Visioning: A Navigational Tool in Schools

Recent years have witnessed an increased use of ultrasound in evaluation of the airway and the lower parts of the respiratory system. Ultrasound examination is fast and reliable and can be performed at the bedside and does not carry the risk of exposure to ionizing radiation. Apart from use in diagnostics it may also provide safe guidance for invasive and semi-invasive procedures. Ultrasound examination of the oral cavity structures, epiglottis, vocal cords, and subglottic space may help in the prediction of difficult intubation. Preoperative ultrasound may diagnose vocal cord palsy or deviation or stenosis of the trachea. Ultrasonography can also be used for confirmation of endotracheal tube, double-lumen tube, or laryngeal mask placement. This can be achieved by direct examination of the tube inside the trachea or by indirect methods evaluating lung movements. Postoperative airway ultrasound may reveal laryngeal pathology or subglottic oedema. Conventional ultrasound is a reliable real-time navigational tool for emergency cricothyrotomy or percutaneous dilational tracheostomy. Endobronchial ultrasound is a combination of bronchoscopy and ultrasonography and is used for preoperative examination of lung cancer and solitary pulmonary nodules. The method is also useful for real-time navigated biopsies of such pathological structures.

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A More Comprehensive Habitable Zone for Finding Life on Other Planets

Geosciences ◽

10.3390/geosciences8080280 ◽

2018 ◽

Vol 8 (8) ◽

pp. 280 ◽

Cited By ~ 29

Author(s):

Ramses Ramirez

Keyword(s):

Greenhouse Gases ◽

Main Sequence ◽

Habitable Zone ◽

Circular Region ◽

Main Sequence Stars ◽

Habitable Planets ◽

Host Life ◽

Navigational Tool ◽

Bodies Of Water

The habitable zone (HZ) is the circular region around a star(s) where standing bodies of water could exist on the surface of a rocky planet. Space missions employ the HZ to select promising targets for follow-up habitability assessment. The classical HZ definition assumes that the most important greenhouse gases for habitable planets orbiting main-sequence stars are CO2 and H2O. Although the classical HZ is an effective navigational tool, recent HZ formulations demonstrate that it cannot thoroughly capture the diversity of habitable exoplanets. Here, I review the planetary and stellar processes considered in both classical and newer HZ formulations. Supplementing the classical HZ with additional considerations from these newer formulations improves our capability to filter out worlds that are unlikely to host life. Such improved HZ tools will be necessary for current and upcoming missions aiming to detect and characterize potentially habitable exoplanets.

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Low Frequency Sound as a Navigational Tool for People with Visual Impairments

Journal of Low Frequency Noise Vibration and Active Control ◽

10.1260/026309202321834645 ◽

2002 ◽

Vol 21 (4) ◽

pp. 199-205 ◽

Cited By ~ 4

Author(s):

Daniel Ashmead ◽

Robert Wall

Keyword(s):

Wall Motion ◽

Visual Impairments ◽

Low Frequency ◽

Sound Field ◽

Frequency Sound ◽

Acoustic Information ◽

Large Structures ◽

Dominant Feature ◽

Mistaken Assumption ◽

Navigational Tool

For decades, a mistaken assumption in the habilitation of travel for people with visual impairments has been that the use of “echolocation” is a dominant feature of acoustic information for the guidance of locomotion. This paper outlines a theoretical model of acoustic information available in many travel situations. The acoustic information consists of a build up of low frequency sound along large structures such as walls. Useful frequencies are low enough that the experience of this build up is often one of feeling rather than hearing. Experimental validation of this model was accomplished by having participants with visual impairments walk along walls with varying types of auditory occlusion and through laboratory based manipulations of acoustic information. Results indicate that the model is appropriate. Useful acoustic information appears to extend up to 1 m from a wall. There is strong evidence that participants make use of binaural information, gauging the similarity of acoustic information reaching each ear to maintain orientation to a wall. Motion through the sound field near the wall makes the information more useful but it is unclear whether motion in certain directions or conditions is more useful than others.

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