49 results about "Aortic pressure" patented technology

Apparatus and method for noninvasively determining cardiac performance parameters including 1) lengths of systolic time intervals, (2) contractility index, (3) pulse amplitude ratios while performing the Valsalva maneuver, (4) cardiac output index, and (5) a pulse wave velocity index. A catheter having at least one balloon is inserted into the esophagus and pressurized and positioned adjacent the aortic arch to sense aortic pressure. The effects of aortic pressure on the balloon are utilized to determine at least one of the cardiac performance parameters. The catheter may include a second balloon which is spaced from the aortic balloon a distance such that when the second balloon is in a position adjacent the left atrium to sense left atrial pressure the aortic balloon is in a position adjacent the aortic arch to sense aortic pressure, this distance being related to the distance between the left atrium and aortic arch in most adult persons.

An apparatus for a heart assist device, comprising a processing unit for computing the blood flow rate from the arterial pressure curve and for predicting at every heartbeat the closing time of the heart valve from the curve of the blood flow rate. The processing unit is adapted to deliver a signal for controlling a heart assist device at a point in time, a period ahead in time of the closing time of the heart valve, wherein the mechanical properties of the said heart assist device are taken into account in determining the period. The apparatus adapts itself to changes in a patient's heart frequency and aortic pressure.

Various techniques are provided for assessing the reliability of left atrial pressure (LAP) estimates made by an implantable medical device based on impedance values or related electrical values. In one example, various cardioelectric and cardiomechanical parameters are used to corroborate LAP estimation in circumstances where the LAP estimates deviate from an acceptable, satisfactory or otherwise healthy range. The cardioelectric parameters include, e.g.: ST elevation; heart rate (HR); heart rate variability (HRV); T-wave alternans (TWA); QRS waveform parameters; P-wave duration; evoked response (ER) parameters; and intrinsic PV / AV / VV conduction delays. The cardiomechanical parameters include, e.g.: heart rate turbulence (HRT); cardiogenic impedance signals; heart sounds; and non-LAP blood pressure measurements, such as aortic pressure measurements. The device compares the cardioelectric and cardiomechanical parameters against corresponding baseline values to determine whether variations in the parameters corroborate the LAP estimates. If not, the LAP estimates are selectively cancelled or suspended, or the overall procedure is re-calibrated.

A pulse oximeter system comprises a data processor configured to perform a method that combines a sigma point Kalman filter (SPKF) or sequential Monte Carlo (SMC) algorithm with Bayesian statistics and a mathematical model comprising a cardiovascular model and a plethysmography model to remove contaminating noise and artifacts from the pulse oximeter sensor output and measure blood oxygen saturation, heart rate, left-ventricular stroke volume, aortic pressure and systemic pressures.

A method of deriving central aortic systolic pressure comprises (a) creating a set having a predetermined number of blood pressure measurements, the set representative of an arterial waveform; (b) determining an integer interval value; (c) averaging a series of consecutive blood pressure measurement readings in the set equal to the integer interval value commencing from the fth blood pressure measurement in the set; (d) storing the averaged value in a central aortic systolic pressure set; and (e) setting the central aortic systolic pressure as the highest value in the central aortic pressure set. Steps (c) and (d) are repeated with the value of f being incremented by 1 each time until the value of f plus the integer interval value equals the predetermined number of blood pressure measurements in the set.

An apparatus that continuously monitors the arterial pressure measured by a pressure sensor in an artery, which pressure is regarded as the reading Pao that approximately corresponds to the aortal pressure. In principle, the arterial pressure can be measured in the aorta, near the aorta, or in the arterial tree. To provide a second reading, the apparatus, via the input channel, continuously monitors the central venous pressure (CVP), which is regarded as the reading PIT that approximately corresponds to the intrathoracic pressure (ITP). The third reading is provided via the input channel as a reading Z which expresses the thoracic compliance. Via known algorithms of the pulse contour analysis, the apparatus calculates the stroke volume variation, using as the determining pressure the transmural pressure which is calculated according to the formulaPtransmural=Pao−f(C)*PITThe cardiac volume responsiveness indicator (CVRI) is calculated for mechanical positive respiration according to the formulaCVRI=k*(SVV / ΔCVP)or for spontaneous breathing according to the formulaCVRI=l−m*(ΔCVP / SVV).

Techniques are provided for detecting pulmonary congestion based on an increase in right ventricular (RV) stroke volume over left ventricular (LV) stroke volume. In one example, the device generates an index based on accumulated differences between RV stroke volume and LV stroke volume while RV stroke volume exceeds LV stroke volume, such that the index is indicative of an ongoing imbalance between RV and LV stroke volume. The index is compared to a suitable threshold to detect a severe imbalance indicative of pulmonary edema. Additionally, techniques are described for estimating RV and LV stroke volumes based on pulmonary artery pressure, left atrial pressure, aortic pressure, LV strain or on various intracardiac or extracardiac impedance measurements.

Disclosed is a central aortic pressure detection system and method based on oscillating sphygmomanometer signals. The system comprises a signal acquiring module, a pressure wave decomposition module, a phase shift module and a reconfigurable computing module. The method includes amplifying oscillating wave signals detected through a left upper arm blood pressure meter on the condition of high cuff operating pressure to acquire an approximation of brachial artery blood pressure waves, dividing the brachial artery blood pressure waves into two blood pressure wave components of front transfer and rear transfer, then performing phase shift on the blood pressure wave components of the front pass and the rear pass of the brachial artery to acquire blood pressure wave components of the front transfer and the rear transfer of the central artery of the subclavian artery, then reconstructing the central aortic pressure wave by combining the blood pressure wave components of the front transfer and the rear transfer of the central artery, performing wave analysis, and computing systolic pressure, diastolic pressure and pulse pressure of the central artery. The method and device has the advantages that the central artery pressure is estimate and detected rapidly and noninvasively, individual factors of a patient can be considered more completely in the signal processing process, and accordingly a more accurate detecting result can be acquired.

Described herein is a guide wire that includes one, two or multiple pressure transducers for use in TAVI. The guide wire may include an aortic pressure sensor spaced from a left ventricular pressure sensor with sufficient length to allow the aortic pressure sensor to be located in the aorta while the ventricular pressure sensor is simultaneously located in the left ventricle. The pressure readings between the left ventricle and aorta may be subtracted to determine an improved indication of the prognosis of a patient with intermediate post-TAVR aortic regurgitation after assessment with transesophageal echocardiography.

A pulse oximeter system comprises a data processor configured to perform a method that combines a sigma point Kalman filter (SPKF) or sequential Monte Carlo (SMC) algorithm with Bayesian statistics and a mathematical model comprising a cardiovascular model and a plethysmography model to remove contaminating noise and artifacts from the pulse oximeter sensor output and measure blood oxygen saturation, heart rate, left-ventricular stroke volume, aortic pressure and systemic pressures.

A method of estimating blood pressure Pulse Wave Velocity (PWV) in the aorta from a recording of a pressure waveform at a single site. The method comprises the following steps: 1. measuring the patient's arterial pressure relative to time in order to estimate a central pressure waveform (CPW); 2. estimating the patient's aortic pressure pulse transit time (PPTT) from the CPW; 3. estimating the patient's carotid to femoral arterial distance from the patient's physical characteristics; and 4. dividing the patient's estimated carotid to femoral arterial distance by the patient's estimated PPTT to estimate the patient's PWV.

The invention discloses a thoracoabdominal alternate pressing type cardio-pulmonary resuscitator which comprises a back plate, a support frame, a left support, a right support and two press devices. The press devices are used for thoracoabdominal-alternate-pressing cardio-pulmonary resuscitation. Telescoping mechanisms used for adjusting the interval between the press devices are arranged between the press devices. The press device used for pressing the chest is fixedly connected to the support frame. The upper ends of the left support and the right support are hinged to two ends of the support frame through hinges respectively. The lower ends of the left support and the right support are fixed with two ends of the back plate through fasteners respectively. The thoracoabdominal alternate pressing type cardio-pulmonary resuscitator belongs to the field of medical instruments, has two additional functions of lifting and pressing abdomens, overcomes the single thoracic-pressing resuscitation mode of existing cardiac resuscitators, promotes returned blood volume, increases cardiac preload and assists in increasing salvage success rate; by thoracoabdominal alternate pressing, flowing of blood towards important organs is facilitated, aortic pressure and central arterial pressure are increased, and blood supply and oxygen supply for the important organs are guaranteed.

Methods for determining central systolic pressure are disclosed. A first method determines the time of peak in a measured carotid waveform and then determines the pressure in a measured radial waveform at the corresponding time. A second method utilises only a measured radial waveform. The waveform is analysed to determine a time indicative of lower body waveform and determines the pressure at this time. In each case, the determined pressure is substantially the same as the central systolic pressure.

Techniques are provided for detecting pulmonary congestion based on an increase in right ventricular (RV) stroke volume over left ventricular (LV) stroke volume. In one example, the device generates an index based on accumulated differences between RV stroke volume and LV stroke volume while RV stroke volume exceeds LV stroke volume, such that the index is indicative of an ongoing imbalance between RV and LV stroke volume. The index is compared to a suitable threshold to detect a severe imbalance indicative of pulmonary edema. Additionally, techniques are described for estimating RV and LV stroke volumes based on pulmonary artery pressure, left atrial pressure, aortic pressure, LV strain or on various intracardiac or extracardiac impedance measurements.

The invention discloses a device for acquiring aortic pressure when measuring a blood flow reserve fraction. The device comprises a blood pressure collecting terminal, wherein the blood pressure collecting terminal is provided with a blood pressure sensor, a one-way valve and a zero-calibration valve, wherein one end of the one-way valve is connected with a saline bag through an infusion tube, theother end of the one-way valve is connected to the blood pressure sensor, an allowable flow direction of the one-way valve is from the saline bag to the blood pressure sensor, the other end of the blood pressure sensor is connected with the zero-calibration valve, the other end of the zero-calibration valve is connected to the aorta of a patient through an external device, and the blood pressurecollecting terminal is also provided with a peristaltic pump and a zero-calibration valve electric-driving system. The device for acquiring the aortic pressure when measuring the blood flow reserve fraction overcomes the defects that existing equipment acquires the aortic pressure inconveniently and needs manual exhausting, and the peristaltic pump and the zero-calibration valve electric-driving system are arranged, so that the pressure measuring device is convenient to use, can automatically exhaust and can perform zero calibration automatically.

A processing system received data from a Fractional Flow Reserve device and communicates data to a conventional hemodynamic monitoring system having pressure displays. The processing system receives proximal pressure measurement signal from an aortic pressure measurement device and a distal pressure measurement signal from a distal pressure measurement device. A processor computes an FFR ratio from the proximal pressure measurement signal and the distal pressure measurement signal, and converts FFR ratio to a pressure format such that the FFR ratio reads on the conventional hemodynamic monitoring system as a pressure in units of pressure. The processing system transmits the proximal pressure measurement signal, the distal pressure measurement signal, and the FFR ratio in pressure format to the conventional hemodynamic monitoring system.

Methods for determining central systolic pressure are disclosed. A first method determines the time of peak in a measured carotid waveform and then determines the pressure in a measured radial waveform at the corresponding time. A second method utilises only a measured radial waveform. The waveform is analysed to determine a time indicative of lower body waveform and determines the pressure at this time. In each case, the determined pressure is substantially the same as the central systolic pressure.

The invention discloses a wireless fractional flow reserve measurement system which comprises a sensor unit, an acquisition and transmission unit and a processing terminal, wherein the sensor unit comprises a first pressure sensor unit and a second pressure sensor; the first pressure sensor unit comprises a first pressure sensor and a pressure guide wire; one end of the pressure guide wire is connected with the acquisition and transmission unit; the first pressure sensor is arranged at the other end of the pressure guide wire; the first pressure sensor is wirelessly connected with the acquisition and transmission unit; the second pressure sensor is integrated on the acquisition and transmission unit or is connected to the acquisition and transmission unit; the processing terminal is connected with the acquisition and transmission unit, and used for receiving pressure data collected by the acquisition and transmission unit and processing the pressure data to obtain the fractional flow reserve. The wireless fractional flow reserve measurement system provided by the invention integrates the measurement of an aortic pressure and a distal pressure of diseased stenosis in the same acquisition and transmission unit, thereby greatly simplifying the conventional equipment volume and line connection and increasing the surgical operation space.

The present document describes a system for equalizing the pressure of a pressure guidewire against the pressure of an aortic pressure device: the system comprising two methods of equalizing the pressure against each other, one method that involves a gain adjustment and another method that involves the addition of an offset; the method further comprising a method for detecting which method should be applied to the situation, the detecting methods including: the contribution of the operator; an algorithm detecting the first equalization from subsequent post procedure equalizations, the algorithm including various factors such as incrementing the equalization requests, measuring the elapsed time and others.

The present invention provides a combined direct cardiac compression and aortic counterpulsation device comprising: an inflatable direct cardiac compression jacket configured when inflated to directly compress a heart and assist in displacing blood therefrom, an aortic counterpulsation chamber configured when inflated to displace aortic volume for the purposes of causing a counterpulsation effect, and a driver operably connected to said inflatable direct cardiac compression jacket and to said aortic counterpulsation chamber, said driver is configured to inflate said direct cardiac compression jacket and to deflate said aortic counterpulsation chamber during systole of the heart; said driver is further configured to deflate said direct cardiac compression jacket and to inflate said aortic counterpulsation chamber during diastole of the heart.

A method of deriving central aortic systolic pressure comprising the steps of: a) creating a set having a predetermined number of blood pressure measurements, the set representative of an arterial waveform; b) determining an integer interval value; c) averaging a series of consecutive blood pressure measurement readings in the set equal to the integer interval value commencing from the fth blood pressure measurement in the set; d) storing the averaged value in a central aortic systolic pressure set; and e) setting the central aortic systolic pressure as the highest value in the central aortic pressure set, where steps c. and d. are repeated with the value of f being incremented by 1 each time until the value of f plus the integer interval value equals the predetermined number of blood pressure measurements in the set.

The invention provides a coronary artery capillary resistance index acquiring method, a medium and equipment. The coronary artery capillary resistance index acquiring method includes the steps: coronary artery images are obtained, wherein the coronary artery images comprise images obtained by continuously scanning a target object many times within a period of time after a contrast agent is injected into the target object; according to developing states of the contrast agent, a start frame and a stop frame of the coronary artery images are recognized; according to the start frame, the stop frame and scanning parameters, contrast agent conduction time is calculated; aortic pressure is obtained, and according to the aortic pressure, epicardium coronary artery distal pressure is calculated; and according to the epicardium coronary artery distal pressure and the contrast agent conduction time, a coronary artery capillary resistance index is acquired. The coronary artery capillary resistanceindex acquiring method is easy to implement and does not rely on complex high-value consumables, no complex operation needs to be done by doctors, and large-scale application of IMR in clinical use can be achieved.

A method of estimating blood pressure Pulse Wave Velocity (PWV) in the aorta from a recording of a pressure waveform at a single site. The method comprises the following steps: 1. measuring the patient's arterial pressure relative to time in order to estimate a central pressure waveform (CPW); 2. estimating the patient's aortic pressure pulse transit time (PPTT) from the CPW; 3. estimating the patient's carotid to femoral arterial distance from the patient's physical characteristics; and 4. dividing the patient's estimated carotid to femoral arterial distance by the patient's estimated PPTT to estimate the patient's PWV.

The invention provides a coronary artery microvascular resistance index calculation device and method. The coronary artery microvascular resistance index calculating device comprises an aortic pressure obtaining module, a coronary artery microvascular resistance index calculating module and a coronary artery microvascular resistance index calculating module, the DSA image acquisition module is used for acquiring a coronary artery DSA image sequence; the change curve generation module is connected with the DSA image acquisition module and is used for generating a contrast agent area change curve according to the imaging areas of the contrast agent in a plurality of target frames and the imaging time of the target frames; the curve slope acquisition module is connected with the change curvegeneration module and is used for acquiring the average slope of the contrast agent area change curve; and the resistance index calculation module is connected with the aortic pressure acquisition module and the curve slope acquisition module and is used for calculating the coronary microvascular resistance index according to the aortic pressure and the average slope. The coronary artery microvascular resistance index calculation device basically does not need doctor participation in the process of calculating the coronary artery microvascular resistance index, and is simple to operate.

A method of deriving central aortic systolic pressure comprises (a) creating a set having a predetermined number of blood pressure measurements, the set representative of an arterial waveform; (b) determining an integer interval value; (c) averaging a series of consecutive blood pressure measurement readings in the set equal to the integer interval value commencing from the fth blood pressure measurement in the set; (d) storing the averaged value in a central aortic systolic pressure set; and (e) setting the central aortic systolic pressure as the highest value in the central aortic pressure set. Steps (c) and (d) are repeated with the value of f being incremented by 1 each time until the value of f plus the integer interval value equals the predetermined number of blood pressure measurements in the set.

The application provides a method and device for adjusting blood flow rate under the largest congestion state based on a microcirculation drag index. The method for adjusting the blood flow rate underthe largest congestion state based on the microcirculation drag index comprises the following steps of according to the blood flow rate v, an aortic pressure wave form and physiological parameters, obtaining a microcirculation drag index iFMR in a diastolic phase; if the microcirculation drag index iFMR in the diastolic phase is less than K, then enabling an adjusting parameter r to be 1; and ifthe microcirculation drag index iFMR in the diastolic phase is larger than or equal to K, enabling an adjusting parameter r to be shown as the description, wherein K is a positive number less than 100. For the method disclosed by the invention, according to the physiological parameters, the microcirculation drag index iFMR in the diastolic phase is obtained, then iFMR is compared with K to obtainthe adjusting parameter, and then through the product of the adjusting parameter and the blood flow rate under the largest congestion state, the amended blood flow rate under the largest congestion state is obtained, so that the measuring result is more pointed, the individualization difference is obvious, and the method is more accurate.

The invention relates to the technical field of medical apparatuses and instruments, and discloses a cardiopulmonary-cerebral-resuscitation rescuing device. The cardiopulmonary-cerebral-resuscitationrescuing device comprises a fixed base, two fixed pipes are fixedly installed at the top of the fixed base, a fixed plate located between the two fixed pipes is fixedly installed at the top of the fixed base, a buffering pad is fixedly installed at the top of the fixed plate, buffering springs are fixedly installed inside the buffering pad, and a carrying pad is laid at the top of the buffering pad. According to the cardiopulmonary-cerebral-resuscitation rescuing device, by rotating a sleeving piece, an inner thread ring rotates around an outer thread ring in a thread manner, an interval between the two connecting rods is changed accordingly, and it is achieved that a suitable interval is adjusted according to bodily forms of different patients; suction cups fit the chest of a patient in amost-suitable manner, the stability of the cardiopulmonary-cerebral-resuscitation process is guaranteed, the chest of the patient is effectively pressed, aortic pressure and central arterial pressureof the patient are increased, and the reliability of the rescuing process is improved.