It may look strange, but there is a new way to help medical staff find your veins when they need to give you a needle. It won't take away the fear of needles, but it will improve the chances of your having to get stuck just once.

Rather than multiple needle sticks while a clinician tries to find just the right spot for a blood draw? There's no need if your nurse is using this new technology, called the Vein Viewer.

Judith Lohman manages nursing at Chula Vista hospital in San Diego.

"You couldn't get anything easier than flip a switch, and press a button, and you're ready to go."

It uses an infrared light, which is on a stand above the patient casting its light down onto the patient. It produces an image of veins on the skin. You can even see a patient's blood flow.

Here's how it works. The light is absorbed by the hemoglobin in the blood vessels, resulting in a green square of fluorescent light that clearly displays patients' veins on the surface so caregivers don't have to guess – and risk guessing wrong.

Lohman says, "I promise you, this thing has been all over this hospital. From the emergency room, to outpatient surgery, to the operating room, to all of the inpatient units, we have used it."

It's not just on the arm. The vein viewer can scan the entire body, showing veins up to 8 millimetres deep.

Lohman adds, "We could even visualize something on someone's scalp, or in their neck."

Having hard-to-find veins can happen for many reasons, including illness, being extremely young or old, obesity, or having dark skin.

But now, hidden veins or not, hopefully the procedure will be a little less painful. Lohman says, "This is safe. This gives us an extra level of assurance that we're going to be able to take care of you in one time."

The vein viewer can also be used for patients receiving medication intravenously to make sure that medication is delivered to their blood stream and not their tissue, which can lead to complications including amputation.