CLINICAL EVALUATION AND REFINEMENT OF AN ULTRASONIC BLADDER VOLUME DETERMINATION SYSTEM

Abstract

An ultrasonic method to determine bladder volumes could help eliminate some of the risk and discomfort resulting from catheterizations. A system using "A" mode ultra-sound correctly estimates bladder volumes to within 50 cc's. Near and far walls of bladder sections found at various positions define the bladder, and volumes calculated from these sections are added together for a bladder volume estimate. Accurate volume estimates (mean error of -1.9 cc.'s with standard deviation of 28 cc.'s) were obtained when bladder section characteristics such as: depth of the near wall of the bladder, thickness of the far wall echo, distance between near and far bladder walls, and amplitude of the far bladder wall echo, were considered. Most bladders were completely scanned with the transducer placed at the bodies midline, approximately 5 to 7.5 cm. above the pubic bone.