Visual Guidance for User Placement in Avatar-Mediated Telepresence between Dissimilar Spaces.

Rapid advances in technology gradually realize immersive mixed-reality (MR) telepresence between distant spaces. This paper presents a novel visual guidance system for avatar-mediated telepresence, directing users to optimal placements that facilitate the clear transfer of gaze and pointing contexts through remote avatars in dissimilar spaces, where the spatial relationship between the remote avatar and the interaction targets may differ from that of the local user. Representing the spatial relationship between the user/avatar and interaction targets with angle-based interaction features, we assign recommendation scores of sampled local placements as their maximum feature similarity with remote placements. These scores are visualized as color-coded 2D sectors to inform the users of better placements for interaction with selected targets. In addition, virtual objects of the remote space are overlapped with the local space for the user to better understand the recommendations. We examine whether the proposed score measure agrees with the actual user perception of the partner's interaction context and find a score threshold for recommendation through user experiments in virtual reality (VR). A subsequent user study in VR investigates the effectiveness and perceptual overload of different combinations of visualizations. Finally, we conduct a user study in an MR telepresence scenario to evaluate the effectiveness of our method in real-world applications.

The association between cognition and gait disturbance in central nervous system demyelinating disorder with mild disability.

INTRODUCTION: Gait disturbance in central nervous system (CNS) demyelinating disorders, including multiple sclerosis (MS) and neuromyelitis optica (NMO) is one of the most troublesome problems that has a direct impact on the quality of life. However, the associations between gait disturbance and other clinical variables of these two diseases have not been fully elucidated. OBJECTIVE: This study aimed to evaluate gait disturbance using a computerized gait analysis system and its association with various clinical variables in patients with MS and NMO. METHODS: A total of 33 patients (14 with MS and 19 with NMO) with minor disabilities, who were able to walk independently and had passed their acute phase, were enrolled in the study. Gait analysis were performed using a computer-based instrumented walkway system. (Walk-way MG-1000, Anima, Japan) Clinical variables, such as disease duration, medication, body mass index (BMI), hand grip power, and muscle mass were recorded. The Montreal Cognitive Assessment (MOCA), Beck Depression Inventory score-II (BDI), and fatigue scale were measured using the Functional Assessment of Chronic Illness Therapy-fatigue scale (FACIT-fatigue) scale. A trained neurologist scored the Expanded Disability Status Scale (EDSS). RESULTS: Gait speed was the single parameter that showed a significant positive correlation with MOCA (p < 0.001). The stance phase time was the single parameter that showed a significant negative correlation with EDSS (p < 0.001). Hand grip strength showed a significant positive correlation with skeletal muscle mass as assessed by bioimpedance analysis (p < 0.05). The FACIT-fatigue scale score showed a significant negative correlation with the BDI (p < 0.001). CONCLUSION: In our patients with MS/NMO with mild disability, cognitive impairment was significantly correlated with gait speed, and the degree of disability was significantly correlated with stance phase time. Our findings may imply that early detection of a decrease in gait speed and an increase in stance phase time can predict the progression of cognitive impairment in patients with MS/NMO with mild disability.

The feasibility of mixed reality-based upper extremity self-training for patients with stroke-A pilot study.

Mixed reality (MR), which combines virtual reality and tangible objects, can be used for repetitive training by patients with stroke, allowing them to be immersed in a virtual environment while maintaining their perception of the real world. We developed an MR-based rehabilitation board (MR-board) for the upper limb, particularly for hand rehabilitation, and aimed to demonstrate the feasibility of the MR-board as a self-training rehabilitation tool for the upper extremity in stroke patients. The MR-board contains five gamified programs that train upper-extremity movements by using the affected hand and six differently shaped objects. We conducted five 30-min training sessions in stroke patients using the MR-board. The sensor measured hand movement and reflected the objects to the monitor so that the patients could check the process and results during the intervention. The primary outcomes were changes in the Box and Block Test (BBT) score, and the secondary outcomes were changes in the Fugl-Meyer assessment and Wolf Motor Function Test (WMFT) scores. Evaluations were conducted before and after the intervention. In addition, a usability test was performed to assess the patient satisfaction with the device. Ten patients with hemiplegic stroke were included in the analysis. The BBT scores and shoulder strength in the WMFT were significantly improved (p < 0.05), and other outcomes were also improved after the intervention. In addition, the usability test showed high satisfaction (4.58 out of 5 points), and patients were willing to undergo further treatment sessions. No safety issues were observed. The MR-board is a feasible intervention device for improving upper limb function. Moreover, this instrument could be an effective self-training tool that provides training routines for stroke patients without the assistance of a healthcare practitioner. Trial registration: This study was registered with the Clinical Research Information Service (CRIS: KCT0004167).

Placement Retargeting of Virtual Avatars to Dissimilar Indoor Environments.

Rapidly developing technologies are realizing a 3D telepresence, in which geographically separated users can interact with each other through their virtual avatars. In this article, we present novel methods to determine the avatar's position in an indoor space to preserve the semantics of the user's position in a dissimilar indoor space with different space configurations and furniture layouts. To this end, we first perform a user survey on the preferred avatar placements for various indoor configurations and user placements, and identify a set of related attributes, including interpersonal relation, visual attention, pose, and spatial characteristics, and quantify these attributes with a set of features. By using the obtained dataset and identified features, we train a neural network that predicts the similarity between two placements. Next, we develop an avatar placement method that preserves the semantics of the placement of the remote user in a different space as much as possible. We show the effectiveness of our methods by implementing a prototype AR-based telepresence system and user evaluations.

Association between scrub typhus encephalitis and diffusion tensor tractography detection of Papez circuit injury: A case report.

BACKGROUND: It is difficult to restore the cognitive functions of patients with impaired cognition caused by brain injury. Diffusion tensor imaging can visualize the integrity of neural tracts in the white matter (WM) three-dimensionally. It is unclear whether encephalitis following scrub typhus damages the WM. For the first time, we aimed to report diffusion tensor tractography (DTT) findings in a chronic patient with cognitive impairment following scrub typhus encephalitis, which revealed injury to the Papez circuit of the WM. CASE SUMMARY: A 70-year-old male patient was affected by encephalitis caused by scrub typhus that occurred 23 years ago. He had poor cognition and his clinical examination findings were as follows: Mini-Mental Status Examination score, 14; and handgrip strength (right/left, kg), 32.3/31.3. DTT revealed serious injuries of the left thalamocingulate tract and right mammillothalamic tract in the Papez circuit, and a partial injury of the anterior part of the fornix. CONCLUSION: Using DTT, we found a relationship between cognitive impairment and the integrity of the Papez circuit following scrub typhus.

Evaluation of balance functions using temporo-spatial gait analysis parameters in patients with brain lesions.

This study aimed to compare gait analysis and balance function measurements, such as the Berg balance scale (BBS) score to seek specific measurements that can represent the balance functions of patients with brain lesions. Additionally, we also compared other different gait function scale scores with gait analysis measurements. This study included 77 patients with brain lesions admitted to our institution between January 2017 and August 2020. Their gait analysis parameters and clinical data, including personal data; clinical diagnosis; duration of the disease; cognition, ambulation, and stair-climbing sub-scores of the modified Barthel index (MBI); manual muscle test (MMT) findings of both lower extremities; functional ambulation category (FAC); and BBS score, were retrospectively analyzed. A multiple linear regression analysis was performed to identify the gait analysis parameters that would significantly correlate with the balance function and other physical performances. In the results, the BBS scores were significantly correlated with the gait speed and step width/height2. However, the other gait function measurements, such as the FAC and ambulation and stair-climbing sub-scores of the MBI, were correlated only with the gait speed. Additionally, both the summations of the lower extremity MMT findings and anti-gravity lower extremity MMT findings were correlated with the average swing phase time. Therefore, in the gait analysis, the gait speed may be an important factor in determining the balance and gait functions of the patients with brain lesions. Moreover, the step width/height2 may be a significant factor in determining their balance function. However, further studies with larger sample sizes should be performed to confirm this relationship.

Cognitive Training Using Fully Immersive, Enriched Environment Virtual Reality for Patients With Mild Cognitive Impairment and Mild Dementia: Feasibility and Usability Study.

BACKGROUND: Cognitive training using virtual reality (VR) may result in motivational and playful training for patients with mild cognitive impairment and mild dementia. Fully immersive VR sets patients free from external interference and thus encourages patients with cognitive impairment to maintain selective attention. The enriched environment, which refers to a rich and stimulating environment, has a positive effect on cognitive function and mood. OBJECTIVE: The aim of this study was to investigate the feasibility and usability of cognitive training using fully immersive VR programs in enriched environments with physiatrists, occupational therapists (OTs), and patients with mild cognitive impairment and mild dementia. METHODS: The VR interface system consisted of a commercialized head-mounted display and a custom-made hand motion tracking module. We developed the virtual harvest and cook programs in enriched environments representing rural scenery. Physiatrists, OTs, and patients with mild cognitive impairment and mild dementia received 30 minutes of VR training to evaluate the feasibility and usability of the test for cognitive training. At the end of the test, the usability and feasibility were assessed by a self-report questionnaire based on a 7-point Likert-type scale. Response time and finger tapping were measured in patients before and after the test. RESULTS: Participants included 10 physiatrists, 6 OTs, and 11 patients with mild cognitive impairment and mild dementia. The mean scores for overall satisfaction with the program were 5.75 (SD 1.00) for rehabilitation specialists and 5.64 (SD 1.43) for patients. The response time of the dominant hand in patients decreased after the single session of cognitive training using VR, but this was not statistically significant (P=.25). There was no significant change in finger tapping in either the right or left hand (P=.48 and P=.42, respectively). None of the participants reported headaches, dizziness, or any other motion sickness after the test. CONCLUSIONS: A fully immersive VR cognitive training program may be feasible and usable in patients with mild cognitive impairment and mild dementia based on the positive satisfaction and willingness to use the program reported by physiatrists, OTs, and patients. Although not statistically significant, decreased response time without a change in finger tapping rate may reflect a temporary increase in attention after the test. Additional clinical trials are needed to investigate the effect on cognitive function, mood, and physical outcomes.

Bus Workers' Experiences with and Perceptions of a Health Promotion Program: A Qualitative Study Using a Focus Group Discussion.

We conducted a focus group discussion with bus workers to evaluate their experiences and perceptions, as well as their reasons for participating in a program for vulnerable workers. The study also sought to identify the strengths and weaknesses of the program. A total of nine bus workers participated in the focus group discussion. The focus group discussion was conducted based on a semi-structured guide, which was developed from discussions among the researchers and a review of major preliminary studies. The verbatim transcriptions were analyzed using content analysis. The sole existence of a health promotion program for vulnerable workers in Ulsan was sufficient to attract participants who had not been involved in other health management programs. Participants reported that participation in the program mitigated some of their musculoskeletal symptoms, which are often faced by bus workers. The findings of this study may contribute to the expansion of the health promotion program targeting workers in vulnerable working environments in Ulsan and other places. In order to increase users' satisfaction and the sustainability of the program, it is necessary to develop a strategy to increase the accessibility of the program and enhance the self-efficacy of participants.

Quantitative autonomic function test in differentiation of multiple system atrophy from idiopathic Parkinson disease.

BACKGROUND: Differential diagnosis of idiopathic Parkinson disease (IPD) and multiple system atrophy-Parkinson type (MSA-P) is challenging since they share clinical features with parkinsonism and autonomic dysfunction. To distinguish MSA-P from IPD when the symptoms are relatively mild, we investigated the usefulness of the quantitative fractionalized autonomic indexes and evaluated the correlations of autonomic test indexes and functional status. METHODS: Thirty-six patients with parkinsonism (22 with IPD and 14 with MSA-P) in Soonchunhyang University Bucheon Hospital from February 2014 to June 2015 were prospectively enrolled in the study. We compared fractionalized autonomic indexes and composite autonomic scoring scale between patients with IPD and MSA-P with Hoehn and Yahr (H&Y) score ≤3. Parasympathetic indexes included expiratory/inspiratory ratio during deep breathing, Valsalva ratio (VR), and regression slope of systolic blood pressure (BP) in early phase II (vagal baroreflex sensitivity) during Valsalva maneuver. Sympathetic adrenergic indexes were pressure recovery time (PRT) and adrenergic baroreflex sensitivity (BRSa) (BP decrement associated with phase 3 divided by the PRT), sympathetic index 1, sympathetic index 3, early phase II mean BP drop, and pulse pressure reduction rate. Additionally, we compared the unified multiple system atrophy rating scale (UMSARS) and H&Y scores and the autonomic indexes in all patients. RESULTS: PRT was significantly different between the IPD and MSA-P groups (P = 0.004) despite the similar BP drop during tilt. Cut-off value of PRT was 5.5 s (sensitivity, 71.4%; specificity, 72.7%). VR (r = -0.455, P = 0.009) and BRSa (r = -0.356, P = 0.036) demonstrated a significant correlation with UMSARS and H&Y scores. CONCLUSIONS: Among the cardiovascular autonomic indexes, PRT can be a useful parameter in differentiating the early stage of MSA-P from that of IPD. Moreover, VR, and BRSa may be the optimal indexes in determining functional symptom severity.

Effect of smartphone application-supported self-rehabilitation for frozen shoulder: a prospective randomized control study.

OBJECTIVES:: To evaluate the clinical efficacy of smartphone-assisted self-rehabilitation in patients with frozen shoulder. DESIGN:: A single-center, randomized controlled trial. SETTING:: Orthopedic department of a university hospital. SUBJECTS:: A total of 84 patients with frozen shoulder were recruited. INTERVENTION:: Patients were randomly divided into two groups: a smartphone-assisted exercise group ( n = 42) and a conventional self-exercise group ( n = 42). The study was performed over three months, during which each group performed home-based rehabilitation. MAIN MEASURES:: Visual analogue scale for pain and passive shoulder range of motion were assessed at baseline and after 4, 8, and 12 weeks of treatment. Technology Acceptance Model-2 and Usefulness, Satisfaction, and Ease of Use scores were evaluated in the smartphone group. RESULTS:: Initial visual analogue scale for pain of the smartphone group was 6.0 ± 2.2 and ended up with 1.8 ± 2.5 after 12 weeks, whereas the self-exercise group showed 5.8 ± 2.3 for the baseline visual analogue scale for pain and 2.2 ± 1.7 at the end. Significant time-dependent improvements in all measured values were observed in both groups (all Ps < 0.001), but no significant intergroup difference was observed after 4, 8, or 12 weeks of treatment. In the smartphone group, Technology Acceptance Model-2 and Usefulness, Satisfaction, and Ease of Use scores showed high patient satisfaction with smartphone-assisted exercise. CONCLUSION:: There was no difference between home-based exercise using a smartphone application and a conventional self-exercise program for the treatment of frozen shoulder in terms of visual analogue scale for pain and range of motions.

Which Neural Tract Plays a Major Role in Memory Impairment After Multiple Cerebral Infarcts? A Case Report.

Injury to the thalamocortical tract (one in the Papez circuit) that leads to memory impairment following brain injury is very rare. In this study, we present a case of partial injury to the thalamocortical tract that causes memory impairment after concurrent thalamic and hippocampal infarct. A 20-year-old male complained of memory impairment 1 month after partial injury to the thalamocortical tract. Using a probabilistic diffusing tensor tractography, it was found that the right thalamocortical tract was thinner than the left thalamocortical tract. However, all other neural tracts including the fornix, cingulum, and mammillothalamic tract were intact on both hemispheres. Therefore, the memory impairment in this patient was considered as being due to thalamic infarct based on the observation that the fornix from hippocampal infarct was intact. This case suggests that the assessment of lesions in the neural tracts of the Papez circuit might be useful for understanding the mechanism of memory impairment following cerebral infarction.

Mechanism of cognitive impairment in chronic patients with putaminal hemorrhage: A diffusion tensor tractography.

It is not clear whether the fornix and cingulum are involved in cognition after putaminal hemorrhage (PH). We investigated structural changes and differences of the neural tracts, and the relationship between the integrity of the neural tracts and cognition not only at the affected but also at the unaffected side.Sixteen patients with left chronic putaminal hemorrhage and 20 healthy volunteers were enrolled. Using diffusion tensor tractography (DTT), we compared fiber number (FN), fractional anisotropy (FA), and apparent diffusion coefficient (ADC) of the neural tracts between patient and control groups. The relationship between the neural tract parameters and neuropsychological results was also analyzed.The left fornix FN was significantly lower than the right fornix FN in the patient group. Except for the cingulum FA, the neural tracts parameters for both the affected and unaffected hemispheres differed significantly between the groups. The fornix FA and ADC at the affected side were significantly correlated with intelligence quotient (IQ), mini-mental status examination (MMSE), and short-term memory. Interestingly, the fornix ADC at the unaffected side was significantly correlated with MMSE. However, none of the cingulum parameters was correlated with neuropsychological results.The fornix integrity is critical for cognitive impairment after putaminal hemorrhage.

Influence of abutment materials on the implant-abutment joint stability in internal conical connection type implant systems.

PURPOSE: This study evaluated the influence of abutment materials on the stability of the implant-abutment joint in internal conical connection type implant systems. MATERIALS AND METHODS: Internal conical connection type implants, cement-retained abutments, and tungsten carbide-coated abutment screws were used. The abutments were fabricated with commercially pure grade 3 titanium (group T3), commercially pure grade 4 titanium (group T4), or Ti-6Al-4V (group TA) (n=5, each). In order to assess the amount of settlement after abutment fixation, a 30-Ncm tightening torque was applied, then the change in length before and after tightening the abutment screw was measured, and the preload exerted was recorded. The compressive bending strength was measured under the ISO14801 conditions. In order to determine whether there were significant changes in settlement, preload, and compressive bending strength before and after abutment fixation depending on abutment materials, one-way ANOVA and Tukey's HSD post-hoc test was performed. RESULTS: Group TA exhibited the smallest mean change in the combined length of the implant and abutment before and after fixation, and no difference was observed between groups T3 and T4 (P>.05). Group TA exhibited the highest preload and compressive bending strength values, followed by T4, then T3 (P<.001). CONCLUSION: The abutment material can influence the stability of the interface in internal conical connection type implant systems. The strength of the abutment material was inversely correlated with settlement, and positively correlated with compressive bending strength. Preload was inversely proportional to the frictional coefficient of the abutment material.

Acute spinal subdural hematoma with hemiplegia after acupuncture: a case report and review of the literature.

BACKGROUND CONTEXT: Subdural spinal hematoma (SDH) is a very rare entity; however, it can lead to serious complications resulting from injuries to the spinal cord and roots. Although acupuncture has been a popular method for the management of pain control, we encountered the first case of SDH after acupuncture. PURPOSE: The purpose of this case report was to present the first case of subdural hematoma after acupuncture and the reasons for the risks of blind cervical acupuncture. STUDY DESIGN: A case report and review of the previous literature are presented. METHODS: A 69-year-old man complained of progressive weakness in the right upper and lower extremities 2 hours after acupuncture on the cervical spine and back. The diagnosis was delayed because of unilateral weakness, and the symptom was initially misinterpreted as a transient ischemic attack because of no sensory change and pain and normal findings of two brain magnetic resonance imaging (MRI). RESULTS: Cervical MRI 36 hours after onset revealed acute hematoma from the C3-C5 level; hematoma showed an isointensity on T1-weighted image (WI) with the preservation of epidural fat and a hypointensity on T2WI. A decompressive surgery was scheduled to perform within 2 days after the cervical MRI scan because of a previous anticoagulation therapy, but the patient refused it. Finally, 9 days after the onset, surgical decompression and removal of hematoma were performed. Three months postoperatively, the patient had fully recovered demonstrating fine hand movement and good ability to walk up and down the stairs. CONCLUSIONS: Our study indicates that it is essential to perform cervical MRI when a patient does not show an improvement in the neurologic deficit and has a negative brain MRI after acupuncture. In addition, blind acupuncture if not correctly practiced may be harmful to the cervical structures.

Diagnosing Tapia syndrome using a videofluoroscopic swallowing study and electromyography after anterior cervical spine surgery.

A couple of the most common complications after anterior cervical spine surgery are dysphagia and hoarseness. This is often related to recurrent laryngeal nerve palsy and it can also be caused by injury to the branches of the lower cranial nerves. In general, Tapia syndrome is combined injuries of the recurrent laryngeal nerve of the vagus and the hypoglossal nerves. There has been no reported case until now of Tapia syndrome after a patient underwent anterior cervical spine surgery. We present here the case of a 42-yr-old man who complained of hoarseness, dysphagia, and right deviation of the tongue with an atrophic change for 2 mos after he underwent C3-4 discectomy and anterior fusion body. We found that he has a diagnosis of a variant of Tapia syndrome, although recurrent laryngeal nerve injury did not seem to be involved according to a videofluoroscopic swallowing study and electromyography. Our case report demonstrates that the combined diagnostic tools of videofluoroscopic swallowing study, electromyography, and laryngoscopy can be very useful in localizing and evaluating the level of lesions in patients with Tapia syndrome.