f View

Bioengineering: Looking Into The 21 st Century Max E. Valentinuzzi

Editor’s Note: This article is based on the plenary presentation offered by the author on the occasion of the XVI Annual Con- gress of the Spanish Society of Biomedical Engineering, Valen- cia, Spain, Sept. 21-23, 1998.

he year 2000 is almost here. With the nearing of the T millenium, a good, or at least entertaining, exercise is to try to visualize what subjects or areas will be the concern of bioengi- neering in the coming century.

Back in 1898, Nikola Tesla envisioned a fully communicated world [ l , 21, and he did work toward this objective, making out- standing contributions. Today, that dream has come true, and we all enjoy the efficiency and pleasure of being in touch almost continuously with relatives, friends, colleagues, and busi- ness-partners, no matter how distant they may be. It is the fulfill- ment of the human communication need, which is as strong perhaps as the other biological basic drives (nourishment, sleep, reproduction). Telecommunications will continue to grow, in perfection and in breadth, thrusting into every daily activity.

Computers were born but 50 years ago and have spread out widely within the last quarter of this century. They are an essen- tial tool and also part of the communication network. The Internet would not exist without them. Hence, they will continue to proliferate, in all directions, always deeper and deeper [3].

Everything directly or indirectly related to human health is at- tractive to the human mind, and bioengineering, with its broad scope, is easily perceived as the third discipline heading straight into a brilliant future, closely supported and interwoven with communications and computers. Almost 30 years ago these three disciplines were already seen as activities fully open to research, development, and applications of all sorts [4]. Now, entering on the threshold of the Third Millenium, that vision is a certainty. Amazing fruits will begin to pop out and crop up. Interestingly enough, however, the words “bioengineering” and “biomedical engineering” were not known in the late 1950s. There had been only a small professional “Group on Medical Electronics” within the then IRE (Institute of Radio Engineers, a forerunner of our present IEEE) and a just-started International Federation for Medical and Biological Engineering, in 1958 [5]. Thus, what we call bioengineering or biomedical engineering is, at most, just or barely 40 years old, and its future goes hand in hand with tele- communications and computers.

Health: Environmental, Vegetal, Animal, and Human People usually speak in terms only of human health, perhaps forget- ting or not recognizing that without environmental, vegetal, and ani- mal health, the former is simply not viable. The three latter areas comprise what is called “ecology.” Influences oiecology on human health are strong, sometimes imperceptible, but are long lasting and far reaching; eventually, the effects may be even irreversible, as al- ready documented by several sad world expenences.

Consider a common wild bird that every morning comes to the table and takes a few bread crumbs almost from the hand, al- though it never dares actually touchiiig Somehow, this nice little animal has changed its behavior and acts more confident and friendly with a human being Also consider a “singing frog” with its singing bag at maximuin capacity Air moves back and forth between the lungs and the bag, producing the sweet froggy sound when passing through the opening connecting those two cham- bers-a true living musical instrument, indeed Maybe it is call- ing a would-be mating female, or perhaps it isexpressing happiness for a long-needed, moist rain Obviously, a typical 1 frog behavior

Why do these little animals act the way they do7 How do they modify their usual imprinted behavioral patterns? How does the ecosystem influence them? Traditionally, it is (or it was) the dis- cipline of biology that answered these kind of questions But bio- engineering may also help, with good results too, by loolung at these questions from a different angle or reference frame as well as by perhaps making use of other tools, either instrumental, computational, or mathematical

In spite of the tremendous interdisciplinary aspects of bioengi- neering, most of the educational programs all over the world are built on the basis of a more or less strong relationship between engineering andmedical schools, or, in other words, on activities mainly centered around human health Apparently, the other three “types of health” do not count or are left aside. Nonetheless, a wider view calls for a closer and deeper interrelationship be- tween basic biology and the engineering sciences; that is, many basic problems require a true bioengineering appioach

There are already clear indications in that direction. The Na- tional Institutes of Health (NIH), for example, since 1993 has in- creased its budget allotted to bioengineering research projects by 37%, reaching a total of $417 million in 1996 This engineering discipline has the highest growth rate as compared to other, more traditional engineering specialties The study of complex biolog- ical processes by means of engineering techniques and proce- dures will only grow [6]

Possible Subject Areas The mechanisms of learning and memory fixation at the cellular level and in lower animals are receiving increased attention hom research groups, which is perhaps redefining those concepts that, in their common language usage, have a highly complex struc- ture and meaning Dr Arnold Eskm and collaborators at the Uni- versity of Houston, Texas, are currently workmg with a giant sea snail, Aplysia, by studying responses when the aninial is stimu- lated and proceedmg down to its genetic expressions and possi- ble changes

Genes may be a culprit in cardiovascular disease Mutations of the gene NKX2-5 lead, in all probability, to atrial septal defect (an abnormal foramen) [7,8]. This gene seems to be also respon- sible for the long QT syndrome, which is a prolongation of this

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1. In order to define the meter, Pierre MCchain and Jean Baptiste Delambre developed instruments to measure the meridian between Barcelona and Dunkirk, passing through Paris (from [12]).

electrocardiographic segment that, in turn, influences the possi- ble triggering of such arrhythmias as ventricular tachycardia and lethal fibrillation. Another electrical manifestation due to this mutation is a PR interval longer than normal, even with the ap- pearance of occasional atrio-ventricular blocks. Why does all this happen?

On top of the former etiological possibilities for cardiovascular pathologies, other investigators have traced the cause of atheromas to infectious bacteria, such as Chlumydiupneumoniue [9]. These microscopic organisms initiate an inflammatory pro- cess on the inner arterial wall which, with time, favor the deposi- tion of cells, leading to build up of plaque.

Molecular and cellular biology thus are very specific areas to explore, including knowledge about their mechanical and elec- trical properties that, somehow, may contribute to tissue growth and regenerative stimulation. These factors are extremely impor- tant for cellular and tissue grafts as well as organ transplants and implants and lead directly to the concept of artificial tissues and biomaterials, in general. There is certainly ample room for the basic-science-oriented bioengineer working at the side of biolo- gists and biochemists.

In biomechanics, the universal picture is no less attractive, challenging, and wide. Starting with tissue engineering to bone structure, from the dynamics of muscular activity in sports to re- habilitation engineering and medicine, this field proceeds to arti- ficial limbs, myoelectric prosthesis, orthesis of different kinds, and studies in specific biomechanical activities (uterus, bladder, gall bladder, gastrointestinal tract, respiratory, and other physio- logical systems or subsystems). Microsensors of all types will play an essential role, as already hinted at by implants that permit the follow up of knee surgery [lo, 111.

People do not like to experience pain. Who does! Remember that simple and almost nalve question most of us have asked, ei- ther overtly or covertly, at least once in our lives when, as pa- tients, we faced an imminent medical act: “Does it hurt?” Noninvasive techniques (which include medical imaging), which are sometimes more expensive, more complex, or even more erroneous, are so appealing because they have a straight and firm answer from the medical side: “No Sir or Madam, just relax because it won’t hurt a bit.” And for these noninvasive tech-

niques, mathematical models, algorithms, and computers are no doubt the stars to call for-all the better if the model also has pre- diction capability.

Final Remarks As with any more traditional engineering specialty, be it civil or industrial, mechanical, naval or aeronautical, electronics or com- puting, bioengineering has three well-differentiated fields of ac- tivity: the industry (where most of the graduates usually go), sales (taking only a very small percentage), and teaching, re- search, and development (which may absorb perhaps 10- or 1.5 % of the population). Bioengineering (want to call it biomedical en- gineering?), however, has in front of it a unique avenue leading to a multifaceted field of action, the health-care system, barely touched or essentially untouched in most countries of the world. Many bioengineering graduates, from the technician and bache- lor levels up to the master and doctorate graduate degrees, will enter this system and thus become clinical engineers. Just count how many countries have not yet appreciated this concept in their respective medical systems. Count how many hospitals of differ- ent sizes there are and how many countries are barely beginning to recognize bioengineering, biomedical engineering, and clini- cal engineering, and you can estimate the number of bioengineers needed in the next century. For sure, there are not enough schools in the world to satisfy that demand. Fortunately, for the time being it is only a potential demand.

The relatively small number of biomedical engineers devoted to R&D activities can be part of the team by contributing recording techniques, mathematical and computer models, and perhaps even forecasting possible behaviors. However, there is a far-reaching contribution: to integrate new concepts in the biomedical sci- ences-concepts brought about from other reference frames; for example, the concepts of electrical impedance, hydraulic imped- ance, pressure-volume diagrams, or properties arising from sig- nal-processing algorithms. They enrich, no doubt, the biological disciplines and offer, at the same time, a tremendous armamentar- ium that leads to a wealth of new information.

About 200 hundreds years ago, exactly between June 1792 and June 1799, two scientists (both astronomers and geographers), Pierre MCchain and Jean Baptiste Delambre, were commis- sioned by the French Assembly, in the midst of the French Revo- lution, to obtain a universal measure: the meter, “pour tous le temps, pour tous les ...” They developed instruments (the the- odolite, to measure angles) and methods (triangulation) to mea- sure the meridian between Barcelona and Dunkirk, passing through Paris [12]. The meter was defined as 2.5 x lOexp(-9)xL, where L is the length of that full 360 degree meridian (Fig. 1). This was the basis and the beginning of the actual metric system, and with it the road for easier and more precise quantification in science, technology, business, and daily life was opened.

One of the objectives of bioengineering, perhaps its only great objective, is to help in the quantification process of the biological and medical sciences as a way to better understand and eventu- ally predict their highly complex phenomena, both normal and pathological. Let us invoke those suffering pioneers from the past as a source of inspiration for the task. The 21st Century will not see idle bioengineers, indeed!

References 1. Cheney, Margaret: Tesla: Man ouc ofTime. New York Barnes &Noble, 1993. 2. Seifer, MJ: Wizard: The Life and Times of Nikola Tesla. Biography of a Genius. Secaucus, NJ: Birch Lane Press, Carol Publ. Group, 1996.

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Januaryhebruory 1999 IEEE ENGINEERING IN MEDICINE AND BIOLOGY 17

biodegradable polymer containing the anticancer drug carmustine. After the brain tumor is surgically removed, the space formerly occupied by the tumor is lined with polymer wa- fers containing the drug. As the polymer degrades over time, the anticancer drug is released directly to the brain in concentra- tions that cannot be achieved by administering the drug via the blood stream. As a result, the reoccurrence of the disease is di- minished and chemotherapy side effects are reduced because the drug is delivered only where it is needed. Drug delivery

products for vaccine delivery, anemia, and cancer treatment are expected to be available shortly. Other drug delivery research is 1 currently focused on developing targeted polymer delivery sys- tems (such as biodegradable microparticles to the lungs) and developing polymer delivery vehicles for gene therapy.

Michael V. Pishko, PhD., is an Assistant Professor in the Depart- ment of Chemical Engineering at Texas A&M University. E-mail: pishko@tamu.edu.

Point of View (continued from page 17)

3. ~ a ~ ~ ~ e l ~ , E: John von Neumann, John Mauchly, and the invention of the modern computer: A story of genius and controversy. Currents Contents, No. 9, March 4, 1991. 4. Valentinuzzi, ME: Telecomunicaciones, Computadoras y Bioingenierfa. Electvdnica y F~ituro, 1(3): 5-7, Marzo-Abril, 1970. 5. Saito M, Hopps J (editors): A History of the IFMBE. Amsterdam: IFMBE, 1997. 6. NHI Plans Bioengineering Initiative, Science, 281: 1516-1518. June 5 , 1998.

10 McKee EL, Lindsey DP, Hull ML, Howell SM: Telemetry system for monitoring anterior cruciate ligament graft forces in vivo, M&BE&C, 36

11 Lindsey DP, McKee EL, Hull ML, Howell SM: A new technique for transmmion of signals from implantable transducers IEEE Trans BME, 45

12 Guedj D: La Mesure du Monde La Me'rzdzenne, Paris Robert Laffont S A , 1997

330-336, 1998

614-619, 1998

7. Barinaga, M: Tracking down mutations that can stop the heart. Science, 281: 32-4. July 3, 1998. 8. Schott, JJ et al.: Congenital heart disease caused by mutations in the tran- scription factor "2-5. Science, 281: 108-111, July 3, 1998. 9. Gura, T: Infections: A cause of artery-clogging plaques?. Science, vol.

M~~ E, Valentinuzzi is with the Institute de ~ i ~ i ~ ~ ~ ~ i ~ ~ i ~ , ~

Facultad de Ciencias Exactas y Tecnologia, Universidad 1

Nacional de TucumBn in TucumBn, Argentina. Fax: W O 1 8 1-36-4120/25-2037. E-inail: bioing@satlink.com or bioing @ herrera.unt.edu.ar 281: 35-37, July 3, 1998.

Around the World (continued from page 18)

and the National Center of Microelectronics of Barcelona were well represented in the exhibit. Visitors could easily appreciate the high level reached by these institutions.

Extra activities included a visit to the Laboratorio Integrado de Bioiiigenieria of the Universidad PolitCcnica de Valencia, whose director is Dr. JosC Maria Ferrero. Research areas here include bioseiisors and antibodies, instrumentation, cardiac models and electrodes, telemedicine, and imaging techniques. Several of its members are currently publishing in well-reputed international journals.

The social activity could not be missed. There was a wonderful show at the Hemisferic (a new high-tech planetarium), after which we all left with symptoms of seasickness. No doubt the vi- sual stimuli can indeed elicit significant physiological re-

sponses! It was a virtual-reality environment that, one suppose could be used by an evil mind to make people believe they are h ing in a world that, in fact, does not exist. Excellent show! Do n miss it if you plan to stop off at Valencia But this was just the b ginning of the tour, and we proceeded to the city of Gandia learn about the medieval Sant Geroni Convent and its gardei and to get acquainted with the Palau de Francisco Borja and 1

amazing history through the witty and spicy talk of a JesL Brother. The tour ended with a collection of savory and generoi appetizing morsels of all kinds, as well as plenty of liquid r freshments, at the Alqueria del Duc It was rmdnight when we g back to our hotels-it certainly was a night to remember.

Max Valentinuzzi. Institute of Biomedical Engineering (Tucumkn, Argentin

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