Abstract: An improved sensor apparatus of a kind that positions a semi-permeable membrane adjacent to an electrode assembly, for measuring a predetermined parameter, e.g., glucose concentration, of an adjacent fluid sample. A special compressible ring serves a first function of tensioning the membrane so that it is maintained in intimate contact with the electrode assembly, and it further serves a second function of sealing the fluid sample from the external environment.

Abstract: A method of using a multi-compartment fluid assembly for calibrating an apparatus external to the assembly, while conveniently maintaining sterility. The method includes providing calibration fluid in a closed calibration container disposed within a bag that includes a connector for conveying fluids between the interior of the bag and a conventional intravascular tube. In use, fluids may be directed through the external apparatus and the intravascular tube and into the bag's interior. At an appropriate time, the calibration container is opened and the calibration fluid is withdrawn from the container to the intravascular tube, through the connector, without mixing the calibration fluid with any fluids in a remaining volume of the bag. Subsequently, the calibration fluid is transferred from the intravascular tube to the bag's interior, again through the connector.

Abstract: A fiber-optic transducer apparatus, and a related method of manufacturing it, for particular use in medical applications such as invasive blood pressure and body temperature measurement. The apparatus includes a catheter comprised of a sheath and an enclosed first set of optical fibers for transmitting a light beam to and from the remote end of the catheter, where a transducer modulates it in accordance with the variable to be measured, e.g., blood pressure. A photosensor located at the near end of the catheter measures the modulated intensity of the returned beam, to produce a corresponding measurement signal. The catheter is further comprised of a second set of optical fibers located within the sheath, for transmitting a reference light beam to and from the remote end of the catheter. A second photosensor measures the intensity of the returned reference light beam, to produce a correction signal indicative of variations in transmittance caused by bending of the catheter.

Abstract: A source fiber receives light from a light source and conducts the light through a catheter to transmit the light to a reflective surface at the catheter end. The reflective surface has a predetermined range of movement and forms a reflected beam from the light transmitted by the source fiber. A reference fiber is located such that it is entirely within the reflected beam throughout the entire range of movement of the reflective surface and its output is substantially constant throughout that range of movement. The output of the reference fiber is used to adjust the light output of the light source. A signal fiber is located such that it is covered by the reflected beam to an extent which is dependent upon the position of the reflective surface in its range of movement. The light output of the signal fiber changes by a relatively large amount through the range of movement of the reflective surface and its output may be used to determine the position of the reflective surface.

Abstract: A catheter assembly comprising a catheter having a lumen and characterized by a flexible distal extremity. The assembly further comprises a bolt having a threaded distal extremity for threading into an opening in the skull in sterile relation. The bolt includes an elongated chamber extending between its distal extremity and a threaded proximal extremity of the bolt. The catheter is disposed through the bolt chamber, and includes an opening from the lumen to the exterior of its flexible distal extremity. A clamp is threaded onto the catheter proximal extremity and is operative to forcibly engage the catheter and constrain it against movement relative to the bolt to thereby maintain a predetermined depth of insertion of the catheter into the skull.

Abstract: A drop sensing unit and associated, disposable drip chamber for dedicated use with the sensing unit in an IV fluid administration system, the sensing unit being adapted for convenient installation on and removal from the drip chamber, with cooperable engaging means on the sensing unit and chamber serving to locate and retain them in the desired relative position during use. Such engaging means provide for contact between the sensing unit and chamber at vertically spaced locations for effective retention, and are constructed and arranged to aid in preventing use of the sensing unit on drip chambers which differ from the specially designed chamber.

Abstract: A temperature sensing probe is provided including a probe shaft rigidly mounted on a handle and having a temperature sensing tip at the distal end of the shaft. A disposable cover is provided in the form of a unitary elongated tube constructed of heat conductive material and having an open proximal end arranged to slide over the probe shaft and a closed distal end arranged to tightly engage the temperature sensing tip of the shaft in order to retain the cover on the shaft and provide a positive conduction of heat to the temperature sensing tip. For the purpose of selectively ejecting the cover after temperature measurement, the probe handle includes a movable ejection button for manually driving the cover forwardly with sufficient force to disengage the cover from the tight engagement with the temperature sensing tip.

Abstract: An improved method and apparatus for parenteral administration of medical fluids, wherein a normally shut-off intravenous feeding tube is selectively opened at a frequency and open period duration automatically regulated by a digital control system to establish a fluid flow rate at any selected rate over a wide dynamic range. Measured and desired flow rates are converted to digital electrical signals and compared, the electrical difference being used to vary a control voltage which establishes the width of energizing pulses controlling a member for opening the feeding tube. The frequency of the energizing pulses is preferably a non-integral multiple of the desired drop flow rate and varies from a very high ratio, e.g. 15.5, at very low flow rates to a much smaller ratio, e.g. 2.5, at very high flow rates.

Abstract: Apparatus for fluid flow control in a parenteral administration system, utilizing a syringe pump operated by a motor to repetitively fill and empty a syringe cartridge over a plurality of operational cycles of successive fill stroke and pump stroke periods. The apparatus repetitively and sequentially opens and closes a pair of intake and output I.V. tubes communicating with a syringe, the tubes alternating opened and closed states, one tube always being open while the other is closed, by means of a pair of L-shaped pivotal tube pinchers, one pincher controlling each I.V. tube, each pincher being normally spring biased to the tube clamping shut-off state. The tube pinchers are alternately pivoted to a non-clamping, tube-open position by a spring biased, intermittent motion, reciprocating slide bar under the control of a reversible, rotating cam, the cam being driven by the same motor as that used to drive the piston of the syringe through its fill and pump strokes.

Abstract: A drop sensing unit and associated, disposable drip chamber for dedicated use with the sensing unit in an IV fluid administration system, the sensing unit being adapted for convenient installation on and removal from the drip chamber, with cooperable engaging means on the sensing unit and chamber serving to locate and retain them in the desired relative position during use. Such engaging means provide for contact between the sensing unit and chamber at vertically spaced locations for effective retention, and are constructed and arranged to aid in preventing use of the sensing unit on drip chambers which differ from the specially designed chamber.