Home imaging system for chronic liver patients
Liver disease is the 5th leading cause of death in Europe and there are currently more than 1.5 million advanced cirrhosis patients in need of regular monitoring, as currently the mortality stands at 170,000 deaths a year. Using imaging techniques, we have recently started a clinical study in Royal Free Hospital to measure the development of jaundice and change of skin perfusion in liver patients, two signs of deterioration of cirrhosis. In the proposed project, we aim to take this work further and develop a home monitoring system, which can be used by the patient at home with minimal training, to track the progress of patients with cirrhosis, alerting the need for intervention. This would save the NHS a huge amount of healthcare cost.
Jaundice is caused by the accumulation of bilirubin (yellow colour), leading to yellow discoloration on their skin and eyes (sclera). The first aim of the home imaging system is to estimate bilirubin level based on the sclera colour in an adult cirrhosis patient population. An increased bilirubin level would indicate the deterioration of the liver function. The second aim of the system is to monitor skin perfusion through photoplethysmography which captures the subtle change of skin colour due to pulsations of arteries, by filming the skin surface and performing spectral analysis on pixel values over time. Pulsations with reduced magnitude indicate poor perfusion.
This home imaging system is based on a low-cost digital camera and LED lighting. Its development involves a range of optical and imaging techniques, including visible and near infrared optical spectroscopy, colour constancy algorithms, multispectral imaging, and image processing.
Clinical theme: Infection and Inflammation Imaging
Patients suffering from chronic liver failure are frequently admitted to the hospital when their conditions deteriorate, often caused by infection. At the early stage, noticeable changes are present. The proposed imaging system targets two aspects of change, namely the development of jaundice (skin and sclera colour become more yellow) and a change in skin perfusion (change in arterial pulsation magnitude). Other changes such as mottling patterns appearing on the skin have been reported and will also be investigated.
Methodological themes: Imaging devices & image analysis
The proposed home imaging system consists of both the hardware (imaging devices) and software (image analysis). The hardware will be based on consumer electronics such as digital cameras and LED illumination. As such, the cost would be low, suitable for a home setting. The software performs image analysis to predict bilirubin level from the sclera colour and to estimate the arterial pulsation magnitude. Other visual features will also be characterised and used in the early diagnosis.