Abstract: The present invention involves a method and an apparatus for analyzing measured signals, including the determination of a measurement of correlation in the measured signals during a calculation of a physiological parameter of a monitored patient. Use of this invention is described in particular detail with respect to blood oximetry measurements.

Abstract: The disclosure includes pulse oximetry systems and methods for determining point-by-point saturation values by encoding photoplethysmographs in the complex domain and processing the complex signals. The systems filter motion artifacts and other noise using a variety of techniques, including statistical analysis such as correlation, or phase filtering.

Abstract: A pulse and active pulse spectraphotometry system comprises a light source adapted to illuminate a tissue site with optical radiation having a plurality of wavelengths selected from at least one of a primary band of about 1620 nm to about 1730 nm and a secondary band of about 1000 nm to about 1380 nm.

Abstract: A physiological monitor for determining blood oxygen saturation of a medical patient includes a sensor, a signal processor and a display. The sensor includes at least three light emitting diodes. Each light emitting diode is adapted to emit light of a different wavelength. The sensor also includes a detector, where the detector is adapted to receive light from the three light emitting diodes after being attenuated by tissue. The detector generates an output signal based at least in part upon the received light. The signal processor determines blood oxygen saturation based at least upon the output signal, and the display provides an indication of the blood oxygen saturation.

Abstract: A blood constituent monitoring method for inducing an active pulse in the blood volume of a patient. The induction of an active pulse results in a cyclic, and periodic change in the flow of blood through a fleshy medium under test. By actively inducing a change of the blood volume, modulation of the volume of blood can be obtained to provide a greater signal to noise ratio. This allows for the detection of constituents in blood at concentration levels below those previously detectable in a non-invasive system. Radiation which passes through the fleshy medium is detected by a detector which generates a signal indicative of the intensity of the detected radiation. Signal processing is performed on the electrical signal to isolate those optical characteristics of the electrical signal due to the optical characteristics of the blood.

Abstract: The present invention involves a method and an apparatus for analyzing measured signals, including the determination of a measurement of correlation in the measured signals during a calculation of a physiological parameter of a monitored patient. Use of this invention is described in particular detail with respect to blood oximetry measurements.

Abstract: The present invention involves a method and an apparatus for analyzing measured signals, including the determination of a measurement of correlation in the measured signals during a calculation of a physiological parameter of a monitored patient. Use of this invention is described in particular detail with respect to blood oximetry measurements.

Abstract: An improved pulse oximeter provides for simultaneous, noninvasive oxygen status and photoplethysmograph measurements at both single and multiple sites. In particular, this multiple-site, multiple-parameter pulse oximeter, or “stereo pulse oximeter” simultaneously measures both arterial and venous oxygen saturation at any specific site and generates a corresponding plethysmograph waveform. A corresponding computation of arterial minus venous oxygen saturation is particularly advantageous for oxygen therapy management. An active pulse-inducing mechanism having a scattering-limited drive generates a consistent pulsatile venous signal utilized for the venous blood measurements. The stereo pulse oximeter also measures arterial oxygen saturation and plethysmograph shape parameters across multiple sites.

Abstract: A pulse oximetry sensor has an emitter adapted to transmit optical radiation of at least two wavelengths into a tissue site and a detector adapted to receive optical radiation from the emitter after tissue site absorption. A tape assembly is adapted to attach the emitter and detector to the tissue site. A flexible housing is disposed around and optically shields the detector.

Abstract: A method and an apparatus to analyze two measured signals that are modeled as containing desired and undesired portions such as noise, FM and AM modulation. Coefficients relate the two signals according to a model defined in accordance with the present invention. In one embodiment, a transformation is used to evaluate a ratio of the two measured signals in order to find appropriate coefficients. The measured signals are then fed into a signal scrubber which uses the coefficients to remove the unwanted portions. The signal scrubbing is performed in either the time domain or in the frequency domain. The method and apparatus are particularly advantageous to blood oximetry and pulserate measurements. In another embodiment, an estimate of the pulserate is obtained by applying a set of rules to a spectral transform of the scrubbed signal. In another embodiment, an estimate of the pulserate is obtained by transforming the scrubbed signal from a first spectral domain into a second spectral domain.

Abstract: A physiological parameter tracking system generates a reference parameter and a slowly varying parameter responsive to a physiological signal input. The slowly varying parameter is generated according to an update command. A physiological measurement output is provided that is responsive to a tracking function of the reference parameter and the slowly varying parameter.

Abstract: A time domain rule-based processor provides recognition of individual pulses in a pulse oximeter-derived photo-plethysmograph waveform.

Abstract: A pulse oximeter has an integrated mode in which it operates as a plug-in module for a multiparameter patient monitoring system (MPMS). The pulse oximeter also has a portable mode in which operates separately from the MPMS as a battery-powered handheld or standalone instrument. The pulse oximeter has a sensor port that receives a photo-plethysmographic signal as input to an internal processor. The pulse oximeter processes this sensor signal to derive oxygen saturation and pulse rate measurements. In the portable mode, this information is provided on its display, and stored in memory for trend capability. In the integrated mode, the pulse oximeter provides oxygen saturation and pulse rate measurements to the MPMS through a docking station to be displayed on a MPMS monitor. In the integrated mode, the portable pulse oximeter docks to the docking station, which in turn is inserted in one or more MPMS slots.

Abstract: An optical probe, which is particularly suited to reduce noise in measurements taken on an easily compressible material, such as a finger, a toe, a forehead, an earlobe, or a lip, measures characteristics of the material. A neonatal and adult disposable embodiment of the probe include adhesive coated surfaces to securely affix the probe onto the patient. In addition, the surface of the probe is specially constructed to reduce the effect of ambient noise.

Abstract: A physiological monitor utilizes Faraday rotation measurements to estimate mean photon pathlengths through tissue. These pathlength estimates, along with corresponding optical spectroscopy measurements allow the noninvasive monitoring of blood constituent concentrations. The technique is particularly applicable to noninvasive blood glucose measurements. The physiological monitor has a polarized light source for illuminating tissue and a magnetic field generator which creates a magnetic field within the tissue during illumination. The magnetic field imparts a Faraday rotation in the plane of polarization of the incident light beam as it propagates through the tissue and emerges as a transmitted light beam. A polarimeter is used to measure the rotation of the transmitted light. A signal processor then computes an estimate of the mean pathlength from the polarimeter output.

Abstract: A monitor has a primary input from which a spectral characteristic of a tissue site can be derived. The monitor also has a secondary input from which at least one parameter can be determined. A compensation relationship of the spectral characteristic, the parameter and a compensated physiological measurement is determined. A processor is configured to output the compensated physiological measurement in response to the primary input and the secondary input utilizing the compensation relationship.

Abstract: An optical probe, which is particularly suited to reduce noise in measurements taken on an easily compressible material, such as a finger, a toe, a forehead, an earlobe, or a lip, measures characteristics of the material. A neonatal and adult disposable embodiment of the probe include adhesive coated surfaces to securely affix the probe onto the patient. In addition, the surface of the probe is specially constructed to reduce the effect of ambient noise.

Abstract: An optical probe, which is particularly suited to reduce noise in measurements taken on an easily compressible material, such as a finger, a toe, a forehead, an earlobe, or a lip, measures characteristics of the material. A neonatal and adult disposable embodiment of the probe include adhesive coated surfaces to securely affix the probe onto the patient. In addition, the surface of the probe is specially constructed to minimize light piping effects. Furthermore, a flex circuit acts as a spring to absorb shock which may misalign the emitter and detector. One embodiment of the adult probe includes a cushioning pocket formed for a fingertip to align the probe and to absorb motion of the probe due to contact. The neonatal probe is formed with a unique V-configuration which provides multiple advantages.

Abstract: A monitor has a primary input responsive to a first property of a tissue site. An uncompensated measurement is determinable from the primary input. A parameter input is responsive to a second property associated with the tissue site, where the first property is dependent upon the second property. The monitor also has a compensation relationship of the primary input, the parameter input and a compensated measurement. A processor is configured to output a compensated measurement from the primary input and the parameter input utilizing the compensation relationship, where the compensated measurement more accurately represents the first property than the uncompensated measurement.

Abstract: An optical probe, which is particularly suited to reduce noise in measurements taken on an easily compressible material, such as a finger, a toe, a forehead, an earlobe, or a lip, measures characteristics of the material. A neonatal and adult disposable embodiment of the probe include adhesive coated surfaces to securely affix the probe onto the patient. In addition, the surface of the probe is specially constructed to reduce the effect of ambient noise.