No description available.

Essential Tremor (ET), a condition characterized by postural and kinetic tremor in the upper limbs, is one of the most prevalent movement disorders. While pharmaceutical and surgical treatment options exist, they are not ideal. Assistive devices have the potential to provide relief to patients but are largely unexplored for ET. Furthermore, prior characterizations of essential tremor have focused on endpoint tremor and provide insufficient detail for designing such a device. We propose and demonstrate a novel method for characterizing essential tremor in the 7 proximal degrees of freedom (DOF) of the upper limb in various postures. In addition, we provide a preliminary characterization in a small number of patients with mild ET. We collected data from 10 patients with ET. Subjects were instrumented with four electromagnetic sensors that recorded orientation of upper limb segments. After a calibration, each subject positioned his/her upper limb in 16 different postures for 15 seconds each. This procedure was repeated 4 times for each subject, with each repetition being considered a run. Sensor data were converted to angular kinematic data for each DOF using inverse kinematics, a practice unique to this study. These data were then analyzed in the frequency domain to calculate the power associated with the tremor in each DOF and posture. More specifically, we computed the area of the periodogram over the 4-12 Hz frequency band typically associated with ET [narrow-band area (NBA)] and over the wider frequency band from 2 Hz to the Nyquist frequency [wide-band area (WBA)]. If significant peaks were found in the 4-12 Hz band, their frequency and amplitude were reported. Mixed-model ANOVA tests were used to investigate effects of DOF, posture, run, gravity, and patient characteristics on reported measures. NBA and WBA varied significantly between DOF, being lowest in the wrist, intermediate in the shoulder, and greatest in the elbow and forearm (pronation-supination). NBA and WBA also varied significantly with posture. Only 5% of observations had significant peaks, with 49% of peaks occurring in wrist flexion-extension and 39% occurring in wrist radial-ulnar deviation. Peak frequency was quite stereotyped (5.7 Hz ± 1.3Hz). Run had no significant effects, indicating that tremor measures were consistent over the duration of the experiment. Effects of gravity and demographic factors on measures were mixed and did not present a discernible pattern. This preliminary characterization suggests that tremor may be focused in a subset of upper limb DOF, being greatest (in terms of power) in elbow flexion-extension and forearm pronation-supination, and most concentrated (with peaks at a stereotyped frequency) in wrist flexion-extension and radial-ulnar deviation. Our method of 7 DOF characterization through inverse kinematics, in conjunction with future research (isolation studies, EMG, and finger DOF) may allow for optimal tremor suppression by an orthosis.

No description available.

No description available.

No description available.

No description available.

Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2018-11-09T12:49:49Z No. of bitstreams: 1 Luiz Ricardo Bertoldi de Oliveira_.pdf: 1661331 bytes, checksum: f12138d995d58da8ed2a061c78f62d58 (MD5) / Made available in DSpace on 2018-11-09T12:49:49Z (GMT). No. of bitstreams: 1 Luiz Ricardo Bertoldi de Oliveira_.pdf: 1661331 bytes, checksum: f12138d995d58da8ed2a061c78f62d58 (MD5) Previous issue date: 2018-07-19 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A simulação de figuras articuladas em computação gráfica que representam animais, pessoas ou robôs, normalmente, são compostas por uma cadeia de segmentos rígidos conectados por juntas dispostas de maneira hierárquica. Quando estas figuras possuem muitos segmentos, e precisam ser animadas por cinemática inversa, sua configuração de movimento pode apresentar múltiplas soluções ou soluções não-lineares além de singularidades de movimento. Este trabalho propõe uma nova topologia de juntas de hierarquia variável , generalista o suficiente para se aplicar a qualquer modelo articulado. Além disto, propõe um algoritmo de cinemática inversa que supra a não-linearidade dos modelos propostos até o momento. Um modelo como este, formaliza a animação de figuras articuladas que não precisam ter uma hierarquia de juntas rígida ou que possuam muitas juntas e segmentos. Para validação do modelo foi usada a Distância de Hausdorff para cálculo da similaridade do end-effector e um conjunto de pontos ideais com uma precisão 91.23%. O movimento foi suavizado em comparação a outros modelos por meio da minimização de 8,7% nos ângulos nas juntas. / The simulation of articulated figures in computer graphics that represents animals, people or robots is usually composed of a chain of rigid segments connected by joints arranged in a hierarchical way. When these figures have many segments and need to be animated by inverse kinematics, their motion configuration may present multiple solutions or nonlinear solutions and motion singularities. This work proposes a new topology of joints of a variable hierarchy, general enough to apply to any articulated model. In addition, it proposes an inverse kinematics algorithm to supply the non linearity of the models already proposed A model like this generalizes the animation of articulated figures because it do not need to have a rigid joints topology and works to figures with many joints and segments. Hausdorff Distance was used to calculate the end-effector similarity with an ideal set of points. The accuracy achieved is 91,23% of similarity. Motion of all joints is smoother when compared to other models by minimizing 8,7% of the angles.

Baigiamajame magistro darbe nagrinėjamas šešiakojo roboto judėjimas. Pateikiami vienos kojos atvirkštinės kinematikos uždavinio sprendimai Denavito ir Hartenbergo bei geometriniu metodais. Analizuojamas vienos kojos trajektorijos sudarymo metodas ir pateikiams jos aprašymo būdas. Pateikiami galimi trajektorijų pavyzdžiai. Sudaroma trikojės roboto eisenos seka bei diagrama. Darbe pateikiamas roboto valdymo algoritmas ir valdymo programa, atsižvelgiant į apibrėžtus variklių valdymo kriterijus. Eksperimentiškai tiriamas roboto judėjimas lygiu paviršiumi taikant trikoję eiseną. Pagal rezultatus koreguojama eisena. Atliekami trajektorijos pakartojimo tikslumo bandymai. Įvertinus rezultatus pateikiamos baigiamojo darbo išvados ir pasiūlymai. / Hexapod robot locomotion is analyzed in this paper. Inverse kinematics solutions are proposed for one leg using Denavit-Hartenberg and geometric methods. Trajectory forming for one leg is analyzed and solution for delineating trajectory is introduced. Possible leg trajectory examples are presented. Tripod gait sequence and diagram is designed for robot. Work presents robot control algorithm and program according to motor control parameters. Robot locomotion over regular terrain using tripod gait is tested. Gait then is corrected according to test results. Tests are made for trajectory repeating accuracy. Conclusions and solutions are made according to results.

<p>Nuclear magnetic resonance (NMR) spectroscopy is an established technique for macromolecular structure determination at atomic resolution. However, the majority of the current structure determination approaches require a large set of experiments and use large amount of data to elucidate the three dimensional protein structure. While current structure determination protocols may perform well in data-rich settings, protein structure determination still remains to be a difficult task in a sparse-data setting. Sparse data arises in high-throughput settings, for larger proteins, membrane proteins, and symmetric protein complexes; thereby requiring novel algorithms that can compute structures with provable guarantees on solution quality and running time.</p><p>In this dissertation project we made an effort to address the key computational bottlenecks in NMR structural biology. Specifically, we improved and extended the recently-developed techniques by our laboratory, and developed novel algorithms and computational tools that will enable protein structure determination from sparse NMR data. An underlying goal of our project was to minimize the number of NMR experiments, hence the amount of time and cost to perform them, and still be able to determine protein structures accurately from a limited set of experimental data. The algorithms developed in this dissertation use the global orientational restraints from residual dipolar coupling (RDC) and residual chemical shift anisotropy (RCSA) data from solution NMR, in addition to a sparse set of distance restraints from nuclear Overhauser effect (NOE) and paramagnetic relaxation enhancement (PRE) measurements. We have used tools from algebraic geometry to derive analytic expressions for the bond vector and peptide plane orientations, by exploiting the mathematical interplay between RDC- or RCSA-derived sphero-conics and protein kinematics, which in addition to improving our understanding of the geometry of the restraints from these experimental data, have been used by our algorithms to compute the protein structures provably accurately. Our algorithms, which determine protein backbone global fold from sparse NMR data, were used in the high-resolution structure determination protocol developed in our laboratory to solve the solution NMR structures of the FF Domain 2 of human transcription elongation factor CA150 (RNA polymerase II C-terminal domain interacting protein), which have been deposited into the Protein Data Bank. We have developed a novel, sparse data, RDC-based algorithm to compute ensembles of protein loop conformations in the presence of a moderate level of dynamics in the loop regions. All the algorithms developed in this dissertation have been tested on experimental NMR data. The promising results obtained by our algorithms suggest that our algorithms can be successfully applied to determine high-quality protein backbone structures from a limited amount of experimental NMR data, and hence will be useful in automated NOE assignments and high-resolution protein backbone structure determination from sparse NMR data. The algorithms and the software tools developed during this project are made available as free open-source to the scientific community.</p> / Dissertation

This thesis analyzes the kinematical structure of Puma 760 arm and introduces the implementation of image based pick and place application by taking care of the obstacles in the environment. Forward and inverse kinematical solutions of PUMA 760 are carried out. A control software has been developed to calculate both the forward and inverse kinematics solution of this manipulator. The control program enables user to perform both offline programming and real time realization by transmitting the VAL commands (Variable Assembly Language) to the control computer. Using the proposed inverse kinematics solutions, an interactive application is generated on PUMA 760 arm. The picture of the workspace is taken using a fixed camera attached above the robot workspace. The captured image is then processed to find the position and the distribution of all objects in the workspace. The target is differentiated from the obstacles by analyzing some specific properties of all objects, i.e. roundness. After determining the configuration of the workspace, a clustering based search algorithm is executed to find a path to pick the target object and places it to the desired place. The trajectory points in pixel coordinates, are mapped into the robot workspace coordinates by using the camera calibration matrix obtained in the calibration procedure of the robot arm with respect to the attached camera. The required joint angles, to get the end effector of the robot arm to the desired location, are calculated using the Jacobian type inverse kinematics algorithm. The VAL commands are generated and sent to the control computer of PUMA 760 to pick the object and places it to a user defined location.