Non-invasive jaundice measurement using magnetic induction spectroscopy technique

Abstract

Neonatal jaundice is a yellowing of the skin and other tissues of newborn infants. The vast majority of newborn infants suffers from jaundice during their first week of life. Therefore, the heel puncture technique is used to determine the total serum bilirubin (TSB) by taking blood sample from the baby’s heel. This approach, however, may cause skin infection and lead to more damage. Other approach such as jaundice meters may possess some vulnerability due to the fact that the device implements optical based measurement, in which the value of light absorption varies for every skin colour. Thus, Magnetic Induction spectroscopy (MIS) technique is introduced to overcome the weaknesses of the previous approaches. MIS method implements phase shift measurements. This technique is capable of measuring phase angle between primary signal and the secondary signal. The secondary signal comes from eddy current generated by the object under investigation. A 3D model of MIS system for jaundice measurement consisted of transmitter, receiver and baby finger was designed and simulated using COMSOL Multiphysics 5.0.The transmitter and receiver were modelled using circular coil (copper wire) with 1 mm diameter and simulated at different operating frequencies under beta dispersion region which are 2 MHz, 4 MHz, 6 MHz, 8 MHz and 10 MHz. To experimentally evaluate the performance of the MIS system, five sample solution to mimic bilirubin concentrations (85.0 μmole/L, 170.0 μmole/L, 255.0 μmole/L, 290.0 μmole/L and 331.5 μmole/L) were tested using MIS circuit. In this research, two pairs of transmitter and receiver (Tx-Rx) which only differ at receiver size were tested; Tx5-Rx8 and Tx5-Rx12. The results have shown that Tx5-Rx8 has less sensitivity to detect phase shift compared to Tx5-Rx12. This is due to the greater gradient value of Tx5-Rx12 with 0.0594 relative to Tx5-Rx8 which is 0.0584. Through this research study, it is proven that higher frequency gives higher phase shift where our MIS system recorded that at 10 MHz, phase shift increased from 0.2758 to 0.3004 degree when the electrical conductivity of five samples solution increased. This contributes to an easy calculation of phase difference between primary field and the secondary field. This study shows that MIS system has the potential to detect jaundice in newborn infants through non-invasive method.