The Sphygmometer

"AN INSTRUMENT WHICH MAKES EVERY ACTION OF THE ARTERIES APPARENT TO THE EYE"

The medical Definition of sphygmometer is an instrument for measuring the strength of the pulse beat. The name is derived from the Ancient Greek, σφυγμός, sphygmós (“pulsation”) and -meter (“to measure”).

The concept of the sphygmometer was originally invented by Jules Herisson, a French doctor who published his memoir on the device in 1835.

“The sphygmometer, an instrument which renders the action of the arteries apparent to the eye : the utility of this instrument in the study of disease, researches on the affections of the heart, and on the proper means of discriminating them considered : being a memoir, presented to the Institute of France”

Not much larger than the average retractable pen with a grip, the sphygmometer could easily fit in a physician’s pocket, making it a popular instrument in Europe for medical diagnostics from the 1890s through the 1920s. The original design was introduced around 1888 by the French physician Adolphe-Moïse Bloch (1842-1920). It featured a circular dial with a rotating needle. The French manufacturer Charles Verdin simplified it by replacing the bulky dial with a telescoping scale.

To use the device the physician would rest his finger over the patient’s radial pulse, place the padded tip of the device onto his finger, and then, applying downward force on the rod, push his finger into the patient’s wrist. This caused the scale to rise from the interior of the rod. He continued this pressure until he no longer felt the patient’s pulse. At this point the physician would note how far the telescoping bar had emerged from the rod, or how far the needle had moved along the scale. The scale is graduated in grams from 100 to 1200. Later versions were marked in millimeters of mercury as well. After researchers demonstrated that readings from these types of sphygmometers were consistently unreliable, their use fell out of favor.

There are several sphygmometers in the O’Brien/HealthWorks Collection, with the most notable being the ones from Bloch and Cruise.

A rare 1908 “Sphygmometer de Sir Francis R Cruise” made by Collin who was a well know French instrument maker. Cruise’s instrument used an anaeroid manometer to demonstrate the pressure it took to obliterate the pulse.

The instrument was held vertically over the supinated wrist by the red Bakelite handle between thumb and forefinger. The lower end of the manometer would be placed on a bulb over the radial pulse. Pressure downwards through the handle was measured on the dial and the reading would be taken at the point at which the radial pulse disappeared.

Sir Francis Richard Cruise (1835-1912) a famous Irish Surgeon ranks among the good and great of the medical profession and was also known for inventing the endoscope. He was the physician of King Edward VII.

A rare 1888 Bloch sphygmometer made by Boulitte in Paris.

This sphygmometer was inspired by one designed by physician A.M. Bloch. It measured blood pressure by slowly applying a measured force to the skin over an artery until the pulse disappeared. However, the instrument was not widely used as doctors were wary of replacing traditional methods of using their fingers to determine pulse or that any information from the sphygmomanometer was useful. This variation was devised by A. M. Bloch. It uses a spring to record the weight necessary to obliterate the pulse.

When it was first created, the sphygmometer was thought of as a highly important scientific and diagnostics tool and indeed became part of the everyday panoply of tools used by doctors. In 1986 the great cardiologist Edouard Toulouse undertook a scientific examination of French writer Emile Zola to demonstrate the direct link between superior intellect and neuropathy. Dr A. M. Bloch used his new achromatometer to measure the capillary circulation in Zola’s fingers, and a sphygmometer recorded his pulse.

Results of Emile Zola’s sphygmometer test. Included in Edouard Toulouse, Emile Zola: Enquête médico-psychologique

These two magnificent devices illustrate the minutious way in which way the doctors of the day approached scientific discovery and the analysis of the human body. Unfortunately they also heralded the demise of palpation, which was replaced by mechanical devices.

Discover these, and many other magnificent antique blood pressure devices on https://www.bloodpressurehistory.com