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

Abstract: A parenteral solution administration system having a conduit for communication with a source of parenteral solution, a drip chamber carried by the conduit, drop detector circuit for detecting drops falling through the drip chamber and flow control circuit including an occlusion device moving between first and second positions for opening and closing the conduit. Feedback circuit is provided for controlling the flow control circuit to cause the rate of drops falling through the drip chamber, as sensed by the drop detector circuit, to correspond to a predetermined drop rate. The occlusion device is preferably operated by a stepper motor, and the system is disengagable so that at the occurrence of a predetermined circumstance, the occlusion device can be disengaged from the motor circuit and can be moved without corresponding action of the motor circuit.

Abstract: An exemplary embodiment comprises a metering device which can be worn on the body or which is preferably implantable in the body, the metering device exhibiting a delivery unit for the dosed delivery of the fluid from a supply container to a discharge aperture of a catheter and also exhibiting an appertaining operating circuit, and an external control and programming device. The operating circuit in the metering device and the control circuit in the control device can be inductively coupled for operational signal transmission, to which end at least one transmission coil is present in the control device and at least one reception coil is present in the metering device. Given implanted devices, it is the object of the disclosure to guarantee the highest degree of patient security.

Abstract: Metering apparatus for metering the flow of fluid through an administration set includes a peristaltic-type metering pump which repeatedly and progressively compresses a section of vinyl tubing of the administration set to provide a desired flow rate. For improved metering accuracy the fluid is maintained under pressure downline of the metering pump by a downline occlusion station. A protective circuit responsive to the pressure in the tubing downline of the occlusion station stops the metering apparatus and sounds an alarm in the event the pressure in the tubing exceeds a predetermined level, as in the event of an occlusion, downline of the metering apparatus and upline of the patent.

Abstract: A system for injecting fluid into a patient and monitoring the blood pressure of the patient comprising an injector for incrementally injecting the fluid through a delivery tube into the vascular system of the patient at selected prescribed rates with display means and rate indicator means generating an output indicative of the rate of fluid injection connected to the display means for visually displaying the rate at which the fluid is being injected; a blood pressure monitor including transducer means communicating with the vascular system of the patient through the delivery tube on the injector for providing an output indicative of the patient's blood pressure and pressure detector means responsive to the output of the transducer means to generate an output indicative of the systolic and diastolic blood pressures of the patient; and mounting means for selectively mounting the blood pressure monitor on the injector and including connector means connecting the output of the pressure detector means in the bloo

Abstract: An improved fluid additive system is disclosed. The first embodiment of the invention is formed by a system (10) including a controller (26) which automatically delivers a preselected quantity of a secondary fluid from a secondary container (14) at a preselected rate and subsequently delivers a preselected quantity of a primary fluid from a primary container (12) at a preselected rate. Within the controller (26) are input controls (48) for operator input of the desired preselected rates and quantity of fluid to be infused. A passive metering unit (36, 36') is provided in the controller for metering a known quantity of fluid to a delivery line upon each activation thereof. A microprocessor (40) responds to the rates amd quantity input into the input controls (48) to direct a drive unit (38) to activate the metering unit (36) to achieve the desired rates and quantity of infusion of the primary and secondary fluids.

Abstract: A bio-medical flow sensor (FIG. 1) including a packageable unit of a bottle (10), tubing (11) and hypodermic needle (12) which can be pre-sterilized and is disposable. The tubing (11) has spaced apart tubular metal segments (18,19). The temperature of the metal segments and fluid flow therein is sensed by thermistors (23,24) and at a downstream location heat is input by a resistor 25 (FIG. 2) to the metal segment (19) by a control electronics (16, FIG. 2). The fluid flow and the electrical power required of the resistor (25) to maintain a constant temperature differential between the tubular metal segments (18,19) is a measurable function of fluid flow through the tubing (11). The differential temperature measurement is made in a control electronics 16 (FIG. 2) and also can be used to control a flow control valve or pump (17) on the tubing (11) to maintain a constant flow in the tubing (11) and to shut off the tubing when air is present in the tubing.

Abstract: Intravenous monitor for monitoring drip rate being delivered to a patient from an intravenous solution container and visually displaying the drip rate on a digital readout of the monitor. The monitor includes an alarm for signaling deviations from predetermined adjustable maximum and minimum drip rates. The intravenous monitor includes a photocell reader sensor which positions around a drip chamber below the intravenous container and a horizontal support which maintains vertical orientation of the drip chamber.

Abstract: An implantable programmable medication infusion system comprises an implantable portion (2) having a medication reservoir (10) at below body pressure and isolated at its input from the body in which it is implanted by an antechamber (8) the pressure integrity of which is checked before filling the medication reservoir (10). Safety features include a leak detector (35), inlet and outlet valves (14 and 212) used with flow impeding filters (12 and 218), and a maximum allowable pressure in a pulsatile bellows pump (202) all of which prevent undesired infusion of medication. Medication flow from the pulsatile bellows pump (202) is in response to programming commands from a drug programming system (1) and processed in an electronics section (30) which uses the commands to program memory units (320 and 322) and to request pulses of medication. Hardwired limit controls (324 and 326) prevent excessive dosage requests from reaching the pulsatile bellows pump (202).

Abstract: A change in the internal pressure of the fluid-infusion tube of a peristaltic fluid-infusion pump due to occlusion in the fluid-infusion tube is detected through a change in the diameter of the fluid-infusion tube. The occlusion is detected by detection of the change in the distance between the opposite wall portions of the tube.

Abstract: A system for use in flow metering apparatus for detecting bubble formation in both clear and opaque fluids in an administration set includes a light source and a light detector positioned on opposite sides of a transparent tubing segment of the administration set such that light transmitted through the tubing to the detector is dependent on the presence or absence of fluid in the tubing. With clear fluid present, a first comparator in the system interrupts operation of the metering apparatus when the light detector output falls below a predetermined minimum level. With opaque fluid present, a second comparator interrupts operation of the apparatus when the light detector output rises above a predetermined maximum level. The detection system is automatically conditioned to either clear or opaque operating modes without input from the operator, and incorporates protection circuitry for interrupting operation of the metering apparatus in the event of failure of either the light source or the light detector.

Abstract: To provide for constant and easily adjusted flow rate of liquids from a container (5), which may be a flexible bag, an indexed feeding chamber (1) is directly connected by gravity with the liquid container (5) and provided with a tubular passage (12) therethrough communicating with the outside, preferably through a filter at an end and with the chamber bottom at the other end. The bottom of the feeding chamber (1) is connected to a dripping tube (1A) positioned below, which in turn communicates with the inlet (21) of a device (2) for the microregulation and stabilization of the liquid flow rate. This device, essentially consists of a holder (44) with a cavity (51) therein and two tubular inlet (41) and outlet (47) passages connecting said cavity with the outside, and having a flexible membrane (43) removably covering the opening of the outlet passage within the cavity. Device (2) is height adjustably supported by a slider (31) on a scale (3) fixed to the stand (4 ) which supports the liquid container (5).

Abstract: An apparatus and method are provided for diluting a concentrated solution to be analyzed which includes a Y-coupling for combining a diluent and the concentrated solution to form a mixture. The mixture is then divided into first and second parts, such as by a pumping arrangement, with the second part of the mixture being proportional in quantity to the quantity of concentrated solution. The first part of the mixture is then supplied to an analytical device for analyzing the mixture. A chamber including a movable wall element is provided which divides the chamber into two subchambers. The first part of the mixture is supplied to the subchamber on one side of the movable wall element, which causes the movable wall element to force a proportional quantity of diluent out of the subchamber on the other side of the movable wall element. The dispensed diluent is then conveyed to mix with the concentrated solution.

Abstract: A rate meter senses successive drops of fluid flowing through a conduit and produces gating periods with time durations corresponding to the period of time between such successive drops. The rate meter then determines the number of incremental time periods in each gating period. The rate meter generates the reciprocal of this determination to obtain an indication of the rate of fluid flow. The rate meter may be self-contained. It includes a housing having a vertically disposed channel constructed to retain the conduit and a horizontally disposed channel communicating with the vertically disposed channel. The horizontally disposed channel is constructed to receive a cross bar made from a resilient material and fixedly disposed on the conduit. The cross bar supports the rate meter in a freestanding relationship. The cross bar may be provided with slots near its ends to enhance its resiliency.

Abstract: A self-compensating optical drop count apparatus for measuring volumetric fluid flow by optically counting the number of drops of fluid that pass through a drop chamber, each drop being formed so as to be of approximate equal volume. Optical counting circuitry is designed to count each drop only once. The count is accumulated in a holding register where it may interface with external instrumentation equipment adapted to display the count and/or convert it to a volumetric measurement by multiplying it by the average volume of fluid contained in each drop. A compensation technique is utilized to maintain the intensity of a light beam, through which the drops must pass, at a constant level. Compensation is achieved in a closed loop system which varies the drive current to the light emitter to compensate for long-term variations that occur in the intensity of the light beam as sensed at a light detector.

Abstract: A drop controller is provided for controlling the rate at which drops of a fluid flow to a patient. The drop controller includes a socket for receiving a cassette having a constrainable member adjustable in position. This constrainable member controls the size of an adjustable passage through which the fluid flows to the patient. The socket is defined by a plurality of spring fingers for releasably holding the cassette. A lever is mounted on the housing for the drop controller and is pivotable to a cocked position by the cassette when the cassette is disposed in the socket. The lever can be pivoted to a second position to obtain a removal of the cassette from the socket.An arrangement is also included for releasably and adjustably positioning the controller relative to a support pole. The arrangement includes a shaft and an arm at the end of the shaft for providing an engagement of the support pole between the arm and the housing of the controller.

Abstract: In a flow metering apparatus a bubble detector for detecting bubble formation in tubing subject to deformation from internal fluid pressure includes a light source and a light detector. The light detector is positioned on the opposite side of the tubing from the light source such that the light transmitted through the tubing to the detector is dependent on the presence of fluid in the tubing and on the shape of the lumen of the tubing. A control circuit responsive to the output of the detector interrupts operation of the metering apparatus when the light transmitted through the tubing falls below a predetermined minimum level. False interruptions resulting from deformation of the tubing by pressure changes in the fluid are prevented by forming members which engage the wall of the tubing adjacent the light source and light detector.

Abstract: A counter counts the time intervals of falling instilled drops in response to a signal issued each time a falling instilled drop is detected. A memory is supplied with data representing the quantities of a falling instilled drop corresponding to the time intervals at which the drops fall. The data corresponding to the time intervals thereof which have been counted by the counter are read out of the memory. The data thus read out are accumulated to determine the total quantities of the drops.

Abstract: A volumetric infusion pump useful in intravenous feeding includes a detector which provides an alarm when the supply bag or reservoir becomes empty or an occlusion occurs between the supply bag and the pump. The pump includes a first pumping chamber having a cylinder, a piston, a first flexible diaphragm and first and second valves. The piston is driven by a first cam through a first cam follower which is connected to the piston. The empty supply bag detector senses contact between the first cam and the first cam follower. During normal operation, when the first valve opens and the second valve closes the first pumping chamber fills due to the head pressure of fluid from the bag, and the cam follower remains in contact with the cam.

Abstract: A device for monitoring and controlling the operation of a motorized syringe to dispense a predetermined drug dosage comprises, according to one aspect of this invention, a combination of a trigger, a first signal monitor, a first timer, a second signal monitor and a second timer. The trigger is operable by the patient to initiate a demand signal indicative of a demand for an individual drug dose. The first signal monitor serves to record the total number of occasions on which a demand signal is initiated by operation of the trigger. The first timer receives the demand signal and selectively rejects the demand signal or emits the demand signal as an inject signal. The second signal monitor records the total number of occasions on which the first timer emits a demand signal. The second timer receives the inject signal and is operable upon receipt of the inject signal to activate a motorized syringe for a preselected time period to dispense a predetermined individual dose of drug.

Abstract: The invention corresponds to a device used in conjunction with a resectoscope in endoscopic surgical operations which includes a housing, pumping means, means for controlling, measuring and displaying the speed of said pumping means in order to make corrections in the inflow and outflow rate of irrigating fluid from the patient thereby maintaining a constant distention of the bladder. The device also includes a plurality of audio-visual alarms that alert the operating physician to any abnormal condition.

Abstract: An artificial endocrinal gland comprises a blood dialyzer for transferring part of the blood to a measuring liquid in a separate circuit, an analyzer for quantatively determining this part and producing in the measuring liquid conversion products compatible to the patient's metabolism, a controller responsive to the analyzer and a device for supplying quantities of hormone to the patient's body under the control of the controller.

Abstract: This combination device consists primarily of a stem with a pointed float with plate means at one end, which is freely received in an opaque walled sensing chamber, that removably receives a sensing plug, which is attached to an alerting device, for indicating the ceasing of flow, of intra-venous fluid to a patient. The pointed float also serves as a means, for easy insertion of the flow-meter stylus of the assembly, during insertion, into a bottle of intra-venous fluid. The sensing plug includes a pair of prongs, one of which, has a light emitting diode therein, and the other prong includes a photo-sensitive transistor, and the plate end of the float stem, when lowered between the prongs by low fluid level, will activate the circuitry of an alerting device.

Abstract: Disclosed is a dripping fluid level detector comprising a pair of electrodes oppositely disposed around a drip chamber of a supply passage of dripping medical fluid and a detecting circuit which detects the remaining amount of medical fluid according to changes in the electrostatic capacity caused between said pair of electrodes.

Abstract: The present blood flow monitoring and control apparatus is especially use in connection with the so-called single needle technique, for example, for treatments such as dialysis, perfusion, or diafiltration. The blood pressure control is accomplished by a measuring chamber including a pressure equalizing device operatively connected between the blood cleaning apparatus and the blood pump. Sensors are operatively connected to the volume measuring chamber. The volume sensors provide electric control input signals to a control circuit which in turn controls the blood pumps and/or valves. A reading may be provided on a display or an alarm may be given when the blood pressure or blood quantity or volume is not within predetermined limits as calculated by an electronic computer.

Abstract: Improvements in infusion controlling apparatus used in limiting the flow rate of an intravenous solution to a patient. The improvements provide coarse and fine orientations of a casette through which the solution passes relative to a controller which valves the casette's inlet and outlet to provide measured volumes of fluid. The coarse alignment device includes spaced apart metal sections which grasp onto the casette and move it towards the controller's valving members. As the casette reaches the valving members, protuberances on the controller fit into indentations on the casette, as the fine adjustment. The indentations into which the protuberances fit form part of the casette's base section of plastic notwithstanding the location of a cover slip between these two items. The valving members couple to a rocker arm which pivots about a point located at its middle and has magnetic poles at its ends.

Abstract: A mechanism for aurally instructing a patient whose circulatory system is coupled to an infusion or exchanging machine and which includes a comparing means for discriminating between various malfunctions of the machine and reporting serially those of higher priority, with the objective of instituting a corrective feedback through specific directions to operator.

Abstract: Apparatus for protecting a pressure sensitive transducer in an extracorporeal blood system and for providing a sterile barrier while the apparatus transmits the blood pressure to the pressure sensitive transducer. The apparatus includes a pressure chamber having a lateral inlet and a lateral outlet, to enable convenient packaging, and having a membrane disposed transverse the chamber and surrounded by the chamber to segregate an inlet side of the chamber from the outlet side of the chamber. The membrane has a generally planar, circular center portion which lies in a plane between the outer peripheral portion of the membrane and the outlet side of the chamber. The membrane has an intermediate portion contiguous with and between the central portion and the outer peripheral portion, with the intermediate portion having a generally U-shaped cross-sectional configuration.

Abstract: A system for infusing fluids into the human body includes a peristaltic-type metering apparatus which controls the flow of fluid through a disposable administration set. The metering apparatus includes a control system which allows the volume and rate of flow of the fluid to be infused to be accurately preset by the operator. The control system provides an alarm function in the event of malfunction of the pump or occlusion of the tubing of the administration set, and a minimum pumping rate for maintaining fluid flow through the system after the desired volume of fluid has been infused. Novel power supply circuitry within the control system renders the system immune to power line transients, and a novel bubble detector circuit provides for more reliable detection of air bubbles in the tubing.

Abstract: A system for infusing fluids into the human body includes a peristaltic-type metering apparatus which controls the flow of fluid through a disposable administration set. The metering apparatus includes a control system which allows the volume and rate of flow of the fluid to be infused to be accurately preset by the operator. The control system provides an alarm function in the event of malfunction of the pump or occlusion of the tubing of the administration set, and a minimum pumping rate for maintaining fluid flow through a system after the desired volume of fluid has been infused. Novel power supply circuitry within the control system renders the system immune to power line transients, and a novel bubble detector circuit provides for more reliable detection of air bubbles in the tubing.

Abstract: An electronic method and apparatus for evaluation of the quality of drop detection in apparatus for parenteral administration of medical fluids, wherein the waveforms of electrical signals representing drop flow detection are evaluated for conformity with both prescribed amplitude and time duration characteristics. Separate counters record the total number of drop events evaluated and the portion of the total which are determined to be non-conforming, and the latter counter triggers alarms if a predetermined limit is exceeded within a prescribed number of total events.

Abstract: Automated dispensing apparatus is disclosed for administering intravenous fluid to a patient at a controlled volumetric rate such that deviations from the desired fluid volumetric flow rate are automatically corrected. In accordance with the invention, the width and silhouette of each drop of fluid are measured and give rise to representative signals of each such parameter. These signals are then multiplied to obtain a signal proportional to the volume of the drop. This drop volume signal is combined with a rate control signal to modify the latter to reflect deviations in the measured drop volume from a nominal value. The thus modified control signal is compared against the actual rate of drop administration, and any necessary adjustment made in the constriction of a fluid-passing tube. The rate at which intravenous fluid is supplied to the patient is thus maintained at the desired volumetric rate.

Abstract: An automated electronic microsurgical control system is disclosed which is capable of performing the various aspiration functions customarily performed manually by a surgical assistant. The system is entirely subservient to the surgeon's foot control unit which is adapted to control seven different surgical functions. In addition, the electronic control system is designed to communicate audibly with the surgeon regarding actual fluid flow and the build-up of vacuum pressure in the aspiration lines connected to the microsurgical cutting instrument, thus permitting the surgeon to audibly ascertain complete information as to the actual activity within the aspiration line without requiring him to take his eyes from the operating microscope.

Abstract: Apparatus is described for controlling blood glucose concentration in a subject by selected infusion of insulin into the blood stream of such subject, depending upon the general blood glucose concentration. This apparatus comprises in combination sensor means for determining the blood glucose concentration and for providing computer input signals based on such measurement, computer means for receving such input signals and for providing output signals based upon such input signals, and pump means responsive to such computer output signals to supply insulin to such subject at a rate determined by such output signals. The computer means is programmed to derive the output signals in accordance with specific equations employing certain independently selected values relating to basal blood glucose concentrations and basal insulin infusion rates at such basal blood glucose concentrations.

Abstract: There is disclosed herein a blood pressure alarm system for use in a dialysis machine whereby alarms may be activated, and a blood pump deactivated if the actual blood pressure increases above or decreases below predetermined levels. The levels are determined by setting a particular blood pressure point and setting the amount by which the pressure can vary above and below the set point; the range of variation is sometimes referred to as the alarm window. A digital memory is provided for storing the set point and preventing variation of the set point with time.

Abstract: The flow control hereof is applied to a known system of feeding a patient intravenously and contemplates the use of a clamp applied externally to the delivery tube extending from the intravenous bag, bottle or other appropriate container to the patient, said clamp being selectively successively opened and then closed to correspondingly meter the feeding flow of the intravenous fluid on a selected volume per time basis, e.g. 1 cc/minute, so that intravenous feeding of the patient is achieved according to a desired time schedule. The external application of the clamp does not detract from conventional sterile conditions of the system. Also, and most important, the operation of the clamp is related to the weight of the intravenous fluid, which weight, if the feeding is proceeding as it should, should progressively diminish in a predictable way. The flow control hereof thus allows uninterrupted flow if the weight is not diminishing at the rate that it should; or it terminates flow, if the rate is too rapid.

Abstract: A syringe pump operated by a stepping motor to repetitively fill and empty a syringe cartridge over a plurality of operational cycles of successive fill stroke and pump stroke periods. The motor is driven by drive pulses from a digital pulse generation and control system, the pulse frequency establishing a predetermined fixed rate of fill during the fill stroke and being preselected, in accordance with desired output flow rate, to establish the rate at which the syringe is emptied during the pump stroke. The drive pulse rate during a fill stroke exceeds the maximum pulse rate during a pump stroke and, in order to maintain a proportional relationship between the preselected pumping rate and the actual pumping rate over each complete cycle of successive fill and pump strokes, the drive pulse frequency during each pump stroke is automatically increased to compensate for the time lost during each fill stroke.

Abstract: A disposable venous blood pressure manometer of provided which includes a transparent tray having a longitudinal interior channel with a transparent plastic manometer tube disposed in the channel, a calibrated scale member in the tray behind the tube, and a cover closing the back of the tray and which may be used as a label. The cover and body member provide a container which may contain a plastic extension tube and a three-way valve. The container can be opened by peeling back a bottom end portion of the cover from the body member. The extension tube and valve can then be removed for use in connecting the manometer tube in an infusion and pressure measuring system. The level of liquid in the manometer tube during use and the scale can be seen through the transparent tray for taking pressure readings. The container performs a functional part of the manometer during use.

Abstract: A method is disclosed for controlling the dispensing of fluid from a source at a hydrostatic pressure involving the sequential measuring and dispensing of predetermined volumetric increments of fluid from the source of fluid during different ones of a series of time intervals. Apparatus is also provided for controlling the dispensing of fluid, including metering means for receiving a predetermined increment of fluid and for emptying the predetermined increment of fluid, conduit means for delivering fluid from a source of fluid to the metering means, and control means for actuating the metering means between a condition for receiving one predetermined increment of fluid and a condition for emptying the predetermined increment of fluid.

Abstract: An automatic air-in-line detector for either a transparent or an opaque fluid including first detector means for detecting air-in-line in the transparent fluid and second detector means for detecting air-in-line in the opaque fluid, and additionally including control means coupled to the first and second detector means and automatically responsive to the difference between the transparent fluid and the opaque fluid for enabling the first detector means in response to the transparent fluid and for enabling the second detector means in response to the opaque fluid and with an alarm in accordance with the detection of air-in-line in either the transparent or opaque fluid. If any of the detectors fail, the system either automatically alarms or becomes more sensitive. If the control means fail, the system automatically alarms.

Abstract: Automated intravenous fluid dispensing apparatus regulating intravenously administered electrolyte solution, nutrient or other fluid flow employs a bidirectionally motor-driven clamp for selectively constricting a fluid passing conduit, typically a tube. The apparatus employs a relaxation oscillator, or timing circuit, having a variable period dependent upon whether fluid is being administered at a specified rate, or too rapidly or too slowly. When either of the latter two conditions obtain, the tube pinch-off motor is excited in an appropriate corrective direction to cause the desired fluid flow rate.In accordance with varying aspects of the present invention, motor and timing circuit modulation (i.e., speed of system correction response) varies for excess/deficient flow rate conditions depending upon the specified flow rate and upon the constrictive state of the fluid delivery tubing. Also, audio/visual alarming is provided for defined conditions.

Abstract: A roller pump having one or more hoses is combined with a control system including a potentiometer for controlling the speed of the pump motor. A manually settable control provides an output corresponding to the diameter of the hose, and a further control provides an output corresponding to the number of hoses. An electronic circuit connected to receive the outputs of the controls, provides an output signal corresponding to the flow rate of the pump. This signal is applied to an indicator, so that an operator may adjust the speed of the pump to obtain a desired flow rate.

Abstract: A method and apparatus for parenteral administration of medical fluids has a normally closed clamp on the intraveneous feeding tube which is opened by means of an electromagnetic actuator at a preselected drop frequency rate and closed when a drop is detected by a conductive path established by the drop passing between two opposing electrodes. The electrical system governing the drop counting electrodes also is provided with drop size measuring means which acts to control the preselected drop frequency rate wherein a desired volumetric rate is maintained. Safety features are also provided to prevent excessive or insufficient flow rates.

Abstract: There is disclosed herein a blood pressure alarm system for use in a dialysis machine whereby alarms may be activated, and a blood pump deactivated if the actual blood pressure increases above or decreases below predetermined levels. The levels are determined by setting a particular blood pressure point and setting the amount by which the pressure can vary above and below the set point. A memory is provided for storing the set point and preventing variation of the set point with time. The dialysis machine and alarm system can malfunction under certain conditions and protection circuitry operates the alarms if a malfunction occurs.

Abstract: Electronic control apparatus for controlling the administration of a plurality of separate fluids independently and consecutively, includes electrical circuitry connected with a plurality of valve operators to operate valves in a plurality of sets to control flow therethrough.

Abstract: Injection of barium into the lower digestive tract of a patient to be examined and subsequent reflux and evacuation of the barium by air compression is effected by remote control whereby greater safety is achieved in production of double contrast studies or fluoroscopic examination. The apparatus employs detachable anal insertion units which are the only portion of the apparatus in direct contact with a patient. A new anal insertion unit is used for each patient, whereby cleaning of the apparatus is made easier and hygiene is improved.

Abstract: A reliable and inexpensive method has been developed to continually regulate the blood pressure of mammals at virtually any desired level. The pressure thus regulated may be maintained within 10 mm Hg tolerances. The method may be carried out by a closed loop apparatus with which (1) the actual blood pressure is continually measured, (2) a function of the actual blood pressure is compared with a desired blood pressure, (3) any difference between the blood pressure expressed by the function of the actual blood pressure and the desired blood pressure is converted into an error signal, (4) the error signal is converted into proportional and derivative functions which in turn (5) control the rate of pumping of a supply of a liquid hypertensive agent or a hypotensive agent into the circulatory system of the mammal.

Abstract: Apparatus for feeding liquids, particularly medications such as insulin, or the like, to humans or animals comprising a supply reservoir for the liquid, a conveying arrangement connected to the supply reservoir and including a pressure generating device for feeding the liquid by pressure application from the supply reservoir to the body, and a controllable dosing arrangement for producing a desired rate of infusion. The pressure generating device includes an overpressure generator which constantly maintains the liquid present in the supply reservoir under overpressure as distinct from the pressure prevailing at the point of liquid discharge. The dosing arrangement comprises a pilot or switching valve for periodically releasing liquid from the supply reservoir to the body, the switching valve being switchable for the purpose of fine dosing by the discharge of preselectable constant volumes of liquid at periodic intervals predeterminable in accordance with the treatment program.

Abstract: The control apparatus of the invention comprises a feedback system to maintain the level of glucose in a diabetic within predetermined limits. Surgically implanted in the body are a means for sensing glucose levels and a means for dispensing insulin in an amount determined by the sensing mechanism. The sensing mechanism employs a chemical solution, which, like the insulin, is stored within a reservoir forming part of the surgical implant. Means are additionally provided to couple these reservoirs to the surface of the skin so as to permit their rechargings at regular time intervals. Integrated circuit technology is employed to translate an indication of an unacceptable glucose level into an automatic injection of insulin, with the electronics being of the type capable of being powered by batteries of the kind employed in pacemaker technology.