VeinViewer brings deep veins to light

03 Nov 2005

The problem of finding and accessing a vein to draw blood from could soon be solved thanks to work at Luminetx.

An optical system that projects an image of a patient's veins on to their skin could soon be helping medical professionals locate deep and buried veins. Developed by US firm Luminetx, the VeinViewer will be commercially available in the first quarter of 2006 and can be used in any application where the clinician needs to access a vein.

"The original idea that we thought of was phlebotomy where you need to get something out of a vein - a blood sample or a blood donation," Herbert Zeman, Luminetx's chief research officer, told Optics.org. "It could also be used to guide intravenous access to supply medication or fluids."

p>The VeinViewer enhances the contrast between the veins and their surroundings. This involves illuminating the skin with infrared light, capturing an image of the region of interest, enhancing the vein contrast using software and finally projecting the enhanced image back on to the skin so it exactly overlays the target area.

The infrared light source comprises LEDs emitting at 760 nm. Light is scattered and reflected from the tissue and is collected by a camera with both an infrared and a polarisation filter. This removes visible light and ensures that any light which has retained its original polarization is does not enter the camera.

The infrared images are then processed and enhanced before being passed to a projector. "We have a projector which is LED illuminated with green light which projects the veins back on to the skin in accurate alignment with the original anatomy," said Zeman. "The image on the skin is 64 x 48 mm."

To ensure the enhanced vein image is projected over the skin accurately, Zeman explains that a test pattern of four dots at the corners of a 320 x 240 pixel rectangle is imaged by the camera. This allows the enhanced image to be magnified in order to align it with the subject's veins.

Having successfully undergone clinical trials, Luminetz has optimized its prototype and is now finalising a compact and robust product that can be used in clinics. Luminetx has also negotiated a distribution deal with Diomed, which will distribute the VeinViewer for vascular applications.

"The VeinViewer can be used in vascular surgery for cosmetic treatment of spider veins," said Zeman. "These spider veins are fed from a feeder vein which often isn't visible. If you try to treat the spider veins without treating the feeder vein, it doesn't work. The VeinViwer can see the feeder veins - every one of them every time - making vascular surgery a lot easier and more effective."

Zeman adds that another potential application is using the VeinViewer in anti-wrinkle Botox treatments. The instrument ensures that the drug is injected into muscle and not a vein.

Luminetx gave an update on its work at the Optical Society of America's annual meeting, which was held last month.

Author
Jacqueline Hewett is technology editor on Optics.org and Opto & Laser Europe magazine.