The defibrillator has now become so refined that it is facilitating the saving of many lives by first responders and regular civilians. However, the invention of the defibrillator took many decades of work starting over 90 years ago.
In 1925 the power company Consolidated Edison of New York funded a handful of sites around the United States including Johns Hopkins University to study the ravages of electric shock. They had witnessed the bleak fates of many power utility linemen who died on the job due to electrical shocks. The investigation at Hopkins, under the general direction of Hopkins physician William Henry Howell, included a wildly disparate interdisciplinary team spearheaded by someone with no medical background at all—William B. Kouwenhoven, a professor of electrical engineering known for his creative mind.
By 1933, the team had stumbled across an amazing finding: by administering another surge of electricity, called a countershock, they were able to restore sinus rhythm and normal contraction, making a dog’s fibrillating heart beat normally again–a process called defibrillation. Confirming the results of an all-but-forgotten paper that had appeared in an 1889 medical journal, Kouwenhoven’s team prompted scientists elsewhere, including those at Case Western Reserve, who used the technique on patients who had slipped into ventricular fibrillation during surgery. In 1947, Case Western’s Claude Beck, a 1921 graduate of the School of Medicine, was the first to place electrodes directly on the heart of a patient suffering VF during surgery.
At Hopkins, Kouwenhoven’s studies also inspired Division of Anesthesiology researchers James Elam and Peter Safir, who would go on in the 1940s to perfect the emergency mouth-to-mouth method of lung ventilation, crucial for oxygenating the blood when the heart stops.
Kouwenhoven and team member Milnor, a cardiovascular surgeon, began working on a closed-chest defibrillator in 1950, testing various electrical currents, pulses and electrodes to find the ideal combination that would jar the heart back to normal cadence. After hundreds of laboratory tests, they developed a prototype machine to do the job on humans.
The novel contraption was unwieldy–a hefty 200 pounds mounted on a wheeled cart–and delivered AC current via two main electrodes placed on the chest. During the initial experiments on dogs, Knickerbocker, a young engineer on the team, noticed a small rise in blood pressure when the electrodes were pressed into position, even before any current passed through them. Was it possible, he speculated, that pressing rhythmically on the chest could cause the blood to circulate? From that observation, Knickerbocker and Kouwenhoven led the way to the team’s third major discovery: cardiac massage, the technique that would become key to cardiopulmonary resuscitation.
Finally, in 1957, for the first time, the defibrillator saved the life of a patient suffering VF in a Hopkins operating room. Three years later an emergency use of the machine at the hospital set the course for the principal use of the remarkable machine.
With this success, electric companies urged further experiments, encouraging the development of a closed-chest defibrillator that would be portable and also inexpensive. The innovative Kouwenhoven went on to develop that smaller model–svelte in comparison at only 45 lbs, 20” x 15” x 7 1/2” and powered by a small battery or AC current.
For his remarkable contributions to cardiology, in 1969 Kouwenhoven received the first-ever honorary Doctor of Medicine degree from Hopkins. Four years later, his tremendous trio of contributions–confirmation of the effects of countershock, the refinement of open- and closed-chest defibrillators, and the development of external cardiac massage–earned him the U.S.’s most prestigious scientific honor: The Albert and Mary Lasker Foundation Award.
Read the whole article: HopkinsMedicine.org