Fibre-optic implant could monitor wounds for infection

Fibre-optic implants could be used to monitor healing wounds for signs of infection if research by Aston University scientists is successful.

A team of researchers plans to study how to turn fibre-optic technology that can measure temperature and detect biological signs of disease into a device for implanting into a wound at surgery.

Doctors currently tend to check for infection by monitoring a patient’s temperature, but catching the problem before it has had a chance to affect the whole body could stop it becoming more serious.

The research, funded by the Aston Research Centre for Healthy Ageing (ARCHA), could be particularly beneficial for older people who are less able to fight infection and for whom it is vital to spot problems as early as possible.

Dr Andrew Sutherland in Aston’s chemical engineering group is leading the project with colleagues Dr Anna Hine and Dr David Webb, who have already carried out research into the use of fibre optics in this way.

‘We wanted to address this wound-healing problem and one of the obvious things is that you get a localised inflammation that leads to a localised temperature increase,’ Sutherland told The Engineer.

‘If you get some kind of biomarker released to go along with that then maybe that would give you more of a clue as to what is going on at the site of the wound.’

The project will involve looking at potential problems, such as how to stop the fibres becoming a conduit for infection, as well as practical issues, such as what would be the best material to use to avoid damaging the wounded tissue further.

‘The fundamental work has been done,’ said Sutherland. ‘What hasn’t been done is putting everything together in a single technology platform in a way that is comfortable for the patient.’

Optical fibres can measure temperature using a grating — effectively a short segment of fibre with parallel lines that reflect light at a certain wavelength.

Changes in temperature will affect the distance between the lines and so alter the wavelength of light they reflect.

Biomarkers (molecules produced by a specific disease) attached to the outside of the fibre can also be picked up using part of the optical signal known as an evanescent wave.

This wave can be deflected outside of the cladding of the fibre where specific receptor molecules can be attached. When the biomarkers bind to the receptors, the wave is modified in a way that can be detected.