Hewlett-packard Company

Other

Lothar Rupp

Ganapati R Mauze

Martin Wunderling

Martin Guenther

A sensor (10) is provided for detecting the concentration of potassium ions which comprises a molecule which selectively complexes potassium ions. The molecule, e.g., 2,2-bis[3,4-(15-crown-5)-2-nitrophenylcarbamoxymethyl]tetradecanol-14, has at least one binding site and is provided with a fluorophore group, e.g., Rhodamine-B, at that site. The molecule is one that expands upon complexation of potassium ions, such that the intensity of fluorescence increases. The change in fluorescent intensity is a direct measure of the concentration of potassium ions. A detector employing the sensor is also provided.

Fiber optic potassium ion sensor

A method for pretreating the surface of a medical device, and of applying a biological coating in a further step, uses the plasma polymerization technique or the plasma grafting technique. A functional monomer, i.e. a monomer with a functional group, or a mixture of a pure monomer and a substance which can provide the required functional groups under spark discharge or under the influence of charge carriers, results in a polymer coating with free functional groups which may react with the biological coating to provide optimum adhesion of the biological coating. The process is carried out in a pressure-tight chamber with an inlet for the functional monomer under low pressure and electromagnetic radiation provided by a radiation source.

Method for pretreating the surface of a medical device

An improved optical probe for the invasive measurement of partial carbon dioxide pressures is disclosed that minimizes pCO.sub.2 reading drift. An optical probe for the invasive measurement of the partial carbon dioxide pressure comprises an optical fiber and a pCO.sub.2 sensor. The pCO.sub.2 sensor comprises a diffusion zone with a dye-containing gel that is optically sensitive to H.sup.+ ions and a semi-permeable membrane that is permeable to CO.sub.2 molecules, but is substantially nonpermeable to hydrogen ions Components of the pCO.sub.2 sensor, such as the part of the optical fiber extending into the sensor or a reflector, are covered with a substance--preferably with a coating--that is substantially nonpermeable to hydrogen ions. This prevents the hydrogen ions from diffusing into the sensor components, which otherwise would cause an imbalance of hydrogen ions and, therefore, a drift in the pCO.sub.2 reading.

Optical probe

A sensor (10) is provided for detecting the concentration of potassium ions which comprises a molecule which selectively complexes potassium ions. The molecule, e.g., 2,2-bis(3,4-(15-crown-5)-2-nitrophenylcarbamoxymethyl)tetradecanol-14, has at least one binding site and is provided with a fluorophore group, e.g., Rhodamine-B, at that site. The molecule is one that expands upon complexation of potassium ions, such that the intensity of fluorescence increases. The change in fluorescent intensity is a direct measure of the concentration of potassium ions. A detector employing the sensor is also provided.

Polyacrylamide gels containing bound dye indicator molecules being sensitive to pH variation are treated with an aqueous solution for a period of time until the shifting of the pK value of the gel, due to the treatment, has finished.

Polyacrylamide gels and method for the preparation of polyacrylamide gels

Probes, preferably optical probes for the invasive measurement of blood parameters consist of a plurality of sensors (or at least one sensor and a stabilizing core, or at least one single sensor), (11,17), each of these sensors (11,17) having a diffusion zone with a selective membrane (15) and all together surrounded by a stabilizing sheath (18); this sheath (18) is to be fastened on the sensor(s) (11,17) by a glue (22). A method is described for manufacturing such probes. This method includes the steps of covering the selective membrane (15) by a hardenable and soluble cover material (21), in particular a silicate, then fastening said sheath (18) on the sensors (11,17) by glue (22)--which cannot reach the selective membranes (15) as they are just covered by the cover material (21)--and then dissolving said cover material (21). This method guarantees that the selective membranes (15) are free of glue (22) after the manufacturing process.

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Aldingen, Germany

Lothar Rupp