Scholars@Duke
Shekh md mahmudul Islam

Shekh md mahmudul Islam

Postdoctoral Associate
Biomedical Engineering

Selected Publications

Non-Contact Monitoring and Recognition of Varied Respiratory Patterns From Dual-Subject Across Sleep Postures Using CW Radar

Journal Article IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology · March 1, 2026 Objectives: Non-contact and continuous respiratory monitoring is vital for detecting health risks such as sleep apnea, cardiac events, and respiratory disorders. Non-contact methods using Radar offer an unobtrusive solution but face challenges when multipl ... Full text Cite

Noncontact Arterial Pulse Wave Measurement in a Two-Subject Scenario Using Millimeter-Wave Radar

Journal Article IEEE Sensors Letters · October 1, 2025 Noncontact radar-based arterial pulse wave measurement in multisubject scenarios with multiple people remains a critical challenge because multiple echoes are received from various body parts of multiple subjects. This letter explores the feasibility of us ... Full text Cite

Building occupancy estimation using single channel CW radar and deep learning.

Journal Article Scientific reports · April 2025 Counting the number of people in a room is crucial for optimizing smart buildings, enhancing energy efficiency, and ensuring security while preserving privacy. This study introduces a novel radar-based occupancy estimation method leveraging a 24-GHz Contin ... Full text Cite

A Dual-Radar Noise Compensation System for UAV-Born Cardiopulmonary Vital Signs Detection

Journal Article IEEE Transactions on Microwave Theory and Techniques · January 1, 2025 Uncrewed aerial vehicles (UAVs) equipped with Doppler radar for remote life sensing have the potential to offer an effective solution for search and rescue applications. Interference introduced by the moving UAV platform can, however, obscure human vital s ... Full text Cite

Guest Editorial Latest Advances on Radar-Based Physiological Sensors and Their Applications

Journal Article IEEE Transactions on Microwave Theory and Techniques · January 1, 2025 Full text Cite

Autonomous Integrated Sensing and Processing for Bioradar: Advancing Non-Invasive Biomedical Monitoring and Signal Analysis

Conference 2025 IEEE MTT S International Microwave Biomedical Conference Imbioc 2025 · January 1, 2025 This paper presents a novel automated system that leverages a Raspberry Pi to operate a 24 GHz single-channel continuous wave (CW) radar for through-the-wall concurrent vital sign monitoring of two subjects. The system autonomously performs independent com ... Full text Cite

24-GHz Single-Channel Continuous Wave Doppler Radar for Recognizing Diverse Breathing Patterns: A Feasibility Study

Conference 2025 IEEE MTT S International Microwave Biomedical Conference Imbioc 2025 · January 1, 2025 Clinical monitoring of breathing patterns using non-invasive methods has gained significant attention due to its non-contact and unobtrusive nature. Previous research has explored various radar configurations, including quadrature channel continuous wave ( ... Full text Cite

Through-the-Wall Concurrent Vital Signs Monitoring of Three Subjects Using Single-Channel CW Radar and Independent Component Analysis

Conference IEEE MTT S International Microwave Symposium Digest · January 1, 2025 This paper reports, for the first time, the capability of a single-channel continuous wave (CW) radar to perform through-the-wall concurrent vital sign monitoring of three subjects using a simpler radar system architecture. Initially, independent component ... Full text Cite

Microwave Doppler Radar Occupancy Sensing for HVAC Energy Savings

Journal Article IEEE Journal of Microwaves · January 1, 2024 Buildings consume about 30% of the world's energy, and produce 37% of global energy-related CO2 emissions. Building energy efficiency is becoming even more critical as climate change related events take a toll on human life, and further increase ... Full text Cite

Separation of Heartbeat Waveforms of Simultaneous Two-Subjects Using Independent Component Analysis and Empirical Mode Decomposition

Journal Article IEEE Microwave and Wireless Technology Letters · January 1, 2024 Vital sign monitoring using continuous wave (CW) microwave Doppler radar is gaining attention due to its simpler architecture and fewer signal processing chains. Existing literature focuses on utilizing the direction of arrival (DOA) technique of CW radar ... Full text Cite

Noncontact Soil Moisture Estimation Using Continuous Wave Radar and Deep Learning

Journal Article IEEE Sensors Journal · January 1, 2024 Estimating soil moisture (SM) using microwave Doppler radar is gaining attention to save fresh water and enhance crop growth and yield in agriculture due to its noncontact form of measurement. Most of the work in the literature focused on utilizing frequen ... Full text Cite

Through the wall human heart beat detection using single channel CW radar

Journal Article Frontiers in Physiology · January 1, 2024 Single-channel continuous wave (CW) radar is widely used and has gained popularity due to its simple architecture despite its inability to measure the range and angular location of the target. Its popularity arises in the industry due to the simplicity of ... Full text Cite

Heart Rate Variability-Based Obstructive Sleep Apnea Events Classification Using Microwave Doppler Radar

Journal Article IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology · December 1, 2023 Obstructive Sleep Apnea (OSA) is the most common type of sleep disorder that consists of multiple episodes of partial or complete closure (apnea, hypopnea) of the upper airway during sleep and underdiagnosed problems as there is no reliable portable in-hom ... Full text Cite

Non‐contact vital signs monitoring in broiler chickens

Journal Article The Journal of Engineering · November 2023 AbstractMeasuring the heartbeat and respiration of animals continuously can provide valuable information about their health status. Respiratory‐related diseases are very common in the poultry industry and ... Full text Cite

Cross-Modality Continuous User Authentication and Device Pairing With Respiratory Patterns

Journal Article IEEE Internet of Things Journal · August 15, 2023 At-home screening systems for obstructive sleep apnea (OSA) can bring convenience to remote chronic disease management. However, the unsupervised home environment is subject to spoofing and unintentional interference from the household member. To improve r ... Full text Cite

Respiratory Feature Extraction for Contactless Breathing Pattern Recognition Using a Single Digital Camera

Journal Article IEEE Transactions on Human Machine Systems · June 1, 2023 Non-contact respiratory monitoring is gaining attention due to its unobtrusive form of measurement. Among all other non-contact sensing modalities, optical sensors integrated with commercial video cameras have received more attention due to their ease of u ... Full text Cite

Building occupancy estimation using microwave Doppler radar and wavelet transform

Journal Article Building and Environment · May 15, 2023 Room-level occupancy estimation is a critical input for real estate management, including building utilization optimization, energy-efficient building control, building security, and occupant health and well-being. Knowing how many people are using a room ... Full text Cite

Doppler radar remote sensing of respiratory function.

Journal Article Frontiers in physiology · January 2023 Doppler radar remote sensing of torso kinematics can provide an indirect measure of cardiopulmonary function. Motion at the human body surface due to heart and lung activity has been successfully used to characterize such measures as respiratory rate and d ... Full text Cite

Unobtrusive occupancy and vital signs sensing for human building interactive systems.

Journal Article Scientific reports · January 2023 Cognitive buildings use data on how occupants respond to the built environment to proactively make occupant-centric adjustments to lighting, temperature, ventilation, and other environmental parameters. However, sensors that unobtrusively and ubiquitously ... Full text Cite

Contactless vital sign monitoring with unmanned aerial vehicle-borne radar

Journal Article IEEE Potentials · January 1, 2023 When most people think of drones, they may imagine utilitarian Amazon deliveries or have frightening visions of military assaults. Either way, such technology is finding its way into a variety of fields, where it is reshaping our world. ... Full text Cite

Heart Rate Variability Assessment Using Single Channel CW Doppler Radar

Conference 2023 IEEE Microwaves Antennas and Propagation Conference Mapcon 2023 · January 1, 2023 Heart Rate Variability (HRV) represents the variation in the interbeat interval of a heart signal and is also a reflection of the adaptability of the cardiovascular system to unexpected physiological and psychological changes. Radar-based non-contact HRV m ... Full text Cite

Occupant Entry and Exit Event Extraction Using Continuous Wave (CW) Doppler Radar and Wavelet Analysis

Conference IEEE MTT S International Microwave Symposium Digest · January 1, 2023 Occupancy estimation and occupant entry/exit detection can play a significant role in designing energy-efficient heating, ventilation, and air conditioning (HVAC) systems. Radar-based occupancy estimation is gaining attention as it is unobtrusive and does ... Full text Cite

Identity Authentication in Two-Subject Environments Using Microwave Doppler Radar and Machine Learning Classifiers

Journal Article IEEE Transactions on Microwave Theory and Techniques · November 1, 2022 Identity authentication based on Doppler radar respiration sensing is gaining attention as it requires neither contact nor line of sight and does not give rise to privacy concerns associated with video imaging. Prior research demonstrating the recognition ... Full text Cite

A Multivariate Statistical Study of Dhaka’s Quality of Life Based on Residents’ Perception

Journal Article International Review for Spatial Planning and Sustainable Development · April 15, 2022 Full text Cite

Sleep Posture Recognition with a Dual-Frequency Microwave Doppler Radar and Machine Learning Classifiers

Journal Article IEEE Sensors Letters · March 1, 2022 An automated, robust, noncontact sleep posture recognition technique is proposed in this letter, which uses optimizable (Bayesian hyperparameter tuning) machine learning (ML) classifiers applied to dual-frequency (2.4 GHz, 5.8 GHz) monostatic continuous-wa ... Full text Cite

Radar-based remote physiological sensing: Progress, challenges, and opportunities.

Journal Article Frontiers in physiology · January 2022 Modern microwave Doppler radar-based physiological sensing is playing an important role in healthcare applications and during the last decade, there has been a significant advancement in this non-contact respiration sensing technology. The advantages of co ... Full text Cite

Empirical Mode Decomposition (EMD) for Platform Motion Compensation in Remote Life Sensing Radar

Conference IEEE Radio and Wireless Symposium Rws · January 1, 2022 Radar sensing of respiratory motion from unmanned aerial vehicles (UAVs) offers great promise for remote life sensing especially in post-disaster search and rescue applications. One major challenge for this technology is the management of motion artifacts ... Full text Cite

Laser-Based Noncontact Blood Pressure Estimation Using Human Body Displacement Waveforms

Conference IEEE MTT S International Microwave Symposium Digest · January 1, 2022 Measurement of the body's displacement at multiple positions allows heart pulse wave propagation to be observed; this is an important step toward noncontact blood pressure measurement. This study investigates the feasibility of performing blood pressure me ... Full text Cite

BreathID: Radar's New Role in Biometrics

Journal Article IEEE Aerospace and Electronic Systems Magazine · December 1, 2021 This article is focused on providing some insight into the requirements for a non-contact continuous identity authentication system using radar sensing technologies. This article also discusses the basic principles supporting the potential new role of rada ... Full text Cite

An Adaptive Filter Technique for Platform Motion Compensation in Unmanned Aerial Vehicle Based Remote Life Sensing Radar

Conference 2020 50th European Microwave Conference Eumc 2020 · January 12, 2021 Unmanned Aerial Vehicles (UAVs) have demonstrated efficacy as a platform for remote life sensing in post-disaster search and rescue applications. Radar-assisted UAV respiration motion sensing technology also shows promise yet a significant technological ch ... Full text Cite

Can Radar Remote Life Sensing Technology Help Combat COVID-19?

Journal Article Frontiers in Communications and Networks · January 1, 2021 COVID-19, caused by SARS-CoV-2, is now a global pandemic disease. This outbreak has affected every aspect of life including work, leisure, and interaction with technology. Governments around the world have issued orders for travel bans, social distancing, ... Full text Cite

Insider-Resistant Context-Based Pairing for Multimodality Sleep Apnea Test

Conference Proceedings IEEE Global Communications Conference Globecom · January 1, 2021 The increasingly sophisticated at-home screening systems for obstructive sleep apnea (OSA), integrated with both contactless and contact-based sensing modalities, bring convenience and reliability to remote chronic disease management. However, the device p ... Full text Cite

Sleep posture recognition with a dual-frequency cardiopulmonary doppler radar

Journal Article IEEE Access · January 1, 2021 While Doppler radar can be used to measure cardiopulmonary vital signs during sleep, meaningful diagnostic assessments are often subject to knowledge of a subject's changing sleep posture. The torso Effective Radar Cross Section (ERCS) and displacement mag ... Full text Cite

Radar-Based Non-Contact Physiological Sensing

Chapter · January 1, 2021 Radar remote respiration sensing technology is gaining attention and over the last four decades, there has been significant advancement to utilize this technology in different biomedical application areas. Microwave Radar sensing technologies and systems a ... Full text Cite

Development of A Low-Cost Real-Time Bioelectrical Signal Acquisition Module

Conference 2020 2nd International Conference on Sustainable Technologies for Industry 4 0 Sti 2020 · December 19, 2020 Human Machine Interface (HMI) is gaining attention in the healthcare field and the acquisition of different bioelectrical signals simultaneously through one portable system remains still under active investigations, which can help further advancement of HM ... Full text Cite

Obstructive Sleep Apnea (OSA) Events Classification by Effective Radar Cross Section (ERCS) Method Using Microwave Doppler Radar and Machine Learning Classifier

Conference 2020 IEEE MTT S International Microwave Biomedical Conference Imbioc 2020 · December 14, 2020 In-home sleep monitoring system using Microwave Doppler radar is gaining attention as it is unobtrusive and noncontact form of measurement. Most of the reported results in literature focused on utilizing radar-reflected signal amplitude to recognize Obstru ... Full text Cite

Extracting Individual Respiratory Signatures from Combined Multi-Subject Mixtures with Varied Breathing Pattern Using Independent Component Analysis with the JADE Algorithm

Conference Asia Pacific Microwave Conference Proceedings APMC · December 8, 2020 Concurrent respiration monitoring of multiple subjects remains a challenge in microwave Doppler radar-based non-contact physiological sensing technology. Prior research using Independent component analysis with the JADE algorithm has been limited to the se ... Full text Cite

Comparative Analysis of Phase-Comparison Monopulse and MUSIC Algorithm Methods for Direction of Arrival (DOA) of Multiple-Subject Respiration Measured with Doppler Radar

Conference Asia Pacific Microwave Conference Proceedings APMC · December 8, 2020 While Doppler radar measurement of respiration has shown promise for various healthcare applications, simultaneous sensing of respiration for multiple subjects in the radar field of view remains a significant challenge as reflections from the subjects are ... Full text Cite

UAV Radar Sensing of Respiratory Variations for COVID-Type Disorders

Conference Asia Pacific Microwave Conference Proceedings APMC · December 8, 2020 Unmanned Aerial Vehicles (UAVs) with onboard Doppler radar sensors can be used for health reconnaissance including the remote detection of respiratory patterns associated with COVID-19. While respiratory diagnostics have been demonstrated with radar, the m ... Full text Cite

Non-contact vital signs monitoring for multiple subjects using a millimeter wave FMCW automotive radar

Conference IEEE MTT S International Microwave Symposium Digest · August 1, 2020 Technology for in-cabin non-contact monitoring of driver vital signs is a growing area of interest for automotive applications. This has been spurred in part by successful demonstrations of remote sensing of human physiological motion using radar, for heal ... Full text Cite

Radar-based non-contact continuous identity authentication

Journal Article Remote Sensing · July 1, 2020 Non-contact vital signs monitoring using microwave Doppler radar has shown great promise in healthcare applications. Recently, this unobtrusive form of physiological sensing has also been gaining attention for its potential for continuous identity authenti ... Full text Cite

Concurrent Respiration Monitoring of Multiple Subjects by Phase-Comparison Monopulse Radar Using Independent Component Analysis (ICA) with JADE Algorithm and Direction of Arrival (DOA)

Journal Article IEEE Access · January 1, 2020 While non-contact monitoring of human respiration has been demonstrated using Doppler radar, the concurrent monitoring of multiple equidistant subjects remains a significant technological challenge. Reported research has so far been limited to maintaining ... Full text Cite

Respiratory Feature Extraction for Radar-Based Continuous Identity Authentication

Conference IEEE Radio and Wireless Symposium Rws · January 1, 2020 Radar is an attractive approach for identity authentication because it requires no contact and is unobtrusive. Most reported results have focused only on sedentary breathing patterns, without considering how respiratory patterns may change due to physiolog ... Full text Cite

Optimizing Patient–Ventilator Synchrony Utilizing Radar-Based Respiratory Features for Monitoring COVID-19 Patients

Journal Article Frontiers in Communications and Networks · January 1, 2020 During this COVID-19 pandemic time, an unprecedented number of patients with severe respiratory illness require intensive care units (ICUs) under mechanical ventilation (MV) for sustaining life. Patient–ventilator asynchrony (PVA) is very common, and it oc ... Full text Cite

Identity Authentication of OSA Patients Using Microwave Doppler radar and Machine Learning Classifiers

Conference IEEE Radio and Wireless Symposium Rws · January 1, 2020 Non-contact home-based sleep monitoring will bring a paradigm shift to diagnosis and treatment of Obstructive Sleep Apnea (OSA) as it can facilitate easier access to specialized care in order to reach a much boarder set of patients. However, current remote ... Full text Cite

A programmable robotic phantom to simulate the dynamic respiratory motions of humans for continuous identity authentication

Conference Asia Pacific Microwave Conference Proceedings APMC · December 1, 2019 Non-contact continuous identity authentication using microwave Doppler radar has shown great promises in security and surveillance applications and yet not mature. Reported results for unobtrusive identity authentication system are focused on dynamic segme ... Full text Cite

Identity Authentication System using a Support Vector Machine (SVM) on Radar Respiration Measurements

Conference 2019 93rd Arftg Microwave Measurement Conference Measurement Challenges for the Upcoming RF and mm Wave Communications and Sensing Systems Arftg 2019 · June 1, 2019 Non-contact continuous authentication system can play an important role in maintaining security for a system throughout a login session. Unobtrusive respiration measurement using microwave Doppler radar has shown great promises in healthcare applications a ... Full text Cite

Multiple subject respiratory pattern recognition and estimation of direction of arrival using phase-comparison monopulse radar

Conference IEEE Radio and Wireless Symposium Rws · May 14, 2019 A scalable non-contact respiratory monitoring approach is introduced for the practical separation and recognition of multiple simultaneous human respiratory patterns, using a 24-GHz phase-comparison Monopulse radar. The proposed system demonstrates a compu ... Full text Cite

Deposition and Optical Characterization of ZnO Thin films on Glass Substrate

Conference Journal of Physics Conference Series · September 13, 2018 ZnO is a wide band gap (3.37 eV) compound semiconductor which can be used in short wavelength optoelectronic devices.Here in this work we chose spin coating method as growth mechanism as it is simple, less expensive and in addition film uniformity is maint ... Full text Cite

Direction of arrival estimation of physiological signals of multiple subjects using phase comparison monopulse radar

Conference Asia Pacific Microwave Conference Proceedings APMC · July 2, 2018 While non-contact respiration monitoring using microwave Doppler radar has shown great promises over the last four decades, the isolation of one subject when multiple subjects are in view remains a challenge. In this paper, we employed a new, cost effectiv ... Full text Cite

Separation of Respiratory Signatures for Multiple Subjects Using Independent Component Analysis with the JADE Algorithm.

Conference Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference · July 2018 Respiration monitoring using microwave Doppler radar has attracted significant interest over the last four decades due to its non-invasive and non-contact form of measurement. However, this technology is still not at the level of practical implementations ... Full text Cite

Smart physical layer based directional communication networking

Conference 2017 32nd General Assembly and Scientific Symposium of the International Union of Radio Science Ursi Gass 2017 · November 10, 2017 In this paper, a smart physical layer based directional communication networking approach is described. It consists of 'smart nodes,' equipped with multiple directional antennas and propagation modeling capabilities. This approach brings more 'intelligence ... Full text Cite

Advanced directional networking: LTE vs WiFi radios

Conference 2017 IEEE Antennas and Propagation Society International Symposium Proceedings · October 18, 2017 Advanced Nodes are the main components of Physical Layer based fully-directional networks. They consist of sets of appropriately programmed antenna arrays that enable them to conform to the standards of the radio being used. This paper provides an in-depth ... Full text Cite

Microcontroller based earthquake detection system for spontaneous cut-off of domestic utility lines for safety measures

Conference Proceedings of 9th International Conference on Electrical and Computer Engineering Icece 2016 · February 13, 2017 Bangladesh is a country with a high frequency of earthquakes. Since the country lies at the junction of three tectonic plates, the intensity of earthquakes felt in this region is moderate. Surprisingly, the number of deaths and financial loss in this regio ... Full text Cite

Effect of technology scaling on leakage power consumption in on-chip switches

Conference 2014 International Conference on Informatics Electronics and Vision Iciev 2014 · January 1, 2014 On-chip switches in reconfigurable computing systems are prone to heavy drawing of current even when they are switched off. In this work, we have evaluated the effect of shrinking dimension of electronic devices on the basis of two fundamental factors: tem ... Full text Cite

A study of phantoms of multi-frequency Electrical Impedance Spectroscopy(EIS) system for early detection of breast cancer

Conference 2013 International Conference on Informatics Electronics and Vision Iciev 2013 · September 9, 2013 Breast Cancer is among the top five cause of cancer death and topmost cause among women worldwide. Multi-frequency Electrical Impedance Spectroscopy seems to be promising imaging technique as it is non-invasive, comparatively cheap and no known health haza ... Full text Cite

Performances of Multi-Frequency Voltage to Current Converters for Bioimpedance Spectroscopy

Journal Article Bangladesh Journal of Medical Physics · April 19, 2013 Breast cancer is one of the most common diseases affecting women and the mortality rate is very high in Bangladesh, mainly due to the lack of early diagnosis. X-ray mammography is not available widely in Bangladesh, besides it has an associated bio ... Full text Cite