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A Robotic System for Soft Tissue Characterization
P,Vacalebri,R,Lazzarini,S,Roccella,F,Vecchi,M,C,Carrozza,M,Zecca,P,Dario 한국과학기술원 인간친화 복지 로봇 시스템 연구센터 2003 International Journal of Assistive Robotics and Me Vol.4 No.2
A miniature robotic system has been designed and fabricated to perform in vivo mechanical characterization of soft tissues. The tissue tester employs a stepper motor, which is controlled using micro-stepping techniques to prevent irregular rotation of motor shaft at low speeds. There is also a load cell to measure the reaction force of the tissue under test. At the end of tests session, data could be post elaborated on a PC with special software that reconstructs the force-displacement curves of the tissues being tested. Position and rate feedback are implemented with a digital encoder to minimize errors in motor control during the evaluation of typical viscoelastic phenomena of biological tissues. Calibration tests indicate that the force-displacement curves of the miniature robotic indenter are consistent with that obtained using an ordinary universal testing machine.
Shape memory alloy clamping devices of a capsule for monitoring tasks in the gastrointestinal tract
Menciassi, A,Moglia, A,Gorini, S,Pernorio, G,Stefanini, C,Dario, P IOP 2005 JOURNAL OF MICROMECHANICS AND MICROENGINEERING - Vol.15 No.11
<P>This paper describes the development of an active clamping mechanism to be integrated into a swallowable pill for the diagnosis of the gastrointestinal (GI) tract. The clamping system allows us to stop the pill at desired sites of the GI tract for long monitoring purposes. After discussing the major technical constraints, the design of the core component, i.e. the gripper, based on FEA (finite element analysis), is illustrated as well as its fabrication process. Symmetric and asymmetric gripper designs are described. The actuation is provided by shape memory alloys (SMA), and it is driven by a dedicated electrical interface. Then the working prototypes have been tested <I>in vitro</I>: for both kinds of grippers a pull-back force up to 0.6 N has been measured. A preliminary theoretical model for the gripper has been derived and compared to the experimental results.</P>
Regulation of photosystem I light harvesting by zeaxanthin
Ballottari, Matteo,Alcocer, Marcelo J. P.,D’Andrea, Cosimo,Viola, Daniele,Ahn, Tae Kyu,Petrozza, Annamaria,Polli, Dario,Fleming, Graham R.,Cerullo, Giulio,Bassi, Roberto National Academy of Sciences 2014 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.111 No.23
<P>In oxygenic photosynthetic eukaryotes, the hydroxylated carotenoid zeaxanthin is produced from preexisting violaxanthin upon exposure to excess light conditions. Zeaxanthin binding to components of the photosystem II (PSII) antenna system has been investigated thoroughly and shown to help in the dissipation of excess chlorophyll-excited states and scavenging of oxygen radicals. However, the functional consequences of the accumulation of the light-harvesting complex I (LHCI) proteins in the photosystem I (PSI) antenna have remained unclarified so far. In this work we investigated the effect of zeaxanthin binding on photoprotection of PSI–LHCI by comparing preparations isolated from wild-type <I>Arabidopsis thaliana</I> (i.e., with violaxanthin) and those isolated from the <I>A</I>. <I>thaliana</I> nonphotochemical quenching 2 mutant, in which violaxanthin is replaced by zeaxanthin. Time-resolved fluorescence measurements showed that zeaxanthin binding leads to a previously unrecognized quenching effect on PSI–LHCI fluorescence. The efficiency of energy transfer from the LHCI moiety of the complex to the PSI reaction center was down-regulated, and an enhanced PSI resistance to photoinhibition was observed both in vitro and in vivo. Thus, zeaxanthin was shown to be effective in inducing dissipative states in PSI, similar to its well-known effect on PSII. We propose that, upon acclimation to high light, PSI–LHCI changes its light-harvesting efficiency by a zeaxanthin-dependent quenching of the absorbed excitation energy, whereas in PSII the stoichiometry of LHC antenna proteins per reaction center is reduced directly.</P>
A New Mechanism for Mesoscale Legged Locomotion in Compliant Tubular Environments
Valdastri, P.,Webster, R.J.,Quaglia, C.,Quirini, M.,Menciassi, A.,Dario, P. IEEE 2009 IEEE Transactions on Robotics Vol.25 No.5
<P>We present design and experimental performance results for a novel mechanism for robotic legged locomotion at the mesoscale (from hundreds of microns to tens of centimeters). The new mechanism is compact and strikes a balance between conflicting design objectives, exhibiting high foot forces and low power consumption. It enables a small robot to traverse a compliant, slippery, tubular environment, even while climbing against gravity. This mechanism is useful for many mesoscale locomotion tasks, including endoscopic capsule robot locomotion in the gastrointestinal tract. It has enabled fabrication of the first legged endoscopic capsule robot whose mechanical components match the dimensions of commercial pill cameras (11 mm diameter by 25 mm long). A novel slot-follower mechanism driven via lead screw enables the mechanical components of the capsule robot to be as small while simultaneously generating 0.63 N average propulsive force at each leg tip. In this paper, we describe kinematic and static analyses of the lead screw and slot-follower mechanisms, optimization of design parameters, and experimental design and tuning of a gait suitable for locomotion. A series of <I>ex vivo</I> experiments demonstrate capsule performance and ability to traverse the intestine in a manner suitable for inspection of the colon in a time period equivalent to standard colonoscopy.</P>
M,J,Johnson,G,A,Di Lauro,M,C,Carrozza,E,Gugllelmelli,P,Dario 한국과학기술원 인간친화 복지 로봇 시스템 연구센터 2003 International Journal of Assistive Robotics and Me Vol.4 No.1
To reduce the potential healthcare costs arising from a rapidly aging industrial world population, the problem of sustaining independent living for the elderly and persons with low to high levels of disabilities must be addressed. Using the kitchen as a microcosmic design space for the residential environment, the proposed design solution is the development of the GIVING-A-HAND system, a low cost, modular system of aids that relies on domotic, telematic, and robotic technologies to provide more affordable and universally accessible solutions to elderly and disabled persons. This paper presents the system concept and the results of interviews with elderly and people with medium to high level functional disabilities, which prioritized and refined requirements for the robotic component of the system: a small, counter-top mobile robot, “Addams Hand” that users can remotely control to interact with typical kitchen appliances.
M. Zecca,G. Cappiello,F. Sebastiani,S. Roccella,F. Vecchi,M. C. Carrozza,P. Dario 한국과학기술원 인간친화 복지 로봇 시스템 연구센터 2003 International Journal of Assistive Robotics and Me Vol.4 No.4
The development of a prosthetic hand able to replicate as much as possible the grasping and sensory features of the natural hand represents an ambitious project for scientists. State of the art technology is still far to provide engineers with components with similar performance of their natural models, and active prosthetic hands can be only a pale replication of the missing natural limb. <BR>This paper presents the current research efforts towards the development of a self-adaptative and anthropomorphic prosthetic hand. In particular, the paper is focused on the problem of replicating the natural sensory system of the hand with an artificial proprioceptive and exteroceptive sensory system.