6 research outputs found
POINT CLOUD ANALYSIS FOR UAV-BORNE LASER SCANNING WITH HORIZONTALLY AND VERTICALLY ORIENTED LINE SCANNERS – CONCEPT AND FIRST RESULTS
In this paper, we focus on UAV-borne laser scanning with the objective of densely sampling object surfaces in the local surrounding of
the UAV. In this regard, using a line scanner which scans along the vertical direction and perpendicular to the flight direction results in a
point cloud with low point density if the UAV moves fast. Using a line scanner which scans along the horizontal direction only delivers
data corresponding to the altitude of the UAV and thus a low scene coverage. For these reasons, we present a concept and a system for
UAV-borne laser scanning using multiple line scanners. Our system consists of a quadcopter equipped with horizontally and vertically
oriented line scanners. We demonstrate the capabilities of our system by presenting first results obtained for a flight within an outdoor
scene. Thereby, we use a downsampling of the original point cloud and different neighborhood types to extract fundamental geometric
features which in turn can be used for scene interpretation with respect to linear, planar or volumetric structures
Cardiac tamponade related to a coronary injury by a pericardial calcification: an unusual complication
<p>Abstract</p> <p>Background</p> <p>Cardiac tamponade is a rare but severe complication of pericardial effusion with a poor prognosis. Prompt diagnosis using transthoracic echocardiography allows guiding initial therapeutic management. Although etiologies are numerous, cardiac tamponade is more often due to a hemopericardium. Rarely, a coronary injury may result in such a hemopericardium with cardiac tamponade. Coronary artery aneurysm are the main etiologies but blunt, open chest trauma or complication of endovascular procedures have also been described.</p> <p>Case presentation</p> <p>A 83-year-old hypertensive man presented for dizziness and hypotension. The patient had oliguria and mottled skin. Transthoracic echocardiography disclosed a circumferential pericardial effusion with a compressed right atrium, confirmed by contrast-enhanced thoracic CT scan. A pig-tail catheter allowed to withdraw 500 mL of blood, resulting in a transient improvement of hemodynamics. Rapidly, recurrent hypotension prompted a reoperation. An active bleeding was identified at the level of the retroventricular coronary artery. The pericardium was thickened with several "sharping" calcified plaques in the vicinity of the bleeding areas. On day 2, vasopressors were stopped and the patient was successfully extubated. Final diagnosis was a spontaneous cardiac tamponade secondary to a coronary artery injury attributed to a "sharping"calcified pericardial plaque.</p> <p>Conclusion</p> <p>Cardiac tamponade secondary to the development of a hemopericardium may develop as the result of a myocardial and coronary artery injury induced by a calcified pericardial plaque.</p
An analysis on the effectiveness of the Philippine Amanah Bank in financial intermediation
POINT CLOUD ANALYSIS FOR UAV-BORNE LASER SCANNING WITH HORIZONTALLY AND VERTICALLY ORIENTED LINE SCANNERS – CONCEPT AND FIRST RESULTS
In this paper, we focus on UAV-borne laser scanning with the objective of densely sampling object surfaces in the local surrounding of
the UAV. In this regard, using a line scanner which scans along the vertical direction and perpendicular to the flight direction results in a
point cloud with low point density if the UAV moves fast. Using a line scanner which scans along the horizontal direction only delivers
data corresponding to the altitude of the UAV and thus a low scene coverage. For these reasons, we present a concept and a system for
UAV-borne laser scanning using multiple line scanners. Our system consists of a quadcopter equipped with horizontally and vertically
oriented line scanners. We demonstrate the capabilities of our system by presenting first results obtained for a flight within an outdoor
scene. Thereby, we use a downsampling of the original point cloud and different neighborhood types to extract fundamental geometric
features which in turn can be used for scene interpretation with respect to linear, planar or volumetric structures