Abstract: A drip chamber including an inlet member, a transparent housing chamber and an outlet member wherein an impinging member connected to the inlet member breaks the flow of the intravenous fluid when the fluid forms a indiscernible fluid stream to cause the fluid to accumulate into droplets that are readily visible by medical personnel.

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 centrifugal blood pump driver comprises a motor housing and the housing contains a motor for rotationally driving the centrifugal blood pump and a controller operatively associated with the motor for controlling the rotational speed of the motor; a speed selector for generating a selected speed signal signifying a selected rotational speed for the motor; sensors operatively associated with the motor or controller for sensing the rotational speed of the motor and outputting a monitor signal signifying such rotational speed; program memory for storage of a program of microprocessor readable instructions; a microprocessor under program control, in electrical connection with the controller, the speed selector, the sensor and the program memory, for receiving the selected speed signal and generating a speed control signal to the controller signifying the selected speed for the controller, and for receiving the monitor signal and outputting a display signal; a display in electrical communication with the micropro

Abstract: The present invention concerns a pump provided with a control module and an attachable fluid reservoir cassette. The control module includes a pumping mechanism for pumping fluid from the fluid reservoir to the patient. The cassette is provided with appropriate indicia to identify differences between a plurality of cassettes. The control module further includes cassette indicia identification structure for identifying indicia on the cassette. One type of cassette identification system includes a projection extending from the cassette and structure associated with the control module which engages the projection. Another type of cassette identification system includes a light reflecting system which utilizes light from the control module and reflected off the cassette. Still other types of cassette identification systems utilize other non-contact switches or sensors to sense indicia on the cassette to identify the cassette from a plurality of cassettes.

Abstract: A multi-drug intravenous infusion apparatus which comprises a plurality of vials containing drugs to be provided to a patient; a fluid container containing fluid to be mixed with the drugs; conduit mechanism for leading drugs from the vials, mixed with the fluid from the container, to mechanism for introducing the drugs with the fluid into the patient's body, the conduit mechanism comprising: a main section, a plurality of individual sections, each comprising at least a collapsible portion, connected to the vials and to the main sections, a terminal section connected to the main section and the mechanism for introducing the drugs with the fluid into the patient's body, and a fluid section leading fluid from the fluid container to the terminal section; a switching unit comprising a plurality of switches, each one associated with one of the individual sections, wherein each switch is capable of either blocking the drug flow in the associated section by exerting pressure whereby to collapse the collapsible porti

Abstract: A blood transfusion device has at least one blood accelerating pump, a variable volume reservoir, at least one single-use blood supply bag, a platen, a blood reheater, a single-use blood reheater bag, a filtration system and a perfusion line. The variable volume reservoir varies in volume using an accordion-like bellows or a flexible pocket acted upon by the blood accelerating pump. The single-use blood supply bag contains concentrated corpuscles, plasma, or a solution of albumin. The blood supply bag is disposed between two plates precisely spaced apart. The platen is acted upon by the accordion-like bellows or the flexible pocket to slide in parallel to the two plates, and is disposed between the variable volume reservoir and the blood supply bag. The blood reheater includes an assembly of two double plates, each double plate having a preheating plate heated to a constant temperature slightly less than 38.degree.

Abstract: A device for sensing gas bubbles in a liquid flowing through a duct, particularly the outlet duct of a peristaltic pump, including two piezoelectric components shaped and excited so that they vibrate axially. One of the components is a transmitter and the other is a receiver. One of the piezoelectric components is secured to a movable support, and its displacement is detected in order to detect excess pressure in the liquid flowing through the duct.

Abstract: The Blood Infusion Control System of the present invention integrates components of rapid infusion systems with a computer controller designed to synchronize two infusion pumps in a manner that produces a pre-selected patient hematocrit (HCT*) while reporting the patient's estimated blood volume (BV.sub.E). In order to attain HCT*, the Blood Replacement Controller (BRC) drives a dual-pump assembly to deliver streams of asanguinous fluid and blood through flexible conduits into intravenous (IV) catheters to mix with the patient's blood volume having an initial hematocrit (HCT.sub.i). The BRC utilizes measured patient data as feedback input to control flowrates of the two-pump infusion assembly. The patient's estimated blood volume is extrapolated from hematocrit changes in response to the fluid and blood infusion.

Abstract: A blood aspirator is composed of a suction circuit adapted to receive a flow of blood, a sensor associated with the suction circuit for generating a signal relating to the presence of bubbles in aspirated blood in the suction circuit, a variable speed pump coupled to the suction circuit and adapted to pump blood through the suction circuit, and a controller for controlling the speed of the pump. The controller causes the pump to adjust the blood flow through the suction circuit so that a predetermined, nonzero concentration of bubbles flows through the suction circuit.

Abstract: A microwave antenna senses the temperature of tissue into which a fluid is to be injected. The fluid is injected by a needle or other vascular entry device connected to a fluid injector by a connector tube. The fluid temperature is measured by a temperature sensor attached to the connector tube. An alarm processor determines whether an extravasation occurs by comparing a temperature discrimination function derived from tissue temperature taken at different times with a calculated threshold value. The threshold value is calculated from the tissue temperature and the fluid temperature. The threshold value is recalculated and updated continuously during the fluid injection.

Abstract: The invention relates to a method and system for monitoring pressure conditions in the fluid pressure upstream and downstream of an intravenous fluid administration system and to detect upstream and/or downstream occlusions. In addition, the invention incorporates a method for detecting pressure conditions at an upstream or downstream detector across the wall of the tubing to identify upstream or downstream occlusions, respectively. The present invention also relates to a process for determining the fluid pressure in a fluid tube across the tube wall where the normal tube force changes over time, and more particularly, using a normalization process to eliminate changes in the tubing resilience.

Abstract: The present invention relates to a method of preparing and administering one or more drug solutions for continuous infusion. Flow rates are standardized by varying the drug concentrations according to a preestablished set of tables. The method of the present invention greatly simplifies clinical application of continuous infusion anesthesia, and allows easy preparation of different volumes which can minimize drug wastage. The standardization of rate taught by the present method eases interpretation and mixing, resulting in easier application of drugs and increased patient safety. An apparatus is desirably used to assist in achieving the objectives of the present invention. The device facilitates accurate and efficient conversion to the nonstandard flow rates required for special applications such as neonatal anesthesia and others.

Abstract: The invention relates to an apparatus for irrigating body cavities with a fluid, comprising a reservoir containing the irrigating fluid, a pumping unit which pumps the irrigating fluid from the reservoir via an instrument into the body cavity to be treated, a collector vessel receiving the irrigating fluid flowing out of the body cavity, and measuring means which detect the difference between the introduced quantity of irrigating fluid and the flowing-out quantity of irrigating fluid. The invention excels itself by the aspect that an electronic evaluation unit determines, on the basis of the output signal of the measuring means, the quantity of irrigating fluid lost and additionally the rate of variation of the lost quantity versus time.

Abstract: A centrifugal blood pump driver comprises a motor housing and the housing contains a motor for rotationally driving the centrifugal blood pump and a controller operatively associated with the motor for controlling the rotational speed of the motor; a speed selector for generating a selected speed signal signifying a selected rotational speed for the motor; sensors operatively associated with the motor or controller for sensing the rotational speed of the motor and outputting a monitor signal signifying such rotational speed; program memory for storage of a program of microprocessor readable instructions; a microprocessor under program control, in electrical connection with the controller, the speed selector, the sensor and the program memory, for receiving the selected speed signal and generating a speed control signal to the controller signifying the selected speed for the controller, and for receiving the monitor signal and outputting a display signal; a display in electrical communication with the micropro

Abstract: An apparatus and method for delivering a fluid during a series of infusion intervals, consecutive infusion intervals being separated by a non-infusion interval, each infusion interval beginning at a predetermined time and having a first predetermined period, and each non-infusion interval beginning at a predetermined time and having a second predetermined period. The apparatus comprises a pump mechanism and circuitry operatively connected to the pump mechanism. The circuitry is configured so that, if the pump is disabled during one of the infusion intervals, the circuitry will determine the length of time the pump is disabled, interrupt the infusion interval while the pump is disabled, and delay the beginning of subsequent infusion and non-infusion intervals for a length of time approximately equal to the length of time the pump is disabled.

Abstract: A remotely programmable infusion system. The remotely programmable infusion system comprises a memory for storing a programmable protocol and a remote communication port for sending a voice signal to a remote touch-tone transceiver and for receiving a remote programming signal from the remote touch-tone transceiver. The remotely programmable infusion system also comprises a voice storage unit for storing the voice signal. The remotely programmable infusion system further comprises a processor, coupled to the remote communication port, to the voice storage unit, and to the memory, for accessing the voice signal from the voice storage unit and the programmable protocol from the memory, and for processing the programmable protocol in response to receiving the remote programming signal.

Abstract: An infusion device with a disposable administration set which is inexpensive to manufacture. In the preferred embodiment of the present invention the disposable administration set has a plurality of elongated cam followers connected to a plate assembly, wherein the cam followers are displaced in a predetermined sequence and forced against a delivery tube by cam means driven by rotary drive means. The device also includes an optical occlusion sensor which is synchronized to operate in phase with the movement of the cam followers to measure pressure within the delivery tube at one pump phase, thereby sensing downstream occlusions, and to measure vacuum within the delivery tube at a second pump phase, thereby sensing upstream occlusions. The occlusion sensor is optical, and measures the degree of total internal reflection at the interface of the tube and the plate assembly. occlusion in the tubing.

Abstract: This invention relates generally to the field of medical devices for delivering contrast media during medical diagnostic and therapeutic imaging procedures and more particularly, this invention relates to improved contrast media delivery systems and methods of use which allow adjustment of contrast media concentration and injection parameters either before or during an injection procedure.

Abstract: The invention discloses a method for treating brain and associated nervous tissue injury. The invention also discloses a method for preserving organs in brain-dead humans or cadavers which allows additional time for the organs to remain viable such that they may be harvested for subsequent transplantation. Also disclosed is a method for organ preservation which employs body cavity perfusion. The methods include the introduction of temperature-controlled solutions to slow the metabolism of the brain, associated nervous tissue or organ(s) to inhibit degeneration thereof. A device which performs these methods is also disclosed. The device includes a fluid reservoir, an oxygen source, a heat exchanger and removable catheter lines.

Abstract: A system and method are disclosed for internally administering a medicinal agent to a patient under the automatic control of a computer. A diagnostic imaging modality, such as a CAT or MRI scanning system, generates one or more images of the patient's anatomy showing a diseased area such as a tumor to which it is desired to deliver the medicinal agent by injection. For each such image, location coordinates with respect to a patient support structure are calculated by the computer for each individual pixel making up the image. Location coordinates are then defined for a select body region corresponding to pixels of the anatomical image(s) designated by a user of the system to receive the medicinal agent. The computer then operates a manipulator arm in order to position an injection needle mounted on the arm adjacent to the select body region and insert the needle into the region at the appropriate depth.

Abstract: The invention discloses methods for preserving organs in brain-dead humans or cadavers which allows additional time for the organs to remain viable such that they may be harvested for subsequent transplantation. This invention also discloses methods for preserving and/or resuscitating organs in live (nonbrain-dead) patients, allowing for additional time to stabilize the patient's condition. The methods include the steps of instrumentizing (e.g., catheterizing, cannulating, injecting, etc.) the vessels or tissues around the organ, or the organ itself sought to be preserved and/or resuscitated, the body cavity, or cavities of the body, and introducing a temperature-controlled solution to preserve and/or resuscitate the organ(s). The temperature-controlled organ preservation solution includes components such as oxygen carrying agents, antioxidants, tissue damage reversing and protecting agents, carrier vehicles, diluents, nutrients, and anti-coagulating agents.

Abstract: A closed-loop drug delivery system uses patient response and rule based decision making methods to achieve operator specified responses for diagnostic purposes. In the preferred embodiment, cardiac diagnosis is performed by pharmacologically stressing the heart by administration of an exercise simulating agent drug. In the preferred method, a protocol is defined, which preferably includes a target for a physiologic variable, such as heart rate, and a plan to achieve that target value. Preferably, the plan includes a specification of the desired rate of increase in that variable, such as the rate of increase in the heart rate per minute. The plan comprises the desired changes in the physiologic variable as a function of time. While any desired function may be used, the more common modes include RAMP, HOLD, LEVEL and TARGET mode. In one aspect of this invention, the protocol may be varied by the operator after drug administration has begun.

Abstract: Apparatus for carrying out peritoneal dialysis. The apparatus comprises a weighing device (37) provided with a case (50) for forming an airtight space. A heat bag (38) and, optionally, a discharge bag (42) are positioned in the space, said bags being connected with a catheter for the patient, who is to perform peritoneal dialysis. The apparatus comprises a pump arrangement (57) connected with the case (50) for producing overpressure and underpressure, respectively, in the space inside the case. Valve arrangements (39, 44) are adapted to connect either the discharge bag (42) or the heat bag (38) with the patient's catheter. By providing an underpressure in the case (50). fresh dialysis solution is provided to the heat bag (38) from supply bags, whereupon used dialysis fluid is extracted from a patient to the discharge bag (42).

Abstract: The invention relates to a method and system for monitoring pressure conditions in the fluid pressure upstream and downstream of an intravenous fluid administration system and to detect upstream and/or downstream occlusions. In addition, the invention incorporates a method for detecting pressure conditions at an upstream or downstream detector across the wall of the tubing to identify upstream or downstream occlusions, respectively. The present invention also relates to a process for determining the fluid pressure in a fluid tube across the tube wall where the normal tube force changes over time, and more particularly, using a normalization process to eliminate changes in the tubing resilience.

Abstract: An infusion method and apparatus for infusing liquid into a patient, the infusion apparatus being compatible with a plurality of different types of cassettes which are adapted to be insertable into and removable from the infusion apparatus. The infusion apparatus has a housing adapted to receive a first type of cassette and a second type of cassette, a pump disposed in the housing and adapted to pump liquid through a conduit, and a cassette sensor disposed in the housing, the cassette sensor being capable of determining whether the first type of cassette is inserted into the housing or the second type of cassette is inserted into the housing. The infusion apparatus includes control means for controlling the operation of the pump which causes a first course of control action to be taken when the first type of cassette is inserted into the housing and a second course of control action to be taken when the second type of cassette is inserted into the housing.

Abstract: Apparatus for supplying liquid to a body cavity during an endoscopic procedure includes a feedback loop-controlled liquid supply device inherently capable of supplying liquid at a substantially constant pressure substantially independent of the flow rate of liquid delivered by the liquid supply device within a relatively wide range of flow rate. Also disclosed are a disposable plastic pump cassette having an inflow pump in a housing, and an operative cannula. The surgical procedure is performed with continuous control over the body cavity pressure, regardless of the outflow flow rate.

Abstract: A pressure plate for use with a peristaltic pump having a base with a plurality of ribs attached to one surface of the base, each rib having a bottom surface, a top surface and an angled surface extending at an angle from the bottom to the top surface. Each rib being attached to the base such that the angled surface of each rib is oppositely disposed from the angled surface of another rib so that a channel is formed between each pair of oppositely disposed ribs. A securing mechanism is attached to the pressure plate to secure a compressible tube and an attachment mechanism is provided for attaching a pump mechanism to the pressure plate. One securing mechanism includes two clamps at opposite ends of the pressure plate with spaced apart retaining lips. Adhesive attachment of the tube to the pressure plate is also provided.

Abstract: The present invention relates to systems and methods for operating ambulatory medical devices, such as drug delivery devices. The pump includes the pump control system for activating a pumping mechanism wherein the pump control system includes a processor, a flash memory electrically interconnected to the processor for storing pump operation information, and a communications port electrically interconnected to the flash memory to permit transfer of the pump information into the flash memory from outside the pump. Communication with the pump can be through a computer system located locally or remotely with respect to the pump. The flash memory is utilized to initially program the pump electronically, or to reprogram the pump to change operation of the pump.

Abstract: An method and apparatus for determining a degree of occlusion in the tubing loop disposed in the raceway of a peristaltic pump. An electrical circuit is formed in tubing loop by filling the loop with an electrically conductive fluid, such as blood, and electrically connecting the inlet portion to the outlet portion of the tubing loop. An excitation coil, which encircles a portion of the tubing loop, induces an alternating current in the tubing fluid. A sensing coil, also encircling a portion of the tubing loop, senses the induced current. The degree if occlusion in the tubing loop is correlated to the magnitude of the sensed current. The degree of occlusion may be adjusted, in response to the determined occlusion, while the pump is in operation using an occlusion adjuster.

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 IV rack is a frame having spaced horizontal bars. IV containers are hung from the top bar. Pumps are mounted between the lower bars. Conductors and accessible contacts for the respective pumps are mounted in and form a part of the IV rack so that the pumps can be connected to a single DC power supply and a single AC power supply.

Abstract: A system of infusing fluids in a patient includes an infusion pump for infusing fluids into a patient in accordance with instructions to carry out a desired course of infusion therapy. The system includes a physiological sensor for sensing conditions of the patient during the course of the infusion and a remote infusion controlling system for monitoring the course of the infusion and generating suggested adapted instructions.

Abstract: Pumping mechanisms for performing peritoneal dialysis and the like employ a pumping mechanism comprising a diaphragm that operate in response to applied fluid pressure. Flexible tubing is attached to the pumping mechanism for carrying liquid to and from the patient's peritoneal cavity. An actuating station for pumping mechanism receives the pumping mechanism and attached tubing. A pressure transfer element conveys fluid pressure to the diaphragm for moving liquid through the cassette. An occluder element contacts and crimps closed the tubing attached to the cassette. A first reservoir inflates with positive fluid pressure for contacting the pressure transfer element to hold it in operative contact against the diaphragm. A second reservoir inflates with positive fluid pressure for contacting the occluding element to hold it away from crimping contact with the tubing. At least one of the first and second reservoirs also transports fluid pressure to the pressure transfer element for conveyance to the diaphragm.

Abstract: An infusion apparatus includes a pump and a fluid delivery set. The infusion apparatus is adapted to monitor the fluid delivery set for insuring proper placement in relation to the pump. The infusion apparatus further includes a sensor which operates to detect the proper alignment of the fluid delivery set and also the proper operating position of the infusion apparatus. The infusion apparatus includes a cover which is adapted to be in a closed position when the infusion apparatus is in proper operating position. The cover operates to secure the fluid delivery set within the mounted position in the infusion apparatus.

Abstract: A liquid flowed detection system is disclosed for monitoring continuous and discontinuous liquid flow in a fluid circuit. The system includes a holding device for maintaining a drip chamber so that its elongated axis generally lies in a vertical plane. A light emitter is oriented to transmit light along an optical path through the drip chamber and intersecting its elongated axis. A light detector located in the optical path opposite the light emitter, generates a signal representative of light received from the light emitter. A processor receives information from the detector and generates a control signal representative of a variability over time of the light detector signal. When the control signal drops below a predetermined level, a flow absence signal is generated which is then correlated to the system's pump velocity corresponding to a time interval (T). If the flow absence signal occurs continuously in a comparison time interval (T), a warning signal is generated.

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: Impedance to fluid flow in a fluid delivery line is measured. Two techniques are used depending on the flow rate selected. For high flow rates, the pump is controlled to vary the flow rate and the change in pressure is divided by the change in flow to directly determine the resistance. For low flow rates, a processor controls the pump to pump flow quantities in accordance with a pseudo-random binary code. The resulting pressure signal sensed at the conduit is decoded in accordance with that code. Pressures received during code periods of no flow are subtracted from pressures received during code periods of flow. Pressure offset is also removed and a least squares estimation approach is used with a linear prediction model to determine impedance. The coefficients determined in the model are used to calculate the resistance to fluid flow of the system. A quality supervisor monitors the resistance determination process and controls the display of resistance depending on the quality determined.

Abstract: A novel integral cardiotomy/venous blood reservoir, blood oxygenator and heat exchanging device, method of making a blood oxygenating and heat exchanging device and an extracorporeal circulatory support circuit. The reservoir includes a novel blood defoaming and filtering chamber closely receiving filtering and defoaming media. The blood oxygenating and heat exchanging device includes thermal formed housing portions, and a heat exchanging barrier, blood oxygenating medium and/or filtering medium, which are sealed by potting compound at one time. The oxygenating medium comprises a hollow fiber type medium, with its ends left open to be sealingly mounted in a gas path by a novel mounting bracket.

Abstract: A remotely programmable infusion system. The remotely programmable infusion system comprises a memory for storing a programmable protocol and a remote communication port for sending a voice signal to a remote touch-tone transceiver and for receiving a remote programming signal from the remote touch-tone transceiver. The remotely programmable infusion system also comprises a voice storage unit for storing the voice signal. The remotely programmable infusion system further comprises a processor, coupled to the remote communication port, to the voice storage unit, and to the memory, for accessing the voice signal from the voice storage unit and the programmable protocol from the memory, and for processing the programmable protocol in response to receiving the remote programming signal.

Abstract: An enteral fluid infusion system wherein fluid is pumped through a conduit from a fluid supply source to a patient by a rotary peristaltic pump operating in an intermittent duty cycle mode which includes a free flow detector. The free flow detector includes a sensor for the operation of the peristaltic pump, as for example by the rotation of the rotor and/or motor; a sensor for the flow of fluid in the conduit. The free flow detector compares the sensed operation of the pump with the sensed flow against predetermined criteria. During operation of the fluid infusion system, if flow is sensed when the pump is not operating, as determined by the fact that no rotation is occurring, an alarm will be initiated to indicate that a free flow condition exists.

Abstract: A liquid level sensing and monitoring system for a medical fluid infusion system has an IV spike with a pressure sensor which contacts fluid in an infusion container such as an IV bag or bottle. When an adequate amount of fluid is in the container, the resulting pressure on the sensor is at a relatively high level; however, when the fluid reservoir is nearly depleted, the pressure on the sensor falls to a low level, thereby activating the sensor and associated control circuitry which operates an alarm or warning indicator. In lieu of the pressure sensor, the device may use a resistive or capacitive sensor. When the liquid level falls below the electrical sensor, its state changes, and the alarm circuitry is activated.

Abstract: A pressure sensor (10) that responds to stress introduced into a pair of cantilevered beams (42, 44), to sense pressures at two measurement points in a cassette (80). The pressure sensor includes a base (12) on which the cantilevered beams are mounted. The base also supports two S-shaped flat springs (34, 36) mounted in spaced-apart, parallel array. Pins (28, 29) supported by the S-shaped flat springs each contact a free end of a different one of the cantilevered beams. The pins transfer a force from an elastomeric membrane (86). This force is developed by fluid pressure acting on the elastomeric membrane in a fluid passage of a cassette used for pumping fluid. The pins transmit the force to the free ends of the cantilevered beams as an applied stress. Strain gauges (58, 60) that are fixed to the cantilevered beams each respond by producing a signal indicative of fluid pressure.

Abstract: A non-intrusive optical transmission liquid monitoring system that detects bubbles in a transparent liquid flowing through a transparent tubing. The system dynamically compensates for changes in optical transmission efficiency of the monitored liquid and distinguishes between the transition from liquid to air and air to liquid. A system comprising a light transmitter and a light sensitive receiver secured on opposite sides of a transparent tubing. The output of the receiver is fed into a self-referencing and drift compensation circuit. The integrated output is connected to circuitry sensitive to a change in the integrated output and triggers one of two possible alarms to indicate a detected transition from liquid to air, or air to liquid.

Abstract: A method and system for calibrating and controlling the withdrawal of a fluid, such as blood, from a fluid source, such as a blood vessel, includes a fluid pump, a pressure sensor, a flow rate sensor, and a microprocessor based flow control subsystem. The flow control subsystem optimizes the flow rate by sensing zero flow rate pressure within the subject, making a plurality of periodic flow path pressure measurements and extrapolating a calibration flow rate curve. A control curve is generated by utilizing the zero-flow rate pressure point, the slope of the calibration curve, and an empirically predetermined pressure. The blood pump is then operated at a maximum speed that is limited by the flow control curve to maximize flow without occlusion or collapse of the blood vessel during blood withdrawal. The method and system of the invention is particularly applicable to automated apheresis systems.

Abstract: The present invention concerns a pump provided with a control module and an attachable fluid reservoir cassette. The control module includes a pumping mechanism for pumping fluid from the fluid reservoir to the patient. The cassette is provided with appropriate indicia to identify differences between a plurality of cassettes. The control module further includes cassette indicia identification structure for identifying indicia on the cassette. One type of cassette identification system includes a projection extending from the cassette and structure associated with the control module which engages the projection. Another type of cassette identification system includes a light reflecting system which utilizes light from the control module and reflected off the cassette. Still other types of cassette identification systems utilize other non-contact switches or sensors to sense indicia on the cassette to identify the cassette from a plurality of cassettes.

Abstract: The present invention concerns a pump provided with a control module and an attachable fluid reservoir cassette. The control module includes a pumping mechanism for pumping fluid from the fluid reservoir to the patient. The cassette is provided with appropriate indicia to identify differences between a plurality of cassettes. The control module further includes cassette indicia identification structure for identifying indicia on the cassette. One type of cassette identification system includes a projection extending from the cassette and structure associated with the control module which engages the projection. Another type of cassette identification system includes a light reflecting system which utilizes light from the control module and reflected off the cassette. Still other types of cassette identification systems utilize other non-contact switches or sensors to sense indicia on the cassette to identify the cassette from a plurality of cassettes.

Abstract: An infusion delivery system eliminates the requirement for individual "smart pump" assemblies each of which includes a processor, power supply and operator I/O for each IV container suspended on an IV rack. An acquisition module capable of supporting multiple IV containers is suspended from the hospital bed frame and includes a plurality of ports into which a connector is inserted for controlling a dumb pump on each IV container. The acquisition module includes a processor, power supply and operator input/output mechanism for programming the delivery schedule for each of several IV containers. The dumb pump on each IV container includes only the mechanical components required for pumping the IV fluid to the patient. The infusion delivery system thus provides a less cluttered, more compact, and economical delivery system for IV fluids compared to the prior art.

Abstract: A pressure sensor 16 has a length C and a width D identical respectively to a length A and a width B of a fluid pumping section 11 and is provided in a portion of a cover 15 opposite to the fluid pumping section 11. The fluid pumping section 11 has a structure for pressing a tube placed in a groove 13 by means of fingers which advance and retract in a cavity 14 formed in a wall 12 of a main body. A possible erroneous placement of the tube is detected according to a change of pressure force exerted from each of the fingers, detected by the pressure sensor 16 . The pressure sensor 16, which is provided within a range in which the fingers can press the tube, can detect even a slight displacement, of the tube from the range in which the fingers can press the tube, to thereby allow detection of erroneous tube placement free of a dead zone to be achieved.

Abstract: In a method and apparatus for determining the volume of a bellows reservoir for medication in an infusion system which is implantable in a patient, the pressure in the reservoir is measured and the corresponding volume is determined from a predetermined relationship between pressure and volume. A pressure gauge is disposed for measuring the pressure in the bellows reservoir, and a signal corresponding to the measured pressure is supplied to a memory unit wherein a corresponding volume is determined from the measured pressure value by means of the predetermined relationship between pressure and volume being stored in the memory unit.

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.