Abstract: A system and a method for detecting the presence of air bubbles in an intravenous (IV) line supplying a medicinal liquid to a patient. An air bubble sensor includes an ultrasonic transmitter acoustically coupled to an ultrasonic receiver to detect the presence of a gas (e.g., air) in a portion of a tube comprising the IV line. The transmitter and receiver are mounted on pivoting transducers that are disposed on opposite sides of the tube. A spring biases the transducers inwardly toward each other so that the transmitter and receiver contact opposite sides of the tubing. This assembly automatically accommodates different sizes of tubing and tubing of a relatively wide range of stiffness. The tube is connected to a disposable pumping cassette that is engaged in a pump chassis on which the transducers are pivotally mounted.

Abstract: A connector is provided for terminating a multi-conductor, flexible cable of the flat ribbon type which has a plurality of conductors in side-by-side parallel, spaced relationship within a web of encapsulating insulation from which projects a pre-stripped, bare, distal end portion of each conductor. The connector includes a housing defining a passage extending from an open first end to an open second end. The housing includes divider walls defining a plurality of slots each opening outwardly and each communicating with the passage at the second end. The housing has a support wall defining a bottom in each slot. An insulated length of cable can extend through the open first end of the housing passage toward the open second end where each bare, distal end portion of the conductor can be exposed and bent in one of the slots around the support wall adjacent a bottom of a slot.

Abstract: A cover for a battery compartment in a medical device such as an ambulatory pump that is used for infusing a medicinal fluid. The battery compartment cover includes a lever that is pivotal between an open and a closed position. The lever is connected to a plunger that applies a compressive force against an O-ring, which is trapped between a shoulder on a washer through which the plunger extends and an end of the plunger. When the lever is pivoted to its open position, the compressive force on the O-ring is released, enabling the battery compartment cover to be removed from the opening into the battery compartment. However, when the lever is pivoted to its closed position, it draws the plunger outwardly, applying a compressive force to the O-ring that causes the O-ring to expand radially outward, sealing the opening into the battery compartment against the intrusion of water or other liquids and securing the battery compartment cover in engagement with the opening.

Abstract: Apparatus and a method for monitoring a percentage of the oxygen saturation in the hemoglobin of blood flowing through a blood vessel. An optical sensor that detects the percentage oxygen saturation in blood is disposed proximate a proximal end of the catheter. A thermistor is disposed adjacent to the distal end of the catheter and it is employed to detect changes in blood temperature that indicate the position of the catheter's distal end in the blood vessel. Indicia or marks visible at intervals on the outer surface of the catheter enable a medical practitioner to determine the length of the catheter that has been introduced into the blood vessel. A strain relief that is flexible and resists stretching extends along the length of the catheter. For flushing the distal end of the catheter, a fluid supply may be connected to a lumen running through the catheter to provide the flushing fluid.

Abstract: An electronic circuit and a method for accurately measuring intermittent current pulses supplied by a storage battery to energize a load. In the preferred embodiment, an analog integrator accumulates current pulses in response to a voltage drop across a sense resistor that is connected in series between the storage battery and the load. The voltage drop is proportional to the flow of current from the battery through the load. The output of the integrator is filtered with a low pass filter to block high frequency noise, and the output of the filter is coupled to an analog to digital (A/D) converter that transforms the filtered analog signal into a corresponding digital signal. The output of the A/D converter is supplied to a port of a processor. The processor provides a signal to actuate a reset switch coupled across the integrator. When closed at the end of each integration time period, this switch zeroes the output of the analog integrator.

Abstract: A system and a method for detecting the presence of an occlusion in an intravenous (IV) line supplying a medicinal liquid to a patient. Two pressure occlusion sensors are employed to produce a value for the proximal and distal pressures within an IV pumping cassette that is disposed in the fluid path of the IV line. Each pressure occlusion sensor includes a strain gauge connected to a leaf spring that is fixed at one end within a pump chassis and a rod that is disposed transverse to the leaf spring. Each rod has one end that responds to the force of a portion of an elastomeric membrane inside the pumping cassette and another end that contacts a free end of the leaf spring. When a leaf spring is flexed by the movement of a rod, the strain gauge mounted on the leaf spring produces a differential voltage that corresponds to a fluid pressure within the pumping cassette.

Abstract: A system is provided for draining an anesthetic agent from a reservoir of an anesthetic vaporizer. The system includes an anesthetic agent container having an inlet into which the agent can drain. The vaporizer has a draining station that defines an outlet and that defines a drain passage between the vaporizer reservoir and the outlet. A valve is operable to open and close the drain passage. A connector is provided with a receiving end for connecting to the draining station at the outlet. The connector has a discharge end for connecting to the container inlet. The connector holds the container below the draining station outlet and defines a transfer passage between the receiving end and the discharge end for draining the agent from the draining station into the container. Structural key configurations, uniquely associated with a specific anesthetic, are preferably provided at the connection of the container and connector and at the connection of the draining station and connector.

Abstract: A prefilled, two-constituent system is provided with first and second containers or barrels. The first barrel includes a first chamber having a dispensing end or delivery end. The delivery end defines a dispensing passage or delivery passage communicating through the delivery end to accommodate the dispensing of fluid from the first chamber. A movable seal or reciprocable stopper is slidably disposed in the first chamber, and a first constituent is provided in the first chamber between the delivery end and the stopper. A second container or barrel is sized to be disposed in the first barrel and has a discharge end defining a discharge passage communicating through the discharge end to accommodate the discharge of fluid from the second barrel. A plunger is slidably disposed within the second barrel. A liquid second constituent is provided in the second barrel between the discharge end and the plunger.

Abstract: A peristaltic pump is provided with a housing, a pump head in the housing, and a receiving path defined along a housing and pump head for receiving tubing. An air sensor assembly in the pump has a slot for receiving a section of the tubing in the receiving path. A position covering the receiving path and an open position exposing the receiving path. An engaging member is provided for pushing the tubing in the slot. The engaging member is pivotally mounted to the door for rotation about an axis parallel to the door pivot axis. The engaging member has a ram for contacting the tubing. The orientation of the ram relative to the door can change as the ram enters the slot when the door closes so that the tubing is pushed relatively evenly and along a substantially straight line into the slot.

Abstract: A disposable pumping cassette having an integral auxiliary flow control and pressure monitoring member is used for delivering a medicinal fluid to a patient. The pumping cassette includes an elastomeric member mounted in a rigid body having an inlet and an outlet. An inlet valve and an outlet valve on the cassette are opened, and the flow control is positioned to allow the medicinal fluid to flow freely through the cassette, priming it before the outlet is connected to the patient. The cassette is then coupled to an associated pump driver, closing the flow control to disable free fluid flow through the cassette, and the outlet to the cassette is coupled in fluid communication with the patient's body.

Abstract: A system and apparatus are provided for connecting an anesthetic container (14) to a vaporizer. Indicia are provided on the container (14) or on a transfer tube (12) connected to the container (14) and the indicia can include mechanical keys, electrical keys and electronic keys. A transfer device is provided for mounting to the vaporizer and engaging the container (14) or transfer tube (12) connected to the container (14). The transfer device includes a sensing system such as a key or code reader system. A clamping mechanism is provided for clamping the container (14), or end pin (16) of a transfer tube (12) connected to the container (14), in a leak-tight engagement within the transfer device. The transfer device can accommodate movement between a fill position and a drain position. The internal fluid flow passages are blocked except when the transfer device is in the fill or drain position.

Abstract: The injection molded luer cap of the present invention includes a stiff body having a circumferential sleeve extending downward from the body. The sleeve has an inner circumferential surface for sealingly fitting over the exterior surface of the fitment. A solid stem extends downward concentrically within the sleeve. The stem has an outside surface for a slip fit within the bore of the fitment and supports the male luer fitment during heat sterilization.

Abstract: A voltage converter and a method for converting AC to DC. A MOSFET (42, 118) conveys current from a full wave rectifier to charge a capacitor (60) that supplies current to a load (64). In a first embodiment, two transistors (32, 34) are connected as a differential pair to control the voltage applied to the gate of the MOSFET, referenced to a zener voltage developed across zener diode (36) that is connected to the emitters of the two transistors. In a second embodiment, a single transistor controls the voltage applied to the gate of the MOSFET, relative to a zener voltage of a zener diode (132). The MOSFET charges the capacitor while the voltage applied to its gate from the rectified signal is greater than the voltage across the capacitor.

Abstract: A drug delivery system includes first drug (110) and second diluent (182) syringe assemblies which are respectively pre-filled with a drug concentrate and a liquid diluent. The diluent syringe assembly is positionable in operative association within a sterility maintenance sleeve (150) of the first syringe assembly so that the assemblies are joined in fluid communication. This fluid transfer connection permits the diluent to be transferred from the second syringe assembly into a sterile mixing chamber defined by a reciprocable stopper (134) in the first syringe assembly. Thereafter, the second syringe assembly can be moved with respect to the barrel of the first syringe assembly so that the resulting mixture can be delivered for patient administration.

Abstract: A coupling system for transferring fluids from a medicament-containing cartridge to an injection site comprises a fluid flow channel, a blunt cannula defining the distal end of the fluid flow channel, a needle cannula defining the proximal end of the fluid flow channel, and means for fixedly connecting the needle cannula to the blunt cannula.

Abstract: The syringe system of the present invention includes a first or primary syringe barrel having a substantially closed end defining a delivery passage and an opposite open end. A removable closure seals the delivery passage of the first syringe barrel so as to define a container for containing a medical solution. A plurality of longitudinal channels are positioned on the inner surface of an enlarged diameter venting portion of the syringe barrel at the open end. A reciprocable stopper is provided for sealing the open end of the barrel so that the reciprocable stopper has a first position abutting the channels of the inner surface of the barrel so as to allow the medical solution to be lyophilized through the channels. The reciprocable stopper can then be longitudinally moved to a second position in the barrel in the in the direction of the delivery passage and beyond the channels to seal the lyophilized drug within the barrel.

Abstract: A port and cap assembly for a solution container is provided. The port includes a tubular wall having a first end and second end, the first end securable to the container and the second end being open and opposite to the first end. An annular flange extends perpendicularly outward from the cylindrical wall between the first end and the second end to define a neck portion of the cylindrical wall. A circumferential sleeve extends longitudinally downward from the annular flange. A radial lip extends generally perpendicularly inward from the sleeve. A resilient cap is also provided which includes a first portion resiliently stretched to cover the open end of the port and a second portion removably captured between the annular flange and the radial lip. The second portion of the cap after being removed from between the annular flange and the radial lip is not recapturable between the annular flange and the radial lip so as to indicate that the port has been uncovered.

Abstract: Parameters for controlling a drug infusion pump (10) are selected by scrolling through sets of predefined values. A value for either a rate and/or a volume of a fluid to be infused (VTBI) is displayed by pressing a quickset key (38) on a control panel (18) of the pump. Each time that the quickset key is depressed, the value appearing on a display (22) changes to the next value in the corresponding predefined set of values. It is also contemplated that holding the quickset key depressed for at least a predetermined time will cause the display to continuously scroll through successive values from the set of predefined values. The predefined values are selected in the set because they represent the most common values for the parameters used by the pump. An operator can "fine tune" the displayed value to a desired value that is not in the set of predefined values by pressing either a down arrow key (50) or an up arrow control key (52).

Abstract: A flush device for an intravenous blood pressure monitoring system has a main body which includes a continuous capillary flow channel and a fast flush channel. The continuous capillary flow channel is separated from the fast flush channel by a median wall. A fast flush opening in the median wall is blocked by an elastomeric member. When the member is distended, the fast flush opening is unblocked. An alternative embodiment of the fast flush device has a tubular body with a capillary channel formed on an inner wall. An elastomeric member contained within the tubular body enables flow to the capillary channel when the elastomeric member is in an initial position. When the elastomeric member is in a distended position fluid is allowed to overflow the capillary channel thus permitting a fast flush flow.

Abstract: An infusion system for administering multiple infusates at individually programmable rates, volumes, and sequences in any order from any one or more of plural fluid input ports through a patient output port and into the circulatory system of a patient. Infusates may be either continuously or time sequentially administered, and infusates may be either intermittently administered at selectively regular intervals or in time overlap to administer a dilution. Various error conditions are automatically detected and alarms generated in the event of conflicts between infusates, to identify times of no infusions, and to identify system malfunctions. The system is selectively operable, among others, in a priming mode, a maintenance mode, a normal-on mode, and a manual override mode. The system is operative to adapt actual to desired flow rates in normal operation. All fluids flow through a unitary disposable cassette without making any other system contact.