To evaluate feasibility of photoplethysmography (PPG) of pulmonary arteries in adults children and neonates and to compare normal controls to premature newborns suffering from patent ductus arteriosus and neonates suffering from pulmonary hypertension.

This study aims to check a new device for measuring lung photoplethysmography (PPG) of pulmonary arteries by delivering light through the chest wall. The aim is to evaluate pulmonary arteries' elasticity and oxygen saturation.

We will study adults children and neonates. We will study 20 healthy adults, 20 healthy children aged 2-8 years, twenty healthy neonates, 20 preterm neonates with patent ductus arteriosus (PDA) and 20 preterm neonates with no PDA. We will study also 20 neonates with pulmonary hypertension.

Each participant will be examined for 5 minutes and PPG signal will be recorded in a computer and evaluated offline later on. Pulmonic saturation will be calculated from absorption difference between two wave lengths of infrared light that will be used.

Our hypothesis is that the mentioned clinical conditions will affect PPG signal and pulmonary arterial oxygen saturation.

Inclusion Criteria:

• Hemodynamic stability

Exclusion Criteria:

• hemodynamic instability

Healthy volunteer adults and children, normal newborns, normal premature newborns and newborns suffering from patent ductus arteriosus and pulmonary hypertension