Blood pressure - how was it measured 300 years ago?

Today, blood pressure measurement is one of the most effective, simple and fastest methods for diagnosing diseases of the cardiovascular system and other body systems. Incredibly, a mechanical blood pressure measuring device similar to today's was only constructed at the end of the 19th century, around 1896. So, we have been measuring blood pressure effectively and quickly for just over 100 years.

How was blood pressure measured before?

Until 1709, blood pressure was not measured at all, as no methods were described for doing so. In 1709, Stephen Hales began experiments on animals to measure blood pressure. Stephen succeeded in developing the first invasive method of measuring blood pressure, where a tube with a scale was inserted directly into an artery and the blood pressure was measured. A sketch of the test being performed, made by an unknown artist, survives to this day:

It goes without saying that the method was quite dangerous and painful, so the scientist did not dare to measure blood pressure in humans using this method, but the foundation for further blood pressure measurement research was laid.

It took over 100 years to improve Stefan's method so that blood pressure could be measured not directly with a graduated tube with a scale, but using a mercury manometer. The manometer was connected directly to the artery and blood pressure was measured in this way. The method was first described by the physician Jean-Louis Marie Poiseuille in 1828. The method is undoubtedly superior to the previously developed method of Stefan Hales, but it is still primitive and dangerous.

The real "leap" in the history of blood pressure measurement can be called the discovery of Karl von Vierordt - the sphygmograph. With its help, the scientist measured the force required to completely stop blood flow in the brachial artery in 1855. This is the first non-invasive method of blood pressure measurement, which, although significantly improved, is still used today.

Karl von Vierordt's blood pressure measurement method was improved by various scientists from all over the world, but the most similar to the current mechanical blood pressure machine was created by Riva-Rocci in 1896. His machine had a cuff, a balloon, and a blood pressure measuring scale - all parts are identical to those used today. The only difference is that blood pressure was recorded not with a mechanical (as it is now), but with a mercury manometer. You can see Riva-Rocci's blood pressure machine below:

However, one part – the stethoscope – was missing from the Riva-Rocci apparatus. At that time, only systolic blood pressure was measured, since the monometer recorded only it. In 1905, the Russian scientist Nikolai Korotkov described the aural method of measuring blood pressure using a stethoscope and the Riva-Rocci blood pressure measuring apparatus. This method is still used today. It is very simple and clear – air is blown into the cuff, which compresses the brachial artery and cuts off blood flow in it. Then the air is gradually released from the cuff and the sounds are listened to with the help of a stethoscope. The beginning of the sounds reflects the systolic blood pressure, and the end of the sounds – diastolic blood pressure.