Abstract: A medical device, for example, an IV cannula or a syringe which has a hollow needle 4 with a sharp distal end 6 for piercing the skin of a patient includes means for protecting the sharp end 6 of the needle 4 after use to minimise the possibility of accidental needle stick. The means includes a rod 12 mounted for movement through the needle 4 between a needle end protection position and a retracted position within the hollow needle 4; and means for maintaining the rod towards the needle end protection position.

Abstract: The pulsed optical rotary encoder digitally samples the operation of the optical rotary encoder to obtain the same information that is obtained by the use of the continuously active light-emitting devices but in a much more energy-efficient manner. In particular, the light-emitting devices are pulsed into operation for a short duration and at a frequent rate. The signals produced by the light detectors associated with the light-emitting devices are sampled at a predetermined time after firing the light-emitting devices to obtain the data necessary to determine the rotation of the coding disk.

Abstract: A heated humidifier for an infant incubator wherein the flow of air through the humidifier that picks up water vapor from the surface of the water is controlled in response to the temperature of the heater used to heat the water. In the preferred embodiment, the heater is an active heater located above the surface of the water and includes an extruded heat exchanger that depends downwardly from the heater to below the level of the water. A thermal actuator is located in good heat transfer association with the extruded heat exchanger at a point above the surface of the water and that thermal actuator controls the position of a valve in the outlet of the humidifier.

Abstract: An anesthetic vaporizer 1 includes an inlet 2 for carrier gas, an outlet 4 for carrier gas and anesthetic agent, a first passage 6 interconnecting the inlet to the outlet and a first fixed flow restrictor 8 located in the passage 6. A second passage 56 extends between a vaporizing chamber and the outlet 4 and located therein is a second fixed flow restrictor 54 and also a solenoid valve 58. A first pressure transducer 50 generates an electrical signal corresponding to the pressure differential P1 across the restrictor 8; and a second pressure transducer 52 generates an electrical signal corresponding to the pressure differential P2 between the passages 6, 56. A controller responsive to said electrical signals from the pressure transducers 50, 52 transmits an electrical signal to the valve 58 for controlling the flow of gaseous anesthetic agent through the passage 56 such that P2=P1.times.constant.

Abstract: Concomitant measurement of EtCO.sub.2, EtN.sub.2 and (FiO.sub.2 -FeO.sub.2) concentrations are used to detect a VAE. In a respiratory gas monitoring system, continuous measurements of end-tidal carbon dioxide, end-tidal nitrogen and the difference between inspired and expired oxygen concentrations are averaged using a predetermined time period and stored as historical data. Periodically, a present value of each of these concentrations is compared to its respective historical average for a predetermined time period. If the following conditions are met, the device signals the presence of a venous air embolism: 1) a decrease in the EtCO.sub.2 concentration of 1.5 mm Hg; 2) an increase in the FeN.sub.2 concentration of 0.03 vol %; and 3) a decrease in the difference between the inspired oxygen concentration and the expired oxygen concentration of 0.20 vol %.

Abstract: An infant incubator tilt mechanism is disclosed that allows infinite adjustment of the tilt angle of the infant mattress within certain limits. The mechanism includes a bent rod positioned within the infant incubator itself and underlying the infant bed and which has an offset portion that engages a bed lifter. As the bent rod is rotated about an axis, the bent rod moves the bed lifter to raise and/or lower the infant bed. One end of the bent rod extends outwardly to the exterior of the infant compartment and is rotatable by an exterior mechanism having a lead screw that is rotated by the operator to cause lateral movement of a link mechanism along an axis at about ninety degrees to the axis of rotation of the bent rod. The lateral movement of the link is again translated into rotational movement and connects to the bent rod to translate that rotational movement to the bent rod. The entire tilt mechanism is readily removable so as to be easily cleaned.

Abstract: A method and apparatus for determining the composition and concentration of gases present in a gas sample by measurement of the spectrum of Raman scattered light from these gases. A diode laser illuminates the unknown gas which is contained inside a long hollow tube having a highly reflective interior wall. A laser line pass filter at an entrance aperture of the hollow tube prevents all wavelengths except specific wavelengths characteristic of the laser from entering the long hollow tube. The laser beam and Raman scattered light from the gas sample reflect inside the hollow tube from the highly reflective interior wall. A laser line rejection filter at an exit aperture of the hollow tube prevents the laser beam from exiting the hollow tube but transmits the Raman scattered light from the gas sample. A spectrograph detector or array of discrete filters and detectors detects the Raman scattered light.

Abstract: A device comprises an elongate, tubular sheath (4) having an anterior and a posterior end (6; 8), a pointed needle (18) arranged in the sheath (4) for displacement between a first and a second end position, a catheter (26) initially supported by the needle (18), and an attachment for displacing the needle (18) between the first and the second end position. The novelty of the invention resides in that the sealing means for sealing the anterior, initially open end (6) of the sheath (4) is detachably connected to the attachment, that the sealing means further is detachably connected to the catheter (26), that the sealing means, during the displacement of the needle (18) from the first to the second end position, is moved towards the anterior end (6) of the sheath (4) to a sealing position, and that the sealing means is fixed in the sealing position for substantial sealing of the anterior end (6) of the sheath (4).

Abstract: An anaesthetic vaporizer includes a concentration dial for controlling the concentration of anaesthetic leaving the vaporizer. The vaporizer is adapted to be mounted on a back bar of an anaesthesia machine. An exclusion pin is mounted adjacent the back bar and forms part of an interlock system for preventing rotation of the concentration dial when a second vaporizer is also mounted on the back bar and is dispensing anaesthetic vapor. A button assembly is mounted on the concentration dial and must be depressed before the concentration dial can be rotated. The button assembly incorporates an overload device which, if excessive force is applied to the button assembly in order to override the effect of the exclusion pin will render the button assembly inoperative.

Abstract: A vaporizer for introducing a vapor of an anesthetic liquid into t carrier gas for introduction into a patient is disclosed. The vaporizer directly vaporizes the liquid by introducing the liquid into a vaporizing chamber having an extremely large width to height ratio, i.e. in excess of 600:1. The carrier gas flows in laminar flow through the vaporizing chamber and the liquid anesthetic is introduced at a controlled flow such that it immediately vaporizes upon introduction to the entrance of the vaporizing chamber. A control scheme utilizing a CPU controls the percentage of anesthetic vapor in the outlet gas by sensing certain parameters and then controlling the flow of liquid anesthetic by controlling the speed of a controllable speed pump.

Abstract: The improved pulse oximeter preprocesses the sets of red and infrared signals received from the probe. The set of pairs of processed red and infrared data points are fitted to a linear equation to compute the slope of the best fit line through these data points and account for noise in both of these sets of data points. A measure of the linearity of the input data points, if less than a predetermined threshold, indicates that a distorted signal has been received from the probe. The computed slope of the best fit line is converted to a RRatio which is used in a empirical calibration formula to compute the average SpO.sub.2 value.

Abstract: The twice scaled waveform display apparatus combines a twice scaled factor indication with the autoscaled waveform display so that an input data quality indication is produced based on factors such as signal strength, wherein the twice scaled factor is used to modulate the size of the display that is presented to the user. Thus, the generated waveform occupies a predetermined portion of the display when the signal strength and/or other input data qualities are at an acceptable level. The size of the waveform presented to the user on the display is reduced in magnitude when there is a degradation in the input signal magnitude or other quality factors.

Abstract: An infant care center or infant care warmer having as it source of heat, an infrared emitter that is located above the infant bed and which is relatively small in dimensions so as to not impede the access to the infant by attending personnel at any time, including when X-rays are being taken to the infant. The emitter is contained in a sealed emitter assembly and includes a lens that focuses and directs the infrared radiation to a desired footprint on the infant bed. In a specific embodiment, the infrared emitter is shaped generally in the form of a parabola and a honeycomb material comprising a plurality of hexagonal openings receives the infrared radiation from the parabolic shaped emitter and redirects the radiation into a desired pattern toward the infant bed.

Abstract: A Raman spectroscopy system and method for determining a zero-calibration level. A gas sample chamber is located within a resonant cavity. A light source is located to cause light to be incident on the gas sample, the light resonates in the resonant cavity. Typically, the light source and resonator cavity in conjunction form a laser source which propagates coherent, monochromatic laser light energy through the gas sample. This causes Raman scattering from the gases constituent in the gas sample. The amount of Raman scattered light is measured at detectors along with light due to dark noise inherent in the detectors and glow from the laser source, i.e., light at wavelengths other than the laser light wavelength produced by the laser source. The resonator cavity is obstructed, via a ball inserted into the path of the laser beam for example, to prevent resonance. If the light source and resonant cavity in conjunction form a laser, prevention of resonance causes cessation of lasing.

Abstract: An illuminator for use with a variety of end use light emitting devices for administering light for therapy and/or observation of an infant. One of the end use emitting devices is a device to provide phototherapy to the infant and is prevented by the illuminator from emitting light that has not been filtered to select the desire spectrum of wavelengths for phototherapy. The illuminator prevents the introduction of a connector to the phototherapy device from being inserted to an operative, secured position unless the proper filter is in position to filter out all of the undesired wavelengths before the light radiation can reach the phototherapy end use emitting device. Other end use light emitting devices may, however, be used with the same illuminator and their connectors are readily inserted into the illuminator to receive light radiating from the illuminator to the end use light emitting device.

Abstract: An anaesthetic vaporizer includes a passageway 10, 30 for directing carrier gas through a fixed laminar restrictor 32 to a vaporizing chamber 26. Liquid anaesthetic agent is injected into the vaporizing chamber 26 from a constant level tank 12 the output of which is controlled by a laminar control valve 28. Liquid anaesthetic agent flow is determined by the pressure of carrier gas in the passageway 10, 30 and the setting of the liquid laminar control valve 28.

Abstract: The pulse oximeter probe uses an inexpensive connector to electrically interconnect the sensor elements with the pulse oximeter. One segment of the probe connector contains a set of connector pins that are wired to the sensor elements. Another segment of the probe connector is equipped with a mating configuration of sockets which align with these pins. Three projections function to automatically align the connector pins with the connector sockets. Two of the projections engage a mating aperture in the other connector segment to fasten the two connector segments together, while a third projection aligns with an edge of the other connector segment to position the two connector segments.

Abstract: A system for delivery of volatile liquid drugs as supplied to a patient by an anaesthetic vaporizer comprises a supply container (2) and a vaporizer (32) which includes a sump. Each of the supply container and the vaporizer is provided with a valve assembly (6, 34) which, when closed, prevent passage of fluid from the supply container into the sump. The supply container and the sump are connected to one another by means of a bayonet connection, which is made when indexing elements on the containers correspond. The valve assemblies in the containers are opened when the containers are connected to one another by means of an insert (40) located within an inlet conduit (10) linking the two containers.The inlet conduit (10) is rotatable between lowered and raised positions, to open a valve (37) by which flow of fluid into and out of a reservoir for fluid in the sump can be controlled.

Abstract: An in bed infant scale for use with an infant care center and which may be slid underneath the infant platform of the infant care center while the infant is positioned within the center and which causes little disruption to the infant. The infant scale is thus movable from infant care center to infant care center conveniently. The infant scale is easily slid into the infant care center and raises the infant platform on which the infant is positioned such that the infant platform is raised off of its position on its supporting frame and becomes fully supported on the infant scale. Thus the infant scale can weigh the infant platform and the infant resting on that infant platform.