Methods for Detection of Bioimpedance Variations in Resource Constrained Environments

Sensors

Marek Rist¹  Eiko Priidel¹  Mart Min¹  Paul Annus¹  Olev Märtens¹  Andrei Krivošei¹  Raul Land¹ 

[1] Thomas Johann Seebeck Department of Electronics, Tallinn University of Technology, 12616 Tallinn, Estonia;

关键词: bioimpedance;    dynamic range;    synchronous measurement;    lock-in detection;    differentiation;    cardiovascular system;    non-invasive measurements;    wearable devices;   

DOI  :  10.3390/s20051363

来源: DOAJ

【 摘 要 】

Changes in a certain parameter are often a few magnitudes smaller than the base value of the parameter, specifying significant requirements for the dynamic range and noise levels of the measurement system. In case of electrical bioimpedance acquisition, the variations can be 1000 times smaller than the entire measured value. Synchronous or lock-in measurement of these variations is discussed in the current paper, and novel measurement solutions are presented. Proposed methods are simple and robust when compared to other applicable solutions. A common feature shared by all members of the group of the proposed solutions is differentiation. It is achieved by calculating the differences between synchronously acquired consecutive samples, with lock-in integration and analog differentiation. All these methods enable inherent separation of variations from the static component of the signal. The variable component of the bioimpedance can, thus, be acquired using the full available dynamic range of the apparatus for its detection. Additive disturbing signals and omnipresent wideband noise are considered and the method for their reduction is proposed.

【 授权许可】

Unknown