Quantity   Component name
10 × Photodiode Receives reflected light from brain
4 × 730nm LED Illuminates non oxygen carrying hemoglobin
4 × 850nm LED Illuminates oxygen carrying hemoglobin
1 × Atmega8U2 Microprocessors, Microcontrollers, DSPs / ARM, RISC-Based Microcontrollers
1 × LTC2494 Data Converters / Analog to Digital Converter ICs (ADCs)