Abstract:
A system (1) and a method for determining a residual volume of a container unit (2) is disclosed. The system (1) comprises a container unit (2) comprising at least a primary container (3), means for applying a pressure inside the primary container (3), a flow restrictor (14) fluidly connected between the primary container (3) and the exterior of the container unit (2), means (P1, P3) for measuring a rate of pressure change of a pressure of the container unit (2), and means for determining a residual volume of the container unit (2) based on a measured rate of pressure change. The pressure inside the primary container (3) is allowed to adapt to the pressure of the exterior position in a controlled manner via the flow restrictor (14). Knowing the initial pressure in the primary container (3), and the flow resistance of the flow restrictor (14) the rate of pressure change is defined by the volume of the primary container (3), and this volume can thereby be determined. The volume of the primary container (3) thus determined may be the residual volume. Alternatively, the volume of the primary container (3) may be used for deriving another residual volume of the container unit (2).
Abstract:
A method of forming a flow restriction in a fluid communication system is disclosed. The method comprises the steps of providing a flow restricting section having a cross sectional area and a length, measuring the flow resistivity of the flow restricting section, and modifying the cross sectional area and/or the length of the flow restricting section until a desired flow resistivity of the flow restricting section is obtained. The method provides the possibility of forming a flow restriction in an easy and cost effective manner, and to subsequently adjust the flow resistivity of the flow restriction, thereby obtaining an accurate flow resistivity.
Abstract:
A method of making a micro-dialysis probe (6) by providing a first flow channel (4), a second flow channel (5) and a separating wall (3) arranged in such a manner that it separates the first flow channel (4) and the second flow channel (5). The method further comprises providing at least one opening (7) in an outer wall (2) of the first (4) or second (5) flow channel, and arranging a semi-permeable membrane tube (8) therein. Finally, the method comprises removing material from the separating wall (3), thereby providing a communication opening (9) providing fluid communication between the first flow channel (4) and the second flow channel (5). The method is very easy to perform, and it is suitable for mass production. The invention further relates to a micro-dialysis probe (6).
Abstract:
A system for analysing a fluid, the system comprising a base station, an analysing unit being remote from the base station, and a substance collecting device being remote both from the base station and from the analysing unit, a first fluid communication link for communicating fluid between the base station and the analysing unit, and a second fluid communication link for communicating fluid between the analysing unit and the substance collecting device, wherein the analysing unit comprises sensing means adapted to provide data representing a content of a substance in the fluid and wherein the base station comprises data processing means being adapted to process the data to provide information regarding the content of the substance in the fluid.
Abstract:
The invention provides a micro fluid device comprising a substrate with a channel forming a receiving cavity, an outer chamber, and an inner chamber, the device further comprising a multi lumen hose with a free end portion which is fixed in the receiving cavity. The multi lumen hose forming a first conduit and at least one second conduit located radially offset from the first conduit, and the outer chamber is in fluid communication with at least one second conduit, and the inner chamber is in fluid communication with the first conduit. The chambers are separated by an inner sealing member located between the substrate and the hose. To simplify the manufacturing of the device, the channel is formed by a groove in an upper surface of a body of the substrate, which groove closed by an essentially plane cover which is sealed to the upper surface.
Abstract:
A flow system, preferably a micro fluidic system, having a base part (4) with at least one flow path formed therein and a lid part (5) being attached to the base part (4) in such a manner that it covers the flow path(s). The flow path(s) comprise(s) a flow restrictor (1) and a flow channel comprising an inlet section positioned immediately upstream relatively to the flow restrictor (1). At least the inlet section of the flow channel has a cross section defining at least two distinct depths of the flow channel. This may be achieved by defining a centre section (3) and at least one peripheral section (2), the centre section (3) having a depth and a width which are substantially larger than the depth(s) and width(s) of the peripheral section(s) (2). If air bubbles are formed in the system this design of the inlet section will allow a flow of liquid to enter the shallower parts of the flow channel, while the air bubbles are confined to the deeper parts of the flow channel. Thereby air bubbles are prevented from entering the flow restrictor (1), thereby reducing the risk of air bubbles blocking the flow path through the flow restrictor (1). Simultaneously liquid is allowed to flow into the flow restrictor (1) substantially unaffected by the air bubble. Accordingly the flow system operates in a very reliable manner.