Does Noninvasive Electrical Stimulation of Acupuncture Points (NESAP) Reduce Heelstick Pain in Infants?

The purpose of the study is to determine whether noninvasive electrical stimulation at acupuncture points (NESAP) and/or 24% sucrose is effective in reducing pain in infants during invasive procedures. The investigators hypothesize that: * Gentle noninvasive electrical stimulation at selected acupuncture points and/or oral use of 24% sucrose with pacifier will reduce the newborn infant's responses to heelstick pain, as measured by the Premature Infant Pain Profile (PIPP), heart rate variability, duration of crying, and salivary cortisol levels. * The effects of combined therapies will be additive. * The analgesic effects of NESAP and/or sucrose will continue for the duration of the heelstick, reflected by the first two minutes of heelstick and the first two minutes of recovery.