An amplitude-to-time conversion technique suitable for multichannel data acquisition and bioimpedance imaging

Area of Science:

• Electrical Engineering
• Biomedical Engineering
• Signal Processing

Background:

• Traditional amplitude measurement in high channel count systems is component-intensive.
• Existing methods for bioimpedance and impedance imaging are often costly and bulky.
• Portable sinusoidal recording systems require efficient and low-power amplitude measurement.

Purpose of the Study:

• To develop a novel amplitude measurement approach for high channel count portable sinusoidal recording systems.
• To reduce component count, cost, size, and power consumption in bioimpedance measurements.
• To enhance the convenience and efficiency of impedance imaging systems.

Main Methods:

• Exploiting high timing resolution of microprocessors for amplitude measurement.
• Utilizing two high-performance comparators to convert amplitude difference to timing difference.
• Employing a high-speed microprocessor for data capture and a straightforward algorithm for offset removal.

Main Results:

• The developed approach significantly reduces component requirements per channel.
• Three operational modes (fast, normal, high precision) were proposed.
• Mean signal-to-noise ratios of 40, 81, and 112.4 dB were achieved in fast, normal, and high precision modes, respectively.

Conclusions:

• The novel amplitude measurement technique is suitable for high channel count portable sinusoidal recording systems.
• This method offers a cost-effective, size-efficient, and power-saving alternative to traditional approaches.
• The approach demonstrates high signal-to-noise ratios across different operational modes, validating its effectiveness for bioimpedance applications.