Saturday, January 23. 2010
This post is the first in a series based on my soon-to-be published book, The History & Future of Medical Technology. Each week I’ll present highlights from one of thirteen chapters.
The Hidden World
How did the human race learn to prevent and cure diseases, repair and replace body parts, and improve the quality of life for chronic disease sufferers? The history of medicine is usually depicted as the gradual accumulation of knowledge over two thousands years punctuated in the late 20th century by the sudden convergence of biology and engineering. The problem with that narrative is that it misses two key events: an epochal invention and a scientific rebellion (discussed in chapter 2).
The microscope enabled not only modern medicine but all of the life sciences. As British biologist Brian J. Ford reminds us, the microscope has come to symbolize laboratory research.
Outsiders often do the most to prove and improve a new technology. The first person to observe microorganisms, Antony Leeuwenhoek, was a Dutch draper. Joseph Jackson (J.J.) Lister, who figured out a reliable way to manufacture low distortion microscopes, was a British wine merchant. These two hobbyists made immense and lasting contributions.
It’s hard to imagine how Leeuwenhoek must have felt when he first discovered creatures too small to be seen with the unaided eye. And it’s no wonder that he saw no link between microorganisms and disease: he also found “animalcules” in the mouths and excrement of healthy people.
Leeuwenhoek made his own single-lens microscopes. These were not mere magnifying glasses, though. They consisted of small, hand-polished lenses that could magnify objects up to 270 times mounted between two metal plates.
Many natural philosophers doubted Leeuwenhoek’s credibility; after all, he was untrained and didn’t know Latin. But time after time, Leeuwenhoek’s discoveries were verified by others. He even demonstrated some of his discoveries to Russian Tsar Peter the Great, who was touring Europe incognito.
Leeuwenhoek’s simple microscopes were difficult to use; most natural philosophers preferred compound microscopes. Unfortunately, the instruments suffered from spherical and chromatic aberration. Good microscope makers found they could reduce distortion by using combinations of offsetting lenses. However, producing good instruments was still a trial and error affair.
J.J. Lister is one of the most underappreciated figures in the history of science. (He's best known as the father of Joseph Lister, who introduced antiseptics to surgery and wound care.) In 1829, he discovered the law of aplanatic foci. Now there was a reliable method for producing relatively low distortion microscopes. The floodgates opened to further discoveries. The cell nucleus was first described in detail in 1831. By the 1850s, the germ theory of disease was widely accepted.
Others, such as Ernst Abbe, made important contributions to optical microscope technology. By the early 20th century, microscopes were bumping up against a performance ceiling: the wavelength of visible light. Ernst Ruska won the 1986 Nobel Prize in Physics for developing the first electron microscope, a device that used electromagnetic coils as virtual lenses. Electron microscopes can magnify objects up to one million times. In 1981, a type of electron microscope was employed to produce the first image of an individual atom.
The latest advances include confocal laser scanning microscopes, vitrification of specimens for electron microscopes, and magnetic resonance force microscopes. Confocal microscopes can produce three dimensional images of live specimens. Electron microscopes and magnetic resonance force microscopes are enabling scientists to observe the structure of complex organic molecules.
I suspect we will eventually be able to directly observe most of life’s underlying chemical machinery--both its structure and processes. That portends a future that is at once wonderful and frightening. We will be better equipped to prevent and cure genetic diseases. But we will also learn how to produce custom genomes.
Next time: Medicine's First Power Users
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Thursday, December 3. 2009
My soon-to-be-published book tells the story of how today’s amazing medical technologies were developed, how they work, and how they are likely to evolve over the next several years. There are thirteen chapters on topics including the microscope and the birth of modern medicine; x-rays and computed tomography (CT); diagnostic and therapeutic ultrasound; magnetic resonance imaging (MRI) and nanomedicine; diagnostic and therapeutic nuclear medicine; heart rhythm management; replacement tissues and organs; hospital networks, telemedicine, and mobile healthcare; laser eye surgery; and dental technology.
The book fills the gap between the simplistic explanations often found in newspaper articles and the jargon-laden, highly mathematical descriptions found in textbooks. For example, the chapter on MRI begins with the experiments in the early 1900s that forced scientists to accept the theory (quantum mechanics) that for atoms (and smaller particles) energy, mass and even spatial orientation come only in discrete packages. The chapter proceeds to I.I. Rabi’s discovery of how to make the nuclei of atoms flip from one discrete orientation to another—an effect known as nuclear magnetic resonance. Gradually, physicists such as Erwin Hahn learned how to make atomic nuclei dance in unison, emitting faint but detectable signals. In the 1970s, investigators Raymond Damadian, Paul Lauterbur, and Peter Mansfield—each working independently—began using the signals to construct images of the inside of the body.
The book is primarily about the researchers who uncovered fundamental scientific effects and the inventors and entrepreneurs who exploited those discoveries. Over the next few months, I’ll post highlights from each chapter. What follows are select questions and answers concerning some of the big picture issues.
Weren’t the biggest gains in average lifespan the result of public sanitation rather than modern medicine?
At first glance, this appears to be true. It’s easier to prevent disease than to cure it, so measures such as water filtration, street sanitation, and quarantining those with contagious diseases proved extremely effective. However, public sanitation wasn’t firmly embraced until the germ theory of disease gained acceptance. It would be fairer to say that medical research explained why public sanitation is necessary and how best to go about it.
Are expensive medical tests over-prescribed?
Many people feel that physicians over-prescribe expensive tests to protect themselves against malpractice lawsuits. No doubt the third-party payer system and large malpractice awards influence physicians’ judgment. However, considering how important early detection of disease is to effective treatment, most people would benefit from periodic screening. Instead of reducing the number of medical tests performed, we should focus on reducing the costs of routine screening.
As medical technology advances, doesn’t it become harder for consumers to participate in their own health care decisions?
As technology advances, it typically becomes more accessible and user-friendly. The first computers were very expensive, room-size machines. Now, personal computers are a common household item in developed countries. In the future, there will be more diagnostic tests that can be performed at home, and more online health care services. For the first time, consumers have the ability to create and maintain their own personal health records.
Isn’t government better qualified to conduct medical research than the private sector?
People tend to believe that the private sector is only concerned with near-term profits. History suggests otherwise. For example, oil magnate John D. Rockefeller had a tremendous positive impact on medical research. He didn’t just give money away and wash his hands of it; he used the same business skills that enabled him to acquire tremendous wealth to manage his philanthropic endeavors and ensure that they met ambitious goals. In addition to founding the Rockefeller Institute for Medical Research, John D. Rockefeller started an organization that eradicated hookworm disease in the southern U.S.
What amazing medical technology developments can we expect next?
There isn’t room here to talk about all of the solutions under development. I want to briefly mention one area about which I’ll have more to say later. Nanomedicine promises earlier detection of diseases and more targeted therapies. Later, nanotechnology may play a major role in repairing and replacing damaged tissues and organs. Nanomedicine also offers opportunities for enhancing human performance.
How will health care delivery evolve over the next decade?
Health care in the United States is becoming increasingly bureaucratic. Physicians are herded into large group practices. The Food and Drug Administration decides what medicines we can take. Insurance companies pre-certify hospitalization.
Expect a growing number of people--in an effort to circumvent the bureaucracy--to take a more active role in managing their own health care. Personal devices will help people stay healthy (such as daily activity monitors); manage specific medical conditions (such as glucose monitors); and access medical information while mobile (such as iPhone applications). Consumers will rely more and more on online resources. The ultimate tool for managing your own health may be the (now available) personal health record.
Next time: The hidden world
Saturday, February 7. 2009
Late 19th century American industrialists were latter day robber barons, amassing great wealth through unfair and anti-competitive business practices.
At least, that’s how they are routinely portrayed by radicals, opportunists, and sore losers.
Consider the case of John D. Rockefeller, Senior. Rockefeller made a fortune producing and distributing kerosene for household lighting in the 1870s. Rockefeller was a devoted member of his church, vowed to give away 10% of his earnings from the time he landed his first job, and was always looking for ways to cut costs. Though some believe he was the richest man in history, he and his wife Cettie lived relatively simple lives. Rockefeller was a great philanthropist—as skilled in donating money for the benefit of mankind as he was at earning it.
Rockefeller had a hugely positive impact on education, medical research, and the welfare of disadvantaged Americans. He transformed a small college into a world-class university (the University of Chicago). He founded the Rockefeller Institute for Medical Research (now Rockefeller University). Growing up in the 1850s, he found slavery repugnant, and educating African Americans became a life-long cause. Rockefeller started an organization that eradicated hookworm disease in the southern U.S. He gave generously to Johns Hopkins University in Baltimore and Peking Union Medical College in China.
Rockefeller is accused of being a monopolist who conspired to crush competitors in order to drive up prices. That is simply not true. Rockefeller did leave competitors in the dust—by developing more efficient means of drilling oil, refining it, and distributing kerosene and other products. Though he dominated the market for many years, he had substantial competition. By the time efforts to break up Standard Oil got into gear, the company was losing share in a changing market. Ironically, the breakup drove up the value of Rockefeller’s stock holdings, making him richer than before.
Rockefeller’s detractors were motivated by more than just a sense of fairness. His first vocal critic, Henry Demarest Lloyd, once referred to himself as a “socialist-anarchist-communist-individualist-collectivist-cooperative-aristocratic-democrat.” Rockefeller’s most effective critic, Ida Tarbell, was hardly in a position to be objective: her father entered the oil production and refining business just as Rockefeller’s business was taking off. Though Tarbell did not paint Rockefeller as all bad, she accused him of cheating the widow of a small lubricant manufacturer when he purchased her husband’s business. Actually, out of charity Rockefeller knowingly paid more than the business was worth. After receiving an accusatory letter from the widow, Rockefeller offered to return the business for a refund. She did not accept his offer.
The Rockefeller Institute for Medical Research (RIMR) was founded in 1901 to conduct biomedical research. Though Rockefeller favored homeopathic remedies for himself, he was convinced by Frederick T. Gates of the need for a scientific institute along the lines of the Pasteur Institute in France and Koch Institute in Germany. RIMR went on to become the home of more than 20 Nobel Prize winners. One of the Prize recipients was Alexis Carrel, who developed a standard technique for suturing blood vessels and collaborated with Charles Lindbergh on research that led to open heart surgery and organ transplants.
Was Rockefeller a business cheat? Certainly he was a tough businessman and some of his tactics are now considered anti-competitive. However, there were few rules at the time, and it’s hard to see how teaming up with others to drive down prices paid by consumers was such a bad thing. Perhaps Rockefeller’s biggest mistake was delegating authority to less fastidious employees.
Rockefeller did not give away money just to deflect criticism. He devoted tremendous time and energy to ensure his philanthropic enterprises met their goals. Yes, he built an oil empire and became extremely wealthy. But he gave back to society even more.
Tuesday, March 4. 2008
I recently learned about three episodes in the history of medicine that most people will find surprising. They remind us that some of the medical technology we take for granted evolved from exotic and even shocking early work. Pun intended.
Episode #1: The first open heart surgeries were performed on children using a parent as the heart-lung machine. One physician quipped that this was the only medical procedure with the potential for 200% mortality. Fortunately, it wasn't long after that that machines capable of aerating the patient's own blood were invented.
Episode #2: Doctors knew for many years that some patients suffer from abnormally slow heart rate (also known as Stokes-Adams disease or "heart block") and that the problem eventually kills them. Then it was discovered that the body controls heart rhythm using electrical signals. Paul Zoll pioneered the use of artificial electricity to treat heart block. Shocks were administered to the patient's chest; the implantable pacemaker had not yet been invented. Obviously, Zoll's method could only be used temporarily--for example, after surgery. Some patients tolerated the shocks quite well, while others could be observed jumping with each electrical pulse.
Episode #3: For a short period, the standard procedure for treating ventricular fibrillation was to cut open the patient's chest and massage the heart directly. Worse, this usually had to be done on an emergency basis wherever the person happened to be at the time.
These methods, as unpleasant as they sound, led to the development of safer and more effective solutions.
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