Other

Spacelabs, Inc.

John A Kater

Glenn Pelikan

A sample of a body fluid, such as blood, is collected in a cartridge having a sample chamber for storing the sample and one or more calibration chambers, each for storing a respective calibration fluid. The fluid sample is drawn ino the sample chamber by placing the sample chamber in fluid communication with a needle inserted into the fluid sample and applying a vacuum to the chamber using either a syringe or internal vacuum. A body fluid sample may also be drawn into the sample chamber from a syringe or capillary tube containing the fluid sample. The cartridge may be either planar or cylindrical. The chambers of a cylindrical cartridge may be either elongated voids symmetrically positioned about the longitudinal axis of the cartridge or axially spaced annular voids. One or more sensors, such as ion-sensitive electrodes, are placed in contact with the fluid sample and calibrating fluids(s) by either placing the sensor(s) in contact with externally accessible chambers or by allowing the fluid sample and calibrating fluid(s) to flow from the chambers past the sensor(s). In the event that the sensor(s) are placed in direct contact with externally accessible chambers, the sensor(s) may be scanned from one chamber to the next by an automatic drive mechanism.

Contamination-free method and apparatus for measuring body fluid

An improved blood samplng device is disclosed which includes a coupling device connected to a needle for receiving blood withdrawn from a patient. The coupling device includes first and second ports in flow communication with the needle and is adapted to conduct blood to either the first or second port. The first port includes an adapter sleeve which is adapted to receive a vacutainer-type blood storage device for storing blood samples taken from the patient. A microporous hydrophobic plug is positioned within the coupling device intermediate the first port and the needle for venting air which is trapped within the coupling device during the initial stages of the sampling operation. The second port is connected to the coupling device intermediate the plug and the needle and is adapted to receive a syringe for temporarily storing a first portion of blood withdrawn from the patient thereby to ensure that blood subsequently delivered to the vacutainer contains gases having relative partial pressures and activities of ionic species substantially equal to those of the patient's in vivo conditions.

Device for the conditioning, handling and measurement of blood

A method and apparatus are disclosed in which body fluid chemistry is measured in either differential or nondifferential mode using apparatus of the kind employed in infusing fluids into patients' blood streams, either with or without combination with such infusion, to the end that measurement of body fluid chemistry is conveniently and measured automatically at selected frequency.

Measurement of body fluid chemistry

A reference electrode (102), standard calibration solutions (72 and 76) and a sample solution (80) are all placed in liquid contact with one another and a reference solution (70). Contact between the reference solution (70), the sample (80) and the calibration solutions (72 and 76) is made through salt bridges (82, 74 and 78). A special conical shaped solution container (FIG. 5) having a porous plug or other salt bridge extending through the container wall at the apex provides special advantage.

Ion selective measurements

An ion selective electrode capable of production in miniaturized form suitable for in vivo monitoring is produced by coating a metal-metal salt half cell with a layer of hydrophilic material containing electrolyte with an over-layer of an ion selective membrane. The coatings may be applied by a dipping and drying process. Stability is enhanced by addition of silver black and platinum black to the half cell and those materials may be added as layers in a similar dip and dry process. A companion reference electrode half cell is made of the same materials that are used in making the 'half cell' portion of the selective electrode, except that the reference half cell is coated with a protein layer. Special packaging and a special procedure facilitate calibration.

Ion selective electrodes

An electrolyte for a bio-electric event measuring electrode combines a salt with adhesive. The adhesive serves as the vehicle for dispersing solvent to form the electrolyte in a solid or semisolid mixture. The adhesive serves further as a structural element in holding the parts of a practical electrode together and in making the electrode adhere to a subject's skin.

Bio-event electrode material

An electrolyte for a bio-electric event measuring electrode combines a salt with adhesive. The adhesive serves as the vehicle for dispersing solvent to form the electrolyte in a solid or semi-solid mixture. The adhesive serves further as a structural element in holding the parts of a practical electrode together and in making the electrode adhere to a subject's skin. Such an electrolyte is combined with a mesh or otherwise foraminated patch of pliant material and a connector to form what can be an inexpensive, effective electrode having long shelf life, low irritation, and low electrical resistivity.

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Santa Ana, CA, United States of America

John A Kater