In this study, an automatic blood vessel searching system (BVSS) is newly developed, which is built in the health
monitoring system (HMS) and the drug delivery system (DDS) to extract the blood, evaluates the blood sugar level and
injects the insulin for the diabetic patients. Main subjects of our BVSS development are 1) a transmittance photo imaging
of the finger by using the LED light as a near-infrared light source with peak wave length of 870 nm, and 2) an image
processing to detect the location of the center of the blood vessel cross section.
The sharp edge focus method was applied in our BVSS to detect the depth of blood vessel. We carried out
experiments by using blood vessel phantoms, which consist of an artificial cylindrical blood vessel and skin tissue,
which are made of the teflon tube and the silicone rubber. The teflon tube has the size of 0.6 mm in diameter and is filled
with the human blood. The experimental results demonstrated that the estimated depth, which is obtained by image
analysis corresponding to given depths, shows a good agreement with the real values, and consequently the availability
of our BVSS is confirmed.