Device To Help Vampires (& Phlebotomists) Find Veins
Sun, 17th Oct 2004
Part of the show Dreams, Sleep, and The Body Clock
Doctors, phlebotomists, and vampires could soon have a new tool at their disposal to help them find suitable veins for taking blood or inserting a drip. Biomedical scientist Herbert Zeman, from the University of Tennessee in Memphis, this week unveiled a new device which uses near-infrared light to scan the skin for juicy veins. An image of what the camera sees is then projected back onto the patient's skin, producing a blood vessel 'road-map' to guide doctors to the best sites for inserting a drip, or collecting a blood sample. The machine illuminates the skin with an array of near-infrared LEDs, which are clustered around the camera and emit light at a wavelength of 740 nm. Light of this wavelength is strongly absorbed by blood, but scattered and reflected by other tissues. So blood vessels look dark whilst the surrounding tissues look much brighter. Set up correctly, the new device, which is about the size of a shoebox, can 'see' up to 8mm into the skin, and pinpoint the position of a vein with an accuracy of 0.06mm (1/20th of a mm). It is likely to prove particularly useful for young children because their veins are often difficult to locate due to their small size and the presence 'puppy fat'.