A Multichannel Real-Time Bioimpedance Measurement Device for Pulse Wave Analysis

• Published in: IEEE transactions on biomedical circuits and systems Vol. 12; no. 3; pp. 614 - 622
• Main Authors: Kusche, Roman, Klimach, Paula, Ryschka, Martin
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.06.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adult; Analog circuits; Analog to digital conversion; Analog to digital converters; Aorta; Aortic pulse wave velocity; Bioimpedance; bioimpedance measurements; Biomedical measurement; Cardiovascular system; Channels; Current measurement; Data analysis; Data buses; Data processing; Data storage; Digitization; Electric Impedance; Graphical user interface; Humans; Impedance; Impedance measurement; impedance plethysmography; Information systems; Male; Microcontrollers; Morphology; multi-channel; Noise levels; precision rectifier; Pressure sensors; Pulse measurements; pulse wave analysis; Pulse Wave Analysis - instrumentation; Pulse Wave Analysis - methods; Real time; real-time analysis; Signal Processing, Computer-Assisted - instrumentation; Universal Serial Bus; Voltage measurement; Wave analysis; Wave velocity
• DOI: 10.1109/TBCAS.2018.2812222
• ISSN: 1932-4545; 1940-9990

Pulse wave analysis is an important method used to gather information about the cardiovascular system. Instead of detecting the pulse wave via pressure sensors, bioimpedance measurements can be performed to acquire minuscule changes in the conductivity of the tissue, caused by the pulse wave. This work presents a microcontroller-based bioimpedance measurement system, which has the capability to acquire impedance measurements from up to four independent channels simultaneously. By combining a problem-specific analog measurement circuit with a 24 bits analog-to-digital converter, the system is capable of acquiring 1000 impedances per second with a signal-to-noise ratio in a range from 92 to 96 dB. For data storage and analysis, the digitized data are sent via universal serial bus to a host PC. A graphical user interface filters and plots the data of all channels in real-time. The performance of the system regarding measuring constant impedances, as well as impedance changes over time is demonstrated. Two different applications for pulse wave analysis via multichannel bioimpedance measurements are presented. Additionally, first measurement results from a human subject are shown to demonstrate the system's applicability of analyzing the pulse wave morphology as well as the aortic pulse wave velocity.