Application of compressive sensing in SFAI measurement for faster sound speed assessment.

Quick quality assessment of fluid (liquid and gas) is a key requirement for many industries. Acoustic parameters like sound speed in fluid or sound attenuation in fluid can serve as a crucial marker for assessing fluid quality as any deviation of those parameters points to adulteration or degradation of the fluid. Swept Frequency Acoustic Interferometry (SFAI) is a well-known noninvasive technique for taking measurements of fluid's acoustic parameters (e.g. sound speed in fluid, sound attenuation in fluid, etc.) from outside the container walls. In this work, we focused on assessing sound speed in liquid through SFAI while applying compressive sensing technique to make very fast scans which are otherwise not possible through standard SFAI measurements. We report the possibility of 25 times faster scanning speed to measure sound speed in fluid when compared to standard SFAI based frequency scans. In addition, the proposed technique significantly reduces the volume of data that needs to be processed twenty-four hours a day basis.

Surface Potential Simulation and Electrode Design for in-Ear EEG Measurement.

The need for everyday-real-time EEG sensing has resulted in the development of minimalistic and discreet wearable EEG measuring devices. A front runner in this race is in-ear worn device. However, the position of the ear as well as its restricted accessibility poses certain challenges in the design of such devices - from the type of materials used to the placement of electrodes. These choices are important as they will determine the quality of the EEG signal available and in turn the accuracy of the application. We therefore create a simulation model of the human ear, allowing us to understand the impact of these choices on our design of an In-Ear EEG wearable. We first study the signal acquisition characteristics of a proposed gold-plated electrode against two other state-of-the-art electrode materials for in-ear EEG data collection. We further validate this electrode choice by fabricating a personalized silicone-based earpiece and collecting in-situ EEG data. This work explores the properties of using gold plated electrodes in capturing in-ear EEG signals enabling unobtrusive collection of the brain physiology data in real world setting.

A Novel Approach to the Identification of Compromised Pulmonary Systems in Smokers by Exploiting Tidal Breathing Patterns.

Smoking causes unalterable physiological abnormalities in the pulmonary system. This is emerging as a serious threat worldwide. Unlike spirometry, tidal breathing does not require subjects to undergo forceful breathing maneuvers and is progressing as a new direction towards pulmonary health assessment. The aim of the paper is to evaluate whether tidal breathing signatures can indicate deteriorating adult lung condition in an otherwise healthy person. If successful, such a system can be used as a pre-screening tool for all people before some of them need to undergo a thorough clinical checkup. This work presents a novel systematic approach to identify compromised pulmonary systems in smokers from acquired tidal breathing patterns. Tidal breathing patterns are acquired during restful breathing of adult participants. Thereafter, physiological attributes are extracted from the acquired tidal breathing signals. Finally, a unique classification approach of locally weighted learning with ridge regression (LWL-ridge) is implemented, which handles the subjective variations in tidal breathing data without performing feature normalization. The LWL-ridge classifier recognized compromised pulmonary systems in smokers with an average classification accuracy of 86.17% along with a sensitivity of 80% and a specificity of 92%. The implemented approach outperformed other variants of LWL as well as other standard classifiers and generated comparable results when applied on an external cohort. This end-to-end automated system is suitable for pre-screening people routinely for early detection of lung ailments as a preventive measure in an infrastructure-agnostic way.

A Universal Noninvasive Continuous Blood Pressure Measurement System for Remote Healthcare Monitoring.

BACKGROUND: The effectiveness of any remote healthcare monitoring system depends on how much accurate, patient-friendly, versatile, and cost-effective measurement it is delivering. There has always been a huge demand for such a long-term noninvasive remote blood pressure (BP) measurement system, which could be used worldwide in the remote healthcare industry. Thus, noninvasive continuous BP measurement and remote monitoring have become an emerging area in the remote healthcare industry. INTRODUCTION: Photoplethysmography-based (PPG) BP measurement is a continuous, unobtrusive, patient-friendly, and cost-effective solution. However, BP measurements through PPG sensors are not much reliable and accurate due to some major limitations like pressure disturbance, motion artifacts, and variations in human skin tone. MATERIALS AND METHODS: A novel reflective PPG sensor has been developed to eliminate the abovementioned pressure disturbance and motion artifacts during the BP measurement. Considering the variations of the human skin tone across demography, a novel algorithm has been developed to make the BP measurement accurate and reliable. The training dataset captured 186 subjects' data and the trial dataset captured another new 102 subjects' data. RESULTS AND DISCUSSION: The overall accuracy achieved by using the proposed method is nearly 98%. Thus, demonstrating the efficacy of the proposed method. CONCLUSIONS: The developed BP monitoring system is quite accurate, reliable, cost-effective, handy, and user friendly. It is also expected that this system would be quite useful to monitor the BP of infants, elderly people, patients having wounds, burn injury, or in the intensive care unit environment.

A Literature Review on Current and Proposed Technologies of Noninvasive Blood Pressure Measurement.

BACKGROUND: Noninvasive continuous blood pressure (BP) measurement has become an evolving topic in the field of remote healthcare. The classical noninvasive BP measurement techniques provide spontaneous values of systolic and diastolic BP. On the other hand, intrusive type BP measurement techniques provide continuous values of systolic and diastolic BP. However, these techniques are very painful, cannot be used for long-term monitoring, and are obtainable only in an intensive care unit environment. With the advancement of the remote healthcare industry, there is a growing demand for noninvasive continuous BP monitoring. OBJECTIVE: The objective of this research was to present a compact literature review on the various prospective approaches of noninvasive continuous BP measurement techniques. MATERIALS & METHODS: The most contemporary and advanced technologies on noninvasive continuous BP measurement are Tactile Sensing, Vascular Unloading Technique, Pulse Transit Time, Photoplethysmography, Ultrasound-based BP measurement, BP measurement from image processing, etc. The literature search based on these technologies was conducted in EMBASE, Web of Science, IEEE, PubMed, and Ovid MEDLINE databases. In this study, each selected approach was evaluated and characterized using the following criteria: (1) accuracy; (2) cost; (3) portability; (4) comfort and convenience of use; (5) clinical health and safety; and (6) ability to integrate with the remote healthcare system. RESULTS: A detailed technical analysis was done to determine the advantages and limitations of each technique in the context of the abovementioned parameters. It was observed that BP measurement, using photoplethysmography (using camera or sensor or both), perhaps was the most promising technique among all. CONCLUSION: The study emphasized the fact that the noninvasive, continuous BP measurement technique needs to evolve further to make it reliable, accurate, and user-friendly. Lastly, a possible direction toward a more reliable and comfortable noninvasive continuous BP measurement technique has been discussed.

The Ultrasonic Directional Tidal Breathing Pattern Sensor: Equitable Design Realization Based on Phase Information.

Pulmonary ailments are conventionally diagnosed by spirometry. The complex forceful breathing maneuver as well as the extreme cost of spirometry renders it unsuitable in many situations. This work is aimed to facilitate an emerging direction of tidal breathing-based pulmonary evaluation by designing a novel, equitable, precise and portable device for acquisition and analysis of directional tidal breathing patterns, in real time. The proposed system primarily uses an in-house designed blow pipe, 40-kHz air-coupled ultrasound transreceivers, and a radio frequency (RF) phase-gain integrated circuit (IC). Moreover, in order to achieve high sensitivity in a cost-effective design philosophy, we have exploited the phase measurement technique, instead of selecting the contemporary time-of-flight (TOF) measurement; since application of the TOF principle in tidal breathing assessments requires sub-micro to nanosecond time resolution. This approach, which depends on accurate phase measurement, contributed to enhanced sensitivity using a simple electronics design. The developed system has been calibrated using a standard 3-L calibration syringe. The parameters of this system are validated against a standard spirometer, with maximum percentage error below 16%. Further, the extracted respiratory parameters related to tidal breathing have been found to be comparable with relevant prior works. The error in detecting respiration rate only is 3.9% compared to manual evaluation. These encouraging insights reveal the definite potential of our tidal breathing pattern (TBP) prototype for measuring tidal breathing parameters in order to extend the reach of affordable healthcare in rural regions and developing areas.