Lung Function Testing in the 21st Century

Methodologies and Tools Bridging Engineering to Clinical Practice

Clara Ionescu

• Publisher: Academic Press
• Year: 2018
• ISBN:
  9780128146132
• Topic: Biowissenschaften
• Subtopic: Biotechnologie

Lung Function Testing in the 21st Century: Methodologies and Tools Bridging Engineering to Clinical Practice covers the complete aspects of lung function testing, ranging from standardized to newly introduced (IOS, FOT) methods. It provides an updated overview of advances in respiratory engineering, along with advice on which lung function tests are appropriate for which purpose. The author discusses non-standardized lung function testing, methods, clinical tests, diagnosis and future perspectives. Lung function measurement devices and protocols are also covered. This book covers multidisciplinary domains, bringing new technology ideas from mathematics, physics, biology and engineering into the field of respiratory engineering.

Users will find a single resource that brings together all of the disparate information on lung function testing technology currently contained in many journal articles.

• Bridges the gap between engineers and clinicians with regard to pulmonary function techniques, from research, to design and clinical practice
• Provides a comprehensive overview of all tools available for lung function testing, detailing their pros and cons
• Includes information on incorporating new devices into existing procedures, along with methods for lung function testing

Chapter 1

Introduction

Clara M. Ionescu     Ghent University, Dynamical Systems and Control Research Group, Ghent, Belgium

Abstract

This introductory chapter explains the rationale motivating this book project and sets the stage for the reader to understand the importance of this work in the field. The content and timing have been carefully chosen to shape the current state of the art in a rather dark light, for it is necessary to observe its great potential improvement.

Keywords

Economical impact; Lung function set; Population trends; Respiratory disease; Societal impact

Contents

1. Generic Context
2. About This Book
3. Beyond This Book
4. References

Generic Context

At the confluence of medicine, biology, and engineering stands bioengineering. This increasingly important emerging field of practice and research has put forward numerous tools and knowledge over the past half century [1]. It is, however, the technological development of the last few decades that has helped surpass the informational barrier and expand its impact on society and man at large. Nevertheless, there is a large discrepancy between the traditional fields as medicine and technology-enabled fields, in terms of information processing and systems engineering in their broadest sense. Witness is the exponential amount of information and interaction flowing vertically and horizontally in all levels of action–reaction tasks of our daily life. Sadly, when it comes to medicine, this exponential growth is very limited. Medical intervention is still at its best an art rather than a science and based on a great deal of practice, personal expertise, and subjective perception. Time and money are perhaps inefficiently spent on searching, gathering, and processing data already available elsewhere or in prior circumstances.

The purpose of this book is to show the very large potential for development toward a systematic and unabridged know-how in respiratory medicine. Lung disease, being in the global top ten of leading causes of death and global top three of leading socioeconomic costs, is a burden with long shadows over health care in general [2]. Despite efforts, this burden is just as large as it was two decades ago, and projections for the next years to come are not encouraging, unless a different course of action is taken. Of all respiratory impairments, COPD (chronic obstructive pulmonary disease) and lung cancer are at the top of the pyramid in number of deaths and overall costs. The distribution of the costs, however, is unequally balanced, as in COPD there is a long timeline of treatment, disease management, and disability, whereas in lung cancer these are concentrated over a much smaller time span. One in five deaths worldwide are projected by the World Health Organization to be due to respiratory diseases.

Coming down to numbers, the European Union alone has costs of over 380 billion EUR annually from respiratory disease management. This includes disability, premature mortality, direct health service costs, drugs prescribed, as well as indirect costs related to lost production [3]. Disability-adjusted life years seem to be an important percent of total costs, i.e., about 100k EUR for a life-year lost owing to respiratory disease per person. Between asthma and COPD, the latter induces a twofold increase in total costs (direct and indirect). As the individual mortality from lung cancer may be indeed much higher, the course of COPD and asthma extends over many years. Although costs should not be the first incentive for progress and improved health care, they play an important role as a decision factor in the sociopolitical context. The greatest source of heterogeneity in any health care median is the variation in health care systems across EU countries and worldwide. This is for a significant deal dictated by culture, tradition, and economic and societal development.

Nevertheless, a great deal of items are potentially preventable or the decline in the disease progression may be minimized. For instance, smoking-induced COPD still contributes a staggering 60% of all causes of respiratory disease. According to the review performed in [4], the annual decline rate in the forced expiratory volume in the first second (FEV1) recorded in Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage I-IV indicates the highest descent in stage II-III. As the evidence indicates, it is clear that the loss of lung function assessed as expiratory airflow reduction is more accelerated and relevant at early stages of COPD. It follows that, if any attempt is made to positively interfere with the natural history of COPD by using different therapeutic options, this should be focused on patients as soon as in GOLD stage II.

The decision to change is, however, in the hands of the laboratory director [5]. He/she is responsible for the development of procedures as to interpret the lung function test results and select appropriate reference values. These may vary from one laboratory/institution to another, depending on geographical location and population characteristics. The question one naturally asks is: how often are these protocols and reference values revisited? Perhaps an equally important question is: are they still up-to-date to current know-how? And finally, from a future perspective point of view: are their possible improvements reported and recorded?

About This Book

The content of this book has been selected based on several features. To begin with, relevant information to lung function testing was included. Contributions on standardized and nonstandardized tests are included, discussing their protocol, information retrieved from the respiratory function, and their role within the diagnostic and follow-up management of respiratory disease. Spirometry and body plethysmography are well-established techniques, whereas oscillometry is somewhat limited in its practice, being a nonstandardized lung function test. Nevertheless, the information combined from all tests may bring useful items forward into a more complete context than that of separately evaluated tests.

A full chapter is dedicated on how to derive additional information from the measured lung function signals. This can be via stress–strain curves, work of breathing, and impedance models in an either rational or nonrational form. A special section discusses the importance of capturing heterogeneity, especially as the disease progresses, in the lung tissue and its effects on the measured signal values. Related to changes in lung structure and parenchymal tissue, is diffusion. Small airways are becoming important in respiratory diseases such as COPD, and means to evaluate diffusion are necessary to accurately describe the real situation at hand. A mathematical framework is provided for geometrical changes and porosity in the alveolar tissue and their relation to diffusion.

Next, the potential importance and added value of other clinical tests are emphasized. Computed tomography scans, sound-based methods, and electrical impedance tomography are summarized in a chapter. Their contribution to further specify the tissue structure and porosity and evaluate diffusion mechanism and lung function in general is crucial in the fine-tuning of long-term treatment and drug management.

There is a full chapter dedicated to the challenge of diagnosing asthma and COPD, with preference for COPD since most of the complementary information deals with small airways. Some suggestions as to how to pair various tests to obtain a broader image of the patient's respiratory function status are formulated here.

The main contributions of the book for the future directions of research, practice, and decision-making actors are summarized in the concluding chapter. The purpose is to set the starting point for broadening the current practice and make use of the vast amount of information at hand in an efficient and useful manner to the practitioner and caregiver.

Beyond This Book

This book is intended for medical and engineering practitioners, scientists, and researchers. The reason for the interwoven aspects, much like a caduceus, is the potential for improving current health care in respiratory medicine by pushing the right tools forward (tools often from engineering). The book is by no means exhaustive—it has been limited to several elements directly incidental to asthma and COPD, selected from all respiratory diseases. Their selection is based on the fact that most prevention and slowing down of the disease progress may be achieved by combining the various information pieces provided by the tools summarized in this book.

Ideally, this book will initiate a series of similar works, tailored for other respiratory diseases, in other medical sections. Moreover, the book is a good basis for researchers to motivate the funding agencies to invest in this new way of integrated medicine, where various aspects are interrelated to see their synergic effect.

References

[1] Magin R.L. Bioengineering and cybernetics - a modern caduceus. IEEE Pulse. January-February 2017(1):44–47. doi: 10.1109/MPUL.2016.2627461.

[2] Society ER, ed. European Lung - White Book, European Lung Foundation, Vol. The Burden of Lung Disease. 2016:2–15. https://www.erswhitebook.org/.

[3] Society ER, ed. European Lung - White Book, European Lung Foundation, Vol. The Economic Burden of Lung Disease. 2016:16–27. https://www.erswhitebook.org/.

[4] Tantucci C, Modina D. Lung function decline in COPD. Int. J. COPD. 2012;7:95–99. doi: 10.2147/COPD.S27480.

[5] Miller M, Crapo R, Hankinson J, Brusasco V, Burgos F, Casaburi R, et al. General considerations for lung function testing. Eur. Respir. J. 2005;26:153–161. doi: 10.1183/09031936.05.00034505.

Chapter 2

Standar...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• About the Contributors
• Preface
• Acknowledgment
• Chapter 1. Introduction
• Chapter 2. Standardized Pulmonary Function Testing
• Chapter 3. Oscillometry for Lung Function Testing
• Chapter 3.1. Nonstandardized Lung Function Tests
• Chapter 3.2. Oscillometry for Lung Function Testing
• Chapter 4. Information From Time-Based Signals
• Chapter 5. Diffusion
• Chapter 6. Added Value of Other Clinical Tests
• Chapter 7. Diagnosis of Asthma and Chronic Obstructive Pulmonary Disease
• Chapter 8. Perspectives
• Index