Shocking History: How a NIST Engineer Helped Create Lifesaving CPR

Even if you’ve never learned the first-aid technique CPR, you’ve probably seen it on a TV show or movie and would recognize it happening: A person in medical distress lies on their back while a responder kneels over them, rhythmically pressing their hands into the patient’s chest to keep the heart pumping.

Somewhat surprisingly to me, two electrical engineers, one of whom worked here at NIST, helped create the technique we know today as cardiopulmonary resuscitation, or CPR.

As a NIST librarian interested in our organization’s history, I started looking into the origins of CPR after coming across a photo from 1932. NIST, then known as the National Bureau of Standards (NBS), published this photo in a household safety publication. It was labeled a resuscitation technique but didn’t look like CPR as I recognized it.

The pictured technique is called “Schafer’s prone pressure method,” and it was developed by British physiologist Edward Sharpey-Schafer in 1903 to help revive drowning victims. In the first half of the 20th century, it became the standard technique for artificial breathing.

From Drowning to Electric Shock

By the early 1900s, the use of industrial and residential electrical equipment had grown rapidly. However, there was a hazardous lack of standardization in its design, construction, operation and maintenance. This led to NIST developing the National Electrical Safety Code, which we published from 1913 to 1972. (After 1972, this responsibility transitioned to a private sector association.)

The new safety code for electrical equipment recommended that a copy of instructions for the prone pressure method be available to help revive victims of electrical shock. NIST and other interested groups officially made Schafer’s prone pressure method of first aid a standard in 1927, helping to broaden the technique's use in the United States.

In the 1920s, electric companies rapidly expanded. At the same time, their utility line workers who accidentally received even small shocks of electricity were dying. So, one of the largest utility companies, Consolidated Edison of New York, worked with Johns Hopkins University medical experts to study the effects of electricity on the human body. They asked Johns Hopkins electrical engineering professor William B. Kouwenhoven, who’d previously worked as a NIST researcher during World War I, to contribute to the effort.

Inventing CPR

The researchers determined that small electrical shocks could interfere with the natural rhythm of the human heart (a condition called ventricular fibrillation). Applying a second jolt of electricity, known as a “counter-shock,” would restore the heart’s normal rhythm. Kouwenhoven developed a device to apply the lifesaving counter-shock directly to the heart. This invention was called a defibrillator.

But there was a problem. The defibrillator required cutting open the patient’s chest to access the heart and could only be used in a hospital setting. Kouwenhoven’s next goal was to create a defibrillator that didn’t require surgery and would be easy to use in any setting.

His efforts were disrupted by World War II, during which he collaborated again with NIST to work on battery standards. After the war ended, Kouwenhoven returned to his defibrillator idea and recruited two assistants to help: electrical engineering graduate student G. Guy Knickerbocker and physician James R. Jude.

By the late 1950s, the three men had built a functioning closed-chest defibrillator. Their prototype weighed 90 kilograms (200 pounds) and used heavy copper paddles to apply the counter-shock to the chest. As they tested the device on a dog, Knickerbocker noticed that the weight of the paddles alone pressing on the dog’s chest increased its blood pressure.

The team experimented with manually compressing the chest with their hands. They worked out a technique that could restore about 50% of normal blood circulation, enough to keep a patient alive until further medical treatment was available. They called their hands-on process closed-chest cardiac massage, which would eventually acquire the more clinical name cardiopulmonary resuscitation, or CPR.

Kouwenhoven, Knickerbocker and Jude published their technique in the Journal of the American Medical Association in 1960. In the following years, they promoted CPR to the medical community across the U.S. and internationally. By the end of that decade, CPR had replaced Schafer’s prone pressure method as a primary first-aid technique.

CPR Today

More than 350,000 people experience cardiac arrest while outside of hospital settings each year, with about 40% receiving bystander CPR, according to the American Heart Association.

Defibrillators have become more commonly available. More than 200,000 portable defibrillators are sold in the U.S. annually, with an estimated 1,700 lives saved by their use.

CPR and defibrillators are also an important part of NIST’s own safety culture. We offer training to our employees in these techniques and tools, continuing the lifesaving legacy of a former NIST staffer from the distant past.