Abstract: A catheter hub assembly is disclosed wherein the assembly contains a membrane useful in preventing backflow of blood into the flash chamber. The hub assembly contains a membrane opener which operates upon the insertion of a luer locking mechanism into the catheter hub. This membrane opener allows flow of nutritional fluid into the body by causing the opening of the membrane during use of the catheter after removal of the catheter needle.

Abstract: The deflation of the inflatable and deflatable cuff worn by a subject during automatic sphygmomanometric measurement is accomplished in unequal size decrements and principally in larger steps than 7 Torr. Each step after detection of the initial oscillations is determined in the first instance by reference to a look-up table or an equation as a function of prevailing cuff pressure. This Base Step dimension is augmented by a factor proportional to the last oscillation amplitude, the factor being increased after detection of the maximum oscillation amplitude. A valve mechanism with at least two different effective orifice sizes is used for deflation, the smaller size effective orifice being used first, to maintain control over the decrement step rate while holding the time for decrement within a predetermined limit of 8 mSec. per Torr, i.e., maintaining the rate above 125 Torr per second.

Abstract: A catheter is provided which deters the backflow of blood between the insertion needle and the catheter cannula by forming the distal end of the catheter hub so as to restrict the inner diameter of the catheter cannula to a wiping fit with the engaged insertion needle. In a first embodiment the distal end of the catheter hub is pre-formed to its desired final inner dimension. The distal end of the hub is stretched to an oversize condition, the catheter cannula is attached to the hub, and the distal end of the catheter hub is heated, causing a stress relief of the previously stretched hub. The distal end of the catheter hub returns to its pre-formed dimension which will mechanically restrict the diameter of the catheter cannula at that point to form the wiping fit with the engaged needle.

Abstract: A sensor for measuring the oxygen availability of blood flow within the skull is described. In a first embodiment the sensor comprises a photodetector and a pair of light emitting diodes surface mounted near the end of a length of flexible printed wiring. The sensor is sealed by a coating of rubber or polymeric material which has an optical window over the photodetector and light emitting diodes. The sensor is inserted through a burr hole drilled in the skull and slides between the skull and the dura of the drain. The light emitting diodes are pulsed to illuminate blood flow in the brain beneath the dura with light, and light reflected by the blood is received by the photodetector and converted to electrical signals. The signals are processed by a pulse oximeter to provide an indication of blood availability. In a second embodiment the photodetector and light emitting diodes are mounted at the end of a core of compressible foam extending from the end of a hollow bone screw.

Abstract: A catheter device is described with a safety needle guard that covers and protects the needle after use of the device. The device includes a semi-tubular needle housing containing a flash chamber with a hollow needle extending from the distal end of the flash chamber. A tubular needle guard concentrically fits and slides within the needle housing. The needle guard has a longitudinal slot through which the mounting base of the flash chamber passes as the guard slides within the housing. The top of the semi-tubular housing is open so that a user may access the top of the tubular needle guard with a finger to urge the needle guard to an extended position from the distal end of the housing and in a surrounding position about the needle. As the needle guard attains its fully extended position about the needle, it locks in place in the needle housing.

Abstract: A through the needle catheter device is described which includes apparatus for threading a catheter into a blood vessel. The apparatus is irreversible during the threading process. The catheter device also includes means for irreversibly withdrawing and splitting the needle. A technique is provided for inserting the needle, threading the catheter, and withdrawing the needle from a patient.

Abstract: A looseleaf notebook is provided for retaining bar code listings which denote conditions of a patient in a hospital. The notebok includes a strap which encircles the binding of the notebook. Preferably this strap is fixed in place between the notebook ring mechanism and the inside of the binding panel of the notebook. The strap is also preferably adjustable or resiliently stretchable. The strap permits the notebook to be held open and manipulated by a user who slides a hand between the strap and the binding panel while supporting the opened covers of the notebook with the thumb and fingers of the hand. With the notebook being held in one hand in this manner, the user's other hand is free to manipulate a bar code reader over the patient condition bar codes, or to perform other information-gathering or medical functions.

Abstract: A through the needle catheter device is described in which a catheter is located inside a splittable needle for insertion into the body. Means are provided for preventing rearward motion of the catheter relative to the needle as the needle and catheter are inserted into the body. As the needle is withdrawn from the body, a splitting mechanism splits the needle, releasing the enclosed catheter. Means are provided for preventing forward motion of the needle relative to the catheter as the needle is withdrawn, thereby preventing inadvertent perforation of the catheter during withdrawal. After the needle has been withdrawn and split, the catheter assembly, including a catheter cannula, a section of extension tubing and a luer, fall away from the patient-facing side of the device. In a preferred embodiment a taping wing is provided at the proximal end of the catheter cannula.

Abstract: A through the needle catheter device is described which includes apparatus for threading a catheter into a blood vessel. The apparatus is irreversible during the threading process. The catheter device also includes means for irreversibly withdrawing and splitting the needle. A technique is provided for inserting the needle, threading the catheter, and withdrawing the needle from a patient.

Abstract: An I.V. catheter is described, including a catheter and hub assembly and a needle and hub assembly. A needle guard, including a tubular distal portion and a split proximal flange, is located about the needle at the distal end of the needle hub. The needle includes a slot near the needle tip. As the needle assembly is withdrawn from the catheter, the needle guard slides along the needle until the split flange engages the needle slot, which locks the tubular distal portion of the guard over the needle tip.

Abstract: A dual source parenteral infusion system includes a primary controller which controls the flow rate of a parenteral solution, a display which displays parameters associated with the delivery of a primary solution, and pushbuttons for entering solution delivery parameters into the controller. The primary controller communicates with a secondary infusion module which is programmed to deliver solution from a secondary source, with the flow rate being controlled by the primary controller. The secondary infusion module includes a display for displaying parameters associated with the delivery of the secondary solution and a drop detector, and mounts about a drip chamber for the secondary solution. The module may also include pushbuttons for entering fluid delivery parameters for the secondary solution into the module.

Abstract: A flash plug for an I.V. catheter is formed of a body of polymeric material, and has a narrow distal end for insertion within a catheter flash chamber and a larger proximal end which extends from the flash chamber. The flash plug has an aperture extending through it from the distal to the proximal end. An insert of a porous material is located within the aperture, and is capable of passing air and blocking the flow of blood. The catheter body is compatible with flash chamber material so as to remain securely located within the flash chamber and provides protection for the insert. The aperture diameter is sized to retain the porous insert securely within the flash plug body.

Abstract: A catheter assembly is provided to facilitate taping of the emplaced catheter onto the patient's body. The assembly comprises a catheter extending distally from a catheter hub. The hub has a hub axis co-axially aligned with the catheter and provided with a pair of opposed wings integral with the hub. Each of the wings having a proximal edge and a distal edge are such that a portion of at least one of these edges forms an acute angle with the axis of the hub of from about 35.degree. to about 55.degree. whereby the taping operation of the wings to the patient's body may be facilitated.

Abstract: A pump control system is described in which the pumping mechanism causes corresponding movement of a pair of capacitor plates. The plates are energized by an a.c. signal, and the signal produced by the plates is amplitude detected, with the amplitude modulation representing pumping force. The pumping force is converted to pumping pressure. The pumping pressure peak during pumping and the pressure minimum during filling are detected to determine the portion of a pumping cycle required to make the transition between these two pressure levels. The difference between the two pressure levels divided by the transition portion of the pumping cycle gives a measure of the compliance of the pump chamber. The ratio of the compliance measure to the total cycle, when multiplied by the nominal chamber volume, gives a measure of unpumped volume, which is subtracted from the nominal volume to give the volume actually pumped during a pump cycle.

Abstract: A pulse oximeter is provided including two light emitting diodes. Each LED is energized by a unique modulation signal. Light produced by the LEDs passes through the tissue of a subject and is detected by a photodiode. The photodiode signal is separated by tuned circuits resonant at the two modulation signal frequencies and physiological information signals are recovered from the separated signals by amplitude demodulation. The inventive arrangement provides identification of back-to-back coupled LEDs and narrow band filtering for good noise immunity.

Abstract: A disposable diaphragm pump cassette comprises a flexible diaphragm member comprising hinged, rigid plates hingingly mounted on an inflexible plate and opposed to a pumping chamber surface to form a pumping chamber. The pump includes check valve means comprising movable circular plates integrally connected with the inflexible plate by flexible, extendable webs. The flexible diaphragm member comprises at least three inflexible diaphragm plates with edges in a common plane, each diaphragm plate having at least two straight diaphragm plate hinge edges. Each diaphragm plate hinge edge is adjacent to and aligned with a second diaphragm plate hinge edge of an adjacent diaphragm plate. The adjacent edges of each diaphragm plate hinge edge and second diaphragm plate hinge edge are attached together by a flexible hinge strip.

Abstract: A parenteral solution container spike is provided which accesses a solution container with a pointed end, provides means for attaching a drip chamber at the other end with a drop former extending from the spike into the drip chamber, and an annular projection extending outward from the drip chamber end of the spike for attaching to a droplet detector with the drip chamber properly positioned in the droplet detector.

Abstract: An improved over-the-needle catheter assembly is provided with means for facilitating one-handed separation of the catheter hub from the needle hub. The improvement comprises providing the catheter with a top outside surface presenting a generally smooth surface interrupted by a depression. The depression has a bearing wall for transmitting a force component applied by the finger of a user; such force component having a distal, coaxial direction with respect to the catheter hub.

Abstract: A dual parenteral solution apparatus for delivering predetermined volumes of two solutions at predetermined flow rates with increased accuracy. The apparatus has a shut-off valve in the supplementary solution supply system which is immediately activated when the supplemental solution supply is depleted.