MoRe-T2 (mobility research trajectory tracker): validation and application

It is important to assess the suitability of mobility aids before prescribing them to patients. This assessment is often subjectively completed by a therapist and it often includes a variety of basic practical tests. An objective assessment of a patient's capability, which captures not only speed of task completion and success, but also accuracy and risk of manoeuvres, would be both a fairer and safer approach. Yet until now such an assessment would have been cost-prohibitive, especially in low resource settings. We pave the way towards this end goal, by describing, validating and demonstrating a low-cost computer vision based system called MoRe-T2 (mobility research trajectory tracker). The open-source MoRe-T2 system uses low-cost off-the-shelf webcams to track the pose of fiducial markers, which are simply printed onto regular office paper. In this article, we build upon previous work and benchmark the accuracy of MoRe-T2 against an industry standard motion capture system. In particular, we show that MoRe-T2 achieves accuracy comparable to CODA motion tracking system. We go on to demonstrate a use case of MoRe-T2 in assessing wheelchair manoeuvrability over a relatively large area. The results show that MoRe-T2 is scalable at a much lower cost than typical industry-standard motion trackers. Therefore, MoRe-T2 can be used to develop more objective and reliable assessments of mobility aids, especially in low-resource settings

Pedestrian level of interaction on platform conflict areas by real-scale laboratory experiments

The objective of this work was to develop a new method to measure the interaction of passengers boarding and alighting at metro stations. This method included the Level of Interaction (LOI) as more precise indicator compared to the Level of Service (LOS). The method consisted of building a mock-up of a metro car and a series of simulation experiments in University College London’s Pedestrian Accessibility Movement Environmental Laboratory (PAMELA) based on observation at two London Underground station. This mock-up included Platform Edge Doors (PEDs) and a new space defined as Platform Conflict Area in front of the train doors in which the density of passengers was high. Results of the laboratory experiments were expressed according to the types of queues, formation of lanes, density by layer, and distance between passengers, in which the interaction followed a Logarithmic Distribution and no statistical differences were found with PEDs. These results are helpful for traffic engineers and policy makers to measure the interaction and use the LOI as a new indicator for the design of spaces in metro systems

Estimation of the passenger space in the boarding and alighting at metro stations

Platform edge doors (PEDs) have been used in various metro stations to improve safety and ventilation conditions, however limited research has been done to estimate the passenger space (PS) in the boarding and alighting process when PEDs are installed. The aim of this study was to estimate the space needed for boarding and alighting at metro stations. The method was based on a mock-up carriage and the relevant portion of the platform at University College London´s Pedestrian Accessibility Movement Environmental Laboratory (PAMELA), in which different load scenarios of boarding and alighting were conducted. The scenarios were based in a preliminary analysis observed at Westminster Station, in which PEDs are installed. To obtain the position of each passenger on the platform a tracking tool was used. The hypothesis of this research was that PS for alighting passengers can be represented as an asymmetrical ellipse, in which the longitudinal and lateral radii changed according to the negotiation with other passengers alighting or waiting on the platform to board the train. Therefore, there is a relationship between PS and the level of interaction, which suggests that passengers adjust their PS to avoid collision. This research can be used by traffic engineers to estimate PS of passengers boarding and alighting when PEDs are used. This in turn can help in designing the platform train interface (PTI) and platforms at transport infrastructures

Mobility in the built environment: age-related changes in gait characteristics when walking on complex terrain

BACKGROUND: An understanding of how common features in the built environment influence how people walk is needed to maintain mobility for older people. METHODS: The study included 71 healthy subjects with an age range of 18 to 92 years. Using inertial measurement units, participants’ gaits were assessed while walking across a complex terrain created in a controlled laboratory environment. RESULTS: Participants found stair climbing and stepping on obstacles to be the most challenging activities, as judged by step time. These activities also showed the most significant age-related changes, with significant effects in both step time and shank angle at touch down being observed from around the age of 60 years. CONCLUSIONS: The changes observed in this study are consistent with decreasing muscle power causing limited ability to negotiate stairs

Passenger Boarding Time, Mobility and Dwell Time for High Speed 2

HS2 has a challenging dwell time of 2 minutes at some of its stations. Achieving this will be influenced by a number of factors including the platform-train interface and the relative heights of each. This paper will describe the research relating to the effect of the height difference and the provision of steps on the dwell time, The project also looked at the impact of passenger demographics and passengers with luggage on boarding and alighting times. The main experimental research was conducted in collaboration with University College London, using the PAMELA research facility to build a rig of the train and platform for testing with subjects. We also conducted a number of real life observations at train stations within the UK to validate the experimental findings. The research programme also included a literature review and observational study to examine issues around mobility and ageing that affect walking speed and movement around the station. This also used another CCD/HS2 research project that looked at the demographics of the future passenger population and how this would impact on passenger movements. The research programme made a number of recommendations around the configuration of the platform-train interface to optimise boarding times

Design requirements and challenges for intelligent power wheelchair use in crowds: learning from expert wheelchair users

An intelligent or smart power wheelchair is normally built on a standard power wheelchair with additional modules for perception, navigation or interaction purposes. It adds autonomy to the wheelchair and provides a technical solution to the safety concerns, thus opening the possibility for people who are considered not suitable to use a standard power wheelchair. Although the research in this field has been going on for decades, most of them focus on dealing with static or simple dynamic environments. In addition, the role of the user is sometimes overlooked during the design and development process. In our project, we aim to design a user-centred intelligent wheelchair and extend its application area to one of the most difficult scenarios faced by wheelchair users­, ­­navigating among crowds. As we start the process of designing a smart wheelchair, we present the results of an initial study with expert wheelchair users' to gain insights into their design requirements and challenges when navigating in crowds

A Case Study on Improving Accessibility of Healthcare Care Facility in Low-resource Settings

Accessibility in a hospital is challenging for people in low-income countries due to a lack of accessible mediums to communicate wayfinding, accessibility, and healthcare information. This results in delays and stress but can also result in sub-optimal treatment or sometimes a complete lack of treatment for the visitors. Sensible physical and digital interventions can greatly ease the experience of visitors and reduce the work-related stress of healthcare providers. We present a case study on wayfinding and service design for a mega ophthalmic care facility that has a daily footfall of 2500 patients. From our mixed-methods study we identified: (i) there are very few accessible mediums available to communicate wayfinding, accessibility, and healthcare information; (ii) there is a lack of inclusively designed interventions to accommodate the diversity of visitors; (iii) spatial ambiguity and situational impairment due to crowd density exasperate the situation and (iv) there exist missing as well as misleading information. We developed a spectrum of solutions on the environmental and digital infrastructures available within this context to deliver wayfinding and procedural information. We completed a progressive intervention across digital and physical mediums over a duration of 18 months. This has shown the impact of each medium on visitors' experience. We found the choice of interface to access information depends on the ease of access, and ease of access depends on visitors' abilities. Therefore, both the environment and digital mediums are found to be useful for visitors. Based on these empirical findings, we draw recommendations for an inclusive service design that incorporates using elements of the environment, human and digital infrastructure to support a more positive healthcare visitors experience

Effect of Environmental Factors on How Older Pedestrians Detect an Upcoming Step

The relationships between environmental features and older people’s ability to safely move around a complex pedestrian environment are, as yet, poorly understood. Specifically, the impact of light levels on trip hazard detection during walking has received relatively little attention. This study investigates the effect of illuminance on people’s ability to detect steps of different heights in a laboratory-based controlled environment. Sixteen young and 15 older participants walked along a 13.2 m walkway towards an either ascending or descending step at 200 lux or 4 lux light levels. Trial time, gaze behaviour and distance at which the step was first visually fixated (detection distance) were measured using an eye-tracker. It was found that both the trial time and detection distance of older participants were affected by light level whereas the fixation number and fixation duration of young participants were affected by step-height. Shorter detection distance, greater number of fixations and longer fixation duration were found among older participants as opposed to young participants. The results suggest that the processing efficiency for visual information on an upcoming step is slower among older people than among young people. This implies that the vulnerability of older pedestrians maybe be reduced if better lighting or a simplified visual environment is provided

A Basic Study on Temporal Parameter Estimation of Wheelchair Propulsion based on Measurement of Upper Limb Movements Using Inertial Sensors

Wheelchairs are the most widely used assistive device to aid activities of daily living (ADL) for disabled people. However, manual pushing of a wheelchair frequently leads to overuse of upper extremities causing shoulder pain and carpal tunnel syndrome. The purpose of this study was to test a novel method of estimating temporal parameters of wheelchair propulsion using inertial sensors. In this paper, normalized coordinate values of the vector defined on the upper arm were calculated from an inertial sensor attached on the upper arm. The number of strokes and push cycle timings including duration of propulsion and recovery phases were estimated for steady state wheelchair propulsion. This estimation was completed using a novel vector-based approach and a previously published resultant acceleration method; both were compared to timings measured using the SmartWheel. Measurements were performed on level and sloped surfaces with 10 able bodied subjects. The vector-based method improved estimation of the number of strokes when compared to the resultant acceleration method. However, the push cycle was estimated with better accuracy by the resultant acceleration method. Therefore, a combination of the vector-based and the resultant acceleration methods is proposed to ensure more accurate estimation of temporal parameters. The results suggest inertial sensors can be used to measure wheelchair activity accurately and reliably