SPHERE Movement Sensors
Dr Emma Stack, SPHERE Research Fellow from the University of Southampton
Room 0.3 Merchant Venturers Building, Woodland Road
Do Different SPHERE Movement Sensors Agree with the Gold Standard? Can Sensors Identify when Someone Is At High Risk of an Imminent Fall?
Our first collaborative study within SPHERE revealed that people with Parkinson’s at very high risk of falling are highly sedentary, perhaps because their balance is threatened whenever they stand up, walk, turn, tackle steps or other tasks in standing or when they sit down again. Most, if not all, of these actions are necessary when following the habitual path from favourite chair to the bottom of the stairs, so we suggest that researchers focus observation on this route to provide useful data about mobility without compromising people’s privacy by covering their entire homes with movement sensors.
That study revealed something else equally important about evaluating mobility and balance using sensors in the home: whatever their advantages over a human observer (and they certainly have some), sensors are useless if:
- their ‘view’ of the target is obscured;
- they were in the wrong place to begin with; or
- they are not recording when they are supposed to.
Therefore, in our second and third collaborative studies, we have recruited further participants at high risk of falling and invited them to help answer the questions posed in the title. To establish the extent to which data from SPHERE-type sensors (Kinect and wearable) agree with the Gold Standards (CODA 3-D motion analysis technology and experienced/expert clinicians/observers), we set out to record participants performing 12 mobility and balance tests while the sensors recorded under ‘optimal’ conditions (i.e. operated by a specialist, while participants performed isolated movements in unobstructed view).
Part of the work was conducted in a movement laboratory and part in the much more challenging residential environment. Whilst to validate agreement the scientists evaluating different sensors must remain blind to each other’s evaluations, eventually data from the Gold Standards (CODA and the experts) will allow the development and refinement of video and accelerometer-based algorithms that will facilitate ‘automatic’ recognition of movement type, quality and stability.
To test the possibility that wearable sensors can identify ‘near-misses’, ‘wobbles’ and other signs of imminent fall-risk at least as well as an observer, we have recorded other participants walking repeatedly between their chairs and stairs at home while wearing five sensors over the lumbar spine and extremities. It is possible that the accelerometry will allow researchers to identify aspects of impending instability that the participants reported or perceived but that would not be observable by anyone else, such as ‘dizziness’ or ‘fatigue’. This would mark a potentially significant improvement in healthcare: instead of relying on history, or trying to replicate symptoms after the event, SPHERE technology could record instability in real-time, aiding both communication and timely intervention.
The analysis of both studies is ongoing but we will present preliminary findings.
SPHERE Project Administrator and PA to the Director, Prof. Ian Craddock
Merchant Venturers' Building
0117 331 5689