Abstract: A flow-through fluid reservoir includes a body with a first fluid port, a member movable within the body by an actuator to increase or decrease a volume of a chamber defined by a sidewall of the body. The actuator has a second fluid port. Movable member has a fluid path therethrough such that fluid ports are in fluid communication irrespective of the position of the movable member or the volume of chamber. A shaped slot on the shell of the actuator and a projection on the body cooperate to constrain relative movement of the body and actuator along a path corresponding to the shaped slot. The slot advantageously may include a stop intermediate therealong. A canted aspect of the slot may be used to initiate relative movement of the member within body. The body includes an end wall through which the first fluid port communicates. A shroud is defined by a coaxial extension of the sidewall beyond the end wall to surround the first fluid port, and gripping elements may be provided on the shroud.

Abstract: A flow-through fluid reservoir includes a body with a first fluid port, a member movable within the body by an actuator to increase or decrease a volume of a chamber defined by a sidewall of the body. The actuator has a second fluid port. Movable member has a fluid path therethrough such that fluid ports are in fluid communication irrespective of the position of the movable member or the volume of chamber. A shaped slot on the shell of the actuator and a projection on the body cooperate to constrain relative movement of the body and actuator along a path corresponding to the shaped slot. The slot advantageously may include a stop intermediate therealong. A canted aspect of the slot may be used to initiate relative movement of the member within body. The body includes an end wall through which the first fluid port communicates. A shroud is defined by a coaxial extension of the sidewall beyond the end wall to surround the first fluid port, and gripping elements may be provided on the shroud.

Abstract: A pressure transducer (10) for measuring fluid pressure in a fluid path comprising a strain gauge circuit (37) of thick film piezoresistors formed on an alumina diaphragm (36) in a Wheatstone bridge configuration. Each resistance leg of the bridge typically includes a thick film measuring piezoresistor (R1A) to which selected thick film patch-in piezoresistors (R1B, R1C, R1D, R1E) are selectively connected to create a measuring resistance network (PN1). The measuring resistance network is adjusted to a predetermined resistance value to balance and optimize the electrical symmetry of the bridge. The pressure transducer (10) includes a mechanical stop member (46) located adjacent the alumina diaphragm (36) such that the fully deflected diaphragm contacts the stop thereby physically preventing the diaphragm from deflecting an amount that would cause the diaphragm to rupture.

Abstract: In a blood gas sensing probe, a cylindrical sleeve contains an optical fiber. The end of the optical fiber is withdrawn into the sleeve thereby creating a receptacle at the end of the sleeve. A sensitive dye, HOPSA for example, is encapsulated in a gel and deposited in the receptacle to form the probe. In making the probe, the end of the optical fiber is in the same plane as the end of the sleeve in which it is placed. The dye and gel contact the combined ends of optical fiber and sleeve. The fiber is withdrawn into the sleeve thereby creating a vacuum which is filled by the dye and gel.

Abstract: A blood chemical sensor has a blood gas sensitive dye contained in a hydrogel matrix, the combination of dye and gel being mounted on the end of an optical fiber. The hydrogel is freeze-dried to facilitate packaging and handling.

Abstract: In a blood gas sensing probe, a cylindrical sleeve contains an optical fiber. The end of the optical fiber is withdrawn into the sleeve thereby creating a receptacle at the end of the sleeve. A sensitive dye, HOPSA for example, is encapsulated in a gel and deposited in the receptacle to form the probe. In making the probe, the end of the optical fiber is in the same plane as the end of the sleeve in which it is placed. The dye and gel contact the combined ends of optical fiber and sleeve. The fiber is withdrawn into the sleeve thereby creating a vacuum which is filled by the dye and gel.