Coronary pressure measurements: catheter induced errors

Estimation of discretization errors in contact pressure measurements.

Contact pressure measurements in total knee replacements are often made using a discrete sensor such as the Tekscan K-Scan sensor. However, no method currently exists for predicting the magnitude of sensor discretization errors in contact force, peak pressure, average pressure, and contact area, making it difficult to evaluate the accuracy of such measurements. This study identifies a non-dimen...

Airborne measurements of terrain-induced pressure perturbations

Airborne measurement of the horizontal pressure field using differential GPS technology has been established during the last few years. Accurate aircraft measurement of the horizontal pressure gradient force requires an independent determination of the height of the airborne platform above some reference level. Here the authors demonstrate a differential GPS technique that uses data from a fixe...

Pulling geometry-induced errors in single molecule force spectroscopy measurements.

In AFM-based single molecule force spectroscopy, it is tacitly assumed that the pulling direction coincides with the end-to-end vector of the molecule fragment being stretched. By systematically varying the position of the attachment point on the substrate relative to the AFM tip, we investigate empirically and theoretically the effect of the pulling geometry on force-extension characteristics ...

Catheter-Induced Spiral Dissection of the Left Main Coronary Artery

Catheter-induced spasm of the left main coronary artery.

Catheter-induced spasm of the left main coronary artery is rare during catheterization. We present several cases in which the occurrence of both ostial left main and right coronary spasm suggests that multiple sites of spasm may be a clue to this important diagnosis.