Design, implementation and control of rehabilitation robots for upper and lower limbs

We present two novel rehabilitation robots for stroke patients. For lower limb stroke rehabilitation, we present a novel self-aligning exoskeleton for the knee joint. The primal novelty of the design originates from its kinematic structure that allows translational movements of the knee joint on the sagittal plane along with the knee rotation. Automatically adjusting its joint axes, the exoskeleton enables a perfect match between human joint axes and the device axes. Thanks to this feature, the knee exoskeleton is not only capable of guaranteeing ergonomy and comfort throughout the therapy, but also extends the usable range of motion for the knee joint. Moreover, this adjustability feature significantly shortens the setup time required to attach the patient to the robot, allowing more effective time be spend on exercises instead of wasting it for adjustments. We have implemented an impedance-type concept of the knee exoskeleton, experimentally characterized its closed-loop performance and demonstrated ergonomy and useability of this device through human subject experiments. To administer table top exercises during upper limb stroke rehabilitation, we present a novel Mecanum-wheeled holonomic mobile rehabilitation robot for home therapy. The device can move/rotate independently on its unlimited planar workspace to provide assistance to patients. We have implemented two different concepts of holonomic mobile platform based on different actuation and sensing principles: an admittance-type mobile robot and a mobile platform with series elastic actuation. The admittance-type robot is integrated with virtual reality simulations and can assist patients through virtual tunnels designed around nominal task trajectories. The holonomic platform with series elastic actuation eliminates the need for costly force sensors and enables implementation of closed loop force control with higher controller gains, providing robustness against imperfections in the power transmission and allowing lower cost drive components to be utilized. For contour following tasks with the holonomic platforms, we have synthesized passive velocity field controllers (PVFC) that ensure coordination and synchronization between various degrees of freedom of the patient arm, while letting patients to complete the task at their own preferred pace. PVFC not only minimizes the contour error but also ensures coupled stability of the human-in-the-loop system

Evaluation of Germination, Emergence and Physiological Properties of Sugar Beet Cultivars Under Salinity

DergiPark: 947001trkjnatThis study aimed to determine a useful selection criterion for salt tolerance during the early development stage of sugar beet. Four sugar beet cultivars (Orthega, Valentina, FD Shoot, and Mohican) were exposed to NaCl stresses (Control, 5, 10, and 15 dS m-1), and morphological and physiological characteristics were investigated. Germination percentage, mean germination time (MGT), seedling length, and seedling fresh weight (SFW) in germination test; emergence percentage, mean emergence time (MET), root length, shoot length, plant fresh weight, relative chlorophyll content (Chl), relative water content (RWC) and electrolyte leakage of the plants grown in pod experiment were measured. The results showed that the maximum germination at control was recorded in FD Shoot, but it gave the lowest germination at 15 dS m-1. In the pod experiment, the highest emergence rate was detected in Orthega and Mohican at all levels of NaCl. Increased salinity delayed MET and led to reduction in shoot length, root length, and RWC of sugar beet cultivars. Relative Chl content and electrolyte leakage enhanced from 32.7 SPAD and 21.6% in control to 38.5 SPAD and 35.6% in 10 dS m-1, respectively. In general, there were significant differences among sugar beet cultivars, and they could keep the salinity up to 5 dS m-1 in terms of the investigated traits. It was concluded that relative Chl content and electrolyte leakage should be used a promising clue for selection of tolerant or sensitive sugar beet cultivars for salinity.Bu çalışmada, erken gelişim döneminde şeker pancarının tuza toleransı için faydalı bir seçim kriteri belirlemek amaçlanmıştır. NaCl stresine (Kontrol, 5, 10 ve 15 dS m-1) maruz bırakılan dört şeker pancarı çeşidinde (Orthega, Valentina, FD Shoot ve Mohican) morfolojik ve fizyolojik özellikler incelenmiştir. Çimlenme testinde; çimlenme yüzdesi, ortalama çimlenme süresi, fide uzunluğu ve fide yaş ağırlığı, çıkış testinde; çıkış yüzdesi, ortalama çıkış süresi, kök uzunluğu, sürgün uzunluğu, bitki yaş ağırlığı, bağıl su içeriği, bağıl klorofil içeriği ve elektrolit sızıntısı ölçülmüştür. Sonuçlar, FD Shoot çeşidinde en yüksek çimlenmenin kontrol, en düşük çimlenmenin ise 15 dS m-1 seviyesinde kaydedildiğini göstermiştir. Çıkış testindeki tüm NaCl seviyelerinde en yüksek çıkış yüzdesi Orthega ve Mohican çeşitlerinde tespit edilmiştir. Artan NaCl seviyeleri ile şeker pancarı çeşitlerinde ortalama çıkış süresi gecikmiş ve sürgün uzunluğu, kök uzunluğu ve bağıl su içeriği azalmıştır. Bağıl klorofil içeriği ve elektrolit sızıntısı, kontrol ve 10 dS m-1 seviyelerinde sırasıyla 32,7 SPAD ve %21,6; 38,5 SPAD ve %35,6 olarak belirlenmiştir. Genel olarak, şeker pancarı çeşitleri arasında önemli farklılıklar bulunmuş ve incelenen özellikler açısından çeşitler 5 dS m-1'e kadar olan tuzluluğa tolerans göstermişlerdir. Bağıl klorofil içeriği ve elektrolit sızıntısının, tuzluluğa toleranslı veya hassas şeker pancarı çeşitlerinin seçiminde umut verici bir ipucu olarak kullanılması gerektiği sonucuna varılmıştır.

AssistOn-SE: a self-aligning shoulder-elbow exoskeleton

We present AssistOn-SE:, a novel powered exoskeleton for robot-assisted rehabilitation that allows for movements of the shoulder girdle as well as shoulder rotations. Automatically adjusting its joint axes, AssistOn-SE: can enable a perfect match between human joint axes and the device axes, not only guaranteeing ergonomy and comfort throughout the therapy, but also extending the usable range of motion for the shoulder joint. Moreover, the adjustability feature significantly shortens the setup time required to attach the patient to the exoskeleton, allowing more effective time be spend on exercises instead of wasting this valuable resource for adjustments. Back-driveable design of AssistOn-SE: supports both passive translational movements of the center of glenohumeral joint and independent active control of these degrees of freedom. Thanks to this property, glenohumeral mobilization and scapular stabilization exercises can also be delivered with AssistOn-SE:, extending the type of therapies that can be administered using upper-arm exoskeletons. We introduce the design of the exoskeleton and present the kinematic analysis of its self-aligning joint. We also provide implementation details for an early prototype as well as some experimental results detailing range of motion of the device and its ability to track movements of the shoulder girdle

Alt Uzuv Dış İskelet Robot Eklemlerinde Kararlılık İçin Sönümleme Katsayıları ve Momentlerinin Hesaplanması

Exoskeleton robots are wearable electromechanical structures which can work interacting with human limbs. Theserobotsareused as assistivelimbs, rehabilitationandpoweraugmentationpurposesforelderly or paralyzedpersons andhealthypersons respectively.Human body neuro-muscular system varies the stiffness and damping of the human joints regularly and thus provides flexible and stable movement capability with minimum energy consumption. Damping coefficients and torques in the joints needs to be adjusted with the change of stiffness to provide stable behavior during walking cycles. Magneto-rheological brake are the passive actuators that can adjust the damping torques in a very short response time. However, the maximum values of damping coefficients and torques are needed for the design of MR dampers to be used in the joints of exoskeleton robots. Shamaei et. al. (2013) derived a set of statistical equations to predict thejoint stiffnessin a gait cycle for the persons with different height and weights. In this paper, the maximum values of damping coefficients and torques are calculated for the design of MR dampers to provide stability in the joints of exoskeleton robots. The results can be used as initial design criteria of MR dampers which will be added to the biomimetic joints of exoskeleton robots, prostheses, ortheses and humanoid robot

A self-adjusting knee exoskeleton for robot-assisted treatment of knee injuries

In this study, we present a novel active device for robot-assisted rehabilitation that accommodates transitional movements of the knee joint as well as its rotation, enabling a perfect match between human joint axes and the device axes. Automatically adjusting its joint axes, the proposed device is not only capable of guaranteeing ergonomy and comfort throughout the therapy, but also extends the usable range of motion for the knee joint. Moreover, the adjustability feature significantly shortens the setup time required to attach the patient to the exoskeleton, allowing more effective time be spend on exercises instead of wasting it for adjustments. The proposed system is different from the similar works in literature in that it supports both passive translational movements of the knee joint and independent active control of these degrees of freedom. In particular, we introduce implementation details of a prototype that features compact design and combines the power of three actuators to achieve high rotational torques, detail the model based impedance controller utilized to adjust interaction forces and present the experimental characterization of the exoskeleton

Design of a new MR-compatible haptic interface with six actuated degrees of freedom

Abstract—Functional magnetic resonance imaging is an often adopted tool to study human motor control mechanisms. Highly controlled experiments as required by this form of analysis can be realized with haptic interfaces. Their design is challenging because of strong safety and MR compatibility requirements. Existing MR-compatible haptic interfaces are restricted to maximum three actuated degrees of freedom. We propose an MR-compatible haptic interface with six actuated degrees of freedom to be able to study human brain mechanisms of natural pick-and-place movements including arm transport. In this work, we present its mechanical design, kinematic and dynamic model, as well as report on its model-based characterization. A novel hybrid control scheme for the employed ultrasonic motors is introduced. Preliminary MR compatibility tests based on one complete actuator-sensor module are performed. No measurable noise is found and thus, bidirectional compatibility of the six DoF interface can be expected. I

AssistOn-Mobile: A series elastic holonomic mobile platform for upper extremity rehabilitation

We present the design and control of series elastic holonomic mobile platform, ASSISTON-MOBILE, aimed to administer therapeutic table-top exercises to patients who have suffered injuries that affect the function of their upper extremities. The proposed mobile platform is a low-cost, portable, easy-to-use rehabilitation device for home use. ASSISTON-MOBILE consists of four actuated Mecanum wheels and a compliant, low-cost, multi degree-of-freedom Series Elastic Element as its force sensing unit. Thanks to its series elastic actuation, ASSISTON-MOBILE is highly back-driveable and can provide assistance/resistance to patients, while performing omni-directional movements on plane. Feasibility tests and preliminary usability studies with the robot are presented. The device holds promise in improving accuracy and effectiveness of repetitive movement therapies completed at home, while also providing quantitative measures of patient progress