Since the publication of the first edition of the Handbook in 2002, optical methods for biomedical diagnostics have developed in many well-established directions, and new trends have also appeared. To encompass all current methods, the text has been updated and expanded into two volumes.
Volume 2: Methods begins by describing the basic principles and diagnostic applications of optical techniques based on detecting and processing the scattering, fluorescence, FT IR, and Raman spectroscopic signals from various tissues, with an emphasis on blood, epithelial tissues, and human skin. The second half of the volume discusses specific imaging technologies, such as Doppler, laser speckle, optical coherence tomography (OCT), and fluorescence and photoacoustic imaging.
This Handbook is the second edition of the monograph initially published in 2002. The first edition described some aspects of laser/cell and laser/tissue interactions that are basic for biomedical diagnostics and presented many optical and laser diagnostic technologies prospective for clinical applications. The main reason for publishing such a book was the achievements of the last millennium in light scattering and coherent light effects in tissues, and in the design of novel laser and photonics techniques for the examination of the human body. Since 2002, biomedical optics and biophotonics have had rapid and extensive development, leading to technical advances that increase the utility and market growth of optical technologies. Recent developments in the field of biophotonics are wide-ranging and include novel light sources, delivery and detection techniques that can extend the imaging range and spectroscopic probe quality, and the combination of optical techniques with other imaging modalities.
The innovative character of photonics and biophotonics is underlined by two Nobel prizes in 2014 awarded to Eric Betzig, Stefan W. Hell, and William E. Moerner for the development of super-resolved fluorescence microscopy" and to Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura for the invention of efficient blue light-emitting diodes which has enabled bright and energy-saving white light sources." The authors of this Handbook have a strong input in the development of new solutions in biomedical optics and biophotonics and have conducted cutting-edge research and developments over the last 10 - 15 years, the results of which were used to modify and update early written chapters. Many new, world-recognized experts in the field have joined the team of authors who introduce fresh blood in the book and provide a new perspective on many aspects of optical biomedical diagnostics.
The optical medical diagnostic field covers many spectroscopic and laser technologies based on near-infrared (NIR) spectrophotometry, fluorescence and Raman spectroscopy, optical coherence tomography (OCT), confocal microscopy, optoacoustic (photoacoustic) tomography, photon-correlation spectroscopy and imaging, and Doppler and speckle monitoring of biological flows. These topics - as well as the main trends of the modern laser diagnostic techniques, their fundamentals and corresponding basic research on laser tissue interactions, and the most interesting clinical applications - are discussed in the framework of this Handbook. The main unique features of the book are as follows:
- Several chapters of basic research that discuss the updated results on light scattering, speckle formation, and other nondestructive interactions of laser light with tissue; they also provide a basis for the optical and laser medical diagnostic techniques presented in the other chapters.
- A detailed discussion of blood optics, blood and lymph flow, and blood-aggregation measurement techniques, such as the well-recognized laser Doppler method, speckle technique, and OCT method.
- A discussion of the most-recent prospective methods of laser (coherent) tomography and spectroscopy, including OCT, optoacoustic (photoacoustic) imaging, diffusive wave spectroscopy (DWS), and diffusion frequency-domain techniques.
The intended audience of this book consists of researchers, postgraduate and undergraduate students, biomedical engineers, and physicians who are interested in the design and applications of optical and laser methods and instruments for medical science and practice. Due to the large number of fundamental concepts and basic research on laser tissue interactions presented here, it should prove useful for a much broader audience that includes students and physicians, as well. Investigators who are deeply involved in the field will find up-to-date results for the topics discussed. Each chapter is written by representatives of the leading research groups who have presented their classic and most recent results. Physicians and biomedical engineers may be interested in the clinical applications of designed techniques and instruments, which are described in a few chapters. Indeed, laser and photonics engineers may also be interested in the book because their acquaintance with a new field of laser and photonics applications can stimulate new ideas for lasers and photonic devices design. The two volumes of this Handbook contain 21 chapters, divided into four parts (two per volume):
- Part I describes the fundamentals and basic research of the extinction of light in dispersive media; the structure and models of tissues, cells, and cell ensembles; blood optics; coherence phenomena and statistical properties of scattered light; and the propagation of optical pulses and photon-density waves in turbid media. Tissue phantoms as tools for tissue study and calibration of measurements are also discussed.
- Part II presents time-resolved (pulse and frequency-domain) imaging and spectroscopy methods and techniques applied to tissues, including optoacoustic (photoacoustic) methods. The absolute quantification of the main absorbers in tissue by a NIR spectroscopy method is discussed. An example biomedical application - the possibility of monitoring brain activity with NIR spectroscopy - is analyzed.
- Part III presents various spectroscopic techniques of tissues based on elastic and Raman light scattering, Fourier transform infrared (FTIR), and fluorescence spectroscopies. In particular, the principles and applications of backscattering diagnostics of red blood cell (RBC) aggregation in whole blood samples and epithelial tissues are discussed. Other topics include combined back reflectance and fluorescence, FTIR and Raman spectroscopies of the human skin in vivo, and fluorescence technologies for biomedical diagnostics.
- The final section, Part IV, begins with a chapter on laser Doppler microscopy, one of the representative coherent-domain methods applied to monitoring blood in motion. Methods and techniques of real-time imaging of tissue ultrastructure and blood flows using OCT is also discussed. The section also describes various speckle techniques for monitoring and imaging tissue, in particular, for studying tissue mechanics and blood and lymph flow.
Financial support from a FiDiPro grant of TEKES, Finland (40111/11) and Academic D.I. Mendeleev Fund Program of Tomsk National Research State University have helped me complete this book project. I greatly appreciate the cooperation and contribution of all of the authors and co-editors, who have done a great work on preparation of this book. I would like to express my gratitude to Eric Pepper and Tim Lamkins for their suggestion to prepare the second edition of the Handbook and to Scott McNeill for assistance in editing the manuscript. I am very thankful to all of my colleagues from the Chair and Research Education Institute of Optics and Biophotonics at Saratov National Research State University and the Institute of Precision Mechanics and Control of RAS for their collaboration, fruitful discussions, and valuable comments. I am very grateful to my wife and entire family for their exceptional patience and understanding.
Valery V. Tuchin