80 results about "Photoelectric plethysmography" patented technology

The present invention is directed toward a pulse oximetry system for the determination of a physiological parameter capable of removing motion artifacts from physiological signals comprises a hardware subsystem and a software subsystem. The software subsystem is used in conjunction with the hardware subsystem to perform a method for removing a plurality of motion artifacts from the photo-plethysmographic data and for obtaining a measure of at least one physiological parameter from the data. The method comprises acquiring the raw photo-plethysmographic data, transforming the data into the frequency domain, analyzing the transformed data to locate a series of candidate cardiac spectral peaks (primary plus harmonics), reconstructing a photo-plethysmographic signal in the time domain with only the candidate cardiac spectral peaks (primary plus harmonics), computing the second order derivative of the reconstructed photo-plethysmographic signal, analyzing the candidate second order derivative photo-plethysmographic signal to determine the absence or presence of cardiac physiologic signal characteristics, and finally selecting the best physiologic candidate from the series of potential cardiac spectral peaks (primary plus harmonics) based upon a second derivative scoring system. This scoring system is preferentially based upon second derivative processing analysis, but can be equally applied using the first, third, fourth or other similar derivative processing analysis.

A method and system for assessing blood volume within a subject includes generating a cardiovascular waveform representing physiological characteristics of a subject and determining blood volume of the subject by analyzing the cardiovascular waveform. The step of analyzing includes generating a first trace of the per heart-beat maximums of the cardiovascular waveform, which is representative of the systolic pressure upon the cardiovascular signal, generating a second trace of the per heart-beat minimums of the cardiovascular waveform, which is representative of the diastolic pressure upon the cardiovascular signal, and comparing the respective first trace and the second trace to generate an estimate of relative blood volume within the subject. In accordance with an alternate method of analyzing harmonic analysis is applied to the cardiovascular waveform, extracting a frequency signal created by ventilation and applying the extracted frequency signal in determining blood volume of the subject.

Game controllers having a communication link to a game systems, a processor, and a photoelectric plethysmography, a galvanometer, or a thermocouple. Video game systems having a video game processor, a computer readable medium containing executable instructions for providing a video game and the game controller.

Wrist-worn devices and related methods measure a pulse transit time non-invasively and calculate a blood pressure value using the pulse transit time. A wrist-worn device includes an accelerometer, a photo-plethysmogram (PPG) or a pulse pressure sensor, and a controller. The PPG or the pulse pressure sensor coupled to the wrist-worn device for detecting an arrival of a blood pressure pulse at the user's wrist. The controller is configured to process output signals from the accelerometer to detect when the blood pressure pulse is propagated from the left ventricle of the user's heart, process a signal from the PPG or the pulse pressure sensor to detect when the blood pressure pulse arrives at the wrist, calculate a pulse transit time (PTT) for propagation of the blood pressure pulse from the left ventricle to the wrist, and generate one or more blood pressure values for the user based on the PTT.

Several techniques are disclosed for isolating either heart or breath rate data from a photoplethysmograph, which is a time domain signal such as from a pulse oximeter. The techniques involve the use of filtering in the frequency domain, after a Fast Fourier Transform (FFT) has been conducted on a given photoplethysmograph also references as a given set of discrete time-domain data. The filtering may be applied to an identified fundamental frequency and one or more harmonics for heart related parameters. The filter may be truncated to the frequency data set and further applied multiple times to improve roll off. After filtering, an Inverse FFT (IFFT) is used to reconstruct the time-domain signal, except with undesirable frequency content eliminated or reduced. Calculation or measurement of parameters is then conducted on this reconstructed time-domain signal.

A photoplethysmographic system and method is provided for filtering a photoplethysmographic (pleth) signal to reduce the effects of noise in the signal. The system and method utilize a combination of frequency, time and/or magnitude information, to identify and separate transient signal components within a pleth signal from repeating signal components within the pleth signal. Typically, signal components of interest repeat over a period that corresponds with a patient's heartbeat. Such periodically repeating signals may be identified as stationary signals/objects within a frequency and time-based analysis. In contrast, motion artifacts or other sources of noise are often isolated (i.e., non-repeating) transient events and may be identified as non-stationary objects in a frequency and time-based analysis. Data associated with identified transient events may be filtered from or otherwise removed from a given signal. In this regard, a pleth signal may be cleansed prior to its use for, e.g., blood analyte determinations.

Wrist-worn devices and related methods measure a pulse transit time non-invasively and calculate a blood pressure value using the pulse transit time. A wrist-worn device include a wrist-worn elongate band, at least four EKG or ICG electrodes coupled to the wrist-worn device for detecting a ventricular ejection of a heart, a photo-plethysmogram (PPG) sensor coupled to the wrist-worn device for detecting arrival of a blood pressure pulse at the user's wrist, and a controller configured to calculate a pulse transit time (PTT) for the blood pressure pulse. The controller calculates one or more blood pressure values for the user based on the PTT.

A device is worn adjacent to tissue of a patient to detect vasovagal syncope (VVS). The device includes a photoplethysmographic sensor that measures a plethysmographic signal through tissue, and a processor that derives an indicator of an autonomous nervous system (ANS) activity from the plethysmographic signal and estimates a probability that the patient will experience VVS as a function of the indicator.

The invention relates to the technical field of non-invasive blood pressure detection, in particular to a non-invasive blood pressure detection method based on mixing of photoelectric green-light pulses and an electrocardiogram. A multi-mode bioelectricity sensor is adopted in the non-invasive blood pressure detection method. The non-invasive blood pressure detection method includes the following steps that a conventional method based on photoelectric plethysmography (PPG) is adopted, the characteristic parameters in PPG signals are extracted, a measurement model of the blood pressure of the human body is built, blood pressure calibration is carried out, the calibration parameters closely related to the blood pressure value of the human body are obtained, and then the calibration parameters are used to carry out blood pressure measurement of pulse waves based on PPG waveform and ECG waveform; a multi-parameter blood-pressure estimation model is built with the wave velocity measurement method of the pulse waves based on the PPG waveform and the ECG waveform, and the final measured data is compared, analyzed and corrected. According to the non-invasive blood pressure detection method, as the mixing mode of the PPG waveform and the ECG waveform is used for detection, the detection accuracy is effectively increased; the non-invasive blood pressure detection method and the multi-mode bioelectricity sensor have the extremely-high hardware integrating degree, and good conditions are created for convenience and miniaturization of products.

The invention provides a measurement device and a measurement method for pulse wave velocity physiological parameters based on photoelectric plethysmography. The measurement device comprises a first pulse wave collecting channel and a second pulse wave collecting channel which are connected with a pulse wave analog processing device; the pulse wave analog processing device is also connected with a single chip microcomputer through a signal; the single chip microcomputer is electrically connected with a power module and is connected with a handheld terminal through a wireless module by utilizing the signal; the single chip microcomputer is also connected with a pulse wave velocity measurement module in a communication way; the single chip microcomputer is a central control processing unit and internally comprises a clock circuit, a storage, a timer, an A/D (Analog/Digital) converter and an I/O (Input/Output) interface which are controlled to connect through a single chip microcomputer processor; and the delay error can be effectively reduced by adopting the measurement device together with the measurement method.

The invention discloses a photoelectric plethysmography photoelectric detection sensor. The photoelectric plethysmography photoelectric detection sensor comprises a first photoelectric detection assembly, a second photoelectric detection assembly and a third photoelectric detection assembly, wherein the first photoelectric detection assembly comprises a first light emitting module, a first reflecting mirror which is matched with the first light emitting module, a first light filter and a first photosensitive pipe, a light signal transmitted by the first light emitting module is reflected by the first reflecting mirror to run through the first light filter to be received by the photosensitive pipe, and the first light emitting module comprises a green-light LED lamp. According to the photoelectric plethysmography photoelectric detection sensor, green light and infrared light are adopted as light sources, the reflecting rate of the green light is high, the reflected light intensity is high, the measuring perceiving degree of the photosensitive pipe is high, the signal detected by the photosensitive pipe is processed through an amplifier, so that the precision of the sensor is high, and the sensitivity is good; the light filter which is coated with a nanometer coating is arranged in front of the photosensitive pipe, so that the light of a non-test light source and the light beyond the wavelength range of the photosensitive pipe can be effectively filtered.

A system and method of digital control for a blood pressure measurement system is provided. According to at least one embodiment, a photo-plethysmographic (PPG) system produces a frequency signal that corresponds to the measured light in the PPG system. Such light may be indicative of blood volume in a vein or artery. The frequency signal may be used to control one or more pressure valves of the system in order to measure blood pressure and hold the frequency signal constant.

A sensor system for continuous non-invasive arterial blood pressure (CNAP) is provided. The CNAP-sensor comprises of a base portion and a detachable and disposable portion. The base portion is connected to a control system. The disposable portion is for attachment to a human body part. The CNAP-sensor system includes a photo-plethysmographic (PPG) system having at least one light source, at least one light detector, electrical supplies, light coupling systems, one or more connectors, and a cuff including air supplies.

The invention discloses a method for estimating an exercise load level based on cardiogenic signals. The method comprises the following steps: firstly, extracting a great number of characteristics from electrocardiogram, beat-to-beat blood pressure and photoelectric plethysmography in a resting-exercise experiment; secondly, screening individual exercise load sensitive indexes from the characteristics to form an individual exercise load sensitive index vector; thirdly, estimating coefficients of an exercise load estimation equation through a numerical computation method according to the individual exercise load sensitive index vector; finally, in an actual exercise state or a non-exercise state, substituting the individual exercise load sensitive index vector screened from the characteristic parameters, obtained by real-time detection and computation, of the electrocardiogram, the beat-to-beat blood pressure and the photoelectric plethysmography into the load estimation equation to estimate an actual exercise load level. According to the technical scheme, the limitation on estimation of the exercise load level through a single independent index is avoided, and the exercise load level is accurately and comprehensively estimated through various cardiogenic signals.

The application provides a dominant limb determination method and apparatus, and relates to the field of wearable devices. The method comprises the following steps: acquiring the first photoelectric plethysmography PPG information of the first limb of a user; and determining whether the first limb is the dominant limb based on the first PPG information and reference information. The method and apparatus are beneficial to automatically configuring the device worn by the user based on the determination result, and enhancing the user experience.

When evaluating the quality of photoplethysmography (PPG) signal (52) measured from a patient monitor (e.g., a finger sensor or the like), multiple features of the PPG signal are extracted and analyzed to facilitate assigning a score to the PPG signal or portions (e.g., heartbeats) thereof. Heartbeats in the PPG signal are segmented out using concurrently captured electrocardiograph (ECG) signal (50), and for each heartbeat, a plurality of extracted features are analyzed. If all extracted features satisfy one or more predetermined criteria for each feature, then the heartbeat waveform is compared to a predefined heartbeat template. If the waveform matches the template (e.g., within a predetermined match percentage or the like), then the heartbeat is classified as 'clean'. If the heartbeatdoes not patch the template, or if one or more of the extracted features fails to satisfy its one or more predetermined criteria, the heartbeat is classified as 'noisy'.

The invention provides an intelligent-terminal-camera-based method for analyzing short-time pulse rate variability. A camera of an intelligent terminal is used for collecting and capturing a small change of a color of blood in an artery blood vessel; a gray scale value is extracted to simulate a photoelectric plethysmography signal; and then the photoelectric plethysmography signal is processed, thereby realizing a short-time pulse rate variability analysis. With the method, stability of pulse wave collection by a camera as well as characteristic point identification precision is improved; and compared with a long-time pulse rate variability analysis, the short-time pulse rate variability analysis can be realized conveniently and rapidly; and pulse rate variability monitoring can be popularized and applied widely.

A body-worn medication delivery pump having a patch form factor is provided that includes an integrated plethysmographic module that employs a photoplethysmographic multi-chip package disposed in a frame designed to maintain contact with a wearer's skin during motion, and reduces cross-talk and ingress of stray light, a controller of the pump programmed to adjust its medication delivery algorithms responsive to outputs of the plethysmographic module.