Quantifying the Human Likeness of a Humanoid Robot

In research of human-robot interactions, human likeness (HL) of robots is frequently used as an individual, vague parameter to describe how a robot is perceived by a human. However, such a simplification of HL is often not sufficient given the complexity and multidimensionality of human-robot interaction. Therefore, HL must be seen as a variable influenced by a network of parameter fields. The first goal of this paper is to introduce such a network which systematically characterizes all relevant aspects of HL. The network is subdivided into ten parameter fields, five describing static aspects of appearance and five describing dynamic aspects of behavior. The second goal of this paper is to propose a methodology to quantify the impact of single or multiple parameters out of these fields on perceived HL. Prior to quantification, the minimal perceivable difference, i.e. the threshold of perception, is determined for the parameters of interest in a first experiment. Thereafter, these parameters are modified in whole-number multiple of the threshold of perception to investigate their influence on perceived HL in a second experiment. This methodology was illustrated on the parameters speed and sequencing (onset of joint movements) of the parameter field movement as well as on the parameter sound. Results revealed that the perceived HL is more sensitive to changes in sequencing than to changes in speed. The sound of the motors during the movement also reduced perceived HL. The presented methodology should guide further, systematic explorations of the proposed network of HL parameters in order to determine and optimize acceptance of humanoid robot

A reconfigurable, tendon-based haptic interface for research into human-environment interactions

Human reaction to external stimuli can be investigated in a comprehensive way by using a versatile virtual-reality setup involving multiple display technologies. It is apparent that versatility remains a main challenge when human reactions are examined through the use of haptic interfaces as the interfaces must be able to cope with the entire range of diverse movements and forces/torques a human subject produces. To address the versatility challenge, we have developed a large-scale reconfigurable tendon-based haptic interface which can be adapted to a large variety of task dynamics and is integrated into a Cave Automatic Virtual Environment (CAVE). To prove the versatility of the haptic interface, two tasks, incorporating once the force and once the velocity extrema of a human subject's extremities, were implemented: a simulator with 3-DOF highly dynamic force feedback and a 3-DOF setup optimized to perform dynamic movements. In addition, a 6-DOF platform capable of lifting a human subject off the ground was realized. For these three applications, a position controller was implemented, adapted to each task, and tested. In the controller tests with highly different, task-specific trajectories, the three robot configurations fulfilled the demands on the application-specific accuracy which illustrates and confirms the versatility of the developed haptic interfac

A neurorobotic platform for locomotor prosthetic development in rats and mice

Objectives. We aimed to develop a robotic interface capable of providing finely-tuned, multidirectional trunk assistance adjusted in real-time during unconstrained locomotion in rats and mice. Approach. We interfaced a large-scale robotic structure actuated in four degrees of freedom to exchangeable attachment modules exhibiting selective compliance along distinct directions. This combination allowed high-precision force and torque control in multiple directions over a large workspace. We next designed a neurorobotic platform wherein real-time kinematics and physiological signals directly adjust robotic actuation and prosthetic actions. We tested the performance of this platform in both rats and mice with spinal cord injury. Main Results. Kinematic analyses showed that the robotic interface did not impede locomotor movements of lightweight mice that walked freely along paths with changing directions and height profiles. Personalized trunk assistance instantly enabled coordinated locomotion in mice and rats with severe hindlimb motor deficits. Closed-loop control of robotic actuation based on ongoing movement features enabled real-time control of electromyographic activity in anti-gravity muscles during locomotion. Significance. This neurorobotic platform will support the study of the mechanisms underlying the therapeutic effects of locomotor prosthetics and rehabilitation using high-resolution genetic tools in rodent models

Evaluating Nutraceuticals for Selective Toxicity Toward Leukemia Stem Cells

Targeting leukemia stem cells (LSCs) is critical to improving the poor outcome of acute myeloid leukemia (AML) patients. Nutraceuticals (i.e., food derived bioactive compounds) provide a wealthy resource for novel anti-cancer, and specifically anti-AML drug discovery. With the advent of novel LSC cell lines, preliminary screening of these compounds against LSC-like cells can be achieved rapidly. To identify potential novel anti-LSC therapeutics, we created and screened a unique library consisting of 288 nutraceuticals in an MTS assay against TEX leukemia cells, a surrogate LSC line and K562, a control cell line which does not possess LSC activity. Here, we identified diosmetin, a flavonoid found in citrus fruits and various green plants, as a novel anti- LSC agent (EC50: 6.0 ± 1.7μM). To confirm its activity, diosmetin (10μM) reduced clonogenic growth of primary AML cells (n = 4) with no effect on normal CD34 positive bone marrow derived stem cells (n = 3) observed in colony forming cell assays. A dose-response and time course analysis performed via the Annexin/PI assay and flow cytometry revealed that diosmetin induced apoptosis, as evidenced by the accumulation of ANN+/PI- cells. Apoptosis was further confirmed by a subG1 peak after performing cell cycle analysis. Utilizing the Database for Annotation, Visualization and Integrated Discovery (DAVID) tool, we determined that the estrogen receptor (ER) was a potential molecular target for diosmetin’s anti-leukemia activity. To assess the role of estrogen receptors, we measured ERα and ERβ protein levels in diosmetin sensitive and insensitive cell lines. Interestingly, diosmetin sensitive cell lines display significantly elevated ERβ protein levels compared to diosmetin insensitive cells. However, this pattern was not observed for ERα. Similar results were observed through quantitative PCR measures, as TEX cells displayed levels of ESR2 (ERβ) mRNA, with no observed levels of ESR1 (ERα) mRNA levels. The opposite results were observed in K562 cells. Through ER reporter assays, it was demonstrated that diosmetin acts as a partial agonist in ERβ reporter cells, increasing luciferase activity with increasing doses of diosmetin in ERβ reporter cells. Moreover, we find that caspase 8 but not caspase 9 is elevated following diosmetin treatment, consistent with the extrinsic pathway of apoptosis and our observed increased in TNF-α, similar to previous reports highlighting the link between ERβ agonists and cancer cell death. In summary, these studies highlight that estrogen receptors, specifically ERβ, is a novel LSC therapeutic target, and the potential role of nutraceuticals as promising compounds for future drug discovery endeavours

Rehabilitative Soft Exoskeleton for Rodents

Robotic exoskeletons provide programmable, consistent and controllable active therapeutic assistance to patients with neurological disorders. Here we introduce a prototype and preliminary experimental evaluation of a rehabilitative gait exoskeleton that enables compliant yet effective manipulation of the fragile limbs of rats. To assist the displacements of the lower limbs without impeding natural gait movements, we designed and fabricated soft pneumatic actuators (SPAs). The exoskeleton integrates two customizable SPAs that are attached to a limb. This configuration enables a 1 N force load, a range of motion exceeding 80 mm in the major axis, and speed of actuation reaching two gait cycles/s. Preliminary experiments in rats with spinal cord injury validated the basic features of the exoskeleton. We propose strategies to improve the performance of the robot and discuss the potential of SPAs for the design of other wearable interfaces

Apparatus to apply forces in a three-dimensional space

The present invention relates to a robotic system useful to unload an object/person from its weight. The robotic system is useful in locomotor rehabilitation programs and allows the manipulation of forces in a three-dimensional space with far lower actuator requirements and a much higher precision than prior-art systems. The apparatus combines passive and active elements to minimize actuation requirements while still keeping inertia to a minimum and control precision to a maximum. It requires minimal actuators and at the same time has a low inertia

Apparatus and method for restoring voluntary control of locomotion in neuromotor impairments

It is disclosed an apparatus for restoring voluntary control of locomotion in a subject suffering from a neuromotor impairment comprising a multidirectional trunk support system and a device for epidural electrical stimulation. The robotic interface is capable of evaluating, enabling and training motor pattern generation and balance across a variety of natural walking behaviors in subjects with neuromotor impairments. Optionally, pharmacological cocktails can be administered to enhance rehabilitation results. It is also disclosed a method for the evaluation, enablement and training of a subject suffering from neuromotor impairments by combining robotically assisted evaluation tools with sophisticated neurobiomechanical and statistical analyses. A method for the rehabilitation (by this term also comprising restoring voluntary control of locomotion) of a subject suffering from a neuromotor impairment in particular partial or total paralysis of limbs, is also disclosed

Quantifying the Human Likeness of a Humanoid Robot

ISSN:1875-4791ISSN:1875-480