Sex differences in the shoulder joint position sense acuity: a cross-sectional study.

PubMed

Vafadar, Amir K; Côté, Julie N; Archambault, Philippe S

2015-09-30

Work-related musculoskeletal disorders (WMSD) is the most expensive form of work disability. Female sex has been considered as an individual risk factor for the development of WMSD, specifically in the neck and shoulder region. One of the factors that might contribute to the higher injury rate in women is possible differences in neuromuscular control. Accordingly the purpose of this study was to estimate the effect of sex on shoulder joint position sense acuity (as a part of shoulder neuromuscular control) in healthy individuals. Twenty-eight healthy participants, 14 females and 14 males were recruited for this study. To test position sense acuity, subjects were asked to flex their dominant shoulder to one of the three pre-defined angle ranges (low, mid and high-ranges) with eyes closed, hold their arm in that position for three seconds, go back to the starting position and then immediately replicate the same joint flexion angle, while the difference between the reproduced and original angle was taken as the measure of position sense error. The errors were measured using Vicon motion capture system. Subjects reproduced nine positions in total (3 ranges × 3 trials each). Calculation of absolute repositioning error (magnitude of error) showed no significant difference between men and women (p-value ≥ 0.05). However, the analysis of the direction of error (constant error) showed a significant difference between the sexes, as women tended to mostly overestimate the target, whereas men tended to both overestimate and underestimate the target (p-value ≤ 0.01, observed power = 0.79). The results also showed that men had a significantly more variable error, indicating more variability in their position sense, compared to women (p-value ≤ 0.05, observed power = 0.78). Differences observed in the constant JPS error suggest that men and women might use different neuromuscular control strategies in the upper limb. In addition, higher JPS

Position sense at the human elbow joint measured by arm matching or pointing.

PubMed

Tsay, Anthony; Allen, Trevor J; Proske, Uwe

2016-10-01

Position sense at the human elbow joint has traditionally been measured in blindfolded subjects using a forearm matching task. Here we compare position errors in a matching task with errors generated when the subject uses a pointer to indicate the position of a hidden arm. Evidence from muscle vibration during forearm matching supports a role for muscle spindles in position sense. We have recently shown using vibration, as well as muscle conditioning, which takes advantage of muscle's thixotropic property, that position errors generated in a forearm pointing task were not consistent with a role by muscle spindles. In the present study we have used a form of muscle conditioning, where elbow muscles are co-contracted at the test angle, to further explore differences in position sense measured by matching and pointing. For fourteen subjects, in a matching task where the reference arm had elbow flexor and extensor muscles contracted at the test angle and the indicator arm had its flexors conditioned at 90°, matching errors lay in the direction of flexion by 6.2°. After the same conditioning of the reference arm and extension conditioning of the indicator at 0°, matching errors lay in the direction of extension (5.7°). These errors were consistent with predictions based on a role by muscle spindles in determining forearm matching outcomes. In the pointing task subjects moved a pointer to align it with the perceived position of the hidden arm. After conditioning of the reference arm as before, pointing errors all lay in a more extended direction than the actual position of the arm by 2.9°-7.3°, a distribution not consistent with a role by muscle spindles. We propose that in pointing muscle spindles do not play the major role in signalling limb position that they do in matching, but that other sources of sensory input should be given consideration, including afferents from skin and joint.

Effect of proprioception training on knee joint position sense in female team handball players.

PubMed

Pánics, G; Tállay, A; Pavlik, A; Berkes, I

2008-06-01

A number of studies have shown that proprioception training can reduce the risk of injuries in pivoting sports, but the mechanism is not clearly understood. To determine the contributing effects of propioception on knee joint position sense among team handball players. Prospective cohort study. Two professional female handball teams were followed prospectively for the 2005-6 season. 20 players in the intervention team followed a prescribed proprioceptive training programme while 19 players in the control team did not have a specific propioceptive training programme. The coaches recorded all exposures of the individual players. The location and nature of injuries were recorded. Joint position sense (JPS) was measured by a goniometer on both knees in three angle intervals, testing each angle five times. Assessments were performed before and after the season by the same examiner for both teams. In the intervention team a third assessment was also performed during the season. Complete data were obtained for 15 subjects in the intervention team and 16 in the control team. Absolute error score, error of variation score and SEM were calculated and the results of the intervention and control teams were compared. The proprioception sensory function of the players in the intervention team was significantly improved between the assessments made at the start and the end of the season (mean (SD) absolute error 9.78-8.21 degrees (7.19-6.08 degrees ) vs 3.61-4.04 degrees (3.71-3.20 degrees ), p<0.05). No improvement was seen in the sensory function in the control team between the start and the end of the season (mean (SD) absolute error 6.31-6.22 degrees (6.12-3.59 degrees ) vs 6.13-6.69 degrees (7.46-6.49 degrees ), p>0.05). This is the first study to show that proprioception training improves the joint position sense in elite female handball players. This may explain the effect of neuromuscular training in reducing the injury rate.

Changes in balance and joint position sense during a 12-day high altitude trek: The British Services Dhaulagiri medical research expedition.

PubMed

Clarke, Sarah B; Deighton, Kevin; Newman, Caroline; Nicholson, Gareth; Gallagher, Liam; Boos, Christopher J; Mellor, Adrian; Woods, David R; O'Hara, John P

2018-01-01

Postural control and joint position sense are essential for safely undertaking leisure and professional activities, particularly at high altitude. We tested whether exposure to a 12-day trek with a gradual ascent to high altitude impairs postural control and joint position sense. This was a repeated measures observational study of 12 military service personnel (28±4 years). Postural control (sway velocity measured by a portable force platform) during standing balance, a Sharpened Romberg Test and knee joint position sense were measured, in England (113m elevation) and at 3 research camps (3619m, 4600m and 5140m) on a 12-day high altitude trek in the Dhaulagiri region of Nepal. Pulse oximetry, and Lake Louise scores were also recorded on the morning and evening of each trek day. Data were compared between altitudes and relationships between pulse oximetry, Lake Louise score, and sway velocity were explored. Total sway velocity during standing balance with eyes open (p = 0.003, d = 1.9) and during Sharpened Romberg test with eyes open (p = 0.007, d = 1.6) was significantly greater at altitudes of 3619m and 5140m when compared with sea level. Anterior-posterior sway velocity during standing balance with eyes open was also significantly greater at altitudes of 3619m and 5140m when compared with sea level (p = 0.001, d = 1.9). Knee joint position sense was not altered at higher altitudes. There were no significant correlations between Lake Louise scores, pulse oximetry and postural sway. Despite a gradual ascent profile, exposure to 3619 m was associated with impairments in postural control without impairment in knee joint position sense. Importantly, these impairments did not worsen at higher altitudes of 4600 m or 5140 m. The present findings should be considered during future trekking expeditions when developing training strategies targeted to manage impairments in postural control that occur with increasing altitude.

Surgical Reconstruction with the Remnant Ligament Improves Joint Position Sense as well as Functional Ankle Instability: A 1-Year Follow-Up Study

PubMed Central

Iwao, Kamizato; Masataka, Deie; Kohei, Fukuhara

2014-01-01

Introduction. Chronic functional instability—characterized by repeated ankle inversion sprains and a subjective sensation of instability—is one of the most common residual disabilities after an inversion sprain. However, whether surgical reconstruction improves sensorimotor control has not been reported to date. The purpose of this study was to assess functional improvement of chronic ankle instability after surgical reconstruction using the remnant ligament. Materials and Methods. We performed 10 cases in the intervention group and 20 healthy individuals as the control group. Before and after surgical reconstruction, we evaluated joint position sense and functional ankle instability by means of a questionnaire. Results and Discussion. There was a statistically significant difference between the control and intervention groups before surgical reconstruction. Three months after surgery in the intervention group, the joint position sense was significantly different from those found preoperatively. Before surgery, the mean score of functional ankle instability in the intervention group was almost twice as low. Three months after surgery, however, the score significantly increased. The results showed that surgical reconstruction using the remnant ligament was effective not only for improving mechanical retensioning but also for ameliorating joint position sense and functional ankle instability. PMID:25401146

Evaluation of joint position sense measured by inversion angle replication error in patients with an osteochondral lesion of the talus.

PubMed

Nakasa, Tomoyuki; Adachi, Nobuo; Shibuya, Hayatoshi; Okuhara, Atsushi; Ochi, Mitsuo

2013-01-01

The etiology of the osteochondral lesion of the talar dome (OLT) remains unclear. A joint position sense deficit of the ankle is reported to be a possible cause of ankle disorder. Repeated contact of the articular surface of the talar dome with the plafond during inversion might be a cause of OLT. The aim of the present study was to evaluate the joint position sense deficit by measuring the replication error of the inversion angle in patients with OLT. The replication error, which is the difference between the index angle and replication angle in inversion, was measured in 15 patients with OLT. The replication error in 15 healthy volunteers was evaluated as a control group. The side to side differences of the replication errors between the patients with OLT and healthy volunteers and the replication errors in each angle between the involved and uninvolved ankle in the patients with OLT were investigated. Finally, the side to side differences of the replication errors between the patients with OLT with a traumatic and nontraumatic history were compared. The side to side difference in the patients with OLT (1.3° ± 0.2°) was significantly greater than that in the healthy subjects (0.4° ± 0.7°) (p ≤ .05). Significant differences were found between the involved and uninvolved sides at 10°, 15°, 20°, and 25° in the patients with OLT. No significant difference (p > .05) was found between the patients with traumatic and nontraumatic OLT. The present study found that the patients with OLT have a joint position sense deficit during inversion movement, regardless of a traumatic history. Although various factors for the etiology of OLT have been reported, the joint position sense deficit in inversion might be a cause of OLT. Copyright © 2013 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Relationship between Joint Position Sense, Force Sense, and Muscle Strength and the Impact of Gymnastic Training on Proprioception

PubMed Central

Kochanowicz, Andrzej

2018-01-01

The aims of this study were (1) to assess the relationship between joint position (JPS) and force sense (FS) and muscle strength (MS) and (2) to evaluate the impact of long-term gymnastic training on particular proprioception aspects and their correlations. 17 elite adult gymnasts and 24 untrained, matched controls performed an active reproduction (AR) and passive reproduction (PR) task and a force reproduction (FR) task at the elbow joint. Intergroup differences and the relationship between JPS, FS, and MS were evaluated. While there was no difference in AR or PR between groups, absolute error in the control group was higher during the PR task (7.15 ± 2.72°) than during the AR task (3.1 ± 1.93°). Mean relative error in the control group was 61% higher in the elbow extensors than in the elbow flexors during 50% FR, while the gymnast group had similar results in both reciprocal muscles. There was no linear correlation between JPS and FS in either group; however, FR was negatively correlated with antagonist MS. In conclusion, this study found no evidence for a relationship between the accuracy of FS and JPS at the elbow joint. Long-term gymnastic training improves the JPS and FS of the elbow extensors. PMID:29670901

Systematic changes in position sense accompany normal aging across adulthood.

PubMed

Herter, Troy M; Scott, Stephen H; Dukelow, Sean P

2014-03-25

Development of clinical neurological assessments aimed at separating normal from abnormal capabilities requires a comprehensive understanding of how basic neurological functions change (or do not change) with increasing age across adulthood. In the case of proprioception, the research literature has failed to conclusively determine whether or not position sense in the upper limb deteriorates in elderly individuals. The present study was conducted a) to quantify whether upper limb position sense deteriorates with increasing age, and b) to generate a set of normative data that can be used for future comparisons with clinical populations. We examined position sense in 209 healthy males and females between the ages of 18 and 90 using a robotic arm position-matching task that is both objective and reliable. In this task, the robot moved an arm to one of nine positions and subjects attempted to mirror-match that position with the opposite limb. Measures of position sense were recorded by the robotic apparatus in hand-and joint-based coordinates, and linear regressions were used to quantify age-related changes and percentile boundaries of normal behaviour. For clinical comparisons, we also examined influences of sex (male versus female) and test-hand (dominant versus non-dominant) on all measures of position sense. Analyses of hand-based parameters identified several measures of position sense (Variability, Shift, Spatial Contraction, Absolute Error) with significant effects of age, sex, and test-hand. Joint-based parameters at the shoulder (Absolute Error) and elbow (Variability, Shift, Absolute Error) also exhibited significant effects of age and test-hand. The present study provides strong evidence that several measures of upper extremity position sense exhibit declines with age. Furthermore, this data provides a basis for quantifying when changes in position sense are related to normal aging or alternatively, pathology.

Ankle instability effects on joint position sense when stepping across the active movement extent discrimination apparatus.

PubMed

Witchalls, Jeremy; Waddington, Gordon; Blanch, Peter; Adams, Roger

2012-01-01

Individuals with and without functional ankle instability have been tested for deficits in lower limb proprioception with varied results. To determine whether a new protocol for testing participants' joint position sense during stepping is reliable and can detect differences between participants with unstable and stable ankles. Descriptive laboratory study. University clinical laboratory. Sample of convenience involving 21 young adult university students and staff. Ankle stability was categorized by score on the Cumberland Ankle Instability Tool; 13 had functional ankle instability, 8 had healthy ankles. Test-retest of ankle joint position sense when stepping onto and across the Active Movement Extent Discrimination Apparatus twice, separated by an interim test, standing still on the apparatus and moving only 1 ankle into inversion. Difference in scores between groups with stable and unstable ankles and between test repeats. Participants with unstable ankles were worse at differentiating between inversion angles underfoot in both testing protocols. On repeated testing with the stepping protocol, performance of the group with unstable ankles was improved (Cohen d = 1.06, P = .006), whereas scores in the stable ankle group did not change in the second test (Cohen d = 0.04, P = .899). Despite this improvement, the unstable group remained worse at differentiating inversion angles on the stepping retest (Cohen d = 0.99, P = .020). The deficits on proprioceptive tests shown by individuals with functional ankle instability improved with repeated exposure to the test situation. The learning effect may be the result of systematic exposure to ankle-angle variation that led to movement-specific learning or increased confidence when stepping across the apparatus.

Mutual coordination strengthens the sense of joint agency in cooperative joint action.

PubMed

Bolt, Nicole K; Poncelet, Evan M; Schultz, Benjamin G; Loehr, Janeen D

2016-11-01

Philosophers have proposed that when people coordinate their actions with others they may experience a sense of joint agency, or shared control over actions and their effects. However, little empirical work has investigated the sense of joint agency. In the current study, pairs coordinated their actions to produce tone sequences and then rated their sense of joint agency on a scale ranging from shared to independent control. People felt more shared than independent control overall, confirming that people experience joint agency during joint action. Furthermore, people felt stronger joint agency when they (a) produced sequences that required mutual coordination compared to sequences in which only one partner had to coordinate with the other, (b) held the role of follower compared to leader, and (c) were better coordinated with their partner. Thus, the strength of joint agency is influenced by the degree to which people mutually coordinate with each other's actions. Copyright © 2016 Elsevier Inc. All rights reserved.

Robotic assessment of the contribution of motor commands to wrist position sense.

PubMed

Contu, Sara; Marini, Francesca; Masia, Lorenzo

2017-07-01

Assessing joint position sense for rehabilitation after neurological injury provides a prognostic factor in recovery and long-term functional outcomes. A common method for testing joint position sense involves the active replication of a joint configuration presented via a passive movement. However, recent evidence showed how this sense is mediated by the centrally generated signals of motor command, such that movements produced volitionally may be coded differently from passive movements and accuracy may be different when matching targets presented actively. To verify this hypothesis we asked ten participants to actively replicate a target wrist angle with the help of a visual feedback in two conditions, which differed in the mode of target presentation: active (aaJPM) or passive (paJPM). The accuracy of target matching, directional bias and variability were analyzed, as well as speed and smoothness of the matching movement and criterion movement in the aaJPM. Overall results indicate higher accuracy and lower variability in the paJPM, while directional bias showed the tendency to overshoot the target regardless of condition. The speed did not differ in the two conditions and movements were smoother in the aaJPM, suggesting a higher confidence by participants in their matching ability. In conclusion, this study suggests that motor commands negatively affect the accuracy of joint position sense when matching involves the integration of visual and proprioceptive information.

Ankle Instability Effects on Joint Position Sense When Stepping Across the Active Movement Extent Discrimination Apparatus

PubMed Central

Witchalls, Jeremy; Waddington, Gordon; Blanch, Peter; Adams, Roger

2012-01-01

Context Individuals with and without functional ankle instability have been tested for deficits in lower limb proprioception with varied results. Objective To determine whether a new protocol for testing participants' joint position sense during stepping is reliable and can detect differences between participants with unstable and stable ankles. Design Descriptive laboratory study. Setting University clinical laboratory. Patients or Other Participants Sample of convenience involving 21 young adult university students and staff. Ankle stability was categorized by score on the Cumberland Ankle Instability Tool; 13 had functional ankle instability, 8 had healthy ankles. Intervention(s) Test-retest of ankle joint position sense when stepping onto and across the Active Movement Extent Discrimination Apparatus twice, separated by an interim test, standing still on the apparatus and moving only 1 ankle into inversion. Main Outcome Measure(s) Difference in scores between groups with stable and unstable ankles and between test repeats. Results Participants with unstable ankles were worse at differentiating between inversion angles underfoot in both testing protocols. On repeated testing with the stepping protocol, performance of the group with unstable ankles was improved (Cohen d = 1.06, P = .006), whereas scores in the stable ankle group did not change in the second test (Cohen d = 0.04, P = .899). Despite this improvement, the unstable group remained worse at differentiating inversion angles on the stepping retest (Cohen d = 0.99, P = .020). Conclusions The deficits on proprioceptive tests shown by individuals with functional ankle instability improved with repeated exposure to the test situation. The learning effect may be the result of systematic exposure to ankle-angle variation that led to movement-specific learning or increased confidence when stepping across the apparatus. PMID:23182010

Vision and spectroscopic sensing for joint tracing in narrow gap laser butt welding

NASA Astrophysics Data System (ADS)

Nilsen, Morgan; Sikström, Fredrik; Christiansson, Anna-Karin; Ancona, Antonio

2017-11-01

The automated laser beam butt welding process is sensitive to positioning the laser beam with respect to the joint because a small offset may result in detrimental lack of sidewall fusion. This problem is even more pronounced in case of narrow gap butt welding, where most of the commercial automatic joint tracing systems fail to detect the exact position and size of the gap. In this work, a dual vision and spectroscopic sensing approach is proposed to trace narrow gap butt joints during laser welding. The system consists of a camera with suitable illumination and matched optical filters and a fast miniature spectrometer. An image processing algorithm of the camera recordings has been developed in order to estimate the laser spot position relative to the joint position. The spectral emissions from the laser induced plasma plume have been acquired by the spectrometer, and based on the measurements of the intensities of selected lines of the spectrum, the electron temperature signal has been calculated and correlated to variations of process conditions. The individual performances of these two systems have been experimentally investigated and evaluated offline by data from several welding experiments, where artificial abrupt as well as gradual deviations of the laser beam out of the joint were produced. Results indicate that a combination of the information provided by the vision and spectroscopic systems is beneficial for development of a hybrid sensing system for joint tracing.

Elbow joint position sense after neuromuscular training with handheld vibration.

PubMed

Tripp, Brady L; Faust, Donald; Jacobs, Patrick

2009-01-01

Clinicians use neuromuscular control exercises to enhance joint position sense (JPS); however, because standardizing such exercises is difficult, validations of their use are limited. To evaluate the acute effects of a neuromuscular training exercise with a handheld vibrating dumbbell on elbow JPS acuity. Crossover study. University athletic training research laboratory. Thirty-one healthy, college-aged volunteers (16 men, 15 women, age = 23 + or - 3 years, height = 173 + or - 8 cm, mass = 76 + or - 14 kg). We measured and trained elbow JPS using an electromagnetic tracking device that provided auditory and visual biofeedback. For JPS testing, participants held a dumbbell and actively identified the target elbow flexion angle (90 degrees ) using the software-generated biofeedback, followed by 3 repositioning trials without feedback. Each neuromuscular training protocol included 3 exercises during which participants held a 2.55-kg dumbbell vibrating at 15, 5, or 0 Hz and used software-generated biofeedback to locate and maintain the target elbow flexion angle for 15 seconds. We calculated absolute (accuracy) and variable (variability) errors using the differences between target and reproduced angles. Training protocols using 15-Hz vibration enhanced accuracy and decreased variability of elbow JPS (P < or = .005), whereas 5-Hz vibration did not affect accuracy (F(1,61) = 2.625, P = .100) but did decrease variability (F(1,61) = 7.250, P = .009). The control condition and 0-Hz training protocol had no effect on accuracy or variability (P > or = .200). Our results suggest these neuromuscular control exercises, which included low-magnitude, low-frequency handheld vibration, may enhance elbow JPS. Future researchers should examine vibration of various durations and frequencies, should include injured participants and functional multijoint and multiplanar measures, and should examine long-term effects of training protocols on JPS and injury.

Effects of Warm-Up and Fatigue on Knee Joint Position Sense and Jump Performance.

PubMed

Romero-Franco, N; Jiménez-Reyes, P

2017-01-01

The purpose of this study was to evaluate the effects of a warm-up and fatigue protocol on the vertical jump and knee joint position sense of sprinters. Thirty-two sprinters were randomly allocated to either a control group (CONT) or a plyometric group (PLYO) that performed a warm-up, followed by a high-intensity plyometric protocol. Absolute (AAE), relative (RAE), and variable (VAE) angular errors and vertical jump were evaluated before and after the warm-up, as well as after the plyometric protocol and again 5 min later. After the warm-up, athletes improved RAE and jump performance. After the plyometric protocol, scores on the RAE, VAE, and the vertical jump performance worsened compared to the control group and to the values obtained after the warm-up. Five minutes later, RAE and vertical jump continued to be impaired. AAE did not show significant differences. The vertical jump is improved after the warm-up, although it is deteriorated after high-intensity plyometry. Regarding knee proprioception, the lack of impairments in the AAE make unclear the effects of the plyometric exercises on knee proprioception.

Elbow Joint Position Sense After Neuromuscular Training With Handheld Vibration

PubMed Central

Tripp, Brady L.; Faust, Donald; Jacobs, Patrick

2009-01-01

Abstract Context: Clinicians use neuromuscular control exercises to enhance joint position sense (JPS); however, because standardizing such exercises is difficult, validations of their use are limited. Objective: To evaluate the acute effects of a neuromuscular training exercise with a handheld vibrating dumbbell on elbow JPS acuity. Design: Crossover study. Setting: University athletic training research laboratory. Patients or Other Participants: Thirty-one healthy, college-aged volunteers (16 men, 15 women, age  =  23 ± 3 years, height  =  173 ± 8 cm, mass  =  76 ± 14 kg). Intervention(s): We measured and trained elbow JPS using an electromagnetic tracking device that provided auditory and visual biofeedback. For JPS testing, participants held a dumbbell and actively identified the target elbow flexion angle (90°) using the software-generated biofeedback, followed by 3 repositioning trials without feedback. Each neuromuscular training protocol included 3 exercises during which participants held a 2.55-kg dumbbell vibrating at 15, 5, or 0 Hz and used software-generated biofeedback to locate and maintain the target elbow flexion angle for 15 seconds. Main Outcome Measure(s): We calculated absolute (accuracy) and variable (variability) errors using the differences between target and reproduced angles. Results: Training protocols using 15-Hz vibration enhanced accuracy and decreased variability of elbow JPS (P ≤ .005), whereas 5-Hz vibration did not affect accuracy (F1,61  =  2.625, P  =  .100) but did decrease variability (F1,61  =  7.250, P  =  .009). The control condition and 0-Hz training protocol had no effect on accuracy or variability (P ≥ .200). Conclusions: Our results suggest these neuromuscular control exercises, which included low-magnitude, low-frequency handheld vibration, may enhance elbow JPS. Future researchers should examine vibration of various durations and frequencies, should include injured participants and

Changes in head and neck position have a greater effect on elbow joint position sense in people with whiplash-associated disorders.

PubMed

Knox, Joanna Joy; Beilstein, Darren Jay; Charles, Scott Darren; Aarseth, Geir Arne; Rayar, Shivanthi; Treleaven, Julia; Hodges, Paul William

2006-01-01

It has been shown that perception of elbow joint position is affected by changes in head and neck position. Further, people with whiplash-associated disorders (WAD) present with deficits in upper limb coordination and movement. This study is aimed to determine whether the effect of changes in head position on elbow joint position error (JPE) is more pronounced in people with WAD, and to determine whether this is related to the participant's pain and anxiety levels. Nine people with chronic and disabling WAD and 11 healthy people participated in this experiment. The ability to reproduce a position at the elbow joint was assessed after changes in the position of the head and neck to 30 degrees , and with the head in the midline. Pain was monitored in WAD participants. Absolute elbow JPE with the head in neutral was not different between WAD and control participants (P=0.5). Changes in the head and neck position increased absolute elbow JPE in the WAD group (P<0.05), but did not affect elbow JPE in the control group (P=0.4). There was a connection between pain during testing and the effect of changes in head position on elbow JPE (P<0.05). Elbow JPE is affected by movement of the head and neck, with smaller angles of neck rotation in people with WAD than in healthy individuals. This observation may explain deficits in upper limb coordination in people with WAD, which may be due to the presence of pain or reduced range of motion in this population.

Effect of different levels of localized muscle fatigue on knee position sense.

PubMed

Gear, William S

2011-01-01

There is little information available regarding how proprioceptive abilities decline as the amount of exertion increases during exercise. The purpose of this study was to determine the role of different levels of fatigue on knee joint position sense. A repeated measures design was used to examine changes in active joint reposition sense (AJRS) prior to and following three levels of fatigue. Eighteen participants performed knee extension and flexion isokinetic exercise until torque output was 90%, 70%, or 50% of the peak hamstring torque for three consecutive repetitions. Active joint reposition sense at 15, 30, or 45 degrees was tested following the isokinetic exercise session. Following testing of the first independent measure, participants were given a 20 minute rest period. Testing procedures were repeated for two more exercise sessions following the other levels of fatigue. Testing of each AJRS test angle was conducted on three separate days with 48 hours between test days. Significant main effect for fatigue was indicated (p = 0.001). Pairwise comparisons indicated a significant difference between the pre-test and following 90% of peak hamstring torque (p = 0.02) and between the pre-test and following 50% of peak hamstring torque (p = 0.02). Fatigue has long been theorized to be a contributing factor in decreased proprioceptive acuity, and therefore a contributing factor to joint injury. The findings of the present study indicate that fatigue may have an effect on proprioception following mild and maximum fatigue. Key pointsA repeated measures design was used to examine the effect of different levels of fatigue on active joint reposition sense (AJRS) of the knee at joint angles of 15°, 30° and 45° of flexion.A statistically significant main effect for fatigue was found, specifically between no fatigue and mild fatigue and no fatigue and maximum fatigue.A statistically significant interaction effect between AJRS and fatigue was not found.Secondary analysis

Limb position sense, proprioceptive drift and muscle thixotropy at the human elbow joint

PubMed Central

Tsay, A; Savage, G; Allen, T J; Proske, U

2014-01-01

These experiments on the human forearm are based on the hypothesis that drift in the perceived position of a limb over time can be explained by receptor adaptation. Limb position sense was measured in 39 blindfolded subjects using a forearm-matching task. A property of muscle, its thixotropy, a contraction history-dependent passive stiffness, was exploited to place muscle receptors of elbow muscles in a defined state. After the arm had been held flexed and elbow flexors contracted, we observed time-dependent changes in the perceived position of the reference arm by an average of 2.8° in the direction of elbow flexion over 30 s (Experiment 1). The direction of the drift reversed after the arm had been extended and elbow extensors contracted, with a mean shift of 3.5° over 30 s in the direction of elbow extension (Experiment 2). The time-dependent changes could be abolished by conditioning elbow flexors and extensors in the reference arm at the test angle, although this led to large position errors during matching (±10°), depending on how the indicator arm had been conditioned (Experiments 3 and 4). When slack was introduced in the elbow muscles of both arms, by shortening muscles after the conditioning contraction, matching errors became small and there was no drift in position sense (Experiments 5 and 6). These experiments argue for a receptor-based mechanism for proprioceptive drift and suggest that to align the two forearms, the brain monitors the difference between the afferent signals from the two arms. PMID:24665096

Influence of chronic neck pain on cervical joint position error (JPE): Comparison between young and elderly subjects.

PubMed

Alahmari, Khalid A; Reddy, Ravi Shankar; Silvian, Paul; Ahmad, Irshad; Nagaraj, Venkat; Mahtab, Mohammad

2017-11-06

Evaluation of cervical joint position sense in subjects with chronic neck pain has gained importance in recent times. Different authors have established increased joint position error (JPE) in subjects with acute neck pain. However, there is a paucity of studies to establish the influence of chronic neck pain on cervical JPE. The objective of the study was to understand the influence of chronic neck pain on cervical JPE, and to examine the differences in cervical JPE between young and elderly subjects with chronic neck pain. Forty-two chronic neck pain patients (mean age 47.4) were compared for cervical JPE with 42 age-matched healthy subjects (mean age 47.8), using a digital inclinometer. The cervical JPE were measured in flexion, extension, and rotation in right and left movement directions. The comparison of JPE showed significantly larger errors in subjects with chronic neck pain when compared to healthy subjects (p< 0.001). The errors were larger in all of the movement directions tested. Comparison between young and older subjects with chronic neck pain revealed no significant differences (P> 0.05) in cervical JPE. Cervical joint position sense is impaired in subjects with chronic neck pain.

Evaluating the neck joint position sense error with a standard computer and a webcam.

PubMed

Basteris, Angelo; Pedler, Ashley; Sterling, Michele

2016-12-01

Joint Position Sense Error (JPSE) is a measure of cervical spine proprioception, and a simple method for measuring the JPSE could help in monitoring and evaluating the outcomes of rehabilitation of people with neck pain. In this study we demonstrate preliminary results of a method for measuring JPSE that does not require the participant to wear any equipment. Based on free publicly available head tracking software, compatible with any webcam, we developed a webpage which instructs the participant in performing a self-administered version of the test. The aim of this proof-of-concept study was to demonstrate the viability of this system. We compared our absolute error values (3.68 ± 1.2° after extension, 3.46 ± 1.66° after flexion, 3.89 ± 2.34° after rotation to the left and 4.02 ± 1.82°after rotation to the right) to values from literature, finding that our results do not differ from those of 6 out of 11 studies (which used more complex and expensive setups). The results indicate that our system allows assessment of the JPSE with a standard computer. Being based on a website, the system has potential for telemedicine use. Further research is required to validate the system before it can be recommended for use in clinical practice. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of Different Levels of Localized Muscle Fatigue on Knee Position Sense

PubMed Central

Gear, William S.

2011-01-01

There is little information available regarding how proprioceptive abilities decline as the amount of exertion increases during exercise. The purpose of this study was to determine the role of different levels of fatigue on knee joint position sense. A repeated measures design was used to examine changes in active joint reposition sense (AJRS) prior to and following three levels of fatigue. Eighteen participants performed knee extension and flexion isokinetic exercise until torque output was 90%, 70%, or 50% of the peak hamstring torque for three consecutive repetitions. Active joint reposition sense at 15, 30, or 45 degrees was tested following the isokinetic exercise session. Following testing of the first independent measure, participants were given a 20 minute rest period. Testing procedures were repeated for two more exercise sessions following the other levels of fatigue. Testing of each AJRS test angle was conducted on three separate days with 48 hours between test days. Significant main effect for fatigue was indicated (p = 0.001). Pairwise comparisons indicated a significant difference between the pre-test and following 90% of peak hamstring torque (p = 0.02) and between the pre-test and following 50% of peak hamstring torque (p = 0.02). Fatigue has long been theorized to be a contributing factor in decreased proprioceptive acuity, and therefore a contributing factor to joint injury. The findings of the present study indicate that fatigue may have an effect on proprioception following mild and maximum fatigue. Key points A repeated measures design was used to examine the effect of different levels of fatigue on active joint reposition sense (AJRS) of the knee at joint angles of 15°, 30° and 45° of flexion. A statistically significant main effect for fatigue was found, specifically between no fatigue and mild fatigue and no fatigue and maximum fatigue. A statistically significant interaction effect between AJRS and fatigue was not found. Secondary

Military exercises, knee and ankle joint position sense, and injury in male conscripts: a pilot study.

PubMed

Mohammadi, Farshid; Azma, Kamran; Naseh, Iman; Emadifard, Reza; Etemadi, Yasaman

2013-01-01

The high incidence of lower limb injuries associated with physical exercises in military conscripts suggests that fatigue may be a risk factor for injuries. Researchers have hypothesized that lower limb injuries may be related to altered ankle and knee joint position sense (JPS) due to fatigue. To evaluate if military exercises could alter JPS and to examine the possible relation of JPS to future lower extremity injuries in military service. Cohort study. Laboratory. A total of 50 male conscripts (age = 21.4 ± 2.3 years, height = 174.5 ± 6.4 cm, mass = 73.1 ± 6.3 kg) from a unique military base were recruited randomly. main outcome measure(s): Participants performed 8 weeks of physical activities at the beginning of a military course. In the first part of the study, we instructed participants to recognize predetermined positions before and after military exercises so we could examine the effects of military exercise on JPS. The averages of the absolute error and the variable error of 3 trials were recorded. We collected data on the frequency of lower extremity injuries over 8 weeks. Next, the participants were divided into 2 groups: injured and uninjured. Separate 2 × 2 × 2 (group-by-time-by-joint) mixed-model analyses of variance were used to determine main effects and interactions of these factors for each JPS measure. In the second part of the study, we examined whether the effects of fatigue on JPS were related to the development of injury during an 8-week training program. We calculated Hedges effect sizes for JPS changes postexercise in each group and compared change scores between groups. We found group-by-time interactions for all JPS variables (F range = 2.86-4.05, P < .01). All participants showed increases in JPS errors postexercise (P < .01), but the injured group had greater changes for all the variables (P < .01). Military conscripts who sustained lower extremity injuries during an 8-week military exercise program had greater loss of JPS acuity

A New Joint-Blade SENSE Reconstruction for Accelerated PROPELLER MRI.

PubMed

Lyu, Mengye; Liu, Yilong; Xie, Victor B; Feng, Yanqiu; Guo, Hua; Wu, Ed X

2017-02-16

PROPELLER technique is widely used in MRI examinations for being motion insensitive, but it prolongs scan time and is restricted mainly to T2 contrast. Parallel imaging can accelerate PROPELLER and enable more flexible contrasts. Here, we propose a multi-step joint-blade (MJB) SENSE reconstruction to reduce the noise amplification in parallel imaging accelerated PROPELLER. MJB SENSE utilizes the fact that PROPELLER blades contain sharable information and blade-combined images can serve as regularization references. It consists of three steps. First, conventional blade-combined images are obtained using the conventional simple single-blade (SSB) SENSE, which reconstructs each blade separately. Second, the blade-combined images are employed as regularization for blade-wise noise reduction. Last, with virtual high-frequency data resampled from the previous step, all blades are jointly reconstructed to form the final images. Simulations were performed to evaluate the proposed MJB SENSE for noise reduction and motion correction. MJB SENSE was also applied to both T2-weighted and T1-weighted in vivo brain data. Compared to SSB SENSE, MJB SENSE greatly reduced the noise amplification at various acceleration factors, leading to increased image SNR in all simulation and in vivo experiments, including T1-weighted imaging with short echo trains. Furthermore, it preserved motion correction capability and was computationally efficient.

Multi-field coupled sensing network for health monitoring of composite bolted joint

NASA Astrophysics Data System (ADS)

Wang, Yishou; Qing, Xinlin; Dong, Liang; Banerjee, Sourav

2016-04-01

Advanced fiber reinforced composite materials are becoming the main structural materials of next generation of aircraft because of their high strength and stiffness to weight ratios, and excellent designability. As key components of large composite structures, joints play important roles to ensure the integrity of the composite structures. However, it is very difficult to analyze the strength and failure modes of composite joints due to their complex nonlinear coupling factors. Therefore, there is a need to monitor, diagnose, evaluate and predict the structure state of composite joints. This paper proposes a multi-field coupled sensing network for health monitoring of composite bolted joints. Major work of this paper includes: 1) The concept of multifunctional sensor layer integrated with eddy current sensors, Rogowski coil and arrayed piezoelectric sensors; 2) Development of the process for integrating the eddy current sensor foil, Rogowski coil and piezoelectric sensor array in multifunctional sensor layer; 3) A new concept of smart composite joint with multifunctional sensing capability. The challenges for building such a structural state sensing system and some solutions to address the challenges are also discussed in the study.

A New Joint-Blade SENSE Reconstruction for Accelerated PROPELLER MRI

PubMed Central

Lyu, Mengye; Liu, Yilong; Xie, Victor B.; Feng, Yanqiu; Guo, Hua; Wu, Ed X.

2017-01-01

PROPELLER technique is widely used in MRI examinations for being motion insensitive, but it prolongs scan time and is restricted mainly to T2 contrast. Parallel imaging can accelerate PROPELLER and enable more flexible contrasts. Here, we propose a multi-step joint-blade (MJB) SENSE reconstruction to reduce the noise amplification in parallel imaging accelerated PROPELLER. MJB SENSE utilizes the fact that PROPELLER blades contain sharable information and blade-combined images can serve as regularization references. It consists of three steps. First, conventional blade-combined images are obtained using the conventional simple single-blade (SSB) SENSE, which reconstructs each blade separately. Second, the blade-combined images are employed as regularization for blade-wise noise reduction. Last, with virtual high-frequency data resampled from the previous step, all blades are jointly reconstructed to form the final images. Simulations were performed to evaluate the proposed MJB SENSE for noise reduction and motion correction. MJB SENSE was also applied to both T2-weighted and T1-weighted in vivo brain data. Compared to SSB SENSE, MJB SENSE greatly reduced the noise amplification at various acceleration factors, leading to increased image SNR in all simulation and in vivo experiments, including T1-weighted imaging with short echo trains. Furthermore, it preserved motion correction capability and was computationally efficient. PMID:28205602

Two-dimensional Inductive Position Sensing System

NASA Technical Reports Server (NTRS)

Youngquist, Robert C. (Inventor); Starr, Stanley O. (Inventor)

2015-01-01

A two-dimensional inductive position sensing system uses four drive inductors arranged at the vertices of a parallelogram and a sensing inductor positioned within the parallelogram. The sensing inductor is movable within the parallelogram and relative to the drive inductors. A first oscillating current at a first frequency is supplied to a first pair of the drive inductors located at ends of a first diagonal of the parallelogram. A second oscillating current at a second frequency is supplied to a second pair of the drive inductors located at ends of a second diagonal of the parallelogram. As a result, the sensing inductor generates a first output voltage at the first frequency and a second output voltage at the second frequency. A processor determines a position of the sensing inductor relative to the drive inductors using the first output voltage and the second output voltage.

Proprioceptive assessment in clinical settings: Evaluation of joint position sense in upper limb post-stroke using a robotic manipulator

PubMed Central

Kager, Simone; Budhota, Aamani; Deshmukh, Vishwanath A.; Kuah, Christopher W. K.; Yam, Lester H. L.; Xiang, Liming; Chua, Karen S. G.; Masia, Lorenzo; Campolo, Domenico

2017-01-01

Proprioception is a critical component for motor functions and directly affects motor learning after neurological injuries. Conventional methods for its assessment are generally ordinal in nature and hence lack sensitivity. Robotic devices designed to promote sensorimotor learning can potentially provide quantitative precise, accurate, and reliable assessments of sensory impairments. In this paper, we investigate the clinical applicability and validity of using a planar 2 degrees of freedom robot to quantitatively assess proprioceptive deficits in post-stroke participants. Nine stroke survivors and nine healthy subjects participated in the study. Participants’ hand was passively moved to the target position guided by the H-Man robot (Criterion movement) and were asked to indicate during a second passive movement towards the same target (Matching movement) when they felt that they matched the target position. The assessment was carried out on a planar surface for movements in the forward and oblique directions in the contralateral and ipsilateral sides of the tested arm. The matching performance was evaluated in terms of error magnitude (absolute and signed) and its variability. Stroke patients showed higher variability in the estimation of the target position compared to the healthy participants. Further, an effect of target was found, with lower absolute errors in the contralateral side. Pairwise comparison between individual stroke participant and control participants showed significant proprioceptive deficits in two patients. The proposed assessment of passive joint position sense was inherently simple and all participants, regardless of motor impairment level, could complete it in less than 10 minutes. Therefore, the method can potentially be carried out to detect changes in proprioceptive deficits in clinical settings. PMID:29161264

Sensing Super-Position: Human Sensing Beyond the Visual Spectrum

NASA Technical Reports Server (NTRS)

Maluf, David A.; Schipper, John F.

2007-01-01

The coming decade of fast, cheap and miniaturized electronics and sensory devices opens new pathways for the development of sophisticated equipment to overcome limitations of the human senses. This paper addresses the technical feasibility of augmenting human vision through Sensing Super-position by mixing natural Human sensing. The current implementation of the device translates visual and other passive or active sensory instruments into sounds, which become relevant when the visual resolution is insufficient for very difficult and particular sensing tasks. A successful Sensing Super-position meets many human and pilot vehicle system requirements. The system can be further developed into cheap, portable, and low power taking into account the limited capabilities of the human user as well as the typical characteristics of his dynamic environment. The system operates in real time, giving the desired information for the particular augmented sensing tasks. The Sensing Super-position device increases the image resolution perception and is obtained via an auditory representation as well as the visual representation. Auditory mapping is performed to distribute an image in time. The three-dimensional spatial brightness and multi-spectral maps of a sensed image are processed using real-time image processing techniques (e.g. histogram normalization) and transformed into a two-dimensional map of an audio signal as a function of frequency and time. This paper details the approach of developing Sensing Super-position systems as a way to augment the human vision system by exploiting the capabilities of Lie human hearing system as an additional neural input. The human hearing system is capable of learning to process and interpret extremely complicated and rapidly changing auditory patterns. The known capabilities of the human hearing system to learn and understand complicated auditory patterns provided the basic motivation for developing an image-to-sound mapping system. The

Assessment of Knee Proprioception in the Anterior Cruciate Ligament Injury Risk Position in Healthy Subjects: A Cross-sectional Study.

PubMed

Mir, Seyed Mohsen; Talebian, Saeed; Naseri, Nasrin; Hadian, Mohammad-Reza

2014-10-01

[Purpose] Knee joint proprioception combines sensory input from a variety of afferent receptors that encompasses the sensations of joint position and motion. Poor proprioception is one of the risk factors of anterior cruciate ligament injury. Most studies have favored testing knee joint position sense in the sagittal plane and non-weight-bearing position. One of the most common mechanisms of noncontact anterior cruciate ligament injury is dynamic knee valgus. No study has measured joint position sense in a manner relevant to the mechanism of injury. Therefore, the aim of this study was to measure knee joint position sense in the noncontact anterior cruciate ligament injury risk position and normal condition. [Subjects and Methods] Thirty healthy male athletes participated in the study. Joint position sense was evaluated by active reproduction of the anterior cruciate ligament injury risk position and normal condition. The dominant knees of subjects were tested. [Results] The results showed less accurate knee joint position sense in the noncontact anterior cruciate ligament injury risk position rather than the normal condition. [Conclusion] The poorer joint position sense in non-contact anterior cruciate ligament injury risk position compared with the normal condition may contribute to the increased incidence of anterior cruciate ligament injury.

Crankshaft position sensing with combined starter alternator

DOEpatents

Brandenburg, Larry Raymond; Miller, John Michael

2000-06-13

A crankshaft position sensing apparatus for use with an engine (16) having a combined starter/alternator assembly (18). The crankshaft position sensing apparatus includes a tone ring (38) with a sensor (36) and bandpass filter (46), having a cylinder identification input from a camshaft sensor (48), and a gain limiter (54). The sensing apparatus mounts near the rotor (30) of the combined starter/alternator assembly (18). The filtered crankshaft position signal can then be input into a vehicle system controller (58) and an inner loop controller (60). The starter/alternator assembly (18) in combination with an internal combustion engine is particularly useful for a hybrid electric vehicle system.

Sensing Super-position: Visual Instrument Sensor Replacement

NASA Technical Reports Server (NTRS)

Maluf, David A.; Schipper, John F.

2006-01-01

The coming decade of fast, cheap and miniaturized electronics and sensory devices opens new pathways for the development of sophisticated equipment to overcome limitations of the human senses. This project addresses the technical feasibility of augmenting human vision through Sensing Super-position using a Visual Instrument Sensory Organ Replacement (VISOR). The current implementation of the VISOR device translates visual and other passive or active sensory instruments into sounds, which become relevant when the visual resolution is insufficient for very difficult and particular sensing tasks. A successful Sensing Super-position meets many human and pilot vehicle system requirements. The system can be further developed into cheap, portable, and low power taking into account the limited capabilities of the human user as well as the typical characteristics of his dynamic environment. The system operates in real time, giving the desired information for the particular augmented sensing tasks. The Sensing Super-position device increases the image resolution perception and is obtained via an auditory representation as well as the visual representation. Auditory mapping is performed to distribute an image in time. The three-dimensional spatial brightness and multi-spectral maps of a sensed image are processed using real-time image processing techniques (e.g. histogram normalization) and transformed into a two-dimensional map of an audio signal as a function of frequency and time. This paper details the approach of developing Sensing Super-position systems as a way to augment the human vision system by exploiting the capabilities of the human hearing system as an additional neural input. The human hearing system is capable of learning to process and interpret extremely complicated and rapidly changing auditory patterns. The known capabilities of the human hearing system to learn and understand complicated auditory patterns provided the basic motivation for developing an

Age-Related Decline of Wrist Position Sense and its Relationship to Specific Physical Training.

PubMed

Van de Winckel, Ann; Tseng, Yu-Ting; Chantigian, Daniel; Lorant, Kaitlyn; Zarandi, Zinat; Buchanan, Jeffrey; Zeffiro, Thomas A; Larson, Mia; Olson-Kellogg, Becky; Konczak, Jürgen; Keller-Ross, Manda L

2017-01-01

Perception of limb and body positions is known as proprioception. Sensory feedback, especially from proprioceptive receptors, is essential for motor control. Aging is associated with a decline in position sense at proximal joints, but there is inconclusive evidence of distal joints being equally affected by aging. In addition, there is initial evidence that physical activity attenuates age-related decline in proprioception. Our objectives were, first, to establish wrist proprioceptive acuity in a large group of seniors and compare their perception to young adults, and second, to determine if specific types of training or regular physical activity are associated with preserved wrist proprioception. We recruited community-dwelling seniors ( n = 107, mean age, 70 ± 5 years, range, 65-84 years) without cognitive decline (Mini Mental State Examination-brief version ≥13/16) and young adult students ( n = 51, mean age, 20 ± 1 years, range, 19-26 years). Participants performed contralateral and ipsilateral wrist position sense matching tasks with a bimanual wrist manipulandum to a 15° flexion reference position. Systematic error or proprioceptive bias was computed as the mean difference between matched and reference position. The respective standard deviation over five trials constituted a measure of random error or proprioceptive precision . Current levels of physical activity and previous sport, musical, or dance training were obtained through a questionnaire. We employed longitudinal mixed effects linear models to calculate the effects of trial number, sex, type of matching task and age on wrist proprioceptive bias and precision. The main results were that relative proprioceptive bias was greater in older when compared to young adults (mean difference: 36% ipsilateral, 88% contralateral, p < 0.01). Proprioceptive precision for contralateral but not for ipsilateral matching was smaller in older than in young adults (mean difference: 38% contralateral, p < 0

Age-Related Decline of Wrist Position Sense and its Relationship to Specific Physical Training

PubMed Central

Van de Winckel, Ann; Tseng, Yu-Ting; Chantigian, Daniel; Lorant, Kaitlyn; Zarandi, Zinat; Buchanan, Jeffrey; Zeffiro, Thomas A.; Larson, Mia; Olson-Kellogg, Becky; Konczak, Jürgen; Keller-Ross, Manda L.

2017-01-01

Perception of limb and body positions is known as proprioception. Sensory feedback, especially from proprioceptive receptors, is essential for motor control. Aging is associated with a decline in position sense at proximal joints, but there is inconclusive evidence of distal joints being equally affected by aging. In addition, there is initial evidence that physical activity attenuates age-related decline in proprioception. Our objectives were, first, to establish wrist proprioceptive acuity in a large group of seniors and compare their perception to young adults, and second, to determine if specific types of training or regular physical activity are associated with preserved wrist proprioception. We recruited community-dwelling seniors (n = 107, mean age, 70 ± 5 years, range, 65–84 years) without cognitive decline (Mini Mental State Examination-brief version ≥13/16) and young adult students (n = 51, mean age, 20 ± 1 years, range, 19–26 years). Participants performed contralateral and ipsilateral wrist position sense matching tasks with a bimanual wrist manipulandum to a 15° flexion reference position. Systematic error or proprioceptive bias was computed as the mean difference between matched and reference position. The respective standard deviation over five trials constituted a measure of random error or proprioceptive precision. Current levels of physical activity and previous sport, musical, or dance training were obtained through a questionnaire. We employed longitudinal mixed effects linear models to calculate the effects of trial number, sex, type of matching task and age on wrist proprioceptive bias and precision. The main results were that relative proprioceptive bias was greater in older when compared to young adults (mean difference: 36% ipsilateral, 88% contralateral, p < 0.01). Proprioceptive precision for contralateral but not for ipsilateral matching was smaller in older than in young adults (mean difference: 38% contralateral, p < 0

The deficit of joint position sense in the chronic unstable ankle as measured by inversion angle replication error.

PubMed

Nakasa, Tomoyuki; Fukuhara, Kohei; Adachi, Nobuo; Ochi, Mitsuo

2008-05-01

Functional instability is defined as a repeated ankle inversion sprain and a giving way sensation. Previous studies have described the damage of sensori-motor control in ankle sprain as being a possible cause of functional instability. The aim of this study was to evaluate the inversion angle replication errors in patients with functional instability after ankle sprain. The difference between the index angle and replication angle was measured in 12 subjects with functional instability, with the aim of evaluating the replication error. As a control group, the replication errors of 17 healthy volunteers were investigated. The side-to-side differences of the replication errors were compared between both the groups, and the relationship between the side-to-side differences of the replication errors and the mechanical instability were statistically analyzed in the unstable group. The side-to-side difference of the replication errors was 1.0 +/- 0.7 degrees in the unstable group and 0.2 +/- 0.7 degrees in the control group. There was a statistically significant difference between both the groups. The side-to-side differences of the replication errors in the unstable group did not statistically correlate to the anterior talar translation and talar tilt. The patients with functional instability had the deficit of joint position sense in comparison with healthy volunteers. The replication error did not correlate to the mechanical instability. The patients with functional instability should be treated appropriately in spite of having less mechanical instability.

Experimental Robot Position Sensor Fault Tolerance Using Accelerometers and Joint Torque Sensors

NASA Technical Reports Server (NTRS)

Aldridge, Hal A.; Juang, Jer-Nan

1997-01-01

Robot systems in critical applications, such as those in space and nuclear environments, must be able to operate during component failure to complete important tasks. One failure mode that has received little attention is the failure of joint position sensors. Current fault tolerant designs require the addition of directly redundant position sensors which can affect joint design. The proposed method uses joint torque sensors found in most existing advanced robot designs along with easily locatable, lightweight accelerometers to provide a joint position sensor fault recovery mode. This mode uses the torque sensors along with a virtual passive control law for stability and accelerometers for joint position information. Two methods for conversion from Cartesian acceleration to joint position based on robot kinematics, not integration, are presented. The fault tolerant control method was tested on several joints of a laboratory robot. The controllers performed well with noisy, biased data and a model with uncertain parameters.

Flexor bias of joint position in humans during spaceflight

NASA Technical Reports Server (NTRS)

McCall, G. E.; Goulet, C.; Boorman, G. I.; Roy, R. R.; Edgerton, V. R.

2003-01-01

The ability to estimate ankle and elbow joint position was tested before, during, and after a 17-day spaceflight. Subjects estimated targeted joint angles during isovelocity (IsoV) joint movements with agonist muscle groups either active or relaxed. These movements included elbow extension (EE) and elbow flexion (EF), and plantarflexion (PF) and dorsiflexion (DF) of the ankle. Subjects also estimated these joint positions while moving the dynamometer at their chosen (variable) velocity (VarV) during EE and PF. For IsoV tests, no differences were observed between active and passive movements for either the ankle or elbow. Compared with those of pre-flight test days, estimates of targeted elbow joint angles were approximately 5 degrees to 15 degrees more flexed in-flight, and returned toward the pre-flight values during recovery. The spaceflight effects for the ankle were inconsistent and less prevalent than those for the elbow. The VarV PF test condition for the 120 degrees target angle at the ankle exhibited approximately 5 degrees to 7 degrees more DF target angle estimates in-flight compared with those pre- or post-flight. In contrast, during IsoV PF there was a tendency for ankle estimates to be approximately 2 degrees to 3 degrees more PF after 2-3 days exposure to spaceflight. These data indicate that during spaceflight the perception of elbow extension is greater than actuality, and are consistent with the interpretation that microgravity induced a flexor bias in the estimation of the actual elbow joint position. Moreover, these effects in joint proprioception during spaceflight were observed in individual isolated single-joint movements during tasks in which vestibular function in maintaining posture were minimal.

Flexor bias of joint position in humans during spaceflight.

PubMed

McCall, G E; Goulet, C; Boorman, G I; Roy, R R; Edgerton, V R

2003-09-01

The ability to estimate ankle and elbow joint position was tested before, during, and after a 17-day spaceflight. Subjects estimated targeted joint angles during isovelocity (IsoV) joint movements with agonist muscle groups either active or relaxed. These movements included elbow extension (EE) and elbow flexion (EF), and plantarflexion (PF) and dorsiflexion (DF) of the ankle. Subjects also estimated these joint positions while moving the dynamometer at their chosen (variable) velocity (VarV) during EE and PF. For IsoV tests, no differences were observed between active and passive movements for either the ankle or elbow. Compared with those of pre-flight test days, estimates of targeted elbow joint angles were approximately 5 degrees to 15 degrees more flexed in-flight, and returned toward the pre-flight values during recovery. The spaceflight effects for the ankle were inconsistent and less prevalent than those for the elbow. The VarV PF test condition for the 120 degrees target angle at the ankle exhibited approximately 5 degrees to 7 degrees more DF target angle estimates in-flight compared with those pre- or post-flight. In contrast, during IsoV PF there was a tendency for ankle estimates to be approximately 2 degrees to 3 degrees more PF after 2-3 days exposure to spaceflight. These data indicate that during spaceflight the perception of elbow extension is greater than actuality, and are consistent with the interpretation that microgravity induced a flexor bias in the estimation of the actual elbow joint position. Moreover, these effects in joint proprioception during spaceflight were observed in individual isolated single-joint movements during tasks in which vestibular function in maintaining posture were minimal.

Virtual Passive Controller for Robot Systems Using Joint Torque Sensors

NASA Technical Reports Server (NTRS)

Aldridge, Hal A.; Juang, Jer-Nan

1997-01-01

This paper presents a control method based on virtual passive dynamic control that will stabilize a robot manipulator using joint torque sensors and a simple joint model. The method does not require joint position or velocity feedback for stabilization. The proposed control method is stable in the sense of Lyaponov. The control method was implemented on several joints of a laboratory robot. The controller showed good stability robustness to system parameter error and to the exclusion of nonlinear dynamic effects on the joints. The controller enhanced position tracking performance and, in the absence of position control, dissipated joint energy.

Impaired limb position sense after stroke: a quantitative test for clinical use.

PubMed

Carey, L M; Oke, L E; Matyas, T A

1996-12-01

A quantitative measure of wrist position sense was developed to advance clinical measurement of proprioceptive limb sensibility after stroke. Test-retest reliability, normative standards, and ability to discriminate impaired and unimpaired performance were investigated. Retest reliability was assessed over three sessions, and a matched-pairs study compared stroke and unimpaired subjects. Both wrists were tested, in counterbalanced order. Patients were tested in hospital-based rehabilitation units. Reliability was investigated on a consecutive sample of 35 adult stroke patients with a range of proprioceptive discrimination abilities and no evidence of neglect. A consecutive sample of 50 stroke patients and convenience sample of 50 healthy volunteers, matched for age, sex, and hand dominance, were tested in the normative-discriminative study. Age and sex were representative of the adult stroke population. The test required matching of imposed wrist positions using a pointer aligned with the axis of movement and a protractor scale. The test was reliable (r = .88 and .92) and observed changes of 8 degrees can be interpreted, with 95% confidence, as genuine. Scores of healthy volunteers ranged from 3.1 degrees to 10.9 degrees average error. The criterion of impairment was conservatively defined as 11 degrees (+/-4.8 degrees) average error. Impaired and unimpaired performance were well differentiated. Clinicians can confidently and quantitatively sample one aspect of proprioceptive sensibility in stroke patients using the wrist position sense test. Development of tests on other joints using the present approach is supported by our findings.

Novel Methods for Sensing Acoustical Emissions From the Knee for Wearable Joint Health Assessment.

PubMed

Teague, Caitlin N; Hersek, Sinan; Toreyin, Hakan; Millard-Stafford, Mindy L; Jones, Michael L; Kogler, Geza F; Sawka, Michael N; Inan, Omer T

2016-08-01

We present the framework for wearable joint rehabilitation assessment following musculoskeletal injury. We propose a multimodal sensing (i.e., contact based and airborne measurement of joint acoustic emission) system for at-home monitoring. We used three types of microphones-electret, MEMS, and piezoelectric film microphones-to obtain joint sounds in healthy collegiate athletes during unloaded flexion/extension, and we evaluated the robustness of each microphone's measurements via: 1) signal quality and 2) within-day consistency. First, air microphones acquired higher quality signals than contact microphones (signal-to-noise-and-interference ratio of 11.7 and 12.4 dB for electret and MEMS, respectively, versus 8.4 dB for piezoelectric). Furthermore, air microphones measured similar acoustic signatures on the skin and 5 cm off the skin (∼4.5× smaller amplitude). Second, the main acoustic event during repetitive motions occurred at consistent joint angles (intra-class correlation coefficient ICC(1, 1) = 0.94 and ICC(1, k) = 0.99). Additionally, we found that this angular location was similar between right and left legs, with asymmetry observed in only a few individuals. We recommend using air microphones for wearable joint sound sensing; for practical implementation of contact microphones in a wearable device, interface noise must be reduced. Importantly, we show that airborne signals can be measured consistently and that healthy left and right knees often produce a similar pattern in acoustic emissions. These proposed methods have the potential for enabling knee joint acoustics measurement outside the clinic/lab and permitting long-term monitoring of knee health for patients rehabilitating an acute knee joint injury.

Estimation of Finger Joint Angles Based on Electromechanical Sensing of Wrist Shape.

PubMed

Kawaguchi, Junki; Yoshimoto, Shunsuke; Kuroda, Yoshihiro; Oshiro, Osamu

2017-09-01

An approach to finger motion capture that places fewer restrictions on the usage environment and actions of the user is an important research topic in biomechanics and human-computer interaction. We proposed a system that electrically detects finger motion from the associated deformation of the wrist and estimates the finger joint angles using multiple regression models. A wrist-mounted sensing device with 16 electrodes detects deformation of the wrist from changes in electrical contact resistance at the skin. In this study, we experimentally investigated the accuracy of finger joint angle estimation, the adequacy of two multiple regression models, and the resolution of the estimation of total finger joint angles. In experiments, both the finger joint angles and the system output voltage were recorded as subjects performed flexion/extension of the fingers. These data were used for calibration using the least-squares method. The system was found to be capable of estimating the total finger joint angle with a root-mean-square error of 29-34 degrees. A multiple regression model with a second-order polynomial basis function was shown to be suitable for the estimation of all total finger joint angles, but not those of the thumb.

Validity and Reliability of a Digital Inclinometer to Assess Knee Joint Position Sense in a Closed Kinetic Chain.

PubMed

Romero-Franco, Natalia; Montaño-Munuera, Juan Antonio; Jiménez-Reyes, Pedro

2017-01-01

Knee joint position sense (JPS) is a key parameter for optimum performance in many sports but is frequently negatively affected by injuries and/or fatigue during training sessions. Although evaluation of JPS may provide key information to reduce the risk of injury, it often requires expensive and/or complex tools that make monitoring proprioceptive deterioration difficult. To analyze the validity and reliability of a digital inclinometer to measure knee JPS in a closed kinetic chain (CKC). The validity and intertester and intratester reliability of a digital inclinometer for measuring knee JPS were assessed. Biomechanics laboratory. 10 athletes (5 men and 5 women; 26.2 ± 1.3 y, 71.7 ± 12.4 kg; 1.75 ± 0.09 m; 23.5 ± 3.9 kg/m 2 ). Knee JPS was measured in a CKC. Absolute angular error (AAE) of knee JPS in a CKC. Intraclass correlation coefficient (ICC) and standard error of the mean (SEM) were calculated to determine the validity and reliability of the inclinometer. Data showed that the inclinometer had a high level of validity compared with an isokinetic dynamometer (ICC = 1.0, SEM = 1.39, p < 0.001), and there was very good intra- and inter-tester reliability for reading the inclinometer (ICC = 1.0, SEM = 0.85, p < 0.001). Compared with AutoCAD video analysis, inclinometer validity was very high (ICC = 0.980, SEM = 3.46, p < 0.001) for measuring AAE during knee JPS in a CKC. In addition, the intertester reliability of the inclinometer for obtaining AAE was very high (ICC = .994, SEM = 1.67, p < 0.001). The inclinometer provides a valid and reliable method for assessing knee JPS in a CKC. Health and sports professionals could take advantage of this tool to monitor proprioceptive deterioration in athletes.

Validity and Reliability of a Digital Inclinometer to Assess Knee Joint Position Sense in an Open Kinetic Chain.

PubMed

Romero-Franco, Natalia; Montaño-Munuera, Juan Antonio; Fernández-Domínguez, Juan Carlos; Jiménez-Reyes, Pedro

2017-12-18

New methods are being validated to easily evaluate the knee joint position sense (JPS) due to its role in sports movement and the risk of injury. However, no studies to date have considered the open kinetic chain (OKC) technique, despite the biomechanical differences compared to closed kinetic chain movements. To analyze the validity and reliability of a digital inclinometer to measure the knee JPS in the OKC movement. The validity, inter-tester and intra-tester reliability of a digital inclinometer for measuring knee JPS were evaluated. Sports research laboratory. Eighteen athletes (11 males and 7 females; 28.4 ± 6.6 years; 71.9 ± 14.0 kg; 1.77 ± 0.09 m; 22.8 ± 3.2 kg/m 2 ) voluntary participated in this study. Absolute angular error (AAE), relative angular error (RAE) and variable angular error (VAE) of knee JPS in an OKC. Intraclass correlation coefficient (ICC) and standard error of the mean (SEM) were calculated to determine the validity and reliability of the inclinometer. Data showed excellent validity of the inclinometer to obtain proprioceptive errors compared to the video analysis in JPS tasks (AAE: ICC = 0.981, SEM = 0.08; RAE: ICC = 0.974, SEM = 0.12; VAE: ICC = 0.973, SEM = 0.07). Inter-tester reliability was also excellent for all the proprioceptive errors (AAE: ICC = 0.967, SEM = 0.04; RAE: ICC = 0.974, SEM = 0.03; VAE: ICC = 0.939, SEM = 0.08). Similar results were obtained for intra-tester reliability (AAE: ICC = 0.861, SEM = 0.1; RAE: ICC = 0.894, SEM = 0.1; VAE: ICC = 0.700, SEM = 0.2). The digital inclinometer is a valid and reliable method to assess the knee JPS in OKC. Sport professionals may evaluate the knee JPS to monitor its deterioration during training or improvements throughout the rehabilitation process.

Quantification of upper limb position sense using an exoskeleton and a virtual reality display.

PubMed

Deblock-Bellamy, Anne; Batcho, Charles Sebiyo; Mercier, Catherine; Blanchette, Andreanne K

2018-03-16

Proprioceptive sense plays a significant role in the generation and correction of skilled movements and, consequently, in most activities of daily living. We developed a new proprioception assessment protocol that enables the quantification of elbow position sense without using the opposite arm, involving active movement of the evaluated limb or relying on working memory. The aims of this descriptive study were to validate this assessment protocol by quantifying the elbow position sense of healthy adults, before using it in individuals who sustained a stroke, and to investigate its test-retest reliability. Elbow joint position sense was quantified using a robotic device and a virtual reality system. Two assessments were performed, by the same evaluator, with a one-week interval. While the participant's arms and hands were occluded from vision, the exoskeleton passively moved the dominant arm from an initial to a target position. Then, a virtual arm representation was projected on a screen placed over the participant's arm. This virtual representation and the real arm were not perfectly superimposed, however. Participants had to indicate verbally the relative position of their arm (more flexed or more extended; two-alternative forced choice paradigm) compared to the virtual representation. Each participant completed a total of 136 trials, distributed in three phases. The angular differences between the participant's arm and the virtual representation ranged from 1° to 27° and changed pseudo-randomly across trials. No feedback about results was provided to the participants during the task. A discrimination threshold was statistically extracted from a sigmoid curve fit representing the relationship between the angular difference and the percentage of successful trials. Test-retest reliability was evaluated with 3 different complementary approaches, i.e. a Bland-Altman analysis, an intraclass correlation coefficient (ICC) and a standard error of measurement (SEm

Optical sample-position sensing for electrostatic levitation

NASA Technical Reports Server (NTRS)

Sridharan, G.; Chung, S.; Elleman, D.; Whim, W. K.

1989-01-01

A comparative study is conducted for optical position-sensing techniques applicable to micro-G conditions sample-levitation systems. CCD sensors are compared with one- and two-dimensional position detectors used in electrostatic particle levitation. In principle, the CCD camera method can be improved from current resolution levels of 200 microns through the incorporation of a higher-pixel device and more complex digital signal processor interface. Nevertheless, the one-dimensional position detectors exhibited superior, better-than-one-micron resolution.

Joint positions matter for ultrasound examination of RA patients-increased power Doppler signal in neutral versus flat position of hands.

PubMed

Husic, Rusmir; Lackner, Angelika; Stradner, Martin H; Hermann, Josef; Dejaco, Christian

2017-08-01

Position of joints might influence the result of US examination in patients with RA. The purpose of this work was to compare grey-scale (GS) and power Doppler (PWD) findings obtained in neutral vs flat position of hands. A cross-sectional study of 42 RA patients with active disease. Two dimensional and 3D sonography of wrists and MCP joints were conducted in two different joint positions: neutral position, which is a slight flexion of the fingers with relaxed extensor muscles; and flat position, where all palm and volar sides of fingers touch the Table. Two dimensional GS synovitis (GSS) and PWD signals were scored semi-quantitatively (0-3). For 3D sonography, the percentage of PWD voxels within a region of interest was calculated. GSS was not quantified using 3D sonography. Compared with neutral position, 2D PWD signals disappeared in 28.3% of joints upon flattening. The median global 2D PWD score (sum of all PWD scores of an individual patient) decreased from 8 to 3 ( P < 0.001), and the global 3D PWD voxel score from 3.8 to 0.9 ( P < 0.001). The reduction of PWD scores was similar in all joints (2D: minus 50%, 3D: minus 66.4-80.1%). Inter- and intrareader agreement of PWD results was good (intraclass correlation coefficient: 0.75-0.82). In RA, a neutral position of the hands is linked to a higher sensitivity of 2D and 3D sonography in detecting PWD signals at wrists and MCP joints, compared with a flat position. Standardization of the scanning procedure is essential for obtaining comparable US results in RA patients in trials and clinical routines. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Effects of joint position on the distraction distance during grade III glenohumeral joint distraction in healthy individuals

PubMed Central

Park, Sam-Sik; Kim, Bo-Kyung; Moon, Ok-Kon; Choi, Wan-Suk

2015-01-01

[Purpose] The study investigated the effects of joint position on the distraction distance during Grade III glenohumeral joint distraction in healthy individuals. [Subjects and Methods] Twenty adults in their forties without shoulder disease were randomly divided into neutral position group (NPG; n = 7), resting position group (RPG; n = 7), and end range position group (ERPG; n = 6). After Kaltenborn Grade III distraction for 40s, the distance between glenoid fossa and humeral head was measured by ultrasound. [Results] The average distances between the humeral head and glenoid fossa before distraction were 2.86 ± 0.81, 3.21 ± 0.47, and 3.55 ± 0.59 mm for the NP, RP, and ERP groups. The distances after applying distraction were 3.12 ± 0.51, 3.86 ± 0.55, and 4.35 ± 0.32 mm. Between-group comparison after applying distraction revealed no significant differences between the NP and RP groups, while there was a statistically significant difference between the NP and RP groups, as well as between the NP and ERP groups. [Conclusion] Joint space was largest in ERP individuals when performing manual distraction. PMID:26644692

A novel 4-DOF surgical instrument with modular joints and 6-Axis Force sensing capability.

PubMed

Li, Kun; Pan, Bo; Zhang, Fuhai; Gao, Wenpeng; Fu, Yili; Wang, Shuguo

2017-03-01

It is difficult for surgeons to exert appropriate forces during delicate operations due to lack of force feedback in robot-assisted minimally invasive surgery (RMIS). A 4-DOF surgical grasper with a modular wrist and 6-axis force sensing capability is developed. A grasper integrated with a miniature force and torque sensor based on the Stewart platform is designed, and a cable tension decomposition mechanism is designed to alleviate influence of the cable tension to the sensor. A modularized wrist consisting of four joint units is designed to facilitate integration of the sensor and eliminate coupled motion of the wrist. Sensing ranges of this instrument are ±10 N and ±160 N mm, and resolutions are 1.2% in radial directions, 5% in axial direction, and 4.2% in rotational directions. An ex vivo experiment shows that this instrument prototype successfully measures the interaction forces. A 4-DOF surgical instrument with modular joints and 6-axis force sensing capability is developed. This instrument can be used for force feedback in RMIS. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Elastic Tape Improved Shoulder Joint Position Sense in Chronic Hemiparetic Subjects: A Randomized Sham-Controlled Crossover Study.

PubMed

Santos, Gabriela Lopes Dos; Souza, Matheus Bragança; Desloovere, Kaat; Russo, Thiago Luiz

2017-01-01

Elastic tape has been widely used in clinical practice in order to improve upper limb (UL) sensibility. However, there is little evidence that supports this type of intervention in stroke patients. To verify the effect of elastic tape, applied to the paretic shoulder, on joint position sense (JPS) during abduction and flexion in subjects with chronic hemiparesis compared to sham tape (non-elastic tape). Furthermore, to verify if this potential effect is correlated to shoulder subluxation measurements and sensorimotor impairment. A crossover and sham-controlled study was conducted with post-stroke patients who were randomly allocated into two groups: 1) those who received Sham Tape (ST) first and after one month they received Elastic Tape (ET); 2) those who received Elastic Tape (ET) first and after one month they received Sham Tape (ST). The JPS was evaluated using a dynamometer. The absolute error for shoulder abduction and flexion at 30° and 60° was calculated. Sensorimotor impairment was determined by Fugl-Meyer, and shoulder subluxation was measured using a caliper. Thirteen hemiparetic subjects (average time since stroke 75.23 months) participated in the study. At baseline (before interventions), the groups were not different for abduction at 30° (p = 0.805; p = 0.951), and 60° (p = 0.509; p = 0.799), or flexion at 30° (p = 0.872; p = 0.897) and 60° (p = 0.853; p = 0.970). For the ET group, differences between pre and post-elastic tape for abduction at 30° (p<0.010) and 60° (p<0.010), and flexion at 30° p<0.010) and 60° (p<0.010) were observed. For the ST group, differences were also observed between pre and post-elastic tape for abduction at 30° (p<0.010) and 60° (p<0.010), and flexion at 30° (p<0.010,) and 60° (p<0.010). Potential effects were only correlated with shoulder subluxation during abduction at 30° (p = 0.001, r = -0.92) and 60° (p = 0.020, r = -0.75). Elastic tape improved shoulder JPS of subjects with chronic hemiparesis

Robotic Quantification of Position Sense in Children With Perinatal Stroke.

PubMed

Kuczynski, Andrea M; Dukelow, Sean P; Semrau, Jennifer A; Kirton, Adam

2016-09-01

Background Perinatal stroke is the leading cause of hemiparetic cerebral palsy. Motor deficits and their treatment are commonly emphasized in the literature. Sensory dysfunction may be an important contributor to disability, but it is difficult to measure accurately clinically. Objective Use robotics to quantify position sense deficits in hemiparetic children with perinatal stroke and determine their association with common clinical measures. Methods Case-control study. Participants were children aged 6 to 19 years with magnetic resonance imaging-confirmed unilateral perinatal arterial ischemic stroke or periventricular venous infarction and symptomatic hemiparetic cerebral palsy. Participants completed a position matching task using an exoskeleton robotic device (KINARM). Position matching variability, shift, and expansion/contraction area were measured with and without vision. Robotic outcomes were compared across stroke groups and controls and to clinical measures of disability (Assisting Hand Assessment) and sensory function. Results Forty stroke participants (22 arterial, 18 venous, median age 12 years, 43% female) were compared with 60 healthy controls. Position sense variability was impaired in arterial (6.01 ± 1.8 cm) and venous (5.42 ± 1.8 cm) stroke compared to controls (3.54 ± 0.9 cm, P < .001) with vision occluded. Impairment remained when vision was restored. Robotic measures correlated with functional disability. Sensitivity and specificity of clinical sensory tests were modest. Conclusions Robotic assessment of position sense is feasible in children with perinatal stroke. Impairment is common and worse in arterial lesions. Limited correction with vision suggests cortical sensory network dysfunction. Disordered position sense may represent a therapeutic target in hemiparetic cerebral palsy. © The Author(s) 2016.

Simultaneous piston position and tilt angle sensing for large vertical displacement micromirrors by frequency detection inductive sensing

NASA Astrophysics Data System (ADS)

Tseng, V. F.-G.; Xie, H.

2015-11-01

This paper presents a frequency detection based inductive eddy current sensing mechanism to simultaneously sense the piston position and tilt angle of the mirror plate of large vertical displacement micromirrors that exhibit piston scan ranges above 100 μm. This is accomplished by sensing the inductance change, and thus resonant frequency shift, of two microfabricated sensing coils packaged underneath the mirror plate. For demonstration purpose, the coils were paired with discrete circuit components to oscillate at 11.9 MHz and 12.5 MHz, respectively. The piston position and tilt angle of the mirror plate could be simultaneously monitored over a 500 μm piston scan range, achieving a maximum piston sensitivity of 4.15 kHz/μm with a piston sensing resolution of 96 nm and a maximum tilt angle sensitivity of 60.5 kHz/° with a tilt angle sensing resolution of 0.0013°. Analytical modeling of the coil inductance change via image theory was also conducted, showing that the sensor sensitivity and resolution could be improved by increasing the coil oscillation frequency and decreasing the coil size.

Upper Limb Asymmetries in the Perception of Proprioceptively Determined Dynamic Position Sense

ERIC Educational Resources Information Center

Goble, Daniel J.; Brown, Susan H.

2010-01-01

Recent studies of position-related proprioceptive sense have provided evidence of a nonpreferred left arm advantage in right-handed individuals. The present study sought to determine whether similar asymmetries might exist in "dynamic position" sense. Thirteen healthy, right-handed adults were blindfolded and seated with arms placed on…

Knee joint position sense ability in elite athletes who have returned to international level play following ACL reconstruction: A cross-sectional study.

PubMed

Relph, Nicola; Herrington, Lee

2016-12-01

Following an ACL injury, reconstruction (ACL-R) and rehabilitation, athletes may return to play with a proprioceptive deficit. However, literature is lacking to support this hypothesis in elite athletic groups who have returned to international levels of performance. It is possible the potentially heightened proprioceptive ability evidenced in athletes may negate a deficit following injury. The purpose of this study was to consider the effects of ACL injury, reconstruction and rehabilitation on knee joint position sense (JPS) on a group of elite athletes who had returned to international performance. Using a cross-sectional design ten elite athletes with ACL-R and ten controls were evaluated. JPS was tested into knee extension and flexion using absolute error scores. Average data with 95% confidence intervals between the reconstructed, contralateral and uninjured control knees were analyzed using t-tests and effect sizes. The reconstructed knee of the injured group demonstrated significantly greater angle of error scores when compared to the contralateral and uninjured control into knee flexion (p=0.0001, r=0.98) and knee extension (p=0.0001, r=0.91). There were no significant differences between the contralateral uninjured knee of the injured group and the uninjured control group. Elite athletes who have had an ACL injury, reconstruction, rehabilitation and returned to international play demonstrate lower JPS ability compared to control groups. It is unclear if this deficiency affects long-term performance or secondary injury and re-injury problems. In the future physical therapists should monitor athletes longitudinally when they return to play. Copyright © 2016 Elsevier B.V. All rights reserved.

System Wide Joint Position Sensor Fault Tolerance in Robot Systems Using Cartesian Accelerometers

NASA Technical Reports Server (NTRS)

Aldridge, Hal A.; Juang, Jer-Nan

1997-01-01

Joint position sensors are necessary for most robot control systems. A single position sensor failure in a normal robot system can greatly degrade performance. This paper presents a method to obtain position information from Cartesian accelerometers without integration. Depending on the number and location of the accelerometers. the proposed system can tolerate the loss of multiple position sensors. A solution technique suitable for real-time implementation is presented. Simulations were conducted using 5 triaxial accelerometers to recover from the loss of up to 4 joint position sensors on a 7 degree of freedom robot moving in general three dimensional space. The simulations show good estimation performance using non-ideal accelerometer measurements.

Dizziness and unsteadiness following whiplash injury: characteristic features and relationship with cervical joint position error.

PubMed

Treleaven, Julia; Jull, Gwendolen; Sterling, Michele

2003-01-01

Dizziness and/or unsteadiness are common symptoms of chronic whiplash-associated disorders. This study aimed to report the characteristics of these symptoms and determine whether there was any relationship to cervical joint position error. Joint position error, the accuracy to return to the natural head posture following extension and rotation, was measured in 102 subjects with persistent whiplash-associated disorder and 44 control subjects. Whiplash subjects completed a neck pain index and answered questions about the characteristics of dizziness. The results indicated that subjects with whiplash-associated disorders had significantly greater joint position errors than control subjects. Within the whiplash group, those with dizziness had greater joint position errors than those without dizziness following rotation (rotation (R) 4.5 degrees (0.3) vs 2.9 degrees (0.4); rotation (L) 3.9 degrees (0.3) vs 2.8 degrees (0.4) respectively) and a higher neck pain index (55.3% (1.4) vs 43.1% (1.8)). Characteristics of the dizziness were consistent for those reported for a cervical cause but no characteristics could predict the magnitude of joint position error. Cervical mechanoreceptor dysfunction is a likely cause of dizziness in whiplash-associated disorder.

Characterisation of a knee-joint energy harvester powering a wireless communication sensing node

NASA Astrophysics Data System (ADS)

Kuang, Yang; Zhu, Meiling

2016-05-01

Human-based energy harvesters are attractive as sustainable replacements for batteries to power wearable or implantable devices and body sensor networks. In the work presented here, a knee-joint energy harvester (KEH) was introduced to power a customer-built wireless communication sensing node (WCSN). The KEH used a mechanical plucking technique to provide sufficient frequency up-conversion—from a few Hz to the resonant frequency of the KEH—so as to generate the high power required. It was actuated by a knee-joint simulator, which reproduced the knee-joint motion of human gaits at a walking frequency of 0.9 Hz. The energy generated was first stored in a reservoir capacitor and then released to the WCSN in a burst mode with the help of an energy aware interface. The WCSN was deployed with a three-axis accelerometer, a temperature sensor, and a light detector for data sensing. A Jennic microcontroller was utilised to collect and transmit the measured data to a base station placed at a distance of 4 m. The energy generation by the KEH and the energy distribution in the system was characterised in real time by an in-house-built set-up. The results showed that the KEH generated an average power output of 1.76 mW when powering the WCSN. After charging the reservoir capacitor for 28.4 s, the KEH can power the WCSN for a 46 ms period every 1.25 s. The results also clearly illustrated how the energy generated by the KEH was distributed in the system and highlighted the importance of using a high performance power management approach to improve the performance of the whole system.

Mathematical model of a DIC position sensing system within an optical trap

NASA Astrophysics Data System (ADS)

Wulff, Kurt D.; Cole, Daniel G.; Clark, Robert L.

2005-08-01

The quantitative study of displacements and forces of motor proteins and processes that occur at the microscopic level and below require a high level of sensitivity. For optical traps, two techniques for position sensing have been accepted and used quite extensively: quadrant photodiodes and an interferometric position sensing technique based on DIC imaging. While quadrant photodiodes have been studied in depth and mathematically characterized, a mathematical characterization of the interferometric position sensor has not been presented to the authors' knowledge. The interferometric position sensing method works off of the DIC imaging capabilities of a microscope. Circularly polarized light is sent into the microscope and the Wollaston prism used for DIC imaging splits the beam into its orthogonal components, displacing them by a set distance determined by the user. The distance between the axes of the beams is set so the beams overlap at the specimen plane and effectively share the trapped microsphere. A second prism then recombines the light beams and the exiting laser light's polarization is measured and related to position. In this paper we outline the mathematical characterization of a microsphere suspended in an optical trap using a DIC position sensing method. The sensitivity of this mathematical model is then compared to the QPD model. The mathematical model of a microsphere in an optical trap can serve as a calibration curve for an experimental setup.

The mechanoreceptors of the costo-vertebral joints

PubMed Central

Godwin-Austen, R. B.

1969-01-01

1. Unitary recording in the thoracic dorsal roots of mechanoreceptor discharges from the costo-vertebral joints was carried out in the cat and rabbit. Criteria for the identification of costo-vertebral joint mechanoreceptors were established. 2. The majority of rib joint mechanoreceptors are slowly adapting and fifty-three such receptors were studied. Five rapidly adapting receptors were also identified. 3. The responses of these receptors have been correlated with rib position and movement. The slowly adapting receptors gave a monotonic response to different rib positions. 72% showed an increase of discharge rate with displacements towards expiratory rib positions. 4. In response to manually imposed rib movements slowly adapting joint mechanoreceptors gave a dynamic response which was directly related to the velocity of the movement and adapted within 2 sec. The movements of breathing produced a corresponding alteration of the discharge frequency of the slowly adapting receptors. 5. Slowly adapting receptors were localized to the capsule of the costo-transverse joint by probing. They responded to increased intra-articular pressure with an increase of discharge rate and were silenced by intra-articular lignocaine, 0·4%. 6. Rapidly adapting joint mechanoreceptors responded to rib movement with a brief burst of discharges. 7. The rib joint mechanoreceptors signal rib joint position, and the direction and velocity of rib movement. It is suggested that these afferent discharges provide the basis for the perception of respiratory movements of the chest. The significance of these receptors to the `sense of effort' resulting from a resistance to breathing is discussed. PMID:5789947

Action planning and position sense in children with Developmental Coordination Disorder.

PubMed

Adams, Imke L J; Ferguson, Gillian D; Lust, Jessica M; Steenbergen, Bert; Smits-Engelsman, Bouwien C M

2016-04-01

The present study examined action planning and position sense in children with Developmental Coordination Disorder (DCD). Participants performed two action planning tasks, the sword task and the bar grasping task, and an active elbow matching task to examine position sense. Thirty children were included in the DCD group (aged 6-10years) and age-matched to 90 controls. The DCD group had a MABC-2 total score ⩽5th percentile, the control group a total score ⩾25th percentile. Results from the sword-task showed that children with DCD planned less for end-state comfort. On the bar grasping task no significant differences in planning for end-state comfort between the DCD and control group were found. There was also no significant difference in the position sense error between the groups. The present study shows that children with DCD plan less for end-state comfort, but that this result is task-dependent and becomes apparent when more precision is needed at the end of the task. In that respect, the sword-task appeared to be a more sensitive task to assess action planning abilities, than the bar grasping task. The action planning deficit in children with DCD cannot be explained by an impaired position sense during active movements. Copyright © 2016 Elsevier B.V. All rights reserved.

A Police and Insurance Joint Management System Based on High Precision BDS/GPS Positioning

PubMed Central

Zuo, Wenwei; Guo, Chi; Liu, Jingnan; Peng, Xuan; Yang, Min

2018-01-01

Car ownership in China reached 194 million vehicles at the end of 2016. The traffic congestion index (TCI) exceeds 2.0 during rush hour in some cities. Inefficient processing for minor traffic accidents is considered to be one of the leading causes for road traffic jams. Meanwhile, the process after an accident is quite troublesome. The main reason is that it is almost always impossible to get the complete chain of evidence when the accident happens. Accordingly, a police and insurance joint management system is developed which is based on high precision BeiDou Navigation Satellite System (BDS)/Global Positioning System (GPS) positioning to process traffic accidents. First of all, an intelligent vehicle rearview mirror terminal is developed. The terminal applies a commonly used consumer electronic device with single frequency navigation. Based on the high precision BDS/GPS positioning algorithm, its accuracy can reach sub-meter level in the urban areas. More specifically, a kernel driver is built to realize the high precision positioning algorithm in an Android HAL layer. Thus the third-party application developers can call the general location Application Programming Interface (API) of the original standard Global Navigation Satellite System (GNSS) to get high precision positioning results. Therefore, the terminal can provide lane level positioning service for car users. Next, a remote traffic accident processing platform is built to provide big data analysis and management. According to the big data analysis of information collected by BDS high precision intelligent sense service, vehicle behaviors can be obtained. The platform can also automatically match and screen the data that uploads after an accident to achieve accurate reproduction of the scene. Thus, it helps traffic police and insurance personnel to complete remote responsibility identification and survey for the accident. Thirdly, a rapid processing flow is established in this article to meet the

A Police and Insurance Joint Management System Based on High Precision BDS/GPS Positioning.

PubMed

Zuo, Wenwei; Guo, Chi; Liu, Jingnan; Peng, Xuan; Yang, Min

2018-01-10

Car ownership in China reached 194 million vehicles at the end of 2016. The traffic congestion index (TCI) exceeds 2.0 during rush hour in some cities. Inefficient processing for minor traffic accidents is considered to be one of the leading causes for road traffic jams. Meanwhile, the process after an accident is quite troublesome. The main reason is that it is almost always impossible to get the complete chain of evidence when the accident happens. Accordingly, a police and insurance joint management system is developed which is based on high precision BeiDou Navigation Satellite System (BDS)/Global Positioning System (GPS) positioning to process traffic accidents. First of all, an intelligent vehicle rearview mirror terminal is developed. The terminal applies a commonly used consumer electronic device with single frequency navigation. Based on the high precision BDS/GPS positioning algorithm, its accuracy can reach sub-meter level in the urban areas. More specifically, a kernel driver is built to realize the high precision positioning algorithm in an Android HAL layer. Thus the third-party application developers can call the general location Application Programming Interface (API) of the original standard Global Navigation Satellite System (GNSS) to get high precision positioning results. Therefore, the terminal can provide lane level positioning service for car users. Next, a remote traffic accident processing platform is built to provide big data analysis and management. According to the big data analysis of information collected by BDS high precision intelligent sense service, vehicle behaviors can be obtained. The platform can also automatically match and screen the data that uploads after an accident to achieve accurate reproduction of the scene. Thus, it helps traffic police and insurance personnel to complete remote responsibility identification and survey for the accident. Thirdly, a rapid processing flow is established in this article to meet the

Whole-body vibration does not influence knee joint neuromuscular function or proprioception.

PubMed

Hannah, R; Minshull, C; Folland, J P

2013-02-01

This study examined the acute effects of whole-body vibration (WBV) on knee joint position sense and indices of neuromuscular function, specifically strength, electromechanical delay and the rate of force development. Electromyography and electrically evoked contractions were used to investigate neural and contractile responses to WBV. Fourteen healthy males completed two treatment conditions on separate occasions: (1) 5 × 1 min of unilateral isometric squat exercise on a synchronous vibrating platform [30 Hz, 4 mm peak-to-peak amplitude] (WBV) and (2) a control condition (CON) of the same exercise without WBV. Knee joint position sense (joint angle replication task) and quadriceps neuromuscular function were assessed pre-, immediately-post and 1 h post-exercise. During maximum voluntary knee extensions, the peak force (PF(V)), electromechanical delay (EMD(V)), rate of force development (RFD(V)) and EMG of the quadriceps were measured. Twitch contractions of the knee extensors were electrically evoked to assess EMD(E) and RFD(E). The results showed no influence of WBV on knee joint position, EMD(V), PF(V) and RFD(V) during the initial 50, 100 or 150 ms of contraction. Similarly, electrically evoked neuromuscular function and neural activation remained unchanged following the vibration exercise. A single session of unilateral WBV did not influence any indices of thigh muscle neuromuscular performance or knee joint proprioception. © 2011 John Wiley & Sons A/S.

Correlations among pelvic positions and differences in lower extremity joint angles during walking in female university students.

PubMed

Cho, Misuk

2015-06-01

[Purpose] This study aimed to identify correlations among pelvic positions and differences in lower extremity joint angles during walking in female university students. [Subjects] Thirty female university students were enrolled and their pelvic positions and differences in lower extremity joint angles were measured. [Methods] Pelvic position, pelvic torsion, and pelvic rotation were assessed using the BackMapper. In addition, motion analysis was performed to derive differences between left and right flexion, abduction, and external rotation ranges of hip joints; flexion, abduction, and external rotation ranges of knee joints; and dorsiflexion, inversion, and abduction ranges of ankle joints, according to X, Y, and Z-axes. [Results] Pelvic position was found to be positively correlated with differences between left and right hip flexion (r=0.51), hip abduction (r=0.62), knee flexion (r=0.45), knee abduction (r=0.42), and ankle inversion (r=0.38). In addition, the difference between left and right hip abduction showed a positive correlation with difference between left and right ankle dorsiflexion (r=0.64). Moreover, differences between left and right knee flexion exhibited positive correlations with differences between left and right knee abduction (r=0.41) and ankle inversion (r=0.45). [Conclusion] Bilateral pelvic tilt angles are important as they lead to bilateral differences in lower extremity joint angles during walking.

Influence of a Full-Body Compression Suit on Trunk Positioning and Knee Joint Mechanics During Lateral Movements.

PubMed

Mornieux, Guillaume; Weltin, Elmar; Pauls, Monika; Rott, Franz; Gollhofer, Albert

2017-08-01

Trunk positioning has been shown to be associated with knee joint loading during athletic tasks, especially changes of direction. The purpose of the present study was to test whether a full-body compression suit (FBCS) would improve trunk positioning and knee joint control during lateral movements. Twelve female athletes performed lateral reactive jumps (LRJ) and unanticipated cuttings with and without the customized FBCS, while 3D kinematics and kinetics were measured. FBCS did not influence trunk positioning during LRJ and led to increased trunk lateral lean during cuttings (P < .001). However, while wearing FBCS, knee joint abduction and internal rotation angles were reduced during LRJ (P < .001 and P = .013, respectively), whereas knee joint moments were comparable during cuttings. FBCS cannot support the trunk segment during unanticipated dynamic movements. But, increased trunk lateral lean during cutting maneuvers was not high enough to elicit increased knee joint moments. On the contrary, knee joint abduction and internal rotation were reduced during LRJ, speaking for a better knee joint alignment with FBCS. Athletes seeking to improve trunk positioning may not benefit from a FBCS.

Automatic control of positioning along the joint during EBW in conditions of action of magnetic fields

NASA Astrophysics Data System (ADS)

Druzhinina, A. A.; Laptenok, V. D.; Murygin, A. V.; Laptenok, P. V.

2016-11-01

Positioning along the joint during the electron beam welding is a difficult scientific and technical problem to achieve the high quality of welds. The final solution of this problem is not found. This is caused by weak interference protection of sensors of the joint position directly in the welding process. Frequently during the electron beam welding magnetic fields deflect the electron beam from the optical axis of the electron beam gun. The collimated X-ray sensor is used to monitor the beam deflection caused by the action of magnetic fields. Signal of X-ray sensor is processed by the method of synchronous detection. Analysis of spectral characteristics of the X-ray sensor showed that the displacement of the joint from the optical axis of the gun affects on the output signal of sensor. The authors propose dual-circuit system for automatic positioning of the electron beam on the joint during the electron beam welding in conditions of action of magnetic interference. This system includes a contour of joint tracking and contour of compensation of magnetic fields. The proposed system is stable. Calculation of dynamic error of system showed that error of positioning does not exceed permissible deviation of the electron beam from the joint plane.

The role of sense of coherence and physical activity in positive and negative affect of Turkish adolescents.

PubMed

Oztekin, Ceyda; Tezer, Esin

2009-01-01

This study investigated the role of sense of coherence and total physical activity in positive and negative affect. Participants were 376 (169 female, 206 male, and 1 missing value) student volunteers from different faculties of Middle East Technical University. Three questionnaires: Sense of Coherence Scale (SOC), Physical Activity Assessment Questionnaire (PAAQ), and Positive and Negative Affect Schedule (PANAS) were administered to the students together with the demographic information sheet. Two separate stepwise multiple linear regression analyses were conducted to examine the predictive power of sense of coherence and total physical activity on positive and negative affect scores. Results revealed that both sense of coherence and total physical activity predicted the positive affect whereas only the sense of coherence predicted the negative affect on university students. Findings are discussed in light of sense of coherence, physical activity, and positive and negative affect literature.

The double universal joint wrist on a manipulator: Solution of inverse position kinematics and singularity analysis

NASA Technical Reports Server (NTRS)

Williams, Robert L., III

1992-01-01

This paper presents three methods to solve the inverse position kinematics position problem of the double universal joint attached to a manipulator: (1) an analytical solution for two specific cases; (2) an approximate closed form solution based on ignoring the wrist offset; and (3) an iterative method which repeats closed form position and orientation calculations until the solution is achieved. Several manipulators are used to demonstrate the solution methods: cartesian, cylindrical, spherical, and an anthropomorphic articulated arm, based on the Flight Telerobotic Servicer (FTS) arm. A singularity analysis is presented for the double universal joint wrist attached to the above manipulator arms. While the double universal joint wrist standing alone is singularity-free in orientation, the singularity analysis indicates the presence of coupled position/orientation singularities of the spherical and articulated manipulators with the wrist. The cartesian and cylindrical manipulators with the double universal joint wrist were found to be singularity-free. The methods of this paper can be implemented in a real-time controller for manipulators with the double universal joint wrist. Such mechanically dextrous systems could be used in telerobotic and industrial applications, but further work is required to avoid the singularities.

Position Sensing for Rotor in Hybrid Stepper Motor

NASA Technical Reports Server (NTRS)

Howard, David E. (Inventor); Alhorn, Dean C. (Inventor); Smith, Dennis A. (Inventor)

2011-01-01

A method and system are provided for sensing the position of a rotor in a hybrid stepper motor. First and second Hall sensors are positioned in a spaced-apart relationship with the first and second armatures of the rotor such that the first and second Hall sensors generate electrical outputs that are 90.degree. out of phase with one another as the rotor rotates. The electrical outputs are adjusted relative to a reference, and the amplitude of the electrical outputs is further adjusted to account for spacing differences between the rotor and each of the first and second Hall sensors.

High-resolution ultrasonography in assessing temporomandibular joint disc position.

PubMed

Talmaceanu, Daniel; Lenghel, Lavinia Manuela; Bolog, Nicolae; Popa Stanila, Roxana; Buduru, Smaranda; Leucuta, Daniel Corneliu; Rotar, Horatiu; Baciut, Mihaela; Baciut, Grigore

2018-02-04

The purpose of this study was to determine the diagnostic value of high-resolution ultrasonography (US) in temporomandibular joint (TMJ) disc displacements. A number of 74 patients (148 TMJs) with signs and symptoms of TMJ disorders, according to the Research Diagnostic Criteria for Temporomandibular Disorders, were included in this study. All patients received US and magnetic resonance imaging (MRI) of both TMJs 1 to 5 days after the clinical examination. MRI examinations were performed using 1.5 T MRI equipment (Siemens Avanto, Siemens, Erlangen). Ultrasonographic examination was performed on a Hitachi EUB 8500 (Hitachi Medical Corp., Tokyo, Japan) scanner with L 54 M6.5-13 MHz linear transducer. MRI depicted 68 (45.95%) normal joints, 47 (31.76%) with disc displacement with reduction, 33 (22.3%) with disc displacement without reduction and 34 (22.97%) with degenerative changes. US detected 78 (52.7%) normal joints, 37 (25%) with disc displacement with reduction, 33 (22.3%) with disc displacement without reduction and 21 (14.19%) with degenerative changes. Compared to MRI, US showed a sensitivity of 93.1%, specificity of 87.88%, accuracy of 90.32%, a positive predictive value of 87.1% and a negative predictive value of 93.55% for overall diagnosis of disc displacement. The Youden index was 0.81. Based on our results, high-resolution ultrasonography showed high sensitivity, specificity and accuracy in the diagnosis of TMJ disc displacement. It could be a valuable imaging technique in assessing TMJ disc position. The diagnostic value of high-resolution ultrasonography depends strictly on the examiner's skills and on the equipment used.

Temporomandibular joint involvement as a positive clinical prognostic factor in necrotising external otitis.

PubMed

Yeheskeli, E; Eta, R Abu; Gavriel, H; Kleid, S; Eviatar, E

2016-05-01

Necrotising otitis externa is associated with high morbidity and mortality rates. This study investigated whether temporomandibular joint involvement had any prognostic effect on the course of necrotising otitis externa in patients who had undergone hyperbaric oxygen therapy after failed medical and sometimes surgical therapy. A retrospective case series was conducted of patients in whom antibiotic treatment and surgery had failed, who had been hospitalised for further treatment and hyperbaric oxygen therapy. Twenty-three patients with necrotising otitis externa were identified. The temporomandibular joint was involved in four patients (17 per cent); these patients showed a constant gradual improvement in C-reactive protein and were eventually discharged free of disease, except one patient who was lost to follow up. Four patients (16 per cent) without temporomandibular joint involvement died within 90 days of discharge, while all patients with temporomandibular joint involvement were alive. Three patients (13 per cent) without temporomandibular joint involvement needed recurrent hospitalisation including further hyperbaric oxygen therapy; no patients with temporomandibular joint involvement required such treatment. Patients with temporomandibular joint involvement had lower rates of recurrent disease and no mortality. Therefore, we suggest considering temporomandibular joint involvement as a positive prognostic factor in necrotising otitis externa management.

Position Sense in Chronic Pain: Separating Peripheral and Central Mechanisms in Proprioception in Unilateral Limb Pain.

PubMed

Tsay, Anthony J; Giummarra, Melita J

2016-07-01

Awareness of limb position is derived primarily from muscle spindles and higher-order body representations. Although chronic pain appears to be associated with motor and proprioceptive disturbances, it is not clear if this is due to disturbances in position sense, muscle spindle function, or central representations of the body. This study examined position sense errors, as an indicator of spindle function, in participants with unilateral chronic limb pain. The sample included 15 individuals with upper limb pain, 15 with lower limb pain, and 15 sex- and age-matched pain-free control participants. A 2-limb forearm matching task in blindfolded participants, and a single-limb pointer task, with the reference limb hidden from view, was used to assess forearm position sense. Position sense was determined after muscle contraction or stretch, intended to induce a high or low spindle activity in the painful and nonpainful limbs, respectively. Unilateral upper and lower limb chronic pain groups produced position errors comparable with healthy control participants for position matching and pointer tasks. The results indicate that the painful and nonpainful limb are involved in limb-matching. Lateralized pain, whether in the arm or leg, does not influence forearm position sense. Painful and nonpainful limbs are involved in bilateral limb-matching. Muscle spindle function appears to be preserved in the presence of chronic pain. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Trunk and Shank Position Influences Patellofemoral Joint Stress in the Lead and Trail Limbs During the Forward Lunge Exercise.

PubMed

Hofmann, Cory L; Holyoak, Derek T; Juris, Paul M

2017-01-01

Study Design Controlled laboratory study, repeated-measures design. Background The effects of trunk and shank position on patellofemoral joint stress of the lead limb have been well studied; however, the effects on the trail limb are not well understood. Objectives To test the hypothesis that trunk and shank position may influence patellofemoral joint stress in both limbs during the forward lunge exercise. Methods Patellofemoral kinetics were quantified from 18 healthy participants performing the lunge exercise with different combinations of trunk and shank positions (vertical or forward). A 2-by-3 (limb-by-lunge variation) repeated-measures analysis of variance was performed, using paired t tests for post hoc comparisons. Results The trail limb experienced greater total patellofemoral joint stress relative to the lead limb, regardless of trunk and shank position (P<.0001). The lunge variation with a vertical shank position resulted in significantly greater peak patellofemoral joint stress in the trail limb relative to the lead limb (P<.0001). A forward trunk and shank position resulted in the highest patellofemoral stress in the lead limb (P<.0001). Conclusion Trunk and shank positions have a significant influence on patellofemoral joint loading of both limbs during the forward lunge, with the trail limb generally experiencing greater total joint stress. Restricting forward translation of the lead-limb shank may reduce patellofemoral joint stress at the expense of increased stress in the trail limb. Technique recommendations should consider the demands imposed on both knees during this exercise. J Orthop Sports Phys Ther 2017;47(1):31-40. Epub 4 Nov 2016. doi:10.2519/jospt.2017.6336.

The importance of position and path repeatability on force at the knee during six-DOF joint motion.

PubMed

Darcy, Shon P; Gil, Jorge E; Woo, Savio L-Y; Debski, Richard E

2009-06-01

Mechanical devices, such as robotic manipulators have been designed to measure joint and ligament function because of their ability to position a diarthrodial joint in six degrees-of-freedom with fidelity. However, the precision and performance of these testing devices vary. Therefore, the objective of this study was to determine the effect of systematic errors in position and path repeatability of two high-payload robotic manipulators (Manipulators 1 and 2) on the resultant forces at the knee. Using a porcine knee, the position and path repeatability of these manipulators were determined during passive flexion-extension with a coordinate measuring machine. The position repeatability of Manipulator 1 was 0.3 mm in position and 0.2 degrees in orientation while Manipulator 2 had a better position repeatability of 0.1 mm in position and 0.1 degrees in orientation throughout the range of positions examined. The corresponding variability in the resultant force at the knee for these assigned positions was 32+/-33 N for Manipulator 1 and 4+/-1 N for Manipulator 2. Furthermore, the repeatability of the trajectory of each manipulator while moving between assigned positions (path repeatability) was 0.8 mm for Manipulator 1 while the path repeatability for Manipulator 2 was improved (0.1 mm). These path discrepancies produced variability in the resultant force at the knee of 44+/-24 and 21+/-8 N, respectively, for Manipulators 1 and 2 primarily due to contact between the articular surfaces of the tibia and femur. Therefore, improved position and path repeatability yields lower variability in the resultant forces at the knee. Although position repeatability has been the most common criteria for evaluating biomechanical testing devices, the current study has clearly demonstrated that path repeatability can have an even larger effect on the variability in resultant force at the knee. Consequently, the repeatability of the path followed by the joint throughout its prescribed

A Framework for a Supervisory Expert System for Robotic Manipulators with Joint-Position Limits and Joint-Rate Limits

NASA Technical Reports Server (NTRS)

Mutambara, Arthur G. O.; Litt, Jonathan

1998-01-01

This report addresses the problem of path planning and control of robotic manipulators which have joint-position limits and joint-rate limits. The manipulators move autonomously and carry out variable tasks in a dynamic, unstructured and cluttered environment. The issue considered is whether the robotic manipulator can achieve all its tasks, and if it cannot, the objective is to identify the closest achievable goal. This problem is formalized and systematically solved for generic manipulators by using inverse kinematics and forward kinematics. Inverse kinematics are employed to define the subspace, workspace and constrained workspace, which are then used to identify when a task is not achievable. The closest achievable goal is obtained by determining weights for an optimal control redistribution scheme. These weights are quantified by using forward kinematics. Conditions leading to joint rate limits are identified, in particular it is established that all generic manipulators have singularities at the boundary of their workspace, while some have loci of singularities inside their workspace. Once the manipulator singularity is identified the command redistribution scheme is used to compute the closest achievable Cartesian velocities. Two examples are used to illustrate the use of the algorithm: A three link planar manipulator and the Unimation Puma 560. Implementation of the derived algorithm is effected by using a supervisory expert system to check whether the desired goal lies in the constrained workspace and if not, to evoke the redistribution scheme which determines the constraint relaxation between end effector position and orientation, and then computes optimal gains.

Shoulder Joint For Protective Suit

NASA Technical Reports Server (NTRS)

Kosmo, Joseph J.; Smallcombe, Richard D.

1994-01-01

Shoulder joint allows full range of natural motion: wearer senses little or no resisting force or torque. Developed for space suit, joint offers advantages in protective garments for underwater work, firefighting, or cleanup of hazardous materials.

Development of a revolute-joint robot for the precision positioning of an x-ray detector

NASA Astrophysics Data System (ADS)

Preissner, Curt A.; Royston, Thomas J.; Shu, Deming

2003-10-01

This paper profiles the initial phase in the development of a six degree-of-freedom robot, with 1 μm dynamic positioning uncertainty, for the manipulation of x-ray detectors or test specimens at the Advanced Photon Source (APS). While revolute-joint robot manipulators exhibit a smaller footprint along with increased positioning flexibility compared to Cartesian manipulators, commercially available revolute-joint manipulators do not meet our size, positioning, or environmental specifications. Currently, a robot with 20 μm dynamic positioning uncertainty is functioning at the APS for cryogenic crystallography sample pick-and-place operation. Theoretical, computational and experimental procedures are being used to (1) identify and (2) simulate the dynamics of the present robot system using a multibody approach, including the mechanics and control architecture, and eventually to (3) design an improved version with a 1 μm dynamic positioning uncertainty. We expect that the preceding experimental and theoretical techniques will be useful design and analysis tools as multi-degree-of-freedom manipulators become more prevalent on synchrotron beamlines.

An automatic 2D–3D image matching method for reproducing spatial knee joint positions using single or dual fluoroscopic images

PubMed Central

Zhu, Zhonglin; Li, Guoan

2013-01-01

Fluoroscopic image technique, using either a single image or dual images, has been widely applied to measure in vivo human knee joint kinematics. However, few studies have compared the advantages of using single and dual fluoroscopic images. Furthermore, due to the size limitation of the image intensifiers, it is possible that only a portion of the knee joint could be captured by the fluoroscopy during dynamic knee joint motion. In this paper, we presented a systematic evaluation of an automatic 2D–3D image matching method in reproducing spatial knee joint positions using either single or dual fluoroscopic image techniques. The data indicated that for the femur and tibia, their spatial positions could be determined with an accuracy and precision less than 0.2 mm in translation and less than 0.4° in orientation when dual fluoroscopic images were used. Using single fluoroscopic images, the method could produce satisfactory accuracy in joint positions in the imaging plane (average up to 0.5 mm in translation and 1.3° in rotation), but large variations along the out-plane direction (in average up to 4.0 mm in translation and 2.28 in rotation). The precision of using single fluoroscopic images to determine the actual knee positions was worse than its accuracy obtained. The data also indicated that when using dual fluoroscopic image technique, if the knee joint outlines in one image were incomplete by 80%, the algorithm could still reproduce the joint positions with high precisions. PMID:21806411

Elbow joint variability for different hand positions of the round off in gymnastics.

PubMed

Farana, Roman; Irwin, Gareth; Jandacka, Daniel; Uchytil, Jaroslav; Mullineaux, David R

2015-02-01

The aim of the present study was to conduct within-gymnast analyses of biological movement variability in impact forces, elbow joint kinematics and kinetics of expert gymnasts in the execution of the round-off with different hand positions. Six international level female gymnasts performed 10 trials of the round-off from a hurdle step to a back-handspring using two hand potions: parallel and T-shape. Two force plates were used to determine ground reaction forces. Eight infrared cameras were employed to collect the kinematic data automatically. Within gymnast variability was calculated using biological coefficient of variation (BCV) discretely for ground reaction force, kinematic and kinetic measures. Variability of the continuous data was quantified using coefficient of multiple correlations (CMC). Group BCV and CMC were calculated and T-test with effect size statistics determined differences between the variability of the two techniques examined in this study. The major observation was a higher level of biological variability in the elbow joint abduction angle and adduction moment of force in the T-shaped hand position. This finding may lead to a reduced repetitive abduction stress and thus protect the elbow joint from overload. Knowledge of the differences in biological variability can inform clinicians and practitioners with effective skill selection. Copyright © 2014 Elsevier B.V. All rights reserved.

Mobile Phone-Based Joint Angle Measurement for Functional Assessment and Rehabilitation of Proprioception

PubMed Central

Mourcou, Quentin; Fleury, Anthony; Diot, Bruno; Franco, Céline; Vuillerme, Nicolas

2015-01-01

Assessment of joint functional and proprioceptive abilities is essential for balance, posture, and motor control rehabilitation. Joint functional ability refers to the capacity of movement of the joint. It may be evaluated thereby measuring the joint range of motion (ROM). Proprioception can be defined as the perception of the position and of the movement of various body parts in space. Its role is essential in sensorimotor control for movement acuity, joint stability, coordination, and balance. Its clinical evaluation is commonly based on the assessment of the joint position sense (JPS). Both ROM and JPS measurements require estimating angles through goniometer, scoliometer, laser-pointer, and bubble or digital inclinometer. With the arrival of Smartphones, these costly clinical tools tend to be replaced. Beyond evaluation, maintaining and/or improving joint functional and proprioceptive abilities by training with physical therapy is important for long-term management. This review aims to report Smartphone applications used for measuring and improving functional and proprioceptive abilities. It identifies that Smartphone applications are reliable for clinical measurements and are mainly used to assess ROM and JPS. However, there is lack of studies on Smartphone applications which can be used in an autonomous way to provide physical therapy exercises at home. PMID:26583101

A novel secret sharing with two users based on joint transform correlator and compressive sensing

NASA Astrophysics Data System (ADS)

Zhao, Tieyu; Chi, Yingying

2018-05-01

Recently, joint transform correlator (JTC) has been widely applied to image encryption and authentication. This paper presents a novel secret sharing scheme with two users based on JTC. Two users must be present during the decryption that the system has high security and reliability. In the scheme, two users use their fingerprints to encrypt plaintext, and they can decrypt only if both of them provide the fingerprints which are successfully authenticated. The linear relationship between the plaintext and ciphertext is broken using the compressive sensing, which can resist existing attacks on JTC. The results of the theoretical analysis and numerical simulation confirm the validity of the system.

Polarization-controlled directional scattering for nanoscopic position sensing

PubMed Central

Neugebauer, Martin; Woźniak, Paweł; Bag, Ankan; Leuchs, Gerd; Banzer, Peter

2016-01-01

Controlling the propagation and coupling of light to sub-wavelength antennas is a crucial prerequisite for many nanoscale optical devices. Recently, the main focus of attention has been directed towards high-refractive-index materials such as silicon as an integral part of the antenna design. This development is motivated by the rich spectral properties of individual high-refractive-index nanoparticles. Here we take advantage of the interference of their magnetic and electric resonances to achieve strong lateral directionality. For controlled excitation of a spherical silicon nanoantenna, we use tightly focused radially polarized light. The resultant directional emission depends on the antenna's position relative to the focus. This approach finds application as a novel position sensing technique, which might be implemented in modern nanometrology and super-resolution microscopy set-ups. We demonstrate in a proof-of-concept experiment that a lateral resolution in the Ångström regime can be achieved. PMID:27095171

Effects on Subtalar Joint Stress Distribution After Cannulated Screw Insertion at Different Positions and Directions.

PubMed

Yuan, Cheng-song; Chen, Wan; Chen, Chen; Yang, Guang-hua; Hu, Chao; Tang, Kang-lai

2015-01-01

We investigated the effects on subtalar joint stress distribution after cannulated screw insertion at different positions and directions. After establishing a 3-dimensional geometric model of a normal subtalar joint, we analyzed the most ideal cannulated screw insertion position and approach for subtalar joint stress distribution and compared the differences in loading stress, antirotary strength, and anti-inversion/eversion strength among lateral-medial antiparallel screw insertion, traditional screw insertion, and ideal cannulated screw insertion. The screw insertion approach allowing the most uniform subtalar joint loading stress distribution was lateral screw insertion near the border of the talar neck plus medial screw insertion close to the ankle joint. For stress distribution uniformity, antirotary strength, and anti-inversion/eversion strength, lateral-medial antiparallel screw insertion was superior to traditional double-screw insertion. Compared with ideal cannulated screw insertion, slightly poorer stress distribution uniformity and better antirotary strength and anti-inversion/eversion strength were observed for lateral-medial antiparallel screw insertion. Traditional single-screw insertion was better than double-screw insertion for stress distribution uniformity but worse for anti-rotary strength and anti-inversion/eversion strength. Lateral-medial antiparallel screw insertion was slightly worse for stress distribution uniformity than was ideal cannulated screw insertion but superior to traditional screw insertion. It was better than both ideal cannulated screw insertion and traditional screw insertion for anti-rotary strength and anti-inversion/eversion strength. Lateral-medial antiparallel screw insertion is an approach with simple localization, convenient operation, and good safety. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Autonomous sensing of composites with carbon nanotubes for structural health monitoring

NASA Astrophysics Data System (ADS)

Liu, Yingtao; Yekani Fard, Masoud; Rajadas, Abhishek; Chattopadhyay, Aditi

2012-04-01

The development of structural health monitoring techniques leads to the integration of sensing capability within engineering structures. This study investigates the application of multi walled carbon nanotubes in polymer matrix composites for autonomous damage detection through changes in electrical resistance. The autonomous sensing capabilities of fiber reinforced nanocomposites are studied under multiple loading conditions including tension loads. Single-lap joints with different joint lengths are tested. Acoustic emission sensing is used to validate the matrix crack propagation. A digital image correlation system is used to measure the shear strain field of the joint area. The joints with 1.5 inch length have better autonomous sensing capabilities than those with 0.5 inch length. The autonomous sensing capabilities of nanocomposites are found to be sensitive to crack propagation and can revolutionize the research on composite structural health management in the near future.

Quantitative optical imaging and sensing by joint design of point spread functions and estimation algorithms

NASA Astrophysics Data System (ADS)

Quirin, Sean Albert

The joint application of tailored optical Point Spread Functions (PSF) and estimation methods is an important tool for designing quantitative imaging and sensing solutions. By enhancing the information transfer encoded by the optical waves into an image, matched post-processing algorithms are able to complete tasks with improved performance relative to conventional designs. In this thesis, new engineered PSF solutions with image processing algorithms are introduced and demonstrated for quantitative imaging using information-efficient signal processing tools and/or optical-efficient experimental implementations. The use of a 3D engineered PSF, the Double-Helix (DH-PSF), is applied as one solution for three-dimensional, super-resolution fluorescence microscopy. The DH-PSF is a tailored PSF which was engineered to have enhanced information transfer for the task of localizing point sources in three dimensions. Both an information- and optical-efficient implementation of the DH-PSF microscope are demonstrated here for the first time. This microscope is applied to image single-molecules and micro-tubules located within a biological sample. A joint imaging/axial-ranging modality is demonstrated for application to quantifying sources of extended transverse and axial extent. The proposed implementation has improved optical-efficiency relative to prior designs due to the use of serialized cycling through select engineered PSFs. This system is demonstrated for passive-ranging, extended Depth-of-Field imaging and digital refocusing of random objects under broadband illumination. Although the serialized engineered PSF solution is an improvement over prior designs for the joint imaging/passive-ranging modality, it requires the use of multiple PSFs---a potentially significant constraint. Therefore an alternative design is proposed, the Single-Helix PSF, where only one engineered PSF is necessary and the chromatic behavior of objects under broadband illumination provides the

Positron source position sensing detector and electronics

DOEpatents

Burnham, Charles A.; Bradshaw, Jr., John F.; Kaufman, David E.; Chesler, David A.; Brownell, Gordon L.

1985-01-01

A positron source, position sensing device, particularly with medical applications, in which positron induced gamma radiation is detected using a ring of stacked, individual scintillation crystals, a plurality of photodetectors, separated from the scintillation crystals by a light guide, and high resolution position interpolation electronics. Preferably the scintillation crystals are several times more numerous than the photodetectors with each crystal being responsible for a single scintillation event from a received gamma ray. The light guide will disperse the light emitted from gamma ray absorption over several photodetectors. Processing electronics for the output of the photodetectors resolves the location of the scintillation event to a fraction of the dimension of each photodetector. Because each positron absorption results in two 180.degree. oppositely traveling gamma rays, the detection of scintillation in pairs permits location of the positron source in a manner useful for diagnostic purposes. The processing electronics simultaneously responds to the outputs of the photodetectors to locate the scintillations to the source crystal. While it is preferable that the scintillation crystal include a plurality of stacked crystal elements, the resolving power of the processing electronics is also applicable to continuous crystal scintillators.

Joint Attention Initiation with and without Positive Affect: Risk Group Differences and Associations with ASD Symptoms

PubMed Central

Gangi, Devon N.; Ibañez, Lisa V.; Messinger, Daniel S.

2014-01-01

Infants at risk for Autism Spectrum Disorders (ASD) may have difficulty integrating smiles into initiating joint attention (IJA) bids. A specific IJA pattern, anticipatory smiling, may communicate preexisting positive affect when an infant smiles at an object and then turns the smile toward the social partner. We compared the development of anticipatory smiling at 8, 10, and 12 months in infant siblings of children with ASD (high-risk siblings) and without ASD (low-risk siblings). High-risk siblings produced less anticipatory smiling than low-risk siblings, suggesting early differences in communicating preexisting positive affect. While early anticipatory smiling distinguished the risk groups, IJA not accompanied by smiling best predicted later severity of ASD-related behavioral characteristics among high-risk siblings. High-risk infants appear to show lower levels of motivation to share positive affect with others. However, facility with initiating joint attention in the absence of a clear index of positive affective motivation appears to be central to the prediction of ASD symptoms. PMID:24281421

A Data-Gathering Scheme with Joint Routing and Compressive Sensing Based on Modified Diffusion Wavelets in Wireless Sensor Networks.

PubMed

Gu, Xiangping; Zhou, Xiaofeng; Sun, Yanjing

2018-02-28

Compressive sensing (CS)-based data gathering is a promising method to reduce energy consumption in wireless sensor networks (WSNs). Traditional CS-based data-gathering approaches require a large number of sensor nodes to participate in each CS measurement task, resulting in high energy consumption, and do not guarantee load balance. In this paper, we propose a sparser analysis that depends on modified diffusion wavelets, which exploit sensor readings' spatial correlation in WSNs. In particular, a novel data-gathering scheme with joint routing and CS is presented. A modified ant colony algorithm is adopted, where next hop node selection takes a node's residual energy and path length into consideration simultaneously. Moreover, in order to speed up the coverage rate and avoid the local optimal of the algorithm, an improved pheromone impact factor is put forward. More importantly, theoretical proof is given that the equivalent sensing matrix generated can satisfy the restricted isometric property (RIP). The simulation results demonstrate that the modified diffusion wavelets' sparsity affects the sensor signal and has better reconstruction performance than DFT. Furthermore, our data gathering with joint routing and CS can dramatically reduce the energy consumption of WSNs, balance the load, and prolong the network lifetime in comparison to state-of-the-art CS-based methods.

Utility of percutaneous joint aspiration and synovial biopsy in identifying culture-positive infected hip arthroplasty.

PubMed

Cross, M Connor; Kransdorf, Mark J; Chivers, F Spencer; Lorans, Roxanne; Roberts, Catherine C; Schwartz, Adam J; Beauchamp, Christopher P

2014-02-01

Percutaneous synovial biopsy has recently been reported to have a high diagnostic value in the preoperative identification of periprosthetic infection of the hip. We report our experience with this technique in the evaluation of patients undergoing revision hip arthroplasty, comparing results of preoperative synovial biopsy with joint aspiration in identifying an infected hip arthroplasty by bacteriological analysis. We retrospectively reviewed the results of the 110 most recent revision hip arthroplasties in which preoperative synovial biopsy and joint aspiration were both performed. Revision surgery for these patients occurred during the period from September 2005 to March 2012. Using this study group, results from preoperative cultures were compared with preoperative laboratory studies and the results of intraoperative cultures. Synovial aspiration was done using an 18- or 20-gauge spinal needle. Synovial biopsy was done coaxially following aspiration using a 22-gauge Chiba needle or 21-gauge Sure-Cut needle. Standard microbiological analysis was performed on preoperative synovial fluid aspirate and synovial biopsy. Intraoperative tissue biopsy bacteriological analysis results at surgical revision were accepted as the "gold standard" for the presence or absence of infection. Seventeen of 110 (15 %) of patients had intraoperative culture-positive periprosthetic infection. Of these 17 cases, there were ten cases where either the synovial fluid aspiration and/or the synovial biopsy were true positive (sensitivity of 59 %, specificity of 100 %, positive predictive value of 100 % and accuracy of 94 %). There were seven cases where aspiration and biopsy results were both falsely negative, but no false-positive results. Similar results were found for synovial fluid aspiration alone. The results of synovial biopsy alone resulted in the identification of seven infected joints with no false-positive result (sensitivity of 41 %, specificity of 100 %, positive

Effects of Initial Graft Tension on the Tibiofemoral Compressive Forces and Joint Position Following ACL Reconstruction

PubMed Central

Brady, Mark F.; Bradley, Michael P.; Fleming, Braden C.; Fadale, Paul D.; Hulstyn, Michael J.; Banerjee, Rahul

2007-01-01

Background The initial tension applied to an ACL graft at the time of fixation modulates knee motion and the tibiofemoral compressive loads. Purpose To establish the relationships between initial graft tension, tibiofemoral compressive force, and the neutral tibiofemoral position in the cadaver knee. Study Design Controlled Laboratory Study. Methods The tibiofemoral compressive forces and joint positions were determined in the ACL-intact knee at 0°, 20° and 90° knee flexion. The ACL was excised and reconstructed with a patellar tendon graft using graft tensions of 1, 15, 30, 60 and 90 N applied at 0°, 20° and 90° knee flexion. The compressive forces and neutral positions were compared between initial tension conditions and the ACL-intact knee. Results Increasing initial graft tension increased the tibiofemoral compressive forces. The forces in the medial compartment were 1.8 times those in the lateral compartment. The compressive forces were dependent on the knee angle at which the tension was applied. The greatest compressive forces occurred when the graft was tensioned with the knee in extension. An increase in initial graft tension caused the tibia to rotate externally compared to the ACL-intact knee. Increases in initial graft tension also caused a significant posterior translation of the tibia relative to the femur. Conclusions Different initial graft tension protocols produced predictable changes in the tibiofemoral compressive forces and joint positions. Clinical Relevance The tibiofemoral compressive force and neutral joint position were best replicated with a low graft tension (1–15 N) when using a patellar tendon graft. PMID:17218659

Optical Fiber Distributed Sensing Structural Health Monitoring (SHM) Strain Measurements Taken During Cryotank Y-Joint Test Article Load Cycling at Liquid Helium Temperatures

NASA Technical Reports Server (NTRS)

Allison, Sidney G.; Prosser, William H.; Hare, David A.; Moore, Thomas C.; Kenner, Winfred S.

2007-01-01

This paper outlines cryogenic Y-joint testing at Langley Research Center (LaRC) to validate the performance of optical fiber Bragg grating strain sensors for measuring strain at liquid helium temperature (-240 C). This testing also verified survivability of fiber sensors after experiencing 10 thermal cool-down, warm-up cycles and 400 limit load cycles. Graphite composite skins bonded to a honeycomb substrate in a sandwich configuration comprised the Y-joint specimens. To enable SHM of composite cryotanks for consideration to future spacecraft, a light-weight, durable monitoring technology is needed. The fiber optic distributed Bragg grating strain sensing system developed at LaRC is a viable substitute for conventional strain gauges which are not practical for SHM. This distributed sensing technology uses an Optical Frequency Domain Reflectometer (OFDR). This measurement approach has the advantage that it can measure hundreds of Bragg grating sensors per fiber and the sensors are all written at one frequency, greatly simplifying fiber manufacturing. Fiber optic strain measurements compared well to conventional strain gauge measurements obtained during these tests. These results demonstrated a high potential for a successful implementation of a SHM system incorporating LaRC's fiber optic sensing system on the composite cryotank and other future cryogenic applications.

Oceanographic Remote Sensing; A Position Paper,

DTIC Science & Technology

1979-01-26

The purpose of a Navy R&D remote sensing plan should be to set forth the requirements and direction of basic and exploratory research in satellite... remote sensing which supports the overall Navy oceanographic research and operational programs. The aim of the plan would be to outline the established...addressed. The plan should help serve as a single technology and program reference for implementation and planning of Navy related satellite remote

Radiological study of the knee joint line position measured from the fibular head and proximal tibial landmarks.

PubMed

Havet, Eric; Gabrion, Antoine; Leiber-Wackenheim, Frederic; Vernois, Joël; Olory, Bruno; Mertl, Patrice

2007-06-01

Restoring the joint line level is one of the surgical challenges during revision of total knee arthroplasty. The position of the tibial surface is commonly estimated by its distance to the apex of fibular head, but no study evaluating this distance accurately has been published yet. The purpose of this work was to study the distance between the knee joint line and the apex of the fibular head and the proximal tibia, particularly the tibial tuberosity. Variability with clinical data and relations with other local measurements have been evaluated on knee radiographs (an antero-posterior view, a medio-lateral view and an anteroposterior full length view) of 100 subjects (125 knees). Results showed no correlation between the joint line-fibular head apex distance and any clinical data of the patients, or any other performed measurements. Relations between tibial measurements and the sexe or the height of the subjects were noted. Besides, the review of the 25 bilateral cases did not show statistically significant side difference but the descriptive analysis showed too large discrepancies for the joint line-fibular head apex distance to be used as a landmark. We conclude that the fibular head apex cannot be used as a morphologic landmark to determine the knee joint line position. Its interest in clinical and surgical practice must be discussed.

Quantum Tomography Protocols with Positivity are Compressed Sensing Protocols (Open Access)

DTIC Science & Technology

2015-12-08

ARTICLE OPEN Quantum tomography protocols with positivity are compressed sensing protocols Amir Kalev1, Robert L Kosut2 and Ivan H Deutsch1...Characterising complex quantum systems is a vital task in quantum information science. Quantum tomography, the standard tool used for this purpose, uses a well...designed measurement record to reconstruct quantum states and processes. It is, however, notoriously inefficient. Recently, the classical signal

Effect of cooling on thixotropic position-sense error in human biceps muscle.

PubMed

Sekihara, Chikara; Izumizaki, Masahiko; Yasuda, Tomohiro; Nakajima, Takayuki; Atsumi, Takashi; Homma, Ikuo

2007-06-01

Muscle temperature affects muscle thixotropy. However, it is unclear whether changes in muscle temperature affect thixotropic position-sense errors. We studied the effect of cooling on thixotropic position-sense errors induced by short-length muscle contraction (hold-short conditioning) in the biceps of 12 healthy men. After hold-short conditioning of the right biceps muscle in a cooled (5.0 degrees C) or control (36.5 degrees C) environment, subjects perceived greater extension of the conditioned forearm at 5.0 degrees C. The angle differences between the two forearms following hold-short conditioning of the right biceps muscle in normal or cooled conditions were significantly different (-3.335 +/- 1.680 degrees at 36.5 degrees C vs. -5.317 +/- 1.096 degrees at 5.0 degrees C; P=0.043). Induction of a tonic vibration reflex in the biceps muscle elicited involuntary forearm elevation, and the angular velocities of the elevation differed significantly between arms conditioned in normal and cooled environments (1.583 +/- 0.326 degrees /s at 36.5 degrees C vs. 3.100 +/- 0.555 degrees /s at 5.0 degrees C, P=0.0039). Thus, a cooled environment impairs a muscle's ability to provide positional information, potentially leading to poor muscle performance.

Microwave remote sensing of sea ice in the AIDJEX Main Experiment. [Arctic Ice Dynamics Joint Experiment

NASA Technical Reports Server (NTRS)

Campbell, W. J.; Wayenberg, J.; Ramseyer, J. B.; Ramseier, R. O.; Vant, M. R.; Weaver, R.; Redmond, A.; Arsenault, L.; Gloersen, P.; Zwally, H. J.

1978-01-01

A microwave remote sensing program of sea ice in the Beaufort Sea was conducted during the Arctic Ice Dynamics Joint Experiment (AIDJEX). Several types of both passive and active sensors were used to perform surface and aircraft measurements during all seasons of the year. In situ observations were made of physical properties (salinity, temperature, density, surface roughness), dielectric properties, and passive microwave measurements were made of first-year, multiyear, and first-year/multiyear mixtures. Airborne passive microwave measurements were performed with the electronically scanning microwave radiometer while airborne active microwave measurements were performed by synthetic aperture radar, X- and L-band radar, and a scatterometer.

Making sense of 'place': Reflections on pluralism and positionality in place research

Treesearch

Daniel R. Williams

2014-01-01

Drawing on critical pluralism and positionality, this essay offers a four-part framework for making sense of the manifold ways place has been studied and applied to landscape planning and management. The first element highlights how diverse intellectual origins behind place research have inhibited a transdisciplinary understanding of place as an object of study in...

Deficits in Upper Limb Position Sense of Children with Spastic Hemiparetic Cerebral Palsy Are Distance-Dependent

ERIC Educational Resources Information Center

Smorenburg, Ana R. P.; Ledebt, Annick; Deconinck, Frederik J. A.; Savelsbergh, Geert J. P.

2012-01-01

This study examined the arm position sense in children with Spastic Hemiparetic Cerebral Palsy (SHCP) and typically developing children (TD) by means of a contralateral matching task. This task required participants to match the position of one arm with the position of the other arm for different target distances and from different starting…

Positive Affect Processing and Joint Attention in Infants at High Risk for Autism: An Exploratory Study

PubMed Central

Key, Alexandra P.; Ibanez, Lisa V.; Henderson, Heather A.; Warren, Zachary; Messinger, Daniel S.; Stone, Wendy L.

2014-01-01

Few behavioral indices of risk for autism spectrum disorders (ASD) are present before 12 months, and potential biomarkers remain largely unexamined. This prospective study of infant siblings of children with ASD (n=16) and low-risk comparison infants (n= 15) examined group differences in event-related potentials (ERPs) indexing processing of facial positive affect (N290/P400, Nc) at 9 months and their relation to joint attention at 15 months. Group differences were most pronounced for subtle facial expressions, in that the low-risk group exhibited relatively longer processing (P400 latency) and greater attention resource allocation (Nc amplitude). Exploratory analyses found associations between ERP responses and later joint attention, suggesting that attention to positive affect cues may support the development of other social competencies. PMID:25056131

Who do you think they were? How family historians make sense of social position and inequality in the past.

PubMed

Bottero, Wendy

2012-03-01

How do social comparisons over time shape perceptions of inequality? In thinking about subjective inequality, it is important to ask which social comparisons matter in establishing people's sense of relative social position and wider inequalities. These issues are discussed by drawing on a qualitative study of popular genealogy, which examines how people make sense of social position in the past, and explores how social change affects people's sense of social hierarchies. The gaze of family history promotes certain sorts of social comparisons, between 'then and now', and between immediate kin, which can flatten the sense of social hierarchies. However, the ability to determine social position also depends on the quality of information available, and how different practical engagements facilitate 'sideways' comparisons between contemporaries, affording different fields of vision on relative inequalities. On this evidence, when exploring subjective inequality it is necessary to examine when and how people engage in social comparison as part of everyday practical activities. © London School of Economics and Political Science 2012.

Effects of ankle joint position and submaximal muscle contraction intensity on soleus H-reflex modulation in young and older adults.

PubMed

Chen, Yung-Sheng; Zhou, Shi; Cartwright, Colleen

2014-04-01

This study investigated the effects of ankle joint position and submaximal contraction intensity on soleus (SOL) H-reflex modulation. Twenty young (25.1 ± 4.8 years) and 20 older adults (74.2 ± 5.1 years) performed plantar flexions during 10%, 30% and 50% maximal voluntary contractions (MVC) and at ankle positions of neutral (0°), plantar flexion (20°) and dorsiflexion (-20°) in a sitting position. The SOL H-reflex gain in older adults was relatively lower than that in young adults during 10%, 30% and 50% MVC. The SOL H-reflex gain was significantly affected by the intensity of plantar flexion in the respective ankle joint position in both age groups. The latency of H-reflex was prolonged in older adults and was ankle joint dependent in young adults. Young adults demonstrated a shorter duration of the H-reflex response than that of older adults. The results indicated that there were age-related changes in the SOL H-reflex during the ankle plantar flexors activities.

Robot Position Sensor Fault Tolerance

NASA Technical Reports Server (NTRS)

Aldridge, Hal A.

1997-01-01

Robot systems in critical applications, such as those in space and nuclear environments, must be able to operate during component failure to complete important tasks. One failure mode that has received little attention is the failure of joint position sensors. Current fault tolerant designs require the addition of directly redundant position sensors which can affect joint design. A new method is proposed that utilizes analytical redundancy to allow for continued operation during joint position sensor failure. Joint torque sensors are used with a virtual passive torque controller to make the robot joint stable without position feedback and improve position tracking performance in the presence of unknown link dynamics and end-effector loading. Two Cartesian accelerometer based methods are proposed to determine the position of the joint. The joint specific position determination method utilizes two triaxial accelerometers attached to the link driven by the joint with the failed position sensor. The joint specific method is not computationally complex and the position error is bounded. The system wide position determination method utilizes accelerometers distributed on different robot links and the end-effector to determine the position of sets of multiple joints. The system wide method requires fewer accelerometers than the joint specific method to make all joint position sensors fault tolerant but is more computationally complex and has lower convergence properties. Experiments were conducted on a laboratory manipulator. Both position determination methods were shown to track the actual position satisfactorily. A controller using the position determination methods and the virtual passive torque controller was able to servo the joints to a desired position during position sensor failure.

Association between disk position and degenerative bone changes of the temporomandibular joints: an imaging study in subjects with TMD.

PubMed

Cortés, Daniel; Sylvester, Daniel Cortés; Exss, Eduardo; Marholz, Carlos; Millas, Rodrigo; Moncada, Gustavo

2011-04-01

The aim of this study was to determine the frequency and relationship between disk position and degenerative bone changes in the temporomandibular joints (TMJ), in subjects with internal derangement (ID). MRI and CT scans of 180 subjects with temporomandibular disorders (TMD) were studied. Different image parameters or characteristics were observed, such as disk position, joint effusion, condyle movement, degenerative bone changes (flattened, cortical erosions and irregularities), osteophytes, subchondral cysts and idiopathic condyle resorption. The present study concluded that there is a significant association between disk displacement without reduction and degenerative bone changes in patients with TMD. The study also found a high probability of degenerative bone changes when disk displacement without reduction is present. No association was found between TMD and condyle range of motion, joint effusion and/or degenerative bone changes. The following were the most frequent morphological changes observed: flattening of the anterior surface of the condyle; followed by erosions and irregularities of the joint surfaces; flattening of the articular surface of the temporal eminence, subchondral cysts, osteophytes; and idiopathic condyle resorption, in decreasing order.

Simultaneous data communication and position sensing with an impact ionization engineered avalanche photodiode array for free space optical communication

NASA Astrophysics Data System (ADS)

Ferraro, Mike S.; Mahon, Rita; Rabinovich, William S.; Murphy, James L.; Dexter, James L.; Clark, William R.; Waters, William D.; Vaccaro, Kenneth; Krejca, Brian D.

2017-02-01

Photodetectors in free space optical communication systems perform two functions: reception of data communication signals and position sensing for pointing, tracking, and stabilization. Traditionally, the optical receive path in an FSO system is split into separate paths for data detection and position sensing. The need for separate paths is a consequence of conflicting performance criteria between position sensitive detectors (PSD) and data detectors. Combining the functionality of both detector types requires that the combinational sensor not only have the bandwidth to support high data rate communication but the active area and spatial discrimination to accommodate position sensing. In this paper we present a large area, concentric five element impact ionization engineered avalanche photodiode array rated for bandwidths beyond 1GHz with a measured carrier ionization ratio of less than 0.1 at moderate APD gains. The integration of this array as a combinational sensor in an FSO system is discussed along with the development of a pointing and stabilization algorithm.

Reliable fusion of control and sensing in intelligent machines. Thesis

NASA Technical Reports Server (NTRS)

Mcinroy, John E.

1991-01-01

Although robotics research has produced a wealth of sophisticated control and sensing algorithms, very little research has been aimed at reliably combining these control and sensing strategies so that a specific task can be executed. To improve the reliability of robotic systems, analytic techniques are developed for calculating the probability that a particular combination of control and sensing algorithms will satisfy the required specifications. The probability can then be used to assess the reliability of the design. An entropy formulation is first used to quickly eliminate designs not capable of meeting the specifications. Next, a framework for analyzing reliability based on the first order second moment methods of structural engineering is proposed. To ensure performance over an interval of time, lower bounds on the reliability of meeting a set of quadratic specifications with a Gaussian discrete time invariant control system are derived. A case study analyzing visual positioning in robotic system is considered. The reliability of meeting timing and positioning specifications in the presence of camera pixel truncation, forward and inverse kinematic errors, and Gaussian joint measurement noise is determined. This information is used to select a visual sensing strategy, a kinematic algorithm, and a discrete compensator capable of accomplishing the desired task. Simulation results using PUMA 560 kinematic and dynamic characteristics are presented.

Achievements of the DOT-NASA Joint Program on Remote Sensing and Spatial Information Technologies: Application to Multimodal Transportation

NASA Technical Reports Server (NTRS)

2002-01-01

This report presents three-year accomplishments from the national program on Commercial Remote Sensing and Geospatial Technology (CRSGT) application to transportation, administered by the U.S. Department of Transportation (U.S. DOT) in collaboration with the National Aeronautics and Space Administration (NASA). The joint program was authorized under Section 5113 of the Transportation Equity Act for the 21st Century (TEA-21). This is the first national program of its type focusing on transportation applications of emerging commercial remote sensing technologies. U.S. DOT's Research and Special Programs Administration manages the program in coordination with NASA's Earth Science Enterprise's application programs. The program focuses on applications of CRSGT products and systems for providing smarter and more efficient transportation operations and services. The program is performed in partnership with four major National Consortia for Remote Sensing in Transportation (NCRST). Each consortium focuses on research and development of products in one of the four priority areas for transportation application, and includes technical application and demonstration projects carried out in partnership with industries and service providers in their respective areas. The report identifies products and accomplishments from each of the four consortia in meeting the goal of providing smarter and more efficient transportation services. The products and results emerging from the program are being implemented in transportation operations and services through state and local agencies. The Environmental Assessment and Application Consortium (NCRST-E) provides leadership for developing and deploying cost effective environmental and transportation planning services, and integrates CRSGT advances for achieving smarter and cost effective corridor planning. The Infrastructure Management Consortium (NCRST-I) provides leadership in technologies that achieve smarter and cheaper ways of managing

Improving the position control of a two degrees of freedom robotic sensing antenna using fractional-order controllers

NASA Astrophysics Data System (ADS)

Feliu-Talegon, D.; Feliu-Batlle, V.

2017-06-01

Flexible links combined with force and torque sensors can be used to detect obstacles in mobile robotics, as well as for surface and object recognition. These devices, called sensing antennae, perform an active sensing strategy in which a servomotor system moves the link back and forth until it hits an object. At this instant, information of the motor angles combined with force and torque measurements allow calculating the positions of the hitting points, which are valuable information about the object surface. In order to move the antenna fast and accurately, this article proposes a new closed-loop control for driving this flexible link-based sensor. The control strategy is based on combining a feedforward term and a feedback phase-lag compensator of fractional order. We demonstrate that some drawbacks of the control of these sensing devices like the apparition of spillover effects when a very fast positioning of the antenna tip is desired, and actuator saturation caused by high-frequency sensor noise, can be significantly reduced by using our newly proposed fractional-order controllers. We have applied these controllers to the position control of a prototype of sensing antenna and experiments have shown the improvements attained with this technique in the accurate and vibration free motion of its tip (the fractional-order controller reduced ten times the residual vibration obtained with the integer-order controller).

Position Sensitive Proximity Charge Sensing Readout of HPGe Detectors

NASA Astrophysics Data System (ADS)

Priest, Anders Peterson

Electrode segmentation is a necessity to achieve position sensitivity in semicon- ductor radiation detectors. Traditional segmentation requires decreasing electrode sizes while increasing channel numbers to achieve very fine position resolution. These electrodes can be complicated to fabricate, and many electrodes with individual electronic channels are required to instrument large detector areas. To simplify the fabrication process, we have moved the readout electrodes onto a printed circuit board that is positioned above the ionization type detection material. In this scheme, charge from radiation interactions will be shared amongst several electrodes, allowing for position interpolation. Because events can be reconstructed in between electrodes, fewer electrodes are needed to instrument large detector areas. The proximity charge sensing method of readout promises to simplify detector fabrication while maintaining the position resolution that is required by fields such as homeland security, astrophysics, environmental remediation, nuclear physics, and medical imaging. We performed scanning measurements on a proof of principle detector that we fabricated at Lawrence Berkeley National Laboratory (LBNL). These measurements showed that position resolution much finer than the strip pitch was achievable using the proximity charge readout method. We performed analytic calculations and Monte Carlo modeling to optimize the readout electrode geometry for a larger detector to test the limits of this technology. We achieved an average position resolution of 288 microm with eight proximity electrodes at a 5 mm pitch and 1 mm strip width, set 100 microm away from the detector surface by a Kapton spacer. To achieve this resolution using standard technologies, 300 microm pitch strips are necessary, and would require 100 channels to instrument the same area. Through our optimization calculations, we found that there is a trade-off between position resolution and energy resolution

A Business Case Analysis of Pre-Positioned Expeditionary Assistance Kit Joint Capability Technology Demonstration

DTIC Science & Technology

2013-12-01

of power from sunlight or a wind turbine (same solar panel tarps used in NEST Raptor Solar Light Trailer) • Global Positioning System (GPS) devices...satellite-enabled rapid wireless communications to the most critical areas and functions, working with Joint Task Forces. The first priority after the...a rapid response wireless communications system from military, civilian government, and non-government organizations. The tasks performed by HFN

Extended hybrid-space SENSE for EPI: Off-resonance and eddy current corrected joint interleaved blip-up/down reconstruction.

PubMed

Zahneisen, Benjamin; Aksoy, Murat; Maclaren, Julian; Wuerslin, Christian; Bammer, Roland

2017-06-01

Geometric distortions along the phase encode direction caused by off-resonant spins are still a major issue in EPI based functional and diffusion imaging. If the off-resonance map is known it is possible to correct for distortions. Most correction methods operate as a post-processing step on the reconstructed magnitude images. Here, we present an algebraic reconstruction method (hybrid-space SENSE) that incorporates a physics based model of off-resonances, phase inconsistencies between k-space segments, and T2*-decay during the acquisition. The method can be used to perform a joint reconstruction of interleaved acquisitions with normal (blip-up) and inverted (blip-down) phase encode direction which results in reduced g-factor penalty. A joint blip-up/down simultaneous multi slice (SMS) reconstruction for SMS-factor 4 in combination with twofold in-plane acceleration leads to a factor of two decrease in maximum g-factor penalty while providing off-resonance and eddy-current corrected images. We provide an algebraic framework for reconstructing diffusion weighted EPI data that in addition to the general applicability of hybrid-space SENSE to 2D-EPI, SMS-EPI and 3D-EPI with arbitrary k-space coverage along z, allows for a modeling of arbitrary spatio-temporal effects during the acquisition period like off-resonances, phase inconsistencies and T2*-decay. The most immediate benefit is a reduction in g-factor penalty if an interleaved blip-up/down acquisition strategy is chosen which facilitates eddy current estimation and ensures no loss in k-space encoding in regions with strong off-resonance gradients. Copyright © 2017 Elsevier Inc. All rights reserved.

Sensory innervation of the temporomandibular joint in the mouse.

PubMed

Dreessen, D; Halata, Z; Strasmann, T

1990-01-01

The sensory innervation of the temporomandibular joints (TMJs) of 8 STR/IN mice was investigated by means of light and electron microscopy. Through the cutting of complete semithin sections in series it was possible to investigate the joints thoroughly. Additionally, one joint with its nerve supply was reconstructed three-dimensionally with a computerized three-dimensional programme. The reconstruction was based on one complete semithin section series. The joint's nerve supply originates from the nervus auriculotemporalis and additionally from motor branches of the n. mandibularis: n. massetericus, n. pterygoideus lateralis and the nn. temporales posteriores. The greatest number of nerve fibres and endings is located in the dorsolateral part of the joint capsule. They lie only in the stratum fibrosum and subsynovially. Neither the stratum synoviale nor the discus articularis contain any nerve fibres or endings, whereas the peri-articular loose connective tissue is richly innervated. The only type of nerve ending observed within the joint was the free nerve ending, which is assumed to serve not only as a nociceptor but also as a polymodal mechanoreceptor. Merely within the insertion of the musculus pterygoideus lateralis at the collum mandibulae single stretch receptors of the Ruffini type were observed. Ultrastructurally, they correspond to those described in the cat's knee joint. Neither lamellated nor nerve endings of the Golgi or Pacini type were observed in the joint or in the peri-articular connective tissue. The unexpected paucity of nerve fibres and endings in the TMJ itself of the mouse suggests that the afferent information from the joint is less important for position sense and movement than the afferent information from muscles, tendons and periodontal ligaments.

Targeting agr- and agr-Like Quorum Sensing Systems for Development of Common Therapeutics to Treat Multiple Gram-Positive Bacterial Infections

PubMed Central

Gray, Brian; Hall, Pamela; Gresham, Hattie

2013-01-01

Invasive infection by the Gram-positive pathogen Staphylococcus aureus is controlled by a four gene operon, agr that encodes a quorum sensing system for the regulation of virulence. While agr has been well studied in S. aureus, the contribution of agr homologues and analogues in other Gram-positive pathogens is just beginning to be understood. Intriguingly, other significant human pathogens, including Clostridium perfringens, Listeria monocytogenes, and Enterococcus faecalis contain agr or analogues linked to virulence. Moreover, other significant human Gram-positive pathogens use peptide based quorum sensing systems to establish or maintain infection. The potential for commonality in aspects of these signaling systems across different species raises the prospect of identifying therapeutics that could target multiple pathogens. Here, we review the status of research into these agr homologues, analogues, and other peptide based quorum sensing systems in Gram-positive pathogens as well as the potential for identifying common pathways and signaling mechanisms for therapeutic discovery. PMID:23598501

Joint Attention Initiation with and without Positive Affect: Risk Group Differences and Associations with ASD Symptoms

ERIC Educational Resources Information Center

Gangi, Devon N.; Ibañez, Lisa V.; Messinger, Daniel S.

2014-01-01

Infants at risk for autism spectrum disorders (ASD) may have difficulty integrating smiles into initiating joint attention (IJA) bids. A specific IJA pattern, anticipatory smiling, may communicate preexisting positive affect when an infant smiles at an object and then turns the smile toward the social partner. We compared the development of…

Gram-positive marine bacteria as a potential resource for the discovery of quorum sensing inhibitors.

PubMed

Teasdale, Margaret E; Donovan, Kellye A; Forschner-Dancause, Stephanie R; Rowley, David C

2011-08-01

Inhibitors of bacterial quorum sensing have been proposed as potentially novel therapeutics for the treatment of certain bacterial diseases. We recently reported a marine Halobacillus salinus isolate that secretes secondary metabolites capable of quenching quorum sensing phenotypes in several Gram-negative reporter strains. To investigate how widespread the production of such compounds may be in the marine bacterial environment, 332 Gram-positive isolates from diverse habitats were tested for their ability to interfere with Vibrio harveyi bioluminescence, a cell signaling-regulated phenotype. Rapid assay methods were employed where environmental isolates were propagated alongside the reporter strain. "Actives" were defined as bacteria that interfered with bioluminescence without visible cell-killing effects (antibiotic activity). A total of 49 bacterial isolates interfered with bioluminescence production in the assays. Metabolite extracts were generated from cultures of the active isolates, and 28 reproduced the bioluminescence inhibition against V. harveyi. Of those 28, five extracts additionally inhibited violacein production by Chromobacterium violaceum. Chemical investigations revealed that phenethylamides and a cyclic dipeptide are two types of secondary metabolites responsible for the observed activities. The active bacterial isolates belonged primarily to either the genus Bacillus or Halobacillus. The results suggest that Gram-positive marine bacteria are worthy of further investigation for the discovery of quorum sensing antagonists.

AAE and AAOMR Joint Position Statement: Use of Cone Beam Computed Tomography in Endodontics 2015 Update.

PubMed

2015-10-01

The following statement was prepared by the Special Committee to Revise the Joint American Association of Endodontists/American Academy of Oral and Maxillofacial Radiology Position on Cone Beam Computed Tomography, and approved by the AAE Board of Directors and AAOMR Executive Council in May 2015. AAE members may reprint this position statement for distribution to patients or referring dentists. Copyright © 2015 American Academy of Oral and Maxillofacial Radiology and American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Hip joint centre position estimation using a dual unscented Kalman filter for computer-assisted orthopaedic surgery.

PubMed

Beretta, Elisa; De Momi, Elena; Camomilla, Valentina; Cereatti, Andrea; Cappozzo, Aurelio; Ferrigno, Giancarlo

2014-09-01

In computer-assisted knee surgery, the accuracy of the localization of the femur centre of rotation relative to the hip-bone (hip joint centre) is affected by the unavoidable and untracked pelvic movements because only the femoral pose is acquired during passive pivoting manoeuvres. We present a dual unscented Kalman filter algorithm that allows the estimation of the hip joint centre also using as input the position of a pelvic reference point that can be acquired with a skin marker placed on the hip, without increasing the invasiveness of the surgical procedure. A comparative assessment of the algorithm was carried out using data provided by in vitro experiments mimicking in vivo surgical conditions. Soft tissue artefacts were simulated and superimposed onto the position of a pelvic landmark. Femoral pivoting made of a sequence of star-like quasi-planar movements followed by a circumduction was performed. The dual unscented Kalman filter method proved to be less sensitive to pelvic displacements, which were shown to be larger during the manoeuvres in which the femur was more adducted. Comparable accuracy between all the analysed methods resulted for hip joint centre displacements smaller than 1 mm (error: 2.2 ± [0.2; 0.3] mm, median ± [inter-quartile range 25%; inter-quartile range 75%]) and between 1 and 6 mm (error: 4.8 ± [0.5; 0.8] mm) during planar movements. When the hip joint centre displacement exceeded 6 mm, the dual unscented Kalman filter proved to be more accurate than the other methods by 30% during multi-planar movements (error: 5.2 ± [1.2; 1] mm). © IMechE 2014.

European nursing organizations stand up for family presence during cardiopulmonary resuscitation: a joint position statement.

PubMed

Moons, Philip; Norekvål, Tone M

2008-01-01

Empirical evidence suggests that family presence during cardiopulmonary resuscitation (CPR) has beneficial effects. Although many American professional organizations have endorsed the idea of family presence, there is less formal support in Europe. In addition, the attitude of nurses from Anglo-Saxon countries, such as United Kingdom and Ireland, is more positive toward family presence than the attitude of nurses of mainland Europe. In order to support existing guidelines and to stimulate health care organizations to develop a formal policy with respect to family witnessed CPR, 3 important European nursing organizations have recently developed a joint position statement.

Block sparsity-based joint compressed sensing recovery of multi-channel ECG signals.

PubMed

Singh, Anurag; Dandapat, Samarendra

2017-04-01

In recent years, compressed sensing (CS) has emerged as an effective alternative to conventional wavelet based data compression techniques. This is due to its simple and energy-efficient data reduction procedure, which makes it suitable for resource-constrained wireless body area network (WBAN)-enabled electrocardiogram (ECG) telemonitoring applications. Both spatial and temporal correlations exist simultaneously in multi-channel ECG (MECG) signals. Exploitation of both types of correlations is very important in CS-based ECG telemonitoring systems for better performance. However, most of the existing CS-based works exploit either of the correlations, which results in a suboptimal performance. In this work, within a CS framework, the authors propose to exploit both types of correlations simultaneously using a sparse Bayesian learning-based approach. A spatiotemporal sparse model is employed for joint compression/reconstruction of MECG signals. Discrete wavelets transform domain block sparsity of MECG signals is exploited for simultaneous reconstruction of all the channels. Performance evaluations using Physikalisch-Technische Bundesanstalt MECG diagnostic database show a significant gain in the diagnostic reconstruction quality of the MECG signals compared with the state-of-the art techniques at reduced number of measurements. Low measurement requirement may lead to significant savings in the energy-cost of the existing CS-based WBAN systems.

MRI of the sacroiliac joints in spondyloarthritis: the added value of intra-articular signal changes for a 'positive MRI'.

PubMed

Laloo, Frederiek; Herregods, N; Jaremko, J L; Verstraete, K; Jans, L

2018-05-01

To determine if intra-articular signal changes at the sacroiliac joint space on MRI have added diagnostic value for spondyloarthritis, when compared to bone marrow edema (BME). A retrospective study was performed on the MRIs of sacroiliac joints of 363 patients, aged 16-45 years, clinically suspected of sacroiliitis. BME of the sacroiliac joints was correlated to intra-articular sacroiliac joint MR signal changes: high T1 signal, fluid signal, ankylosis and vacuum phenomenon (VP). These MRI findings were correlated with final clinical diagnosis. Sensitivity (SN), specificity (SP), likelihood ratios (LR), predictive values and post-test probabilities were calculated. BME had SN of 68.9%, SP of 74.0% and LR+ of 2.6 for diagnosis of spondyloarthritis. BME in absence of intra-articular signal changes had a lower SN and LR+ for spondyloarthritis (SN = 20.5%, LR+ 1.4). Concomitant BME and high T1 signal (SP = 97.2%, LR + = 10.5), BME and fluid signal (SP = 98.6%, LR + = 10.3) or BME and ankylosis (SP = 100%) had higher SP and LR+ for spondyloarthritis. Concomitant BME and VP had low LR+ for spondyloarthritis (SP = 91%, LR + =0.9). When BME was absent, intra-articular signal changes were less prevalent, but remained highly specific for spondyloarthritis. Our results suggest that both periarticular and intra-articular MR signal of the sacroiliac joint should be examined to determine whether an MRI is 'positive' or 'not positive' for sacroiliitis associated with spondyloarthritis.

MEMS high-speed angular-position sensing system with rf wireless transmission

NASA Astrophysics Data System (ADS)

Sun, Winston; Li, Wen J.

2001-08-01

A novel surface-micromachined non-contact high-speed angular-position sensor with total surface area under 4mm2 was developed using the Multi-User MEMS Processes (MUMPs) and integrated with a commercial RF transmitter at 433MHz carrier frequency for wireless signal detection. Currently, a 2.3 MHz internal clock of our data acquisition system and a sensor design with a 13mg seismic mass is sufficient to provide visual observation of a clear sinusoidal response wirelessly generated by the piezoresistive angular-position sensing system within speed range of 180 rpm to around 1000 rpm. Experimental results showed that the oscillation frequency and amplitude are related to the input angular frequency of the rotation disk and the tilt angle of the rotation axis, respectively. These important results could provide groundwork for MEMS researchers to estimate how gravity influences structural properties of MEMS devices under different circumstances.

Whatever Happened to Joint Vision 2010

DTIC Science & Technology

2010-04-02

submitted to the Faculty of the Joint Advanced Warfighting School in partial satisfaction of the requirements of a Master of Science Degree in Joint...Service efforts and evolve “jointness” beyond the dictates of the 1986 Goldwater-Nichols Act. JV2010 delineated a common set of environmental ...towards something that is fresh, new and important. In this sense, the term vision may have been the wrong term. Warren Bennis and Burt Nanus, noted

Techniques of Force and Pressure Measurement in the Small Joints of the Wrist.

PubMed

Schreck, Michael J; Kelly, Meghan; Canham, Colin D; Elfar, John C

2018-01-01

The alteration of forces across joints can result in instability and subsequent disability. Previous methods of force measurements such as pressure-sensitive films, load cells, and pressure-sensing transducers have been utilized to estimate biomechanical forces across joints and more recent studies have utilized a nondestructive method that allows for assessment of joint forces under ligamentous restraints. A comprehensive review of the literature was performed to explore the numerous biomechanical methods utilized to estimate intra-articular forces. Methods of biomechanical force measurements in joints are reviewed. Methods such as pressure-sensitive films, load cells, and pressure-sensing transducers require significant intra-articular disruption and thus may result in inaccurate measurements, especially in small joints such as those within the wrist and hand. Non-destructive methods of joint force measurements either utilizing distraction-based joint reaction force methods or finite element analysis may offer a more accurate assessment; however, given their recent inception, further studies are needed to improve and validate their use.

Dealing with Daily Challenges in Dementia (Deal-id Study): An Experience Sampling Study to Assess Caregivers' Sense of Competence and Experienced Positive Affect in Daily Life.

PubMed

van Knippenberg, Rosalia J M; de Vugt, Marjolein E; Ponds, Rudolf W; Myin-Germeys, Inez; Verhey, Frans R J

2017-08-01

Positive emotions and feelings of competence seem to play an important role in the well-being of caregivers of people with dementia. Both are likely to fluctuate constantly throughout the caretaking process. Unlike standard retrospective methods, momentary assessments in daily life can provide insight into these moment-to-moment fluctuations. Therefore, in this study both retrospective and momentary assessments were used to examine the relationship between caregivers' sense of competence and their experienced positive affect (PA) in daily life. Thirty Dutch caregivers provided momentary data on PA and daily sense of competence ratings for 6 consecutive days using the experience sampling methodology. Additionally, they reported retrospectively on their sense of competence with a traditional questionnaire. A positive association was found between retrospective and daily measured sense of competence. Caregivers reported corresponding levels of sense of competence on both measures. Both daily and retrospective sense of competence were positively associated with the experienced levels of PA. However, daily sense of competence appeared to be the strongest predictor. Regarding the variability in PA, only daily sense of competence showed a significant association, with a higher daily sense of competence predicting a more stable PA pattern. This study provides support for redirecting caregiver support interventions toward enhancement of positive rather than negative experiences and focusing more on caregivers' momentary emotional experiences. Momentary assessments are a valuable addition to standard retrospective measures and provide a more comprehensive and dynamic view of caregiver functioning. Copyright © 2016 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Sacroiliac joint dysfunction.

PubMed

Ilaslan, Hakan; Arslan, Ahmet; Koç, Omer Nadir; Dalkiliç, Turker; Naderi, Sait

2010-07-01

Sacroiliac joint dysfunction is a disorder presenting with low back and groin pain. It should be taken into consideration during the preoperative differential diagnosis of lumbar disc herniation, lumbar spinal stenosis and facet syndrome. Four cases with sacroiliac dysfunction are presented. The clinical and radiological signs supported the evidence of sacroiliac dysfunction, and exact diagnosis was made after positive response to sacroiliac joint block. A percutaneous sacroiliac fixation provided pain relief in all cases. The mean VAS scores reduced from 8.2 to 2.2. It is concluded that sacroiliac joint dysfunction diagnosis requires a careful physical examination of the sacroiliac joints in all cases with low back and groin pain. The diagnosis is made based on positive response to the sacroiliac block. Sacroiliac fixation was found to be effective in carefully selected cases.

Teachers' Positioning towards an Educational Innovation in the Light of Ownership, Sense-Making and Agency

ERIC Educational Resources Information Center

Ketelaar, Evelien; Beijaard, Douwe; Boshuizen, Henny P. A.; Den Brok, Perry J.

2012-01-01

The positioning of eleven teachers towards an innovation was studied in the light of ownership, sense-making and agency. Semi-structured and video-stimulated interviews were used for data collection. The findings show that these three concepts are useful for describing similarities and differences between teachers in terms of their positioning…

Strand-specific, real-time RT-PCR assays for quantification of genomic and positive-sense RNAs of the fish rhabdovirus, Infectious hematopoietic necrosis virus

USGS Publications Warehouse

Purcell, Maureen K.; Hart, S. Alexandra; Kurath, Gael; Winton, James R.

2006-01-01

The fish rhabdovirus, Infectious hematopoietic necrosis virus (IHNV), is an important pathogen of salmonids. Cell culture assays have traditionally been used to quantify levels of IHNV in samples; however, real-time or quantitative RT-PCR assays have been proposed as a rapid alternative. For viruses having a single-stranded, negative-sense RNA genome, standard qRT-PCR assays do not distinguish between the negative-sense genome and positive-sense RNA species including mRNA and anti-genome. Thus, these methods do not determine viral genome copy number. This study reports development of strand-specific, qRT-PCR assays that use tagged primers for enhancing strand specificity during cDNA synthesis and quantitative PCR. Protocols were developed for positive-strand specific (pss-qRT-PCR) and negative-strand specific (nss-qRT-PCR) assays for IHNV glycoprotein (G) gene sequences. Validation with synthetic RNA transcripts demonstrated the assays could discriminate the correct strand with greater than 1000-fold fidelity. The number of genome copies in livers of IHNV-infected fish determined by nss-qRT-PCR was, on average, 8000-fold greater than the number of infectious units as determined by plaque assay. We also compared the number of genome copies with the quantity of positive-sense RNA and determined that the ratio of positive-sense molecules to negative-sense genome copies was, on average, 2.7:1. Potential future applications of these IHNV strand-specific qRT-PCR assays are discussed.

Markerless Knee Joint Position Measurement Using Depth Data during Stair Walking

PubMed Central

Mita, Akira; Yorozu, Ayanori; Takahashi, Masaki

2017-01-01

Climbing and descending stairs are demanding daily activities, and the monitoring of them may reveal the presence of musculoskeletal diseases at an early stage. A markerless system is needed to monitor such stair walking activity without mentally or physically disturbing the subject. Microsoft Kinect v2 has been used for gait monitoring, as it provides a markerless skeleton tracking function. However, few studies have used this device for stair walking monitoring, and the accuracy of its skeleton tracking function during stair walking has not been evaluated. Moreover, skeleton tracking is not likely to be suitable for estimating body joints during stair walking, as the form of the body is different from what it is when it walks on level surfaces. In this study, a new method of estimating the 3D position of the knee joint was devised that uses the depth data of Kinect v2. The accuracy of this method was compared with that of the skeleton tracking function of Kinect v2 by simultaneously measuring subjects with a 3D motion capture system. The depth data method was found to be more accurate than skeleton tracking. The mean error of the 3D Euclidian distance of the depth data method was 43.2 ± 27.5 mm, while that of the skeleton tracking was 50.4 ± 23.9 mm. This method indicates the possibility of stair walking monitoring for the early discovery of musculoskeletal diseases. PMID:29165396

Position feedback control system

DOEpatents

Bieg, Lothar F.; Jokiel, Jr., Bernhard; Ensz, Mark T.; Watson, Robert D.

2003-01-01

Disclosed is a system and method for independently evaluating the spatial positional performance of a machine having a movable member, comprising an articulated coordinate measuring machine comprising: a first revolute joint; a probe arm, having a proximal end rigidly attached to the first joint, and having a distal end with a probe tip attached thereto, wherein the probe tip is pivotally mounted to the movable machine member; a second revolute joint; a first support arm serially connecting the first joint to the second joint; and coordinate processing means, operatively connected to the first and second revolute joints, for calculating the spatial coordinates of the probe tip; means for kinematically constraining the articulated coordinate measuring machine to a working surface; and comparator means, in operative association with the coordinate processing means and with the movable machine, for comparing the true position of the movable machine member, as measured by the true position of the probe tip, with the desired position of the movable machine member.

Position of the prosthesis components in total ankle replacement and the effect on motion at the replaced joint.

PubMed

Cenni, Francesco; Leardini, Alberto; Cheli, Andrea; Catani, Fabio; Belvedere, Claudio; Romagnoli, Matteo; Giannini, Sandro

2012-03-01

In some cases of total ankle replacement, perfect alignment of the prosthetic components is not achieved. This study analyses the extent to which component positioning is critical for the final range of motion. Fourteen patients undergoing total ankle replacement were assessed preoperatively and postoperatively at seven and 13 months follow-up. X-ray pictures of the ankle were taken in static double leg stance, i.e. at neutral joint position, and in maximum plantarflexion and dorsiflexion. Measurements were obtained by a specially devised computer program based on anatomical reference points digitised on the radiograms. These allowed calculation of the position and orientation of the components in the sagittal and coronal planes, together with the joint range of motion. The mean range of motion was about 34 degrees at the first follow-up and maintained at the second. Tibial and talar components were more anterior than the mid-tibial shaft in 11 and nine patients, respectively. Mean inclination was about four degrees posterior for the tibial component and nearly one degree anterior for the talar component. A significantly larger range of motion was found in ankles both with the talar component located and inclined more anteriorly than the tibial. Correlation, though weak, was found between motion at the replaced ankle and possible residual subluxation and inclination of the components. However, a satisfactory range of motion was also achieved in those patients where recommended locations for the components could not be reached because of the size of the original joint deformity.

Estimation of Time-Varying, Intrinsic and Reflex Dynamic Joint Stiffness during Movement. Application to the Ankle Joint

PubMed Central

Guarín, Diego L.; Kearney, Robert E.

2017-01-01

Dynamic joint stiffness determines the relation between joint position and torque, and plays a vital role in the control of posture and movement. Dynamic joint stiffness can be quantified during quasi-stationary conditions using disturbance experiments, where small position perturbations are applied to the joint and the torque response is recorded. Dynamic joint stiffness is composed of intrinsic and reflex mechanisms that act and change together, so that nonlinear, mathematical models and specialized system identification techniques are necessary to estimate their relative contributions to overall joint stiffness. Quasi-stationary experiments have demonstrated that dynamic joint stiffness is heavily modulated by joint position and voluntary torque. Consequently, during movement, when joint position and torque change rapidly, dynamic joint stiffness will be Time-Varying (TV). This paper introduces a new method to quantify the TV intrinsic and reflex components of dynamic joint stiffness during movement. The algorithm combines ensemble and deterministic approaches for estimation of TV systems; and uses a TV, parallel-cascade, nonlinear system identification technique to separate overall dynamic joint stiffness into intrinsic and reflex components from position and torque records. Simulation studies of a stiffness model, whose parameters varied with time as is expected during walking, demonstrated that the new algorithm accurately tracked the changes in dynamic joint stiffness using as little as 40 gait cycles. The method was also used to estimate the intrinsic and reflex dynamic ankle stiffness from an experiment with a healthy subject during which ankle movements were imposed while the subject maintained a constant muscle contraction. The method identified TV stiffness model parameters that predicted the measured torque very well, accounting for more than 95% of its variance. Moreover, both intrinsic and reflex dynamic stiffness were heavily modulated through the

High angle of attack position sensing for the Southampton University magnetic suspension and balance system

NASA Technical Reports Server (NTRS)

Parker, David H.

1987-01-01

An all digital five channel position detection system is to be installed in the Southampton University Magnetic Suspension and Balance System (SUMSBS). The system is intended to monitor a much larger range of model pitch attitudes than has been possible hitherto, up to a maximum of a 90 degree angle of attack. It is based on the use of self-scanning photodiode arrays and illuminating laser light beams, together with purpose built processing electronics. The principles behind the design of the system are discussed, together with the results of testing one channel of the system which was used to control the axial position of a magnetically suspended model in SUMSBS. The removal of optically coupled heave position information from the axial position sensing channel is described.

Evaluation of three force-position hybrid control methods for a robot-based biological joint-testing system.

PubMed

Hsieh, Hong-Jung; Hu, Chih-Chung; Lu, Tung-Wu; Lu, Hsuan-Lun; Kuo, Mei-Ying; Kuo, Chien-Chung; Hsu, Horng-Chaung

2016-06-07

Robot-based joint-testing systems (RJTS) can be used to perform unconstrained laxity tests, measuring the stiffness of a degree of freedom (DOF) of the joint at a fixed flexion angle while allowing the other DOFs unconstrained movement. Previous studies using the force-position hybrid (FPH) control method proposed by Fujie et al. (J Biomech Eng 115(3):211-7, 1993) focused on anterior/posterior tests. Its convergence and applicability on other clinically relevant DOFs such as valgus/varus have not been demonstrated. The current s1tudy aimed to develop a 6-DOF RJTS using an industrial robot, to propose two new force-position hybrid control methods, and to evaluate the performance of the methods and FPH in controlling the RJTS for anterior/posterior and valgus/varus laxity tests of the knee joint. An RJTS was developed using an industrial 6-DOF robot with a 6-component load-cell attached at the effector. The performances of FPH and two new control methods, namely force-position alternate control (FPA) and force-position hybrid control with force-moment control (FPHFM), for unconstrained anterior/posterior and valgus/varus laxity tests were evaluated and compared with traditional constrained tests (CT) in terms of the number of control iterations, total time and the constraining forces and moments. As opposed to CT, the other three control methods successfully reduced the constraining forces and moments for both anterior/posterior and valgus/varus tests, FPHFM being the best followed in order by FPA and FPH. FPHFM had root-mean-squared constraining forces and moments of less than 2.2 N and 0.09 Nm, respectively at 0° flexion, and 2.3 N and 0.14 Nm at 30° flexion. The corresponding values for FPH were 8.5 N and 0.33 Nm, and 11.5 N and 0.45 Nm, respectively. Given the same control parameters including the compliance matrix, FPHFM and FPA reduced the constraining loads of FPH at the expense of additional control iterations, and thus increased total time, FPA

Integrating remote sensing, geographic information systems and global positioning system techniques with hydrological modeling

NASA Astrophysics Data System (ADS)

Thakur, Jay Krishna; Singh, Sudhir Kumar; Ekanthalu, Vicky Shettigondahalli

2017-07-01

Integration of remote sensing (RS), geographic information systems (GIS) and global positioning system (GPS) are emerging research areas in the field of groundwater hydrology, resource management, environmental monitoring and during emergency response. Recent advancements in the fields of RS, GIS, GPS and higher level of computation will help in providing and handling a range of data simultaneously in a time- and cost-efficient manner. This review paper deals with hydrological modeling, uses of remote sensing and GIS in hydrological modeling, models of integrations and their need and in last the conclusion. After dealing with these issues conceptually and technically, we can develop better methods and novel approaches to handle large data sets and in a better way to communicate information related with rapidly decreasing societal resources, i.e. groundwater.

[Analysis of influential factors for job burnout among managers in a joint venture in Guangzhou, China].

PubMed

Lin, Qiu-hong; Jiang, Chao-qiang; Liu, Yi-min; Guo, Jing-yi; Lam, Tai Hing

2013-12-01

To investigate the influential factors for job burnout among the managerial staff in a Sino-Japanese joint venture automobile manufacturer in Guangzhou, China. A total of 288 managers in a Sino-Japanese joint venture automobile manufacturer were surveyed using the Occupational Stress Indicator, Maslach Burnout Inventory (MBI), Eysenck Personality Questionnaire, Simplified Coping Style Questionnaire, and Social Support Rating Scale. On the depersonalization dimension, the male managers had significantly higher scores than the female managers. The scores of emotion exhaustion and depersonalization of MBI showed significant differences among the managers with different levels of occupational stress. The path analysis showed that occupational stress, neuroticism, and psychoticism had negative effects on emotion exhaustion, while job satisfaction and utilization of social support had direct positive effects on emotion exhaustion. Occupational stress, psychoticism, and passive coping style had direct negative effects on depersonalization, while job satisfaction, objective support, and utilization of social support had positive effects on depersonalization. Job satisfaction and active coping style had positive effects on sense of personal accomplishment, while passive coping style had a negative effect on sense of personal accomplishment. Personality exerted its effect on social support through coping style and thus on job satisfaction and job burnout. Male managers have a greater propensity to depersonalization than their female counterparts. High occupational stress is a risk factor for job burnout. Personality, social support, and coping style are influential factors for job burnout.

The correlation between proprioception and handwriting legibility in children

PubMed Central

Hong, So Young; Jung, Nam-Hae; Kim, Kyeong Mi

2016-01-01

[Purpose] This study investigated the association between proprioception, including joint position sense and kinetic sense, and handwriting legibility in healthy children. [Subjects and Methods] Assessment of joint position sense, kinetic sense, and handwriting legibility was conducted for 19 healthy children. Joint position sense was assessed by asking the children to flex their right elbow between 30° to 110° while blindfolded. The range of elbow movement was analyzed with Compact Measuring System 10 for 3D motion Analysis. Kinetic sense was assessed using the Sensory Integration and Praxis Test. The children were directed to write 30 words from the Korean alphabet, and the legibility of their handwriting was scored for form, alignment, space, size, and shape. To analyze the data, descriptive statistics and Spearman correlation analysis were conducted using IBM SPSS Statistics 20.0. [Results] There was significant negative correlation between handwriting legibility and Kinetic sense. A significant correlation between handwriting legibility and Joint position sense was not found. [Conclusion] This study showed that a higher Kinetic sense was associated with better legibility of handwriting. Further work is needed to determine the association of handwriting legibility and speed with Joint position sense of the elbow, wrist, and fingers. PMID:27821948

Aircraft remote sensing of phytoplankton spatial patterns during the 1989 Joint Global Ocean Flux Study (JGOFS) North Atlantic bloom experiment

NASA Technical Reports Server (NTRS)

Yoder, James A.; Hoge, Frank E.

1991-01-01

Mesoscale phytoplankton chlorophyll variability near the Joint Global Ocean Flux study sites along the 20 W meridian at 34 N, 47 N, and 59 N is discussed. The NASA P-3 aircraft and the Airborne Oceanographic Lidar (AOL) system provides remote sensing support for the North Atlantic Bloom Experiment. The principal instrument of the AOL system is the blue-green laser that stimulates fluorescence from photoplankton chlorophyll, the principal photosynthetic pigment. Other instruments on the NASA P-3 aircraft include up- and down-looking spectrometers, PRT-5 for infrared measurements to determine sea surface temperature, and a system to deploy and record AXBTs to measure subsurface temperature structure.

Joint Contributions of Negative Emotionality, Positive Emotionality, and Effortful Control on Depressive Symptoms in Youth.

PubMed

Van Beveren, Marie-Lotte; Mezulis, Amy; Wante, Laura; Braet, Caroline

2016-11-02

From a clinical developmental perspective, temperament has been shown to confer vulnerability to depression among youth. High negative emotionality (NE), low positive emotionality (PE), and low effortful control (EC) have repeatedly been independently associated with youth depressive symptoms. However, far less research has examined the joint contributions of NE, PE, and EC on such symptoms. The present study builds upon previous research by examining how NE, PE, and EC jointly predict change in depressive symptoms over time among 211 youngsters (7-14 years, M = 10.7, SD = 1.81) who participated in an 8-month prospective study. Self-reported temperament and symptoms were assessed at baseline; self-reported symptoms were measured again at follow-up. Results suggest that all 3 temperamental traits need to be considered jointly in predicting change in depressive symptoms. Furthermore, results provide further support for the "best two out of three" principle. Surprisingly, results reveal that high EC might be maladaptive in the context of high emotional reactivity. Last, results show that the combination of high NE and low EC could be a possible pathway to the development of symptoms. The current study clarified how NE, PE, and EC may jointly confer risk-or protection for developing depressive symptoms during adolescence. The results highlight the need of taking into account all three temperamental traits in order to provide a more nuanced understanding of the risk for developing depressive symptoms at an early stage, as well as to provide customized care targeting temperamental vulnerability in depressed youth.

Vision-based real-time position control of a semi-automated system for robot-assisted joint fracture surgery.

PubMed

Dagnino, Giulio; Georgilas, Ioannis; Tarassoli, Payam; Atkins, Roger; Dogramadzi, Sanja

2016-03-01

Joint fracture surgery quality can be improved by robotic system with high-accuracy and high-repeatability fracture fragment manipulation. A new real-time vision-based system for fragment manipulation during robot-assisted fracture surgery was developed and tested. The control strategy was accomplished by merging fast open-loop control with vision-based control. This two-phase process is designed to eliminate the open-loop positioning errors by closing the control loop using visual feedback provided by an optical tracking system. Evaluation of the control system accuracy was performed using robot positioning trials, and fracture reduction accuracy was tested in trials on ex vivo porcine model. The system resulted in high fracture reduction reliability with a reduction accuracy of 0.09 mm (translations) and of [Formula: see text] (rotations), maximum observed errors in the order of 0.12 mm (translations) and of [Formula: see text] (rotations), and a reduction repeatability of 0.02 mm and [Formula: see text]. The proposed vision-based system was shown to be effective and suitable for real joint fracture surgical procedures, contributing a potential improvement of their quality.

Coding of position by simultaneously recorded sensory neurones in the cat dorsal root ganglion

PubMed Central

Stein, R B; Weber, D J; Aoyagi, Y; Prochazka, A; Wagenaar, J B M; Shoham, S; Normann, R A

2004-01-01

Muscle, cutaneous and joint afferents continuously signal information about the position and movement of individual joints. How does the nervous system extract more global information, for example about the position of the foot in space? To study this question we used microelectrode arrays to record impulses simultaneously from up to 100 discriminable nerve cells in the L6 and L7 dorsal root ganglia (DRG) of the anaesthetized cat. When the hindlimb was displaced passively with a random trajectory, the firing rate of the neurones could be predicted from a linear sum of positions and velocities in Cartesian (x, y), polar or joint angular coordinates. The process could also be reversed to predict the kinematics of the limb from the firing rates of the neurones with an accuracy of 1–2 cm. Predictions of position and velocity could be combined to give an improved fit to limb position. Decoders trained using random movements successfully predicted cyclic movements and movements in which the limb was displaced from a central point to various positions in the periphery. A small number of highly informative neurones (6–8) could account for over 80% of the variance in position and a similar result was obtained in a realistic limb model. In conclusion, this work illustrates how populations of sensory receptors may encode a sense of limb position and how the firing of even a small number of neurones can be used to decode the position of the limb in space. PMID:15331686

WaterSense Specification for Showerheads Supporting Statement

EPA Pesticide Factsheets

WaterSense collaborated with the American Society of Mechanical Engineers (ASME)/Canadian Standards Association (CSA) Joint Harmonization Task Force to develop the specification criteria for high-efficiency showerheads.

Spatial and physical frames of reference in positioning a limb.

PubMed

Garrett, S R; Pagano, C; Austin, G; Turvey, M T

1998-10-01

Splints attached to the right forearm were used to rotate the forearm's physical reference frame, as defined by the eigenvectors of its inertia tensor, relative to its spatial reference frame. In two experiments, when subjects were required to orient the forearm parallel to, or at 45 degrees to, the environmental horizontal, they produced limb orientations that were systematically deflected from the forearm's longitudinal spatial axis in the direction of the forearm's physical axes. The position sense seems to be based on inertial eigenvectors rather than on joint angles or gravitational torques.

Multi-class geospatial object detection based on a position-sensitive balancing framework for high spatial resolution remote sensing imagery

NASA Astrophysics Data System (ADS)

Zhong, Yanfei; Han, Xiaobing; Zhang, Liangpei

2018-04-01

Multi-class geospatial object detection from high spatial resolution (HSR) remote sensing imagery is attracting increasing attention in a wide range of object-related civil and engineering applications. However, the distribution of objects in HSR remote sensing imagery is location-variable and complicated, and how to accurately detect the objects in HSR remote sensing imagery is a critical problem. Due to the powerful feature extraction and representation capability of deep learning, the deep learning based region proposal generation and object detection integrated framework has greatly promoted the performance of multi-class geospatial object detection for HSR remote sensing imagery. However, due to the translation caused by the convolution operation in the convolutional neural network (CNN), although the performance of the classification stage is seldom influenced, the localization accuracies of the predicted bounding boxes in the detection stage are easily influenced. The dilemma between translation-invariance in the classification stage and translation-variance in the object detection stage has not been addressed for HSR remote sensing imagery, and causes position accuracy problems for multi-class geospatial object detection with region proposal generation and object detection. In order to further improve the performance of the region proposal generation and object detection integrated framework for HSR remote sensing imagery object detection, a position-sensitive balancing (PSB) framework is proposed in this paper for multi-class geospatial object detection from HSR remote sensing imagery. The proposed PSB framework takes full advantage of the fully convolutional network (FCN), on the basis of a residual network, and adopts the PSB framework to solve the dilemma between translation-invariance in the classification stage and translation-variance in the object detection stage. In addition, a pre-training mechanism is utilized to accelerate the training procedure

Photonic Waveguide Choke Joint with Non-Absorptive Loading

NASA Technical Reports Server (NTRS)

Wollack, Edward J. (Inventor); U-Yen, Kongpop (Inventor); Chuss, David T. (Inventor)

2016-01-01

A waveguide choke joint includes a first array of pillars positioned on a substrate, each pillar in the first array of pillars having a first size and configured to receive an input plane wave at a first end of the choke joint. The choke joint has a second end configured to transmit the input plane wave away from the choke joint. The choke joint further includes a second array of pillars positioned on the substrate between the first array of pillars and the second end of the choke joint. Each pillar in the second array of pillars has a second size. The choke joint also has a third array of pillars positioned on the substrate between the second array and the second end of the choke joint. Each pillar in the third array of pillars has a third size.

Joint Agency Commercial Imagery Evaluation (JACIE)

USGS Publications Warehouse

Jucht, Carrie

2010-01-01

Remote sensing data are vital to understanding the physical world and to answering many of its needs and problems. The United States Geological Survey's (USGS) Remote Sensing Technologies (RST) Project, working with its partners, is proud to sponsor the annual Joint Agency Commercial Imagery Evaluation (JACIE) Workshop to help understand the quality and usefulness of remote sensing data. The JACIE program was formed in 2001 to leverage U.S. Federal agency resources for the characterization of commercial remote sensing data. These agencies sponsor and co-chair JACIE: U.S. Geological Survey (USGS) National Aeronautics and Space Administration (NASA) National Geospatial-Intelligence Agency (NGA) U.S. Department of Agriculture (USDA) JACIE is an effort to coordinate data assessments between the participating agencies and partners and communicate the knowledge and results of the quality and utility of the remotely sensed data available for government and private use.

Intellectual Disability Policy as Developed, Expressed, and Evaluated in AAIDD/The Arc Joint Statements: The Role of Organization Position Statements.

PubMed

Luckasson, Ruth; Ford, Marty E; McMillan, Elise D; Misilo, Frederick M; Nygren, Margaret A

2017-07-01

The American Association on Intellectual and Developmental Disabilities (AAIDD) and The Arc of the United States (The Arc) have a long history of joined efforts to develop, express, and evaluate disability policies. These efforts have resulted in a series of formal statements on critical issues such as education, healthcare, human rights, and criminal justice. Their joint efforts further important policy goals including providing clear strong communication about important policy values and directions, promulgating key principles of high quality supports and services, affirming best professional practices, and emphasizing personal outcomes. In addition, the joint efforts (a) affirm important aspects of organization identity; (b) enhance the organizations' abilities to assure the input of a wide variety of perspectives; (c) engage members' expanded ranges of experiences and talents; (d) multiply staff and leadership resources; (e) increase communication strength and avenues; and (f) establish processes for timely review and revision of policies as critical disability issues arise or change, and new opportunities for policy integration and advancement occur. This article describes the processes used to develop, express, and evaluate the position statements; summarizes the policy content of several joint statements; and discusses the role of these organization position statements.

The reliability of knee joint position testing using electrogoniometry

PubMed Central

Piriyaprasarth, Pagamas; Morris, Meg E; Winter, Adele; Bialocerkowski, Andrea E

2008-01-01

Background The current investigation examined the inter- and intra-tester reliability of knee joint angle measurements using a flexible Penny and Giles Biometric® electrogoniometer. The clinical utility of electrogoniometry was also addressed. Methods The first study examined the inter- and intra-tester reliability of measurements of knee joint angles in supine, sitting and standing in 35 healthy adults. The second study evaluated inter-tester and intra-tester reliability of knee joint angle measurements in standing and after walking 10 metres in 20 healthy adults, using an enhanced measurement protocol with a more detailed electrogoniometer attachment procedure. Both inter-tester reliability studies involved two testers. Results In the first study, inter-tester reliability (ICC[2,10]) ranged from 0.58–0.71 in supine, 0.68–0.79 in sitting and 0.57–0.80 in standing. The standard error of measurement between testers was less than 3.55° and the limits of agreement ranged from -12.51° to 12.21°. Reliability coefficients for intra-tester reliability (ICC[3,10]) ranged from 0.75–0.76 in supine, 0.86–0.87 in sitting and 0.87–0.88 in standing. The standard error of measurement for repeated measures by the same tester was less than 1.7° and the limits of agreement ranged from -8.13° to 7.90°. The second study showed that using a more detailed electrogoniometer attachment protocol reduced the error of measurement between testers to 0.5°. Conclusion Using a standardised protocol, reliable measures of knee joint angles can be gained in standing, supine and sitting by using a flexible goniometer. PMID:18211714

Positive Development, Sense of Belonging, and Support of Peers among Early Adolescents: Perspectives of Different Actors

ERIC Educational Resources Information Center

Drolet, Marie; Arcand, Isabelle

2013-01-01

Trusting relationships at school and within other social networks emerge as protective factors that are crucial to the positive development of early adolescents. School is one of the critical environments where they can develop a sense of belonging. This study involved 20 qualitative interviews with school staff and youth workers recruited from…

Joint Rhythmic Movement Increases 4-Year-Old Children's Prosocial Sharing and Fairness Toward Peers.

PubMed

Rabinowitch, Tal-Chen; Meltzoff, Andrew N

2017-01-01

The allocation of resources to a peer partner is a prosocial act that is of fundamental importance. Joint rhythmic movement, such as occurs during musical interaction, can induce positive social experiences, which may play a role in developing and enhancing young children's prosocial skills. Here, we investigated whether joint rhythmic movement, free of musical context, increases 4-year-olds' sharing and sense of fairness in a resource allocation task involving peers. We developed a precise procedure for administering joint synchronous experience, joint asynchronous experience, and a baseline control involving no treatment. Then we tested how participants allocated resources between self and peer. We found an increase in the generous allocation of resources to peers following both synchronous and asynchronous movement compared to no treatment. At a more theoretical level, this result is considered in relation to previous work testing other aspects of child prosociality, for example, peer cooperation, which can be distinguished from judgments of fairness in resource allocation tasks. We draw a conceptual distinction between two types of prosocial behavior: resource allocation (an other-directed individual behavior) and cooperation (a goal-directed collaborative endeavor). Our results highlight how rhythmic interactions, which are prominent in joint musical engagements and synchronized activity, influence prosocial behavior between preschool peers.

Self-calibrating solar position sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maxey, Lonnie Curt

A sun positioning sensor and method of accurately tracking the sun are disclosed. The sensor includes a position sensing diode and a disk having a body defining an aperture for accepting solar light. An extension tube having a body that defines a duct spaces the position sensing diode from the disk such that the solar light enters the aperture in the disk, travels through the duct in the extension tube and strikes the position sensing diode. The extension tube has a known length that is fixed. Voltage signals indicative of the location and intensity of the sun are generated bymore » the position sensing diode. If it is determined that the intensity values are unreliable, then historical position values are used from a table. If the intensity values are deemed reliable, then actual position values are used from the position sensing diode.« less

Muscle Activation Differs between Three Different Knee Joint-Angle Positions during a Maximal Isometric Back Squat Exercise

PubMed Central

Jarbas da Silva, Josinaldo; Jon Schoenfeld, Brad; Nardi, Priscyla Silva Monteiro; Pecoraro, Silvio Luis; D'Andréa Greve, Julia Maria; Hartigan, Erin

2016-01-01

The purpose of this study was to compare muscle activation of the lower limb muscles when performing a maximal isometric back squat exercise over three different positions. Fifteen young, healthy, resistance-trained men performed an isometric back squat at three knee joint angles (20°, 90°, and 140°) in a randomized, counterbalanced fashion. Surface electromyography was used to measure muscle activation of the vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), semitendinosus (ST), and gluteus maximus (GM). In general, muscle activity was the highest at 90° for the three quadriceps muscles, yet differences in muscle activation between knee angles were muscle specific. Activity of the GM was significantly greater at 20° and 90° compared to 140°. The BF and ST displayed similar activation at all joint angles. In conclusion, knee position alters muscles activation of the quadriceps and gluteus maximus muscles. An isometric back squat at 90° generates the highest overall muscle activation, yet an isometric back squat at 140° generates the lowest overall muscle activation of the VL and GM only. PMID:27504484

Joint Attention in Autism: Teaching Smiling Coordinated with Gaze to Respond to Joint Attention Bids

ERIC Educational Resources Information Center

Krstovska-Guerrero, Ivana; Jones, Emily A.

2013-01-01

Children with autism demonstrate early deficits in joint attention and expressions of affect. Interventions to teach joint attention have addressed gaze behavior, gestures, and vocalizations, but have not specifically taught an expression of positive affect such as smiling that tends to occur during joint attention interactions. Intervention was…

An Inertial Sensor-Based Method for Estimating the Athlete's Relative Joint Center Positions and Center of Mass Kinematics in Alpine Ski Racing

PubMed Central

Fasel, Benedikt; Spörri, Jörg; Schütz, Pascal; Lorenzetti, Silvio; Aminian, Kamiar

2017-01-01

For the purpose of gaining a deeper understanding of the relationship between external training load and health in competitive alpine skiing, an accurate and precise estimation of the athlete's kinematics is an essential methodological prerequisite. This study proposes an inertial sensor-based method to estimate the athlete's relative joint center positions and center of mass (CoM) kinematics in alpine skiing. Eleven inertial sensors were fixed to the lower and upper limbs, trunk, and head. The relative positions of the ankle, knee, hip, shoulder, elbow, and wrist joint centers, as well as the athlete's CoM kinematics were validated against a marker-based optoelectronic motion capture system during indoor carpet skiing. For all joints centers analyzed, position accuracy (mean error) was below 110 mm and precision (error standard deviation) was below 30 mm. CoM position accuracy and precision were 25.7 and 6.7 mm, respectively. Both the accuracy and precision of the system to estimate the distance between the ankle of the outside leg and CoM (measure quantifying the skier's overall vertical motion) were found to be below 11 mm. Some poorer accuracy and precision values (below 77 mm) were observed for the athlete's fore-aft position (i.e., the projection of the outer ankle-CoM vector onto the line corresponding to the projection of ski's longitudinal axis on the snow surface). In addition, the system was found to be sensitive enough to distinguish between different types of turns (wide/narrow). Thus, the method proposed in this paper may also provide a useful, pervasive way to monitor and control adverse external loading patterns that occur during regular on-snow training. Moreover, as demonstrated earlier, such an approach might have a certain potential to quantify competition time, movement repetitions and/or the accelerations acting on the different segments of the human body. However, prior to getting feasible for applications in daily training, future studies

An Inertial Sensor-Based Method for Estimating the Athlete's Relative Joint Center Positions and Center of Mass Kinematics in Alpine Ski Racing.

PubMed

Fasel, Benedikt; Spörri, Jörg; Schütz, Pascal; Lorenzetti, Silvio; Aminian, Kamiar

2017-01-01

For the purpose of gaining a deeper understanding of the relationship between external training load and health in competitive alpine skiing, an accurate and precise estimation of the athlete's kinematics is an essential methodological prerequisite. This study proposes an inertial sensor-based method to estimate the athlete's relative joint center positions and center of mass (CoM) kinematics in alpine skiing. Eleven inertial sensors were fixed to the lower and upper limbs, trunk, and head. The relative positions of the ankle, knee, hip, shoulder, elbow, and wrist joint centers, as well as the athlete's CoM kinematics were validated against a marker-based optoelectronic motion capture system during indoor carpet skiing. For all joints centers analyzed, position accuracy (mean error) was below 110 mm and precision (error standard deviation) was below 30 mm. CoM position accuracy and precision were 25.7 and 6.7 mm, respectively. Both the accuracy and precision of the system to estimate the distance between the ankle of the outside leg and CoM (measure quantifying the skier's overall vertical motion) were found to be below 11 mm. Some poorer accuracy and precision values (below 77 mm) were observed for the athlete's fore-aft position (i.e., the projection of the outer ankle-CoM vector onto the line corresponding to the projection of ski's longitudinal axis on the snow surface). In addition, the system was found to be sensitive enough to distinguish between different types of turns (wide/narrow). Thus, the method proposed in this paper may also provide a useful, pervasive way to monitor and control adverse external loading patterns that occur during regular on-snow training. Moreover, as demonstrated earlier, such an approach might have a certain potential to quantify competition time, movement repetitions and/or the accelerations acting on the different segments of the human body. However, prior to getting feasible for applications in daily training, future studies

Investigation of the role of GBF1 in the replication of positive-sense single-stranded RNA viruses.

PubMed

Ferlin, Juliette; Farhat, Rayan; Belouzard, Sandrine; Cocquerel, Laurence; Bertin, Antoine; Hober, Didier; Dubuisson, Jean; Rouillé, Yves

2018-06-20

GBF1 has emerged as a host factor required for the replication of positive-sense single-stranded RNA viruses of different families, but its mechanism of action is still unknown. GBF1 is a guanine nucleotide exchange factor for Arf family members. Recently, we identified Arf4 and Arf5 (class II Arfs) as host factors required for the replication of hepatitis C virus (HCV), a GBF1-dependent virus. To assess whether a GBF1/class II Arf pathway is conserved among positive-sense single-stranded RNA viruses, we investigated yellow fever virus (YFV), Sindbis virus (SINV), coxsackievirus B4 (CVB4) and human coronavirus 229E (HCoV-229E). We found that GBF1 is involved in the replication of these viruses. However, using siRNA or CRISPR-Cas9 technologies, it was seen that the depletion of Arf1, Arf3, Arf4 or Arf5 had no impact on viral replication. In contrast, the depletion of Arf pairs suggested that class II Arfs could be involved in HCoV-229E, YFV and SINV infection, as for HCV, but not in CVB4 infection. In addition, another Arf pair, Arf1 and Arf4, appears to be essential for YFV and SINV infection, but not for infection by other viruses. Finally, CVB4 infection was not inhibited by any combination of Arf depletion. We conclude that the mechanism of action of GBF1 in viral replication appears not to be conserved, and that a subset of positive-sense single-stranded RNA viruses from different families might require class II Arfs for their replication.

10-fold detection range increase in quadrant-photodiode position sensing for photonic force microscope

NASA Astrophysics Data System (ADS)

Perrone, Sandro; Volpe, Giovanni; Petrov, Dmitri

2008-10-01

We propose a technique that permits one to increase by one order of magnitude the detection range of position sensing for the photonic force microscope with quadrant photodetectors (QPDs). This technique takes advantage of the unavoidable cross-talk between output signals of the QPD and does not assume that the output signals are linear in the probe displacement. We demonstrate the increase in the detection range from 150 to 1400 nm for a trapped polystyrene sphere with radius of 300 nm as probe.

10-fold detection range increase in quadrant-photodiode position sensing for photonic force microscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perrone, Sandro; Volpe, Giovanni; Petrov, Dmitri

2008-10-15

We propose a technique that permits one to increase by one order of magnitude the detection range of position sensing for the photonic force microscope with quadrant photodetectors (QPDs). This technique takes advantage of the unavoidable cross-talk between output signals of the QPD and does not assume that the output signals are linear in the probe displacement. We demonstrate the increase in the detection range from 150 to 1400 nm for a trapped polystyrene sphere with radius of 300 nm as probe.

10-fold detection range increase in quadrant-photodiode position sensing for photonic force microscope.

PubMed

Perrone, Sandro; Volpe, Giovanni; Petrov, Dmitri

2008-10-01

We propose a technique that permits one to increase by one order of magnitude the detection range of position sensing for the photonic force microscope with quadrant photodetectors (QPDs). This technique takes advantage of the unavoidable cross-talk between output signals of the QPD and does not assume that the output signals are linear in the probe displacement. We demonstrate the increase in the detection range from 150 to 1400 nm for a trapped polystyrene sphere with radius of 300 nm as probe.

Joint Rhythmic Movement Increases 4-Year-Old Children’s Prosocial Sharing and Fairness Toward Peers

PubMed Central

Rabinowitch, Tal-Chen; Meltzoff, Andrew N.

2017-01-01

The allocation of resources to a peer partner is a prosocial act that is of fundamental importance. Joint rhythmic movement, such as occurs during musical interaction, can induce positive social experiences, which may play a role in developing and enhancing young children’s prosocial skills. Here, we investigated whether joint rhythmic movement, free of musical context, increases 4-year-olds’ sharing and sense of fairness in a resource allocation task involving peers. We developed a precise procedure for administering joint synchronous experience, joint asynchronous experience, and a baseline control involving no treatment. Then we tested how participants allocated resources between self and peer. We found an increase in the generous allocation of resources to peers following both synchronous and asynchronous movement compared to no treatment. At a more theoretical level, this result is considered in relation to previous work testing other aspects of child prosociality, for example, peer cooperation, which can be distinguished from judgments of fairness in resource allocation tasks. We draw a conceptual distinction between two types of prosocial behavior: resource allocation (an other-directed individual behavior) and cooperation (a goal-directed collaborative endeavor). Our results highlight how rhythmic interactions, which are prominent in joint musical engagements and synchronized activity, influence prosocial behavior between preschool peers. PMID:28694786

Experimental joint immobilization in guinea pigs. Effects on the knee joint

NASA Technical Reports Server (NTRS)

Marcondesdesouza, J. P.; Machado, F. F.; Sesso, A.; Valeri, V.

1980-01-01

In young and adult guinea pigs, the aftermath experimentally induced by the immobilization of the knee joint in hyperextended forced position was studied. Joint immobilization which varied from one to nine weeks was attained by plaster. Eighty knee joints were examined macro and microscopically. Findings included: (1) muscular hypotrophy and joint stiffness in all animals, directly proportional to the length of immobilization; (2) haemoarthrosis in the first week; (3) intra-articular fibrous tissue proliferation ending up with fibrous ankylosis; (4) hyaline articular cartilage erosions; (5) various degrees of destructive menisci changes. A tentative explanation of the fibrous tissue proliferation and of the cartilage changes is offered.

Intrinsic embedded sensors for polymeric mechatronics: flexure and force sensing.

PubMed

Jentoft, Leif P; Dollar, Aaron M; Wagner, Christopher R; Howe, Robert D

2014-02-25

While polymeric fabrication processes, including recent advances in additive manufacturing, have revolutionized manufacturing, little work has been done on effective sensing elements compatible with and embedded within polymeric structures. In this paper, we describe the development and evaluation of two important sensing modalities for embedding in polymeric mechatronic and robotic mechanisms: multi-axis flexure joint angle sensing utilizing IR phototransistors, and a small (12 mm), three-axis force sensing via embedded silicon strain gages with similar performance characteristics as an equally sized metal element based sensor.

The unsuspected prosthetic joint infection : incidence and consequences of positive intra-operative cultures in presumed aseptic knee and hip revisions.

PubMed

Jacobs, A M E; Bénard, M; Meis, J F; van Hellemondt, G; Goosen, J H M

2017-11-01

Positive cultures are not uncommon in cases of revision total knee and hip arthroplasty (TKA and THA) for presumed aseptic causes. The purpose of this study was to assess the incidence of positive intra-operative cultures in presumed aseptic revision of TKA and THA, and to determine whether the presence of intra-operative positive cultures results in inferior survival in such cases. A retrospective cohort study was assembled with 679 patients undergoing revision knee (340 cases) or hip arthroplasty (339 cases) for presumed aseptic causes. For all patients three or more separate intra-operative cultures were obtained. Patients were diagnosed with a previously unsuspected prosthetic joint infection (PJI) if two or more cultures were positive with the same organism. Records were reviewed for demographic details, pre-operative laboratory results and culture results. The primary outcome measure was infection-free implant survival at two years. The incidence of unsuspected PJI was 27 out of 340 (7.9%) in TKA and 41 out of 339 (12.1%) in THA. Following revision TKA, the rate of infection-free implant survival in patients with an unsuspected PJI was 88% (95% confidence intervals (CI) 60 to 97) at two years compared with 98% (95% CI 94 to 99) in patients without PJI (p = 0.001). After THA, the rate of survival was similar in those with unsuspected PJI (92% (95% CI 73 to 98) at two years) and those without (94% (95% CI 89 to 97), p = 0.31). Following revision of TKA and THA for aseptic diagnoses, around 10% of cases were found to have positive cultures. In the knee, such cases had inferior infection-free survival at two years compared with those with negative cultures; there was no difference between the groups following THA. Cite this article: Bone Joint J 2017;99-B:1482-9. ©2017 The British Editorial Society of Bone & Joint Surgery.

Position sense at the human forearm in the horizontal plane during loading and vibration of elbow muscles

PubMed Central

Ansems, G E; Allen, T J; Proske, U

2006-01-01

When blindfolded subjects match the position of their forearms in the vertical plane they rely on signals coming from the periphery as well as from the central motor command. The command signal provides a positional cue from the accompanying effort sensation required to hold the arm against gravity. Here we have asked, does a centrally generated effort signal contribute to position sense in the horizontal plane, where gravity cannot play a role? Blindfolded subjects were required to match forearm position for the unloaded arm and when flexors or extensors were bearing 10%, 25% or 40% of maximum loads. Before each match the reference arm was conditioned by contracting elbow muscles while the arm was held flexed or extended. For the unloaded arm conditioning led to a consistent pattern of errors which was attributed to signals from flexor and extensor muscle spindles. When elbow muscles were loaded the errors from conditioning converged, presumably because the spindles had become coactivated through the fusimotor system during the load-bearing contraction. However, this convergence was seen only when subjects supported a static load. When they moved the load differences in errors from conditioning persisted. Muscle vibration during load bearing or moving a load did not alter the distribution of errors. It is concluded that for position sense of an unloaded arm in the horizontal plane the brain relies on signals from muscle spindles. When the arm is loaded, an additional signal of central origin contributes, but only if the load is moved. PMID:16873408

[Minimally invasive approaches to hip and knee joints for total joint replacement].

PubMed

Rittmeister, M; König, D P; Eysel, P; Kerschbaumer, F

2004-11-01

The manuscript features the different minimally invasive approaches to the hip for joint replacement. These include medial, anterior, anterolateral, and posterior approaches. The concept of minimally invasive hip arthroplasty makes sense if it is an integral part of a larger concept to lower postoperative morbidity. Besides minimal soft tissue trauma, this concept involves preoperative patient education, preemptive analgesia, and postoperative physiotherapy. It is our belief that minimal incision techniques for the hip are not suited for all patients and all surgeons. The different minimally invasive approaches to the knee joint for implantation of a knee arthroplasty are described and discussed. There have been no studies published yet that fulfill EBM criteria. The data so far show that minimally invasive approaches and implantation techniques for total knee replacements lead to quicker rehabilitation of patients.

Use of an absorbable membrane to position biologically inductive materials in the periprosthetic space of cemented joints.

PubMed

DiResta, Gene R; Brown, Holly; Aiken, Sean; Doty, Steven; Schneider, Robert; Wright, Timothy; Healey, John H

2006-01-01

A device is presented that positions ultrahigh molecular weight polyethylene (UHMWPE) debris against periprosthetic bone surfaces. This can facilitate the study of aseptic loosening associated with cemented joint prostheses by speeding the appearance of this debris within the periprosthetic space. The device, composed of a 100 microm thick bioabsorbable membrane impregnated with 1.4 x 10(9) sub-micron particles of UHMWPE debris, is positioned on the endosteum of the bone prior to the insertion of the cemented orthopedic implant. An in vitro pullout study and an in vivo canine pilot study were performed to investigate its potential to accelerate "time to aseptic loosening" of cemented prosthetic joints. Pullout studies characterized the influence of the membrane on initial implant fixation. The tensile stresses (mean+/-std.dev.) required to withdraw a prosthesis cemented into canine femurs with and without the membrane were 1.15+/-0.3 and 1.54+/-0.01 MPa, respectively; these findings were not significantly different (p > 0.4). The in vivo pilot study, involving five dogs, was performed to evaluate the efficacy of the debris to accelerate loosening in a canine cemented hip arthroplasty. Aseptic loosening and lameness occurred within 12 months, quicker than the 30 months reported in a retrospective clinical review of canine hip arthroplasty.

Standing Balance and Trunk Position Sense in Impaired Glucose Tolerance (IGT)-Related Peripheral Neuropathy

PubMed Central

Goldberg, Allon; Russell, James William; Alexander, Neil Burton

2009-01-01

Type 2 diabetes mellitus (T2DM) and pre-diabetes or impaired glucose tolerance (IGT) affects a large segment of the population. Peripheral neuropathy (PN) is a common complication of T2DM, leading to sensory and motor deficits. While T2DM-related PN often results in balance- and mobility-related dysfunction which manifests as gait instability and falls, little is known about balance capabilities in patients who have evidence of PN related to IGT (IGT-PN). We evaluated patients with IGT-PN on commonly-used clinical balance and mobility tests as well as a new test of trunk position sense and balance impairment, trunk repositioning errors (TREs). Eight participants aged 50–72 years with IGT-PN, and eight age and gender matched controls underwent balance, mobility and trunk repositioning accuracy tests at a university neurology clinic and mobility research laboratory. Compared to controls, IGT-PN participants had as much as twice the magnitude of TREs and stood approximately half as long on the single leg balance test. People with IGT-PN exhibit deficits in standing balance and trunk position sense. Furthermore, there was a significant association between performance on commonly-used clinical balance and mobility tests, and electrophysiological and clinical measures of neuropathy in IGT-PN participants. Because IGT-related neuropathy represents the earliest stage of diabetic neuropathy, deficits in IGT-PN participants highlights the importance of early screening in the dysglycemic process for neuropathy and associated balance deficits. PMID:18439624

Intrinsic Embedded Sensors for Polymeric Mechatronics: Flexure and Force Sensing

PubMed Central

Jentoft, Leif P.; Dollar, Aaron M.; Wagner, Christopher R.; Howe, Robert D.

2014-01-01

While polymeric fabrication processes, including recent advances in additive manufacturing, have revolutionized manufacturing, little work has been done on effective sensing elements compatible with and embedded within polymeric structures. In this paper, we describe the development and evaluation of two important sensing modalities for embedding in polymeric mechatronic and robotic mechanisms: multi-axis flexure joint angle sensing utilizing IR phototransistors, and a small (12 mm), three-axis force sensing via embedded silicon strain gages with similar performance characteristics as an equally sized metal element based sensor. PMID:24573310

Eyes that bind us: Gaze leading induces an implicit sense of agency.

PubMed

Stephenson, Lisa J; Edwards, S Gareth; Howard, Emma E; Bayliss, Andrew P

2018-03-01

Humans feel a sense of agency over the effects their motor system causes. This is the case for manual actions such as pushing buttons, kicking footballs, and all acts that affect the physical environment. We ask whether initiating joint attention - causing another person to follow our eye movement - can elicit an implicit sense of agency over this congruent gaze response. Eye movements themselves cannot directly affect the physical environment, but joint attention is an example of how eye movements can indirectly cause social outcomes. Here we show that leading the gaze of an on-screen face induces an underestimation of the temporal gap between action and consequence (Experiments 1 and 2). This underestimation effect, named 'temporal binding,' is thought to be a measure of an implicit sense of agency. Experiment 3 asked whether merely making an eye movement in a non-agentic, non-social context might also affect temporal estimation, and no reliable effects were detected, implying that inconsequential oculomotor acts do not reliably affect temporal estimations under these conditions. Together, these findings suggest that an implicit sense of agency is generated when initiating joint attention interactions. This is important for understanding how humans can efficiently detect and understand the social consequences of their actions. Copyright © 2017 Elsevier B.V. All rights reserved.

Self-Alining Quick-Connect Joint

NASA Technical Reports Server (NTRS)

Lucy, M. H.

1983-01-01

Quick connect tapered joint used with minimum manipulation and force. Split ring retainer holds locking ring in place. Minimal force required to position male in female joint, at which time split-ring retainers are triggered to release split locking rings. Originally developed to assemble large space structures, joint is simple, compact, strong, lightweight, self alining, and has no loose parts.

Self-sensing in Bacillus subtilis quorum-sensing systems

PubMed Central

Bareia, Tasneem; Pollak, Shaul; Eldar, Avigdor

2017-01-01

Bacterial cell-cell signaling, or quorum sensing, is characterized by the secretion and group-wide detection of small diffusible signal molecules called autoinducers. This mechanism allows cells to coordinate their behavior in a density-dependent manner. A quorum-sensing cell may directly respond to the autoinducers it produces in a cell-autonomous and quorum-independent manner, but the strength of such self-sensing effect and its impact on bacterial physiology are unclear. Here, we explored the existence and impact of self-sensing in the Bacillus subtilis ComQXP and Rap-Phr quorum-sensing systems. By comparing the quorum-sensing response of autoinducer-secreting and non-secreting cells in co-culture, we found that secreting cells consistently showed a stronger response than non-secreting cells. Combining genetic and quantitative analyses, we demonstrated this effect to be a direct result of self-sensing and ruled out an indirect regulatory effect of the autoinducer production genes on response sensitivity. In addition, self-sensing in the ComQXP system affected persistence to antibiotic treatment. Together, these findings indicate the existence of self-sensing in the two most common designs of quorum-sensing systems of Gram-positive bacteria. PMID:29038467

Functional disorders of the temporomandibular joints: Internal derangement of the temporomandibular joint.

PubMed

Chang, Chih-Ling; Wang, Ding-Han; Yang, Mu-Chen; Hsu, Wun-Eng; Hsu, Ming-Lun

2018-04-01

Temporomandibular joint (TMJ) is one of the most complex joints of the human body. Due to its unique movement, in terms of combination of rotation and translator movement, disc of the joint plays an important role to maintain its normal function. In order to sustain the normal function of the TMJ, disc must be kept in proper position as well as maintain normal shape in all circumstances. Once the disc is not any more in its normal position during function of the joint, disturbance of the joint can be occurred which will lead to subsequent distortion of the disc. Shape of the disc can be influenced by many factors i.e.: abnormal function or composition of the disc itself. Etiology of the internal derangement of the disc remains controversial. Multifactorial theory has been postulated in most of previous manuscripts. Disc is composed of mainly extracellular matrix. Abnormal proportion of collagen type I & III may also leads to joint hypermobility which may be also a predisposing factor of this disorder. Thus it can be recognized as local manifestation of a systemic disorder. Different treatment modalities with from conservative treatment to surgical intervention distinct success rate have been reported. Recently treatment with extracellular matrix injection becomes more and more popular to strengthen the joint itself. Since multifactorial in character, the best solution of the treatment modalities should be aimed to resolve possible etiology from different aspects. Team work may be indication to reach satisfied results. Copyright © 2018. Published by Elsevier Taiwan.

Adaptive Postural Control for Joint Immobilization during Multitask Performance

PubMed Central

Hsu, Wei-Li

2014-01-01

Motor abundance is an essential feature of adaptive control. The range of joint combinations enabled by motor abundance provides the body with the necessary freedom to adopt different positions, configurations, and movements that allow for exploratory postural behavior. This study investigated the adaptation of postural control to joint immobilization during multi-task performance. Twelve healthy volunteers (6 males and 6 females; 21–29 yr) without any known neurological deficits, musculoskeletal conditions, or balance disorders participated in this study. The participants executed a targeting task, alone or combined with a ball-balancing task, while standing with free or restricted joint motions. The effects of joint configuration variability on center of mass (COM) stability were examined using uncontrolled manifold (UCM) analysis. The UCM method separates joint variability into two components: the first is consistent with the use of motor abundance, which does not affect COM position (VUCM); the second leads to COM position variability (VORT). The analysis showed that joints were coordinated such that their variability had a minimal effect on COM position. However, the component of joint variability that reflects the use of motor abundance to stabilize COM (VUCM) was significant decreased when the participants performed the combined task with immobilized joints. The component of joint variability that leads to COM variability (VORT) tended to increase with a reduction in joint degrees of freedom. The results suggested that joint immobilization increases the difficulty of stabilizing COM when multiple tasks are performed simultaneously. These findings are important for developing rehabilitation approaches for patients with limited joint movements. PMID:25329477

Plant gravity sensing

NASA Technical Reports Server (NTRS)

Sack, F. D.

1991-01-01

This review of plant gravity sensing examines sensing in organ gravitropism, sensing in single-cell gravitropism, and nongravitropic sensing. Topics related to sensing in organ gravitropism are (1) identification of the gravitropic susceptors, including intracellular asymmetry in equilibrium position and after reorientation, susceptor signal-to-noise ratio, signal integration over threshold stimulation periods, intracellular asymmetry and gravitropic competence, and starch deficiency and gravitropic competence; (2) possible root statocytes and receptors, including identification of presumptive statocytes, cytology, and possible receptors and models of sensing; and (3) negatively gravitropic organs, including identification and distribution of presumptive statocytes and cytology and possible receptors. Topics related to nongravitropic sensing include gravitaxis, reaction wood, gravimorphogenesis, other gravity-influenced organ movements, and cytoplasmic streaming.

Functional anatomy of the temporomandibular joint (I).

PubMed

Sava, Anca; Scutariu, Mihaela Monica

2012-01-01

Jaw movement is analyzed as the action between two rigid components jointed together in a particular way, the movable mandible against the stabilized cranium. Jaw articulation distinguishes form most other synovial joints of the body by the coincidence of certain characteristic features. Its articular surfaces are not covered by hyaline cartilage as elsewhere. The two jointed components carry teeth the shape, position and occlusion of which having a unique influence on specific positions and movements within the joint. A fibrocartilaginous disc is interposed between upper and lower articular surfaces; this disc compensates for the incongruities in opposing parts and allows sliding, pivoting, and rotating movements between the bony components. These are the reasons for our review of the functional anatomy of the temporomandibular joint.

Self-Sensing of Position-Related Loads in Continuous Carbon Fibers-Embedded 3D-Printed Polymer Structures Using Electrical Resistance Measurement

PubMed Central

Luan, Congcong; Shen, Hongyao; Fu, Jianzhong

2018-01-01

Condition monitoring in polymer composites and structures based on continuous carbon fibers show overwhelming advantages over other potentially competitive sensing technologies in long-gauge measurements due to their great electromechanical behavior and excellent reinforcement property. Although carbon fibers have been developed as strain- or stress-sensing agents in composite structures through electrical resistance measurements, the electromechanical behavior under flexural loads in terms of different loading positions still lacks adequate research, which is the most common situation in practical applications. This study establishes the relationship between the fractional change in electrical resistance of carbon fibers and the external loads at different loading positions along the fibers’ longitudinal direction. An approach for real-time monitoring of flexural loads at different loading positions was presented simultaneously based on this relationship. The effectiveness and feasibility of the approach were verified by experiments on carbon fiber-embedded three-dimensional (3D) printed thermoplastic polymer beam. The error in using the provided approach to monitor the external loads at different loading positions was less than 1.28%. The study fully taps the potential of continuous carbon fibers as long-gauge sensory agents and reinforcement in the 3D-printed polymer structures. PMID:29584665

Positive position control of robotic manipulators

NASA Technical Reports Server (NTRS)

Baz, A.; Gumusel, L.

1989-01-01

The present, simple and accurate position-control algorithm, which is applicable to fast-moving and lightly damped robot arms, is based on the positive position feedback (PPF) strategy and relies solely on position sensors to monitor joint angles of robotic arms to furnish stable position control. The optimized tuned filters, in the form of a set of difference equations, manipulate position signals for robotic system performance. Attention is given to comparisons between this PPF-algorithm controller's experimentally ascertained performance characteristics and those of a conventional proportional controller.

Inertial sensing microelectromechanical (MEM) safe-arm device

DOEpatents

Roesler, Alexander W [Tijeras, NM; Wooden, Susan M [Sandia Park, NM

2009-05-12

Microelectromechanical (MEM) safe-arm devices comprise a substrate upon which a sense mass, that can contain an energetic material, is constrained to move along a pathway defined by a track disposed on the surface of the substrate. The pathway has a first end comprising a "safe" position and a second end comprising an "armed" position, whereat the second end the sense mass can be aligned proximal to energetic materials comprising the explosive train, within an explosive component. The sense mass can be confined in the safe position by a first latch, operable to release the sense mass by an acceleration acting in a direction substantially normal to the surface of the substrate. A second acceleration, acting in a direction substantially parallel to the surface of the substrate, can cause the sense mass to traverse the pathway from the safe position to the armed position.

Horizontal slip along Alleghanian joints of the Appalachian plateau: evidence showing that mild penetrative strain does little to change the pristine appearance of early joints

NASA Astrophysics Data System (ADS)

Engelder, Terry; Haith, Benjamin F.; Younes, Amgad

2001-07-01

Some Alleghanian joints in black shales of the Geneseo and Middlesex Formations of the Catskill Delta complex, Finger Lakes district, New York, slipped horizontally up to 8 cm. Horizontal slip is measured by the offset of ENE-striking joints. Alleghanian joints striking 330-350° display a right-lateral slip with an average value of 1.9 cm, while joints striking 004-010° slip in the left-lateral sense with an average value of 1.3 cm. The maximum horizontal stress (SH) driving this slip falls between 350° and 004°, the orientation of local Alleghanian layer-parallel shortening as indicated by both disjunctive and pencil cleavage. By commonality of orientation, we infer that slip on Alleghanian joints is driven contemporaneously with layer-parallel shortening. If so, the offset ENE-striking joints predate the Alleghanian stress field. These observations mean that both pre-Alleghanian and early Alleghanian joints persist through a period of penetrative strain.

Objective Assessment of Joint Stiffness: A Clinically Oriented Hardware and Software Device with an Application to the Shoulder Joint.

PubMed

McQuade, Kevin; Price, Robert; Liu, Nelson; Ciol, Marcia A

2012-08-30

Examination of articular joints is largely based on subjective assessment of the "end-feel" of the joint in response to manually applied forces at different joint orientations. This technical report aims to describe the development of an objective method to examine joints in general, with specific application to the shoulder, and suitable for clinical use. We adapted existing hardware and developed laptop-based software to objectively record the force/displacement behavior of the glenohumeral joint during three common manual joint examination tests with the arm in six positions. An electromagnetic tracking system recorded three-dimensional positions of sensors attached to a clinician examiner and a patient. A hand-held force transducer recorded manually applied translational forces. The force and joint displacement were time-synchronized and the joint stiffness was calculated as a quantitative representation of the joint "end-feel." A methodology and specific system checks were developed to enhance clinical testing reproducibility and precision. The device and testing protocol were tested on 31 subjects (15 with healthy shoulders, and 16 with a variety of shoulder impairments). Results describe the stiffness responses, and demonstrate the feasibility of using the device and methods in clinical settings.

Who Benefits From Humor-Based Positive Psychology Interventions? The Moderating Effects of Personality Traits and Sense of Humor

PubMed Central

Wellenzohn, Sara; Proyer, René T.; Ruch, Willibald

2018-01-01

The evidence for the effectiveness of humor-based positive psychology interventions (PPIs; i.e., interventions aimed at enhancing happiness and lowering depressive symptoms) is steadily increasing. However, little is known about who benefits most from them. We aim at narrowing this gap by examining whether personality traits and sense of humor moderate the long-term effects of humor-based interventions on happiness and depressive symptoms. We conducted two placebo-controlled online-intervention studies testing for moderation effects. In Study 1 (N = 104) we tested for moderation effects of basic personality traits (i.e., psychoticism, extraversion, and neuroticism) in the three funny things intervention, a humor-based PPI. In Study 2 (N = 632) we tested for moderation effects of the sense of humor in five different humor-based interventions. Happiness and depressive symptoms were assessed before and after the intervention, as well as after 1, 3, and 6 months. In Study 2, we assessed sense of humor before and 1 month after the intervention to investigate if changes in sense of humor go along with changes in happiness and depressive symptoms. We found moderating effects only for extraversion. Extraverts benefitted more from the three funny things intervention than introverts. For neuroticism and psychoticism no moderation effects were found. For sense of humor, no moderating effects were found for the effectiveness of the five humor-based interventions tested in Study 2. However, changes in sense of humor from pretest to the 1-month follow-up predicted changes in happiness and depressive symptoms. Taking a closer look, the playful attitude- and sense of humor-subscales predicted changes in happiness and depression for up to 6 months. Overall, moderating effects for personality (i.e., extraversion) were found, but none for sense of humor at baseline. However, increases in sense of humor during and after the intervention were associated with the interventions�

Who Benefits From Humor-Based Positive Psychology Interventions? The Moderating Effects of Personality Traits and Sense of Humor.

PubMed

Wellenzohn, Sara; Proyer, René T; Ruch, Willibald

2018-01-01

The evidence for the effectiveness of humor-based positive psychology interventions (PPIs; i.e., interventions aimed at enhancing happiness and lowering depressive symptoms) is steadily increasing. However, little is known about who benefits most from them. We aim at narrowing this gap by examining whether personality traits and sense of humor moderate the long-term effects of humor-based interventions on happiness and depressive symptoms. We conducted two placebo-controlled online-intervention studies testing for moderation effects. In Study 1 ( N = 104) we tested for moderation effects of basic personality traits (i.e., psychoticism, extraversion, and neuroticism) in the three funny things intervention, a humor-based PPI. In Study 2 ( N = 632) we tested for moderation effects of the sense of humor in five different humor-based interventions. Happiness and depressive symptoms were assessed before and after the intervention, as well as after 1, 3, and 6 months. In Study 2, we assessed sense of humor before and 1 month after the intervention to investigate if changes in sense of humor go along with changes in happiness and depressive symptoms. We found moderating effects only for extraversion. Extraverts benefitted more from the three funny things intervention than introverts. For neuroticism and psychoticism no moderation effects were found. For sense of humor, no moderating effects were found for the effectiveness of the five humor-based interventions tested in Study 2. However, changes in sense of humor from pretest to the 1-month follow-up predicted changes in happiness and depressive symptoms. Taking a closer look, the playful attitude- and sense of humor-subscales predicted changes in happiness and depression for up to 6 months. Overall, moderating effects for personality (i.e., extraversion) were found, but none for sense of humor at baseline. However, increases in sense of humor during and after the intervention were associated with the interventions

Lower limb joint work and joint work contribution during downhill and uphill walking at different inclinations.

PubMed

Alexander, Nathalie; Strutzenberger, Gerda; Ameshofer, Lisa Maria; Schwameder, Hermann

2017-08-16

Work performance and individual joint contribution to total work are important information for creating training protocols, but were not assessed so far for sloped walking. Therefore, the purpose of this study was to analyze lower limb joint work and joint contribution of the hip, knee and ankle to total lower limb work during sloped walking in a healthy population. Eighteen male participants (27.0±4.7yrs, 1.80±0.05m, 74.5±8.2kg) walked on an instrumented ramp at inclination angles of 0°, ±6°, ±12° and ±18° at 1.1m/s. Kinematic and kinetic data were captured using a motion-capture system (Vicon) and two force plates (AMTI). Joint power curves, joint work (positive, negative, absolute) and each joint's contribution to total lower limb work were analyzed throughout the stance phase using an ANOVA with repeated measures. With increasing inclination positive joint work increased for the ankle and hip joint and in total during uphill walking. Negative joint work increased for each joint and in total work during downhill walking. Absolute work was increased during both uphill (all joints) and downhill (ankle & knee) walking. Knee joint contribution to total negative and absolute work increased during downhill walking while hip and ankle contributions decreased. This study identified, that, when switching from level to a 6° and from 6° to a 12° inclination the gain of individual joint work is more pronounced compared to switching from 12° to an 18° inclination. The results might be used for training recommendations and specific training intervention with respect to sloped walking. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stereosat: A proposed private sector/government joint venture in remote sensing from space

NASA Technical Reports Server (NTRS)

Anglin, R. L.

1980-01-01

Stereosat, a free flying Sun synchronous satellite whose purpose is to obtain worldwide cloud-free stereoscopic images of the Earth's land masses, is proposed as a joint private sector/government venture. A number of potential organization models are identified. The legal, economic, and institutional issues which could impact the continuum of potential joint private sector/government institutional structures are examined.

Remote Sensing Via Satellite: The Canadian Experience

ERIC Educational Resources Information Center

Classen, Hans George

1974-01-01

Describes the joint effort of Canada and NASA in monitoring the Canadian environment using remote-sensing techniques. The project involves the Earth Resources Technology Satellite and has been used to observe seasonal changes, extent of snow cover, crop growth, sea ice, and land use patterns. (GS)

Second-site prosthetic joint infection in patients with multiple prosthetic joints.

PubMed

Clesham, Kevin; Hughes, Andrew J; O' hEireamhoin, Sven; Fleming, Catherine; Murphy, Colin G

2018-04-10

Prosthetic joint infections (PJIs) are among the most serious complications in arthroplasty. A second-site PJI in patients with multiple prosthetic joints increases morbidity, with many requiring further revision procedures. We aimed to establish why some patients with multiple joints develop second-site infections. Our institution's arthroplasty database was reviewed from 2004 to 2017. All PJIs were identified, and all patients with more than one prosthetic joint in situ were included. We recorded risk factors, causative organisms, number of procedures and length of stay. Forty-four patients meeting the criteria were identified. Four patients (9.1%) developed second-site infection. Eight patients (18.2%) developed re-infection of the primary PJI. Positive MRSA carrier status and PJI of a total knee replacement were associated with an increased risk of a second episode of infection. Patients who developed further infection had more frequent admission and longer lengths of stay than isolated PJIs. Higher morbidity and use of hospital resources are associated with this cohort of patients. PJIs in total knee replacements and positive MRSA status are associated with higher rates of second infection. Identifying this vulnerable cohort of patients at an early stage is critical to ensure measures are taken to reduce the risks of further infection.

Influence of the position of the foot on MRI signal in the deep digital flexor tendon and collateral ligaments of the distal interphalangeal joint in the standing horse.

PubMed

Spriet, M; Zwingenberger, A

2009-05-01

Hyperintense signal is sometimes observed in ligaments and tendons of the equine foot on standing magnetic resonance examination without associated changes in size and shape. In such cases, the presence of a true lesion or an artifact should be considered. A change in position of a ligament or tendon relative to the magnetic field can induce increased signal intensity due to the magic angle effect. To assess if positional rotation of the foot in the solar plane could be responsible for artifactual changes in signal intensity in the collateral ligaments of the distal interphalangeal joint and in the deep digital flexor tendon. Six isolated equine feet were imaged with a standing equine magnetic resonance system in 9 different positions with different degrees of rotation in the solar plane. Rotation of the limb induced a linear hyperintense signal on all feet at the palmar aspect of one of the lobes of the deep digital flexor tendon and at the dorsal aspect of the other lobe. Changes in signal intensity in the collateral ligaments of the distal interphalangeal joint occurred with rotation of the limb only in those feet where mediolateral hoof imbalance was present. The position and conformation of the foot influence the signal intensity in the deep digital flexor tendon and in the collateral ligaments of the distal interphalangeal joint. The significance of increased signal intensity in the deep digital flexor tendon and in the collateral ligaments of the distal interphalangeal joint should be interpreted with regard to the position and the conformation of the foot.

Precise tracking of remote sensing satellites with the Global Positioning System

NASA Technical Reports Server (NTRS)

Yunck, Thomas P.; Wu, Sien-Chong; Wu, Jiun-Tsong; Thornton, Catherine L.

1990-01-01

The Global Positioning System (GPS) can be applied in a number of ways to track remote sensing satellites at altitudes below 3000 km with accuracies of better than 10 cm. All techniques use a precise global network of GPS ground receivers operating in concert with a receiver aboard the user satellite, and all estimate the user orbit, GPS orbits, and selected ground locations simultaneously. The GPS orbit solutions are always dynamic, relying on the laws of motion, while the user orbit solution can range from purely dynamic to purely kinematic (geometric). Two variations show considerable promise. The first one features an optimal synthesis of dynamics and kinematics in the user solution, while the second introduces a novel gravity model adjustment technique to exploit data from repeat ground tracks. These techniques, to be demonstrated on the Topex/Poseidon mission in 1992, will offer subdecimeter tracking accuracy for dynamically unpredictable satellites down to the lowest orbital altitudes.

Multitask SVM learning for remote sensing data classification

NASA Astrophysics Data System (ADS)

Leiva-Murillo, Jose M.; Gómez-Chova, Luis; Camps-Valls, Gustavo

2010-10-01

Many remote sensing data processing problems are inherently constituted by several tasks that can be solved either individually or jointly. For instance, each image in a multitemporal classification setting could be taken as an individual task but relation to previous acquisitions should be properly considered. In such problems, different modalities of the data (temporal, spatial, angular) gives rise to changes between the training and test distributions, which constitutes a difficult learning problem known as covariate shift. Multitask learning methods aim at jointly solving a set of prediction problems in an efficient way by sharing information across tasks. This paper presents a novel kernel method for multitask learning in remote sensing data classification. The proposed method alleviates the dataset shift problem by imposing cross-information in the classifiers through matrix regularization. We consider the support vector machine (SVM) as core learner and two regularization schemes are introduced: 1) the Euclidean distance of the predictors in the Hilbert space; and 2) the inclusion of relational operators between tasks. Experiments are conducted in the challenging remote sensing problems of cloud screening from multispectral MERIS images and for landmine detection.

Effects of age, sex and arm on the precision of arm position sense-left-arm superiority in healthy right-handers.

PubMed

Schmidt, Lena; Depper, Lena; Kerkhoff, Georg

2013-01-01

Position sense is an important proprioceptive ability. Disorders of arm position sense (APS) often occur after unilateral stroke, and are associated with a negative functional outcome. In the present study we assessed horizontal APS by measuring angular deviations from a visually defined target separately for each arm in a large group of healthy subjects. We analyzed the accuracy and instability of horizontal APS as a function of age, sex and arm. Subjects were required to specify verbally the position of their unseen arm on a 0-90° circuit by comparing the current position with the target position indicated by a LED lamp, while the arm was passively moved by the examiner. Eighty-seven healthy subjects participated in the study, ranging from 20 to 77 years, subdivided into three age groups. The results revealed that APS was not a function of age or sex, but was significantly better in the non-dominant (left) arm in absolute errors (AE) but not in constant errors (CE) across all age groups of right-handed healthy subjects. This indicates a right-hemisphere superiority for left APS in right-handers and neatly fits to the more frequent and more severe left-sided body-related deficits in patients with unilateral stroke (i.e. impaired APS in left spatial neglect, somatoparaphrenia) or in individuals with abnormalities of the right cerebral hemisphere. These clinical issues will be discussed.

Evaluation of orthognathic surgery on articular disc position and temporomandibular joint symptoms in skeletal class II patients: A Magnetic Resonance Imaging study.

PubMed

Firoozei, Gholamreza; Shahnaseri, Shirin; Momeni, Hasan; Soltani, Parisa

2017-08-01

The purpose of orthognathic surgery is to correct facial deformity and dental malocclusion and to obtain normal orofacial function. However, there are controversies of whether orthognathic surgery might have any negative influence on temporomandibular (TM) joint. The purpose of this study was to evaluate the influence of orthognathic surgery on articular disc position and temporomandibular joint symptoms of skeletal CI II patients by means of magnetic resonance imaging. For this purpose, fifteen patients with skeletal CI II malocclusion, aged 19-32 years (mean 23 years), 10 women and 5 men, from the Isfahan Department of Oral and Maxillofacial Surgery were studied. All received LeFort I and bilateral sagittal split osteotomy (BSSO) osteotomies and all patients received pre- and post-surgical orthodontic treatment. Magnetic resonance imaging was performed 1 day preoperatively and 3 month postoperatively. Descriptive statistics and Wilcoxon and Mc-Nemar tests were used for statistical analysis. P <0.05 was considered significant. Disc position ranged between 4.25 and 8.09 prior to surgery (mean=5.74±1.21). After surgery disc position range was 4.36 to 7.40 (mean=5.65±1.06). Statistical analysis proved that although TM disc tended to move anteriorly after BSSO surgery, this difference was not statistically significant ( p value<0.05). The findings of the present study revealed that orthognathic surgery does not alter the disc and condyle relationship. Therefore, it has minimal effects on intact and functional TM joint. Key words: Orthognathic surgery, skeletal class 2, magnetic resonance imaging, temporomandibular disc.

The influence of hand positions on biomechanical injury risk factors at the wrist joint during the round-off skills in female gymnastics.

PubMed

Farana, Roman; Jandacka, Daniel; Uchytil, Jaroslav; Zahradnik, David; Irwin, Gareth

2017-01-01

The aim of this study was to examine the biomechanical injury risk factors at the wrist, including joint kinetics, kinematics and stiffness in the first and second contact limb for parallel and T-shape round-off (RO) techniques. Seven international-level female gymnasts performed 10 trials of the RO to back handspring with parallel and T-shape hand positions. Synchronised kinematic (3D motion analysis system; 247 Hz) and kinetic (two force plates; 1235 Hz) data were collected for each trial. A two-way repeated measure analysis of variance (ANOVA) assessed differences in the kinematic and kinetic parameters between the techniques for each contact limb. The main findings highlighted that in both the RO techniques, the second contact limb wrist joint is exposed to higher mechanical loads than the first contact limb demonstrated by increased axial compression force and loading rate. In the parallel technique, the second contact limb wrist joint is exposed to higher axial compression load. Differences between wrist joint kinetics highlight that the T-shape technique may potentially lead to reducing these bio-physical loads and consequently protect the second contact limb wrist joint from overload and biological failure. Highlighting the biomechanical risk factors facilitates the process of technique selection making more objective and safe.

Metal to ceramic sealed joint

DOEpatents

Lasecki, J.V.; Novak, R.F.; McBride, J.R.

1991-08-27

A metal to ceramic sealed joint which can withstand wide variations in temperature and maintain a good seal is provided for use in a device adapted to withstand thermal cycling from about 20 to about 1000 degrees C. The sealed joint includes a metal member, a ceramic member having an end portion, and an active metal braze forming a joint to seal the metal member to the ceramic member. The joint is positioned remote from the end portion of the ceramic member to avoid stresses at the ends or edges of the ceramic member. The sealed joint is particularly suited for use to form sealed metal to ceramic joints in a thermoelectric generator such as a sodium heat engine where a solid ceramic electrolyte is joined to metal parts in the system. 11 figures.

Metal to ceramic sealed joint

DOEpatents

Lasecki, John V.; Novak, Robert F.; McBride, James R.

1991-01-01

A metal to ceramic sealed joint which can withstand wide variations in temperature and maintain a good seal is provided for use in a device adapted to withstand thermal cycling from about 20 to about 1000 degrees C. The sealed joint includes a metal member, a ceramic member having an end portion, and an active metal braze forming a joint to seal the metal member to the ceramic member. The joint is positioned remote from the end portion of the ceramic member to avoid stresses at the ends or edges of the ceramic member. The sealed joint is particularly suited for use to form sealed metal to ceramic joints in a thermoelectric generator such as a sodium heat engine where a solid ceramic electrolyte is joined to metal parts in the system.

[Temporo-mandibular joint. Morpho-functional considerations].

PubMed

Scutariu, M D; Indrei, Anca

2004-01-01

The temporo-mandibular joint is distinguished from most other synovial joints of the body by two features: 1. the two jointed components carry teeth whose position and occlusion introduce a very strong influence on the movements of the temporo-mandibular joint and 2. its articular surfaces are not covered by hyaline cartilage, but by a dense, fibrous tissue. This paper describes the parts of the temporo-mandibular joint: the articular surfaces (the condylar process of the mandible and the glenoid part of the temporal bone), the fibrocartilaginous disc which is interposed between the mandibular and the temporal surface, the fibrous capsule of the temporo-mandibular joint and the ligaments of this joint. All these parts present a very strong adaptation at the important functions of the temporo-mandibular joint.

A clamping force measurement system for monitoring the condition of bolted joints on railway track joints and points

NASA Astrophysics Data System (ADS)

Tesfa, B.; Horler, G.; Thobiani, F. Al; Gu, F.; Ball, A. D.

2012-05-01

Many industrial structures associated with railway infrastructures rely on a large number of bolted joint connections to ensure safe and reliable operation of the track and trackside furniture. Significant sums of money are spent annually to repair the damage caused by bolt failures and to maintain the integrity of bolted structures. In the UK, Network Rail (the organization responsible for rail network maintenance and safety) conducts corrective and preventive maintenance manually on 26,000 sets of points (each having approximately 30 bolted joints per set), in order to ensure operational success and safety for the travelling public. Such manual maintenance is costly, disruptive, unreliable and prone to human error. The aim of this work is to provide a means of automatically measuring the clamping force of each individual bolted joint, by means of an instrumented washer. This paper describes the development of a sensor means to be used in the washer, which satisfies the following criteria. Sense changes in the clamping force of the joint and report this fact. Provide compatibility with the large dynamic range of clamping force. Satisfy the limitations in terms of physical size. Provide the means to electronically interface with the washer. Provide a means of powering the washer in situ. Provide a solution at an acceptable cost. Specifically the paper focuses on requirements 1, 2 and 3 and presents the results that support further development of the proposed design and the realization of a pre-prototype system. In the paper, various options for the force sensing element (strain gage, capacitor, piezo-resistive) have been compared, using design optimization techniques. As a result of the evaluation, piezo-resistive sensors in concert with a proprietary force attenuation method, have been found to offer the best performance and cost trade-off The performance of the novel clamping force sensor has been evaluated experimentally and the results show that a smart washer

A technique for position sensing and improved momentum evaluation of microparticle impacts in space.

NASA Technical Reports Server (NTRS)

Mcdonnell, J. A. M.; Abellanas, C.

1972-01-01

The design of a three element piezoelectric microparticle impact sensing diaphragm is described which is sensitive to the detection of momentum propagated by the bending wave. The design achieves a sensitivity of .03 microdyn/sec and optimizes the detection of the direct-path pulse from impact relative to secondary reflections and interference from discontinuities. Measurement of the relative arrival times and the maximum amplitudes of the outputs from the three piezoelectric sensors leads to the determination of the impact position and the normally resolved impact momentum exchange. Coincidence of the signals and a partial redundancy of data leads to a very high noise discrimination.

Soft Smart Garments for Lower Limb Joint Position Analysis.

PubMed

Totaro, Massimo; Poliero, Tommaso; Mondini, Alessio; Lucarotti, Chiara; Cairoli, Giovanni; Ortiz, Jesùs; Beccai, Lucia

2017-10-12

Revealing human movement requires lightweight, flexible systems capable of detecting mechanical parameters (like strain and pressure) while being worn comfortably by the user, and not interfering with his/her activity. In this work we address such multifaceted challenge with the development of smart garments for lower limb motion detection, like a textile kneepad and anklet in which soft sensors and readout electronics are embedded for retrieving movement of the specific joint. Stretchable capacitive sensors with a three-electrode configuration are built combining conductive textiles and elastomeric layers, and distributed around knee and ankle. Results show an excellent behavior in the ~30% strain range, hence the correlation between sensors' responses and the optically tracked Euler angles is allowed for basic lower limb movements. Bending during knee flexion/extension is detected, and it is discriminated from any external contact by implementing in real time a low computational algorithm. The smart anklet is designed to address joint motion detection in and off the sagittal plane. Ankle dorsi/plantar flexion, adduction/abduction, and rotation are retrieved. Both knee and ankle smart garments show a high accuracy in movement detection, with a RMSE less than 4° in the worst case.

Soft Smart Garments for Lower Limb Joint Position Analysis

PubMed Central

Totaro, Massimo; Poliero, Tommaso; Mondini, Alessio; Lucarotti, Chiara; Cairoli, Giovanni; Ortiz, Jesùs; Beccai, Lucia

2017-01-01

Revealing human movement requires lightweight, flexible systems capable of detecting mechanical parameters (like strain and pressure) while being worn comfortably by the user, and not interfering with his/her activity. In this work we address such multifaceted challenge with the development of smart garments for lower limb motion detection, like a textile kneepad and anklet in which soft sensors and readout electronics are embedded for retrieving movement of the specific joint. Stretchable capacitive sensors with a three-electrode configuration are built combining conductive textiles and elastomeric layers, and distributed around knee and ankle. Results show an excellent behavior in the ~30% strain range, hence the correlation between sensors’ responses and the optically tracked Euler angles is allowed for basic lower limb movements. Bending during knee flexion/extension is detected, and it is discriminated from any external contact by implementing in real time a low computational algorithm. The smart anklet is designed to address joint motion detection in and off the sagittal plane. Ankle dorsi/plantar flexion, adduction/abduction, and rotation are retrieved. Both knee and ankle smart garments show a high accuracy in movement detection, with a RMSE less than 4° in the worst case. PMID:29023365

Factors determining the level and changes in intra-articular pressure in the knee joint of the dog.

PubMed Central

Nade, S; Newbold, P J

1983-01-01

Intra-articular pressure levels were determined for joint positions throughout the normal physiological range of movement of dogs' knee joints. Change in joint position resulted in change in intra-articular pressure. It was demonstrated that intra-articular pressure is highest with the joint in the fully flexed position. Minimum pressure was recorded at a position between 80 degrees and 120 degrees. Minimum pressures were usually subatmospheric. The rate of change of joint position affected intra-articular pressure. The relationship of intra-articular pressure and joint position before and after full flexion demonstrated a hysteresis effect; the pressures were lower than for the same joint position before flexion. Maintenance of the joint in the fully flexed position for increasing periods of time between repeated movement cycles resulted in a similar reduction, of constant magnitude, in pressure between joint positions before and after each period of flexion. However, there was also a progressive decrease in pressure for all joint angles over the total number of movement cycles. There is a contribution to intra-articular pressure of joint capsular compliance and fluid movement into and out of the joint (both of which are time-dependent). The recording of intra-articular pressure in conscious, upright dogs revealed similar pressure levels to those measured in anaesthetized supine dogs. The major determinants of intra-articular pressure in normal dog knee joints include joint size, synovial fluid volume, position of joint, peri-articular tissue and joint anatomy, membrane permeability, capsular compliance, and movement of fluid into and out of the joint. Images Fig. 1 PMID:6875957

Symmetry of proprioceptive sense in female soccer players.

PubMed

Iwańska, Dagmara; Karczewska, Magdalena; Madej, Anna; Urbanik, Czesław

2015-01-01

The purpose of the study was to assess the symmetry of proprioceptive sense among female soccer players when trying to reproduce isometric knee extensions (right and left) and to analyze the impact of a given level of muscle force on proprioception. The study involved 12 soccer players aged 19.5 ± 2.65 years. Soccer players performed a control measurement of a maximum 3s (knee at the 90°) position in the joint. Subsequently, 70%, 50%, and 30% of the maximum voluntary contraction (MVC) were all calculated and then reproduced by each subject with feedback. Next, the players reproduced the predefined muscle contraction values in three sequences: A - 50%, 70%, 30%; B - 50%, 30%, 70%; C - 70%, 30%, 50% of MVC without visual control. In every sequence, the participants found obtaining the value of 30% of MVC the most difficult. The value they reproduced most accurately was 70% of MVC. Both trial II and trial III demonstrated that the symmetry index SI significantly differed from values considered acceptable (SIRa). In each successive sequence the largest asymmetry occurred while reproducing the lowest values of MVC (30%) (p < 0.05). High level of prioprioceptive sense is important to soccer players due to the extensive overload associated with dynamics stops or changes in direction while running. Special attention should be paid to develop skills in sensing force of varying levels. It was much harder to reproduce the predefined values if there was no feedback.

Sensing land pollution.

NASA Technical Reports Server (NTRS)

Bowden, L. W.

1971-01-01

Land pollution is described in numerous ways by various societies. Pollutants of land are material by-products of human activity and range from environmentally ineffective to positively toxic. The pollution of land by man is centuries old and correlates directly with economy, technology and population. In order to remotely sense land pollution, standards or thresholds must be established. Examples of the potential for sensing land pollution and quality are presented. The technological capabilities for remotely sensed land quality is far advanced over the judgment on how to use the sensed data. Until authoritative and directive decisions on land pollution policy are made, sensing of pollutants will be a random, local and academic affair.

Inflammatory disorders mimicking periprosthetic joint infections may result in false positive α-defensin.

PubMed

Plate, Andreas; Stadler, Laura; Sutter, Reto; Anagnostopoulos, Alexia; Frustaci, Dario; Zbinden, Reinhard; Fucentese, Sandro F; Zinkernagel, Annelies S; Zingg, Patrick O; Achermann, Yvonne

2018-02-26

The antimicrobial peptide α-defensin has recently been introduced as potential "single" biomarker with a high sensitivity and specificity for the preoperative diagnosis of periprosthetic joint infections (PJIs). However, most studies assessed the benefits of the test with exclusion of patients with rheumatic diseases. We aimed to evaluate the α-defensin test in a cohort study without exclusion of cases with inflammatory diseases. Between June 2016 and June 2017, we prospectively included cases with a suspected PJI and an available lateral flow test α-defensin (Synovasure®) in synovial fluid. We compared the test result to the diagnostic criteria for PJIs published by an International Consensus Group in 2013. We included 109 cases (49 hips, 60 knees) in which preoperative α-defensin tests had been performed. Thereof, 20 PJIs (16 hips, 4 knees) were diagnosed. Preoperative α-defensin tests were positive in 25 cases (22.9%) with a test sensitivity and specificity of 90% and 92.1% (95% confidence interval [CI], 68.3 - 98.8% and 84.5 - 96.8%, respectively), and a high negative predictive value of 97.6% (95% CI, 91.7 - 99.4%). We interpreted seven α-defensin tests as false positive, mainly in cases with inflammatory rheumatic diseases, including crystal deposition diseases. A negative synovial α-defensin test can reliably rule out a PJI. However, the test can be false positive in conjunction with an underlying non-infectious inflammatory disease. We therefore propose to use the α-defensin test only in addition to MSIS criteria and assessment for crystals in synovial aspirates. Copyright © 2018. Published by Elsevier Ltd.

Linezolid in late-chronic prosthetic joint infection caused by gram-positive bacteria.

PubMed

Cobo, Javier; Lora-Tamayo, Jaime; Euba, Gorane; Jover-Sáenz, Alfredo; Palomino, Julián; del Toro, Ma Dolores; Rodríguez-Pardo, Dolors; Riera, Melchor; Ariza, Javier

2013-05-01

Linezolid may be an interesting alternative for prosthetic joint infection (PJI) due to its bioavailability and its antimicrobial spectrum. However, experience in this setting is scarce. The aim of the study was to assess linezolid's clinical and microbiological efficacy, and also its tolerance. This was a prospective, multicenter, open-label, non-comparative study of 25 patients with late-chronic PJI caused by Gram-positive bacteria managed with a two-step exchange procedure plus 6 weeks of linezolid. Twenty-two (88%) patients tolerated linezolid without major adverse effects, although a global decrease in the platelet count was observed. Three patients were withdrawn because of major toxicity, which reversed after linezolid stoppage. Among patients who completed treatment, 19 (86%) demonstrated clinical and microbiological cure. Two patients presented with clinical and microbiological failure, and one showed clinical cure and microbiological failure. In conclusion, linezolid showed good results in chronic PJI managed with a two-step exchange procedure. Tolerance seems acceptable, though close surveillance is required. Copyright © 2013 Elsevier Inc. All rights reserved.

A New Technique for Compensating Joint Limits in a Robot Manipulator

NASA Technical Reports Server (NTRS)

Litt, Jonathan; Hickman, Andre; Guo, Ten-Huei

1996-01-01

A new robust, optimal, adaptive technique for compensating rate and position limits in the joints of a six degree-of-freedom elbow manipulator is presented. In this new algorithm, the unmet demand as a result of actuator saturation is redistributed among the remaining unsaturated joints. The scheme is used to compensate for inadequate path planning, problems such as joint limiting, joint freezing, or even obstacle avoidance, where a desired position and orientation are not attainable due to an unrealizable joint command. Once a joint encounters a limit, supplemental commands are sent to other joints to best track, according to a selected criterion, the desired trajectory.

A Novel Wireless Power Transfer-Based Weighed Clustering Cooperative Spectrum Sensing Method for Cognitive Sensor Networks.

PubMed

Liu, Xin

2015-10-30

In a cognitive sensor network (CSN), the wastage of sensing time and energy is a challenge to cooperative spectrum sensing, when the number of cooperative cognitive nodes (CNs) becomes very large. In this paper, a novel wireless power transfer (WPT)-based weighed clustering cooperative spectrum sensing model is proposed, which divides all the CNs into several clusters, and then selects the most favorable CNs as the cluster heads and allows the common CNs to transfer the received radio frequency (RF) energy of the primary node (PN) to the cluster heads, in order to supply the electrical energy needed for sensing and cooperation. A joint resource optimization is formulated to maximize the spectrum access probability of the CSN, through jointly allocating sensing time and clustering number. According to the resource optimization results, a clustering algorithm is proposed. The simulation results have shown that compared to the traditional model, the cluster heads of the proposed model can achieve more transmission power and there exists optimal sensing time and clustering number to maximize the spectrum access probability.

Influence of Passive Joint Stiffness on Proprioceptive Acuity in Individuals With Functional Instability of the Ankle.

PubMed

Marinho, Hellen Veloso Rocha; Amaral, Giovanna Mendes; de Souza Moreira, Bruno; Araújo, Vanessa Lara; Souza, Thales Rezende; Ocarino, Juliana Melo; da Fonseca, Sérgio Teixeira

2017-12-01

Study Design Controlled laboratory study, cross-sectional. Background Deficits in ankle proprioceptive acuity have been reported in persons with functional instability of the ankle. Passive stiffness has been proposed as a possible mechanism underlying proprioceptive acuity. Objective To compare proprioceptive acuity and passive ankle stiffness in persons with and without functional ankle instability, and to assess the influence of passive joint stiffness on proprioceptive acuity in persons with functional ankle instability. Methods A sample of 18 subjects with and 18 without complaints of functional ankle instability following lateral ankle sprain participated. An isokinetic dynamometer was used to compare motion perception threshold, passive position sense, and passive ankle stiffness between groups. To evaluate the influence of passive stiffness on proprioceptive acuity, individuals in the lateral functional ankle instability group were divided into 2 subgroups: "high" and "low" passive ankle stiffness. Results The functional ankle instability group exhibited increased motion perception threshold when compared with the corresponding limb of the control group. Between-group differences were not found for passive position sense and passive ankle stiffness. Those in the functional ankle instability group with higher passive ankle stiffness had smaller motion perception thresholds than those with lower passive ankle stiffness. Conclusion Unlike motion perception threshold, passive position sense is not affected by the presence of functional ankle instability. Passive ankle stiffness appears to influence proprioceptive acuity in persons with functional ankle instability. J Orthop Sports Phys Ther 2017;47(12):899-905. Epub 7 Oct 2017. doi:10.2519/jospt.2017.7030.

Joint document concerning geological studies from 1971 - 1975

NASA Technical Reports Server (NTRS)

1977-01-01

In 1971, a joint Soviet-Americam Working Group on Remote Sensing of the Natural Environment was established. It was organized into a number of discipline panels, one of which was on geology. Membership on this panel came from the Geological Survey of the United States and from the Institute of Geology of the U.S.S.R. Academy of Sciences and Ministry Geology of the U.S.S.R.. During the period 1971-1975, this panel conducted coordinated research in the use of space remote sensing data in the field of geology. A summary of that coordinated research effort is presented.

Ego depletion and positive illusions: does the construction of positivity require regulatory resources?

PubMed

Fischer, Peter; Greitemeyer, Tobias; Frey, Dieter

2007-09-01

Individuals frequently exhibit positive illusions about their own abilities, their possibilities to control their environment, and future expectations. The authors propose that positive illusions require resources of self-control, which is considered to be a limited resource similar to energy or strength. Five studies revealed that people with depleted self-regulatory resources indeed exhibited a less-optimistic sense of their own abilities (Study 1), a lower sense of subjective control (Study 2), and less-optimistic expectations about their future (Study 3). Two further studies shed light on the underlying psychological process: Ego-depleted (compared to nondepleted) individuals generated/retrieved less positive self-relevant attributes (Studies 4 and 5) and reported a lower sense of general self-efficacy (Study 5), which both partially mediated the impact of ego depletion on positive self-views (Study 5).

Efficient Wideband Spectrum Sensing with Maximal Spectral Efficiency for LEO Mobile Satellite Systems

PubMed Central

Li, Feilong; Li, Zhiqiang; Li, Guangxia; Dong, Feihong; Zhang, Wei

2017-01-01

The usable satellite spectrum is becoming scarce due to static spectrum allocation policies. Cognitive radio approaches have already demonstrated their potential towards spectral efficiency for providing more spectrum access opportunities to secondary user (SU) with sufficient protection to licensed primary user (PU). Hence, recent scientific literature has been focused on the tradeoff between spectrum reuse and PU protection within narrowband spectrum sensing (SS) in terrestrial wireless sensing networks. However, those narrowband SS techniques investigated in the context of terrestrial CR may not be applicable for detecting wideband satellite signals. In this paper, we mainly investigate the problem of joint designing sensing time and hard fusion scheme to maximize SU spectral efficiency in the scenario of low earth orbit (LEO) mobile satellite services based on wideband spectrum sensing. Compressed detection model is established to prove that there indeed exists one optimal sensing time achieving maximal spectral efficiency. Moreover, we propose novel wideband cooperative spectrum sensing (CSS) framework where each SU reporting duration can be utilized for its following SU sensing. The sensing performance benefits from the novel CSS framework because the equivalent sensing time is extended by making full use of reporting slot. Furthermore, in respect of time-varying channel, the spatiotemporal CSS (ST-CSS) is presented to attain space and time diversity gain simultaneously under hard decision fusion rule. Computer simulations show that the optimal sensing settings algorithm of joint optimization of sensing time, hard fusion rule and scheduling strategy achieves significant improvement in spectral efficiency. Additionally, the novel ST-CSS scheme performs much higher spectral efficiency than that of general CSS framework. PMID:28117712

Virtual trajectories, joint stiffness, and changes in the limb natural frequency during single-joint oscillatory movements.

PubMed

Latash, M L

1992-07-01

In the framework of the equilibrium-point hypothesis, virtual trajectories and patterns of joint stiffness were reconstructed during voluntary single-joint oscillatory movements in the elbow joint at a variety of frequencies and against two inertial loads. At low frequencies, virtual trajectories were in-phase with the actual joint trajectories. Joint stiffness changed at a doubled frequency. An increase in movement frequency and/or inertial load led to an increase in the difference between the peaks of the actual and virtual trajectories and in both peak and averaged values of joint stiffness. At a certain, critical frequency, virtual trajectory was nearly flat. Further increase in movement frequency led to a 180 degree phase shift between the actual and virtual trajectories. The assessed values of the natural frequency of the system "limb + manipulandum" were close to the critical frequencies for both low and high inertial loads. Peak levels and integrals of the electromyograms of two flexor and two extensor muscles changed monotonically with movement frequency without any special behavior at the critical frequencies. Nearly flat virtual trajectories at the natural frequency make physical sense as hypothetical control signals, unlike the electromyographic recordings, since a system at its natural frequency requires minimal central interference. Modulation of joint stiffness is assumed to be an important adaptive mechanism attenuating difference between the system's natural frequency and desired movement frequency. Virtual trajectory is considered a behavioral observable. Phase transitions between the virtual and actual trajectories are illustrations of behavioral discontinuities introduced by slow changes in a higher level control parameter, movement frequency. Relative phase shift between these two trajectories may be considered an order parameter.

Subtalar joint stress imaging with tomosynthesis.

PubMed

Teramoto, Atsushi; Watanabe, Kota; Takashima, Hiroyuki; Yamashita, Toshihiko

2014-06-01

The purpose of this study was to perform stress imaging of hindfoot inversion and eversion using tomosynthesis and to assess the subtalar joint range of motion (ROM) of healthy subjects. The subjects were 15 healthy volunteers with a mean age of 29.1 years. Coronal tomosynthesis stress imaging of the subtalar joint was performed in a total of 30 left and right ankles. A Telos stress device was used for the stress load, and the load was 150 N for both inversion and eversion. Tomographic images in which the posterior talocalcaneal joint could be confirmed on the neutral position images were used in measurements. The angle of the intersection formed by a line through the lateral articular facet of the posterior talocalcaneal joint and a line through the surface of the trochlea of the talus was measured. The mean change in the angle of the calcaneus with respect to the talus was 10.3 ± 4.8° with inversion stress and 5.0 ± 3.8° with eversion stress from the neutral position. The result was a clearer depiction of the subtalar joint, and inversion and eversion ROM of the subtalar joint was shown to be about 15° in healthy subjects. Diagnostic, Level IV.

Wrist joint assembly

NASA Technical Reports Server (NTRS)

Kersten, L.; Johnson, J. D. (Inventor)

1978-01-01

A wrist joint assembly is provided for use with a mechanical manipulator arm for finely positioning an end-effector carried by the wrist joint on the terminal end of the manipulator arm. The wrist joint assembly is pivotable about a first axis to produce a yaw motion, a second axis is to produce a pitch motion, and a third axis to produce a roll motion. The wrist joint assembly includes a disk segment affixed to the terminal end of the manipulator arm and a first housing member, a second housing member, and a third housing member. The third housing member and the mechanical end-effector are moved in the yaw, pitch, and roll motion. Drive means are provided for rotating each of the housings about their respective axis which includes a cluster of miniature motors having spur gears carried on the output drive shaft which mesh with a center drive gear affixed on the housing to be rotated.

GPS meteorology - Remote sensing of atmospheric water vapor using the Global Positioning System

NASA Technical Reports Server (NTRS)

Bevis, Michael; Businger, Steven; Herring, Thomas A.; Rocken, Christian; Anthes, Richard A.; Ware, Randolph H.

1992-01-01

We present a new approach to remote sensing of water vapor based on the Global Positioning System (GPS). Geodesists and geophysicists have devised methods for estimating the extent to which signals propagating from GPS satellites to ground-based GPS receivers are delayed by atmospheric water vapor. This delay is parameterized in terms of a time-varying zenith wet delay (ZWD) which is retrieved by stochastic filtering of the GPS data. Given surface temperature and pressure readings at the GPS receiver, the retrieved ZWD can be transformed with very little additional uncertainty into an estimate of the integrated water vapor (IWV) overlying that receiver. Networks of continuously operating GPS receivers are being constructed by geodesists, geophysicists, and government and military agencies, in order to implement a wide range of positioning capabilities. These emerging GPS networks offer the possibility of observing the horizontal distribution of IWV or, equivalently, precipitate water with unprecedented coverage and a temporal resolution of the order of 10 min. These measurements could be utilized in operational weather forecasting and in fundamental research into atmospheric storm systems, the hydrologic cycle, atmospheric chemistry, and global climate change.

Body position reproducibility and joint alignment stability criticality on a muscular strength research device

NASA Astrophysics Data System (ADS)

Nunez, F.; Romero, A.; Clua, J.; Mas, J.; Tomas, A.; Catalan, A.; Castellsaguer, J.

2005-08-01

MARES (Muscle Atrophy Research and Exercise System) is a computerized ergometer for neuromuscular research to be flown and installed onboard the International Space Station in 2007. Validity of data acquired depends on controlling and reducing all significant error sources. One of them is the misalignment of the joint rotation axis with respect to the motor axis.The error induced on the measurements is proportional to the misalignment between both axis. Therefore, the restraint system's performance is critical [1]. MARES HRS (Human Restraint System) assures alignment within an acceptable range while performing the exercise (results: elbow movement:13.94mm+/-5.45, Knee movement: 22.36mm+/- 6.06 ) and reproducibility of human positioning (results: elbow movement: 2.82mm+/-1.56, Knee movement 7.45mm+/-4.8 ). These results allow limiting measurement errors induced by misalignment.

Deep learning decision fusion for the classification of urban remote sensing data

NASA Astrophysics Data System (ADS)

Abdi, Ghasem; Samadzadegan, Farhad; Reinartz, Peter

2018-01-01

Multisensor data fusion is one of the most common and popular remote sensing data classification topics by considering a robust and complete description about the objects of interest. Furthermore, deep feature extraction has recently attracted significant interest and has become a hot research topic in the geoscience and remote sensing research community. A deep learning decision fusion approach is presented to perform multisensor urban remote sensing data classification. After deep features are extracted by utilizing joint spectral-spatial information, a soft-decision made classifier is applied to train high-level feature representations and to fine-tune the deep learning framework. Next, a decision-level fusion classifies objects of interest by the joint use of sensors. Finally, a context-aware object-based postprocessing is used to enhance the classification results. A series of comparative experiments are conducted on the widely used dataset of 2014 IEEE GRSS data fusion contest. The obtained results illustrate the considerable advantages of the proposed deep learning decision fusion over the traditional classifiers.

Joint Coordination and Muscle Activities of Ballet Dancers During Tiptoe Standing.

PubMed

Tanabe, Hiroko; Fujii, Keisuke; Kouzaki, Motoki

2017-01-01

We aimed to investigate joint coordination of lower limbs in dancers during tiptoe standing and the relationship between joint coordination and muscle coactivation. Seven female ballet dancers performed tiptoe standing with six leg positions (fi e classical dance positions and one modern dance position) for 10 s. The kinematic data of the metatarsophalangeal (MP), ankle, knee, and hip joints was collected, and surface electromyography (EMG) of over 13 lower limb muscles was conducted. Principal component analysis was performed to determine joint coordination. MP-ankle and ankle-knee had in-phase coordination, whereas knee-hip showed anti-phase coordination in the sagittal plane. In addition, most EMG-EMG coherence around the MP and ankle joints was significant up to 50 Hz when these two joints swayed with in-phase. This suggests that different joint coordination patterns are associated with neural processing related to different muscle coactivation patterns. In conclusion, ballet dancers showed in-phase coordination from the MP to knee joints, which was associated with muscle coactivation to a higher frequency domain (up to 50 Hz) in comparison with anti-phase coordination.

Measurement of strain and tensile force of the supraspinatus tendon under conditions that simulates low angle isometric elevation of the gleno-humeral joint: Influence of adduction torque and joint positioning.

PubMed

Miyamoto, Hiroki; Aoki, Mitsuhiro; Hidaka, Egi; Fujimiya, Mineko; Uchiyama, Eiichi

2017-12-01

Recently, supraspinatus muscle exercise has been reported to treat rotator cuff disease and to recover shoulder function. However, there have been no report on the direct measurement of strain on the supraspinatus tendon during simulated isometric gleno-humeral joint elevation. Ten fresh-frozen shoulder specimens with the rotator cuff complex left intact were used as experimental models. Isometric gleno-humeral joint elevation in a sitting position was reproduced with low angle of step-by-step elevation in the scapular plane and strain was measured on the surface layer of the supraspinatus tendon. In isometric conditions, applied tensile force of the supraspinatus tendon increased significantly with increases in adduction torque on the gleno-humeral joint. Significant increases in the strain on the layer were observed by increase in adduction torque, which were recorded in isometric elevation at -10° and 0°, but little increase in the strain was observed at 10° or greater gleno-humeral elevation. Increased strain on the surface layer of the supraspinatus tendon was observed during isometric gleno-humeral elevation from -10 to 0°. These findings demonstrate a potential risk of inducing overstretching of the supraspinatus tendon during supraspinatus muscle exercise. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impacts of making sense of adversity on depression, posttraumatic stress disorder, and posttraumatic growth among a sample of mainly newly diagnosed HIV-positive Chinese young homosexual men: the mediating role of resilience.

PubMed

Yu, Nancy Xiaonan; Chen, Lihua; Ye, Zhi; Li, Xiaoming; Lin, Danhua

2017-01-01

The experience of HIV, as a life-transforming event, might produce both negative and positive outcomes. Guided by the stress appraisal model, the present study investigated the hypothesized pathways in predicting symptomatology and posttraumatic growth (PTG) in a sample of Chinese male patients with HIV (PHIV) who were mainly newly diagnosed, young, and homosexual. In this cross-sectional study, 141 Chinese male PHIV (87.2% of them were homosexual) completed measures of making negative/positive sense of adversity, resilience, depression, posttraumatic stress disorder (PTSD), and PTG. The path analysis results showed that making negative sense of adversity was associated with depression and PTSD, partially mediated by low levels of resilience, whereas making positive sense of adversity was associated with PTG, partially mediated by resilience. The results suggest that negative and positive outcomes of trauma are impacted by making negative and positive sense of adversity, respectively, via two separate pathways, both mediated by resilience. Our findings contribute to an understanding of the cognitive process of symptomatology and PTG in the HIV context. Theoretical considerations, clinical implications, and future directions are discussed.

Comparable outcome of culture-negative and culture-positive periprosthetic hip joint infection for patients undergoing two-stage revision.

PubMed

Wang, Jin; Wang, Qiaojie; Shen, Hao; Zhang, Xianlong

2018-03-01

Lack of peri-operative microbiological evidence is an unfavourable factor in one-stage revision. The objective of this study was to figure out whether being culture-negative was an unfavourable factor for periprosthetic hip joint infection (PHJI) in patients undergoing two-stage revision. Records of PHJI patients treated between October 2003 and December 2016 were reviewed at our institution. Information such as microbiological data, clinical outcomes, and other details of patients' clinical courses were recorded. A total of the 58 cases were reviewed. The median follow-up duration was 68.5 months. The infection control rate of PHJI was 93.1% after two-stage revision. Kaplan-Meier analysis showed no significant difference in infection control rates between culture-negative and culture-positive groups. Culture-positive sinus secretions were significantly associated with an increased rate of reinfection (P = 0.039). Two-stage revision had a high success rate for eradication of PHJI. Culture-negative PHJI had a comparable outcome with culture-positive PHJI.

Combining Sense and Intelligence for Smart Structures

NASA Technical Reports Server (NTRS)

2002-01-01

IFOS developed the I*Sense technology with assistance from a NASA Langley Research Center SBIR contract. NASA and IFOS collaborated to create sensing network designs that have high sensitivity, low power consumption, and significant potential for mass production. The joint- research effort led to the development of a module that is rugged, compact and light-weight, and immune to electromagnetic interference. These features make the I*Sense multisensor arrays favorable for smart structure applications, including smart buildings, bridges, highways, dams, power plants, ships, and oil tankers, as well as space vehicles, space stations, and other space structures. For instance, the system can be used as an early warning and detection device, with alarms being set to monitor the maximum allowable strain and stress values at various points of a given structure.

Effects of local treatment with and without sensorimotor and balance exercise in individuals with neck pain: protocol for a randomized controlled trial.

PubMed

Sremakaew, Munlika; Jull, Gwendolen; Treleaven, Julia; Barbero, Marco; Falla, Deborah; Uthaikhup, Sureeporn

2018-02-13

Impaired cervical joint position sense and balance are associated with neck pain. Specific therapeutic exercise and manual therapy are effective for improving neck pain and functional ability but their effects on joint position sense and balance impairments remain uncertain. Changes in the joint position sense and balance may need to be addressed specifically. The primary objective is to investigate the most effective interventions to improve impaired cervical joint position sense and balance in individuals with neck pain. The secondary objective is to assess the effectiveness of the interventions on pain intensity and disability, pain location, dizziness symptoms, cervical range of motion, gait speed, functional ability, treatment satisfaction and quality of life. A 2 × 2 factorial, single blind RCT with immediate, short- and long-term follow-ups. One hundred and sixty eight participants with neck pain with impaired joint position sense and balance will be recruited into the trial. Participants will be randomly allocated to one of four intervention groups: i) local neck treatment, ii) local treatment plus tailored sensorimotor exercises, iii) local treatment plus balance exercises, and iv) local treatment plus sensorimotor and balance exercises. Participants receive two treatments for 6 weeks. Primary outcomes are postural sway and cervical joint position error. Secondary outcomes include gait speed, dizziness intensity, neck pain intensity, neck disability, pain extent and location, cervical range of motion, functional ability, perceived benefit, and quality of life. Assessment will be measured at baseline, immediately after treatment and at 3, 6, 12 month-follow ups. Neck pain is one of the major causes of disability. Effective treatment must address not only the symptoms but the dysfunctions associated with neck pain. This trial will evaluate the effectiveness of interventions for individuals with neck pain with impaired cervical joint position sense and

Shoulder and Lower Back Joint Reaction Forces in Seated Double Poling.

PubMed

Lund Ohlsson, Marie; Danvind, Jonas; Holmberg, L Joakim

2018-04-13

Overuse injuries in the shoulders and lower back are hypothesized to be common in cross-country sit-skiing. Athletes with reduced trunk muscle control mainly sits with their knees higher than hips (KH). To reduce spinal flexion, a position with the knees below the hips (KL) was enabled for these athletes using a frontal trunk support. The aim of the study was to compare the shoulder joint (glenohumeral joint) and L4-L5 joint reactions between the sitting positions KL and KH. Five able-bodied female athletes performed submaximal and maximal exercise tests in the sitting positions KL and KH on a ski-ergometer. Measured pole forces and 3-dimensional kinematics served as input for inverse-dynamics simulations to compute the muscle forces and joint reactions in the shoulder and L4-L5 joint. This was the first musculoskeletal simulation study of seated double poling. The results showed that the KH position was favorable for higher performance and decreased values of the shoulder joint reactions for female able-bodied athletes with full trunk control. The KL position was favorable for lower L4-L5 joint reactions and might therefore reduce the risk of lower back injuries. These results indicate that it is hard to optimize both performance and safety in the same sit-ski.

Robotic joint experiments under ultravacuum

NASA Technical Reports Server (NTRS)

Borrien, A.; Petitjean, L.

1988-01-01

First, various aspects of a robotic joint development program, including gearbox technology, electromechanical components, lubrication, and test results, are discussed. Secondly, a test prototype of the joint allowing simulation of robotic arm dynamic effects is presented. This prototype is tested under vacuum with different types of motors and sensors to characterize the functional parameters: angular position error, mechanical backlash, gearbox efficiency, and lifetime.

Quorum-sensing regulators in Gram-positive bacteria: 'cherchez le peptide'.

PubMed

Monnet, V; Gardan, R

2015-07-01

Gram-positive bacteria can regulate gene expression at the population level via a mechanism known as quorum sensing. Oligopeptides serve as the signaling molecules; they are secreted and then are either detected at the bacterial surface by two-component systems or reinternalized via an oligopeptide transport system. In the latter case, imported peptides interact with cognate regulators (phosphatases or transcriptional regulators) that modulate the expression of target genes. These regulators help control crucial functions such as virulence, persistence, conjugation and competence and have been reported in bacilli, enterococci and streptococci. They form the rapidly growing RRNPP group. In this issue of Molecular Microbiology, Hoover et al. (2015) highlight the group's importance: they have identified a new family of regulators, Tprs (Transcription factor regulated by a Phr peptide), which work with internalized Phr-like peptides. The mechanisms underlying the expression of the genes that encode these internalized peptides are poorly documented. However, Hoover et al. (2015) have provided a new insight: an environmental molecule, glucose, can inhibit expression of the Phr-like peptide gene via catabolic repression. This previously undescribed regulatory pathway, controlling the production of a bacteriocin, might influence Streptococcus pneumonia's fitness in the nasopharynx, where galactose is present. © 2015 John Wiley & Sons Ltd.

Characterization of nitrogen and water status in oat leaves using optical sensing approach.

PubMed

Zhao, Baoping; Ma, Bao-Luo; Hu, Yuegao; Liu, Jinghui

2015-01-01

Optical sensing is a potential tool to estimate plant N status, but soil water deficits may interefere with forming a clear relationship. A greenhouse study was conducted with oat plants treated with three water regimes and four N levels to determine whether optical sensing could be used to estimate leaf N and relative water content (RWC). Leaf N was strongly correlated with reflectance at 550 nm and at around 705 nm, and N treatments caused a red-edge peak shift to lower wavelength. The ratio of the first derivative reflectance at 741-696 nm (FDRE) was identified to be a good estimator of leaf N at jointing (R(2) = 0.90) and heading (R(2) = 0.86) stages across water treatments. Leaf N also had a stronger association with the red-edge position (REP) at both stages (R(2) = 0.83 and 0.78), or with the ratio R4 (R760/R550) at jointing (R(2) = 0.88), than with chlorophyll meter (SPAD) readings. Under water stress, the predictive accuracy of leaf N increased with these reflectance indices, but decreased using SPAD readings. The results indicate that specific reflectance indices of FDRE, REP and R4 may be used for a rapid and non-destructive estimation of oat plant N status over a range of water regimes. © 2014 Her Majesty the Queen in Right of Canada Journal of the Science of Food and Agriculture © 2014 Society of Chemical Industry.

Design of a telerobotic controller with joint torque sensors

NASA Technical Reports Server (NTRS)

Jansen, J. F.; Herndon, J. N.

1990-01-01

The purpose was to analytically show how to design a joint controller for a telerobotic system when joint torque sensors are available. Other sensors such as actuator position, actuator velocity, joint position, and joint velocity are assumed to be accessible; however, the results will also be useful when only partial measurements are available. The controller presented can be applied to either mode of operation of a manipulator (i.e., teleoperation or robotic). Mechanical manipulators with high levels of friction are assumed. The results are applied to a telerobotic system built for NASA. Very high levels of friction have been reduced using high-gain feedback while avoiding limit cycles.

Sensing our Environment: Remote sensing in a physics classroom

NASA Astrophysics Data System (ADS)

Isaacson, Sivan; Schüttler, Tobias; Cohen-Zada, Aviv L.; Blumberg, Dan G.; Girwidz, Raimund; Maman, Shimrit

2017-04-01

Remote sensing is defined as data acquisition of an object, deprived physical contact. Fundamentally, most remote sensing applications are referred to as the use of satellite- or aircraft-based sensor technologies to detect and classify objects mainly on Earth or other planets. In the last years there have been efforts to bring the important subject of remote sensing into schools, however, most of these attempts focused on geography disciplines - restricting to the applications of remote sensing and to a less extent the technique itself and the physics behind it. Optical remote sensing is based on physical principles and technical devices, which are very meaningful from a theoretical point of view as well as for "hands-on" teaching. Some main subjects are radiation, atom and molecular physics, spectroscopy, as well as optics and the semiconductor technology used in modern digital cameras. Thus two objectives were outlined for this project: 1) to investigate the possibilities of using remote sensing techniques in physics teaching, and 2) to identify its impact on pupil's interest in the field of natural sciences. This joint project of the DLR_School_Lab, Oberpfaffenhofen of the German Aerospace Center (DLR) and the Earth and Planetary Image Facility (EPIF) at BGU, was conducted in 2016. Thirty teenagers (ages 16-18) participated in the project and were exposed to the cutting edge methods of earth observation. The pupils on both sides participated in the project voluntarily, knowing that at least some of the project's work had to be done in their leisure time. The pupil's project started with a day at EPIF and DLR respectively, where the project task was explained to the participants and an introduction to remote sensing of vegetation was given. This was realized in lectures and in experimental workshops. During the following two months both groups took several measurements with modern optical remote sensing systems in their home region with a special focus on flora

A comparison of force sensing techniques for planetary manipulation

NASA Technical Reports Server (NTRS)

Helmick, Daniel; Okon, Avi; DiCicco, Matt

2006-01-01

Five techniques for sensing forces with a manipulator are compared analytically and experimentally. The techniques compared are: a six-axis wrist force/torque sensor, joint torque sensors, link strain gauges, motor current sensors, and flexibility modeling. The accuracy and repeatability fo each technique is quantified and compared.

Contraction Sensing with Smart Braid McKibben Muscles

PubMed Central

Felt, Wyatt; Chin, Khai Yi; Remy, C. David

2016-01-01

The inherent compliance of soft fluidic actuators makes them attractive for use in wearable devices and soft robotics. Their flexible nature permits them to be used without traditional rotational or prismatic joints. Without these joints, however, measuring the motion of the actuators is challenging. Actuator-level sensors could improve the performance of continuum robots and robots with compliant or multi-degree-of-freedom joints. We make the reinforcing braid of a pneumatic artificial muscle (PAM or McKibben muscle) “smart” by weaving it from conductive, insulated wires. These wires form a solenoid-like circuit with an inductance that more than doubles over the PAM contraction. The reinforcing and sensing fibers can be used to measure the contraction of a PAM actuator with a simple, linear function of the measured inductance. Whereas other proposed self-sensing techniques rely on the addition of special elastomers or transducers, the technique presented in this work can be implemented without modifications of this kind. We present and experimentally validate two models for Smart Braid sensors based on the long solenoid approximation and the Neumann formula, respectively. We test a McKibben muscle made from a Smart Braid in quasistatic conditions with various end-loads and in dynamic conditions. We also test the performance of the Smart Braid sensor alongside steel. PMID:28503062

Estimating anatomical wrist joint motion with a robotic exoskeleton.

PubMed

Rose, Chad G; Kann, Claudia K; Deshpande, Ashish D; O'Malley, Marcia K

2017-07-01

Robotic exoskeletons can provide the high intensity, long duration targeted therapeutic interventions required for regaining motor function lost as a result of neurological injury. Quantitative measurements by exoskeletons have been proposed as measures of rehabilitative outcomes. Exoskeletons, in contrast to end effector designs, have the potential to provide a direct mapping between human and robot joints. This mapping rests on the assumption that anatomical axes and robot axes are aligned well, and that movement within the exoskeleton is negligible. These assumptions hold well for simple one degree-of-freedom joints, but may not be valid for multi-articular joints with unique musculoskeletal properties such as the wrist. This paper presents an experiment comparing robot joint kinematic measurements from an exoskeleton to anatomical joint angles measured with a motion capture system. Joint-space position measurements and task-space smoothness metrics were compared between the two measurement modalities. The experimental results quantify the error between joint-level position measurements, and show that exoskeleton kinematic measurements preserve smoothness characteristics found in anatomical measures of wrist movements.

Sacroiliac joint tuberculosis

PubMed Central

Govender, S.

2006-01-01

Infections of the sacroiliac joint are uncommon and the diagnosis is usually delayed. In a retrospective study, 17 patients who had been treated for tuberculosis sacroiliitis between 1994 and 2004 were reviewed. Two patients were excluded due to a short follow-up (less than 2 years). Low back pain and difficulty in walking were the most common presenting features. Two patients presented with a buttock abscess and spondylitis of the lumbar spine was noted in two patients. The Gaenslen’s and FABER (flexion, abduction and external rotation) tests were positive in all patients. Radiological changes included loss of cortical margins with erosion of the joints. An open biopsy and curettage was performed in all patients; histology revealed chronic infection and acid-fast bacilli were isolated in nine patients. Antituberculous (TB) medication was administered for 18 months and the follow-up ranged from 3 to 10 years (mean: 5 years). The sacroiliac joint fused spontaneously within 2 years. Although all patients had mild discomfort in the lower back following treatment they had no difficulty in walking. Sacroiliac joint infection must be included in the differential diagnosis of lower back pain and meticulous history and clinical evaluation of the joint are essential. PMID:16673102

Three-dimensional motion of the uncovertebral joint during head rotation.

PubMed

Nagamoto, Yukitaka; Ishii, Takahiro; Iwasaki, Motoki; Sakaura, Hironobu; Moritomo, Hisao; Fujimori, Takahito; Kashii, Masafumi; Murase, Tsuyoshi; Yoshikawa, Hideki; Sugamoto, Kazuomi

2012-10-01

The uncovertebral joints are peculiar but clinically important anatomical structures of the cervical vertebrae. In the aged or degenerative cervical spine, osteophytes arising from an uncovertebral joint can cause cervical radiculopathy, often necessitating decompression surgery. Although these joints are believed to bear some relationship to head rotation, how the uncovertebral joints work during head rotation remains unclear. The purpose of this study is to elucidate 3D motion of the uncovertebral joints during head rotation. Study participants were 10 healthy volunteers who underwent 3D MRI of the cervical spine in 11 positions during head rotation: neutral (0°) and 15° increments to maximal head rotation on each side (left and right). Relative motions of the cervical spine were calculated by automatically superimposing a segmented 3D MR image of the vertebra in the neutral position over images of each position using the volume registration method. The 3D intervertebral motions of all 10 volunteers were standardized, and the 3D motion of uncovertebral joints was visualized on animations using data for the standardized motion. Inferred contact areas of uncovertebral joints were also calculated using a proximity mapping technique. The 3D animation of uncovertebral joints during head rotation showed that the joints alternate between contact and separation. Inferred contact areas of uncovertebral joints were situated directly lateral at the middle cervical spine and dorsolateral at the lower cervical spine. With increasing angle of rotation, inferred contact areas increased in the middle cervical spine, whereas areas in the lower cervical spine slightly decreased. In this study, the 3D motions of uncovertebral joints during head rotation were depicted precisely for the first time.

Registration of knee joint surfaces for the in vivo study of joint injuries based on magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Cheng, Rita W. T.; Habib, Ayman F.; Frayne, Richard; Ronsky, Janet L.

2006-03-01

In-vivo quantitative assessments of joint conditions and health status can help to increase understanding of the pathology of osteoarthritis, a degenerative joint disease that affects a large population each year. Magnetic resonance imaging (MRI) provides a non-invasive and accurate means to assess and monitor joint properties, and has become widely used for diagnosis and biomechanics studies. Quantitative analyses and comparisons of MR datasets require accurate alignment of anatomical structures, thus image registration becomes a necessary procedure for these applications. This research focuses on developing a registration technique for MR knee joint surfaces to allow quantitative study of joint injuries and health status. It introduces a novel idea of translating techniques originally developed for geographic data in the field of photogrammetry and remote sensing to register 3D MR data. The proposed algorithm works with surfaces that are represented by randomly distributed points with no requirement of known correspondences. The algorithm performs matching locally by identifying corresponding surface elements, and solves for the transformation parameters relating the surfaces by minimizing normal distances between them. This technique was used in three applications to: 1) register temporal MR data to verify the feasibility of the algorithm to help monitor diseases, 2) quantify patellar movement with respect to the femur based on the transformation parameters, and 3) quantify changes in contact area locations between the patellar and femoral cartilage at different knee flexion angles. The results indicate accurate registration and the proposed algorithm can be applied for in-vivo study of joint injuries with MRI.

Joint Source-Channel Coding by Means of an Oversampled Filter Bank Code

NASA Astrophysics Data System (ADS)

Marinkovic, Slavica; Guillemot, Christine

2006-12-01

Quantized frame expansions based on block transforms and oversampled filter banks (OFBs) have been considered recently as joint source-channel codes (JSCCs) for erasure and error-resilient signal transmission over noisy channels. In this paper, we consider a coding chain involving an OFB-based signal decomposition followed by scalar quantization and a variable-length code (VLC) or a fixed-length code (FLC). This paper first examines the problem of channel error localization and correction in quantized OFB signal expansions. The error localization problem is treated as an[InlineEquation not available: see fulltext.]-ary hypothesis testing problem. The likelihood values are derived from the joint pdf of the syndrome vectors under various hypotheses of impulse noise positions, and in a number of consecutive windows of the received samples. The error amplitudes are then estimated by solving the syndrome equations in the least-square sense. The message signal is reconstructed from the corrected received signal by a pseudoinverse receiver. We then improve the error localization procedure by introducing a per-symbol reliability information in the hypothesis testing procedure of the OFB syndrome decoder. The per-symbol reliability information is produced by the soft-input soft-output (SISO) VLC/FLC decoders. This leads to the design of an iterative algorithm for joint decoding of an FLC and an OFB code. The performance of the algorithms developed is evaluated in a wavelet-based image coding system.

Optimisation of sensing time and transmission time in cognitive radio-based smart grid networks

NASA Astrophysics Data System (ADS)

Yang, Chao; Fu, Yuli; Yang, Junjie

2016-07-01

Cognitive radio (CR)-based smart grid (SG) networks have been widely recognised as emerging communication paradigms in power grids. However, a sufficient spectrum resource and reliability are two major challenges for real-time applications in CR-based SG networks. In this article, we study the traffic data collection problem. Based on the two-stage power pricing model, the power price is associated with the efficient received traffic data in a metre data management system (MDMS). In order to minimise the system power price, a wideband hybrid access strategy is proposed and analysed, to share the spectrum between the SG nodes and CR networks. The sensing time and transmission time are jointly optimised, while both the interference to primary users and the spectrum opportunity loss of secondary users are considered. Two algorithms are proposed to solve the joint optimisation problem. Simulation results show that the proposed joint optimisation algorithms outperform the fixed parameters (sensing time and transmission time) algorithms, and the power cost is reduced efficiently.

FBG in PVC foils for monitoring the knee joint movement during the rehabilitation process.

PubMed

Rocha, R P; Silva, A F; Carmo, J P; Correia, J H

2011-01-01

This paper presents a sensing electronic-free wearable solution for monitoring the body kinematics. The measuring of the knee movements, flexion and extension, with the corresponding joint acting as the rotation axis is shown as working principle. The proposed sensing system is based on a single optical Fiber-Bragg Grating (FBG) with a resonance wavelength of 1547.76 nm. The optical fiber with the FBG is placed inside a new polymeric foil composed by three flexible layers which facilitates its placement in the anatomic parts under investigation while maintaining full sensing capabilities. The way the device is placed in the specific body part to be measured enables the clear detection of the movements in respect to the joint. The proposed solution was tested using a prototype that was built to evaluate the device under different condition tests and also to assess the system's consistency. The designed and fabricated system demonstrates clear advantages in medical fields like physical therapy applications as optical fiber is not affected by electromagnetic interference nor does the system needs complex and expensive electronic systems and mechanical parts. Another advantage is the possibility to measure, record and evaluate specific mechanical parameters of the limbs' motion. Patients with bone, muscular and joint related health conditions, as well as athletes, are within the most important end-user applications.

Can symptomatic acromioclavicular joints be differentiated from asymptomatic acromioclavicular joints on 3-T MR imaging?

PubMed

Choo, Hye Jung; Lee, Sun Joo; Kim, Jung Han; Cha, Seong Sook; Park, Young Mi; Park, Ji Sung; Lee, Jun Woo; Oh, Minkyung

2013-04-01

To evaluate retrospectively whether symptomatic acromioclavicular joints can be differentiated from asymptomatic acromioclavicular joints on 3-T MR imaging. This study included 146 patients who underwent physical examination of acromioclavicular joints and 3-T MR imaging of the shoulder. Among them, 67 patients showing positive results on physical examination were assigned to the symptomatic group, whereas 79 showing negative results were assigned to the asymptomatic group. The following MR findings were compared between the symptomatic and asymptomatic groups: presence of osteophytes, articular surface irregularity, subchondral cysts, acromioclavicular joint fluid, subacromial fluid, subacromial bony spurs, joint capsular distension, bone edema, intraarticular enhancement, periarticular enhancement, superior and inferior joint capsular distension degree, and joint capsular thickness. The patients were subsequently divided into groups based on age (younger, older) and the method of MR arthrography (direct MR arthrography, indirect MR arthrography), and all the MR findings in each subgroup were reanalyzed. The meaningful cutoff value of each significant continuous variable was calculated using receiver operating characteristic analysis. The degree of superior capsular distension was the only significant MR finding of symptomatic acromioclavicular joints and its meaningful cutoff value was 2.1mm. After subgroup analyses, this variable was significant in the older age group and indirect MR arthrography group. On 3-T MR imaging, the degree of superior joint capsular distension might be a predictable MR finding in the diagnosis of symptomatic acromioclavicular joints. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Geometric correction of synchronous scanned Operational Modular Imaging Spectrometer II hyperspectral remote sensing images using spatial positioning data of an inertial navigation system

NASA Astrophysics Data System (ADS)

Zhou, Xiaohu; Neubauer, Franz; Zhao, Dong; Xu, Shichao

2015-01-01

The high-precision geometric correction of airborne hyperspectral remote sensing image processing was a hard nut to crack, and conventional methods of remote sensing image processing by selecting ground control points to correct the images are not suitable in the correction process of airborne hyperspectral image. The optical scanning system of an inertial measurement unit combined with differential global positioning system (IMU/DGPS) is introduced to correct the synchronous scanned Operational Modular Imaging Spectrometer II (OMIS II) hyperspectral remote sensing images. Posture parameters, which were synchronized with the OMIS II, were first obtained from the IMU/DGPS. Second, coordinate conversion and flight attitude parameters' calculations were conducted. Third, according to the imaging principle of OMIS II, mathematical correction was applied and the corrected image pixels were resampled. Then, better image processing results were achieved.

Official Positions for FRAX® Bone Mineral Density and FRAX® simplification from Joint Official Positions Development Conference of the International Society for Clinical Densitometry and International Osteoporosis Foundation on FRAX®.

PubMed

Lewiecki, E Michael; Compston, Juliet E; Miller, Paul D; Adachi, Jonathan D; Adams, Judith E; Leslie, William D; Kanis, John A; Moayyeri, Alireza; Adler, Robert A; Hans, Didier B; Kendler, David L; Diez-Perez, Adolfo; Krieg, Marc-Antoine; Masri, Basel K; Lorenc, Roman R; Bauer, Douglas C; Blake, Glen M; Josse, Robert G; Clark, Patricia; Khan, Aliya A

2011-01-01

Tools to predict fracture risk are useful for selecting patients for pharmacological therapy in order to reduce fracture risk and redirect limited healthcare resources to those who are most likely to benefit. FRAX® is a World Health Organization fracture risk assessment algorithm for estimating the 10-year probability of hip fracture and major osteoporotic fracture. Effective application of FRAX® in clinical practice requires a thorough understanding of its limitations as well as its utility. For some patients, FRAX® may underestimate or overestimate fracture risk. In order to address some of the common issues encountered with the use of FRAX® for individual patients, the International Society for Clinical Densitometry (ISCD) and International Osteoporosis Foundation (IOF) assigned task forces to review the medical evidence and make recommendations for optimal use of FRAX® in clinical practice. Among the issues addressed were the use of bone mineral density (BMD) measurements at skeletal sites other than the femoral neck, the use of technologies other than dual-energy X-ray absorptiometry, the use of FRAX® without BMD input, the use of FRAX® to monitor treatment, and the addition of the rate of bone loss as a clinical risk factor for FRAX®. The evidence and recommendations were presented to a panel of experts at the Joint ISCD-IOF FRAX® Position Development Conference, resulting in the development of Joint ISCD-IOF Official Positions addressing FRAX®-related issues. Copyright © 2011 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

[Range of Hip Joint Motion and Weight of Lower Limb Function under 3D Dynamic Marker].

PubMed

Xia, Q; Zhang, M; Gao, D; Xia, W T

2017-12-01

To explore the range of reasonable weight coefficient of hip joint in lower limb function. When the hip joints of healthy volunteers under normal conditions or fixed at three different positions including functional, flexed and extension positions, the movements of lower limbs were recorded by LUKOtronic motion capture and analysis system. The degree of lower limb function loss was calculated using Fugl-Meyer lower limb function assessment form when the hip joints were fixed at the aforementioned positions. One-way analysis of variance and Tamhane's T2 method were used to proceed statistics analysis and calculate the range of reasonable weight coefficient of hip joint. There were significant differences between the degree of lower limb function loss when the hip joints fixed at flexed and extension positions and at functional position. While the differences between the degree of lower limb function loss when the hip joints fixed at flexed position and extension position had no statistical significance. In 95% confidence interval, the reasonable weight coefficient of hip joint in lower limb function was between 61.05% and 73.34%. Expect confirming the reasonable weight coefficient, the effects of functional and non-functional positions on the degree of lower limb function loss should also be considered for the assessment of hip joint function loss. Copyright© by the Editorial Department of Journal of Forensic Medicine

Why is joint attention a pivotal skill in autism?

PubMed Central

Charman, Tony

2003-01-01

Joint attention abilities play a crucial role in the development of autism. Impairments in joint attention are among the earliest signs of the disorder and joint attention skills relate to outcome, both in the 'natural course' of autism and through being targeted in early intervention programmes. In the current study, concurrent and longitudinal associations between joint attention and other social communication abilities measured in a sample of infants with autism and related pervasive developmental disorders at age 20 months, and language and symptom severity at age 42 months, were examined. Extending the findings from previous studies, joint attention ability was positively associated with language gains and (lower) social and communication symptoms, and imitation ability was also positively associated with later language. Some specificity in the association between different aspects of joint attention behaviours and outcome was found: declarative, triadic gaze switching predicted language and symptom severity but imperative, dyadic eye contact behaviours did not. Further, although joint attention was associated with later social and language symptoms it was unrelated to repetitive and stereotyped symptoms, suggesting the latter may have a separate developmental trajectory. Possible deficits in psychological and neurological processes that might underlie the impaired development of joint attention in autism are discussed. PMID:12639329

Does hip joint positioning affect maximal voluntary contraction in the gluteus maximus, gluteus medius, tensor fasciae latae and sartorius muscles?

PubMed

Bernard, J; Beldame, J; Van Driessche, S; Brunel, H; Poirier, T; Guiffault, P; Matsoukis, J; Billuart, F

2017-11-01

Minimally invasive total hip arthroplasty (THA) is presumed to provide functional and clinical benefits, whereas in fact the literature reveals that gait and posturographic parameters following THA do not recover values found in the general population. There is a significant disturbance of postural sway in THA patients, regardless of the surgical approach, although with some differences between approaches compared to controls: the anterior and anterolateral minimally invasive approaches seem to be more disruptive of postural parameters than the posterior approach. Electromyographic (EMG) study of the hip muscles involved in surgery [gluteus maximus (GMax), gluteus medius (GMed), tensor fasciae latae (TFL), and sartorius (S)] could shed light, the relevant literature involves discordant methodologies. We developed a methodology to assess EMG activity during maximal voluntary contraction (MVC) of the GMax, GMed, TFL and sartorius muscles as a reference for normalization. A prospective study aimed to assess whether hip joint positioning and the learning curve on an MVC test affect the EMG signal during a maximal voluntary contraction. Hip positioning and the learning curve on an MVC test affect EMG signal during MVC of GMax, GMed, TFL and S. Thirty young asymptomatic subjects participated in the study. Each performed 8 hip muscle MVCs in various joint positions recorded with surface EMG sensors. Each MVC was performed 3 times in 1 week, with the same schedule every day, controlling for activity levels in the preceding 24h. EMG activity during MVC was expressed as a ratio of EMG activity during unipedal stance. Non-parametric tests were applied. Statistical analysis showed no difference according to hip position for abductors or flexors in assessing EMG signal during MVC over the 3 sessions. Hip abductors showed no difference between abduction in lateral decubitus with hip straight versus hip flexed: GMax (19.8±13.7 vs. 14.5±7.8, P=0.78), GMed (13.4±9.0 vs. 9.9±6

Lower limb joint kinetics and ankle joint stiffness in the sprint start push-off.

PubMed

Charalambous, Laura; Irwin, Gareth; Bezodis, Ian N; Kerwin, David

2012-01-01

Sprint push-off technique is fundamental to sprint performance and joint stiffness has been identified as a performance-related variable during dynamic movements. However, joint stiffness for the push-off and its relationship with performance (times and velocities) has not been reported. The aim of this study was to quantify and explain lower limb net joint moments and mechanical powers, and ankle stiffness during the first stance phase of the push-off. One elite sprinter performed 10 maximal sprint starts. An automatic motion analysis system (CODA, 200 Hz) with synchronized force plates (Kistler, 1000 Hz) collected kinematic profiles at the hip, knee, and ankle and ground reaction forces, providing input for inverse dynamics analyses. The lower-limb joints predominately extended and revealed a proximal-to-distal sequential pattern of maximal extensor angular velocity and positive power production. Pearson correlations revealed relationships (P < 0.05) between ankle stiffness (5.93 ± 0.75 N x m x deg(-1)) and selected performance variables. Relationships between negative power phase ankle stiffness and horizontal (r = -0.79) and vertical (r = 0.74) centre of mass velocities were opposite in direction to the positive power phase ankle stiffness (horizontal: r = 0.85; vertical: r = -0.54). Thus ankle stiffness may affect the goals of the sprint push-off in different ways, depending on the phase of stance considered.

Metatarsophalangeal joint extension changes ultrasound measurements for plantar fascia thickness.

PubMed

Granado, Michael J; Lohman, Everett B; Gordon, Keith E; Daher, Noha S

2018-01-01

Ultrasound is an inexpensive method for quantifying plantar fascia thickness, especially in those with plantar fasciitis. Ultrasound has also been used to assess the effectiveness of various treatments for plantar fasciitis by comparing plantar fascia thickness before and after an intervention period. While a plantar fascia thickness over 4 mm via ultrasound has been proposed to be consistent with plantar fasciitis, some researchers believe the 4 mm plantar fascia thickness level to be a dubious guideline for diagnosing plantar fasciitis due to the lack of standardization of the measurement process for plantar fascia thickness. In particular, no universal guidelines exist on the positioning of the metatarsophalangeal (MTP) joints during the procedure and the literature also has inconsistent protocols. The purpose of this study is to investigate and compare the influence of MTP joint extension on plantar fascia thickness in healthy participants and those with unilateral plantar fasciitis. The plantar fascia thickness of forty participants (20 with unilateral plantar fasciitis and 20 control) was measured via ultrasound three times at three different MTP joint positions: 1) at rest, 2) 30° of extension from the plantar surface, and 3) maximal extension possible. The plantar fascia became significantly thinner as MTP joint extension increased in both the plantar fasciitis group ( p  < 0.001) and the control group ( p  < 0.001). In the plantar fasciitis group, the involved plantar fascia was 1.2 to 1.3 mm thicker (p < 0.001) than the uninvolved side depending on the MTP joint position. In the control group, the difference in plantar fascia thickness between the two sides was less than 0.1 mm ( p  < 0.92) at any MTP joint position. MTP joint position can influence the ultrasound measurement of plantar fascia thickness. It is recommended that plantar fascia thickness measurements be performed with the toes at rest. If MTP joints must be extended

[Joint contractures in nursing textbooks].

PubMed

Bartoszek, G; Meyer, G; Thiesemann, R

2014-01-01

The transparency criteria of the German statutory health insurance on joint contracture prevention have led to controversies about the appropriate assessment, prevention and treatment as well as to various actions in nursing practice. However, appropriate nursing assessments and proven treatment options are lacking so far. It is unclear whether textbooks on nursing reflect these uncertainties. Search for textbooks on nursing through internet-based search engines and publisher registers, data extraction by one investigator and control by a second. A total of 35 textbooks with contributions on joint contractures were identified of which 25 included a definition, causes/risk factors are presented in 32 textbooks and assessments are presented in 5 books. Most often positioning into a physiological or functional neutral position and passive moving of limbs are recommended as passive prophylaxis. Recommended therapeutic and preventive options do not differ. None of the textbooks reflect that there is a lack of scientific knowledge on the subject. Textbooks on nursing do not deal with complete and scientific sound information on joint contractures.

A Distributed Compressive Sensing Scheme for Event Capture in Wireless Visual Sensor Networks

NASA Astrophysics Data System (ADS)

Hou, Meng; Xu, Sen; Wu, Weiling; Lin, Fei

2018-01-01

Image signals which acquired by wireless visual sensor network can be used for specific event capture. This event capture is realized by image processing at the sink node. A distributed compressive sensing scheme is used for the transmission of these image signals from the camera nodes to the sink node. A measurement and joint reconstruction algorithm for these image signals are proposed in this paper. Make advantage of spatial correlation between images within a sensing area, the cluster head node which as the image decoder can accurately co-reconstruct these image signals. The subjective visual quality and the reconstruction error rate are used for the evaluation of reconstructed image quality. Simulation results show that the joint reconstruction algorithm achieves higher image quality at the same image compressive rate than the independent reconstruction algorithm.

MR imaging of the metacarpophalangeal joints of the fingers: evaluation of 38 patients with chronic joint disability.

PubMed

Theumann, Nicolas H; Pessis, Eric; Lecompte, Martin; Le Viet, Dominique; Valenti, Philippe; Chevrot, Alain; Bittoun, Jacques; Schnyder, Pierre; Resnick, Donald; Drapé, Jean-Luc

2005-04-01

To report the MR imaging findings of painful injured metacarpophalangeal (MCP) joints of the fingers. MR imaging of 39 injured MCP joints in 38 patients was performed after a mean delay of 8.8 months. The MR images were obtained with the fingers in extended and flexed positions using T2-weighted and T1-weighted sequences before and after intravenous injection of a gadolinium compound. Ten patients were treated surgically. Mean clinical follow-up was 1.8 years. Tears of the collateral ligaments were the most common lesion (30/39), most being radial in location. Contrast-enhanced axial T1-weighted images with the MCP joint in a flexed position showed these lesions optimally. Ten tears were partial and 20 were complete. In 13 patients, MR images showed 17 associated lesions including injuries of the extensor hood (10/17), interosseous tendon (3/17), palmar plate (3/17), and an osteochondral lesion (1/17). Sagittal MR images were essential to highlight palmar plate tears. Partial or complete tears of the collateral ligaments are prevalent MR imaging findings in patients with chronic disability resulting from injuries to the MCP joints. Although conservative treatment generally is sufficient for isolated injuries of the collateral ligaments, surgical repair is often required in cases of more extensive injuries. MR imaging may clearly delineate associated lesions of and about the MCP joints.

Micro-position sensor using faraday effect

DOEpatents

McElfresh, Michael [Livermore, CA; Lucas, Matthew [Pittsburgh, PA; Silveira, Joseph P [Tracy, CA; Groves, Scott E [Brentwood, CA

2007-02-27

A micro-position sensor and sensing system using the Faraday Effect. The sensor uses a permanent magnet to provide a magnetic field, and a magneto-optic material positioned in the magnetic field for rotating the plane of polarization of polarized light transmitted through the magneto-optic material. The magnet is independently movable relative to the magneto-optic material so as to rotate the plane of polarization of the polarized light as a function of the relative position of the magnet. In this manner, the position of the magnet relative to the magneto-optic material may be determined from the rotated polarized light. The sensing system also includes a light source, such as a laser or LED, for producing polarized light, and an optical fiber which is connected to the light source and to the magneto-optic material at a sensing end of the optical fiber. Processing electronics, such as a polarimeter, are also provided for determining the Faraday rotation of the plane of polarization of the back-reflected polarized light to determine the position of the magnet relative to the sensing end of the optical fiber.

Shear joint capability versus bolt clearance

NASA Technical Reports Server (NTRS)

Lee, H. M.

1992-01-01

The results of a conservative analysis approach into the determination of shear joint strength capability for typical space-flight hardware as a function of the bolt-hole clearance specified in the design are presented. These joints are comprised of high-strength steel fasteners and abutments constructed of aluminum alloys familiar to the aerospace industry. A general analytical expression was first arrived at which relates bolt-hole clearance to the bolt shear load required to place all joint fasteners into a shear transferring position. Extension of this work allowed the analytical development of joint load capability as a function of the number of fasteners, shear strength of the bolt, bolt-hole clearance, and the desired factor of safety. Analysis results clearly indicate that a typical space-flight hardware joint can withstand significant loading when less than ideal bolt hole clearances are used in the design.

The Joint Agency Commercial Imagery Evaluation (JACIE) Team: Overview and IKONOS Joint Characterization Approach

NASA Technical Reports Server (NTRS)

Zanoni, Vicki; Ryan, Robert; Pagnutti, Mary; Baldridge, Braxton; Roylance, Spencer; Snyder, Greg; Lee, George; Stanley, Tom

2002-01-01

An overview of the Joint Agency Commercial Imagery Evalation (JACIE) team is presented. JACIE, composed of the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA), and the U.S. Geological Survey (USGS), was formed to leverage government agencies' capabilities for the characterization of commercial remote sensing data. Each JACIE agency purchases, or plans to purchase, commercial imagery to support its research and applications. It is critical that the data be assessed for its accuracy and utility. Through JACIE, NASA, NIMA, and USGS jointly characterized image products from Space Imaging's IKONOS satellite. Each JACIE agency performed an aspect of the characterization based on its expertise. NASA and its university partners performed a system characterization focusing on radiometric calibration, geopositional accuracy, and spatial resolution assessment; NIMA performed image interpretability and feature extraction evaluations; and USGS assessed geopositional accuracy of several IKONOS products. The JACIE team purchased IKONOS imagery of several study sites to perform the assessments and presented results at an industry-government workshop. Future plans for JACIE include the characterization of DigitalGlobe's QuickBird-2 image products.

Merlin: an integrated path differential absorption (IPDA) lidar for global methane remote sensing

NASA Astrophysics Data System (ADS)

Bode, M.; Alpers, M.; Millet, B.; Ehret, G.; Flamant, P.

2017-11-01

The Methane Remote Sensing LIDAR Mission (MERLIN) is a joint French-German cooperation on the development, launch and operation of a climate monitoring satellite, executed by the French Space Agency CNES and the German Space Administration DLR.

Merlin: an integrated path differential absorption (IPDA) lidar for global methane remote sensing

NASA Astrophysics Data System (ADS)

Bode, M.; Wührer, C.; Alpers, M.; Millet, B.; Ehret, G.; Bousquet, P.

2017-09-01

The Methane Remote Sensing LIDAR Mission (MERLIN) is a joint French-German cooperation on the development, launch and operation of a climate monitoring satellite, executed by the French Space Agency CNES and the German Space Administration DLR.

Micro environmental sensing device

DOEpatents

Polosky, Marc A.; Lukens, Laurance L.

2006-05-02

A microelectromechanical (MEM) acceleration switch is disclosed which includes a proof mass flexibly connected to a substrate, with the proof mass being moveable in a direction substantially perpendicular to the substrate in response to a sensed acceleration. An electrode on the proof mass contacts one or more electrodes located below the proof mass to provide a switch closure in response to the sensed acceleration. Electrical latching of the switch in the closed position is possible with an optional latching electrode. The MEM acceleration switch, which has applications for use as an environmental sensing device, can be fabricated using micromachining.

Ribonuclease from Bacillus Acts as an Antiviral Agent against Negative- and Positive-Sense Single Stranded Human Respiratory RNA Viruses

PubMed Central

Müller, Christin; Romanova, Yulia; Mostafa, Ahmed; Ulyanova, Vera; Pleschka, Stephan; Ilinskaya, Olga

2017-01-01

Bacillus pumilus ribonuclease (binase) was shown to be a promising antiviral agent in animal models and cell cultures. However, the mode of its antiviral action remains unknown. To assess the binase effect on intracellular viral RNA we have selected single stranded negative- and positive-sense RNA viruses, influenza virus, and rhinovirus, respectively, which annually cause respiratory illnesses and are characterized by high contagious nature, mutation rate, and antigen variability. We have shown that binase exerts an antiviral effect on both viruses at the same concentration, which does not alter the spectrum of A549 cellular proteins and expression of housekeeping genes. The titers of influenza A (H1N1pdm) virus and human rhinovirus serotype 1A were reduced by 40% and 65%, respectively. A preincubation of influenza virus with binase before infection significantly reduced viral titer after single-cycle replication of the virus. Using influenza A virus mini genome system we showed that binase reduced GFP reporter signaling indicating a binase action on the expression of viral mRNA. Binase reduced the level of H1N1pdm viral NP mRNA accumulation in A549 cells by 20%. Since the viral mRNA is a possible target for binase this agent could be potentially applied in the antiviral therapy against both negative- and positive-sense RNA viruses. PMID:28546965

Global Positioning System Antenna Fixed Height Tripod Adapter

NASA Technical Reports Server (NTRS)

Dinardo, Steven J.; Smith, Mark A.

1997-01-01

An improved Global Positioning em antenna adaptor allows fixed antenna height measurements by removably attaching an adaptor plate to a conventional surveyor's tripod. Antenna height is controlled by an antenna boom which is a fixed length rod. The antenna is attached to one end of the boom. The opposite end of the boom tapers to a point sized to fit into a depression at the center of survey markers. The boom passes through the hollow center of a universal ball joint which is mounted at the center of the adaptor plate so that the point of the rod can be fixed in the marker's central depression. The mountains of the ball joint allow the joint to be moved horizontally in any direction relative to the tripod. When the ball joint is moved horizontally, the angle between the boom and the vertical changes because the boom's position is fixed at its lower end. A spirit level attached to the rod allows an operator to determine when the boom is plumb. The position of the ball joint is adjusted horizontally until the boom is plumb. At that time the antenna is positioned exactly over the center of the monument and the elevation of the antenna is precisely set by the length of the boom.

Effect of patient positions on measurement errors of the knee-joint space on radiographs

NASA Astrophysics Data System (ADS)

Gilewska, Grazyna

2001-08-01

Osteoarthritis (OA) is one of the most important health problems these days. It is one of the most frequent causes of pain and disability of middle-aged and old people. Nowadays the radiograph is the most economic and available tool to evaluate changes in OA. Error of performance of radiographs of knee joint is the basic problem of their evaluation for clinical research. The purpose of evaluation of such radiographs in my study was measuring the knee-joint space on several radiographs performed at defined intervals. Attempt at evaluating errors caused by a radiologist of a patient was presented in this study. These errors resulted mainly from either incorrect conditions of performance or from a patient's fault. Once we have information about size of the errors, we will be able to assess which of these elements have the greatest influence on accuracy and repeatability of measurements of knee-joint space. And consequently we will be able to minimize their sources.

In Vivo Measurement of Glenohumeral Joint Contact Patterns

NASA Astrophysics Data System (ADS)

Bey, Michael J.; Kline, Stephanie K.; Zauel, Roger; Kolowich, Patricia A.; Lock, Terrence R.

2009-12-01

The objectives of this study were to describe a technique for measuring in-vivo glenohumeral joint contact patterns during dynamic activities and to demonstrate application of this technique. The experimental technique calculated joint contact patterns by combining CT-based 3D bone models with joint motion data that were accurately measured from biplane x-ray images. Joint contact patterns were calculated for the repaired and contralateral shoulders of 20 patients who had undergone rotator cuff repair. Significant differences in joint contact patterns were detected due to abduction angle and shoulder condition (i.e., repaired versus contralateral). Abduction angle had a significant effect on the superior/inferior contact center position, with the average joint contact center of the repaired shoulder 12.1% higher on the glenoid than the contralateral shoulder. This technique provides clinically relevant information by calculating in-vivo joint contact patterns during dynamic conditions and overcomes many limitations associated with conventional techniques for quantifying joint mechanics.

Correlation between MRI evidence of degenerative condylar surface changes, induction of articular disc displacement and pathological joint sounds in the temporomandibular joint.

PubMed

Honda, Kosuke; Natsumi, Yoshiko; Urade, Masahiro

2008-12-01

The relationship of bony changes in the condylar surfaces in articular disc displacement without reduction in temporomandibular joint (TMJ) was investigated using diagnostic imaging. The study also evaluated whether the bony changes in the condylar surfaces limit disc and condyle motion, and produce pathological joint sounds. Thirty-seven joints in 28 patients diagnosed with degenerative bony changes in the condylar surfaces radiographically and anterior disc displacement without reduction using magnetic resonance imaging (MRI) were studied. The bony changes were assessed by radiographic examination and classified into two types: pathological bone changes (PBCs) including erosion, osteophyte formation and deformity, and adaptive bone changes (ABCs) including flattening and concavity. MRI was performed on the TMJ to examine the configuration and position of the discs. Joint sounds in the TMJ were determined using electrovibratograghy with a joint vibration analysis. The articular disc motion to the condyle in the PBC group was smaller than in the ABC group irrespective of the configuration of the disc, even though there were no significant differences between the two types of bony changes in the disc position during jaw closing. The joint vibration analysis of the TMJ showed that joint sounds with a higher frequency were observed in the PBC group than in the ABC group. High energy levels needed to produce the higher frequencies (over 300 Hz) were observed only in the PBC group.

Early Osteoarthritis of the Trapeziometacarpal Joint Is Not Associated With Joint Instability during Typical Isometric Loading

PubMed Central

Halilaj, Eni; Moore, Douglas C.; Patel, Tarpit K.; Ladd, Amy L.; Weiss, Arnold-Peter C.; Crisco, Joseph J.

2015-01-01

The saddle-shaped trapeziometacarpal (TMC) joint contributes importantly to the function of the human thumb. A balance between mobility and stability is essential in this joint, which experiences high loads and is prone to osteoarthritis (OA). Since instability is considered a risk factor for TMC OA, we assessed TMC joint instability during the execution of three isometric functional tasks (key pinch, jar grasp, and jar twist) in 76 patients with early TMC OA and 44 asymptomatic controls. Computed tomography images were acquired while subjects held their hands relaxed and while they applied 80% of their maximum effort for each task. Six degree-of-freedom rigid body kinematics of the metacarpal with respect to the trapezium from the unloaded to the loaded task positions were computed in terms of a TMC joint coordinate system. Joint instability was expressed as a function of the metacarpal translation and the applied force. We found that the TMC joint was more unstable during a key pinch task than during a jar grasp or a jar twist task. Sex, age, and early OA did not have an effect on TMC joint instability, suggesting that instability during these three tasks is not a predisposing factor in TMC OA. PMID:25941135

The contribution of quasi-joint stiffness of the ankle joint to gait in patients with hemiparesis.

PubMed

Sekiguchi, Yusuke; Muraki, Takayuki; Kuramatsu, Yuko; Furusawa, Yoshihito; Izumi, Shin-Ichi

2012-06-01

The role of ankle joint stiffness during gait in patients with hemiparesis has not been clarified. The purpose of this study was to determine the contribution of quasi-joint stiffness of the ankle joint to spatiotemporal and kinetic parameters regarding gait in patients with hemiparesis due to brain tumor or stroke and healthy individuals. Spatiotemporal and kinetic parameters regarding gait in twelve patients with hemiparesis due to brain tumor or stroke and nine healthy individuals were measured with a 3-dimensional motion analysis system. Quasi-joint stiffness was calculated from the slope of the linear regression of the moment-angle curve of the ankle joint during the second rocker. There was no significant difference in quasi-joint stiffness among both sides of patients and the right side of controls. Quasi-joint stiffness on the paretic side of patients with hemiparesis positively correlated with maximal ankle power (r=0.73, P<0.01) and gait speed (r=0.66, P<0.05). In contrast, quasi-joint stiffness in controls negatively correlated with maximal ankle power (r=-0.73, P<0.05) and gait speed (r=-0.76, P<0.05). Our findings suggested that ankle power during gait might be generated by increasing quasi-joint stiffness in patients with hemiparesis. In contrast, healthy individuals might decrease quasi-joint stiffness to avoid deceleration of forward tilt of the tibia. Our findings might be useful for selecting treatment for increased ankle stiffness due to contracture and spasticity in patients with hemiparesis. Copyright © 2011 Elsevier Ltd. All rights reserved.

Messing with Bacterial Quorum Sensing

PubMed Central

González, Juan E.; Keshavan, Neela D.

2006-01-01

Quorum sensing is widely recognized as an efficient mechanism to regulate expression of specific genes responsible for communal behavior in bacteria. Several bacterial phenotypes essential for the successful establishment of symbiotic, pathogenic, or commensal relationships with eukaryotic hosts, including motility, exopolysaccharide production, biofilm formation, and toxin production, are often regulated by quorum sensing. Interestingly, eukaryotes produce quorum-sensing-interfering (QSI) compounds that have a positive or negative influence on the bacterial signaling network. This eukaryotic interference could result in further fine-tuning of bacterial quorum sensing. Furthermore, recent work involving the synthesis of structural homologs to the various quorum-sensing signal molecules has resulted in the development of additional QSI compounds that could be used to control pathogenic bacteria. The creation of transgenic plants that express bacterial quorum-sensing genes is yet another strategy to interfere with bacterial behavior. Further investigation on the manipulation of quorum-sensing systems could provide us with powerful tools against harmful bacteria. PMID:17158701

Joint Duty Prerequisite for Promotion to 07 (Brigadier General

DTIC Science & Technology

1989-03-13

NUMBER)(O LTC Julius E. Coats, Jr. 9. PERFORMING ORGANIZATIN NAME AND ADDRESS I0. PROGRAM ELEMENT. PROJECT. tASK U.S. Army War College AREA 4 WORK...new personnel policy; to wit, the Army leadership at all levels should view joint duty re- quirement for selection for flag officer with a positive...the Army leadership at all levels should view joint duty requirement for selection for flag officer with a positive attitude, not as a means for

Fluoroscopy-Guided Sacroiliac Joint Injection: Description of a Modified Technique.

PubMed

Kasliwal, Prasad Jaychand; Kasliwal, Sapana

2016-02-01

Sacroiliac joint (SIJ) pathology is a common etiologic cause for 10 - 27% of cases of mechanical low back pain (LBP) below the L5 level. In the absence of definite clinical or radiologic diagnostic criteria, controlled blocks of the SIJ have become the choice assessment method for making the diagnosis of SIJ pain. The SI joint is most often characterized as a large, auricular-shaped, diarthrodial synovial joint. In reality, its synovial characteristic is limited only to the distal third and anterior third. In SIJ interventions, the lateral view has been underutilized. In our technique, we used the lateral view to create a three-dimensional view of the SIJ to aid in gauging the accurateness of the contrast spread and to obtain a precise block. After obtaining appropriate fluoroscopic images, a curved tip spinal needle was directed into the inferior aspect of the SIJ using a posterior approach. As the needle contacts firm tissues on the posterior aspect of the joint, position of the needle tip is checked using lateral fluoroscopy. In the lateral view, the needle tip position is manipulated to keep it in the anterior third of the SIJ and contrast is injected. Our criteria for accurate SIJ block, in posteroanterior (PA) view, is the injection of the contrast medium should outline the joint space and the contrast medium should be seen to travel cephalad along the joint line. In the lateral view, the contrast medium most densely outlines the parameter of the joint. We have utilized this method with good effect in approximately 30 cases over one year. Out of 30 cases, needle position and contrast spread was satisfactory in 28 and 27 cases, respectively. So satisfactory needle placement and contrast spread was in 93% and 87% cases. Pain relief of 80% or more after intra-articular injection of local anesthetic was seen in 50% (15 of 30) patients; pain relief of 50 - 79% was witnessed in 30% (9 of 30) patients. Thus, pain decreased 50% or more in 80% (24 of 30) of the joints

Sensing position and speed by recording magnetization transitions on mechanically functional machine members (abstract)

NASA Astrophysics Data System (ADS)

Garshelis, I. J.

1997-04-01

Conventional means of sensing position and speed of moving machine members for control purposes typically requires the use of supplementary, ad hoc devices. Many mechanically functional moving machine members are fabricated from ferromagnetic steels and may, thus, provide an opportunity to themselves carry positionally relevant information in the form of local regions of deliberately instilled remanent magnetization, Mr. To avoid ambiguities associated with the imprecise borders of such regions as well as their possibly preexisting presence, information is more reliably carried in the form of local transitions in the polarity of Mr from a quiescent bias. The presence and physical location of such transitions relative to reference features either on the member itself or on other members undergoing correlated motion constitutes stored information. The presence of a transition is signaled by the transitory appearance of the external field associated with ∇ṡMr as the transition containing region passes by a magnetic-field detecting device fixed to the machine frame. Implanting and removing transitions from parts while in motion is readily accomplished by pulsed currents and biasing magnets. While the whole process of storing, reading, and erasing bits of information in magnetic form follows the concepts and principles of conventional magnetic recording, profoundly different quantitative factors, conditions, and performance requirements affect the implementation of the described sensing system. In particular, the coercivity, Hc, of commonly used steels is 3-30 Oe versus 300-1200 Oe in recording media and both the thickness of the media and the air gaps separating the media surface from the heads used in conventional systems are each 2-3 orders of magnitude smaller than their counterparts in the described system, where speed may also be variable down to zero. While the combined effect of these factors is to greatly diminish the attainable density of recorded

Evaluation of effects of different treatments for the wrist joints of subdominant hands using joint proprioception and writing time.

PubMed

Hu, Chunying; Huang, Qiuchen; Yu, Lili; Hu, Yue; Rongming, Xia; Li, Zhou; Xiaojiao, Fu; Gu, Rui; Cui, Yao; Ge, Meng; Xu, Yanfeng; Liu, Jianfeng

2016-05-01

[Purpose] The purpose of this study was to examine immediate effects of strength training and NJF distal resistance training in wrist joints by using writing time and evaluation of proprioception using the JPE test. [Subjects and Methods] The subjects were 12 young healthy people (24.2 ± 3.1 y, 169.7 ± 6.5 cm, 65.3 ± 12.6 kg). Two isotonic contraction techniques were applied on the wrist joint: wrist joint extension muscle strength training (MST) and the wrist joint extension pattern of NJF. The uppercase English alphabet writing time and joint position errors of the left upper limb were measured before and after one intervention session of MST and NJF. [Results] The decrease in errors in wrist extension angle repetition and the writing time represented the improvement resulting from NJF. [Conclusion] This result suggests that the subdominant hands wrist joint proprioception and writing function can be improved by NJF together with proximal resistance training.

Positioning bedridden patients to reduce interface pressures over the sacrum and great trochanter.

PubMed

Yoshikawa, Y; Maeshige, N; Sugimoto, M; Uemura, M; Noguchi, M; Terashi, H

2015-07-01

In this study, we evaluated the effect of hip-joint rotation on the interface pressure over the sacrum and greater trochanter with a new protocol for positioning of bedridden elderly patients. The interface pressure values over the sacrum and greater trochanter in bedridden patients were evaluated. These were collected in the supine position, 90° lateral position, and 30° and 40° laterally inclined positions with external rotation or neutral positioning of the hip joint. Each interface pressure was assessed with a device measuring pressure distribution, after which, the peak pressure index (PPI) was calculated. In the 17 patients examined, the PPI over the sacrum in the supine position was significantly greater than that in other positions. In the 30° and 40° laterally inclined positions, the PPIs over the greater trochanter were significantly lower in the neutral position of the hip joint compared with those in the external rotation position. Our findings revealed the effects of hip-joint rotation on the interface pressure for the greater trochanter, possibly due to the increased distance between the greater trochanter and the sacrum caused by neutral position of the hip joint. The results demonstrate that it is to best place the hip joint in a neutral position when the legs are in contact with the bed in order to distribute the pressure over the greater trochanter in the 30° and 40° laterally inclined positions. These results can be applied to the clinical setting to improve patient positioning and decrease pressure ulcers. The authors declare that they have no competing financial interests.

Remote Sensing of Ionosphere by IONOLAB Group

NASA Astrophysics Data System (ADS)

Arikan, Feza

2016-07-01

Ionosphere is a temporally and spatially varying, dispersive, anisotropic and inhomogeneous medium that is characterized primarily by its electron density distribution. Electron density is a complex function of spatial and temporal variations of solar, geomagnetic, and seismic activities. Ionosphere is the main source of error for navigation and positioning systems and satellite communication. Therefore, characterization and constant monitoring of variability of the ionosphere is of utmost importance for the performance improvement of these systems. Since ionospheric electron density is not a directly measurable quantity, an important derivable parameter is the Total Electron Content (TEC), which is used widely to characterize the ionosphere. TEC is proportional to the total number of electrons on a line crossing the atmosphere. IONOLAB is a research group is formed by Hacettepe University, Bilkent University and Kastamonu University, Turkey gathered to handle the challenges of the ionosphere using state-of-the-art remote sensing and signal processing techniques. IONOLAB group provides unique space weather services of IONOLAB-TEC, International Reference Ionosphere extended to Plasmasphere (IRI-Plas) model based IRI-Plas-MAP, IRI-Plas-STEC and Online IRI-Plas-2015 model at www.ionolab.org. IONOLAB group has been working for imaging and monitoring of ionospheric structure for the last 15 years. TEC is estimated from dual frequency GPS receivers as IONOLAB-TEC using IONOLAB-BIAS. For high spatio-temporal resolution 2-D imaging or mapping, IONOLAB-MAP algorithm is developed that uses automated Universal Kriging or Ordinary Kriging in which the experimental semivariogram is fitted to Matern Function with Particle Swarm Optimization (PSO). For 3-D imaging of ionosphere and 1-D vertical profiles of electron density, state-of-the-art IRI-Plas model based IONOLAB-CIT algorithm is developed for regional reconstruction that employs Kalman Filters for state

Searching for roots of entrainment and joint action in early musical interactions.

PubMed

Phillips-Silver, Jessica; Keller, Peter E

2012-01-01

When people play music and dance together, they engage in forms of musical joint action that are often characterized by a shared sense of rhythmic timing and affective state (i.e., temporal and affective entrainment). In order to understand the origins of musical joint action, we propose a model in which entrainment is linked to dual mechanisms (motor resonance and action simulation), which in turn support musical behavior (imitation and complementary joint action). To illustrate this model, we consider two generic forms of joint musical behavior: chorusing and turn-taking. We explore how these common behaviors can be founded on entrainment capacities established early in human development, specifically during musical interactions between infants and their caregivers. If the roots of entrainment are found in early musical interactions which are practiced from childhood into adulthood, then we propose that the rehearsal of advanced musical ensemble skills can be considered to be a refined, mimetic form of temporal and affective entrainment whose evolution begins in infancy.

Searching for Roots of Entrainment and Joint Action in Early Musical Interactions

PubMed Central

Phillips-Silver, Jessica; Keller, Peter E.

2012-01-01

When people play music and dance together, they engage in forms of musical joint action that are often characterized by a shared sense of rhythmic timing and affective state (i.e., temporal and affective entrainment). In order to understand the origins of musical joint action, we propose a model in which entrainment is linked to dual mechanisms (motor resonance and action simulation), which in turn support musical behavior (imitation and complementary joint action). To illustrate this model, we consider two generic forms of joint musical behavior: chorusing and turn-taking. We explore how these common behaviors can be founded on entrainment capacities established early in human development, specifically during musical interactions between infants and their caregivers. If the roots of entrainment are found in early musical interactions which are practiced from childhood into adulthood, then we propose that the rehearsal of advanced musical ensemble skills can be considered to be a refined, mimetic form of temporal and affective entrainment whose evolution begins in infancy. PMID:22375113

Joint for deployable structures

NASA Technical Reports Server (NTRS)

Craighead, N. D., II; Preliasco, R. J.; Hult, T. D. (Inventor)

1985-01-01

A joint is described for connecting a pair of beams to pivot them between positions in alignment or beside one another, which is of light weight and which operates in a controlled manner. The joint includes a pair of fittings and at least one center link having opposite ends pivotally connected to opposite fittings and having axes that pass through centerplates of the fittings. A control link having opposite ends pivotally connected to the different fittings controls their relative orientations, and a toggle assemly holds the fittings in the deployed configuration wherein they are aligned. The fittings have stops that lie on one side of the centerplane opposite the toggle assembly.

Design of Restoration Method Based on Compressed Sensing and TwIST Algorithm

NASA Astrophysics Data System (ADS)

Zhang, Fei; Piao, Yan

2018-04-01

In order to improve the subjective and objective quality of degraded images at low sampling rates effectively,save storage space and reduce computational complexity at the same time, this paper proposes a joint restoration algorithm of compressed sensing and two step iterative threshold shrinkage (TwIST). The algorithm applies the TwIST algorithm which used in image restoration to the compressed sensing theory. Then, a small amount of sparse high-frequency information is obtained in frequency domain. The TwIST algorithm based on compressed sensing theory is used to accurately reconstruct the high frequency image. The experimental results show that the proposed algorithm achieves better subjective visual effects and objective quality of degraded images while accurately restoring degraded images.

Comprehensive treatment of temporomandibular joint disorders.

PubMed

Navrátil, Leos; Navratil, Vaclav; Hajkova, Simona; Hlinakova, Petra; Dostalova, Tatjana; Vranová, Jana

2014-01-01

Changing lifestyles, decreasing physical activity, which is increasing the number of degenerative joint diseases of various etiology, and certain dental procedures are increasing the number of patients complaining of pain in their temporomandibular joints. The aim of the study was to assess the benefits of comprehensive physiotherapy sessions in order to decrease the number of temporomandibular joint problems, thereby improving the patient's quality of life. An examination by a dentist determined each patient's treatment plan, which consisted of a medical exam, physical therapy and education. Each form of treatment was applied 10 times at intervals of 7-14 days. The main goal of the therapeutic physical education was to redress the muscle imbalance in the mandibular joint. This was achieved by restoring balance between the masticatory muscles, along with releasing the spastic shrouds found in the masticatory muscles. The aim of education was to teach the patient exercises focused on the temporomandibular joint and masticatory muscles. The intensity of the exercises and their composition were individually adjusted and adapted to their current state. Physical therapy consisted of the application of pulsed magnetic therapy, laser therapy, and non-invasive positive thermotherapy. The above procedure was conducted on a therapeutic group of 24 patients (3 men and 20 women). In the course of therapy, there were no complications, and all patients adhered to the prescribed regime. None reported any side effects. The mean treatment duration was 123 +/- 66 days. The outcome of the therapy was evaluated as described in the methodology, the degree of pain affecting the joint, and the opening ability of the mouth. In both parameters, there was a significant decline in patient pain. In a study devoted to tactics of rehabilitation treatment for temporomandibular joint disorders, the need for comprehensive long-term therapy, involving education, and learning proper chewing habits

System and method for evaluating wind flow fields using remote sensing devices

DOEpatents

Schroeder, John; Hirth, Brian; Guynes, Jerry

2016-12-13

The present invention provides a system and method for obtaining data to determine one or more characteristics of a wind field using a first remote sensing device and a second remote sensing device. Coordinated data is collected from the first and second remote sensing devices and analyzed to determine the one or more characteristics of the wind field. The first remote sensing device is positioned to have a portion of the wind field within a first scanning sector of the first remote sensing device. The second remote sensing device is positioned to have the portion of the wind field disposed within a second scanning sector of the second remote sensing device.

Thematic and positional accuracy assessment of digital remotely sensed data

Treesearch

Russell G. Congalton

2007-01-01

Accuracy assessment or validation has become a standard component of any land cover or vegetation map derived from remotely sensed data. Knowing the accuracy of the map is vital to any decisionmaking performed using that map. The process of assessing the map accuracy is time consuming and expensive. It is very important that the procedure be well thought out and...

Optimal Periodic Cooperative Spectrum Sensing Based on Weight Fusion in Cognitive Radio Networks

PubMed Central

Liu, Xin; Jia, Min; Gu, Xuemai; Tan, Xuezhi

2013-01-01

The performance of cooperative spectrum sensing in cognitive radio (CR) networks depends on the sensing mode, the sensing time and the number of cooperative users. In order to improve the sensing performance and reduce the interference to the primary user (PU), a periodic cooperative spectrum sensing model based on weight fusion is proposed in this paper. Moreover, the sensing period, the sensing time and the searching time are optimized, respectively. Firstly the sensing period is optimized to improve the spectrum utilization and reduce the interference, then the joint optimization algorithm of the local sensing time and the number of cooperative users, is proposed to obtain the optimal sensing time for improving the throughput of the cognitive radio user (CRU) during each period, and finally the water-filling principle is applied to optimize the searching time in order to make the CRU find an idle channel within the shortest time. The simulation results show that compared with the previous algorithms, the optimal sensing period can improve the spectrum utilization of the CRU and decrease the interference to the PU significantly, the optimal sensing time can make the CRU achieve the largest throughput, and the optimal searching time can make the CRU find an idle channel with the least time. PMID:23604027

Functional Multijoint Position Reproduction Acuity in Overhead-Throwing Athletes

PubMed Central

Tripp, Brady L; Uhl, Timothy L; Mattacola, Carl G; Srinivasan, Cidambi; Shapiro, Robert

2006-01-01

Context: Baseball players rely on the sensorimotor system to uphold the balance between upper extremity stability and mobility while maintaining athletic performance. However, few researchers have studied functional multijoint measures of sensorimotor acuity in overhead-throwing athletes. Objective: To compare sensorimotor acuity between 2 high-demand functional positions and among planes of motion within individual joints and to describe a novel method of measuring sensorimotor function. Design: Single-session, repeated-measures design. Setting: University musculoskeletal research laboratory. Patients or Other Participants: Twenty-one National Collegiate Athletic Association Division I baseball players (age = 20.8 ± 1.5 years, height = 181.3 ± 5.1 cm, mass = 87.8 ± 9.1 kg) with no history of upper extremity injury or central nervous system disorder. Main Outcome Measure(s): We measured active multijoint position reproduction acuity in multiple planes using an electromagnetic tracking device. Subjects reproduced 2 positions: arm cock and ball release. We calculated absolute and variable error for individual motions at the scapulothoracic, glenohumeral, elbow, and wrist joints and calculated overall joint acuity with 3-dimensional variable error. Results: Acuity was significantly better in the arm-cock position compared with ball release at the scapulothoracic and glenohumeral joints. We observed significant differences among planes of motion within the scapulothoracic and glenohumeral joints at ball release. Scapulothoracic internal rotation and glenohumeral horizontal abduction and rotation displayed less acuity than other motions. Conclusions: We established the reliability of a functional measure of upper extremity sensorimotor system acuity in baseball players. Using this technique, we observed differences in acuity between 2 test positions and among planes of motion within the glenohumeral and scapulothoracic joints. Clinicians may consider these

Sensing charges of the Ciona intestinalis voltage-sensing phosphatase

PubMed Central

Frezza, Ludivine; Sandtner, Walter

2013-01-01

Voltage control over enzymatic activity in voltage-sensitive phosphatases (VSPs) is conferred by a voltage-sensing domain (VSD) located in the N terminus. These VSDs are constituted by four putative transmembrane segments (S1 to S4) resembling those found in voltage-gated ion channels. The putative fourth segment (S4) of the VSD contains positive residues that likely function as voltage-sensing elements. To study in detail how these residues sense the plasma membrane potential, we have focused on five arginines in the S4 segment of the Ciona intestinalis VSP (Ci-VSP). After implementing a histidine scan, here we show that four arginine-to-histidine mutants, namely R223H to R232H, mediate voltage-dependent proton translocation across the membrane, indicating that these residues transit through the hydrophobic core of Ci-VSP as a function of the membrane potential. These observations indicate that the charges carried by these residues are sensing charges. Furthermore, our results also show that the electrical field in VSPs is focused in a narrow hydrophobic region that separates the extracellular and intracellular space and constitutes the energy barrier for charge crossing. PMID:24127524

Sensing charges of the Ciona intestinalis voltage-sensing phosphatase.

PubMed

Villalba-Galea, Carlos A; Frezza, Ludivine; Sandtner, Walter; Bezanilla, Francisco

2013-11-01

Voltage control over enzymatic activity in voltage-sensitive phosphatases (VSPs) is conferred by a voltage-sensing domain (VSD) located in the N terminus. These VSDs are constituted by four putative transmembrane segments (S1 to S4) resembling those found in voltage-gated ion channels. The putative fourth segment (S4) of the VSD contains positive residues that likely function as voltage-sensing elements. To study in detail how these residues sense the plasma membrane potential, we have focused on five arginines in the S4 segment of the Ciona intestinalis VSP (Ci-VSP). After implementing a histidine scan, here we show that four arginine-to-histidine mutants, namely R223H to R232H, mediate voltage-dependent proton translocation across the membrane, indicating that these residues transit through the hydrophobic core of Ci-VSP as a function of the membrane potential. These observations indicate that the charges carried by these residues are sensing charges. Furthermore, our results also show that the electrical field in VSPs is focused in a narrow hydrophobic region that separates the extracellular and intracellular space and constitutes the energy barrier for charge crossing.

Iron aluminide alloy coatings and joints, and methods of forming

DOEpatents

Wright, Richard N.; Wright, Julie K.; Moore, Glenn A.

1994-01-01

A method of joining two bodies together, at least one of the bodies being predominantly composed of metal, the two bodies each having a respective joint surface for joining with the joint surface of the other body, the two bodies having a respective melting point, includes the following steps: a) providing aluminum metal and iron metal on at least one of the joint surfaces of the two bodies; b) after providing the aluminum metal and iron metal on the one joint surface, positioning the joint surfaces of the two bodies in juxtaposition against one another with the aluminum and iron positioned therebetween; c) heating the aluminum and iron on the juxtaposed bodies to a temperature from greater than or equal to 600.degree. C. to less than the melting point of the lower melting point body; d) applying pressure on the juxtaposed surfaces; and e) maintaining the pressure and the temperature for a time period effective to form the aluminum and iron into an iron aluminide alloy joint which bonds the juxtaposed surfaces and correspondingly the two bodies together. The method can also effectively be used to coat a body with an iron aluminide coating.

Iron aluminide alloy coatings and joints, and methods of forming

DOEpatents

Wright, R.N.; Wright, J.K.; Moore, G.A.

1994-09-27

Disclosed is a method of joining two bodies together, at least one of the bodies being predominantly composed of metal, the two bodies each having a respective joint surface for joining with the joint surface of the other body, the two bodies having a respective melting point, includes the following steps: (a) providing aluminum metal and iron metal on at least one of the joint surfaces of the two bodies; (b) after providing the aluminum metal and iron metal on the one joint surface, positioning the joint surfaces of the two bodies in juxtaposition against one another with the aluminum and iron positioned therebetween; (c) heating the aluminum and iron on the juxtaposed bodies to a temperature from greater than or equal to 600 C to less than the melting point of the lower melting point body; (d) applying pressure on the juxtaposed surfaces; and (e) maintaining the pressure and the temperature for a time period effective to form the aluminum and iron into an iron aluminide alloy joint which bonds the juxtaposed surfaces and correspondingly the two bodies together. The method can also effectively be used to coat a body with an iron aluminide coating.

Uncontrolled Manifold Reference Feedback Control of Multi-Joint Robot Arms

PubMed Central

Togo, Shunta; Kagawa, Takahiro; Uno, Yoji

2016-01-01

The brain must coordinate with redundant bodies to perform motion tasks. The aim of the present study is to propose a novel control model that predicts the characteristics of human joint coordination at a behavioral level. To evaluate the joint coordination, an uncontrolled manifold (UCM) analysis that focuses on the trial-to-trial variance of joints has been proposed. The UCM is a nonlinear manifold associated with redundant kinematics. In this study, we directly applied the notion of the UCM to our proposed control model called the “UCM reference feedback control.” To simplify the problem, the present study considered how the redundant joints were controlled to regulate a given target hand position. We considered a conventional method that pre-determined a unique target joint trajectory by inverse kinematics or any other optimization method. In contrast, our proposed control method generates a UCM as a control target at each time step. The target UCM is a subspace of joint angles whose variability does not affect the hand position. The joint combination in the target UCM is then selected so as to minimize the cost function, which consisted of the joint torque and torque change. To examine whether the proposed method could reproduce human-like joint coordination, we conducted simulation and measurement experiments. In the simulation experiments, a three-link arm with a shoulder, elbow, and wrist regulates a one-dimensional target of a hand through proposed method. In the measurement experiments, subjects performed a one-dimensional target-tracking task. The kinematics, dynamics, and joint coordination were quantitatively compared with the simulation data of the proposed method. As a result, the UCM reference feedback control could quantitatively reproduce the difference of the mean value for the end hand position between the initial postures, the peaks of the bell-shape tangential hand velocity, the sum of the squared torque, the mean value for the torque

Augmented reality environment for temporomandibular joint motion analysis.

PubMed

Wagner, A; Ploder, O; Zuniga, J; Undt, G; Ewers, R

1996-01-01

The principles of interventional video tomography were applied for the real-time visualization of temporomandibular joint movements in an augmented reality environment. Anatomic structures were extracted in three dimensions from planar cephalometric radiographic images. The live-image fusion of these graphic anatomic structures with real-time position data of the mandible and the articular fossa was performed with a see-through, head-mounted display and an electromagnetic tracking system. The dynamic fusion of radiographic images of the temporomandibular joint to anatomic temporomandibular joint structures in motion created a new modality for temporomandibular joint motion analysis. The advantages of the method are its ability to accurately examine the motion of the temporomandibular joint in three dimensions without restraining the subject and its ability to simultaneously determine the relationship of the bony temporomandibular joint and supporting structures (ie, occlusion, muscle function, etc) during movement before and after treatment.

Polarization-based index of refraction and reflection angle estimation for remote sensing applications.

PubMed

Thilak, Vimal; Voelz, David G; Creusere, Charles D

2007-10-20

A passive-polarization-based imaging system records the polarization state of light reflected by objects that are illuminated with an unpolarized and generally uncontrolled source. Such systems can be useful in many remote sensing applications including target detection, object segmentation, and material classification. We present a method to jointly estimate the complex index of refraction and the reflection angle (reflected zenith angle) of a target from multiple measurements collected by a passive polarimeter. An expression for the degree of polarization is derived from the microfacet polarimetric bidirectional reflectance model for the case of scattering in the plane of incidence. Using this expression, we develop a nonlinear least-squares estimation algorithm for extracting an apparent index of refraction and the reflection angle from a set of polarization measurements collected from multiple source positions. Computer simulation results show that the estimation accuracy generally improves with an increasing number of source position measurements. Laboratory results indicate that the proposed method is effective for recovering the reflection angle and that the estimated index of refraction provides a feature vector that is robust to the reflection angle.

Polarization-based index of refraction and reflection angle estimation for remote sensing applications

NASA Astrophysics Data System (ADS)

Thilak, Vimal; Voelz, David G.; Creusere, Charles D.

2007-10-01

A passive-polarization-based imaging system records the polarization state of light reflected by objects that are illuminated with an unpolarized and generally uncontrolled source. Such systems can be useful in many remote sensing applications including target detection, object segmentation, and material classification. We present a method to jointly estimate the complex index of refraction and the reflection angle (reflected zenith angle) of a target from multiple measurements collected by a passive polarimeter. An expression for the degree of polarization is derived from the microfacet polarimetric bidirectional reflectance model for the case of scattering in the plane of incidence. Using this expression, we develop a nonlinear least-squares estimation algorithm for extracting an apparent index of refraction and the reflection angle from a set of polarization measurements collected from multiple source positions. Computer simulation results show that the estimation accuracy generally improves with an increasing number of source position measurements. Laboratory results indicate that the proposed method is effective for recovering the reflection angle and that the estimated index of refraction provides a feature vector that is robust to the reflection angle.

Tennis Coaching: Applying the Game Sense Approach

ERIC Educational Resources Information Center

Pill, Shane; Hewitt, Mitchell

2017-01-01

This article demonstrates the game sense approach for teaching tennis to novice players. In a game sense approach, learning is positioned within modified games to emphasize the way rules shape game behavior, tactical awareness, decision-making and the development of contextualized stroke mechanics.

Flexible Sensing Arrays Fabricated with Carbon Nanofiber Composite Thin Films for Posture Monitoring

NASA Astrophysics Data System (ADS)

Chang, Fuh-Yu; Wang, Ruoh-Huey; Lin, Yu-Hsien; Chen, Tse-Min; Lee, Yueh-Feng; Huang, Shu-Jiuan; Liu, Chia-Ming

2011-06-01

Faulty posture increases joint stress and causes postural pain syndrome. In this paper, we present a portable strain sensing system with flexible sensor arrays to warn patients to correct inappropriate posture. A 3×3 flexible strain sensing array system was fabricated using patterned surface treatment and the tilted-drop process with carbon nanofiber composite solutions on polyimide substrates. Atmospheric plasma was used to enhance or reduce the surface energy in specific areas for patterned surface treatment. A scanning circuit was also developed to capture the signal from the flexible sensing array. The developed system has been used to measure the bent angle of the human neck from 15 to 60°. The results indicate that human posture can be successfully captured by analyzing the measured strains from a flexible strain sensing array.

Train the brain: immediate sensorimotor effects of mentally performed flexor exercises in patients with neck pain. A pilot study.

PubMed

Beinert, Konstantin; Sofsky, Marc; Trojan, Jörg

2018-05-09

Sensorimotor tests, like cranio- cervical flexion and cervical joint position sense tests, share a strong cognitive component during their execution. However, cognitive training for those tests has not been investigated so far. To compare mental and physical exercises for improving the sensorimotor function of the cervical spine. A within-subject design with 16 participants. Outpatient physiotherapy centre. Patients with chronic neck pain. Participants were instructed to perform specific active or mental exercises for the deep and superficial neck flexor muscles. The primary outcomes were cranio-cervical flexion test performance, postural sway, cervical joint position sense and pressure pain threshold. A mixed model analysis was used. The interventions improved cranio-cervical flexion performance (p < 0.001), with no difference between actively or mentally performed exercises. Postural sway increased after actively (p < 0.01) and mentally (p < 0.05) performed deep cervical neck flexor exercises, but not after superficial neck flexor exercises. Mentally performed superficial neck flexor exercises improved cervical joint position sense when compared to mentally performed deep cervical flexor exercises (p < 0.05), and actively performed superficial neck flexor exercises were effective in improving cervical joint position sense acuity compared to mentally performed deep cervical flexor exercises (p < 0.05) for relocation tasks in the transverse plane. The pressure pain threshold at the cervical spine increased after active deep cervical flexor exercises (p < 0.05) and after mental superficial neck flexor exercise (p < 0.05). Mentally performed deep cervical flexor exercises improved cranio-cervical flexion test performance, postural sway and pressure pain threshold at the cervical spine. Mentally performed superficial neck flexor exercises improved cervical joint position sense acuity more than mentally performed deep cervical flexor exercises. Mentally performed

Integrated High-Speed Torque Control System for a Robotic Joint

NASA Technical Reports Server (NTRS)

Davis, Donald R. (Inventor); Radford, Nicolaus A. (Inventor); Permenter, Frank Noble (Inventor); Valvo, Michael C. (Inventor); Askew, R. Scott (Inventor)

2013-01-01

A control system for achieving high-speed torque for a joint of a robot includes a printed circuit board assembly (PCBA) having a collocated joint processor and high-speed communication bus. The PCBA may also include a power inverter module (PIM) and local sensor conditioning electronics (SCE) for processing sensor data from one or more motor position sensors. Torque control of a motor of the joint is provided via the PCBA as a high-speed torque loop. Each joint processor may be embedded within or collocated with the robotic joint being controlled. Collocation of the joint processor, PIM, and high-speed bus may increase noise immunity of the control system, and the localized processing of sensor data from the joint motor at the joint level may minimize bus cabling to and from each control node. The joint processor may include a field programmable gate array (FPGA).

Sense of Place, Fast and Slow: The Potential Contributions of Affordance Theory to Sense of Place.

PubMed

Raymond, Christopher M; Kyttä, Marketta; Stedman, Richard

2017-01-01

Over the past 40 years, the sense of place concept has been well-established across a range of applications and settings; however, most theoretical developments have "privileged the slow." Evidence suggests that place attachments and place meanings are slow to evolve, sometimes not matching material or social reality (lag effects), and also tending to inhibit change. Here, we present some key blind spots in sense of place scholarship and then suggest how a reconsideration of sense of place as "fast" and "slow" could fill them. By this, we mean how direct and immediate perception-action processes presented in affordance theory (resulting in immediately perceived place meanings) can complement slower forms of social construction presented in sense of place scholarship. Key blind spots are that sense of place scholarship: (1) rarely accounts for sensory or immediately perceived meanings; (2) pays little attention to how place meanings are the joint product of attributes of environmental features and the attributes of the individual; and (3) assumes that the relationship between place attachment and behavior is linear and not constituted in dynamic relations among mind, culture, and environment. We show how these blind spots can begin to be addressed by reviewing key insights from affordance theory, and through the presentation of applied examples. We discuss future empirical research directions in terms of: (1) how sense of place is both perceived and socially constructed; (2) whether perceived and socially constructed dimensions of place can relate to one another when perceived meanings become unsituated; and (3) how place attachment may change over different stages of the life course based upon dynamic relationships between processes of perception-action and social construction. We conclude with insights into how processes of perception-action and social construction could be included in the design and management of urban landscapes.

Sense of Place, Fast and Slow: The Potential Contributions of Affordance Theory to Sense of Place

PubMed Central

Raymond, Christopher M.; Kyttä, Marketta; Stedman, Richard

2017-01-01

Over the past 40 years, the sense of place concept has been well-established across a range of applications and settings; however, most theoretical developments have “privileged the slow.” Evidence suggests that place attachments and place meanings are slow to evolve, sometimes not matching material or social reality (lag effects), and also tending to inhibit change. Here, we present some key blind spots in sense of place scholarship and then suggest how a reconsideration of sense of place as “fast” and “slow” could fill them. By this, we mean how direct and immediate perception–action processes presented in affordance theory (resulting in immediately perceived place meanings) can complement slower forms of social construction presented in sense of place scholarship. Key blind spots are that sense of place scholarship: (1) rarely accounts for sensory or immediately perceived meanings; (2) pays little attention to how place meanings are the joint product of attributes of environmental features and the attributes of the individual; and (3) assumes that the relationship between place attachment and behavior is linear and not constituted in dynamic relations among mind, culture, and environment. We show how these blind spots can begin to be addressed by reviewing key insights from affordance theory, and through the presentation of applied examples. We discuss future empirical research directions in terms of: (1) how sense of place is both perceived and socially constructed; (2) whether perceived and socially constructed dimensions of place can relate to one another when perceived meanings become unsituated; and (3) how place attachment may change over different stages of the life course based upon dynamic relationships between processes of perception–action and social construction. We conclude with insights into how processes of perception–action and social construction could be included in the design and management of urban landscapes. PMID:29033871

[Staple fixation for the treatment of hamate metacarpal joint injury].

PubMed

Tang, Yang-Hua; Zeng, Lin-Ru; Huang, Zhong-Ming; Yue, Zhen-Shuang; Xin, Da-Wei; Xu, Can-Da

2014-03-01

To investigate the effcacy of the staple fixation for the treatment of hamate metacarpal joint injury. From May 2009 to November 2012,16 patients with hamate metacarpal joint injury were treated with staple fixation including 10 males and 6 females with an average age of 33.6 years old ranging from 21 to 57 years. Among them, 11 cases were on the fourth or fifth metacarpal base dislocation without fractures, 5 cases were the fourth or fifth metacarpal base dislocation with avulsion fractures of the back of hamatum. Regular X-ray review was used to observe the fracture healing, joint replacement and position of staple fixation. The function of carpometacarpal joint and metacarpophalangeal joint were evaluated according to ASIA (TAM) system evaluation method. All incision were healed well with no infection. All patients were followed up from 16 to 24 months with an average of (10.0 +/- 2.7) months. No dislocation recurred, the position of internal fixator was good,no broken nail and screw withdrawal were occurred. Five patients with avulsion fracture of the back of hamatum achieved bone healing. The function of carpometacarpal joint and metacarpophalangeal was excellent in 10 cases,good in 5 cases, moderate in 1 case. The application of the staple for the treatment of hamatometacarpal joint injury has the advantages of simple operation, small trauma, reliable fixation, early postoperative function exercise and other advantages, which is the ideal operation mode for hamatometacarpal joint injury.

Study on Elastic Helical TDR Sensing Cable for Distributed Deformation Detection

PubMed Central

Tong, Renyuan; Li, Ming; Li, Qing

2012-01-01

In order to detect distributed ground surface deformation, an elastic helical structure Time Domain Reflectometry (TDR) sensing cable is shown in this paper. This special sensing cable consists of three parts: a silicone rubber rope in the center; a couple of parallel wires coiling around the rope; a silicone rubber pipe covering the sensing cable. By analyzing the relationship between the impedance and the structure of the sensing cable, the impedance model shows that the sensing cable impedance will increase when the cable is stretched. This specific characteristic is verified in the cable stretching experiment which is the base of TDR sensing technology. The TDR experiment shows that a positive reflected signal is created at the stretching deformation point on the sensing cable. The results show that the deformation section length and the stretching elongation will both affect the amplitude of the reflected signal. Finally, the deformation locating experiments show that the sensing cable can accurately detect the deformation point position on the sensing cable. PMID:23012560

RSRM Nozzle-to-Case Joint J-leg Development

NASA Technical Reports Server (NTRS)

Albrechtsen, Kevin U.; Eddy, Norman F.; Ewing, Mark E.; McGuire, John R.

2003-01-01

Since the beginning of the Space Shuttle Reusable Solid Rocket Motor (RSRM) program, nozzle-to-case joint polysulfide adhesive gas paths have occurred on several flight motors. These gas paths have allowed hot motor gases to reach the wiper O-ring. Even though these motors continue to fly safely with this condition, a desire was to reduce such occurrences. The RSRM currently uses a J-leg joint configuration on case field joints and igniter inner and outer joints. The J-leg joint configuration has been successfully demonstrated on numerous RSRM flight and static test motors, eliminating hot gas intrusion to the critical O-ring seals on these joints. Using the proven technology demonstrated on the case field joints and igniter joints, a nozzle-to-case joint J-leg design was developed for implementation on RSRM flight motors. This configuration provides an interference fit with nozzle fixed housing phenolics at assembly, with a series of pressurization gaps incorporated outboard of the joint mating surface to aid in joint pressurization and to eliminate any circumferential flow in this region. The joint insulation is bonded to the nozzle phenolics using the same pressure sensitive adhesive used in the case field joints and igniter joints. An enhancement to the nozzle-to-case joint J-leg configuration is the implementation of a carbon rope thermal barrier. The thermal barrier is located downstream of the joint bondline and is positioned within the joint in a manner where any hot gas intrusion into the joint passes through the thermal barrier, reducing gas temperatures to a level that would not affect O-rings downstream of the thermal barrier. This paper discusses the processes used in reaching a final nozzle-to-case joint J-leg design, provides structural and thermal results in support of the design, and identifies fabrication techniques and demonstrations used in arriving at the final configuration.

A self-sensing active magnetic bearing based on a direct current measurement approach.

PubMed

Niemann, Andries C; van Schoor, George; du Rand, Carel P

2013-09-11

Active magnetic bearings (AMBs) have become a key technology in various industrial applications. Self-sensing AMBs provide an integrated sensorless solution for position estimation, consolidating the sensing and actuating functions into a single electromagnetic transducer. The approach aims to reduce possible hardware failure points, production costs, and system complexity. Despite these advantages, self-sensing methods must address various technical challenges to maximize the performance thereof. This paper presents the direct current measurement (DCM) approach for self-sensing AMBs, denoting the direct measurement of the current ripple component. In AMB systems, switching power amplifiers (PAs) modulate the rotor position information onto the current waveform. Demodulation self-sensing techniques then use bandpass and lowpass filters to estimate the rotor position from the voltage and current signals. However, the additional phase-shift introduced by these filters results in lower stability margins. The DCM approach utilizes a novel PA switching method that directly measures the current ripple to obtain duty-cycle invariant position estimates. Demodulation filters are largely excluded to minimize additional phase-shift in the position estimates. Basic functionality and performance of the proposed self-sensing approach are demonstrated via a transient simulation model as well as a high current (10 A) experimental system. A digital implementation of amplitude modulation self-sensing serves as a comparative estimator.

The Sophia-Antipolis Conference: General presentation and basic documents. [remote sensing for agriculture, forestry, water resources, and environment management in France

NASA Technical Reports Server (NTRS)

1980-01-01

The procedures and techniques used in NASA's aerospace technology transfer program are reviewed for consideration in establishing priorities and bases for joint action by technicians and users of remotely sensed data in France. Particular emphasis is given to remote sensing in agriculture, forestry, water resources, environment management, and urban research.

'They don't understand…you cut yourself in order to live.' Interpretative repertoires jointly constructing interactions between adult women who self-harm and professional caregivers.

PubMed

Lindgren, Britt-Marie; Oster, Inger; Aström, Sture; Hällgren Graneheim, Ulla

2011-01-01

The aim of the study was to illuminate interpretative repertoires that jointly construct the interaction between adult women who self-harm and professional caregivers in psychiatric inpatient care. Participant observations and informal interviews were conducted among six women who self-harm and their professional caregivers in two psychiatric inpatient wards, and analysed using the concept of interpretative repertoires from the discipline of discursive psychology. The analysis revealed four interpretative repertoires that jointly constructed the interaction. The professional caregivers used a "fostering repertoire" and a "supportive repertoire" and the women who self-harmed used a "victim repertoire" and an "expert repertoire." The women and the caregivers were positioned and positioned themselves and people around them within and among these interpretative repertoires to make sense of their experiences of the interaction. It was necessary to consider each woman's own life chances and knowledge about herself and her needs. The participants made it clear that it was essential for them to be met with respect as individuals. Professional caregivers need to work in partnership with individuals who self-harm-experts by profession collaborating with experts by experience. Caregivers need to look beyond behavioural symptoms and recognise each individual's possibilities for agency.

Approximate Joint Diagonalization and Geometric Mean of Symmetric Positive Definite Matrices

PubMed Central

Congedo, Marco; Afsari, Bijan; Barachant, Alexandre; Moakher, Maher

2015-01-01

We explore the connection between two problems that have arisen independently in the signal processing and related fields: the estimation of the geometric mean of a set of symmetric positive definite (SPD) matrices and their approximate joint diagonalization (AJD). Today there is a considerable interest in estimating the geometric mean of a SPD matrix set in the manifold of SPD matrices endowed with the Fisher information metric. The resulting mean has several important invariance properties and has proven very useful in diverse engineering applications such as biomedical and image data processing. While for two SPD matrices the mean has an algebraic closed form solution, for a set of more than two SPD matrices it can only be estimated by iterative algorithms. However, none of the existing iterative algorithms feature at the same time fast convergence, low computational complexity per iteration and guarantee of convergence. For this reason, recently other definitions of geometric mean based on symmetric divergence measures, such as the Bhattacharyya divergence, have been considered. The resulting means, although possibly useful in practice, do not satisfy all desirable invariance properties. In this paper we consider geometric means of covariance matrices estimated on high-dimensional time-series, assuming that the data is generated according to an instantaneous mixing model, which is very common in signal processing. We show that in these circumstances we can approximate the Fisher information geometric mean by employing an efficient AJD algorithm. Our approximation is in general much closer to the Fisher information geometric mean as compared to its competitors and verifies many invariance properties. Furthermore, convergence is guaranteed, the computational complexity is low and the convergence rate is quadratic. The accuracy of this new geometric mean approximation is demonstrated by means of simulations. PMID:25919667

Maximum voluntary joint torque as a function of joint angle and angular velocity: model development and application to the lower limb.

PubMed

Anderson, Dennis E; Madigan, Michael L; Nussbaum, Maury A

2007-01-01

Measurements of human strength can be important during analyses of physical activities. Such measurements have often taken the form of the maximum voluntary torque at a single joint angle and angular velocity. However, the available strength varies substantially with joint position and velocity. When examining dynamic activities, strength measurements should account for these variations. A model is presented of maximum voluntary joint torque as a function of joint angle and angular velocity. The model is based on well-known physiological relationships between muscle force and length and between muscle force and velocity and was tested by fitting it to maximum voluntary joint torque data from six different exertions in the lower limb. Isometric, concentric and eccentric maximum voluntary contractions were collected during hip extension, hip flexion, knee extension, knee flexion, ankle plantar flexion and dorsiflexion. Model parameters are reported for each of these exertion directions by gender and age group. This model provides an efficient method by which strength variations with joint angle and angular velocity may be incorporated into comparisons between joint torques calculated by inverse dynamics and the maximum available joint torques.

Nasa's Land Remote Sensing Plans for the 1980's

NASA Technical Reports Server (NTRS)

Higg, H. C.; Butera, K. M.; Settle, M.

1985-01-01

Research since the launch of LANDSAT-1 has been primarily directed to the development of analysis techniques and to the conduct of applications studies designed to address resource information needs in the United States and in many other countries. The current measurement capabilities represented by MSS, TM, and SIR-A and B, coupled with the present level of remote sensing understanding and the state of knowledge in the discipline earth sciences, form the foundation for NASA's Land Processes Program. Science issues to be systematically addressed include: energy balance, hydrologic cycle, biogeochemical cycles, biological productivity, rock cycle, landscape development, geological and botanical associations, and land surface inventory, monitoring, and modeling. A global perspective is required for using remote sensing technology for problem solving or applications context. A successful model for this kind of activity involves joint research with a user entity where the user provides a test site and ground truth and NASA provides the remote sensing techniques to be tested.

Muscle Strength Imbalance in the Hip Joint Caused by Fast Movements

NASA Astrophysics Data System (ADS)

Pontaga, I.

2003-07-01

Eleven male sportsmen at the age of 24.3 ± 4.5 were examined. Their hip joint flexors and extensors were tested by an "REV-9000" Technogym dynamometer system during isokinetic movements at angular velocities of 100 (low) and 200 (high) °/s. The range of hip joint movements was from 30 (in flexion) to 130° (in extension). Torque values and their ratios for hip flexors and extensors at different angular positions were obtained and compared. It is shown that, at high speeds, the flexion movement significantly raises ( p < 0.001) the torque ratios of flexors and extensors in flexion positions of the hip (50 and 60°). These ratios approximately twofold exceed their values at moderate velocities. The weakness of hip joint extensors in extreme flexion positions of the hip may cause injury of this group of muscles at fast movements.

Leveraging EAP-Sparsity for Compressed Sensing of MS-HARDI in (k, q)-Space.

PubMed

Sun, Jiaqi; Sakhaee, Elham; Entezari, Alireza; Vemuri, Baba C

2015-01-01

Compressed Sensing (CS) for the acceleration of MR scans has been widely investigated in the past decade. Lately, considerable progress has been made in achieving similar speed ups in acquiring multi-shell high angular resolution diffusion imaging (MS-HARDI) scans. Existing approaches in this context were primarily concerned with sparse reconstruction of the diffusion MR signal S(q) in the q-space. More recently, methods have been developed to apply the compressed sensing framework to the 6-dimensional joint (k, q)-space, thereby exploiting the redundancy in this 6D space. To guarantee accurate reconstruction from partial MS-HARDI data, the key ingredients of compressed sensing that need to be brought together are: (1) the function to be reconstructed needs to have a sparse representation, and (2) the data for reconstruction ought to be acquired in the dual domain (i.e., incoherent sensing) and (3) the reconstruction process involves a (convex) optimization. In this paper, we present a novel approach that uses partial Fourier sensing in the 6D space of (k, q) for the reconstruction of P(x, r). The distinct feature of our approach is a sparsity model that leverages surfacelets in conjunction with total variation for the joint sparse representation of P(x, r). Thus, our method stands to benefit from the practical guarantees for accurate reconstruction from partial (k, q)-space data. Further, we demonstrate significant savings in acquisition time over diffusion spectral imaging (DSI) which is commonly used as the benchmark for comparisons in reported literature. To demonstrate the benefits of this approach,.we present several synthetic and real data examples.

Remote sensing for detecting and mapping whitefly (Bemisia tabaci) infestations

USDA-ARS?s Scientific Manuscript database

Remote sensing technology has long been used for detecting insect infestations on agricultural crops. With recent advances in remote sensing sensors and other spatial information technologies such as Global Position Systems (GPS) and Geographic Information Systems (GIS), remote sensing is finding mo...

Forward and inverse kinematics of double universal joint robot wrists

NASA Technical Reports Server (NTRS)

Williams, Robert L., II

1991-01-01

A robot wrist consisting of two universal joints can eliminate the wrist singularity problem found on many individual robots. Forward and inverse position and velocity kinematics are presented for such a wrist having three degrees of freedom. Denavit-Hartenberg parameters are derived to find the transforms required for the kinematic equations. The Omni-Wrist, a commercial double universal joint robot wrist, is studied in detail. There are four levels of kinematic parameters identified for this wrist; three forward and three inverse maps are presented for both position and velocity. These equations relate the hand coordinate frame to the wrist base frame. They are sufficient for control of the wrist standing alone. When the wrist is attached to a manipulator arm; the offset between the two universal joints complicates the solution of the overall kinematics problem. All wrist coordinate frame origins are not coincident, which prevents decoupling of position and orientation for manipulator inverse kinematics.

Incidence of inadvertent intra-articular lumbar facet joint injection during fluoroscopically guided interlaminar epidural steroid injection.

PubMed

Huang, Ambrose J; Palmer, William E

2012-02-01

To determine the incidence of inadvertent lumbar facet joint injection during an interlaminar epidural steroid injection (ESI). A total of 686 interlaminar lumbar ESIs were performed from January 1, 2009 to December 31, 2009. Archived images from these cases were retrospectively reviewed on the PACS. Positive cases of inadvertent lumbar facet joint injection were identified by the characteristic sigmoid-shaped contrast pattern projecting over the posterior elements on the lateral view and/or ovoid contrast projecting over the facet joints on the anteroposterior (AP) view. Eight positive events were identified (1.2%). There was no statistically significant gender or lumbar level predilection. In 3/8 of the positive cases (37.5%), the inadvertent facet joint injection was recognized by the operator. The needle was repositioned as a result, and contrast within the posterior epidural space was documented by the end of the procedure. In 5/8 of the positive cases (62.5%), the patients reported an immediate decrease in the presenting pain. The incidence of inadvertent lumbar facet joint injection during an interlaminar epidural steroid injection is low. Recognizing the imaging features of this event permits the operator to redirect the needle tip into the epidural space and/or identify the facet joint(s) as a source of the patient's presenting pain.

Environmental analysis using integrated GIS and remotely sensed data - Some research needs and priorities

NASA Technical Reports Server (NTRS)

Davis, Frank W.; Quattrochi, Dale A.; Ridd, Merrill K.; Lam, Nina S.-N.; Walsh, Stephen J.

1991-01-01

This paper discusses some basic scientific issues and research needs in the joint processing of remotely sensed and GIS data for environmental analysis. Two general topics are treated in detail: (1) scale dependence of geographic data and the analysis of multiscale remotely sensed and GIS data, and (2) data transformations and information flow during data processing. The discussion of scale dependence focuses on the theory and applications of spatial autocorrelation, geostatistics, and fractals for characterizing and modeling spatial variation. Data transformations during processing are described within the larger framework of geographical analysis, encompassing sampling, cartography, remote sensing, and GIS. Development of better user interfaces between image processing, GIS, database management, and statistical software is needed to expedite research on these and other impediments to integrated analysis of remotely sensed and GIS data.

Adaptive independent joint control of manipulators - Theory and experiment

NASA Technical Reports Server (NTRS)

Seraji, H.

1988-01-01

The author presents a simple decentralized adaptive control scheme for multijoint robot manipulators based on the independent joint control concept. The proposed control scheme for each joint consists of a PID (proportional integral and differential) feedback controller and a position-velocity-acceleration feedforward controller, both with adjustable gains. The static and dynamic couplings that exist between the joint motions are compensated by the adaptive independent joint controllers while ensuring trajectory tracking. The proposed scheme is implemented on a MicroVAX II computer for motion control of the first three joints of a PUMA 560 arm. Experimental results are presented to demonstrate that trajectory tracking is achieved despite strongly coupled, highly nonlinear joint dynamics. The results confirm that the proposed decentralized adaptive control of manipulators is feasible, in spite of strong interactions between joint motions. The control scheme presented is computationally very fast and is amenable to parallel processing implementation within a distributed computing architecture, where each joint is controlled independently by a simple algorithm on a dedicated microprocessor.

Temporomandibular joint involvement caused by Borrelia Burgdorferi.

PubMed

Lesnicar, Gorazd; Zerdoner, Danijel

2007-12-01

Lyme borreliosis is an endemic disease in Slovenia with an incidence of around 150 patients per 100,000 inhabitants. Although the large joints are most typically affected in Lyme borreliosis, there are also periods of disease activity with arthritis or arthralgias involving smaller joints, including the temporo-mandibular joint. During the years between 2000 and 2003, two patients with Lyme borreliosis affecting the temporo-mandibular joints were treated. The patients presented with fatigue and pain in diverse muscle groups accompanied by arthralgia, which was most pronounced in the temporomandibular joint area. None of the patients were febrile or had joint effusions. Both patients were examined by means of biochemical and serological examinations for Borrelia burgdorferi using ELISA assay and Western blot test (both for IgM and IgG), plain radiographs, MR and CT scans, and scinti-scan of the temporo-mandibular joints They both had positive serum markers for an acute B. burgdorferi infection and were treated with intravenous ceftriaxone. None of the patients had clinical or laboratory signs of chronic Lyme disease activity two and four years following therapy, respectively. Roentgenographic and nuclear magnetic resonance imaging of the temporo-mandibular joints had not shown any persistent sign of acute inflammation. There are only few reports of patients with manifest temporo-mandibular joint involvement of Lyme borreliosis in the literature. This report emphasizes the importance of differential diagnosis of acute temporo-mandibular joint arthralgia, of early diagnosis of Lyme borreliosis, and of the necessity for prompt antibiotic treatment.

Change in joint space width: hyaline articular cartilage loss or alteration in meniscus?

PubMed

Hunter, D J; Zhang, Y Q; Tu, X; Lavalley, M; Niu, J B; Amin, S; Guermazi, A; Genant, H; Gale, D; Felson, D T

2006-08-01

To explore the relative contribution of hyaline cartilage morphologic features and the meniscus to the radiographic joint space. The Boston Osteoarthritis of the Knee Study is a natural history study of symptomatic knee osteoarthritis (OA). Baseline and 30-month followup assessments included knee magnetic resonance imaging (MRI) and fluoroscopically positioned weight-bearing knee radiographs. Cartilage and meniscal degeneration were scored on MRI in the medial and lateral tibiofemoral joints using a semiquantitative grading system. Meniscal position was measured to the nearest millimeter. The dependent variable was joint space narrowing (JSN) on the plain radiograph (possible range 0-3). The predictor variables were MRI cartilage score, meniscal degeneration, and meniscal position measures. We first conducted a cross-sectional analysis using multivariate regression to determine the relative contribution of meniscal factors and cartilage morphologic features to JSN, adjusting for body mass index (BMI), age, and sex. The same approach was used for change in JSN and change in predictor variables. We evaluated 264 study participants with knee OA (mean age 66.7 years, 59% men, mean BMI 31.4 kg/m(2)). The results from the models demonstrated that meniscal position and meniscal degeneration each contributed to prediction of JSN, in addition to the contribution by cartilage morphologic features. For change in medial joint space, both change in meniscal position and change in articular cartilage score contributed substantially to narrowing of the joint space. The meniscus (both its position and degeneration) accounts for a substantial proportion of the variance explained in JSN, and the change in meniscal position accounts for a substantial proportion of change in JSN.

Measurement of gastrocnemius muscle elasticity by shear wave elastography: association with passive ankle joint stiffness and sex differences.

PubMed

Chino, Kentaro; Takahashi, Hideyuki

2016-04-01

Passive joint stiffness is an important quantitative measure of flexibility, but is affected by muscle volume and all of the anatomical structures located within and over the joint. Shear wave elastography can assess muscle elasticity independent of the influences of muscle volume and the other nearby anatomical structures. We determined how muscle elasticity, as measured using shear wave elastography, is associated with passive joint stiffness and patient sex. Twenty-six healthy men (24.4 ± 5.9 years) and 26 healthy women (25.2 ± 4.8 years) participated in this study. The passive ankle joint stiffness and tissue elasticity of the medial gastrocnemius (MG) were quantified with the ankle in 30° plantar flexion (PF), a neutral anatomical position (NE), and 20° dorsiflexion (DF). No significant difference in passive joint stiffness by sex was observed with the ankle in PF, but significantly greater passive ankle joint stiffness in men than in women was observed in NE and DF. The MG elasticity was not significantly associated with joint stiffness in PF or NE, but it was significantly associated with joint stiffness in DF. There were no significant differences in MG elasticity by sex at any ankle position. Muscle elasticity, measured independent of the confounding effects of muscle volume and the other nearby anatomical structures, is associated with passive joint stiffness in the joint position where the muscle is sufficiently lengthened, but does not vary by sex in any joint position tested.

Biomechanics of the natural, arthritic, and replaced human ankle joint

PubMed Central

2014-01-01

The human ankle joint complex plays a fundamental role in gait and other activities of daily living. At the same time, it is a very complicated anatomical system but the large literature of experimental and modelling studies has not fully described the coupled joint motion, position and orientation of the joint axis of rotation, stress and strain in the ligaments and their role in guiding and stabilizing joint motion, conformity and congruence of the articular surfaces, patterns of contact at the articular surfaces, patterns of rolling and sliding at the joint surfaces, and muscle lever arm lengths. The present review article addresses these issues as described in the literature, reporting the most recent relevant findings. PMID:24499639

Space station rotary joint mechanisms

NASA Technical Reports Server (NTRS)

Driskill, Glen W.

1986-01-01

The mechanism which will be used on the space station to position the solar arrays and radiator panels for Sun pointing and Sun avoidance is described. The unique design features will be demonstrated on advanced development models of two of the joints being fabricated under contract to NASA-MSFC.

Analysis of a Preloaded Bolted Joint in a Ceramic Composite Combustor

NASA Technical Reports Server (NTRS)

Hissam, D. Andy; Bower, Mark V.

2003-01-01

This paper presents the detailed analysis of a preloaded bolted joint incorporating ceramic materials. The objective of this analysis is to determine the suitability of a joint design for a ceramic combustor. The analysis addresses critical factors in bolted joint design including preload, preload uncertainty, and load factor. The relationship between key joint variables is also investigated. The analysis is based on four key design criteria, each addressing an anticipated failure mode. The criteria are defined in terms of margin of safety, which must be greater than zero for the design criteria to be satisfied. Since the proposed joint has positive margins of safety, the design criteria are satisfied. Therefore, the joint design is acceptable.

Joint Dictionary Learning for Multispectral Change Detection.

PubMed

Lu, Xiaoqiang; Yuan, Yuan; Zheng, Xiangtao

2017-04-01

Change detection is one of the most important applications of remote sensing technology. It is a challenging task due to the obvious variations in the radiometric value of spectral signature and the limited capability of utilizing spectral information. In this paper, an improved sparse coding method for change detection is proposed. The intuition of the proposed method is that unchanged pixels in different images can be well reconstructed by the joint dictionary, which corresponds to knowledge of unchanged pixels, while changed pixels cannot. First, a query image pair is projected onto the joint dictionary to constitute the knowledge of unchanged pixels. Then reconstruction error is obtained to discriminate between the changed and unchanged pixels in the different images. To select the proper thresholds for determining changed regions, an automatic threshold selection strategy is presented by minimizing the reconstruction errors of the changed pixels. Adequate experiments on multispectral data have been tested, and the experimental results compared with the state-of-the-art methods prove the superiority of the proposed method. Contributions of the proposed method can be summarized as follows: 1) joint dictionary learning is proposed to explore the intrinsic information of different images for change detection. In this case, change detection can be transformed as a sparse representation problem. To the authors' knowledge, few publications utilize joint learning dictionary in change detection; 2) an automatic threshold selection strategy is presented, which minimizes the reconstruction errors of the changed pixels without the prior assumption of the spectral signature. As a result, the threshold value provided by the proposed method can adapt to different data due to the characteristic of joint dictionary learning; and 3) the proposed method makes no prior assumption of the modeling and the handling of the spectral signature, which can be adapted to different data.

Sample positioning in microgravity

NASA Technical Reports Server (NTRS)

Sridharan, Govind (Inventor)

1991-01-01

Repulsion forces arising from laser beams are provided to produce mild positioning forces on a sample in microgravity vacuum environments. The system of the preferred embodiment positions samples using a plurality of pulsed lasers providing opposing repulsion forces. The lasers are positioned around the periphery of a confinement area and expanded to create a confinement zone. The grouped laser configuration, in coordination with position sensing devices, creates a feedback servo whereby stable position control of a sample within microgravity environment can be achieved.

Sample positioning in microgravity

NASA Technical Reports Server (NTRS)

Sridharan, Govind (Inventor)

1993-01-01

Repulsion forces arising from laser beams are provided to produce mild positioning forces on a sample in microgravity vacuum environments. The system of the preferred embodiment positions samples using a plurality of pulsed lasers providing opposing repulsion forces. The lasers are positioned around the periphery of a confinement area and expanded to create a confinement zone. The grouped laser configuration, in coordination with position sensing devices, creates a feedback servo whereby stable position control of a sample within microgravity environment can be achieved.

[Effect of calcaneocuboid arthrodesis on three-dimensional kinematics of talonavicular joint].

PubMed

Chen, Yanxi; Yu, Guangrong; Ding, Zhuquan

2007-03-01

To discuss the effect of the calcaneocuboid arthrodesis on three-dimensional kinematics of talonavicular joint and its clinical significance. Ten fresh-frozen foot specimens, three-dimensional kinematics of talonavicular joint were determined in the case of neutral position, dorsiflexion. plantoflexion, adduction, abduction, inversion and eversion motion by means of three-dimensional coordinate instrument (Immersion MicroScribe G2X) before and after calcaneocuboid arthrodesis under non-weight with moment of couple, bending moment, equilibrium dynamic loading. Calcaneocuboid arthrodesis was performed on these feet in neutral position and the lateral column of normal length. A significant decrease in the three-dimensional kinematics of talonavicular joint was observed (P < 0.01) in cadaver model following calcaneocuboid arthrodesis. Talonavicular joint motion was diminished by 31.21% +/- 6.08% in sagittal plane; by 51.46% +/- 7.91% in coronal plane; by 36.98% +/- 4.12% in transverse plane; and averagely by 41.25% +/- 6.02%. Calcancocuboid arthrodesis could limite motion of the talonavicular joints, and the disadvantage of calcaneocuboid arthrodesis shouldn't be neglected.

An artery accompanying the sciatic nerve (arteria comitans nervi ischiadici) and the position of the hip joint: a comparative histological study using chick, mouse, and human foetal specimens.

PubMed

Ishizawa, A; Hayashi, S; Nasu, H; Abe, H; Rodríguez-Vázquez, J F; Murakami, G

2013-02-01

Birds and reptiles always carry a long and thick artery accompanying the sciatic nerve (i.e., the sciatic artery), whereas mammals do not. We attempted to demonstrate a difference in courses of the nerve and artery in fetuses in relation with the hip joint posture. Eight mid-term human fetuses (15-18 weeks), five mouse fetuses (E18) and five chick embryos (11 days after incubation) were examined histologically. Thin feeding arteries in the sciatic nerve were consistently observed in human fetuses in spite of the long, inferiorly curved course of the nerve around the ischium. The tissue around the human sciatic nerve was not so tight because of the medial and inferior shift of the nerve away from the hip joint. The fetal hip joint position differed among the species, being highly flexed in humans and almost at right angle flexion in mice and chicks. Because of deep adduction of the hip joint in the mouse, the knee was located near the midline of the body. The mouse sciatic nerve ran through the tight tissue along the head of the femur, whereas the chick nerve ran through the loose space even in the gluteal region. In birds, evolution of the pelvis including the hip joint without adduction seemed to make the arterial development possible. In mammals, highly flexed or adducted hip joint seemed to be one of the disturbing factors against development of the long and thick artery. A slight change in posture may cause significant arterial variation.

Hypnagogic Exploration: Sleep Positions and Personality.

ERIC Educational Resources Information Center

Domino, George; Bohn, Sarah Ann

1980-01-01

Sleep positions, particularly the full fetal position, appear to be related to California Psychological Inventory (CPI) variables of sociability, sense of well being, achievement by conformance, femininity, and social maturity. (Author)

Residential Stability and Academic Sense of Control

ERIC Educational Resources Information Center

Gigliotti, Richard J.

1976-01-01

Suggests that stability level of an individual and the community in which he operates is directly related to a child's sense of control and consequently his achievement in school. Findings indicate that for whites, community stability is positively and significantly related to sense of control, with the inverse for blacks. (Author/AM)

Models for joint ophthalmology-optometry patient management.

PubMed

Kim, John J; Kim, Christine M

2011-07-01

American Academy of Ophthalmology (AAO) and American Society of Cataract and Refractive Surgery (ASCRS) presented a joint position paper in February 2000 declaring that they do not support routine comanagement of patients with the optometrists. American Optometric Association and American Academy of Optometry quickly responded in support of AAO and ASCRS. All four entities did not preclude legitimate and proper comanagement arrangements. Since that time, the pattern of practice has changed, requiring us to rethink our positions. This paper is written to provide a possible model for the ophthalmology-optometry practice management in ophthalmic surgeries including refractive surgery. Since the publication of the Joint Position Paper, the concept of comanagement has faded and a new model of integrated management has evolved. This has occurred as the changes in the employment pattern of the ophthalmic practice have incorporated optometrists into its fold. This evolution allowed ophthalmic and optometric community to co-exist and thrive to provide better patient care.

The effects of load carriage on joint work at different running velocities.

PubMed

Liew, Bernard X W; Morris, Susan; Netto, Kevin

2016-10-03

Running with load carriage has become increasingly prevalent in sport, as well as many field-based occupations. However, the "sources" of mechanical work during load carriage running are not yet completely understood. The purpose of this study was to determine the influence of load magnitudes on the mechanical joint work during running, across different velocities. Thirty-one participants performed overground running at three load magnitudes (0%, 10%, 20% body weight), and at three velocities (3, 4, 5m/s). Three dimensional motion capture was performed, with synchronised force plate data captured. Inverse dynamics was used to quantify joint work in the stance phase of running. Joint work was normalized to a unit proportion of body weight and leg length (one dimensionless work unit=532.45J). Load significantly increased total joint work and total positive work and this effect was greater at faster velocities. Load carriage increased ankle positive work (β coefficient=rate of 6.95×10 -4 unit work per 1% BW carried), and knee positive (β=1.12×10 -3 unit) and negative work (β=-2.47×10 -4 unit), and hip negative work (β=-7.79×10 -4 unit). Load carriage reduced hip positive work and this effect was smaller at faster velocities. Inter-joint redistribution did not contribute significantly to altered mechanical work within the spectrum of load and velocity investigated. Hence, the ankle joint contributed to the greatest extent in work production, whilst that of the knee contributed to the greatest extent to work absorption when running with load. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rotational joint assembly for the prosthetic leg

NASA Technical Reports Server (NTRS)

Owens, L. J.; Jones, W. C. (Inventor)

1977-01-01

A rotational joint assembly for a prosthetic leg has been devised, which enables an artificial foot to rotate slightly when a person is walking, running or turning. The prosthetic leg includes upper and lower tubular members with the rotational joint assembly interposed between them. The assembly includes a restrainer mechanism which consists of a pivotably mounted paddle element. This device applies limiting force to control the rotation of the foot and also restores torque to return the foot back to its initial position.

Switching algorithm for maglev train double-modular redundant positioning sensors.

PubMed

He, Ning; Long, Zhiqiang; Xue, Song

2012-01-01

High-resolution positioning for maglev trains is implemented by detecting the tooth-slot structure of the long stator installed along the rail, but there are large joint gaps between long stator sections. When a positioning sensor is below a large joint gap, its positioning signal is invalidated, thus double-modular redundant positioning sensors are introduced into the system. This paper studies switching algorithms for these redundant positioning sensors. At first, adaptive prediction is applied to the sensor signals. The prediction errors are used to trigger sensor switching. In order to enhance the reliability of the switching algorithm, wavelet analysis is introduced to suppress measuring disturbances without weakening the signal characteristics reflecting the stator joint gap based on the correlation between the wavelet coefficients of adjacent scales. The time delay characteristics of the method are analyzed to guide the algorithm simplification. Finally, the effectiveness of the simplified switching algorithm is verified through experiments.

Switching Algorithm for Maglev Train Double-Modular Redundant Positioning Sensors

PubMed Central

He, Ning; Long, Zhiqiang; Xue, Song

2012-01-01

High-resolution positioning for maglev trains is implemented by detecting the tooth-slot structure of the long stator installed along the rail, but there are large joint gaps between long stator sections. When a positioning sensor is below a large joint gap, its positioning signal is invalidated, thus double-modular redundant positioning sensors are introduced into the system. This paper studies switching algorithms for these redundant positioning sensors. At first, adaptive prediction is applied to the sensor signals. The prediction errors are used to trigger sensor switching. In order to enhance the reliability of the switching algorithm, wavelet analysis is introduced to suppress measuring disturbances without weakening the signal characteristics reflecting the stator joint gap based on the correlation between the wavelet coefficients of adjacent scales. The time delay characteristics of the method are analyzed to guide the algorithm simplification. Finally, the effectiveness of the simplified switching algorithm is verified through experiments. PMID:23112657

Changes in temporomandibular joint spaces after arthroscopic disc repositioning: a self-control study

PubMed Central

Kai Hu, Ying; Abdelrehem, Ahmed; Yang, Chi; Cai, Xie Yi; Xie, Qian Yang; Sah, Manoj Kumar

2017-01-01

Disc repositioning is a common procedure for patients with anterior disc displacement (ADD). The purpose of this retrospective record-based study was to evaluate changes in the widths of joint spaces and condylar position changes in patients with unilateral ADD following arthroscopic disc repositioning, with the healthy sides as self-control, using magnetic resonance images (MRI).Widths of anterior, superior, and posterior joint spaces (AS, SS, and PS) were measured. The condylar position was described as anterior, centric or posterior, expressed as . Paired-t test and Chi-square test were used to analyze the data. Fifty-four records conformed to the inclusion criteria (mean age of 21.02 years). Widths of SS and PS increased significantly after surgery (P < 0.001) on the operative sides, while joint spaces of healthy sides and AS of operative sides had no significant changes. Dominant location of condyles of operative sides changed from a posterior position to an anterior position, while healthy sides were mostly centric condylar position no matter preoperatively or postoperatively. Therefore, the results of this study indicate that unilateral arthroscopic disc repositioning significantly increases the posterior and superior spaces of the affected joints, without affecting spaces of the healthy sides. PMID:28361905

Joint-use park-and-ride lots.

DOT National Transportation Integrated Search

1989-01-01

Joint-use park-and-ride lots have proven successful in Virginia as well as other states. As expected, there are both positive and negative aspects of such lots; these are described in this report. In addition, information on incentives to lot owners,...

Radiation hydrodynamic effects in two beryllium plates with an idealized aluminum joint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belkov, S.A.; Mkhitarian, L.S.; Vinokurov, O.A.

A beryllium capsule formed from two hemispherical shells with a thin bond is one possible ignition target for the National Ignition Facility [J. A. Paisner {ital et al.}, Laser Focus World {bold 30}, 75 (1994)] Nonuniformities in density, opacity, and interface position at the joint between these hemishells will initiate two-dimensional (2-D) perturbations of the shock wave and material behind the shock as the shock passes through the shell perpendicular to the joint width. Rarefaction of material flow behind the shock front can cause the interface between the shell and joint material to oscillate in position. The amplitude of thesemore » oscillations may be comparable to the joint width. The evolution of these perturbations is studied by numerically simulating shock passage through flat beryllium plates containing aluminum joints. Using the MIMOSA-ND code [D. Sofronov {ital et al.}, Vopr. At. Nauki Tekh., Ser: Mat. modelirovanie fizicheskih processov {bold 2}, 3 (1990)] two different cases are calculated{emdash}a wide (10 {mu}m) and a narrow (1 {mu}m) joint of aluminum between two 150 {mu}m long semiinfinite beryllium plates. Both cases showed good agreement with an analytic representation of the oscillation behavior. For the narrow joint, a special technique allows the calculation of mixing between the joint and surrounding material caused by the Kelvin{endash}Helmholtz instability. {copyright} {ital 1999 American Institute of Physics.}« less

Management of acromioclavicular joint injuries.

PubMed

Li, Xinning; Ma, Richard; Bedi, Asheesh; Dines, David M; Altchek, David W; Dines, Joshua S

2014-01-01

Acromioclavicular joint injuries are among the most common shoulder girdle injuries in athletes and most commonly result from a direct force to the acromion with the arm in an adducted position. Acromioclavicular joint injuries often present with associated injuries to the glenohumeral joint, including an increased incidence of superior labrum anterior posterior (SLAP) tears that may warrant further evaluation and treatment. Anteroposterior stability of the acromioclavicular joint is conferred by the capsule and acromioclavicular ligaments, of which the posterior and superior ligaments are the strongest. Superior-inferior stability is maintained by the coracoclavicular (conoid and trapezoid) ligaments. Type-I or type-II acromioclavicular joint injuries have been treated with sling immobilization, early shoulder motion, and physical therapy, with favorable outcomes. Return to activity can occur when normal shoulder motion and strength are obtained and the shoulder is asymptomatic as compared with the contralateral normal extremity. The management of type-III injuries remains controversial and is individualized. While a return to the previous level of functional activity with nonsurgical treatment has been documented in a number of case series, surgical reduction and coracoclavicular ligament reconstruction has been associated with a favorable outcome and can be considered in patients who place high functional demands on their shoulders or in athletes who participate in overhead sports. Surgical management is indicated for high-grade (≥type IV) acromioclavicular joint injuries to achieve anatomic reduction of the acromioclavicular joint, reconstruction of the coracoclavicular ligaments, and repair of the deltotrapezial fascia. Outcomes after surgical reconstruction of the coracoclavicular ligaments have been satisfactory with regard to achieving pain relief and return to functional activities, but further improvements in the biomechanical strength of these

The VI-SENSE-vaginal discharge self-test to facilitate management of vaginal symptoms.

PubMed

Geva, Adam; Bornstein, Jacob; Dan, Michael; Shoham, Hadar Kessary; Sobel, Jack D

2006-11-01

This study was undertaken to evaluate a diagnostic panty liner (VI-SENSE) (Common Sense, Caesarea, Israel) developed to facilitate diagnosis of vaginal infections by detecting disordered acidity level. Five hundred sixteen women with vulvovaginal symptoms were enrolled. Final clinical diagnosis included Amsel criteria, Gram stain analysis, pH determination, and Trichomonas vaginalis and Candida culture. VI-SENSE strip color status estimated by patients was compared with clinical diagnosis and pH measurement by using nitrazine paper. Statistical analysis included sensitivity and specificity calculations. The VI-SENSE test was positive in 226 of 249 patients (90.8%) with bacterial vaginosis or trichomoniasis. Nitrazine pH paper revealed elevated pH in 165 (66.5%) and the amine test was positive in 160 (64.3%) patients. The VI-SENSE test was negative in 217 of 267 patients (81.3%) without trichomoniasis or bacterial vaginosis. The VI-SENSE was positive in 85 of 92 women (92%), with mixed vaginal infection including Candida and bacterial vaginosis or trichomoniasis. Amine test, nitrazine pH paper and physician diagnosis relying only on speculum examination were inferior and positive in only 65 (70%), 59 (64%), and 66 (72%) patients, respectively. The VI-SENSE test was found to be superior to traditional individual tests in facilitating preliminary diagnosis of vaginal infections.

Knee joint effusion following ipsilateral hip surgery.

PubMed

Christodoulou, A G; Givissis, P; Antonarakos, P D; Petsatodis, G E; Hatzokos, I; Pournaras, J D

2010-12-01

To correlate patellar reflex inhibition with sympathetic knee joint effusion. 65 women and 40 men aged 45 to 75 (mean, 65) years underwent hip surgery. The surgery entailed dynamic hip screw fixation using the lateral approach with reflection of the vastus lateralis for pertrochantric fractures (n = 49), and hip hemiarthroplasty or total hip replacement using the Watson-Jones approach (n = 38) or hip hemiarthroplasty using the posterior approach (n = 18) for subcapital femoral fractures (n = 28) or osteoarthritis (n = 28). Knee joint effusion, patellar reflex, and thigh circumference were assessed in both legs before and after surgery (at day 0.5, 2, 7, 14, 30, and 45). Time-sequence plots were used for chronological analysis, and correlation between patellar reflex inhibition and knee joint effusion was tested. In the time-sequence plot, the peak frequency of patellar reflex inhibition (on day 0.5) preceded that of the knee joint effusion and the thigh circumference increase (on day 2). Patellar reflex inhibition correlated positively with the knee joint effusion (r = 0.843, p = 0.035). These 2 factors correlated significantly for all 3 surgical approaches (p < 0.0005). All 3 approaches were associated with patellar reflex inhibition on day 0.5 (p = 0.033) and knee joint effusion on day 2 (p = 0.051). Surgical trauma of the thigh may cause patellar reflex inhibition and subsequently knee joint effusion.

Orthotic arm joint. [for use in mechanical arms

NASA Technical Reports Server (NTRS)

Dane, D. H. (Inventor)

1974-01-01

An improved orthopedic (orthotic) arm joint that can be used in various joint of mechanical arms is described. The arm joints includes a worm, which is coupled to an electric motor for rotating a worm gear carried within a rotatable housing. The worm gear is supported on a thrust bearing and the rotatable housing is supported on a radial thrust bearing. A bolt extends through the housing, bearings, and worm gear for securing the device together. A potentiometer extends through the bolt, and is coupled to the rotatable housing for rotating therewith, so as to produce an electrical signal indicating the angular position of the rotatable housing.

Remote sensing for rural development planning in Africa

NASA Technical Reports Server (NTRS)

Dunford, C.; Mouat, D. A.; Norton-Griffiths, M.; Slaymaker, D. M.

1983-01-01

Multilevel remote-sensing techniques were combined to provide land resource and land-use information for rural development planning in Arusha Region, Tanzania. Enhanced Landsat imagery, supplemented by low-level aerial survey data, slope angle data from topographic sheets, and existing reports on vegetation and soil conditions, was used jointly by image analysts and district-level land-management officials to divide the region's six districts into land-planning units. District-planning officials selected a number of these land-planning units for priority planning and development activities. For the priority areas, natural color aerial photographs provided detailed information for land-use planning discussions between district officials and villagers. Consideration of the efficiency of this remote sensing approach leads to general recommendations for similar applications. The technology and timing of data collection and interpretation activities should allow maximum participation by intended users of the information.

Inter-joint coordination in producing kicking velocity of taekwondo kicks.

PubMed

Kim, Young Kwan; Kim, Yoon Hyuk; Im, Shin Ja

2011-01-01

The purpose of this study was to investigate joint kinematics of the kicking leg in Taekwondo and to examine the role of inter-joint coordination of the leg in producing the kicking velocity. A new inter-joint coordination index that encompasses three- dimensional hip and knee motions, was defined and applied to the joint kinematic results. Twelve elite Taekwondo athletes participated in this study and performed the back kick, thrashing kick, turning-back kick and roundhouse kick. Our results indicate that the back kick utilized a combination of hip and knee extension to produce the kicking velocity, and was characterized by a pushlike movement. The thrashing kick and turning-back kick utilized a greater degree of hip abduction than the roundhouse kick and back kick, and included complicated knee motions. The new index successfully categorized the thrashing kick and turning-back kick into a push-throw continuum, indicating a change from negative index (opposite direction) to positive index (same direction) of hip and knee motions at the end of the movement. This strategy of push-throw continuum increases the kicking velocity at the moment of impact by applying a throwlike movement pattern. Key pointsA variety of Taekwondo kicks have unique inter-joint coordination of the kicking leg.The back kick used a combination of hip and knee extension to produce the kicking velocity, and was characterized by a pushlike movement.The new index explained well the inter-joint coordination of three DOF joint motions of two joints in producing kicking velocity (positive values for throwlike movements and negative values for pushlike movements).The index successfully categorized the thrashing kick and turning-back kick into a push-throw continuum.

Images of a Loving God and Sense of Meaning in Life

ERIC Educational Resources Information Center

Stroope, Samuel; Draper, Scott; Whitehead, Andrew L.

2013-01-01

Although prior studies have documented a positive association between religiosity and sense of meaning in life, the role of specific religious beliefs is currently unclear. Past research on images of God suggests that loving images of God will positively correlate with a sense of meaning and purpose. Mechanisms for this hypothesized relationship…

Utility of Intraoperative Neuromonitoring during Minimally Invasive Fusion of the Sacroiliac Joint.

PubMed

Woods, Michael; Birkholz, Denise; MacBarb, Regina; Capobianco, Robyn; Woods, Adam

2014-01-01

Study Design. Retrospective case series. Objective. To document the clinical utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion for patients diagnosed with sacroiliac joint dysfunction (as a direct result of sacroiliac joint disruptions or degenerative sacroiliitis) and determine stimulated electromyography thresholds reflective of favorable implant position. Summary of Background Data. Intraoperative neuromonitoring is a well-accepted adjunct to minimally invasive pedicle screw placement. The utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion using a series of triangular, titanium porous plasma coated implants has not been evaluated. Methods. A medical chart review of consecutive patients treated with minimally invasive surgical sacroiliac joint fusion was undertaken at a single center. Baseline patient demographics and medical history, intraoperative electromyography thresholds, and perioperative adverse events were collected after obtaining IRB approval. Results. 111 implants were placed in 37 patients. Sensitivity of EMG was 80% and specificity was 97%. Intraoperative neuromonitoring potentially avoided neurologic sequelae as a result of improper positioning in 7% of implants. Conclusions. The results of this study suggest that intraoperative neuromonitoring may be a useful adjunct to minimally invasive surgical sacroiliac joint fusion in avoiding nerve injury during implant placement.

Monitoring of bolted joints using piezoelectric active-sensing for aerospace applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Gyuhae; Farrar, Charles R; Park, Chan - Yik

2010-01-01

This paper is a report of an initial investigation into tracking and monitoring the integrity of bolted joints using piezoelectric active-sensors. The target application of this study is a fitting lug assembly of unmanned aerial vehicles (UAVs), where a composite wing is mounted to a UAV fuselage. The SHM methods deployed in this study are impedance-based SHM techniques, time-series analysis, and high-frequency response functions measured by piezoelectric active-sensors. Different types of simulated damage are introduced into the structure, and the capability of each technique is examined and compared. Additional considerations encountered in this initial investigation are made to guide furthermore » thorough research required for the successful field deployment of this technology.« less

Wavefront Sensing With Switched Lenses for Defocus Diversity

NASA Technical Reports Server (NTRS)

Dean, Bruce H.

2007-01-01

In an alternative hardware design for an apparatus used in image-based wavefront sensing, defocus diversity is introduced by means of fixed lenses that are mounted in a filter wheel (see figure) so that they can be alternately switched into a position in front of the focal plane of an electronic camera recording the image formed by the optical system under test. [The terms image-based, wavefront sensing, and defocus diversity are defined in the first of the three immediately preceding articles, Broadband Phase Retrieval for Image-Based Wavefront Sensing (GSC-14899-1).] Each lens in the filter wheel is designed so that the optical effect of placing it at the assigned position is equivalent to the optical effect of translating the camera a specified defocus distance along the optical axis. Heretofore, defocus diversity has been obtained by translating the imaging camera along the optical axis to various defocus positions. Because data must be taken at multiple, accurately measured defocus positions, it is necessary to mount the camera on a precise translation stage that must be calibrated for each defocus position and/or to use an optical encoder for measurement and feedback control of the defocus positions. Additional latency is introduced into the wavefront sensing process as the camera is translated to the various defocus positions. Moreover, if the optical system under test has a large focal length, the required defocus values are large, making it necessary to use a correspondingly bulky translation stage. By eliminating the need for translation of the camera, the alternative design simplifies and accelerates the wavefront-sensing process. This design is cost-effective in that the filterwheel/lens mechanism can be built from commercial catalog components. After initial calibration of the defocus value of each lens, a selected defocus value is introduced by simply rotating the filter wheel to place the corresponding lens in front of the camera. The rotation of the

Distributed optical fiber vibration sensing using phase-generated carrier demodulation algorithm

NASA Astrophysics Data System (ADS)

Yu, Zhihua; Zhang, Qi; Zhang, Mingyu; Dai, Haolong; Zhang, Jingjing; Liu, Li; Zhang, Lijun; Jin, Xing; Wang, Gaifang; Qi, Guang

2018-05-01

A novel optical fiber-distributed vibration-sensing system is proposed, which is based on self-interference of Rayleigh backscattering with phase-generated carrier (PGC) demodulation algorithm. Pulsed lights are sent into the sensing fiber and the Rayleigh backscattering light from a certain position along the sensing fiber would interfere through an unbalanced Michelson interferometry to generate the interference light. An improved PGC demodulation algorithm is carried out to recover the phase information of the interference signal, which carries the sensing information. Three vibration events were applied simultaneously to different positions over 2000 m sensing fiber and demodulated correctly. The spatial resolution is 10 m, and the noise level of the Φ-OTDR system we proposed is about 10-3 rad/\\surd {Hz}, and the signal-to-noise ratio is about 30.34 dB.

Load positioning system with gravity compensation

NASA Technical Reports Server (NTRS)

Hollow, R. H.

1984-01-01

A load positioning system with gravity compensation has a servomotor, position sensing feedback potentiometer and velocity sensing tachometer in a conventional closed loop servo arrangement to cause a lead screw and a ball nut to vertically position a load. Gravity compensating components comprise the DC motor, gears, which couple torque from the motor to the lead screw, and constant current power supply. The constant weight of the load applied to the lead screw via the ball nut tend to cause the lead screw to rotate, the constant torque of which is opposed by the constant torque produced by the motor when fed from the constant current source. The constant current is preset as required by the potentiometer to effect equilibration of the load which thereby enables the positioning servomotor to see the load as weightless under both static and dynamic conditions. Positioning acceleration and velocity performance are therefore symmetrical.

Airborne Geophysics and Remote Sensing Applied to Study Greenland Ice Dynamics

NASA Technical Reports Server (NTRS)

Csatho, Beata M.

2003-01-01

Overview of project: we combined and jointly analysed geophysical, remote sensing and glaciological data for investigating the temporal changes in ice flow and the role of geologic control on glacial drainage. The project included two different studies, the investigation of recent changes of the Kangerlussuaq glacier and the study of geologic control of ice flow in NW Greenland, around the Humboldt, Petermann and Ryder glaciers.

Positive basis for surface skein algebras

PubMed Central

Thurston, Dylan Paul

2014-01-01

We show that the twisted SL2 skein algebra of a surface has a natural basis (the bracelets basis) that is positive, in the sense that the structure constants for multiplication are positive integers. PMID:24982193

Properties of centralized cooperative sensing in cognitive radio networks

NASA Astrophysics Data System (ADS)

Skokowski, Paweł; Malon, Krzysztof; Łopatka, Jerzy

2017-04-01

Spectrum sensing is a functionality that enables network creation in the cognitive radio technology. Spectrum sensing is use for building the situation awareness knowledge for better use of radio resources and to adjust network parameters in case of jamming, interferences from legacy systems, decreasing link quality caused e.g. by nodes positions changes. This paper presents results from performed tests to compare cooperative centralized sensing versus local sensing. All tests were performed in created simulator developed in Matlab/Simulink environment.

FRAX(®) Clinical Task Force of the 2010 Joint International Society for Clinical Densitometry & International Osteoporosis Foundation Position Development Conference.

PubMed

McCloskey, Eugene V; Binkley, Neil

2011-01-01

The World Health Organization fracture risk assessment tool, FRAX(®), is an advance in clinical care that can assist in clinical decision-making. However, with increasing clinical utilization, numerous questions have arisen regarding how to best estimate fracture risk in an individual patient. Recognizing the need to assist clinicians in optimal use of FRAX(®), the International Osteoporosis Foundation (IOF) in conjunction with the International Society for Clinical Densitometry (ISCD) assembled an international panel of experts that ultimately developed joint Official Positions of the ISCD and IOF advising clinicians regarding FRAX(®) usage. As part of the process, the charge of the FRAX(®) Clinical Task Force was to review and synthesize data surrounding a number of recognized clinical risk factors including rheumatoid arthritis, smoking, alcohol, prior fracture, falls, bone turnover markers and glucocorticoid use. This synthesis was presented to the expert panel and constitutes the data on which the subsequent Official Positions are predicated. A summary of the Clinical Task Force composition and charge is presented here. Copyright © 2011. Published by Elsevier Inc.

Environmental Public Health Survelliance for Exposure to Respiratory Health Hazards: A Joint NASA/CDC Project to Use Remote Sensing Data for Estimating Airborne Particulate Matter Over the Atlanta, Georgia Metropolitan Area

NASA Technical Reports Server (NTRS)

Quattrochi, Dale A.; Rickman, Douglas; Mohammad, Al-Hamdan; Crosson, William; Estes, Maurice, Jr.; Limaye, Ashutosh; Qualters, Judith

2008-01-01

Describes the public health surveillance efforts of NASA, in a joint effort with the Center for Disease Control (CDC). NASA/MSFC and the CDC are partners in linking nvironmental and health data to enhance public health surveillance. The use of NASA technology creates value - added geospatial products from existing environmental data sources to facilitate public health linkages. The venture sought to provide remote sensing data for the 5-country Metro-Atlanta area and to integrate this environmental data with public health data into a local network, in an effort to prevent and control environmentally related health effects. Remote sensing data used environmental data (Environmental Protection Agency [EPA] Air Quality System [AQS] ground measurements and MODIS Aerosol Optical Depth [AOD]) to estimate airborne particulate matter over Atlanta, and linked this data with health data related to asthma. The study proved the feasibility of linking environmental data (MODIS particular matter estimates and AQS) with health data (asthma). Algorithms were developed for QC, bias removal, merging MODIS and AQS particulate matter data, as well as for other applications. Additionally, a Business Associate Agreement was negotiated for a health care provider to enable sharing of Protected Health Information.

Reconstruction of equilibrium trajectories and joint stiffness patterns during single-joint voluntary movements under different instructions.

PubMed

Latash, M L

1994-01-01

A method for reconstructing joint compliant characteristics during voluntary movements was applied to the analysis of oscillatory and unidirectional elbow flexion movements. In different series, the subjects were given one of the following instructions: (1) do not intervene voluntarily; (2) keep the trajectory; (3) in cases of perturbations, return back to the starting position as quickly as possible (only during unidirectional movements). Under the instruction 'keep trajectory', the apparent joint stiffness increased by 50% to 250%. During oscillatory movements, this was accompanied by a decrease in the maximal difference between the actual and equilibrium joint trajectories and, in several cases, led to a change in the phase relation between the two trajectories. The coefficients of correlation between joint torque and angle were very high (commonly, over 0.9) under the 'do not intervene' instruction. They dropped to about 0.6 under the 'keep trajectory' and to about 0.3 under the 'return back' instructions. Under these two instructions, the low values of the coefficients of correlation did not allow reconstruction of segments of equilibrium trajectories and joint stiffness values in all the subjects. The results provide further support for the lambda-version of the equilibrium-point hypothesis and for using the instruction 'do not intervene voluntarily' to obtain reproducible time patterns of the central motor command.

[The effect of supervised rehabilitation on ankle joint function and the risk of recurrence after acute ankle distortion].

PubMed

Barkler, E H; Magnusson, S P; Becher, K; Bieler, T; Aagaard, P; Kjaer, M; Saugbjerg, P A

2001-06-04

The effect of an early rehabilitation programme, including postural training, on ankle joint function after an ankle ligament sprain was investigated prospectively. Ninety-two subjects, matched for age, sex, and level of sports activity, were randomised to a control or training group. All subjects received the same standard information about early ankle mobilisation. In addition, the training group participated in supervised physical therapy rehabilitation (one hour, twice weekly) with emphasis on balance training. Postural sway, position sense, and isometric ankle strength were measured six weeks and four months after the injury, and at 12 months data on re-injury were collected. In both the training group and the control group, there were a significant difference between the injured and the uninjured side for all variables except for position sense at six weeks. The side-to-side differences in per cent were similar for both groups for all variables (p > 0.05) at six weeks, and there were no such differences at four months. Re-injury occurred in 11/38 (29%) is the control group, but in only 2/29 (7%) in the training group (p < 0.05). These data showed that an ankle injury led to reduced ankle strength and postural control at six weeks, but that these variables had become normal at four months, irrespective of supervised rehabilitation. However, the findings also showed that supervised rehabilitation may reduce the number of re-injuries, and may therefore play a role in injury prevention.

An instrumented spatial linkage for measuring knee joint kinematics.

PubMed

Rosvold, Joshua M; Atarod, Mohammad; Frank, Cyril B; Shrive, Nigel G

2016-01-01

In this study, the design and development of a highly accurate instrumented spatial linkage (ISL) for kinematic analysis of the ovine stifle joint is described. The ovine knee is a promising biomechanical model of the human knee joint. The ISL consists of six digital rotational encoders providing six degrees of freedom (6-DOF) to its motion. The ISL makes use of the complete and parametrically continuous (CPC) kinematic modeling method to describe the kinematic relationship between encoder readings and the relative positions and orientation of its two ends. The CPC method is useful when calibrating the ISL, because a small change in parameters corresponds to a small change in calculated positions and orientations and thus a smaller optimization error, compared to other kinematic models. The ISL is attached rigidly to the femur and the tibia for motion capture, and the CPC kinematic model is then employed to transform the angle sensor readings to relative motion of the two ends of the linkage, and thereby, the stifle joint motion. The positional accuracy for ISL after calibration and optimization was 0.3±0.2mm (mean +/- standard deviation). The ISL was also evaluated dynamically to ensure that accurate results were maintained, and achieved an accuracy of 0.1mm. Compared to the traditional motion capture methods, this system provides increased accuracy, reduced processing time, and ease of use. Future work will be on the application of the ISL to the ovine gait and determination of in vivo joint motions and tissue loads. Accurate measurement of knee joint kinematics is essential in understanding injury mechanisms and development of potential preventive or treatment strategies. Copyright © 2015 Elsevier B.V. All rights reserved.

Complex mammary carcinoma with metastases to lymph nodes, subcutaneous tissue, and multiple joints in a dog.

PubMed

McCourt, Maggie R; Dieterly, Alexandra M; Mackey, Paige E; Lyon, Shane D; Rizzi, Theresa E; Ritchey, Jerry W

2018-05-07

An 8-year-old, intact female, mixed-breed dog presented to the Oklahoma State University Boren Veterinary Medical Teaching Hospital for evaluation of progressive lameness and joint effusion of multiple joints. Physical examination revealed joint effusion of the elbow, hock, and stifle joints bilaterally, enlarged left axillary and right popliteal lymph nodes, a subcutaneous mass over the left elbow, and a subcutaneous mass involving the left second and third mammary glands. Cytologic examination of the mammary mass, enlarged lymph nodes, and joint fluid from most affected joints revealed a monomorphic population of loosely cohesive neoplastic epithelial cells. The patient was humanely euthanized, and subsequent necropsy with histopathologic examination revealed a complex mammary carcinoma with metastases to enlarged lymph nodes, subcutaneous tissue over the left elbow, and the synovium of multiple joints. Immunohistochemical stains were performed and showed diffusely positive pan cytokeratin, CK8/18, and CK19 staining in the neoplastic luminal epithelial cells of the mammary carcinoma, synovium, and lymph nodes, and showed diffusely positive vimentin staining of the myoepithelial cells. Myoepithelial calponin positivity was diffuse in the mammary mass and lymph nodes but minimal in the synovium. Only the mammary mass showed p63 positivity. Metastatic mammary neoplasia is relatively common in dogs; however, metastasis to the synovium has only been reported once previously in the literature. This is the first case utilizing immunohistochemistry for confirmation and characterization of metastases. © 2018 American Society for Veterinary Clinical Pathology.

Computerized Neuropsychological Assessment Devices: Joint Position Paper of the American Academy of Clinical Neuropsychology and the National Academy of Neuropsychology†

PubMed Central

Bauer, Russell M.; Iverson, Grant L.; Cernich, Alison N.; Binder, Laurence M.; Ruff, Ronald M.; Naugle, Richard I.

2012-01-01

This joint position paper of the American Academy of Clinical Neuropsychology and the National Academy of Neuropsychology sets forth our position on appropriate standards and conventions for computerized neuropsychological assessment devices (CNADs). In this paper, we first define CNADs and distinguish them from examiner-administered neuropsychological instruments. We then set forth position statements on eight key issues relevant to the development and use of CNADs in the healthcare setting. These statements address (a) device marketing and performance claims made by developers of CNADs; (b) issues involved in appropriate end-users for administration and interpretation of CNADs; (c) technical (hardware/software/firmware) issues; (d) privacy, data security, identity verification, and testing environment; (e) psychometric development issues, especially reliability, and validity; (f) cultural, experiential, and disability factors affecting examinee interaction with CNADs; (g) use of computerized testing and reporting services; and (h) the need for checks on response validity and effort in the CNAD environment. This paper is intended to provide guidance for test developers and users of CNADs that will promote accurate and appropriate use of computerized tests in a way that maximizes clinical utility and minimizes risks of misuse. The positions taken in this paper are put forth with an eye toward balancing the need to make validated CNADs accessible to otherwise underserved patients with the need to ensure that such tests are developed and utilized competently, appropriately, and with due concern for patient welfare and quality of care. PMID:22382386

Computerized Neuropsychological Assessment Devices: Joint Position Paper of the American Academy of Clinical Neuropsychology and the National Academy of Neuropsychology†

PubMed Central

Bauer, Russell M.; Iverson, Grant L.; Cernich, Alison N.; Binder, Laurence M.; Ruff, Ronald M.; Naugle, Richard I.

2013-01-01

This joint position paper of the American Academy of Clinical Neuropsychology and the National Academy of Neuropsychology sets forth our position on appropriate standards and conventions for computerized neuropsychological assessment devices (CNADs). In this paper, we first define CNADs and distinguish them from examiner-administered neuropsychological instruments. We then set forth position statements on eight key issues relevant to the development and use of CNADs in the healthcare setting. These statements address (a) device marketing and performance claims made by developers of CNADs; (b) issues involved in appropriate end-users for administration and interpretation of CNADs; (c) technical (hardware/software/firmware) issues; (d) privacy, data security, identity verification, and testing environment; (e) psychometric development issues, especially reliability and validity; (f) cultural, experiential, and disability factors affecting examinee interaction with CNADs; (g) use of computerized testing and reporting services; and (h) the need for checks on response validity and effort in the CNAD environment. This paper is intended to provide guidance for test developers and users of CNADs that will promote accurate and appropriate use of computerized tests in a way that maximizes clinical utility and minimizes risks of misuse. The positions taken in this paper are put forth with an eye toward balancing the need to make validated CNADs accessible to otherwise underserved patients with the need to ensure that such tests are developed and utilized competently, appropriately, and with due concern for patient welfare and quality of care. PMID:22394228

MRI-based stereolithographic models of the temporomandibular joint: technical innovation.

PubMed

Undt, G; Wild, K; Reuther, G; Ewers, R

2000-10-01

A new technique of manufacturing dual-colour stereolithographic models of hard and soft tissues of the temporomandibular joint (TMJ) is presented. Sagittal T1/PD weighted magnetic resonance (MR) images of joints with and without disc displacement were obtained in the closed and open mouth positions. Individual interactive contour identification of bony structures and the articular disc followed by binary interpolation provided the data for the generation of acrylic TMJ models. Three dimensional in vivo visualization of the articular disc in relation to bony structures in the closed and open mouth positions allows a new perception of normal and pathological TMJ anatomy.

Remote Sensing and the Kyoto Protocol: A Workshop Summary

NASA Technical Reports Server (NTRS)

Rosenqvist, Ake; Imhoff, Marc; Milne, Anthony; Dobson, Craig

2000-01-01

The Kyoto Protocol to the United Nations Framework Convention on Climate Change contains quantified, legally binding commitments to limit or reduce greenhouse gas emissions to 1990 levels and allows carbon emissions to be balanced by carbon sinks represented by vegetation. The issue of using vegetation cover as an emission offset raises a debate about the adequacy of current remote sensing systems and data archives to both assess carbon stocks/sinks at 1990 levels, and monitor the current and future global status of those stocks. These concerns and the potential ratification of the Protocol among participating countries is stimulating policy debates and underscoring a need for the exchange of information between the international legal community and the remote sensing community. On October 20-22 1999, two working groups of the International Society for Photogrammetry and Remote Sensing (ISPRS) joined with the University of Michigan (Michigan, USA) to convene discussions on how remote sensing technology could contribute to the information requirements raised by implementation of, and compliance with, the Kyoto Protocol. The meeting originated as a joint effort between the Global Monitoring Working Group and the Radar Applications Working Group in Commission VII of the ISPRS, co-sponsored by the University of Michigan. Tile meeting was attended by representatives from national government agencies and international organizations and academic institutions. Some of the key themes addressed were: (1) legal aspects of transnational remote sensing in the context of the Kyoto Protocol; (2) a review of the current and future and remote sensing technologies that could be applied to the Kyoto Protocol; (3) identification of areas where additional research is needed in order to advance and align remote sensing technology with the requirements and expectations of the Protocol; and 94) the bureaucratic and research management approaches needed to align the remote sensing

Tibiotalar joint arthrodesis for the treatment of severe ankle joint degeneration secondary to rheumatoid arthritis.

PubMed

Caron, M; Kron, E; Saltrick, K R

1999-04-01

The technical aspects of fusion of the rheumatoid ankle do not deviate from those in the post-traumatic or osteoarthritic ankle. Screw fixation can usually be achieved, and rarely is fixation failure a problem in rheumatoid ankle arthrodesis. If fixation is difficult because of deformity or bone quality, external fixation or locking intramedullary nails should be used. The placement of cannulated screws and adequacy of screw fixation has not been a problem (Fig. 13). Screw fixation provides compression and prevents rotation. The surgeon, however, needs to be assured that no screws invade the subtalar joint and that all threads are beyond the arthrodesis site. A washer may be necessary for further stability if this screw is not inserted at too great an angle. The authors have found that troughing out of the cortical surface of the tibia with a power bur aids in screw insertion. Not only does the trough act as a countersink, but it also provides a path for screw insertion and prevents palpable screw irritation. Malalignment is unforgiving. The foot must be placed neutral to dorsiflexion and plantarflexion. Equinus positioning places added stress on the tibia and a back-knee gait occurs. Approximately 5 degrees of valgus is recommended, and varus positioning is unforgiving. Internal and external rotation is determined by the position of the contralateral extremity. Nonunion does not seem to be a problem with rigid internal fixation to any greater degree in patients with RA. Despite this, patients may continue to have pain despite solid fusion, which can be caused by incomplete correction of deformity, painful internal fixation, or adjacent joint pathology. Additionally, patients may experience supramalleolar pain above the fusion site consistent with tibial stress fracture, which is more common if the subtalar or midtarsal joint is rigid or if the patient is obese. A rocker sole shoe with impact-absorbing soles used after brief periods of guarded mobilization in a

[Displacement and tissue remodeling of temporomandibular joint disc].

PubMed

Wang, M Q

2017-03-09

Sounding takes the highest prevalence of the signs of temporomandibular disorders (TMD). The well accepted theory of the mechanism for temporomandibular joint (TMJ) sounding is the internal derangement typically characterized by disc displacement. However, according to literature, there are approximately one third of asymptomatic joints in population had disc displacement, and, on the other hand, there are one fourth of TMJ sounding patients had not signs or very limited signs of disc displacement. Replacing the displaced disc to the normal position via methods like surgical operation did not achieve satisfactory long-term outcomes. In this review, we discuss and analyze the possible remodeling of the joint disc displacement diagnosed with imaging based on the anatomy and pathophysiology.

Inter-Joint Coordination in Producing Kicking Velocity of Taekwondo Kicks

PubMed Central

Kim, Young Kwan; Kim, Yoon Hyuk; Im, Shin Ja

2011-01-01

The purpose of this study was to investigate joint kinematics of the kicking leg in Taekwondo and to examine the role of inter-joint coordination of the leg in producing the kicking velocity. A new inter-joint coordination index that encompasses three- dimensional hip and knee motions, was defined and applied to the joint kinematic results. Twelve elite Taekwondo athletes participated in this study and performed the back kick, thrashing kick, turning-back kick and roundhouse kick. Our results indicate that the back kick utilized a combination of hip and knee extension to produce the kicking velocity, and was characterized by a pushlike movement. The thrashing kick and turning-back kick utilized a greater degree of hip abduction than the roundhouse kick and back kick, and included complicated knee motions. The new index successfully categorized the thrashing kick and turning-back kick into a push-throw continuum, indicating a change from negative index (opposite direction) to positive index (same direction) of hip and knee motions at the end of the movement. This strategy of push-throw continuum increases the kicking velocity at the moment of impact by applying a throwlike movement pattern. Key points A variety of Taekwondo kicks have unique inter-joint coordination of the kicking leg. The back kick used a combination of hip and knee extension to produce the kicking velocity, and was characterized by a pushlike movement. The new index explained well the inter-joint coordination of three DOF joint motions of two joints in producing kicking velocity (positive values for throwlike movements and negative values for pushlike movements). The index successfully categorized the thrashing kick and turning-back kick into a push-throw continuum. PMID:24149292

Mental health and positive change among Japanese mothers of children with intellectual disabilities: Roles of sense of coherence and social capital.

PubMed

Kimura, Miyako; Yamazaki, Yoshihiko

2016-12-01

We investigated predictors of mental health and positive change among mothers of children with intellectual disabilities in Japan based on the concept of the Double ABCX model. We used variables of having a child with autism spectrum disorder (ASD) and dissatisfaction with systems as stressors, availability of social support and social capital (SC) as existing resources, sense of coherence (SOC) as appraisal of the stressor, and mental health and positive change as adaptation. A self-administered questionnaire was distributed to 10 intellectual disability-oriented special needs schools in Tokyo, and obtained 613 responses from mothers of children under age 20 attending these schools. The results showed that our Double ABCX model explained 46.0% of the variance in mothers' mental health and 38.9% of the variance in positive change. The most powerful predictor of this model was SOC, and SC may be directly and indirectly related to maternal mental health and positive change through mothers' SOC. Increasing opportunity for interaction between neighbors and family of children with disabilities may be one effective way to enhance SOC through SC. Since maternal SOC, SC, mental health, and positive change were significantly correlated with each other, synergy among these elements could be expected. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sensors with centroid-based common sensing scheme and their multiplexing

NASA Astrophysics Data System (ADS)

Berkcan, Ertugrul; Tiemann, Jerome J.; Brooksby, Glen W.

1993-03-01

The ability to multiplex sensors with different measurands but with a common sensing scheme is of importance in aircraft and aircraft engine applications; this unification of the sensors into a common interface has major implications for weight, cost, and reliability. A new class of sensors based on a common sensing scheme and their E/O Interface has been developed. The approach detects the location of the centroid of a beam of light; the set of fiber optic sensors with this sensing scheme include linear and rotary position, temperature, pressure, as well as duct Mach number. The sensing scheme provides immunity to intensity variations of the source or due to environmental effects on the fiber. A detector spatially multiplexed common electro-optic interface for the sensors has been demonstrated with a position and a temperature sensor.

A robust control scheme for flexible arms with friction in the joints

NASA Technical Reports Server (NTRS)

Rattan, Kuldip S.; Feliu, Vicente; Brown, H. Benjamin, Jr.

1988-01-01

A general control scheme to control flexible arms with friction in the joints is proposed in this paper. This scheme presents the advantage of being robust in the sense that it minimizes the effects of the Coulomb friction existing in the motor and the effects of changes in the dynamic friction coefficient. A justification of the robustness properties of the scheme is given in terms of the sensitivity analysis.

Position Tracking During Human Walking Using an Integrated Wearable Sensing System.

PubMed

Zizzo, Giulio; Ren, Lei

2017-12-10

Progress has been made enabling expensive, high-end inertial measurement units (IMUs) to be used as tracking sensors. However, the cost of these IMUs is prohibitive to their widespread use, and hence the potential of low-cost IMUs is investigated in this study. A wearable low-cost sensing system consisting of IMUs and ultrasound sensors was developed. Core to this system is an extended Kalman filter (EKF), which provides both zero-velocity updates (ZUPTs) and Heuristic Drift Reduction (HDR). The IMU data was combined with ultrasound range measurements to improve accuracy. When a map of the environment was available, a particle filter was used to impose constraints on the possible user motions. The system was therefore composed of three subsystems: IMUs, ultrasound sensors, and a particle filter. A Vicon motion capture system was used to provide ground truth information, enabling validation of the sensing system. Using only the IMU, the system showed loop misclosure errors of 1% with a maximum error of 4-5% during walking. The addition of the ultrasound sensors resulted in a 15% reduction in the total accumulated error. Lastly, the particle filter was capable of providing noticeable corrections, which could keep the tracking error below 2% after the first few steps.

Estimation of joint stiffness with a compliant load.

PubMed

Ludvig, Daniel; Kearney, Robert E

2009-01-01

Joint stiffness defines the dynamic relationship between the position of the joint and the torque acting about it. It consists of two components: intrinsic and reflex stiffness. Many previous studies have investigated joint stiffness in an open-loop environment, because the current algorithm in use is an open-loop algorithm. This paper explores issues related to the estimation of joint stiffness when subjects interact with compliant loads. First, we show analytically how the bias in closed-loop estimates of joint stiffness depends on the properties of the load, the noise power, and length of the estimated impulse response functions (IRF). We then demonstrate with simulations that the open-loop analysis will fail completely for an elastic load but may succeed for an inertial load. We further show that the open-loop analysis can yield unbiased results with an inertial load and document IRF length, signal-to-noise ratio needed, and minimum inertia needed for the analysis to succeed. Thus, by using a load with a properly selected inertia, open-loop analysis can be used under closed-loop conditions.

Coordinated joint motion control system with position error correction

DOEpatents

Danko, George L.

2016-04-05

Disclosed are an articulated hydraulic machine supporting, control system and control method for same. The articulated hydraulic machine has an end effector for performing useful work. The control system is capable of controlling the end effector for automated movement along a preselected trajectory. The control system has a position error correction system to correct discrepancies between an actual end effector trajectory and a desired end effector trajectory. The correction system can employ one or more absolute position signals provided by one or more acceleration sensors supported by one or more movable machine elements. Good trajectory positioning and repeatability can be obtained. A two joystick controller system is enabled, which can in some cases facilitate the operator's task and enhance their work quality and productivity.

Coordinated joint motion control system with position error correction

DOEpatents

Danko, George [Reno, NV

2011-11-22

Disclosed are an articulated hydraulic machine supporting, control system and control method for same. The articulated hydraulic machine has an end effector for performing useful work. The control system is capable of controlling the end effector for automated movement along a preselected trajectory. The control system has a position error correction system to correct discrepancies between an actual end effector trajectory and a desired end effector trajectory. The correction system can employ one or more absolute position signals provided by one or more acceleration sensors supported by one or more movable machine elements. Good trajectory positioning and repeatability can be obtained. A two-joystick controller system is enabled, which can in some cases facilitate the operator's task and enhance their work quality and productivity.

Comparison of Effects of a Proprioceptive Exercise Program in Water and on Land the Balance of Chronic Stroke Patients

PubMed Central

Han, Seul Ki; Kim, Myung Chul; An, Chang Sik

2013-01-01

[Purpose] The purpose of this study was to compare changes in balance ability of land exercise and underwater exercise on chronic stroke patients. [Subjects] A total of 60 patients received exercise for 40 minutes, three times a week, for 6 weeks. [Methods] Subjects from both groups performed general conventional treatment during the experimental period. In addition, all subjects engaged in extra treatment sessions. This extra treatment consisted of unstable surface exercise. The underwater exercise group used wonder boards in a pool (depth 1.1m, water temperature 33.5 °C, air temperature 27 °C) dedicated to underwater exercise, and the land exercise group used balance mats. [Result] The joint position sense, sway area, Berg Balance Scale showed significant improvements in both groups. However, the joint position sense test, sway area, and Berg Balance Scale showed there was more improvement in the underwater exercise group than in the land exercise group. [Conclusion] The results suggest that underwater exercise is more effective than land exercise at improving the joint position sense and balance of stroke patients. PMID:24259761

Comparison of effects of a proprioceptive exercise program in water and on land the balance of chronic stroke patients.

PubMed

Han, Seul Ki; Kim, Myung Chul; An, Chang Sik

2013-10-01

[Purpose] The purpose of this study was to compare changes in balance ability of land exercise and underwater exercise on chronic stroke patients. [Subjects] A total of 60 patients received exercise for 40 minutes, three times a week, for 6 weeks. [Methods] Subjects from both groups performed general conventional treatment during the experimental period. In addition, all subjects engaged in extra treatment sessions. This extra treatment consisted of unstable surface exercise. The underwater exercise group used wonder boards in a pool (depth 1.1m, water temperature 33.5 °C, air temperature 27 °C) dedicated to underwater exercise, and the land exercise group used balance mats. [Result] The joint position sense, sway area, Berg Balance Scale showed significant improvements in both groups. However, the joint position sense test, sway area, and Berg Balance Scale showed there was more improvement in the underwater exercise group than in the land exercise group. [Conclusion] The results suggest that underwater exercise is more effective than land exercise at improving the joint position sense and balance of stroke patients.

Ankle joint pressure changes in high tibial and distal femoral osteotomies: a cadaver study.

PubMed

Krause, F; Barandun, A; Klammer, G; Zderic, I; Gueorguiev, B; Schmid, T

2017-01-01

To assess the effect of high tibial and distal femoral osteotomies (HTO and DFO) on the pressure characteristics of the ankle joint. Varus and valgus malalignment of the knee was simulated in human cadaver full-length legs. Testing included four measurements: baseline malalignment, 5° and 10° re-aligning osteotomy, and control baseline malalignment. For HTO, testing was rerun with the subtalar joint fixed. In order to represent half body weight, a 300 N force was applied onto the femoral head. Intra-articular sensors captured ankle pressure. In the absence of restriction of subtalar movement, insignificant migration of the centre of force and changes of maximal pressure were seen at the ankle joint. With restricted subtalar motion, more significant lateralisation of the centre of force were seen with the subtalar joint in varus than in valgus position. Changes in maximum pressure were again not significant. The re-alignment of coronal plane knee deformities by HTO and DFO altered ankle pressure characteristics. When the subtalar joint was fixed in the varus position, migration of centre of force after HTO was more significant than when the subtalar joint was fixed in valgus. Cite this article: Bone Joint J 2017;99-B:59-65. ©2017 The British Editorial Society of Bone & Joint Surgery.

Remote sensing in Michigan for land resource management

NASA Technical Reports Server (NTRS)

Sattinger, I. J.

1972-01-01

This project to demonstrate the application of earth resource survey technology to current problems in Michigan was undertaken jointly by the Environmental Research Institute of Michigan and Michigan State University. Remote sensing techniques were employed to advantage in providing management information for the Pointe Mouillee State Game Area and preparing an impact assessment in advance of the projected construction of the M-14 freeway from Ann Arbor to Plymouth, Michigan. The project also assisted the state government in its current effort to develop and implement a state-wide land management plan.

Is early osteoarthritis associated with differences in joint congruence?

PubMed Central

Conconi, Michele; Halilaj, Eni; Castelli, Vincenzo Parenti; Crisco, Joseph J.

2014-01-01

Previous studies suggest that osteoarthritis (OA) is related to abnormal or excessive articular contact stress. The peak pressure resulting from an applied load is determined by many factors, among which is shape and relative position and orientation of the articulating surfaces or, referring to a more common nomenclature, joint congruence. It has been hypothesized that anatomical differences may be among the causes of OA. Individuals with less congruent joints would likely develop higher peak pressure and thus would be more exposed to the risk of OA onset. The aim of this work was to determine if the congruence of the first carpometacarpal (CMC) joint differs with the early onset of OA or with sex, as the female population has a higher incidence of OA. 59 without and 38 with early OA were CT-scanned with their dominant or arthritic hand in a neutral configuration. The proposed measure of joint congruence is both shape and size dependent. The correlation of joint congruence with pathology and sex was analyzed both before and after normalization for joint size. We found a significant correlation between joint congruence and sex due to the sex-related differences in size. The observed correlation disappeared after normalization. Although joint congruence increased with size, it did not correlate significantly with the onset of early OA. Differences in joint congruence in this population may not be a primary cause of OA onset or predisposition, at least for the CMC joint. PMID:25468667

Institutional Factors That Positively Impact First-Year Students' Sense of Well-Being

ERIC Educational Resources Information Center

Harmening, Debra S.; Jacob, Stacy A.

2015-01-01

This qualitative case study conducted at a single institution in the Midwest examines how institutional context and environment impact college students' sense of well-being. Twenty-seven first-year students participated in one to two hour, in-depth interviews where they talked about their first-year experiences, their concepts of well-being, and…

Constrained tri-sphere kinematic positioning system

DOEpatents

Viola, Robert J

2010-12-14

A scalable and adaptable, six-degree-of-freedom, kinematic positioning system is described. The system can position objects supported on top of, or suspended from, jacks comprising constrained joints. The system is compatible with extreme low temperature or high vacuum environments. When constant adjustment is not required a removable motor unit is available.

Joint scale-change models for recurrent events and failure time.

PubMed

Xu, Gongjun; Chiou, Sy Han; Huang, Chiung-Yu; Wang, Mei-Cheng; Yan, Jun

2017-01-01

Recurrent event data arise frequently in various fields such as biomedical sciences, public health, engineering, and social sciences. In many instances, the observation of the recurrent event process can be stopped by the occurrence of a correlated failure event, such as treatment failure and death. In this article, we propose a joint scale-change model for the recurrent event process and the failure time, where a shared frailty variable is used to model the association between the two types of outcomes. In contrast to the popular Cox-type joint modeling approaches, the regression parameters in the proposed joint scale-change model have marginal interpretations. The proposed approach is robust in the sense that no parametric assumption is imposed on the distribution of the unobserved frailty and that we do not need the strong Poisson-type assumption for the recurrent event process. We establish consistency and asymptotic normality of the proposed semiparametric estimators under suitable regularity conditions. To estimate the corresponding variances of the estimators, we develop a computationally efficient resampling-based procedure. Simulation studies and an analysis of hospitalization data from the Danish Psychiatric Central Register illustrate the performance of the proposed method.

The effect of instability training on knee joint proprioception and core strength.

PubMed

Cuğ, Mutlu; Ak, Emre; Ozdemir, Recep Ali; Korkusuz, Feza; Behm, David G

2012-01-01

Although there are many studies demonstrating increased trunk activation under unstable conditions, it is not known whether this increased activation would translate into meaningful trunk strength with a prolonged training program. Additionally, while balance-training programs have been shown to improve stability, their effect on specific joint proprioception is not clear. Thus the objective of this study was to examine training adaptations associated with a 10-week instability-training program. Participants were tested pre- and post-training for trunk extension and flexion strength and knee proprioception. Forty-three participants participated in either a 10-week (3 days per week) instability-training program using Swiss balls and body weight as resistance or a control group (n = 17). The trained group increased (p < 0. 05) trunk extension peak torque/body weight (23.6%) and total work output (20.1%) from pre- to post-training while the control group decreased by 6.8% and 6.7% respectively. The exercise group increased their trunk flexion peak torque/body weight ratios by 18.1% while the control group decreased by 0.4%. Knee proprioception (combined right and left joint repositioning) improved 44.7% from pre- to post-training (p = 0.0006) and persisted (21.5%) for 9 months post-training. In addition there was a side interaction with the position sense of the right knee at 9 months showing 32.1% (p = 0.03) less deviation from the reference angle than the right knee during pre-testing. An instability-training program using Swiss balls with body weight as resistance can provide prolonged improvements in joint proprioception and core strength in previously untrained individuals performing this novel training stress which would contribute to general health. Key pointsAlthough traditional free weight resistance exercises have been recommended as most beneficial for improving strength and power in athletes (Behm et al., 2010b), an IT program using Swiss balls and body

The Effect of Instability Training on Knee Joint Proprioception and Core Strength

PubMed Central

Cuğ, Mutlu; Ak, Emre; Özdemir, Recep Ali; Korkusuz, Feza; Behm, David G

2012-01-01

Although there are many studies demonstrating increased trunk activation under unstable conditions, it is not known whether this increased activation would translate into meaningful trunk strength with a prolonged training program. Additionally, while balance-training programs have been shown to improve stability, their effect on specific joint proprioception is not clear. Thus the objective of this study was to examine training adaptations associated with a 10-week instability-training program. Participants were tested pre- and post-training for trunk extension and flexion strength and knee proprioception. Forty-three participants participated in either a 10-week (3 days per week) instability-training program using Swiss balls and body weight as resistance or a control group (n = 17). The trained group increased (p < 0. 05) trunk extension peak torque/body weight (23.6%) and total work output (20.1%) from pre- to post-training while the control group decreased by 6.8% and 6.7% respectively. The exercise group increased their trunk flexion peak torque/body weight ratios by 18.1% while the control group decreased by 0.4%. Knee proprioception (combined right and left joint repositioning) improved 44.7% from pre- to post-training (p = 0.0006) and persisted (21.5%) for 9 months post-training. In addition there was a side interaction with the position sense of the right knee at 9 months showing 32.1% (p = 0.03) less deviation from the reference angle than the right knee during pre-testing. An instability-training program using Swiss balls with body weight as resistance can provide prolonged improvements in joint proprioception and core strength in previously untrained individuals performing this novel training stress which would contribute to general health. Key pointsAlthough traditional free weight resistance exercises have been recommended as most beneficial for improving strength and power in athletes (Behm et al., 2010b), an IT program using Swiss balls and body

In vivo recruitment patterns in the anterior oblique and dorsoradial ligaments of the first carpometacarpal joint.

PubMed

Halilaj, Eni; Rainbow, Michael J; Moore, Douglas C; Laidlaw, David H; Weiss, Arnold-Peter C; Ladd, Amy L; Crisco, Joseph J

2015-07-16

The anterior oblique ligament (AOL) and the dorsoradial ligament (DRL) are both regarded as mechanical stabilizers of the thumb carpometacarpal (CMC) joint, which in older women is often affected by osteoarthritis. Inferences on the potential relationship of these ligaments to joint pathomechanics are based on clinical experience and studies of cadaveric tissue, but their functions has been studied sparsely in vivo. The purpose of this study was to gain insight into the functions of the AOL and DRL using in vivo joint kinematics data. The thumbs of 44 healthy subjects were imaged with a clinical computed tomography scanner in functional-task and thumb range-of-motion positions. The origins and insertion sites of the AOL and the DRL were identified on the three-dimensional bone models and each ligament was modeled as a set of three fibers whose lengths were the minimum distances between insertion sites. Ligament recruitment, which represented ligament length as a percentage of the maximum length across the scanned positions, was computed for each position and related to joint posture. Mean AOL recruitment was lower than 91% across the CMC range of motion, whereas mean DRL recruitment was generally higher than 91% in abduction and flexion. Under the assumption that ligaments do not strain by more than 10% physiologically, our findings of mean ligament recruitments across the CMC range of motion indicate that the AOL is likely slack during most physiological positions, whereas the DRL may be taut and therefore support the joint in positions of CMC joint abduction and flexion. Copyright © 2015 Elsevier Ltd. All rights reserved.

In vivo recruitment patterns in the anterior oblique and dorsoradial ligaments of the first carpometacarpal joint

PubMed Central

Halilaj, Eni; Rainbow, Michael J.; Moore, Douglas C.; Laidlaw, David H.; Weiss, Arnold-Peter C.; Ladd, Amy L.; Crisco, Joseph J.

2015-01-01

The anterior oblique ligament (AOL) and the dorsoradial ligament (DRL) are both regarded as mechanical stabilizers of the thumb carpometacarpal (CMC) joint, which in older women is often affected by osteoarthritis. Inferences on the potential relationship of these ligaments to joint pathomechanics are based on clinical experience and studies of cadaveric tissue, but their function has been studied sparsely in vivo. The purpose of this study was to gain insight into the functions of the AOL and DRL using in vivo joint kinematic data. The thumbs of 44 healthy subjects were imaged with a clinical computed tomography scanner in functional-task and thumb range-of-motion positions. The origins and insertion sites of the AOL and the DRL were identified on the 3D bone models and each ligament was modeled as a set of three fibers whose lengths were the minimum distances between insertion sites. Ligament recruitment, which represented ligament length as a percentage of the maximum length across the scanned positions, was computed for each position and related to joint posture. Mean AOL recruitment was lower than 91% across the CMC range of motion, whereas mean DRL recruitment was generally higher than 91% in abduction and flexion. Under the assumption that ligaments do not strain by more than 10% physiologically, our findings of mean ligament recruitments across the CMC range of motion indicate that the AOL is likely slack during most physiological positions, whereas the DRL may be taut and therefore support the joint in positions of CMC joint abduction and flexion. PMID:25964211

Automatically Locking/Unlocking Orthotic Knee Joint

NASA Technical Reports Server (NTRS)

Weddendorf, Bruce

1994-01-01

Proposed orthotic knee joint locks and unlocks automatically, at any position within range of bend angles, without manual intervention by wearer. Includes tang and clevis, locks whenever wearer transfers weight to knee and unlocks when weight removed. Locking occurs at any angle between 45 degrees knee bend and full extension.

[Conserved motifs in voltage sensing proteins].

PubMed

Wang, Chang-He; Xie, Zhen-Li; Lv, Jian-Wei; Yu, Zhi-Dan; Shao, Shu-Li

2012-08-25

This paper was aimed to study conserved motifs of voltage sensing proteins (VSPs) and establish a voltage sensing model. All VSPs were collected from the Uniprot database using a comprehensive keyword search followed by manual curation, and the results indicated that there are only two types of known VSPs, voltage gated ion channels and voltage dependent phosphatases. All the VSPs have a common domain of four helical transmembrane segments (TMS, S1-S4), which constitute the voltage sensing module of the VSPs. The S1 segment was shown to be responsible for membrane targeting and insertion of these proteins, while S2-S4 segments, which can sense membrane potential, for protein properties. Conserved motifs/residues and their functional significance of each TMS were identified using profile-to-profile sequence alignments. Conserved motifs in these four segments are strikingly similar for all VSPs, especially, the conserved motif [RK]-X(2)-R-X(2)-R-X(2)-[RK] was presented in all the S4 segments, with positively charged arginine (R) alternating with two hydrophobic or uncharged residues. Movement of these arginines across the membrane electric field is the core mechanism by which the VSPs detect changes in membrane potential. The negatively charged aspartate (D) in the S3 segment is universally conserved in all the VSPs, suggesting that the aspartate residue may be involved in voltage sensing properties of VSPs as well as the electrostatic interactions with the positively charged residues in the S4 segment, which may enhance the thermodynamic stability of the S4 segments in plasma membrane.

California Schools Develop Joint Faculty Journalism Project.

ERIC Educational Resources Information Center

Patt, Bruce E.

1995-01-01

Describes the Joint Faculty Journalism project, undertaken in 1994-95 by California's community colleges and universities to develop methods for increasing alliances with journalism practitioners. Discusses project objectives and resulting recommendations related to increasing student recruitment and success. Reviews positive project outcomes and…

[Sacroiliac joint disorders in Abidjan: epidemiological, clinical, radiological and etiological characteristics].

PubMed

Diomandé, Mohamed; Eti, E; Ouattara, B; Cheteu, K E; Kouakou Ehaulier Soh, C L; Gbané-Koné, M; Djaha Kouassi, Jean-Mermoze; Kouakou N'zué, M

2014-10-01

The sacroiliac joint remains unknown in sub-Saharan Africa. Studies about the sacroiliac diseases are rare Aim : Describe the epidemiological, clinical, radiological and etiological characteristics of sacroiliac joint diseases in Abidjan Methods : Retrospective and descriptive study concerning 17 patients hospitalized from February 2003 to April 2010 in the department of rheumatology of university hospital center of Cocody (Abidjan) for buttock pain or others functional signs evoking sacroiliac joint which were attested by radiographic lesions. We were interested on the epidemiological, clinical and radiological characteristics and the etiologies in the sacroiliac disease. The hospital prevalence of sacroiliac diseases was 0.55% corresponding in 17 of 3067 rheumatological diseases. The female sex predominated (82.35%) and the mean age of 25.58 years. Gyneco-obstetric events were the predominant risk factors (47.05%). Sacroiliac damage was manifested by inflammatory pain (64.7%) localized at the buttock or lumbar spine, radiating to the thigh (52.9%) and was accompanied by functional disability (82.2%) and fever was not present every time (64.7%). The physical findings were the tripod sign positive (58.8%), the monopodal backing positive (41.2%) and palpation painful of sacroiliac joint. The standard radiograph revealed a blurring aspect and widening of joint space associated with demineralization (68.4%), a joint space narrowing and erosion of articular banks (23.5%). The etiologies found were bacterial arthritis (82.3%) mainly pyogenic (70.58%), osteoarthritis (11.7%) and ankylosing spondylitis (5.9%). Sacroiliac joint diseases are rare in rheumatology practice in Abidjan, concern younger subjects and are dominated by pyogenic sacroiliitis.

Sense Making in the Context of Algebraic Activities

ERIC Educational Resources Information Center

Palatnik, Alik; Koichu, Boris

2017-01-01

This article concerns student sense making in the context of algebraic activities. We present a case in which a pair of middle-school students attempts to make sense of a previously obtained by them position formula for a particular numerical sequence. The exploration of the sequence occurred in the context of two-month-long student research…

Model-Based Estimation of Ankle Joint Stiffness

PubMed Central

Misgeld, Berno J. E.; Zhang, Tony; Lüken, Markus J.; Leonhardt, Steffen

2017-01-01

We address the estimation of biomechanical parameters with wearable measurement technologies. In particular, we focus on the estimation of sagittal plane ankle joint stiffness in dorsiflexion/plantar flexion. For this estimation, a novel nonlinear biomechanical model of the lower leg was formulated that is driven by electromyographic signals. The model incorporates a two-dimensional kinematic description in the sagittal plane for the calculation of muscle lever arms and torques. To reduce estimation errors due to model uncertainties, a filtering algorithm is necessary that employs segmental orientation sensor measurements. Because of the model’s inherent nonlinearities and nonsmooth dynamics, a square-root cubature Kalman filter was developed. The performance of the novel estimation approach was evaluated in silico and in an experimental procedure. The experimental study was conducted with body-worn sensors and a test-bench that was specifically designed to obtain reference angle and torque measurements for a single joint. Results show that the filter is able to reconstruct joint angle positions, velocities and torque, as well as, joint stiffness during experimental test bench movements. PMID:28353683

Fibre optical spectroscopy and sensing innovation at innoFSPEC Potsdam

NASA Astrophysics Data System (ADS)

Haynes, Roger; Reich, Oliver; Rambold, William; Hass, Roland; Janssen, Katja

2010-07-01

In October 2009, an interdisciplinary centre for fibre spectroscopy and sensing, innoFSPEC Potsdam, has been established as joint initiative of the Astrophysikalisches Institut Potsdam (AIP) and the Physical Chemistry group of Potsdam University (UPPC), Germany. The centre focuses on fundamental research in the two fields of fibre-coupled multi-channel spectroscopy and optical fibre-based sensing. Thanks to its interdisciplinary approach, the complementary methodologies of astrophysics on the one hand, and physical chemistry on the other hand, are expected to spawn synergies that otherwise would not normally become available in more standard research programmes. innoFSPEC Potsdam targets future innovations for next generation astrophysical instrumentation, environmental analysis, manufacturing control and process analysis, medical diagnostics, non-invasive imaging spectroscopy, biopsy, genomics/proteomics, high throughput screening, and related applications.

Mechanism of preferential packaging of negative sense genomic RNA by viral nucleoproteins in Crimean-Congo hemorrhagic Fever virus.

PubMed

Dayer, Mohammad Reza; Dayer, Mohammad Saaid; Rezatofighi, Seyedeh Elham

2015-04-01

The Crimean-Congo Hemorrhagic Fever (CCHF) is an infectious disease of high virulence and mortality caused by a negative sense RNA nairovirus. The genomic RNA of CCHFV is enwrapped by its nucleoprotein. Positively charged residues on CCHFV nucleoprotein provide multiple binding sites to facilitate genomic RNA encapsidation. In the present work, we investigated the mechanism underlying preferential packaging of the negative sense genomic RNA by CCHFV nucleoprotein in the presence of host cell RNAs during viral assembly. The work included genome sequence analyses for different families of negative and positive sense RNA viruses, using serial docking experiments and molecular dynamic simulations. Our results indicated that the main determinant parameter of the nucleoprotein binding affinity for negative sense RNA is the ratio of purine/pyrimidine in the RNA molecule. A negative sense RNA with a purine/pyrimidine ratio (>1) higher than that of a positive sense RNA (<1) exhibits higher affinity for the nucleoprotein. Our calculations revealed that a negative sense RNA expresses about 0.5 kJ/mol higher binding energy per nucleotide compared to a positive sense RNA. This energy difference produces a binding energy high enough to make the negative sense RNA, the preferred substrate for packaging by CCHFV nucleoprotein in the presence of cellular or complementary positive sense RNAs. The outcome of this study may contribute to ongoing researches on other viral diseases caused by negative sense RNA viruses such as Ebola virus which poses a security threat to all humanity.

Chinese American Adolescents’ Perceptions of the Language Brokering Experience as a Sense of Burden and Sense of Efficacy

PubMed Central

Wu, Nina H.

2009-01-01

Children of immigrants who do translations and who interpret for others using their heritage language and English are known as language brokers. Although prior research suggests that children of immigrants’ perceptions of the language brokering experience vary greatly—from feeling a sense of efficacy to feeling a sense of burden—what remains unanswered in the literature is identification of the antecedents and processes that help to explain the varying psychological experience of language brokers. Using data from a two-wave prospective longitudinal study of 256 Chinese American adolescents, the present study tested potential mechanisms that may be responsible for adolescents’ perceptions of the language brokering experience as a sense or burden or sense of efficacy. The results demonstrate that adolescents’ Chinese orientation sets in motion a family process that is linked to variations in the perceptions of adolescents’ language brokering experience. Adolescents who are more Chinese oriented have a stronger sense of familial obligation, and these adolescents are more likely to perceive that they matter to their parents. Adolescents’ perceived sense of mattering to parents, in turn, is associated positively with a sense efficacy, and negatively with a sense of burden as language brokers. Those adolescents who are less Chinese oriented have a weaker sense of familial obligation, and these adolescents are more likely to feel a sense of alienation from their parents. Adolescents’ sense of perceived alienation from parents, in turn, is associated with a sense of burden as language brokers. Implications for developing interventions for children who act as language brokers for their parents are discussed. PMID:19636765