CMOS Spectrophotometric Microsystem for Malaria Detection.

Area of Science:

• Biomedical Engineering
• Optical Sensing
• Malaria Diagnostics

Background:

• Current malaria diagnostic methods face limitations in detecting low parasitemia.
• Optical spectrophotometry offers a promising alternative for sensitive malaria parasite quantification.
• Developing automated detection systems is crucial for effective malaria control.

Purpose of the Study:

• To design, simulate, and fabricate a CMOS microelectronic detection system for automatic quantification of malaria parasites.
• To evaluate the system's performance in detecting Plasmodium falciparum at low parasitemia levels.
• To assess the potential of the developed microsystem for field-based malaria diagnosis.

Main Methods:

• The system utilizes an array of silicon junction photodiodes and current-to-frequency converters.
• Simulations were performed using Cadence Tools with UMC 1180 MM/RF technology.
• Fabricated photodiodes and converters were characterized, and the microsystem was validated with infected red blood cells.

Main Results:

• The current-to-frequency converter demonstrated high linearity (up to 1800 nA) and sensitivity (4430 Hz/nA).
• Photodiodes exhibited a responsivity peak of 120 mA/W at 570 nm and low dark current (7.15 pA).
• The microsystem successfully distinguished between healthy and infected red blood cells with a sensitivity of 4.5 Hz/parasites.μL⁻¹.

Conclusions:

• The developed CMOS microelectronic system can automatically quantify malaria parasites.
• The system demonstrates high sensitivity and linearity, suitable for detecting low parasitemia.
• This technology holds significant potential for improving malaria diagnosis in field settings.