A 1 MHz Miniaturized Electrical Impedance Tomography System for Prostate Imaging

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Electrical Engineering

Background:

• Prostate cancer screening requires advanced imaging techniques for early detection.
• High-frequency electrical impedance tomography (EIT) offers a promising non-invasive imaging modality.
• Miniaturized systems are crucial for developing practical EIT devices.

Purpose of the Study:

• To present a novel application-specific integrated circuit (ASIC) for a high-frequency EIT system.
• To enable a small form-factor EIT architecture for prostate cancer screening.
• To achieve a high signal-to-noise ratio (SNR) at MHz frequencies for enhanced imaging.

Main Methods:

• Designed and fabricated a 4-channel ASIC in 0.18-μm CMOS technology.
• Integrated a novel current driver, instrumentation amplifier, variable gain amplifier (VGA), and ADC with SPI interface.
• Developed a prototype miniaturized EIT system with a transrectal imaging probe.

Main Results:

• The ASIC-based EIT system achieved an SNR between 66 and 76 dB from 500 Hz to 1 MHz.
• The system successfully depicted a small metal inclusion, modeling prostate cancer lesions, in saline.
• Demonstrated the feasibility of imaging prostate cancer using a miniaturized EIT system.

Conclusions:

• The developed ASIC enables a high-frequency EIT system suitable for prostate cancer screening.
• The miniaturized system demonstrates high SNR and effective imaging of simulated lesions.
• This technology holds potential for advancing non-invasive prostate cancer detection.