Theme:

Medical Engineering

Background

Prosthetics is an obviously emotive issue, as the absence of a limb, either by amputation or by congenital defect is a highly visible ‘disability’. Despite this prejudice, many of those with congenital defects do not consider themselves disabled, or in need of a prosthesis, due to their existing ability to adapt to the surrounding environment or task. Others, including the majority of amputees, often wish to regain some of the functionality (or at least, the appearance) lost with the limb, by the use of a prosthesis. However, the potential use of functional prostheses, or cybernetic systems, involving an interface between man and machine, is also sometimes viewed as unnatural or unappealing. Consequently issues such as anthropomorphism become as critical in prosthesis design as the size, weight, and power consumption of the device.

The Southampton Philosophy

The Southampton Artificial Hand has been in existence for several decades, and is based upon the original hypothesis for the development of a hierarchically controlled, myoelectric prosthetic hand. Although the mechanics of the Southampton hand has undergone several evolutionary stages, it is the main control hypothesis that forms the foundation of the Southampton Hand.

In order to grip an object with a natural hand, the brain utilises vast quantities of information from sites all over the hand and fingertips, to provide muscular reflexes that adjust the grip to ensure that the object doesn’t slip. Conventional myo-devices require the user to decide how much force to exert on an object by control of the EMG signals in the forearm. The main difficulty is that there is no feedback (other than visual), hence it becomes very difficult for the user to maintain any form of minimal grip without the object slipping.

The Southampton philosophy concentrates on devolving the responsibility of grip adjustment from the user to the hand itself. The ‘intelligent’ hand uses sensors, electronics and microprocessor technology to allow this adaptive device to maintain optimum grip (thereby ensuring that objects do not slip from the hand) under the jurisdiction of a state driven control system (which allows easy control of the prosthesis).

At present a multiple degree of freedom device is under development, utilising lightweight materials to produce a highly functional, adaptive prosthesis. Funding from Remedi (Rehabilitation and Medical Research Trust) has enabled the realisation of prototype systems, which will undergo further development and evaluation.

Funding from the Engineering and Physical Sciences Research Council (EPSRC) allowed us to investigate the use of thick-film technology to design and construct sensors to improve the functionality of the hand. The approach adopted has been to instrument the fingertips with sensors to measure grip force and object temperature and to develop sensors to detect the onset of object slip as part of an autonomous control system with the aim of automatically adjusting hand grip strength or posture to prevent slip occurring. As part of this project, a new generation of hand has been produced.

Future work will concentrate on developing the ‘intelligent’ finger: a self-contained modular unit that combines both sensors and associated instrumentation circuits and that communicates with a central control system (potentially located on the palm or the wrist socket) through an RF wireless link.

Research Areas Involved

This project spans a wide range of disciplines which is often the case in biomedical engineering. The diversity of these knowledge requirements is frequently overlooked, yet the very essence of the Southampton Hand lies in the control of motor-drive systems. Although the overall research continues at postgraduate level, undergraduates are actively involved in specific areas of the work, which forms the basis of final year projects, or group projects. Examples of student projects include the modelling of the mechanical design, development of force/slip sensors, and associated work such as the design of a rehabilitation gripper for fitment to a wheelchair.

A computer animation of the latest version of the Southampton Hand showing the thumb moving across the palm to oppose the index finger can be found here.

Recent Publications

Thick-film force, slip and temperature sensors for a prosthetic hand
Contact force sensor for artificial hands with a digital interface for a controller
Intelligent multifunction myoelectric control of hand prosthesis
The design of anthropomorphic prosthetic hands: A study of the Southampton Hand
Development of a lightweight and adaptable multiple-axis hand prosthesis

Primary investigators

• phc
• Neil White

Secondary investigator

• awc

Associated research group

• Electronics and Electrical Engineering

Date:

2002-2004

Themes:

Sensor Technology, Intelligent Control, Communications, Environmental Monitoring

To make new autonomous sub-glacial probes for glaciology research. This involves the design of small probes containing sensors and transponders which will be placed inside and under a glacier. They will be monitored over a year by a base station, which will collect the measurements, measure the probe positions and transmit data to a web server in the UK. The projects also involves the Geography Department.

Primary investigators

• Kirk Martinez
• Dr J.K. Hart

Secondary investigator

• Harvey Nicholas Rutt

Associated research group

• Intelligence, Agents, Multimedia Group

Date:

2001-2004

Theme:

Sensor Technology

Funding:

EU

In electricity generation, online monitoring of critical components is key to making advances. Uninterrupted operation can bring about big reductions in operating costs and is vital to the implementation of modern asset management principles. The resulting energy cost reductions in Europe amount to multi-milliopn Euro savings, with similar potential within the petrochemical and other industries.

This project's main objective is to produce a multi-channel, passive, batteryless, remote monitoring system operating at 600C. The sensors will be based on surface acoustic wave devices on a special piezoelectric substrate material.

Primary investigator

• Neil White

Secondary investigator

• mnbh01r

Partners

• Iberdrola Generacion, Spain
• Electricite de France
• Corus
• SenTec Electronik GmbH
• Ilmenau Technical University, Germany
• AVL GmbH, Austria
• SJB Engineering Ltd

Associated research groups

• Electronic Systems and Devices Group
• Electronics and Electrical Engineering

Date:

2001-2003

Theme:

Sensor Technology

Funding:

EPSRC (GR/R35858/01)

The project is a multi-disciplinary venture to design and manufacture novel instrumentation for monitoring oil/gas/water separation processes (up to 150 bar) and temperatures up to 150C. Multi-modal distributed sensors immune to sludge deposition will provide measurements in the hostile multi-phase environment. The instrument will be tested in offshore separators and will have potential for use down-hole.

Conventional sensor materials are not suitable for use at the high temperatures and pressures encountered down-hole. The ideal candidates are thick-film conductors and piezoelectrics implemented on ceramic substrates. They will combine outstanding mechanical and electrical properties, which will be thoroughly tested for robustness and finctionality in this novel application. To obtain a reliable and accurate picture of phase distribution, two measurement modalities will be required: electrical impedance and ultrasonic. This multi-modal measurement will be modelled and then tested experimentally. Sensor surfaces will be kept free from deposits by using active control mechanisms.

Primary investigators

• Neil White
• Prof. Tom Dyakowski, UMIST
• Dr Jack Hale, Newcastle University
• Dr Artur Jaworski, Manchester University

Secondary investigator

• Nick Harris

Partner

• Advanced Research Partnership

Associated research groups

• Electronic Systems and Devices Group
• Electronics and Electrical Engineering

Date:

2000-2003

Theme:

Sensor Technology

Funding:

EPSRC (GR/N05970/01)

This research will benefit any device manufacturing that requires ferroelectric active layers with thickness in the range 10 to 100 microns. In the short term, investigations into both piezoelectric and pyroelectric materials will allow the integration of this fabrication process into numerous devices. Examples range from actuators, sound and pressure sensors to IR 'uncooled' thermal detectors. In the longer term it is anticipated that the results from these trials may offer benefits to other manufacturing techniques, such as ceramic processing. There is also interest into incorporating the stable 'composite' suspension into the more conventional screen printing technique.

Primary investigators

• Neil White
• Prof. Roger Whatmore, Cranfield University

Secondary investigator

• Steve Beeby

Associated research groups

• Electronic Systems and Devices Group
• Electronics and Electrical Engineering

Date:

2001-2004

Theme:

Sensor Technology

Funding:

DERA

Ultrasonic waves have been shown to provide a means of liquid/solid separation. When a standing wave is set up in a liquid, forces act on particles acting towards nodal planes within the liquid. The effect has been used in the past for cell separation in biology. The motivation for this proposal is for a flow-through separation technique (acoustic filter). Existing work at Southampton has demonstrated the feasibility of such an approach based on the concept of having a single flow inlet one side of an acoustically-driven rectangular cell and several outlets on the opposite face. The system holds its resonance condition via closed loop electronic control using an embedded microcontroller. The proposed programme of work will aim to produce a microfluidic version of the device capable of filtering solid particles (in the range 1-100 microns) from liquids with relatively low flow-rates. The fabrication will exploit the latest results of our research into combining thick-film processing with silicon micromachining methods. Finite element techniques will be used to model the system.

Primary investigator

• Neil White

Secondary investigators

• Mr Martyn Hill, School of Engineering Science
• Nick Harris
• Steve Beeby

Partner

• DSTL Ltd

Associated research groups

• Electronic Systems and Devices Group
• Electronics and Electrical Engineering

Date:

2001-2004

Theme:

Sensor Technology

Funding:

EPSRC

The field of smart sensor technology continues to mature both in terms of the advances in the characteristics of the sensing elements themselves and also the electronic processing of data. The area of MicroElectroMechanical Systems (MEMS) is a relatively new field for making miniature sensors and actuators using integrated circuit (IC) fabrication and related techniques. A majority of existing MEMS research has concentrated on sensors but the recent interest in areas such as microfluidics has broadened the field to cover micro-actuators. Research at the University of Southampton into thick-film piezoelectric materials has shown that a combination of both silicon micromachining and thick-film techniques can offer a new approach to MEMS strategies.One of the drawbacks of piezoelectric materials for actuator applications is that a relatively large (several hundred volts) excitation voltage is required This limits its use in some applications, particularly in the medical field. An alternative type of actuator is based on the magnetostrictive effect. Modern-day magnetostrictive materials such as Terfenol-D, posses very large magnetostrictive coefficients, producing much greater displacements than their piezoelectric counterparts for a given input power Another potential advantage is that magnetostrictive actuators can be driven by external magnetic fields, thus removing the need for large driving voltages. Untill now, however, there has been no published work on thick-film magnetostrictive materials. The main aim of this proposal, therefore, is to develop and characterise a thick-film magnetostrictive material for use in MEMS applications. It is envisaged that the evolutionary steps in this process will be similar to those experienced with the formulation of our thick-film piezoelectric materials. The combination of thick-film and silicon technologies will therefore lead to a powerful and economic solution for new types of MEMS actuator.

Primary investigator

• Neil White

Secondary investigator

• Neil Jonathan Grabham

Partner

• Newlands Scientific Plc

Associated research groups

• Electronic Systems and Devices Group
• Electronics and Electrical Engineering

Date:

2002-2005

Theme:

Sensor Technology

Funding:

EPSRC (GR/R52626/01)

Current industrial measuring systems based on strain-gauge technology (wire, foil and thin-film devices) suffer from various problems, such as low amplitude intensity signal levels, hysteresis and creep. The purpose of the proposed research is to combine the experiences and academic strengths of two well-established research teams at Brunel and Southampton Universities to provide a practical basis for an alternative generic technology employing small mechanical frequency-based stress gauges which can become available to a wide range of industrial manufacturers and users. Novel robust resonant microsensor modules will be developed based upon miniature triple beam tuning fork structures and fabricated both in steel and on silicon. Excitation and detection will utilise screen-printed PZT thick-inks. Suitable resonator packaging (mechanical/electrical interfaces and integration) will be developed. With the active support of the industrial collaborators (6 SME manufacturers and 7 industrial users), 4 demonstrators will be used to evaluate the application of the microsensor modules: (i) pressure sensor; (ii) continuous torque sensor; (iii) load cell; (iv) wireless stress gauge. The initial demonstrators will employ the small metallic resonators fabricated using etching methods and spot welding, while subsequent demonstrators will employ the miniature silicon resonators fabricated using silicon micromachining.

Primary investigator

• Neil White

Secondary investigators

• Steve Beeby
• John Tudor

Partner

• Brunel University

Associated research groups

• Electronic Systems and Devices Group
• Electronics and Electrical Engineering

Date:

2002-2002

Theme:

Electrostatics

Funding:

Industrial

Two fires have occurred in the copper solvent extraction (CuSX) plant at the Olympic Dam mine in Southern Australia. The first occurred on 21 December 1999, the second occurred on 21 October 2001. Both of these fires occurred in the same area of the SX plant and their origins were attributed to static electricity.

In the areas where the fires originated, low conductivity solvent (Shellsol) with some additives, is transported at various velocities through HDPE and MDPE pipe work. Although the flashpoint of the solvent is relatively high at 78ºC, temperatures within the plant may periodically reach 70-80ºC. In addition, the pipes can on occasion, be partially filled with solvent and air. Droplets or solvent mist may also be generated.

This project will examine the electrostatic charging characteristics of the process, the solvents used and the flammability of the solvents in mist form. A code of practice will be developed to ensure future safe operation.

Primary investigator

• G.L. Hearn

Secondary investigators

• J.R. Ballard
• T.J. Williams

Partners

• Western Mining Corporation
• Shell

Date:

2000-2004

Themes:

Software Engineering, Business Process Modelling, Systems Engineering

Funding:

EPSRC (GR/N11513 and GR/R31973)

The overall objective of the RICES project is to provide the means whereby architects and designers of inter-enterprise IT solutions will be able to ensure that new business processes or new services launched into the everything-connected-to-everything-else world will indeed survive and function well, despite having to work with only partially-consistent information.

Primary investigator

• ph

Partners

• ICL
• DERA

Associated research group

• Dependable Systems & Software Engineering