234 results about "Coronary circulation" patented technology

Devices and methods are provided for temporarily inducing cardioplegic arrest in the heart of a patient and for establishing cardiopulmonary bypass in order to facilitate surgical procedures on the heart and its related blood vessels. Specifically, a catheter based system is provided for isolating the heart and coronary blood vessels of a patient from the remainder of the arterial system and for infusing a cardioplegic agent into the patient's coronary arteries to induce cardioplegic arrest in the heart. The system includes an endoaortic partitioning catheter having an expandable balloon at its distal end which is expanded within the ascending aorta to occlude the aortic lumen between the coronary ostia and the brachiocephalic artery. Means for centering the catheter tip within the ascending aorta include specially curved shaft configurations, eccentric or shaped occlusion balloons and a steerable catheter tip, which may be used separately or in combination. The shaft of the catheter may have a coaxial or multilumen construction. The catheter may further include piezoelectric pressure transducers at the distal tip of the catheter and within the occlusion balloon. Means to facilitate nonfluoroscopic placement of the catheter include fiberoptic transillumination of the aorta and a secondary balloon at the distal tip of the catheter for atraumatically contacting the aortic valve. The system further includes a dual purpose arterial bypass cannula and introducer sheath for introducing the catheter into a peripheral artery of the patient.

A method and system for multi-scale anatomical and functional modeling of coronary circulation is disclosed. A patient-specific anatomical model of coronary arteries and the heart is generated from medical image data of a patient. A multi-scale functional model of coronary circulation is generated based on the patient-specific anatomical model. Blood flow is simulated in at least one stenosis region of at least one coronary artery using the multi-scale function model of coronary circulation. Hemodynamic quantities, such as fractional flow reserve (FFR), are computed to determine a functional assessment of the stenosis, and virtual intervention simulations are performed using the multi-scale function model of coronary circulation for decision support and intervention planning.

Method and apparatus for detecting and analyzing heart mechanical activity at a region of interest of a patient's heart are provided. The method comprises acquiring a time sequence of 2-dimensional X-ray images of a region of interest over at least part of a cardiac cycle; detecting coronary vessels in the X-ray images; tracking the coronary vessels through the sequence of images to identify movements of the coronary vessels; and analyzing the movements of the coronary vessels to quantify at least one parameter characterizing heart wall motion in the region of interest.

A guiding catheter for use in coronary angioplasty and other cardiovascular interventions which incorporates a plurality of segment of selected flexural modulus in the shaft of the device. The segments which have a different flexibility than the sections immediately proximal and distal to them, creating zones in the catheter shaft which are either more or less flexible than other zones of the shaft. The flexibility and length of the shaft in a given zone is then matched to its clinical function and role. A mid-shaft zone is significantly softer than a proximal shaft or distal secondary curve to better traverse the aortic arch shape without storing too much energy. A secondary zone section is designed to have maximum stiffness to provide optimum backup support and stability.

A method and system for providing detecting and classifying coronary stenoses in 3D CT image data is disclosed. Centerlines of coronary vessels are extracted from the CT image data. Non-vessel regions are detected and removed from the coronary vessel centerlines. The cross-section area of the lumen is estimated based on the coronary vessel centerlines using a trained regression function. Stenosis candidates are detected in the coronary vessels based on the estimated lumen cross-section area, and the significant stenosis candidates are automatically classified as calcified, non-calcified, or mixed.

Disclosed is a “tracker system” that includes implanted electrical leads which are part of an implanted cardiotracker plus external equipment that includes external alarm means and a physician's programmer. The tracker system is designed to monitor the degradation of a patient's cardiovascular condition from one or more causes. These causes include the rejection of a transplanted heart and/or the progression of a stenosis in a coronary artery. As one or more stenoses in a coronary artery become progressively more narrow thereby causing reduced blood flow to the heart muscle coronary circulation, the tracker system can alert the patient by either or both internal and/or external alarm means to take the appropriate medical action. The physician's programmer can be used to display histograms of key heart signal parameters that are indicative of the patient's cardiovascular condition.

A method of coronary vessel segmentation and visualization includes providing a digitized coronary image, placing a plurality of seed points along an estimated centerline of a coronary vessel, selecting a seed point and constructing a cyclic graph around the seed point in a plane perpendicular to the centerline at the seed point, performing a multi-scale-mean shift filtering in the perpendicular plane to estimate image gradient values, detecting a vessel boundary using a minimum-mean-cycle optimization that minimizes a ratio of a cost of a cycle to a length of a cycle, constructing a sub-voxel accurate vessel boundary about a point on the centerline, and refining the location of the centerline point from the sub-voxel accurate boundary, where the steps of constructing a sub-voxel accurate vessel boundary and refining the centerline point location are repeated until convergence.

Methods and kits for delivering pharmaceutical agents to the adventitia surrounding a blood vessel utilize a catheter having a microneedle. The microneedle is positioned in the perivascular space and delivers an amount of pharmaceutical agent sufficient to circumferentially permeate around the blood vessel and, in many cases, extend longitudinally along the blood vessel and in some cases to the adventitia surrounding other blood vessels.

A method of treatment of congestive heart failure comprises the steps of introducing an aortic occlusion catheter through a patient's peripheral artery, the aortic occlusion catheter having an occluding member movable from a collapsed position to an expanded position; positioning the occluding member in the patient's ascending aorta; moving the occluding member from the collapsed shape to the expanded shape after the positioning step; introducing cardioplegic fluid into the patient's coronary blood vessels to arrest the patient's heart; maintaining circulation of oxygenated blood through the patient's arterial system; and reshaping an outer wall of the patient's heart while the heart is arrested so as to reduce the transverse dimension of the left ventricle. The ascending aorta may be occluded and cardioplegic fluid delivered by means of an occlusion balloon attached to the distal end of an elongated catheter positioned transluminally in the aorta from a femoral, subclavian, or other appropriate peripheral artery.

A system is disclosed for cannulating the vena cava of a patient during cardiopulmonary bypass procedures. Such cannulation is necessary for drainage of venous blood from the patient so that it may be oxygenated and pumped back to the patient to perfuse tissues during cardiac surgery and, more specifically, during periods of ischemic cardiac arrest or dysfunction. The device of the present invention not only provides venous drainage for cardiopulmonary bypass, but also performs the function of routing cardioplegic solution through the heart in the retrograde direction. Such cardioplegia provides protection to the heart during periods of ischemic cardiac arrest. This invention replaces a plurality of cannulae currently used for open-heart surgery, thus simplifying the surgical field and improving visibility of the heart. The device allows for the delivery of retrograde cardioplegia to the coronary circulation of both the right and the left side of the heart. The device further includes protection mechanisms to prevent overinflation or excessive pressurization of the right atrium during retrograde delivery of cardioplegia solution.

This invention describes methods to compute coronary physiology indexes using a high precision registration model, which consists of acquiring coronary angiography images of coronary vessels, performing intravascular imaging, and registering the coronary angiography images with intravascular images to create a high precision registration model, based upon which the coronary flow, fractional flow reserve (FFR) and index of microcirculation resistance (IMR) can be computed. The methods described in this invention to compute coronary flow, FFR, IMR are based on both coronary angiography and intravascular images, and the accuracy is better than those derived from coronary angiography alone or intravascular imaging alone, and have high practical values.

Methods and kits for delivering pharmaceutical agents to the adventitia surrounding a blood vessel utilize a catheter having a microneedle. The microneedle is positioned in the perivascular space and delivers an amount of pharmaceutical agent sufficient to circumferentially permeate around the blood vessel and, in many cases, extend longitudinally along the blood vessel and in some cases to the adventitia surrounding other blood vessels.

A perfusion circuit and a use thereof for delivering a substance to a subject's heart in situ during cardiopulmonary bypass surgery are provided. The perfusion circuit defines a path for re-circulating a solution containing a macromolecular complex through a coronary circulation circuit (50) through a subject's heart during a surgical procedure in which the substance is prevented from being delivered to the subject's other organs.

A method and system for extracting motion-based layers from fluoroscopic image sequences are disclosed. Portions of multiple objects, such as anatomical structures, are detected in the fluoroscopic images. Motion of the objects is estimated between the images is the sequence of fluoroscopic images. The images in the fluoroscopic image sequence are then divided into layers based on the estimated motion. In a particular implementation, the coronary vessel tree and the diaphragm can be extracted in separate motion layers from coronary angiograph fluoroscopic image sequence.

A virtual map of vessels of interest in medical procedures, such as coronary angioplasty is created so that doses of contrasting agent given to a patient may be reduced. A position of a coronary guidewire is determined and locations of vessel boundaries are found. When the contrast agent has dissipated, virtual maps of the vessels are created as new images. The locations of the determined vessel boundaries are imported to a mapping system and an image obtained without using a contrast agent is modified based on the imported locations of vessel boundaries. This creates a virtual map of the vessels.

A method and system for non-invasive assessment of coronary artery stenosis is disclosed. Patient-specific anatomical measurements of the coronary arteries are extracted from medical image data of a patient acquired during rest state. Patient-specific rest state boundary conditions of a model of coronary circulation representing the coronary arteries are calculated based on the patient-specific anatomical measurements and non-invasive clinical measurements of the patient at rest. Patient-specific rest state boundary conditions of the model of coronary circulation representing the coronary arteries are calculated based on the patient-specific anatomical measurements and non-invasive clinical measurements of the patient at rest. Hyperemic blood flow and pressure across at least one stenosisregion of the coronary arteries are simulated using the model of coronary circulation and the patient-specific hyperemic boundary conditions. Fractional flow reserve (FFR) is calculated for the at least one stenosis region based on the simulated hyperemic blood flow and pressure.

A method and system for extracting coronary vessels fluoroscopic image sequences using coronary digital subtraction angiography (DSA) are disclosed. A set of mask images of a coronary region is received, and a sequence of contrast images for the coronary region is received. For each contrast image, vessel regions are detected in the contrast image using learning-based vessel segment detection and a background region of the contrast image is determined based on the detected vessel regions. Background motion is estimated between one of the mask images and the background region of the contrast image, and the mask image is warped based on the estimated background motion to generate an estimated background layer. The estimated background layer is subtracted from the contrast image to extract a coronary vessel layer for the contrast image.

Catheter devices and methods for their use in enhancing fluid flow through a vascular site occupied by a vascular occlusion are provided. The subject catheter devices include at least a first, second and third lumen, where: (a) the first lumen is used for delivery of an acidic dissolution solution to the vascular site; (b) the second lumen is used for delivery of a buffer solution to the vascular site; and (c) the third lumen is used for removal of fluid from the vascular site. In many preferred embodiments, the first, second and third lumens are coaxial. In practicing the subject methods, the vascular site is flushed simultaneously with an acidic dissolution fluid and a buffer solution, where flushing is carried out in a manner such that only a surface of the vascular occlusion is contacted with the acidic dissolution fluid and the remainder of the vascular site is not contacted with fluid having a pH that is lower than about 4. Flushing is carried out in this manner for a period of time sufficient for fluid flow through the vascular site to be enhanced, e.g. increased or established. The subject catheter devices and methods find use in the treatment of a variety of different vascular diseases characterized by the presence of calcified vascular occlusions, including peripheral and coronary vascular diseases.

Catheter systems and methods for their use in enhancing fluid flow through a vascular site occupied by a vascular occlusion are provided. The subject catheter systems include at least an aspiration catheter and at least one of a total occlusion insert catheter and a partial occlusion insert catheter, where the insert catheters are capable of being slidably moved in the lumen of the aspiration catheter. In practicing the subject methods, a surface of the vascular occlusion is flushed with an acidic dissolution fluid using the subject catheter systems for a period of time sufficient for fluid flow through the vascular site to be enhanced, e.g. increased or established. The subject catheter systems and methods find use in the treatment of a variety of different vascular diseases characterized by the presence of calcified vascular occlusions, including peripheral and coronary vascular diseases.