69 results about "Arterial oxygen" patented technology

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. A corresponding calculation of delta arterial saturation and comparison of plethysmograph shape parameters between multiple sites is particularly advantageous for the detection and management of persistent pulmonary hypertension in neonates (PPHN), a patent ductus arteriosis (PDA), and aortic coarctation.

A non-invasive optical sensor which uses the motion signal to calculate the physiological characteristic being measured. For pulse oximetry, a least squares or a ratio-of-ratios technique can be applied to the motion signal itself. This is made possible by selecting a site on the patient where variations in motion produce signals of two wavelengths which are sufficiently correlated. In particular, it has been determined that a sensor placed on a nail, in particular a thumbnail, exhibits the characteristics of having the red and infrared signals correlated when used for pulse oximetry, and the resulting signals correlate to arterial oxygen saturation.

The invention comprises a method and apparatus for processing signals reflecting a physiological characteristic by performing an error minimizing mathematical combination between signals from at least two independent sensors. For example, the intensity of light is detected following tissue absorption at two wavelengths and the signals are corrected. Preferably, corrected intensity signals are derived by orthogonal regression. In one embodiment, the method and apparatus are used to determine arterial oxygen saturation.

An active-pulse blood analysis system has an optical sensor that illuminates a tissue site with multiple wavelengths of optical radiation and outputs sensor signals responsive to the optical radiation after attenuation by pulsatile blood flow within the tissue site. A monitor communicates with the sensor signals and is responsive to arterial pulses within a first bandwidth and active pulses within a second bandwidth so as to generate arterial pulse ratios and active pulse ratios according to the wavelengths. An arterial calibration curve relates the arterial pulse ratios to a first arterial oxygen saturation value and an active pulse calibration curve relates the active pulse ratios to a second arterial oxygen saturation value. Decision logic outputs one of the first and second arterial oxygen saturation values based upon perfusion and signal quality.

The present invention relates to novel nasal pulse oximeter probes that are configured to be placed across the septum of the nose. These probes are fabricated to provide signals to obtain arterial oxygen saturation and other photoplethysmographic data. The present invention also relates to a combined nasal pulse oximeter probe / nasal cannula. The present invention also relates to other devices that combine a pulse oximeter probe with a device supplying oxygen or other oxygen-containing gas to a person in need thereof, and to sampling means for exhaled carbon dioxide in combination with the novel nasal probe. In certain embodiments, an additional limitation of a control means to adjust the flow rate of such gas is provided, where such control is directed by the blood oxygen saturation data obtained from the pulse oximeter probe.

A method for calibrating a pulse oximeter device and an apparatus incorporating the method and a system for utilizing the method. The method is based on modeling light propagation in tissue at two wavelengths, typically, one in the red and one in the infrared range of the spectrum. A formula is derived relating the arterial oxygen saturation to a ratio R commonly measured by standard pulse oximeters. A specific parameter is identified and utilized in the calibration of the oximeter. This parameter is formulated in terms of the DC signals measured by the pulse oximeter at the two wavelengths. An empirical method for estimating this parameter based on experimental data is also described.

The present invention relates to a novel non-invasive perfusion / resistance status monitor system and methods of using the same, and more specifically, a vascular perfusion status monitor system receiving and processing signals from at least two pulse oximeter probes, where each of the at least two pulse oximeter probes are situated at advantageously different locations in a patient. Novel pulse oximeter probes are configured to be placed, respectively, across the lip or cheek, across the septum or nares of the nose, and on the tongue. These probes are fabricated to provide signals to estimate arterial oxygen saturation. Conventional oximeter probes also can be configured to function according to the novel methods of determining differences in peripheral blood flow and / or resistance described herein.

A method and an apparatus for distinguishing concentrations of blood constituents among distinct vascular components in situ. The method has steps of inducing periodic vibration, characterized by a frequency, in a limb of a person in such as manner as to selectively excite a resonant response in a specified blood vessel of the person, an artery or a vein, illuminating the limb of the person with a light source, and synchronously detecting a plethysmographic signal for discriminating response attributable to the specified blood vessel.

The invention is method and apparatus for determining a physiological characteristic by detecting the intensity of light following tissue absorption at two wavelengths, estimating the pulse amplitude and indexing a calculated physiological characteristic to the estimated pulse amplitude. In one embodiment, the ratio of logarithms of absorbance signal amplitude is indexed to the pulse amplitude to improve the accuracy of arterial oxygen saturation as determined by a pulse oximeter.

A system and method for organization and analysis of complex and dynamically interactive time series is disclosed. One example comprises a processor based system for relational analysis of physiologic signals for providing early recognition of catastrophic and pathologic events such as pathophysiologic divergence. The processor is programmed to identify pathophysiologic divergence of at least one of first and second physiologic parameters in relationship to the other and to output an indication of the divergence. An object-based method of iterative relational processing waveform fragments in the time domain is described wherein each more complex waveform object inherits the characteristics of the waveform objects from which it is derived. The first physiologic parameter can be the amplitude and frequency of the variation in chest wall impedance or nasal pressure and the second parameter can be a measure or indication of the arterial oxygen saturation.

A method and a device for the continuous, mobile non-invasive and aesthetically unobtrusive measurement of important vital parameters, in particular body(core)temperature, arterial oxygen saturation, heart rate, respiration rate (by pulse oximetry), blood pressure, ECG, and substance concentrations in blood or tissue. The measuring site and the position of the sensor components is the (proximal) auditory canal, whereby there results an unobtrusive sensor technology suitable for a stable monitoring in everyday life i.e. even unaffected by motion. The sensor system includes a small evaluation unit and electronics for signal processing and e.g. means for wireless transmission to a mobile phone. Thus physiological parameters become available for long term diagnostics, for outpatients, for monitoring during rehabilitation, or for monitoring the health status in everyday life, while doing sports and during training, for an increase of the safety of individuals or of people with dangerous occupations or risky hobbies.

The invention comprises a method and apparatus for processing signals reflecting a physiological characteristic by detecting the intensity of light following tissue absorption at two wavelengths and subtracting the best estimate of the desired signal from the difference between the signals. Corrected first and second intensity signals are determined by applying a residual derived from a combination of the first and second intensity signals as multiplied by a residual factor and subtracted from a difference between the first and second intensity signals to the first and second intensity signals. In one embodiment, the method and apparatus are used to determine arterial oxygen saturation.

A system and method for organization and analysis of complex and dynamically interactive time series is disclosed. One example comprises a processor based system for relational analysis of physiologic signals for providing early recognition of catastrophic and pathologic events such as pathophysiologic divergence. The processor is programmed to identify pathophysiologic divergence of at least one of first and second physiologic parameters in relationship to the other and to output an indication of the divergence. An object-based method of iterative relational processing waveform fragments in the time domain is described wherein each more complex waveform object inherits the characteristics of the waveform objects from which it is derived. The first physiologic parameter can be the amplitude and frequency of the variation in chest wall impedance or nasal pressure and the second parameter can be a measure or indication of the arterial oxygen saturation.

A pulse oximeter for measuring arterial oxygen saturation levels is provided. The pulse oximeter includes an LED signal generator for transmitting one or more light signals to a testing medium and a photodetector signal generator for processing at least a portion of the light signal generated by the LED signal generator into a photocurrent. The pulse oximeter further includes an integrated information transmission component for transmitting information corresponding to the pulse oximeter and which is integrated with the pulse oximeter without requiring additional wiring. A processing system within the pulse oximeter can generate a voltage to the integrated information transmission component to read the information stored in the component without causing the LED signal generator to generate a signal.

A congestive heart failure (CHF) mortality risk metric is automatically generated using an implantable medical device and, if it exceeds a predetermined threshold, a warning signal is issued indicating a significant risk of mortality due to CHF, perhaps necessitating more aggressive medical therapy. The CHF mortality risk metric is calculated based on a combination of estimated ventilatory response values and the slope of heart rate reserve as a function of predicted heart rates. Ventilatory response is estimated based on detected values of actual heart rate, arterial oxygen saturation, right ventricular O2, stroke volume, tidal volume, and respiration rate. Heart rate reserve values are derived from the actual heart rate along with patient age and rest heart rate. The predicted heart rates, which represent the heart rates the patient would achieve if healthy, are derived from activity sensor signals. The CHF mortality risk metric is then calculated as a ratio of ventilatory response and the slope of the heart rate reserve. If the CHF mortality risk metric exceeds a critical threshold value, such as 90, the warning signal is generated. Also described herein are various techniques for estimating ventilatory response.

A method and apparatus for determining an index indicative of a subject's response to an oxygen desaturation condition is provided. The method includes the steps of: a) providing a NIRS tissue sensor, a pulse oximetry sensor, and a processor in communication with the NIRS tissue sensor and the pulse oximetry sensor; b) sensing the subject's tissue using the NIRS tissue sensor and producing first signals; c) sensing the subject's tissue using the pulse oximetry sensor and producing second signals; d) processing the first signals to determine a change in tissue oxygen saturation values, processing the second signals to determine a change in arterial oxygen saturation values; and e) determining the index indicative of the subject's response to the oxygen desaturation condition using the change in tissue oxygen saturation values and the change in arterial oxygen saturation values.

The invention discloses a measurement method of blood oxygen saturation for eliminating motion interference. Photo-plethysmography (PPG) is interfered under motion influence, which results in a great error generated in noninvasive measurement of blood oxygen saturation. The measurement method comprises the following steps: firstly taking the difference between two wavelength-standardized PPG signals as an ideal signal to create an adaptive filter, filtering the two wavelength PPG signals to weaken partial interference, respectively building a reference signal series according to 0-100% of the blood oxygen saturation, and computing the current arterial oxygen saturation with the correlation between FFT coefficients of a reference signal and an original signal as an identification method of the arterial oxygen saturation.

The invention discloses a calculation method for arterial oxygen saturation by using the characteristic quantity of a dual-wavelength photoelectric volume pulse wave. The calculation method comprises the following steps of synchronously acquiring pulse oximeter signals with different wavelengths under sources during a period of time and taking the logarithm to obtain a logarithmic under two wavelengths; extracting characteristic quantities of dual wavelengths by using an extraction method for direct current characteristic quantity and alternating current characteristic quantity of the dual wavelengths in a time domain or a frequency domain; removing the direct current characteristic quantity and the alternating current characteristic quantity which have gross errors according to the 3sigma criterion, and taking a mean value of the direct current characteristic quantity and the alternating current characteristic quantity of which coarse noises are removed as a final characteristic quantities of dual-wavelength photoelectric volume pulse wave; extracting a certain quantity of characteristic quantity samples of the photoelectric volume pulse wave, measuring a truth value of the arterial oxygen saturation by using a blood-gas analyzer, and establishing a correction model of the truth value of the arterial oxygen saturation and the characteristic quantity of the photoelectric volume pulse wave; extracting the characteristic quantity of the photoelectric volume pulse wave of a detected object, and calculating the arterial oxygen saturation by using the correction model.

The present invention provides an oxygen concentration control apparatus for an incubator and an incubator using the same also suitable for continuous use for a long period. A pulse oximeter measures percutaneous arterial oxygen saturation (SpO2) of a newborn accommodated in an incubator, and a control unit obtains fraction of inspired oxygen (FiO2) used for setting the measured value of the percutaneous arterial oxygen saturation (SpO2) obtained by the pulse oximeter to a predetermined set value. In the measurement of the percutaneous arterial oxygen saturation (SpO2) by the pulse oximeter, it is unnecessary to warm the skin of a region to be measured. Consequently, even if the percutaneous arterial oxygen saturation (SpO2) is measured continuously for a long period, there is low possibility that the accommodated newborn suffers a cold burn.

The invention discloses a sudden death early-warning method, device and system. The method comprises the steps of 1, extracting and detecting physiological information, wherein respiration, oxyhemoglobin saturation, heart rate and heart rate variability information of a testee are extracted, and totally the 6 monitoring indexes of the respiratory rate, the AHI index, the arterial oxygen saturation, the heart rate, the Poincare map indexes SDI and SD2 are obtained; 2, detecting abnormity of the physiological information, wherein various kinds of physiological information obtained in step 1 aresubjected to abnormity detection and early-warning level calculation; when abnormity is detected, step 3 is executed if the result shows abnormity, and detection continues if the result shows normality; 3, conducting sound, light and vibration alarming, wherein an alarm apparatus is driven to give out sound, light and vibration, and the corresponding early-warning level is offered; it shows that the higher the early-warning level is, the higher the risk of sudden death is, and when the early-warning level is larger than 3, the testee needs to see a doctor, and if the early-warning level is larger than 5, the testee needs to see a doctor urgently. The sudden death early-warning device comprises a respiratory sensor module, an oxyhemoglobin saturation sensor module, a heart rate sensor module and a microprocessor module.

The present invention concerns an optical based pulse oximetry device comprising:first, second and third light emitting means, for placement on the skin surface of a body part to inject light in a tissue of said part, the wavelengths of the light emitted by said second and third means being different from each otherlight detecting means located at a relatively short distance from said first light emitting means and at relatively long distance from said second light emitting means and said third light emitting means, for collecting at the skin surface light of said emitting means having travelled through said tissue,first computing means for denoising the output signals of said long distance light detecting means from the output signals of said short distance light detecting means, andsecond computing means for deriving oximetry measurements from the denoised output signals of said long distance light detecting means.

A wearable device includes an information acquisition section which acquires environmental information including at least one of location information of a user, atmospheric pressure information, and weather information, a sensor which acquires arterial oxygen saturation information, a processing section which generates notification information associated with an arterial oxygen saturation based on the environmental information and the arterial oxygen saturation information, and an output section which outputs the notification information.