Matchbox-sized device opens gait for medical assessment

The Datagait system consists of a device worn on the small of a patient’s back that sends data to an external laptop where special software interprets it for review by GPs, nurses or physiotherapists.

Many neurological conditions, such as Parkinson’s disease, muscular dystrophy and motor-neurone disease, are characterised by an impaired gait and it is often one of the earliest manifestations of a condition.

In fact, patients often visit their GP complaining that they have developed a ‘funny walk’, as project lead Dr John Hart of Oxford Brookes pointed out.

In such situations, GPs currently rely on visual assessments and simple tests such as a timed 10m walk. Occasionally, patients might be referred to a specialist gait clinic that has optical motion-capture systems.

What the Datagait offers is a ‘gait lab in a box’ that can easily be used by clinicians, nurses, physiotherapists or clinical-trial investigators after a short period of training — permitting individual patient assessments in under 15 minutes.

The system incorporates an Inertial Measurement Unit (IMU) that is around the size of a matchbox and is stuck with tape to the lower back of the patient, at the body’s projected centre of mass. It incorporates accelerometers, gyroscopes and magnetometers to measure acceleration, velocity, position and orientation.

‘The are quite a few of these IMUs on the market, but the trick really was in the software,’ said Hart. ’It’s unique and allows us to pull out the gait data. We’re working on a series of disease conditions to validate it — in other words, to show that it faithfully represents the movement in different diseases. We’ve got Parkinson’s and Huntington’s already under our belt.’

The software is based on the use of quaternion mathematics and is subject to a patent application by the university.

Ultimately, the device could be used to help with diagnosis, alongside other techniques; but, perhaps more importantly, it should be able to monitor patients’ progress and the effectiveness of drugs over time or during clinical trials.

Hart believes that, once the device becomes more widespread, the medical community will come to rely more routinely on gait data for neurological and other conditions.

‘This is like a gold mine of information that people are just ignoring — gait is just crying out for better use,’ Hart said.

It is also an example of where wireless monitoring devices and smart software can help clinicians gain information from their patients in a cost-effective manner.