Nailfold Capillary Microscopy (2011-2013)
Diseases such as Systemic Sclerosis (SSc) attack the blood vessels, causing them first to swell up like a balloon before eventually bursting and dying off altogether. This prevents blood from supplying body tissue with oxygen, such that the tissue dies and may need to be amputated. This has a devastating impact on quality of life, and can incur significant costs to healthcare programs. A system that could measure the current state and progression of the disease would enable us to diagnose the disease better and measure the effect of potential drugs.
Because the thinnest and most fragile vessels (capillaries) are found in the fingers and toes, these are the areas that are affected in the earliest stages of the disease. When viewed under a microscope, blood can be seen flowing through the vessels beneath the edge of the fingernail. By capturing images and videos through the microscope, we can count the number of vessels, measure their shape and size, and also measure the rate of blood flow. This is known as nailfold capillary microscopy (NCM, or just nailfold capillaroscopy).
In healthy subjects the vessels are straight, narrow and point in the same directon (top image). Vascular disease, however, causes these vessels to become twisted, wider and to point in many different directions (bottom image). These are all properties that we can measure from the images we capture, enabling us to diagnose disease. More importantly, objective - rather than subjective - measures of changes in vessel shape, size and number enables us to quantify the effect of new drugs during clinical trials.
Currently, nailfold microscopy systems take a number of images at different locations on the nailfold and must 'stitch' them together into a single panorama. Specific points on the vessels within the panorama are then labelled by the clinician using the mouse during what is a very time-consuming process that drastically limits the system's acceptance in the clinic. The aim of this project is to develop a clinically usable system that captures the images easily and computes all measurements automatically, thus freeing up the clinician to take care of clinical duties.
This project is funded by the Wellcome Trust.