Design and analysis of a haptic device design for large and fast movements

Haptic devices tend to be kept small as it is easier to achieve a large change of stiffness with a low associated apparent mass. If large movements are required there is a usually a reduction in the quality of the haptic sensations which can be displayed. The typical measure of haptic device performance is impedance-width (z-width) but this does not account for actuator saturation, usable workspace or the ability to do rapid movements. This paper presents the analysis and evaluation of a haptic device design, utilizing a variant of redundant kinematics, sometimes referred to as a macro-micro configuration, intended to allow large and fast movements without loss of impedance-width. A brief mathematical analysis of the design constraints is given and a prototype system is described where the effects of different elements of the control scheme can be examined to better understand the potential benefits and trade-offs in the design. Finally, the performance of the system is evaluated using a Fitts’ Law test and found to compare favourably with similar evaluations of smaller workspace devices

Multi-finger grasps in a dynamic environment

Most current state-of-the-art haptic devices render only a single force, however almost all human grasps are characterised by multiple forces and torques applied by the fingers and palms of the hand to the object. In this chapter we will begin by considering the different types of grasp and then consider the physics of rigid objects that will be needed for correct haptic rendering. We then describe an algorithm to represent the forces associated with grasp in a natural manner. The power of the algorithm is that it considers only the capabilities of the haptic device and requires no model of the hand, thus applies to most practical grasp types. The technique is sufficiently general that it would also apply to multi-hand interactions, and hence to collaborative interactions where several people interact with the same rigid object. Key concepts in friction and rigid body dynamics are discussed and applied to the problem of rendering multiple forces to allow the person to choose their grasp on a virtual object and perceive the resulting movement via the forces in a natural way. The algorithm also generalises well to support computation of multi-body physic

Developmental pathways in netball match officiating:Examining the potential role of technology

Research aim: This research sought to explore the role of technology within development pathways in netball match officiating.Research methods: A qualitative methodology was employed to gain insight into technology within development pathways. 28 participants were sampled across the five global netball regions, fulfilling single and mixed umpiring (N = 21), assessing (N = 7), coaching (N = 5), tutoring (N = 5), mentoring (N = 3), administration (N = 3), and bench officiating (N = 1) roles, with thematic analysis using inductive coding adopted to investigate perspectives specifically towards technology use.Results and findings: Video within assessment processes and its implementation in analysis practices was highlighted as important for providing effective feedback. The effect might not be due to the technology alone and interactions between the individuals providing and receiving feedback should also be considered. Creating learning provision, enabling the sharing of resources and greater access to development opportunities were discussed as crucial, especially in developing world regions. However, socio-cultural differences might impact upon personal preferences in using technology or its perceived need, and regular monitoring of provision is crucial to ensure impact is occurring. Adopting processes to share knowledge across regions and creating greater assessment and mentoring opportunities were also seen to enhance development and learning. Implementation of technology should be considered in relation to different stages of development that are apparent across nations, with factors such as cost, required skills, and the compatibility being crucial to ensuring needs are met appropriately.Implications: The findings identify how technology could act to benefit match officiating pathways. The crucial factor is ensuring that equity is sought in providing mechanisms of this manner, adopting policies that are aimed at effecting the global development landscape. This might, however, be impacted by cost and availability, and as such considerations need to be made towards accessible opportunities, irrespective of geographical location.Research contribution: This research provides detail on the role of technology within development processes of sport officials and in a previously under researched sport

Dietary Supplementation with Soluble Plantain Non-Starch Polysaccharides Inhibits Intestinal Invasion of Salmonella Typhimurium in the Chicken

Soluble fibres (non-starch polysaccharides, NSP) from edible plants but particularly plantain banana (Musa spp.), have been shown in vitro and ex vivo to prevent various enteric pathogens from adhering to, or translocating across, the human intestinal epithelium, a property that we have termed contrabiotic. Here we report that dietary plantain fibre prevents invasion of the chicken intestinal mucosa by Salmonella. In vivo experiments were performed with chicks fed from hatch on a pellet diet containing soluble plantain NSP (0 to 200 mg/d) and orally infected with S.Typhimurium 4/74 at 8 d of age. Birds were sacrificed 3, 6 and 10 d post-infection. Bacteria were enumerated from liver, spleen and caecal contents. In vitro studies were performed using chicken caecal crypts and porcine intestinal epithelial cells infected with Salmonella enterica serovars following pre-treatment separately with soluble plantain NSP and acidic or neutral polysaccharide fractions of plantain NSP, each compared with saline vehicle. Bacterial adherence and invasion were assessed by gentamicin protection assay. In vivo dietary supplementation with plantain NSP 50 mg/d reduced invasion by S.Typhimurium, as reflected by viable bacterial counts from splenic tissue, by 98.9% (95% CI, 98.1–99.7; P<0.0001). In vitro studies confirmed that plantain NSP (5–10 mg/ml) inhibited adhesion of S.Typhimurium 4/74 to a porcine epithelial cell-line (73% mean inhibition (95% CI, 64–81); P<0.001) and to primary chick caecal crypts (82% mean inhibition (95% CI, 75–90); P<0.001). Adherence inhibition was shown to be mediated via an effect on the epithelial cells and Ussing chamber experiments with ex-vivo human ileal mucosa showed that this effect was associated with increased short circuit current but no change in electrical resistance. The inhibitory activity of plantain NSP lay mainly within the acidic/pectic (homogalacturonan-rich) component. Supplementation of chick feed with plantain NSP was well tolerated and shows promise as a simple approach for reducing invasive salmonellosis

Effects of a high-dose 24-h infusion of tranexamic acid on death and thromboembolic events in patients with acute gastrointestinal bleeding (HALT-IT): an international randomised, double-blind, placebo-controlled trial

Background: Tranexamic acid reduces surgical bleeding and reduces death due to bleeding in patients with trauma. Meta-analyses of small trials show that tranexamic acid might decrease deaths from gastrointestinal bleeding. We aimed to assess the effects of tranexamic acid in patients with gastrointestinal bleeding. Methods: We did an international, multicentre, randomised, placebo-controlled trial in 164 hospitals in 15 countries. Patients were enrolled if the responsible clinician was uncertain whether to use tranexamic acid, were aged above the minimum age considered an adult in their country (either aged 16 years and older or aged 18 years and older), and had significant (defined as at risk of bleeding to death) upper or lower gastrointestinal bleeding. Patients were randomly assigned by selection of a numbered treatment pack from a box containing eight packs that were identical apart from the pack number. Patients received either a loading dose of 1 g tranexamic acid, which was added to 100 mL infusion bag of 0·9% sodium chloride and infused by slow intravenous injection over 10 min, followed by a maintenance dose of 3 g tranexamic acid added to 1 L of any isotonic intravenous solution and infused at 125 mg/h for 24 h, or placebo (sodium chloride 0·9%). Patients, caregivers, and those assessing outcomes were masked to allocation. The primary outcome was death due to bleeding within 5 days of randomisation; analysis excluded patients who received neither dose of the allocated treatment and those for whom outcome data on death were unavailable. This trial was registered with Current Controlled Trials, ISRCTN11225767, and ClinicalTrials.gov, NCT01658124. Findings: Between July 4, 2013, and June 21, 2019, we randomly allocated 12 009 patients to receive tranexamic acid (5994, 49·9%) or matching placebo (6015, 50·1%), of whom 11 952 (99·5%) received the first dose of the allocated treatment. Death due to bleeding within 5 days of randomisation occurred in 222 (4%) of 5956 patients in the tranexamic acid group and in 226 (4%) of 5981 patients in the placebo group (risk ratio [RR] 0·99, 95% CI 0·82–1·18). Arterial thromboembolic events (myocardial infarction or stroke) were similar in the tranexamic acid group and placebo group (42 [0·7%] of 5952 vs 46 [0·8%] of 5977; 0·92; 0·60 to 1·39). Venous thromboembolic events (deep vein thrombosis or pulmonary embolism) were higher in tranexamic acid group than in the placebo group (48 [0·8%] of 5952 vs 26 [0·4%] of 5977; RR 1·85; 95% CI 1·15 to 2·98). Interpretation: We found that tranexamic acid did not reduce death from gastrointestinal bleeding. On the basis of our results, tranexamic acid should not be used for the treatment of gastrointestinal bleeding outside the context of a randomised trial

Improved haptic interaction for large workspace, multi-sensory, dynamic virtual environments

Virtual Reality (VR) is a rapidly advancing scientific field which enables humans to experience environments other than that which they physically inhabit. Humans use all their senses to interact in the real world and there should be no difference when using VR. This thesis explores the current state-of-the-art in Multi-Sensory Virtual Reality (MSVR) and presents new techniques for improving the level of interaction and realism in touch enabled MSVR. It is shown that, of the three senses which are commonly included in MSVR: vision, audition and haptics (touch), haptics is the least well represented. Further, it is observed that haptic interaction is particularly lacking in two areas: natural object manipulation and large workspace interaction. Object manipulation is limited by the number of contact points a haptic device can provide and there are both hardware and software challenges related to this. It is also limited by the realism of simulated object motion which is more complex for haptics than purely visual-auditory simulations. A novel haptic rendering algorithm, called the xFCA, has been designed to improve multi-finger manipulation of arbitrarily shaped objects. Also, a software platform known as MUSI has been developed which integrates the xFCA into a dynamic rigid-body simulator to allow the natural manipulation of virtual objects. The challenges in the development of MUSI, along with its advantages and limitations are discussed. Two new approaches to increasing the workspace of haptic devices have been investigated. The first, a novel haptic rendering technique which provides force feedback related to velocity is applied to a virtual shopping trolley. The second, a novel method of chaining devices together, is used to create a multi-finger haptic interface for both large and fast movements. Finally, both systems have been integrated into an MSVR simulator and the results of this are also discussed.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Spirituality: nurturing life before, within and beyond COVID-19

No abstract available

Design and development of a haptic dental training system - hapTEL

This paper presents a novel design of a virtual dental training system (hapTEL) using haptic technology. The system allows dental students to learn and practice procedures such as dental drilling, caries removal and cavity preparation for tooth restoration. This paper focuses on the hardware design, development and evaluation aspects in relation to the dental training and educational requirements. Detailed discussions on how the system offers dental students a natural operational position are documented. An innovative design of measuring and connecting the dental tools to the haptic device is also shown. Evaluation of the impact on teaching and learning is discussed