Present-day performance qualities of cardiotocographs.

Legislation and standards applying to medical electrical equipment are reviewed. Although there are no official standards for cardiotocographs, de facto standards can be defined. The paper introduces the present-day performance qualities of cardiotocographs and the factors which affect the quality of the data. The measures used to evaluate the ability of cardiotocographs to indicate correctly the fetal heart rate and maternal uterine activity are discussed. Present-day cardiotocographs generally perform well but the physiological variables need to be defined in order to produce equipment in keeping with clinical needs.