Bioimpedance Spectroscopy in Subjects with Auricular Vagus Nerve Stimulation

Abstract

In this paper, single side body impedance spectroscopy is performed between wrist and ankle in response to auricular transcutaneous electrical vagus stimulation, to obtain the Cole parameters R<inf>o</inf>, R<inf>∞</inf> and f<inf>c</inf>. Following a resting period of 5 minutes in supine position, left ear vagus nerve was stimulated for 3 minutes and BIS performed every 10 seconds, on 8 healthy subjects with age: 23,6±1,5 years, height: 175±8,3 cm, weight: 69,5±18,7 kg and BMI: 22,6±5,5 kg/cm2. Cole circles moved to the right (inreased R<inf>o</inf> and R<inf>∞</inf>) with stimulation while the centers shifted upwards. Intracellular and extracellular resistances and the capacitance C<inf>m</inf> all increased at the onset of vagus stimulation, resulting in a decrease of 3,4±1.33% in f<inf>c</inf>. Changes in R<inf>i</inf> mainly indicate water shift between cells and extracellular fluid, physiological changes occurred on cell membrane. f<inf>c</inf> independent of the participants' anthropomorphic factors could be used as an indicator to vagus nerve stimulation, without further normalization. This preliminary study was realized with a limited number of participants, however, to reach statistically meaningful results measurements will be performed over a larger sample size. © 2019 Elsevier B.V., All rights reserved.