The Biomedical Engineering Handbook Third Edition Medical Devices and Systems Bronz: “2122_c000” — 2006/2/24 — 11:31 — page ii — #2 The Electrical Engineering Handbook Series Series Editor Richard C. Dorf University of California, Davis Titles Included in the Series The Handbook of Ad Hoc Wireless Networks, Mohammad Ilyas The Avionics Handbook, Cary R. Spitzer The Biomedical Engineering Handbook, Third Edition, Joseph D. Bronzino The Circuits and Filters Handbook, Second Edition, Wai-Kai Chen The Communications Handbook, Second Edition, Jerry Gibson The Computer Engineering Handbook, Vojin G. Oklobdzija The Control Handbook, William S. Levine The CRC Handbook of Engineering Tables, Richard C. Dorf The Digital Signal Processing Handbook, Vijay K. Madisetti and Douglas Williams The Electrical Engineering Handbook, Third Edition, Richard C. Dorf The Electric Power Engineering Handbook, Leo L. Grigsby The Electronics Handbook, Second Edition, Jerry C. Whitaker The Engineering Handbook, Third Edition, Richard C. Dorf The Handbook of Formulas and Tables for Signal Processing, Alexander D. Poularikas The Handbook of Nanoscience, Engineering, and Technology, William A. Goddard, III, Donald W. Brenner, Sergey E. Lyshevski, and Gerald J. Iafrate The Handbook of Optical Communication Networks, Mohammad Ilyas and Hussein T. Mouftah The Industrial Electronics Handbook, J. David Irwin The Measurement, Instrumentation, and Sensors Handbook, John G. Webster The Mechanical Systems Design Handbook, Osita D.I. Nwokah and Yidirim Hurmuzlu The Mechatronics Handbook, Robert H. Bishop The Mobile Communications Handbook, Second Edition, Jerry D. Gibson The Ocean Engineering Handbook, Ferial El-Hawary The RF and Microwave Handbook, Mike Golio The Technology Management Handbook, Richard C. Dorf The Transforms and Applications Handbook, Second Edition, Alexander D. Poularikas The VLSI Handbook, Wai-Kai Chen The Biomedical Engineering Handbook Third Edition Edited by Joseph D. Bronzino Biomedical Engineering Fundamentals Medical Devices and Systems Tissue Engineering and Artificial Organs The Biomedical Engineering Handbook Third Edition Medical Devices and Systems Edited by Joseph D. Bronzino Trinity College Hartford, Connecticut, U.S.A. Boca Raton London New York A CRC title, part of the Taylor & Francis imprint, a member of the Taylor & Francis Group, the academic division of T&F Informa plc. 2122_Discl.fm Page 1 Wednesday, December 14, 2005 4:52 PM Published in 2006 by CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2006 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group No claim to original U.S. Government works Printed in the United States of America on acid-free paper 10 9 8 7 6 5 4 3 2 1 International Standard Book Number-10: 0-8493-2122-0 (Hardcover) International Standard Book Number-13: 978-0-8493-2122-1 (Hardcover) Library of Congress Card Number 2005056892 This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. A wide variety of references are listed. Reasonable efforts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use. No part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers. For permission to photocopy or use material electronically from this work, please access www.copyright.com (http://www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC) 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organization that provides licenses and registration for a variety of users. For organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe. Library of Congress Cataloging-in-Publication Data Medical devices and systems / edited by Joseph D. Bronzino. p. cm. -- (The electrical engineering handbook series) Includes bibliographical references and index. ISBN 0-8493-2122-0 1. Medical instruments and apparatus--Handbooks, manuals, etc. I. Bronzino, Joseph D., 1937- II. Title. III. Series. R856.15.B76 2006 610.28--dc22 2005056892 Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com Taylor & Francis Group and the CRC Press Web site at is the Academic Division of Informa plc. http://www.crcpress.com Introduction and Preface During the past five years since the publication of the Second Edition — a two-volume set — of the BiomedicalEngineeringHandbook,thefieldofbiomedicalengineeringhascontinuedtoevolveandexpand. Asaresult, thisThirdEditionconsistsof athreevolumeset, whichhasbeensignificantlymodifiedto reflectthestate-of-the-fieldknowledgeandapplicationsinthisimportantdiscipline. Morespecifically, thisThirdEditioncontainsanumberofcompletelynewsections,including: • MolecularBiology • Bionanotechnology • Bioinformatics • Neuroengineering • InfraredImaging aswellasanewsectiononethics. Inaddition,allofthesectionsthathaveappearedinthefirstandsecondeditionshavebeensignificantly revised. Therefore, this Third Edition presents an excellent summary of the status of knowledge and activitiesofbiomedicalengineersinthebeginningofthe21stcentury. Assuch,itcanserveasanexcellentreferenceforindividualsinterestednotonlyinareviewoffunda- mentalphysiology,butalsoinquicklybeingbroughtuptospeedincertainareasofbiomedicalengineering research.Itcanserveasanexcellenttextbookforstudentsinareaswheretraditionaltextbookshavenot yetbeendevelopedandasanexcellentreviewofthemajorareasofactivityineachbiomedicalengineering subdiscipline,suchasbiomechanics,biomaterials,bioinstrumentation,medicalimaging,etc. Finally,it canserveasthe“bible”forpracticingbiomedicalengineeringprofessionalsbycoveringsuchtopicsasahis- toricalperspectiveof medicaltechnology,theroleof professionalsocieties,theethicalissuesassociated withmedicaltechnology,andtheFDAprocess. Biomedical engineering is now an important vital interdisciplinary field. Biomedical engineers are involvedinvirtuallyallaspectsofdevelopingnewmedicaltechnology.Theyareinvolvedinthedesign, development,andutilizationofmaterials,devices(suchaspacemakers,lithotripsy,etc.)andtechniques (suchassignalprocessing,artificialintelligence,etc.)forclinicalresearchanduse;andserveasmembers of the health care delivery team (clinical engineering, medical informatics, rehabilitation engineering, etc.)seekingnewsolutionsfordifficulthealthcareproblemsconfrontingoursociety.Tomeettheneeds ofthisdiversebodyofbiomedicalengineers,thishandbookprovidesacentralcoreofknowledgeinthose fieldsencompassedbythediscipline.However,beforepresentingthisdetailedinformation,itisimportant toprovideasenseof theevolutionof themodernhealthcaresystemandidentifythediverseactivities biomedicalengineersperformtoassistinthediagnosisandtreatmentofpatients. Evolution of the Modern Health Care System Before 1900, medicine had little to offer the average citizen, since its resources consisted mainly of the physician, his education, and his “little black bag.” In general, physicians seemed to be in short Bronz: “2122_c000” — 2006/2/24 — 11:31 — page v — #5 supply, but the shortage had rather different causes than the current crisis in the availability of health careprofessionals.Althoughthecostsofobtainingmedicaltrainingwererelativelylow,thedemandfor doctors’servicesalsowasverysmall,sincemanyoftheservicesprovidedbythephysicianalsocouldbe obtainedfromexperiencedamateursinthecommunity. Thehomewastypicallythesitefortreatment andrecuperation,andrelativesandneighborsconstitutedanableandwillingnursingstaff.Babieswere delivered by midwives, and those illnesses not cured by home remedies were left to run their natural, albeitfrequentlyfatal,course.Thecontrastwithcontemporaryhealthcarepractices,inwhichspecialized physicians and nurses located within the hospital provide critical diagnostic and treatment services, is dramatic. Thechangesthathaveoccurredwithinmedicalscienceoriginatedintherapiddevelopmentsthattook placeintheappliedsciences(chemistry,physics,engineering,microbiology,physiology,pharmacology, etc.) at the turn of the century. This process of development was characterized by intense interdis- ciplinary cross-fertilization, which provided an environment in which medical research was able to take giant strides in developing techniques for the diagnosis and treatment of disease. For example, in 1903, Willem Einthoven, a Dutch physiologist, devised the first electrocardiograph to measure the electrical activity of the heart. In applying discoveries in the physical sciences to the analysis of the biologic process, he initiated a new age in both cardiovascular medicine and electrical measurement techniques. Newdiscoveriesinmedicalsciencesfollowedoneanotherlikeintermediatesinachainreaction.How- ever, the most significant innovation for clinical medicine was the development of x-rays. These“new kinds of rays,” as their discoverer W.K. Roentgen described them in 1895, opened the“inner man”to medicalinspection.Initially,x-rayswereusedtodiagnosebonefracturesanddislocations,andinthepro- cess,x-raymachinesbecamecommonplaceinmosturbanhospitals.Separatedepartmentsofradiology wereestablished,andtheirinfluencespreadtootherdepartmentsthroughoutthehospital.Bythe1930s, x-rayvisualizationofpracticallyallorgansystemsofthebodyhadbeenmadepossiblethroughtheuseof bariumsaltsandawidevarietyofradiopaquematerials. X-raytechnologygavephysiciansapowerfultoolthat,forthefirsttime,permittedaccuratediagnosis of a wide variety of diseases and injuries. Moreover, since x-ray machines were too cumbersome and expensive for local doctors and clinics, they had to be placed in health care centers or hospitals. Once there,x-raytechnologyessentiallytriggeredthetransformationofthehospitalfromapassivereceptacle forthesicktoanactivecurativeinstitutionforallmembersofsociety. Foreconomicreasons,thecentralizationofhealthcareservicesbecameessentialbecauseofmanyother importanttechnologicalinnovationsappearingonthemedicalscene.However,hospitalsremainedinsti- tutionstodread,anditwasnotuntiltheintroductionofsulfanilamideinthemid-1930sandpenicillinin theearly1940sthatthemaindangerofhospitalization,thatis,cross-infectionamongpatients,wassigni- ficantlyreduced.Withthesenewdrugsintheirarsenals,surgeonswereabletoperformtheiroperations withoutprohibitivemorbidityandmortalityduetoinfection. Furthermore, eventhoughthedifferent bloodgroupsandtheirincompatibilitywerediscoveredin1900andsodiumcitratewasusedin1913to prevent clotting, full development of blood banks was not practical until the 1930s, when technology providedadequaterefrigeration.Untilthattime,“fresh”donorswerebledandthebloodtransfusedwhile itwasstillwarm. Once these surgical suites were established, the employment of specifically designed pieces of med- ical technology assisted in further advancing the development of complex surgical procedures. For example, the Drinker respirator was introduced in 1927 and the first heart-lung bypass in 1939. By the1940s,medicalproceduresheavilydependentonmedicaltechnology,suchascardiaccatheterization andangiography(theuseofacannulathreadedthroughanarmveinandintotheheartwiththeinjection of radiopaque dye) for the x-ray visualization of congenital and acquired heart disease (mainly valve disordersduetorheumaticfever)becamepossible, andaneweraof cardiacandvascularsurgerywas established. FollowingWorldWarII,technologicaladvanceswerespurredonbyeffortstodevelopsuperiorweapon systems and establish habitats in space and on the ocean floor. As a by-product of these efforts, the Bronz: “2122_c000” — 2006/2/24 — 11:31 — page vi — #6 developmentofmedicaldevicesacceleratedandthemedicalprofessionbenefitedgreatlyfromthisrapid surgeoftechnologicalfinds.Considerthefollowingexamples: 1. Advancesinsolid-stateelectronicsmadeitpossibletomapthesubtlebehaviorofthefundamental unitofthecentralnervoussystem—theneuron—aswellastomonitorthevariousphysiological parameters,suchastheelectrocardiogram,ofpatientsinintensivecareunits. 2. Newprostheticdevicesbecameagoalofengineersinvolvedinprovidingthedisabledwithtoolsto improvetheirqualityoflife. 3. Nuclear medicine — an outgrowth of the atomic age — emerged as a powerful and effective approachindetectingandtreatingspecificphysiologicabnormalities. 4. Diagnosticultrasoundbasedonsonartechnologybecamesowidelyacceptedthatultrasonicstudies arenowpartoftheroutinediagnosticworkupinmanymedicalspecialties. 5. “Spare parts” surgery also became commonplace. Technologists were encouraged to provide cardiac assist devices, such as artificial heart valves and artificial blood vessels, and the artifi- cial heart program was launched to develop a replacement for a defective or diseased human heart. 6. Advancesinmaterialshavemadethedevelopmentofdisposablemedicaldevices,suchasneedles andthermometers,aswellasimplantabledrugdeliverysystems,areality. 7. ComputerssimilartothosedevelopedtocontroltheflightplansoftheApollocapsulewereused tostore,process,andcross-checkmedicalrecords,tomonitorpatientstatusinintensivecareunits, andtoprovidesophisticatedstatisticaldiagnosesofpotentialdiseasescorrelatedwithspecificsets ofpatientsymptoms. 8. Developmentofthefirstcomputer-basedmedicalinstrument,thecomputerizedaxialtomography scanner,revolutionizedclinicalapproachestononinvasivediagnosticimagingprocedures,which nowincludemagneticresonanceimagingandpositronemissiontomographyaswell. 9. A wide variety of new cardiovascular technologies including implantable defibrillators and chemicallytreatedstentsweredeveloped. 10. Neuronalpacingsystemswereusedtodetectandpreventepilepticseizures. 11. Artificialorgansandtissuehavebeencreated. 12. Thecompletionofthegenomeprojecthasstimulatedthesearchfornewbiologicalmarkersand personalizedmedicine. The impact of these discoveries and many others has been profound. The health care system of today consistsof technologicallysophisticatedclinicalstaff operatingprimarilyinmodernhospitalsdesigned toaccommodatethenewmedicaltechnology.Thisevolutionaryprocesscontinues,withadvancesinthe physicalsciencessuchasmaterialsandnanotechnology,andinthelifesciencessuchasmolecularbiology, thegenomeprojectandartificialorgans.Theseadvanceshavealteredandwillcontinuetoalterthevery natureofthehealthcaredeliverysystemitself. Biomedical Engineering: A Definition Bioengineeringisusuallydefinedasabasicresearch-orientedactivitycloselyrelatedtobiotechnologyand geneticengineering,thatis,themodificationofanimalorplantcells,orpartsofcells,toimproveplants oranimalsortodevelopnewmicroorganismsforbeneficialends.Inthefoodindustry,forexample,this has meant the improvement of strains of yeast for fermentation. In agriculture, bioengineers may be concernedwiththeimprovementof cropyieldsbytreatmentof plantswithorganismstoreducefrost damage. It is clear that bioengineers of the future will have a tremendous impact on the qualities of human life. The potential of this specialty is difficult to imagine. Consider the following activities of bioengineers: • Developmentofimprovedspeciesofplantsandanimalsforfoodproduction • Inventionofnewmedicaldiagnostictestsfordiseases Bronz: “2122_c000” — 2006/2/24 — 11:31 — page vii — #7