Project Type: Research

Themes: Assistive & Accessible Technology

PhD Research: The ACCESS framework - Using inertial sensors to understand and improve manual wheelchair navigation in cities

Project Overview

Accessibility of the environment is one of the main barriers that wheelchair users report, which prevents them from being active. Cities are working on improving this. However, some of the places that have been labelled as ‘accessible’ are still not frequented as much by wheelchair users. Accessibility of an urban landscape for people with mobility impairments is defined usually by basic one-dimensional metrics (how many ramps there are in a particular area for example). However, this simplistic quantification does not tell the whole story. Currently, researchers have begun to develop systems for measuring the difficulty of routes and mapping accessible points of interest for wheelchair users. These systems are developing accessible maps for end users and are mostly based on crowd-sourced solutions or computer vision or assessment of Google earth or similar satellite maps. However, these tend to be ‘documentation efforts’, and not an easy-to-understand assessment of the accessibility of pedestrian routes.

This project is the PhD thesis of student Roxana Ramirez Herrera as part of UCL Interaction Centre, GDI Hub, and Aspire CREATE lab . The research is taking place in UCL Bloomsbury Campus (London).

Currently ( August – Oct 2021): Conducting co-design workshops and interviews with adult manual wheelchair users to improve the wheelchair navigation experience in cities. If you are a manual wheelchair user and would like to participate in this study, email or the following link:

The Challenge

The main research question that this project aims to answer is the following:

Can we use ubiquitous computing to provide a ‘comprehensive’ measure of the accessibility of an urban landscape?

The studies carried out for this project are looking at answering the following sub-questions:

  1. What defines the difficulty of navigating a particular pedestrian route in a city?
  2. Which elements can better summarize the difficulty of any given path?
  3. How can we use sensors to provide a measure of these elements?
  4. How can we present these measures in a way that is easy for the users to understand?


It is hoped that this project will be a step forward to presenting accessibility information to both wheelchair users and urban planners. On one hand, this could help wheelchair users better plan their journeys and enjoy a more pleasurable experience when moving around, and on the other hand, it could provide a clearer picture of the accessibility problems of pedestrian routes in cities.

Twitter: @Roxana_RamirezH




Joshi, S., Ramirez Herrera, R., Springett, D. N., Weedon, B. D., Morgado Ramirez, D. Z., Holloway, C., Dawes, H. (2020). A Cross-Sectional Study Using Wireless Electrocardiogram to Investigate Physical Workload of Wheelchair Control in Real World Environments. Advances in Intelligent Systems and Computing (Vol. 953, pp. 14–25). Springer Verlag.

Joshi, S., Ramirez Herrera, R., Springett, D. N., Weedon, B. D., Ramirez, D. Z. M., Holloway, C.,Ayaz, H. (2020). Neuroergonomic Assessment of Wheelchair Control Using Mobile fNIRS. IEEE Transactions on Neural Systems and Rehabilitation Engineering, 28(6), 1488–1496.

Ramirez Herrera, R., Holloway, C., Morgado Ramirez, D. Z., Zhang, B., & Cho, Y. (2020). Breathing Biofeedback Relaxation Intervention for Wheelchair Users in City Navigation. In Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS (Vol. 2020-July, pp. 4575–4578). IEEE.

Ramirez Herrera, R., Joshi, S., Zuleima, D., Ramirez, M., Carlson, T., Dawes, H., & Holloway, C. (2019). Novice vs experienced wheelchair users: perceived difficulty of task performance with and without a push-rim-activated power assisted wheelchair (PAPAW). In RESNA 2019, Assistive Technology (Vol. 31, pp. 231–250).

Ramirez Herrera, R., Momahed Heravi, B., Barbareschi, G., Carlson, T., & Holloway, C. (2018). Towards a Wearable Wheelchair Monitor: Classification of Push Style Based on Inertial Sensors at Multiple Upper Limb Locations. In 2018 IEEE International Conference on Systems, Man, and Cybernetics (SMC) (pp. 1535–1540). IEEE.


Ramirez Herrera, R., Holloway, C., Heravi, B. M., & Carlson, T. (2017). Towards a Sensor-based System for Assessing Powered Mobility Skills in Children. In Proceedings of the 19th International ACM SIGACCESS Conference on Computers and Accessibility - ASSETS ’17 (pp. 345–346). New York, New York, USA: ACM Press.

Project Team

Person's image is not available

Dr Tom Carlson