Abstract: An infant incubator is disclosed having a hood that encloses the infant compartment. In the base of the incubator is the heating air and ducting means and which provides heated through an ever open outlet in the base and which heated air passes from the base through a flow path formed by the hood that circulates around the infant and re-enters the base through an inlet. That heated air is thus introduced into or along the access door in the front of the hood from the outlet and travels through or along the access door and through or along the hood around the infant and is returned to the base for recirculation. The hood itself is pivotally attached to the base at the rear of the incubator so that it can be opened from the front for complete access to the infant. The access door in the front of the hood is pivotally attached to the incubator base and can also be opened for access to the infant. When the access door is in its closed position, it forms part of the air path for the heated air.

Abstract: A resilient valve core, biased against its seat in a molded body, controls large flow volumes for flushing. A small resilient tube embedded in the core bypasses the valve to provide smaller flow volumes for IV-fluid drip. For flushing, the core is deformed, rather than bodily moved, relative to the body. A fluid-flow channel is recessed along one side of the valve cavity, and the valve seat forms a short barrier across this channel. The core is a T-shaped unitary member; the center of the "upper" surface of the T crossbar is biased against the seat, and the extrema of the crossbar are hermetically sealed against the valve body, while the stem of the T extends outward from the body. A user squeezes a cowling mounted outside the body to start and control flushing. The cowling itself deforms to pull the stem of the T outward, deforming the T and separating the middle of its crossbar portion from the valve seat. A user can elect to grasp and pull the stem directly.

Abstract: The molecular concentration of a constituent such as oxygen of an anesthetic agent in a gas is measured by contacting the gas with the surface of a solid body, momentarily heating the surface so that the constituent reacts at the surface to alter a property of the surface such as reflectivity, and determining the degree or rate of alteration occasioned by the heating step. The momentary heating operation may be performed by light from a laser focused on to a small localized region. The body surface can include a thin film of a material such as a metal reactive with the gas constituent of interest at elevated temperatures. The preferred methods provide extraordinarily rapid response, and also form a permanent record of each measurement. Where the gas is at substantially constant pressure, the measured molecular concentration can be interpreted as an indication of the proportion of the constituent in the gas.

Abstract: A selector valve for use with a hospital vacuum on position in pressure module to supply vacuum or pressure to a utilization means. The selector valve has two or more positions and includes a positive stop at each of its positions through the use of molded plastic parts that interact together to eliminate springs or other components that are tedious to assemble. The entire selector valve is comprised of a minimum of parts and costly lapped surfaces are eliminated by molding a gasket material to one of the components of the valve. The overall multiposition selector valve is thus inexpensive to manufacture by utilizing a minimal number of plastic molded parts and that are easy to assemble.

Abstract: A catheter probe for use in the analysis of gases absorbed in liquids, particularly suitable for the in vivo analysis of blood gases, the probe includes an equilibration chamber disposed within the active length of the probe at the distal end of the probe and which is surrounded by a gas permeable membrane. A carrier gas is introduced into the probe and enters the equilibration chamber where the gas sought to be analyzed from the blood equilibrates with the carrier gas and forms a bolus of sample gas. That bolus is then caused to flow out of the probe to an analyzer. The equilibration chamber is formed of an elongated, tortuous path that allows a high surface area to unit volume ratio, that is, the ratio of the area of the equilibration chamber that is immediately beneath the gas permeable chamber to the volume of the flow path though the equilibration chamber is high. Preferable the equilibration chamber is formed as a spiral path.

Abstract: Respiratory therapy apparatus is provided with setting elements such as knobs for inputting set values for various parameters. A digital display is provided for showing measured values of operational variables. The set point for each parameter is displayed on the display apparatus along with the measured values only when the knob or setting element for the particular parameter is engaged by the operator's hand.

Abstract: A pulse oximeter or plethysmographic device utilizes light varying in intensity at a predetermined carrier frequency. A passive resonant circuit having a resonant frequency substantially equal to the carrier frequency is connected between the photodetector and the first amplifier. The resonant circuit serves to suppress spurious DC and low frequency components such as those due to ambient light and ambient light flicker and also to suppress high frequency interference. Because ambient light signals are suppressed, there is no need for dark current correction or restoration. Suppression of ambient light and other interference upstream of the front end amplifier avoids saturation of the amplifier and permits use of a front end amplifier having high gain.

Abstract: A medical gas adapter useable for connecting a gas tubing or other end use device to a gas service outlet to supply the gas for its end use. The adapter has a fixed adapter assembly including an elongated nose that fits within the gas service outlet to activate a valve for releasing gas to the adapter. The fixed adapter assembly also includes a connector means at its other end for connection to the end use device. A release knob is rotatably affixed to the fixed adapter assembly and can be rotated between a first position where a locking mechanism retains the adapter held within the service outlet and a second position where the adapter is released from the service outlet. The release knob is spring biased to return to its first position in the preferred embodiment by a pair of molded leaf springs integrally molded with the release knob for inexpensive manufacture and assembly.

Abstract: An intermittent suction regulator is disclosed operating from a vacuum system and is used to provide a plurality of pneumatic output signals to a positive pulse device for returning fluids removed from a patient during drainage thereof to clear the removal passageways. The suction regulator or control unit provides two (2) timed output signals, from one (1) intermittent vacuum to atmospheric pressure input. One output signal continually switches from a regulated vacuum signal to an atmospheric pressure signal while the other output signal switches from providing an unregulated vacuum signal to an atmospheric pressure signal. The signals are timed such that both are initially set to provide vacuum signals simultaneously, however there is a predetermined time delay between the time the regulated vacuum output signal switches from vacuum to atmospheric and when the unregulated vacuum output signal switches from vacuum to atmospheric.

Abstract: A water separator is disclosed for removing water from a minute flow of gas/water sampled from a patients exhalation and prior to the gas being introduced into an analyzer. The separator comprises a housing with an inlet, an outlet, and a pair of chambers in series through which the sample is drawn. The first chamber has a pair of substantially closely aligned wall surfaces of predetermined narrow distance from each other such that the surface tension causes the liquid in the sample to adhere to the wall surfaces. As the sample progresses to the second chamber, the wall surfaces are further apart and thus the tension effect is broken and only the gas continues through the second chamber to the separator outlet. A drain is located in the lower part of the first chamber for withdrawal of the accumulated liquid from that chamber.

Abstract: A mass spectrometer adapted to monitor respiratory gases includes a spectrometer chamber arranged selectively to receive respiratory gas or an oxygen containing gas substantially free of carbon dioxide, together with means for correcting the detected level of carbon dioxide during respiration by that threshold level detected during the period when the mass spectrometer is responsive only to the oxygen containing gas.

Abstract: A heater traverse mechanism used with an infant care center is disclosed. The traverse mechanism allows the heater that is focused on or about the infant positioned on the infant care center to be moved aside for better access to the infant, yet, as the heater is moved, the traverse mechanism automatically adjusts the heater such that its focus remains on the infant so that even at various points along a locus, the footprint of heat on or about the infant remains relatively constant.

Abstract: A probe for monitoring the blood pressure of a patient includes a light reflective diaphragm 4 deformable in response to the blood pressure. A single emitter light guide 10 is arranged off-set from the central axis of the diaphragm 4 and directs light at an off-axis region of the diaphragm. A pair of receiver light guides 8, 12 are arranged one on each side of the emitter light guide 10 so that the axes of the light guides lie in or adjacent the same plane as the center of the diaphragm 4. Each receiver light guide 8, 12 receives light reflected from the diaphragm 4 in accordance with movement of the diaphragm 4.

Abstract: Apparatus and method for measuring the level of a constituent such as oxygen in the blood of a living subject. Light at a plurality of wavelengths is emitted and directed through the patient's body to a photodetector. The amplitude of the emitted light at each wavelength is varied in accordance with a different carrier frequency, and the photodetector signal thus includes a component at each carrier frequency. Each such component represents transmissivity of the body structure at one wavelength of the emitted light. The photodetector signal is subdivided by frequency so as to separate the components at the different carrier frequencies. The constituent level is determined from these separated components.

Abstract: A pendent assembly is disclosed for suspending from a hospital room ceiling to provide various services used in a hospital operating room. The pendent has a distribution head with outlets for such services, including, for example, electrical, gas and vacuum outlets and which is moveable upwardly and downwardly through a motive means operated by personnel using the pendant. An automatic stop mechanism is included and which comprises one or more sets of electrical contacts interposed between upper and lower housings in the distribution head. The lower housing is suspended from the upper housing at a predetermined distance therefrom and is moveable over that predetermined distance with respect to the upper housing. When the distribution head is lowered such that it encounters an obstruction, the lower head is forced upwardly and the contacts between the housings contact each other to complete an electrical circuit.

Abstract: An intermittent suction regulator is disclosed operating from a vacuum system and is used to provide a plurality of pneumatic output signals to a positive pulse device for returning fluids removed from a patient during drainage thereof to clear the removal passageways. The suction regulator or control unit provides two (2) timed output signals, from one (1) intermittent vacuum to atmospheric pressure input. One output signal continually switches from a regulated vacuum signal to an atmospheric pressure signal while the other output signal switches from providing an unregulated vacuum signal to an atmospheric pressure signal. The signals are timed such that both are initially set to provide vacuum signals simultaneously, however there is a predetermined time delay between the time the regulated vacuum output signal switches from vacuum to atmospheric and when the unregulated vacuum output signal switches from vacuum to atmospheric.

Abstract: In photoelectric apparatus such as a pulse oximeter for monitoring a parameter of the blood in a living organism, a dark current correction signal is applied to the input at the preamplifier. The correction signal is substantially equal in magnitude but opposite in sense to the photodetector output during dark intervals when the illumination means of the apparatus is disabled. Because dark current correction is accomplished at the input of the preamplifier, the preamplifier has substantially increased resistance to overloading caused by ambient light and hence may have higher gain.

Abstract: A handhole for use on an incubator is disclosed and which comprises only two main components, an injection molded frame attachable to the incubator by hand tightened screws and an injection molded door that is hingedly attached to the frame to pivot between open and closed positions. A bump or projection is formed on the side of the door or flange between the door and frame such that when the door is in its closed position, the bump is caught between the frame and door to cause bending of the door. By location and size of the bump, the amount of bending can be determined such that, when unlatched, the door will spring open a predetermined amount. Thus, the door's flexibility causes initial opening thereof without the need for springs or other accessories. As an added feature, the injected molded frame may include a flange for attaching a conventional wristlet thereto.

Abstract: A catheter pulse device is disclosed which is activated by vacuum signals and which is used adjacent to or directly attached to a catheter for withdrawing fluids from a patient's body cavity, such as the stomach. The device operates immediately following the normal cessation of suction in an intermittent suction system and returns a minute quantity of the withdraw fluid back into the catheter itself to clear the withdrawal passageways. The pulse device provides protection against an excess of vacuum from reaching the patients cavity by utilizing a specially designed valve that opens and closes the path between a source of regulated vacuum and the patient. That valve is balanced such that it initially opens at or approximately at the point the vacuum on the patient side of the valve reaches the regulated vacuum set by the doctor or other knowledgeable personnel, and thus the vacuum to the patient does not exceed a set amount.

Abstract: An interlock system for use with two or more vaporizers when mounted in plug-in fashion on the back bar of an anaesthesia machine includes a spacer 22 of generally channel shaped section having spaced arms 10, 11 engageable by pins which extend outwardly from individual vaporizers when a concentration dial on the vaporizer is moved from an off position to an operative position. Outward movement of the pins causes the spacer to slide on the back bar between adjacent units thereby preventing outward movement of a pin on a similar adjacent unit.