogradov, Vasiliy Y.; Morozov, Oleg G.; Nureev, Ilnur I.; Kuznetzov, Artem A.

    2015-03-01

    In this paper we consider the integrated approach to development of the aero-acoustical methods for diagnostics of aircraft gas-turbine engine flow-through passages by using as the base the passive fiber-optic and location technologies.

  15. Miniature fiber-optic multiphoton microscopy system using frequency-doubled femtosecond Er-doped fiber laser

    PubMed Central

    Huang, Lin; Mills, Arthur K.; Zhao, Yuan; Jones, David J.; Tang, Shuo

    2016-01-01

    We report on a miniature fiber-optic multiphoton microscopy (MPM) system based on a frequency-doubled femtosecond Er-doped fiber laser. The femtosecond pulses from the laser source are delivered to the miniature fiber-optic probe at 1.58 µm wavelength, where a standard single mode fiber is used for delivery without the need of free-space dispersion compensation components. The beam is frequency-doubled inside the probe by a periodically poled MgO:LiNbO3 crystal. Frequency-doubled pulses at 786 nm with a maximum power of 80 mW and a pulsewidth of 150 fs are obtained and applied to excite intrinsic signals from tissues. A MEMS scanner, a miniature objective, and a multimode collection fiber are further used to make the probe compact. The miniature fiber-optic MPM system is highly portable and robust. Ex vivo multiphoton imaging of mammalian skins demonstrates the capability of the system in imaging biological tissues. The results show that the miniature fiber-optic MPM system using frequency-doubled femtosecond fiber laser can potentially bring the MPM imaging for clinical applications. PMID:27231633

  16. Using fiber-optic sensor technology to measure strains under the asphalt layer of a flexible pavement structure.

    DOT National Transportation Integrated Search

    2006-01-01

    In this study, a flexible pavement system was instrumented using fiber-optic strain sensors (FOSS). The purpose of this study was to demonstrate the feasibility of a FOSS installation, monitor the long-term strains under repeated traffic loading, and...

  17. "Fiberoptic variable message signs" : Ladd Canyon - Drinking Fountain Grade Section , Old Oregon Trail Highway (Interstate 84) : final report.

    DOT National Transportation Integrated Search

    1995-02-01

    The SYLVIA fiberoptic variable message signs (VMS) were installed on the Old Oregon Trail Highway (I-84) at milepost 263.4 near La Grande and at milepost 286.7 near North Powder. The purpose of the signs is to warn motorists of fog, winter blizzard c...

  18. Seismic Monitoring of Permafrost During Controlled Thaw: An Active-Source Experiment Using a Surface Orbital Vibrator and Fiber-Optic DAS Arrays

    NASA Astrophysics Data System (ADS)

    Dou, S.; Wood, T.; Lindsey, N.; Ajo Franklin, J. B.; Freifeld, B. M.; Gelvin, A.; Morales, A.; Saari, S.; Ekblaw, I.; Wagner, A. M.; Daley, T. M.; Robertson, M.; Martin, E. R.; Ulrich, C.; Bjella, K.

    2016-12-01

    Thawing of permafrost can cause ground deformations that threaten the integrity of civil infrastructure. It is essential to develop early warning systems that can identify critically warmed permafrost and issue warnings for hazard prevention and control. Seismic methods can play a pivotal role in such systems for at least two reasons: First, seismic velocities are indicative of mechanical strength of the subsurface and thus are directly relevant to engineering properties; Second, seismic velocities in permafrost systems are sensitive to pre-thaw warming, which makes it possible to issue early warnings before the occurrence of hazardous subsidence events. However, several questions remain: What are the seismic signatures that can be effectively used for early warning of permafrost thaw? Can seismic methods provide enough warning times for hazard prevention and control? In this study, we investigate the feasibility of using permanently installed seismic networks for early warnings of permafrost thaw. We conducted continuous active-source seismic monitoring of permafrost that was under controlled heating at CRREL's Fairbanks permafrost experiment station. We used a permanently installed surface orbital vibrator (SOV) as source and surface-trenched DAS arrays as receivers. The SOV is characterized by its excellent repeatability, automated operation, high energy level, and the rich frequency content (10-100 Hz) of the generated wavefields. The fiber-optic DAS arrays allow continuous recording of seismic data with dense spatial sampling (1-meter channel spacing), low cost, and low maintenance. This combination of SOV-DAS provides unique seismic datasets for observing time-lapse changes of warming permafrost at the field scale, hence providing an observational basis for design and development of early warning systems for permafrost thaw.

  19. Effectiveness of mouthpiece nebulization and nasal swab stick packing for topical anesthesia in awake fiberoptic nasotracheal intubation.

    PubMed

    Techanivate, Anchalee; Leelanukrom, Ruenreong; Prapongsena, Prut; Terachinda, Danuchit

    2007-10-01

    To evaluate the effectiveness of using mouthpiece nebulization and nasal swab stick packing for topical anesthesia in awake fiberoptic nasotracheal intubation. This was a prospective descriptive study of 30 patients with ASA I-II who underwent elective surgery and suspected of difficult intubation between March 2004 and June 2006. After 2% lidocaine 5 ml was nebulizated in a micronebulizer using oxygen 10 L/min as a driving gas through a standard mouthpiece and 10% cocaine 1 ml on cotton swab-stick was applied to the selected nostril for 15 min, fiberoptic nasotracheal intubation was done while the patient was awake. If the patient had severe gag or cough reflex, 1% lidocaine 5 ml per each time could be injected through the working channel of the fiberoptic bronchoscope. The descriptive statistics were calculated by using SPSS version 11.0. The success rate of awake fiberoptic nasotracheal was 100%. The mean duration of awake fiberoptic nasotracheal intubation was 119.0 +/- 76.8 sec. The responses of the patient to instrumentation during 4 periods, i.e.: passing the endotracheal tube into the nose, passing the bronchoscope into the pharynx-larynx, passing the bronchoscope into the trachea-carina and passing the endotracheal tube into the trachea were, as follows: no response in about 53.3%, 63.3%, 23.3%,and 13.3%; mild pain or reflex in about 46.7%, 10%, 70%, and 86.7%; moderate pain or reflex in about 0%, 3.3%, 6.7%, and 0%; and severe pain or reflex requiring more local anesthetic in about 0%, 23.3%, 0%, and 0%, respectively. Despite complete topical anesthesia in the majority of the patients, two patients required 5 ml more 1% lidocaine and five patients required 10 mL more of the drug through the fiberoptic bronchoscope. There was no serious complication such as hypoxemia, arrhythmia. Twenty-four patients (80%) were satisfied with mouthpiece nebulization and nasal swab packing because they felt safe, did not have pain, and were comfortable; only three patients

  20. Factors predicting early diagnosis of pediatric laryngotracheobronchial foreign bodies.

    PubMed

    Parida, Pradipta; Nirmal, Nirmal Shanmugasundaram; Gopalakrishnan, Surianarayanan; Saxena, Sunil Kumar

    2015-01-01

    To study the clinical and radiological findings to make early diagnosis of foreign body (FB) aspiration in children. This prospective study was conducted on 45 children below 12 years of age with a clinical diagnosis of FB aspiration undergone rigid bronchoscopy from September 2008 to may 2010. Bronchoscopy was positive for FB in 37 children. The results of these 37 children (15 female and 22 male) were analyzed. 81% of children were in age group of 1-3 years. Penetration syndrome (sudden onset coughing, choking and gagging when the child is having something in the mouth) (89.2%) and decreased breath sounds (86.5%) were the most common clinical features. Cough, respiratory difficulty and fever were present in 83.8%, 78.4% and 27% respectively. Tachypnoea, tachycardia, chest retractions, decreased chest movements and wheeze were present in 83.3%, 83.3%, 83.3%, 51.4% and 43.2% respectively. Unilateral hyperinflation (64.9%), mediastinal shift (45.9%), and collapse (21.6%) were common radiological sign on chest radiograph and in 13.5% patients the chest X-rays were normal. Sites of FB lodgments were larynx, trachea, right main bronchus, left main bronchus and bilateral bronchi in 10.8%, 10.8%, 35.1%, 37.8 and 5.5% respectively. Food related FBs were present in 30 cases (peanut in 54.1%) and inorganic FBs were present in 7 cases. FBs were removed successfully by rigid bronchoscopy in all cases without any mortality. Penetration syndrome, localized decreased breath sounds, unilateral hyperinflation and/or mediastinal shift on radiology are predictors for early diagnosis of FB aspiration.

  1. Highly sensitive rotation sensing based on orthogonal fiber-optic structures

    NASA Astrophysics Data System (ADS)

    Yang, Yi; Wang, Zi-nan; Xu, Lian-yu; Wang, Cui-yun; Jia, Lei; Yu, Xiao-qi; Shao, Shan; Li, Zheng-bin

    2011-08-01

    In traditional fiber-optic gyroscopes (FOG), the polarization state of counter propagating waves is critically controlled, and only the mode polarized along one particular direction survives. This is important for a traditional single mode fiber gyroscope as the requirement of reciprocity. However, there are some fatal defects such as low accuracy and poor bias stability in traditional structures. In this paper, based on the idea of polarization multiplexing, a double-polarization structure is put forward and experimentally studied. In highly birefringent fibers or standard single mode fibers with induced anisotropy, two orthogonal polarization modes can be used at the same time. Therefore, in polarization maintaining fibers (PMF), each pair of counter propagating beams preserve reciprocity within their own polarization state. Two series of sensing results are gotten in the fast and slow axes in PMF. The two sensing results have their own systematic drifts and the correlation of random noise in them is approximately zero. So, beams in fast and slow axes work as two independent and orthogonal gyroscopes. In this way, amount of information is doubled, providing opportunity to eliminate noise and improve sensitivity. Theoretically, this double-polarization structure can achieve a sensitivity of 10-18 deg/h. Computer simulation demonstrates that random noise and systematic drifts are largely reduced in this novel structure. In experiment, a forty-hour stability test targeting the earth's rotation velocity is carried out. Experiment result shows that the orthogonal fiber-optic structure has two big advantages compared with traditional ones. Firstly, the structure gets true value without any bias correction in any axis and even time-varying bias does not affect the acquisition of true value. The unbiasedness makes the structure very attractive when sudden disturbances or temperature drifts existing in working environment. Secondly, the structure lowers bias for more than

  2. Fiberoptic spectrophotometer

    DOEpatents

    Tans, Petrus P.; Lashof, Daniel A.

    1986-01-01

    A device for determining the relative composition of a sample of a gas by comparison of the Raman-scattered light of the sample with that of a known gas comprising: a means for passing a single light source through the unknown and the known gases, choppers to alternate the Raman-scattered light into a common light detection and measuring system, optical fiber networks for spatially mixing the resulting Raman scattered light from each sample and directing the mixed light to selective detectors, and a compiler to record the light intensity of each wavelength of Raman-scattered light as a function of the sample from which it originated.

  3. Fiberoptic spectrophotometer

    DOEpatents

    Tans, P.P.; Lashof, D.A.

    1986-12-23

    A device is described for determining the relative composition of a sample of a gas by comparison of the Raman-scattered light of the sample with that of a known gas comprising: a means for passing a single light source through the unknown and the known gases, choppers to alternate the Raman-scattered light into a common light detection and measuring system, optical fiber networks for spatially mixing the resulting Raman scattered light from each sample and directing the mixed light to selective detectors, and a compiler to record the light intensity of each wavelength of Raman-scattered light as a function of the sample from which it originated. 6 figs.

  4. Fabrication of All-SiC Fiber-Optic Pressure Sensors for High-Temperature Applications

    PubMed Central

    Jiang, Yonggang; Li, Jian; Zhou, Zhiwen; Jiang, Xinggang; Zhang, Deyuan

    2016-01-01

    Single-crystal silicon carbide (SiC)-based pressure sensors can be used in harsh environments, as they exhibit stable mechanical and electrical properties at elevated temperatures. A fiber-optic pressure sensor with an all-SiC sensor head was fabricated and is herein proposed. SiC sensor diaphragms were fabricated via an ultrasonic vibration mill-grinding (UVMG) method, which resulted in a small grinding force and low surface roughness. The sensor head was formed by hermetically bonding two layers of SiC using a nickel diffusion bonding method. The pressure sensor illustrated a good linearity in the range of 0.1–0.9 MPa, with a resolution of 0.27% F.S. (full scale) at room temperature. PMID:27763494

  5. Passive-quadrature demodulated localized-Michelson fiber-optic strain sensor embedded in composite materials

    NASA Astrophysics Data System (ADS)

    Valis, Tomas; Tapanes, Edward; Liu, Kexing; Measures, Raymond M.

    1991-04-01

    A strain sensor embedded in composite materials that is intrinsic, all fiber, local, and phase demodulated is described. It is the combination of these necessary elements that represents an advance in the state of the art. Sensor localization is achieved by using a pair of mirror-ended optical fibers of different lengths that are mechanically coupled up until the desired gauge length for common-mode suppression has been reached. This fiber-optic sensor has been embedded in both thermoset (Kevlar/epoxy and graphite/epoxy) and thermoplastic (graphite/PEEK) composite materials in order to make local strain measurements at the lamina level. The all-fiber system uses a 3 x 3 coupler for phase demodulation. Parameters such as strain sensitivity, transverse strain sensitivity, failure strain, and frequency response are discussed, along with applications.

  6. Structural Health Monitoring in Composite Structures by Fiber-Optic Sensors.

    PubMed

    Güemes, Alfredo; Fernández-López, Antonio; F Díaz-Maroto, Patricia; Lozano, Angel; Sierra-Perez, Julian

    2018-04-04

    Fiber-optic sensors cannot measure damage; to get information about damage from strain measurements, additional strategies are needed, and several alternatives are available in the existing literature. This paper discusses two independent procedures. The first is based on detecting new strains appearing around a damage spot. The structure does not need to be under loads, the technique is very robust, and damage detectability is high, but it requires sensors to be located very close to the damage, so it is a local technique. The second approach offers wider coverage of the structure; it is based on identifying the changes caused by damage on the strain field in the whole structure for similar external loads. Damage location does not need to be known a priori, and detectability is dependent upon the sensor's network density, the damage size, and the external loads. Examples of application to real structures are given.

  7. Steady-state performance analysis of fiber-optic ring resonator

    NASA Astrophysics Data System (ADS)

    Seraji, Faramarz E.

    2009-01-01

    This paper presents a full steady-state analysis of a fiber-optic ring resonator (FORR). Although in the literature the steady-state response of the FORR has been described, a detailed description of the same is not available. As an understanding of the different steady-state characteristics of the FORR is required to appreciate its characteristic response, in this paper, the expressions for the output and loop intensities, phase angles of the fields, conditions for resonance, output and loop intensities at resonance and off-resonance, finesse, and group delay of the FORR are given for different ideal and practical operating conditions of the resonator. Graphical plots of all the above characteristics are given, by highlighting the important results. The information presented in this paper will be helpful in explaining and understanding the pulse response of the resonator used in different applications of FORR.

  8. A novel fiber-optical vibration defending system with on-line intelligent identification function

    NASA Astrophysics Data System (ADS)

    Wu, Huijuan; Xie, Xin; Li, Hanyu; Li, Xiaoyu; Wu, Yu; Gong, Yuan; Rao, Yunjiang

    2013-09-01

    Capacity of the sensor network is always a bottleneck problem for the novel FBG-based quasi-distributed fiberoptical defending system. In this paper, a highly sensitive sensing network with FBG vibration sensors is presented to relieve stress of the capacity and the system cost. However, higher sensitivity may cause higher Nuisance Alarm Rates (NARs) in practical uses. It is necessary to further classify the intrusion pattern or threat level and determine the validity of an unexpected event. Then an intelligent identification method is proposed by extracting the statistical features of the vibration signals in the time domain, and inputting them into a 3-layer Back-Propagation(BP) Artificial Neural Network to classify the events of interest. Experiments of both simulation and field tests are carried out to validate its effectiveness. The results show the recognition rate can be achieved up to 100% for the simulation signals and as high as 96.03% in the real tests.

  9. Fiber-optic miniature sensor for in situ temperature monitoring of curing composite material

    NASA Astrophysics Data System (ADS)

    Sampath, Umesh; Kim, Dae-gil; Kim, Hyunjin; Song, Minho

    2018-04-01

    This study proposes a fiber-optic temperature sensor with a single-mode fiber tip covered with a thermo-sensitive polymer resin. The temperature is sensed by measuring the Fresnel reflection from the optical fiber/polymer interface. Because the thermo-optic coefficients differ between the optical fiber and the polymer, the in situ temperature can be measured even in curing composite materials. In initial experiments, the proposed sensor successfully measured and recovered the temperature information. The measured sensor data were linearly correlated, with an R2 exceeding 0.99. The standard deviation in the long-term measurements of constant temperature was 2.6%. The durability and stability of the sensor head material in long-term operation was validated by Fourier transform infrared spectroscopy and X-ray diffraction analysis. In further experiments, the suggested miniature temperature sensor obtained the internal temperatures of curing composite material over a wide range (30-110 °C).

  10. Noise-figure limit of fiber-optical parametric amplifiers and wavelength converters: experimental investigation

    NASA Astrophysics Data System (ADS)

    Tang, Renyong; Voss, Paul L.; Lasri, Jacob; Devgan, Preetpaul; Kumar, Prem

    2004-10-01

    Recent theoretical work predicts that the quantum-limited noise figure of a chi(3)-based fiber-optical parametric amplifier operating as a phase-insensitive in-line amplifier or as a wavelength converter exceeds the standard 3-dB limit at high gain. The degradation of the noise figure is caused by the excess noise added by the unavoidable Raman gain and loss occurring at the signal and the converted wavelengths. We present detailed experimental evidence in support of this theory through measurements of the gain and noise-figure spectra for phase-insensitive parametric amplification and wavelength conversion in a continuous-wave amplifier made from 4.4 km of dispersion-shifted fiber. The theory is also extended to include the effect of distributed linear loss on the noise figure of such a long-length parametric amplifier and wavelength converter.

  11. Highly stable families of soliton molecules in fiber-optic systems

    NASA Astrophysics Data System (ADS)

    Moubissi, A.-B.; Tchofo Dinda, P.; Nse Biyoghe, S.

    2018-04-01

    We develop an efficient approach to the design of families of single solitons and soliton molecules most suited to a given fiber system. The obtained solitonic entities exhibit very high stability, with a robustness which allows them to propagate over thousands of kilometers and to survive collisions with other solitonic entities. Our approach enables the generation of a large number of solitonic entities, including families of single solitons and two-soliton molecules, which can be distinguished sufficiently by their respective profiles or energy levels, and so can be easily identifiable and detectable without ambiguity. We discuss the possible use of such solitonic entities as symbols of a multi-level modulation format in fiber-optic communication systems.

  12. Structural Health Monitoring in Composite Structures by Fiber-Optic Sensors †

    PubMed Central

    Güemes, Alfredo; Díaz-Maroto, Patricia F.; Lozano, Angel; Sierra-Perez, Julian

    2018-01-01

    Fiber-optic sensors cannot measure damage; to get information about damage from strain measurements, additional strategies are needed, and several alternatives are available in the existing literature. This paper discusses two independent procedures. The first is based on detecting new strains appearing around a damage spot. The structure does not need to be under loads, the technique is very robust, and damage detectability is high, but it requires sensors to be located very close to the damage, so it is a local technique. The second approach offers wider coverage of the structure; it is based on identifying the changes caused by damage on the strain field in the whole structure for similar external loads. Damage location does not need to be known a priori, and detectability is dependent upon the sensor’s network density, the damage size, and the external loads. Examples of application to real structures are given. PMID:29617345

  13. Radioactivity measurement of radioactive contaminated soil by using a fiber-optic radiation sensor

    NASA Astrophysics Data System (ADS)

    Joo, Hanyoung; Kim, Rinah; Moon, Joo Hyun

    2016-06-01

    A fiber-optic radiation sensor (FORS) was developed to measure the gamma radiation from radioactive contaminated soil. The FORS was fabricated using an inorganic scintillator (Lu,Y)2SiO5:Ce (LYSO:Ce), a mixture of epoxy resin and hardener, aluminum foil, and a plastic optical fiber. Before its real application, the FORS was tested to determine if it performed adequately. The test result showed that the measurements by the FORS adequately followed the theoretically estimated values. Then, the FORS was applied to measure the gamma radiation from radioactive contaminated soil. For comparison, a commercial radiation detector was also applied to measure the same soil samples. The measurement data were analyzed by using a statistical parameter, the critical level to determine if net radioactivity statistically different from background was present in the soil sample. The analysis showed that the soil sample had radioactivity distinguishable from background.

  14. An all fiber-optic multi-parameter structure health monitoring system

    DOE PAGES

    Hu, Chennan; Yu, Zhihao; Wang, Anbo

    2016-08-24

    In this article, we present an all fiber-optics based multi-parameter structure health monitoring system, which is able to monitor strain, temperature, crack and thickness of metal structures. This system is composed of two optical fibers, one for laser-acoustic excitation and the other for acoustic detection. A nano-second 1064 nm pulse laser was used for acoustic excitation and a 2 mm fiber Bragg grating was used to detect the acoustic vibration. The feasibility of this system was demonstrated on an aluminum test piece by the monitoring of the temperature, strain and thickness changes, as well as the appearance of an artificialmore » crack. The multiplexing capability of this system was also preliminarily demonstrated.« less

  15. An all fiber-optic multi-parameter structure health monitoring system

    SciT

    Hu, Chennan; Yu, Zhihao; Wang, Anbo

    In this article, we present an all fiber-optics based multi-parameter structure health monitoring system, which is able to monitor strain, temperature, crack and thickness of metal structures. This system is composed of two optical fibers, one for laser-acoustic excitation and the other for acoustic detection. A nano-second 1064 nm pulse laser was used for acoustic excitation and a 2 mm fiber Bragg grating was used to detect the acoustic vibration. The feasibility of this system was demonstrated on an aluminum test piece by the monitoring of the temperature, strain and thickness changes, as well as the appearance of an artificialmore » crack. The multiplexing capability of this system was also preliminarily demonstrated.« less

  16. Multimode fiber-optic temperature sensor system based on dual-wavelength difference absorption principle

    NASA Astrophysics Data System (ADS)

    Zhang, Zaixuan; Lin, Dan; Fang, Xiao; Jing, Shangzhong

    1991-08-01

    The multimode fiber optical temperature sensor system is a cobalt salt solution (CoCl26H2O) in the isoptopyl alcohol and water thermochromic transducer based on the dual-wavelength difference absorption principle. The digital locking-in detection, the operation of signal division and temperature calibration is operated by IBM PC computer. The measurement temperature range of the fiber-optic sensor system is 30 degree(s)C to 50 degree(s)C, accuracy is +/- 0.15 degree(s)C, and the temperature resolution is 0.02 degree(s)C. The most accurate measurements resulting from repeated stability tests over 6 and 12 hours (40 degree(s)C) are +/- $0.05 degree(s)C and +/- 0.18 degree(s)C, and the temperature mean is displayed in real time.

  17. A review of fiber-optic corrosion sensor in civil engineering

    NASA Astrophysics Data System (ADS)

    Luo, Dong; Li, Junnan; Li, Yuanyuan

    2018-05-01

    Fiber-optical corrosion sensor (FOCS) is the research hotspot of corrosion monitoring sensor in recent years. It has the advantages of lightness, simplicity, anti-electromagnetic interference and distributed measurement, so it has an attractive application prospect. In this paper, the mechanism of metal corrosion is introduced. Several common methods for detecting optical fiber corrosion sensors are presented, and the latest progress of optical fiber corrosion sensors in recent years is described. We need to design a set of sensor devices that can directly monitor the corrosion of reinforcing steel bars directly, and propose a method of time dependent reliability assessment based on monitoring data, so as to form a complete research path.

  18. Fiber-Optic Pyrometer with Optically Powered Switch for Temperature Measurements

    PubMed Central

    Pérez-Prieto, Sandra; López-Cardona, Juan D.; Blanco, Enrique; Moreno-López, Jorge

    2018-01-01

    We report the experimental results on a new infrared fiber-optic pyrometer for very localized and high-speed temperature measurements ranging from 170 to 530 °C using low-noise photodetectors and high-gain transimpedance amplifiers with a single gain mode in the whole temperature range. We also report a shutter based on an optical fiber switch which is optically powered to provide a reference signal in an optical fiber pyrometer measuring from 200 to 550 °C. The tests show the potential of remotely powering via optical means a 300 mW power-hungry optical switch at a distance of 100 m, avoiding any electromagnetic interference close to the measuring point. PMID:29415477

  19. Fiber-Optic Pyrometer with Optically Powered Switch for Temperature Measurements.

    PubMed

    Vázquez, Carmen; Pérez-Prieto, Sandra; López-Cardona, Juan D; Tapetado, Alberto; Blanco, Enrique; Moreno-López, Jorge; Montero, David S; Lallana, Pedro C

    2018-02-06

    We report the experimental results on a new infrared fiber-optic pyrometer for very localized and high-speed temperature measurements ranging from 170 to 530 °C using low-noise photodetectors and high-gain transimpedance amplifiers with a single gain mode in the whole temperature range. We also report a shutter based on an optical fiber switch which is optically powered to provide a reference signal in an optical fiber pyrometer measuring from 200 to 550 °C. The tests show the potential of remotely powering via optical means a 300 mW power-hungry optical switch at a distance of 100 m, avoiding any electromagnetic interference close to the measuring point.

  20. Temperature-independent refractometer based on fiber-optic Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Li, Jiacheng; Qiao, Xueguang; Wang, Ruohui; Rong, Qiangzhou; Bao, Weijia; Shao, Zhihua; Yang, Tingting

    2016-04-01

    A miniature fiber-optic refractometer based on Fabry-Perot interferometer (FPI) has been proposed and experimentally demonstrated. The sensing head consists of a short section of photonics crystal fiber (PCF) spliced to a single mode fiber (SMF), in which the end-face of the PCF is etched to remove holey structure with hydrofluoric (HF) acid. A Fabry-Perot interference spectrum is achieved based on the reflections from the fusion splicing interface and the end-face of the core of PCF. The interference fringe is sensitive to the external refractive index (RI) with an intensity-referenced sensitivity of 358.27 dB/RIU ranging from 1.33 to 1.38. The sensor has also been implemented for the concentration measurement of λ-phage DNA solution. In addition, the dip intensity is insensitive to the ambient temperature variation, making it a good candidate for temperature-independent bio-sensing area.

  1. Fiber-optic Michelson interferometer fixed in a tilted tube for direction-dependent ultrasonic detection

    NASA Astrophysics Data System (ADS)

    Gang, Tingting; Hu, Manli; Qiao, Xueguang; Li, JiaCheng; Shao, Zhihua; Tong, Rongxin; Rong, Qiangzhou

    2017-01-01

    A fiber-optic interferometer is proposed and demonstrated experimentally for ultrasonic detection. The sensor consists of a compact Michelson interferometer (MI), which is fixed in a tilted-tube end-face (45°). Thin gold films are used for the reflective coatings of two arms and one of the interference arms is etched serving as the sensing arm. The spectral sideband filter technique is used to interrogate the continuous and pulse ultrasonic signals (with frequency of 300 KHz). Furthermore, because of the asymmetrical structure of the sensor, it presents strong direction-dependent ultrasonic sensitivity, such that the sensor can be considered a vector detector. The experimental results show that the sensor is highly sensitive to ultrasonic signals, and thus it can be a candidate for ultrasonic imaging of seismic physical models.

  2. A Fiber-Optic System Generating Pulses of High Spectral Density

    NASA Astrophysics Data System (ADS)

    Abramov, A. S.; Zolotovskii, I. O.; Korobko, D. A.; Fotiadi, A. A.

    2018-03-01

    A cascade fiber-optic system that generates pulses of high spectral density by using the effect of nonlinear spectral compression is proposed. It is demonstrated that the shape of the pulse envelope substantially influences the degree of compression of its spectrum. In so doing, maximum compression is achieved for parabolic pulses. The cascade system includes an optical fiber exhibiting normal dispersion that decreases along the fiber length, thereby ensuring that the pulse envelope evolves toward a parabolic shape, along with diffraction gratings and a fiber spectral compressor. Based on computer simulation, we determined parameters of cascade elements leading to maximum spectral density of radiation originating from a subpicosecond laser pulse of medium energy.

  3. Fiber-optic sensor for handgrip-strength monitoring: conception and design

    NASA Astrophysics Data System (ADS)

    Paul, Jinu; Zhao, Liping; Ngoi, Bryan K. A.

    2005-06-01

    Handgrip strength is an easy measure of skeletal muscle function as well as a powerful predictor of disability, morbidity, and mortality. In order to measure grip strength, a novel fiber-optic approach is proposed and demonstrated. The strain-dependent wavelength response of fiber Bragg gratings has been utilized to obtain the strength of individual fingers. Finite-element analysis is carried out to optimize the pressure transmission from the finger to the fiber Bragg grating. The effect of stiffness of the pressurizing media, its thickness, and the effect of contact fraction are evaluated. It is found that significant enhancement in the pressure sensitivity and wavelength-tuning range is achievable by optimizing these parameters. Also the stress-induced birefringence could be reduced to an insignificant near-zero value. The device is calibrated in terms of load to convert the wavelength shift to the strength of the grip. The time-dependent wavelength fluctuation is also studied and presented.

  4. Wavelength division multiplexing of chaotic secure and fiber-optic communications.

    PubMed

    Zhang, Jian-Zhong; Wang, An-Bang; Wang, Juan-Fen; Wang, Yun-Cai

    2009-04-13

    Wavelength division multiplexing (WDM) transmission of chaotic optical communication (COC) and conventional fiber-optic communication (CFOC) is numerically confirmed and analyzed. For an 80-km-long two-channel communication system, a 1-Gb/s secure message in COC channel and 10-Gb/s digital signal in CFOC channel are simultaneously achieved with 100 GHz channel spacing. Our numerical simulations demonstrate that the COC and CFOC can realize no-crosstalk transmission of 80 km when the peak power of CFOC channel is less than 8dBm. We also find that the crosstalk between COC and CFOC does not depend on channel spacing when the channel spacing exceeds 100GHz. Moreover, the crosstalk does not limit channel number by comparing the synchronization performance of COC in four- and six-channel WDM systems.

  5. Modeling of Distributed Sensing of Elastic Waves by Fiber-Optic Interferometry

    PubMed Central

    Agbodjan Prince, Just; Kohl, Franz; Sauter, Thilo

    2016-01-01

    This paper deals with the transduction of strain accompanying elastic waves in solids by firmly attached optical fibers. Stretching sections of optical fibers changes the time required by guided light to pass such sections. Exploiting interferometric techniques, highly sensitive fiber-optic strain transducers are feasible based on this fiber-intrinsic effect. The impact on the actual strain conversion of the fiber segment’s shape and size, as well as its inclination to the elastic wavefront is studied. FEM analyses show that severe distortions of the interferometric response occur when the attached fiber length spans a noticeable fraction of the elastic wavelength. Analytical models of strain transduction are presented for typical transducer shapes. They are used to compute input-output relationships for the transduction of narrow-band strain pulses as a function of the mechanical wavelength. The described approach applies to many transducers depending on the distributed interaction with the investigated object. PMID:27608021

  6. Modeling of Distributed Sensing of Elastic Waves by Fiber-Optic Interferometry.

    PubMed

    Agbodjan Prince, Just; Kohl, Franz; Sauter, Thilo

    2016-09-06

    This paper deals with the transduction of strain accompanying elastic waves in solids by firmly attached optical fibers. Stretching sections of optical fibers changes the time required by guided light to pass such sections. Exploiting interferometric techniques, highly sensitive fiber-optic strain transducers are feasible based on this fiber-intrinsic effect. The impact on the actual strain conversion of the fiber segment's shape and size, as well as its inclination to the elastic wavefront is studied. FEM analyses show that severe distortions of the interferometric response occur when the attached fiber length spans a noticeable fraction of the elastic wavelength. Analytical models of strain transduction are presented for typical transducer shapes. They are used to compute input-output relationships for the transduction of narrow-band strain pulses as a function of the mechanical wavelength. The described approach applies to many transducers depending on the distributed interaction with the investigated object.

  7. Fabrication of All-SiC Fiber-Optic Pressure Sensors for High-Temperature Applications.

    PubMed

    Jiang, Yonggang; Li, Jian; Zhou, Zhiwen; Jiang, Xinggang; Zhang, Deyuan

    2016-10-17

    Single-crystal silicon carbide (SiC)-based pressure sensors can be used in harsh environments, as they exhibit stable mechanical and electrical properties at elevated temperatures. A fiber-optic pressure sensor with an all-SiC sensor head was fabricated and is herein proposed. SiC sensor diaphragms were fabricated via an ultrasonic vibration mill-grinding (UVMG) method, which resulted in a small grinding force and low surface roughness. The sensor head was formed by hermetically bonding two layers of SiC using a nickel diffusion bonding method. The pressure sensor illustrated a good linearity in the range of 0.1-0.9 MPa, with a resolution of 0.27% F.S. (full scale) at room temperature.

  8. A fiber-optic sensor for accurately monitoring biofilm growth in a hydrogen production photobioreactor.

    PubMed

    Zhong, Nianbing; Liao, Qiang; Zhu, Xun; Chen, Rong

    2014-04-15

    A new simple fiber-optic evanescent wave sensor was created to accurately monitor the growth and hydrogen production performance of biofilms. The proposed sensor consists of two probes (i.e., a sensor and reference probe), using the etched fibers with an appropriate surface roughness to improve its sensitivity. The sensor probe measures the biofilm growth and change of liquid-phase concentration inside the biofilm. The reference probe is coated with a hydrophilic polytetrafluoroethylene membrane to separate the liquids from photosynthetic bacteria Rhodopseudomonas palustris CQK 01 and to measure the liquid concentration. We also developed a model to demonstrate the accuracy of the measurement. The biofilm measurement was calibrated using an Olympus microscope. A linear relationship was obtained for the biofilm thickness range from 0 to 120 μm with a synthetic medium under continuous supply to the bioreactor. The highest level of hydrogen production rate occurred at a thickness of 115 μm.

  9. Common-path low-coherence interferometry fiber-optic sensor guided microincision

    NASA Astrophysics Data System (ADS)

    Zhang, Kang; Kang, Jin U.

    2011-09-01

    We propose and demonstrate a common-path low-coherence interferometry (CP-LCI) fiber-optic sensor guided precise microincision. The method tracks the target surface and compensates the tool-to-surface relative motion with better than +/-5 μm resolution using a precision micromotor connected to the tool tip. A single-fiber distance probe integrated microdissector was used to perform an accurate 100 μm incision into the surface of an Intralipid phantom. The CP-LCI guided incision quality in terms of depth was evaluated afterwards using three-dimensional Fourier-domain optical coherence tomography imaging, which showed significant improvement of incision accuracy compared to free-hand-only operations.

  10. Common-path low-coherence interferometry fiber-optic sensor guided microincision

    PubMed Central

    Zhang, Kang; Kang, Jin U.

    2011-01-01

    We propose and demonstrate a common-path low-coherence interferometry (CP-LCI) fiber-optic sensor guided precise microincision. The method tracks the target surface and compensates the tool-to-surface relative motion with better than ±5 μm resolution using a precision micromotor connected to the tool tip. A single-fiber distance probe integrated microdissector was used to perform an accurate 100 μm incision into the surface of an Intralipid phantom. The CP-LCI guided incision quality in terms of depth was evaluated afterwards using three-dimensional Fourier-domain optical coherence tomography imaging, which showed significant improvement of incision accuracy compared to free-hand-only operations. PMID:21950912

  11. U-shaped, double-tapered, fiber-optic sensor for effective biofilm growth monitoring

    PubMed Central

    Zhong, Nianbing; Zhao, Mingfu; Li, Yishan

    2016-01-01

    To monitor biofilm growth on polydimethylsiloxane in a photobioreactor effectively, the biofilm cells and liquids were separated and measured using a sensor with two U-shaped, double-tapered, fiber-optic probes (Sen. and Ref. probes). The probes’ Au-coated hemispherical tips enabled double-pass evanescent field absorption. The Sen. probe sensed the cells and liquids inside the biofilm. The polyimide–silica hybrid-film-coated Ref. probe separated the liquids from the biofilm cells and analyzed the liquid concentration. The biofilm structure and active biomass were also examined to confirm the effectiveness of the measurement using a simulation model. The sensor was found to effectively respond to the biofilm growth in the adsorption through exponential phases at thicknesses of 0–536 μm. PMID:26977344

  12. U-shaped, double-tapered, fiber-optic sensor for effective biofilm growth monitoring.

    PubMed

    Zhong, Nianbing; Zhao, Mingfu; Li, Yishan

    2016-02-01

    To monitor biofilm growth on polydimethylsiloxane in a photobioreactor effectively, the biofilm cells and liquids were separated and measured using a sensor with two U-shaped, double-tapered, fiber-optic probes (Sen. and Ref. probes). The probes' Au-coated hemispherical tips enabled double-pass evanescent field absorption. The Sen. probe sensed the cells and liquids inside the biofilm. The polyimide-silica hybrid-film-coated Ref. probe separated the liquids from the biofilm cells and analyzed the liquid concentration. The biofilm structure and active biomass were also examined to confirm the effectiveness of the measurement using a simulation model. The sensor was found to effectively respond to the biofilm growth in the adsorption through exponential phases at thicknesses of 0-536 μm.

  13. Chronology of Fabry-Perot Interferometer Fiber-Optic Sensors and Their Applications: A Review

    PubMed Central

    Islam, Md. Rajibul; Ali, Muhammad Mahmood; Lai, Man-Hong; Lim, Kok-Sing; Ahmad, Harith

    2014-01-01

    Optical fibers have been involved in the area of sensing applications for more than four decades. Moreover, interferometric optical fiber sensors have attracted broad interest for their prospective applications in sensing temperature, refractive index, strain measurement, pressure, acoustic wave, vibration, magnetic field, and voltage. During this time, numerous types of interferometers have been developed such as Fabry-Perot, Michelson, Mach-Zehnder, Sagnac Fiber, and Common-path interferometers. Fabry-Perot interferometer (FPI) fiber-optic sensors have been extensively investigated for their exceedingly effective, simple fabrication as well as low cost aspects. In this study, a wide variety of FPI sensors are reviewed in terms of fabrication methods, principle of operation and their sensing applications. The chronology of the development of FPI sensors and their implementation in various applications are discussed. PMID:24763250

  14. Supersonic Flow Field Investigation Using a Fiber-optic based Doppler Global Velocimeter

    NASA Technical Reports Server (NTRS)

    Meyers, James F.; Lee, Joseph W.; Fletcher, Mark T.; Cavone, Angelo A.; AscencionGuerreroViramontes, J.

    2006-01-01

    A three-component fiber-optic based Doppler Global Velocimeter was constructed, evaluated and used to measure shock structures about a low-sonic boom model in a Mach 2 flow. The system was designed to have maximum flexibility in its ability to measure flows with restricted optical access and in various facilities. System layout is described along with techniques developed for production supersonic testing. System evaluation in the Unitary Plan Wind Tunnel showed a common acceptance angle of f4 among the three views with velocity measurement resolutions comparable with free-space systems. Flow field measurements of shock structures above a flat plate with an attached ellipsoid-cylinder store and a low-sonic boom model are presented to demonstrate the capabilities of the system during production testing.

  15. Investigation of aquifer-estuary interaction using wavelet analysis of fiber-optic temperature data

    Henderson, R.D.; Day-Lewis, Frederick D.; Harvey, Charles F.

    2009-01-01

    Fiber-optic distributed temperature sensing (FODTS) provides sub-minute temporal and meter-scale spatial resolution over kilometer-long cables. Compared to conventional thermistor or thermocouple-based technologies, which measure temperature at discrete (and commonly sparse) locations, FODTS offers nearly continuous spatial coverage, thus providing hydrologic information at spatiotemporal scales previously impossible. Large and information-rich FODTS datasets, however, pose challenges for data exploration and analysis. To date, FODTS analyses have focused on time-series variance as the means to discriminate between hydrologic phenomena. Here, we demonstrate the continuous wavelet transform (CWT) and cross-wavelet transform (XWT) to analyze FODTS in the context of related hydrologic time series. We apply the CWT and XWT to data from Waquoit Bay, Massachusetts to identify the location and timing of tidal pumping of submarine groundwater.

  16. Spectrum-modulating fiber-optic sensors for aircraft control systems

    NASA Technical Reports Server (NTRS)

    Beheim, Glenn; Fritsch, Klaus

    1987-01-01

    A family of fiber-optic sensors for aircraft engine control systems is described. Each of these sensors uses a spectrum-modulation method to obtain an output which is largely independent of the fiber link transmissivity. A position encoder is described which uses a code plate to digitally modulate the sensor output spectrum. Also described are pressure and temperature sensors, each of which uses a Fabry-Perot cavity to modulate the sensor output spectrum as a continuous function of the measurand. A technique is described whereby a collection of these sensors may be effectively combined to perform a number of the measurements which are required by an aircraft-engine control system.

  17. Detection of low levels of Listeria monocytogenes cells by using a fiber-optic immunosensor.

    PubMed

    Geng, Tao; Morgan, Mark T; Bhunia, Arun K

    2004-10-01

    Biosensor technology has a great potential to meet the need for sensitive and nearly real-time microbial detection from foods. An antibody-based fiber-optic biosensor to detect low levels of Listeria monocytogenes cells following an enrichment step was developed. The principle of the sensor is a sandwich immunoassay where a rabbit polyclonal antibody was first immobilized on polystyrene fiber waveguides through a biotin-streptavidin reaction to capture Listeria cells on the fiber. Capture of cells on the fibers was confirmed by scanning electron microscopy. A cyanine 5-labeled murine monoclonal antibody, C11E9, was used to generate a specific fluorescent signal, which was acquired by launching a 635-nm laser light from an Analyte 2000 and collected by a photodetector at 670 to 710 nm. This immunosensor was specific for L. monocytogenes and showed a significantly higher signal strength than for other Listeria species or other microorganisms, including Escherichia coli, Enterococcus faecalis, Salmonella enterica, Lactobacillus plantarum, Carnobacterium gallinarum, Hafnia alvei, Corynebacterium glutamicum, Enterobacter aerogenes, Pseudomonas aeruginosa, and Serratia marcescens, in pure or in mixed-culture setup. Fiber-optic results could be obtained within 2.5 h of sampling. The sensitivity threshold was about 4.3 x 10(3) CFU/ml for a pure culture of L. monocytogenes grown at 37 degrees C. When L. monocytogenes was mixed with lactic acid bacteria or grown at 10 degrees C with 3.5% NaCl, the detection threshold was 4.1 x 10(4) or 2.8 x 10(7) CFU/ml, respectively. In less than 24 h, this method could detect L. monocytogenes in hot dog or bologna naturally contaminated or artificially inoculated with 10 to 1,000 CFU/g after enrichment in buffered Listeria enrichment broth.

  18. Blood interference in fiber-optical based fluorescence guided resection of glioma using 5-aminolevulinic acid

    NASA Astrophysics Data System (ADS)

    Haj-Hosseini, Neda; Lowndes, Shannely; Salerud, Göran; Wårdell, Karin

    2011-03-01

    Fluorescence guidance in brain tumor resection is performed intra-operatively where bleeding is included. When using fiber-optical probes, the transmission of light to and from the tissue is totally or partially blocked if a small amount of blood appears in front of the probe. Sometimes even after rinsing with saline, the remnant blood cells on the optical probe head, disturb the measurements. In such a case, the corresponding spectrum cannot be reliably quantified and is therefore discarded. The optimal case would be to calculate and take out the blood effect systematically from the collected signals. However, the first step is to study the pattern of blood interference in the fluorescence spectrum. In this study, a fiber-optical based fluorescence spectroscopy system with a laser excitation light of 405 nm (1.4 J/cm2) was used during fluorescence guided brain tumor resection using 5-aminolevulinic acid (5-ALA). The blood interference pattern in the fluorescence spectrum collected from the brain was studied in two patients. The operation situation was modeled in the laboratory by placing blood drops from the finger tip on the skin of forearm and the data was compared to the brain in vivo measurements. Additionally, a theoretical model was developed to simulate the blood interference pattern on the skin autofluorescence. The blood affects the collected fluorescence intensity and leaves traces of oxy and deoxy-hemoglobin absorption peaks. According to the developed theoretical model, the autofluorescence signal is considered to be totally blocked by an approximately 500 μm thick blood layer.

  19. Real-time In vivo Diagnosis of Nasopharyngeal Carcinoma Using Rapid Fiber-Optic Raman Spectroscopy.

    PubMed

    Lin, Kan; Zheng, Wei; Lim, Chwee Ming; Huang, Zhiwei

    2017-01-01

    We report the utility of a simultaneous fingerprint (FP) (i.e., 800-1800 cm -1 ) and high-wavenumber (HW) (i.e., 2800-3600 cm -1 ) fiber-optic Raman spectroscopy developed for real-time in vivo diagnosis of nasopharyngeal carcinoma (NPC) at endoscopy. A total of 3731 high-quality in vivo FP/HW Raman spectra (normal=1765; cancer=1966) were acquired in real-time from 204 tissue sites (normal=95; cancer=109) of 95 subjects (normal=57; cancer=38) undergoing endoscopic examination. FP/HW Raman spectra differ significantly between normal and cancerous nasopharyngeal tissues that could be attributed to changes of proteins, lipids, nucleic acids, and the bound water content in NPC. Principal components analysis (PCA) and linear discriminant analysis (LDA) together with leave-one subject-out, cross-validation (LOO-CV) were implemented to develop robust Raman diagnostic models. The simultaneous FP/HW Raman spectroscopy technique together with PCA-LDA and LOO-CV modeling provides a diagnostic accuracy of 93.1% (sensitivity of 93.6%; specificity of 92.6%) for nasopharyngeal cancer identification, which is superior to using either FP (accuracy of 89.2%; sensitivity of 89.9%; specificity of 88.4%) or HW (accuracy of 89.7%; sensitivity of 89.0%; specificity of 90.5%) Raman technique alone. Further receiver operating characteristic (ROC) analysis reconfirms the best performance of the simultaneous FP/HW Raman technique for in vivo diagnosis of NPC. This work demonstrates for the first time that simultaneous FP/HW fiber-optic Raman spectroscopy technique has great promise for enhancing real-time in vivo cancer diagnosis in the nasopharynx during endoscopic examination.

  20. A microvolume molecularly imprinted polymer modified fiber-optic evanescent wave sensor for bisphenol A determination.

    PubMed

    Xiong, Yan; Ye, Zhongbin; Xu, Jing; Liu, Yucheng; Zhang, Hanyin

    2014-04-01

    A fiber-optic evanescent wave sensor for bisphenol A (BPA) determination based on a molecularly imprinted polymer (MIP)-modified fiber column was developed. MIP film immobilized with BPA was synthesized on the fiber column, and the sensor was then constructed by inserting the optical fiber prepared into a transparent capillary. A microchannel (about 2.0 μL) formed between the fiber and the capillary acted as a flow cell. BPA can be selectively adsorbed online by the MIP film and excited to produce fluorescence by the evanescent wave produced on the fiber core surface. The conditions for BPA enrichment, elution, and fluorescence detection are discussed in detail. The analytical measurements were made at 276 nm/306 nm (λ(ex)/λ(em)), and linearity of 3 × 10(-9)-5 × 10(-6) g mL(-1) BPA, a limit of detection of 1.7 × 10(-9) g mL(-1) BPA (3σ), and a relative standard deviation of 2.4% (n = 5) were obtained. The sensor selectivity and MIP binding measurement were also evaluated. The results indicated that the selectivity and sensitivity of the proposed fiber-optic sensor could be greatly improved by using MIP as a recognition and enrichment element. Further, by modification of the sensing and detection elements on the optical fiber, the proposed sensor showed the advantages of easy fabrication and low cost. The novel sensor configuration provided a platform for monitoring other species by simply changing the light source and sensing elements. The sensor presented has been successfully applied to determine BPA released from plastic products treated at different temperatures.

  1. Online quantitative monitoring of live cell engineered cartilage growth using diffuse fiber-optic Raman spectroscopy.

    PubMed

    Bergholt, Mads S; Albro, Michael B; Stevens, Molly M

    2017-09-01

    Tissue engineering (TE) has the potential to improve the outcome for patients with osteoarthritis (OA). The successful clinical translation of this technique as part of a therapy requires the ability to measure extracellular matrix (ECM) production of engineered tissues in vitro, in order to ensure quality control and improve the likelihood of tissue survival upon implantation. Conventional techniques for assessing the ECM content of engineered cartilage, such as biochemical assays and histological staining are inherently destructive. Raman spectroscopy, on the other hand, represents a non-invasive technique for in situ biochemical characterization. Here, we outline current roadblocks in translational Raman spectroscopy in TE and introduce a comprehensive workflow designed to non-destructively monitor and quantify ECM biomolecules in large (>3 mm), live cell TE constructs online. Diffuse near-infrared fiber-optic Raman spectra were measured from live cell cartilaginous TE constructs over a 56-day culturing period. We developed a multivariate curve resolution model that enabled quantitative biochemical analysis of the TE constructs. Raman spectroscopy was able to non-invasively quantify the ECM components and showed an excellent correlation with biochemical assays for measurement of collagen (R 2  = 0.84) and glycosaminoglycans (GAGs) (R 2  = 0.86). We further demonstrated the robustness of this technique for online prospective analysis of live cell TE constructs. The fiber-optic Raman spectroscopy strategy developed in this work offers the ability to non-destructively monitor construct growth online and can be adapted to a broad range of TE applications in regenerative medicine toward controlled clinical translation. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Focus scanning with feedback control for fiber-optic nonlinear endomicroscopy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Li, Ang; Liang, Wenxuan; Li, Xingde

    2017-02-01

    Fiber-optic nonlinear endomicroscopy represents a strong promise to enable translation of nonlinear microscopy technologies to in vivo applications, particularly imaging of internal organs. Two-dimensional imaging beam scanning has been accomplished by using fiber-optic scanners or MEMS scanners. Yet nonlinear endomicroscopy still cannot perform rapid and reliable depth or focus scanning while maintaining a small form factor. Shape memory alloy (SMA) wire had shown promise in extending 2D endoscopic imaging to the third dimension. By Joule heating, the SMA wire would contract and move the endomicroscope optics to change beam focus. However, this method suffered from hysteresis, and was susceptible to change in ambient temperature, making it difficult to achieve accurate and reliable depth scanning. Here we present a feedback-controlled SMA actuator which addressed these challenges. The core of the feedback loop was a Hall effect sensor. By measuring the magnetic flux density from a tiny magnet attached to the SMA wire, contraction distance of the SMA wire could be tracked in real time. The distance was then fed to the PID algorithm running in a microprocessor, which computed the error between the command position and the current position of the actuator. The current running through the SMA wire was adjusted accordingly. Our feedback-controlled SMA actuator had a tube-like shape with outer diameter of 5.5 mm and length of 25 mm, and was designed to house the endomicroscope inside. Initial test showed that it allowed more than 300 microns of travel distance, with an average positioning error of less than 2 microns. 3D imaging experiments with the endomicroscope is underway, and its imaging performance will be assessed and discussed.

  3. Fiber-optic video study of the post-laryngectomized voice.

    PubMed

    Brewer, D W; Gould, L V; Casper, J

    1975-04-01

    Simultaneous video-fluoroscopy and fiber-optic video laryngoscopy was carried out on a series of eight laryngectomees. Previous concepts supported by an earlier report1 indicated that the folds of the rebuilt cricopharyngeal sphincter were seen to represent the primary source of sound vibration for voice production. Fold vibration was envisioned as an essential for sound production. Present findings present a challenge to the older concept. The fluoroscopic studies showed a considerable variation in the vertical thickness of the sphincteric area--from several millimeters to as many as 10 centimeters. Mucus bubbles in rapid motion were easily visible immediately above the narrowest portion of the reconstructed cervical esophagus. Ingestion of barium only enhanced the visualization of this bubbling. Vibration of a long vertical area of the thin anterior and thicker posterior esophageal walls well above and well below this point was regularly noted. Fiber-optic visualization failed to show actual fold vibration at any time. Momentary opening of the food tract during air injection or intake, immediately prior to the onset of phonation, was seen on many occasions. During phonation, routinely, the anticipated pseudoglottic opening was obscured by bubbles of mucus or barium. These findings suggest that the air, when accumulated below the narrowest spot in the hypopharyngeal-esophageal tract and when forced upward through a narrow opening, sets the accumulated mucus, not the mucous membrane, into vibration; further, that this vibration is of sufficient amplitude to transmit itself to both the anterior wall and the posterior wall of an extensive vertical portion of the neck.

  4. Borosilicate Glass Fiber-Optic Biosensor for the Detection of Escherichia coli.

    PubMed

    Maas, Michael B; Maybery, Giles H C; Perold, Willem J; Neveling, Deon P; Dicks, Leon M T

    2018-02-01

    Polyclonal antibodies against Escherichia coli and fluorescent, secondary, antibodies were immobilized on borosilicate glass fibers pre-treated with 3-glycidyloxypropyl trimethoxysilane (GPS). Light with an average wavelength of 627 nm, emitted by a diode placed at one end of the glass fiber, was detected by an ultrasensitive photodiode with peak sensitivity at 640 nm. Changes in fluorescence, caused by binding of E. coli to the antibodies, changed the net refractive index of the glass fiber and thus the internal reflection of light. These evanescent changes in photon energy were recorded by an ultrasensitive photodiode. Signals were amplified and changes in voltage recorded with a digital multimeter. A linear increase in voltage readings was recorded over 2 h when 3.0 × 10 7 CFU/ml and 2.77 × 10 9 CFU/ml E. coli were adhered to the antibodies. Voltage readings were recorded with E. coli cell numbers from 2 × 10 3 CFU/ml to 2 × 10 6 CFU/ml, but readings remained unchanged for 2 h, indicating that the limit of detection is 3.0 × 10 7 CFU/ml. This simple technology may be used to develop a low-cost, portable, fiber-optic biosensor to detect E. coli in infections and may have applications in the medical field. Research is in progress to optimize the sensitivity of the fiber-optic biosensor and determine its specificity.

  5. Solar radiative heating of fiber-optic cables used to monitor temperatures in water

    NASA Astrophysics Data System (ADS)

    Neilson, Bethany T.; Hatch, Christine E.; Ban, Heng; Tyler, Scott W.

    2010-08-01

    In recent years, applications of distributed temperature sensing (DTS) have increased in number and diversity. Because fiber-optic cables used for DTS are typically sheathed in dark UV-resistant materials, the question arises as to how shortwave solar radiation penetrating a water column influences the accuracy of absolute DTS-derived temperatures in aquatic applications. To quantify these effects, we completed a modeling effort that accounts for the effects of radiation and convection on a submersed cable to predict when solar heating may be important. Results indicate that for cables installed at shallow depths in clear, low-velocity water bodies, measurable heating of the cable is likely during peak solar radiation. However, at higher velocities, increased turbidity and/or greater depths, the effects of solar heating are immeasurable. A field study illustrated the effects of solar radiation by installing two types of fiber-optic cable at multiple water depths (from 0.05 to 0.8 m) in the center and along the sidewall of a trapezoidal canal. Thermistors were installed at similar depths and shielded from solar radiation to record absolute water temperatures. During peak radiation, thermistor data showed small temperature differences (˜0.003°C-0.04°C) between depths suggesting minor thermal stratification in the canal center. DTS data from cables at these same depths show differences of 0.01°C-0.17°C. The DTS differences cannot be explained by stratification alone and are likely evidence of additional heating from solar radiation. Sidewall thermistor strings also recorded stratification. However, corresponding DTS data suggested that bed conduction overwhelmed the effects of solar radiation.

  6. LED backlight system with fiber-optic red, green, blue to white color combiner

    NASA Astrophysics Data System (ADS)

    Kim, Hye R.; Jeong, Yunsong; Lee, Jhang-Woo; Oh, Kyunghwan

    2006-09-01

    As an application in the backlight system of small LCD display, we realized a pure white light source by mixing red, green, blue (RGB) lights using a 3 X 3 Hard Plastic Cladding Fiber (HPCF) coupler. We also proposed the 0.44 inch LED backlight system with these fiber-optic pure white sources and characterized its illumination characteristics. Using optimized fusion-tapering technique, we fabricated HPCF coupler which combines three input lights over the circularly formed waist. HPCF has the core diameter of 200 μm and clad diameter of 230 μm. The fabricated 3 X 3 HPCF coupler has the perfect uniformity of about 0.3 dB, low insertion loss of 5.5 dB, and low excess loss of 0.8 dB, which shows excellent uniform power splitting ratio. In order to improve the transmission performance, The RGB chip LEDs were butt-coupled directly to the ferruled input ports of the coupler and packaged by TO46-can type. In the produced white color by HPCF coupler, the photometric brightness at the circular endface of outputs of HPCF coupler was in a rage of 10062 ~ 10094 cd/m2. The fiber optic white color combiner provides tunable white sources excluding heat source and having thickness of 200 μm. We also proposed a 0.44 inch LED backlight system with these fiber-optic pure white sources. With the proposed device, we obtain the improved uniformity in luminance distribution and wide color gamut by using the white light mixing red, green and blue lights.

  7. In-vivo fluorescence detection of breast cancer growth factor receptors by fiber-optic probe

    NASA Astrophysics Data System (ADS)

    Bustamante, Gilbert; Wang, Bingzhi; DeLuna, Frank; Sun, LuZhe; Ye, Jing Yong

    2018-02-01

    Breast cancer treatment options often include medications that target the overexpression of growth factor receptors, such as the proto-oncogene human epidermal growth factor receptor 2 (HER2/neu) and epidermal growth factor receptor (EGFR) to suppress the abnormal growth of cancerous cells and induce cancer regression. Although effective, certain treatments are toxic to vital organs, and demand assurance that the pursued receptor is present at the tumor before administration of the drug. This requires diagnostic tools to provide tumor molecular signatures, as well as locational information. In this study, we utilized a fiber-optic probe to characterize in vivo HER2 and EGFR overexpressed tumors through the fluorescence of targeted dyes. HER2 and EGFR antibodies were conjugated with ICG-Sulfo-OSu and Alexa Fluor 680, respectively, to tag BT474 (HER2+) and MDA-MB-468 (EGFR+) tumors. The fiber was inserted into the samples via a 30-gauge needle. Different wavelengths of a supercontinuum laser were selected to couple into the fiber and excite the corresponding fluorophores in the samples. The fluorescence from the dyes was collected through the same fiber and quantified by a time-correlated single photon counter. Fluorescence at different antibody-dye concentrations was measured for calibration. Mice with subcutaneous HER2+ and/or EGFR+ tumors received intravenous injections of the conjugates and were later probed at the tumor sites. The measured fluorescence was used to distinguish between tumor types and to calculate the concentration of the antibody-dye conjugates, which were detectable at levels as low as 40 nM. The fiber-optic probe presents a minimally invasive instrument to characterize the molecular signatures of breast cancer in vivo.

  8. Achievable Information Rates for Coded Modulation With Hard Decision Decoding for Coherent Fiber-Optic Systems

    NASA Astrophysics Data System (ADS)

    Sheikh, Alireza; Amat, Alexandre Graell i.; Liva, Gianluigi

    2017-12-01

    We analyze the achievable information rates (AIRs) for coded modulation schemes with QAM constellations with both bit-wise and symbol-wise decoders, corresponding to the case where a binary code is used in combination with a higher-order modulation using the bit-interleaved coded modulation (BICM) paradigm and to the case where a nonbinary code over a field matched to the constellation size is used, respectively. In particular, we consider hard decision decoding, which is the preferable option for fiber-optic communication systems where decoding complexity is a concern. Recently, Liga \\emph{et al.} analyzed the AIRs for bit-wise and symbol-wise decoders considering what the authors called \\emph{hard decision decoder} which, however, exploits \\emph{soft information} of the transition probabilities of discrete-input discrete-output channel resulting from the hard detection. As such, the complexity of the decoder is essentially the same as the complexity of a soft decision decoder. In this paper, we analyze instead the AIRs for the standard hard decision decoder, commonly used in practice, where the decoding is based on the Hamming distance metric. We show that if standard hard decision decoding is used, bit-wise decoders yield significantly higher AIRs than symbol-wise decoders. As a result, contrary to the conclusion by Liga \\emph{et al.}, binary decoders together with the BICM paradigm are preferable for spectrally-efficient fiber-optic systems. We also design binary and nonbinary staircase codes and show that, in agreement with the AIRs, binary codes yield better performance.

  9. Pharyngeal Residue Severity Rating Scales Based on Fiberoptic Endoscopic Evaluation of Swallowing: A Systematic Review.

    PubMed

    Neubauer, Paul D; Hersey, Denise P; Leder, Steven B

    2016-06-01

    Identification of pharyngeal residue severity located in the valleculae and pyriform sinuses has always been a primary goal during fiberoptic endoscopic evaluation of swallowing (FEES). Pharyngeal residue is a clinical sign of potential prandial aspiration making an accurate description of its severity an important but difficult challenge. A reliable, validated, and generalizable pharyngeal residue severity rating scale for FEES would be beneficial. A systematic review of the published English language literature since 1995 was conducted to determine the quality of existing pharyngeal residue severity rating scales based on FEES. Databases were searched using controlled vocabulary words and synonymous free text words for topics of interest (deglutition disorders, pharyngeal residue, endoscopy, videofluoroscopy, fiberoptic technology, aspiration, etc.) and outcomes of interest (scores, scales, grades, tests, FEES, etc.). Search strategies were adjusted for syntax appropriate for each database/platform. Data sources included MEDLINE (OvidSP 1946-April Week 3 2015), Embase (OvidSP 1974-2015 April 20), Scopus (Elsevier), and the unindexed material in PubMed (NLM/NIH) were searched for relevant articles. Supplementary efforts to identify studies included checking reference lists of articles retrieved. Scales were compared using qualitative properties (sample size, severity definitions, number of raters, and raters' experience and training) and psychometric analyses (randomization, intra- and inter-rater reliability, and construct validity). Seven articles describing pharyngeal residue severity rating scales met inclusion criteria. Six of seven scales had insufficient data to support their use as evidenced by methodological weaknesses with both qualitative properties and psychometric analyses. There is a need for qualitative and psychometrically reliable, validated, and generalizable pharyngeal residue severity rating scales that are anatomically specific, image

  10. Videolaryngoscopy versus Fiber-optic Intubation through a Supraglottic Airway in Children with a Difficult Airway: An Analysis from the Multicenter Pediatric Difficult Intubation Registry.

    PubMed

    Burjek, Nicholas E; Nishisaki, Akira; Fiadjoe, John E; Adams, H Daniel; Peeples, Kenneth N; Raman, Vidya T; Olomu, Patrick N; Kovatsis, Pete G; Jagannathan, Narasimhan; Hunyady, Agnes; Bosenberg, Adrian; Tham, See; Low, Daniel; Hopkins, Paul; Glover, Chris; Olutoye, Olutoyin; Szmuk, Peter; McCloskey, John; Dalesio, Nicholas; Koka, Rahul; Greenberg, Robert; Watkins, Scott; Patel, Vikram; Reynolds, Paul; Matuszczak, Maria; Jain, Ranu; Khalil, Samia; Polaner, David; Zieg, Jennifer; Szolnoki, Judit; Sathyamoorthy, Kumar; Taicher, Brad; Riveros Perez, N Ricardo; Bhattacharya, Solmaletha; Bhalla, Tarun; Stricker, Paul; Lockman, Justin; Galvez, Jorge; Rehman, Mohamed; Von Ungern-Sternberg, Britta; Sommerfield, David; Soneru, Codruta; Chiao, Franklin; Richtsfeld, Martina; Belani, Kumar; Sarmiento, Lina; Mireles, Sam; Bilen Rosas, Guelay; Park, Raymond; Peyton, James

    2017-09-01

    The success rates and related complications of various techniques for intubation in children with difficult airways remain unknown. The primary aim of this study is to compare the success rates of fiber-optic intubation via supraglottic airway to videolaryngoscopy in children with difficult airways. Our secondary aim is to compare the complication rates of these techniques. Observational data were collected from 14 sites after management of difficult pediatric airways. Patient age, intubation technique, success per attempt, use of continuous ventilation, and complications were recorded for each case. First-attempt success and complications were compared in subjects managed with fiber-optic intubation via supraglottic airway and videolaryngoscopy. Fiber-optic intubation via supraglottic airway and videolaryngoscopy had similar first-attempt success rates (67 of 114, 59% vs. 404 of 786, 51%; odds ratio 1.35; 95% CI, 0.91 to 2.00; P = 0.16). In subjects less than 1 yr old, fiber-optic intubation via supraglottic airway was more successful on the first attempt than videolaryngoscopy (19 of 35, 54% vs. 79 of 220, 36%; odds ratio, 2.12; 95% CI, 1.04 to 4.31; P = 0.042). Complication rates were similar in the two groups (20 vs. 13%; P = 0.096). The incidence of hypoxemia was lower when continuous ventilation through the supraglottic airway was used throughout the fiber-optic intubation attempt. In this nonrandomized study, first-attempt success rates were similar for fiber-optic intubation via supraglottic airway and videolaryngoscopy. Fiber-optic intubation via supraglottic airway is associated with higher first-attempt success than videolaryngoscopy in infants with difficult airways. Continuous ventilation through the supraglottic airway during fiber-optic intubation attempts may lower the incidence of hypoxemia.

  11. Using passive fiber-optic distributed temperature sensing to estimate soil water content at a discontinuous permafrost site

    NASA Astrophysics Data System (ADS)

    Wagner, A. M.; Lindsey, N.; Ajo Franklin, J. B.; Gelvin, A.; Saari, S.; Ekblaw, I.; Ulrich, C.; Dou, S.; James, S. R.; Martin, E. R.; Freifeld, B. M.; Bjella, K.; Daley, T. M.

    2016-12-01

    We present preliminary results from an experimental study targeting the use of passive fiber-optic distributed temperature sensing (DTS) in a variety of geometries to estimate moisture content evolution in a dynamic permafrost system. A 4 km continuous 2D array of multi-component fiber optic cable (6 SM/6 MM) was buried at the Fairbanks Permafrost Experiment Station to investigate the possibility of using fiber optic distributed sensing as an early detection system for permafrost thaw. A heating experiment using 120 60 Watt heaters was conducted in a 140 m2 area to artificially thaw the topmost section of permafrost. The soils at the site are primarily silt but some disturbed areas include backfilled gravel to depths of approximately 1.0 m. Where permafrost exists, the depth to permafrost ranges from 1.5 to approximately 5 m. The experiment was also used to spatially estimate soil water content distribution throughout the fiber optic array. The horizontal fiber optic cable was buried at depths between 10 and 20 cm. Soil temperatures were monitored with a DTS system at 25 cm increments along the length of the fiber. At five locations, soil water content time-domain reflectometer (TDR) probes were also installed at two depths, in line with the fiber optic cable and 15 to 25 cm below the cable. The moisture content along the fiber optic array was estimated using diurnal effects from the dual depth temperature measurements. In addition to the horizontally installed fiber optic cable, vertical lines of fiber optic cable were also installed inside and outside the heater plot to a depth of 10 m in small diameter (2 cm) boreholes. These arrays were installed in conjunction with thermistor strings and are used to monitor the thawing process and to cross correlate with soil temperatures at the depth of the TDR probes. Results will be presented from the initiation of the artificial thawing through subsequent freeze-up. A comparison of the DTS measured temperatures and

  12. Embedded fiber-optic sensing for accurate internal monitoring of cell state in advanced battery management systems part 2: Internal cell signals and utility for state estimation

    NASA Astrophysics Data System (ADS)

    Ganguli, Anurag; Saha, Bhaskar; Raghavan, Ajay; Kiesel, Peter; Arakaki, Kyle; Schuh, Andreas; Schwartz, Julian; Hegyi, Alex; Sommer, Lars Wilko; Lochbaum, Alexander; Sahu, Saroj; Alamgir, Mohamed

    2017-02-01

    A key challenge hindering the mass adoption of Lithium-ion and other next-gen chemistries in advanced battery applications such as hybrid/electric vehicles (xEVs) has been management of their functional performance for more effective battery utilization and control over their life. Contemporary battery management systems (BMS) reliant on monitoring external parameters such as voltage and current to ensure safe battery operation with the required performance usually result in overdesign and inefficient use of capacity. More informative embedded sensors are desirable for internal cell state monitoring, which could provide accurate state-of-charge (SOC) and state-of-health (SOH) estimates and early failure indicators. Here we present a promising new embedded sensing option developed by our team for cell monitoring, fiber-optic (FO) sensors. High-performance large-format pouch cells with embedded FO sensors were fabricated. This second part of the paper focuses on the internal signals obtained from these FO sensors. The details of the method to isolate intercalation strain and temperature signals are discussed. Data collected under various xEV operational conditions are presented. An algorithm employing dynamic time warping and Kalman filtering was used to estimate state-of-charge with high accuracy from these internal FO signals. Their utility for high-accuracy, predictive state-of-health estimation is also explored.

  13. Development of a 2-channel embedded infrared fiber-optic temperature sensor using silver halide optical fibers.

    PubMed

    Yoo, Wook Jae; Jang, Kyoung Won; Seo, Jeong Ki; Moon, Jinsoo; Han, Ki-Tek; Park, Jang-Yeon; Park, Byung Gi; Lee, Bongsoo

    2011-01-01

    A 2-channel embedded infrared fiber-optic temperature sensor was fabricated using two identical silver halide optical fibers for accurate thermometry without complicated calibration processes. In this study, we measured the output voltages of signal and reference probes according to temperature variation over a temperature range from 25 to 225 °C. To decide the temperature of the water, the difference between the amounts of infrared radiation emitted from the two temperature sensing probes was measured. The response time and the reproducibility of the fiber-optic temperature sensor were also obtained. Thermometry with the proposed sensor is immune to changes if parameters such as offset voltage, ambient temperature, and emissivity of any warm object. In particular, the temperature sensing probe with silver halide optical fibers can withstand a high temperature/pressure and water-chemistry environment. It is expected that the proposed sensor can be further developed to accurately monitor temperature in harsh environments.

  14. Research on a new fiber-optic axial pressure sensor of transformer winding based on fiber Bragg grating

    NASA Astrophysics Data System (ADS)

    Liu, Yuan; Li, Lianqing; Zhao, Lin; Wang, Jiqiang; Liu, Tongyu

    2017-12-01

    Based on the principle of the fiber Bragg grating, a new type of fiber-optic pressure sensor for axial force measurement of transformer winding is designed, which is designed with the structure of bending plate beam, the optimization of the packaging process, and material of the sensor. Through the calibration experiment to calibrate the sensor, the field test results of the Taikai transformer factory show that the sensitivity of the sensor is 0.133 pm/kPa and the repeatability error is 2.7% FS. The data of the fiber-optic pressure sensor in different positions maintain consistent and repeatable, which can meet the requirement of the real-time monitoring of the axial force of transformer winding.

  15. Tuning operating point of extrinsic Fabry-Perot interferometric fiber-optic sensors using microstructured fiber and gas pressure.

    PubMed

    Tian, Jiajun; Zhang, Qi; Fink, Thomas; Li, Hong; Peng, Wei; Han, Ming

    2012-11-15

    Intensity-based demodulation of extrinsic Fabry-Perot interferometric (EFPI) fiber-optic sensors requires the light wavelength to be on the quadrature point of the interferometric fringes for maximum sensitivity. In this Letter, we propose a novel and remote operating-point tuning method for EFPI fiber-optic sensors using microstructured fibers (MFs) and gas pressure. We demonstrated the method using a diaphragm-based EFPI sensor with a microstructured lead-in fiber. The holes in the MF were used as gas channels to remotely control the gas pressure inside the Fabry-Perot cavity. Because of the deformation of the diaphragm with gas pressure, the cavity length and consequently the operating point can be remotely tuned for maximum sensitivity. The proposed operating-point tuning method has the advantage of reduced complexity and cost compared to previously reported methods.

  16. An arc tangent function demodulation method of fiber-optic Fabry-Perot high-temperature pressure sensor

    NASA Astrophysics Data System (ADS)

    Ren, Qianyu; Li, Junhong; Hong, Yingping; Jia, Pinggang; Xiong, Jijun

    2017-09-01

    A new demodulation algorithm of the fiber-optic Fabry-Perot cavity length based on the phase generated carrier (PGC) is proposed in this paper, which can be applied in the high-temperature pressure sensor. This new algorithm based on arc tangent function outputs two orthogonal signals by utilizing an optical system, which is designed based on the field-programmable gate array (FPGA) to overcome the range limit of the original PGC arc tangent function demodulation algorithm. The simulation and analysis are also carried on. According to the analysis of demodulation speed and precision, the simulation of different numbers of sampling points, and measurement results of the pressure sensor, the arc tangent function demodulation method has good demodulation results: 1 MHz processing speed of single data and less than 1% error showing practical feasibility in the fiber-optic Fabry-Perot cavity length demodulation of the Fabry-Perot high-temperature pressure sensor.

  17. A Fiber-Optic Probe Design for Combustion Chamber Flame Detection Applications-Design Criteria, Performance Specifications, and Fabrication Technique

    NASA Technical Reports Server (NTRS)

    Borg, Stephen E.; Harper, Samuel E.

    2001-01-01

    This paper documents the design and development of the fiber-optic probes utilized in the flame detection systems used in NASA Langley Research Center's 8-Foot High Temperature Tunnel (8-ft HTT). Two independent flame detection systems are utilized to monitor the presence and stability of the main-burner and pilot-level flames during facility operation. Due to the harsh environment within the combustor, the successful development of a rugged and efficient fiber-optic probe was a critical milestone in the development of these flame detection systems. The final optical probe design for the two flame detection systems resulted from research that was conducted in Langley's 7-in High Temperature Pilot Tunnel (7-in HTT). A detailed description of the manufacturing process behind the optical probes used in the 8-ft HTT is provided in Appendix A of this report.

  18. Application of thin dielectric films in low coherence fiber-optic Fabry-Pérot sensing interferometers: comparative study

    NASA Astrophysics Data System (ADS)

    Hirsch, Marzena; Wierzba, Paweł; Jedrzejewska-Szczerska, Małgorzata

    2016-11-01

    We examine the application of selected thin dielectric films, deposited by atomic layer deposition (ALD), in a low coherence fiber-optic Fabry-Pérot interferometer designed for sensing applications. Such films can be deposited on the end-face of a single mode optical fiber (SMF-28) in order to modify the reflectivity of the Fabry-Pérot cavity, to provide protection of the fibers from aggressive environments or to create a multi-cavity interferometric sensor. Spectral reflectance of films made from zinc oxide (ZnO), titanium dioxide (TiO2), aluminum oxide (Al2O3) and boron nitride (BN) was calculated for various thickness of the films and compared. The results show that the most promising materials for use in fiber-optic Fabry-Pérot interferometer are TiO2 and ZnO, although Al2O3 is also suitable for this application.

  19. Analysis and Design of a Fiber-optic Probe for DNA Sensors Final Report CRADA No. TSB-1147-95

    SciT

    Molau, Nicole; Vail, Curtis

    In 1995, a challenge in the field of genetics dealt with the acquisition of efficient DNA sequencing techniques for reading the 3 billion base-pairs that comprised the human genome. AccuPhotonics, Inc. proposed to develop and manufacture a state-of-the-art near-field scanning optical microscopy (NSOM) fiber-optic probe that was expected to increase probe efficiency by two orders of magnitude over the existing state-of-the-art and to improve resolution to 10Å. The detailed design calculation and optimization of electrical properties of the fiber-optic probe tip geometry would be performed at LLNL, using existing finite-difference time-domain (FDTD) electromagnetic (EM) codes.

  20. Three-dimensional optical-transfer-function analysis of fiber-optical two-photon fluorescence microscopy.

    PubMed

    Gu, Min; Bird, Damian

    2003-05-01

    The three-dimensional optical transfer function is derived for analyzing the imaging performance in fiber-optical two-photon fluorescence microscopy. Two types of fiber-optical geometry are considered: The first involves a single-mode fiber for delivering a laser beam for illumination, and the second is based on the use of a single-mode fiber coupler for both illumination delivery and signal collection. It is found that in the former case the transverse and axial cutoff spatial frequencies of the three-dimensional optical transfer function are the same as those in conventional two-photon fluorescence microscopy without the use of a pinhole.However, the transverse and axial cutoff spatial frequencies in the latter case are 1.7 times as large as those in the former case. Accordingly, this feature leads to an enhanced optical sectioning effect when a fiber coupler is used, which is consistent with our recent experimental observation.