The man who invented the heart-lung machine was better known for a creative use of pig hairs

Did you know that the heart-lung machine was invented twice? And that, in typical scientific fashion, almost no one credits the original inventor. Instead, this neuroscientist is known for calibrated pig bristles. To be fair, he didn't invent those, and no one today credits the pigs.

The oldest rule in science is that the person who invented something, be it a concrete object or an airy idea, never gets credit for it. Among those whose names are cruelly stripped from history, one who has more cause to complain than most is Maximilian von Frey. Over half a century before Americans got around to it, the heart-lung machine was invented at the Leipzig Physiological Institute.

The machine allows doctors to attend to the damaged organs while it oxygenates the blood and pushes it around the body. It drains the de-oxygenated blood directly from the heart into a reservoir, and then passes it through a part of the machine with a many crenelations leading to a large, fine surface area. Oxygen is pushed between the surfaces, and the blood, allowing the cells to pick up oxygen atoms, and then sent through the body. It's a pretty complicated piece of machinery . . . especially since it was invented in 1885. It was used nearly exclusively on dogs, and as part of an experimental way to separate out organ groups and design machines to perform their functions. Von Frey's fairly simple device oxygenated blood by slowly pouring it into a cylinder that was rotated around an oblique axis so some blood ran very thinly down one wall. Oxygen was pumped over the blood. Carbon dioxide was pumped away. It worked on dogs, but none of them ever lived, since medicine at the time was not widely advanced enough to keep up with the machine. It was lost in obscurity until it was invented again, in 1953, by Doctor John Gibbons, who gets the credit today.

The man who invented the heart-lung machine was better known for a creative use of pig hairs


Poor von Frey had to think up an invention that wasn't quite so ahead of its time, and he came up with pig hair. (Some say horse hair.) Whatever animal's hide it came out of, it was a sensory gauge; series of stiff hairs, each a little wider in diameter than the last. Either the width or the end of hairs was pressed against any specific part of the body. At some point, either a point of the skin or a width of a hair, the nerves registered the sensation. Von Frey used these to put out a sensory map of the skin, pinpointing spots that were able to register pain sensations, as well as cold and heat.

It's good work, but a heart-lung machine is, anyone will admit, more impressive. Still, Von Frey Hairs are still used in labs, although now they're made of nylon with clearly marked and carefully calibrated widths. There's a lesson to be learned in all of this: Getting too far ahead of your time will just leave you forgotten when your time actually arrives.

Top Image: Eli Rainey

Von Frey Kit Image: Phenome Jax.org
Via Wiley, Brain Behavior Test, Medscape, HSforum, and Neuroportraits.