Abstract: An irrigation/aspiration apparatus is provided for use with surgical instrumentation requiring irrigation and aspiration of fluids and a peristaltic pump. The apparatus includes a housing and a manifold for connecting a transfer tube with aspiration and irrigation lines from the surgical instrumentation and with waste and supply lines. An opening the housing enables access to the transfer tube in order to control fluid flow therein. A diaphragm mounted to the housing and in fluid communication with the aspiration tube enables both pressure measurement and pressure control in the tubing when the housing is inserted into a drawer in the console and in operative engagement with a peristaltic pump head disposed therein.

Abstract: An irrigation system and method for providing fluid from a source of irrigating fluid to a surgical site, in particular a surgical site access to which is provided by a small incision or a natural orifice of the body. The irrigation system includes a control unit that is used with a cassette. The control unit includes a motor under the control of a controller, a sensor for sensing the flow of fluid in the cassette, a sensor for sensing pressure in the cassette, and a user control panel. The cassette includes a fluid flow passageway having an inlet connected to the source of irrigating fluid and an outlet for providing fluid to the surgical site. A pump located in the cassette is driven by the motor. The pump has limited efficiency when presented with back pressure to thereby limit to a safe level an amount of pressure that can be delivered to the surgical site. The system may be used to irrigate or distend a surgical site.

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.

Abstract: Methods and devices for the diagnosis, evaluation and treatment of coronary artery disease (CAD) by means of a closed-loop drug delivery system that delivers an exercise simulating agent, including novel exercise simulating agents which elicit both acute and adaptive cardiovascular responses similar to those elicited by aerobic activity are provided. The acute responses to the exercise simulating agent are used to diagnose and evaluate CAD in lieu of the acute responses to aerobic exercise. Due to their adaptive responses these compounds may be used to treat CAD in lieu of the adaptive responses caused by aerobic exercise training or to treat other conditions where the adaptive responses caused by aerobic exercise are desirable.

Abstract: A volume sensor is described for automating an extracorporeal system used for the recovery and concentration of salvaged blood. The system includes a disposable plastic reservoir in which blood is collected from the surgical site and stored for processing. Volume is sensed in one embodiment by a strain gage device which is sensitive to vertical forces. In another embodiment volume is sensed by measuring the transit time of an ultrasonic pulse-echo signal generated by piezoelectric transducer.

Abstract: An intravenous system for monitoring the flow of IV fluids to a patient is embodied in a wristwatch sized unit for placement on the patient. The device includes a flow indicator switch capable of detecting when flow starts or stops. In one embodiment, the range of flow rates which may trigger a signal is increased using a plurality of sensor elements. The flow indicator switch uses a conical chamber with a movable flow element which reacts to the motion of the IV fluid. A light emitter-sensor arrangement provides a means for converting physical displacement into an electrical signal indicating displacement of the movable member.

Abstract: An improved device and process of assuring separation of an anticoagulant type fluid from a saline type fluid each of which is utilized in the process and operation of a plasmapheresis apparatus or the process of collecting donor blood, is disclosed. The improvement includes a cross-spike prevention receptacle which is dimensioned, and installed positionally in reference to a plasmapheresis or blood donor apparatus, to receive an anticoagulant fluid container to which a proper respective supply communication line will connect, and to exclude and not receive a saline fluid container or container holding a similiar type of fluid, whose fluid line will not reach and connect to the installed cross-spike prevention receptacle.

Abstract: Bidirectional flow patterns are induced in a fluid supply line and the reverse flow resistance and the forward flow resistance are measured and compared. A measure of the resistance to flow is made by normalizing a sum of the entire pressure response about a pressure baseline according to the volume of fluid in the bidirectional flow pattern. In the event that the cannula is positioned near or against the vessel wall, the resulting relatively large negative pressure response can indicate the positional irregularity. In one embodiment, a time period of zero flow is included between the positive and negative flow volumes to permit the system to stabilize.

Abstract: A method for testing for patency at a venous access site during intravenous infusion of a medical solution includes the steps of occluding an intravenous injection tube upstream from the venous access site and monitoring the time and fluid pressure within the tube while the fluid pressure within the tube is varied by external contact with the tube. An apparatus for practicing the method of the invention includes a housing formed with a tube receiving portion for holding a portion of the tube in contact with an occluder finger, a fluid moving finger and a pressure transducer. The fluid moving finger is adapted to contact the tube so as to achieve a testing base pressure in the fluid, after occlusion by the occluder finger. A sequence of pressure drops are then effected by moving the fluid moving finger in stepped increments.

Abstract: A pain comforter system for providing pain relieving medication to a patient at a rate which is variable as a function of changes in conditions, this system comprising a line for feeding medication from a source to the patient; a pump to feed the medication; means to sense the conditions of the patient and the medication; and a controller coupled to the sensors adapted to energize and de-energize the pump as a result of the sensed conditions.

Abstract: A medical pump drive for automatically displaying not only the flow rate of circulating blood but also blood flow rate per surface area of the body of a patient in a medical treatment such as extracorporeal circulation includes at least a pump driving circuit, an ultrasonic transceiver and ultrasonic oscillator for measuring flow rate of the blood conveyed by a pump, a CPU, to which values of height and weight of a patient are entered, for calculating the body surface area of the patient as well as the blood flow rate per body surface area of the patient based upon the blood flow rate and body surface area obtained, an LCD for displaying the calculated blood flow rate per body surface area, and an LED for displaying the blood flow rate obtained.

Abstract: A cardioplegia administration system includes a tubing set, a positive displacement pump and a mixing system. The tubing set has a cardioplegia supply tube; a blood supply tube; and a cardioplegia administration tube connected to the cardioplegia and blood supply tubes. The positive displacement pump engages the cardioplegia administration tube to pump fluid therethrough. The mixing system includes pinch valves for alternately-continually pinching the cardioplegia and blood supply tubes to close and open the cardioplegia and blood supply tubes such that only one of the cardioplegia and blood supply tubes is open at a time, and a controller that controls the intervals during which the pinch valves are open to control the ratio of the cardioplegia medication and blood or blood substitute administered through the cardioplegia administration tube.

Abstract: A calibration system comprising a sensor cassette including at least one sensor to be calibrated and a housing having a liquid passage including a chamber. The housing is coupled to the sensor cassette to place the liquid passage in fluid communication with the sensor cassette. The housing has a gas injection passage through which a gas can be injected into the liquid passage to mix with a calibration liquid in the housing. A gas vent vents the gas from the housing. Porous media is provided in the chamber. The gas and calibration liquid pass through the porous media, and the porous media assists in rapid mixing of the gas and the calibration liquid.

Abstract: A fluid transfusing device and method of control therefor includes a plurality of pump driving portions and a microprocessor. Each pump driving portion is for driving a pump, and the microprocessor controls the pump driving portions. The microprocessor executes a fluid transfusing device control program, and interrupts the fluid transfusing device control program upon receiving a pump interrupt. The microprocessor then executes a pump driving interrupt module. When the microprocessor executes the pump driving module, the microprocessor generates a pump driving pulse to control a pump driving portion associated with the pump corresponding to the pump interrupt, determines receipt of another pump interrupt corresponding to a another pump, and generates a pump driving pulse to control a pump driving portion associated with the another pump corresponding to the another pump interrupt.

Abstract: A method and system for the infusion of a drug into a patient involving: (i) calculating a multiplicity of infusion rate profiles for a selected drug by monitoring drug efflux from the body of a group of patients for a corresponding multiplicity of target concentrations of the selected drug; (ii) determining the body size of the patient, such as their Lean Body Mass; (iii) selecting a target concentration of the drug to, in turn, cause selection from the multiplicity of infusion rate profiles of an infusion rate profile substantially corresponding to the infusion rate profile for the selected target concentration; (iv) scaling the selected infusion rate profile by the determined body size or Lean Body Mass of the patient; and (v) administering the drug to the patient in accordance with the scaled profile by means of an infusion device which is controlled to deliver said drug at said scaled infusion rate profile.

Abstract: In an infusion apparatus for use in the medical field, a peristaltic pump mechanism pumps an infusion fluid including medication through an administration tube toward a patient. A clock powered independent of the apparatus counts a predetermined unit time. A CPU accumulates data representing an incremental unit of fluid of the infusion fluid delivered by the pump mechanism to measure an accumulated infusion fluid volume each time the clock counts the unit time. Data as to the current accumulated infusion fluid volume is stored in a second storage section of a RAM. Each time the clock counts the unit time, data representing the accumulated infusion fluid volume stored in the second storage section is written to a ring buffer in the RAM, so that the ring buffer stores data representing a plurality of accumulated infusion fluid volumes in one-to-one correspondence with a plurality of times at which the plurality of accumulated infusion fluid volumes were measured.

Abstract: An improved infusion pump and a method for infusing patients using same. The infusion pump is modified to utilize a plurality of different drugs, each formulated at a mean effective dosage and toxicity level such that the infusion rate is the same for the drugs. More specifically, the control means of the infusion pump has a single drug label plate affixed to the pump and adjustable controls which are used in setting the mean effective dosage of the drug to be infused, the body weight of the patient to be infused, and the bolus or initial dosage of the drug to be infused. The method of the present invention comprises preparing the formulation of the plurality of different drugs, each at a mean effective dosage and, in combination with the infusion pump of the invention, infusing the drugs into patients at the same rate.

Abstract: A programmable infusion pump which combines automatic and demand doses of medication with any basal rates on a real-time basis to determine an effective rate at anytime during the delivery cycle without under-delivering fluid due to the minimum increment of fluid delivery by the pump.

Abstract: The invention relates to an apparatus and a method for setting the level of a liquid in a chamber of an extracorporeal blood circuit. The chamber contains liquid in its lower portion and air in its upper portion. It is connected to a pump for causing the quantity of air to vary in the chamber. According to the invention, the chamber is provided with a level detector that transmits data to a control unit. The control unit actuates an air pump to vary the amount of air in the chamber and thereby ensures that the liquid level in the chamber is equal to a desired level.

Abstract: An infusion system with an air-in-line sensor is provided with improved apparatus and method for quickly and easily clearing small quantities of undissolved gas such as air from the sensor detection field. The infusion system includes an infusion pump having control components responsive to the air-in-line sensor to activate an alarm and/or to cease pump operation when undissolved gas is detected. A "clear air" key or switch is provided on the pump for actuation by medical personnel to operate the pump in a manner delivering a small pulse of the infusion liquid to move a small detected quantity of gas past the air-in-line sensor. The system can be adapted for actuation of the "clear air" key up to a selected number of times, while monitoring and accumulating the total fluid quantity delivered to a patient.

Abstract: The present invention relates to a control system for use with an automated intravenous drug and fluid infusion system having plural pumping channels that operate independently for intravenously infusing drugs and fluid. The pumping channels are controlled by a microprocessor-based host controller that monitors each of the channels concurrently. In an exemplary embodiment, the system functions include identifying the particular drug that is to be pumped through a channel, preventing priming of a channel unless verification is provided that the channel is not connected to a patient and initiating the priming of each of the pumping channels independently.

Abstract: The device for simultaneous weighing and agitation comprises a tray (14) for receiving an object (15) to be weighed, which object is a receptacle (15) for progressively receiving a substance (18), and the tray (14) is associated both with means (16) enabling the weight of said object to be measured, and with means (1) enabling agitation motion to be imparted thereto. The tray (14) and the agitation means (1) are mounted on a common support (17) on which exact measurement is then performed with an error of not more than 5% of the weight of the combined device and object (15) to be weighed during agitation.

Abstract: A slit disk having a hole at a specified portion of its flat surface and a plurality of slits at regular intervals at a peripheral portion thereof is mounted to a shaft of an infusion pump. A controller clears a live band determination counter based on a light detection signal from a sensor when the hole is detected, and increments the count value of a live band determination counter when an side edge of one of the plurality of slit is detected. When the count value of the live band determination counter falls within "10" to "24" or "0" to "2", it is determined that the infusion pump is in a live band, and the count value of the live band counter is incremented. Thus an operation amount of the infusion pump in the live band is detected to measure a fluid delivery rate taking a dead band into account.

Abstract: A blood pumping system and method in which a selective backflow warning is generated in response to the detection of a backflow condition only in the absence of electrical interference that could cause the generation of a false backflow warning. Detection of a backflow condition is performed by activating the transmitter and receiver of a flow detector to determine the direction of blood flow and detection of the electrical interference is performed by activating the receiver of the flow detector while the transmitter is not activated. If electrical interference that could cause the generation of a false backflow warning exceeds a threshold, the system does not generate a backflow warning.

Abstract: A compact, integrated intravenous fluid delivery device. In one embodiment, the invention may be used with first and second intravenous fluid sources and an intravenous fluid line. This embodiment includes a spike for connecting the device to the first intravenous fluid source. A fluid passageway passes through the spike. A connection site (e.g. a puncture site) connects the device to the second intravenous fluid source. This embodiment also includes a drip chamber, through which the fluid may flow to the intravenous fluid line. This embodiment may include an adjustable valve, which includes a flexible tube mounted so that fluid may pass from the fluid passageway in the spike, from the connection site, and through the tube. The valve includes an actuator mounted with respect to the tube so that it may be urged to compress the tube. The spike, the adjustable valve, and the drip chamber are rigidly attached to each other, with no flexible tubing between the various components.

Abstract: A compliant chamber is formed in a fluid line which connects a fluid supply to a fluid receiver. The compliant chamber is alternately in fluid communication with the upstream and downstream segments of the fluid line. When the chamber communicates with the upstream segment it receives and stores fluid at the head pressure. When the segment communicates with the downstream segment, a pressure equalization pulse occurs. A pressure sensor in the downstream segment measures the pressure equalization pulse which is proportional to the head pressure. Processing the equalization pulse with the downstream fluid system resistance, the compliance of the compliant chamber and the equilibrium pressure results in a determination of the head pressure. Comparing the head pressure to thresholds permits determination of an occlusion or empty fluid supply. Where a peristaltic pump is used, the chamber is formed between the end fingers of the pump.

Abstract: An IV flow monitor is connected to a conventional IV bag via a self-contained puncture tube, and includes a liquid reservoir at the top, which allows the liquid to transfer through a transfer tube and then through a calibrated orifice tube into an orifice chamber, from which the liquid falls through an exit tube connected to a patient or other IV equipment. A manometer tube is connected between the liquid reservoir and the orifice chamber and is aligned with a measurement scale fixed to a backing plate upon which the apparatus is mounted. The pressure drop across the calibrated orifice tube produces a standing column of liquid in the manometer tube and principles of fluid flow allow the rate of flow through the apparatus to be read from the scale. An air trap chamber in an upper portion of the orifice chamber and hydrophobic gas membranes provide safety features that prevent air from being entrained in the liquid flowing through the exit tube to the patient.

Abstract: A drop detector circuit and method are provided for a drop detector of the type including a drop chamber and an electro-optical sensor. A detector detects drops passing through the drop detector in an optical sensing path between the detector and at least one light source. In response to the detection of a drop passing through the optical path, the detector produces an output signal. A capacitor is connected between the detector and an amplifier to block the DC component of the output signal. After amplification, the signal is passed through a low pass filter to further block signals caused by undesirable factors. The cutoff frequency of the low pass filter is controlled by a microprocessor that controls the pump that pumps liquid from the drop chamber. The detector and light source or sources are arranged to detect drops falling in the drop chamber at virtually any angle and in virtually any ambient light condition.

Abstract: A system is disclosed for detecting extravasation of injected liquid from the blood vessel of a patient. The system operates by monitoring electromagnetic microwave emission from the patient at the injection site by means of a microwave antenna assembly and processing apparatus connected to the antenna assembly for responding to changes in the microwave emission characteristics representative of extravasation. The antenna assembly has a reusable antenna element connected to the processing apparatus, a disposable attachment element for adhering to the patient's skin, and interfitting male and female coupling formations on the attachment element and the antenna element respectively for releasably coupling the reusable element to the disposable element.

Abstract: A drip detecting device for detecting drips dropping in a drip cylinder, includes an image detecting portion disposed in the vicinity of the outer wall surface of the drip cylinder for detecting the state in the drip cylinder as an image, and a drip detecting portion for detecting a drip dripping in the drip cylinder on the basis of the image. Disclosed also is a drip alarming device which includes a drip rate detecting portion for detecting the rate of dripping on the basis of the data detected by the drip detecting device, a determining portion for determining whether the detected dripping rate is proper, and a generating portion for generating an alarm in accordance with the result of the determination. A drip rate control device also is detected which has a drip rate detecting portion for detecting the rate of dripping on the basis of the data detected by the drip detecting device, and a drip rate control portion for controlling the drip rate to a required rate.

Abstract: Apparatus located in an implantable medication infusion pump for quickly and easily detecting a condition adversely affecting medication delivery in the implantable medication infusion pump is disclosed which can reliably detect occurrences including an occluded catheter, the presence of air in the pumping mechanism, and the failure of the pumping mechanism. The system uses the amplitude of an acoustic signal generated by operation of the pumping mechanism as compared with a baseline signal to detect an encapsulated or occluded catheter or air in the fluid line. In addition, the system can detect a partially encapsulated or occluded catheter by detecting repeated downward slope patterns during repetitive, closely spaced pumping cycles.

Abstract: A variable ratio, blood-additive solution, mixing device and delivery system that permits the varying of the ratio of blood to solution from either all blood to pure solution and any ratio of the two, either continuously or intermittently, prior to or during cardiovascular and cardiac perfusion procedures, particularly warm or cold cardioplegia procedures for open heart surgery.

Abstract: An infusion management and pumping system is disclosed. Infusion prescriptions are generated and monitored by a pharmacy management system. Labels for each infusion to be given to a patient are generated and printed in a bar code format. Each label contains data regarding a prescribed infusion program, including the drug or drugs to be infused, the infusion regimen, the expiration date, and the patient to whom the infusion is to be administered. The management system checks for incompatibilities between drugs that are being prescribed for simultaneous infusion. Each label generated by the management system is attached to the container which holds the infusion solution. The data on the label is transferred to an infusion pumping system by a bar code reader at the infusion pumping system. The pumping system checks that all necessary data has been entered. During operation, the pumping system checks for a variety of alarm conditions and stores any alarms in a ranking according to urgency.

Abstract: A peristaltic pumping apparatus has a misloaded-tube detector. The detector is constituted of a pair of pressure sensors and a CPU. The pressure sensors are located on both sides of a fluid propelling portion onto which an IV tube containing a solution is loaded. The detector detects a tube misloading by making use of pressure which is applied to one pressure sensor when the tube is displaced onto the pressure sensor and is forced against it by the closing of a door. Each sensor consists of first and second electrodes spaced from each other, a pressure-resistive conductive element attached to the first electrode and spaced from the second electrode and capable of connecting thereto, and a resistor connected to the first and second electrodes. The CPU judges from a resistance value of the pressure sensor as to whether the tube is properly loaded or misloaded or whether the pressure sensor is in an operative state.

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.

Abstract: An infusion apparatus is provided with a clock, a power-on-time counter for counting a period of time in which power is supplied to the infusion apparatus from an AC power source or a backup battery for backing up the AC power source, a pump-on-time counter for counting a period of time in which a pump mechanism operates, and a battery-on-time counter for counting a period of time in which power is supplied to the infusion apparatus from the backup battery. A CPU displays a time value counted by the counters on a display unit. The time value displayed on the display unit indicates the degree of deterioration of charge capability of the backup battery, from which a time for replacing the backup battery and the other parts can be easily perceived.

Abstract: A rotary encoder comprises a rotary plate having a plurality of primary slits defined in the rotary plate in a circular row coaxial with the axis of rotation of the rotary plate. The rotary plate also has at least one reference slit defined therein at a position radially of the circular row of the primary slits. A primary photoelectric detector including a source of light and a photo-sensor positioned one above the other with the circular row of the primary slits intervening therebetween is used to detect the passage of the primary slits therethrough while an auxiliary photoelectric detector including a source of light and a photo-sensor positioned one above the other with the path of travel of the reference slit intervening therebetween is used to detect the passage of the reference slit therethrough.

Abstract: A calibration system comprising a sensor cassette including at least one sensor to be calibrated and a housing having a liquid passage including a chamber. The housing is coupled to the sensor cassette to place the liquid passage in fluid communication with the sensor cassette. The housing has a gas injection passage through which a gas can be injected into the liquid passage to mix with a calibration liquid in the housing. A gas vent vents the gas from the housing. Porous media is provided in the chamber. The gas and calibration liquid pass through the porous media, and the porous media assists in rapid mixing of the gas and the calibration liquid.

Abstract: A pressure monitoring device for indicating to the administrator of an injection to a patient that an excess of force has been exerted on the plunger and thereby the fluids contained within the syringe.

Abstract: Optical components and methods for an I.V. flow detector providing complete coverage of a drip chamber through the use of a single emitter and receiver. The optical components take the light of a single emitter and spread it uniformly across the entire drip chamber. Furthermore, the light is collimated as it passes through the chamber. In addition, the optics collimates the light at some point in its path from the emitter to the drip chamber. Similarly, it collimates the beam of radiation at some point in its path from the drip chamber to the receiver. Further, the optics creates a plane of symmetry for the light path passing through the center of the drip chamber and lies perpendicular to the path of the light. The design specifically takes into account the optical characteristics of the drip chamber itself.

Abstract: A drop detector for intravenous systems in which an infrared emitter is pulsed at 10 kHz. The pulsed radiation passes through a drip chamber and then to a detector. The detector circuit determines the amplitude modulation of the 10 kHz. carrier frequency. This provides an indication of when the drop falling through the drip chamber has interrupted the light beam. An automatic gain control circuit maintains the output of the detector, on a long time constant basis, at a constant level to eliminate the vagaries of drip chambers with different optical characteristics and the like. When the AGC circuit lacks the ability to maintain the output of the detector circuitry at a constant level, a fault detector provides an alarm to indicate that the circuitry has exceeded its operational range.

Abstract: An infusion pump system for dispensing a drug to a patient in accordance with a predetermined therapeutic modality, said system including a drug delivering member controlled by a microprocessor and replaceable memory modules coupled to said microprocessor for configuring specific pump user interface and other characteristics required for differing therapeutic modalities. Information specific to a particular patient is entered through input features on the pump.

Abstract: A drop detector circuit and method are provided for a drop detector of the type including a drop chamber and an electro-optical sensor. A photodiode detects drops passing through its optical sensing path, and a capacitor is connected between the photodiode and an amplifier to block the DC component of the diode signal. After amplification, the signal is passed through a low pass filter to further block signals caused by undesirable factors. The cutoff frequency of the low pass filter is controlled by a microprocessor that controls the pump that pumps liquid from the drop chamber.

Abstract: A semi-automatic infusion system for administration of neuromuscular agents and the like includes a microcomputer-controlled infusion pump with a data input pad. A clinician enters the desired paralysis level and performs periodically an electro-stimulation test to determine the actual paralysis level of the patient. This information is also entered in to the system by the physician which then calculates and administers a new dosage.

Abstract: Tourniquet apparatus for use in intravenous regional anesthesia and limb surgery includes a pressurizing cuff for substantially encircling a limb and applying a varying pressure to an underlying vein in response to variations in a pressure control signal, applied venous pressure sensing means for producing an applied venous pressure signal representative of a pressure applied by the cuff to the underlying vein, venous fluid pressure estimation means for producing a venous fluid pressure signal representative of the pressure of fluid in the vein distal to the cuff, and pressure control means responsive to the venous fluid pressure signal and applied venous pressure signal for generating a pressure control signal to maintain a predetermined relationship between the applied venous pressure signal and the venous fluid pressure signal. The apparatus automatically controls the introduction, retention and release of anesthetic fluid in the limb.

Abstract: An apparatus for controlling the rate of dripping of an intravenous fluid, comprising (i) a drip-detecting device for detecting that an intravenous fluid has dripped into a drip-feed bottle, (ii) a clock for measuring time and indicating the current time, (iii) a constricting arrangement connected to a fluid-supply pipe extending from the drip-feed bottle in a downstream direction, for constricting the supply tube, and (iv) a flow controller for controlling the amount of constriction of the supply pipe by the constricting arrangement, based on a signal from the drip-detecting device indicating detection of a drip and a time signal from the clock. The apparatus enables one to accurately control the interval of time at which an intravenous fluid drips into the drip-feed bottle and, hence, to administer the fluid to a patient at a desired rate.

Abstract: An apparatus for determining whether an IV infusion set has infiltrated the tissue of a patient includes a pump for pumping fluid through the IV set into the patient and a pressure transducer operably engaged with the IV set between the pump and patient. The pressure transducer is electrically connected to a microprocessor, and the microprocessor is electrically connected to the motor of the pump to control the pump to alternately withdraw from and infuse into the patient a predetermined volume of fluid.This predetermined volume of fluid is withdrawn from the patient by the pump at a preselected withdrawal pressure, while the pump infuses the predetermined volume of fluid into the patient at a preselected infusion pressure. The microprocessor measures both the time period for infusing the predetermined volume of fluid and the time period for withdrawing the predetermined volume of fluid. Based upon these time periods, the microprocessor evaluates whether the IV set has infiltrated the patient's tissue.

Abstract: Medical infusion apparatus comprises a housing in which a standard flexible liquid reservoir is disposed. A constant-force spring applies pressure to the reservoir to force liquid out of the reservoir and along a conduit to a patient. The spring is energized by the opening of a lid of the housing which permits replacement of the reservoir.The liquid flowing out of the reservoir passes through a molded conduit part which is configured so that it is positioned at a predetermined location with respect to a flow monitor. The flow monitor injects a pulse of heat, and detects the rate at which the heat pulse travels along the conduit. A microprocessor uses the sensed flow rate to control a stepper motor which regulates fluid flow by squeezing the conduit via a spring-biased member. The apparatus has active and standby modes in which the monitor is operated respectively more and less frequently.

Abstract: An improved multiple fluid delivery system usable for the delivery of intravenous fluids to a patient from a plurality of fluid sources includes flexible tubing members for coupling the sources to a fluid junction member. The fluid junction member, wherein little or no interfluid mixing occurs, is coupled by an output conduit to a controllable pump. Output from the pump, via a further fluid flow conduit, can be coupled to the patient's catheter. The system can multiplex a plurality of different fluids. Spaced apart sequences of fluid quanta are injected into the output conduit from the fluid flow junction. The fluids are either mixed, or not, in the output conduit as desired. Operator interaction and control of the system can occur either through a display screen or by means of a bar code sensor. Hard copy records can be provided of fluid flow delivery schedules or other related information.

Abstract: A system for controlling and monitoring the extracorporeal circulation of fluids, which is particularly useful in controlling and monitoring the circulation of blood and cardioplegia solution in surgical procedures. A set of perfusion assemblies are mounted in a transportable console, each perfusion assembly having a separable pump and control module pod. Virtually all the instrumentation for the monitoring and controlling of the pump and the fluid being pumped by that perfusion assembly are present on the pump and control module pod for that perfusion assembly, without the need for any separate control screen. Further, the perfusion assembly uses removable circuit cards and associated instrumentation strips to custom configure the perfusion assembly for each application. The perfusion assembly thereby provides complete information at a glance and complete control of the perfusion assembly by using dedicated controls that are grouped to each perfusion assembly.