Motion Cues Analysis for Parkinson Gait Recognition

Background: Previous assessment methods for PG recognition used sensor mechanisms for PG that may cause discomfort. In order to avoid stress of applying wearable sensors, computer vision (CV) based diagnostic systems for PG recognition have been proposed. Main constraints in these methods are the laboratory setup procedures: Novel colored dresses for the patients were specifically designed to segment the test body from a specific colored background. Objective: To develop an image processing tool for home-assessment of Parkinson Gait(PG) by analyzing motion cues extracted during the gait cycles. Methods: The system is based on the idea that a normal body attains equilibrium during the gait by aligning the body posture with the axis of gravity. Due to the rigidity in muscular tone, persons with PD fail to align their bodies with the axis of gravity. The leaned posture of PD patients appears to fall forward. Whereas a normal posture exhibits a constant erect posture throughout the gait. Patients with PD walk with shortened stride angle (less than 15 degrees on average) with high variability in the stride frequency. Whereas a normal gait exhibits a constant stride frequency with an average stride angle of 45 degrees. In order to analyze PG, levodopa-responsive patients and normal controls were videotaped with several gait cycles. First, the test body is segmented in each frame of the gait video based on the pixel contrast from the background to form a silhouette. Next, the center of gravity of this silhouette is calculated. This silhouette is further skeletonized from the video frames to extract the motion cues. Two motion cues were stride frequency based on the cyclic leg motion and the lean frequency based on the angle between the leaned torso tangent and the axis of gravity. The differences in the peaks in stride and lean frequencies between PG and normal gait are calculated using Cosine Similarity measurements. Results: High cosine dissimilarity was observed in the stride and lean frequencies between PG and normal gait. High variations are found in the stride intervals of PG whereas constant stride intervals are found in the normal gait. Conclusions: We propose an algorithm as a source to eliminate laboratory constraints and discomfort during PG analysis. Installing this tool in a home computer with a webcam allows assessment of gait in the home environment.

Automatic spiral analysis for objective assessment of motor symptoms in Parkinson's disease

A challenge for the clinical management of advanced Parkinson’s disease (PD) patients is the emergence of fluctuations in motor performance, which represents a significant source of disability during activities of daily living of the patients. There is a lack of objective measurement of treatment effects for in-clinic and at-home use that can provide an overview of the treatment response. The objective of this paper was to develop a method for objective quantification of advanced PD motor symptoms related to off episodes and peak dose dyskinesia, using spiral data gathered by a touch screen telemetry device. More specifically, the aim was to objectively characterize motor symptoms (bradykinesia and dyskinesia), to help in automating the process of visual interpretation of movement anomalies in spirals as rated by movement disorder specialists. Digitized upper limb movement data of 65 advanced PD patients and 10 healthy (HE) subjects were recorded as they performed spiral drawing tasks on a touch screen device in their home environment settings. Several spatiotemporal features were extracted from the time series and used as inputs to machine learning methods. The methods were validated against ratings on animated spirals scored by four movement disorder specialists who visually assessed a set of kinematic features and the motor symptom. The ability of the method to discriminate between PD patients and HE subjects and the test-retest reliability of the computed scores were also evaluated. Computed scores correlated well with mean visual ratings of individual kinematic features. The best performing classifier (Multilayer Perceptron) classified the motor symptom (bradykinesia or dyskinesia) with an accuracy of 84% and area under the receiver operating characteristics curve of 0.86 in relation to visual classifications of the raters. In addition, the method provided high discriminating power when distinguishing between PD patients and HE subjects as well as had good test-retest reliability. This study demonstrated the potential of using digital spiral analysis for objective quantification of PD-specific and/or treatment-induced motor symptoms.

Motion cue analysis for parkinsonian gait recognition

This paper presents a computer-vision based marker-free method for gait-impairment detection in Patients with Parkinson's disease (PWP). The system is based upon the idea that a normal human body attains equilibrium during the gait by aligning the body posture with Axis-of-Gravity (AOG) using feet as the base of support. In contrast, PWP appear to be falling forward as they are less-able to align their body with AOG due to rigid muscular tone. A normal gait exhibits periodic stride-cycles with stride-angle around 45o between the legs, whereas PWP walk with shortened stride-angle with high variability between the stride-cycles. In order to analyze Parkinsonian-gait (PG), subjects were videotaped with several gait-cycles. The subject's body was segmented using a color-segmentation method to form a silhouette. The silhouette was skeletonized for motion cues extraction. The motion cues analyzed were stride-cycles (based on the cyclic leg motion of skeleton) and posture lean (based on the angle between leaned torso of skeleton and AOG). Cosine similarity between an imaginary perfect gait pattern and the subject gait patterns produced 100% recognition rate of PG for 4 normal-controls and 3 PWP. Results suggested that the method is a promising tool to be used for PG assessment in home-environment.

Understanding parental motivators and barriers to uptake of child poison safety strategies: a qualitative study

Objectives: To develop an understanding of factors acting as barriers and motivators to parental uptake of child poison safety strategies.

Design: A qualitative study involving semistructured interviews and focus groups. A grounded theory approach was used for the collection and analysis of data.

Participants: Sixty five parents of children under 5 years of age, some of whom had experienced an unintentional child poisoning incident.

Results: A range of knowledge based, environmental, and behavioral barriers to comprehensive parental uptake of poison safety practices were identified. As a result there tended to be only partial implementation of safety initiatives in the home. Selection of safety practices was often guided by the interests and behaviors of the child. This made the child vulnerable to changes in the home environment, inadequate supervision, and/or shifts in their own behavior and developmental ability. Personal or vicarious exposure of a parent to a child poisoning incident was a significant motivator for parental review of safety practices.

Conclusion: Environmental measures targeting child resistant containers, warning labels, and lockable poisons cupboards will support parents’ efforts to maintain poison safety. Additional education campaigns using stories of actual poisoning incidents may help to increase awareness of risk and encourage increased uptake.

The BEST plus approach to assisting families recover from youth substance problems

The Best plus program is a whole-of-family therapy option for families to address not only youth substance abuse issues, but also challenging and antisocial adolescent behaviours. It uses an evidence-based strategy that can be implemented widely in the community, and is proving to be a popular and relevant framework for professionals to engage and assist families in reducing adolescent problem behaviours. Evaluations indicate that the program is an effective forum for parents and siblings of adolescent drug abusers to redevelop positive family environments that encourage responsible behaviour and recovery from drug abuse.

Managing intravenous medications in the non-hospital setting: an ethnographic investigation

Little published information exists about the issues involved in conducting complex intravenous medication therapy in patients’ homes. An ethnographic study of a local hospital-in-the-home program in the Australian Capital Territory explored this phenomenon to identify those factors that had an impact on the use of medicine in the home environment. This article focuses on one of the three themes identified in the study—Clinical Practice. Within this theme, topics related to the organization and management of intravenous medications, geography and diversity of patient caseload, and communication in the practice setting are discussed. These findings have important implications for policy development and establishment of a research agenda for hospital-in-the-home services.

Family circumstance and adolescent dietary behaviours

The available information on the contribution of family circumstance to adolescent dietary behaviours is inconsistent. Indicators of family circumstance may impact adolescent behaviours by influencing their daily home environment. This study examined cross-sectional and longitudinal relationships between indicators of family circumstance and (i) breakfast skipping and (ii) consumption of snack food, fast food, fruits and vegetables among adolescents. Dietary behaviour was assessed using a web-based survey completed by 1884 adolescents from years 7 and 9 of secondary schools in Victoria, Australia, at baseline and 2 years later. Five indicators of family circumstance (parental marital status, maternal education, maternal employment status, number of brothers and number of sisters) were assessed with a questionnaire completed by parents at baseline only. Logistic regression was used to examine cross-sectional associations between indicators of family circumstance and dietary behaviours. Multinomial logistic regression was used to examine associations between indicators of family circumstance and 2-year change in dietary behaviours. Individual indicators of family circumstance were differentially associated with adolescent dietary behaviours. Cross-sectional and longitudinal associations differed for adolescent boys and girls highlighting the importance of assessing specific dietary behaviours and food types individually by gender. This study highlights the complexity of the relationships between family circumstance and adolescent dietary behaviours. Future research needs to assess the efficacy of strategies promoting maternal nutritional knowledge on the dietary behaviours of adolescents.

Reduction of vividness and associated craving in personalized food imagery

This study aimed to extend recent experimental work on the efficacy of visuo-spatial working memory-based techniques for reducing food cravings by adopting a more naturalistic methodology. Fifty undergraduate women formed images of their favorite foods while performing a visuo-spatial task across six successive trials. Vividness and craving intensity were rated for each food image. Concurrent visuo-spatial processing reduced the vividness of, and craving reactivity to, personally relevant food images. Forehead tracking, a novel self-administered task, proved to be as effective in reducing vividness and craving ratings as the established visuo-spatial working memory laboratory tasks of eye movements, dynamic visual noise, and spatial tapping, and thus presents a simple, accessible technique potentially applicable in the home environment. All four tasks maintained their reducing effect over multiple trials. Individual differences in imaging ability and habitual food craving did not impact upon their effectiveness, indicating that visuo-spatial tasks can be successfully used to reduce food cravings across a range of people.

Family correlates of fruit and vegetable consumption in children and adolescents : a systematic review

Objectives To review associations between the family environment and young people’s fruit and vegetable consumption.

Design A systematic review. Published English-language (n 60) papers were identified using electronic databases and manual searches of personal files and reference lists. Observational research reporting a measure of fruit/vegetable intake for children (aged 6–11 years) and/or adolescents (aged 12–18 years) and at least one potential family correlate of dietary intake was included.

Results Parental modelling and parental intake were consistently and positively associated with children’s fruit and fruit, juice and vegetable (FJV) consumption. There were also positive associations between home availability, family rules and parental encouragement and children’s fruit and vegetable consumption. Parental intake was positively associated with adolescents’ fruit and vegetable consumption. There were also positive associations between parental occupational status and adolescent fruit consumption and between parental education and adolescents’ FJV consumption.

Conclusions Our findings highlight the importance of targeting the family environment for the promotion of healthy eating behaviours among children and adolescents. Future interventions should encourage parents to be positive role models by targeting parental intake and to create a supportive home environment through increased encouragement and availability of fruits and vegetables and employing rules to govern eating behaviours. For adolescents, indicators of family circumstances (e.g. parental education) should be used to identify target groups for interventions aimed at promoting healthy eating.

Evaluation of the childhood obesity prevention program kids - go for your life

Background
Kids - 'Go for your life' (K-GFYL) is an award-based health promotion program being implemented across Victoria, Australia. The program aims to reduce the risk of childhood obesity by improving the socio-cultural, policy and physical environments in children's care and educational settings. Membership of the K-GFYL program is open to all primary and pre-schools and early childhood services across the State. Once in the program, member schools and services are centrally supported to undertake the health promotion (intervention) activities. Once the K-GFYL program 'criteria' are reached the school/service is assessed and 'awarded'. This paper describes the design of the evaluation of the statewide K-GFYL intervention program.

Methods/Design
The evaluation is mixed method and cross sectional and aims to:
1) Determine if K-GFYL award status is associated with more health promoting environments in schools/services compared to those who are members only;
2) Determine if children attending K-GFYL award schools/services have higher levels of healthy eating and physical activity-related behaviors compared to those who are members only;
3) Examine the barriers to implementing and achieving the K-GFYL award; and
4) Determine the economic cost of implementing K-GFYL in primary schools
Parent surveys will capture information about the home environment and child dietary and physical activity-related behaviors. Environmental questionnaires in early childhood settings and schools will capture information on the physical activity and nutrition environment and current health promotion activities. Lunchbox surveys and a set of open-ended questions for kindergarten parents will provide additional data. Resource use associated with the intervention activities will be collected from primary schools for cost analysis.

Discussion
The K-GFYL award program is a community-wide intervention that requires a comprehensive, multi-level evaluation. The evaluation design is constrained by the lack of a non-K-GFYL control group, short time frames and delayed funding of this large scale evaluation across all intervention settings. However, despite this, the evaluation will generate valuable evidence about the utility of a community-wide environmental approach to preventing childhood obesity which will inform future public health policies and health promotion programs internationally.

Trial Registration
ACTRN12609001075279

Gatekeeper influence on food acquisition, food preparation and family diet

The problems associated with overweight and obesity has focused attention on obesogenic, or obesity promoting environments. The home environment, in particular the role of the main food gatekeeper, has come under particular scrutiny for its impact on the family diet (Campbell et al, 2007; Coveney, 2004; Crawford et al, 2007). 326 US and 323 Australian gatekeepers are studied to understand relationships between healthy eating capability, food acquisition and food preparation behaviours, and satisfaction with the household diet. The results suggest that gatekeeper attitudes and perceived control over family diet play a significant role in shaping food-related behaviours and diet satisfaction. Impulsiveness, focusing on freshness, meal planning, and vegetable prominence in meals are also important behavioural factors for satisfaction with diet.

A chemotactic-based model for spatial activity recognition

Spatial activity recognition in everyday environments is particularly challenging due to noise incorporated during video-tracking. We address the noise issue of spatial recognition with a biologically inspired chemotactic model that is capable of handling noisy data. The model is based on bacterial chemotaxis, a process that allows bacteria to survive by changing motile behaviour in relation to environmental dynamics. Using chemotactic principles, we propose the chemotactic model and evaluate its classification performance in a smart house environment. The model exhibits high classification accuracy (99%) with a diverse 10 class activity dataset and outperforms the discrete hidden Markov model (HMM). High accuracy (>89%) is also maintained across small training sets and through incorporation of varying degrees of artificial noise into testing sequences. Importantly, unlike other bottom–up spatial activity recognition models, we show that the chemotactic model is capable of recognizing simple interwoven activities.

Human behavior recognition with generic exponential family duration modeling in the hidden semi-Markov model

The ability to learn and recognize human activities of daily living (ADLs) is important in building pervasive and smart environments. In this paper, we tackle this problem using the hidden semi-Markov model. We discuss the state-of-the-art duration modeling choices and then address a large class of exponential family distributions to model state durations. Inference and learning are efficiently addressed by providing a graphical representation for the model in terms of a dynamic Bayesian network (DBN). We investigate both discrete and continuous distributions from the exponential family (Poisson and Inverse Gaussian respectively) for the problem of learning and recognizing ADLs. A full comparison between the exponential family duration models and other existing models including the traditional multinomial and the new Coxian are also presented. Our work thus completes a thorough investigation into the aspect of duration modeling and its application to human activities recognition in a real-world smart home surveillance scenario.

Persistent audio modelling for background determination

This paper is concerned with modelling background audio online to detect foreground sounds in complex audio environments for surveillance and smart home applications. We examine and expand upon previous work in the audio and video domains, and propose a new implementation of an audio background modelling algorithm, addressing the complexities of audio data. A number of audio features characterising different aspects of the audio content were analysed to determine the factors relevant to the determination of the background audio. We test the algorithms on three audio data sets of varying complexity. The new approach was successful in modelling the background audio for the test data.

A middle approach to literacy in a minority Indigenous Australian language context.

Kunib-dji live in Maningrida, a remote community in the Northern Territory and speak Ndj-bbana as their preferred language of communication. Kunib-dji are one of many groups of Indigenous Australian languages who speak a minority language. Very little has been documented about the social practices of literacy with speakers of such languages, particularly with the texts that mediate these languages. Knowing about the beliefs and attitudes towards enacted by these speakers towards these texts is useful for understanding the process of learning of minority and majority languages. This paper presents a middle approach to literacy as distinct form top-down and bottom-up approaches, that has emerged from the minority Indigenous Australian language context in Maningrida. The proposed middle approach to literacy incorporates non-indigenous intervention in Indigenous social practices and technological transform of Indigenous texts. The methodological aspects of such intervention and transformation together with the implications of a middle approach to literacy are presented in this paper. Throughout the paper references are made to Kunib-dji children's access to digital Ndj-bbana texts and their engagement with these texts in a home environment.