Acoustic Detection of Coronary Occlusions before and after Stent Placement Using an Electronic Stethoscope Andrei Dragomir 1, Allison Post 1, Yasemin M. Akay 1, Hani Jneid 2,3, David Paniagua 2,3,Ali Denktas 2,3, Biykem Bozkurt 2,3 and Metin Akay 1,*1 Department of Biomedical Engineering, University of Houston, Houston, TX 77204, USA; Andrei.Drag@gmail.com (A.D.); Allison.Post@central.uh.edu (A.P.); email@example.com (Y.M.A.)2 Winters Center for Heart Failure Research, The Michael E. DeBakey VA Medical Center, Houston, TX 77030,USA; firstname.lastname@example.org (H.J.); email@example.com (D.P.); firstname.lastname@example.org (A.D.);email@example.com (B.B.) 3 Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA * Correspondence: firstname.lastname@example.org; Tel.: +1-832-842-8860 Academic Editors: Raúl Alcaraz Martínez and Kevin H. Knuth Received: 27 April 2016; Accepted: 23 July 2016; Published: 29 July 2016 Abstract: More than 370,000 Americans die every year from coronary artery disease (CAD).Early detection and treatment are crucial to reducing this number. Current diagnostic and disease-monitoring methods are invasive, costly, and time-consuming. Using an electronic stethoscope and spectral and nonlinear dynamics analysis of the recorded heart sound, we investigated the acoustic signature of CAD in subjects with only a single coronary occlusion before and after stent placement, as well as subjects with clinically normal coronary arteries. The CAD signature was evaluated by estimating power ratios of the total power above 150 Hz over the total power below 150 Hz of the FFT of the acoustic signal. Additionally, approximate entropy values were estimated to assess the differences induced by the stent placement procedure to the acoustic signature of the signals in the time domain. The groups were identified with this method with 82% sensitivity and 64% specificity (using the power ratio method) and 82% sensitivity and 55% specificity (using the approximate entropy). Power ratios and approximate entropy values after stent placement are not statistically different from those estimated from subjects with no coronary occlusions. Our approach demonstrates that the effect of stent placement on coronary occlusions can be monitored using an electronic stethoscope.
A wearable chemical–electrophysiological hybrid biosensing system for real-time health and fitness monitoring Somayeh Imani , Amay J. Bandodkar , A. M. Vinu Mohan , Rajan Kumar , Shengfei Yu , Joseph Wang & Patrick P. Mercie Abstract Flexible, wearable sensing devices can yield important information about the underlying physiology of a human subject for applications in real-time health and fitness monitoring. Despite significant progress in the fabrication of flexible biosensors that naturally comply with the epidermis, most designs measure only a small number of physical or electrophysiological parameters, and neglect the rich chemical information available from biomarkers. Here, we introduce a skin-worn wearable hybrid sensing system that offers simultaneous real-time monitoring of a biochemical (lactate) and an electrophysiological signal (electrocardiogram), for more comprehensive fitness monitoring than from physical or electrophysiological sensors alone. The two sensing modalities, comprising a three-electrode amperometric lactate biosensor and a bipolar electrocardiogram sensor, are co-fabricated on a flexible substrate and mounted on the skin. Human experiments reveal that physiochemistry and electrophysiology can be measured simultaneously with negligible cross-talk, enabling a new class of hybrid sensing devices. Introduction Wearable sensors present an exciting opportunity to measure human physiology in a continuous, real-time and non-invasive manner1,2. Recent advances in hybrid fabrication techniques have enabled the design of wearable sensing devices in thin, conformal form factors that naturally comply with the smooth curvilinear geometry of human skin, thereby enabling intimate contact necessary for robust physiological measurements1,3,4. Development of such epidermal electronic sensors has enabled devices that can monitor respiration rate5,6,7, heart rate8,9, electrocardiograms4,10,11,12, blood oxygenation13, skin temperature14,15, bodily motion16,17,18,19,20, brain activity21,22,23 and blood pressure24,25. To date, most systems have targeted only a single measurement at a time, and most such sensors measure only physical and electrophysiological parameters, significantly limiting monitoring and diagnostic opportunities. For example, the human body undergoes complex physiological changes during physical activities such as exercise26,27, and monitoring the physiologic effect of physical activity can be important for a wide variety of subjects ranging from athletes to the elderly28,29,30. However, current wearable devices that only measure heart rate, motion and electrocardiogram provide an incomplete picture of the complex physiological changes taking place. As a result, further progress in the area of wearable sensors must include new, relevant sensing modalities, and must integrate these different modalities into a single platform for continuous, simultaneous sensing of multiple parameters relevant to a wide range of conditions, diseases, health and performance states. Inclusion of chemical measurements can provide extremely useful insights not available from physical or electrophysiological sensors31. Chemical information can be conventionally acquired via clinical labs or point-of-care devices32,33,34; unfortunately, such approaches do not support continuous, real-time measurements, therefore limiting their utility to applications where stationary, infrequent tests are sufficient. While recent work, including our own, has demonstrated that chemicals such as electrolytes and metabolites can be measured continuously using epidermal electronics on the skin35,36,37,38, or through non-invasive monitoring of other body fluids38,39,40, these devices measure only a single parameter at once, and are not integrated with other sensing modalities. Recently, Gao et al.41 demonstrated a wearable patch that can simultaneously track levels of metabolites and electrolytes in human sweat. However, electrophysiology sensors were not included, and such multimodal sensor fusion is crucial to obtain a more comprehensive knowledge about a wearer’s well-being.
Knitted Strain Sensor Textiles of Highly Conductive All-Polymeric Fibers Shayan Seyedin†‡, Joselito M. Razal*†‡, Peter C. Innis†, Ali Jeiranikhameneh†, Stephen Beirne†, and Gordon G. Wallace*† † Intelligent Polymer Research Institute, ARC Centre of Excellence for Electromaterials Science, AIIM Facility, Innovation Campus, University of Wollongong, Wollongong, New South Wales 2522, Australia ‡ Institute for Frontier Materials, Deakin University, Geelong, Victoria 3216, Australia ACS Appl. Mater. Interfaces, 2015, 7 (38), pp 21150–21158 Abstract A scaled-up fiber wet-spinning production of electrically conductive and highly stretchable PU/PEDOT:PSS fibers is demonstrated for the first time. The PU/PEDOT:PSS fibers possess the mechanical properties appropriate for knitting various textile structures. The knitted textiles exhibit strain sensing properties that were dependent upon the number of PU/PEDOT:PSS fibers used in knitting. The knitted textiles show sensitivity (as measured by the gauge factor) that increases with the number of PU/PEDOT:PSS fibers deployed. A highly stable sensor response was observed when four PU/PEDOT:PSS fibers were co-knitted with a commercial Spandex yarn. The knitted textile sensor can distinguish different magnitudes of applied strain with cyclically repeatable sensor responses at applied strains of up to 160%. When used in conjunction with a commercial wireless transmitter, the knitted textile responded well to the magnitude of bending deformations, demonstrating potential for remote strain sensing applications. The feasibility of an all-polymeric knitted textile wearable strain sensor was demonstrated in a knee sleeve prototype with application in personal training and rehabilitation following injury.
SHIMMER PARTNERS WITH HARVARD'S WYSS INSTITUTE TO ADVANCE THE FIELD OF REMOTE PATIENT MONITORING USING WEARABLE SENSING TECHNOLOGY DUBLIN, 13 June 2016 - Shimmer Sensing, a leading provider of medical grade wearable wireless sensors, announced today a partnership with the Wyss Institute for Biologically Inspired Engineering at Harvard University in support of ongoing research focused on remote patient monitoring using wearable sensing technology. The research is led by Paolo Bonato, Ph.D., who is an Associate Faculty Member at the Wyss Institute and an Associate Professor in the Department of Physical Medicine and Rehabilitation at Harvard Medical School. "Partnering with Shimmer Sensing will allow us to further develop our remote patient monitoring platform called MercuryLive," said Bonato. MercuryLive is a platform designed to support clinicians’ remote monitoring of patients – who, for example, could have Parkinson’s disease or be stroke survivors, traumatic brain injury survivors, or children with cerebral palsy – via live streaming of wearable sensor data and an interactive video feed. Bonato’s team at the Wyss Institute is developing the latest version of the MercuryLive platform, which enables the integration of a variety of wireless devices.Shimmer’s financial support of the research and its technical expertise in wireless medical sensors will accelerate the development of MercuryLive towards applications in remote patient monitoring. Among other clinical applications, the platform being developed will allow clinicians to remotely monitor patients with knee osteoarthritis using a knee sleeve with embedded wireless sensors and observe older adults in their home using wearable sensors and a mobile robot designed to navigate the environment and reach the subject in case of an emergency. “The Wyss Institute is renowned for taking academic innovation to the next level, and partnering with physicians and the industry to bring new technologies to the bedside. We are very enthusiastic about the opportunity to support Prof. Bonato's research team and their work toward the development of the next generation of remote clinical monitoring systems,” commented Patrick White, the CEO of Shimmer Sensing. “Wearable patient monitoring systems represent the future of ambulatory medicine, and we are excited to help catalyze collaborations between engineers, clinicians and industrial partners to make this a reality,” said Wyss Institute Founding Director Donald Ingber, M.D., Ph.D., who is also the Judah Folkman Professor of Vascular Biology at Boston Children's Hospital and Harvard Medical School and Professor of Bioengineering at the Harvard John A. Paulson School of Engineering and Applied Science.
Abstract of PhD Thesis Intelligent Data Processing and Its Applications Aniko Szilvia Vanger 1 Introduction Nowadays the rapidly increasing performance of hardware and the efficient intelligent scientific algorithms enable us to store and process big data. This tendency will cover more opportunities to get more and more information from the large amount of data. My thesis is only a precursor of this topic, because I did not have sufficient hardware and I had only a little data to be processed. However, all the topics of my thesis belong to the intelligent data processing. In Chapter 2 of my thesis I introduce a new clustering algorithm named GridOPTICS, whose goal is to accelerate the well-known OPTICS density clustering technique. The density-based clustering techniques are capable of recognizing arbitrary-shaped clusters in a point set. The DBSCAN results in only one cluster set, but the OPTICS generates a reachability plot from which a lot of cluster sets can be read as a result without having to execute the whole algorithm again. I experienced that it is very slow for large data sets, so I wanted to nd a solution to accelerate it. I wanted to see that the speed of the GridOptics is better than OPTICS, so I executed both the algorithms on several point sets. In Chapter 3 of my thesis I introduce two new modules of the Cardiospy system of Labtech Ltd. On these two projects I worked together with Istvan Juhasz, Laszlo Farkas, Peter Toth, and 4 students of the university, Jozsef Kuk, Adam Balazs,Bela Vamosi, and David Angyal.Bela Kincs, who was the executive of the Labtech Ltd., wanted the Cardiospy system to be improved. He and his team surveyed what the demand of the users are in this area and how their software could be better. The Labtech Ltd. And the University of Debrecen worked together in two projects. In both cases theLabtech had early solutions for the algorithms, but they were insufficient and slow, the results could not be validated, or they gave insufficient results. Moreover, there were no visualization tools for either problems. The tasks of the team of the University of Debrecen were to give a quick algorithm and to create an interactive visualization interface for each problem. The goal of the first module of Cardiospy is to cluster and visualize the long (up to 24-hours) recordings of ECG signals, because the manual evaluation of long recordings is a lengthy and tedious task. During this project I recognized that it is a very interesting topic to find out how the OPTICS can be accelerated with a grid clustering method independently, without any ECG signals. The goal of the second module of Cardiospy is to calculate and visualize the steps of the blood pressure measurement and the values of blood pressure. The recordings (which can contain a sequence of measurements) are collected by a microcontroller, but this module runs on a PC. With the help of the application the physicians can recognize the types of errors on the measurements and they can also find the noisy measurements. In Chapter 4 I introduce how I applied an active learning method in a subject whose topic is database programming. I taught Oracle SQL and PL/SQL in the Advanced DBMS 1 subject, and I saw that the students do not practice at home. The prerequirements of this subject are the Programming language and the Database systems courses, so they are not absolute beginners in the field. I wanted to force the students to try out the programming tools independently, but with the help of the teacher. To support the active learning method, an application had to be built. The application helps the teacher organize and monitor the tasks and their solutions of the students. Moreover the application can verify the syntax of the solutions before the students upload them. If the syntax is wrong, the student cannot upload it. This feature makes the task of the teacher easier. To demonstrate whether the active learning method is good or not, I gathered and examined the results of the students during the 3 years when I used this method. New results The abstract of the thesis presents new results grouped into four main statements. The first statement deals with a clustering method, the second one demonstrates an application of this clustering method, namely clustering of ECG signals, which can be considered as an application of the GridOPTICS clustering method. The third statement introduces the visualization of the steps of the blood pressure measurement, whereas the last statement demonstrates how the solutions of the students can easily be managed during an active learning method for database programming. 2.1 A clustering algorithm Cluster analysis is an important research field of data mining, which is applied on many other disciplines, such as pattern recognition, image processing, machine learning, bioinformatics, information retrieval, artificial intelligence, marketing, psychology, etc. The density-based clustering approach is capable of finding arbitrarily shaped clusters, but they have a disadvantage, namely it is hard to choose parameter values in order that the algorithm gives an appropriate result (Gan et al., 2007). The OPTICS (Ankerst et al., 1999) clustering algorithm gives not only one result but a set of the results. It builds a reachability plot, namely it orders the input points, and it assigns a reachability distance to an input point. Based on the reachability plot, the algorithm can produce a lot of clustering results. Building the reachability plot is slow, but reading the clusters from the reachability plot is fast.
Report from The International Society for Nomenclature of Paediatric and Congenital Heart Disease: cardiovascular catheterisation for congenital and paediatric cardiac disease Lisa Bergersen • Harvard Medical School Allen Dale Everett Jorge Manuel Giroud Jeffrey Phillip Jacobs Abstract Interventional cardiology for paediatric and congenital cardiac disease is a relatively young and rapidly evolving field. As the profession begins to establish multi-institutional databases, a universal system of nomenclature is necessary for the field of interventional cardiology for paediatric and congenital cardiac disease. The purpose of this paper is to present the results of the efforts of The International Society for Nomenclature of Paediatric and Congenital Heart Disease to establish a system of nomenclature for cardiovascular catheterisation for congenital and paediatric cardiac disease, focusing both on procedural nomenclature and on the nomenclature of complications associated with interventional cardiology. This system of nomenclature for cardiovascular catheterisation for congenital and paediatric cardiac disease is a component of The International Paediatric and Congenital Cardiac Code. This manuscript is the first part of a two-part series. Part 1 will cover the procedural nomenclature associated with interventional cardiology as treatment for paediatric and congenital cardiac disease. This procedural nomenclature of The International Paediatric and Congenital Cardiac Code will be used in the IMPACT Registry™ (Pedcath) (IMproving Pediatric and Adult Congenital Treatment) of the National Cardiovascular Data Registry® of The American College of Cardiology. Part 2 will cover the nomenclature of complications associated with interventional cardiology as treatment for paediatric and congenital cardiac disease. Cardiology in the Young (2011), 21, 252–259
Neural Control of Vascular Reactions: Impact of Emotion and Attention Hadas Okon-Singer, Jan Mehnert, Jana Hoyer, Lydia Hellrung, Herma Lina Schaare, Juergen Dukart and Arno Villringer Journal of Neuroscience 19 March 2014, 34 (12) 4251-4259; DOI: https://doi.org/10.1523/JNEUROSCI.0747-13.2014 ABSTRACT This study investigated the neural regions involved in blood pressure reactions to negative stimuli and their possible modulation by attention. Twenty-four healthy human subjects (11 females; age = 24.75 ± 2.49 years) participated in an affective perceptual load task that manipulated attention to negative/neutral distractor pictures. fMRI data were collected simultaneously with continuous recording of peripheral arterial blood pressure（CareTaker 、Emperical Technologies）;. A parametric modulation analysis examined the impact of attention and emotion on the relation between neural activation and blood pressure reactivity during the task. When attention was available for processing the distractor pictures, negative pictures resulted in behavioral interference, neural activation in brain regions previously related to emotion, a transient decrease of blood pressure, and a positive correlation between blood pressure response and activation in a network including prefrontal and parietal regions, the amygdala, caudate, and mid-brain. These effects were modulated by attention; behavioral and neural responses to highly negative distractor pictures (compared with neutral pictures) were smaller or diminished, as was the negative blood pressure response when the central task involved high perceptual load. Furthermore, comparing high and low load revealed enhanced activation in frontoparietal regions implicated in attention control. Our results fit theories emphasizing the role of attention in the control of behavioral and neural reactions to irrelevant emotional distracting information. Our findings furthermore extend the function of attention to the control of autonomous reactions associated with negative emotions by showing altered blood pressure reactions to emotional stimuli, the latter being of potential clinical relevance.
Comparisons of microvascular and macrovascular changes in aldosteronism-related hypertension and essential hypertension Monica Varano, Pierluigi Iacono, Massimiliano M. Tedeschi, Claudio Letizia, Mario Curione, Claudio Savoriti, Erika Baiocco, Laura Zinnamosca, Cristiano Marinelli, Barbara Boccassini Mariacristina Parravano Abstract Case-control observational study to evaluate the microvascular and macrovascular changes in patients with hypertension secondary to primary aldosteronism (PA), essential hypertension (EH) and healthy subjects. Measurements of arterial stiffness including augmentation index (AIx) and pulse wave velocity (PWV) were assessed using a TensioClinic arteriograph system. Retinal microcirculation was imaged by a Retinal Vessel Analyzer (RVA) and a non-midriatic camera (Topcon-TRC-NV2000). IMEDOS software analyzed the retinal artery diameter (RAD), retinal vein diameters (RVD) and arteriole-to-venule ratio (AVR) of the vessels coming off the optic disc. Thirty, 39 and 35 patients were included in the PA, EH and control group, respectively. The PA group showed higher PWV values compared only with the control group. The mean brachial and aortic AIx values did not show significant difference between groups. In the PA group, the mean RVD and AVR values were significantly lower than in the EH and control groups, whereas the parameters did not differ between the EH and control groups. In conclusion, AVR appears significantly modified in the PA group compared with the EH group and could represent an early and more reliable indicator of microvascular remodeling.
Arterial stiffness estimation in healthy subjects: a validation of oscillometric (Arteriograph) and tonometric (SphygmoCor) techniques Open Margareta Ring1,2, Maria Jolanta Eriksson1,2, Juleen Rae Zierath3 and Kenneth Caidahl1,2 1Section of Clinical Physiology, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden 2Department of Clinical Physiology, Karolinska University Hospital, Karolinska University Hospital, Stockholm, Sweden 3Section of Integrative Physiology, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden Correspondence: M Ring, Department of Clinical Physiology, Karolinska Institutet, Karolinska University Hospital N2:01, Solna, 171 76 Stockholm, Sweden. E-mail: email@example.com Received 27 December 2013; Revised 29 May 2014; Accepted 6 June 2014 Advance online publication 24 July 2014 Topof page Abstract Arterial stiffness is an important cardiovascular risk marker, which can be measured noninvasively with different techniques. To validate such techniques in healthy subjects, we compared the recently introduced oscillometric Arteriograph (AG) technique with the tonometric SphygmoCor (SC) method and their associations with carotid ultrasound measures and traditional risk indicators. Sixty-three healthy subjects aged 20–69 (mean 48±15) years were included. We measured aortic pulse wave velocity (PWVao) and augmentation index (AIx) by AG and SC, and with SC also the PWVao standardized to 80% of the direct distance between carotid and femoral sites (St-PWVaoSC). The carotid strain, stiffness index and intima–media thickness (cIMTmean) were evaluated by ultrasound. PWVaoAG (8.00±2.16 m s−1) was higher (P<0.001) than PWVaoSC (6.87±1.47 m s−1), but did not differ from St-PWVaoSC (7.68±1.58 m s−1), and correlated (P<0.001) with both (r=0.54 and 0.59). St-PWVaoSC was significantly (P<0.01) higher than PWVaoAG for values below median (7.4 m s−1). PWVao by SC and AG differed significantly in females (P<0.001), but not in males (P=0.40). AIxaoAG (27.5±14.5%) was higher (P<0.001) than AIxaoSC (20.5±17.4%), but related closely (r=0.97, P<0.001). St-PWVaoSC, PWVao and AIxao by SC, and PWVao and AIxao by AG were all related to serum cholesterol and to cIMTmean (P<0.001). Arterial stiffness indices by AG and SC correlate with vascular risk markers in healthy subjects. AIxao results by AG and SC are closely interrelated, but higher values are obtained by AG. In the lower range, PWVao values by AG and SC are similar, but differ for higher values. Our results imply the necessity to apply one and the same technique for repeated studies.