Patent application number | Description | Published |
20090326349 | Consistent Signal Selection By Signal Segment Selection Techniques - According to embodiments, techniques for selecting a consistent part of a signal, including a photoplethysmograph (PPG) signal, are disclosed. A pulse oximetry system including a sensor or probe may be used to obtain a PPG signal from a subject. Signal peaks may be identified in the PPG signal. Characteristics of the signal peaks, including the amplitude levels of the signal peaks and/or the time-distance between the signal peaks may be used to determine if the PPG signal is consistent. In an embodiment, signal peaks are processed based on a consistency metric, and the processed signal peaks are compared to the consistency metric to determine if the PPG signal is consistent. If the PPG signal is determined to be consistent, the PPG signal may be further analyzed to determine an underlying signal parameter, including, for example, a patient respiration rate. If the PPG signal is determined to be inconsistent, the inconsistent portion of the signal may be removed from the overall signal or otherwise transformed. | 12-31-2009 |
20100286495 | Selection Of Signal Regions For Parameter Extraction - According to embodiments, techniques for extracting a signal parameter from a selected region of a generally repetitive signal are disclosed. A pulse oximetry system including a sensor or probe may be used to obtain an original photoplethysmograph (PPG) signal from a subject. A filter transformation may be applied to the original PPG signal to produce a baseline PPG signal. The baseline PPG signal may contain artifacts and/or noise, and a region of the baseline PPG signal suitable for extracting the signal parameter may be selected. A suitable region of the baseline PPG signal may be selected by applying one or more thresholds to the baseline PPG signal, where the values of the thresholds may be set based on derivative values, amplitude-based percentiles, and/or local minima and maxima of the baseline PPG signal. A portion of the original PPG signal corresponding to the selected region may be processed, and the signal parameter may be extracted from the processed region. In an embodiment, the signal parameter may correspond to the respiration rate of a patient. | 11-11-2010 |
20120253140 | Systems And Methods For Autonomic Nervous System Monitoring - Methods and systems are disclosed for determining physiological information about a patient's autonomic nervous system based on at least one physiological signal measured from the patient and at least one known characteristic of a patient's respiration. Respiration protocol may be provided to guide characteristics of the patient's respiration. The physiological signal measured from the patient may be transformed using a wavelet transform to create a transformed signal, and a scalogram may be generated based at least in part on the transformed signal. A metric that may indicate information about the patient's autonomic nervous system may be determined from the scalogram and the known characteristic of the patient's respiration. | 10-04-2012 |
20130079601 | SYSTEMS AND METHODS FOR ANALYZING A PHYSIOLOGICAL SENSOR SIGNAL - The present disclosure relates generally to patient monitoring systems and, more particularly, to signal analysis for patient monitoring systems. In one embodiment, a method of analyzing a detector signal of a physiological patient sensor includes obtaining the detector signal from the physiological patient sensor, wherein the detector signal crosses a horizontal boundary more than once. The method also includes determining the relative time and the slope of the detector signal at each boundary crossing. The method further includes estimating the amplitude of the detector signal based, at least in part, on the determined relative time and slope of the detector signal at each boundary crossing. The method also includes determining a physiological parameter of a patient based, at least in part, on the estimate of the amplitude of the detector signal. | 03-28-2013 |
20130079606 | SYSTEMS AND METHODS FOR DETERMINING RESPIRATION INFORMATION FROM A PHOTOPLETHYSMOGRAPH - A patient monitoring system may receive a photoplethysmograph (PPG) signal including samples of a pulse waveform. The PPG signal may demonstrate morphology changes based on respiration. The system may calculate morphology metrics from the PPG signal, the first derivative of the PPG signal, the second derivative of the PPG signal, or any combination thereof. The morphology metrics may demonstrate amplitude modulation, baseline modulation, and frequency modulation of the PPG signal that is related to respiration. Morphology metric signals generated from the morphology metrics may be used to determine respiration information such as respiration rate. | 03-28-2013 |
20130079656 | SYSTEMS AND METHODS FOR DETERMINING RESPIRATION INFORMATION FROM A PHOTOPLETHYSMOGRAPH - A signal representing physiological information may include information related to respiration. A patient monitoring system may generate a plurality of autocorrelation sequences from the signal and combine the autocorrelation sequences to generate a combined autocorrelation sequence. The combined autocorrelation sequence may be analyzed to identify one or more peaks that may correspond to respiration information. Respiration information such as respiration rate may be determined based on the one or more peaks. | 03-28-2013 |
20130079657 | SYSTEMS AND METHODS FOR DETERMINING RESPIRATION INFORMATION FROM A PHOTOPLETHYSMOGRAPH - A signal representing physiological information may include information related to respiration. A patient monitoring system may utilize a wavelet transform to generate a scalogram from the signal. A threshold for the scalogram may be calculated, and scalogram values may be compared to the threshold. One of the scales meeting the threshold may be selected as representing respiration information such as respiration rate. The respiration information may be determined based on the selected scale. | 03-28-2013 |
20130080489 | SYSTEMS AND METHODS FOR DETERMINING RESPIRATION INFORMATION FROM A PHOTOPLETHYSMOGRAPH - A patient monitoring system may receive a photoplethysmograph (PPG) signal including samples of a pulse waveform. A plurality of morphology metric signals may be generated from the PPG signal. The system may generate an autocorrelation sequence for each of the morphology metric signals. An autocorrelation metric may be generated from each of the autocorrelation sequences and may represent the regularity or periodicity of the morphology metric signal. The autocorrelation sequences may be combined to generate a combined autocorrelation sequence, with the weighting of the autocorrelation sequences based on the autocorrelation metric. The combined autocorrelation sequence may be used to determine physiological information. | 03-28-2013 |
20130137936 | SYSTEMS AND METHODS FOR DETERMINING RESPIRATION INFORMATION USING HISTORICAL DISTRIBUTION - A patient monitoring system may generate an autocorrelation sequence for a physiological signal such as a photoplethysmograph signal. A series of peak values may be identified for the autocorrelation sequence. The peak values may be modified based on a historical distribution of a physiological parameter. A physiological parameter such as respiration rate may be determined based on the modified peak values. | 05-30-2013 |
20130137945 | Pulse Rate Determination Using Gaussian Kernel Smoothing of Multiple Inter-Fiducial Pulse Periods - Systems and methods are provided for determining the pulse rate of a patient from multiple fiducial points using Gaussian kernel smoothing. Based on acquired pleth signals, each recorded fiducial pulse period is converted to a Gaussian kernel function. The Gaussian kernel functions for all recorded fiducial points are summed to generate a Gaussian kernel smoothed curve. The pulse rate of a patient may be determined from the Gaussian kernel smoothed curve. All acquired fiducial pulse periods contribute to generate the Gaussian kernel smoothing curve. The number of fiducial points utilized may change to improve pulse rate determination or provide additional functionality to the system. | 05-30-2013 |
20130172686 | SYSTEMS AND METHODS FOR DETERMINING PHYSIOLOGICAL INFORMATION USING AUTOCORRELATION WITH GAPS - A patient monitoring system may receive a physiological signal having gap portions in the received data. The gap portions may be identified and a plurality of morphology metric signals may be modified based on the identified gap portions. The morphology metric signals may be modified based on the identified gaps, and a combined autocorrelation sequence may be generated based on the modified morphology metric signals. The combined autocorrelation sequence may be used to determine physiological information. | 07-04-2013 |
20130172767 | SYSTEMS AND METHODS FOR DETERMINING RESPIRATION INFORMATION USING PHASE LOCKED LOOP - A patient monitoring system may receive a physiological signal such as a photoplethysmograph (PPG) signal that exhibits frequency and amplitude modulation based on respiration. A phase locked loop may generate a frequency demodulated signal and an amplitude demodulated signal from the PPG signal. An autocorrelation sequence may be generated for each of the frequency demodulated signal and the amplitude demodulated signal. The autocorrelation sequences may be combined and respiration information may be determined based on the combined autocorrelation sequence. | 07-04-2013 |
20140012109 | CONSISTENT SIGNAL SELECTION BY SIGNAL SEGMENT SELECTION TECHNIQUES - According to embodiments, techniques for selecting a consistent part of a signal, including a photoplethysmograph (PPG) signal, are disclosed. A pulse oximetry system including a sensor or probe may be used to obtain a PPG signal from a subject. Signal peaks may be identified in the PPG signal. Characteristics of the signal peaks, including the amplitude levels of the signal peaks and/or the time-distance between the signal peaks may be used to determine if the PPG signal is consistent. In an embodiment, signal peaks are processed based on a consistency metric, and the processed signal peaks are compared to the consistency metric to determine if the PPG signal is consistent. If the PPG signal is determined to be consistent, the PPG signal may be further analyzed to determine an underlying signal parameter, including, for example, a patient respiration rate. If the PPG signal is determined to be inconsistent, the inconsistent portion of the signal may be removed from the overall signal or otherwise transformed. | 01-09-2014 |
20140073888 | NON-INVASIVE METHOD FOR MONITORING AUTOREGULATION - A system includes a controller that receives a blood pressure signal and an oxygen saturation signal. The blood pressure signal represents a non-invasive measure of blood pressure. The oxygen saturation signal represents a non-invasive measure of oxygen saturation. The controller generates an autoregulation status signal representing a status of cerebral autoregulation. The autoregulation status signal is based, at least in part, on a relationship between the measured blood pressure and the measured oxygen saturation. An exemplary method may include receiving the blood pressure signal and the oxygen saturation signal, defining a relationship between the measured blood pressure and the measured oxygen saturation, determining an autoregulation status based at least in part on the defined relationship, and generating an autoregulation status signal representing the determined autoregulation status. | 03-13-2014 |
20140073930 | MEASURE OF BRAIN VASCULATURE COMPLIANCE AS A MEASURE OF AUTOREGULATION - A system includes a controller that receives a physiological signal representing a non-invasive measure of a physiological parameter. The controller applies a compliance metric to the physiological signal and generates an autoregulation status signal that indicates a status of cerebral autoregulation in the patient. The autoregulation status signal is based at least in part on the compliance metric applied to the physiological signal. | 03-13-2014 |
20140266695 | SYSTEM AND METHOD FOR DISINFECTING AND CHARGING A SENSOR - Methods and systems are provided for disinfecting and recharging a sensor. The sensor may be a wireless sensor, or the sensor may be configured to operate in a wireless mode and in a wired mode. The system may include a charging device configured to provide power to the sensor and/or to recharge a power source of the sensor. The sensor may include a proximity detector configured to provide information relating to a proximity of the sensor to the charging device. Additionally, the sensor may include additional sensors configured to provide information relating to a disinfection process utilized to disinfect the sensor. | 09-18-2014 |
20140266696 | SYSTEMS AND METHODS FOR IDENTIFYING A MEDICALLY MONITORED PATIENT - Systems and methods provided relate to patient sensors and/or patient monitors that recognize and/or identify a patient with physiological signals obtained from the sensor. A scalogram may be produced by applying a wavelet transform for the physiological signals obtained from the sensor. The scalogram may be a three dimensional model (having time, scale, and magnitude) from which certain physiological information may be obtained. For example, unique human physiological characteristics, also known as biometrics, may be determined from the scalograms. More specifically, monitoring the changes in the morphology of the photoplethysmographic (PPG) waveform transforms (e.g., scalogram) may determine patient-specific information that may be used to recognize and/or identify the patient, and that may be used to determine a proper or improper association between the patient and the wireless sensor and/or patient monitor. | 09-18-2014 |
20140275887 | Systems And Methods For Monitoring Respiratory Depression - Methods and systems are disclosed for analyzing a physiological respiratory signal in order to monitor respiratory depression events. In certain embodiments, respiratory depression is monitored by extracting a respiratory signal from a photoplethysmograph (“PPG”) signal, identifying a morphological characteristic of the respiratory signal, and generating a respiratory condition signal. In certain embodiments, an alarm and therapeutic intervention strategy are triggered upon determination of respiratory depression event. In certain embodiments, a plurality of physiological signals are used to determine a respiratory depression event | 09-18-2014 |
20140276165 | SYSTEMS AND METHODS FOR IDENTIFYING PATIENT TALKING DURING MEASUREMENT OF A PHYSIOLOGICAL PARAMETER - A patient monitoring system may include a microphone that generates a sound signal based on sound emanated from a patient. A patient monitoring unit may process the sound signal to identify respiration information such as respiration rate and to determine whether the patient was talking. If the patient was talking, a confidence value may be calculated, which may be used to generate a respiration information value. | 09-18-2014 |
20140323824 | SYSTEMS AND METHODS FOR DETERMINING FLUID RESPONSIVENESS - Provided are systems and methods for processing a physiological signal in order to determine fluid responsiveness of a subject. In some embodiments, a respiration rate of the subject is received or determined, the signal is filtered based on the respiration rate to generate a filtered signal, and the filtered signal is processed to determine fluid responsiveness. In some embodiments, regular respiration is detected and fluid responsiveness is determined when regular respiration is detected. In some embodiments, the respiration of a subject is controlled, and fluid responsiveness is determined during controlled respiration. | 10-30-2014 |
20140323874 | SYSTEMS AND METHODS FOR DETERMINING FLUID RESPONSIVENESS - Provided are systems and methods for processing a physiological signal in order to determine fluid responsiveness of a subject. In some embodiments, a respiration rate of the subject is received or determined, the signal is filtered based on the respiration rate to generate a filtered signal, and the filtered signal is processed to determine fluid responsiveness. In some embodiments, regular respiration is detected and fluid responsiveness is determined when regular respiration is detected. In some embodiments, the respiration of a subject is controlled, and fluid responsiveness is determined during controlled respiration. | 10-30-2014 |
20140323876 | SYSTEMS AND METHODS FOR DETERMINING FLUID RESPONSIVENESS IN THE PRESENCE OF GAIN CHANGES AND BASELINE CHANGES - Methods and systems are provided for determining fluid responsiveness based on physiological signals. The system may detect gain changes or excessive baseline modulations. In some embodiments, based on the detected gain changes or excessive baseline modulations, the system may ignore portions of physiological signals and determine a parameter indicative of fluid responsiveness based on a plurality of amplitudes determined from other portions of the physiological signals. In some embodiments, based on the detected gain changes or excessive baseline modulations, the system may determine fluid responsiveness, or refrain from determining fluid responsiveness. | 10-30-2014 |
20150057554 | SYSTEMS AND METHODS FOR MONITORING BLOOD PRESSURE - Various methods and systems for blood pressure monitoring are provided. A device for monitoring blood pressure may include a memory storing instructions for receiving one or more signals representative of one or more patient parameters, wherein at least one of the one or more signals comprises a plethysmography signal. The memory also stores instructions for determining a change in a pulse shape metric of the plethysmography signal and determining a change in a blood pressure signal over a period of time based on the one or more signals. The memory also stores instructions for determining a confidence level of the blood pressure signal based at least in part on a correlation between the change in the blood pressure signal and the change in the pulse shape metric over the period of time. The device also includes a processor configured to execute the instructions. | 02-26-2015 |