Design and dynamic characterization of a gyroscopic system for aerobatic UAV helicopters

This paper describes the design, development and dynamic characterization of a high performance MEMS-based gyroscopic control system for the yaw channel of Unmanned Aerial Vehicles (UAVs) Radio Controlled (RC) helicopters for aerobatic maneuvers. A new asymmetrical controller has been developed that compensates the torque of the main rotor thus providing equal dynamic response in clockwise and anticlockwise pirouettes. The \u201cin flight\u201d dynamic characterization showed that the proposed system can be up to five times faster than the state of the art for commercial gyros at higher yaw rates; the regime yaw rate characterization demonstrated a high and constant pirouette speed. Aerobatic tests demonstrated high accuracy entry into the maneuvers

Ex vivo Time Evolution of Thrombus Growth through Optical and Electrical Impedance data fusion

We designed a novel sensor specifically aimed at ex vivo measurements of white thrombus volume growth; a white thrombus is induced within an artificial micro-channel where hemostasis takes place starting from whole blood under flow conditions. The advantage of the proposed methodology is to identify the time evolution of the thrombus volume by means of an original data fusion methodology based on 2D optical and electrical impedance data simultaneously processed. On the contrary, the present state of the art optical imaging methodologies allow the thrombus volume estimation only at the end of the hemostatic process

Protein Aggregation Measurement through Electrical Impedance Spectroscopy

The paper presents a novel methodology to measure the fibril formation in protein solutions. We designed a bench consisting of a sensor having interdigitated electrodes, a PDMS hermetic reservoir and an impedance meter automatically driven by calculator. The impedance data are interpolated with a lumped elements model and their change over time can provide information on the aggregation process. Encouraging results have been obtained by testing the methodology on K-casein, a protein of milk, with and without the addition of a drug inhibiting the aggregation. The amount of sample needed to perform this measurement is by far lower than the amount needed by fluorescence analysis

Fast blood impedance measurements as quality indicators in the pre-analytical phase to prevent laboratory errors

In clinical laboratories, the major proportion of errors regarding blood analyses occurs in the pre-analytical phase. Pre-analytical conditions are key, necessary factors in maintaining the high quality of specimens, limiting day-to-day and batch variations, and guaranteeing the absolute reliability and accuracy of clinical results and related diagnoses. The quality of serum samples must be very high in order to avoid interferences due to hemolysis, thereby preventing measurement errors. In addition, the quality of the blood should always be fast monitored to identify inadequacies and guarantee their complete usability in transfusion procedures. In the near future, the solution could be to supply laboratories with smart and portable devices that are able to perform fast quality tests for every sample. Electrical impedance has relevant potential in analyzing and monitoring blood quality. We propose a new, simple impedancebased biosensor that can perform accurate and efficient single and multi-frequency impedance measurements in the pre-analytical phase and to check the quality of blood samples using quantitative thresholds as useful indicators to ensure the reliability of results and thereby prevent laboratory errors. The proposed sensor allows for discriminating different blood components, identifying hemolysis in serum, evaluating blood quality, and rapidly quantifying its hematocrit

A new method for accurate platelet thrombi volume measurement using a confocal microscope

The accuracy of quantitative measurements represents an essential pre-requisite to the characterization and definition of the complex dynamic phenomena occurring in the field of cell biology. In research projects that involve the induction of blood coagulation under flow in microfluidic artificial channels, thrombus volume is an important quantity for estimation as a significant index related to the individual thrombotic risk profile. Concerning its importance in the early diagnosis of cardiovascular diseases, the estimated thrombus volume should reflect and represent reality. In 3D confocal microscopy, systematic errors can arise from distortions of the axial distance, whose accurate calibration remains a challenge. As a result, the 3D reconstructions show a noticeable axial elongation, and the volume measurements are thus overestimated. In this paper, a 400-600 % volume overestimation is demonstrated, and a new easy to use and automatic calibration procedure is outlined for this specific microfluidic and optical context. The adaptive algorithm proposed leads to the automatic compensation of the elongation error and to the accurate thrombus volume measurement. The method has been calibrated using fluorescent beads of known volume, validated with groups of several distinct platelets and finally applied on platelet thrombi

Wearable instrument to measure simultaneously cardiac and electrodermal activities

The paper presents the design and characterization of a wearable instrument which measures simultaneously the electrodermal activity and the heart rate variability. The device measures the electrocardiogram on three channels and the skin potential response (endosomatic electrodermal activity) with a sample rate 1 kSa/s, 12 bits resolution. The bandwidth of ECG channels is [0.025, 160] Hz and the bandwidth of electrodermal channel is [0.08, 40] Hz. Data are transmitted via Bluetooth to a developed graphical user interface, which can run on a laptop or smartphone/tablet. The system is a useful tool to assess the sympathetic activity on heart rate variability

Design and characterization of a real-time, wearable, endosomatic electrodermal system

This paper presents the design and characterization of a compact wearable system for long-term assessment of skin potential response, with the aim of monitoring mental stress in a variety of applications. Literature reports that the expected skin potential has peak-to-peak amplitudes of few millivolts in the frequency band [0.1, 10] Hz. The designed system is characterized by a slightly wider bandwidth of [0.08, 40] Hz, and it is based on a 12-bit ADC working with a sampling rate of 200 Sa/s, which can be increased up to 3.5 kSa/s. Data can be continuously acquired for up to 40 h with a battery of 3.7 V/1800 mAh. A Graphical User Interface was also developed for the host computer in.NET framework. The system, to our knowledge the first example of wearable endosomatic electrodermal activity sensor, joins to several skin conductance wearable measuring systems recently proposed in literature, and opens up opportunities for future comparisons of endosomatic and exosomatic responses in real life. The device is thoroughly characterized in accordance with the state-of-the-art of the metrological research in the field. \ua9 2015 Elsevier Ltd. All rights reserved

Wearable instrument for skin potential response analysis in AAL applications

A novel instrument able to acquire Skin Potential Response (SPR) signals is proposed; SPR is a branch of Electrodermal Activity (EDA) and consists of reading nervous electric pulses that arise when the sympathetic nervous system activates sweat glands as a reaction of an external stressing stimulus. Scientific literature shows that EDA is a good methodology to detect workload, increased stress level and many neurological diseases or addictions. In this paper, we present the design and characterization of a wearable, battery operated, wireless device which can acquire SPR data and can be integrated in a wireless sensor network for the AAL. The developed control panel is responsible of receiving the SPR data, plotting them in real time and, on a secondary screen, providing to the patient visual and auditory stimuli; as a further stimuli generator, an adaptive game controlled by the SPR signal has been developed. The synchronous plot of stimuli markers and SPR signal on the same graph can provide a very useful information for the SPR analysis

Development of an enhanced MHD micromixer based on axial flow modulation

A magneto-hydrodynamic (MHD) stirrer was analytically modeled, designed and experimentally tested. A novel modulation technique is presented which allows enhancing the mixing quality in a short amount of time. The stirrer was realized with two PCB layers and a glass cover; the channel presents electrodes posed on the bottom wall and on the sidewalls. All the electrodes are AC fed in order to avoid electrolysis and bubble formation during the stirring process. A fully programmable circuit allows creating vortices inside the mixing channel and to move the fluids with an oscillating motion from inlet to outlet: the electrodes on the bottom wall provide contra-rotating vortices and are fed with AC zero mean value square waves in-phase and in opposition of phase with respect to a magnetic field generated by an electromagnet. The siclewalls are fed by a modulated signal whose carrier is in phase with the magnetic field, while the modulant is a low frequency square wave with programmable frequency, amplitude, DC offset and duty-cycle; as an effect it is possible to make oscillate the fluid from inlet to outlet and enhance the stirring process by interaction of this axial oscillation with the contra-rotating vortices. Experimental efficiency of 90% can be reached in an amount of time of 24s