Little more than a century ago, life was a minefield of illness and injury. Women died giving birth, children succumbed to contagious diseases, and a compound fracture—a break in the skin as well as the bone—could prove fatal. You were lucky if you survived to age 40. Now we are living twice as long. We can prevent and cure diseases, and repair and replace many body parts.
How was this radical makeover achieved? The history of medicine is usually described as the slow accretion of knowledge over hundreds of years, punctuated in the late 20th century by the sudden convergence of engineering and biology. The only problem with that narrative is that it misses the two factors most responsible for the development of clinically effective medicine: an epochal invention and a scientific rebellion.
Ironically, that invention was nearly overlooked. While it would enable not only modern medicine but all of the life sciences, it languished in the shadow of a related invention.
The History & Future of Medical Technology
by Ira Brodsky
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.
In the late 16th century, natural philosophers discovered that certain combinations of glass lenses could be used to make distant objects appear closer. The military, commercial, and religious implications of the telescope—sizing up enemy armies, spotting approaching merchant ships, and surveying the heavens—were immediate and stunning. Use a different configuration of lenses, and the very small could appear larger, but that seemed merely a clever technical trick. Its military implications were hard to imagine, and its commercial implications—a customer’s ability to magnify flaws—were hardly welcome.
The microscope’s benefits—if there were any—were unclear. But that wasn’t the only thing that was unclear. Early telescopes and compound microscopes produced notoriously fuzzy and distorted images. By the 1660s, Isaac Newton demonstrated a “reflecting telescope” that, at least in theory, eliminated most of the distortion. Unfortunately, there was no “reflecting microscope” in the offing. Almost two centuries would pass before low- distortion microscopes appeared.
As often happens, the individuals who did the most to prove and improve the technology labored outside the scientific mainstream. A hobbyist named Antony Leeuwenhoek was the first to discover a miniature world teeming with life. And it wasn’t a fluke. He continued making historic discoveries while others scrambled just to replicate his latest finds.
When microscope images finally became sharper and truer in 1829— mainly thanks to the work of another hobbyist, Joseph Jackson (J.J.) Lister— there was still a fog in front of physicians’ eyes. Sciences such as physics and chemistry were advancing by leaps and bounds. But medicine seemed immune to progress. Two thousand years after Hippocrates, physicians still attributed health to a proper balance of humors. There was little knowledge of physiology and no one understood the role of microorganisms in disease processes. Working in the 18th century, a leading English physician attributed bacterial infections to factors such as a “delicate constitution” and weather that was “excessively wet and rainy and moist and cold with Westerly winds.” Purging and bleeding remained the treatments of choice.
J.J. Lister’s ingenious invention (the achromatic microscope) made it possible to see the finest details of cells and tissues—both healthy and diseased. It was no longer necessary to speculate about hidden causes. Armed with Lister’s innovations, scientists in Germany and France rebelled against the medical establishment. In less than two decades, the two millennia old idea that health hinges on a balance of humors was abandoned. The new science of experimental physiology was in, much of it microscope-driven.
By the late 1800s the microscope blossomed as a clinical research tool. Specific disease-causing microorganisms were finally being identified, replacing centuries of misinformation and old wives’ tales with accurate etiology. Optical microscopes evolved to magnify objects up to 1,500 times with 0.25 micron resolution. (There are roughly 25,000 microns to an inch.) Limited by the wavelength of visible light, optical microscopes were pressing against a performance ceiling.
Scientists in the 20th century circumvented the performance ceiling with maneuvers resembling American football “end runs.” Having discovered that beams of electrons behave like light rays, they used electric and magnetic fields to create virtual lenses, and magnified objects more than one million times their size—enough to visualize molecules and even atoms. The inner working of cells, including their genetic machinery, could now be observed in freeze frame video.