Abstract: The present invention is directed to an oximeter sensor that may be employed with a variety of oximeter processing and display units. The oximeter sensor includes a plurality of radiation emitting devices that are capable of providing a spectral content that is useful in the correlation of a number of different oximeter processing and display units. The oximeter sensor further includes a plurality of resistors, with each resistor being connected to a different oximeter processing and display unit to permit the particular oximeter processing and display unit to select an appropriate correlation curve.

Abstract: The present invention provides an oximeter sensor holder that includes first and second lateral members for receiving the sensor, a living hinge connecting proximal ends of the first and second lateral members, and first and second press tabs for moving the first and second lateral members about the living hinge. The first lateral member and the first press tab are in an opposed and spaced-apart relationship to the second lateral member and second press tab, respectively. To open and close the lateral members, at least one of the press tabs pivots about the living hinge away from and toward the other press tab. The holder can include one or more retaining walls to inhibit lateral movement of the sensor when positioned between the first and second lateral members.

Abstract: A mechanism for aligning the elements of an optical system is disclosed. One aspect of the present invention is an alignment mechanism which includes lead screws placed on opposite corners of the elements to be aligned. The elements are provided with threaded holes of different pitch, and the lead screw is provided with threads of the same unequal pitches as the elements, thereby forming a differential lead screw. The threads include a locking thread which assures a positive lock between the lead screw and the elements to be aligned and eliminates backlash between them. Another aspect of the present invention is an interference fit mechanism which is provided by the employment of a slightly-oversized flexible boss which mates with a cavity. The boss is provided with a thin outer wall capable of flexing when the boss is inserted into the cavity. Yet another aspect of the present invention includes a wobble plate comprising a spherical socket and housing.

Abstract: A respiratory gas monitor for measuring the concentration of certain gases in a respiratory gas stream has a compact and unitary lid assembly having an integral low-profile motor and a cylindrical infrared light beam chopper. The lid assembly also contains a motor position sensor and flex circuit for passing electrical signals through epoxy sealed orifices in the lid to a processing and control unit in the monitor. The flexible circuit uses releasable connectors to facilitate removal of the monitor from an external controller and the removal of the lid assembly from the bottom portion of the monitor.

Abstract: An infant incubator having a base and a hood positioned atop of the base to form an infant compartment therebetween. The hood has a front access door that is hinged so as to move between an open and a closed position. The edge of the door opposite the hinged part has a magnetic strip that mates with a strip of magnetically attractable material positioned on the edge of the hood opening such that the door is retained in its closed position by a magnetic force. At least one door handle is mounted to the door at or near the end of the magnetic strip at the top of the door and can be pulled to open the door. The door is sufficiently flexible that pulling the handle causes a peeling effect such that relatively little force need be exerted to open the door from the corner, yet considerable force is required to open the door from inside the incubator by an infant residing therein.

Abstract: The manufacture of the electronics component of the probe is simplified by using an integral lead frame on which is mounted all of the passive and active elements so that the entire electronics module can be assembled independent of the housing in a simplified form prior to integration into the housing. The lead frame provides not only the electrical interconnections but the support and positioning of the various light emitting elements that comprise the electronics of the probe. The remaining segment of the manufacturing process is simplified since the workers do not have to assemble multiple diverse elements to create the device housing. The light reflecting and lens assemblies lock together and enclose an epoxy material which encapsulates the electronics elements and provides improved optical transmissivity of the generated light.

Abstract: Efficient management of breathing gases and anesthesia is achieved in an anesthesia delivery system which incorporates a flow minimization routine. The breathing circuit is provided with a pop-off valve and a flow sensor for detecting the pop-off flow. The flow rate of fresh gas into the breathing circuit is controlled, preferably via a digital computer, to minimize the amount of gas exhausted from the circuit. A control routine determines the minimal fresh gas flow necessary to maintain appropriate oxygen concentration, anesthetic agent concentration pop-off flow. A minimum value for the fresh gas flow may also be input to the control system. A fresh gas flow boost routine provides quick responses to charges in the user-set oxygen and agent concentrations. A circuit fill routine provides fresh gas to fill the breathing circuit until pop-off flow is sensed.

Abstract: A heat flux sensor is used in conjunction with a patient sensor, such as a patient temperature sensor, and which is secured to the patient in close proximity to the patient sensor. The heat flux sensor monitors the heat flux between the patient and the environment. Upon dislodgement of the patient probe, the heat flux sensor senses a change in heat flux that is of a predetermined amount and provides a signal indicating that the patient probe has become partially or fully dislodged from the patient. In the case of a patient heat sensor, the use of a heat flux sensor provides a quicker and larger signal than would be seen by merely monitoring the change in temperature due to partial or full probe dislodgement.

Abstract: An infrared spectrometer for anesthetic gas monitoring using an infrared light source is divided into two separately sealed sections. A partition wall separating the two sections contains a partition window allowing infrared light to pass from the infrared source into a sealed sample chamber. In case of a failure of the sealed sample chamber the gas does not come into contact with the infrared source, thereby minmizing the risk of possible explosion. A gasket of neoprene or butyl rubber is used to seal the two sections from one another. The signal produced by the spectrometer indicating the composition of the sample gas is monitored to alert the user of a single point failure at the seal of the sample chamber.

Abstract: The integrated multimode optical coupling apparatus comprises an N-to-M optical coupling arrangement that is simple to manufacture, minimizes optical losses and is significantly less expensive than the prior art arrangements of coupling optical signals. The preferred embodiment of the apparatus of the present invention comprises a substrate into which is formed a plurality of optical channels, each of which is joined at one end into a single output optical channel. This integrated optical coupler is formed by diffusing silver ions or other equivalent ions into the glass substrate in these defined areas to form channels of high optical refractive index in the body of the substrate. At one end of each of the optical channels that are formed in the substrate, the plurality of the optical channels are joined together in a volumetric region of the substrate wherein the individual channels merge into one unified common structure.

Abstract: Noise content in the output signal of a system using time division multiplexing (TDM) is measured to determine whether the output signal represents a reliable measurement. A "dark" channel in a TDM input signal may be used to isolate noise which is present in the input signal from desired informational content in the signal. The noise is processed to determine if any component of the noise will be "imaged" into the passband of the system. Any such components are then processed in a manner approximating the system transfer function to produce a noise signal indicative of the noise content of the system output signal. In one embodiment of the invention, the noise signal is used to remove noise from the output signal of the system.

Abstract: The system of the preferred embodiment of the invention contains a processor as well as a permanently mounted programmable FLASH memory in which the firmware resides. The system makes use of a socket in which a memory device can be installed. The socket accepts a firmware update memory device which has stored thereon the firmware revisions or replacement firmware. Once the firmware update memory device is installed, the processor downloads the instructions contained therein to the permanent FLASH memory device. Once the program is transferred to the permanent memory, the system operation is not dependent on the reliability of the socket. In addition, program changes can be input to the system without requiring that the system be equipped with a data input/output device, such as a modem, floppy disk drive or the like.

Abstract: A control system where the clinician can have manual control of the state for various alarms, generally volume alarms and apnea alarms. The control is interactive, that is, while the clinician can manually set the state in a variety of settings, the control system automatically overrides the clinician's selection to activate both the volume and apnea alarms wherever the mechanical ventilator is turned on. In addition, there is another override where a breath is detected by the ventilator to turn all of the alarm systems from both being inactive to both alarms being active.

Abstract: An improved method and apparatus for the monitoring perfusion of the tissue of a patient by arterial blood is provided. An optical path length change is calculated for a number of digitized samples of a received light intensity signal generated by a photo detector that receives light directed into a patient's tissue by one or more light emitting diodes or laser diodes. The optical path length changes are summed over a predetermined time such as one half cardiac cycle or other set interval to generate a perfusion index. An average perfusion index value may also be generated. In calculating the perfusion index spectral content compensation may be employed to compensate for the variety of center wavelengths associated with the spectral contents of various emitters.

Abstract: A connection, preferably for use in a medical environment, for joining a rigid circular port from a medical machine to an elastomeric hose cuff having a medical hose extending therefrom. The rigid cuff has an external annular bead formed at its outward end while the elastomeric hose cuff has an internal annular bead formed at its distal end. When the components are coupled together by sliding the hose cuff over the rigid port, a double seal is formed between the various annular beads and the surfaces of the component to provide a substantially leakproof seal between the elastomeric hose cuff and the rigid port to prevent gasses from escaping to the surrounding environment.

Abstract: A system for continuing the monitoring of certain gases delivered to a patient during the administration of nitric oxide to provide therapy to the patient. The nitric oxide is controlled by a electrically operated valve that is operated by means of an electrical signal from a CPU. At times when the various gas monitors are being calibrated, the normal alarms based upon those gas monitors are conventionally disabled during that calibration time. With the present invention, the electrical signal to the electrically operated valve is detected at the time the system goes into a calibration cycle and that detected electrical signal is used to establish limits such as a upper limit and a lower limit. Therefore, when the electrical signal to the valve is thereafter monitored and its value exceeds either of those limits, the overall nitric oxide delivery system will activate an alarm to alert the user of an abnormal condition.

Abstract: A single multifunction fixture secures an electronic device in a predetermined position and provides guide slots for the worker to place the individual conductors of a multiconductor cable in place such that each conductor aligns with a corresponding contact on the device when both the cable and the device are secured in the fixture. The fixture includes a movable head that can be brought into contact with the conductors once they are positioned over the corresponding electrical contacts to form electrically conductive paths through the head, electrical conductor, device contact and fixture for each of the cable conductors. The electrically conductive paths through the fixture form high current carrying capacity paths which, when sufficient current is passed therethrough, function to weld the cable conductors to their corresponding electrical contact on the device.

Abstract: A control system for a single-valve controlled medical ventilator adaptively invokes separate flow delivery or flow exhaust control functions in response to the sensed dynamic state of the ventilator without any dependence on measured patient parameters. The control system selects either the flow delivery control system or flow exhaust control system based on a determination of the mode in which the ventilator is operating. The determination is made using a sensed ventilator operational parameter, such as the ratio of manifold pressure to flow output, to select the appropriate control function. A hysteresis routine is provided to prevent "hair triggering" between the flow delivery and flow exhaust control systems.

Abstract: A system for the delivery of nitric oxide therapy to a patient that allows interventions by a user by activating a pause mode through a user input. A CPU in the system recognizes the activation of the pause mode and sends a signal to close a valve in order to discontinue the supply of nitric oxide to the patient. The activation of the pause mode also deactivates the normal alarm systems. A timer is activated when the system enters the pause mode and the timer allows a predetermined amount of time to pass while the pause mode is in effect. After that predetermined period of time has elapsed, the timer causes the CPU to reopen the valve to reestablish the flow of nitric oxide for the continued therapy and reestablish the alarm systems. The pause mode can be thus carried out without changing any alarm settings, established flows and the like so that the therapy is again recommenced at the same conditions as were in effect prior to the initiation of the pause mode.

Abstract: A system for correcting the concentration of NO.sub.2 detected by an electrochemical monitor in an apparatus for administering NO to a patient for therapeutic purposes. The system determines the effective monitoring time between the point in time that the sample of NO containing gas is removed by a sample conduit from the supply conduit to the patient and the point in time that the NO.sub.2 monitor actually analyzes the sample and determines the additional amount of NO.sub.2 that has been formed in the time-related reaction between NO and O.sub.2 in the sample conduit. Using that additional NO.sub.2 calculated value, the reading of the NO.sub.2 monitor is corrected to subtract that additional calculated NO.sub.2 from the monitor read value to produce a corrected, more accurate reading to the user.