Editor's Note
Inside the Black Box
For physicians, the human body is a black box, and the practice of medicine is a quest for clues about what lies therein. Like players in the game 20 Questions, physicians interrogate that box. Like carpenters searching for studs in walls, they tap on it. Like safecrackers listening for tumblers, they auscultate from top to bottom. When the talking, tapping, and listening aren’t enough, physicians look to technology for more insight.
Perhaps no region of that living, breathing black box is more obscure than the abdomen. During my introduction to physical diagnosis in medical school, I remember listening to attending physicians describe the details of examining an abdomen and thinking, Is that all we can do? The cardiac exam with its murmurs, rubs, and neck veins seemed to yield true physiological clues. The lungs with their rhonchi, rales, and “dullness to percussion” seemed almost tangible below my stethoscope. But abdomens were amorphous blobs of tissue hiding subtle liver edges, ill-defined masses, and that most elusive of physical findings, the spleen. Today, abdomens are getting bigger and trickier to examine, as America’s obesity epidemic complicates the investigation of the gut.
Gastroenterologists needed a tool for looking inside that black box, and they found it in the form of thousands of glass fibers that could let them peer into the darkness of the intestinal tract and, rather than infer disease, see it.
Like many modern innovations, fiberoptics has a long history. In 1841, Swiss engineer Daniel Colladon demonstrated “light guiding,” in which light from an arc lamp was carried through a stream of water. Light guiding was relegated to parlor tricks and fair displays until 1888, the year two Vienna physicians used a glass rod illuminated at one end to examine a throat. Later, inventors started using smaller and smaller glass rods, sometimes produced by attaching hot glass to an arrow and shooting the arrow to stretch the glass to .0001 inch in diameter.
Yet all this experimentation didn’t significantly touch the medical field until German medical student Heinrich Lamm, realizing the limitations of rigid gastroscopes, started working with bundles of flexible glass rods, which he theorized could transmit an image by internal reflection. Lamm bundled small glass fibers, gave them a bend, focused the light from a V-shaped filament light bulb at one end of the bundle, and saw a faint “V” at the other end. In 1930, at the age of 22, Lamm recorded the image on photographic film. Unfortunately, Lamm’s research stalled when he fled Nazi Germany for the United States and became a practicing physician in Harlington, Texas. His discovery faded into obscurity only to be rediscovered in the 1950s by scientists who refined the glass bundles, the light source, and the optics to make the forerunner of the flexible scopes used in gastroenterology today.
The current generation of scopes permits not just looking but fixing. So gastroenterologists who extract common bile duct stones, probe through the stomach wall, and use ultrasound at the end of an endoscope owe a debt to Daniel Colladon, Heinrich Lamm, and their scientific descendents. Those snaky bundles of fibers have shed great light into the darkness of the human black box and made gastroenterology into the science it is today.
Charles R. Meyer, M.D., editor in chief
Dr. Meyer can be reached at
cmeyer1@fairview.org