Peter R. Warner

Actuators for rehabilitation robots

This paper describes the use of pneumatic muscle actuators in rehabilitation robotics. The history and application of this type of actuator is reviewed, and the design of an electric wheelchair mounted rehabilitation robot, utilizing a new form of pneumatic muscle actuator, the flexator, is discussed. The theory of controllable compliance is detailed and experimental results based on the flexator actuator are given to support this theory.

Wheelchair-mounted robots for the home environment

Statistics on people with disabilities, together with data on the number and use of wheelchairs in the United Kingdom, are summarized. The history of electric-wheelchair-mounted robotic devices is detailed and critically reviewed. A novel design for a hybrid electropneumatic wheelchair-mounted robot for the home environment is presented.

Validation methods for an accessible user interface for a rehabilitation robot

This paper describes the research methods required for the development and validation of a user interface for a wheelchair mounted manipulator for use by severely disabled persons. It explains the construction of the interface using tasks to define the user interface architecture. It outlines the experiments used to evaluate the user responses and draws conclusions about the effectiveness of the whole system. A systematic procedure is defined to obtain numerical estimates of the effectiveness of task analysis for individual use. This approach marries engineering procedures with a consideration of the human interaction. The prototype robot used several gesture recognition systems to achieve a better level of accessibility and usability than other robots used for rehabilitation at this time. Two different approaches to user interfaces were tested with different input devices.

The Middlesex University rehabilitation robot

This paper describes the development of an electrically powered wheelchair-mounted manipulator for use by severely disabled persons. A detailed review is given explaining the specification. It describes the construction of the device and its control architecture. The prototype robot used several gesture recognition and other input systems. The system has been tested on disabled and non-disabled users. They observed that it was easy to use but about 50% slower than comparable systems before design modifications were incorporated. The robot has a payload of greater than 1 kg with a maximum reach of 0.7 – 0.9 m.

Gesture recognition for control of rehabilitation robots

This paper describes the development of a control user interface for a wheelchair-mounted manipulator for use by severely disabled persons. It explains the construction of the interface using tasks to define the user interface architecture. The prototype robot used several gesture recognition systems to achieve a level of usability better than other robots used for rehabilitation at the time. The use of neural networks and other procedures is evaluated. It outlines the experiments used to evaluate the user responses and draws conclusions about the effectiveness of the whole system. It demonstrates the possibility of control using a head mouse.

An adaptable user interface and controller for a rehabilitation robotic arm

Previous evaluations of rehabilitation robotic systems have highlighted the need for the development of adaptable user interfaces and controller software, to cater for the varied functional ability and requirements of the potential user population. This paper outlines an approach to the development of an adaptable control system and user interface for a wheelchair-mounted robotic manipulator. A software architecture has been developed that allows a rehabilitation professional to configure a system, the interface and complexity of which matches the requirements of the user. An initial evaluation by an individual with spinal cord injury has provided encouraging results regarding the systems usability and adaptability.

A new development in low cost pneumatic actuators

Outlines the history of pneumatic muscle actuators as applied to prosthetics, orthotics and rehabilitation robotics. The advantages of low cost pneumatic muscles over more conventional forms of actuation are described, together with details of a single-axis test-rig which is being used to analyse the static and dynamic performance of a new type of muscle system in twenty different variations of length and width. A theoretical analysis using the nonsteady flow energy equation is proposed and some early experimental results are presented. Finally, the results of this study can be used to develop an electric wheelchair mounted robotic arm incorporating pneumatic muscle actuators.<<ETX>>

A novel pneumatic actuator

Middlesex University has been investigating the static and dynamic performance characteristics of a new low-cost pneumatic actuator, the Flexator, invented by Jim Hennequin of Airmuscle Ltd, for use in a hybrid electric-pneumatic wheelchair-mounted robotic arm.<<ETX>>