Non-invasive hemoglobin measurement using embedded platform

This paper is based on the design and development of an in-house algorithm system to Estimate Total Hemoglobin in human blood using the Arduino based Embedded system. In our present society, monitoring Hemoglobin of subjects is very important in hospitals to keep track of low/high hemoglobin count during operations, delivery, dialysis, blood donations, perform stress test, monitoring patients in intensive care units, etc. is often done using invasive methods. In our approach, we have designed a finger probe using five LEDs on a multi-chip having wavelengths 670 nm/770 nm/810 nm/850 nm and 950 nm, and a single silicon photo detector with an inbuilt trans-impedance amplifier to acquire the signals through the finger using the Photoplethysmography (PPG) principle. The non-invasive method can be replaced in hospitals and homes to monitor the total hemoglobin level which is in real-time, painless, and infection-free from needles. We have tested our system on 8 subjects for three and five wavelengths and the values were compared to the hemoglobin measured using invasive methods in the pathology laboratory. The result demonstrates that the five wavelengths PPG method significantly improves the measurement accuracy of total hemoglobin, reducing the mean absolute error between the reference and the estimated hemoglobin values from 1.3778 g/dL for three wavelengths PPG to 0.3499 g/dL for five wavelengths PPG. The five wavelengths PPG system designed showed good linearity to estimate hemoglobin with the Regression Coefficient (R-2 = 0.964) compared to three wavelengths PPG system with the Regression Coefficient (R-2 = 0.688).