13 research outputs found
Low-complexity framework for movement classification using body-worn sensors
No full textWe present a low-complexity framework for classifying elementary arm-movements (reach-retrieve, lift-cup-to-mouth, rotate-arm) using wrist-worn, inertial sensors. We propose that this methodology could be used as a clinical tool to assess rehabilitation progress in neurodegenerative pathologies tracking occurrence of specific movements performed by patients with their paretic arm. Movements performed in a controlled training-phase are processed to form unique clusters in a multi-dimensional feature-space. Subsequent movements performed in an uncontrolled testing-phase are associated to the proximal cluster using a minimum distance classifier (MDC). The framework involves performing the compute-intensive clustering on the training-dataset offline (Matlab) whereas the computation of selected features on the testing-dataset and the minimum distance (Euclidean) from pre-computed cluster centroids are done in hardware with an aim of low-power execution on sensor nodes.The architecture for feature-extraction and MDC are realized using Coordinate Rotation Digital Computer based design which classifies a movement in (9n+31) clock cycles, n being number of data samples. The design synthesized in STMicroelectronics 130nm technology consumed 5.3 nW @50 HZ, besides being functionally verified upto 20 MHz, making it applicable for real-time high-speed operations. Our experimental results show that the system can recognize all three arm-movements with average accuracies of 86% and 72% for four healthy subjects using accelerometer and gyroscope data respectively, whereas for stroke survivors the average accuracies were 67% and 60%. The framework was further demonstrated as a FPGA-based real-time system, interfacing with a streaming sensor unit
Recognition of elementary arm movements using orientation of a tri-axial accelerometer located near the wrist
No full textIn this paper we present a method for recognising three fundamental movements of the human arm (reach and retrieve, lift cup to mouth, rotation of the arm) by determining the orientation of a tri-axial accelerometer located near the wrist. Our objective is to detect the occurrence of such movements performed with the impaired arm of a stroke patient during normal daily activities as a means to assess their rehabilitation. The method relies on accurately mapping transitions of predefined, standard orientations of the accelerometer to corresponding elementary arm movements. To evaluate the technique, kinematic data was collected from four healthy subjects and four stroke patients as they performed a number of activities involved in a representative activity of daily living, 'making-a-cup-of-tea'. Our experimental results show that the proposed method can independently recognise all three of the elementary upper limb movements investigated with accuracies in the range 91–99% for healthy subjects and 70–85% for stroke patients
Tratamiento quirúrgico de la endometriosis . Consideraciones técnicas. Nuestro concepto
No full textThe author supports the conservative surgery in the genital endometriosis. Is, however, some difficulties in practice that rarely diagnosed preoperatively is associated with injuries requiring a greater resection or is diagnosed in women above the fourth decade of life. The possibilities of conservative surgery in endometriosis are: conserving surgery generative function, resection of uterine endometriosis, ovarian and partial resection or oophorectomy unillaterales salpingectomy, etc. Menstruo conservative surgery, indicated exclusively internal endometriosis, hysterectomy with Achner fundic, partial amputations and histeromiometrectomía. Conservative surgery of endocrine function, internal endometriosis heritage, with preservation of gonads. Study the possibilities of hormone therapy as an adjunct to conservative surgery but with residual lesions, using progestin.El autor apoya la cirugía conservadora en la endometriosis genital. Encuentra, sin embargo, algunas dificultades en su práctica por el hecho de que con poca frecuencia se diagnostica pre-operatoriamente, se asocia con lesiones que obligan a, una mayor exéresis o se diagnostica en mujeres por encima del cuarto decenio de la vida. Las posibilidades de la cirugía conservadora en la endometriosis son: Cirugía conservadora de la función generativa, con resecciones de endometriosis uterinas, resección parcial de ovarios y ooforectomía o salpingectomías unillaterales, etc. Cirugía menstruo conservadora, de indicación exclusiva en la endometriosis interna, con la histerectomía fúndica de Achner, las amputaciones parciales y la histeromiometrectomía. La cirugía conservadora de la función endocrina, patrimonio de la endometriosis interna, con conservación de gonadas. Estudio las posibilidades de la terapia hormonal como complemento de una cirugía conservadora pero con lesiones residuales, aprovechando los gestágenos
Detecting elementary arm movements by tracking upper limb joint angles with MARG sensors
No full textThis paper reports an algorithm for the detection of three elementary upper limb movements, i.e., reach and retrieve, bend the arm at the elbow and rotation of the arm about the long axis. We employ two MARG sensors, attached at the elbow and wrist, from which the kinematic properties (joint angles, position) of the upper arm and forearm are calculated through data fusion using a quaternion-based gradient-descent method and a two-link model of the upper limb. By studying the kinematic patterns of the three movements on a small dataset, we derive discriminative features that are indicative of each movement; these are then used to formulate the proposed detection algorithm. Our novel approach of employing the joint angles and position to discriminate the three fundamental movements was evaluated in a series of experiments with 22 volunteers who participated in the study: 18 healthy subjects and four stroke survivors. In a controlled experiment, each volunteer was instructed to perform each movement a number of times. This was complimented by a seminaturalistic experiment where the volunteers performed the same movements as subtasks of an activity that emulated the preparation of a cup of tea. In the stroke survivors group, the overall detection accuracy for all three movements was 93.75% and 83.00%, for the controlled and seminaturalistic experiment, respectively. The performance was higher in the healthy group where 96.85% of the tasks in the controlled experiment and 89.69% in the seminaturalistic were detected correctly. Finally, the detection ratio remains close (±6%) to the average value, for different task durations further attesting to the algorithms robustness
Auswirkungen des DRG-Katalogs 2004 auf die Eingruppierung der Stroke-Unit- und Schlaganfallbehandlung
No full textAnforderungsanalyse für die nutzergerechte Gestaltung eines Bedienkonzepts für robotergestützte Telerehabilitationssysteme in der motorischen Schlaganfallrehabilitation
No full textS.125-132Die motorische Rehabilitationsbehandlung nach Schlaganfall ist sehr langwierig, eine Fortsetzung der Übungstherapiebehandlung nach Entlassung aus der Rehaklinik ist daher für jeden Patienten von großer Bedeutung für einen dauerhaften und nachhaltigen Therapieerfolg. Mangels geeigneter Möglichkeiten der häuslichen Therapiedurchführung und -unterstützung von Patienten, bestehen hierbei in der Praxis große Defizite. Eine Möglichkeit der Verbesserung dieser Situation bietet ein Telerehabilitationssystem. Dabei spielt ein intuitives Bedienkonzept, welches für den Patienten leicht verständlich und zugänglich ist, eine wichtige Rolle. In diesem Beitrag werden die Ergebnisse der therapeutischen Anforderungsanalyse an das multimodale robotergestützte System für motorische Rehabilitation nach Schlaganfall in häuslicher Umgebung dargestellt
Let's do this together: Bi-Manu-Interact, a novel device for studying human haptic interactive behavior
No full textS.708-713Our area of interest is robotic-based rehabilitation after stroke, and our goal is to help patients achieve optimal motor learning during high-intensity repetitive movement training through the assistance of robots. It is important, that the robotic assistance is adapted to the patients' abilities, thereby ensuring that the device is only supporting the patient as necessary ('assist-as-needed'). We hypothesize that natural and learning-effective human-machine interaction can be achieved by programming the robot's control, so that it emulates how a physiotherapist adaptively supports the patients' limb movement during stroke rehabilitation. This paper introduces the design of a novel interactive device Bi-Manu-Interact. This device is suited to be used as an experimental setup for the investigation of haptic human-human interaction and for collecting data to model therapists' haptic behavior. In this paper, we present mechanical and sensory specifications as well as task s visualizations for future investigations. Results of a pilot clinical evaluation of the Bi-Manu-Interact with nine stroke patients are also presented in this work
Interatomic resonant Auger effect in NO
No full textThe interatomic resonant Auger effect in NO is investigated experimentally and theoretically. We observe variations of the ratio between the yields of 1s-photoionization of the central and terminal nitrogen atom in the photon energy range across the O 1s → π* excitation. The present ab initio calculations of electronic structure and dynamics attribute these variations to the Fano interference between the direct N 1s-photoionizations and the resonant O 1s → π* excitation followed by Auger decays into the respective core–shell continua. The theory reveals that this interatomic core–hole-transfer effect is governed entirely by an energy transfer mechanism, and not by charge transfer
The anti-atherosclerotic effect of chronic AT1 receptor blocker treatment also depends on the ACE2/Ang(1-7)/Mas axis
No full textBlockade of AT(1)-receptors by telmisartan (TEL) has anti-atherosclerotic efficacy. We investigated to what extent the ACE2/Ang1–7/Mas axis-dependent mechanism contributes to the TEL-induced protection of endothelial function. Atherosclerosis was induced in C57BL/6 N, Mas-knock out (ko), and Ace2-ko mice by AAV-PCSK9(DY) (2 ×10(11) VG) injections plus Western diet (WD) feeding (12w). Mice were treated (12w) with TEL or vehicle. Controls received no PCSK9(DY), chow-feeding, and vehicle-treatment. In the aortae of mice, the plaque burden was determined, RNAseq analyses were performed and functional properties were assessed by quantifying the mechanical properties of the endothelial surface by Atomic Force Microscopy. Regardless of strain, plaque burden and total cholesterol were increased upon AAV-PCSK9(DY)+WD but decreased by TEL. Cortical stiffness was also enhanced in all strains by AAV-PCSK9(DY)+WD but reduced under TEL only in the C57BL/6 N, while remaining still high in both knockout strains. Plasma NO negatively correlated with cortical stiffness in C57BL/6 N, but not in transgenic mice. TNFα plasma levels and aortic MMP12 expression was increased in PCSK9(DY)/WD vehicle-treated controls and was normalized by TEL in C57BL/6 N but not in Mas-ko and Ace2-ko mice. We conclude that TEL-induced reduction of endothelial stiffness occurred only in the C57BL/6 N but not in the Mas-ko and Ace2-ko mice. We suggest that the protective TEL effect is partly due to an Ang(1−7)/ACE2/Mas axis mediated mechanism. Since Mmp12 has well-known proatherogenic properties but was not altered in the two transgenic mouse lines, follow-up studies are required to further elucidate the correlation between Mmp12 and the Ang(1−7)/ACE2/Mas axis with respect to atherosclerosis
Accurate prediction of X-ray pulse properties from a free-electron laser using machine learning
No full textFree-electron lasers providing ultra-short high-brightness pulses of X-ray radiation have great potential for a wide impact on science, and are a critical element for unravelling the structural dynamics of matter. To fully harness this potential, we must accurately know the X-ray properties: intensity, spectrum and temporal profile. Owing to the inherent fluctuations in free-electron lasers, this mandates a full characterization of the properties for each and every pulse. While diagnostics of these properties exist, they are often invasive and many cannot operate at a high-repetition rate. Here, we present a technique for circumventing this limitation. Employing a machine learning strategy, we can accurately predict X-ray properties for every shot using only parameters that are easily recorded at high-repetition rate, by training a model on a small set of fully diagnosed pulses. This opens the door to fully realizing the promise of next-generation high-repetition rate X-ray lasers
