Abstract: A combination load and latch mechanism for fluid flow control apparatus, wherein a latch mounted for pivotal movement may be manually opened to disengage an electromechanical manipulating device to permit loading or unloading a feeding tube, the latch automatically closing and the device re-engaging upon release of the latch. The latch includes a slotted side wall that defines a retaining surface for capturing the tube relative to the manipulating device, and a cam surface upon which the tube acts during loading to cam the latch open. Means are included for sensing movement of the latch prior to any disengagement of the manipulating device.

Abstract: Method and apparatus for detecting occlusions in a parenteral administration system of a type having a peristaltic pump for pumping a fluid through a feeding tube to a patient. A pressure transducer measures the cyclicly varying pressure of the fluid in the feeding tube and produces a corresponding pressure signal, and a comparator compares the pressure signal to a selected one of several thresholds, depending on the current stage of the pumping cycle. An occlusion alarm is actuated whenever the selected threshold is exceeded.

Abstract: A mechanism for screw drive and syringe plunger engagement and disengagement for a syringe infusion pump, wherein a split-nut pair are moveable into and out of engagement with a lead screw by means of rotary cam control, the rotary cam being keyed with a crank disk that is coupled to a crank arm, which operates as the syringe plunger mover. The crank arm is rotatable into and out of engagement with the syringe plunger, such rotation also causing the split-nut pair to move into and out of engagement with the lead screw. Index and cam means are carried by the crank arm to aid in proper alignment with the syringe plunger, and a sensor is provided for monitoring proper engagement of the crank arm with the plunger.

Abstract: A pressure detector for particular use in a system for administering parenteral fluid to a human patient. The pressure detector includes a conventional pressure diaphragm having a flexible membrane that is movable in accordance with the pressure of the fluid being administered. The pressure detector further includes a special receptacle for retaining the pressure diaphragm, and a special follower assembly that is moved in a prescribed fashion by installation of the diaphragm in the receptacle and by movement of the diaphragm membrane due to variations in fluid pressure. A pair of electrical contacts are controllably moved together and apart by the follower assembly, to provide an electrical signal whenever the diaphragm is not installed or, if it is installed, whenever the fluid pressure exceeds a prescribed threshold.

Abstract: A pressure diaphragm, wherein at least a portion of an elongate fluid channel is formed diametrically across, and is open through, a flat raised surface of a substantially rigid, disk-like body, and wherein a flexible membrane overlies the raised surface and is sealed to a surrounding flange. The fluid channel communicates with fluid inlet and outlet fittings carried by the body, which are adapted for connection with the tubes of an IV set, and the cross-sectional flow area of the fluid channel is substantially equal to or less than the cross-sectional flow area of any IV tube adapted for connection to the fluid inlet fitting.

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 digital servo control system for a d.c. motor to achieve stepping motor precision and a wider speed control range than either a conventional d.c. motor or a stepping motor, as may be typically utilized in an IV syringe pump. Motor position and direction sensing, as well as motor advance signals at the desired motor rate, condition motor advance and retard logic which, in turn, effects a unique counter-controlled motor drive subsystem to cause the d.c. motor to move forward, reverse, coast or slow down over a 1,000 to 1 speed control range.

Abstract: A temperature sensing probe is provided including a probe shaft rigidly mounted on a handle and having a temperature sensing tip at the distal end of the shaft. A disposable cover is provided in the form of a unitary elongated tube constructed of heat conductive material and having an open proximal end arranged to slide over the probe shaft and a closed distal end arranged to tightly engage the temperature sensing tip of the shaft in order to retain the cover on the shaft and provide a positive conduction of heat to the temperature sensing tip. For the purpose of selectively ejecting the cover after temperature measurement, the probe handle includes a movable ejection button for manually driving the cover forwardly with sufficient force to disengage the cover from the tight engagement with the temperature sensing tip.

Abstract: An improved method and apparatus for parenteral administration of medical fluids, wherein a normally shut-off intravenous feeding tube is selectively opened at a frequency and open period duration automatically regulated by a digital control system to establish a fluid flow rate at any selected rate over a wide dynamic range. Measured and desired flow rates are converted to digital electrical signals and compared, the electrical difference being used to vary a control voltage which establishes the width of energizing pulses controlling a member for opening the feeding tube. The frequency of the energizing pulses is preferably a non-integral multiple of the desired drop flow rate and varies from a very high ratio, e.g. 15.5, at very low flow rates to a much smaller ratio, e.g. 2.5, at very high flow rates.

Abstract: An electronic method and apparatus for automatically determining systolic and diastolic blood pressure and heart rate by accurately detecting, verifying and evaluating the full stream of korotkoff sounds produced as electrical signals from a microphone in a cuff occluding the brachial artery of a patient. Waveform analysis is first performed upon the incoming signal waveforms by an analog prescreening subsystem to initially separate true korotkoff sound signals from a variety of artifact and noise signals and to provide an output pulse stream correctly indicating korotkoff sound occurrences in the time and blood pressure domain, with each pulse proportional in amplitude to the amplitude of the corresponding korotkoff sound represented.

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.