Search results for " Sensor"
showing 10 items of 1714 documents
Multimodal device for assessment of skin malformations
2013
A variety of multi-spectral imaging devices is commercially available and used for skin diagnostics and monitoring; however, an alternative cost-efficient device can provide an advanced spectral analysis of skin. A compact multimodal device for diagnosis of pigmented skin lesions was developed and tested. A polarized LED light source illuminates the skin surface at four different wavelengths – blue (450 nm), green (545 nm), red (660 nm) and infrared (940 nm). Spectra of reflected light from the 25 mm wide skin spot are imaged by a CMOS sensor. Four spectral images are obtained for mapping of the main skin chromophores. The specific chromophore distribution differences between different skin…
LASCA and PPG imaging for non-contact assessment of skin blood supply
2013
Laser speckle contrast analysis (LASCA) offers a non-contact, full-field, and real-time mapping of capillary blood flow and can be considered as an alternative method to Laser Doppler perfusion imaging (LDPI). Photoplethysmography (PPG) is well known technique for assessment of skin blood pulsations that can be related to blood flow. In recent years several studies have been done on development of non-contact PPG imaging (PPGI). LASCA and PPGI techniques are simpler and cheaper compared with LDPI. LASCA technique has been implemented in several commercial instruments. However, these systems are still too expensive and bulky to be widely available. Several optical techniques have found new i…
The blood perfusion mapping in the human skin by photoplethysmography imaging
2010
A CMOS camera-based imaging photoplethysmographic (PPGI) system is described to detect the blood pulsations in tissue. Attention of PPGI is drawn to the potential applications in visualized blood perfusion. Intensity variations of three wavelengths (620 nm, 520 nm and 432 nm) were detected and analyzed in each pixel of image. To obtain a twodimensional mapping of the dermal perfusion measurement, custom image-processing software has been developed. The high-resolution PPGI images were derived from human fingers (transmission mode) and face (reflection mode), evaluated at three wavelengths. The newly developed system can be usable in skin blood perfusion monitoring for clinical applications.
Giant Magnetoresistance (GMR) Magnetometers
2016
Since its discovering in 1988, the Giant Magnetoresistance (GMR) effect has been widely studied both from the theoretical and the applications points of view. Its rapid development was initially promoted by their extensive use in the read heads of the massive data magnetic storage systems, in the digital world. Since then, novel proposals as basic solid state magnetic sensors have been continuously appearing. Due to their high sensitivity, small size and compatibility with standard CMOS technologies, they have become the preferred choice in scenarios traditionally occupied by Hall sensors. In this chapter, we analyze the main properties of GMR sensors regarding their use as magnetometers. W…
Stronger proprioceptive BOLD-responses in the somatosensory cortices reflect worse sensorimotor function in adolescents with and without cerebral pal…
2020
Graphical abstract
Measurement of brain tissue pressure in cold induced cerebral oedema.
1973
Experiments were performed in order to evaluate the concept that brain oedema is associated with an increase in local interstitial fluid pressure. Assuming that the pressure measured by the cotton wick technique represents the hydrostatic interstitial fluid pressure, the tissue pressure was recorded with pressure transducers in the white matter adjacent and remote to a local cold injury, in the opposite hemisphere, and in the cisterna magna. In 9 cats during steady-state conditions mean tissue pressures between 1.20±0.30 mm Hg and 2.33±0.80 mm Hg were found, as compared to a mean CSF pressure of 5.17±0.82 mm Hg. The tissue pressure was found to increase significantly adjacent to the lesion …
Vertical standing copper nanowires for electrochemical sensor of nitrate in water
2020
Nitrogen, in the forms of nitrate (NO3-), nitrite, or ammonium, is a nutrient needed for plant growth and it is a common constituent of fertilizers [1]. When fertilizers are overused, they contaminate the ground water and then the food chain. For humans, a low level of nitrate is advisable because it increases the blood flow and has a good effect on both blood pressure and cardiovascular system. On the contrary, a high concentration of nitrate can be dangerous for humans. Nitrate ions undergoes different chemical transformations (i.e. to nitrite ions by Escherichia coli) producing different nitrogen-based compound such as nitrite ions, nitric oxide and ammonia [2]. These chemicals lead to s…
EFFECT OF CANOPY MANAGEMENT TECHNIQUES ON THE NUTRITIONAL QUALITY OF MONTEPULCIANO GRAPEVINE IN PUGLIA (SOUTHERN ITALY)
2012
<p style="text-align: justify;"><strong>Aims</strong>: Tests were carried out to assess the effects of early defoliation, cluster thinning and cluster cutting on the basic and nutritional composition of musts and wines of <em>Vitis vinifera</em> L. cv. Montepulciano.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Both production and quality variables of the musts were evaluated. Antioxidant activity was determined on berries and on wines, as were the phenol and anthocyanin concentrations. The wines were compared by sensory evaluation. The results attested to a positive effect of the treatments on grape compositi…
Boundary elements analysis of adhesively bonded piezoelectric active repair
2009
Abstract This paper presents the analysis of active piezoelectric patches for cracked structures by the boundary element method. A two-dimensional boundary integral formulation based on the multidomain technique is used to model cracks and to assemble the multi-layered piezoelectric patches to the host damaged structures. The fracture mechanics behavior of the repaired structures is analyzed for both perfect and imperfect interface between patches and host beams. The imperfect interface, representing the adhesive between two different layers, is modeled by using a “spring model” that involves linear relationships between the interface tractions, in normal and tangential directions, and the …
Observation of topological gravity-capillary waves in a water wave crystal
2019
The discovery of topological phases of matter, initially driven by theoretical advances in quantum condensed matter physics, has been recently extended to classical wave systems, reaching out to a wealth of novel potential applications in signal manipulation and energy concentration. Despite the fact that many realistic wave media (metals at optical frequencies, polymers at ultrasonic frequencies) are inherently dispersive, topological wave transport in photonic and phononic crystals has so far been limited to ideal situations and proof-of-concept experiments involving dispersionless media. Here, we report the first experimental demonstration of topological edge states in a classical water …