Estimation of body fluid losses during abdominal surgery and haemodialysis by impedance measurement technique

Abstract

In this study a portable, easy to use instrument ISdesigned to detect body fluid loss III patients undergoinghaemodialysis and abdominal surgery. Electrical impedances ofthe arm, the leg and the trunk are measured separately fromthe right side of the body at the frequency of 50 KHz (1 rnArms) before and after the process. The tetrapolar (currentdrive-voltage sense) measurement technique IS used withdisposable ECG electrodes. Electrical impedance changes arecorrelated with weight changes actually measured. Electricalimpedance measurements are performed on the patient, atintervals of 15 minutes, during abdominal surgeries, to detectthe instantaneous body fluid losses.The experimental results strongly support the clinicalusefulness of this technique in determining body fluid losses,especially during surgeries.