Abstract: A number of embodiments of an oximeter sensor having a flat lower surface for interfacing with the patient are disclosed. Each sensor includes a laminated sensor housing. Part of a cable that interconnects the oximeter sensor with an oximeter is disposed within this laminated sensor housing. In one embodiment, a foam preform having a flat lower surface is disposed between an upper film assembly that is sealed to a lower film assembly which collectively define an oximeter sensor housing. This preform includes a slot in which the cable may be positioned. In another embodiment, the upper and lower film assemblies of the sensor housing are sealed together at a location which is at least generally coplanar with the lower extreme of the cable to provide the desired flat lower surface for the laminated oximeter sensor housing.

Abstract: A heater control system for use with a radiant heater of an infant warmer. The system utilizes a patient skin temperature and a set temperature inputted by a user and initially subtracts the patient temperature from the set point temperature to arrive at a differential signal identified as the Patient Temperature Gradient (PTG). That PTG is the used to directly control the power to the radiant heater by modifying the power to the heater depending upon the sign and the magnitude of the PTG. Thus, the method of the present invention is not a proportional control system but seeks and finds its own level of power that is not governed by any specific temperature difference and will adjust the heater power where the resulting heater power adjustment may be different for a variety of conditions.

Abstract: An infant care apparatus such as an incubator or infant warmer having a mattress for supporting the infant on an infant platform that can, at times, by fully rotated 360 degrees to obtain full access to the infant. In the incubator, a translation platform can be slid into and out of the infant compartment and the mattress tray is pivoted to that translation platform so as to rotate at a pivot point that connects the mattress tray to the translation platform. Accordingly, when all of the doors of the infant incubator are in the closed position, the mattress tray is constrained from rotational movement but that mattress tray can be rotated a full 360 degrees whenever both doors are open or when the translation platform has been moved to a position at least partially exterior of the infant compartment. In all, the apparatus provides easy and convenient access to the infant for carrying out procedures on the infant while it is still supported by the infant care apparatus.

Abstract: An inventive apparatus and method as disclosed for the automatic identification of a given one of a predetermined plurality of cuff assemblies interconnectable to a sphygmomanometer for use in a blood pressure measurement procedure. The invention provides for the obtainment of a pressure measurement(s) during deflation of an inflatable cuff, and utilization of such measurement(s) to identify the cuff assembly. More particularly, each different cuff assembly may be provided with a corresponding gas-flow restrictor which allows the pressure measurement(s) made during deflation of a given cuff assembly to be correlated in fashion that allows for identification. Preferably, first and second pressure transducers are provided for automatic pressure measurements both upstream and downstream of a cuff assembly during the deflation portion of a cuff identification operation.

Abstract: A safety system that is used with an infant care apparatus comprising an infant platform with a planar surface for supporting the infant and a canopy that is vertically movable over the planar surface. A powered lifting mechanism operated by an electric motor causes the canopy to be selectively moved upwardly or downwardly by the user to enclose or open the space surrounding the infant. The safety system provides a continuous monitor of the torque of the motor and, when the torque exceeds a predetermined amount, the system disables the motor so that it terminates any further movement of the canopy. Thus, if the canopy encounters an obstacle in its travel upwardly or downwardly, the motor torque will increase as the motor tries to overcome that obstacle and the system will immediately disable the motor and terminate any further movement of the canopy to prevent damage to the obstacle or to the powered lifting mechanism.

Abstract: A pulse oximetry method and system for improved motion correction is disclosed. The method/system provides for the use of a detector output signal to obtain a different plurality of differential absorption data sets in corresponding relation to each of a succession of measurement, wherein each of the data sets includes differential absorption values for light of a first wavelength and light of a second wavelength. The data sets are processed to obtain a relative motion estimate value for each measurement. When the relative motion estimate value for a given measurement falls within a predetermined range (i.e., corresponding with clinical motion), a corresponding blood analyte indicator value is adjusted in a predetermined manner, wherein the corresponding adjusted blood analyte indicator is employable to obtain at least one blood analyte concentration value. In one embodiment, blood analyte indicator values may be readily multiplied by a predetermined adjustment factor (i.e.

Abstract: An incubator for use in caring for an infant having an infant platform underlying the infant and a plurality of sides extending upwardly from the infant platform and having a cover to form therein an infant compartment surrounding the infant in a controlled environment. A convective heating system is located in a heating and air moving compartment located beneath the infant and which serves to force heated air into the infant compartment to heat the infant and to withdraw return air from the infant compartment for re-circulation. The heated air is forced into the infant compartment through openings formed in the infant platform along both of the longitudinal sides of the generally rectangular infant compartment and then through double walls to emerge generally at the top of the infant compartment. The return air leaves the infant compartment through opening formed in the infant platform along both of the ends of the infant platform.

Abstract: An infant care apparatus is provided that includes a support for underlying the infant within the apparatus for providing care to that infant. The infant care apparatus includes a base, a generally rectangular infant platform supported on said base and has walls that extend upwardly from the base and covered with a hood to form an infant compartment for containing an infant in a controlled atmosphere. The hood is specially configured so as to have a lower edge that interfits over the walls in forming that infant compartment and has side panels that extend upwardly and inwardly from the sides of the hood and front and rear panels. The panels form an upper top surface that is also a flat, planar surface that preferably tapers outward toward the front panel and also is inclined downward at a slight angle toward the front panel.

Abstract: A photoplethysmographic monitoring system such as a pulse oximeter collects data regarding the blood analyte concentration and pulse rate of a patient through the analysis of light transmitted form an emitter through tissue to a photo detector. It is often necessary to review the collected data, such as oxygen saturation, pulse rate and pulsatility value at a location remote to the patient being monitored. The photoplethysmographic system formats the selected data for transmittal to a remote facsimile machine via standard telephone communication systems using an internal or external modem. The formatter is able to function within the processing and memory constraints of pulse oximeters by formatting and transmitting the data in sections. Formatted data may be sent via hard-wired telephone, cellular phone, PCS digital telephones or through satellite communication systems enabling transmittal of data from a portable photoplethysmographic system.

Abstract: A system is provided for improving photoplethysmographic analyte measurements by de-emphasizing motion-contaminated data and/or emphasizing motion-free data. The system 100 is used in a measurement instrument which includes at least illumination source 104 for transmitting at least two light signals at two center wavelengths through a patient's appendage 106 and a sensor 108 for converting the light signals transmitted through the appendage into electrical output signals. The system 100 includes a first buffer 116 configured to temporarily store at least one pulse cycle of output signals received from the sensor 108. A motion estimator 122 quantifies an amount of motion associated with the output signals stored in the first buffer 116 by performing a principal component analysis on differential absorption values derived from the output signals. Based on the amount of motion estimated, a weight application module 118 is configured to associate a weight with the output signals in the first buffer.

Abstract: An oversampling pulse oximeter includes an analog to digital converter with a sampling rate sufficient to take multiple samples per source cycle. In one embodiment, a pulse oximeter (100) includes two mor more light sources (102) driven by light source drives (104) in response to drive signals from a digital signal processing unit (116). The source drives (104) may drive the sources (102) to produce a frequency division multiplex signal. The optical signals transmitted by the light sources (102) are transmitted through a patient's appendage (103) and impinge on a detector (106). The detector (106) provides an analog current signal representative of the received optical signals. An amplifier circuit (110) converts the analog current signal to an analog voltage signal in addition to performing a number of other functions. The amplifier circuit (110) outputs an analog voltage signal which is representative of the optical signals from the sources (102).

Abstract: The improved pulse oximeter preprocesses the sets of red and infrared signals received from the probe to remove ambient light to remove noise and to de-exponentiate the signals. The linearity of the processed red and infrared signals allows the use of statistical techniques such as linear regression and linear correlation to fit a straight line to the set of pairs of processed red and infrared data points and to best measure the goodness of the straight line fit to these data points. The result of this analysis is a linear regression slope and a goodness of fit correlation coefficient. The correlation coefficient is a measure of the linearity of the input data points and if less than a predetermined threshold it indicates that a distorted signal has been received from the probe. This permits the pulse oximeter to detect probe off conditions and/or motion in the patient.

Abstract: An improved system for making an accurate determination of the patient's compliance and airway resistance by ensuring that the flow to and/or from the patient at the end of a ventilator pause is, in fact, reduced to zero flow. The normal ventilator pause occurs at the end of an inspiratory cycle where the ventilator terminates the breathing air delivery to the patient and then enters a pause period. Values are taken for the airway flow and pressure at the beginning of the pause period, that is at peak pressure, and a second set of readings is taken at the end of the pause period, called the plateau pressure. This second set of readings greatly simplifies solving the equations for patient resistance and compliance if the flow at that time is assumed to be zero.

Abstract: An improved method and apparatus is disclosed for use in frequency division multiplexed spectrophotometric systems. In photoplethysmographic applications the invention provides for the modulation of a plurality of light sources at different frequencies and in accordance with a predetermined phase relationship. Light from the sources that is transmitted through a tissue under test is detected at a detector. A composite signal indicative of the intensity of light received at the detector is demodulated based on the different modulation frequencies and predetermined phase relationship to obtain signal portions corresponding with each of the light sources. Modulation and demodulation are synchronized during each measurement period. The modulation waveforms used to modulate the light sources and corresponding demodulation waveforms used to demultiplex the composite signal are symmetrically timed about a center point for each of the measurement periods.

Abstract: The pulse oximeter instrument of the present invention includes switched gain, channel rotation and bootstrap amplification features. In one embodiment, a time-division multiplexed gain circuit is provided in receiver circuitry and is equipped with a switched gain amplifier to faciliate the use of a fixed light source drive and otherwise improve the signal processing characteristics of the instrument. Signal processing is further enhanced via use of a transimpedance amplifier and bootstrap amplifier interconnected across one or more photodiodes. The apparatus time division multiplexes (TDM) the optical input channels to customize the gain response of the apparatus to the variable characteristics of each input channel. Thus, the channel-specific error sources are determined and precisely eliminated from the input data. The channels may also be rotated in subsequent signal conditioning that entails demultiplexing/multiplexing.

Abstract: An infant care apparatus is provided that includes a support for underlying the infant within the apparatus for providing care to that infant. The apparatus has an alarm system that triggers upon the occurrence of some event indicating that a particular parameter or condition of the apparatus or infant is outside the prescribed limits or other fault condition. The alarm system thus provides a signal indicative of that alarm condition to activate a means of warning the caregiver of the existence of the alarm condition. A sound producing device and/or light producing device receives the signal produced by the audible sound or light producing device to alert the caregiver of the alarm condition. The sound producing device and the light producing device are positioned on the apparatus such that there is a sound barrier and light barrier, respectively, between the particular device and the infant so that the infant is protected from being startled, and thus stressed, by the alarm audible sound or light activation.

Abstract: An over molded reflective optical fiber terminal (100) generally includes an end portion of an optical fiber (102) that has been stripped of its buffer (104), a terminal block (106), an integral mirror (108) formed on the terminal block (106), and an optical element such as a window (112). The terminal block (106) is preferably formed from transparent injection molded plastic. The block can be molded so as to define a profile for the mirror (108). By virtue of this design, construction and alignment of the terminal/mirror system is simplified and costs are reduced. In addition, the reflective surface of the mirror (108) may be protected against dust or other optical interference. Moreover, a compact reliable terminal system for off axis application is provided.

Abstract: An infant care apparatus is provided that includes a specially designed grommet in order to facilitate the introduction of wires and/or tubes through a wall in the infant care apparatus so that wires and/or tubes can be passed through the wall for use with the infant positioned within the infant apparatus and contained with the wall or walls. The grommet is located in one of the walls surrounding the infant and includes a slit formed in a flexible material and where the slit is oriented vertically. The flexible material has a plurality of spaced apart thickened ridges that create barriers to the ease of movement of the wires or tubes along the slit. The thickened ridges preferably are formed in pairs and extend outwardly bidirectionally from the slit and may be tapered inwardly in the direction toward the slit. Thus, a wire or tube may be slid vertically along the slit and located at a desired area between any of the thickened ridges and not interfere with other wires or tubes.