A portable monitoring device (101) performs the monitoring of the short term, mid term and long term risks of Sudden Infant Death Syndrome (SIDS). It is also used to estimate the risk of onset of positional plagiocephaly. The monitoring device (101) is capable to acquire one or more signals associated to the typical breath and positioning patterns of an infant through a tri-axial accelerometer, and to register the data in electronic format. Statistical analysis of the signal and pattern recognition are performed in real time by a processing unit of the monitoring device. The monitoring device (101) can be used for monitoring the breath activity of an infant in various conditions, alerting a caregiver when a potentially dangerous situation is detected, with respect to a SIDS event or to the onset of plagiocephaly. Thanks to its simplicity of use, small encumbrance and low power consumption, it can be turned on and attached to the clothes of the infant for as long as one day (or more), without the need of further supervision. Registered data can be transferred on a computer through a standard USB port, which can also be used for recharging a battery of the monitoring device (101). Statistical analysis of the registered data can be performed by a computer for quantifying the long term SIDS risk, the risk of plagiocephaly and for optimizing the functional parameters of the monitoring device (101). To get a more accurate estimation of the risk of plagiocephaly, the monitoring device (101) can be attached to the head of an infant.
