Abstract: Subtilisin or subtilisin-like enzymes are used in rinse solutions for apparatus analyzing protein-containing biological liquids, such as blood analysis apparatus, to obviate measuring errors ascribable to protein deposits. A preferred rinse solution contains subtilisin, a borate buffer, and germicides.

Abstract: An electrochemical electrode device for simultaneously measuring the partial pressures of two gasses in a medium of limited gas availability one of which is measured potentiometrically and another one of which is measured polarographically comprises an electrode body (18) constituting a reference electrode relative to a pH-electrode (19) of a potentiometric electrode system, and a anode relative to a cathode (20) of a polarographic electrode system. Furthermore, the electrode device comprises an electrolyte solution (28) enclosed between the electrode body and a membrane (30). The membrane comprises a basic membrane layer (31), preferably of polytetrafluoroethylene (PTFE) or fluoroethylenepropylene (FEP) of a thickness of about 12 .mu.m, and a covering (32), preferably a polypropylene layer of a thickness of about 15 .mu.m, which covers part of the basic membrane layer so that an uncovered area (34) is constituted in front of the pH-electrode.

Abstract: An electrochemical measuring electrode device (10) for polarographically measuring the partial pressure of oxygen in an electrolytic medium comprises a cathode (14) which is capable of reducing oxygen and defines an exposed oxygen-reducing cathode surface (20), an anode (18), which defines an exposed anode surface which is arranged relative to the exposed oxygen-reducing cathode surface so as to communicate electrolytically therewith through the electrolytic medium, and a membrane (24), which covers the exposed oxygen-reducing cathode surface and further defines an electrolyte chamber (22) in which the electrolytic medium is confined. In order to effectively promote the decomposition of H.sub.2 O.sub.2 generated in the electrolytic medium as an oxygen reduction intermediate and thereby reduce the response time of the electrode, a stable, non-biological catalytic means is provided catalytically communicating with the H.sub.2O 2.

Abstract: In order to counteract coagulation of a blood sample which is collected from an animal or a human body (24) and introduced into a receptacle, such as a syringe chamber (14), an anticoagulant is added to the sample within the receptacle. The anticoagulant may be capable of binding cation species in the blood, which are subsequently to be measured. Such cation species comprise hydrogen ions, ammonium ions, alkaline metal ions such as potassium and sodium ions, and alkaline earth metal ions such as magnesium and calcium ions. In order to compensate for the proportions of selected cation species which are bound by the anticoagulant, an additive containing such cation species is added to the blood sample so as to obtain substantially the same concentration of the selected cation species in an unbound condition in the anticoagulant treated blood sample as in the untreated blood sample.

Abstract: An electrode device for transcutaneously measuring the blood gas parameter and for sensing a bioelectrical signal and an electrode assembly comprising such an electrode device are disclosed. The electrode assembly for transcutaneously measuring a blood gas parameter and for measuring a bioelectrical signal comprises two separate electrode devices one of which further comprises an electrochemical measuring electrode system. The electrochemical measuring electrode system comprises a reference electrode of a potentiometric electrode system and an anode of a polarographic electrode system constituted by a single metallic body, a pH-electrode of the potentiometric electrode system, and a noble metal cathode of the polarographic electrode system.

Abstract: An ion-sensitive measuring electrode device with an ion-sensitive element based on ion-conducting crystalline ceramic material is provided. The electrode device shows a selectivity to the Na.sup.+ ion versus the H.sup.+ ion corresponding to the selectivity of the known sodium-sensitive glass-based solid membrane electrodes.Ion-sensitive measuring electrode devices showing good selectivity properties are provided on the basis of ion-conducting crystalline material, the crystal structure of which comprises a three-dimensionally extending interstitial space containing positions for the ion, especially material in which the interstitial space has bottlenecks which just permits passage of the ion.A method for preparing polycrystalline ceramic material based on oxides of zirconium, phosphor and silicon is also provided.

Abstract: A blood sampling device (10), in particular intended for arterial blood sampling and blood gas analysis, is disclosed. The sampling device is provided with valve means which in the dry state permits expulsion of gas from the sampler reservoir (18), but which automatically closes on contact with blood. The valve means comprises two mating surfaces (21, 26) retained apart by an interlayer of a porous or fluffy fibrous material (22), which collapses on contact with a liquid.

Abstract: An ion selective electrode device, in particular a pH-sensitive electrode device, employing an intercalation electrode (3) as contact material between an ion selective element (2) and an electrical connection (9).An intercalation electrode comprising an equilibrium mixture of two phases, at least one of the phases working as an intercalation electrode, is disclosed.The electrode device may be constructed as a solid state electrode device showing advantageous electrode properties.

Abstract: A capillary tube containing a sample is anaerobicly sealed by means of closure caps each comprising an end wall and a skirt portion. Each open end of the capillary tube is sealed by inserting the open tube end into the cap skirt portion, and in order to avoid that a volume of air is forced into the capillary tube, the space defined between the open tube end and the cap end wall is vented to the atmosphere through one or more venting passages defined in the walls of the closure cap or between the inner surface of the cap skirt portion and the adjacent outer peripheral surface of the capillary tube. The open tube end is brought into sealing engagement with sealing means on the cap end wall, and frictional engagement established between the inner surface of the cap skirt portion and adjacent outer peripheral surface parts of the capillary tube secures that said sealing engagement is maintained.

Abstract: Salt bridge liquid for use in potentiometric measurement of blood or a blood liquid.The salt bridge liquid contains Na.sup.+ -ions and HCOO.sup.- -ions in substantially equimolar amounts, preferably in a concentration larger than or equal to 1 M, in particular about 4 M.When this salt bridge liquid is used, the potentiometric measurement will give corresponding results when measuring a blood sample and the corresponding plasma sample because the suspension effect which is caused by the erythrocytes and which is seen when using other salt bridge liquids is substantially eliminated. Furthermore, different blood samples with the same ion concentration but with varying erythrocyte content will give corresponding measuring results.

Abstract: In accordance with the principles for transcutaneous measurement of a blood parameter, such as the partial pressure of a blood gas, an electrochemical measuring electrode device (1) is applied to the skin surface (2) of a person. The electrode device has a body (10), e.g. a thick film substrate, which is thermostated to a predetermined temperature and, furthermore, includes a sensor (11) together with a membrane (14) confining an electrolyte solution within an electrolyte reservoir (15). Furthermore, the electrode device includes a jacket having an annular metallic body (16), a metallic body (4) and a thick film substrate (8), which is thermostated to the same temperature as the body (10) of the electrode device.

Abstract: A syringe for collecting a sample of blood or another liquid comprises a syringe cylinder and a piston arranged displaceably therein. One or more axially extending recesses are formed in the inner wall of the syringe cylinder axially spaced from the inner end thereof. The recess or recesses contain a material which is pervious to gas and impervious to liquid, such as a hydrophobic material, a hydrophilic material with capillary effect, or a material which swells when contacted by liquid. The sample collecting chamber within the cylinder may be vented to the atmosphere by placing the piston in the recessed area of the cylinder. Arterial blood may then pass into the syringe under arterial blood pressure, and the flow of blood into the syringe is automatically stopped when the sample collecting chamber of the syringe has been filled, because blood cannot pass the liquid impervious material arranged in the recesses.

Abstract: An electrochemical electrode device comprising a tubular member having a bottom end adapted to be inserted into a liquid sample to be measured, and a top end which is closed by a cap member including electrical conductors by means of which the electrodes of the electrode device are connected to an outer cable. In order to facilitate the introduction of liquid or gel into an inner space defined within the tubular member as well as withdrawal of liquid or gel from that space, a longitudinally extending passage is formed within the cap member. This passage may be selectively opened and closed by means of a closure member which is received in a cavity extending transversely to and intersecting the longitudinal passage. The closure member is preferably in the form of a swingably mounted slide valve member or a rotatable cock member.

Abstract: An apparatus for analyzing biological liquids comprises a measuring block including measuring means for measuring characteristics of said liquids. The measuring block is mounted within a thermal shield or housing by means of a base member interconnecting a minor part of the inner wall of the housing and the measuring block so as to define a space between the inner walls of the housing and the measuring block, said space being filled with air or another medium having a poor thermal conductivity.The thermal shield or housing and the base member are made of a material with good thermal conductivity, and heating and/or cooling means are arranged in heat conductive contact with the said shield. The function of the heating and/or cooling means is controlled by a temperature sensor arranged in heat conductive contact with the measuring block, so as to maintain the temperature of said block at a substantially constant predetermined value.

Abstract: A reference liquid for calibration or quality control of instruments which determine ionized calcium and pH. The reference liquid contains both a particular calcium ion activity and a pH-buffer and can therefore be used for calibration of both the calcium-sensitive electrode and the pH-electrode in the instruments. The pH-buffer is a nitrogen-containing organic sulphonic acid and the salt of this acid, the acid having a pK in the range of 6.6-7.6. The reference liquid has an ionic strength of 0.15-0.17, a buffer capacity .beta. in the range of 0.04-0.10 and is packed in glass ampoules.

Abstract: The invention relates to a method of removing air or gas bubbles tending to collect in the "dead space" of a piston burette or another liquid dosage piston pump during operation thereof. The venting is performed by sucking a substantial volume of air into the pump cylinder in addition to a certain amount of liquid, and the air and part of the liquid within the pump cylinder is thereafter discharged therefrom. A piston dosage pump for carrying out this method comprises a valve mechanism by means of which the pump cylinder may be selectively communicated not only with a liquid inlet conduit and a liquid outlet conduit, but also with an air inlet passage.

Abstract: An electrode device for transcutaneous PCO.sub.2 measurement with a pH-sensitive measuring electrode behind a CO.sub.2 -permeable membrane, a reference electrode, and an electrical heating device for thermostating the measuring electrode and thermally stimulating the blood flow in the skin in the measuring area, the reference electrode being in direct heat-conductive contact with the electrical heating device and being designed so that it surrounds the measuring electrode. This permits compact design of the electrode in a very small size.

Abstract: Deoxygenation of a blood sample prior to determination of carbon monoxide hemoglobin is performed in a capillary tube containing a dry reducing agent. Ready for use capillary tubes having long storage life contain dry reducing agent and are sealed at both ends. Preferred capillary tubes contain mixture of reducing agent, pH buffer and anticoagulating agent present as a dry material on the interior tube wall.

Abstract: The invention relates to an electrochemical measuring device for transcutaneous measurement of arterial partial gas pressure, especially partial pressure of oxygen or carbon dioxide. The measuring device comprises an annular mounting member having a skin contacting surface adapted to be fastened to the skin surface of a patient, and a sensor of the type having a semi-permeable membrane adapted to be releasably connected to the mounting member. In the connected position of the sensor, the membrane is axially spaced from the skin contacting surface of the mounting member so that the membrane, the inner wall of the annular mounting member, and the skin surface define a measuring chamber which may be filled with a gel or another medium, if desired.

Abstract: A stable synthetic water based reference liquid for quality control and/or calibration of blood gas measuring equipment, said liquid being enclosed in a gas-tight container and containing HCO.sub.3.sup.- ions, H.sup.+ ions, CO.sub.2 gas, and O.sub.2 gas plus an additional pH buffer system different from the pH buffer system constituted by the HCO.sub.3.sup.- ions and the CO.sub.2 gas, said liquid showing, at a fixed temperature, known pH, pCO.sub.2 and pO.sub.2 values, said liquid additionally containing oxygen reversibly contained in a dispersed non-proteinaceous organic substance which shows higher solubility for oxygen than does water, and, optionally, a coloring component showing maximum or significant absorption at about 500 nm, said organic substance being(a) a water-insoluble organic substance in which O.sub.2 l is soluble to an extent of at least 12% by volume at 1 atmosphere oxygen pressure and 25.degree. C.