Detailed characterization of microvascular alterations requires high-resolution 3D imaging methods capable of providing both morphological and functional information. Existing optical microscopy tools are routinely used for microangiography, yet offer suboptimal trade-offs between the achievable field of view and spatial resolution with the intense light scattering in biological tissues further limiting the achievable penetration depth. Herein, a new approach for volumetric deep-tissue microangiography based on stereovision combined with super-resolution localization imaging is introduced that overcomes the spatial resolution limits imposed by light diffusion and optical diffraction in wide-field imaging configurations.
View Article and Find Full Text PDFOptoacoustic mesoscopy combines rich optical absorption contrast with high spatial resolution at tissue depths beyond reach for microscopic techniques employing focused light excitation. The mesoscopic imaging performance is commonly hindered by the use of inaccurate delay-and-sum reconstruction approaches and idealized modeling assumptions. In principle, image reconstruction performance could be enhanced by simulating the optoacoustic signal generation, propagation, and detection path.
View Article and Find Full Text PDFWearable robots assist individuals with sensorimotor impairment in daily life, or support industrial workers in physically demanding tasks. In such scenarios, low mass and compact design are crucial factors for device acceptance. Remote actuation systems (RAS) have emerged as a popular approach in wearable robots to reduce perceived weight and increase usability.
View Article and Find Full Text PDFOptoacoustic microscopy (OAM) can image intrinsic optical absorption contrast at depths of several millimeters where state-of-the-art optical microscopy techniques fail due to intense light scattering in living tissues. Yet, wide adoption of OAM in biology and medicine is hindered by slow image acquisition speed, small field of view (FOV), and/or lack of spectral differentiation capacity of common system implementations. We report on a rapid acquisition functional optoacoustic micro-angiography approach that employs a burst-mode laser triggering scheme to simultaneously acquire multi-wavelength 3D images over an extended FOV covering ${50}\;{\rm mm} \times {50}\;{\rm mm}$50mm×50mm in a single mechanical overfly scan, attaining 28 µm and 14 µm resolution in lateral and axial dimensions, respectively.
View Article and Find Full Text PDFFunctional optoacoustic (OA) imaging assisted with genetically encoded calcium ion indicators (GECIs) holds promise for imaging large-scale neuronal activity at depths and spatiotemporal resolutions not attainable with existing optical microscopic techniques. However, currently available GECIs optimized for fluorescence (FL) imaging lack sufficient contrast for OA imaging and respond at wavelengths having limited penetration into the mammalian brain. Here we present an imaging platform capable of rapid assessment and cross-validation between OA and FL responses of sensor proteins expressed in Escherichia coli colonies.
View Article and Find Full Text PDFSecure implant fixation is challenging in osteoporotic bone. Due to the high variability in inter- and intra-patient bone quality, ex vivo mechanical testing of implants in bone is very material- and time-consuming. Alternatively, in silico models could substantially reduce costs and speed up the design of novel implants if they had the capability to capture the intricate bone microstructure.
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