Abstract: A half-nut block containing a threaded bore and a larger, overlapping, unthreaded bore is engaged with a lead screw. The larger bore overlaps the threaded bore so that effectively a half-nut results. The half-nut comprises a face having an acute angle in relation to the lead screw and this angled face contacts the inside of a bearing block within which the half-nut is mounted. The bearing block is slidably mounted on a C-tube which is mounted around and extends along a predetermined length of the lead screw. Also mounted on the C-tube is an arm for transmitting the linear motion of the bearing block to a remote point such as the plunger of a syringe. The arm is coupled to the bearing block at points selected so that transmission to the arm of any wobbling of the bearing block is reduced. The arm includes a lever which engages a cam formed on the half-nut to force the half nut to disengage from the lead screw when the arm is to be moved to a new location on the lead screw.

Abstract: An apparatus and method for detecting pressure and occlusion in a fluid line is for use with a fluid line being operated upon by a positive displacement, peristaltic pump having several cam follower fingers pressing against the fluid line fluid through the line peristaltically. A sensor follower finger is mounted to the cam shaft of the pump among the other peristaltic fingers in order to cyclicly press against the fluid line and displace the fluid line by a predetermined amount as the cam shaft rotates. The sensor follower finger includes a strain gauge mounted on the sensor finger to generate a signal indicating the degree of force being applied by the sensor finger against the tubing, and a signal processor which receives this force signal and determines the pressure within the fluid line based upon the signal. The signal processor determines the existence of an occlusion based on the signal and provides an alarm if an occlusion is determined.

Abstract: A storage chamber large enough to store a predetermined number of probe covers is formed into a dispenser body. A spring biases the probe covers toward one end of the chamber at which is located a slide. The slide has an indentation used to retrieve a single probe cover from the chamber at a time when aligned with the chamber. Located in the indentation is an aperture tube for receiving a probe of the instrument to be covered. The probe is pressed into the probe cover and into the aperture thus causing the probe cover to stretch and cover the probe. A flange formed on the slide is pressed by a user to align the indentation of the slide with the chamber. The slide is spring loaded so that releasing the flange will result in the slide moving such that the identation is located outside the chamber and the retrieved probe cover can be applied to the instrument. A door in the dispenser is raised to allow access to the chamber for the insertion of a stack of probe covers.

Abstract: The method and system for detecting occlusion in a fluid line upstream of a pump concerns a fluid pump with a pump cycle in which the upstream pressure of the fluid line is communicated to the downstream portion of the fluid line. A pressure sensor located downstream of the pump is capable of measuring a relatively large negative-going pressure in the fluid line. A signal is generated to indicate occlusion based upon detection of negative-going pressure.

Abstract: The system and method for detecting abnormalities in infusion of parenteral fluid involves producing perturbation of fluid flow by varying the flow rate of the fluid with respect to an equilibrium flow rate, measuring the pressure level, and measuring the pressure of the fluid over a period of time, to determine equilibrium pressure and a pressure response of the fluid to the perturbation, determining an integral of the difference between the equilibrium pressure and the pressure response, determining resistance to fluid flow, determining a second integral of the difference between the pressure response and equilibrium pressure multiplied by time, and determining compliance by dividing the second integral by the first integral. Resistance and compliance values are displayed, and an alarm is generated when the resistance or compliance parameters fall outside of reference ranges.

Abstract: The protective apparatus for a biomedical thermometer having a protruding probe containing a waveguide includes mounting a transparent window at the patient end of the waveguide to seal the waveguide from contamination while permitting infrared energy to pass. A protective sleeve protects and mounts the transparent window to the waveguide and material is provided along the entire probe-length of the waveguide to protect it. An outer boot is mounted over the transparent window and waveguide protection material to provide further protection and to supply a mounting and retaining surface for a protective probe cover. A disposable protective probe cover having a generally thin, flat, frame member with an aperture therethrough, is sized to fit over and be retained over the base of the probe by a friction interference fit.

Abstract: A disposable cone channel insertion probe is adapted for use in combination with an infrared thermometer. The probe has a generally frusto-conical hollow body portion, an inner reflective surface, and a flange projecting radially outward from the rearward end of the probe. The infrared thermometer also includes a mechanism for retaining the probe and optics for further focusing and collimating the infrared light from the probe to an infrared sensor.

Abstract: The optical interrupter system includes a moving member having a sequence of optical flags, interposed between a source of illumination and a detector, such that as the optical flags of the moving member are illuminated and detected, the detector generates a signal having a waveform with a first portion less than a first threshold, a second portion greater than the first threshold and less than a second threshold, and a third portion greater than the second threshold. Signal processing circuitry operates to generate a count signal indicating a transition between the first and third waveform portions.

Abstract: The clamp for flexible tubing may be used in conjunction with an infusion pump instrument or separately. The clamp includes a pair of elongated clamping members pivotally hinged together and biased to clamp a segment of flexible tubing received between the clamping members. A latch is also preferably provided for allowing the clamping members to be releasably latched apart. The latch, and the elongated clamping members are arranged in a manner such that when the clamp has a segment of flexible tubing received between the clamping members and the clamp and tubing are set between the housing and door of an infusion pump, closing the door causes the clamp to release to an open position allowing fluid flow, and opening the door causes the clamp to automatically move to a closed position, clamping the tubing so as to prevent fluid flow.

Abstract: The apparatus accurately measures flow rate of fluid within a conduit without direct fluid contact, based on the introduction of a thermal marker into the fluid stream by means of at least one externally mounted heater, and detection of the thermal marker by means of at least one externally mounted sensor. The transit time of the thermal marker can be ascertained for transit of the thermal marker from a heater to a sensor, or from one sensor to another sensor. A preferred embodiment of the heater comprises a resonant microwave cavity which heats the fluid radiatively, and a preferred embodiment of the sensor comprises a resonant microwave cavity through which a portion of the fluid conduit passes, the resonant characteristics of said microwave sensor being perturbed by the passage of the thermal marker.

Abstract: The negative pressure monitor is intended for use in combination with an IV administration set, for monitoring venous, arterial and other physiological pressure signals. The system provides a coupling mechanism with a sealed vacuum chamber between a fluid chamber in communication with the fluid in line, and the pressure transducer. The vacuum in the coupling mechanism serves not only to communicate pressure changes within the fluid chamber to the pressure transducer, but also functions to maintain the fluid chamber in pressure communication with the pressure transducer.

Abstract: The infrared thermometer optical chopper includes a planar shutter having infrared radiation transmissive and infrared reflective portions arranged on the shutter, and a mechanism for rotating the shutter sequentially through a series of stop positions in which the transmissive and reflective portions are sequentially aligned with the internal optics of the infrared thermometer. A mechanism is also preferably provided for sensing the positioning of the shutter at the stop positions, to determine whether the shutter stop position alignment is in an infrared radiation transmissive phase or in an infrared radiation reflective phase.

Abstract: A prime mover module used in a fluid delivery micropump, especially for pharmaceutical purposes, transports an electrochemically active material, such as oxygen, at a steady rate across an ion exchange cell to apply external pressure to a collapsible reservoir and expel fluid therefrom. An air-actuated battery, such as a zinc-air battery, which is located in the module in a fixed closed circuit with the cell and which shares one of its electrodes with the cell, is activated by peeling off an adhesive tape covering air inlet ports to thereby establish a voltage gradient acrosss the cell and control the rate at which fluid is expelled from the reservoir in accordance with the value of a resistor in the cell/battery circuit. The reservoir is filled or refilled by inserting a vented needle into an air bleed port while discharging a fluid-filled syringe inserted into a fluid injection port.

Abstract: A biomedical thermometer for taking the temperature of a person at various body sites, including the ear, includes a radiation detector, a temperature detector for measuring the temperature of the radiation detector, and a heating and cooling unit for changing the temperature of the radiation detector. The system also includes a temperature processor for generating an output proportional to the absolute temperature of the radiation detector, responsive to signals generated by the radiation detector and the temperature detector.