In order to work at higher ultrasonic frequencies, for instance, to increase the resolution, it is necessary to fabricate smaller and higher frequency transducers. This paper presents an ultrasonic transducer capable of being made at a very small size and operated at GHz frequencies. The transducers are activated and read optically using pulsed lasers and without physical contact between the in...

High-resolution volumetric optical imaging modalities, such as confocal microscopy, two-photon microscopy, and optical coherence tomography, have become increasingly important in the biomedical imaging field. However, due to strong light scattering, the penetration depths of these imaging modalities are limited to the optical transport mean free path in biological tissues, for example, ∼1 mm in...

An original method to denoise ultrasonic images affected by speckle is presented. Speckle is modeled as a signal-dependent noise corrupting the image. Noise reduction is approached as a Wiener-like filtering performed in a shift-invariant wavelet domain by means of an adaptive rescaling of the coefficients of an undecimated octave decomposition. The scaling factor of each coefficient is calcula...

A flying robot is localized using ultrasonic sensor network distributed on the ground. This requires localization of sensor nodes first. In absence of RF link between target and sensors, weighted Multi-Dimensional Scaling (MDS) with Gradient Descent is used to localize the sensors from outlier free data obtained from generating a locally linear manifold. After initialization, an Extended Kalman...

Either electric or magnetic field can be employed for micro actuation. Each type of actuation principle has its own advantages and drawbacks. This paper presents a comparative study of micro actuators driven by electric and magnetic principles. It is shown that the electrostatic and piezoelectric actuators have good scaling effects whereas the electromagnetic actuators have higher power density...

We describe simple simulation models of collective swarm behaviour of simple robots. We have experimented with mixed avoidance and seeking behaviour using triwheeled robots using simple ultrasonic proximity sensors. Our model assumes a radial distance of attraction or repulsion and supports multiple species in the swarm based on sensor recognition protocols. We describe the surprising success o...

UNLABELLED Infectious diseases endanger all dental personnel during treatment, especially when spatter and aerosols are produced. Therefore, there is a strong need for better infection control principles during all treatments. The purpose of this in-vitro pilot study was to measure the environmental spatter contamination through a fluorescence technique. Scaling was performed using different po...

BACKGROUND The aim of this study was to analyze the CO2 laser effects on root surfaces affected by periodontal disease in comparison to scaling and root planing for fibroblast attachment. METHODS Thirty single-rooted human teeth extracted because of advanced periodontal disease were included in this study. A total of 60 specimens, obtained from all selected teeth, were randomly assigned to 3 ...

Data (n = 2,658) from live animal ultrasonic measures from 17 Angus herds were used to evaluate a multiplicative mixed model that incorporates scaling factors to correct for across-herd heterogeneity of variance. Traits included were ribeye muscle area (EMA), surface fat at the P8 site (P8), surface fat between the 12th and 13th ribs (RIB12), and weight at scanning (WEIGHT). Cattle ranged in ag...