Ultrafiltrate sampling device for continuous monitoring

A light, portable sampling device for ?he continuous collection and storage of subcutaneous fluid is described. It consists of a hollow-fibre probe for ultrafiltration, a long tube for sample storage and a vacuum tube as driving force. introduction of a restriction in the flow path allows a constant pulse-free flow as low as 100 nl min(-1). The contents of the storage tube reflect the metabolic events that have happened during the 24 h collection period, The ultrafiltrate fluid collected from the subcutaneous tissue is free from large molecules and can be continuously analysed. An application in combination with a bionsensor fbr the analysis of glucose is described, but the device also allows monitoring of other subcutaneous constituents such as ions, metabolites, drugs and their metabolites.