Abstract: Provided is a method of calibrating a pulse oximeter, in which the effects caused by tissue of a subject can be taken into account. A detector output signal is measured when living tissue of the subject is present between emitters and the detector in a sensor. Nominal calibration and nominal calibration characteristics are read from a memory, whereupon values for the same nominal characteristics for the sensor on living tissue of the subject are established using the detector output signal. Then, changes in the nominal calibration characteristics induced by the living tissue are calculated and a subject-specific calibration is formed by correcting the nominal calibration with the changes. Finally, the hemoglobin fractions are solved using the corrected nominal calibration.

Abstract: An inventive method and system are provided for identifying a compatible photoplethysmographic sensor when interconnected to a given photoplethysmographic monitor. The method and system may further provide for the identification of which of a plurality of compatible sensors is interconnected to allow for selective calibration of the photoplethysmographic monitor. In this regard, the system and method may entail provision of a predetermined drive or test signal to a light source and/or identification element (i.e., sensor elements) of a photoplethysmographic sensor, and the obtainment of a corresponding output signal for use in sensor identification. In one approach, an output signal is obtained from at least one of three sensor elements each of which is interconnected between a different pair of sensor terminals which is a unique combination of two of four sensor terminals on the sensor.

Abstract: A system and method are for monitoring control signals provided to a medical apparatus bases upon tactile feedback from the apparatus. The system and method employ a monitoring signal indicative of a parameter relating to the apparatus or to a condition of a patient associated with the apparatus.

Abstract: A method for integrating a ventilator device with a monitoring device and other medical devices that allows the function of the monitoring device and medical devices to automatically change based on initiation of a respiratory therapy procedure. In addition, modification of behavior on the part of the ventilator is automatic in response to activation of a medical procedure from the medical device or the monitoring device.

Abstract: A conformable medical sensor is provided that has particular applicability for positioning a pulse oximeter sensor relative to a patient appendage. In one embodiment, the sensor holder includes a patient engaging member that is plastically deformable to permit the sensor holder to be conformed to the patient appendage, and plastically deformable to provide a retention force relative to the patient appendage. For example, the engaging member may be bent into a first shape that disposes first and second portions of the sensor holder into an opposing relationship the for receiving a patient appendage therebetween. Once deformed, the engaging member may be elastically deformed to a second shape to provide a retention force so as to maintain the sensor holder and a sensor interconnected thereto in contact with the patient appendage.

Abstract: The present invention is directed to a socket connector to couple electrical plugs to sockets mounted on circuit boards or cable ends. The socket connector includes a socket that receives an electrical plug and a socket silo. The silo may contain a beveled outer surface that receives a beveled face on the plug. The plug is held in the socket by latches disposed on the plug. The latches include pawls that fit within pawl receiving chambers in the socket and couple the plug to the socket. The latch and hinged section may rotate into a recessed section on the plug from an extended to a retracted position.

Abstract: The present invention is directed to a holder for use in positioning a pulse oximeter sensor in multiple selectable locations relative to a patient's extremities. The holder includes at least one flexible elongate member that is conformable to and, preferably, about a patient's extremity. A connector on the elongate member is utilized to secure the elongate member to the patient's extremity. Additionally, the elongate member's inside surface contains one or more recesses for selectively receiving a sensor and holding that sensor relative to one or more positions on the inside surface of the flexible sensor holder. The inclusion of multiple recesses allows medical personnel flexibility in positioning a medical sensor. In one embodiment, the holder includes two elongate members for conforming about two portions of a patient's extremity to reduce movement between the extremity and a sensor held by the sensor holder.

Abstract: An adapter couples a patient's breathing circuit to a ventilator. In the preferred embodiment, the adapter comprises an inhalation conduit having a first end for coupling the adapter to the ventilator and a second end for coupling the adapter to the patient breathing circuit; an exhalation conduit having a first end for coupling the adapter to the patient breathing circuit and a discharge conduit, the discharge conduit transversely oriented to the inhalation conduit; an exhaust port communicating with the discharge conduit for releasing breathed gas from same; a valve selectively opening and closing the discharge conduit to release gas from same; and a base comprising means for releasably coupling the adapter to the ventilator.

Abstract: Processing of plethysmographic signals via the cepstral domain is provided. In one embodiment, a cepstral domain plethysmographic signal processing method (200) includes the steps of obtaining (210) time domain plethysmographic signals, smoothing (220) the time domain plethysmographic signals, performing (230) a first-stage Fourier transformation of the time domain plethysmographic signals to frequency domain plethysmographic signals, computing (240) power spectrums from the frequency domain plethysmographic signals, scaling (250) the power spectrums with a logarithmic function, performing (260) a second-stage Fourier transformation on log-scaled spectrums to transform the power spectrums into cepstrums, and examining (270) the cepstrums to obtain information therefrom relating to a physiological condition of the patient such as the patient's pulse rate or SPO2 level.

Abstract: The present invention is directed to a socket connector to couple electrical plugs to sockets mounted on circuit boards or cable ends. The socket connector includes a socket that receives an electrical plug and a socket silo. The silo may contain a beveled outer surface that receives a beveled face on the plug. The plug is held in the socket by latches disposed on the plug. The latches include pawls that fit within pawl receiving chambers in the socket and couple the plug to the socket. The latch and hinged section may rotate into a recessed section on the plug from an extended to a retracted position. A locking portion on the pawl and the receiving chamber may be angled to develop a desired pullout force.

Abstract: An infant warming apparatus having a canopy movable with respect to an infant support between a lower position where the canopy mates with an upper peripheral edge of vertical walls extending upwardly from the infant support to enclose the infant in an infant compartment and an upper position opening the infant compartment. There is an adjustable mounting system that allows the canopy to be initially moved along and rotated about various axes in order to align the canopy with the vertical walls during the assembly of the infant warming apparatus. Once properly aligned, the canopy can be fixed in a desired orientation and/or allowed some motion between the canopy and the vertical walls to assure of a correct alignment of the canopy with the walls to create an isolated infant compartment.

Abstract: A method and system for transferring patient information from a source patient monitor having a source patient database to a destination patient monitor having a destination patient database. In a preferred embodiment, a transport module is connectable to a source patient monitor and a destination patient monitor. The transport module is also connectable to a patient for receiving patient information. The transport module contains a transport database for storing patient information. The transport module is connected to the patient. The transport module is then connected to the source patient monitor. Upon receiving a request to move the patient, patient information is uploaded from the source patient database to the transport database. The transport module is then disconnected from the source patient monitor. The patient is then moved.

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 or 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: A method and apparatus are disclosed for using photoplethysmography to obtain physiological parameter information related to respiration rate, heart rate, heart rate variability, blood volume variability and/or the autonomic nervous system. In one implementation, the process involves obtaining (2502) a pleth, filtering (2504) the pleth to remove unwanted components, identifying (2506) a signal component of interest, monitoring (2508) blood pressure changes, monitoring (2510) heart rate, and performing (2512) an analysis of the blood pressure signal to the heart rate signal to identify a relationship associated with the component of interest. Based on this relationship, the component of interest may be identified (2514) as relating to the respiration or Mayer Wave. If it is related to the respiration wave (2516), a respiratory parameter such as breathing rate may be determined (2520).

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-exponeniate 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 best fit straight line to the set of pairs of processed red and infrared data points and to 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: The present invention provides an apparatus and method for formatting data from a pulse oximetry monitoring device to include display layout information for use by a remotely located display unit. In this regard, the remotely located display unit is in data communication with the pulse oximetry through a communications network. The data communications network may be an analog network such as a telephony network or a digital network such as the internet. In any case, upon receiving the pulse oximetry data, a remote display device may utilize the display layout information to provide an output of the monitored data. This output may be a visual display or a hard copy output.

Abstract: An infant care apparatus having a canopy movable with respect to an infant support for supporting an infant between a lower position enclosing the infant in an infant compartment and an upper position opening the infant compartment. The canopy has an opening and a door that can be closed to block the opening and opened to unblock the opening. A radiant heater is located in a fixed position above the infant support to direct infrared energy toward the infant support. The door closes as the canopy moves to its lower position and opens as the canopy moves to its upper position. An object sensing means is provided to detect the presence of an object resting on the upper surface of the door.

Abstract: Pulse oximetry is improved through classification of plethysmographic signals by processing the plethysmographic signals using a neural network that receives input coefficients from multiple signal domains including, for example, spectral, bispectral, cepstral and Wavelet filtered signal domains. In one embodiment, a plethysmographic signal obtained from a patient is transformed (240) from a first domain to a plurality of different signal domains (242, 243, 244, 245) to obtain a corresponding plurality of transformed plethysmographic signals. A plurality of sets of coefficients derived from the transformed plethysmographic signals are selected and directed to an input layer (251) of a neural network (250). The plethysmographic signal is classified by an output layer (253) of the neural network (250) that is connected to the input layer (251) by one or more hidden layers (252).

Abstract: A system for facilitating the delivery of a liquid anesthetic agent from an anesthetic bottle to an anesthetic vaporizer. The system includes a bottle adapter, an anesthetic bottle and a filler arrangement positioned on the anesthetic vaporizer. The bottle adapter and filler arrangement each include a keyed configuration such that only the correct type of anesthetic agent can be emptied into the anesthetic vaporizer. The bottle adapter includes an adapter valve assembly that engages a filler valve assembly contained within the filler. The dimensions and arrangement of the adapter valve assembly and the filler valve assembly insure anesthetic agent is delivered to the anesthetic vaporizer only when the anesthetic agent can safely flow from the anesthetic bottle to the anesthetic vaporizer.

Abstract: A heater control system for an infant warming apparatus. The apparatus has a radiant heater comprising a heating element that is energized by an electrical supply to emit radiant energy toward the infant on the platform. The power delivered to the heater element is directly ascertained by measuring the voltage across the heater element and the current passing through the heater element and by computing directly the actual power applied to the heater element. By knowing the actual power applied to the heater, that heater power can be more precisely controlled to a desired power level.