33 results about "Arterial tree" patented technology

A method and system for imaging an artery contained in an arterial tree. A microprocessor generates a three-dimensional reconstruction of the arterial tree from two or more angiographic images obtained from different perspectives. The orientation of the axis of the artery in the arterial tree is then determined, and a perspective of the artery perpendicular to the axis of the artery is determined. A three dimensional reconstruction of the artery from angiographic images obtained from the determined perspective is then generated.

The methods and systems for estimating cardiac output and total peripheral resistance include observing arterial blood pressure waveforms to determine intra-beat and inter-beat variability in arterial blood pressure and estimating from the variability a time constant for a lumped parameter beat-to-beat averaged Windkessel model of the arterial tree. Uncalibrated cardiac output and uncalibrated total peripheral resistance may then be calculated from the time constant. Calibrated cardiac output and calibrated total peripheral resistance may be computed using calibration data, assuming an arterial compliance that is either constant or dependent on mean arterial blood pressure. The parameters of the arterial compliance may be estimated in a least-squares manner.

Methods and systems for reconstruction of a three-dimensional representation of a moving arterial tree structure from a pair of sequences of time varying two-dimensional images thereof and for analysis of the reconstructed representation. In one aspect of the invention, a pair of time varying arteriographic image sequences are used to reconstruct a three-dimensional representation of the vascular tree structure as it moves through a cardiac cycle. The arteriographic image sequences maybe obtained from a biplane imaging system or from two sequences of images using a single plane imaging system. Another aspect of the invention then applies analysis methods and systems utilizing the three-dimensional representation to analyze various kinematic and deformation measures of the moving vascular structure. Analysis results may be presented to the user using color coded indicia to identify various kinematic and deformation measures of the vascular tree.

The invention provides a method and an apparatus for a continuous non-invasive and non-obstrusive monitoring of blood pressure. The method comprises the steps of: a) measuring the value (PW) of a Pulse Wave parameter, equal to or derived from the Pulse Wave Velocity (PWV) parameter of a segment of the arterial tree of a subject, b) measuring the value (CO) of the Cardiac Output parameter, and c) determining the value (BP) of the blood pressure that satisfies

where PW is the value measured in step a), (CO, BP) corresponds to a predicted value of the Pulse Wave parameter computed according to a model of the segment of the arterial tree, the value (CO) of the Cardiac Output parameter measured in step b) and an hypothesized value of the blood pressure.

The disclosure relates to an image processing method for estimating a brain shift in a patient, the method involving: the processing of a three-dimensional image of the brain of a patient, acquired before a surgical operation, in order to obtain a reference cerebral arterial tree structure of the patient; the processing of three-dimensional images of the brain of the patient, acquired during the operation, in order to at least partially reconstitute a current cerebral arterial tree structure of the patient; the determination from the combination of the reference and current cerebral arterial tree structures, of a field of shift of the vascular tree representing the shift of the current vascular tree in relation to the reference vascular tree; the application of the determined field of shift of the vascular tree to a biomechanical model of the brain of the patient in order to estimate the brain shift of the patient; and the generation, from the estimated brain shift, of at least one image of the brain of the patient, in which the brain shift is compensated.

A method for determining a cardiac function, comprising (i) determining base anatomical characteristics associated with the subject, (ii) determining pulse delay to a first body site (PD₀₁) and a second body site (PD₀₂) as a function of the anatomical characteristics, wherein the distance via the arterial tree from the aortic valve to the first body site (PD₀₁) is different than the arterial tree distance from the aortic valve to the second body site (PD₀₂), (iii) determining pulse wave velocity between the first body site and the second body site (PWV₁₂), (iv) determining pulse wave velocity between the aortic valve and the first body site (PWV₀₁) as a function of PWV₁₂, and the anatomical characteristics; and (v) determining the pre-ejection period (PEP) as a function of PD₀₁ and PWV₀₁.

The present invention provides methods and apparatus for determining a dynamical property of the systemic or pulmonary arterial tree using long time scale information, i.e., information obtained from measurements over time scales greater than a single cardiac cycle. In one aspect, the invention provides a method and apparatus for monitoring cardiac output (CO) from a single blood pressure signal measurement obtained at any site in the systemic or pulmonary arterial tree or from any related measurement including, for example, fingertip photoplethysmography.

According to the method the time constant of the arterial tree, defined to be the product of the total peripheral resistance (TPR) and the nearly constant arterial compliance, is determined by analyzing the long time scale variations (greater than a single cardiac cycle) in any of these blood pressure signals. Then, according to Ohm's law, a value proportional to CO may be determined from the ratio of the blood pressure signal to the estimated time constant. The proportional CO values derived from this method may be calibrated to absolute CO, if desired, with a single, absolute measure of CO (e.g., thermodilution). The present invention may be applied to invasive radial arterial blood pressure or pulmonary arterial blood pressure signals which are routinely measured in intensive care units and surgical suites or to noninvasively measured peripheral arterial blood pressure signals or related noninvasively measured signals in order to facilitate the clinical monitoring of CO as well as TPR.

A device and method for analyzing of a disturbed pattern of pulse wave front results in a non-invasive, real-time diagnostic tool of arterial vascular performance on both a global and regional scale. The device provides a single number quantifying how well the arterial tree as a whole is coupled to receive and distribute a stroke volume of a single heartbeat. Changing heart rate, contractility, volume status, and afterload will change stroke volume and ejection time. Different vasculatures with different properties (e.g., size and intrinsic stiffness) will be best matched for different stroke volumes and ejection times to provide optimal coupling. The device will allow finding the optimal set of parameters for individual patient.

An image registration system an endoscope (12) and an endoscope controller (22). In operation, the endoscope (12) generates an intra-operative endoscopic image (14) of a vessel tree (e.g., an arterial tree or a venous tree) within an anatomical region, and the endoscope controller (22) image registers the intra-operative endoscopic image (14) of the vessel tree to a pre- operative three-dimensional image (44) of the vessel tree within the anatomical region. The image registration includes an image matching of a graphical representation of each furcation of the vessel tree within the intra-operative endoscopic image (14) of the vessel tree to a graphical representation of each furcation of the vessel tree within the pre-operative three-dimensional image (44) of the vessel tree.

The systems and methods described herein enable reliable estimation of cardiovascular indices on real-time, non-invasive or minimally-invasive, and heat-to-beat basis. Cardiovascular indices which can be estimated include: stroke volume (SV), which being limited to, cardiac output (CO) and total peripheral resistance (TPR). In various embodiments, one or more of these indices are estimated continuously, on a beat-to-beat basis, using peripheral arterial blood pressure (ABP) waveforms and certain parameters derived from the peripheral ABP waveforms. The derived parameters are substantially insensitive to distortions of the ABP waveform arising from tapered arterial branches throughout the arterial tree. The methods describe herein can provide a more accurate and reliable estimate of hemodynarnic parameters than existing techniques.

The invention relates to the technical field of interventional radiology arterial embolism, and discloses a radioembolism dose and injection position evaluation method based on fluid dynamics. Medical imaging images are acquired and preprocessed, and an artery tree is subjected to recognition and three-dimensional reconstruction by using the trained deep learning model and an accurate modeling method; segmenting and naming the reconstructed blood vessel; obtaining the flow of each blood vessel outlet of the embolism part based on fluid dynamics, and calculating embolism efficiency and organ injury conditions during injection at different embolism positions based on the flow of each blood vessel outlet of the embolism part; the method comprises the following steps: calculating the microsphere radiation quantity of each blood vessel outlet based on a flow ratio, then analyzing the radiation dose and distribution of the microspheres by using a statistical simulation method, drawing a radiation dose distribution three-dimensional cloud chart, and evaluating the damage degree of organs based on the radiation dose of the microspheres to ensure the treatment effect on tumors.