Patient's arm is in supination. The brachial artery will be located in 2 cm proximal to the antecubital fossa. Hemodynamic Parameters will be measured by Pulsed-wave Doppler(PWD) ultrasound. The probe will be parallel the long axis of the arm without undue pressure on the artery during the PWD measurements. The volume gate will be positioned in the center of the arterial lumen, and the size of the gate will be 1/3 lumen of the artery. The angle of insonation will be adjusted and maintained at 50-60 degrees. Once a desired PWD spectral waveform is achieved, the arterial hemodynamic parameters will be recorded. The cross-sectional area (CSA) of the artery will be assessed with B-mode imaging. Probe should be as perpendicular as possible to the long axis of the artery to obtain as round an arterial section as possible. The image at end diastole will be chosen and measured with the cine loop.