Dexterous Tasks Research Articles

A Realization of Multilateral Force Feedback Control for Cooperative Motion

This paper proposes a novel control design for multilateral system considering different degrees of freedom (DOF) and structure. The conventional coordinate transformation with respect to the Cartesian coordinate system is not always suitable for bilateral and/or multilateral control for dexterous tasks, including grasping motion. This paper introduces spatial mode transformation, which is corresponding to human's tasks. The spatial modes are abstracted by using mode quarry matrices. The order of the mode quarry matrices means the task DOF, and the decoupled modes correspond to ldquotranslational task,rdquo ldquorotating task,rdquo ldquograsping task,rdquo and so on. Thus, the problems for motion integration of different DOF and structure are solved to design a multilateral controller in the spatial mode coordinate systems. Furthermore, the proposed multilateral control is designed based on acceleration control to realize both the force servoing and the position regulator for action-reaction law in remote environment simultaneously. The proposed multilateral control is applied for a multimaster/single-slave system, where the DOF is different from each other. As a result, a complicated task for the slave system is easily realized by two master systems with vivid force feedback based on modal control design of the multilateral system. The experimental results show viability of the proposed method.

Effects of wearing chemical protective clothing on text entry when using wearable input devices

Wearable computers allow users the freedom to work in any environment including those that may require protective clothing. Past research has shown that protective clothing impedes performance on manual dexterity tasks. Little information exists; however, regarding how protective clothing affects task performance with wearable input devices. A study was conducted to determine the effects of glove thickness and mask use on task performance and user preference. Sixteen male participants used both a wearable mouse and touch pad to enter text. Task completion times were 9% slower when participants wore 25-mil versus 7-mil protective gloves, suggesting that thin protective gloves are more suitable than thicker gloves when using wearable input devices. Mask use did not affect task performance. Subjective ratings of difficulty, confidence, and preference provided strong support for the use of a touch pad device rather than a mouse. Potential applications of this research include design guidelines for development of wearable input devices that are compatible with chemical protective clothing. Relevance to industry Protective clothing is commonly worn in industrial settings, but little is known about its impacts on task performance with wearable computers. This study describes some of the factors that must be considered in the design of wearable input devices that can be used effectively when wearing protective clothing.

Cognitive integrated motion generation for environmental adaptive robots

AbstractRecently, active researches have been performed to increase a robot's intelligence so as to realize dexterous tasks in complex environments such as in the street or homes. However, since skillful human‐like task ability is so difficult to formulate for the robot, not only the analytical and theoretical control researches but also the direct human motion mimetic approach is necessary. In this paper, we propose that to realize the environmental interactive task, it is insufficient to replay the human motion alone. We show a novel motion generation approach to integrate the cognitive information into mimickry of human motions so as to realize the final complex task by the robot. As a detailed example of the task, we consider how to carry up a human by cooperating two hands. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 156(3): 62–70, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20349

Effects of Chemical Protective Clothing on Task Performance Using Wearable Input Devices

Wearable computers allow users the freedom to work in any environment including those that may require protective clothing. Past research has shown that protective clothing impedes performance on manual dexterity tasks. Little information exists, however, regarding how protective clothing affects task performance with wearable input devices. To facilitate future development of wearable input devices, a study was conducted to determine the effects of glove thickness and respirator use on task performance and user preference. Sixteen male participants used both a wearable mouse and touch pad to enter text. Task completion times were 9% slower when participants wore 25-mil versus 7-mil protective gloves, suggesting that thin protective gloves (i.e. 7-mil and 14-mil) are more suitable than thicker gloves when using wearable input devices. Respirator use did not affect task performance. Subjective ratings of difficulty, confidence, and preference provided strong support for the use of a touch pad device rather than a mouse.

High level of dexterity: differential contributions of frontal and parietal areas

In the present functional magnetic resonance imaging experiment, study participants performed a dynamic tracking task in a precision grip configuration. The precision level of the force control was varied while the mean force level of 5 N was kept constant. Contrasts cancelling error rate differences between the conditions showed activation of nonprimary motor areas and other frontal structures in response to increasing precision constraints when the precision of force control could still be increased, and of right primary and associative parietal areas when the precision of the produced force control reached its maximum. These results suggest that the network of frontal and parietal areas, usually working together in fine control of dexterity tasks, can be differentially involved when environmental constraints become very high.

Visual and Tactile Guidance of Dexterous Manipulation Tasks: An fMRI Study

Models of motor guidance that dynamically adjust to the availability and quality of sensory information are based on the observation that dexterous tasks are routinely performed using various combinations of visual and tactile inputs. However, a dynamic neural system that acquires and processes relevant visual and tactile information remains relatively uncharacterized in humans. In this study, whole-brain functional magnetic resonance images were acquired during a dexterous manipulation task, compression of the end caps of a slender spring prone to buckling, to investigate the neural systems associated with motor guidance under four visual and tactile guidance conditions: (1) eyes closed (no visual input), smooth end caps, (2) eyes dosed, rough end caps, (3) eyes open and watching hand, smooth end caps, and (4) eyes open and watching hand, rough end caps. Performance of the dexterous task remained constant in all conditions. Variations in the two levels of visual input resulted in modulation of activity in the middle and inferior occipital gyrii and inferior parietal lobule, and variation in the two levels of tactile input during the task resulted in modulation of activity in the precentral (primary motor) gyrus. Although significantly active in all conditions, cingulate gyrus, medial frontal gyrus, postcentral gyrus, and cerebellum activities were not modulated by levels of either visual or somatosensory input, and no interaction effects were observed. Together, these data indicate that a fine-tuned motor task guided by varying visual and tactile information engages a distributed and integrated neural complex consisting of control and executive functions and regions that process dynamic sensory information related to guidance functions.

Modulation of behavior and cortical motor activity in healthy subjects by a chronic administration of a serotonin enhancer

SSRIs are postulated to modulate motor behavior. A single dose of selective serotoninergic reuptake inhibitors (SSRIs) like fluoxetine, paroxetine, or fluvoxamine, has been shown to improve motor performance and efficiency of information processing for simple sensorimotor tasks in healthy subjects. At a cortical level, a single dose of SSRI was shown to induce a hyperactivation of the primary sensorimotor cortex (S1M1) involved in the movement (Loubinoux, I., Boulanouar, K., Ranjeva, J. P., Carel, C., Berry, I., Rascol, O., Celsis, P., and Chollet, F., 1999. Cerebral functional magnetic resonance imaging activation modulated by a single dose of the monoamine neurotransmission enhancers fluoxetine and fenozolone during hand sensorimotor tasks. J. Cereb. Blood Flow Metab. 19 1365–1375, Loubinoux, I., Pariente, J., Boulanouar, K., Carel, C., Manelfe, C., Rascol, O., Celsis, P., and Chollet, F., 2002. A Single Dose of Serotonin Neurotransmission Agonist Paroxetine Enhances Motor Output. A double-blind, placebo-controlled, fMRI study in healthy subjects. NeuroImage 15 26–36). Since SSRIs are usually given for several weeks, we assessed the behavioral and cerebral effects of a one-month chronic administration of paroxetine on a larger group. In a double-blind, placebo controlled and crossover study, 19 subjects received daily 20 mg paroxetine or placebo, respectively, over a period of 30 days separated by a wash-out period of 3 months. After each period, the subjects underwent an fMRI (active or passive movement, dexterity task, sensory discrimination task) and a behavioral evaluation. Concurrently, a TMS (transcranial magnetic stimulation) study was conducted (Gerdelat-Mas, A., Loubinoux, I., Tombari, D., Rascol, O., Chollet, F., Simonetta-Moreau, M., 2005. Chronic administration of selective serotonin re-uptake inhibitor (SSRI) paroxetine modulates human motor cortex excitability in healthy subjects. NeuroImage 27 314–322). Results: On the one hand, paroxetine improved motor performances at the finger tapping test ( P = 0.02) without affecting choice reaction time, strength and dexterity significantly. Subjects were also faster in processing the spatial incongruency between a stimulus and the motor response ( P = 0.04). In order to differentiate behavioral components, a principal component analysis was performed on all motor tests, and several characteristics were differentiated: strength, speed, skill, attention, and motor response coding. Paroxetine would improve the efficiency of motor response coding (MANOVA on the factors; factor 3, P = 0.01). On the other hand, the chronic administration induced a significant hypoactivation of S1M1 whatever the task: motor or sensory, simple or complex (random effect analysis, P < 0.05). The hypoactivation correlated with the improvement of performances at the finger tapping test ( P < 0.05) suggesting more efficiency in cerebral motor processing. Conclusions: Our results showed a clear modulation of sensory and motor cerebral activation after a chronic paroxetine administration. An improvement in both behavior and cerebral efficiency was suggested. It could be hypothesized that monoamines, by an unspecific effect, may tune the response of pyramidal neurons to optimize performances.

VSOne, a virtual reality simulator for laparoscopic surgery

The introduction of computer‐based training systems for laparoscopic surgery has increased the training quality and made the learning effect measurable with objective criteria. This paper introduces VSOne as a fully‐featured virtual reality training system for laparoscopic surgery. VSOne utilizes the state‐of‐the‐art in virtual reality techniques, soft tissue simulation and haptic device control and guarantees realistic training possibilities for various laparoscopic procedures. An authoring software helps to create individual simulation models easily within the shortest time based on real patient data using standardized data formats. We have developed several Basic Task Training (BTT) modules to improve dexterity and complex Surgical Procedure Task (SPT) modules for full training of laparoscopic procedures such as cholecystectomy, tubal sterilization and myomectomy. VSOne has been evaluated in a comparative study with classic training methods and has shown the typical learning curves for inexperienced trainees and the transferability of the learning effect to the real‐world situation.

Benign childhood epilepsy with occipital paroxysms: Neuropsychological findings

Benign childhood epilepsy with occipital paroxysms is classified among childhood benign partial epilepsies. The absence of neurological and neuropsychological deficits has long been considered as a prerequisite for a diagnosis of benign childhood partial epilepsy. Much evidence has been reported in literature in the latest years suggesting a neuropsychological impairment in this type of epilepsy, particularly in the type with Rolandic paroxysms. The present work examines the neuropsychological profiles of a sample of subjects affected by the early-onset benign childhood occipital seizures (EBOS) described by Panayotopulos. The patient group included 22 children (14 males and 8 females; mean age 10.1 ± 3.3 years) diagnosed as having EBOS. The patients were examined with a set of tests investigating neuropsychological functions: memory, attention, perceptive, motor, linguistic and academic (reading, writing, arithmetic) abilities. The same instruments have been given to a homogeneous control group as regards sex, age, level of education and socio-economic background. None of the subjects affected by EBOS showed intellectual deficit (mean IQ in Wechsler Full Scale 91.7; S.D. 8.9). Results show a widespread cognitive dysfunction in the context of a focal epileptogenic process in EBOS. In particular, children with EBOS show a significant occurrence of specific learning disabilities (SLD) and other subtle neuropsychological deficits. We found selective dysfunctions relating to perceptive-visual attentional ability ( p < 0.05), verbal and visual-spatial memory abilities ( p < 0.01), visual perception and visual-motor integration global abilities ( p < 0.01), manual dexterity tasks ( p < 0.05), some language tasks ( p < 0.05), reading and writing abilities ( p < 0.01) and arithmetic ability ( p < 0.01). The presence of cognitive dysfunctions in subjects with EBOS supports the hypothesis that epilepsy itself plays a role in the development of neuropsychological impairment. Supported by other studies that have documented subtle neuropsychological deficits in benign partial epilepsy, we stress the importance of reconsidering its supposed “cognitive benignity”, particularly in occipital types.

The effect of delayed visual feedback on telerobotic surgery

Telerobotic surgery is ideally suited for remote applications in which the instrument control console is stationed separately from the end-effectors at the patient's bedside. However, if the distance between the console and the patient is great enough, a lag effect or latency between end-effector manipulation and the depicted image leads to alterations in movement patterns. The purpose of this study was to determine the effect of visual delay on surgical task performance. At an endoscopic skill station, an analogue delay device was interposed between the surgical field and monitor to delay the transmission of visual information, thus mimicking the distance effect of data transmission. Three surgeons with similar laparoscopic experience participated in the laparoscopic knot tying portion of the study, and seven residents participated in the accuracy and dexterity tasks. The time to complete a single throw was recorded in seconds after adding consecutively increasingly time delay in 50 ms increments. Similar time delay increments were added for the accuracy and dexterity tasks, which involved passing a needle through two adjacent circles and passing a small cylinder through a larger one to reproduce two-handed coordination and spatial resolution. Data were presented as the median time to complete each task. For all three tasks, an incremental increase in time delay was associated with a significant (p < 0.001) increase in the time to complete the task. For dexterity, a statistically significant (p <or= 0.05) delay was identified at 0.25 s of delay from control values without delay. A move-and-wait strategy was gradually adopted up to 0.4 s of visual delay. Compensation for visually delayed image perception occurs on several levels. Initial adaptations include slower end-effector manipulation; late adaptive changes include a move-and-wait strategy. Increased time to perform surgical maneuvers as well as diminished accuracy, diminished dexterity, and increasing fatigue represent additional performance encumbrances evoked by visual time delay. The nuances of both human and digital compensatory mechanisms for visual time delay must be defined and enhanced to maximize the potential for telerobotic surgical applications.

Factors related to oral hygiene in persons with scleroderma

The purpose of this study was to assess potential risk factors for the development of poor oral hygiene and increased dental caries in individuals with scleroderma. Twenty-two subjects with scleroderma participated in this study. All subjects were examined with the Patient Hygiene Performance (PHP) Index, which assesses the extent of plaque and debris over a tooth surface. In addition, oral aperature, xerostomia and dominant upper extremity strength, motion, skin thickness, and dexterity were measured. None of the subjects had good or excellent hygiene. Fifteen subjects had fair oral hygiene and seven subjects had poor oral hygiene as measured by the PHP Index. Significant differences were seen between these two groups for oral aperture, percentage of teeth with caries, skin thickness, dexterity and finger flexion. Dexterity and joint motion correlated significantly with the number of decayed surfaces and number of caries. Oral aperture correlated with the PHP Index and the number of dental caries. Subjects with poor oral hygiene required more time to complete manual dexterity task and had decreased hand strength and joint motion. Moreover, these same subjects had more contractures, scars, ulcers, and higher skin scores (more disease activity) than subjects in the fair hygiene group. In addition to frequent dental exam and routine cleaning, dental personnel may want to consider exercises to increase oral aperature and investigate toothbrush and dental floss selection used by persons with scleroderma.

環境と接するロボットの感覚運動統合による動作模倣

Recently, active researches have been performed to increase a robot's intelligence so as to realize dexterous tasks in complex environments such as in the street or homes. However, since skillful human-like task ability is so difficult to formulate for the robot, not only the analytical and theoretical control researches but also the direct human motion mimetic approach is necessary. In this paper, we propose that to realize the environmental interactive task, it is insufficient to replay the human motion alone. We show a novel motion generation approach to integrate the cognitive information into mimickry of human motions so as to realize the final complex task by the robot. As a detailed example of the task, we consider how to carry up a human by cooperating two hands. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 156(3): 62–70, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20349

Command and Telemetry Latency Effects on Operator Performance during International Space Station Robotic Operations

International Space Station operations require onboard crewmembers to perform numerous robotic assembly, maintenance, and inspection activities. Ground-based control of the Mobile Servicing System (MSS), in particular the Special Purpose Dexterous Manipulator (SPDM), has been identified as one potential solution to alleviate disproportionate robotic maintenance and inspection timelines that potentially exceed crew availability and duty times. Challenges to operator performance and safety of ground-based control of these manipulators include significant data and telemetry latency. Recent trends of transmissions between the International Space Station and NASA's Mission Control Center have determined the round-trip time delay can range from 6-8 seconds. The purpose of this study was to examine operator performance when subjects performed representative dexterous robotic tasks with anticipated command and telemetry time delays. Results from this study may determine whether augmentations to existing operator tools and procedures are required in order to manually control the SPDM from ground-based workstations.

Technical performance: relation between surgical dexterity and technical knowledge.

Technical performance consists of surgical knowledge, judgment, and dexterity. Although assessment of surgical dexterity is now possible, assessing technical knowledge and its relation to dexterity has not been elucidated. Surgeons of varying experience were recruited to the skills laboratory to undertake three assessments: simple surgical dexterity (at 14 stations scored by motion analysis), an operating room equipment examination, and a novel error analysis. The scores were correlated, and p < 0.05 was deemed to be significant. Thirty surgeons were recruited; and construct validity was exhibited in all areas. Correlations were shown to exist between the two knowledge examinations (Spearman's rho = 0.39). Correlations existed between all dexterity task parameters and the equipment examination, whereas they existed for only 15 of the 28 parameters of the error examination and were always weaker. The stronger correlations between dexterity and instrument and operating room (OR) equipment reflect greater surgical experience and time spent in the OR. The weaker correlations between the error analysis and dexterity suggest that these skills are learned at different times. The identification of common surgical errors should be more formally taught to ensure greater uniformity.

Amyotrophic lateral sclerosis (ALS) and mirror movements in a patient with polymicrogyria.

We report on a case of polymicrogyria with benign childhood epilepsy and amyotrophic lateral sclerosis (ALS). While performing dexterity tasks with either hand, strong unsustained mirror movements of the unintended hand were observed. The patient was seen over a period of three years and, as often seen in ALS, there was a moderate progress of the motor neuron disease affecting the upper and lower motor neuron in an asymmetrical manner. In addition, more rapidly progressive bulbar symptoms could be observed by the clinical and neurophysiological examination. MRI revealed polymicrogyria of the right frontal lobe with irregular bumpy inner and outer surface and abnormally thick and smooth cortex, dysplastic insular cortex and asymmetrically widened Sylvial fissure. No signs of atrophy, especially of the motorcortex and corticospinal tract were observed. The corpus callosum was completely developed and of normal size. We hypothesize an enrolment of the dysplastic right frontal lobe pathophysiology of the observed mirror movements.

Manual dexterity of older Mexican American adults: a cross-sectional pilot experimental investigation

This paper reports results from an experimental pilot study performed to quantify the manual dexterity of older Mexican American adults. The Purdue pegboard test, a two-arm coordination test, and a hand-tool dexterity test were used in this study. To enable cross-sectional comparisons of manual dexterity measures of older Mexican American adults with young Mexican American adults, these tests were administered to 18 older Mexican American adults aged 63–85 (mean age: 71.3 years, SD: 7.0 years), recruited from senior recreation centers in El Paso, and eighteen young adults aged 21–32 (mean age: 25.6 years, SD: 3.8 years) recruited from the student body at the University of Texas at El Paso. For the Purdue pegboard test, the number of pegs placed in 30 s using the preferred hand, the non-preferred hand, and both hands were first individually monitored. Then, scores on an assembly task using the Purdue pegboard were obtained. For the two-arm coordination test, participants were required to trace a star pattern with a stylus using both hands. The time for task completion and the number of errors made during task performance were monitored. For the hand-tool dexterity test, participants were required to use common hand tools and remove nuts and bolts from one side of a wooden upright, and to assemble nuts and bolts in the corresponding holes on the other side of the upright. The time taken for task completion was recorded. Since modified Levene's test showed equality of variances, two sample t-tests, comparing the mean responses of older adults with the mean responses of young adults for each individual test, were conducted. Results indicate that responses for the older adults were statistically significant different ( p<0.001) from young adults for all Purdue pegboard tasks. On the average, older adults performed significantly slower ( p<0.001) than young adults on the two-arm coordination test, and committed more errors before task completion ( p<0.05). Older adults also took longer to complete the hand-tool dexterity task compared to their younger counterparts ( p<0.05). In addition to the t-tests, manual dexterity performance measures from older adults were regressed with age to determine the cross-sectional age effects on manual dexterity measures. Results indicate that all Purdue pegboard performance measures were significantly affected by age ( p<0.05). The time to complete the two-arm coordination test was significantly linearly related to age ( p<0.05). However, the number of errors committed by older adults in the performance of the two-arm coordination test was not significantly linearly related to age. Time to complete the hand-tool dexterity was also significantly linearly related to age ( p<0.05). Accommodating age-related changes in manual dexterity is important for job design in industry, especially in industries employing older adults requiring significant assembly and hand-tool use. Relevance to industry Given the aging of the industrial workforce, it is important to understand how manual dexterity is affected by age, so that jobs requiring significant manual dexterity for task initiation, task performance and task completion are designed to fit older adult dexterity levels.

Motor training effects on recovery of function after striatal lesions and striatal grafts

Environment, training, and experience can influence plasticity and recovery of function after brain damage. However, it is less well known whether, and how, such factors influence the growth, integration, and functional recovery provided by neural grafts placed within the brain. To explore this process, rats were pretrained on the skilled staircase test, then lesioned unilaterally in the lateral dorsal striatum with quinolinic acid. Half of the animals were given suspension grafts prepared from E15 whole ganglionic eminence implanted into the lesioned striatum. For the following 5 months, half of the animals in each group were trained daily in a bilateral manual dexterity task. Then, 23 weeks after surgery, all animals were retested on the staircase test. The grafts promoted recovery in the reaching task, irrespective of the additional dexterity training, and within the trained group recovery was proportional to the volume of the striatal-like tissue in the graft, suggesting that training influenced the pattern of graft-induced functional recovery. The additional training also benefited the rats with lesions alone, raising their performance close to level of the grafted groups. In separate tests of rotation, the grafts reduced drug-induced ipsilateral turning in response to both amphetamine and apomorphine, an effect that was greater in the grafted rats given extra training. The results suggest that both nonspecific motor training and cell transplantation can contribute to recovery of lost function in tests of spontaneous and skilled lateralized motor function after striatal damage, and that these two factors interact in a task-specific manner.

'Toy problem' as the benchmark test for teleoperation systems

A unified hand/arm master–slave system was developed to conduct dexterous tasks by teleoperation. Both the master and the slave consist of a two-fingered hand and a 3-d.o.f. planer manipulator. The system is also aimed at investigating the bottleneck of autonomous robotic manipulation systems. To evaluate the performance of individual teleoperation systems all over the world under equal conditions, we propose toy block assembling (LEGO® blocks) as the benchmark test for teleoperation systems. Using our hand/arm master-slave system, we announce the measured completion time for assembling some block structures, expecting other research group to try the same task in the future.

Kinaesthetic sensitivity and motor skills of school-aged children with a congenital visual impairment

This study examined the relationship between kinaesthetic sensitivity and motor development of children with a congenital visual impairment resulting in partial vision (PV) or severe visual impairment (SVI). It was hypothesised that both groups would exhibit reduced scores on: (i) the Kinaesthetic Acuity component (KAc) of the Kinaesthetic Sensitivity Test (KST) and (ii) tasks derived from the Movement Assessment Battery for Children (M-ABC), when compared to matched peers with full vision. Mean differences in the hypothesised direction were found in the comparisons involving children with SVI on M-ABC tasks, and KAc score differences approached statistical significance. Children with PV did not have reduced KAc scores and were found to have poorer scores on static and dynamic balance tasks, but not manual dexterity tasks from the M-ABC. This may suggest different developmental processes underlying the difficulties in acquisition of motor skills of children with PV and SVI.

Application of Force Control to the Robot of the Engineering Test Satellite VII.

The ETS-VII is the first unmanned satellite with robot arm in the world. Three types of force/torque control functions based on active compliance control were applied to the robot for on-board local compensation of tele-operation and autonomous dexterous task operations. Various robot experiments for on-board servicing technology were conducted successfully with using the force/torque control functions. This paper describes the force control methods, results of flight experiments using the functions and their evaluation.