Development and Evaluation of a Precision Forearm and Hand Volumeter and Measuring Cylinder

An Obturator Reduces Time for Volumetric Measurements of the Foot and Ankle

“…Because residual water adheres to the sides of cylinders when water is transferred, using a single tank as a measuring cylinder eliminated error associated with transferring water into multiple graduated cylinders to determine overall displaced volume. 4 Vernier Calipers To improve precision, measurements of displaced volume were taken with Vernier calipers that measured to a precision of 0.05 mm (Mitutoyo Corporation, Tokyo, Japan). The inside jaws of the calipers were used to measure the distance between levels 1 and 2, which was read from the scale on the calipers ( Figure 2).…”

“…4 Thus, an operator could use the calipers to measure volume changes to a precision of better than 0.5 mL, and no graduated measuring cylinder that was commercially available could match this. The reliability, accuracy, and sensitivity to change in volume of this method has been demonstrated.…”

“…The reliability, accuracy, and sensitivity to change in volume of this method has been demonstrated. 4 Obturator The obturator was a plastic container that was chosen because it both increased displaced volume (proposed to improve accuracy) 13 and occupied a large surface area, which we proposed would reduce the surface area available to transmit turbulence. Two pieces of wood were fixed externally on opposite sides so that the obturator was firmly supported in the volumeter.…”

“…Both the observer and subject could see whether the obturator was used during measurements, but could not see the watch face during measurements. Water was warmed to between 28°C and 32°C during all measurements, 4 and subjects remained seated between measurements.…”

“…16 Water displacement provides a direct measure of volume and is the gold standard or criterion reference for other methods. 2,4,10 The foot is immersed into a water-filled tank and the volume of displaced water is measured. The advantage over tape methods is that volume can actually be determined, compared with indirect estimates of volume that only correlate with volume change.…”