SUPRASTERNAL DOPPLER ULTRASOUND FOR ASSESSMENT OF STROKE DISTANCE

An assessment of a non-invasive technique for measurement of stroke di stance was made using a portable Doppler ultrasound machine. The aim w as to determine the measurement error of repeated stroke distance meas urements (within-observer variability) and to assess measurement agree ment between two operators (between-observer variability), The measure ment error (within-observer variability) for both operators was simila r at approximately 2 cm. :However, the measurements of the two operato rs (between-observer variability) did not agree well. Using the mean ( SD) of three readings by each operator, the mean difference between th e operators was -0.21 cm (1.96) giving a 95% confidence interval for t he differences of -4.0 to +3.6 cm. There were significant positive and negative correlations between stroke distance and a variety of variab les (age, height, weight, heart rate), but the relations were weak. Th e results indicate that the Doppler ultrasound technique for measureme nt of stroke distance would best be used to study trend changes in an individual patient, or subject, by a single operator.