Real-time measurement of radiocarpal joint angle during dart-thrower's movement

Recently, a renewed attention has been drawn into the dart-thrower's motion as the radiocarpal joint is unique to humans and this is believed to have played a pivotal role in human evolution. Considering the importance of the motion and the complexity of the wrist joint, there have been many articles discussing the kinematics behind this movement. CT scan techniques have been used in a number of these research activities. Due to limitations in the speed of the image acquisition, the positions of the wrist were recorded in static postures. To our knowledge, a data acquisition for the motion with realtime capturing has not been reported. This paper presents the use of a 3D vision-based motion capture device. Leap Motion Controller (LMC), for measuring the radiocarpal joint angles during the dart-thrower's motion in a real-time analysis. The practical capability of the LMC in measuring dart-thrower's motion was examined in a trial involving four subjects and the angles were compared to the angles acquired from an inertial measurement unit (IMU). The results confirmed the LMC can successfully be used in the application of measuring radiocarpal kinematics" of dart-thrower's motion.

Air pressure and wind velocity - modelling ember attack within the urban-rural interface

As population change places pressure on expanding regional and metropolitan urban boundaries, so the threat of bushfire at the rural/urban interface increases. This paper presents a range of 2D and 3D 1:40 and full scale modelling investigations. Various relationships are explored between the urban and rural interface with respect to: air pressure; changes in wind pattern; vectorial velocity; and the deposition of hot ash and firebrand deposits around single story building forms, both as standalone and within an orthogonal array and cul-de-sac relationships.

Extracting 3D mesh skeletons using antipodal points locations

Finding the skeleton of a 3D mesh is an essential task for many applications such as mesh animation, tracking, and 3D registeration. In recent years, new technologies in computer vision such as Microsoft Kinect have proven that a mesh skeleton can be useful such as in the case of human machine interactions. To calculate the 3D mesh skeleton, the mesh properties such as topology and its components relations are utilized. In this paper, we propose the usage of a novel algorithm that can efficiently calculate a vertex antipodal point. A vertex antipodal point is the diametrically opposite point that belongs to the same mesh. The set of centers of the connecting lines between each vertex and its antipodal point represents the 3D mesh desired skeleton. Post processing is completed for smoothing and fitting centers into optimized skeleton parts. The algorithm is tested on different classes of 3D objects and produced efficient results that are comparable with the literature. The algorithm has the advantages of producing high quality skeletons as it preserves details. This is suitable for applications where the mesh skeleton mapping is required to be kept as much as possible.

The Pinoke Project Performance

The Pinoke Project is a 6 week creative development to create a full-length transmedia dance performance at the cutting edge of artificially intelligent technology, elite contemporary dance practice, and publication. This process will be a collaboration between creative coders, 3D graphics and motion artists, a dance/choreographer, and an embedded dance critic who will work with an artificially intelligent robot, Pinoke, on the creative development of a new stage production as well as the documentation and dissemination of the process. This project is supported by the Victorian Government through Creative Victoria.

Taking the LEAP with the Oculus HMD and CAD - plucking at thin air?

Achieving adequate visualisation of designs within CAD packages remains a challenge for designers with current methods of 3D CAD visualisation requiring either a high level of technical ability, or expensive hardware and software. The recent re-emergence of consumer VR has lowered the barrier for everyday developers wanting to visualise their designs in true 3D. This paper presents the CAD Interaction Lab (CIL) which employs the Oculus Rift Head Mounted Display (HMD) and Leap Motion Controller (LMC) to provide a low cost method enabling users to use their hands to dissect a mechanic model to manipulate and inspect individual components in realistic 3D. Qualitative observations of user interactions with the CIL show that users were able to intuitively manipulate the CAD model using natural hand movements with only minimal instruction.

2D and 3D modelling of building form subjected to ember attack

This paper furthers the research of Rollo, Luther and Atkinson 1999, and Rollo, Honey, Atkinson and Luther 2003, regarding the way in which building shape appears to contribute to the collection of fire-brand debris subject to ember attack. The paper will present a range of 2D fluid-mapping and 3D wind tunnel studies (Melaragno 1982) which have been correlated with the transportation characteristics of an ember laden air-field (Cheney and Sullivan 1997). Working with a range of generic building types the paper also introduces simple spatial modelling techniques which are being developed to illustrate the relationship between ember capture and changes in wind speed and air pressure.

Modelling yarn balloon motion in ring spinning

Air-drag on a ballooning yarn and balloon shape affect the yarn tension and ends-down (yarn breakage), which in turn affects energy consumption and yarn productivity in ring spinning. In this article, a mathematical model of yarn ballooning motion in ring spinning is established. The model can be used to generate balloon shape and predict tension in the ballooning yarn under given spinning conditions. Yarn tension was measured using a computer data acquisition system and the balloon shapes were captured using a digital camera with video capability during the experiments using cotton and wool yarns at various balloon-heights and with varying yarn-length in the balloon. The air-drag coefficients on ballooning cotton and wool yarns in ring spinning were estimated by making a “best fit” between the theoretical and experimental turning points. The theoretical results were verified with experimental data. The effects of air-drag and balloon shape on yarn tension are discussed.

Can Australain general practitioners tackle chidhood overweight/obesity? Methods and processes from the LEAP (live, eat, and play) randomized controlled trial

Background: General practitioners (GPs) could make an important contribution to management of childhood overweight. However, there are no efficacy data to support this, and the feasibility of this approach is unknown.

Objectives: To determine if GPs and families can be recruited to a randomized controlled trial (RCT), and if GPs can successfully deliver an intervention to families with overweight/obese 5- to 9-year-old children.

Methods: A convenience sample of 34 GPs from 29 family medical practices attended training sessions on management of childhood overweight. Practice staff trained in child anthropometry conducted a cross-sectional body mass index (BMI) survey of 5- to 9-year-old children attending these practices. The intervention focused on achievable goals in nutrition, physical activity and sedentary behaviour, and was delivered in four solution-focused behaviour change consultations over 12 weeks.

Results: General practitioners were recruited from across the sociodemographic spectrum. All attended at least two of the three education sessions and were retained throughout the trial. Practice staff weighed and measured 2112 children in the BMI survey, of whom 28% were overweight/obese (17.5% overweight, 10.5% obese), with children drawn from all sociodemographic quintiles. Of the eligible overweight/obese children, 163 (40%) were recruited and retained in the LEAP RCT; 96% of intervention families attended at least their first consultation.

Conclusions: Many families are willing to tackle childhood overweight with their GP. In addition, GPs and families can participate successfully in the careful trials that are needed to determine whether an individualized, family-based primary care approach is beneficial, harmful or ineffective.

Outcome data from the LEAP (Live, Eat and Play) trial: a randomized controlled trial of a primary care intervention for childhood overweight/mild obesity

OBJECTIVES: To reduce gain in body mass index (BMI) in overweight/mildly obese children in the primary care setting.
DESIGN: Randomized controlled trial (RCT) nested within a baseline cross-sectional BMI survey.
SETTING: Twenty nine general practices, Melbourne, Australia.
PARTICIPANTS: (1) BMI survey: 2112 children visiting their general practitioner (GP) April-December 2002; (2) RCT: individually randomized overweight/mildly obese (BMI z-score <3.0) children aged 5 years 0 months-9 years 11 months (82 intervention, 81 control).
INTERVENTION: Four standard GP consultations over 12 weeks, targeting change in nutrition, physical activity and sedentary behaviour, supported by purpose-designed family materials.
MAIN OUTCOME MEASURES: Primary: BMI at 9 and 15 months post-randomization. Secondary: Parent-reported child nutrition, physical activity and health status; child-reported health status, body satisfaction and appearance/self-worth.
RESULTS: Attrition was 10%. The adjusted mean difference (intervention-control) in BMI was -0.2 kg/m(2) (95% CI: -0.6 to 0.1; P=0.25) at 9 months and -0.0 kg/m(2) (95% CI: -0.5 to 0.5; P=1.00) at 15 months. There was a relative improvement in nutrition scores in the intervention arm at both 9 and 15 months. There was weak evidence of an increase in daily physical activity in the intervention arm. Health status and body image were similar in the trial arms.
CONCLUSIONS: This intervention did not result in a sustained BMI reduction, despite the improvement in parent-reported nutrition. Brief individualized solution-focused approaches may not be an effective approach to childhood overweight. Alternatively, this intervention may not have been intensive enough or the GP training may have been insufficient; however, increasing either would have significant cost and resource implications at a population level.

Economic Evaluation of a Primary Care Trial to Reduce Weight Gain in Overweight/Obese Children: The LEAP Trial

Background:- A common policy response to the childhood obesity epidemic is to recommend that primary care physicians screen for and offer counseling to the overweight/obese. As the literature suggests, this approach may be ineffective; it is important to document the opportunity costs incurred by brief primary care obesity interventions that ultimately may not alter body mass index (BMI) trajectory.

Methods:- Live, Eat and Play (LEAP) was a randomized controlled trial of a brief secondary prevention intervention delivered by family physicians in 2002-2003 that targeted overweight/ mildly obese children aged 5 to 9 years. Primary care utilization was prospectively audited via medical records, and parents reported family resource use by written questionnaire. Outcome measures were BMI (primary) and parent-reported physical activity and dietary habits (secondary) in intervention compared with control children.

Results:- The cost of LEAP per intervention family was AU $4094 greater than for control families, mainly due to increased family resources devoted to child physical activity. Total health sector costs were AU $873 per intervention family and AU $64 per control, a difference of AU $809 {P < .001). At 15 months, intervention children did not differ significantly in adjusted BMI or daily physical activity scores compared with the control group, but dietary habits had improved.

Conclusions:- This brief intervention resulted in higher costs to families and the health care sector, which could have been devoted to other uses that do create benefits to health and/or family well-being. This has implications for countries such as the United States, the United Kingdom, and Australia, whose current guidelines recommend routine surveillance and counseling for high child BMI in the primary care sector.

3D virtual haptic cone for intuitive vehicle motion control

Haptic human-machine interfaces and interaction techniques have been shown to offer advantages over conventional approaches. This work introduces the 3D virtual haptic cone with the aim of improving human remote control of a vehicle's motion. The 3D cone introduces a third dimension to the haptic control surface over existing approaches. This approach improves upon existing methods by providing the human operator with an intuitive method for issuing vehicle motion commands whilst simultaneously receiving real-time haptic information from the remote system. The presented approach offers potential across many applications, and as a case study, this work considers the approach in the context of mobile robot motion control. The performance of the approach in providing the operator with improved motion controllability is evaluated and the performance improvement determined.

3D virtual haptic cone for intuitive vehicle motion control

Haptic technology provides the ability for a system to recreate the sense of touch to a human operator, and as such offers wide reaching advantages. The ability to interact with the human's tactual modality introduces haptic human-machine interaction to replace or augment existing mediums such as visual and audible information. A distinct advantage of haptic human-machine interaction is the intrinsic bilateral nature, where information can be communicated in both directions simultaneously. This paper investigates the bilateral nature of the haptic interface in controlling the motion of a remote (or virtual) vehicle and presents the ability to provide an additional dimension of haptic information to the user over existing approaches [1-4]. The 3D virtual haptic cone offers the ability to not only provide the user with relevant haptic augmentation pertaining to the task at hand, as do existing approaches, however, to also simultaneously provide an intuitive indication of the current velocities being commanded.

Outcomes and costs of primary care surveillance and intervention for overweight or obese children : the LEAP 2 randomised controlled trial

Objective To determine whether ascertainment of childhood obesity by surveillance followed by structured secondary prevention in primary care improved outcomes in overweight or mildly obese children.

Design Randomised controlled trial nested within a baseline cross sectional survey of body mass index (BMI). Randomisation and outcomes measurement, but not participants, were blinded to group assignment.

Setting 45 family practices (66 general practitioners) in Melbourne, Australia.

Participants 3958 children visiting their general practitioner in May 2005-July 2006 were surveyed for BMI. Of these, 258 children aged 5 years 0 months up to their 10th birthday who were overweight or obese by International Obesity Taskforce criteria were randomised to intervention (n=139) or control (n=119) groups. Children who were very obese (UK BMI z score 3.0) were excluded.

Intervention Four standard consultations over 12 weeks targeting change in nutrition, physical activity, and sedentary behaviour, supported by purpose designed family materials.

Main outcomes measures Primary measure was BMI at 6 and 12 months after randomisation. Secondary measures were mean activity count/min by 7-day accelerometry, nutrition score from 4-day abbreviated food frequency diary, and child health related quality of life. Differences were adjusted for socioeconomic status, age, sex, and baseline BMI.

Results Of 781 eligible children, 258 (33%) entered the trial; attrition was 3.1% at 6 months and 6.2% at 12 months. Adjusted mean differences (intervention – control) at 6 and 12 months were, for BMI, –0.12 (95% CI –0.40 to 0.15, P=0.4) and –0.11 (–0.45 to 0.22, P=0.5); for physical activity in counts/min, 24 (–4 to 52, P=0.09) and 11 (–26 to 49, P=0.6); and, for nutrition score, 0.2 (–0.03 to 0.4, P=0.1) and 0.1 (–0.1 to 0.4, P=0.2). There was no evidence of harm to the child. Costs to the healthcare system were significantly higher in the intervention arm.

Conclusions Primary care screening followed by brief counselling did not improve BMI, physical activity, or nutrition in overweight or mildly obese 5-10 year olds, and it would be very costly if universally implemented. These findings are at odds with national policies in countries including the US, UK, and Australia.