Dhaka University Journal of Applied Science & Engineering

• Md. Shariful Alam
  Department of Electrical and Electronic Engineering, University of Dhaka, Dhaka-1000, Bangladesh.
• S M Mostafa Al Mamun
  Department of Electrical and Electronic Engineering, University of Dhaka, Dhaka-1000, Bangladesh.
• Md Adnan Kiber
  Department of Electrical and Electronic Engineering, University of Dhaka, Dhaka-1000, Bangladesh.

Acute Respiratory Distress Syndrome (ARDS) can develop in patients due to COVID-19 or flu like viruses if it enters the lower respiratory tract and damages the lungs. These conditions are more commonly known as Pneumothorax (collapsed lung) and Pulmonary Edema (excess fluid accumulation in the lungs) diseases. Healthy lungs have higher electrical impedance than lungs with Pneumothorax and Pulmonary Edema diseases. Electrical Impedance Technique (EIT) which uses surface electrodes for small amount of current (1 mA, 50 kHz) injection & impedance measurements, can be used for ARDS monitoring. Electrical impedance technique has no known health hazard like harmful radiation as in case of X-ray and CT scan. Therefore, EIT method can be used for continuous monitoring of Pneumothorax and Pulmonary Edema diseases. Alam et. al [4, 5] have developed a new current drive and measurements protocol, the Anterior-Posterior Electrical Impedance (APEI) Technique specifically designed for lungs monitoring and found more sensitive than existing electrical impedance measurement techniques for lung function. The developed APEI technique may be useful for the continuous monitoring of ARDS patients by continuously measuring impedance changes and computing the average Relative Electric Potential Changes (REPC). Using our APEI Technique the average REPC values found were (a) 3.24% for healthy lungs at inspiration and expiration, (b) 5.97% for healthy lungs at inspiration and pneumothorax, (c) 2.82% for healthy lungs at expiration and pneumothorax (d) 8.07% for healthy lungs at inspiration and pulmonary edema and (e) 4.99% for healthy lungs at expiration and pulmonary edema respectively. Whereas using the existing widely used Adjacent Current Drive Electrical Impedance Technique the corresponding average REPC values were 1.41%, 2.97%, 1.59%, 4.50%, 3.15% respectively. It is clear from these results that our developed APEI technique have very good sensitivity and accuracy, and may be used for continuous monitoring of ARDS patients including Covid-19 patients.

1. S Grimnes, G Martinsen: Bioimpedance and Bioelectricity Basics, 2 nded (San Diego: Academic), 2008.