Department of Urology, Collection of Santa Casa da Misericórdia do Porto, deposited in HSA
Developed by the Parisian company "G. BOULITTE" between 1919 and 1925.
Pachon sphygmomanometer was an instrument used to measure the upper (systolic) and lower (diastolic) blood pressure as a function of the oscillating amplitude of the arterial wall under a certain pressure, i.e. blood pressure at the moment the heart contracts and drives blood to the arteries, on the one hand, and vessel resistance to blood passage, on the other.
Doctors have measured systolic (maximum) blood pressure since 1800, but they had difficulty measuring diastolic (minimum) pressure.
The first breakthrough in blood pressure measurement instruments came in 1881 with Austrian physician Samuel von Basch (1837-1905), who developed the first modern sphygmomanometer. In 1896, Italian doctor Riva-Rocci (1863-1937) improved this mechanism by introducing a candlestick and a rubber bag wrapping the arm and establishing complete arterial compression. In 1905, Russian surgeon Nikolai Korotkov (1874-1920) introduced stethoscope auscultation instead of arterial pulse palpation.
In 1909, French physician and physiologist Michel Victor Pachon (1867-1938), in collaboration with engineer Charles Boulitte, proposed a sphygmomanometer that used an operating mechanism based on aneroid barometers and allowed diastolic pressure measurement. Clamp was wrapped around the arm and inflated to make the wrist disappear. Diastolic pressure was obtained from the difference between maximum and minimum needle oscillation.