Experimental implementation of skeleton tracking for collision avoidance in collaborative robotics

Collaborative robotic manipulators can stop in case of a collision, according to the ISO/TS 15066 and ISO 10218-1 standards. However, in a human-robot collaboration scenario where the robot and the human share the workspace, a better solution with concerns to production and operator safety would be to perceive in advance the presence of an obstacle and be able to avoid it, thereby completing the task without halting the robot. In this paper, an obstacle avoidance algorithm is tested using a sensor system for real-time human detection; the operator represents a potential dynamic obstacle that can interfere with the robot motion. The sensor system consists of three RGB-D cameras. A custom software framework has been developed in Python exploiting machine learning tools for human skeleton detection. The coordinates of the human body joints relative to the manipulator base are used as input to the obstacle avoidance algorithm. The use of multiple sensors makes it possible to limit the occlusion problem; in addition, the choice of non-wearable sensors goes in the direction of better operator comfort. A series of experimental tests were performed to verify the accuracy of skeleton detection and the ability of the system to avoid obstacles in real time. The human motion caption system, in particular, was validated through a comparison with a commercial system based on wearable IMU sensors widely used and validated in motion capture. There is an NRMSE of 3.23%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$3.23\%$$\end{document} for the RGB-D camera-based skeleton detection system, against an NRMSE of 12.23%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$12.23\%$$\end{document} for the IMU wearable sensor system. Test results confirm that the system is able to avoid collisions with the human body under various conditions, static or dynamic, ensuring a minimum safety distance to any part of the manipulator. In 44 tests in which the operator moves around the robot with possible collisions (at a speed typical of manufacturing operations), the minimum operator-robot distance averaged 208mm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$208\,\textrm{mm}$$\end{document}, being 200mm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$200\,\textrm{mm}$$\end{document} the limit safety distance set by algorithm

The implications of Methylphenidate use by healthy medical students and doctors in South Africa

Background: The use of medical stimulants to sustain attention, augment memory and enhance intellectual capacity is increasing in society. The use of Methylphenidate for cognitive enhancement is a subject that has received much attention in the literature and academic circles in recent times globally. Medical doctors and medical students appear to be equally involved in the off-label use of Methylphenidate. This presents a potential harm to society and the individual as the long-term side effect profile of this medication is unknown. Discussion: The implication of the use of Methylphenidate by medical students and doctors has not been fully explored. This article considers the impact of this use on the traditional role of medicine, society, the patient and suggests a way forward. We discuss the salient philosophy surrounding the use of cognitive enhancement. We query whether there are cognitive benefits to the use of Methylphenidate in healthy students and doctors and whether these benefits would outweigh the risks in taking the medication. Could these benefits lead to tangible outcomes for society and could the off label-use of Methylphenidate potentially undermine the medical profession and the treatment of patients? If cognitive benefits are proven then doctors may be coerced explicitly or implicitly to use the drug which may undermine their autonomy. The increased appeal of cognitive enhancement challenges the traditional role of medicine in society, and calls into question the role of a virtuous life as a contributing factor for achievement. In countries with vast economic disparity such as South Africa an enhancement of personal utility that can be bought may lead to greater inequities. Summary: Under the status quo the distribution of methylphenidate is unjust. Regulatory governmental policy must seek to remedy this while minimising the potential for competitive advantage for the enhanced. Public debate on the use of cognitive enhancement is long overdue and must be stimulated. The use of Methylphenidate for cognitive enhancement is philosophically defendable if long-term research can prove that the risks are negligible and the outcomes tangible

Evaluation of macular pigment optical density following femtosecond laser-assisted cataract surgery

Background: To evaluate macular pigment optical density (MPOD) after bimanual femtosecond laser-assisted cataract surgery (FLACS) compared to standard bimanual phacoemulsification (B-MICS). Methods: Aprospective, casematched, comparative cohort study conducted at theInstitute of Ophthalmology, University of Modena and Reggio Emilia (Italy); 30 eyes under wentbimanual FLACS with low-energy Ziemer LDV Z8 (FLACS) and 30 underwent B-MICS standard technique (B-MICS). All interventions were conducted by the same expert surgeon. MPOD using the Macular Pigment Screener II (MPS II) was evaluated at baseline, 7 and 30 days after surgery. As secondary outcomes, we considered best corrected visual acuity (BCVA) and central macular thickness (CMT) obtained using optical coherence tomography. Results: In all cases, a BunnyLens AF IOL was safely implanted in the capsular bag through a1.4 mm incision. We found asignificant reductionin MPOD in both groups at 7 and 30 days; 0.16 ±0.14 and 0.10±0.12 (FLACS) and 0.18±0.13 and 0.15±0.14 (B-MICS), respectively (P<0.05). However, there was no significant difference between the two groups at either 7 (P=0.52) or 30 days (P=0.18). BCVA improved significantly in both groups and CMT increased in both groups (P<0.001, P<0.001, respectively). BCVA and CMT were similar between the groups with a significant difference in CMT in favor of the FLACS group at 30 days (P=0.017). Conclusions: MPOD was reduced in both groups without any significant difference between the FLACS and B-MICS cataract interventions. FLACS is associated with a significantly higher increase of macular thickness at 30 days compared to B-MICS

Five-year follow-up of secondary iris-claw intraocular lens implantation for the treatment of aphakia: Anterior chamber versus retropupillary implantation

Background Though several procedures of IOL implantation have been described (sutured scleral fixation, intra-scleral fixation, angle-supported anterior chamber, and anterior chamber or retropupillary iris-claw IOLs), there are no randomized trials which are comparing different techniques. Hence, the surgical treatment of aphakia still remains controversial and challenging. The purpose of this study was to compare the long-term efficacy and the rate of complications of anterior versus posterior Iris-claw intraocular lenses (IOL) implantation to correct for the treatment of aphakia without sufficient capsule support. Methods and findings Consecutive eyes having secondary implantation of aphakic iris-fixated IOLs with a followup of at least 5 years were considered. Mean correct distance visual acuity (CDVA) changes, percentage of eyes with CDVA improvement, mean corneal endothelial cell density (CECD) loss and the rate of other complications were used for statistical analysis. The study evaluated a total of 180 eyes (Group A: 87 anterior chamber iris-claw fixation, Group B: 93 retropupillary iris-claw implantation) of 180 consecutive different patients, with aphakia of various reasons. CDVA improved significantly in both groups after surgery (P<0.001, ANOVA), and was remarkably higher than baseline in both groups from first week and during the entire follow-up (P<0.001, Tukey’s Honest Significant Difference). There was no statistically significant difference in CDVA between the two groups during each follow-up visits (P = NS, unpaired t-test) and in the CDVA improvement percentage between the two groups (P = 0.882, Chi-square test). No significant changes in CECD were noted after surgery in both groups (ANOVA Group A: P = 0.067, Group B: P = 0.330P). No intra-operative complications occurred in both groups. There was no statistically significant difference in the rate of complications between the two groups (P = NS, Chi-square test), except for pigment precipitates which were higher in Group A (P<0.05, Chi-square test). Conclusions Five-year follow-up shows that secondary implantation of aphakic IOLs is effective and safe for the correction treatment of aphakia in eyes without capsule support

Problematic risk-taking involving emerging technologies: A stakeholder framework to minimize harms

Background and aims Despite the many benefits of technological advancements, problematic use of emerging technologies may lead to consumers experiencing harms. Substantial problems and behavioral addictions, such as gambling and gaming disorders, are recognized to be related to Internet-based technologies, including the myriad of new devices and platforms available. This review paper seeks to explore problematic risk-taking behaviors involving emerging technologies (e.g., online gambling and gaming, online sexual behaviors, and oversharing of personal information via social networking sites) that have the potential to lead to problematic outcomes for individuals. Results and discussion Previous research has focused on policy frameworks for responding to specific issues (e.g., online gambling), but a broader framework is needed to address issues as they emerge, given lags in governments and regulators responding to dynamically evolving technological environments. In this paper, key terms and issues involved are identified and discussed. We propose an initial framework for the relative roles and responsibilities of key stakeholder groups involved in addressing these issues (e.g., industry operators, governments and regulators, community groups, researchers, treatment providers, and individual consumers/end users). Conclusion Multidisciplinary collaboration can facilitate a comprehensive, unified response from all stakeholders that balances individual civil liberties with societal responsibilities and institutional duty of care.This work was supported by an Australian Research Council Discovery Early Career Research Award (DE1060100459) awarded to Associate Professor Sally Gainsbury

Limited Vitrectomy versus Complete Vitrectomy for Epiretinal Membranes: A Comparative Multicenter Trial

Purpose. To evaluate whether limited vitrectomy is as effective as complete vitrectomy in eyes with epiretinal membrane (ERM) and to compare the surgical times and rates of complications. Methods. In this multicentre European study, data of eyes with ERM that underwent vitrectomy from January 2017 to July 2018 were analyzed retrospectively. In the limited vitrectomy group, a posterior vitreous detachment (PVD) was induced up till the equator as opposed to complete PVD induction till the vitreous base in the comparison group. Incidence of iatrogenic retinal breaks, retinal detachment, surgical time, and visual outcomes were compared between groups. Results. We included 139 eyes in the analysis with a mean age being 72.2 \ub1 6.9 years. In this, sixty-five eyes (47%) underwent limited vitrectomy and 74 eyes (53%) underwent complete vitrectomy. Iatrogenic retinal tears were seen in both groups (5% in limited vitrectomy versus 7% in complete vitrectomy, p=0.49). Retinal detachment occurred in 2 eyes in the limited vitrectomy group (3%) compared to none in the complete vitrectomy group (p=0.22). Best-corrected visual acuity (BCVA) and central macular thickness improved significantly with no intergroup differences (p=0.18). Surgical time was significantly shorter in the limited vitrectomy group with 91% surgeries taking less than 1 hour compared to 71% in the complete vitrectomy group (p<0.001). Conclusion. A limited vitrectomy is a time-efficient and effective surgical procedure for removal of epiretinal membrane with no additional complications

Intravitreal Dexamethasone Implant as a Sustained Release Drug Delivery Device for the Treatment of Ocular Diseases: A Comprehensive Review of the Literature

Drug delivery into the vitreous chamber remains a great challenge in the pharmaceutical industry due to the complex anatomy and physiology of the eye. Intravitreal injection is the mainstream route of drug administration to the posterior segment of the eye. The purpose of this review is to assess the current literature about the widening use of the intravitreal 0.7 mg dexamethasone (Dex) implant, and to provide a comprehensive collection of all the ocular disorders that benefit from Dex administration. Although anti-vascular endothelial growth-factors (VEGFs) have been largely indicated as a first-choice level, the Dex implant represents an important treatment option, especially in selected cases, such as vitrectomized eyes or patients in whom anti-VEGF failed or are contraindicated. In this article, the safety profile as well as the list of the possible complications related to intravitreal Dex injection are also discussed

Prone position in intubated, mechanically ventilated patients with COVID-19: a multi-centric study of more than 1000 patients

Background: Limited data are available on the use of prone position in intubated, invasively ventilated patients with Coronavirus disease-19 (COVID-19). Aim of this study is to investigate the use and effect of prone position in this population during the first 2020 pandemic wave. Methods: Retrospective, multicentre, national cohort study conducted between February 24 and June 14, 2020, in 24 Italian Intensive Care Units (ICU) on adult patients needing invasive mechanical ventilation for respiratory failure caused by COVID-19. Clinical data were collected on the day of ICU admission. Information regarding the use of prone position was collected daily. Follow-up for patient outcomes was performed on July 15, 2020. The respiratory effects of the first prone position were studied in a subset of 78 patients. Patients were classified as Oxygen Responders if the PaO2/FiO2 ratio increased ≥ 20 mmHg during prone position and as Carbon Dioxide Responders if the ventilatory ratio was reduced during prone position. Results: Of 1057 included patients, mild, moderate and severe ARDS was present in 15, 50 and 35% of patients, respectively, and had a resulting mortality of 25, 33 and 41%. Prone position was applied in 61% of the patients. Patients placed prone had a more severe disease and died significantly more (45% vs. 33%, p < 0.001). Overall, prone position induced a significant increase in PaO2/FiO2 ratio, while no change in respiratory system compliance or ventilatory ratio was observed. Seventy-eight % of the subset of 78 patients were Oxygen Responders. Non-Responders had a more severe respiratory failure and died more often in the ICU (65% vs. 38%, p = 0.047). Forty-seven % of patients were defined as Carbon Dioxide Responders. These patients were older and had more comorbidities; however, no difference in terms of ICU mortality was observed (51% vs. 37%, p = 0.189 for Carbon Dioxide Responders and Non-Responders, respectively). Conclusions: During the COVID-19 pandemic, prone position has been widely adopted to treat mechanically ventilated patients with respiratory failure. The majority of patients improved their oxygenation during prone position, most likely due to a better ventilation perfusion matching. Trial registration: clinicaltrials.gov number: NCT0438867