Ankle–brachial pressure index grossly overestimate the ABI (by approximately 0.3). A Doppler ultrasound blood flow detector, commonly called Doppler wand or Doppler probe, and a sphygmomanometer (blood pressure cuff) are usually needed. The blood pressure cuff is inflated proximal to the artery in question. Measured by the Doppler wand, the inflation continues until the pulse in the artery ceases. The blood pressure cuff is then slowly deflated. When the artery's pulse is re-detected through the Doppler probe the pressure in the cuff at that moment indicates the systolic pressure of that artery. The higher systolic reading of the left and right arm brachial
Brachial plexus block subjected himself to the supraclavicular block. Later that year, Georg Hirschel (18751963) described a percutaneous approach to the brachial plexus from the axilla. In 1928, Kulenkampff and Persky published their experiences with a thousand blocks without apparent major complications. They described their technique with the patient in the sitting position or in the supine position with a pillow between the shoulders. The needle was inserted above the midpoint of the clavicle where the pulse of the subclavian artery could be felt and it was directed medially toward the second or third thoracic spinous process. By the late 1940s, clinical experience