Underwater blood pressure meter


Arterial blood pressure is a vital sign resulting from the heart ejection of blood into the circulation. However, up to now no instrument is available on the market that enables blood pressure measurement underwater. The present work details a novel oscillometirc automatic digital blood pressure measurement device especially designed for this purpose.Prototype It consists mainly of analogue and digital electronics in a lexan housing that is rated up to 200 msw, a cuff and a solenoid for inflation of the cuff with air supplied from a scuba tank. An integrated differential pressure sensor, strictly located to the same water depth of the cuff, allows accurate blood pressure measurements.

Calculation of systolic and diastolic pressures is based on the analysis of pressure oscillations recorded during the deflation. Several tests were conducted in a hyperbaric chamber at a pressure of up to 4 bar: Values and the standard deviation of the prototype were comparable to those obtained with manual measurements and automatic clinical instrumentation.

StudySeveral underwater tests were performed in swimming pools to prove the correct functioning of the system. The quality of the recorded pressure oscillations was very good even at 10 msw depth and allowed significant calculation of diastolic and systolic pressures values.  Based on the results we envisage that this novel device will lead to a better understanding of the human physiology in underwater and hyperbaric environments and contribute to an increased safety for diving related activities.



  • Oscillometric Method
  • Automatic infaltion and deflation from a SCUBA tank
  • Microcontroller based
  • ~ 45 – 60s min per measurment
  • Data storage on SD card
  • Validated at 10 – 40 m in a hyperbaric chamber in comparison to a clinical instrument and manual measurment
  • Studies on 10 breahthold divers (Surface, 10m, 20m)
  • No significant increase (max 10mm Hg) of blood pressure was measured


This project was done by our team in collaboration with the Scuola Superiore Sant Anna, Pisa, Italy and CNR - Institute of Clinical Physiology, Pisa, Italy.



Sieber A, Kuch B, Wagner M, L’Abbate A, Dario P, Bedini R. Underwater blood pressure measurement device. Diving and Hyperbaric Medicine. 2008; 38(3): 128-34.

Sieber A, L'Abbate A, Passera M, Garbella E, Benassi A, Bedini R. Underwater study of arterial blood pressure in breath-hold divers. J Appl Physiol. 2009; 107(5): 1526-31 (get the paper here).







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