Development of bioimpedance sensing device for wearable monitoring of the aortic blood pressure curve

Abstract

Wearable devices that monitor our vital signs have been gaining more importance with each year. Non-invasive, continuous, accurate and precise blood pressure assessment method integrated in a wearable is a multidisciplinary challenge. This work presents an electrical bioimpedance (EBI) unit for multi-frequency measurements on pulsating artery for central aortic pressure (CAP) estimation. The developed device provides low complexity in the electronics design with a frequency range between 1 kHz and 200 kHz. It is able to register the impedance of blood vessel volume change simultaneously at different locations. Experiments were carried out in vivo by using the four-electrode configuration on human thorax, axillary artery and radial artery. Preliminary results show the applicability of the proposed impedance spectroscopy system to measure blood vessel volume changes. The impedance data can be later interpreted into the aortic blood pressure wave by using a generalized transfer function. In addition, experimental test-phantom and electrode design are introduced for testing purposes of the impedance system.

Wrist-wearable bioelectrical impedance analyzer with miniature electrodes for daily obesity management

“…Recently, studies on wearable BIA device have been conducted, including studies on wearable BIA devices 11 , 12 , cuff-less blood pressure sensors 13 , 14 , and bioelectrical impedance spectroscopy 15 . For the wearable solutions, accurate measurement of impedance with miniature electrodes is becoming more important.…”

Methods for Detection of Bioimpedance Variations in Resource Constrained Environments

“…Placement of the electrodes in relation with the wrist and radial artery is further depicted on Figure 2b. Size, distance, location and the construction of the electrodes has been experimented with and refined during longer research period and described in different papers, such as [8] and [15]. In brief summary it can be said that the optimal setup for repeatable results consists of four equally spaced electrodes of 2-4 mm diameter roughly.…”

“…Meas. Figure 3 70.39 0.35 0.5 4.3 Reference [18] 264.57 5.6 Reference [15] 102.8 0.12 0.11 Reference [19] 0.326…”