Use of accelerometers in the control of practical prosthetic arms

Accelerometers can be used to augment the control of powered prosthetic arms. They can detect the orientation of the joint and limb and the controller can correct for the amount of torque required to move the limb. They can also be used to create a platform, with a fixed orientation relative to gravity for the object held in the hand. This paper describes three applications for this technology, in a powered wrist and powered arm. By adding sensors to the arm making these data available to the controller, the input from the user can be made simpler. The operator will not need to correct for changes in orientation of their body as they move. Two examples of the correction for orientation against gravity are described and an example of the system designed for use by a patient. The controller for all examples is a distributed set of microcontrollers, one node for each joint, linked with the Control Area Network (CAN) bus. The clinical arm uses a version of the Southampton Adaptive Manipulation Scheme to control the arm and hand. In this control form the user gives simpler input commands and leaves the detailed control of the arm to the controller

A study of publish/subscribe systems for real-time grid monitoring

Monitoring and controlling a large number of geographically distributed scientific instruments is a challenging task. Some operations on these instruments require real-time (or quasi real-time) response which make it even more difficult. In this paper, we describe the requirements of distributed monitoring for a possible future electrical power grid based on real-time extensions to grid computing. We examine several standards and publish/subscribe middleware candidates, some of which were specially designed and developed for grid monitoring. We analyze their architecture and functionality, and discuss the advantages and disadvantages. We report on a series of tests to measure their real-time performance and scalability

Illumination system for the MICE tracker station assembly QA

Copyright @ 2007 MICEThis document describes the design and preparation of the optical system used to illuminate the scintillating-fibre planes to be used in the MICE Tracker. This illumination test during the tracker station assembly is a part of the quality assurance (QA) scheme. The optical design uses a two-stage approach: first, cylindrical optics are used to focus the round beam from the LED into to a long, thin shape. A mechanical slit is placed here to select an evenly illuminated region, providing it with well-defined edges. The second stage is a set of relay optics which project an image of the slit aperture on to the scintillating-fibre plane. A useful consequence of using relay optics rather than a simple slit close to the fibre plane is that wear or accidental damage to the fibres are avoided when the illumination system is being scanned across

Distributed monitoring and control of future power systems via grid computing

It is now widely accepted within the electrical power supply industry that future power systems operates with significantly larger numbers of small-scale highly dispersed generation units that use renewable energy sources and also reduce carbon dioxide emissions. In order to operate such future power systems securely and efficiently it will be necessary to monitor and control output levels and scheduling when connecting such generation to a power system especially when it is typically embedded at the distribution level. Traditional monitoring and control technology that is currently employed at the transmission level is highly centralized and not scalable to include such significant increases in distributed and embedded generation. However, this paper proposes and demonstrates the adoption of a relatively new technology 'grid computing' that can provide both a scalable and universally adoptable solution to the problems associated with the distributed monitoring and control of future power systems

Ideas and networks: The rise and fall of research bodies for powered artificial arms in America and Canada, 1945-1977

This paper examines the rise and fall of research and development funding programs for upper-limb myoelectric prosthetics in America and Canada from 1945 to 1977. Despite similarities in overall technological goals—to produce electronic arms and hands for veterans in the US and children with phocomelic limbs in Canada—we argue that the reasons for starting and ending the programs reflected different national preoccupations. In the US the reasons for the creation in 1945 and termination in 1977 of funding programs focused on the lack of fundamental research in the field, and role that science could have in the development and design in prosthetics. In Canada, by contrast, there was little discussion about science and its relationship to technology in knowledge creation when the prosthetics research and training unit (PRTU) funding program was founded in 1963 and wound up in 1975. Instead, the policy discussion focused on the importance of regional representation and relationships among different professional groups and sectors of society

GRIDCC: Real-time workflow system

The Grid is a concept which allows the sharing of resources between distributed communities, allowing each to progress towards potentially different goals. As adoption of the Grid increases so are the activities that people wish to conduct through it. The GRIDCC project is a European Union funded project addressing the issues of integrating instruments into the Grid. This increases the requirement of workflows and Quality of Service upon these workflows as many of these instruments have real-time requirements. In this paper we present the workflow management service within the GRIDCC project which is tasked with optimising the workflows and ensuring that they meet the pre-defined QoS requirements specified upon them

Grid computing technologies for renewable electricity generator monitoring and control

In this paper we discuss the use of real-time Grid computing for the monitoring, control and simulation of renewable electricity generators and their associated electrical networks. We discuss briefly the architectural design of GRIDCC and how we have integrated a number of real (solar, CHP) and simulated conventional power generators into the GRIDCC environment. A local weather station has also been attached to an Instrument Manager to alert experts appropriately when the Solar Array is not generating. The customised remote control and monitoring environment (a virtual control room), distributed using a standard web server, is discussed

Characterisation of the Clothespin relocation task as a functional assessment tool

Method: The Clothespin Relocation Task has been adapted from an arm training tool to create an instrument to measure hand function. It is based in the time to move three clothespins from a horizontal to a vertical bar, and back. To be generally useful, the measures need to have their psychometric properties investigated. This paper measures the characteristics of an able bodied population to gain an understanding of the underlying statistical properties of the test, in order that it can then be used to compare with different subject groups. Fifty adults (29 males, 21 females, mean age 31) were tested with five runs of three clothespins moved up and then down. Ten subjects returned twice more to observe repeatability. Results: There was a non-Gaussian range of times, from 2.5s to 7.37s. Mean time for Up was 4.1s, and was 4.0s for Down, with a skew towards the faster times of 0.57 for Up and 0.97 for Down. Over the three sessions there was a small (not significant) increase in speed 4.1+/-0.5s first run Down to 3.5 +/-0.4s for third. Conclusion: These initial tests confirm that it has potential to be used as a measurement of the performance of arm movement

Scalability tests of R-GMA-based grid job monitoring system for CMS Monte Carlo data production

Copyright @ 2004 IEEEHigh-energy physics experiments, such as the compact muon solenoid (CMS) at the large hadron collider (LHC), have large-scale data processing computing requirements. The grid has been chosen as the solution. One important challenge when using the grid for large-scale data processing is the ability to monitor the large numbers of jobs that are being executed simultaneously at multiple remote sites. The relational grid monitoring architecture (R-GMA) is a monitoring and information management service for distributed resources based on the GMA of the Global Grid Forum. We report on the first measurements of R-GMA as part of a monitoring architecture to be used for batch submission of multiple Monte Carlo simulation jobs running on a CMS-specific LHC computing grid test bed. Monitoring information was transferred in real time from remote execution nodes back to the submitting host and stored in a database. In scalability tests, the job submission rates supported by successive releases of R-GMA improved significantly, approaching that expected in full-scale production

A Tool to Assist in the Analysis of Gaze Patterns in Upper Limb Prosthetic Use

Gaze tracking, where the point of regard of a subject is mapped onto the image of the scene the subject sees, can be employed to study the visual attention of the users of prosthetic hands. It can show whether the user is pays greater attention to the actions of their prosthetic hand as they use it to perform manipulation tasks, compared with the general population. Conventional analysis of the video data requires a human operator to identify the key areas of interest in every frame of the video data. Computer vision techniques can assist with this process, but a fully automatic systems requires large training sets. Prosthetic investigations tend to be limited in numbers. However, if the assessment task is well controlled, it is possible to make a much simpler system that uses initial input from an operator to identify the areas of interest and then the computer tracks the objects throughout the task. The tool described here, employs colour separation and edge detection on images of the visual field to identify the objects to be tracked. To simplify the computer's task further, this test uses the Southampton Hand Assessment Procedure (SHAP), to define the activity spatially and temporarily, reducing the search space for the computer. The work reported here is the development a software tool capable of identifying and tracking the Points of Regard and Areas of Interest, throughout an activity with minimum human operator input. Gaze was successfully tracked for fourteen unimpaired subjects, which was compared with the gaze of four users of myoelectric hands. The SHAP cutting task is described and the differences in attention observed with a greater number of shorter fixations by the prosthesis users compared to unimpaired subjects. There was less looking ahead to the next phase of the task by the prosthesis users