St John's College
CDT Postgraduate Studentship in Healthcare Innovation (RCUK Digital Economy Programme grant number EP/G036861/1)
Non-contact vital sign monitoring using webcams
We have been developing novel methods for non-contact vital sign monitoring using a webcam. The webcam measures the light reflected from one or more regions of interest in the patient’s face. Previous work by others has shown that photoplethysmogram (PPG) signals can be remotely acquired from the human face with normal ambient light as the source. We have patented a novel method of identifying spectral components in the PPG image signal which correspond to the heart rate and to the respiratory rate. We are also extending the method to obtain measurements of blood oxygen saturation (SpO2) from the webcam image.
We have large amounts of data already collected from a completed study carried out in the Oxford Kidney Unit. The initial work on the project will require the student to reproduce the results which we have obtained from one or two patients, whose data we have extensively analysed in our current work.
There is a major unmet need to identify a methodology that will enable imminent hypoglycaemia to be detected in a reliable manner. Hypoglycaemia, a well-known side effect of glucose lowering treatments in patients with diabetes mellitus, is often a limiting factor to achieving good glycaemic control. We wish to determine whether hypoglycaemia detection can be enhanced by using data fusion techniques to combine glucose data with non-invasive measurements of vital signs (such as heart rate, skin temperature, respiratory rate and oxygen saturation) that may be influenced by low glucose levels.
The objective of the feasibility study underpinning this short project is to capture changes in value and variability of heart rate, respiratory rate, oxygen saturation, blood pressure, skin temperature and body movement as hypoglycaemia is induced (blood glucose will be lowered to less than 2.2 mmol/l) in 10 volunteers. A high-resolution video camera (Point Gray, Richmont, Canada) will be used to film the volunteer’s forehead throughout the Insulin Tolerance Test (ITT). The data acquired will be used to derive possible skin colour changes during hypoglycaemia, as well as changes in heart rate, respiratory rate and oxygen saturation. Each of the 10 volunteers will have their vital signs double-monitored throughout the ITT.