Determination of Cardiac Output by Peripheral Electrical Bioimpedance

This paper presents the noninvasive determination of cardiac output by peripheral electrical bioimpedance. We validate our approach first with small animals and then with human. We established an experimental protocol that allowed us to perform the measurements of several cardiovascular parameters by two methods, echocardiography and bioimpedance. For the rats, we used a group of 19 Wistar rats. Peripheral bioimpedance allowed us to obtain the blood flow index at the level of the rat's tail without sacrificing it. The objective being the determination of the cardiac output, a correlation with the measurements of the cardiac output by ultrasound has been established. The correlation obtained ‘0.83’ can be considered satisfactory and comparable to those obtained in similar human studies. For humans, a group of 32 healthy women, (age 21.3 ± 1.5 years) has participated in this study. Peripheral bioimpedance allowed us to obtain the index of blood flow at the patient's left arm and echocardiography allowed us to obtain the cardiac output. Then, we established a linear correlation between the two methods. The strength of the correlation obtained is ‘0.89’ and can be considered very satisfactory. The mean percentage of error in estimating cardiac output by the proposed method is 5.6%.