The man behind the science of blood pressure

I recently rediscovered this magnificent photo of a new apparatus for measuring blood pressure. This photo has been previously mislabeled as being a photo of Samuel Von Basch, but as Von Basch was born in 1837 and the device on the photo dates from 1898, it is definitely not Von Basch, but rather Riva-Rocci himself demonstrating the use of his new sphygmomanometer.

Who was Riva Rocci and how did he come to "invent" the blood pressure monitor?

Scipione Riva-Rocci was born next to Turin in 1863. He graduated in medicine at the University of Turin in 1888 and spent his first postgraduate years in the Institute of Clinica Medica. He showed a great creative and critical mind and was a key contributors to the development of the ar­tificial pneumothorax. These studies were the basis for one of the leading therapeutic procedures used for many years in the battle against tuberculosis. Through these studies he gained great expertise in controlled pressures. He then became interested in the problem of noninvasive measurements of blood pressure, which had defied the in­genuity of many investigators for decades. His studies on the subject were presented at the Accademia Medica Reale di Torino in 1896, where he presented "Un nuovo sfigmo­manometro" (a new sphygmomanometer).

A delicate procedure...

The word sphygmomanometer is Greek and means "pulse pressure meter". Riva-Rocci's method involved several steps to obtain the systolic blood-pressure. A rubber cuff covered with a thin cloth was wrapped around the patient’s arm. The physician would feel for the patient’s pulse in the wrist (the radial pulse), and then inflate the cuff using a rubber bulb. The cuff was inflated until the radial pulse could no longer be felt. Pressure in the cuff was measured by the height of the mercury in the sphygmomanometer’s vertical glass tube. The physician would then slowly release the pressure in the cuff while watching the level of the mercury to note at which line the radial pulse could again be felt – This was the systolic pressure.

However, it is important to know that this was not blood pressure as we know it today. Even though Riva-Rocci invented the method that is still in use today, he only measured the systolic blood pressure. It was the Russian scientist Nikolai Korotkoff who first, using the Riva-Rocci device in 1905, started measuring the diastolic blood pressure, thus establishing the basis for blood pressure measurement that we still use today.

There are several Riva-Rocci devices in the HealthWorks Collection. Varying in sizes, details, accuracy, that are a testament to the ingenuity of the people who developed and used them. Discover more of these magnificent devices on www.bloodpressurehistory.com.

The importance of Riva-Rocci's work cannot be emphasized enough. His contribution was fundamental for three reasons:

1) He proposed the use of the brachial rather than the radial artery to measure blood pressure. He had a clear understanding of the advantage of a larger arterial size to give repeatability in blood pressure measurements. Before Riva-Rocci, all the devices such as the Vierrodt or Bloch sphygmometers, the Marey and Dudgeon sphygmographs, used the wrist (radial artery) as a point of reference. Measurement of vital signs at the wrist, because of the ancient art of palpation, was considered as a medical standard.

2) The pneumatic cuff he devised allowed exertion of an even pressure around the artery. This avoided the eccentric compression of the more peripheral arteries which had led previous devices to overestimate blood pressure and made their readings unreliable. Previous devices used rubber balls filled with air or water that were applied directly against the radial arteries, giving uneven pressure distribution.

3) He made the measurement of blood pressure portable and usable outside the laboratory, at the bedside of patients. The idea being to move the devices rather than move the patient, in many ways a precursor, or at least a starting point, for the concept of tele-medicine.

Scipione Riva-Rocci's work made him a precursor of cardiovascular epidemiolo­gy. His device allowed physicians to take large amounts of readings on an even scale for comparisons and analysis of evolution of a specific disease.

What a man...

And more notably, Riva-Rocci always refused to patent his invention and did not make any financial gains from its widespread use.

I am often asked the question about who really invented the blood pressure monitor, as we know it today. The chronology is as following:

1) In 1896, Riva-Rocci discovers that by encircling the brachial artery with a rubber tube, it is possible to measure systolic blood pressure.

2) Harvey Cushing and Theodore Janeway in the USA make substantial improvements on Riva-Rocci's device by increasing the cuff-width (Riva-Rocci's cuff was only 5cm wide).

3) In 1905 Nikolai Korotkoff discovers that it is possible to measure diastolic blood pressure with a Riva-Rocci-like device.

4) Drs Henry Vaquez and Charles Laubry in Paris replace mercury with air and, together with Emile Spengler, manufacture the first aneroid (arm-mounted) sphygmomanometer. For the following 100 years, the mercury column devices created by Riva-Rocci and the aneroid devices created by Spengler lived side by side with no fundamental changes in design.

Now that is a beautiful story...

Discover the history of blood pressure on www.bloodpressurehistory.com