In the past 30 years, several organizations, such as the US Association for the Advancement of Medical Instrumentation (AAMI), the British Hypertension Society, the European Society of Hypertension (ESH) Working Group on Blood Pressure (BP) Monitoring, and the International Organization for Standardization (ISO), have developed protocols for clinical validation of BP measuring devices. However, it is recognized that science, as well as patients, consumers, and manufacturers, would be best served if all BP measuring devices were assessed for accuracy according to an agreed single validation protocol that had global acceptance. Therefore, an international initiative was taken by the AAMI, ESH, and ISO experts who agreed to develop a universal standard for device validation. This statement presents the key aspects of a validation procedure, which were agreed by the AAMI, ESH, and ISO representatives as the basis for a single universal validation protocol. As soon as the AAMI/ESH/ISO standard is fully developed, this will be regarded as the single universal standard and will replace all other previous standards/protocols.

: In the last 30 years, several organizations, such as the US Association for the Advancement of Medical Instrumentation (AAMI), the British Hypertension Society, the European Society of Hypertension (ESH) Working Group on Blood Pressure (BP) Monitoring and the International Organization for Standardization (ISO) have developed protocols for clinical validation of BP measuring devices. However, it is recognized that science, as well as patients, consumers and manufacturers would be best served if all BP measuring devices were assessed for accuracy according to an agreed single validation protocol that had global acceptance. Therefore, an international initiative was taken by AAMI, ESH and ISO experts who agreed to develop a universal standard for device validation. This statement presents the key aspects of a validation procedure, which were agreed by the AAMI, ESH and ISO representatives as the basis for a single universal validation protocol. As soon as the AAMI/ESH/ISO standard is fully developed, this will be regarded as the single universal standard and will replace all other previous standards/protocols.

A ccurate blood pressure (BP) measurement is an essential prerequisite for proper management of hypertension, independently from the technique employed. The use of too narrow or too short bladders may lead to overestimation of BP, a problem often overlooked by many doctors when measuring BP in obese subjects. 1 To avoid the consequences of miscuffing, a number of approaches have been used over the years. 1,2 Correction formulae have been suggested to adjust measurement errors, a procedure which has the disadvantage of further complicating the BP measurement. Other investigators have proposed the availability of a range of cuffs, so that the user after measuring the arm circumference can choose the appropriate cuff size. However, this requirement is usually neglected in clinical practice. More recently, cuffs containing bladders of varying dimensions have been made available but also these models did not find widespread use because of cuff stiffness, and because of its cost. An adjustable cuff which may encircle all adult arms has been designed by a British Company but there is no sufficient experience to recommend its use. 1,2 Automatic devicesIn the modern era of BP assessment, the different function of the cuff in the different measurement methods should be highlighted. Whereas with traditional auscultatory technique the role of the cuff is to compress the artery under a defined reference pressure, with oscillometric devices the cuff is at the same time the signal sensor. Moreover, depending on the device algorithm, the signal sensing may take place not only during the pressure deflationary phase, but also, or even exclusively, at the inflationary phase and the measurement ends after the systolic pressure is detected. This leads to additional cuff performance requirements in oscillometry compared with Korotkoff. Special attention should be put on the signal transmission characteristics with different bladder materials (for example Latex, PVC, TPU), and on the inflation modality that should not generate noise from sticky bladder walls, friction between bladder and enclosure, or instable or worn out Velcro enclosures. It is therefore important in device validation studies also to document the type, shape and material characteristics of the cuff under investigation. It should be reported whether the cuff has a D-ring typical for self-application cuffs, or no D-ring typical for clinical use when the cuff is applied by another person. BP measurement in the obeseObesity is an emerging problem in developed countries and may result in inaccurate BP measurements. The regular adult cuff size is too short for individuals with an arm circumference of 32 cm or larger and thus overweight and obese patients will often require the use of large-sized cuffs. In patients with morbid obesity, one will encounter very large arm circumferences with short upper arm length. In these patients, measurement with a cuff of the appropriate size is often difficult because the elbow end of a large cuff may extend past the elbow by several cen...