31 results about "Arterial pressure waveform" patented technology

One or more cardiovascular parameters is estimated as a function of the arterial pressure waveform, in particular, using at least one statistical moment of pressure waveform having an order greater than one. Arterial compliance, the exponential pressure decay constant, vascular resistance, cardiac output, and stroke volume are examples of cardiovascular parameters that can be estimated using various aspects of the invention. In one embodiment of the invention, not only are the first four moments (mean, standard deviation, skewness, and kurtosis) of the pressure waveform used to estimate the cardiovascular parameter(s) of interest, but also heart rate, statistical moments of a set of pressure-weighted time values, and certain anthropometric patient measurements such as age, sex, body surface area, etc.

Cardiac stroke volume (SV) of a subject is estimated as a function of a value derived from a measured arterial pressure waveform. The value may be the standard deviation, or a function of the difference between maximum and minimum pressure values, or a function of either the maximum value of the first time derivative or the absolute value of the minimum of the first time derivative of the pressure waveform, or both, or a function of the magnitude of one or more spectral components of the pressure waveform at a frequency corresponding to the heart rate. Cardiac output is then estimated as the product of the subject's heart rate and SV, scaled by a calibration constant. Arterial pressure may be measured invasively or non-invasively.

One or more cardiovascular parameters is estimated as a function of the arterial pressure waveform, in particular, using at least one statistical moment of pressure waveform having an order greater than one. Arterial compliance, the exponential pressure decay constant, vascular resistance, cardiac output, and stroke volume are examples of cardiovascular parameters that can be estimated using various aspects of the invention. In one embodiment of the invention, not only are the first four moments (mean, standard deviation, skewness, and kurtosis) of the pressure waveform used to estimate the cardiovascular parameter(s) of interest, but also heart rate, statistical moments of a set of pressure-weighted time values, and certain anthropometric patient measurements such as age, sex, body surface area, etc.

System and method of monitoring a patient including acquiring a respiration waveform and an arterial pressure waveform and determining a window on the respiration waveform that represents end expiration and approximates an apnea condition. The method can include calculating a systolic pressure variation value, a delta up value, and a delta down value based on a portion of the arterial pressure waveform corresponding to the window on the respiration waveform. In some embodiments, the respiration waveform can be acquired without manual interruption of mechanical ventilation and the values can be calculated substantially continuously.

A method for determination of cardiac output from a recording of an arterial pressure waveform (10). The method comprises the steps of measuring the patient's peripheral arterial pressure relative to time in order to estimate a central pressure waveform (CPW) and calculating the patient's cardiac output from the CPW using the Water Hammer formula (as defined herein).

The invention discloses a system and method for central arterial pressure waveform reconstruction based on CNN-BiLSTM, and relates to the technical field of artificial intelligence and medical device research and development. The invention includes a data acquisition control module, a radial artery pressure measurement module, a fingertip arterial pressure measurement module, a data processing module, a central arterial pressure calculation module and a data display module. The invention does not need to manually extract features, and does not need to establish an intermediate simulation model and its parameter estimation, and automatically establishes an end-to-end reconstruction model of peripheral blood pressure and central arterial pressure, which effectively improves the reconstruction accuracy of the central arterial pressure waveform. The improvement of the neural network structure improves the model's ability to learn waveform features. Compared with other artificial neural networks, this network has a stronger learning ability for blood pressure waveforms and better reconstruction of central arterial pressure.

The present invention relates to multivariate statistical models for detecting vascular states, methods for creating these multivariate statistical models, and methods for using the multivariate statistical models to detect vascular states in a subject. This model is created based on arterial pressure waveform data from a first group of subjects experiencing a particular vascular state and a second group of subjects not experiencing the same vascular state. Multivariate statistical models are built to provide different output values ​​for each set of input data. Thus, when data from a subject under observation is input into the model, the relationship between the model output and the established output for which the model is based will indicate whether the subject experienced the vascular state established by these two groups of subjects.

The invention discloses a cardiac output detector wireless transmission device which is mainly applied to detecting transient temperature of human arterial blood. According to the technical scheme that a physical layer and a data link layer of a CAN (controller area network) protocol are integrated in a CAN bus communication interface, the cardiac output detector wireless transmission device is a main unit capable of receiving and controlling wireless transmission of multiple auxiliary units. The cardiac output detector wireless transmission device is structurally characterized by being composed of an infusion connector, a button cell, a wireless communication module, a wireless communication module shell, a temperature sensor, a PICCO (pulse induced contour crdic output) double-cavity tube, a catheter fixator, and a wireless receiving module and a software program of a cardiac output detector; the cardiac output detector also named as a PICCO catheter before innovation is a measuring instrument used at the front end of the cardiac output monitor; the measuring principle of the cardiac output monitor is that single cardiac output (CO) is measured by adopting a hot dilution method, and continuous cardiac output (ICCO) is acquired by analyzing area under arterial pressure-waveform curves; meanwhile, intrathoracic blood volume (ITBV) and extravascular lung water (EVLW) can be calculated.

The present application provides a method, device and storage medium for acquiring blood vessel evaluation parameters based on physiological parameters. The method for acquiring coronary artery evaluation parameters based on physiological parameters includes: acquiring physiological parameters; acquiring blood flow velocity v; acquiring a real-time aortic pressure waveform changing with time; The above physiological parameters were used to obtain the evaluation parameters of coronary arteries. According to blood flow velocity v, aortic pressure waveform, and physiological parameters, the application obtains coronary artery assessment parameters, and performs personalized measurement of coronary artery assessment parameters for patients with different genders and differentiated disease histories. It improves the accuracy of the measurement of coronary artery vascular assessment parameters.

The present application provides a method and device for adjusting the blood flow velocity and flow velocity in the state of maximum congestion based on the microcirculation resistance index. The method for adjusting the blood flow velocity in the state of maximum congestion based on the microcirculation resistance index includes: obtaining the diastolic microcirculation resistance index iFMR according to the blood flow velocity v, the aortic pressure waveform, and the influencing parameters; if the diastolic microcirculation resistance If the index iFMR<K, then the adjustment parameter r=1; if the diastolic microcirculation resistance index iFMR≥K, then the adjustment parameter wherein, K is a positive number less than 100. This application obtains the diastolic microcirculation resistance index iFMR according to the influencing parameters; then compares iFMR with K to obtain the adjustment parameters, and then obtains the corrected maximum hyperemia state through the product of the adjustment parameters and the blood flow velocity in the maximum hyperemia state Blood flow velocity, the measurement results are more targeted, individual differences are obvious, and more accurate.

The invention discloses a central arterial blood pressure measurement device, including brachial arterial blood pressure measurement, electrocardiogram measurement, radial artery blood pressure measurement, data processing, pulse wave transit time evaluation, pulse wave reflection coefficient evaluation, central arterial pressure calculation and data display, etc. module; the pulse wave transit time evaluation module is used to obtain the pulse wave transit time; the pulse wave reflection coefficient evaluation module divides the pulse wave into incident waves and reflected waves, and calculates the sum of the reflected wave amplitude and the sum of the incident wave and reflected wave amplitudes. The ratio of pulse wave reflection coefficient is obtained; the central arterial pressure calculation module calibrates the radial artery blood pressure waveform; at the same time, the pulse wave transit time and pulse wave reflection coefficient are input into the mathematical model to calculate the transfer function, and then use the transfer function and the calibrated The radial artery blood pressure waveform was calculated to calculate the central arterial pressure waveform. The invention can significantly improve the measurement accuracy of the central arterial pressure and reduce the measurement error.

The invention discloses a non-invasive central aortic blood pressure measuring method and device. The non-invasive central aortic blood pressure measuring method includes, according to a human artery network model based on viscous fluid mechanics, a method of calculating artery network model personalized parameters of a measured person through measured radial artery and brachial artery pulse wave signals and arm blood pressure values, a method of calculating an ascending aorta-radial artery transfer function and a method of calculating central arterial pressure waveforms through measured central arterial pressures. The non-invasive central aortic blood pressure continuous measuring device comprises a pulse wave signal processing and analysis unit and a radial artery and brachial artery pulse wave signal acquisition unit worn on a wrist. The method is different from an existing general transfer function method, the artery network model parameters of each person to be measured are measured and calculated and the artery network model parameters are numerical characteristics of the cardiovascular system states of the person to be measured with the calculated central arterial pressure waveforms, and the method and device has important meanings in prevention, curing and control of cardiovascular diseases, especially high-risk diseases, such as hypertensions and coronary heart diseases.