Ira Brodsky.com - The History & Future of Medical Technology

The Future of Mobile Health

nospam@example.com (Ira Brodsky) — Mon, 09 Aug 2010 07:20:51 -0500

A fascinating presentation.

The report's goal is to promote more cost-effective solutions for remote areas in emerging economies. However, I'm concerned that this could become another endless quest for funding. In my experience, it's better to focus on solutions that succeed in the marketplace. That does a better job of driving costs down and identifying business models that work on their own. Once you have a market-tested solution, creative financing and limited subsidies can be used to greater effect.

One of the report's best ideas is "provide good enough analysis." Too many entrepreneurs get distracted by the notion that the best performance wins. History shows that it's the right balance of performance, cost and convenience that wins. Again, I think the marketplace is much better at finding the right balance than grant-driven projects. Grants tend to mask issues that are crucial to long term success.

The best way to serve remote areas in emerging economies is to create winning solutions for developed countries and just keep growing the market. This is precisely why the mobile phone market is growing so rapidly today in countries such as India.

Better Living Through Biomedical Engineering

nospam@example.com (Ira Brodsky) — Wed, 21 Apr 2010 08:45:04 -0500

The following is the Introduction to The History & Future of Medical Technology. The book will begin shipping May 14, 2010 and will retail for $34.90 (hardcover). A special pre-publication price of $19.90 is offered for orders received by May 17th.

Medical technology has come a long way over the last several decades. CT, MRI, and ultrasound machines produce stunning images of your vital organs. Implantable defibrillators intervene when your heart rhythm goes haywire. Teletherapy machines use invisible rays to destroy tumors. Another type of machine takes over for your heart and lungs so that a surgeon can make repairs. If you go deaf, a cochlear implant may restore your hearing. Need a new knee joint? No problem.

And best of all, the era of life saving and enhancing medical technology is just getting started.

I’ve been interested in the history of technology for a long time, having worked in the high-tech industry for 30 years. I wanted to know more about the evolution of modern medical technology, and I was surprised that I couldn’t find a comprehensive history. There are many books on the history of medicine, but few books that explain how today’s wonderful medical technologies were created. So I decided to research and write such a book.

There is so much great medical technology that I had to cast a wide net. The book encompasses microscopes, endoscopes, x-ray machines, CT scanners, ultrasound imaging, magnetic resonance imaging, pacemakers, defibrillators, nuclear medicine, the heart-lung machine, kidney dialysis, artificial hip joints, brain-computer interface chips, laser surgery, and much more.

But I also had to set some boundaries. This book focuses on systems, instruments, and devices—the mechanical and electrical stuff. Pharmaceuticals and genetic engineering are also great medical technologies, but they are a different story for another book. I applied a simple test: If it contains a microprocessor, can communicate via the Internet, or has moving parts, it is probably in this book. If you take it orally one hour before meals, it probably isn’t.

I also drew a line between modern and primitive medical technology. This book is for anyone who wants to know how we got to where we are today and how medical technology is likely to evolve in the next several years. The narrative chronicles discoveries and inventions with long-lasting impact; this is not a book about medieval bone saws and tooth extractors.

I drew one more boundary. This is not one of those esoteric histories for historians. My target audience is consumers, health care professionals, and investors who want to learn how we came to discover the causes of disease, develop powerful diagnostics, and invent effective therapies. My purpose is to inform and inspire by concentrating on the most important figures and events—not ask readers to trudge through minutiae.

The history of medical technology is a confluence of three distinct streams: the history of biological research, the history of clinical practice, and the history of the health care industry. I must warn readers that much of the research described in the following pages was performed on laboratory animals. They—along with the human patients who agreed to undergo experimental procedures—are the unsung heroes of modern medicine.

Many people feel that making profits and saving lives don’t mix. I concede that there are legitimate ethical concerns. However, there’s also wisdom in the saying “Don’t throw the baby out with the bath water.” Businesses have done a good job identifying patient and health care provider needs, adapting new technology to serve those requirements, and figuring out the best way to package and distribute the technology to ensure it gets in the hands of the right people in a form that they can use.

The first decision for anyone writing a history is deciding where to begin. A history of medical technology could begin with the ancient physicians. Or it could begin at some arbitrary starting point, such as the year 1900.

I chose to start with the invention of the microscope. Though introduced at the same time as the telescope, the microscope was practically ignored. The telescope could be used to sight approaching ships, spy on enemy armies, and explore the heavens. The microscope could only be used to examine objects already in hand. Plus, early microscopes produced terribly distorted images and no one had a clue that there was a living microcosm awaiting discovery. Antony Leeuwenhoek, a Dutch draper, was the first person to observe protozoa and bacteria.

Chapter Two shows how the microscope spurred the development of experimental medicine and the germ theory of disease. Today, those ideas seem obvious. Prior to 1850, physicians could do little to cure diseases; many created and maintained an aura of authority by spouting bizarre theories. A new generation of scientists—led by Claude Bernard in France and Hermann Helmholtz in Germany—put medicine on a more solid footing. Louis Pasteur, Robert Koch, and Joseph Lister took the ball and ran with it.

The germ theory of disease encountered fierce resistance. In part, it was because it was difficult to prove that microbes cause disease. But it was largely because physicians did not want to admit that they had unknowingly been spreading diseases. Eventually the body of evidence grew too large to ignore. Vaccines were developed, public sanitation was improved, and aseptic surgery became accepted.

For medicine to advance to the next level, physicians needed some way to see inside the body. Chapter Three chronicles the evolution of endoscopy, the discovery of x-rays, and the progression to computed tomography—the technology behind the CT scanner.

Other diagnostic tools paved the way to timely and effective interventions. Chapter Four describes how Willem Einthoven perfected the electrocardiogram—and how it spawned tools for mapping and even repairing the heart’s electrical system.

Today, getting an artificial pacemaker is a relatively minor procedure. Chapter Five explains how medicine slowly advanced beyond helplessly watching patients with dangerously slow heartbeats die. External pacemakers—intolerable to most patients—came first. Pacemakers requiring major surgery came next; the cure was almost as bad as the disease. The discovery that pacemaker leads could be threaded through the veins made it all worthwhile.

Magnetic resonance imaging (MRI) added a new dimension to diagnostic imaging. Chapter Six describes how a series of discoveries led to what one inventor called “wireless chemistry.” To get there, physicists first had to learn how to make atomic nuclei dance in unison.

Radioactivity is rightly feared. But when used with proper caution, radioactivity is a powerful diagnostic and therapeutic tool. Chapter Seven chronicles the beautiful experiments of Ernest Rutherford and the incredible perseverance of Marie Curie—and how their work led to PET scanners, the Gamma Knife, and proton accelerators.

Physicians also found ways to exploit sound waves. Chapter Eight describes the development of the stethoscope and blood pressure monitor—both of which depend on listening. Decades later, a device developed to detect icebergs and enemy submarines was modified to produce images of the beating heart and even measure the flow of blood through the heart’s chambers and valves. Ultrasound is another powerful diagnostic tool that has also found therapeutic uses.

Chapters Nine and Ten describe how physicians learned to repair, replace, and assist failing organs. To get there, doctors had to develop the habit of keeping accurate records and analyzing the data. First they discovered they could replace blood—but only if they followed certain rules. An unlikely trio—John D. Rockefeller, Charles Lindbergh, and Alexis Carrel—paved the way for John Gibbon’s heart-lung bypass machine.

That brings us to some of the cowboys of medicine: colorful figures such as Werner Forssmann, Andreas Gruentzig, and Christian Barnard. Forssmann experimented on his own heart. The flamboyant Gruentzig found a simpler and safer method (compared to coronary artery bypass graft surgery) to clear clogged arteries. The equally flamboyant Barnard performed the first successful heart transplant. Less well known, Willem Kolff invented kidney dialysis and pioneered the artificial heart.

The success of the cochlear implant gives us reason to be optimistic that we will one day restore vision to the blind. A versatile biological material, small intestine submucosa (SIS), has demonstrated an almost magical ability to replace and even regenerate natural tissues.

Ophthalmology has its own story, told in Chapter Eleven. A series of discoveries—some of them accidental—led to laser-based vision correction surgery, implantable lenses, and new ways to treat sight-threatening disorders such as detached retinas, glaucoma, and age-related macular degeneration.

Dentists are also not to be ignored. As explained in Chapter Twelve, it was a dentist who invented safe and effective anesthesia—benefiting the entire medical profession. Dentists also pioneered body part replacement.

Computers and communications have become ubiquitous in health care. As Chapter Thirteen shows, we are getting our first glimpse of what devices and networks can do. Doctors are accessing diagnostic scans via smartphones. Patients and their families are finding specialists via the Internet. Wireless devices keep patients in touch with their health care providers and advisors. Personal health records enable patients to take a more active role in their own health care.

A note about terminology: I use plain language as much as possible, referring to the official medical terminology only when necessary. Modern medicine is brimming with jargon, and it can be intimidating. However, there is no way to completely avoid technological jargon, so I’ve included a glossary of terms used in the book.

The sources of this work include not only books and journal articles, but interviews with pioneering physicians, lectures, videos, and tours of research labs.

Medical technology can work wonders. That’s not to say, however, that modern medicine is perfect. Success breeds complacency—or at least over-reliance on the same set of procedures and tools. But even when you add all of the minuses to the plusses, we as patients still come out way ahead.

The History & Future of Medical Technology, Chapter 13

nospam@example.com (Ira Brodsky) — Sat, 17 Apr 2010 11:17:46 -0500

This post is the thirteenth 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.

Bodies in Cyberspace

From pacemakers to CT scanners, computers have become ubiquitous in health care. Now networks are taking medicine to the next level. A doctor pulls up a digitized scan on a laptop within seconds. A radiologist in Australia working the day shift reads x-rays in Kansas where it’s 3:00 AM. Hospitals instantly locate IV pumps, wheelchairs, and vital sign monitors scattered around the facility. Surgeons use video cameras, robotic instruments, and speech recognition systems to enhance their operating skills.

No modern hospital is complete without in-building mobile communications. Most install either a distributed antenna system or a wireless local area network. Today’s hospital IT manager can employ tools such as Armstrong World Industries’ ceiling tiles with integrated antennas; Vocera’s Star Trek-like Communications Badges; Air Magnet’s performance and security monitors; and Centrak’s people and equipment tracking system.

The most dramatic changes are coming not in how health care providers communicate amongst themselves, but how they interact with patients. Patients perform an expanding portfolio of diagnostic tests and therapies in the comfort of their own homes. Medical devices are monitored, reconfigured, and updated over phone lines. Medical emergencies are reported and responded to anytime, anywhere. Routine communications between patients, pharmacies, and doctors are automated using mobile phones and the Internet. Qualcomm VP Don Jones calls it “putting every body on the 'Net.”

The Internet gives patients unprecedented access to information about medical conditions and treatments. Patients share their concerns and ideas with each other in online discussion forums. The Internet also enables a new type of voyeurism: Surgeons live-streaming updates from the operating room via Twitter. Though some people consider hyper-access frightening, and not all online information is reliable, it can’t help but empower patients and their families over the long run.

Telemedicine goes beyond remote interpretation of scans. Robotic tools are increasingly used in the OR for greater precision and steadiness. But if a surgeon sitting across a room can operate on a patient using robotics, the same can be done a continent away. And that’s just what is starting to happen. On Sept. 7, 2001, Dr. Jacques Marescaux operating in New York removed the gall bladder of a woman in Strasbourg, France using a remote-control, robot-assisted laparoscopic device. That proved it could be done, but no one has quite figured out the best way to exploit it.

Health care applications for mobile phones are getting ready to take off. CardioNet lets cardiologists monitor patients’ cardiac rhythm and performance. The Pill Phone reminds users when it’s time to take their medicine and even handles refill requests. GreatCall's Jitterbug mobile phone service gives senior citizens 24-hour access to registered nurses.

Expect biological sensors to be integrated with mobile phones in the next few years. For example, Orla Protein Technologies and Japan Radio Company announced they are developing a mobile phone chip that can read swabs and blood samples and transmit the results to doctors.

Microsoft and Google are promoting Internet-based personal health records (PHRs). Microsoft’s HealthVault ecosystem includes major health care providers; patient advocacy groups; and device vendors. Google Health has its own portfolio of online health services. Though PHRs put patients in control of their own medical records, they raise a host of privacy and security concerns.

Some physicians fear that the Internet provides patients information that is wrong, only partly true, or not applicable to their specific circumstances. Those are legitimate concerns, but they apply to all sources of information and not just the Internet. Patients just need a little healthy skepticism.

One clear benefit for patients and their families is the ease with which they can track down physicians and facilities with experience treating rare conditions. In fact, the Internet has taken the quest for optimal health care global. Patients are increasingly traveling overseas for specific medical expertise or to save money—a practice known as “medical tourism.”

Some health care reform advocates believe we rely too much on expensive technology. They have it exactly backwards. As more people monitor themselves we will learn to detect specific health problems during their earliest, most treatable stages. Medical technology isn’t the problem—it’s the solution.

Next time: Better Living Through Biomedical Engineering

Note: If you would like to be notified when The History & Future of Medical Technology is published, please go to Telescope Books and enter your email address in the newsletter sign-up field on the left menu bar. This email list is only used to announce book offers from Telescope Books; your email address will not be shared with third parties.

The History & Future of Medical Technology, Chapter 12

nospam@example.com (Ira Brodsky) — Sat, 10 Apr 2010 12:54:02 -0500

This post is the twelfth 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.

Technology with Real Teeth

We think nothing of it when our teeth do their job—and we can think of little else when they subject us to agony. Perhaps that’s why humorists depict the history of dentistry as a chronicle of pain. If that is true, then it turned out to be just the incentive needed. Dentists pioneered anesthesia, one of the pillars of modern surgery. And dentists scored again by producing some of the first materials and techniques for repairing and replacing body parts—body parts assaulted daily by a phalanx of mechanical and chemical stresses.

Dentistry continues to lead the charge in key areas. Dentists are migrating to digital x-ray technology. Dentists have started to employ computer aided design/computer aided manufacturing (CAD/CAM) to aid restoration. By focusing on the body’s portal for nourishment, dentists are also doing their share to prevent disease.

The French surgeon Pierre Fauchard is considered the father of modern dentistry. Working in Paris, he published a systematic study of the subject in 1728 (The Surgeon Dentist, A Treatise on Teeth). Until that time, the few skilled dentists kept their knowledge secret. Fauchard described a number of dental instruments and recommended the use of human urine to treat early-stage tooth decay—an idea that originated in ancient times. (The ammonia often found in urine is truly beneficial.) Fauchard debunked the “worm theory” of tooth decay, identified sugar derivates such as tartaric acid as the true cause, and prescribed the use of lead fillings.

In 1790, John Greenwood—famous for producing President George Washington’s dentures—used an old spinning wheel to build what may have been the first foot operated drill. Mercifully, he didn’t use it to drill patients’ teeth; he used it to fashion dental prostheses. However, it wasn’t long before dentists began using hand drills running about 15 revolutions per minute (RPM) on patients.

In 1864, British dentist George Fellows Harrington invented a clockwork dental drill—a drill that was wound up like a clock and ran for two minutes. However, that invention was preempted by James Beall Morrison’s 2,000 RPM pedal powered drill in 1871. It reduced drilling time by about 50% but had an unintended downside: In the 19th century, dentistry was completely unregulated, and once the pedal powered drill became affordable, the field was flooded with uneducated, unskilled, and unethical practitioners.

The S.S. White Company introduced the first battery-powered electric drill in 1883. To modern readers, this might suggest the company was seeking to create wireless drills. In truth, they employed batteries because there was no power distribution grid at the time.

High speed (60,000 RPM) turbine drills were developed after World War II by John Walsh, a dentist with the Royal Australian Air Force, and Dr. Robert J. Nelsen, research associate with the American Dental Association at the National Bureau of Standards (NBS) in Washington, D.C. Then Dr. John V. Borden used compressed air to power his 250,000 RPM Airotor. Air turbine units are still used for 95% of dental drilling—though high-speed, microprocessor-controlled electric hand pieces threaten to replace them.

New technologies have been developed for early detection of cavities and even oral cancer. KaVo Dental’s Diagnodent uses a 655 nanometer wavelength laser to detect small cavities. LED Dental’s VELscope employs a blue light to detect fluorescence associated with potentially malignant tissue.

Dentists played a leading role in the development of anesthesia. In 1844, Horace Wells in Connecticut discovered nitrous oxide’s anesthetic properties and used it to perform tooth extractions. He conducted the first public demonstration of anesthesia in 1845, but the demonstration was a failure because the patient cried out. In 1846, Wells’s student William Thomas Green Morton conducted the first successful public demonstration of anesthesia using ether. Many people have pointed out that Morton did not invent ether. However, that argument misses the point. It was Morton who recognized the importance of administering the right amount of anesthetic at the right rate using the right equipment. He invented a way to make anesthesia reliable and safe. (Ironically, today most dental procedures use local anesthetic.)

Roentgen’s discovery of x-rays in 1895 was a boon to dentistry. Dental x-rays reveal problems such as cavities, hidden teeth, and bone loss. Fortunately, most dentists didn’t embrace x-ray technology until after 1930; by that time more was known about the health risks associated with x-rays and exposure times had been greatly reduced. (Even so, many dentists and their assistants developed cancers on their fingers from the habit of holding films in place in their patient’s mouths.)

Traditional film-based dental radiography is being replaced by digital x-ray technology. X-ray film must be shielded from light before use, developed in a darkroom using harsh chemicals, and then physically stored for future reference. Digital x-ray technology is safer, saves time, and ultimately saves money. Digital x-rays can be viewed immediately. It’s easy for dentists to share digital x-ray images with specialists; instead of sending the original film or a copy in an envelope, the images can be sent via email. Another advantage of digital x-ray technology is that it requires less than half as much radiation exposure. There are even special CT scanners for planning dental implants.

Dentistry is rapidly changing thanks to new technology. Or perhaps it would be more accurate to say that consumers’ expectations from dentistry are rapidly changing thanks to new technology. As one dentist told me, dentists who do not use the latest technology, or at least offer referrals to dentists using the latest technology, risk being accused of malpractice.

Next time: Bodies in Cyberspace

Note: If you would like to be notified when The History & Future of Medical Technology is published, please go to Telescope Books and enter your email address in the newsletter sign-up field on the left menu bar. This email list is only used to announce book offers from Telescope Books; your email address will not be shared with third parties.

The History & Future of Medical Technology, Chapter 11

nospam@example.com (Ira Brodsky) — Sun, 04 Apr 2010 13:27:53 -0500

This post is the eleventh 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 Vision Thing

A phalanx of high-tech products provide the ophthalmologist with one of the most advanced toolkits of any medical practitioner. Lasers, corneal mapping systems, and foldable silicone lenses enable ophthalmologists to repair the eye with non-invasive and minimally invasive techniques—often under computer control.

Ophthalmology has benefited more than any other medical specialty from the laser. The same light waves that enable the sense of sight can also be used to treat diseases of the eyes and correct vision. It’s as if the ear could be repaired or improved with carefully measured sounds.

Today, we can repair or even replace parts of the eye. Once we learn how to deliver images directly to the brain, as we almost surely will, then it will be possible to replace the eye entirely.

The history of vision correction surgery is a remarkable saga. It began in the now-defunct Soviet Union. Svyatoslav Fyodorov overcame his father’s denunciation and imprisonment, an accident in which he lost a leg, and massive Soviet bureaucracy to develop a revolutionary technique called radial keratotomy (RK). When Fyodorov’s daring method landed in the U.S., it evolved into today’s popular LASIK vision correction surgery.

In 1973, Fyodorov encountered a patient whose vision (at least in one eye) was corrected by a punch. Fyodorov examined the boy and found a small curvilinear incision outside the visual axis. He confirmed that the boy’s myopia was reduced by three diopters. Fyodorov exclaimed “If a fist can do this, so can I. After all, I am an eye surgeon.”

Once Fyodorov perfected his technique (involving up to 16 straight-line incisions arranged about the center of the cornea like spokes of a wheel), he found he could treat individuals with visual impairment in assembly-line fashion, employing multiple technicians, each assigned to perform a specific step. He established clinics all across Russia. By 1990, the clinics were treating more than 200,000 patients per year.

Fyodorov’s luck ran out when he died in a helicopter crash in 2000. Fortunately, by then his technique had spread beyond Russia. In 1976, Dr. Leo D. Bores of Detroit, Michigan visited Moscow to learn about Fyodorov’s work. Bores returned to Moscow a year later to confirm that RK patients enjoyed good long term results. He invited Fyodorov to lecture at the Kresge Eye Institute in Detroit in 1978. However, ophthalmologists in the U.S. were hesitant to accept RK; many felt cutting healthy corneas was too risky.

Vision correction surgery received a big boost when it was shown that lasers can be used to modify the cornea. Laser eye surgery proved to be faster, more precise, and pain free. I wrote earlier about how Charles H. Townes invented the laser.

Briefly, the operation of the laser is based on an amazing phenomenon called population inversion. An atom with an electron in the excited state emits a photon when the electron drops to the ground state. Einstein realized that an atom with an electron in the excited state can also be stimulated to emit a photon when merely grazed by another photon—turning one photon into two photons. Meanwhile, atoms in the ground state become excited when they absorb photons. If absorption of photons by atoms in the ground state and stimulated emission by atoms in the excited state take place simultaneously, there will soon be more atoms in the excited state than not. If there are more atoms in the excited state, more photons will be emitted than absorbed, and the light used to initiate the process is amplified.

A type of laser well suited to surgery was developed in 1970: the excimer laser. An IBM researcher, Rangaswamy Srinivasan, discovered in 1981 that excimer lasers can be used to finely etch living tissue without damaging surrounding tissue. Each laser pulse removes just 39 millionths of an inch of tissue. Srinivasan teamed up with Steven Trokel, an ophthalmologist at Columbia University, to show that use of the excimer laser was safe and effective.

In the early 1990s, two researchers working independently—Ioannis Pallikaris and Lucio Buratto—used microkeratomes to create and lift corneal flaps, ablate the exposed corneal beds, and replace the flaps. Pallikaris dubbed the technique laser assisted in-situ keratomileusis, or LASIK. Clinical trials of LASIK in the U.S. began in 1996 and the procedure was FDA approved in 1999. In one of the first studies, 70% of approximately 500,000 Americans who underwent LASIK surgery emerged with 20/20 vision.

LASIK is surgery and all forms of surgery entail risk. Many patients fail to obtain 100% correction; while a second procedure is possible it is discouraged. Proponents point out that the risk of serious problems is less than 1%. Critics say that’s still unacceptable.

Ophthalmologists use advanced technology for a number of other purposes including detailed mapping of the cornea; replacing the eye’s crystalline lens when it becomes clouded with an implantable intraocular lens (IOL); and treating detached retinas, secondary cataracts, age-related macular degeneration (AMD), and glaucoma.

The history of ophthalmology reminds us that technology can often achieve more than at first seemed likely. After all, the eye is a very delicate organ. Who would have guessed that vision can be improved by cutting the cornea? Or that the eye’s crystalline lens can be removed and replaced with a man made lens?

Next time: Technology with Real Teeth

Note: If you would like to be notified when The History & Future of Medical Technology is published, please go to Telescope Books and enter your email address in the newsletter sign-up field on the left menu bar. This email list is only used to announce book offers from Telescope Books; your email address will not be shared with third parties.

The History & Future of Medical Technology, Chapter 10

nospam@example.com (Ira Brodsky) — Sun, 28 Mar 2010 11:33:47 -0500

This post is the tenth 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.

Repair or Replace? Part II

What can be done when the heart becomes sick or damaged? Sometimes a ventricular assist device can be used to reduce the heart’s work load until it recovers normal function. Both ventricular assist devices and total artificial hearts can be used to buy time until a suitable donor heart can be found for transplantation.

Heart transplants offer the best hope for long term survival and a return to normal activities. Or even extreme activities; Kelly Perkins became famous as a mountain climber after receiving a heart transplant. Today, more than two-thirds of heart transplant recipients can expect to survive at least five years. According to some observers, the average heart transplant recipient can expect to live 15 years. The longest surviving heart transplant recipient was Tony Huesman who lived 31 years before succumbing to cancer.

The first heart transplant was attempted in 1964 when Dr. James D. Hardy at the University of Mississippi Medical Center implanted the heart of a chimpanzee in the chest of a dying man. The primate heart beat for about 90 minutes before stopping. The highly publicized procedure discouraged further xenografts (transplants between species) but spurred interest in human heart transplants.

Christian Barnard at Groote Shuur Hospital in Cape Town, South Africa performed the first human heart transplant in late 1967. A 54-year old grocer, Louis Washkansky, survived 18 days before succumbing to pneumonia. Less well known is the fact that three of Barnard’s heart transplant patients lived more than 20 years.

Barnard also devised and performed the first heterotopic heart transplant—an operation in which the recipient’s sick heart is left in place and the donor heart is connected to it producing a sort of “double heart.” The advantage of the heterotopic operation is that it gives the recipient’s own heart a chance to recuperate and, theoretically, makes it easier to replace a failed donor heart.

This chapter also traces the development of kidney dialysis machines, artificial hearts, ventricular assist devices, artificial joints, and brain-computer interface chips. Though results from cochlear ear implants have been mixed, we are clearly on the right path, and artificial vision—whether using artificial retinas or sensory substitution—is just a matter of time.

But there is more good news.

Imagine a material that can be fashioned into almost any shape, is highly biocompatible, and stimulates the body to grow replacement natural tissue. Such a material would be a boon to repairing the human body. A material with those qualities was discovered by biomedical engineer Leslie A. Geddes, a Professor at Purdue University who passed away in late 2009. Among the honors Geddes received for his many accomplishments were the IEEE Edison Medal in 1994 and the 2006 National Medal of Technology. I am deeply indebted to Professor Geddes, who encouraged me to call him when I had questions, and whose many articles and patents proved a treasure trove of information.

Like many great discoveries, this one was serendipitous. In 1983, Geddes and undergraduate engineering student Michael Voelz tried oxygenating blood using the small intestine of a dog. It worked, but not very well. However, the experiments gave Geddes another idea. He recalled that blood from an ulcerated small intestine does not clot. He also knew that animals and humans have a good deal of small intestine material. Might the small intestine be a source of material for vascular grafts?

Geddes obtained a $50,000 grant from the Showalter Trust and assembled a team to pursue the research. After a false start, they scraped the small intestine leaving only non-cellular material called small intestine submucosa (SIS). They found that because SIS contains no cells it does not provoke an immune response—even when used in different species.

Next, the team implanted pig-derived SIS grafts in the carotid arteries of a number of dogs. Later, no evidence of SIS could be found at the implantation sites. Tests suggested the SIS turned into host tissue.

SIS has since been used in a wide range of applications—from bioartificial heart valves to hernia repair to treating wounds. It has also been used as a dura mater substitute for covering the brain and to augment bladder volume; in the latter application, the remodeled SIS becomes innervated and contracts well.

The human body is a complex system and there are many challenges to repairing, assisting, and replacing body parts. Though our current capabilities are quite primitive, progress has been made in areas that once seemed unlikely. Who would have thought, for example, that material from a specific organ could be transplanted between species and stimulate growth of replacement host tissue in the process?

Next time: The Vision Thing

Note: If you would like to be notified when The History & Future of Medical Technology is published, please go to Telescope Books and enter your email address in the newsletter sign-up field on the left menu bar. This email list is only used to announce book offers from Telescope Books; your email address will not be shared with third parties.

The History and Future of Medical Technology, Chapter 9

nospam@example.com (Ira Brodsky) — Sat, 20 Mar 2010 09:40:21 -0500

This post is the ninth 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.

Repair or Replace? Part I

All tissues and organs eventually begin to fail. Sometimes they can be repaired. Sometimes it’s possible to compensate for deteriorating function. But the time comes when the only way to preserve health and extend life is to replace worn out body parts.

Some body parts, such as heart valves and knee joints, are eminently replaceable with synthetic equivalents. Others are so complex that transplantation seems the better bet. One organ, the brain, is so entwined with our sense of self and humanity that it defies replacement. To wit, if we could build an artificial brain and upload a stored version of the patient’s personality and memories, then would the recipient be the same person—or even human?

One thing is clear: replacement parts are already saving lives and improving the quality of lives. The benefits of a replacement heart valve are profound and there are few, if any, ethical concerns. Still, we may want to place some limits on body part replacement. Not everything that is technically possible is desirable.

There are different types of replacement parts. There are direct, permanent replacement parts that take the place of the failed organ or tissue. There are indirect replacement parts that take over part or all of the function of the natural organ or tissue. And there are external devices that handle the function of a failed organ—sometimes while waiting for a transplant. Several organs can be transplanted from people who died from unrelated injuries. It may one day be possible to use whole organs harvested from other species (xenografts). We are already able to use acellular material (called small intestine submucosa) harvested from other species.

Blood was one of the first critical body parts to be replaced. (Teeth, discussed in Chapter 12, were another.) The discovery of blood groups, the Rhesus (Rh) factor, anticoagulants, and simple techniques for storage and transfusion enabled today’s blood banks. Let’s hope they don’t need a bailout.

I wrote previously about the seminal contributions of an unlikely trio: oil tycoon John D. Rockefeller, Nobel Prize winning biologist Alexis Carrel, and American adventurer Charles Lindbergh. They laid the foundation for organ transplants and the heart-lung machine.

John Heysham Gibbon, Jr. deserves the lion’s share of credit for bringing the heart-lung machine to fruition. Gibbon came up with the idea independently, pursued it despite others’ skepticism, and devoted nearly two decades of his life to heart-lung machine research and development. He started by experimenting on cats, progressed to dogs, teamed up with IBM Corp., and performed the first successful surgery using a heart-lung machine in 1953. The patient, a young woman named Cecelia Bavolek, reluctantly became a celebrity.

In addition to describing in detail how Gibbon developed the heart-lung machine, the 30-page chapter tells the story of the development of cardiovascular catheterization—initially for diagnostic purposes and eventually enabling procedures that competed with coronary artery bypass graft surgery. The story starts with Werner Forssmann’s unauthorized catheterization of his own heart, additional developments by innovators including André Cournand, Mason Sones, and Charles Dottering, and the development of balloon angioplasty by the flamboyant refugee from East Germany, Andreas Gruentzig.

The chapter wraps up with the development and implantation in 1960 of the first artificial heart valve by surgeon Albert Starr and engineer Lowell Edwards. Today, there are both mechanical and bioartificial replacement heart valves, and their use has become routine. The latest development is minimally invasive implantation of artificial aortic valves using a stent-like device that is delivered via a catheter and pushes the natural valve leaflets aside.

Progress in repairing and replacing body parts—particularly in the cardiovascular system—has been nothing short of amazing. How can we best ensure more of the same? Most of the progress has been driven by individuals. I’m not going to deny reality: today most medical research is conducted by large organizations—and often run by committees. But we need to keep our minds open in case we encounter another Werner Forssmann, the sort of person who does not ask permission to make great discoveries.

Next time: Repair or Replace? Part II

Note: If you would like to be notified when The History & Future of Medical Technology is published, please go to Telescope Books and enter your email address in the newsletter sign-up field on the left menu bar. This email list is only used to announce book offers from Telescope Books; your email address will not be shared with third parties.

The History & Future of Medical Technology, Chapter 8

nospam@example.com (Ira Brodsky) — Fri, 12 Mar 2010 10:24:40 -0600

This post is the eighth 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.

Listening to Your Body

Physicians learned long ago that they could uncover clues about what was going on beneath the skin just by feeling and listening. Medicine took a giant step forward in the 18th century when physicians discovered that they could estimate the size of major organs by tapping on the body (“percussion”). By the 19th century, physicians were associating specific heart sounds with problems observed at autopsy; using body temperature to diagnose and monitor the progress of diseases; and taking accurate blood pressure measurements.

Gathering the data was less than half the battle. Making sense of the observations proved to be the bigger challenge. It didn’t take long to find that “normal” measurements vary widely from individual to individual. Desperately needed were data from the broader population and reliable standards for statistical analysis. To wit, it was important that physicians buy into the idea of regularly collecting and sharing key data. And there had to be a balance: gather the data, use the data—but never forget its limitations.

One simple data gathering technique, tapping on the body, evolved way beyond what its pioneers are likely to have imagined. Ultrasound imaging is the high-tech version of percussion. Employing the same principle that bats use to navigate, ultrasound scanners emit high frequency sound waves to create echoes that let us visualize structures within the body and study their motion. Ultrasound imaging is fast, non-invasive, and does not employ ionizing radiation. And it doubles as a therapeutic technology with applications range from cleaning teeth to breaking up kidney stones.

Today’s ultrasound scanners exploit a discovery made by Pierre and Jacques Curie in 1880. The Curie brothers discovered that mechanical stress causes some materials to generate small electric currents. One of their professors, Gabriel Lippmann, demonstrated the reverse—applying electric currents to the same materials distorts their shapes.

What began as a scientific curiosity evolved by World War I into a technology for detecting icebergs and enemy submarines. Though medical researchers experimented with ultrasound in the years following World War II, it wasn’t until cardiologist Harvey Feigenbaum showed how the technology could be used to diagnose specific heart problems in the 1960s that the technology began to gain traction in the clinic. (It’s also now famous for providing millions of expectant parents the first images of their unborn children.)

Ultrasound continues to demonstrate unique advantages. Ultrasound is less expensive than CT or MRI; near ideal for 4D (3D plus motion) studies; and as a screening tool lends itself to workflow automation. An emerging application, strain imaging, could provide information about the structural integrity of living tissues that can’t be obtained by other means. Strain imaging distinguishes and quantifies tissues in terms of stiffness and softness. In essence, strain imaging shows how each spot of tissue moves and could be used to gauge the overall health of specific types of tissue such as heart muscle.

In that case, ultrasound will not only tell us how well our hearts are performing, but how long they might last.

The evolution of medical diagnostic ultrasound traces back two-hundred and fifty years to when physicians started using percussion. Tap on the body and listen to the sound. A few pioneers working in the 1940s and 50s, beleaguered with doubt, thought that ultrasound echoes from inside the body just might turn out to be clinically useful. Decades later, buoyed by advances in electronics, ultrasound emerged as a key diagnostic tool.

Next time: Repair or Replace? Part I

Note: If you would like to be notified when The History & Future of Medical Technology is published, please go to Telescope Books and enter your email address in the newsletter sign-up field on the left menu bar. This email list is only used to announce book offers from Telescope Books; your email address will not be shared with third parties.

The History & Future of Medical Technology, Chapter 7

nospam@example.com (Ira Brodsky) — Sun, 07 Mar 2010 14:31:10 -0600

This post is the seventh 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 Nuclear Option

Dig into the history of nuclear medicine and you’ll discover some surprising facts. For example, did you know that PET scanners look inside the patient's body for matter-antimatter annihilation events? When a positron emitted by a radioactive tracer encounters an electron, the particles literally destroy each other, leaving only a pair of gamma rays flying off in opposite directions. But that’s jumping ahead in the story. It all started when Henri Becquerel discovered radioactivity by accident. Then Ernest Rutherford acquired basic knowledge about the structure of atoms through incredibly simple “table top” experiments—the likes of which we may never see again. And Marie Curie earned Nobel Prizes in two different scientific fields for, among other things, extracting a tenth of a gram of radium chloride from a ton of pitchblende.

Interesting things also happened when nuclear physics met biology. In 1913, George de Hevesy showed that radioactive tracers can be used to track specific molecules absorbed by plants. Hermann Blumgart took that idea a step further in the 1920s, applying radioactive tracers to medical research. By the 1940s, doctors successfully treated thyroid cancer with what they dubbed an “atomic cocktail.”

Nuclear imaging took off with the development of single photon emission computed tomography (SPECT) and positron emission tomography (PET). Despite their formidable names, SPECT and PET are simply two different ways of displaying metabolic activity—useful for detecting cancers (which are glucose gluttons) and assessing the effectiveness of various treatments. Which one is more appropriate depends on the application. A CT scan can show that there is a tumor; a SPECT or PET scan can show what the tumor is doing. Combine SPECT or PET with CT, and you can match the metabolic activity map to the patient’s anatomy with precision.

Radiation therapy is another important application—crucial to treating many types of cancer. A common trick of the trade is to aim multiple, low-level radiation beams coming from different directions at the target. Only tissue at the point of intersection is destroyed by systems such as the Gamma Knife and Cyberknife. Proton therapy adds another twist, taking advantage of the Bragg peak—the tendency of protons to unload most of their energy in the last few millimeters of travel. The major drawback is that proton therapy requires large and very expensive particle accelerators. Again, the best approach depends on the specific application.

Progress in treating HIV suggests that keeping diseases at bay for long periods may sometimes be more practical than hunting for cures. Perhaps radiation therapy can be improved to the point that it enables physicians to contain most cancers. A combination of nanotechnology and radioactivity may be the key, making it possible to track down and kill individual cancer cells.

There is one other exciting application for radioactivity in medicine—if we can muster the courage to embrace it. The energy locked in atoms can be used to power implantable medical devices for ten years—far longer than chemical batteries. Nuclear-powered pacemakers were introduced at one time, but people freaked out over the Chernobyl and Three Mile Island accidents, and the products were discontinued.

All in all, nuclear medicine has experienced its ups and downs, but it has not lost its glow.

Next time: Sensing Health

Note: If you would like to be notified when The History & Future of Medical Technology is published, please go to Telescope Books and enter your email address in the newsletter sign-up field on the left menu bar. This email list is only used to announce book offers from Telescope Books; your email address will not be shared with third parties.

The History & Future of Medical Technology, Chapter 6

nospam@example.com (Ira Brodsky) — Sat, 27 Feb 2010 16:17:37 -0600

This post is the sixth 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.

Demystifying MRI

Experienced patients know some of the differences between “CAT scans” and “MRIs.” CAT scans are generally fast and easy, but you don’t want to have them repeatedly, because they use x-rays. MRIs are often not as pleasant; you are asked a lot of questions, and then they slide you into a very narrow tube, where you’ll stay for about an hour—assuming you don’t scream “Get me out of here!” before the scan is finished. Whether a CAT scan or MRI is prescribed depends on what your doctor is looking for. Both are expensive.

Perhaps the best way to understand the MRI machine is to compare it with the x-ray machine and CAT scan machine.

A traditional x-ray picture is made by aiming parallel x-ray beams at your body. A piece of film records the amount of x-ray energy that makes it through to the other side. In other words, the image on an x-ray film is a shadow.

A CAT scan also uses x-rays, but with a major twist. Pretend that your body is at the center of a big wheel with spokes. Now imagine that half of the spokes are x-ray beams heading towards your body and the other half of the spokes are the x-ray beams that passed through your body and are heading towards detectors distributed around the edge of the wheel. And yes, the wheel rotates.

Unlike a traditional x-ray, a CAT scan image is not a shadow. Because the x-ray beams rotate around your body, it’s possible to calculate the relative density of specific points inside your body. The result is a finely detailed image of a cross-section of tissue. Repeat the process for adjacent tissue slices, and a three-dimensional image can be constructed.

MRI uses magnetic fields and radio signals instead of x-rays. The first thing you must understand is that the nuclei of many (but not all) types of atoms behave like little magnets. When you get an MRI, you are placed in a very strong magnetic field that causes the little magnets (nuclei) to line up with each other. Actually, just over half line up face forward, and just under half line up face backward. Now, if you turn on a relatively weak radio signal at the right frequency, then it will make a bunch of the little magnets flip around; turn the radio signal off again, and the nuclei gradually return to equilibrium.

What good is this? You may recall from high school physics that thrusting a magnet in and out of a coil of wire produces an electric current in the coil. Similarly, if you can make the nuclei of many atoms swing around in unison, they will produce a signal that can be detected by a coil.

Now that we have a signal, is there any way to extract more information? Yes. One thing I didn’t mention is that the frequency of the radio signal can be set to resonate with a specific type of atom. The most popular choice is hydrogen, because the body is largely composed of water. Another thing I didn’t mention is that if we superimpose a gradient magnetic field on the very strong magnetic field, then there will be slight differences in field strength at each point in the body. We can use these differences to localize the data.

OK, now we can detect the strength and location of the hydrogen signal. Luckily, the signal also varies depending upon the composition of the surrounding tissue. Plus, what I just described is the T1 signal; there is also a related T2 signal. (My book explains more fully how MRI works and how it was developed.)

The original Star Trek television series featured a portable “Tricorder” that could quickly scan a patient—human or alien—providing detailed, on-the-spot diagnosis. A portable device employing MRI’s basic operating principles and using a planet’s ambient magnetic field is not only conceivable, it’s already available for applications such as emergency medicine. Nor is the incredible wealth of data and sophisticated analysis depicted on Star Trek inconceivable. We have only just scratched the surface in exploiting MRI.

Next time: The Nuclear Option

Note: If you would like to be notified when The History & Future of Medical Technology is published, please go to Telescope Books and enter your email address in the newsletter sign-up field on the left menu bar. This email list is only used to announce book offers from Telescope Books; your email address will not be shared with third parties.