82 results about "Mean arterial pressure" patented technology

A method of and a device for non-invasively measuring the neurological depressed state and the hemodynamic state of a human patient and involving steps and units of non-invasively measuring EEG, cardiac cycle period, electrical-mechanical interval, mean arterial pressure, and ejection interval and converting the EEG into a neurological index as well as converting the measured electrical-mechanical interval, mean arterial pressure and ejection interval into the cardiac parameters such as Preload, Afterload and Contractility, which are the common cardiac parameters used by an anesthesiologist. A general anesthetic is administered based upon the converted neurological index. A vasoactive agent is independently administered based upon the converted cardiac parameters as necessary in order to restore cardiovascular homeostasis in the patient. The converted neurological and hemodynamic state of a patient are displayed on a screen as an index value and a three-dimensional vector with each of its three coordinates respectively representing Preload, Afterload and Contractility. Therefore, a medical practitioner looks at the screen and quickly obtains the important and necessary information.

Provided herein are implantable systems, and methods for use therewith, for monitoring a patient's arterial blood pressure. Electrode(s) implanting within and/or on the patient's heart are used to obtain a cardiogenic impedance (CI) signal indicative of cardiac contractile activity. Additionally, a signal (e.g., PPG or IPG signal) indicative of changes in arterial blood volume remote from the patient's heart is obtained using a sensor or electrodes that are implanted remote from the patient's heart. One or more metrics indicative of pulse arrival time (PAT) are determined, where each metric can be determined by determining a time from one of the detected features of the CI signal to one of the detected features of the signal indicative of changes in arterial blood volume. Based on at least one of the metric(s) indicative of PAT, arterial blood pressure is estimated, which can include determining values indicative of systolic blood pressure, diastolic blood pressure, pulse pressure and/or mean arterial blood pressure, and/or changes in such values.

The present invention generally relates to blood pressure monitoring. In some embodiments, methods and devices of measuring a mean arterial pressure are provided and/or monitoring blood pressure changes. A wrist-worn device may include a plurality of sensors backed by a plurality of actuators. Subsets of the plurality of sensors may be selectively actuateable against a wrist of a user using one or more of the plurality of actuators. A preferred sensor and location may be identified based on pressure signals received from each of the sensors. In some embodiments, devices may use a fluid bladder coupled with piezoelectric film sensors. A fluid bladder pressure sensor may be used to calibrate the piezoelectric film signal to provide a static and dynamic pressure reading. In yet another embodiment, a mean arterial pressure may be calculated by processing a swept pressure signal obtained as a sensor is swept through different heights.

A method and system for objectively scoring intra-operative pain during general anaesthesia based on the patient's mean arterial pressure and heart rate. The index is used for closed-loop control of the intra-operative analgesia through adjustment of the drug infusion level according to fuzzy logic. It is further displayed along with other components of anaesthesia and important patient data on a monitoring display for presentation to medical staff.

An apparatus is provided for evaluating cardiovascular functions. The apparatus combines the principles of measuring pressure and pulse signals, and monitors blood pressure, pulse wave velocity and electrocardiogram (ECG) signals simultaneously. An inflatable cuff measures blood pressure and pulse wave velocity. The apparatus also calculates systolic pressure, diastolic pressure, mean arterial pressure and other parameters related to blood pressure. The apparatus not only calculates vascular Stiffness Index (SI), vascular Reflection Index (RI) and other arterial related parameters but also Pulse Wave Velocity (PWV), heartbeat, QRS interval, ST segment, and other ECG parameters.

The present disclosure provides for a method of monitoring the mean arterial pressure of a patient having a blood pump. The method may involve identifying a segment of time associated with diastole of the patient's cardiac cycle, determining a first parameter of the blood pump corresponding to the identified segment of time, and estimating the mean arterial pressure of the patient based at least in part on the first parameter.

Methods of determination of the blood pressure, determination of a heart stroke volume, determination of the state of stress or relaxation of a user, with use of a ballistocardiogram signal reflecting the user's heart beats, with a measure of characteristic amplitude of ballistocardiogram signal, and measure for each couple of consecutive heart beats, beat time intervals DeltaHB(i) between successive heart beats, extracted from a ballistocardiogram signal or from an impedance plethysmography signal measured at the user's foot, leading to determination of a heart rate variability index, over at least six successive heart beats, leading to determination of mean arterial pressure, leading to determination of state of relaxation or stress of the user.

Provided herein are implantable systems that include an implantable photoplethysmography (PPG) sensor, which can be used to obtain an arterial PPG waveform. In an embodiment, a metric of a terminal portion of an arterial PPG waveform is determined, and a metric of an initial portion of the arterial PPG waveform is determined, and a surrogate of mean arterial pressure is determined based on the metric of the terminal portion and the metric of the initial portion. In another embodiment, a surrogate of diastolic pressure is determined based on a metric of a terminal portion of an arterial PPG waveform. In a further embodiment, a surrogate of cardiac afterload is determined based on a metric of a terminal portion of an arterial PPG waveform.

A method for diagnosing pulmonary hypertension from phase-contrast magnetic resonance (MR) images includes providing a time series of one or more magnetic resonance (MR) flow images of a patient's mediastinum during one or more cardiac cycles, segmenting the pulmonary artery within each image of the times series of images, identifying the anterior wall and pulmonary valve within the segmented pulmonary artery, analyzing blood flow during a diastolic phase of the one or more cardiac cycles to determine a relative duration of blood flow, t_streamlines, during the diastolic phase, analyzing blood flow during a latter portion of a systolic phase and a subsequent diastolic phase of the one or more cardiac cycles to detect the presence and duration t_vortex of a vortex, and diagnosing the presence of pulmonary hypertension from t_streamlines and t_vortex.

An arterially measured pressure signal is continuously read in and temporarily stored in the working memory (RAM). The function p(t) is processed by the central processing unit (CPU), to calculate the heart/time volume PCCO and other hemodynamic parameters. The calculation comprises the following steps: The systemic vascular resistance SVR_k is calculated for the current pulse period. The stroke volume SV_k is numerically determined from the pressure values of a pulse period, according to the following equation: ${\mathrm{SV}}_k\propto \sum \left(\frac{p_i\left(t\right)}{{\mathrm{SVR}}_k}+C_k\left(p_i\right)\frac{d{p}_i}{dt}\right)$

with the compliance C(p)=(MAP−CVP)_k/[SVR·<dp/dt>_k]·f(p). The difference between the mean arterial pressure MAP and the central venous pressure CVP, and the mean incline of the pressure curve in the diastole <dp/dt>, are re-determined for the current pulse period. The heart/time volume calculated in the current pulse period results from PCCO_k=SV_k·HR. Therefore, continuous recalibration of the systemic vascular resistance and of the compliance takes place, from the continuously determined pressure measurement data.

The invention provides a non-invasive cardiac output detection method and apparatus based on a pulse wave; wherein, the detection method comprises the following steps: firstly, amplifying and filtering the pressure pulse signals, and detaching the alternating current and direct current by means of amplifying and filtering; secondly, modulus conversion for the alternating current and direct current, and resampling the digital signals converted; fixing heart rate via the feature points on the waveform of the pulse; and fixing the external pressurizing force via calibrating the separated direct current; thirdly, using mathematical analyzing method to estimate time constant Tau for the separated alternating current; fourthly, calibrating the pulse wave to get mean arterial pressure MAP; fifthly, according to the MAP and Tau, calculating the cardiac output. The detecting apparatus comprises a pulse wave detection device, a detection circuit, a cardiac output estimation device and a display unit. The invention has the advantages of obtaining the cardiac output via a mathematical analyzing of the pulse wave on the non-invasive detection and realizing the non-invasive cardiac output detection.

The invention discloses application of penehyclidine hydrochloride in preparation of a medicine for treating a hemorrhagic shock disease. Hemorrhagic shock has a pathological change that the central venous pressure, the peripheral mean arterial pressure and the cardiac output are all obviously reduced and the middle-light microcirculatory disturbance appears, the medicine for treating the hemorrhagic shock disease can be liquid and can also be solid, and the mass percent concentration of the penehyclidine hydrochloride in the medicine is between 0.01 and 2 percent. The application effect is proved through the influence of a penehyclidine hydrochloride water solution on a canine hemorrhagic shock model.

The present invention relates to a blood pressure measurement apparatus comprising: an input unit where at least one value selected from the maximum applied pressure, which is the applied pressure at which the maximum pulse pressure is attained during the pulse pressure measurement at the measurement part, the maximum pulse pressure, which is the pulse pressure at the maximum applied pressure, the depth of blood vessel at the measurement part measured by a pressure sensor, the elasticity of skin tissue at the measurement part and the elasticity of blood vessel at the measurement part is inputted; and a mean arterial press calculation unit where the mean arterial pressure is calculated from the input values of the maximum applied pressure, the depth of blood vessel and the elasticity of skin tissue. The present invention offers more effective and reliable blood pressure measurement apparatus.

The invention discloses a closed-loop external chest compression system. The system comprises a feedback physiological signal acquiring module, a postprocessing and amplifying module, an intelligent controller, a control interface, an electrical external chest compressor and a chest thickness signal acquiring module, wherein the intelligent controller samples an analogue signal which comes from the postprocessing and amplifying module and a patient chest thickness signal which is sampled by the chest thickness signal acquiring module, compares the analogue signal which reflects actual feedback physiological information with a target physiological signal, and generates the depth and frequency control signal of the external chest compression to be implemented, which can accord with the target physiological signal, by combining a fuzzy control algorithm or a fuzzy proportional integral differential (PID) control algorithm. By continuously monitoring partial pressure of end-tidal carbon dioxide (PETCO2) and mean arterial pressure (MARP) in real time and using the feedback physiological signal, the closed-loop control over the depth and the frequency of the external chest compression is performed on the basis of the fuzzy control algorithm or the fuzzy PID control algorithm. The closed-loop external chest compression system is suitable for pre-hospital emergency treatment and continuous treatment of patients with sudden cardiac arrest.

A non-invasive method and apparatus determines continuously cardiac output by first analysing the trace obtained from an optical sensor which has been scaled and calibrated using an electronic sphygmomanometer. From this the mean arterial pressure and time constant are determined. Compliance is determined from the pulse delay between two other optical sensors at well separated sites. Cardiac output is the product of mean arterial pressure and compliance divided by the time constant. A microcomputer provides the necessary calculations.

The present invention relates, inter alia, to a method comprising administering to a subject having high output shock and undergoing treatment with a catecholamine at a dose equivalent to at least about 0.2 mcg/kg/min of norepinephrine a dose of angiotensin II which is effective to raise the blood pressure of the subject to a mean arterial pressure (MAP) of about 65 mm Hg or above, and which is effective to reduce the dose of the catecholamine required to maintain a MAP of about 65 mm Hg to the equivalent of about 0.05-0.2 mcg/kg/min norepinephrine or less, or to the equivalent of about 0.05 mcg/kg/min norepinephrine or less.