Continuous beat-to-beat arterial blood pressure (BP) monitoring with a simultaneous arterial waveform display is typically achieved with an invasive arterial catheter. We evaluated a noninvasive device, the T-Line Tensymeter, that provides a calibrated arterial pressure waveform from which continuous BP measurements and heart rate may be computed by either a bedside host monitor or the tensymeter device itself. In 25 patients given general anesthesia, we measured systolic, mean, and diastolic BPs via the tensymeter and compared these measurements with those obtained from the contralateral radial artery catheter. Data were analyzed using the Bland Altman test to determine agreement between the two systems. The mean +/- sd bias and precision (mm Hg) were as follows: 1.7 +/- 7.0 and 5.7 +/- 4.4 for systolic BP; 2.3 +/- 6.9 and 5.7 +/- 4.5 for diastolic BP; and 1.7 +/- 5.3 and 4.0 +/- 4.8 for mean BP. Noninvasive pressures from the tensymeter-produced arterial waveform agreed with simultaneous contralateral BPs measured from arterial catheters within an acceptable clinical range for a limited population of surgical patients studied over a systolic arterial BP range from 41 to 189 mm Hg without significant temporal performance degradation. The tensymeter may enable physicians to circumvent arterial cannulation in certain circumstances (such as with low- or intermediate-risk procedures) on patients when beat-to-beat BP measurement is desirable.

Artifacts are frequently encountered during echocardiographic examinations. An understanding of the physics and underlying assumptions of ultrasound processing involved with image generation is important for accurate interpretation of 2D grayscale, spectral Doppler, color flow Doppler, and 3D artifacts and their clinical implications.