Echocardiography

The book "Echocardiography - New Techniques" brings worldwide contributions from highly acclaimed clinical and imaging science investigators, and representatives from academic medical centers. Each chapter is designed and written to be accessible to those with a basic knowledge of echocardiography. Additionally, the chapters are meant to be stimulating and educational to the experts and investigators in the field of echocardiography. This book is aimed primarily at cardiology fellows on their basic echocardiography rotation, fellows in general internal medicine, radiology and emergency medicine, and experts in the arena of echocardiography. Over the last few decades, the rate of technological advancements has developed dramatically, resulting in new techniques and improved echocardiographic imaging. The authors of this book focused on presenting the most advanced techniques useful in today's research and in daily clinical practice. These advanced techniques are utilized in the detection of different cardiac pathologies in patients, in contributing to their clinical decision, as well as follow-up and outcome predictions. In addition to the advanced techniques covered, this book expounds upon several special pathologies with respect to the functions of echocardiography

Doctor of Philosophy

dissertationCongenital heart defects are classes of birth defects that affect the structure and function of the heart. These defects are attributed to the abnormal or incomplete development of a fetal heart during the first few weeks following conception. The overall detection rate of congenital heart defects during routine prenatal examination is low. This is attributed to the insufficient number of trained personnel in many local health centers where many cases of congenital heart defects go undetected. This dissertation presents a system to identify congenital heart defects to improve pregnancy outcomes and increase their detection rates. The system was developed and its performance assessed in identifying the presence of ventricular defects (congenital heart defects that affect the size of the ventricles) using four-dimensional fetal chocardiographic images. The designed system consists of three components: 1) a fetal heart location estimation component, 2) a fetal heart chamber segmentation component, and 3) a detection component that detects congenital heart defects from the segmented chambers. The location estimation component is used to isolate a fetal heart in any four-dimensional fetal echocardiographic image. It uses a hybrid region of interest extraction method that is robust to speckle noise degradation inherent in all ultrasound images. The location estimation method's performance was analyzed on 130 four-dimensional fetal echocardiographic images by comparison with manually identified fetal heart region of interest. The location estimation method showed good agreement with the manually identified standard using four quantitative indexes: Jaccard index, Sørenson-Dice index, Sensitivity index and Specificity index. The average values of these indexes were measured at 80.70%, 89.19%, 91.04%, and 99.17%, respectively. The fetal heart chamber segmentation component uses velocity vector field estimates computed on frames contained in a four-dimensional image to identify the fetal heart chambers. The velocity vector fields are computed using a histogram-based optical flow technique which is formulated on local image characteristics to reduces the effect of speckle noise and nonuniform echogenicity on the velocity vector field estimates. Features based on the velocity vector field estimates, voxel brightness/intensity values, and voxel Cartesian coordinate positions were extracted and used with kernel k-means algorithm to identify the individual chambers. The segmentation method's performance was evaluated on 130 images from 31 patients by comparing the segmentation results with manually identified fetal heart chambers. Evaluation was based on the Sørenson-Dice index, the absolute volume difference and the Hausdorff distance, with each resulting in per patient average values of 69.92%, 22.08%, and 2.82 mm, respectively. The detection component uses the volumes of the identified fetal heart chambers to flag the possible occurrence of hypoplastic left heart syndrome, a type of congenital heart defect. An empirical volume threshold defined on the relative ratio of adjacent fetal heart chamber volumes obtained manually is used in the detection process. The performance of the detection procedure was assessed by comparison with a set of images with confirmed diagnosis of hypoplastic left heart syndrome and a control group of normal fetal hearts. Of the 130 images considered 18 of 20 (90%) fetal hearts were correctly detected as having hypoplastic left heart syndrome and 84 of 110 (76.36%) fetal hearts were correctly detected as normal in the control group. The results show that the detection system performs better than the overall detection rate for congenital heart defect which is reported to be between 30% and 60%

Recent Advances in Machine Learning Applied to Ultrasound Imaging

Machine learning (ML) methods are pervading an increasing number of fields of application because of their capacity to effectively solve a wide variety of challenging problems. The employment of ML techniques in ultrasound imaging applications started several years ago but the scientific interest in this issue has increased exponentially in the last few years. The present work reviews the most recent (2019 onwards) implementations of machine learning techniques for two of the most popular ultrasound imaging fields, medical diagnostics and non-destructive evaluation. The former, which covers the major part of the review, was analyzed by classifying studies according to the human organ investigated and the methodology (e.g., detection, segmentation, and/or classification) adopted, while for the latter, some solutions to the detection/classification of material defects or particular patterns are reported. Finally, the main merits of machine learning that emerged from the study analysis are summarized and discussed. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Development of a Novel Dataset and Tools for Non-Invasive Fetal Electrocardiography Research

This PhD thesis presents the development of a novel open multi-modal dataset for advanced studies on fetal cardiological assessment, along with a set of signal processing tools for its exploitation. The Non-Invasive Fetal Electrocardiography (ECG) Analysis (NInFEA) dataset features multi-channel electrophysiological recordings characterized by high sampling frequency and digital resolution, maternal respiration signal, synchronized fetal trans-abdominal pulsed-wave Doppler (PWD) recordings and clinical annotations provided by expert clinicians at the time of the signal collection. To the best of our knowledge, there are no similar dataset available. The signal processing tools targeted both the PWD and the non-invasive fetal ECG, exploiting the recorded dataset. About the former, the study focuses on the processing aimed at the preparation of the signal for the automatic measurement of relevant morphological features, already adopted in the clinical practice for cardiac assessment. To this aim, a relevant step is the automatic identification of the complete and measurable cardiac cycles in the PWD videos: a rigorous methodology was deployed for the analysis of the different processing steps involved in the automatic delineation of the PWD envelope, then implementing different approaches for the supervised classification of the cardiac cycles, discriminating between complete and measurable vs. malformed or incomplete ones. Finally, preliminary measurement algorithms were also developed in order to extract clinically relevant parameters from the PWD. About the fetal ECG, this thesis concentrated on the systematic analysis of the adaptive filters performance for non-invasive fetal ECG extraction processing, identified as the reference tool throughout the thesis. Then, two studies are reported: one on the wavelet-based denoising of the extracted fetal ECG and another one on the fetal ECG quality assessment from the analysis of the raw abdominal recordings. Overall, the thesis represents an important milestone in the field, by promoting the open-data approach and introducing automated analysis tools that could be easily integrated in future medical devices

Brain Tumour Classification Using Deep Features from Structural MRI

C

STATE OF THE ART INVESTIGATION IN MEDICAL ULTRASOUND DIAGNOSTICS USING PATENT PUBLICATIONS DATABASE

Patents are now an integral part of global economy. The creation of the world trade system has also redefined the value of intellectual property protection and generated an unprecedented demand for patent protection that is no longer limited to the traditionally patent-oriented economies of Europe, Japan and the USA. Countries like China, India and Korea, and Singapore and Israel too, are just some of the new players heavily involved in patent-driven innovative competition. Patents protect technical inventions. An invention can, for example, be a product, process or apparatus. Inventions are only patentable if they are novel, industrially applicable and involve an inventive step, but even then patent protection is not granted automatically. The application must be accompanied by a full technical description of the invention, which the Office then examines for compliance with the European Patent Convention. Patents give their owners the right to prevent others from using their invention, and are thus of major economic importance. They also help to recoup research costs, allowing the inventor to reinvest in research and development. The publication requirement allows competitors to build on patented inventions and come up with even better technical solutions. In doing so, patents boost the innovation which Europe badly needs to keep up with other economies, and contribute to the further development of a knowledge society. The 56 million or so patent documents contained in the public EPO database constitute a vast trove of technical information. The field of medical device, according to European Patent Office Annual Report of 2005, is one of the technical fields with the most filings. This state of the art investigation, performed using the patent publications database, is focused on the field of diagnostic ultrasound, a field that thanks to its non ionizing nature and low cost is a very high growing area and a lot of scientific research is made. Scope of this work is to provide an useful tool that allows to check the level of the ultrasound technology and to indicate the future direction of this technique. Scope of this work is also to provide information to all the researchers and inventors who want to set out a patent procedure of an invention. As known, the patent procedure, from the filing day until the decision of granting the patent is quite expensive, this work could be used as a primary consultation tool before to present a patent application. All chapters of this work contains an introduction that explain the technical problematic of a field and in the subsequent sections the solutions are described. In the first chapter of this work the European Patent Office and the world of patents is introduced. A special attention is revolted to several articles of the EPC (European Patent Convention) and to the classification system adopted by the EPO. Some statistics about European patent application filed in 2005 are illustrated and the difference between the first to invent system adopted by EPO (and by the majority of countries) and the first to invent system (adopted by U.S.A.) will be treated at the end of this chapter. In the second chapter the basics of ultrasound are illustrated with particular attention to the physics principles that are at the base of ultrasound devices described in this state of the art investigation. The state of the art is divided in 5 chapters, from 3 to 7, each chapter is about a specific technique. In the third chapter the ultrasound contrast agents are introduced and their main diagnostic application are disclosed. The fourth chapter is about three dimensional imaging, this field is divided in 4 section: mechanical, free-hand, 2D arrays and catheters. In the fifth chapter the technique of elastography and its application is described focusing on the stimulation protocols and methods. The sixth chapter is directed to all the devices that allow to study the blood flow inside vessels and arteries and the seventh chapter treats about the ultrasound catheters and their characteristics. At the end of each chapter statistics about the trends in European patent application in the last 25 years will be illustrated. In the conclusion of this work the future developments field of ultrasound technique will be illustrated

Infrasonic Stethoscope for Monitoring Physiological Processes

An infrasonic stethoscope for monitoring physiological processes of a patient includes a microphone capable of detecting acoustic signals in the audible frequency bandwidth and in the infrasonic bandwidth (0.03 to 1000 Hertz), a body coupler attached to the body at a first opening in the microphone, a flexible tube attached to the body at a second opening in the microphone, and an earpiece attached to the flexible tube. The body coupler is capable of engagement with a patient to transmit sounds from the person, to the microphone and then to the earpiece