Underwater object inspection by optical sensors is usually unreliable in turbid or dark environments. Here, we designed a biomimetic 'electric camera', inspired by weakly electric fish Gnathonemus petersii, which successfully use active electrolocation for this task. The device probed nearby objects with a weak electric field and captured 'electric images' of the targets by processing the object-evoked field modulations.
View Article and Find Full Text PDFMany sighted animals use color as a salient and reliable cue [1] to identify conspecifics [2-4], predators, or food [5-7]. Similarly, nocturnal, weakly electric fish Gnathonemus petersii might rely on "electric colors" [8] for unambiguous, critical object recognitions. These fish identify nearby targets by emitting electric signals and by sensing the object-evoked signal modulations in amplitude and waveform with two types of epidermal electroreceptors (active electrolocation) [9-12].
View Article and Find Full Text PDFDuring active electrolocation, the weakly electric fish judges the distance and impedance of nearby objects. Capacitive objects, which modulate local amplitude and waveform of the fish's electric probing signals, cast amplitude and waveform images onto the fish's electroreceptive skin. For an unambiguous estimation of the impedance and distance of an object, the animal has to deal with multiple dependencies of object and image parameters.
View Article and Find Full Text PDFCoronary artery disease-currently one of the most frequent causes of death-is characterized by atherosclerotic plaques grown in the wall of blood vessels and inhibiting blood flow. Preventive assessment focusses on critical sizes of structural plaque parameters like relative lipid core area and cap thickness to identify high-risk plaques called thin cap fibroatheromas. Although state-of-the-art catheter systems were successfully applied in invasive plaque diagnostics, the high costs induced by these devices inhibit usage in daily clinical practice.
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