Development of a miniature and ASIC based impedance cardiograph

Area of Science:

• Biomedical Engineering
• Cardiovascular Technology
• Medical Instrumentation

Background:

• Impedance cardiography (ICG) is crucial for cardiac output monitoring.
• Existing ICG devices may have limitations in signal resolution and current delivery.
• Miniaturization is desirable for portable cardiovascular monitoring solutions.

Purpose of the Study:

• To develop a miniature impedance cardiograph for cardiac output monitoring.
• To enhance the performance of a specific integrated circuit for ICG applications.
• To create a user-friendly system for acquiring and displaying ICG data.

Main Methods:

• Developed a miniature impedance cardiograph utilizing an Analog Front End chip (AFE4300).
• Enhanced carrier current capability to 3.2 milliamperes and amplified sensed signals for improved resolution (10-50 Ohms).
• Interfaced the AFE chip with a PC via a microcontroller and USB, using custom software for data acquisition and display.

Main Results:

• Successfully enhanced the carrier current capability of the AFE4300 chip.
• Achieved increased signal resolution for impedance measurements in the 10-50 Ohm range.
• Demonstrated consistent ICG recordings from volunteers over fifteen-minute periods.

Conclusions:

• The developed miniature impedance cardiograph is suitable for cardiac output monitoring.
• The modifications to the AFE chip and external amplification improve ICG data quality.
• The system provides a reliable platform for real-time cardiovascular monitoring.