Psychophysiological signals associated with affective states

8noneembargoed_20131014Mauri, Maurizio; Magagnin, Valentina; Cipresso, Pietro; Mainardi, Luca; Brown, Emery N; Cerutti, Sergio; Villamira, Marco; Barbieri, and RiccardoMauri, Maurizio; Magagnin, Valentina; Cipresso, Pietro; Mainardi, Luca; Brown, Emery N; Cerutti, Sergio; Villamira, Marco; Barbieri, Riccard

Nearly automated analysis of coronary Doppler flow velocity from transthoracic ultrasound images: validation with manual tracings

Coronary flow velocity reserve is obtained by manual tracings of transthoracic coronary Doppler flow velocity profiles as the ratio of stress versus baseline diastolic peak velocities. This approach introduces subjectivity in the measurements and limits the information which could be exploited from the Doppler velocity profile. Accordingly, our goals were to develop a technique for nearly automated detection of Doppler coronary flow velocity profile, and automatically compute both conventional and additional amplitude, derivative and temporal parameters, and validate it with manual tracings. A total of 100 patients (17 normals, 15 patients with severe coronary stenosis, 41 with connective tissue disease and 27 with diabetes mellitus) were studied. Linear correlation and Bland-Altman analyses showed that the proposed method was highly accurate and repeatable compared to the manual measurements. Comparison between groups evidenced significant differences in some of the automated parameters, thus representing potentially additional indices useful for the noninvasive diagnosis of microcirculatory or coronary artery disease

Semi-automated analysis of coronary flow doppler images: validation with manual tracings

European finalist for Young Investigator Student Paper Awar

The first 3D-printed z-axis accelerometers with differential capacitive sensing

In this work, additive manufacturing and wet metallization process are combined to fabricate three prototypes of differential electro-mechanical z-axis accelerometers. The smart combination of existing fabrication processes makes the proposed fabrication flow unique in the sensors field. The mechanical design of the three proposed devices exploits the three-dimensionality of the 3D-printing technique and the electrostatic differential readout is allowed thanks to the wet-metallization process of the printed structure. Experimental measurements show a very good agreement with theoretical predictions thus proving a good reliability of the proposed design flow and fabrication process. With their relative small footprints (minimum dimension in the order of hundreds of μ m), good performances (sensitivity > 12 fF/g, sub % linearity error up to 11 g of full scale and theoretical noise estimation of few tens of ng/√Hz) and high customizability, they represent an important step toward novel application fields of inertial sensors

RR-SAP causality in heart transplant recipients.

An information domain approach to the assessment of causality was applied to the beat-to-beat variability of heart period and systolic arterial pressure to test the open loop condition along baroreflex in heart transplant recipients. The closed loop between heart period and systolic arterial pressure was detected as open at the level of the baroreflex if systolic arterial pressure is more easily predictable from heart period than vice versa according to a conditional entropy approach. We found that in short-term heart transplant (STHT) recipients (less than 2 years after transplantation) the closed loop between heart period and systolic arterial pressure was open at the level of baroreflex. Baroreflex appeared to be involved in the heart period regulation in long-term heart transplant (LTHT) recipients (more than 2 years after transplantation). The significant linear correlation of causality index on the number of months after transplantation suggests that baroreflex control recovers after transplantation.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Design, Fabrication and Testing of the First 3D-Printed and Wet Metallized z-Axis Accelerometer

In this work the design, fabrication and testing of the first 3D-printed and wet metallized capacitive z-axis accelerometer with a volume of 3.4 cm × 8 mm × 2.5 mm is presented. Preliminary results well match the modelling, both in terms of electromechanical parameters and of measured sensitivity, thus validating the proposed concept and fabrication process. With a spring thickness of 300 µm and a gap size of 200 µm for capacitive read-out, the presented device and the shown results can be considered as the first step toward 3D-printed MEMS (Micro-Electro-Mechanical Systems) inertial sensors

Psychophysiological signals associated with affective states

We present a preliminary quantitative study aimed at developing an optimal standard protocol for automatic classification of specific affective states as related to human- computer interactions. This goal is mainly achieved by comparing standard psychological test-reports to quantitative measures derived from simultaneous non-invasive acquisition of psychophysiological signals of interest, namely respiration, galvanic skin response, blood volume pulse, electrocardiogram and electroencephalogram. Forty-three healthy students were exposed to computer-mediated stimuli, while wearable non-invasive sensors were applied in order to collect the physiological data. The stimuli were designed to elicit three distinct affective states: relaxation, engagement and stress. In this work we report how our quantitative analysis has helped in redefining important aspects of the protocol, and we show preliminary findings related to the specific psychophysiological patterns correlating with the three target affective states. Results further suggest that some of the quantitative measures might be useful in characterizing specific affective states.National Institutes of Health (U.S.) (Grant R01-HL084502)National Institutes of Health (U.S.) (Grant DP1-OD003646

3D-printing and wet metallization for uniaxial and multi-axial accelerometers

In recent years, 3D-printing techniques are attracting increasing interest because of the variety of possible applications (i.e. biomedical applications, design), the large versatility and relative low-costs. Moreover, by combining the 3D-printing technology with other processes (i.e. wet metallization), it is possible to provide an innovative, high-customizable and cheap fabrication procedure for sensors, such as accelerometers. In this work, the design and the fabrication of a uniaxial and a multi-axial accelerometers are proposed from the simulation to the final prototyping