Development of a Novel Contactless Mechanocardiograph Device

A novel method of detecting mechanical movement of the heart, Mechanocardiography (MCG), with no connection to the subject's body is presented. This measurement is based on radar technology and it has been proven through this research work that the acquired signal is highly correlated to the phonocardiograph signal and acceleration-based ballistocardiograph signal (BCG) recorded directly from the sternum. The heart rate and respiration rate have been extracted from the acquired signal as two possible physiological monitoring applications of the radar-based MCG device

A CNN based Multifaceted Signal Processing Framework for Heart Rate Proctoring Using Millimeter Wave Radar Ballistocardiography

The recent pandemic has refocused the medical world's attention on the diagnostic techniques associated with cardiovascular disease. Heart rate provides a real-time snapshot of cardiovascular health. A more precise heart rate reading provides a better understanding of cardiac muscle activity. Although many existing diagnostic techniques are approaching the limits of perfection, there remains potential for further development. In this paper, we propose MIBINET, a convolutional neural network for real-time proctoring of heart rate via inter-beat-interval (IBI) from millimeter wave (mm-wave) radar ballistocardiography signals. This network can be used in hospitals, homes, and passenger vehicles due to its lightweight and contactless properties. It employs classical signal processing prior to fitting the data into the network. Although MIBINET is primarily designed to work on mm-wave signals, it is found equally effective on signals of various modalities such as PCG, ECG, and PPG. Extensive experimental results and a thorough comparison with the current state-of-the-art on mm-wave signals demonstrate the viability and versatility of the proposed methodology. Keywords: Cardiovascular disease, contactless measurement, heart rate, IBI, mm-wave radar, neural networkComment: 13 pages, 10 figures, Submitted to Elsevier's Array Journa

Challenges in Design and Fabrication of Flexible/Stretchable Carbon- and Textile-Based Wearable Sensors for Health Monitoring: A Critical Review

To demonstrate the wearable flexible/stretchable health-monitoring sensor, it is necessary to develop advanced functional materials and fabrication technologies. Among the various developed materials and fabrication processes for wearable sensors, carbon-based materials and textile-based configurations are considered as promising approaches due to their outstanding characteristics such as high conductivity, lightweight, high mechanical properties, wearability, and biocompatibility. Despite these advantages, in order to realize practical wearable applications, electrical and mechanical performances such as sensitivity, stability, and long-term use are still not satisfied. Accordingly, in this review, we describe recent advances in process technologies to fabricate advanced carbon-based materials and textile-based sensors, followed by their applications such as human activity and electrophysiological sensors. Furthermore, we discuss the remaining challenges for both carbon- and textile-based wearable sensors and then suggest effective strategies to realize the wearable sensors in health monitoring

Optogenetics: Background, Methodological Advances and Potential Applications for Cardiovascular Research and Medicine

Optogenetics is an elegant approach of precisely controlling and monitoring the biological functions of a cell, group of cells, tissues, or organs with high temporal and spatial resolution by using optical system and genetic engineering technologies. The field evolved with the need to precisely control neurons and decipher neural circuity and has made great accomplishments in neuroscience. It also evolved in cardiovascular research almost a decade ago and has made considerable progress in both in vitro and in vivo animal studies. Thus, this review is written with an objective to provide information on the evolution, background, methodical advances, and potential scope of the field for cardiovascular research and medicine. We begin with a review of literatures on optogenetic proteins related to their origin, structure, types, mechanism of action, methods to improve their performance, and the delivery vehicles and methods to express such proteins on target cells and tissues for cardiovascular research. Next, we reviewed historical and recent literatures to demonstrate the scope of optogenetics for cardiovascular research and regenerative medicine and examined that cardiac optogenetics is vital in mimicking heart diseases, understanding the mechanisms of disease progression and also in introducing novel therapies to treat cardiac abnormalities, such as arrhythmias. We also reviewed optogenetics as promising tools in providing high-throughput data for cardiotoxicity screening in drug development and also in deciphering dynamic roles of signaling moieties in cell signaling. Finally, we put forth considerations on the need of scaling up of the optogenetic system, clinically relevant in vivo and in silico models, light attenuation issues, and concerns over the level, immune reactions, toxicity, and ectopic expression with opsin expression. Detailed investigations on such considerations would accelerate the translation of cardiac optogenetics from present in vitro and in vivo animal studies to clinical therapies

Medical Devices for Measuring Respiratory Rate in Children: a Review

Respiratory rate is an important vital sign used for diagnosing illnesses in children as well as prioritising patient care. All children presenting acutely to hospital should have a respiratory rate measured as part of their initial and ongoing assessment. However measuring the respiratory rate remains a subjective assessment and in children can be liable to measurement error especially if the child is uncooperative. Devices to measure respiratory rate exist but many provide only an estimate of respiratory rate due to the associated methodological complexities. Some devices are used within the intensive care, post-operative or more specialised investigatory settings none however have made their way into the everyday clinical setting. A non-contact device may be better tolerated in children and not cause undue stress distorting the measurement. Further validation and adaption to the acute clinical setting is needed before such devices can supersede current methods

Recent Application in Biometrics

In the recent years, a number of recognition and authentication systems based on biometric measurements have been proposed. Algorithms and sensors have been developed to acquire and process many different biometric traits. Moreover, the biometric technology is being used in novel ways, with potential commercial and practical implications to our daily activities. The key objective of the book is to provide a collection of comprehensive references on some recent theoretical development as well as novel applications in biometrics. The topics covered in this book reflect well both aspects of development. They include biometric sample quality, privacy preserving and cancellable biometrics, contactless biometrics, novel and unconventional biometrics, and the technical challenges in implementing the technology in portable devices. The book consists of 15 chapters. It is divided into four sections, namely, biometric applications on mobile platforms, cancelable biometrics, biometric encryption, and other applications. The book was reviewed by editors Dr. Jucheng Yang and Dr. Norman Poh. We deeply appreciate the efforts of our guest editors: Dr. Girija Chetty, Dr. Loris Nanni, Dr. Jianjiang Feng, Dr. Dongsun Park and Dr. Sook Yoon, as well as a number of anonymous reviewers

Cuffless calibration and estimation of continuous arterial blood pressure.

Gu, Wenbo.Thesis (M.Phil.)--Chinese University of Hong Kong, 2009.Includes bibliographical references.Abstract also in Chinese.Acknowledgment --- p.iAbstract --- p.ii摘要 --- p.iiiList of Figures --- p.viList of Tables --- p.viiList of Abbreviations --- p.viiiContents --- p.ixChapter 1. --- Introduction --- p.1Chapter 1.1. --- Arterial blood pressure and its importance --- p.1Chapter 1.2. --- Current methods for non-invasive blood pressure measurement --- p.4Chapter 1.2.1. --- The auscultatory method (mercury sphygmomanometer) --- p.4Chapter 1.2.2. --- The oscillometric method --- p.5Chapter 1.2.3. --- The tonometric method --- p.7Chapter 1.2.4. --- The volume-clamp method --- p.7Chapter 1.3. --- Blood pressure estimation based on pulse arrival time --- p.8Chapter 1.4. --- Objectives and structures of this thesis --- p.10Chapter 2. --- Hemodynamic models: relationship between PAT and BP --- p.14Chapter 2.1. --- The generation of arterial pulsation --- p.14Chapter 2.2. --- Pulse wave velocity along the arterial wall --- p.15Chapter 2.2.1. --- Moens-Korteweg equation --- p.15Chapter 2.2.2. --- Bergel wave velocity --- p.18Chapter 2.3. --- Relationship between PWV and BP --- p.19Chapter 2.3.1. --- Bramwell-Hill´ةs model --- p.20Chapter 2.3.2. --- Volume-pressure relationship --- p.20Chapter 2.3.3. --- Hughes' model --- p.22Chapter 2.4. --- The theoretical expression of PAT-BP relationship --- p.23Chapter 3. --- Estimation and calibration of arterial BP based on PAT --- p.25Chapter 3.1. --- PAT measurement --- p.25Chapter 3.1.1. --- Principle of ECG measurement --- p.25Chapter 3.1.2. --- Principle of PPG measurement --- p.26Chapter 3.1.3. --- Calculation of PAT --- p.28Chapter 3.2. --- Calibration methods for PAT-BP estimation --- p.29Chapter 3.2.1. --- Calibration based on cuff BP readings --- p.30Chapter 3.2.2. --- Calibration by hydrostatic pressure changes --- p.31Chapter 3.2.3. --- Calibration by multiple regression --- p.33Chapter 3.3. --- Model-based calibration with PPG waveform parameters --- p.34Chapter 3.3.1. --- Model-based equation with parameters from PPG waveform --- p.34Chapter 3.3.2. --- Selection of parameters from PPG waveform --- p.36Chapter 4. --- Cuffless calibration approach using PPG waveform parameter for PAT-BP estimation --- p.43Chapter 4.1. --- Introduction --- p.43Chapter 4.2. --- Experiment I: young group in sitting position including rest and after exercise states --- p.43Chapter 4.2.1. --- Experiment protocol --- p.43Chapter 4.2.2. --- Data Analysis --- p.44Chapter 4.2.3. --- Experiment results --- p.46Chapter 4.3. --- Experiment II: over-month observation using wearable device in sitting position --- p.48Chapter 4.3.1. --- Body sensor network for blood pressure estimation --- p.49Chapter 4.3.2. --- Experiment protocol and data collection --- p.50Chapter 4.3.3. --- Experiment results --- p.50Chapter 4.4. --- Experiment III: contactless monitoring in supine position --- p.51Chapter 4.4.1. --- The design of the contactless system --- p.52Chapter 4.4.2. --- Experiment protocol and data collection --- p.53Chapter 4.4.3. --- Experiment results --- p.53Chapter 4.5. --- Discussion --- p.55Chapter 4.5.1. --- Discussion of Experiments I and II --- p.55Chapter 4.5.2. --- Discussion of Experiments II and III --- p.57Chapter 4.5.3. --- Conclusion --- p.58Chapter 5. --- Cuff-based calibration approach for BP estimation in supine position --- p.61Chapter 5.1. --- Introduction --- p.61Chapter 5.2. --- Experiment protocol --- p.61Chapter 5.2.1. --- Experiment IV: exercise experiment in supine position in lab --- p.61Chapter 5.2.2. --- Experiment V: exercise experiment in supine position in PWH --- p.63Chapter 5.3. --- Data analysis --- p.65Chapter 5.3.1. --- Partition of signal trials and selection of datasets --- p.65Chapter 5.3.2. --- PPG waveform processing --- p.66Chapter 5.4. --- Experiment results --- p.68Chapter 5.4.1. --- Range and variation of reference SBP --- p.68Chapter 5.4.2. --- PAT-BP individual best regression --- p.69Chapter 5.4.3. --- Multiple regression using ZX and arm length --- p.72Chapter 5.4.4. --- One-cuff calibration improved by PPG waveform parameter --- p.72Chapter 5.5. --- Discussion --- p.74Chapter 6. --- Conclusion --- p.7