A venous occlusion plethysmography using a load cell as the sensing element

An application of the load cell as a sensor in venous occlusion plethysmography is presented. In this method the limb volume changes that follow venous occlusion are converted into water volume changes using a water tank for volume change detection. The hydrostatic pressure, as well as the water surface level, is measured and used for the calculation of the volume change. By using this method the influence of water pressure on limb blood flow, as well as drift and leakage of the sensing element, is avoided. The load cell has the advantage of measuring the weight of the displaced water volume, which simplifies the design principles of the plethysmography. The plethysmography is found to be sensitive, highly linear, and easy to handle. It has been evaluated in several subjects, and the results of these studies are in agreement with earlier results