Healthy , full-term 4 - to 8-week-old infants were randomised to sleep either in a commercially available hammock ( n = 14 ) or a standard bassinet ( n = 9 ) , and sleep state , oxygen desaturation ( a fall in peripheral haemoglobin oxygen saturation ( SpO2 ) 4 % , for 4 sec from baseline to nadir ) , apnoea and hypopnoea , and mean SpO2 were analysed .