Research and Innovation
Research and Innovation
Dr. Saikia’s research group is a highly interdisciplinary research team devoted to developing next-generation biomedical sensors and systems for fundamental and applied research studies. Our research thrusts include bio-instrumentation, wearable bio-electronics, embedded systems, bio-sensors, bio-signal processing and artificial intelligence (AI) in healthcare. What sets us apart is our capacity to engineer end-to-end healthcare systems— developing both hardware and software in-house from scratch—unlike many research efforts that depend on off-the-shelf devices or focus only on partial system development. Through this, we uncover new biomarkers and mechanisms for early diagnosis, intervention, and disease management. We are deeply committed to real-world impact. Beyond academic discovery, we aim to translate our innovations into commercially viable products that reach patients, caregivers, and clinicians, ultimately improving lives. Our work is driven by the vision of revolutionizing healthcare, making it more accessible, affordable, and efficient.
Key Research Areas:
Biomedical Sensor Design and Development
Creation of novel biosensors for monitoring physiological, biochemical, and biophysical signals.
Wearable Bioelectronics and Smart Systems
Development of compact, wearable, and body-integrated devices for real-time health monitoring.
Bio-Instrumentation and Embedded Systems
Design of custom hardware and embedded systems for data acquisition and biomedical interfacing.
Physiological Signal/Image Processing
Advanced techniques for processing and interpreting signals and medical images
Artificial Intelligence in Healthcare
Application of machine learning and AI algorithms for diagnostics, decision support, and predictive analytics.
Multimodal Sensing and Sensor Fusion
Integration of diverse sensing modalities for comprehensive and robust health assessment.
Experimental Validation and Biomarker Discovery
Rigorous validation of systems through phantom, animal, and human-subject studies to discover new health biomarkers.
End-to-End Healthcare System Prototyping
Development of fully integrated prototypes, from hardware to AI-enabled mobile apps, tailored for specific health conditions.
Translational Research and Technology Commercialization
Bridging the gap between lab innovation and real-world impact through clinical translation and commercialization efforts.
We are innovating next-generation multimodal wearable medical devices by developing various sensors and advanced technologies from scratch (end-to-end development).
This research thrust focuses on innovating biomedical sensors and hardware for obtaining high-quality medical-grade multi-modal raw data from modular wearable devices.
Oral squamous cell carcinoma (OSCC) is the most common oral cancer, with a poor prognosis and rising global incidence. Tumor-infiltrating lymphocytes (TILs) are crucial for OSCC grading, but current manual assessment methods are subjective and inconsistent. To solve this, we introduce OralTILs-ViT, a novel AI-powered framework that combines cellular and tissue-level insights for accurate and automated TILs classification.
Key Innovations:
Joint Representation Learning: Unlike existing methods that focus only on tissue-level analysis, OralTILs-ViT captures both cellular and tissue interactions. It processes cellular density maps alongside H&E-stained tissue images, providing a more comprehensive understanding of TILs distribution.
TILSeg-MobileViT – A Novel Segmentation Model: Our first stage involves TILSeg-MobileViT, a multiclass segmentation model that utilizes a weakly supervised learning approach to generate precise cellular density maps for key components like tumor cells, stromal cells, and lymphocytes. This method significantly reduces the need for manual annotation, making TILs assessment more scalable and efficient.
Accurate and Automated TILs Classification: Using a dual-encoder model, OralTILs-ViT effectively classifies TILs infiltration levels into three clinically relevant categories: "Moderate to Marked," "Slight," and "None to Very Less", aligning with pathology practices.
Superior Performance and Reliability: Through extensive evaluations, our framework has been shown to outperform existing single-modality approaches. OralTILs-ViT achieved: 96.37% accuracy, 96.34% precision, 96.37% recall, & 96.35% F1 score. Additionally, TOPSIS analysis confirmed that our method ranks first across all TILs infiltration categories, reinforcing its effectiveness.
Advancing OSCC Diagnosis with AI: By combining AI and pathology, this approach enhances the reproducibility and objectivity of OSCC grading. The ability to automate TILs classification with high accuracy opens new doors for faster cancer diagnoses, better treatment decisions, and improved patient outcomes.
This research represents a significant step forward in AI-driven cancer diagnostics, paving the way for more efficient, scalable, and precise pathology tools.
Paper Link: https://www.nature.com/articles/s41598-025-86527-5
The field of Information Assurance (IA) has evolved significantly over the years, shaped by technological advancements and emerging cybersecurity threats. To better understand this transformation, our latest research leverages Large Language Models (LLMs) and NLP techniques to analyze over 62,000 documents from 1967 to 2024, providing a decade-wise breakdown of key trends in IA research.
What Makes Our Approach Unique?
Innovative “Ensemble Prompts (Ev2)” Method: Our advanced prompt engineering technique enhances summarization by combining Chain of Density (CoD), Few-Shot Learning, role-based structuring, and adversarial testing to improve relevance, conciseness, and thematic richness.
Comprehensive Literature Analysis: We use BERTopic for topic detection and LLMs for automatic summarization, creating a structured overview of IA research across decades.
Beyond Traditional Summarization: Unlike existing methods that focus only on reducing redundancy, our approach provides targeted summaries for each decade, ensuring that key bibliographic references and logical topic progressions remain intact.
Improved Performance: Outperforms traditional summarization methods by 16.7% to 29.6% in keyword definition tasks. Excels in 5 out of 7 tested metrics, while maintaining the logical integrity of references.
Paper Link: https://www.nature.com/articles/s41598-025-94551-8
Focal cortical dysplasia type II (FCD-II) is a prominent cortical development malformation associated with drug-resistant epileptic seizures that leads to lifelong cognitive impairment.
In this work, we proposed a deep learning framework to tackle the intricate task of identifying FCD-II and its subtypes (FCD-IIa and FCD-IIb).
The framework analyzes MRI images from multiple planes (axial, coronal, and sagittal) across T1-weighted and FLAIR MRI modalities, providing a comprehensive view of brain abnormalities.
We presented approximately 700 result images and plots (main paper and supplementary results) from different detection tasks, which provide advanced and insightful details, highlighting significant findings from the analysis. https://doi.org/10.1038/s44303-024-00031-5
We are shaping the future of epilepsy treatment, bringing us closer to a world where every patient can receive the right diagnosis and the best possible care.
Paper Link: https://www.nature.com/articles/s44303-024-00031-5
In this research a novel Smart Fabric Pressure Sensor (SFPS) was designed to measure high-pressure levels with remarkable precision and reliability. Through an iterative design process, the sensor’s range, sensitivity, and linearity were improved. A dedicated biasing circuit and a microcontroller-based data acquisition (DAQ) system were developed to ensure precise data collection.
Performance and Results:
The sensor was rigorously tested under controlled conditions, applying pressures between 4.63 and 300 kPa.
Linear measurement range: 4.63 to 74.08 kPa (r = -0.99)
High sensitivity: 0.0296 V/kPa
Accuracy: 97.72%
Excellent repeatability: Standard error of the mean (SEM) = 0.25 kPa
These results validate the SFPS as a reliable, high-performance wearable sensor, paving the way for further research in smart fabrics and electronic textiles (e-textiles) for high-pressure monitoring applications.
Implications for Wearable Technology:
With its high accuracy and responsiveness, the SFPS could be a game-changer in fields such as:
Healthcare – Monitoring pressure in prosthetics, compression therapy, and medical wearables
Sports & Performance – Enhancing athlete monitoring and equipment optimization
Industrial Safety – Detecting excessive pressure in protective gear
This research marks a significant step toward integrating e-textile-based sensors into real-world applications, making wearable technology more advanced and functional.
Paper Link: https://doi.org/10.1109/tim.2023.3312487
Colorectal cancer is one of the deadliest malignancies, and traditional manual examination methods often lack consistency and efficiency. To address this, our study explores advanced segmentation models—VGG16-UNet, ResNet50-UNet, MobileNet-UNet, and MobileViT-UNet. Notably, this is the first study to integrate 𝐌𝐨𝐛𝐢𝐥𝐞𝐕𝐢𝐓 as a UNet encoder.
Our findings highlight 𝐌𝐨𝐛𝐢𝐥𝐞𝐕𝐢𝐓-𝐔𝐍𝐞𝐭 𝐰𝐢𝐭𝐡 𝐃𝐢𝐜𝐞 𝐥𝐨𝐬𝐬 as the leading model, achieving impressive metrics:
Dice ratio: 0.944 ± 0.030
Jaccard index: 0.897 ± 0.049
Precision: 0.955 ± 0.046
Recall: 0.939 ± 0.038
Using 𝐓𝐎𝐏𝐒𝐈𝐒-𝐛𝐚𝐬𝐞𝐝 𝐦𝐮𝐥𝐭𝐢-𝐜𝐫𝐢𝐭𝐞𝐫𝐢𝐚 𝐝𝐞𝐜𝐢𝐬𝐢𝐨𝐧 𝐚𝐧𝐚𝐥𝐲𝐬𝐢𝐬, it ranked as the best model, significantly outperforming existing benchmarks in colorectal histopathology segmentation.
This breakthrough has the potential to improve the accuracy and efficiency of colorectal cancer diagnosis, making a real impact in healthcare.
Paper Link: https://peerj.com/articles/cs-2633/?td=wk
Epilepsy affects millions worldwide, and accurate, real-time detection is crucial for effective treatment. We propose a computationally efficient framework that integrates:
Hurst Exponent Analysis – Used to examine the long-term memory characteristics of EEG signals.
Daubechies 4 Discrete Wavelet Transformation – Applied for feature extraction.
ANOVA & Random Forest Regression – Utilized for feature selection.
Machine Learning Models – Trained and tested multiple models, including: Random Forest Classifier, Support Vector Machine (SVM), & Long Short-Term Memory (LSTM) Network.
Key Findings
The Random Forest classifier outperforms other models, achieving: 97% accuracy & 97.2% sensitivity
Effective classification using single-channel EEG with minimal handcrafted features.
Demonstrates strong generalization on the CHB-MIT scalp EEG database.
Computationally efficient design, making it suitable for real-time implementation on edge hardware.
Paper Link: https://doi.org/10.3390/bioengineering12040355
We have developed a 𝐛𝐢𝐨𝐦𝐞𝐝𝐢𝐜𝐚𝐥 𝐰𝐞𝐚𝐫𝐚𝐛𝐥𝐞 𝐝𝐞𝐯𝐢𝐜𝐞 that advances the field of 𝐩𝐞𝐫𝐬𝐨𝐧𝐚𝐥𝐢𝐳𝐞𝐝 𝐡𝐞𝐚𝐥𝐭𝐡 𝐦𝐨𝐧𝐢𝐭𝐨𝐫𝐢𝐧𝐠 and 𝐞𝐚𝐫𝐥𝐲 𝐝𝐢𝐚𝐠𝐧𝐨𝐬𝐢𝐬.
In this work, we developed a 𝐬𝐞𝐥𝐟-𝐩𝐨𝐰𝐞𝐫𝐞𝐝 𝐩𝐨𝐫𝐭𝐚𝐛𝐥𝐞 𝐞𝐥𝐞𝐜𝐭𝐫𝐨𝐧𝐢𝐜 𝐦𝐨𝐝𝐮𝐥𝐞 designed for 𝐫𝐞𝐚𝐥-𝐭𝐢𝐦𝐞 𝐞𝐥𝐞𝐜𝐭𝐫𝐨𝐜𝐚𝐫𝐝𝐢𝐨𝐠𝐫𝐚𝐦 (𝐄𝐂𝐆) 𝐬𝐢𝐠𝐧𝐚𝐥 𝐩𝐫𝐨𝐜𝐞𝐬𝐬𝐢𝐧𝐠. Here's what makes it stand out:
𝐄𝐧𝐞𝐫𝐠𝐲-𝐄𝐟𝐟𝐢𝐜𝐢𝐞𝐧𝐭 𝐃𝐞𝐬𝐢𝐠𝐧: An onboard 𝐞𝐧𝐞𝐫𝐠𝐲-𝐡𝐚𝐫𝐯𝐞𝐬𝐭𝐢𝐧𝐠 system powered by lithium-ion batteries, silicon photodiode arrays, and solar panels ensures continuous operation.
𝐈𝐧𝐧𝐨𝐯𝐚𝐭𝐢𝐯𝐞 𝐒𝐢𝐠𝐧𝐚𝐥 𝐏𝐫𝐨𝐜𝐞𝐬𝐬𝐢𝐧𝐠: We introduced a 𝐝𝐲𝐧𝐚𝐦𝐢𝐜 𝐦𝐮𝐥𝐭𝐢-𝐥𝐞𝐯𝐞𝐥 𝐰𝐚𝐯𝐞𝐥𝐞𝐭 𝐩𝐚𝐜𝐤𝐞𝐭 𝐝𝐞𝐜𝐨𝐦𝐩𝐨𝐬𝐢𝐭𝐢𝐨𝐧 𝐟𝐫𝐚𝐦𝐞𝐰𝐨𝐫𝐤 framework to process ECG signals efficiently by removing overlapping samples.
𝐀𝐝𝐯𝐚𝐧𝐜𝐞𝐝 𝐌𝐚𝐜𝐡𝐢𝐧𝐞 𝐋𝐞𝐚𝐫𝐧𝐢𝐧𝐠: Our custom Random Forest with Deep Decision Tree (RFDDT) model achieved a remarkable 99.72% accuracy in offline ECG signal classification.
𝐒𝐮𝐬𝐭𝐚𝐢𝐧𝐚𝐛𝐥𝐞 𝐚𝐧𝐝 𝐏𝐨𝐫𝐭𝐚𝐛𝐥𝐞: With the integration of a BQ25505 IC, solar cells, and photodiodes, the module supports uninterrupted operation with ambient light.
The results demonstrate significant improvements in: Signal processing accuracy and efficiency, Energy optimization for wearable devices, and Low computing cost for personalized healthcare.
Paper Link: https://doi.org/10.3390/bioengineering11121252
Stress plays a critical role in perception, cognition, and decision-making, especially for individuals in high-stress professions like the military. This research study investigates how operationally relevant emotional stressors impact key cognitive functions, including:
Memory Encoding & Recall – Does stress impair recognition memory?
Spatial Learning & Navigation – How does stress influence orientation?
Decision-Making Under Uncertainty – How do ambiguous threats affect rapid decisions?
Using a Threat of Shock (TOS) paradigm, we found:
TOS increased sympathetic arousal but did not impact emotional or hormonal stress responses.
Stress influenced decision times and confidence in a shoot/don’t shoot task, but not accuracy.
Uncertainty (stimulus clarity) played a bigger role in decision-making than stress itself.
Recognition memory and spatial orienting were unaffected by TOS.
Why It Matters:
Understanding the cognitive effects of stress is crucial for military training, high-risk professions, and real-world decision-making. Our findings highlight the need for better stress-induction methods to simulate real-world military conditions in laboratory settings.
Paper Link: https://doi.org/10.1371/journal.pone.0312443
𝐀𝐈’𝐬 𝐏𝐨𝐭𝐞𝐧𝐭𝐢𝐚𝐥: AI-driven solutions can enhance disease detection, drug discovery, resource management, and diagnostic accuracy.
𝐓𝐞𝐜𝐡𝐧𝐨𝐥𝐨𝐠𝐲 𝐓𝐫𝐞𝐧𝐝𝐬: Most studies rely on machine learning (ML) and artificial neural networks (ANNs) for various healthcare applications.
𝐓𝐫𝐮𝐬𝐭 & 𝐄𝐭𝐡𝐢𝐜𝐬 𝐆𝐚𝐩: There is a significant gap in integrating ethical, legal, and regulatory-compliant AI in Indian healthcare settings.
𝐅𝐮𝐭𝐮𝐫𝐞 𝐑𝐨𝐚𝐝𝐦𝐚𝐩: The study highlights opportunities to develop AI solutions prioritizing patient safety, data privacy, and regulatory compliance.
We hope this research sparks important conversations on building 𝐫𝐞𝐬𝐩𝐨𝐧𝐬𝐢𝐛𝐥𝐞 and 𝐢𝐦𝐩𝐚𝐜𝐭𝐟𝐮𝐥 𝐀𝐈 𝐬𝐨𝐥𝐮𝐭𝐢𝐨𝐧𝐬 for healthcare in India. Let's collaborate to make AI in healthcare 𝐭𝐫𝐮𝐬𝐭𝐰𝐨𝐫𝐭𝐡𝐲, 𝐬𝐜𝐚𝐥𝐚𝐛𝐥𝐞, 𝐚𝐧𝐝 𝐩𝐚𝐭𝐢𝐞𝐧𝐭-𝐜𝐞𝐧𝐭𝐫𝐢𝐜!
Paper Link: https://doi.org/10.3390/ai6010010
Alzheimer’s patients temporarily recollected the forgotten memories after listening to familiar music.
We predicted the familiarity of music using machine learning algorithms on data collected by single channel with an accuracy of 66.9%.
This method is easy to use, noninvasive, and providing quick feedback for for tracking memory loss in dementia.
This technology may potentially become become a therapeutic device that monitor and improve memory retention and communication.
Paper Link: https://doi.org/10.1109/EMBC53108.2024.10782402
Proposed a non-linear semi-analytic reconstruction method for continuous-wave diffuse optical tomography (CW-DOT), utilizing a Gaussian distribution framework.
Experimental validation on phantom and in-vivo finger joint imaging of a healthy volunteer, showcasing the method's efficacy in providing consistently accurate estimates of tissue oxygenation levels (StO2) and oxygen capacity (CB), surpassing generalized methods that model photon paths as curved lines.
Paper Link: https://doi.org/10.1109/JSEN.2023.3326974
Patent # 3096/CHE/2015 was granted. https://drive.google.com/drive/folders/1qGxX-XyGWQM1yCGPd4sutQENv8u-W24K?usp=sharing
We introduced a 3D CNN-based multi-modal feature fusion technique for the prediction of HPV association in primary tumor lesions.
The results demonstrate that the PET and CT ensemble model with soft voting outperformed the single-modality PET or CT-based model, with an AUC of 0.76 and an F1 score of 0.75.
Paper Link: https://doi.org/10.3390/bioengineering11010013
Digital Therapy for Mindful Breathing to unlock the power of breath with BreathHRV App
This revolutionary App was designed to help you harness the ancient practice of mindful breathing for improved well-being and mental health.
Our App offers a unique combination of guided breathing exercises, meditation techniques, and personalized insights to help you achieve balance, reduce stress, and enhance your overall quality of life.
Download at: https://breathhrv.com/
Our sensor and systems research has been extended to agricultural applications, and we have been developing technologies for smart, precision, and sustainable agriculture.
ViT-SmartAgri: Vision Transformer and Smartphone-based Plant Disease Detection for Smart Agriculture
Smartphone contact imaging and CNN-based tea leaf chlorophyll estimation for low-cost non-destructive sustainable agriculture.
Deep Learning for Coconut Pest Damage Identification Leveraging CNNs with Field Data
Paper Links: https://doi.org/10.3390/agronomy14020327
Three types of seizure — absence, complex partial, and myoclonic seizures using multichannel EEG signals have been discriminated.
Phase synchronization among pairs of multichannel EEG were measured to form a phase synchronization matrix, which has been further transformed into 2D images.
Next, images were fed into 2D CNN pipeline to learn detailed as well as hidden key features and discriminate types of seizure.
The performance metrics accuracy, sensitivity, specificity & weighted F1-score after 5-fold cross-validation recorded up to 80.8%, 79.6%, 89.2%, and 79.5% respectively.
Paper Links: https://doi.org/10.1109/BSN58485.2023.10331565
At the Center for Applied Brain and Cognitive Sciences (CABCS) in collaboration with Tufts University and the U.S. Army DEVCOM SC,
We designed, developed, and deployed a Body Sensor Network (BSN) architecture to collect multimodal data consisting of the brain, body, and behavioral information of U.S. soldiers in virtual reality (VR) environments.
We developing signal processing methods and Artificial Intelligence (AI) models to answer some of the important research questions in the projects under investigation.
The overall goal is to measure, predict, and enhance cognitive capabilities and human-system interactions for individuals and teams working in naturalistic high-stakes environments.
Approximately 10 million people live with Parkinson’s disease (PD) globally. While PD is a progressive and incurable neurological movement disorder, symptomatic treatment is available but requires patients to make periodic clinic visits for chronic management. Telemedicine can enhance the clinical care for PD but demands an Internet-of-Things (IoT) infrastructure that can enable symptom monitoring in out-of-clinic settings, such as homes.
We developed an IoT framework consisting of a Body Sensor Network (BSN) integrated with a Fog computing module to detect and classify upper limb movement tasks intended for symptom assessment enabling objective monitoring of PD in patients’ homes.
We designed smart gloves integrated with finger flex sensors, an inertial measurement unit (IMU), and a wireless embedded system.
The Fog-based BSN architecture connects the smart gloves to a companion Fog device that hosts the Machine Learning (ML) based classification of hand movement tasks.
The results from the conducted study on PD patients encourage us to further deploy the Fog-driven BSN architecture in real-world telemedicine.
Paper Link: https://doi.org/10.1016/j.smhl.2022.100351
We designed and developed a wearable wireless functional near-infrared spectroscopy (fNIRS) brain imaging device, WearLight, under the project funded by the NSF (~$6 million grant).
WearLight was built upon an Internet-of-Things embedded architecture for onboard intelligence, configurability, computation, and data transmission. We designed the PCB, tested all the electronics and optical components, and build the entire system in our lab.
We performed rigorous experimental studies on human participants to validate the system and found that the WearLight can monitor the functional activities of the brain of a freely moving subject in naturalistic environments.
Most importantly, we observed that WearLight has a capacity to measure hemodynamic responses in various setups including arterial occlusion on the forearm and frontal lobe brain activity.
Hence, our system is not only applicable for the diagnostic purpose or to study the complex human brain, but it could also be used to perform a variety of brain studies, such as training a sportsperson or a mediator for performance improvement with real-time brain functional activity monitoring.
Funded by NSF EPSCoR Research Infrastructure #1539068
Paper Link: https://doi.org/10.1109/TBCAS.2018.2876089
Muscle clinical metrics are crucial for spastic cocontraction management in children with Cerebral Palsy (CP). We proposed an ankle plantar flexors cocontraction index (CCI) normalized with respect to the bipedal heel rise (BHR) approach that provided more robust spastic cocontraction estimates compared to standard maximal isometric plantar flexion (IPF).
A study was conducted with 10 control and 10 CP children with equinus gait patterns. They performed the BHR and IPF testing and walked barefoot 10-m distance.
We compared agonist medial gastrocnemius EMG during both testing and CCIs obtained as the ratios of antagonist EMG during the swing phase of gait and either BHR or IPF agonist EMG.
Agonist EMG values from the BHR were: (i) internally reliable, (ii) ~50 ± 0.4% larger than IPF, (iii) and positively correlated.
The biomarker represents a step forward towards improved accuracy of spastic gait management in pediatrics.
Paper Link: https://doi.org/10.1109/TNSRE.2023.3329057
In this work, a spectroscopic diffuse optical tomography (DOT) system for the non-invasive continuous 3-D imaging of tissue was developed.
The system was built on an embedded system architecture along with an algorithm that performs entire system control, data acquisition, noise-free lock-in detection, and wireless data transmission to a host computer, equipped with a graphics processing unit (GPU).
The host computer sends commands to the DOT server system and collects data, and simultaneously performs high-speed 3D spectroscopic image reconstruction to display images in real-time.
The simulation and experimental results showed the spectroscopic imaging capability of the system to map the concentration of oxyhemoglobin, deoxyhemoglobin, and water, and to characterize the tumor located deep inside the tissue.
The proposed system uses low-cost LEDs, photodiode detectors, embedded system, and algorithms to perform high-speed 3D functional imaging and can be further miniaturized. Our promising results pave the way for the development of a low-cost handheld spectroscopic DOT system for the real-time onsite functional imaging of biological tissue.
Paper Link: https://doi.org/10.1109/TIM.2021.3082314
Although fNIRS electronic circuit has been miniaturized significantly, one of the least elucidated elements of the portable fNIRS systems is the process for developing optodes (light sources and detectors) for the improvements in skin-optode coupling, signal-to-noise ratio (SNR), user’s comfort level, and motion artifact reduction.
We have used modern design tools such as 3D printing and laser cutting to fabricate human-centered fNIRS optodes. Feedback was taken from participants of different groups throughout the iterative design process.
Two types of fNIRS optodes were designed; one was based on a forehead patch and the other was integrable into an electrode head cap. The noise characteristics of the optodes for the long-term brain imaging settings, while subjects were performing physical activities, was systemically studied in each of the iterations and designs.
Experimental results of SNR and resistance to the motion artifacts show that our method can be effective for the development of fNIRS optode.
These fNIRS optodes prove to not only be easy to use and comfortable but also capable of acquiring the fNIRS signal with other brain monitoring modalities such as electroencephalography (EEG).
Funded by NSF EPSCoR #1539068
Paper Link: https://doi.org/10.1117/12.2510955
Medical parameters are continuously monitored in premature infants in the Neonatal Intensive Care Units (NICU) using a set of wired, sticky electrodes attached to the body. Also, the medical adhesives used on the electrodes can be harmful to the baby, causing skin injuries, discomfort, and irritation.
We designed and validated an e-textile pressure sensor system for noninvasive respiratory rate (RR) monitoring in NICU.
We designed two e-textile, piezoresistive pressure sensors made of Velostat for noninvasive RR monitoring; one was hand-stitched on a mattress topper material, and the other was embroidered on a denim fabric using an industrial embroidery machine.
We developed a data acquisition system for validation experiments conducted on a high-fidelity, programmable NICU baby mannequin. We designed a signal processing pipeline to compute RR and quality matrix to compare various sensor designs.
The results showed that the relative accuracy of the hand-stitched sensor was 98.68, while the accuracy of the embroidered sensor was 99.39. The promising result encourages us for more research on e-textile design, human factors, and human experimentation.
Funded by NSF # 2139724
Paper Link: https://doi.org/10.1007/s11265-021-01669-9
Machine learning (ML) has the potential to classify mental states from the functional near-infrared spectroscopy (fNIRS) signal to build a brain-computer interface (BCI) system.
In this work, we have used our portable fNIRS system, WearLight, to image the prefrontal cortex of the brain of 25 participants while performing n-back working memory (WM) tasks.
We performed signal processing and extracted eight important features to construct the feature matrix and trained different ML classifiers. We achieved a maximum of 75 % classification accuracy in mental load in WM tasks using our device and method.
We also proposed an unsupervised ML clustering method to study the relationship between WM task difficulty, user performance, and hemodynamic brain response in the clusters (groups) in this study, and an interesting study results were found.
Funded by XSDE # IBN200011
Paper Link: https://doi.org/10.1117/12.2578952
Portable functional near-infrared spectroscopy (fNIRS) systems have the potential to image the brain in naturalistic settings. Experimental studies are essential to validate such fNIRS systems. The prefrontal cortex (PFC) brain area is involved in the processing of working memory (WM).
We assessed the PFC brain during n-back WM tasks in a group of 25 college students using our laboratory-developed portable fNIRS system, WearLight. We designed an experimental protocol with 32 n-back WM task blocks with four different pseudo-randomized task difficulty levels.
The experimental results showed the incremental mean hemodynamic activation induced by the increasing WM load. The left-PFC area was more activated in the WM task compared to the right-PFC. The task performance was also seen to be related to the hemodynamic responses.
Since the WearLight was wearable and operated wirelessly, it was possible to measure the cognitive load in the naturalistic environment, which could also lead to the development of a user-friendly brain-computer interface system.
Paper Link: https://doi.org/10.3390/s21113810
We invented a fast and cost-effective 3D diffuse optical tomography (DOT) instrument for the early detection of breast cancer and tumor.
We designed and fabricated the instrument comprising an optical fiber switching mechanism to illuminate multiple portions on the tissue surface at four different NIR wavelengths, and a photodetector-based light measurement system to accurately measure low-intensity light at a high speed.
The instrument comprises an ARM-based 32-bit processor (driven by an ARM Cortex- A7 Dual-core CPU and Mali400MP2 GPU), functioning under Linux operating system to control the selection of the wavelength, switching of the light sources, detector selection, directing the detector signal to a lock-in amplifier, and transferring data (wired or wirelessly) to a GPU enabled the main computer for high-speed 3-D DOT image reconstruction.
The experimental validation of the system was performed with tissue-mimicking experimental phantoms of various shapes (cylindrical and breast-shaped) and sizes, having inhomogeneities of various sizes and contrast embedded inside.
The system is capable of non-invasively reconstruct 3D images of tissue with a superb imaging quality, localization, and contrast at a frame rate of 2 fps.
Funded by DST # DSTO1163
The 3D diffuse optical tomographic (3D DOT) image reconstruction demands high computational power, especially in the case of estimating fully 3D tissue properties inside a human breast and head, which hampers physicians to view images and monitor a patient in real-time. The reconstruction time for a 3-D DOT image normally takes a few hours and so reconstructions are mostly carried out as offline operations.
We proposed an Algorithm that can perform real-time 3D DOT image reconstruction that enabled the visualization of images as the patient is undergoing a scan.
The reduction in the computation time for the 3-D DOT image reconstruction was achieved through (1) an algorithmic improvement that uses Broyden approach for updating the Jacobian matrix and thereby updating the parameter matrix, and (2) the multi-node multi-threaded GPU computation in CUDA parallel computing platform.
Funded by DST # DSTO1163
Paper Link: https://doi.org/10.1155/2014/376456
We proposed a region-of-interest (ROI) tissue scanning method based on diffuse optical tomography (DOT) principles with a limited number of measurement data. Confining to ROI and limiting the measurement data can help us to rapidly survey the pathological and functional status of an interested region inside the tissue at a high speed.
We also have designed a wearable silicone rubber patch containing LEDs and photodetectors. The patch was mounted on the surface of the dynamic phantoms for carrying out the ROI experimental measurements.
The system can continuously acquire measurement data and reconstruct 3-D optical properties distributions of the dynamic resin and intralipid phantoms to visualize changes in optical properties.
Another imaging modality such as ultrasound (US) or magnetic resonance imaging (MRI) can be initially employed to get the structural information of the tissue, and then ROI DOT system can be explicitly used to monitor the interested region continuously.
The results from this work further encouraged us to develop a functional ROI DOT system for 3-D spectroscopic imaging that derives the concentration of important chromophores such as oxyhemoglobin, deoxyhemoglobin, fat and water to characterize tumors located deep within the tissue.
Paper Link: https://doi.org/10.1063/1.4939054