An adjustable blood pressure cuff to correct errors due to variations in arm circumference.

A well-recognized source of error in the indirect measurement of blood pressure results from using the standard sphygmomanometer cuff for arms of widely different diameters (Pickering, 1955). When the arm is thicker than usual, blood pressure readings are higher than those obtained by direci intra-arterial measurement; when the arm is thinner; the readings are lower. Hence, for correct indirect measurement, the width of the blood pressure cuff should be in proportion to the circumference of the arm (Bordley et al., 1951). Since it is impractical to use a large series of cuffs of different widths, a special cuff was constructed that could be adjusted to the appropriate width for each subject. With this adjustable cuff, the error in blood pressure reading due to variation in thecircumference of the arm was largely eliminated.