The arterial tonometer is an instrument used to measure arterial blood pressure. It differs from sphygmomanometer in that, rather than measuring the pressure at greatest contraction and greatest heart dilation (systolic and diastolic) it provides continuous measurement throughout the heart’s pumping cycle. Normally, the instrument sensor is placed over a superficial artery; the radial artery pulse point at the wrist is one appropriate site for tonometer measurements.
We have a number of types of sphygmomanometers that are available for non-invasive blood pressure measurements. However, these instruments are generally not capable of continuous blood pressure measurement additionally their long-term use isn’t feasible. The blood pressure cuff hinders venous return and results in peripheral oedema. On the other hand, the arterial tonometer can be used for beat-by-beat blood pressure measurement over long periods of time with minimal oedema. Key disadvantages of the arterial tonometer include its sensitivity to sensor placement and movement artifacts, effects of anatomical variations, and the greater complexity and cost relative to a conventional sphygmomanometer.
Also read: How a Tonometer is used to Measure Eye Pressure
