Technology evaluation report: obtaining pulse oximeter signals when the usual probe cannot be used

We studied the function of four different monitoring probes used with the Satlite pulse oximeter (Datex, Helsinki). The aim was to evaluate ease of use and compare the function of the probes and their attachment methods in different locations (finger, toe, ear, thumb web, instep, wrist, and ankle). Two similar pulse wave oximeters were used in the study. To select the best signal we determined the absolute height of the plethysmographic waveform for each probe. Probes were compared on awake normal adult volunteers (N = 13), in anesthetized adult patients (N = 12), and in neonates weighting 500-1000 g (N = 8). In all the adult trials, the clip-on finger probe was used as a reference, and probes taped or clipped onto the finger provided adequate signal from the ear or from the thumb web, however. In the neonates, taped-on probes were most satisfactory.