Most of you are quite familiar how your doctor feels the pulse. It is not uncommon to find children amused at the physician's ways checking their vital signs, especially the blood pressure, at some point in time when they complained of sickness. But have you ever wondered what it takes to measure such a vital parameter called blood pressure, which holds the key to your health "from cradle to grave"? The instrument called sphygmomanometer is equipped with sophisticated software to read the values of blood pressure that allows your physician to gauge the systolic (highest pressure) and diastolic (lowest or resting) heart beats in conjunction with a stethoscope. There are at least three types of sphygmomanometers, with research constantly developing newer and more efficient versions.
Digital Sphygmomanometer
An improved version over the manual one, the digitally validated piece is equipped with sophisticated software that can collect the data and play back the recorded sound and pressure differences for assessment of systolic and diastolic heart beats. This system has been developed by Dr. Lee and colleagues at the Department of Biomedical Engineering, Hanyang University, Seoul, Korea (Lee J, Park D, Oh H, Kim I, Shen D, Chee Y. Digital recording system of sphygmomanometry. Blood Press Monit. April 2009). The data collection from patients is enabled by the measurement device, while the cuff, microphone, and amplifier add to the user-friendly features of the recording system.
Automated Oscillometric Blood Pressure Monitors
Researchers find that the automated versions may be used to accurately measure ankle brachial pressure index (ABPI) in non-diabetics in the community. ABPI is used to check whether or not you have a cardiovascular ailment called peripheral arterial disease. Indeed, accuracy (specificity and sensitivity) is critical in the measurement of blood pressure to diagnose heart conditions, and also to exclude risk in certain patients. (MacDonald E, Froggatt P, Lawrence G, Blair S. Are automated blood pressure monitors accurate enough to calculate the ankle brachial pressure index? (J Clin Monit Comput. 2008 Oct 22(5):381-4)
Conventional Sphygmomanometers
These are operated manually: the mercury sphygmomanometer is a reliable device, while the conventional aneuroid BP cuff with hand-held Doppler is less accurate. Both work on the inflation-deflation principle, and your physician still needs a stethoscope to measure the blood pressure (O'Brien E, Petrie J, Littler WA, de Swiet M, Padfield PD, Dillon MJ. London: BMJ Books; 1997. Blood pressure measurement: Recommendations of the British Hypertension Society. 3rd ed.). The risk of mercury contamination by accidental spillage can be real, and it is only appropriate that cutting-edge electronic instruments that are validated and automated for accurate calibration. In any case, the accuracy of blood pressure measurement depends not just on the instrument but on the individual and your physician, who interprets the readings to reflect your health status at a given point in time.
References
- Lee, Jongshill; Park, Daekyu; Oh, Hongsic; Kim, Inyoung; Shen, Dongfan; Chee, Youngjoon. Digital recording system of sphygmomanometry. Blood Pressure Monitor. 2009 April; 14(2):77-81
- MacDonald E, Froggatt P, Lawrence G, Blair S. Are automated blood pressure monitors accurate enough to calculate the ankle brachial pressure index? J Clin Monit Comput. 2008 Oct 22(5):381-4
- O'Brien E, Petrie J, Littler WA, de Swiet M, Padfield PD, Dillon MJ. London: BMJ Books; 1997. Blood pressure measurement: Recommendations of the British Hypertension Society. 3rd ed.
