The Ankle Mimicking Prosthetic (AMP-) Foot 2 is a new energy efficient, powered transtibial prosthesis mimicking intact ankle behavior. The author's research is focused on the use of a low power actuator which stores energy in springs during the complete stance phase. At push-off, this energy can be released hereby providing propulsion forces and torques to the amputee. With the use of the so-called catapult actuator, the size and weight of the drive can be decreased compared to state-of-the-art powered prostheses, while still providing the full power necessary for walking.

In this article, the authors present a detailed description of the catapult actuator followed by a comparison with existing actuator technology in powered prosthetic feet with regard to torque and power requirements. The implication on the actuator's design will then be outlined. Further, a description of the control strategy behind the AMP-Foot 2 and 2.1 will be given. In the last section of the article, the actuation principle and control are illustrated by experimental validation with a transfemoral amputee. Conclusions and future work complete the paper.

This paper introduces a novel approach to motion planning for a rapid mobile manipulator using inverted pendulum models. Our aim was to realize an actual rapid mobile manipulator with high acceleration and speed performance for an object's delivery. In our research, we developed an actual rapid mobile manipulator called KDMR-1. We proposed simple motion planning methods using a single inverted pendulum model (SIPM) and a double inverted pendulum model (DIPM), which are easily adaptable to a real-time system with only a small computational burden. The SIPM was useful for basic movement but did not provide object carrying capability. For that, a DIPM was proposed. In both models, we designed linear quadratic optimal controllers to stabilize the Zero Moment Point (ZMP). Two kinds of ZMP stabilization strategies were proposed, fixed ZMP and relaxed ZMP. Using these strategies, we realized optimal ZMP stabilizations for a real-time rapid mobile manipulator. For decoupled forward and rotational linear DIPM, we designed a centrifugal acceleration compensation model in the manner of feedback linearization. The experimental results showed high acceleration and speed performances during rapid object delivery.

We propose a novel control approach for cooperative dual-arm manipulation tasks. Our scheme has three typical features: (1) the task performed by two robots is represented as a motion of a virtual mechanism and the task execution is accomplished by controlling the virtual mechanism; (2) the two arms and the task form a joined kinematic chain; (3) the scheme allows a cooperative dual-arm system to perform the task also when robot base is moving. The calculation of the Jacobian matrix of a chained two-arm mechanisms is based on a methodology which is using the Jacobian matrices of particular robot mechanisms and their end-effector positions and orientations. The proposed algorithm for dual-arm manipulation is verified by simulations of two cooperating planar robots and by experiments on a dual-arm robot consisting of two KUKA LWR arms.

We present AssistOn-Finger, a novel under-actuated active exoskeleton for robot-assisted tendon therapy of human fingers. The primary use for the exoskeleton is to assist flexion/extension motions of a finger within its full range, while decreasing voluntary muscle contractions helping to keep the tendon tension levels to stay within acceptable limits, avoiding gap formation or rupture of the suture. The device can also be employed to administer range of motion (RoM)/strengthening exercises. AssistOn-Finger is designed to be passively back-driveable, can cover the whole RoM of patients, and can do so in a natural and coordinated manner. In particular, the device employs human finger as an integral part of its kinematics and when coupled to a human operator, the parallel kinematic structure of exoskeleton supports three independent degrees of freedom, dictated by the kinematics of the human finger. Automatically aligning its joint axes to match finger joint axes, AssistOn-Finger can guarantee ergonomy and comfort throughout the therapy. The self-aligning feature also significantly shortens the setup time required to attach the patient to the exoskeleton. We present the kinematic type selection for the exoskeleton to satisfy the design requirements for tendon therapy applications, detail optimal dimensional synthesis of the device considering trade-offs between multiple design criteria and discuss implementation details of the exoskeleton. We also present feasibility studies conducted on healthy volunteers and provide statistical evidence on the efficacy of exoskeleton driven exercises in keeping the average muscle recruitment and the maximum tendon tension levels as low as human guided therapies.

Patients with damage to the cerebellum make reaching movements that are uncoordinated or “ataxic.” One prevailing hypothesis is that the cerebellum functions as an internal model for planning movements, and that damage to the cerebellum results in movements that do not properly account for arm dynamics. An exoskeleton robot was used to record multi-joint reaching movements. Subsequently, joint-torque trajectories were calculated and a gradient descent algorithm found optimal, patient-specific perturbations to actual limb dynamics predicted to reduce directional reaching errors by an average of 41%, elucidating a promising form of robotic intervention and adding support to the internal model hypothesis.

Although proprioceptive impairment is likely to affect in a significant manner the capacity of stroke patients to recover functionality of upper limb, clinical assessment methods currently in use are rather crude, with a low level of reliability and a limited capacity to discriminate the relevant features of this severe deficit. In the present paper, we describe a new technique based on robot technology, with the goal of providing a reliable, accurate, and quantitative evaluation of kinesthetic acuity, which can be integrated in robot therapy. The proposed technique, based on a pulsed assistance paradigm, has been evaluated on a group of healthy subjects.

Robotic devices are well-suited to provide high intensity upper limb therapy in order to induce plasticity and facilitate recovery from brain and spinal cord injury. In order to realise gains in functional independence, devices that target the distal joints of the arm are necessary. Further, the robotic device must exhibit key dynamic properties that enable both high dynamic transparency for assessment, and implementation of novel interaction control modes that significantly engage the participant. In this paper, we present the kinematic design, dynamical characterization, and clinical validation of the RiceWrist-S, a serial robotic mechanism that facilitates rehabilitation of the forearm in pronation-supination, and of the wrist in flexion-extension and radial-ulnar deviation. The RiceWrist-Grip, a grip force sensing handle, is shown to provide grip force measurements that correlate well with those acquired from a hand dynamometer. Clinical validation via a single case study of incomplete spinal cord injury rehabilitation for an individual with injury at the C3-5 level showed moderate gains in clinical outcome measures. Robotic measures of movement smoothness also captured gains, supporting our hypothesis that intensive upper limb rehabilitation with the RiceWrist-S would show beneficial outcomes.