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481 results on '"Dosen, Strahinja"'

103. Statistical Characterization of Closed-Loop Latency at the Mobile Edge

Author

Suman, Suraj, Chiariotti, Federico, Stefanovic, Cedomir, Dosen, Strahinja, and Popovski, Petar

Abstract

The stringent timing and reliability requirements in mission-critical applications require a detailed statistical characterization of end-to-end latency. Teleoperation is a representative use case, in which a human operator (HO) remotely controls a robot by exchanging command and feedback signals. We present a framework to analyze the latency of a closed-loop teleoperation system consisting of three entities: an HO, a robot located in remote environment, and a Base Station (BS) with Mobile edge Computing (MEC) capabilities. A model of each component is used to analyze the closed-loop latency and optimize the compression strategy. The closed-form expression of the distribution of the closed-loop latency is difficult to estimate, such that suitable upper and lower bounds are obtained. We formulate a non-convex optimization problem to minimize the closed-loop latency. Using the obtained upper and lower bound on the closed-loop latency, a computationally efficient procedure to optimize the closed-loop latency is presented. The simulation results reveal that compression of sensing data is not always beneficial, while system design based on average performance leads to under-provisioning and may cause performance degradation. The applicability of the proposed analysis is much wider than teleoperation, including a large class of systems whose latency budget consists of many components.

Published
2023
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104. Moving-window dynamic optimization: design of stimulation profiles for walking

Author

Dosen, Strahinja and Popovic, Dejan B.

Subjects
Algorithms -- Usage, Mathematical optimization -- Research, Gait -- Physiological aspects, Walking -- Physiological aspects, Electric stimulation -- Methods, Algorithm, Biological sciences, Business, Computers, Health care industry
Abstract

The overall goal of the research is to improve control for electrical stimulation-based assistance of walking in hemiplegic individuals. We present the simulation for generating offline input (sensors) output (intensity of muscle stimulation) representation of walking that serves in synthesizing a rule-base for control of electrical stimulation for restoration of walking. The simulation uses new algorithm termed moving-window dynamic optimization (MWDO). The optimization criterion was to minimize the sum of the squares of tracking errors from desired trajectories with the penalty function on the total muscle efforts. The MWDO was developed in the MATLAB environment and tested using target trajectories characteristic for slow-to-normal walking recorded in healthy individual and a model with the parameters characterizing the potential hemiplegic user. The outputs of the simulation are piecewise constant intensities of electrical stimulation and trajectories generated when the calculated stimulation is applied to the model. We demonstrated the importance of this simulation by showing the outputs for healthy and hemiplegic individuals, using the same target trajectories. Results of the simulation show that the MWDO is an efficient tool for analyzing achievable trajectories and for determining the stimulation profiles that need to be delivered for good tracking. Index Terms--Biomechanical modeling, functional electrical stimulation (FES), gait restoration, optimal control.

Published
2009

107. Accelerometers and force sensing resistors for optimal control of walking of a hemiplegic

Author

Dosen, Strahinja and Popovic, Dejan B.

Subjects
Resistors -- Usage, Neural networks -- Design and construction, Neural stimulation -- Methods, Gait -- Control, Machine learning -- Research, Hemiplegia -- Care and treatment, Accelerometers -- Usage, Resistor, Neural network, Biological sciences, Business, Computers, Health care industry
Abstract

We developed a method for use of accelerometers and force sensing resistors (FSRs) within an optimal controller of walking for hemiplegic individuals. The data from four dual-axis accelerometers and four FSRs were inputs, while six muscle activation profiles were outputs. The controller includes two stages: 1) estimating the target gait pattern using artificial neural networks; and 2) optimal control minimizing tracking errors (from the estimated gait pattern) and muscle efforts. The controller was tested using data collected from six healthy subjects walking at five speeds (0.6-1.4 m/s). The average root mean square errors (RMSEs) normalized by the peak-to-peak value of the target signals [normalized RMSE (NRMSE)] were below 6%, 7%, 8%, and 3% for estimation of joint angles, hip acceleration, ground reaction force, and movement of the center of pressure, respectively. Using the estimated data as inputs, the simulation generated the target healthy-like gait patterns and reproducible muscle activation profiles in 90% of 300 tested gait trials. Overall tracking NRMSE was between 2% and 9%. The optimal controller was developed for testing the feasibility of healthy-like gait patterns in hemiplegic individuals, and generating a knowledge base that is required for the synthesis of a sensory-driven control of walking assisted by functional electrical stimulation. Index Terms--Artificial neural networks (ANNs), functional electrical stimulation (FES), gait, machine learning, optimal control, sensory system.

Published
2008

108. Soft Active Hand Orthosis

Author

Abdelhafiz, Mohamed, Struijk, Lotte Najanguaq Søvsø Andreasen, Dosen, Strahinja, and Spaich, Erika Geraldina

Subjects
body regions, equipment and supplies, musculoskeletal system
Abstract

The invention relates to a hand orthosis (1) for assisting the movements of a user's hand. The hand orthosis comprises a soft glove (2) adapted to receive at least a part of the user's hand with finger sections of the glove receiving each of the user's fingers. It further comprises at least one actuator box (3), and a power transmission (4) for transferring forces from the at least one actuator box to different parts of the glove via exo-tendons (5). The exo-tendons are arranged on a dorsal side, on a palmar side, or on both a dorsal side and a palmar side of the glove. The exo-tendons are arranged so that the glove can assist flexion, extension, or both extension and flexion of the fingers, respectively and so that the exo-tendons act on the fingers to produce motion that mimics the movement of a human hand. The hand orthosis provides different grasp types, self- adaptation of the fingers' motion to the shape of the object, and physiologically appropriate distribution of finger forces.

Published
2020

109. Introduction to EU-H2020 project WEARPLEX:wearable multiplexed biomedical electrodes - alpha results

Author

Torah, Russel, Komolafe, Abiodun, Beeby, Steve, Kostic, Milos, Strbac, Matija, Keller, Thierry, Perinka, Nikola, Lanceros-Mendez, Senentxu, Ersman, Peter Andersson, Mulla, Yusuf, Polomoshnov, Maxim, Murciego, Luis Pelaez, Dosen, Strahinja, Spaich, Erika G., Wendelbo, Rune, Motealleh, Azadeh, Chardonnens, Severine, Junker, Katja, Isotalo, Jenni, Aalpoel, Roelof, and Tauriainen, Antti

Published
2020

123. Introduction to EU-H2020 project WEARPLEX: wearable multiplexed biomedical electrodes

Author

Torah, Russel, Beeby, Stephen, Kostic, Milos, Keller, Thierry, Lanceros-Mendez, Senentxu, Andersson Ersman, Peter, Zillger, Tino, Dosen, Strahinja, Wendelbo, Rune, Chardonnens, Severine, and Tauriainen, Antti

Abstract

WEARPLEX is a multidisciplinary research and innovation action with the overall aim to integrate printed electronics with flexible and wearable textile-based biomedical multi-pad electrodes. It aims to answer the growing need for user-friendly electrodes for pervasive measurement of electrophysiological signals and application of electrical stimulation. It focuses on the development of the printable electronics and manufacturing processes for stretchable textile based multi-pad electrodes with integrated logic circuits that enable a significant increase in the number of electrode pads (channels) and facilitate the creation of new products in the sectors of medical electronics and life-style. The advanced printed electronics integrated in WEARPLEX electrodes will allow the individual pads to be connected in arbitrary configurations to the output leads of the electrode. Therefore, the pads will be flexibly organized into several virtual electrodes of arbitrary position, shape and size that can be connected to any standard multi-channel recording and stimulation system. In addition, software methods will be developed for automatic calibration of these virtual electrodes, to detect stimulation/recording hotspots and adjust the virtual electrodes accordingly. Therefore, the WEARPLEX project will lead to a new generation of smart electrodes that will be able to adapt simultaneously to the user (wearable and stretchable garment), recording/stimulation scenario (movement type and target muscles) and recording/stimulation system (number of channels). This is a paradigm shift in designing the recording and stimulation systems, as the switching electronics is shifted from the custom-made stimulator/recording device to the smart electrode, leading to a universal solution compatible with any system. WEARPLEX is funded under the EU Horizon2020 call ICT-02-2018, the work program is over 3 years starting on the 1st of January 2019; this abstract is therefore an opportunity to introduce the project to the community and discuss research directions and early results for the project. The individual components of the project are at TRL2-4 with the goal of improving and combining them to achieve TRL6-7 industrial demonstrators by the end of the project.

Published
2019

125. Brain-state dependent peripheral nerve stimulation for plasticity induction targeting upper-limb

Author

Mrachacz-Kersting, Natalie, Dosen, Strahinja, Aliakbaryhosseinabadi, Susan, Pereira, Esther M., Stevenson, Andrew James Thomas, Jiang, Ning, Farina, Dario, Masia, Lorenzo, Micera, Silvestro, Akay, Metin, and Pons, José L.

Abstract

Brain-computer interfaces have increasingly found applications within the rehabilitation of lost motor function in stroke patients. Most studies have targeted upper limb muscles and used sensorimotor rhythms as the control signal. In a series of studies, we have introduced an associative BCI modeled on known theories of memory and learning that implements the movement related cortical potential (MRCP) as a way to control an external device that provides afferent generated feedback to the user’s brain at the time of the peak negative phase of the MRCP. In its application to lower limb muscles it demonstrates significant plasticity induction that requires no user training. In the current study, we tested if this associative BCI is effective when targeting upper limb muscles. Further, we explored if there is a difference when the MRCP is gen- erated as part of a simple (wrist extension) versus a complex (reach and grasp) movement.

Published
2019
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127. Feel-Good Robotics: Requirements on Touch for Embodiment in Assistive Robotics

Author

Beckerle, Philipp, Kõiva, Risto, Kirchner, Elsa Andrea, Bekrater-Bodmann, Robin, Dosen, Strahinja, Christ, Oliver, Abbink, David A., Castellini, Claudio, Lenggenhager, Bigna, Beckerle, Philipp, Kõiva, Risto, Kirchner, Elsa Andrea, Bekrater-Bodmann, Robin, Dosen, Strahinja, Christ, Oliver, Abbink, David A., Castellini, Claudio, and Lenggenhager, Bigna

Abstract

The feeling of embodiment, i.e., experiencing the body as belonging to oneself and being able to integrate objects into one’s bodily self-representation, is a key aspect of human self-consciousness and has been shown to importantly shape human cognition. An extension of such feelings toward robots has been argued as being crucial for assistive technologies aiming at restoring, extending, or simulating sensorimotor functions. Empirical and theoretical work illustrates the importance of sensory feedback for the feeling of embodiment and also immersion; we focus on the the perceptual level of touch and the role of tactile feedback in various assistive robotic devices. We critically review how different facets of tactile perception in humans, i.e., affective, social, and self-touch, might influence embodiment. This is particularly important as current assistive robotic devices – such as prostheses, orthoses, exoskeletons, and devices for teleoperation–often limit touch low-density and spatially constrained haptic feedback, i.e., the mere touch sensation linked to an action. Here, we analyze, discuss, and propose how and to what degree tactile feedback might increase the embodiment of certain robotic devices, e.g., prostheses, and the feeling of immersion in human-robot interaction, e.g., in teleoperation. Based on recent findings from cognitive psychology on interactive processes between touch and embodiment, we discuss technical solutions for specific applications, which might be used to enhance embodiment, and facilitate the study of how embodiment might alter human-robot interactions. We postulate that high-density and large surface sensing and stimulation are required to foster embodiment of such assistive devices.

Published
2019

128. Improving bimanual interactions between myoelectric prosthesis and sound limb

Author

Volkmar, Robin, Markovic, Marko, and Dosen, Strahinja

Subjects
myocontrol, myoelectric prosthesis, semi-autonomous, wearable system, hand prosthesis, ddc: 610, assistive system, electromyographie, 610 Medical sciences, Medicine, prosthetics, IMU-based, robotic hand
Abstract

Objectives: The loss of a hand is a traumatizing experience that can comprise an individual capability to interact intuitively with his environment. The state-of-the-art (SoA) functional replacement for the lost limbs are myoelectric prostheses. Their overall mechanical design and dexterity have improved[for full text, please go to the a.m. URL], Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2018)

Published
2018

129. Decoding Phantom Limb Neuro-Mechanical Function for a New Paradigm of Mind-Controlled Bionic Limbs

Author

Sartori, Massimo, Durandau, Guillaume, Dosen, Strahinja, Farina, Dario, Masia, Lorenzo, Micera, Silvestro, Akay, Metin, and Pons, Jose L.

Subjects
Alternative methods, Bionics, medicine.diagnostic_test, Computer science, media_common.quotation_subject, Phantom limb, Control engineering, Electromyography, Kinematics, medicine.disease, Robustness (computer science), medicine, Function (engineering), Decoding methods, media_common
Abstract

Mind controlled bionic limbs promise to replace mechanical function of lost biological extremities and restore amputees’ motor capacity. State of the art approaches use machine learning for establishing a mapping function between electromyography (EMG) and joint kinematics. However, current approaches require frequent recalibration with lack of robustness, thus providing control paradigms that are sensitive to external conditions. This paper presents an alternative method based on the authors’ recent findings. That is, a biomimetic decoder comprising a computational model that explicitly synthesizes the dynamics of the musculoskeletal system as controlled by EMG-derived neural activation signals.

Published
2018
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130. Psychophysical Evaluation of Subdermal Electrical Stimulation in Relation to Sensory Feedback

Author

Geng, Bo, Dong, Jian, Jensen, Winnie, Dosen, Strahinja, Farina, Darion, and Kamavuako, Ernest Nlandu

Subjects
sensory feedback, PROSTHESES, electrocutaneous stimulation, subdermal electrical stimulation
Abstract

This study systematically evaluated the perceptual properties of subdermal electrical stimulation to test its efficacy in providing sensory feedback for limb prostheses. The detection threshold (DT), pain threshold (PT), just noticeable difference (JND), as well as the elicited sensation quality, comfort, intensity and location were assessed in 16 healthy volunteers during stimulation of the ventral and dorsal forearm with subdermal electrodes. Moreover, the results were compared with those obtained from transcutaneous electrical stimulation. Despite a lower DT and PT, subdermal stimulation attained a greater relative dynamic range (i.e., PT/DT) and significantly smaller JNDs for stimulation amplitude. Muscle twitches and movements were more commonly elicited by surface stimulation, especially at the higher stimulation frequencies, whereas the pinprick sensation was more often reported with subdermal stimulation. Less comfort was perceived in subdermal stimulation of the ventral forearm at the highest tested stimulation frequency of 100 Hz. In summary, subdermal electrical stimulation was demonstrated to be able to produce similar sensation quality as transcutaneous stimulation and outperformed the latter in terms of energy efficiency and sensitivity. These results suggest that stimulation through implantable subdermal electrodes may lead to an efficient and compact sensory feedback system for substituting the lost sense in amputees.

Published
2018
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139. Feel-Good Robotics: Requirements on Touch for Embodiment in Assistive Robotics

Author

Beckerle, Philipp, Kõiva, Risto, Kirchner, Elsa Andrea, Bekrater-Bodmann, Robin, Dosen, Strahinja, Christ, Oliver, Abbink, David A., Castellini, Claudio, Lenggenhager, Bigna, Beckerle, Philipp, Kõiva, Risto, Kirchner, Elsa Andrea, Bekrater-Bodmann, Robin, Dosen, Strahinja, Christ, Oliver, Abbink, David A., Castellini, Claudio, and Lenggenhager, Bigna

Abstract

The feeling of embodiment, i.e., experiencing the body as belonging to oneself and being able to integrate objects into one’s bodily self-representation, is a key aspect of human self-consciousness and has been shown to importantly shape human cognition. An extension of such feelings toward robots has been argued as being crucial for assistive technologies aiming at restoring, extending, or simulating sensorimotor functions. Empirical and theoretical work illustrates the importance of sensory feedback for the feeling of embodiment and also immersion; we focus on the the perceptual level of touch and the role of tactile feedback in various assistive robotic devices. We critically review how different facets of tactile perception in humans, i.e., affective, social, and self-touch, might influence embodiment. This is particularly important as current assistive robotic devices – such as prostheses, orthoses, exoskeletons, and devices for teleoperation–often limit touch low-density and spatially constrained haptic feedback, i.e., the mere touch sensation linked to an action. Here, we analyze, discuss, and propose how and to what degree tactile feedback might increase the embodiment of certain robotic devices, e.g., prostheses, and the feeling of immersion in human-robot interaction, e.g., in teleoperation. Based on recent findings from cognitive psychology on interactive processes between touch and embodiment, we discuss technical solutions for specific applications, which might be used to enhance embodiment, and facilitate the study of how embodiment might alter human-robot interactions. We postulate that high-density and large surface sensing and stimulation are required to foster embodiment of such assistive devices.

Published
2018

140. Feel-good robotics: Requirements on touch for embodiment in assistive robotics

Author

Beckerle, Philipp (author), Kõiva, Risto (author), Kirchner, Elsa Andrea (author), Bekrater-Bodmann, Robin (author), Dosen, Strahinja (author), Christ, Oliver (author), Abbink, D.A. (author), Castellini, Claudio (author), Lenggenhager, Bigna (author), Beckerle, Philipp (author), Kõiva, Risto (author), Kirchner, Elsa Andrea (author), Bekrater-Bodmann, Robin (author), Dosen, Strahinja (author), Christ, Oliver (author), Abbink, D.A. (author), Castellini, Claudio (author), and Lenggenhager, Bigna (author)

Abstract

The feeling of embodiment, i.e., experiencing the body as belonging to oneself and being able to integrate objects into one's bodily self-representation, is a key aspect of human self-consciousness and has been shown to importantly shape human cognition. An extension of such feelings toward robots has been argued as being crucial for assistive technologies aiming at restoring, extending, or simulating sensorimotor functions. Empirical and theoretical work illustrates the importance of sensory feedback for the feeling of embodiment and also immersion; we focus on the the perceptual level of touch and the role of tactile feedback in various assistive robotic devices. We critically review how different facets of tactile perception in humans, i.e., affective, social, and self-touch, might influence embodiment. This is particularly important as current assistive robotic devices - such as prostheses, orthoses, exoskeletons, and devices for teleoperation-often limit touch low-density and spatially constrained haptic feedback, i.e., the mere touch sensation linked to an action. Here, we analyze, discuss, and propose how and to what degree tactile feedback might increase the embodiment of certain robotic devices, e.g., prostheses, and the feeling of immersion in human-robot interaction, e.g., in teleoperation. Based on recent findings from cognitive psychology on interactive processes between touch and embodiment, we discuss technical solutions for specific applications, which might be used to enhance embodiment, and facilitate the study of how embodiment might alter human-robot interactions. We postulate that high-density and large surface sensing and stimulation are required to foster embodiment of such assistive devices., Human-Robot Interaction

Published
2018
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141. List of contributors

Author

Arslan, Dilek Betul, Badi, Marion, Baldi, Rebecca, Bensmaia, Sliman J., Bjånes, David A., Blum, Kyle P., Borgognon, Simon, Caldwell, David J., Callier, Thierri, Cappello, Leonardo, Chowdhury, Raeed H., Cimolato, Andrea, Cipriani, Christian, Cronin, Jeneva A., del Valle, Jaume, Devecioğlu, İsmail, Dideriksen, Jakob, Dosen, Strahinja, Dupan, Sigrid, Erdogan, Ezgi Tuna, Frederik, Leonard, Güçlü, Burak, Hebert, Jacqueline S., Iberite, Francesco, Jabban, Leen, Karamursel, Sacit, Katic, Natalija, Kırtaş, Oğuzhan, Levinson, Lila H., Marasco, Paul D., Mazzoni, Alberto, Mendez, Vincent, Merrill, Daniel R., Metcalfe, Benjamin W., Micera, Silvestro, Miller, Lee E., Moritz, Chet T., Mutlu, Senol, Navarro, Xavier, Nazarpour, Kianoush, Öztürk, Sevgi, Ozturk-Isik, Esin, O’Doherty, Joseph E., P.N. Rao, Rajesh, Preatoni, Greta, Raspopovic, Stanisa, Rodríguez-Meana, Bruno, Samur, Evren, Shokur, Solaiman, Sombeck, Joseph, Valle, Giacomo, Versteeg, Christopher, and Yalug, Buse Buz

Published
2021
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146. Electrical Stimulation of Afferent Pathways for the Suppression of Pathological Tremor

Author

European Commission, Dideriksen, Jakob L., Laine, Christopher M., Dosen, Strahinja, Muceli, S., Rocón, Eduardo, Pons Rovira, José Luis, Benito-León, Julián, Farina, Dario, European Commission, Dideriksen, Jakob L., Laine, Christopher M., Dosen, Strahinja, Muceli, S., Rocón, Eduardo, Pons Rovira, José Luis, Benito-León, Julián, and Farina, Dario

Abstract

Pathological tremors are involuntary oscillatory movements which cannot be fully attenuated using conventional treatments. For this reason, several studies have investigated the use of neuromuscular electrical stimulation for tremor suppression. In a recent study, however, we found that electrical stimulation below the motor threshold also suppressed tremor, indicating involvement of afferent pathways. In this study, we further explored this possibility by systematically investigating how tremor suppression by afferent stimulation depends on the stimulation settings. In this way, we aimed at identifying the optimal stimulation strategy, as well as to elucidate the underlying physiological mechanisms of tremor suppression. Stimulation strategies varying the stimulation intensity and pulse timing were tested in nine tremor patients using either intramuscular or surface stimulation. Significant tremor suppression was observed in six patients (tremor suppression > 75% was observed in three patients) and the average optimal suppression level observed across all subjects was 52%. The efficiency for each stimulation setting, however, varied substantially across patients and it was not possible to identify a single set of stimulation parameters that yielded positive results in all patients. For example, tremor suppression was achieved both with stimulation delivered in an out-of-phase pattern with respect to the tremor, and with random timing of the stimulation. Overall, these results indicate that low-current stimulation of afferent fibers is a promising approach for tremor suppression, but that further research is required to identify how the effect can be maximized in the individual patient.

Published
2017

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